An Evaluation of the Sensitivity and Applicability of a Droplet Digital Polymerase Chain Reaction Assay to Simultaneously Detect Pseudomonas aeruginosa and Pseudomonas fragi in Foods.

Achieving effective control over microbial contamination necessitates the precise and concurrent identification of numerous pathogens. As a common bacterium in the environment, Pseudomonas is rich in variety. It not only has pathogenic strains, but also spoilage bacteria that cause food spoilage. In this research, we devised a remarkably sensitive duplex droplet digital PCR (dddPCR) reaction system to simultaneously detect pathogenic Pseudomonas aeruginosa (P. aeruginosa) and spoilage Pseudomonas fragi (P. fragi). By employing comparative genomics, we identified four genes of P. fragi. Through a specific analysis, the RS22680 gene was selected as the detection target for P. fragi, and the lasR gene was chosen for P. aeruginosa, which were applied to construct a dddPCR reaction. In terms of specificity, sensitivity and anti-interference ability, the constructed dddPCR detection system was verified and analyzed. The assay showed excellent sensitivity and applicability, as evidenced by a limit of detection of 100 cfu/mL. When the concentration of natural background bacteria in milk or fresh meat was 100 times that of the target detection bacteria, the method was still capable of completing the absolute quantification. In the simulation of actual sample contamination, P. aeruginosa could be detected after 3 h of enrichment culture, and P. fragi could be detected after 6 h. The established dddPCR detection system exhibits exceptional performance, serving as a foundation for the simultaneous detection of various pathogenic bacteria in food products.

Diagnostic challenges and proposed classification of myeloid neoplasms with overlapping features of thrombocytosis, ring sideroblasts and concurrent del(5q) and SF3B1 mutations.

Not available.

Predicting multiple observations in complex systems through low-dimensional embeddings.

Forecasting all components in complex systems is an open and challenging task, possibly due to high dimensionality and undesirable predictors. We bridge this gap by proposing a data-driven and model-free framework, namely, feature-and-reconstructed manifold mapping (FRMM), which is a combination of feature embedding and delay embedding. For a high-dimensional dynamical system, FRMM finds its topologically equivalent manifolds with low dimensions from feature embedding and delay embedding and then sets the low-dimensional feature manifold as a generalized predictor to achieve predictions of all components. The substantial potential of FRMM is shown for both representative models and real-world data involving Indian monsoon, electroencephalogram (EEG) signals, foreign exchange market, and traffic speed in Los Angeles Country. FRMM overcomes the curse of dimensionality and finds a generalized predictor, and thus has potential for applications in many other real-world systems.

A specific inflammatory suppression fibroblast subpopulation characterized by MHCII expression in human dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is a significant cause of heart failure that requires heart transplantation. Fibroblasts play a central role in the fibro-inflammatory microenvironment of DCM. However, their cellular heterogeneity and interaction with immune cells have not been well identified. An integrative analysis was conducted on single-cell RNA sequencing (ScRNA-Seq) data from human left ventricle tissues, which comprised 4 hearts from healthy donors and 6 hearts with DCM. The specific antigen-presenting fibroblast (apFB) was explored as a subtype of fibroblasts characterized by expressing MHCII genes, the existence of which was confirmed by immunofluorescence staining of 3 cardiac tissues from DCM patients with severe heart failure. apFB highly expressed the genes that response to IFN-γ, and it also have a high activity of the JAK-STAT pathway and the transcription factor RFX5. In addition, the analysis of intercellular communication between apFBs and CD4+T cells revealed that the anti-inflammatory ligand-receptor pairs TGFB-TGFR, CLEC2B-KLRB1, and CD46-JAG1 were upregulated in DCM. The apFB signature exhibited a positive correlation with immunosuppression and demonstrated diagnostic and prognostic value when evaluated using a bulk RNA dataset comprising 166 donors and 166 DCM samples. In conclusion, the present study identified a novel subpopulation of fibroblasts that specifically expresses MHCII-encoding genes. This specific apFBs can suppress the inflammation occurring in DCM. Our findings further elucidate the composition of the fibro-inflammatory microenvironment in DCM, and provide a novel therapeutic target.

