[Estimation of PM2.5 Hourly Concentration in Sichuan Province Based on GTWR-XGBoost Model].

Aerosol optical depths of satellites and meteorological factors have been widely used to estimate concentrations of surface particulate matter with an aerodynamic diameter ≤ 2.5 µm. Research on a high time resolution and high-precision PM2.5 concentration estimation method is of great significance for timely and accurate air quality prediction and air pollution prevention and mitigation. Himawari-8 AOD hour product and ERA5 meteorological reanalysis data were used as estimation variables, and a GTWR-XGBoost combined model was proposed to estimate hourly PM2.5 concentration in Sichuan Province. The results showed that:① the performance of the proposed combination model was better than that of the KNN, RF, AdaBoost, GTWR, GTWR-KNN, GTWR-RF, and GTWR-AdaBoost models in the full dataset; the fitting accuracy indexes R2, MAE, and RMSE were 0.96, 3.43 µg·m-3, and 5.52 µg·m-3, respectively; and the verification accuracy indexes R2, MAE, and RMSE were 0.9, 4.98 µg·m-3, and 7.92 µg·m-3, respectively. ② The model had a high goodness of fit (R2 of the whole dataset was 0.96, and R2 of different times ranged from 0.91 to 0.98) when applied to the estimation of PM2.5 concentration hour. It showed that the model had good time stability for hourly estimation and could provide accurate estimation information for regional air quality assessment. ③ In terms of time, the annual average PM2.5hourly concentration estimation showed an inverted U-shaped trend. It began to increase gradually at 09:00 am to a peak of 44.56 µg·m-3 at 11:00 and then gradually decreased. Moreover, the seasonal variation was very obvious, with winter>spring>autumn>summer. ④ In terms of spatial distribution, it showed the characteristics of high in the east and low in the west and a high degree of local pollution.

Long non-coding RNA LINC01207 promotes prostate cancer progression by downregulating microRNA-1972 and upregulating LIM and SH3 protein 1.

Prostate cancer is a heritable and clinically heterogeneous cancer. Both long non-coding RNAs (lncRNAs) and microRNAs (miRs) have been implicated in the pathogenesis and development of prostate cancer. Analysis of microarray data indicated that the lncRNA LINC01207 was differentially expressed in prostate cancer. In silico analysis predicted the interaction between LINC01207 and miR-1972 as well as the interaction between miR-1972 and the mRNAs LIM and SH3 protein 1 (LASP1). Thus, we explored the role of LINC01207 and miR-1972 in the growth and progression of prostate cancer. Quantitative real-time polymerase chain reaction revealed that LINC01207 and LASP1 were highly expressed in prostate cancer, while miR-1972 expression was lower. The interaction among LINC01207, miR-1972, and LASP1 was confirmed by RNA-fluorescence in situ hybridization, RNA immunoprecipitation, and dual luciferase reporter assay, which verified that LINC01207 could bind to miR-1972 and downregulate miR-1972, and miR-1972 targeted LASP1 and negatively regulated its expression. Both in vitro and in vivo experiments found that silencing LINC01207 inhibited cell proliferation, migration, invasion and tumor formation and enhanced apoptosis in prostate cancer cells, suggesting that LINC01207 functioned as a tumor promoter in prostate cancer and that it may represent a novel therapeutic target.

Dynamic "Scanning-Mode" Meniscus Confined Electrodepositing and Micropatterning of Individually Addressable Ultraconductive Copper Line Arrays.

Micro- and nanopatterning of cost-effective addressable metallic nanostructures has been a long endeavor in terms of both scientific understanding and industrial needs. Herein, a simple and efficient dynamic meniscus-confined electrodeposition (MCED) technique for precisely positioned copper line micropatterns with superior electrical conductivity (greater than 1.57 × 104 S/cm) on glass, silicon, and gold substrates is reported. An unexpected higher printing speed in the evaporative regime is realized for precisely positioned copper lines patterns with uniform width and height under horizontal scanning-mode. The final line height and width depend on the typical behavior of traditional flow coating process, while the surface morphologies and roughness are mainly governed by evaporation-driven electrocrystallization dynamics near the receding moving contact line. Integrated 3D structures and a rapid prototyping of 3D hot-wire anemometer are further demonstrated, which is very important for the freedom integration applications in advanced conceptual devices, such as miniaturized electronics and biomedical sensors and actuators.

