• Frederick Jessen opublikował 5 miesięcy, 1 tydzień temu

    LC-MS-oriented fractionation of the sponge Aaptos suberitoides resulted in the isolation of four heptacyclic alkaloids, aaptodines A-D (1-4), which contain 9,10-dihydrofuro[2,3-f][1,3]oxazolo[5,4-h]quinolone and 7,8-dihydrocyclopenta[de][1,6]naphthyridine subunits with a spiro carbon atom. The structures were determined on the basis of NMR spectroscopic and single-crystal X-ray diffraction data analysis aided by electronic circular dichroism calculations and Mosher’s method. A biosynthetic pathway for the formation of aaptodines A-D is postulated. Aaptodine D exhibits potent inhibition against osteoclast formation.Integration of individual molecular components such as molecular motors or switches into larger meta-functional systems represents a current challenge at the forefront of molecular machine research. Here we present a modular supramolecular approach to relay the photoinduced geometry changes of a hemithioindigo based molecular motor into catalytic efficiency of a chemical reaction. Using the intrinsic chemical nature of the motor for recognition of different hydrogen-bonding organocatalysts a greater than 10-fold modulation in binding affinity is achieved upon photoisomerization. This change in affinity is then translated effectively into control of catalytic competence of the organocatalysts without direct interference by the motor. As an example the organocatalysed Michael addition reaction between nitrostyrene and 3-methoxy-dimethyl aniline was modulated in situ by visible light irradiation. Thus, dynamic and reversible remote control of catalytic processes by the switching capacity of a hemithioindigo molecular motor is established in a multicomponent chemical system. The high intrinsic modularity of this approach presents further advantages, e.g., for easy tailoring of conditions or facile exchange of catalysts and reactions. These results represent a first stepping stone into integrated chemical networks regulated by molecular machines in a fully dynamic way.Alchemical free energy simulations have long been utilized to predict free energy changes for binding affinity and solubility of small molecules. However, while the theoretical foundation of these methods is well established, seamlessly handling many of the practical aspects regarding the preparation of the different thermodynamic end states of complex molecular systems and the numerous processing scripts often remains a burden for successful applications. In this work, we present CHARMM-GUI Free Energy Calculator (http//www.charmm-gui.org/input/fec) that provides various alchemical free energy perturbation molecular dynamics (FEP/MD) systems with input and post-processing scripts for NAMD and GENESIS. Four submodules are available Absolute Ligand Binder (for absolute ligand binding FEP/MD), Relative Ligand Binder (for relative ligand binding FEP/MD), Absolute Ligand Solvator (for absolute ligand solvation FEP/MD), and Relative Ligand Solvator (for relative ligand solvation FEP/MD). Each module is designed to build multiple systems of a set of selected ligands at once for high-throughput FEP/MD simulations. The capability of Free Energy Calculator is illustrated by absolute and relative solvation FEP/MD of a set of ligands and absolute and relative binding FEP/MD of a set of ligands for T4-lysozyme in solution and the adenosine A2A receptor in a membrane. The calculated free energy values are overall consistent with the experimental and published free energy results (within ∼1 kcal/mol). We hope that Free Energy Calculator is useful to carry out high-throughput FEP/MD simulations in the field of biomolecular sciences and drug discovery.Recent interest in transition-metal complexes as potential quantum bits (qubits) has reinvigorated the investigation of fundamental contributions to electron spin relaxation in various ligand scaffolds. From quantum computers to chemical and biological sensors, interest in leveraging the quantum properties of these molecules has opened a discussion of the requirements to maintain coherence over a large temperature range, including near room temperature. Here we compare temperature-, magnetic field position-, and concentration-dependent electron spin relaxation in copper(II) phthalocyanine (CuPc) and vanadyl phthalocyanine (VOPc) doped into diamagnetic hosts. While VOPc demonstrates coherence up to room temperature, CuPc coherence times become rapidly T1-limited with increasing temperature, despite featuring a more covalent ground-state wave function than VOPc. As rationalized by a ligand field model, this difference is ascribed to different spin-orbit coupling (SOC) constants for Cu(II) versus V(IV). The manifestation of SOC contributions to spin-phonon coupling and electron spin relaxation in different ligand fields is discussed, allowing for a further understanding of the competing roles of SOC and covalency in electron spin relaxation.Monitoring cell-state transition in pluripotent cells is invaluable for application and basic research. In this study, we demonstrate the pertinence of noninvasive, label-free Raman spectroscopy to monitor and characterize the cell-state transition of mouse stem cells undergoing reprogramming. Using an isogenic cell line of mouse stem cells, reprogramming from neuronal cells was performed, and we showcase a comparative analysis of living single-cell spectral data of the original stem cells, their neuronal progenitors, and reprogrammed cells. Neural network, regression models, and ratiometric analyses were used to discriminate the cell states and extract several important biomarkers specific to differentiation or reprogramming. Our results indicated that the Raman spectrum allowed us to build a low-dimensional space allowing us to monitor and characterize the dynamics of cell-state transition at a single-cell level, scattered in heterogeneous populations. The ability of monitoring pluripotency by Raman spectroscopy and distinguishing differences between ES and reprogrammed cells is also discussed.The novel coronavirus (nCOV-2019) outbreak has put the world on edge, causing millions of cases and hundreds of thousands of deaths all around the world, as of June 2020, let alone the societal and economic impacts of the crisis. The spike protein of nCOV-2019 resides on the virion’s surface mediating coronavirus entry into host cells by binding