NiRu-Mo2Ti2C3O2 as an efficient catalyst for alkaline hydrogen evolution reactions: the role of bimetallic site interactions in promoting Volmer-step kinetics.

The Volmer step in alkaline hydrogen evolution reactions (HERs), which supplies H* to the following steps by cleaving H-O-H bonds, is considered the rate-determining step of the overall reaction. The Volmer step involves water dissociation and adsorbed hydroxyl (*OH) desorption; Ru-based catalysts display a compelling water dissociation process in an alkaline HER. Unfortunately, the strong affinity of Ru for *OH blocks the active sites, resulting in unsatisfactory performance during HER processes. Hence, this study investigates a series of key descriptors (ΔG*H2O, ΔG*H-OH, ΔG*H, and ΔG*OH) of TM (Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, or Pt)-Ru/Mo2Ti2C3O2 to systematically explore the effects of bimetallic site interactions on the kinetics of the Volmer step. The results indicate that bimetallic catalysts effectively reduced the strong adsorption of *OH on Ru sites; especially, the NiRu diatomic state shows the highest electron-donating ability, which promoted the smooth migration of *OH from Ru sites to Ni sites. Therefore, Ru, Ni and MXenes are suitable to serve as water adsorption and dissociation sites, *OH desorption sites, and H2 release sites, respectively. Ultimately, NiRu/Mo2Ti2C3O2 promotes Volmer kinetics and has the potential to improve alkaline HERs. This work provides theoretical support for the construction of synergistic MXene-based diatomic catalysts and their wide application in the field of alkaline HERs.

20(R)-ginsenoside Rg3 attenuates cerebral ischemia-reperfusion injury by mitigating mitochondrial oxidative stress via the Nrf2/HO-1 signaling pathway.

Reducing mitochondrial oxidative stress has become an important strategy to prevent neuronal death in ischemic stroke. Previous studies have shown that 20(R)-ginsenoside Rg3 can significantly improve behavioral abnormalities, reduce infarct size, and decrease the number of apoptotic neurons in cerebral ischemia/reperfusion injury rats. However, it remains unclear whether 20(R)-ginsenoside Rg3 can inhibit mitochondrial oxidative stress in ischemic stroke and the potential molecular mechanism. In this study, we found that 20(R)-ginsenoside Rg3 notably inhibited mitochondrial oxidative stress in middle cerebral artery occlusion/reperfusion (MCAO/R) rats and maintained the stability of mitochondrial structure and function. Treatment with 20(R)-ginsenoside Rg3 also decreased the levels of mitochondrial fission proteins (Drp1 and Fis1) and increased the levels of fusion proteins (Opa1, Mfn1, and Mfn2) in MCAO/R rats. Furthermore, we found that 20(R)-ginsenoside Rg3 promoted nuclear aggregation of nuclear factor erythroid2-related factor 2 (Nrf2) but did not affect Kelch-like ECH-associated protein-1 (Keap1), resulting in the downstream expression of antioxidants. In in vitro oxygen-glucose deprivation/reperfusion stroke models, the results of PC12 cells treated with 20(R)-ginsenoside Rg3 were consistent with animal experiments. After transfection with Nrf2 short interfering RNA (siRNA), the protective effect of 20(R)-ginsenoside Rg3 on PC12 cells was reversed. In conclusion, the inhibition of mitochondrial oxidative stress plays a vital position in the anti-cerebral ischemia-reperfusion injury of 20(R)-ginsenoside Rg3, and its neuroprotective mechanism is related to the activation of the nuclear factor erythroid2-related factor 2/heme oxygenase 1 signaling pathway.

In Situ Formation ZnIn2 S4 /Mo2 TiC2 Schottky Junction for Accelerating Photocatalytic Hydrogen Evolution Kinetics: Manipulation of Local Coordination and Electronic Structure.

