• Bek Stokholm opublikował 1 rok, 3 miesiące temu

    After that, discriminant models of linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), and partial least squares-discriminant analysis (PLS-DA) were tested to find the best discrimination line and also detection of the lowest level of adulterants. Among different models, the QDA model outperformed other methods and showed the ability to predict adulterants at 5% w/w level with 100% accuracy and precision. Finally, the developed QDA model was successfully used to discriminate a set of mixed samples of saffron and four adulterants as well as some commercial samples.For the first time, widespread aqueous biphasic polymer-salt extraction system was applied for selective separation of Pd(II) and Pt(IV) from chloride technological solutions by countercurrent chromatography using a rotating coiled column (an analog of centrifugal extractor). The principle novelty of the proposed approach is the possibility of multistage extraction process and the needlessness to add any specific reagents for targeted metal binding. The results showed that the use of poly(ethylene glycol)-1500 (PEG-1500) as a stationary phase allows 96-100% of both Pd(II) and Pt(IV) to be recovered from chloride solutions containing copper and nickel. To obtain individual solutions of targeted metals it is enough to change the composition of the salt-rich phase for stripping stage, in particular the salt concentration and pH value. The final purity of the targeted metal fractions obtained after their extraction from model technological solutions is ≥ 99.9%. The components of the aqueous biphasic system are recyclable, non-toxic, available, and widespread in laboratory and technology practice. A scheme of the multistage separation of platinum metals using a rotating coiled column is proposed.Understanding how Marine Protected Areas (MPAs) improve conservation outcomes across anthropogenic pressures can improve the benefits derived from them. Effects of protection for coral reefs in the western and central Indian Ocean were assessed using size-spectra analysis of fish and the relationships of trophic group biomass with human population density. Length-spectra relationships quantifying the relative abundance of small and large fish (slope) and overall productivity of the system (intercept) showed inconsistent patterns with MPA protection. The results suggest that both the slopes and intercepts were significantly higher in highly and well-protected MPAs. This indicates that effective MPAs are more productive and support higher abundances of smaller fish, relative to moderately protected MPAs. Trophic group biomass spanning piscivores and herbivores, decreased with increasing human density implying restoration of fish functional structure is needed. This would require addressing fisher needs and supporting effective MPA management to secure ecosystem benefits for coastal communities.The evaluation of anthropogenic pressures in marine environments commonly involves sediments, water and marine biota. However, the evaluation of the quality of the beach sediment and sediments from shallow areas are scarce compared to sediments from deeper areas in environmental assessment studies. In this study polycyclic aromatic hydrocarbons and linear alkylbenzenes were assessed in sediments from shallow areas of the São Sebastião channel, southeastern Brazil. The channel is part of the Marine Protected Area of the Northern Coast of São Paulo State besides holds the largest petroleum terminal in South America further than three sewage outfalls. Despite the concentrations of these contaminants in the sediments were relatively low compared to those found in the sediments from deeper areas of the channel, suggesting low toxicity of the beach sediments, the contamination reflected the pattern of the sediments of the São Sebastião channel.Atlantic horse mackerel is one of the most commercially important species in Europe. It can reach a longevity of 30 years, with potential implications in lifespan mercury contamination. This study conducted along the Portuguese coast aimed at evaluating the total Hg content and tissue distribution, to determine the annual mercury bioaccumulation patterns and the associated risk for consumption. The T-Hg accumulation patterns observed followed the order muscle (0.34) > liver (0.28) > heart (0.19) > gills (0.11) > brain (0.041 mg kg-1). Significant differences between tissues reflect the role of the different tissues in storage and redistribution. Significant relationships observed between age and T-Hg for all tissues highlight the continuous nature of the bioaccumulation process. European food safety guidelines signalled significant risk of consumption in about 30% of the samples. Still, there was an overall low risk from the consumption of this species, which can be further minimized through consumer options to avoid health issues.Stranded marine debris (MD) has become a hot topic on Bali Island because it threatens coastal tourism sustainability. This study aims to investigate the spatiotemporal abundance and characteristics of MD on 14 touristic beaches in Bali Island. Sampling is carried out twice every season by adapting methods from NOAA’s MD program. We found that the average MD abundance and weight were 0.356 ± 0.366 items/m2 and 4.057 ± 3.892 g/m2, respectively. Plastic dominated the MD based on abundance (86.9%) and weight (40.1%). Plastic bags, straws, and plastic cups are the most common items among plastics. The MD is originated from Indonesia and is dominated by land-based sources. The beaches are categorized as dirty in the rainy seasons and clean in the dry seasons. Statistically, the MD based on abundance, weight, category, source, and level of cleanliness varied significantly between seasons.We assessed the effect of sewage-derived materials on the structural and functional attributes of the soft-bottom macrofauna at an increasing distance from the entire diffusion area. Our results showed clear spatial changes of macrofaunal density and biomass along the distance gradient from the main outfall. High values of biodiversity, species composition, and species linked to organic enrichment near the duct suggested that moderate organic stress affected this community. The traits analysis abundance-based, compared to biomass-based one, distinguished most clearly sewage contamination conditions. Functional diversity displayed spatial patterns with higher values in the less impacted sites and was significantly related to species numbers and the biotic indices (like M-AMBI). This approach is ideal for detecting macrofaunal functional changes due to sewage contamination. Thus, we infer that traits analyses could offer great potential for environmental assessment and monitoring of coastal areas influenced by human activities.Unperturbed human locomotion presumably results from feedforward shifts in stable body equilibrium in the environment, thus avoiding falling and subsequent catching considered in alternative theories of locomotion. Such shifts are achieved by relocation of the referent body configuration at which multiple muscle recruitment begins. Rather than being directly specified by a central pattern generator, multiple muscles are activated depending on the extent to which the body is deflected from the referent, threshold body configuration, as confirmed in previous studies. Based on the referent control theory of action and perception, solutions to classical problems in motor control are offered, including the previously unresolved problem of the integration of central and reflex influences on motoneurons and the problem of how posture and movement are related. The speed of locomotion depends on the rate of shifts in the referent body configuration. The transition from walking to running results from increasing the rate of referent shifts. It is emphasised that there is a certain hierarchy between reciprocal and co-activation of agonist and antagonist muscles during locomotion and other motor actions, which is also essential for the understanding of how locomotor speed is regulated. The analysis opens a new avenue in neurophysiological approaches to human locomotion with clinical implications.

