Display omitted
•Progress of NMR analysis in polysaccharide structure and conformation is summarized.•NMR spectra data of typical polysaccharides are collected.•NMR analysis in cell wall structure in ...situ and other applications are hotspots.•Challenges and perspertives of NMR analysis in polysaccharides are pointed out.
Nuclear magnetic resonance (NMR) has been widely used as an analytical chemistry technique to investigate the molecular structure and conformation of polysaccharides. Combined with 1D spectra, chemical shifts and coupling constants in both homo- and heteronuclear 2D NMR spectra are able to infer the linkage and sequence of sugar residues. Besides, NMR has also been applied in conformation, quantitative analysis, cell wall in situ, degradation, polysaccharide mixture interaction analysis, as well as carbohydrates impurities profiling. This review summarizes the principle and development of NMR in polysaccharides analysis, and provides NMR spectra data collections of some common polysaccharides. It will help to promote the application of NMR in complex polysaccharides of biochemical interest, and provide valuable information on commercial polysaccharide products.
Charge separation/transfer is generally believed to be the most key factor affecting the efficiency of photocatalysis, which however will be counteracted if not taking the active site engineering ...into account for a specific photoredox reaction. Here, a 3D heterostructure composite is designed consisting of MoS2 nanoplatelets decorated on reduced graphene oxide‐wrapped TiO2 nanotube arrays (TNTAs@RGO/MoS2). Such a cascade configuration renders a directional migration of charge carriers and controlled immobilization of active sites, thereby showing much higher photoactivity for water splitting to H2 than binary TNTAs@RGO and TNTAs/MoS2. The photoactivity comparison and mechanistic analysis reveal the double‐edged sword role of RGO on boosted charge separation/transfer versus active site control in this composite system. The as‐observed inconsistency between boosted charge transfer and lowered photoactivity over TNTAs@RGO is attributed to the decrease of active sites for H2 evolution, which is significantly different from the previous reports in literature. The findings of the intrinsic relationship of balanced benefits from charge separation/transfer and active site control could promote the rational optimization of photocatalyst design by cooperatively manipulating charge flow and active site control, thereby improving the efficiency of photocatalysis for target photoredox processes.
A 3D cascade heterostructure consisting of MoS2 nanoplatelets uniformly decorated on the RGO‐wrapped TiO2 nanotube arrays is designed via a step‐by‐step integration strategy. The double‐edged sword role of graphene on boosted charge separation/transfer versus active site control is revealed.
Hybrid manganese halide has attracted much attention in the field of environment friendly ferroelectric and photo‐responsive multifunctional materials. Here, the highly efficient photoluminescent ...inorganic framework MnBr42− is utilized to conceive and synthesize a series of hybrid manganese bromide compounds RQ2MnBr4 by introducing precisely designed quasi‐spherical cations RQ+ (R = H, Me, Et, FEt, Q = quinuclidine). The accurate and effective modification of cations not only achieves the satisfactory ferroelectricity, but also enhances the photoluminescence quantum yield from 38.7% to 83.65%. Moreover, FEtQ2MnBr4 shows a highly efficient X‐ray scintillator performance, including a large range of linear response to X‐ray dose rate from 0.3 to 414.2 μGyair s−1, a high light yield of 34 438 photons per MeV, and a low detection limit of 258 nGyair s−1. This work provides an efficient strategy for the preparation of hybrid manganese halide ferroelectrics with highly efficient light‐emission and X‐ray detection.
By coupling the design for high Curie temperature ferroelectrics and the modulation of photo‐responsive properties through precise modification of spherical cations, an A2MnBr4‐type hybrid ferroelectric with a high photoluminescence quantum yield of 83.65% is obtained. Moreover, the eco‐friendly crystal is promising for high performance X‐ray detectors compared with commercially available scintillators such as bismuth germanium oxide and lutetium yttrium oxyorthosilicate.
The efficacy of osimertinib was compromised by the development of resistance mechanisms, such as EGFR C797S. In vitro study proved that cells harboring EGFR C797S in trans with T790M are sensitive to ...a combination of first- and third-generation EGFR tyrosine kinase inhibitors. However, this has not been reported clinically.