Regulating electronic structures of the active site by manipulating the local coordination is one of the advantageous means to improve photocatalytic hydrogen evolution (PHE) kinetics. Herein, the ZnIn2 S4 /Mo2 TiC2 Schottky junctions are designed to be constructed through the interfacial local coordination of In3+ with the electronegative O terminal group on Mo2 TiC2 based on the different work functions. Kelvin probe force microscopy and charge density difference reveal that an electronic unidirectional transport channel across the Schottky interface from ZnIn2 S4 to Mo2 TiC2 is established by the formed local nucleophilic/electrophilic region. The increased local electron density of Mo2 TiC2 inhibits the backflow of electrons, boosts the charge transfer and separation, and optimizes the hydrogen adsorption energy. Therefore, the ZnIn2 S4 /Mo2 TiC2 photocatalyst exhibits a superior PHE rate of 3.12 mmol g-1 h-1 under visible light, reaching 3.03 times that of the pristine ZnIn2 S4 . This work provides some insights and inspiration for preparing MXene-based Schottky catalysts to accelerate PHE kinetics.

ARF6 promotes hepatocellular carcinoma proliferation through activating STAT3 signaling.

BACKGROUND: Hepatocellular Carcinoma (HCC) possesses the high mortality in cancers worldwide. Nevertheless, the concrete mechanism underlying HCC proliferation remains obscure. In this study, we show that high expression of ARF6 is associated with a poor clinical prognosis, which could boost the proliferation of HCC. METHODS: Immunohistochemistry and western blotting were used to detect the expression level of ARF6 in HCC tissues. We analyzed the clinical significance of ARF6 in primary HCC patients. We estimated the effect of ARF6 on tumor proliferation with in vitro CCK8, colony formation assay, and in vivo nude mouse xenograft models. Immunofluorescence was conducted to investigate the ARF6 localization. western blotting was used to detect the cell cycle-related proteins with. Additionally, we examined the correlation between ARF6 and STAT3 signaling in HCC with western blotting, immunohistochemistry and xenograft assay. RESULTS: ARF6 was upregulated in HCC tissues compared to adjacent normal liver tissues. The increased expression of ARF6 correlated with poor tumor differentiation, incomplete tumor encapsulation, advanced tumor TNM stage and poor prognosis. ARF6 obviously promoted HCC cell proliferation, colony formation, and cell cycle progression. In vivo nude mouse xenograft models showed that ARF6 enhanced tumor growth. Furthermore, ARF6 activated the STAT3 signaling and ARF6 expression was positively correlated with phosphorylated STAT3 level in HCC tissues. Furthermore, after intervening of STAT3, the effect of ARF6 on tumor-promoting was weakened, which demonstrated ARF6 functioned through STAT3 signaling in HCC. CONCLUSIONS: Our results indicate that ARF6 promotes HCC proliferation through activating STAT3 signaling, suggesting that ARF6 may serve as potential prognostic and therapeutic targets for HCC patients.

Single atom supported on MXenes for the alkaline hydrogen evolution reaction: species, coordination environment, and action mechanism.

The electrochemical hydrogen evolution reaction (HER) in alkaline media provides an environmentally friendly industrial application approach to replace traditional fossil energy. The search for efficient, low-cost, and durable active electrocatalysts is central to the development of this area. Transition metal carbides (MXenes) have been emerging as a new family of two-dimensional (2D) materials that have great potential in the HER. Herein, density functional theory calculations are performed to systematically explore the structural and electronic properties and alkaline HER performances of Mo-based MXenes, as well as the influence of species and the coordination environment of single atoms on the improvement of the electrocatalytic activity of Mo2Ti2C3O2. The results show that Mo-based MXenes (Mo2CO2, Mo2TiC2O2, and Mo2Ti2C3O2) exhibit excellent H binding ability, while slow water decomposition kinetics hinders their HER performance. Replacing the O-terminal of Mo2Ti2C3O2 with a Ru single-atom (RuS-Mo2Ti2C3O2) could promote the decomposition of water owing to the stronger electron-donating ability of the atomic state Ru. In addition, Ru could also improve the binding ability of the catalyst to H by adjusting the surface electron distribution. As a result, RuS-Mo2Ti2C3O2 exhibits excellent HER performance with a water decomposition potential barrier of 0.292 eV and a H adsorption Gibbs free energy of -0.041 eV. These explorations bring new prospects for single atoms supported on Mo-based MXenes in the alkaline hydrogen evolution reaction.