    Vestibular evoked myogenic potentials (VEMP) were investigated to differentiate between parkinsonian syndromes. We correlated balance and VEMP parameters to investigate the VEMP brainstem circuits as possible origin for postural instability.

    We assessed clinical status, ocular and cervical VEMP (oVEMP, cVEMP) and conducted a balance assessment (posturography, Activities-specific Balance Confidence Scale, Berg Balance Scale, modified Barthel Index) in 76 subjects 30 with Parkinson’s disease (PD), 16 with atypical parkinsonism (AP) and 30 healthy controls. VEMP were elicited by using a mini-shaker on the forehead.

    Patients with PD had a prolonged oVEMP n10 in comparison to controls and prolonged p15 compared to controls and AP. Patients with AP showed reduced oVEMP amplitudes compared to PD and controls. CVEMP did not differ between groups. Postural impairment was higher in AP compared to controls and PD, particularly in the rating scales. No correlations between VEMP and posturography were found. A support vector machine classifier was able to automatically classify controls and patient subgroups with moderate to good accuracy based on oVEMP latencies and balance questionnaires.

    Both oVEMP and posturography, but not cVEMP, may be differentially affected in PD and AP. We did not find evidence that impairment of the cVEMP or oVEMP pathways is directly related to postural impairment.

    OVEMP and balance assessment could be implemented in the differential diagnostic work-up of parkinsonian syndromes.

    OVEMP and balance assessment could be implemented in the differential diagnostic work-up of parkinsonian syndromes.Mechanical forces were arguably among the first stimuli to be perceived by cells, and they continue to shape the evolution of all organisms. Great strides have been made in recent years in the field of plant cell and molecular mechanobiology, in part owing to focused efforts on key model systems. Here, we propose to enrich such work through evolutionary mechanobiology, or 'evo-mechano’, and describe three major themes that could drive research in this area. We use plastid evo-mechano as a case study, describing how plastids from different lineages perceive their mechanical environments, how their mechanical properties vary across lineages, and their distinct roles in graviperception. Finally, we argue that future research into the biomechanical properties and mechanobiological signaling mechanisms that have been elaborated by green species over the past 1.5 billion years will help us understand both the universal and the unique adaptations of plants to their physical environment.

    Neurodevelopmental disorders (NDD) may present as neuropsychiatric problems as well as impairments of motor, cognitive, social and communication functioning. This study describes the introduction of a specialist service with expertise in NDD into an existing court mental health liaison and diversion service to determine if the service would impact on the health needs or disposal outcomes of defendants.

    We examined referrals of defendants with NDD disorders over 30-months at a London Magistrates’ Court. The pre-existing Court Mental Health (CMH) service was enhanced to provide additional expertise and hereafter referred to as the CMH + NDD Service. Baseline data including gender, ethnicity, remands and the rates of mental disorders was collected from the CMH Service using the existing minimum mental health service dataset. This was compared with data collected from the CMH + NDD Service.

    We found the following rates of NDD 9.5 % (n = 43) for the CMH service, and 9.5 % (n = 79) for the CMH + NDD service. cost-benefit analysis is required to understand whether an approach involving a cluster of Courts, as opposed to a single site is the most effective approach for this group of defendants.In this study, we considered two subscales of attention problem (AP) behaviour, inattentiveness and hyperactivity/impulsivity, as latent traits, extreme values of which indicate attention deficit hyperactivity disorder (ADHD). We examined gender differences in these traits in a community sample of Russian schoolchildren and estimated the extent to which the association of AP behaviour and math achievement varied for boys and girls. The data from a three-wave longitudinal study of math achievement of 958 children (49 % girls) were used, and growth in math achievement was estimated. The levels of inattentiveness and hyperactivity/impulsivity of each child were measured based on teachers’ responses using the Behaviour Rating Scale (BRS). The results demonstrated that inattentiveness had a negative association with math achievement, while hyperactivity/impulsivity was positively associated with math achievement when inattentiveness was controlled for. Inattentiveness was negatively associated with math achievement in both boys and girls. However, the size of this association decreased over time for boys, so the gap between boys with high inattentiveness and low inattentiveness decreased from grade 1 to grade 2. Meanwhile, for girls, the association between inattentiveness and math remained stable, so the gap between girls with high inattentiveness and girls with low inattentiveness did not change.