Effects of hypoxia in cardiac metabolic remodeling and heart failure.

Aerobic cellular respiration requires oxygen, which is an essential part of cardiomyocyte metabolism. Thus, oxygen is required for the physiologic metabolic activities and development of adult hearts. However, the activities of metabolic pathways associated with hypoxia in cardiomyocytes (CMs) have not been conclusively described. In this review, we discuss the role of hypoxia in the development of the hearts metabolic system, and the metabolic remodeling associated with the hypoxic adult heart. Hypoxia-inducible factors (HIFs), the signature transcription factors in hypoxic environments, is also investigated for their potential to modulate hypoxia-induced metabolic changes. Metabolic remodeling existing in hypoxic hearts have also been shown to occur in chronic failing hearts, implying that novel therapeutic options for heart failure (HF) may exist from the hypoxic perspective. The pressure overload-induced HF and diabetes-induced HF are also discussed to demonstrate the effects of HIF factor-related pathways to control the metabolic remodeling of failing hearts.

Single-cell genotypic and phenotypic analysis of measurable residual disease in acute myeloid leukemia.

Measurable residual disease (MRD), defined as the population of cancer cells that persist following therapy, serves as the critical reservoir for disease relapse in acute myeloid leukemia and other malignancies. Understanding the biology enabling MRD clones to resist therapy is necessary to guide the development of more effective curative treatments. Discriminating between residual leukemic clones, preleukemic clones, and normal precursors remains a challenge with current MRD tools. Here, we developed a single-cell MRD (scMRD) assay by combining flow cytometric enrichment of the targeted precursor/blast population with integrated single-cell DNA sequencing and immunophenotyping. Our scMRD assay shows high sensitivity of approximately 0.01%, deconvolutes clonal architecture, and provides clone-specific immunophenotypic data. In summary, our scMRD assay enhances MRD detection and simultaneously illuminates the clonal architecture of clonal hematopoiesis/preleukemic and leukemic cells surviving acute myeloid leukemia therapy.

Universal window size-dependent transition of correlations in complex systems.

Correlation analysis serves as an easy-to-implement estimation approach for the quantification of the interaction or connectivity between different units. Often, pairwise correlations estimated by sliding windows are time-varying (on different window segments) and window size-dependent (on different window sizes). Still, how to choose an appropriate window size remains unclear. This paper offers a framework for studying this fundamental question by observing a critical transition from a chaotic-like state to a nonchaotic state. Specifically, given two time series and a fixed window size, we create a correlation-based series based on nonlinear correlation measurement and sliding windows as an approximation of the time-varying correlations between the original time series. We find that the varying correlations yield a state transition from a chaotic-like state to a nonchaotic state with increasing window size. This window size-dependent transition is analyzed as a universal phenomenon in both model and real-world systems (e.g., climate, financial, and neural systems). More importantly, the transition point provides a quantitative rule for the selection of window sizes. That is, the nonchaotic correlation better allows for many regression-based predictions.

Co3O4 Nanoparticle-Modified Porous Carbons with High Microwave Absorption Performances.

Carbon materials derived from natural biomaterials have received increasing attention because of their low cost, accessibility, and renewability. In this work, porous carbon (DPC) material prepared from D-fructose was used to make a DPC/Co3O4 composite microwave absorbing material. Their electromagnetic wave absorption properties were thoroughly investigated. The results show that the composition of Co3O4 nanoparticles with DPC had enhanced microwave absorption (-60 dB to -63.7 dB), reduced the frequency of the maximum reflection loss (RL) (16.9 GHz to 9.2 GHz), and had high reflection loss over a wide range of coating thicknesses (2.78-4.84 mm, highest reflection loss <-30 dB). This work provided a way for further research on the development of biomass-derived carbon as a sustainable, lightweight, high-performance microwave absorber for practical applications.

Highly sensitive single tube B-lymphoblastic leukemia/lymphoma minimal/measurable residual disease test robust to surface antigen directed therapy.