Incidence, associated factors, and outcomes of delirium in critically ill children in china: a prospective cohort study.

BACKGROUND: Delirium occurs frequently in critically ill children and has been reported in many countries, but delirium is not well-characterized in China. The aim of this study was to represent the incidence of delirium in critically ill children in China, its associated factors, and the influence of delirium on in-hospital outcomes. METHODS: This observational prospective cohort study was set up in a large academic medical center with a 57-bed PICU in southwestern China. Critically ill children who required PICU stays over 24 h and were admitted between November 2019 and February 2022 were included in this study. The Cornell Assessment of Pediatric Delirium was used twice daily for delirium evaluation by bedside nurses, and twenty-four clinical features were collected from medical and nursing records during hospitalization. RESULTS: The incidence of delirium was 26.0% (n = 410/1576). Multivariate analysis revealed that seven independent risk factors including days of mechanical ventilation and physical restraints, admission diagnosis (neurologic disorder), sleep deprivation, use of benzodiazepines and dexmedetomidine, liver failure/liver dysfunction associated with delirium in critically ill children. One potentially protective factor was the watching television /listening to music/playing with toys. Children with delirium had longer lengths of stay in the PICU (median 11 vs. 10 days, p < 0.001) and hospital (median 18 vs. 15 days, p < 0.001) compared to those without delirium. Additionally, the in-hospital mortality rates were 4.63% and 0.77% in patients with and without delirium (p < 0.05). CONCLUSIONS: Delirium is common in critically ill children in China and related to poor outcomes. Interventional studies are warranted to determine the best practices to reduce delirium exposure in at-risk children.

Global, regional, and national burden of kidney dysfunction from 1990 to 2019: a systematic analysis from the global burden of disease study 2019.

OBJECTIVE: We aim to explore the prevalence and temporal trends of the burden of kidney dysfunction (KD) in global, regional and national level, since a lack of related studies. DESIGN: Cross-sectional study. MATERIALS: The data of this research was obtained from Global Burden of Diseases Study 2019. The estimation of the prevalence, which was measured by the summary exposure value (SEV), and attributable burden of KD was performed by DisMod-MR 2.1, a Bayesian meta-regression tool. The Spearman rank order correlation method was adopted to perform correlation analysis. The temporal trends were represented by the estimated annual percentage change (EAPC). RESULTS: In 2019, there were total 3.16 million deaths and 76.5 million disability-adjusted life years (DALYs) attributable to KD, increased by 101.1% and 81.7% compared with that in 1990, respectively. From 1990 to 2019, the prevalence of KD has increased in worldwide, but decreased in High-income Asia Pacific. Nearly 48.5% of countries globally, such as South Africa, Egypt and Mexico had increased mortality rates of KD from 1990 to 2019 while 44.6% for disability rate. Countries with lower socio-demographic index (SDI) are facing a higher prevalence as well as mortality and disability rate compared with those with higher SDI. Compared with females, the prevalence of KD was lower in males, however the attributable mortality and disability rate were higher in all years from 1990 to 2019. CONCLUSION: With the progress of senescent, we will face more severe challenges of reducing the prevalence and attributable burden of KD, especially in regions with lower SDI. Effective measures are urgently required to alleviate the prevalence and burden of KD.

A novel splice site variant in the POPDC3 causes autosomal recessive limb-girdle muscular dystrophy type 26.