its receptor binding domain (RBD) to the host cell surface receptor protein, angiotensin converter enzyme (ACE2). Our goal is to provide a detailed structural mechanism of how nCOV-2019 recognizes and establishes contacts with ACE2 and its difference with an earlier severe acute respiratory syndrome coronavirus (SARS-COV) in 2002 via extensive molecular dynamics (MD) simulations. Numerous mutations have been identified in the RBD of nCOV-2019 strains isolated from humans in different parts of the world. In this study, we investigated the effect of these mutations as well as other Ala-scanning mutations on the stability of the RBD/ACE2 complex. It is found that most of the naturally occurring mutations to the RBD either slightly strengthen or have the same binding affinity to ACE2 as the wild-type nCOV-2019. This means that the virus had sufficient binding affinity to its receptor at the beginning of the crisis. This also has implications for any vaccine design endeavors since these mutations could act as antibody escape mutants. Furthermore, in silico Ala-scanning and long-timescale MD simulations highlight the crucial role of the residues at the interface of RBD and ACE2 that may be used as potential pharmacophores for any drug development endeavors. From an evolutional perspective, this study also identifies how the virus has evolved from its predecessor SARS-COV and how it could further evolve to become even more infectious.Polycyclic aromatic hydrocarbons (PAHs) are common atmospheric pollutants and known to cause adverse health effects. Nitrated PAHs (NPAHs) are formed in combustion activities and by nitration of PAHs in the atmosphere and may be equally or more toxic, but their spatial and temporal distribution in the atmosphere is not well characterized. Using the global EMAC model with atmospheric chemistry and surface compartments coupled, we investigate the formation, abundance, and fate of two secondarily formed NPAHs, 2-nitrofluoranthene (2-NFLT) and 2-nitropyrene (2-NPYR). The default reactivity scenario, the model with the simplest interpretation of parameters from the literature, tends to overestimate both absolute concentrations and NPAH/PAH ratios at observational sites. Sensitivity scenarios indicate that NO2-dependent NPAH formation leads to better agreement between measured and predicted NPAH concentrations and that photodegradation is the most important loss process of 2-NFLT and 2-NPYR. The highest concentrations of 2-NFLT and 2-NPYR are found in regions with strong PAH emissions, but because of continued secondary formation from the PAH precursors, these two NPAHs are predicted to be spread across the globe.The formation of purine and pyrimidine base pairs (BPs), which contributes to shaping of the canonical and noncanonical 3D structures of nucleic acids, is one the most investigated phenomena in chemistry and life sciences. In this contribution, the anatomy of the bond energy (BDE) of the base-pairing interaction in 39 different arrangements found experimentally or predicted for DNA structures containing the four common nucleobases (A, C, G, T) in their neutral or protonated forms is described in light of the theory of interacting quantum atoms within the context of the quantum theory of atoms in molecules. The interplay of individual energy components involved in the three stages of the bond formation process (structural deformation, electron-density promotion, and intermolecular interaction) is studied. We recognized that for the neutral BPs, variations in the kinetic and electrostatic contributions to the BDE are rather negligible, leaving the exchange-correlation energy as the main stabilizing component. It is shown that the contribution of the exchange-correlation term can be recovered by including atoms that are formally assumed to be hydrogen bonded (primary interaction). In contrast, to recover the electrostatic component of interaction, one must consider both the primary and secondary (formally nonbonded atoms) interatomic interactions. The results of our study were employed to design new types of BPs with altered bonding anatomy. We demonstrate that improving the electrostatic characteristics of the BPs does not necessarily result in greater interaction energies if weak secondary hydrogen bonding is destroyed. However, the main tuning factor for systems with conserved interacting faces (primary interactions) is the electrostatic component of the interaction energy resulting from the secondary atom-atom electrostatics.Genomic DNA is chemically reactive and therefore susceptible to damage by many exogenous and endogenous sources. Lesions produced from these damaging events can have various mutagenic and genotoxic consequences. This Perspective follows the journey of one particular lesion, 1,N6-ethenoadenine (εA), from its formation to replication and repair, and its role in cancerous tissues and inflammatory diseases. εA is generated by the reaction of adenine (A) with vinyl chloride or lipid peroxidation products. We present the miscoding properties of εA with an emphasis on how bacterial and mammalian cells can process lesions differently, leading to varied mutational spectra. But with information from these assays, we can better understand how the miscoding properties of εA lead to biological consequences and how genomic stability can be maintained via DNA repair mechanisms. We discuss how base excision repair (BER) and direct reversal repair (DRR) can minimize the biological consequences of εA lesions. Kinetic parameters of glycosylases and AlkB family enzymes are described, along with a discussion of the relative contributions of the BER and DRR pathways in the repair of εA. Because eukaryotic DNA is packaged in chromatin, we also discuss the impact of this packaging on BER and DRR, specifically in regards to repair of εA. Studying DNA lesions like εA in this context, from origin to biological implications, can provide crucial information to better understand prevention of mutagenesis and cancer.Organic mixed ionic-electronic conductors (OMIECs) are an emerging family of materials crucial in the development of flexible, bio-, and optoelectronics. In electrochromic polymers, the cyclic redox reaction is associated with a mechanical breathing strain, which deforms the OMIECs and degrades the device reliability. We set forth an in situ nanoindentation approach to measure the breathing strain