Interface Visualization of Bio-material Interaction Via Cryo-AEM Using the Biosynthesis of Iron-Based Nanoparticles as a Model.

Although interaction between organisms and nonorganisms is vital in environmental processes, it is difficult to characterize at nanoscale resolution. Biosynthesis incorporates intracellular and extracellular processes involving crucial interfacial functions and electron and substance transfer processes, especially on the inorganic-organic interface. This work chooses the biosynthesis of iron-based nanoparticles (nFe) as a model for biomaterial interaction and employs Cryo-AEM (i.e., S/TEM, EELS, and EDS analysis based on sample preparation with cryo-transfer holder system), combined with CV, Raman, XPS, and FTIR to reveal the inorganic-organic interface process. The inorganic-organic interactions in the biosynthesis of iron-based nanoparticles by Shewanella oneidensis MR-1 (M-nFe) were characterized by changes in electron cloud density, and the corresponding chemical shifts of Fe and C EELS edges confirm that M-nFe acquires electrons from MR-1 on the interface. Capturing intact filamentous-like, slightly curved, and bundled structure provides solid evidence of a "circuit channel" for electron transfer between organic and inorganic interface. CV results also confirm that adding M-nFe can enhance electron transfer from MR-1 to ferric ions. A mechanism for the synthesis of M-nFe with MR-1 based on intracellular and extracellular conditions under facultative anaerobic was visualized, providing a protocol for investigating the organic-inorganic interface.

Harmonizing the cyano-group and Na to enhance selective photocatalytic O2 activation on carbon nitride for refractory pollutant degradation.

Manipulating exciton dissociation and charge-carrier transfer processes to selectively generate free radicals of more robust photocatalytic oxidation capacity for mineralizing refractory pollutants remains challenging. Herein, we propose a strategy by simultaneously introducing the cyano-group and Na into graphitic carbon nitride (CN) to obtain CN-Cy-Na, which makes the charge-carrier transfer pathways the dominant process and consequently achieves the selective generation of free radicals. Briefly, the cyano-group intensifies the local charge density of CN, offering a potential well to attract the hole of exciton, which accelerates the exciton dissociation. Meanwhile, the separated electron transfers efficiently under the robust built-in electric field induced by the cyano-group and Na, and eventually accumulates in the heptazine ring of CN for the following O2 reduction due to the reinforced electron sink effect caused by Na. As a result, CN-Cy-Na exhibits 4.42 mmol L-1 h-1 productivity with 97.6% selectivity for free radicals and achieves 82.1% total organic carbon removal efficiency in the tetracycline photodegradation within 6 h. Additionally, CN-Cy-Na also shows outstanding photodegradation efficiency of refractory pollutants, including antibiotics, pesticide plastic additives, and dyes. This work presents an innovative approach to manipulating the exciton effect and enhancing charge-carrier mobility within two-dimensional photocatalysts, opening an avenue for precise control of free radical generation.

Mendelian randomization study of IGF-1, childhood obesity and obesity-related asthma.

Insulin-like growth factor 1 (IGF-1) has been reported to potentially link with childhood obesity and obesity-related asthma, although a causal effect has not been illustrated. This study aimed to assess their association via multi-variable Mendelian randomization (MR) analysis with two-sample summary-level data on genetic variants as instrumental variables, thus estimating a causal effect. Genetic variants associated with serum IGF-1 at genome-wide significance (GWS) in the UK Biobank study involving 363,228 individuals of European descent were introduced as instrumental variables. Summary-level data on childhood obesity and obesity-related asthma were obtained from genome-wide association studies (GWAS). Here, MR-Egger, inverse-variance weighted (IVW), simple median, weighted median and penalized weighted median methods were used in the MR study. Results showed that there were strong causal associations of IGF-1 with childhood obesity (OR, 1.27; 95% CI 1.01-1.60; P<0.05) and obesity-related asthma (OR, 1.22; 95% CI 1.07-1.38; P<0.005). In conclusion, A causal association between high IGF-1 levels and high risks of childhood obesity and obesity-related asthma is estimated, which requires further validation in large-scale trials.