Limb-Girdle muscular dystrophy (LGMD) is a group of muscle disorders with highly heterogeneous genetic patterns and clinical phenotypes, and this group includes multiple subtypes. Different LGMD subtypes have similar phenotypes and clinical overlaps, these subtypes are difficult to distinguish by clinical symptoms alone and can only be accurately diagnosed by analysis in combination with definitive genetic test results. Here, we report a female presenting features of LGMD. After analysis of whole-exome sequencing data, a novel homozygous POPDC3 variant c.486-1G>A (rs113419658) located in the acceptor splice site of intron 2 was identified in the proband. The variant effect on splicing were analyzed by genetic analysis based on cDNA synthesized by the patient's RNA. cDNA analysis indicated that the novel homozygous POPDC3 splice variant disrupted original acceptor splice site, which can cause a frameshift in the mRNA of the POPDC3 gene, thereby producing a truncated POPDC3 protein and ultimately affecting its normal function. POPDC3 variant was recently associated with recessive limb-girdle muscular dystrophy type 26 (LGMDR26). Based on the above results, we hypothesize that this variant is probably a pathogenic variant, and expand the gene variant spectrum of POPDC3.

Theoretical insights into effective electron transfer and migration behavior for CO2 reduction on the BiOBr(001) surfaces.

Carbon dioxide (CO2) activation by effective electrons has been regarded as the rather necessary first-step for a CO2 reduction reaction (CO2RR). In addition, the electron migration and photoreaction selectivity are closely associated with the dominant crystal surface of a catalyst. Therefore, it is very interesting and important to elucidate the electron transfer and charge density effects on the catalyst surface for the CO2RR. In this work, the dominant highly-active BiOBr(001) surfaces with Bi-, O- and Br-termination atoms are designed so that their electron distributions and CO2RR behaviors can be observed. The electron-rich sites on the BiOBr(001) surfaces, where more effective electrons will migrate to achieve the activation of the adsorbed CO2, are firstly confirmed by the electron density difference based on density functional theory calculations. Next, the CO2RR pathways at the electron-rich sites are investigated to explore the migration mechanism of effective photo-induced electrons. The results obtained reveal that if a larger number of electrons transfer to CO2, then less energy is needed to break the CO bond, and the formation of a *COOH intermediate corresponds to the ability of the surface to take part in protonation. Furthermore, the interface Bi atom can boost the transfer efficiency of effective electrons to CO2, but the exposed Br atom with a longer electron transfer distance, because of the steric hindrance of the interface Br atoms, makes it difficult for the electrons to migrate, resulting in it being harder to fracture the CO bond to benefit the formation of the HCOOH product. These findings should give deep insight into the migration behaviors of effective electrons for CO2 photoreduction on the BiOBr(001) surface and provide new perspectives for better understanding the structure-performance relationship at the molecular level.

Comprehensive analysis of lncRNA expression profiles in rats with cerebral ischemia-reperfusion injury after treatment with 20(R)-ginsenoside Rg3.

This study was aimed at investigating the differentially expressions of long noncoding RNAs (lncRNAs) and mRNAs in the brains of a middle cerebral artery occlusion/reperfusion (MCAO/R) group and a MCAO/R + 20(R)-Rg3 group. Biological enrichment analysis was performed, and a lncRNA-mRNA coexpression network was constructed, to reveal the targets and pathways of 20(R)-Rg3 involved in the regulation of cerebral ischemia-reperfusion injury (CIRI). The RNA-seq high-throughput sequencing method was employed to detect differentially-expressed genes between the groups, which were verified by RT-PCR. Functional enrichment analyses of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were performed to explore the biological functions and relevant pathways. The coexpression network of the screened lncRNAs and mRNAs was built by using Cytoscape software. The results identified 77 upregulated lncRNAs, 162 downregulated lncRNAs, 66 upregulated mRNAs and 472 downregulated mRNAs in the MCAO/R + 20(R)-Rg3 group, compared with those in the MCAO/R group. GO enrichment analysis showed that the GO terms were mainly enriched in stimulation response, cellular response, and stress response. KEGG pathways were mainly related to the tumor necrosis factor (TNF), NF-κB, cytokine, and other receptor signaling pathways. In addition, the coexpression analysis between lncRNA and mRNA identified 314 nodes and 515 connections between 6 lncRNAs and 308 mRNAs, of which 511 were positive and 4 were negative. Among them, ENSRNOG-00000059555 was strongly correlated with AABR07001160.1. This study revealed multiple lncRNAs were involved in the neuroprotection of 20(R)-Rg3 against CIRI and thereby provided new insights into the use of 20(R)-Rg3 as a novel neuro protectant in ischemic stroke management.