    To compare physical impairments between patients with hip-related pain and those with non-hip-related groin pain, and to compare both patient groups with healthy controls.

    Cross-sectional.

    Eighty-one hip and groin pain patients were consecutively included and categorized into having hip-related pain or non-hip-related groin pain. Twenty-eight healthy controls were recruited.

    Tertiary care.

    All participants performed physical impairment testing including hip ROM, muscle function, and functional tasks. An analysis of covariates was used for analysis between patients groups and controls.

    Patients with hip-related pain showed reduced hip ROM in internal rotation compared to patients with non-hip-related groin pain and controls (p≤0.026, d-0.65;-0.97). No differences in muscle function or performance in functional tasks were observed between patients with hip-related pain and those with non-hip-related groin pain (p≥0.136, d 0.00; 0.68). Both patient groups had worse muscle function and worse performance in functional tasks compared to controls (p≤0.048, d-0.67;-1.83).

    Both patients with and without hip-related pain had worse muscle function and worse performance in functional tasks compared to matched controls but no differences were observed between the patient groups. Only patients with hip-related pain had reduced ROM in internal rotation.

    Both patients with and without hip-related pain had worse muscle function and worse performance in functional tasks compared to matched controls but no differences were observed between the patient groups. Only patients with hip-related pain had reduced ROM in internal rotation.

    Pneumoperitoneum usually requires emergency surgery. Asymptomatic idiopathic pneumoperitoneum is a rare subgroup of pneumoperitoneum for which a management algorithm has not been established.

    In an 88-year-old female patient, pneumoperitoneum was found incidentally by chest computed tomography during a periodic follow-up for sarcoidosis. Emergency admission was ordered for conservative treatment. Upper gastrointestinal endoscopy revealed edematous mucosa in the entire gastric vestibule. After being discharged on the 7th day, her clinical course was uneventful over 2months of follow-up.

    The initial clinical manifestations of pneumoperitoneum are variable and range widely from asymptomatic to septic shock. The etiology of pneumoperitoneum in our patient implied a subclinical visceral perforation that resolved without treatment. We advocate an algorithm for the initial management of pneumoperitoneum according to the extent of peritonitis and impaired conditions.

    Incidentally found asymptomatic pneumoperitoneum does not always require intervention. Careful and repeated physical assessment with investigation of underlying etiology is important in the management of pneumoperitoneum.

    Incidentally found asymptomatic pneumoperitoneum does not always require intervention. Careful and repeated physical assessment with investigation of underlying etiology is important in the management of pneumoperitoneum.

    Shoulder manipulation under ultrasound-guided cervical nerve root block (MUC) gives good clinical results in patients with frozen shoulder 1week after the procedure. However, some patients are refractory to MUC. The present study was performed to investigate the prognostic factors of MUC for frozen shoulder.

    We evaluated 73 frozen shoulders (70 patients) to investigate the prognostic factors of MUC. The patients’ mean age was 56.6years, and 60% were female. The mean duration of symptoms before MUC was 8.6months. We assessed pain using a numeric rating scale (NRS), range of motion (ROM), and the American Shoulder and Elbow Surgeons (ASES) score before and 1year after MUC. We compared patients with an ASES score of <80 (defined as a poor clinical result) with those with an ASES score of ≥80 (good clinical result). To identify the risk factors for a poor clinical result, multiple logistic regression analysis was performed using the following variables age, sex, duration of symptoms before MUC, diabetes mellitus (DM), initial NRS score, and initial ROM.

    The initial NRS score and the prevalence of DM were significantly greater in the poor clinical results group. Multiple logistic regression analysis revealed that DM was the only independent risk factor for a poor clinical result after MUC (odds ratio, 51; 95% confidence interval, 10.9-237; p=.01).

    DM is a negative prognostic factor of MUC for frozen shoulder, and patients with DM should be informed of this before they undergo treatment for frozen shoulder.

    DM is a negative prognostic factor of MUC for frozen shoulder, and patients with DM should be informed of this before they undergo treatment for frozen shoulder.

    Despite the fact that hydatid disease is endemic in some countries, its cervical location remains very rare.

    We report two cases of primary cervical hydatid disease in two children from rural areas. The imaging was not specific, since the location is rare; the diagnosis was only confirmed after surgery.

    Hydatid cyst is a rare pathology. Thus clinical presentation, radiological examinations, fine needle aspiration and serology can be useful to suspect the diagnosis.

    Hydatid disease should be considered when dealing with slow-growing renitent neck swelling in endemic countries.

    Hydatid disease should be considered when dealing with slow-growing renitent neck swelling in endemic countries.

    Isolated gallbladder tuberculosis is extremely rare even in endemic regions posing diagnostic challenges as the presentation mimics other gallbladder diseases such as cholecystitis and gallbladder carcinoma. Preoperative suspicion index is negligible with most cases being diagnosed postoperatively from resected specimen.

    Herein, we report an elderly man who presented with jaundice, and was clinically diagnosed with gallbladder carcinoma.

    Histopathology of resected gallbladder revealed gallbladder tuberculosis. No features of tuberculous infection were found elsewhere.

    Healthcare providers should have a high index of suspicion particularly for patients in endemic areas presenting with cholecystitis to obtain a pre-operative diagnosis.

    Healthcare providers should have a high index of suspicion particularly for patients in endemic areas presenting with cholecystitis to obtain a pre-operative diagnosis.

