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Allen Haagensen opublikował 5 miesięcy, 1 tydzień temu
This strong enhancement of light-matter coupling by localization of light opens an avenue for manufacturing powerful sensing tools.A new one-dimensional (1D) face-shared hybrid lead bromide of (2cepiH)PbBr3, which exhibits intrinsic broadband yellow-light emission with a quantum yield of 16.8% outperforming all previously reported 1D face-shared hybrid metal halides, is obtained. The origin of broadband emission and the coexistence of free excitons and self-trapped excitons are deeply investigated by variable-temperature photoluminescence spectra. Our work paves the way to discovering more wonderful light-emitting materials.We present sensing time-lapse morphogenesis of living bone cells under micro-fluidic shear stress (FSS) by digital holographic (DH) microscopy. To remove the effect of aberrations on quantitative measurements, we propose a numerical and automatic method to compensate for aberrations based on a convolutional neural network (CNN). For the first time, the aberration compensation issue is considered as a regression task where optimal coefficients for constructing the phase aberration map act as responses corresponding to the input aberrated phase image. We adopted tens of thousands of living cells’ phase images reconstructed from digital holograms for training the CNN. The experiments demonstrate that, based on the trained network, phase aberrations can be totally removed in real-time without any hypothesis of object and aberration phase, knowledge of the setup’s physical parameters, and the operation of selecting background regions; hence, the morphogenesis of the bone cells under FSS is accurately detected and quantitatively analyzed. The results show that the proposed method could provide a highly efficient and versatile way to investigate the effects of micro-FSS on living biological cells in microfluidic lab-on-chip platforms thanks to the combination of phase-contrast label-free microcopy with artificial intelligence.Type 2 diabetes mellitus is associated with an increased risk for stroke and unfavorable outcomes following stroke. Matrix metalloproteinase-9 (MMP-9) is a potential contributor to the poor prognosis of diabetic ischemic stroke. Investigations on diabetic stroke are limited by the lack of non-invasive imaging techniques. In this study, we report a fast and ultra-sensitive MMP-activatable optical imaging probe (MMP-P12) to achieve non-invasive and real-time visualization of the dynamic expression of MMP-9 in diabetic stroke. Moreover, by using this probe, we aim to detect the therapeutic efficacy of CD28 SA in diabetic stroke. Serial near-infrared fluorescence (NIRF) imaging was performed on wild-type and STZ-induced diabetic mice after MMP-P12 probe injection on days 1, 3, and 7 post ischemic stroke. The dynamic change in MMP-9 expression after CD28 SA treatment was also imaged on days 1, 3, and 7 post stroke and confirmed by immunohistochemistry staining and western blotting. NIRF imaging showed that diabetic stroke mice presented a trend of higher levels of MMP-9. CD28 SA treatment significantly downregulated the expression of MMP-9 on day 7 post stroke. Glucose also had a downward trend in CD28 SA treated diabetic stroke mice. In conclusion, our data suggest that MMP-P12 probe successfully detect the dynamic change of MMP-9 in diabetic stroke by utilizing optical imaging. CD28 SA treatment decreased the expression of MMP-9 and could be a promising therapeutic strategy for the treatment of diabetic stroke.A Bi2Te3/Bi2S3@Bi nanocomposite with a network microstructure was successfully synthesized via a hydrothermal method and spark plasma sintering. This composite was constructed from Bi2Te3 nanoparticles and Bi2S3@Bi nanowires, and its network structure is beneficial for obtaining excellent thermoelectric performance. A ZT peak of 1.2 at 450 K was realized for the nanocomposite sample.Pathogenic E. coli pose a significant threat to public health, as strains of this species cause both foodborne illnesses and urinary tract infections. Using a rapid bioconjugation reaction, we selectively capture E. coli at a disposable gold electrode from complex solutions and accurately quantify the pathogenic microbes using electrochemical impedance spectroscopy.Circular dichroism (CD) spectroscopy is commonly used for investigation of the secondary structure of biomolecular compounds as well as polymers in isotropic solution. In anisotropic solution, the usage of the apparent CD is prone to misinterpretations due to artefacts from contributions of e.g. linear dichroism (LD). Herein, a method for the complete cancelation of anisotropic artefacts in the apparent CD is developed and its validity proven. The approach is further used for investigation of the conformation and the lyotropic liquid crystalline (LLC) structure of a copolyaspartate. For this system, a temperature-dependent change of the polymer’s helical conformation (helix reversal) is known. Furthermore, a rotation of the aligned polymer helices inside a magnetic field (helix realignment) is independently present, occurring at a lower temperature compared to the helix reversal. In the current study, the helix reversal is confirmed and found to be accompanied by a change of the LLC structure. A cholesteric structure is detected and revealed to change its sense (cholesteric reversal) at the temperature at which the helix realigns in the magnetic field. The determination of the cholesteric sense is enabled by measuring the induced CD of an achiral dye, dissolved in the anisotropic polymer solution. Investigation of the anisotropic polymer