Comprehensive Analysis of the Effect of 20(R)-Ginsenoside Rg3 on Stroke Recovery in Rats via the Integrative miRNA-mRNA Regulatory Network.

MicroRNAs (miRNAs) are a class of small, endogenous, noncoding RNAs. Recent research has proven that miRNAs play an essential role in the occurrence and development of ischemic stroke. Our previous studies confirmed that 20(R)-ginsenosideRg3 [20(R)-Rg3] exerts beneficial effects on cerebral ischemia-reperfusion injury (CIRI), but its molecular mechanism has not been elucidated. In this study, we used high-throughput sequencing to investigate the differentially expressed miRNA and mRNA expression profiles of 20(R)-Rg3 preconditioning to ameliorate CIRI injury in rats and to reveal its potential neuroprotective molecular mechanism. The results show that 20(R)-Rg3 alleviated neurobehavioral dysfunction in MCAO/R-treated rats. Among these mRNAs, 953 mRNAs were significantly upregulated and 2602 mRNAs were downregulated in the model group versus the sham group, whereas 437 mRNAs were significantly upregulated and 35 mRNAs were downregulated in the 20(R)-Rg3 group in contrast with those in the model group. Meanwhile, the expression profile of the miRNAs showed that a total of 283 differentially expressed miRNAs were identified, of which 142 miRNAs were significantly upregulated and 141 miRNAs were downregulated in the model group compared with the sham group, whereas 34 miRNAs were differentially expressed in the 20(R)-Rg3 treatment group compared with the model group, with 28 miRNAs being significantly upregulated and six miRNAs being significantly downregulated. Furthermore, 415 (391 upregulated and 24 downregulated) differentially expressed mRNAs and 22 (17 upregulated and 5 downregulated) differentially expressed miRNAs were identified to be related to 20(R)-Rg3's neuroprotective effect on stroke recovery. The Kyoto Encyclopedia of Genes and Genomes (KEGG) results showed that 20(R)-Rg3 could modulate multiple signaling pathways related to these differential miRNAs, such as the cGMP-PKG, cAMP and MAPK signaling pathways. This study provides new insights into the protective mechanism of 20(R)-Rg3 against CIRI, and the mechanism may be partly associated with the regulation of brain miRNA expression and its target signaling pathways.

Prevalence of post-traumatic stress disorders and associated factors one month after the outbreak of the COVID-19 among the public in southwestern China: a cross-sectional study.

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) pandemic has rapidly spread across the whole world and brought strong psychological impact. This study aimed to evaluate the prevalence of post-traumatic stress disorders (PTSD) in the general people of southwestern China and associated factors 1 month after the outbreak of the COVID-19. METHODS: This study was started on 4-10 Feb 2020 based on online survey. The present work was carried out in the provinces of southeastern China, including Sichuan Province, Guizhou Province, Yunnan Province, and Chongqing City.1593 respondents aged 18 years and above administered to this study. Data on whether they have experienced confirmed or suspected COVID-19 of themselves/family members/acquaintances were also collected, and based on 'yes' answers, the number of affected individuals (via COVID-19) were categorized into four exposure levels i.e., non-affected, less, moderately, or significantly affected. The civilian version of the PTSD checklist and the self-reported information about COVID-19 were used. RESULTS: The prevalence of PTSD was approximately 25.2%(n = 401/1593). The chances of developing PTSD were 6.053(OR = 6.053, 95% CI 1.394 to 26.280) or 3.673(OR = 3.673, 95% CI 1.738 to 7.765) times higher among respondents who had been significantly and moderately affected than those who had not been affected, accordingly. Male (OR = 1.484, 95% CI 1.147 to 1.920),younger age individuals (40 ~ 49 age group/<30 age group, OR = 0.395, 95% CI 0.258 to 0.606) and health care workers (OR = 1.788, 95% CI 1.155 to 2.277) were at higher risk of developing PTSD. CONCLUSION: Our findings highlight that a positive correlation between the pandemic and PTSD. It is urgent to establish a screening and prevention systems for the population who are significantly exposed to COVID-19,and provide different psychological intervention strategies for different groups.