of a poly(3,4-propylenedioxythiophene) (PProDOT) thin film in a customized liquid cell during electrochromic cycles. A breathing volumetric strain of 12-25% is persistent in different sets of electrolytes of various solvents, salts, and salt molarities. The electrochemical conditioning, intermittence time, and cyclic protocol have minor effects on the mechanical response of PProDOT. The mechanical behavior and anion diffusivity measurement further infer the redox kinetics. Heavily cycled PProDOT films show reduced volumetric strain and accumulated mechanical damage of channel cracks and dysfunctional regions of slow and inhomogeneous electrochromic switching. This work is a systematic characterization of mechanical deformation and damage in a model OMIEC and informs the mechanical reliability of organic electrochromic devices.Over 100 nations signed the Minamata Convention on Mercury to control the adverse effects of mercury (Hg) emissions on human beings. A spatially explicit analysis is needed to identify the specific sources and distribution of Hg-related health impacts. This study maps China’s Hg-related health impacts and global supply chain drivers (i.e., global final consumers and primary suppliers) at a high spatial resolution. Here we show significant spatial heterogeneity in hotspots of China’s Hg-related health impacts. Approximately 1% of the land area holds only 40% of the Chinese population but nearly 70% of the fatal heart attack deaths in China. Moreover, approximately 3% of the land area holds nearly 60% of the population but 70% of the intelligence quotient (IQ) decrements. The distribution of hotspots of China’s Hg-related health impacts and global supply chain drivers are influenced by various factors including population, economy, transportation, resources, and dietary intake habits. These spatially explicit hotspots can support more effective policies in various stages of the global supply chains and more effective international cooperation to reduce Hg-related health impacts. This can facilitate the successful implementation of the Minamata Convention on Mercury.The photoinduced reactions of tetraphenyldiphosphine disulfide with a range of organic dichalcogenides successfully afforded a series of phosphorus(V)-chalcogen interelement compounds via a radical process. The relative reactivities of the organic dichalcogenides (i.e., (PhS)2, (PhSe)2, and (PhTe)2) toward the PIII or PV groups in the diphosphine analogues under light were investigated in detail, and a convenient method was developed to form P-S or P-Se interelement compounds from tetraphenyldiphosphine disulfide and (PhS)2 or (PhSe)2 upon photoirradiation. Furthermore, the relative photochemical properties and reactivities of tetraphenyldiphophine (P-P interelement compound) and its analogues toward photoinduced radical addition reactions were also discussed. The formed P-E (E = S, Se) interelement compounds could be utilized for ionic reactions, and they could be transformed into various phosphine reagents via one-pot processes.Recently, innovations of nano/microcarrier formulations have been focused on improving application efficiencies and retention time. In this study, a water-based 2.5% λ-cyhalothrin (LC) microcapsule suspension (CS) was developed by orthogonal test with biodegradable and adhesive polydopamine (PDA) microcapsules (MCs) as carriers. The obtained LC-PDA CS had good suspension properties, flow behavior, storage stability, and rheological properties. LC-PDA CS had higher retention, wettability, and decreased rainwater washing out on the leaves than commercial CS. LC-PDA CS displayed higher insecticidal activity against Lipaphis erysimi compared to commercial CS. LC-PDA CS reduced the toxicity of LC to the aquatic organism Danio rerio compared to LC. The above results demonstrated that LC-PDA CS would be eco-friendly water-based pesticides carrier system for prolonging the retention time on target leaf and reducing toxicity to aquatic organisms.The unique aroma and flavor of oolong tea develop during the withering stage of postharvest processing. We explored the roles of miRNA-related regulatory networks during tea withering and their effects on oolong tea quality. We conducted transcriptome and miRNA analyses to identify differentially expressed (DE) miRNAs and target genes among fresh leaves, indoor-withered leaves, and solar-withered leaves. We identified 32 DE-miRNAs and 41 target genes involved in phytohormone signal transduction and ABC transporters. Further analyses indicated that these two pathways regulated the accumulation of flavor-related metabolites during tea withering. Flavonoid accumulation was correlated with the miR167d_1-ARF-GH3, miR845-ABCC1-3/ABCC2, miR166d-5p_1-ABCC1-2, and miR319c_3-PIF-ARF modules. Terpenoid content was correlated with the miR171b-3p_2-DELLA-MYC2 and miR166d-5p_1-ABCG2-MYC2 modules. These modules inhibited flavonoid biosynthesis and enhanced terpenoid biosynthesis in solar-withered leaves. Low auxin and gibberellic acid contents and circRNA-related regulatory networks also regulated the accumulation of flavor compounds in solar-withered leaves. Our analyses reveal how solar withering produces high-quality oolong tea.An effective therapy for human adenovirus (HAdV) infections in immunocompromised patients and healthy individuals with community-acquired pneumonia remains an unmet medical need. We herein reported a series of novel substituted N-(4-amino-2-chlorophenyl)-5-chloro-2-hydroxybenzamide analogues as potent HAdV inhibitors. Compounds 6, 15, 29, 40, 43, 46, 47, and 54 exhibited increased selectivity indexes (SI > 100) compared to the lead compound niclosamide, while maintaining sub-micromolar to low micromolar potency against HAdV. The preliminary mechanistic studies indicated that compounds 6 and 43 possibly target the HAdV DNA replication process, while compounds 46 and 47 suppress later steps of HAdV life cycle. Notably, among these derivatives, compound 15 showed improved anti-HAdV activity (IC50 = 0.27 μM), significantly decreased cytotoxicity (CC50 = 156.8 μM), and low in vivo toxicity (maximum tolerated dose = 150 mg/kg in hamster) as compared with niclosamide, supporting its further in vivo efficacy studies for the treatment of HAdV infections.The potential of 2-benzothiazolyl-decorated liposomes as theragnostic systems for Alzheimer’s disease was evaluated in vitro, using