Prognostic value of B7-H3 expression in patients with solid tumors: a meta-analysis.

Increasing evidence suggests B7-H3 is aberrantly expressed in various cancers, though its prognostic significance in solid tumors remains controversial. We therefore performed a meta-analysis to clarify the prognostic value of B7-H3 expression in human solid tumors. The PubMed and Embase databases were searched, and 28 studies involving 4623 patients were ultimately included in the analysis. Hazard ratios (HRs) with 95% confidence intervals (CIs) were utilized as effect estimates to evaluate the association between B7-H3 expression and overall survival (OS), progression-free survival (PFS) and recurrence-free survival (RFS). The pooled results showed B7-H3 was associated with poor OS (HR = 1.58; 95% CI: 1.32-1.90; P < 0.00001) and PFS (HR = 1.67; 95% CI: 1.05-2.65; P = 0.031), but not RFS (HR = 1.17; 95% CI: 0.89-1.53; P = 0.267). These results suggest B7-H3 is a negative predictor of OS and PFS in patients with solid tumors. B7-H3 may thus be a useful prognostic biomarker and therapeutic target for human solid tumors. However, further studies will be needed to more precisely determine the prognostic value of B7 H3 expression.

Expression and significance of B7-H3 and Tie-2 in the tumor vasculature of clear cell renal carcinoma.

Tumor angiogenesis is required for tumor growth and metastasis, and the Ang/Tie-2 axis plays a pivotal role in angiogenesis. B7-H3, a new member of the B7 family of costimulatory molecules, has a critical function in the T-cell-mediated antitumor immune response, and abnormal tumor B7-H3 expression is frequently associated with a poor prognosis. However, the relationship between B7-H3 and angiogenesis in clear cell renal carcinoma (ccRCC) remains unclear. In this study, we used immunohistochemical methods to detect tumor vascular expression of B7-H3 and Tie-2 in tissue microarrays of 82 ccRCC patient samples. According to the results, B7-H3 is highly expressed in the tumor vascular endothelium of ccRCC and is associated with the ccRCC grade and tumor-node-metastasis (TNM) stage. Although vascular Tie-2 expression was also correlated with T stage and lymph node metastasis, it was not related to ccRCC grade or distant metastasis. The microvessel density (MVD) labeled by CD34 was correlated with tumor grade and TNM stage. Expression of B7-H3 and Tie-2 was positively correlated, and the levels were positively associated with the MVD. Additionally, immunofluorescence staining revealed coexpression of B7-H3 and Tie-2 in the vascular endothelia of ccRCC. Collectively, our findings suggest that expression of B7-H3 and Tie-2 in ccRCC tumor vasculature is closely related to the progression and prognosis of the disease. Furthermore, B7-H3 possibly promotes ccRCC angiogenesis through the Tie-2 pathway. Thus, B7-H3 might serve as an effective endothelial marker for ccRCC prognosis and become a promising target for ccRCC anti-angiogenic-targeted therapy.

Ultralow flexural properties of copper microhelices fabricated via electrodeposition-based three-dimensional direct-writing technology.

Helical metallic micro/nanostructures as functional components have considerable potential for future miniaturized devices, based on their unique mechanical and electrical properties. Thus, understanding and controlling the mechanical properties of metallic helices is desirable for their practical application. Herein, we implemented a direct-writing technique based on the electrodeposition method to grow copper microhelices with well-defined and programmable three-dimensional (3D) features. The mechanical properties of the 3D helical structures were studied by the electrically induced quasistatic and dynamic electromechanical resonance technique. These methods mainly explored the static pull-in process and the dynamic electromechanical response, respectively. It was found that the center-symmetric and vertical double copper microhelix structure with 1.2 µm wire diameter has a flexural rigidity of 0.9 × 10-14 N m2 and the single vertical copper microhelix structure with 1.1 µm wire diameter has a flexural rigidity of 0.5989 × 10-14 N m2. By comparing with microwires and other reported micro/nanohelices, we found that the copper microhelices reported here had an ultralow stiffness (about 0.13 ± 0.01 N m-1). It is found that the experimental results agree well with the finite element calculations. The proposed method can be used to fabricate and measure the flexural properties of three-dimensional complex micro/nanowire structures, and may have a profound effect on the application of microhelices in various useful microdevices such as helix-based microelectromechanical switches, sensors and actuators based on their unique mechanical properties.