solution is, thus, only made possible by cancellation of the aforementioned anisotropic artefacts. This allows the observation of changes of the liquid crystal structure from right-handed cholesteric, through left-handed cholesteric, to nematic with increasing temperature.The geometries, electronic structures and bonding of early actinide-noble gas complexes are studied computationally by density functional and wavefunction theory methods, and by ab initio molecular dynamics. AcHe183+ is confirmed as being an 18-coordinate system, with all of the He atoms accommodated in the primary coordination shell, and this record coordination number is reported for the first time for Th4+ and Th3+. For Pa and U in their group valences of 5 and 6 respectively, the largest number of coordinated He atoms is 17. For AnHe17q+ (An = Ac, q = 3; An = Th, q = 4; An = Pa, q = 5; An = U, q = 6), the average An-He binding energy increases significantly across the series, and correlates linearly with the extent of He → Anq+ charge transfer. The interatomic exchange-correlation term Vxc obtained from the interacting quantum atoms approach correlates linearly with the An-He quantum theory of atoms-in-molecules delocalization index, both indicating that covalency increases from AcHe173+ to UHe176+. The correlation energy in AnHe163+ obtained from MP2 calculations decreases in the order Pa > Th > U > Ac, the same trend found in Vxc. The most stable complexes of Ac3+ with the heavier noble gases Ar-Xe are 12 coordinate, best described as Ng12 cages encapsulating an Ac3+ ion. There is enhanced Ng → Ac3+ charge transfer as the Ng gets heavier, and Ac-Ng covalency increases.Here we report on the electrochemical performance and electromagnetic microwave absorption (EMWA) properties of a novel metal-organic framework derived carbon nanomaterial. This carbon material shows high-performance electrochemical energy storage, and has a maximum reflection loss of 27.6 dB with an effective absorption bandwidth of 2.24 GHz.While the 1 1 reaction of 3 with an N-heterocyclic carbene ((Me)CN(i-Pr)2C) in THF resulted in ligand-substituted product 4, the corresponding 1 2 reaction (in the presence of H2O) gives the first structurally characterized germanium tris(dithiolene)dianion 5 as the major product and the „naked” dithiolene radical 6˙ as a minor by-product. The structure and bonding of 4 and 5 were probed by experimental and theoretical methods. Our study suggests that carbene-mediated partial hydrolysis may represent a new method to access tris(dithiolene) complexes of main-group elements.While the HCI field increasingly examines how digital tools can support individuals in managing mental health conditions, it remains unclear how these tools can accommodate these conditions’ temporal aspects. Based on weekly interviews with five individuals with depression, conducted over six weeks, this study identifies design opportunities and challenges related to extending technology-based support across fluctuating symptoms. Our findings suggest that participants perceive events and contexts in daily life to have marked impact on their symptoms. Results also illustrate that ebbs and flows in symptoms profoundly affect how individuals practice depression self-management. While digital tools often aim to reach individuals while they feel depressed, we suggest they should also engage individuals when they are less symptomatic, leveraging their energy and motivation to build habits, establish plans and goals, and generate and organize content to prepare for symptom onset.Navigating webpages with screen readers is a challenge even with recent improvements in screen reader technologies and the increased adoption of web standards for accessibility, namely ARIA. ARIA landmarks, an important aspect of ARIA, lets screen reader users access different sections of the webpage quickly, by enabling them to skip over blocks of irrelevant or redundant content. However, these landmarks are sporadically and inconsistently used by web developers, and in many cases, even absent in numerous web pages. Therefore, we propose SaIL, a scalable approach that automatically detects the important sections of a web page, and then injects ARIA landmarks into the corresponding HTML markup to facilitate quick access to these sections. The central concept underlying SaIL is visual saliency, which is determined using a state-of-the-art deep learning model that was trained on gaze-tracking data collected from sighted users in the context of web browsing. We present the findings of a pilot study that demonstrated the potential of SaIL in reducing both the time and effort spent in navigating webpages with screen readers.COVID-19 challenged higher education to rapidly shift to remote course delivery. This study surveyed community college students (N = 356) about their confidence in completing learning related tasks before and after the shift, access to technologies used in in remote learning, and disruptions that impacted their learning. Results indicated notable declines in confidence across all demographics with significant changes in those age 18-21and for those without prior online course experience. Technology use for remote courses was primarily laptops and smartphones. Students reported the most significant changes to work-life balance came through employment changes and mental health issues. Instructional changes were both positive and negative in workload organization, course delivery, communication and technology. Institutions can use this study’s findings to enact contingency planning, expand online and blended course options, refine academic and social support, and allocate resources to mental health.