PEGylated liposomes that were decorated with two types of 2-benzothiazoles (i) the unsubstituted 2-benzothiazole (BTH) and (ii) the 2-(4-aminophenyl)benzothiazole (AP-BTH). The lipid derivatives of both BTH-lipid and AP-BTH-lipid were synthesized, for insertion in liposome membranes. Liposomes (LIP) containing three different concentrations of benzothiazoles (5, 10, and 20%) were formulated, and their stability, integrity in the presence of serum proteins, and their ability to inhibit β-amyloid (1-42) (Αβ42) peptide aggregation (by circular dichroism (CD) and thioflavin T (ThT) assay), were evaluated. Additionally, the interaction of some LIP with an in vitro model of the blood-brain barrier (BBB) was studied. All liposome types ranged between 92 and 105 nm, with the exception of the 20% AP-BTH-LIP that were larger (180 nm). The 5 and 10% AP-BTH-LIP were stable when stored at 4 °C for 40 days and demonstrated high integrity in the presence of serum proteins for 7 days at 37 °C. Interestingly, CD experiments revealed that the AP-BTH-LIP substantially interacted with Αβ42 peptides and inhibited fibril formation, as verified by ThT assay, in contrast with the BTH-LIP, which had no effect. The 5 and 10% AP-BTH-LIP were the most effective in inhibiting Αβ42 fibril formation. Surprisingly, the AP-BTH-LIP, especially the 5% ones, demonstrated high interaction with brain endothelial cells and high capability to be transported across the BBB model. Taken together, the current results reveal that the 5% AP-BTH-LIP are of high interest as novel targeted theragnostic systems against AD, justifying further in vitro and in vivo exploitation.Twenty-one aspidosperma-aspidosperma alkaloids, including the new tabernaesines A-J (1-9), were obtained from Tabernaemontana pachysiphon. The structures and absolute configurations were elucidated using HRMS and NMR experiments. Compounds 1-9 possessed a rare spiro heterocycle moiety between the monomeric units, while compounds 4 and 5 were characterized by an indole ring fused with an (N,N-diethyl)methyl amino group. Compounds 1, 5-7, 15, and 16 exhibited moderate cytotoxic potency against various human cancer cell lines at IC50 2.5-9.8 μM.Two-photon polymerization stereolithographic three-dimensional (3D) printing is used for manufacturing a variety of structures ranging from microdevices to refractive optics. Incorporation of nanoparticles in 3D printing offers huge potential to create even more functional nanocomposite structures. However, this is difficult to achieve since the agglomeration of the nanoparticles can occur. Agglomeration not only leads to an uneven distribution of nanoparticles in the photoresin but also induces scattering of the excitation beam and altered absorption profiles due to interparticle coupling. Thus, it is crucial to ensure that the nanoparticles do not agglomerate during any stage of the process. To achieve noninteracting and well-dispersed nanoparticles on the 3D printing process, first, the stabilization of nanoparticles in the 3D printing resin is indispensable. We achieve this by functionalizing the nanoparticles with surface-bound ligands that are chemically similar to the photoresin that allows increased nanoparticle loadings without inducing agglomeration. By systematically studying the effect of different nanomaterials (Au nanoparticles, Ag nanoparticles, and CdSe/CdZnS nanoplatelets) in the resin on the 3D printing process, we observe that both, material-specific (absorption profiles) and unspecific (radical quenching at nanoparticle surfaces) pathways co-exist by which the photopolymerization procedure is altered. This can be exploited to increase the printing resolution leading to a reduction of the minimum feature size.Glioblastoma exhibits high mortality rates due to challenges with drug delivery to the brain and into solid tumors. This two-pronged barrier necessitates high doses of systemic therapies, resulting in significant off-target toxicities. Recently, dendrimer-nanomedicines (without ligands) have shown promise for targeting specific cells in brain tumors from systemic circulation, for improved efficacy and amelioration of systemic toxicities. A dendrimer-rapamycin conjugate (D-Rapa) is presented here that specifically targets tumor-associated macrophages (TAMs) in glioblastoma from systemic administration. D-Rapa improves suppression of pro-tumor expression in activated TAMs and antiproliferative properties of rapamycin in glioma cells in vitro. In vivo, D-Rapa localizes specifically within TAMs, acting as depots to release rapamycin into the tumor microenvironment. This targeted delivery strategy yields improved reduction in tumor burden and systemic toxicities in a challenging, clinically relevant orthotopic syngeneic model of glioblastoma, demonstrating the significant potential of dendrimers as targeted immunotherapies for improving glioblastoma treatment, still an unmet need.A formal Betti reaction between variously substituted phenols and benzophenone-derived imines to afford α-triphenylmethylamines is reported. The key to the success of this transformation is the in situ generation of the reactive benzophenone iminium species under organocatalytic conditions. Different phenols reacted smoothly, enabling the synthesis of an array of α-triphenylmethylamines, which are highly valued structural motifs in bioactive molecules and chemical sensors.The rapid growth of time-resolved spectroscopies and the theoretical advances in ab initio molecular dynamics (AIMD) pave the way to look at the real-time molecular motion following the electronic excitation. Here, we exploited the capabilities of AIMD combined with a hybrid implicit/explicit model of solvation to investigate the ultrafast excited-state proton transfer (ESPT) reaction of a super photoacid, known as QCy9, in water solution. QCy9 transfers a proton to a water solvent molecule within 100 fs upon the electronic excitation in aqueous solution, and it is the strongest photoacid reported in the literature so far. Because of the ultrafast kinetics, it has been experimentally hypothesized that the ESPT escapes the solvent dynamics control (Huppert et al., J. Photochem. Photobiol. A2014,277, 90). The sampling of the solvent configuration space on the ground electronic state is the first key step toward the simulation of the ESPT event. Therefore, several configurations in the Franck-Condon region, describing