[A Prediction Model for Human Immunodeficiency Virus Infection and Mother-to-Child Transmission Based on the Expression Levels of Selenoprotein Genes].

Objective To study the expression of selenoprotein genes in human immunodeficiency virus(HIV)infection and its mother-to-child transmission,so as to provide a theoretical basis for the prevention,diagnosis,and treatment of acquired immunodeficiency syndrome.Methods The dataset GSE4124 was downloaded from the Gene Expression Omnibus(GEO).Two groups of HIV-positive mothers(n=25)and HIV-negative mothers(n=20)were designed.HIV-positive mothers included a subset of transmitter(TR)mothers(n=11)and non-transmitter(NTR)mothers(n=14).Then,t-test was carried out to compare the expression levels of selenoprotein genes between the four groups(HIV-positive vs. HIV-negative,NTR vs. HIV-negative,TR vs. HIV-negative,TR vs. NTR).Univariate and multivariate Logistic regression were adopted to analyze the effects of differentially expressed genes on HIV infection and mother-to-child transmission.R software was used to establish a nomogram prediction model and evaluate the model performance.Results Compared with the HIV-negative group,HIV-positive,NTR,and TR groups had 8,5 and 8 down-regulated selenoprotein genes,respectively.Compared with the NTR group,the TR group had 4 down-regulated selenoprotein genes.Univariate Logistic regression analysis showed that abnormally high expression of GPX1,GPX3,GPX4,TXNRD1,TXNRD3,and SEPHS2 affected HIV infection and had no effect on mother-to-child transmission.The multivariate Logistic regression analysis showed that the abnormally high expression of TXNRD3(OR=0.032,95%CI=0.002-0.607,P=0.022)was positively correlated with HIV infection.As for the nomogram prediction model,the area under the receiver-operating characteristic curve for 1-year survival of HIV-infected patients was 0.840(95%CI=0.690-1.000),and that for 3-year survival of HIV-infected patients was 0.870(95%CI=0.730-1.000).Conclusions Multiple selenoprotein genes with down-regulated expression levels were involved in the regulation of HIV infection and mother-to-child transmission.The abnormal high expression of TXNRD3 was positively correlated with HIV infection.The findings provide new ideas for the prevention,diagnosis,and treatment of acquired immunodeficiency syndrome.

Machine-Learning-Assisted Optimization of a Single-Atom Coordination Environment for Accelerated Fenton Catalysis.

Machine learning (ML) algorithms will be enablers in revolutionizing traditional methods of materials optimization. Here, we broaden the use of ML to assist the construction of Fenton-like single-atom catalysts (SACs) by developing a methodology including model building, training, and prediction. Our approach can efficiently extract synthesis parameters that exert a substantial influence on Fenton activity and accurately predict the phenol degradation rate k of SACs with a mean error of ±0.018 min-1. The extended synthesis window with accelerated learning enables the realization that the heating temperatures during SAC synthesis significantly influence the Fe-N coordination number, which ultimately dictates their performance. Through ML-guided optimization, a highly efficient SAC dominated by Fe-N5 sites with exceptional Fenton activity (k = 0.158 min-1) is identified. Our work provides an example for ML-assisted optimization of single-atom coordination environments and illuminates the feasibility of ML in accelerating the development of high-performance catalysts.

Boris knockout eliminates AOM/DSS-induced in situ colorectal cancer by suppressing DNA damage repair and inflammation.