We performed capture-based sequencing on longitudinal plasma samples obtained at various treatment milestones from a patient with advanced lung adenocarcinoma who was undergoing targeted therapy.
At the development of resistance to osimertinib, the patient’s plasma sample revealed EGFR C797S located in trans with T790M. He achieved partial response accompanied by undetectable C797S after commencement of a combinatorial treatment consisting of erlotinib and osimertinib. After 3 months of progression-free survival, he experienced progressive disease with emergence of EGFR C797S located in cis to T790M.
We report the first clinical evidence of efficacy generated by combination therapy consisting of first- and third-generation EGFR tyrosine kinase inhibitors targeting concomitant EGFR T790M and C797S in trans. We also reveal that the clonal progression of C797S from in trans to in cis at disease progression may serve as a potential resistance mechanism.
Strong periodic driving with light offers the potential to coherently manipulate the properties of quantum materials on ultrafast timescales. Recently, strategies have emerged to drastically alter ...electronic and magnetic properties by optically inducing non-trivial band topologies
, emergent spin interactions
and even superconductivity
. However, the prospects and methods of coherently engineering optical properties on demand are far less understood
. Here we demonstrate coherent control and giant modulation of optical nonlinearity in a van der Waals layered magnetic insulator, manganese phosphorus trisulfide (MnPS
). By driving far off-resonance from the lowest on-site manganese d-d transition, we observe a coherent on-off switching of its optical second harmonic generation efficiency on the timescale of 100 femtoseconds with no measurable dissipation. At driving electric fields of the order of 10
volts per metre, the on-off ratio exceeds 10, which is limited only by the sample damage threshold. Floquet theory calculations
based on a single-ion model of MnPS
are able to reproduce the measured driving field amplitude and polarization dependence of the effect. Our approach can be applied to a broad range of insulating materials and could lead to dynamically designed nonlinear optical elements.
IntroductionHereditary spastic paraplegias (HSPs) are uncommon but not rare neurodegenerative diseases. More than 100 pathogenic genes and loci related to spastic paraplegia symptoms have been ...reported. HSPs have the same core clinical features, including progressive spasticity in the lower limbs, though HSPs are heterogeneous (eg, clinical signs, MRI features, gene mutation). The age of onset varies greatly, from infant to adulthood. In addition, the slow and variable rates of disease progression in patients with HSP represent a substantial challenge for informative assessment of therapeutic efficacy. To address this, we are undertaking a prospective cohort study to investigate genetic–clinical characteristics, find surrogates for monitoring disease progress and identify clinical readouts for treatment.Methods and analysisIn this case-control cohort study, we will enrol 200 patients with HSP and 200 healthy individuals in parallel. Participants will be continuously assessed for 3 years at 12-month intervals. Six aspects, including clinical signs, genetic spectrum, cognitive competence, MRI features, potential biochemical indicators and nerve electrophysiological factors, will be assessed in detail. This study will observe clinical manifestations and disease severity based on different molecular mechanisms, including oxidative stress, cholesterol metabolism and microtubule dynamics, all of which have been proposed as potential treatment targets or modalities. The analysis will also assess disease progression in different types of HSPs and cellular pathways with a longitudinal study using t tests and χ2 tests.Ethics and disseminationThe study was granted ethics committee approval by the first affiliated hospital of Fujian Medical University (MRCTA, ECFAH of FMU (2019)194) in 2019. Findings will be disseminated via presentations and peer-reviewed publications. Dissemination will target different audiences, including national stakeholders, researchers from different disciplines and the general public.Trial registration numberNCT04006418.
Objective
Changes in gut microbiota have been linked to systemic lupus erythematosus (SLE), but knowledge is limited. Our study aimed to provide an in‐depth understanding of the contribution of gut ...microbiota to the immunopathogenesis of SLE.
Methods
Fecal metagenomes from 117 patients with untreated SLE and 52 SLE patients posttreatment were aligned with 115 matched healthy controls and analyzed by whole‐genome profiling. For comparison, we assessed the fecal metagenome of MRL/lpr mice. The oral microbiota origin of the gut species that existed in SLE patients was documented by single‐nucleotide polymorphism–based strain‐level analyses. Functional validation assays were performed to demonstrate the molecular mimicry of newly found microbial peptides.