    Damage to the adventitial layer of an artery leads to pseudoaneurysm formation. Pseudoaneurysms caused by complications of orthopaedic constructs are rare.

    Case report 01. A 27-year-old male presented with acute bleeding from an external fixator pin site. He had defaulted follow-up due to covid pandemic and presented with malunited distal tibia fracture and loosened Schanz pins. CT angiogram revealed a pseudoaneurysm of the peroneal artery over the loosened pin site. The patient underwent exploration and ligation of the peroneal artery. Case report 02. 86-year-old female presented with a gradually enlarging lump on her left anteromedial thigh for three months duration. She underwent open reduction and internal fixation of ipsilateral femur fracture 17months back. She was found to have a pseudoaneurysm of the superficial femoral artery caused by exposed screws following bony erosion. Exploration and repair of „neck” the pseudoaneurysm was performed and the recovery was uneventful.

    Pseudoaneurysms are rare but carry devastating complications following various orthopaedic procedures. The common cause for the formation of pseudoaneurysms is trauma during surgery. But loosened Schanz screws and screws are also can be the cause. Early identification of a pseudoaneurysm and proper intervention will reduce morbidities.

    Pseudoaneurysms are rare but carry devastating complications following various orthopaedic procedures. The common cause for the formation of pseudoaneurysms is trauma during surgery. But loosened Schanz screws and screws are also can be the cause. Early identification of a pseudoaneurysm and proper intervention will reduce morbidities.

    Chronic, large, and old incisional hernias often lead to surgical complications and major hindrances during emergent laparotomies. The most challenging stages of the laparotomy in such cases occur during opening and fascial closure.

    This article explains the novel surgical technique employed for the complex abdominal closure upon concluding an emergent laparotomy on a 68-year-old female patient. This innovative technique is appropriate for patients with contaminated abdominal cavities and scant fascia who require abdominal operations in cases where biological mesh is not available or is not a viable option.

    This surgical technique can help surgeons restrict abdominal contents and organs (particularly the bowel loops) and prevent migration out of the abdominal cavity during the early post-operative stages, hence, reducing post-surgical complications. The discussed surgical technique ensures that the abdominal fascia defect is limited using skin flaps. This defect later develops into a small hernia sac within a few weeks. Patients then need to have a secondary delayed elective operation on this significantly smaller sized hernia for repair using synthetic mesh.

    This surgical technique can help surgeons restrict abdominal contents and organs (particularly the bowel loops) and prevent migration out of the abdominal cavity during the early post-operative stages, hence, reducing post-surgical complications. The discussed surgical technique ensures that the abdominal fascia defect is limited using skin flaps. This defect later develops into a small hernia sac within a few weeks. Patients then need to have a secondary delayed elective operation on this significantly smaller sized hernia for repair using synthetic mesh.Rhipicephalus microplus, popularly known as the cattle tick, is the most important tick of livestock as it is responsible for significant economic losses. The use of chemical acaricides is still the most widely used control method despite its known disadvantages. Vaccination would be a safe alternative for the control of R. microplus and holds advantages over the use of chemical acaricides as it is environmental-friendly and leaves no residues in meat or milk. Two vaccines based on the Bm86 protein were commercialized, TickGARD® and Gavac®, with varying reported efficacies in different countries. The use of other vaccines, such as Tick Vac®, Go-Tick®, and Bovimune Ixovac® have been restricted to some countries. Several other proteins have been analyzed as possible antigens for more effective vaccines against R. microplus, including peptidases, serine proteinase inhibitors, glutathione S-transferases, metalloproteases, and ribosomal proteins, with efficacies ranging from 14% to 96%. Nonetheless, more research is needed to develop safe and efficient tick vaccines, such as the evaluation of the efficacy of antigens against other tick species to verify cross-reactivity and inclusion of additional antigens to promote the blocking of the infection and spreading of tick-borne diseases. This review summarizes the discoveries of candidate antigens for R. microplus tick vaccines as well as the methods used to test their efficacy.It is a major challenge to combine the advantages of two kinds of two-dimensional materials to construct a heterojunction and achieve efficient photocatalytic antifouling. In this work, we covalently connected two materials MXenes and covalent organic frameworks (COFs) through the Schiff base reaction and anchored Ag nanoparticles (NPs) to prepare a Ti3C2/TpPa-1/Ag composite material with high efficiency bactericidal properties. The covalent bonding between MXene and COF greatly improved the stability of the material. Ti3C2/TpPa-1/Ag composite showed an excellent antibacterial property against S. aureus and P. aeruginosa. The fluorescence spectra of Ti3C2/TpPa-1/Ag proved that the electron transfer channels formed between the ternary materials could greatly improve the efficiency of carrier separation and prolong the life of photogenerated carriers. Density functional theory calculations showed that the synergistic catalytic effect of Ag and Ti3C2 could greatly reduce the work function along the interface, and the built-in electric field between the layers drive carrier fast migration, which effectively improve the catalytic performance.

    Alkyltrimethoxysilane (ATMS) is among most widely used silane coupling agents. These commercially available, reasonably priced chemicals are often utilized to improve the compatibility of inorganic surfaces with organic coatings. With three hydrolysable moieties, ATMS is an outstanding candidate for solving the hydrophilicity, moisture sensitivity and high cost of silica aerogels. However, ATMS has a non-hydrolysable alkyl chain that undergoes cyclization reactions. The alkyl chain prevents ATMS from being incorporated in aerogel structures. Polyvinyltrimethoxysilane (PVTMS) is a silica precursor that offers two types of crosslinking to the final aerogel product. This strong doubly-crosslinked network can potentially suppress the cyclization reactions of ATMS and include it in aerogel structure.