BACKGROUND: Measurement of minimal/measurable residual disease (MRD) in B-lymphoblastic leukemia/lymphoma (B-ALL) has become a routine clinical evaluation tool and remains the strongest predictor of treatment outcome. In recent years, new targeted anti-CD19 and anti-CD22 antibody-based and cellular therapies have revolutionized the treatment of the high-risk B-ALL. The new treatments raise challenges for diagnostic flow cytometry, which relies on the presence of specific surface antigens to identify the population of interest. So far, reported flow cytometry-based assays are developed to either achieve a deeper MRD level or to accommodate the loss of surface antigens post-target therapies, but not both. METHODS: We developed a single tube flow cytometry assay (14-color-16-parameters). The method was validated using 94 clinical samples as well as spike-in and replicate experiments. RESULTS: The assay was well suited for monitoring response to targeted therapies and reached a sensitivity below 10-5 with acceptable precision (coefficient of variation < 20%), accuracy, and interobserver variability (κ = 1). CONCLUSIONS: The assay allows for sensitive disease detection of B-ALL MRD independent of CD19 and CD22 expression and allows uniform analysis of samples regardless of anti-CD19 and CD22 therapy.

Integrative identification of hub genes in development of atrial fibrillation related stroke.

BACKGROUND: As the most common arrhythmia, atrial fibrillation (AF) is associated with a significantly increased risk of stroke, which causes high disability and mortality. To date, the underlying mechanism of stroke occurring after AF remains unclear. Herein, we studied hub genes and regulatory pathways involved in AF and secondary stroke and aimed to reveal biomarkers and therapeutic targets of AF-related stroke. METHODS: The GSE79768 and GSE58294 datasets were used to analyze AF- and stroke-related differentially expressed genes (DEGs) to obtain a DEG1 dataset. Weighted correlation network analysis (WGCNA) was used to identify modules associated with AF-related stroke in GSE66724 (DEG2). DEG1 and DEG2 were merged, and hub genes were identified based on protein-protein interaction networks. Gene Ontology terms were used to analyze the enriched pathways. The GSE129409 and GSE70887 were applied to construct a circRNA-miRNA-mRNA network in AF-related stroke. Hub genes were verified in patients using quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: We identified 3,132 DEGs in blood samples and 253 DEGs in left atrial specimens. Co-expressed hub genes of EIF4E3, ZNF595, ZNF700, MATR3, ACKR4, ANXA3, SEPSECS-AS1, and RNF166 were significantly associated with AF-related stroke. The hsa_circ_0018657/hsa-miR-198/EIF4E3 pathway was explored as the regulating axis in AF-related stroke. The qRT-PCR results were consistent with the bioinformatic analysis. CONCLUSIONS: Hub genes EIF4E3, ZNF595, ZNF700, MATR3, ACKR4, ANXA3, SEPSECS-AS1, and RNF166 have potential as novel biomarkers and therapeutic targets in AF-related stroke. The hsa_circ_0018657/hsa-miR-198/EIF4E3 axis could play an important role regulating the development of AF-related stroke.

Effects of Medium- and Long-Chain Structured Triacylglycerol on the Therapeutic Efficacy of Vitamin D on Ulcerative Colitis: A Consideration for Efficient Lipid Delivery Systems.

Due to intestinal malabsorption and poor water solubility, vitamin D (VitD) deficiency in ulcerative colitis (UC) continues to increase. Medium- and long-chain triacylglycerols (MLCT), as novel lipids, have been widely applied in the field of functional food and medicine nutrition. Our previous studies showed that the difference in MLCT structure could affect VitD bioaccessibility in vitro. In this study, our results further indicate that, although identical in fatty acid composition, structured triacylglycerol (STG) had a higher VitD bioavailability (AUC = 15470.81 µg/L × h) and metabolism efficacy [s-25(OH)D, p < 0.05] than physical mixtures of triacylglycerol (PM), which further affect the amelioration efficiency in UC mice. Compared with PM, the damage of colonic tissues, intestinal barrier proteins, and inflammatory cytokines in STG showed better amelioration at the same dose of VitD. This study provides a comprehensive understanding of the mechanism of nutrients in different carriers and a solution for developing nutrients with high absorption efficiency.

Diagnostic accuracy of linked colour imaging versus white light imaging for early gastric cancers: a prospective, multicentre, randomized controlled trial study.