The Brother of Regulator of Imprinted Sites (BORIS, gene symbol CTCFL) has previously been shown to promote colorectal cancer cell proliferation, inhibit cancer cell apoptosis, and resist chemotherapy. However, it is unknown whether Boris plays a role in the progression of in situ colorectal cancer. Here Boris knockout (KO) mice were constructed. The function loss of the cloned Boris mutation that was retained in KO mice was verified by testing its activities in colorectal cell lines compared with the Boris wild-type gene. Boris knockout reduced the incidence and severity of azoxymethane/dextran sulfate-sodium (AOM/DSS)-induced colon cancer. The importance of Boris is emphasized in the progression of in situ colorectal cancer. Boris knockout significantly promoted the phosphorylation of γH2AX and the DNA damage in colorectal cancer tissues and suppressed Wnt and MAPK pathways that are responsible for the callback of DNA damage repair. This indicates the strong inhibition of colorectal cancer in Boris KO mice. By considering that the DSS-promoted inflammation contributes to tumorigenesis, Boris KO mice were also studied in DSS-induced colitis. Our data showed that Boris knockout alleviated DSS-induced colitis and that Boris knockdown inhibited the NF-κB signaling pathway in RAW264.7 cells. Therefore Boris knockout eliminates colorectal cancer generation by inhibiting DNA damage repair in cancer cells and relieving inflammation in macrophages. Our findings demonstrate the importance of Boris in the development of in situ colorectal cancer and provide evidence for the feasibility of colorectal cancer therapy on Boris.

Visualizing Dynamic Environmental Processes in Liquid at Nanoscale via Liquid-Phase Electron Microscopy.

Visualizing the structure and processes in liquids at the nanoscale is essential for understanding the fundamental mechanisms and underlying processes of environmental research. Cutting-edge progress of in situ liquid-phase (scanning) transmission electron microscopy (LP-S/TEM) and inferred possible applications are highlighted as a more and more indispensable tool for visualization of dynamic environmental processes in this Perspective. Advancements in nanofabrication technology, high-speed imaging, comprehensive detectors, and spectroscopy analysis have made it increasingly convenient to use LP S/TEM, thus providing an approach for visualization of direct and insightful scientific information with the exciting possibility of solving an increasing number of tricky environmental problems. This includes evaluating the transformation fate and path of contamination, assessing toxicology of nanomaterials, simulating solid surface corrosion processes in the environment, and observing water pollution control processes. Distinct nanoscale or even atomic understanding of the reaction would provide dependable and precise identification and quantification of contaminants in dynamic processes, thus facilitating trouble-tracing of environmental problems with amplifying complexity.

Risk Factors for Short Stature in Children Born Small for Gestational Age at Full-Term.

Objective: This study aims to identify the risk factors associated with short stature in children born small for gestational age (SGA) at full-term. Methods: This was a retrospective study. The subjects were full-term SGA infants who were followed up until the age of 2 years. The risk factors for short stature were identified with univariate and multivariate analyses. Results: Of 456 full-term SGA children enrolled in this study, 28 cases had short stature at 2 years of age. A significant decrease in placental perfusion was found in the short children group with intravoxel incoherent motion (IVIM) technology, which was an advanced bi-exponential diffusion-weighted imaging (DWI) model of magnetic resonance imaging (MRI) (p = 0.012). Compared to non-short children born SGA at full-term, the short children group underwent an incomplete catch-up growth. Mothers who suffered from systemic lupus erythematosus were more likely to have a short child born SGA (p = 0.023). The morbidity of giant placental chorioangioma was higher in the short children group. The pulsatility index (PI), resistivity index (RI), and systolic-diastolic (S/D) ratio of umbilical artery were higher in the short children group than in the non-short control group (p = 0.042, 0.041, and 0.043). Multivariate analysis demonstrated that decrease of perfusion fraction (f p) in IVIM of placental MRI, chromosomal abnormalities, short parental height, and absence of catch-up growth were associated with a higher risk of short stature in children born SGA at full-term. Conclusion: Risk factors for short stature in full-term SGA children at 2 years of age included a decrease of perfusion fraction f p in IVIM of placental MRI, chromosomal abnormalities, and short parental height.

Mechanism for selective binding of aromatic compounds on oxygen-rich graphene nanosheets based on molecule size/polarity matching.