Oral manifestations of patients with systemic sclerosis: a meta-analysis for case-controlled studies.

BACKGROUND: Systemic sclerosis (SSc) is a multisystem rheumatic disease. Orofacial manifestations are commonly in SSc but maybe usually ignored and overshadowed by other systemic complications. Multiple comparative studies have been conducted to investigate the possible links between SSc and oral manifestations. The present study aimed to investigate the oral health status in patients with SSc. METHODS: Pubmed, Embase, Web of Science, and Scopus were searched up to July 2020. Following outcomes were evaluated: Probing depth (PD), Attachment loss (AL), Bleeding on probing (BOP), Number or percentage of Sites with PD ≥ 4 mm, Prevalence of periodontitis, Number of teeth, Decayed Teeth, Missing teeth, Filled teeth, DMFT index, and the interincisal distance. Newcastle-Ottawa Scale (NOS) were applied for quality assessment. The statistical analysis was processed using the software STATA. RESULTS: 11 eligible studies were included. The maximum interincisor distance was significantly restricted in SSc patients (SMD - 1.061; 95 %CI [- 1.546, - 0.576]; Z = 4.29, P = 0.000).The prevalence of Periodontitis (OR 7.007; 95 %CI [3.529, 13.915]; Z = 5.56, P = 0.000), PD (SMD 3.101; 95 %CI [1.374, 4.829]; Z = 3.52, P = 0.000), AL(SMD 2.584; 95 %CI [0.321, 4.846]; Z = 2.24, P = 0.025), sites with PD ≥ 4mm (SMD 2.071 ; 95 %CI [0.267, 3.875]; Z = 2.25, P = 0.024) and the number of decayed teeth (SMD, 0.186; 95 %CI [0.007, 0.365]; Z = 2.04, P = 0.041) were increased significantly in SSc population in comparison with the controls. CONCLUSIONS: SSc patients have limited mouth opening, higher periodontitis prevalence, and worse periodontal status, as well as an increased number of decayed teeth. Routinely oral hygiene instruction and initial periodontal treatment is recommended for SSc patients.

The Identification of Spherical Engineered Microplastics and Microalgae by Micro-hyperspectral Imaging.

Based on the micro-hyperspectral imaging technique, spherical engineered microplastic (polyethylene, 10-45 µm) and microalgae (Isochrysis galbana) (4-7 µm) were identified. In transmittance mode of MHSI, micro image cubes from 400 to 1000 nm were obtained from slides containing MP and MA in thin seawater. Classifiers like Support Vector Machine (SVM(Radial Basis Function (RBF))), Least Squares Support Vector Machine (LSSVM(RBF)), k-Nearest Neighbors, etc. were adopted and compared to classify MP and MA. In order to expand the imaging range of micro imaging, image stitching technology was adopted. In allusion to the stitched image cube, SVM(RBF) is suggested for the identification of MA and MP, with recall and precision > 0.86. The above results demonstrate that the MHSI is a promising technique, which can detect MPs with particle size Limit of Detection of 10-45 µm, and it is potential to further expand this LOD.