BACKGROUND: Linked colour imaging (LCI) is a novel new image-enhanced endoscopy (IEE) technology that produces bright and vivid images. The aim of this study was to assess the ability of LCI to improve the diagnostic accuracy of early gastric cancer (EGC) relative to white light imaging (WLI). MATERIALS AND METHODS: We performed this study on patients undergoing screening endoscopy from 12 medical institutions in China. Patients were randomly assigned to receive WLI followed by LCI or LCI followed by WLI. The primary outcome was to compared the diagnostic accuracy between LCI and WLI for EGC/high-grade intraepithelial neoplasms. Secondary outcomes included the numbers of suspicious lesions, neoplastic lesions and examination time by using LCI detected versus using WLI. RESULTS: A total of 1924 patients were randomly selected, and 1828 were included in the analysis. The diagnostic accuracy for EGC, which was 78.8% by using LCI and 68.4% by using WLI (p < .0001). More suspicious lesions were detected by LCI than by WLI (n = 1235 vs. 1036, p = .031), especially among differentiated EGC (p = .013). LCI greatly shortened the examination time compared with WLI (p = .019). CONCLUSIONS: LCI has better accuracy and shorter examination time in diagnosing EGC than WLI (Clinical trial registration: NCT03092414).Key messagesCompared with white light imaging (WLI), the diagnostic accuracy, sensitivity and specificity increased by using LCI.More lesions were detected by LCI alone than by WLI alone, especially among differentiated EGC.LCI may be used as a screening tool for routine clinical observation.

EGFR Mutation Status and Subtypes Predicted by CT-Based 3D Radiomic Features in Lung Adenocarcinoma.

Objective: In this study, we aim to establish a non-invasive tool to predict epidermal growth factor receptor (EGFR) mutation status and subtypes based on radiomic features of computed tomography (CT). Methods: A total of 233 lung adenocarcinoma patients were investigated and randomly divided into the training and test cohorts. In this study, 2300 radiomic features were extracted from original and filtered (Exponential, Laplacian of Gaussian, Logarithm, Gabor, Wavelet) CT images. The radiomic features were divided into four categories, including histogram, volumetric, morphologic, and texture features. An RF-BFE algorithm was developed to select the features for building the prediction models. Clinicopathological features (including age, gender, smoking status, TNM staging, maximum diameter, location, and growth pattern) were combined to establish an integrated model with radiomic features. ROC curve and AUC quantified the effectiveness of the predictor of EGFR mutation status and subtypes. Results: A set of 10 features were selected to predict EGFR mutation status between EGFR mutant and wild type, while 9 selected features were used to predict mutation subtypes between exon 19 deletion and exon 21 L858R mutation. To predict the EGFR mutation status, the AUC of the training cohort was 0.778 and the AUC of the test cohort was 0.765. To predict the EGFR mutation subtypes, the AUC of training cohort was 0.725 and the AUC of test cohort was 0.657. The integrated model showed the most optimal predictive performance with EGFR mutation status (AUC = 0.870 and 0.759) and subtypes (AUC = 0.797 and 0.554) in the training and test cohorts. Conclusion: CT-based radiomic features can extract information on tumor heterogeneity in lung adenocarcinoma. In addition, we have established a radiomic model and an integrated model to non-invasively predict the EGFR mutation status and subtypes of lung adenocarcinoma, which is conducive to saving clinical costs and guiding targeted therapy.

Shenkang injection protects against renal fibrosis by reducing perforin expression through the STING/TBK1/IRF3 signaling pathways in natural killer cells.