Selective binding of organic compounds is the cornerstone of many important industrial and pharmaceutical applications. Here, we achieved highly selective binding of aromatic compounds in aqueous solution and gas phase by oxygen-enriched graphene oxide (GO) nanosheets via a previously unknown mechanism based on size matching and polarity matching. Oxygen-containing functional groups (predominately epoxies and hydroxyls) on the nongraphitized aliphatic carbons of the basal plane of GO formed highly polar regions that encompass graphitic regions slightly larger than the benzene ring. This facilitated size match-based interactions between small apolar compounds and the isolated aromatic region of GO, resulting in high binding selectivity relative to larger apolar compounds. The interactions between the functional group(s) of polar aromatics and the epoxy/hydroxyl groups around the isolated aromatic region of GO enhanced binding selectivity relative to similar-sized apolar aromatics. These findings provide opportunities for precision separations and molecular recognition enabled by size/polarity match-based selectivity.

Visualizing hazardous solids with cryogenic electron microscopy (Cryo-EM).

Recent developments point to exciting potential of cryogenic electron microscopy (cryo-EM) for fundamental environmental research, especially for characterizing environmental samples with a high-water content. As a matter of fact, most environmental materials including soils, sediments, biomass, solid wastes and sludge are hydrated. This perspective provides a brief synopsis of cryo-EM and highlights emerging applications in environmental research. With cryogenic techniques, specimens are preserved by rapid freezing and observed with electron microscopes operating at high-vacuum and low temperature to keep the ice in amorphous state and reduce the effect of radiation damage. So far, cryo-EM has been successfully applied to advance fundamental understanding of physical, chemical and biological mechanisms due to its desirable properties to maintain the native state of hydrated samples and visualize structures at high resolution in three dimensions. The cryo-EM technique also has significant applications to the technology development of pathogen detection, sludge dewatering, waste treatment, and green chemical production from cellular biomass as cellular water content can be clearly observed and manipulated at the single cell level.

Photoinduced Cascade C-N/C═O Bond Formation from Bromodifluoroalkyl Reagents, Amines, and H2O via a Triple-Cleavage Process.

A green, sustainable, and straightforward method for the synthesis of unsymmetrical oxalamides via photoinduced C-N/C═O bond formation of bromodifluoroacetamide, amine, and H2O through a triple-cleavage process has been developed. In addition, this approach also provides access to the known bioactive compounds, and a feasible reaction mechanism is proposed. Moreover, the advantages of this transformation, including mild reaction conditions, a broad substrate scope, and operational simplicity, make this protocol attractive for further applications.

The distribution and structural fingerprints of metals from particulate matters (PM) deposited in human lungs.

This work investigated the distribution and chemical fingerprints of 24 metals in particulate matter (PM) deposited in nonoccupational human lungs. Metals in the pulmonary PM can be grouped by the mean concentration as > 5 × 103 µg/g (Al/Fe/Ca/Mg/Zn), 1-5 × 103 µg/g (Ti/Ba/Pb/Mn), 0.2-1 × 103 µg/g (Cu/Cr/As/V) and < 100 µg/g (Ni/Sn/Cd/Sb). Three parameters (LFL, LR, EFP) were defined to predict different metal leaching behaviors. The leaching factor (LFL) of metals was 10-60 for Pb/Sb/Cd/Co/Cu and decreased to 1-2 for Ni/Cr/Mg/Al/Fe. Metals showed a divergent extent of lung retention (LR), including high retention (LR>10, Al/Cd/Cr/Ba/Ni/Ti/Sn/V/Sb), moderate retention (2 

In Situ Visualization on Surface Oxidative Corrosion with Free Radicals: Black Phosphorus Nanoflake as an Example.

Free radicals exert a significant impact on the fate of redox-active substances and play a crucial role in the surface corrosion of solid in environment. Dynamic visualization on the response of the surface to the free radicals at nanoscale is essential to explore the mechanism. Environmental transmission electron microscopy will be a powerful tool for dynamic changes of the interface redox process of solid surface with electron beams induced free radicals, to simulate the redox process of a solid in the environment. Black phosphorus (BP), an environment-sensitive material, is selected as an example to visualize the degradation pathways with environmental transmission electron microscopy. The distribution of the corrosion initiation points, formation and growth of corrosion areas, and the eventual splintering and disappearance of BP nanoflakes are recorded vividly. In situ results are substantiated by the ex situ experiments and density functional theory (DFT) calculations. Results show that degradation originates at the edges and defect structures when the humidity reaches high enough. The microscopic structural oxidative etching of solid surface with radicals in natural light is simulated with radicals produced by electron beam irradiation on suspending medium O2 and H2O for the first time. This method will offer unprecedented details and valuable insights into the mechanism involved in the oxidative etching with natural light.