Metabolic Discrimination of Breast Cancer Subtypes at the Single-Cell Level by Multiple Microextraction Coupled with Mass Spectrometry.

Discrimination of cancer subtypes at the single-cell level is critical for the early diagnosis and accurate treatment of cancer. However, the discrimination of breast cancer subtypes based on their metabolite information, which could provide a new perspective of the cellular metabolomics, is still in its infancy. Herein, a high-coverage single cell metabolic analysis was carried out for the discrimination of breast cancer subtypes by combining multiple microextraction with mass spectrometry (MS). About 4300 ion signals were extracted from each cell and assigned to lipids, energy metabolites, and so on. Based on the multivariate analysis of the metabolite information, four subtypes of breast cancer were successfully discriminated. Characteristic components of each subtype were also identified as potential biomarkers such as phosphatidylcholine (PC; PC (32:1), PC (34:1)), UDP/UDP-HexNAc, and Hex-bis-P/Hex-P). Moreover, metabolomics correlation analysis at the single-cell level further revealed the coregulation clusters of the identified components, which provided more metabolites data for bioinformatics studies. Overall, our results on single cell metabolic analysis could give new insights to precision medicine, early diagnosis, and cancer treatments.

Quantitation of Glucose-phosphate in Single Cells by Microwell-Based Nanoliter Droplet Microextraction and Mass Spectrometry.

Changes of metabolite concentrations in single cells are significant for exploring the dynamic regulation of important biological processes, such as cell development and differentiation. Accurate quantitation of metabolites is essential for single cell analysis. In this work, we proposed a quantitative method for single-cell metabolites by combining microwell array with droplet microextraction-mass spectrometry. The microwell can confine both single cells and extraction solvent in defined space, avoiding the irregular spread of trace internal standard solution during microextraction, which was the key to improve the precision and accuracy of quantification in extremely small-volume single-cell samples. Glucose-phosphate as a crucial metabolite in glycolysis was detected and quantified in single cells at this work. The calibration curve of glucose-phosphate was obtained with a linear range from amol (10-18 mol) to fmol (10-15 mol), providing the foundation of metabolite quantitation of single cells. We applied this method to investigate the changes of metabolites including glucose-phosphate, 2-deoxy-d-glucose-phosphate, and ribose-phosphate in single K562 cells stimulated by 2-deoxy-d-glucose. With the robust quantitative capabilities, the developed method holds great potential for studying a drugs' mechanism of action and resistance at single cell level.

Theoretical insights into photo-induced electron transfer at BiOX (X = F, Cl, Br, I) (001) surfaces and interfaces.

The electron transfer process (ETP) of a photocatalyst plays a crucial role in clarifying its photoelectrochemical catalytic mechanism. BiOX (X = F, Cl, Br, I) (001) surfaces display excellent photocatalytic performance due to the high separation efficiency of photogenerated electron-hole (e--h+) pairs in their own efficient internal electric field (IEF). The oxygen vacancies (OVs) on the surfaces could cause a change in localized electronic states, then improve the photocatalytic activity of BiOX. Here, the ETP at BiOX (001) surfaces with and without surface OVs were calculated and investigated using a DMol3 module based on density functional theory (DFT). The results showed that the electron transfer at the BiOX (001) surfaces and interfaces should be like this: firstly, the [-O-Bi-] layer at the interface received the photon energy, which made the electrons on the O atoms preferentially photo-induced to Bi atoms and left photo-induced holes on the interface O atoms. Then, the effective electrons on the interface Bi atoms were diffused to one- or multi- electron reactions, and at the same time, electrons from the bulk were transferred through the path of O → Bi → X → X → Bi → O on BiOX (001) surfaces under the IEF effect to interface O atoms, and consequently, maintain the stable proceeding of the photocatalytic reaction. More importantly, we found that the X atoms indeed played a key role in connecting the non-bonding interlayers of the BiOX nanocrystals and affecting the ETP on BiOX (001) surfaces as electron transmitters. The exploration of the OV introduction on BiOX (001) surfaces suggested that the OV-induced localized electronic states should increase the electron mobility and the charge carrier density to improve the photocatalytic activity of BiOX, especially for BiOCl and BiOBr. Our findings could provide new insight for deeply understanding the transfer and catalytic behaviour of photo-induced electrons at BiOX (001) surfaces and interfaces.

