The increasing use of antibiotics has attracted widespread attention to their environmental risks. However, the phototoxicity of sulfonamide antibiotics to plants remain unclear. In this study, the mechanism of the effect of sulfamethoxazole on photosynthesis of pakchoi cabbage (Brassica rapa var.
View Article and Find Full Text PDFRecent technological advancements have enabled spatially resolved transcriptomic profiling but at a multicellular resolution that is more cost-effective. The task of cell type deconvolution has been introduced to disentangle discrete cell types from such multicellular spots. However, existing benchmark datasets for cell type deconvolution are either generated from simulation or limited in scale, predominantly encompassing data on mice and are not designed for human immuno-oncology.
View Article and Find Full Text PDFBackground: Medical and nursing students will play an essential role in delivering palliative care in the future. Death education is important in preparing them for future palliative care, however, little is known about students education needs and how death attitudes affect such needs in Mainland China.
Objectives: The purpose of this survey was to investigate the death education needs of medical and nursing students and to evaluate the impact of death attitudes on death education needs.
Resolving the spatial distribution of RNA and protein in tissues at subcellular resolution is a challenge in the field of spatial biology. We describe spatial molecular imaging, a system that measures RNAs and proteins in intact biological samples at subcellular resolution by performing multiple cycles of nucleic acid hybridization of fluorescent molecular barcodes. We demonstrate that spatial molecular imaging has high sensitivity (one or two copies per cell) and very low error rate (0.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2022
The harsh conditions of the gastrointestinal tract limit the potential health benefits of oral probiotics. It is promising that oral bioavailability is improved by strengthening the self-protection of probiotics. Here, we report the encapsulation of a probiotic strain by endogenous production of hyaluronan to enhance the effects of oral administration of the strain.
View Article and Find Full Text PDFAmyloid-β (Aβ) deposition and neurotoxicity play an important role in Alzheimer's disease (AD). Notably, the nonnegligible role of endogenous heparan sulfate (HS) in the release, uptake and misfolding of Aβ sheds light on the discovery of HS as an effective drug for AD. In this work, the effects of HS from porcine mucosa (PMHS) on Aβ-induced neurotoxicity were investigated both in vitro and in vivo.
View Article and Find Full Text PDFAlzheimer's disease (AD) is a neurodegenerative disease characterized by memory loss and cognitive impairments. Amyloid-β (Aβ) deposition and neurotoxicity play important roles in AD. It has been widely reported that heparan sulfate (HS) proteoglycans play a nonnegligible role in the release, uptake and misfolding of Aβ, resulting in the discovery of HS as a therapeutic drug for AD.
View Article and Find Full Text PDFOur previous study found that low molecular weight chondroitin sulfate (LMWCS) had neuroprotective effects against the toxicity of amyloid-β (Aβ) peptides both in vitro and in vivo, and we speculated that the effects might be related with its anti-oxidative activities. In this study, the anti-Alzheimer's disease (AD) activity of LMWCS was further studied in 5XFAD transgenic mice. After 4-month gavage, the levels of Aβ level, amyloid precursor protein (APP) and presenilin 1 (PS1) were significantly decreased in the brains of 5XFAD mice, indicating the alteration of APP metabolism by LMWCS.
View Article and Find Full Text PDFMultidrug resistant organisms are a serious threat to human health. Fast, accurate antibiotic susceptibility testing (AST) is a critical need in addressing escalating antibiotic resistance, since delays in identifying multidrug resistant organisms increase mortality and use of broad-spectrum antibiotics, further selecting for resistant organisms. Yet current growth-based AST assays, such as broth microdilution, require several days before informing key clinical decisions.
View Article and Find Full Text PDFElectrical lysis of mammalian cells has been a preferred method in microfluidic platforms because of its simple implementation and rapid recovery of lysates without additional reagents. However, bacterial lysis typically requires at least a 10-fold higher electric field (∼10 kV/cm), resulting in various technical difficulties. Here, we present a novel, low-field-enabled electromechanical lysis mechanism of bacterial cells using electroconvective vortices near ion selective materials.