[Expression and Regulatory Mechanism of Autophagy-related Genes in Synovial Tissues of Patients with Rheumatoid Arthritis].

Objective To investigate the expression regulation of autophagy-related genes(ATG)and the mechanism of autophagy in rheumatoid arthritis(RA).Methods The differentially expressed genes(DEG)of RA were identified from GSE55235 and GSE55457,on the basis of which the differentially expressed autophagy-related genes(DE-ATG)were selected from the Human Autophagy Database.STRING 11.0 and GeneMANIA were used to establish protein-protein interaction networks.Further,the transcription factor-gene-miRNA co-expression network was established via NetworkAnalyst and Cytoscape.Finally,receiver operating characteristic(ROC)curve and DrugBank were employed to evaluate the efficacy of the predicted biomarkers and the performance of drugs targeting DE-ATG.GraphPad Prism 8.2.1 and R 4.0.3 were used for statistical analysis and graphics.Results A total of 485 DEG were enriched in signaling pathways such as T cell activation,hormone regulation,osteoclast differentiation,RA,and chemokines.Eleven DE-ATG regulated the expression of RUNX1,TP53,SOX2,and hsa-mir-155-5p in synovial tissues of RA patients and were involved in the response to environmental factors such as 2,3,7,8-tetrachlorodibenzodioxin and silicon dioxide.The ROC curve analysis identified the DE-ATG with good sensitivity and specificity,such as MYC,MAPK8,CDKN1A,and TNFSF10,which can be used to distinguish certain phenotypes and serve as novel biomarkers for RA.Conclusions In RA,down-regulated DE-ATG expression may promote apoptosis and lysis of chondrocytes.The identified novel biomarkers provides new ideas and methods for diagnosing and treating RA.The establishment of transcription factor-miRNA-gene co-expression network provides direct evidence for dissecting synovial inflammation and articular cartilage destruction.

Liver-targeted delivery of asiatic acid nanostructured lipid carrier for the treatment of liver fibrosis.

Liver fibrosis is a major global health concern. Management of chronic liver disease is severely restricted in clinics due to ineffective treatment approaches. However, a lack of targeted therapy may aggravate this condition. Asiatic acid (AA), a pentacyclic triterpenoid acid, can effectively protect the liver from hepatic disorders. However, the pharmaceutical application of AA is limited by low oral bioavailability and poor targeting efficiency. This study synthesized a novel liver-targeting material from PEG-SA, chemically linked to ursodeoxycholic acid (UA), and utilized it to modify AA nanostructured lipid carriers (UP-AA-NLC) with enhanced targeting and improved efficacy. The formulation of UP-AA-NLC was optimized via the Box-Behnken Experimental Design (BBD) and characterized by size, zeta potential, TEM, DSC, and XRD. Furthermore, in vitro antifibrotic activity and proliferation of AA and NLCs were assessed in LX-2 cells. The addition of UP-AA-NLC significantly stimulated the TGF-beta1-induced expression of α-SMA, FN1, and Col I α1. In vivo near-infrared fluorescence imaging and distribution trials in rats demonstrated that UP-AA-NLC could significantly improve oral absorption and liver-targeting efficiency. Oral UP-AA-NLC greatly alleviated carbon tetrachloride-induced liver injury and fibrosis in rats in a dosage-dependent manner, as reflected by serum biochemical parameters (AST, ALT, and ALB), histopathological features (H&E and Masson staining), and antioxidant activity parameters (SOD and MDA). Also, treatment with UP-AA-NLC lowered liver hydroxyproline levels, demonstrating a reduction of collagen accumulation in the fibrotic liver. Collectively, optimized UP-AA-NLC has potential application prospects in liver-targeted therapy and holds great promise as a drug delivery system for treating liver diseases.

pH-sensitive chitosan-deoxycholic acid/alginate nanoparticles for oral insulin delivery.