BACKGROUND: Immune activation, chronic inflammation, and renal interstitial fibrosis (RIF) are associated with chronic kidney disease (CKD). The herbal formula, Shenkang injection (SKI), has been reported to attenuate RIF. However, the mechanisms by which SKI alleviates renal fibrosis, especially the role of natural killer (NK) cells, are unknown and require exploration. PURPOSE: This study aimed to determine the mechanisms by which SKI alleviates RIF. METHODS: Differential gene expression between CKD mice and control groups was explored using bioinformatics analysis. To reveal how SKI reduces RIF in CKD, a CKD mouse model was established using folic acid for in vivo studies, and human kidney-2 cells were used for in vitro experiments. The effects of various SKI doses were then determined. Immunohistochemical staining, Enzyme-linked immunosorbent assay, western blotting, and quantitative real-time PCR were used for pathological and molecular expression detection. RESULTS: We first investigated the potential immune dysfunction in CKD using bioinformatics analysis. Some differentially expressed genes were enriched in immune-related functions. The expressions of perforin and interferon (IFN)-γ, which are mainly released by NK cells, were significantly higher in patients with CKD (p< 0.05). In vivo experiments showed that SKI alleviated renal fibrosis in a folic acid-induced renal fibrosis model. Serum creatinine and blood urea nitrogen levels were reduced in the high-dose SKI-treated group. Additionally, the mRNA and protein expression levels of type IV collagen and alpha-spinal muscular atrophy were reduced. Biochemical detection showed that SKI could also downregulate the activity of NK cells (by decreasing the expressions of perforin and IFN-γ). Increased levels of stimulator of interferon genes (STING)/TANK-binding kinase 1 (TBK1)/IFN regulatory factor 3 (IRF3), phosphorylation of TBK1, and IRF3 in FA-induced RIF mice were alleviated by SKI treatment, which was consistent with the results of in vitro experiments. CONCLUSION: These results demonstrated that SKI could decrease the activation of NK cells via the STING/TBK1/IRF3 signaling pathway, thereby alleviating RIF and protecting renal function in CKD. This may provide valuable evidence supporting the clinical use of SKI in the treatment of patients with CKD.

Construction of in vitro 3-D model for lung cancer-cell metastasis study.

BACKGROUND: Cancer metastasis is the main cause of mortality in cancer patients. However, the drugs targeting metastasis processes are still lacking, which is partially due to the short of effective in vitro model for cell invasion studies. The traditional 2-D culture method cannot reveal the interaction between cells and the surrounding extracellular matrix during invasion process, while the animal models usually are too complex to explain mechanisms in detail. Therefore, a precise and efficient 3-D in vitro model is highly desirable for cell invasion studies and drug screening tests. METHODS: Precise micro-fabrication techniques are developed and integrated with soft hydrogels for constructing of 3-D lung-cancer micro-environment, mimicking the pulmonary gland or alveoli as in vivo. RESULTS: A 3-D in vitro model for cancer cell culture and metastasis studies is developed with advanced micro-fabrication technique, combining microfluidic system with soft hydrogel. The constructed microfluidic platform can provide nutrition and bio-chemical factors in a continuous transportation mode and has the potential to form stable chemical gradient for cancer invasion research. Hundreds of micro-chamber arrays are constructed within the collagen gel, ensuring that all surrounding substrates for tumor cells are composed of natural collagen hydrogel, like the in vivo micro-environment. The 3-D in vitro model can also provide a fully transparent platform for the visual observation of the cell morphology, proliferation, invasion, cell-assembly, and even the protein expression by immune-fluorescent tests if needed. The lung-cancer cells A549 and normal lung epithelial cells (HPAEpiCs) have been seeded into the 3-D system. It is found out that cells can normally proliferate in the microwells for a long period. Moreover, although the cancer cells A549 and alveolar epithelial cells HPAEpiCs have the similar morphology on 2-D solid substrate, in the 3-D system the cancer cells A549 distributed sparsely as single round cells on the extracellular matrix (ECM) when they attached to the substrate, while the normal lung epithelial cells can form cell aggregates, like the structure of normal tissue. Importantly, cancer cells cultured in the 3-D in vitro model can exhibit the interaction between cells and extracellular matrix. As shown in the confocal microscope images, the A549 cells present round and isolated morphology without much invasion into ECM, while starting from around Day 5, cells changed their shape to be spindle-like, as in mesenchymal morphology, and then started to destroy the surrounding ECM and invade out of the micro-chambers. CONCLUSIONS: A 3-D in vitro model is constructed for cancer cell invasion studies, combining the microfluidic system and micro-chamber structures within hydrogel. To show the invasion process of lung cancer cells, the cell morphology, proliferation, and invasion process are all analyzed. The results confirmed that the micro-environment in the 3-D model is vital for revealing the lung cancer cell invasion as in vivo.

