Achieving control over symmetry breaking of completely achiral components in the aqueous phase is a significant challenge in supramolecular chemistry. Herein, we demonstrate that it is possible to ...construct chiral nanoassemblies by introducing metal ions (Zn
2+
, Fe
3+
, Al
3+
, Cu
2+
, and Ca
2+
) into completely achiral azobenzene amphiphiles with key structural factors in the pure aqueous phase. It is found that the coordination interactions, stacking, hydrophilic and hydrophobic interactions, hydrogen bonding, and electrostatic interactions are crucial to the metal-ion-induced symmetry breaking of completely achiral building blocks. This study may provide an intriguing model system for constructing chiral assemblies based on completely achiral molecules.
Herein, we demonstrate that it is possible to construct chiral nanoassemblies by achieving control over metal-ion-induced symmetry breaking of completely achiral azobenzene amphiphiles with key structural factors in the pure aqueous phase.
Many Pd-catalyzed C–H functionalization reactions utilize stoichiometric Ag(I)-salts as additives. Ag additives are typically used either as a terminal oxidant or as a halide scavenger for Pd ...catalyst regeneration. However, recent experimental and computational studies have shown that Ag(I)-salts may play additional roles in C–H activation processes. Notably, cooperative Pd–Ag bimetallic C–H activations and Ag(I)-mediated Pd-catalyzed C–H arylations can occur. The non-oxidative roles of Ag(I) salts in Pd-catalyzed C-H activation are highlighted in this mini-review.
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•The roles of Ag(I) salts in Pd-catalyzed C-H activation are highlighted.•Ag additives can be used as a terminal oxidant or as a halide scavenger.•The formation of a bi- or multimetallic Pd–Ag complex facilitates C–H cleavage.
Human action recognition is an important yet challenging task. This paper presents a low-cost descriptor called 3D histograms of texture (3DHoTs) to extract discriminant features from a sequence of ...depth maps. 3DHoTs are derived from projecting depth frames onto three orthogonal Cartesian planes, i.e., the frontal, side, and top planes, and thus compactly characterize the salient information of a specific action, on which texture features are calculated to represent the action. Besides this fast feature descriptor, a new multi-class boosting classifier (MBC) is also proposed to efficiently exploit different kinds of features in a unified framework for action classification. Compared with the existing boosting frameworks, we add a new multi-class constraint into the objective function, which helps to maintain a better margin distribution by maximizing the mean of margin, whereas still minimizing the variance of margin. Experiments on the MSRAction3D, MSRGesture3D, MSRActivity3D, and UTD-MHAD data sets demonstrate that the proposed system combining 3DHoTs and MBC is superior to the state of the art.
Microscale cell carriers have recently garnered enormous interest in repairing tissue defects by avoiding substantial open surgeries using implants for tissue regeneration. In this study, the highly ...open porous microspheres (HOPMs) are fabricated using a microfluidic technique for harboring proliferating skeletal myoblasts and evaluating their feasibility toward cell delivery application in situ. These biocompatible HOPMs with particle sizes of 280–370 µm possess open pores of 10–80 µm and interconnected paths. Such structure of the HOPMs conveniently provide a favorable microenvironment, where the cells are closely arranged in elongated shapes with the deposited extracellular matrix, facilitating cell adhesion and proliferation, as well as augmented myogenic differentiation. Furthermore, in vivo results in mice confirm improved cell retention and vascularization, as well as partial myoblast differentiation. These modular cell‐laden microcarriers potentially allow for in situ tissue construction after minimally invasive delivery providing a convenient means for regeneration medicine.
Highly open porous microspheres (HOPMs) are conveniently designed using a microfluidic setup and evaluated for their feasibility toward minimally invasive cell delivery‐based tissue regeneration. These biocompatible HOPMs with interconnected paths facilitate a high cell proliferation rate, and partial differentiation of skeletal myoblasts. These modular cells‐laden microcarriers provide a convenient means for in situ repair of tissue defects and applications in regenerative medicine.