CRISPR/Cas9-mediated knockout of HBsAg inhibits proliferation and tumorigenicity of HBV-positive hepatocellular carcinoma cells.

Chronic hepatitis B virus (HBV) infection remains the most common risk factor for hepatocellular carcinoma (HCC). High HBV surface antigen (HBsAg) levels are highly correlated with hepatocarcinogenesis and HBV-associated HCC development. However, the role and detailed mechanisms associated with HBsAg in HCC development remain elusive. In this study, we designed specific single guide RNAs (sgRNAs) targeting the open reading frames, preS1/preS2/S, of the HBV genome and established HBsAg knockout HCC cell lines using the CRISPR/Cas9 system. We showed that knockout of HBsAg in HCC cell lines decreased HBsAg expression and significantly attenuated HCC proliferation in vitro, as well as tumorigenicity in vivo. We also found that overexpression of HBsAg, including the large (LHBs), middle (MHBs), and small (SHBs) surface proteins promoted proliferation and tumor formation in HCC cells. Moreover, we demonstrated that knockout of HBsAg in HCC cells decreased interleukin (IL)-6 production and inhibited signal transducer and activator of transcription 3 (STAT3) signaling, while overexpression of HBsAg induced a substantial accumulation of pY-STAT3. Collectively, these results highlighted the tumorigenic role of HBsAg and implied that the IL-6-STAT3 pathway may be implicated in the HBsAg-mediated malignant potential of HBV-associated HCC.

Combination of Droplet Extraction and Pico-ESI-MS Allows the Identification of Metabolites from Single Cancer Cells.

We have combined droplet extraction and a pulsed direct current electrospray ionization mass spectrometry method (Pico-ESI-MS) to obtain information-rich metabolite profiling from single cells. We studied normal human astrocyte cells and glioblastoma cancer cells. Over 600 tandem mass spectra (MS2) of metabolites from a single cell were recorded, allowing the successful identification of more than 300 phospholipids. We found the ratios of unsaturated phosphatidylcholines (PCs) to saturated PCs were significantly higher in glioblastoma cells compared to normal cells. In addition, both isomeric PC (17:1) and (phosphatidylethanolamine) PE (20:1) were found in glioblastoma cells, whereas only PC (17:1) was observed in astrocyte cells. Our method paves the way to characterize the chemical contents of single cells, providing rich metabolome information. We suggest that this technique is general and can be applied to other life science studies such as differentiation and drug resistance of individual cells.

20(R)-Ginsenoside Rg3 protects SH-SY5Y cells against apoptosis induced by oxygen and glucose deprivation/reperfusion.

As shown in our previous studies, 20(R)-ginsenoside Rg3 [20(R)-Rg3] exerts a neuroprotective effect on a rat model of transient focal cerebral ischemia, and the mechanism through which it decreases the mRNA expression of calpain I and caspase-3 has been delineated. However, researchers do not know whether 20(R)-Rg3 exhibits a neuroprotective effect following oxygen-glucose deprivation and reperfusion (OGD/R) injury in vitro. In the present study, 20(R)-Rg3 increased cell viability, decreased the LDH leakage rate, and inhibited the apoptosis rate in a concentration-dependent manner. In addition, 20(R)-Rg3 markedly decreased cleaved caspase-3 protein expression. Furthermore, 20(R)-Rg3 significantly decreased the Bax mRNA and protein levels and increased the levels of Bcl-2 mRNA and protein, subsequently decreasing the Bax/Bcl-2 protein ratio. Based on these findings, 20(R)-Rg3 exerts a neuroprotective effect against OGD/R-induced apoptosis.