    PVTMS was used with ATMS having different alkyl lengths (3-16 carbons) and loadings (25 or 50wt%) as the silica precursors. Acid and base catalysts were used to perform hydrolysis and condensation reactions on the mixture and ATMSPVTMS aerogels were obtained via supercritical drying.

    The incorporation of ATMS in the aerogels was approved by different characterization methods. Results showed that ATMSPVTMS aerogels possess hydrophobicity (θ∼130°), moisture resistance, varying surface area (44-916m

    ·g

    ), meso/microporous structure and thermal insulation properties (λ∼0.03W·m

    K

    ). These samples also showed excellent performance in oil and organic solvent adsorption.

    The incorporation of ATMS in the aerogels was approved by different characterization methods. Results showed that ATMSPVTMS aerogels possess hydrophobicity (θ ∼ 130°), moisture resistance, varying surface area (44-916 m2·g-1), meso/microporous structure and thermal insulation properties (λ ∼ 0.03 W·m-1K-1). These samples also showed excellent performance in oil and organic solvent adsorption.Crystalline hydrates of swelling clay minerals (smectites) exhibit a strong coupling between their ion exchange and hydration/dehydration reactions. The uptake or removal of water from smectite interlayers as a result of a change in the environmental conditions also leads to the partitioning of cations. Three factors, the solid ion composition, the solid basal spacing/water content, and the aqueous solution composition, are all implicated in controlling the thermodynamics of ion exchange. However, conventional approaches to measuring the exchange free energy cannot separate the influence of each of these individual factors. Here, we explore the energetics of the swelling and ion exchange reactions in montmorillonite using a potential of mean force approach and the thermodynamic integration method within molecular simulations. We investigate the influence of solution and clay composition on the spontaneity of the reactions, focusing on the 2 water-layer hydration state. The swelling simulations provide the equilibrium water content, interlayer water structure, and basal spacings, while thermodynamic integration of sodium-potassium exchange in the aqueous solution and solid phase are combined to calculate ion exchange free energies as a function of solution composition. Results confirm the tendency of the clay to collapse to lower hydration states as the concentration of the solution increases. Changes to the equilibrium water content, even at fixed hydration states, and the composition of the mixed electrolyte solution play a critical role in driving ion exchange and the selectivities of the clay to the exchanged cation, while the composition of the solid phase is shown to be insignificant. These findings underscore the extreme sensitivity of clay swelling and ion exchange thermodynamics to small (tenths of an Angstrom) deviations in layer spacing.The heterogeneous Fenton process suffers from low efficiency because of the low electron transfer cycle rate of Fe3+/Fe2+, which often consumes enormous amounts of hydrogen peroxide (H2O2) or other energy. Herein, we report a novel Co-based Fenton-like catalyst (in-situ-Co-g-C3N4) synthesized via the surface complexation method, in which Co species were modified in situ into the framework of the graphitic carbon nitride (g-C3N4) substrate through C-O-Co chemical bonding. The catalyst exhibited higher Fenton-like catalytic activity than pure g-C3N4 in the degradation of various pollutants under neutral conditions, as evidenced by the approximately 150-fold higher Fenton-like reaction rate constant of in-situ-Co-g-C3N4 than that of g-C3N4. Density functional theory (DFT) calculations and a series of experimental and characterization analyses revealed the interfacial reaction mechanism between H2O2, pollutants and in-situ-Co-g-C3N4. During the Fenton-like reaction, the electron-poor C center on the aromatic ring of g-C3N4 could capture the electrons deprived from pollutants, and subsequently deliver them to around the electron-rich Co center to efficiently reduce H2O2 to hydroxyl radicals (•OH), enabling H2O2 to be used efficiently for the degradation of pollutants. This study provides a strategy for improving Fenton-like degradation efficiency by effectively utilizing the energy of organic pollutants.

    Practical applications of non-wetting surfaces require good mechanical durability in the wet environments for which they are intended to be used. Durability of non-wetting surfaces is influenced by the surface features, interaction with the functionalization agent, and the lubricant properties that can be tuned independently to identify optimal combination.

    In this study, superhydrophobic and lubricant-infused surfaces are fabricated on copper tubes using chemical etching and electrodeposition texturing techniques, six different functionalizing agents, and five different infused lubricants. Through 180 fabrication combinations and 102 durability tests, each parameter is systematically studied for contributions to initial non-wetting behavior and its durability in heated, wet environment, under high-energy water jet impingement, and under accelerated flow conditions.

    Among the adsorbing and curing functionalization agents investigated, n-Hexadecyl mercaptan that belongs to the sulfhydryl group and Sylgarerties in dropwise condensation conditions for approximately 1.5 years.The development of functional covalent organic frameworks (COFs) with specific properties is an emerging research field. In the current work, COF-SQ-Ph was synthesized through the aza-Diels-Alder reaction between phenylacetylene and the matrix COF-SQ (triazine-based COF) generated from the organic monomers 2, 4, 6-tris(4-aminophenyl)-1, 3, 5-triazine and 2, 5-dimethoxyterephthalaldehyde in flask. The functionalized COF-SQ-Ph with an extended π-conjugated structure and enhanced structural stability was used as the sulfur loading recipient to prepare sulfur cathodes for lithium-sulfur batteries. Sulfur-impregnated COF-SQ-Ph marked as COF-SQ-Ph-S displayed better cycling stability with a specific capacity of 618 mA h g-1 after 150 cycles due to the lithiophilic interaction between lithium polysulfides and nitrogen atoms from quinoline and triazine moieties in COF-SQ-Ph-S. The functionalization of triazine-based COFs through a cycloaddition reaction in flask could promote the large-scale preparation of tailored COFs and the post-synthesis modification of COF-SQ.