Two MicroRNAs, miR-34a and miR-125a, Are Implicated in Bicuspid Aortopathy by Modulating Metalloproteinase 2.

It has been recognized that wall shear stress plays an important role in the development of Bicuspid Aortopathy (BA), but the intrinsic mechanism is not well elucidated. This study aims to explore the underlying relationship between hemodynamical forces and pathological phenomenon. Total RNA was prepared from aortic wall tissues collected from 20 BA patients. RNA sequencing, bioinformatic analysis and quantitative reverse-transcription PCR validation identified nine miRNAs that were up-regulated in the aortic part exposed to high wall shear stress compared to the low wall shear stress control, and six miRNAs that were down-regulated. Among these candidates, miR-34a and miR-125a, both down-regulated in the high wall shear stress parts, were shown to be potential inhibitors of the metalloproteinase 2 gene. Luciferase reporter assays confirmed that both miRNAs could inhibit the expression of metalloproteinase 2 mRNA in CRL1999 by complementing with its 3' untranslated region. Conversely, immunofluorescence assays showed that inhibition of miR-34a or miR-125a could lead to increased metalloproteinase 2 protein level. On the other hand, both miR-34a and miR-125a were shown to alleviate stretch-induced stimulation of metalloproteinase 2 expression in CRL1999 cells. The results suggested that miR-34a and miR-125a might be implicated in wall shear stress induced aortic pathogenesis due to their apparent regulatory roles in metalloproteinase 2 expression and extracellular matrix remodeling, which are key events in the weakening of aortic walls among BA patients.

Nomogram Predicts Improvement of Ischemic Mitral Regurgitation After Coronary Artery Bypass Grafting.

BACKGROUND: Developing a nomogram to predict improvement in moderate ischemic mitral regurgitation (IMR) after coronary artery bypass grafting (CABG) is in need. METHODS: We retrospectively collected data from 112 patients with prior myocardial infarction and moderate IMR undergoing CABG between 2010 and 2018. Patients were divided into 2 groups based on IMR degree 1 year after CABG as follows: Improved Group with no or mild IMR (n = 54) and Failure Group with moderate or severe IMR (n = 58). To determine the predictors of postoperative IMR improvement, preoperative clinical and echocardiographic data were compared, and a nomogram was formulated based on all independent predictors. Discriminative ability, calibration, and clinical usefulness of the prediction model were assessed. RESULTS: Independent predictors of IMR improvement after CABG constructing the nomogram included duration between infarction and operation, posterior-inferior to left ventricular volume ratio, maximum difference of the time to reach minimum systolic volume of 16 segments, P3 leaflet tethering angle, and annular nonplanar angle. The nomogram exhibited well-fitted calibration curves and excellent discriminative ability. The area under the receiver operating characteristic curve was 0.974. Patients with a score >236 demonstrated a high probability of IMR improvement (sensitivity, 90.7%; specificity, 93.1%). Patients in the Improved Group demonstrated greater actuarial survival rates than those in the Failure Group. CONCLUSIONS: The nomogram combining 5 preoperative clinical and echocardiographic predictors provides an accurate preoperative estimation of moderate IMR improvement after surgery, with excellent discriminative ability. Based on this nomogram, patients with a higher score have predicted higher probabilities of IMR improvement.

Comprehensive growth index monitoring of desert steppe grassland vegetation based on UAV hyperspectral.