an average solvation, were chosen as starting points for the excited-state dynamics. In all cases, the excited-state evolution spontaneously leads to the proton transfer event, whose rate is strongly dependent on the hydrogen bond network around the proton acceptor solvent molecule. Our study revealed that the explicit representation at least of three solvation shells around the proton acceptor molecule is necessary to stabilize the excess proton. Furthermore, the analysis of the solvent molecule motions in proximity of the reaction site suggested that even in the case of the strongest photoacid, the ESPT is actually assisted by the solvation dynamics of the first and second solvation shells of the water accepting molecule.The response of high-energy-density materials to thermal or mechanical insults involves coupled thermal, mechanical, and chemical processes with disparate temporal and spatial scales that no single model can capture. Therefore, we developed a multiscale model for 1,3,5-trinitro-1,3,5-triazinane, RDX, where a continuum description is informed by reactive and nonreactive molecular dynamics (MD) simulations to describe chemical reactions and thermal transport. Reactive MD simulations under homogeneous isothermal and adiabatic conditions are used to develop a reduced-order chemical kinetics model. Coarse graining is done using unsupervised learning via non-negative matrix factorization. Importantly, the components resulting from the analysis can be interpreted as reactants, intermediates, and products, which allows us to write kinetics equations for their evolution. The kinetics parameters are obtained from isothermal MD simulations over a wide temperature range, 1200-3000 K, and the heat evolved is calibrated from adiabatic simulations. We validate the continuum model against MD simulations by comparing the evolution of a cylindrical hotspot 10 nm in diameter. We find excellent agreement in the time evolution of the hotspot temperature fields both in cases where quenching is observed and at higher temperatures for which the hotspot transitions into a deflagration wave. The validated continuum model is then used to assess the criticality of hotspots involving scales beyond the reach of atomistic simulations that are relevant to detonation initiation.Two polycyclic heteroarene derivatives, namely, V-1 and V-2, with a diphenanthro[9,10-b9′,10′-d]thiophene (DPT) core tethered with two diphenylaminophenyl or diphenylamino groups were first synthesized and used as hole-transporting materials (HTMs) in perovskite solar cell (PSC) fabrication. The novel HTMs exhibit appropriate energy-level alignment with the perovskite so as to ensure efficient hole transfer from the perovskite to HTMs. V-2 with the diphenylamino substituent on DPT exhibited impressive photovoltaic performance with a power conversion efficiency of 19.32%, which was higher than that of V-1 (18.60%) and the benchmark 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenyl-amine)-9,9′-spirobifluorene (spiro-OMeTAD) (17.99%), presumably because of a better hole extraction, higher hole mobility, and excellent film-forming ability, which were supported by steady-state photoluminescence (PL), time-resolved PL, the hole mobility experiment, scanning electron microscopy, and atomic force microscopy measurements. Meanwhile, V-2-based PSCs exhibited better long-term durability than that with V-1 and the state-of-the-art spiro-OMeTAD, which is ascribable to the excellent surface morphology and hydrophobicity of the film. This systematic study suggests that DPT-based molecules are good potential candidates as HTMs for achieving high-performance PSCs.Lanthionine synthase from the oral bacterium Fusobacterium nucleatum is a fold type II pyridoxal-5′-phosphate (PLP)-dependent enzyme that catalyzes the β-replacement of l-cysteine by a second molecule of l-cysteine to form H2S and l-lanthionine. The meso-isomer of the latter product is incorporated into the F. nucleatum peptidoglycan layer. Herein, we investigated the catalytic role of S224, which engages in hydrogen-bond contact with the terminal carboxylate of l-lanthionine in the closed conformation of the enzyme. Unexpectedly, the S224A variant elicited a 7-fold increase in the turnover rate for H2S and lanthionine formation and a 70-fold faster rate constant for the formation of the α-aminoacrylate intermediate compared to the wild-type enzyme. Presteady state kinetic analysis further showed that the reaction between S224A and l-cysteine leads to the formation of the more reactive ketoenamine tautomer of the α-aminoacrylate. The α-aminoacrylate with the protonated Schiff base is not an observable intermediate in the analogous reaction with the wild type, which may account for its attenuated kinetic properties. However, the S224A substitution is detrimental to other aspects of the catalytic cycle; it facilitates the α,β-elimination of l-lanthionine, and it weakens the enzyme’s catalytic preference for the formation of l-lanthionine over that of l-cystathionine.The first example of the oxidative addition of a C(sp3)-F bond in trifluoromethylarenes to a nickel(0) complex is described. A nickel(0) complex that bears two N-heterocyclic carbene (NHC) ligands of low steric demand is able to cleave C(sp3)-F bonds of trifluoromethylarenes to afford the corresponding trans-difluorobenzyl nickel(II) fluoride complexes. Isolation and characterization studies suggested that the cleavage of the C(sp3)-F bond proceeds via an η2-arene nickel(0) complex. Taking advantage of the reactivity of these nickel(II) fluoride complexes, we developed a catalytic hydrodefluorination of trifluoromethylarenes using hydrosilanes. A computational study indicated that the electron-rich nickel(0) center supported by two relatively small NHC ligands cleaves the C(sp3)-F bond via a syn-SN2′ mechanism.While zwitterionic interfaces are known for their excellent low-fouling properties, the underlying molecular principles are still under debate. In particular, the role of the zwitterion orientation at the interface has been discussed recently. For elucidation of the effect of this parameter, self-assembled monolayers (SAMs) on gold were prepared from stoichiometric mixtures of oppositely charged alkyl thiols bearing either a quaternary ammonium or a carboxylate moiety. The alkyl chain length of the cationic component (11-mercaptoundecyl)-N,N,N-trimethylammonium, which