    Mixtures of colloids and supramolecular polymers may exhibit stimuli-responsive phase behaviour. However, in theoretical descriptions of such systems, the polymers are commonly described either as flexible chains or as rigid rods, while in experimental systems supramolecular polymers usually fall in between these two limits. We expect the flexibility of the polymers to have a profound effect on the stimuli-responsive phase behaviour.

    We propose a general approach to predict the phase behaviour of colloidal hard spheres mixed with covalent or supramolecular polymers of arbitrary persistence length using free volume theory and an interpolation between flexible and rigid chains.

    The binodals are predicted to shift to lower monomer concentrations as the persistence length is increased, making the polymers more efficient depletants. The persistence length is therefore an additional degree of freedom for manipulating the phase behaviour of colloid-polymer mixtures. We show that by manipulating the persistence length of temperature responsive supramolecular polymers, a wide range of phase diagrams with various topologies can be obtained. For example, we find phase diagrams with a critical point but no triple point or displaying two triple points for temperature-sensitive supramolecular polymers mixed with hard spheres.

    The binodals are predicted to shift to lower monomer concentrations as the persistence length is increased, making the polymers more efficient depletants. The persistence length is therefore an additional degree of freedom for manipulating the phase behaviour of colloid-polymer mixtures. We show that by manipulating the persistence length of temperature responsive supramolecular polymers, a wide range of phase diagrams with various topologies can be obtained. For example, we find phase diagrams with a critical point but no triple point or displaying two triple points for temperature-sensitive supramolecular polymers mixed with hard spheres.

    Wetting characteristics of epoxy and phenolic resins on metals depend on the molecular interactions between resins’ functional groups and metal surface. Those interactions affect the practical adhesion strength of epoxy-phenolic coatings on metals. Estimation of the theoretical adhesion energies can reveal this system’s microscopic adhesion mechanisms.

    Adhesion is estimated theoretically based on resins’ wettability on metals, and experimentally through pull-off adhesion testing of cured coatings. The effect of various functional groups on adhesion is decoupled using epoxy and phenolic resins with different functionalities. To assess the impact of the metal passivation on adhesion, tinplated and tin-free steel substrates are used. Differences in their surface chemical composition and polarity are investigated using XPS.

    Theoretical adhesion results reveal a superior adhesion of epoxy compared to phenolic resins. Moreover, epoxy resins having a higher content of epoxide-to-hydroxyl groups show improved theoretical and practical adhesion. The importance of epoxides in driving resins’ initial adhesion on metals is attributed to the formation of direct chemical bonds with active hydrogen on metal surfaces. The adhesion of coatings on tin-free steel is found to be higher than on tinplated steel. This is associated to the increased hydroxyl fraction on tin-free steel surface leading to more hydrogen bonds formation.

    Theoretical adhesion results reveal a superior adhesion of epoxy compared to phenolic resins. Moreover, epoxy resins having a higher content of epoxide-to-hydroxyl groups show improved theoretical and practical adhesion. The importance of epoxides in driving resins’ initial adhesion on metals is attributed to the formation of direct chemical bonds with active hydrogen on metal surfaces. The adhesion of coatings on tin-free steel is found to be higher than on tinplated steel. This is associated to the increased hydroxyl fraction on tin-free steel surface leading to more hydrogen bonds formation.

    Experimental data suggest a relationship between the macroscopic zeta potential measured on intact rock samples and the sample wettability. However, there is no pore-scale model to quantify this relationship.

    We consider the simplest representation of a rock pore space a bundle of capillary tubes of varying size. Equations describing mass and charge transfer through a single capillary are derived and the macroscopic zeta potential and wettability determined by integrating over capillaries. Model predictions are tested against measured data yielding a good match.