The nucleocapsid (N) protein is an important antigen for coronavirus, which participate in RNA package and virus particle release. In this study, we expressed the N protein of SARS-CoV-2 and ...characterized its biochemical properties. Static light scattering, size exclusive chromatography, and small-angle X-ray scattering (SAXS) showed that the purified N protein is largely a dimer in solution. CD spectra showed that it has a high percentage of disordered region at room temperature while it was best structured at 55 °C, suggesting its structural dynamics. Fluorescence polarization assay showed it has non-specific nucleic acid binding capability, which raised a concern in using it as a diagnostic marker. Immunoblot assays confirmed the presence of IgA, IgM and IgG antibodies against N antigen in COVID-19 infection patients’ sera, proving the importance of this antigen in host immunity and diagnostics.
•SARS-CoV-2 nucleocapsid protein is full of coils and highly disordered.•SARS-CoV-2 N protein forms a dimer by CTD-CTD interaction.•SARS-CoV-2 N protein can bind with non-specific nucleic acid with high affinity.•SARS-CoV-2 N protein can be a good antigen for serological test of COVID-19.
We comprehensively analyzed clinical, genomic, and transcriptomic data of a cohort of 465 primary triple-negative breast cancer (TNBC). PIK3CA mutations and copy-number gains of chromosome 22q11 were ...more frequent in our Chinese cohort than in The Cancer Genome Atlas. We classified TNBCs into four transcriptome-based subtypes: (1) luminal androgen receptor (LAR), (2) immunomodulatory, (3) basal-like immune-suppressed, and (4) mesenchymal-like. Putative therapeutic targets or biomarkers were identified among each subtype. Importantly, the LAR subtype showed more ERBB2 somatic mutations, infrequent mutational signature 3 and frequent CDKN2A loss. The comprehensive profile of TNBCs provided here will serve as a reference to further advance the understanding and precision treatment of TNBC.
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•We build the genomic and transcriptomic landscape of 465 primary TNBCs•Chinese TNBC cases demonstrate more PIK3CA mutations and LAR subtype•Transcriptomic data classify TNBCs into four subtypes•Multi-omics profiling identifies potential targets within specific TNBC subtypes
Jiang et al. characterize primary Chinese triple-negative breast cancer (TNBC) and classify it into four subtypes. They find that these TNBCs have more frequent PIK3CA mutations and chromosome 22q11 copy-number gains than non-Asian TNBCs and that the LAR subtype has more ERBB2 somatic mutations and CDKN2A loss.
Obesity is associated with biological dysfunction in skeletal muscle. As a condition of obesity accompanied by muscle mass loss and physical dysfunction, sarcopenic obesity (SO) has become a novel ...public health problem. Human fibroblast growth factor 19 (FGF19) plays a therapeutic role in metabolic diseases. However, the protective effects of FGF19 on skeletal muscle in obesity and SO are still not completely understood. Our results showed that FGF19 administration improved muscle loss and grip strength in young and aged mice fed a high‐fat diet (HFD). Increases in muscle atrophy markers (FOXO‐3, Atrogin‐1, MuRF‐1) were abrogated by FGF19 in palmitic acid (PA)‐treated C2C12 myotubes and in the skeletal muscle of HFD‐fed mice. FGF19 not only reduced HFD‐induced body weight gain, excessive lipid accumulation and hyperlipidaemia but also promoted energy expenditure (PGC‐1α, UCP‐1, PPAR‐γ) in brown adipose tissue (BAT). FGF19 treatment restored PA‐ and HFD‐induced hyperglycaemia, impaired glucose tolerance and insulin resistance (IRS‐1, GLUT‐4) and mitigated the PA‐ and HFD‐induced decrease in FNDC‐5/irisin expression. However, these beneficial effects of FGF19 on skeletal muscle were abolished by inhibiting AMPK, SIRT‐1 and PGC‐1α expression. Taken together, this study suggests that FGF19 protects skeletal muscle against obesity‐induced muscle atrophy, metabolic derangement and abnormal irisin secretion partially through the AMPK/SIRT‐1/PGC‐α signalling pathway, which might be a potential therapeutic target for obesity and SO.