controls the distance of the positively charged end group from the substrate’s surface, was kept constant. In contrast, the anionic component and, correspondingly, the distance of the negatively charged carboxylate groups from the surface was varied by changing the alkyl chain length in the thiol molecules from 7 (8-mercaptooctanoic acid) to 11 (12-mercaptododecanoic acid) to 15 (16-mercaptohexadecanoic acid). In this way, the charge neutrality of the coating was maintained, but the charged groups exposed at the interface to water were varied, and thus, the orientation of the dipoles in the SAMs was altered. In model biofouling studies, protein adsorption, diatom accumulation, and the settlement of zoospores were all affected by the altered charge distribution. This demonstrates the importance of the dipole orientation in mixed-charged SAMs for their inertness to nonspecific protein adsorption and the accumulation of marine organisms. Overall, biofouling was lowest when both the anionic and the cationic groups were placed at the same distance from the substrate’s surface.Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide since its first incidence in Wuhan, China, in December 2019. Although the case fatality rate of COVID-19 appears to be lower than that of SARS and Middle East respiratory syndrome (MERS), the higher transmissibility of SARS-CoV-2 has caused the total fatality to surpass other viral diseases, reaching more than 1 million globally as of October 6, 2020. The rate at which the disease is spreading calls for a therapy that is useful for treating a large population. Multiple intersecting viral and host factor targets involved in the life cycle of the virus are being explored. Because of the frequent mutations, many coronaviruses gain zoonotic potential, which is dependent on the presence of cell receptors and proteases, and therefore the targeting of the viral proteins has some drawbacks, as strain-specific drug resistance can occur. Moreover, the limited number of proteins in a virus makes the number of available targets small. Although SARS-CoV and SARS-CoV-2 share common mechanisms of entry and replication, there are substantial differences in viral proteins such as the spike (S) protein. In contrast, targeting cellular factors may result in a broader range of therapies, reducing the chances of developing drug resistance. In this Review, we discuss the role of primary host factors such as the cell receptor angiotensin-converting enzyme 2 (ACE2), cellular proteases of S protein priming, post-translational modifiers, kinases, inflammatory cells, and their pharmacological intervention in the infection of SARS-CoV-2 and related viruses.

    Antiplatelet therapy (APT) after interventions for lower extremity artery disease (LEAD) is recommended. However, (inter)national guidelines vary on type and duration of APT. This report aimed to present the results of a survey on antithrombotic prescribing patterns after lower limb interventions in the Netherlands and an overview of the available literature on this topic.

    Vascular surgeons from the Dutch Society for Vascular Surgery and interventional radiologists from the Dutch Society for Interventional Radiology received an online survey on the type and duration of antithrombotic medication after lower limb interventions.

    Surveys were completed by 139 of 285 vascular surgeons (49%) and 24 of 288 (8%) interventional radiologists. Clopidogrel was the most prescribed drug after iliac percutaneous transluminal angioplasty (PTA) (77%), femoral PTA (77%), femoral PTA with drug-coated balloon (66%), and femoropopliteal (80%) and femorocrural (51%) prosthetic bypasses. Dual APT (DAPT), consisting of aspiriniable. These results reflect low-level evidence and discrepancy in current guideline recommendations.Around the end of December 2019, a new beta-coronavirus from Wuhan City, Hubei Province, China began to spread rapidly. The new virus, called SARS-CoV-2, which could be transmitted through respiratory droplets, had a range of mild to severe symptoms, from simple cold in some cases to death in others. The disease caused by SARS-CoV-2 was named COVID-19 by WHO and has so far killed more people than SARS and MERS. Following the widespread global outbreak of COVID-19, with more than 132758 confirmed cases and 4955 deaths worldwide, the World Health Organization declared COVID-19 a pandemic disease in January 2020. Earlier studies on viral pneumonia epidemics has shown that pregnant women are at greater risk than others. During pregnancy, the pregnant woman is more prone to infectious diseases. Research on both SARS-CoV and MERS-CoV, which are pathologically similar to SARS-CoV-2, has shown that being infected with these viruses during pregnancy increases the risk of maternal death, stillbirth, intrauterine growth retardation and, preterm delivery. With the exponential increase in cases of COVID-19 throughout the world, there is a need to understand the effects of SARS-CoV-2 on the health of pregnant women, through extrapolation of earlier studies that have been conducted on pregnant women infected with SARS-CoV, and MERS-CoV. There is an urgent need to understand the chance of vertical transmission of SARS-CoV-2 from mother to fetus and the possibility of the virus crossing the placental barrier. Additionally, since some viral diseases and antiviral drugs may have a negative impact on the mother and fetus, in which case, pregnant women need special attention for the prevention, diagnosis, and treatment of COVID-19.The association of small lymphocytic lymphoma/chronic lymphocytic leukaemia (CLL) with different malignancies has been reported in the literature. Also the occurrence of a second haematological disease has been described, more frequently as a secondary event in patients receiving chemotherapeutic agents. We report a case of CLL with concurrent acute myeloid leukaemia in an untreated patient, with emphasis on the need of a detailed immunomorphological study to identify the coexistence of the two diseases in the same pathological tissue.The interesting case about a patients with myoclonic epilepsy with ragged-red fibers (MERRF) syndrome due to the variant m.8344A>G with a heteroplasmy rate of 95% reported by Felczak et al. expands the phenotypic spectrum of MERRF syndrome. The authors reported a pituitary adenoma, calcium deposits in arterial