The goal of this study was to establish a comprehensive growth index (CGI) of grassland vegetation for monitor the overall condition of the grassland. Taking the desert grassland in Otuoke Banner, Ordos City, Inner Mongolia as the research object, this study integrates five indicators. First, the optimal band of the unmanned aerial vehicle hyperspectral data is optimized using the correlation analysis, successive projection algorithm (SPA), optimum index factor method, and band combination index method. A dual-band spectral index in good correlation with the CGI is then constructed in the optimal band. Afterwards, a CGI characterization model is established in accordance with the partial least squares regression (PLSR) algorithm and its accuracy is analyzed. Finally, the CGI of the study area is estimated. The experimental results are as follows. 1) The R2 of models built using the training samples of the spectral indices corresponding to the optimal spectra screened by the SPA method was 0.7835, RMSE was 0.0712, and RE was 6.89%, less than 10%. The R2 of the Validation samples was 0.7698, RMSE was 0.0471, and RE was 6.36%, less than 10%, highest precision. 2) Models were built using the spectral indices corresponding to the optimal spectra screened by the SPA method, and the CGI mean values were inverted. A comparison of the mean measured CGI values of the sample quadrat of the test area showed that the mean relative error was 3.82%. The results show that the vegetation growth of desert-steppe grasslands can be adequately monitored, providing technical support for the rapid and accurate diagnosis of grassland conditions. However, there are still shortcomings in this study. 1) The research area for this study was mainly in the desert steppe in Otuoke Banner, Ordos, hence the relevance and universality of the findings need to be verified, and subsequent experiments need to be carried out on desert steppes in other regions or even other types of grasslands to test the universality of the model. 2) In this study, the influence of soil background and litter on the spectral reflectance is not considered in depth. In addition, the influence of sensor observation angle and solar elevation angle on the inversion model demands further investigation efforts.

Phase transition and topological transistors based on monolayer Na3Bi nanoribbons.

Recently, a topological-to-trivial insulator quantum-phase transition induced by an electric field has been experimentally reported in monolayer (ML) and bilayer (BL) Na3Bi. A narrow ML/BL Na3Bi nanoribbon is necessary to fabricate a high-performance topological transistor. By using the density functional theory method, we found that wider ML Na3Bi nanoribbons (>7 nm) are topological insulators, featured by insulating bulk states and dissipationless metallic edge states. However, a bandgap is opened for extremely narrow ML Na3Bi nanoribbons (<4 nm) due to the quantum confinement effect, and its size increases with the decrease in width. In the topological insulating ML Na3Bi nanoribbons, a bandgap is opened in the metallic edge states under an external displacement electric field, with strength (∼1.0 V Å-1) much smaller than the reopened displacement electric field in ML Na3Bi (3 V Å-1). An ultrashort ML Na3Bi zigzag nanoribbon topological transistor switched by the electrical field was calculated using first-principles quantum transport simulation. It shows an on/off current/conductance ratio of 4-71 and a large on-state current of 1090 µA µm-1. Therefore, a proof of the concept of topological transistors is presented.

Simethicone administration improves gastric cleanness for esophagogastroduodenoscopy: a randomized clinical trial.

BACKGROUND: Esophagogastroduodenoscopy is very useful in diagnosing and treating upper gastrointestinal mucosal disorders, but too much foam and water in stomach decrease its diagnostic efficiency. Simethicone administration can help remove excessive foam. AIMS: To determine the optimal simethicone administration strategies in a comparative randomized controlled clinical trial. METHODS: Adult outpatients with indications for esophagogastroduodenoscopy were enrolled and randomly divided into group 1 (simethicone solution intake 20-30 min before procedure, n = 110), group 2 (simethicone solution intake 31-60 min before procedure, n = 92), and group 3 (simethicone solution intake > 60 min before procedure). Primary and secondary outcomes were procedure time and the patients' satisfaction after the examination. All symptoms like abdominal pain and distension were recorded. RESULTS: No statistically significant differences were found on the patients' demographic and clinical features and mean examination time (all P values > 0.05). The distribution of patients with different endoscopic and pathological diagnosis was comparable among three groups, respectively (P = 0.607; P = 0.289). However, the proportion of patients with Gastric Cleanness Grade A was most in group 2 (n = 73, 79.3%), and patient proportion with Gastric Cleanness Grade C was most found in group 1 (n = 72, 65.5%), which was greatly different (P < 0.001). There was no statistically significant difference on the satisfaction scores [immediately 6 (3-8) vs. 6 (1-10) vs. 6 (1-9), P = 0.533; 2 h after 10 (8-10) vs. 10 (10-10) vs. 10 (8-10), P = 0.463]. CONCLUSION: Simethicone solution intake 31-60 min before esophagogastroduodenoscopy can help obtain the best gastric cleanness, which is recommended in clinical practice (registered at ClinicalTrials.gov, NCT03776916 on December 13, 2018).