View Article and Find Full Text PDFAlthough the radical ion pair has been frequently invoked as a key intermediate in DNA oxidative damage reactions and photoinduced electron transfer processes, the unambiguous detection and characterization of this species remain formidable and unresolved due to its extremely unstable nature and low concentration. We use the strategy that, at cryogenic temperatures, the transient species could be sufficiently stabilized to be detectable spectroscopically. By coupling the two techniques (the cryogenic stabilization and the time-resolved laser flash photolysis spectroscopy) together, we are able to capture the ion-pair transient G⋯Cl in the chlorine radical-initiated DNA guanine (G) oxidation reaction, and provide direct evidence to ascertain the intricate type of addition/charge separation mechanism underlying guanine oxidation.
View Article and Find Full Text PDFLeukocytes are the essential cells of the immune system that protect the human body against bacteria, viruses, and other foreign invaders. Secretory products of individual leukocytes, such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase (ADAMs), are critical for regulating the inflammatory response and mediating host defense. Conventional single cell analytical methods, such as flow cytometry for cellular surface biomarker studies, are insufficient for performing functional assays of the protease activity of individual leukocytes.
View Article and Find Full Text PDFAccumulation of amyloid beta (Aβ) peptide and hyperphosphorylated tau protein has been proposed to play roles in neural destruction which induce Alzheimer's disease (AD) progresses, glutamate transporter type 1 (GLT-1) and Glycogen synthase kinase3β (GSK3β) may be the pathological links between Aβ and tau pathology. Schisantherin B (STB) is one bioactive of lignans isolated from Schisandra chinensis (Turcz.) Baill which has been commonly used as a traditional herbal medicine for thousands of years.
View Article and Find Full Text PDFPuerarin is a major isoflavone glycoside from the root of It has been reported that puerarin can protect neurons from oxidative stress-induced apoptosis. Emerging evidence suggests that oxidative damage is associated with A-induced neuronal death. In the current study, we evaluated the effect of puerarin on Alzheimer's disease induced by A and explored the potential mechanisms underlying this effect.
View Article and Find Full Text PDFWe investigate the broadband anti-Stokes emission (BASE) from Yb-doped crystals with a laser diode (LD) pumping at 940 nm. Our experiment reveals that Yb-doped crystals with random cracks are able to generate bright BASE at room temperature and atmospheric pressure. By examining the various characteristics of the crystals and the emitted light, we supply a theory for interpreting the underlying physics for this variety of BASE.
View Article and Find Full Text PDFSepsis represents a systemic inflammatory response caused by microbial infection in blood. Herein, we present a novel comprehensive approach to mitigate inflammatory responses through broad spectrum removal of pathogens, leukocytes and cytokines based on biomimetic cell margination. Using a murine model of polymicrobial sepsis induced by cecal ligation and puncture (CLP), we performed extracorporeal blood filtration with the developed microfluidic blood margination (μBM) device.
View Article and Find Full Text PDFCirculating tumor cells (CTCs) are rare cancer cells that are shed from primary or metastatic tumors into the peripheral blood circulation. Phenotypic and genetic characterization of these rare cells can provide important information to guide cancer staging and treatment, and thus further research into their characteristics and properties is an area of considerable interest. In this protocol, we describe detailed procedures for the production and use of a label-free spiral microfluidic device to allow size-based isolation of viable CTCs using hydrodynamic forces that are present in curvilinear microchannels.