walls, and an intra-cerebral lipoma in the corpus callosum in their patient. Shortcomings of the study are that the diagnostic criteria for MERRF were not accomplished, that the patient should be rather diagnosed as a mitochondrial, multiorgan disorder syndrome (MIMODS), that no pedigree and heteroplasmy rates in first degree relative were provided, that hormone levels were not provided despite obvious endocrinological involvement, and that no serum or cerebrospinal fluid (CSF) lactate levels were reported.Historical Museums of Anatomical Pathology are a relevant teaching tool for medical undergraduate students and postgraduate residents. The visualization of real specimens allow a deeper comprehension of diseases, namely of rare conditions as in Teratology. This article emphasizes the need to preserve and use Universities Museums, by presenting a XIXth Thoraco-Abdominopagus Fetus.Genital and pelvic endometriosis is a frequently encountered lesion and its importance rely on associated symptoms and its propensity for malignant transformation. In the present paper we comment on the importance of correctly diagnose the malignant transformation of an endometriotic lesion into a cystic low-grade endometrial stromal sarcoma, which is a very rare event. Moreover, we discuss the ability of a low-grade endometrial stromal sarcoma to locally recurr and the differential diagnosis with stromal endometriosis, a lesion that is very rare, almost always microscopic and solid.Multiple sclerosis (MS) is an autoimmune and degenerative disorder of the central nervous system (CNS) that causes a progressive loss of motor and cognitive performances. Moreover, since the earlier phases, axonal loss as well as neuronal degeneration and a failure of oligodendrocytes to promote myelin repair have been demonstrated. In previous studies, it has been shown that the treatment of rat neuronal primary cultures with serum from MS patients can be toxic for neurons. Here we report a pilot investigation showing that CSF from patients contains extracellular vesicles (EVs) able to induce cell death in rat cultured astrocytes. Although these data are still preliminary, they suggest at least two notable considerations i) EVs can be instrumental to pathology, and their concentration in CSF might be proportional to MS severity; ii) astrocytes can be part of the degenerative process. As a consequence, we propose that cultured astrocytes can be used as a model to study the toxicity of EVs from patients affected by MS at different stages. In addition, we suggest that EVs and their cargoes might be used as biomarkers of MS severity.BRCA1-mutated breast cancer (BC) is responsible for approximately 25% of hereditary breast cancer cases. BRCA1 is a tumor suppressor protein regulating the cell cycle and DNA repair; therefore its dysfunctions play a significant role in carcinogenesis. BRCA1-mutated BC is associated with basal-like phenotype, lack of expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) in addition to frequent TP53 mutations and poor prognosis. Currently used criteria for genetic evaluation of BC for the risk of hereditary mutations are based on patients’ age and family history, and therefore are prone to be imprecise or incomplete. This review discusses recently developed sets of immunohistochemical markers, promising independent markers (nestin, ALDH1, FOXO3, claudins, topoisomerase 1, EGFR) and their potential to be incorporated into clinical practice as a support tool in oncological counseling. This approach could be applied as a screening method for cost-effective selection of cases requiring genetic testing or adapted in pathology laboratories with limited access to molecular techniques. Although not all of the described predictor models have been validated yet, they could further improve the performance of BRCA1 screening methods in BC in the near future via increasing the accuracy of criteria for further genetic evaluation.Cancer stem cells (CSCs) are self-renewable and can be differentiated into different cell types. They play an important role in oncogenic signaling pathways, tumor cell heterogeneity, metastasis, and therapeutic resistance. Aldehyde dehydrogenase 1 (ALDH1) was identified as a specific marker for breast CSCs. The study included a total of 105 patients with a diagnosis of invasive ductal carcinoma (IDC) who underwent mastectomy and with sufficient pathology material for histopathological examination. Patient demographics, tumor location, tumor diameter, the presence of lymphovascular and perineural invasion and lymph node metastasis, surgical margin status, and immunohistochemistry (IHC) staining results were obtained from patients’ records. The tumors were classified into IHC-based molecular subtypes according to the St. Gallen Consensus Conference in 2013. A four-tiered scoring system was used based on ALDH1 staining percentage in tumor cells. The tumor was determined as positive if the score was 2 or higher. Clinical, histopathological findings, and ALDH1 staining results were correlated. Twenty-five cases (23.8%) were ALDH1 positive. The ALDH1 positive group compared to the negative group was found to be associated with ER negativity (p = 0.044), but there was no correlation with other clinical and histopathological findings. ALDH1-positive IDCs may be less sensitive to hormonal therapy and associated with aggressive behavior.It is critical to distinguish the rare neoplasm of mucin-producing urothelial-type adenocarcinoma of the prostate (MPUAP) from either prostate origin or metastatic adenocarcinoma. This is mainly because they have different tumor staging, clinical behavior and treatment plans. In the current study, we try to fulfill the lack of knowledge in this field. There were totally 24 MPUAP cases including previous reported 23 cases and adding one new MPUAP case in the current study. We performed IHC and 78 genes panel analysis in two cases of ours. Most of the cases had urinary obstruction symptoms and normal PSA level. Pathological features showed dissection of the stroma by mucin pools and glands lined by pseudostratified columnar mucinous epithelium with varying degrees of cytological atypia. The IHC results showed positive for CK20, CEA, CDX-2, β-catenin, p53, MUC2 and MUC5AC, negative for PSA, AMACR, GATA3, MUC6, AR and NKX3.1 and variable expression for HMWCK and CK7. Genetic analysis revealed concurrent mutations of