Results
Gut microbiota from individuals with SLE displayed significant differences in microbial composition and function compared to healthy controls. Certain species, including the Clostridium species ATCC BAA‐442 as well as Atopobium rimae, Shuttleworthia satelles, Actinomyces massiliensis, Bacteroides fragilis, and Clostridium leptum, were enriched in SLE gut microbiota and reduced after treatment. Enhanced lipopolysaccharide biosynthesis aligned with reduced branched chain amino acid biosynthesis was observed in the gut of SLE patients. The findings in mice were consistent with our findings in human subjects. Interestingly, some species with an oral microbiota origin were enriched in the gut of SLE patients. Functional validation assays demonstrated the proinflammatory capacities of some microbial peptides derived from SLE‐enriched species.
Conclusion
This study provides detailed information on the microbiota of untreated patients with SLE, including their functional signatures, similarities with murine counterparts, oral origin, and the definition of autoantigen‐mimicking peptides. Our data demonstrate that microbiome‐altering approaches may offer valuable adjuvant therapies in SLE.
A common full-color method involves combining micro-light-emitting diodes (LEDs) chips with color conversion materials such as quantum dots (QDs) to achieve full color. However, during color ...conversion between micro-LEDs and QDs, QDs cannot completely absorb incident wavelengths cause the emission wavelengths that including incident wavelengths and converted wavelength through QDs, which compromises color purity. The present paper proposes the use of a recycling-reflection color-purity-enhancement film (RCPEF) to reflect the incident wavelength multiple times and, consequently, prevent wavelength mixing after QDs conversion. This RCPEF only allows the light of a specific wavelength to pass through it, exciting blue light is reflected back to the red and green QDs layer. The prototype experiment indicated that with an excitation light source wavelength of 445.5 nm, the use of green QDs and RCPEFs increased color purity from 77.2% to 97.49% and light conversion efficiency by 1.97 times and the use of red QDs and RCPEFs increased color purity to 94.68% and light conversion efficiency by 1.46 times. Thus, high efficiency and color purity were achieved for micro-LEDs displays.
Graphical Abstract
Intrinsically disordered regions (IDRs) are widely distributed in proteins and related to many important biological functions. Accurately identifying IDRs is of great significance for protein ...structure and function analysis. Because the long disordered regions (LDRs) and short disordered regions (SDRs) share different characteristics, the existing predictors fail to achieve better and more stable performance on datasets with different ratios between LDRs and SDRs. There are two main reasons. First, the existing predictors construct network structures based on their own experiences such as convolutional neural network (CNN) which is used to extract the feature of neighboring residues in protein, and long short-term memory (LSTM) is used to extract the long-distance dependencies feature of protein residues. But these networks cannot capture the hidden feature associated with the length-dependent between residues. Second, many algorithms based on deep learning have been proposed but the complementarity of the existing predictors is not fully explored and used. In this study, the neural architecture search (NAS) algorithm was employed to automatically construct the network structures so as to capture the hidden features in protein sequences. In order to stably predict both the LDRs and SDRs, the model constructed by NAS was combined with length-dependent models for capturing the unique features of SDRs or LDRs and general models for capturing the common features between LDRs and SDRs. A new predictor called IDP-Fusion was proposed. Experimental results showed that IDP-Fusion can achieve more stable performance than the other existing predictors on independent test sets with different ratios between SDRs and LDRs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Higher-order topological insulators, as newly found non-trivial materials and structures, possess topological phases beyond the conventional bulk-boundary correspondence. In previous studies, in-gap ...boundary states such as the corner states were regarded as conclusive evidence for the emergence of higher-order topological insulators. Here, we present an experimental observation of a photonic higher-order topological insulator with corner states embedded into the bulk spectrum, denoted as the higher-order topological bound states in the continuum. Especially, we propose and experimentally demonstrate a new way to identify topological corner states by exciting them separately from the bulk states with photonic quantum superposition states. Our results extend the topological bound states in the continuum into higher-order cases, providing an unprecedented mechanism to achieve robust and localized states in a bulk spectrum. More importantly, our experiments exhibit the advantage of using the time evolution of quantum superposition states to identify topological corner modes, which may shed light on future exploration between quantum dynamics and higher-order topological photonics.
PDF