    Mixed- and oil-wet models return a macro-scale zeta potential that is a combination of the micro-scale zeta potential of mineral-brine and oil-brine interfaces and the relationship between macro-scale zeta potential and water saturation exhibits hysteresis. The model predicts a similar relationship between zeta potential and wettability to that observed in experimental data but does not provide a perfect match. Fitting the model to experimental tions for surface complexation models and the design of controlled salinity waterflooding of oil reservoirs.Hollow materials have many advantages when acting as electromagnetic wave (EMW) absorber, such as excellent impedance matching properties, rich micro-interfaces and light weight. In this work, a novel hollow particle with double-shell composed with CuS and Mn(OH)2 is synthesized by coordination etching, precipitation and sulfuration using tetrakaidecahedral Cu2O as template. These hollow particles are expected to be used as improved EMW absorption property at an ultra-wide band. In this hollow particle, tetrakaidecaheral CuS acts as inner shell and Mn(OH)2 acted as outer shell, thus having rich heterogeneous interfaces which induce strong interfacial polarization. Moreover, the lower electrical conductivity and loose structure of the Mn(OH)2 shell facilitates the entry of EMW into the absorbers, and the hollow structure in this particle is beneficial to improve the impedance matching according to Maxwell-Garnett (MG) theory. Therefore, hollow CuS@Mn(OH)2 particles with double-shell exhibit excellent EMW absorption performance. The effective absorption bandwidth (reflection loss (RL) ≤ -10 dB) is 6.88 GHz (from 11.12 GHz to 18 GHz) at 2.3 mm thickness of sample.Developing high-performance electrocatalysts with favorable phase, surface structure and electronic structure for oxygen evolution reaction (OER) is crucial for efficient electrocatalytic water splitting. With Fe3+ ions as both dopant and morphology-controlling agent, Fe-doped NiS2 microcrystals with the exposed chemically stable 001 facets were synthesized hydrothermally for electrocatalytic OER. The initial electrocatalytic OER activation processes led to the conversion of iron-rich surface layers of the NiS2 microcrystals into Fe-doped Ni (oxy)hydroxide as the shell and the residual inner of the NiS2 microcrystals as the core. Such Fe-doped NiS2 microcrystals with the derived core/shell structure only required a small OER overpotential of 277 mV to reach an electrochemical current density of 10 mA/cm2, and showed a good stability in a more than 20 h duration test almost without overpotential increase.The low reactivity of zero-valent iron (ZVI) usually limits its application for pollutant remediation. Therefore, a microscopic galvanic cell (mGC) with short-circuited cathode and anode was synthesized to intensify its galvanic corrosion. The prepared mGC exhibited 7.14 times higher Fe(II) release performance than ordinary nanoscale-ZVI (nZVI), rendering efficient Cr(VI) removal performance. Density functional theory (DFT) revealed mutual-activation of the cathode and anode due to close proximity, dramatically enhancing the galvanic corrosion of Fe(0) in mGC. The corrosion potential of mGC was measured as -0.77 V, which was 100 mV more negative than nZVI. The released electrons and surface-bond Fe(II) from anode in mGC was proved to be the dominant reductive species. More importantly, Cr(VI) reduction was slightly inhibited by hydroxyl radicals generated by a series of inherent side-reactions in the system, which could be well eliminated by low concentrations of 4-acetamido phenol. This study provides a promising strategy for ZVI activation, and sheds light on its environmental applications.Development of polymeric magnetic adsorbents is a promising approach to obtain efficient treatment of contaminated water. However, the synthesis of magnetic composites involving multiple components frequently involves tedious preparation steps. In the present study, a magnetic chitosan-palygorskite (MCP) nanocomposite was prepared through a straight-forward one pot synthesis approach to evaluate its lead (Pb2+) removal capacity from aqueous solution. The nano-architectural and physicochemical properties of the newly-developed MCP composite were described via micro- and nano-morphological analyses, and crystallinity, surface porosity and magnetic susceptibility measurements. The MCP nanocomposite was capable to remove up to 58.5 mg Pb2+ g-1 of MCP from water with a good agreement of experimental data to the Langmuir isotherm model (R2 = 0.98). The Pb2+ adsorption process on MCP was a multistep diffusion-controlled phenomenon evidenced by the well-fitting of kinetic adsorption data to the intra-particle diffusion model (R2 = 0.96). Thermodynamic analysis suggested that the adsorption process at low Pb2+ concentration was controlled by chemisorption, whereas that at high Pb2+ concentration was dominated by physical adsorption. X-ray photoelectron and Fourier transform infrared spectroscopy results suggested that the Pb adsorption on MCP was governed by surface complexation and chemical reduction mechanisms. During regeneration, the MCP retained 82% Pb2+ adsorption capacity following four adsorption-desorption cycles with ease to recover the adsorbent using its strong magnetic property. These findings highlight the enhanced structural properties of the easily-prepared nanocomposite which holds outstanding potential to be used as an inexpensive and green adsorbent for remediating Pb2+ contaminated water.

    The salinity at which the dynamic phase inversion of the reference system C

    E

    /n-Octane/Water occurs in the presence of increasing amounts of a test surfactant S

    provides quantitative information on the hydrophilic/lipophilic ratio and on the sensitivity to NaCl

    of S

    .

    The Salinities causing the Phase Inversion (SPI) of the reference system mixed with 12 ionic and 10 nonionic well-defined surfactants are determined in order to quantify the contributions of the nature of the polar head and of the alkyl chain length.

    The SPI varies linearly upon the addition of S

    . The slope of the straight variation with the molar fraction of S

    is called the „SPI-slope”. It quantifies the hydrophilic/lipophilic ratio of S

    in saline environment and its salt-sensitivity with respect to the reference surfactant C

    E

    . The SPI-slopes of C

    surfactants bearing different polar heads are found to decrease in the following order C