Hyperspectral images (HSIs) are often contaminated by several types of noise, which significantly limits the accuracy of subsequent applications. Recently, low-rank modeling based on tensor singular ...value decomposition (T-SVD) has achieved great success in HSI restoration. Most of them use the convex and nonconvex surrogates of the tensor rank, which cannot well approximate the tensor singular values and obtain suboptimal restored results. We suggest a novel HSI restoration model by introducing a fibered rank constrained tensor restoration framework with an embedded plug-and-play (PnP)-based regularization (FRCTR-PnP). More precisely, instead of using the convex and nonconvex surrogates to approximate the fibered rank, the proposed model directly constrains the tensor fibered rank of the solution, leading to a better approximation to the original image. Since exploiting the low-fibered-rankness of HSI is mainly to capture the global structure, we further employ an implicit PnP-based regularization to preserve the image details. Particularly, the above two building blocks are complementary to each other, rather than isolated and uncorrelated. Based on the alternating direction multiplier method (ADMM), we propose an efficient algorithm to tackle the proposed model. For robustness, we develop a three-directional randomized T-SVD (3DRT-SVD), which preserves the intrinsic structure of the clean HSI and removes partial noise by projecting the HSI onto a low-dimensional essential subspace. Extensive experimental results including simulated and real data demonstrate that the proposed method achieves superior performance over compared methods in terms of quantitative evaluation and visual inspection.
Nowadays, great effort has been devoted to establishing wearable electronics with excellent stretchability, high sensitivity, good mechanical strength, and multifunctional characteristics. Herein, a ...soft conductive hydrogel is rationally designed by proportionally mixing silk fibroin, polyacrylamide, graphene oxide, and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). The resultant hydrogel has considerable stretchability and compressibility, which enables it to be assembled into a strain/pressure sensor with a wide sensing range (strain, 2%–600%; pressure, 0.5–119.4 kPa) and reliable stability. Then, the corresponding sensor is capable of monitoring a series of physical signals of the human body (e.g., joint movement, facial gesture, pulse, breathing, etc.). In particular, the hydrogel-based sensor is biocompatible, with no anaphylactic reaction on human skin. More interestingly, this conductive hydrogel exhibits a positive response when it works in a triboelectric nanogenerator; consequently, it lights up 20 commericial green light-emitting diodes. Thus, this silk fibroin-based hydrogel is a kind of multifunctional material toward wearable electronics with versatile applications in health and exercise monitors, soft robots, and power sources.
The task-specific ionic liquid (IL), 1-ethyl-3-methylimidazolium 2-cyanopyrolide (EMIM2-CNpyr), was encapsulated with polyurea (PU) and graphene oxide (GO) sheets via a one-pot Pickering emulsion, ...and these capsules were used to scrub CO2 (0–5000 ppm) from moist air. Up to 60 wt % of IL was achieved in the synthesized capsules, and we demonstrated comparable gravimetric CO2 capacities to zeolites and enhanced absorption rates compared to those of bulk IL due to the increased gas/liquid surface-to-volume area. The reactive IL capsules show recyclability upon mild temperature increase compared to zeolites that are the conventional absorber materials for CO2 scrubbing. The measured breakthrough curves in a fixed bed under 100% relative humidity establish the utility of reactive IL capsules as moisture-stable scrubber materials to separate CO2 from air, outperforming zeolites owing to their higher selectivity. It is shown that thermal stability, CO2 absorption capacity, and rate of uptake by IL capsules can be further modulated by incorporating low-viscosity and nonreactive ILs to the capsule core. This study demonstrates an alternative and facile approach for CO2 scrubbing, where separation from gas mixtures with extremely low partial pressures of CO2 is required.
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