View Article and Find Full Text PDFWe report a new transient spectral method utilizing triplet excited state as sensitive reporters to monitor and differentiate the multiplex G-quadruplex/ligand interactions in a single assay, which is a difficult task and usually requires a combination of several techniques. From a systematic study on the interactions of porphyrin (TMPyP4) with each telomeric G-quadruplex: AG3(T2AG3)3, G2T2G2TGTG2T2G2, (G4T4G4)2, and (TG4T)4, it is convincingly shown that the ligand triplet decay lifetimes are sensitive to the local bound microenvironment within G-quadruplexes, from which the coexisting binding modes of end-stacking, intercalation, and sandwich are distinguished and their respective contribution are determined. The complete scenario of mixed interaction modes is thus revealed, shedding light on the past controversial issues.
View Article and Find Full Text PDFAnnu Rev Biomed Eng
September 2016
Microfluidic cell-separation technologies have been studied for almost two decades, but the limited throughput has restricted their impact and range of application. Recent advances in microfluidics enable high-throughput cell sorting and separation, and this has led to various novel diagnostic and therapeutic applications that previously had been impossible to implement using microfluidics technologies. In this review, we focus on recent progress made in engineering large-volume microfluidic cell-sorting methods and the new applications enabled by them.
View Article and Find Full Text PDFAs key components of autocrine signaling, pericellular proteases, a disintegrin and metalloproteinases (ADAMs) in particular, are known to impact the microenvironment of individual cells and have significant implications in various pathological situations including cancer, inflammatory and vascular diseases. There is great incentive to develop a high-throughput platform for single-cell measurement of pericellular protease activity, as it is essential for studying the heterogeneity of protease response and the corresponding cell behavioral consequences. In this work, we developed a microfluidic platform to simultaneously monitor protease activity of many single cells in a time-dependent manner.
View Article and Find Full Text PDFAlthough numerous studies have been devoted to the charge transfer through double-stranded DNA (dsDNA), one of the major problems that hinder their potential applications in molecular electronics is the fast deprotonation of guanine cation (G(+•)) to form a neutral radical that can cause the termination of hole transfer. It is thus of critical importance to explore other DNA structures, among which G-quadruplexes are an emerging topic. By nanosecond laser flash photolysis, we report here the direct observation and findings of the unusual deprotonation behavior (loss of amino proton N2-H instead of imino proton N1-H) and slower (1-2 orders of magnitude) deprotonation rate of G(+•) within G-quadruplexes, compared to the case in the free base dG or dsDNA.
View Article and Find Full Text PDFCD83 is a highly glycosylated type I transmembrane glycoprotein that belongs to the immunoglobulin superfamily. CD83 is upregulated during dendritic cell (DC) maturation, which is critical for the initiation of adaptive immune responses. The soluble isoform of CD83 (sCD83) is encoded by alternative splicing from full-length CD83 mRNA and inhibits DC maturation, which suggests that sCD83 acts as a potential immune suppressor.
View Article and Find Full Text PDFIn this paper, we evaluate the strategy of using self-assembled microbeads to build a robust and tunable membrane for free-flow zone electrophoresis in a PDMS microfluidic chip. To fabricate a porous membrane as a salt bridge for free-flow zone electrophoresis, we used silica or polystyrene microbeads between 3-6 μm in diameter and packed them inside a microchannel. After complete evaporation, we infiltrated the porous microbead structure with a positively or negatively charged hydrogel to modify its surface charge polarity.
View Article and Find Full Text PDFThe o-hydroxycinnamic derivatives represent efficient caged compounds that can realize quantification of delivery upon uncaging, but there has been lack of time-resolved and mechanistic studies. We used time-resolved infrared (TRIR) spectroscopy to investigate the photochemical uncaging dynamics of the prototype o-hydroxycinnamic compound, (E)-3-(2-hydroxyphenyl)-acrylic acid ethyl ester (HAAEE), leading to coumarin and ethanol upon uncaging. Taking advantage of the specific vibrational marker bands and the IR discerning capability, we have identified and distinguished two key intermediate species, the cis-isomers of HAAEE and the tetrahedral intermediate, in the transient infrared spectra, thus providing clear spectral evidence to support the intramolecular nucleophilic addition mechanism following the trans-cis photoisomerization.
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