FAT1 (c.10001 T>C) and HNF1A in both cases. The similar morphology features of MPUAP and colorectal adenocarcinoma were seen. Membranous staining pattern of β-catenin and genetic mutation of FAT1 and HNF1A are two distinct features in MPUAP.Previous evidence has shown that the long intergenic non-protein coding RNA 858 (LINC00858) is an oncogene in non-small cell lung cancers. However, the role LINC00858 plays in gastric cancer (GC) is not clear. To illustrate the role LINC00858 plays in GC, the LINC00858 expression in GC and normal tissues was firstly detected. Then, the viability, proliferation and migration of GC BGC823 and MGC803 cells were assessed following LINC00858 knockdown by si-LINC00858 transfection. The results showed that LINC00858 had a high level of expressions in GC tissues as demonstrated by both online data and qRT-PCR assay. Also, the knockdown of LINC00858 reduced the proliferation and migration of BGC823 and MGC803 cells in vitro. Taken together, our data indicate that LINC00858 plays an oncogenic role in GC cells and might act as a potential therapeutic target for GC.Malignant mesothelioma (MM) is a rare, highly aggressive tumor. The first symptom of MM is mostly serous effusion, and cytology can be used in diagnosis based on effusion, providing patients with an earlier diagnosis and treatment opportunity. A total of 67 specimens were embedded into cell blocks, and BAP1 immunocytochemistry (ICC) was performed. CDKN2A fluorescence in situ hybridization (FISH) was performed in 45 cases. The sensitivity, specificity and the association between the degree of cell atypia and the results of two auxiliary methods were analyzed. BAP1 ICC showed nonexpression in 13 of 24 cases of MM and 0 of 21 cases of benign mesothelial proliferation (BMP). The sensitivity was 54.2% (13/24), and the specificity was 100% (21/21). In addition, 22 metastatic adenocarcinoma (MA) cases all showed BAP1 expression. MM with BAP1 expression had more obvious cell atypia. CDKN2A deletion was found in 12 of 24 MM cases and 0 of 21 BMP cases. The sensitivity was 50% (12/24), and the specificity was 100% (21/21). BAP1 ICC and CDKN2A FISH are useful methods to differentiate MM from BMP. The cell atypia of MM with BAP1 expression was more obvious than MM with BAP1 nonexpression.Although many studies have been conducted to explore the relationship between mast cells (MC) and angiogenesis, comparison of this relationship with tumor necrosis has not been investigated to the best of our knowledge. Therefore, the relationship between MC and neovascularization in stomach, lung and ovarian malignant epithelial tumors (165 cases) in necrotizing or non-necrotizing cases was explored in this study. We immunohistochemically studied anti-mast cell tryptase antibody for MC and anti-CD34 antibody for vascular structures. MCs in the intra- tumoral and peritumoral fields, as well as vascular structures with luminal and monocellular appearances in the intratumoral field, were counted in each sample. Ten magnification fields were analyzed for each sample. In stomach and lung cases, the non-necrotizing group exhibited a greater number of MC and vascular structures in total. In ovarian cases, more MCs were counted overall in the necrotizing group, but there were fewer vascular structures. The increase in the number of MC and vascular structures in lungs and stomach in the non-necrotizing group supports the theory that MCs are involved in tumor progression. Necrosis, which can be induced on the basis of restricted neovascularization through inhibition of MCs in lung and stomach tumors, may be a treatment method.We aimed to determine the prognostic role of whole tumor-associated inflammatory cells, especially eosinophils, and stromal histological characteristics in relation to other prognostic parameters in patients with colorectal carcinoma (CRC). A total of 122 patients who underwent an operation for CRC were included in this retrospective study. Conventional (tumor grade, TNM stage and venous invasion [VI]) and other histopathological (intratumoral/peritumoral budding [ITB/PTB], desmoplasia) tumor parameters were recorded and classified by density, as were the tumor-associated inflammatory parameters (intratumoral/peritumoral lymphocytes [ITL/PTL], eosinophils [IE/PTE], overall inflammation [ITI/PTI], Crohn-like inflammation [CLI]). Cancer-specific survival data were analyzed with respect to all tumor parameters. High ITB and PTB were significantly correlated with a higher rate of pT4, VI and desmoplasia (p less then 0.05). An association of moderate ITL and extensive PTL with lesser likelihood of VI and metastasis; an association of extensive CLI with a significantly lower rate of metastasis and TNM stage IV; and minimal PTE with a significantly higher rate of pT4 stage, metastasis and ITB were detected (p less then 0.05 for each). Our findings revealed that low score tumoral budding and an increase in tumor-related inflammation were associated with lesser likelihood of poor prognostic tumor parameters. Nonetheless, given the association of an increase in PTE with lesser likelihood of ITB, pT4, metastasis, and with non-significantly for better survival rates, our findings emphasize the potential role of peritumoral eosinophils as an additional prognostic parameter in CRC.Gastrointestinal stromal tumors (GISTs) are rare neoplasms, colorectal location being met in less than 5% of cases. Knowledge about this site related particularities are limited. The aim of this study is to present our experience with colorectal GISTs between 2005 and 2018 from the clinical, morphological, and immunohistochemical perspectives, with emphasis on prognostic factors. From a total of 203 gastrointestinal stromal tumors registered, 12 were colorectal (6%). The number of colonic tumors surpassed that of the rectum (9 3) and on the right side were registered more cases than on the left side (6/3). 9 were primary tumors and 3 were recurrences. Men and women were represented equally and the age range was between 22 and 76. Tumor dimensions varied between 0.5 and 14 cm. Microscopically, spindle cell type was dominant. Mitotic rate was variable between 1 and 115/50HPFs. Accordingly, for primary tumors progression risks were assigned (low risk 2 cases, intermediate risk 3 cases and high risk 4 cases). All GISTs were CD117 and DOG1 positive.

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