    NMe

    Br>C

    E

    >C

    E

    ≥C

    SO

    Na ≈ C

    COONa≥C

    SO

    Na>C

    E

    >C

    E

    >C

    ion is different from that obtained when the phase inversion is caused by a change in temperature (PIT-slope method) because the addition of NaCl in significant amounts (3 to 10 wt%) partially screens the ionic heads and diminishes their apparent hydrophilicities. A simple model, valid for all types of nonionic surfactants, is developed on the basis of the HLDN equation (Normalized Hydrophilic-Lipophilic Deviation) to express the SPI-slope as a function of the hydrophilic/lipophilic ratio (PACN2) and the salinity coefficient (δ2) of S2. All studied surfactants are positioned on a 2D map according to the values of their SPI-slope and their PIT-slope to graphically highlight their hydrophilic/lipophilic ratio and their salt-sensitivity. Finally, a linear model connecting the PIT-slope and the SPI-slope is derived for nonionics, emphasizing that the thermal partitioning of C10E4 towards n-octane is much greater in the PIT-slope than in the SPI-slope experiments.The sluggish redox kinetic and shuttle effect of polysulfides still obstruct the commercial application of lithium-sulfur (Li-S) batteries. Herein, a nanocomposite consisting of well-dispersed and lamellar-like shape CoS anchored on g-C3N4 nanosheets (CoS@g-C3N4) is prepared firstly, and then it is integrated on a polypropylene membrane combined with little conductive Ketjen black (KB) to fabricate a multifunctional and quite thin interlayer, with a thickness of only ∼ 2.1 um and areal mass loading of ∼ 0.07 mg·cm-2. The as-prepared interlayer firstly can capture polysulfides by Li-N bond as well as Lewis acid-base interaction between CoS and polysulfide anions (Sn2-), and more importantly, it also displays a positive effect on catalyzing the redox conversion of intermediate polysulfides. As expected, a Li-S cell assembled with this modified separator and high sulfur content cathode displays an excellent electrochemical performance, with specific capacity of ∼ 1290 mAh g-1 at 0.2C and a low fading rate of 0.03% per cycle after 500 cycles at 1.0C. Furthermore, a high sulfur mass loading of ∼ 4.0 mg·cm-2 electrode paired with this multifunctional separator exhibits a stable specific capacity of ∼ 600 mAh g-1 after 250 cycles under 0.1C. This work can give some guides to rational design a quite thin and light interlayer for improving the utilization of sulfur species, with little damage to the energy density and Li ion transportation in Li-S batteries.Knowledge of the surface tension of cork and its hydrophobicity is of critical importance in many applications of this material at the interface with solid or liquid phases. The conventional technique based on contact angle measurement by sessile drop is not adapted to this naturally textured material and does not allow to accurately determine its hydrophobic character. A study based on capillary rise measurement is reported. A statistical distribution of the surface tension of cork is obtained, based on experiments performed on cork powder with various liquids and using a specific data processing to take into account the intrinsic heterogeneity of cork. This gives a surface tension of 22.6 (±1.2) mN·m-1, with a polar component at 5.2 (±0.5) mN·m-1 and a dispersive component at 17.4 (±1.6) mN·m-1. With a water contact angle of around 90°, cork shows an intermediate hydrophobic/hydrophilic behaviour. Locally, the specific surface texture and chemical composition can reinforce either the hydrophobic or the hydrophilic character. This critical analysis invites reflection on the notion of surface hydrophobicity as it can be determined macroscopically by a contact angle measurement and as defined at the molecular level by the free enthalpy of sorption of water.Although surfactants have been widely used in skin care and other related applications, our knowledge about how surfactants interact with stratum corneum (SC) lipids remains limited. This work reports how surfactants interact with a lipid SC model by neutron diffraction and molecular dynamics (MD) simulations, focusing on examining the impact of surfactant molecular architecture. The surfactant-SC mixed membrane was constructed by an equimolar mixture of ceramide/cholesterol/fatty acids and surfactant at 1% molar ratio of total lipids. The arrangements of water and surfactant molecules in the membrane were obtained through neutron scattering length density (NSLD) profiles via contrast variation method, meanwhile, MD simulation clearly demonstrated the mechanism of hydration change in the surfactant-model SC mixed membrane. No drastic difference was detected in the repeating distance of the short periodicity phase (SPP) upon adding surfactants, however, it significantly enhanced the membrane hydration and reduced the amount of phase separated crystalline cholesterol, showing a strong dependence on surfactant chain length, branching and double bond. This work clearly demonstrates how surfactant architecture affects its interaction with the SC membrane, providing useful guidance for either choosing an existing surfactant or designing a new one for surfactant-based transdermal application.Effective removal of antibiotics in the environment can be a demanding issue concerning the ecosystem and human health. Photocatalysis and peroxymonosulfate (PMS) oxidation have become important methods to effectively remove stubborn pollutants. In this work, by integrating these two technologies, an efficient system for degrading chloramphenicol (CAP) in water was proposed. The system was constructed by coupling strontium-doped lanthanum cobaltate (LSCO5) with chlorine-doped carbon nitride (CGCN). By doping, the increase of oxygen vacancy and the adjustment of bandgap were realized. Photoluminescence and electrochemical impedance experiments showed that the heterojunction can promote electron transfer and photogenerated carrier separation. Under the synergistic effect of PMS oxidation and photocatalysis, the prepared composite with an optimal loading of 40% LSCO5 can degrade 95.6% of CAP within 20 min. Degradation experiments on different pollutants proved the versatility of the catalytic system. The enhanced degradation mechanism of CAP was explored based on the assessment of the degradation efficiency of CAP, electron paramagnetic resonance (EPR), and quenching experiments. Through liquid chromatography-mass spectrometry (LC-MS) analysis, a possible route for CAP degradation was also proposed. This research provides some inspiration for the remediation of polluted water with perovskite-based catalyst under the synergistic effect of PMS and photocatalysis.

Szperamy.pl
Logo
Enable registration in settings - general
Compare items
  • Total (0)
Compare
0