Oral absorption of peptides/proteins is usually compromised by various gastrointestinal tract barriers. To improve delivery efficiency, chitosan-conjugated deoxycholic acid (CS-DCA) coupled with sodium alginate (ALG) was prepared to load insulin into pH-sensitive nanoparticles. The insulin-loaded chitosan-deoxycholic acid/alginate nanoparticles (CDA NPs) were characterized by size (143.3 ± 10.8 nm), zeta potential (19.5 ± 1.6 mV), entrapment efficiency (61.14 ± 1.67%), and insulin drug loading (3.36 ± 0.09%). The CDA NPs exhibited pH-triggered release characteristics in vitro and protected the wrapped insulin from gastric degradation. Stability of the CDA NPs in enzyme-containing simulated gastrointestinal fluids suggested that the NPs could partially protect the wrapped insulin from enzymatic degradation. Additionally, CS-DCA-modified NPs promoted the permeability of Caco-2 cells and enhanced intracellular absorption of FITC-labeled insulin by 9.4 and 1.2-folds, when compared to insulin solution and unmodified NPs, respectively. The positively charged NPs increased intestinal villi adhesion and enhanced insulin absorption in the intestines of diabetic rat models. Furthermore, the hypoglycemic test showed that CDA NPs prolonged insulin release in vivo and exerted a remarkable hypoglycemic effect on diabetic rats with an oral bioavailability of 15%. In conclusion, CDA NPs is a potential oral insulin delivery system.

Visualizing Trace Pollutants in Solids at Nanoscale via Electron Tomography.

Visualizing trace pollutants such as toxic metals and viruses in environmental solids such as soils, sediments, aerosols, and suspended particles in water has long been the holy grail for scientists and engineers. In this Perspective, progress on the state-of-the-art electron tomography is highlighted as an increasingly indispensable tool for visualizing contaminant distribution and transformation in three-dimension (3D), including environmental pollutants at the water-minerals interfaces, toxicology assessment, environmental behavior of viruses in heterogeneous environmental media, etc. Adding a third dimension to the pollutant characterization will surely enrich our understanding on the complex and emerging environmental issues facing the global society, and provide vital support to the ongoing research and development of life-saving mitigation technologies from air filtration, to drinking water purification, to virus disinfection.

MicroRNA-181b Inhibits Inflammatory Response and Reduces Myocardial Injury in Sepsis by Downregulating HMGB1.

MicroRNAs (miRNAs) are short endogenous noncoding RNAs regulating protein translation. However, the specific mechanism by which miR-181b influences sepsis via high-mobility group box-1 protein (HMGB1) still remains unknown. Thus, the aim of this study is to investigate the mechanism of miR-181b in regulating inflammatory response in sepsis-induced myocardial injury through targeting high-mobility group box-1 protein (HMGB1). Through cecal ligation and puncture (CLP), the rat model of sepsis was established. Then, the effect of altered expression of miR-181b and HMGB1 on cardiomyocytes was investigated. The positive expression rate of HMGB1, concentration of inflammatory factors, and serum myocardial enzyme of myocardial tissues were determined. Besides, the binding site between miR-181b and HMGB1 was determined by bioinformatics information and dual-luciferase reporter gene assay. The expression of related genes in cells of each group was determined by RT-qPCR and western blot analysis, and the apoptosis rate of transfected cells in each group was determined by TUNEL assay. HMGB1 expression and inflammatory factors were significantly increased in myocardial tissue of rats with sepsis. Cell morphology and the infiltration of inflammatory cells were significantly improved by overexpression of miR-181b. miR-181b directly targeted HMGB1, and downregulation of HMGB1 reduced inflammatory factors and myocardial injury and inhibited cardiomyocyte apoptosis in sepsis. This present study suggests that miR-181b decreased inflammatory factors and reduced myocardial injury in sepsis through downregulation of HMGB1. Thus, a better understanding of this process may aid in the development of novel therapeutic agents in sepsis.