Differential protein expression in Phalaenopsis under low temperature.

A comparative proteomic analysis was carried out to explore the molecular mechanisms of responses to cold stress in Phalaenopsis after treated by low temperature (13/8 °C day/night) for 15 days. Differentially expressed proteins were examined using two-dimensional electrophoresis (2-DE) and matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-TOF/MS). Among 85 differentially expressed proteins, 73 distinct proteins were identified. Comparative analysis revealed that the identified proteins mainly participate in photosynthesis, protein synthesis, folding and degradation, respiration, defense response, amino acid metabolism, energy pathway, cytoskeleton, transcription regulation, signal transduction, and seed storage protein, while the functional classification of the remaining four proteins was not determined. These data suggested that the proteins might work cooperatively to establish a new homeostasis under cold stress; 37 % of the identified cold-responsive proteins were associated with various aspects of chloroplast physiology, and 56 % of them were predicted to be located in the chloroplasts, implying that the cold stress tolerance of Phalaenopsis was achieved, at least partly, by regulation of chloroplast function. Moreover, the protein destination control, which was mediated by chaperones and proteases, plays an important role in tolerance to cold stress.

Evaluation of internal control for gene expression in Phalaenopsis by quantitative real-time PCR.

The selection of appropriate reference genes is one of the most important steps to obtain reliable results for normalizing quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) of MADS-box gene in Phalaenopsis. In this study, we cloned 12 candidate reference genes including 18S ribosomal RNA (18S), elongation factor 1 alpha (EF1α), cytoskeletal structural protein actin (ACT1, ACT2, ACT3, ACT4, ACT5), ubiquitin protein (UBQ1 and UBQ2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and the cytoskeletal structural proteins α-tubulin (TUA) and ß-tubulin (TUB) in Phalaenopsis and evaluated their expression reliability. The expression of these candidate reference genes was analyzed using geNorm and normFinder software packages; the results showed that ACT2 and ACT4 were the highest stability reference genes for all experiment sets based on normFinder, followed by ACT1 or ACT3, while ACT3 and ACT4 were the highest stability reference genes for most experiment sets based on geNorm, then TUB or others. Taken together, Actin genes were the higher stability reference genes for all tissues at total developmental stages, and similar results came from analysis by normFinder. According to geNorm analysis, ACT3 and ACT4 were the most stable reference genes for all tissues tested and tissues at reproductive stages; TUB and ACT5 or ACT4 were the most stable reference genes for vegetative tissues or roots. The most stable reference genes for all vegetative tissues and only leaves were ACT4 and ACT5, ACT2 and ACT3, respectively; ACT1 and ACT3 were the most stable genes and sufficient for reliable normalization of flower tissues. While EF1α, UBQ1, UBQ2, and GAPDH were found to be unsuitable as a reference gene in our analysis for flower tissues, total tissues, and reproductive stages; UBQ2 and 18S were identified as the least stable reference genes for vegetative tissues at different stages, different tissues at vegetative stages; TUA and 18S were the least reliable reference genes for the samples from roots at all developmental stages. This is the first systematic report on the selection of reference genes in Phalaenopsis, and these data will facilitate future work on gene expression in orchid.

Attenuation of Streptococcus suis virulence by the alteration of bacterial surface architecture.

NeuB, a sialic acid synthase catalyzes the last committed step of the de novo biosynthetic pathway of sialic acid, a major element of bacterial surface structure. Here we report a functional NeuB homologue of Streptococcus suis, a zoonotic agent, and systematically address its molecular and immunological role in bacterial virulence. Disruption of neuB led to thinner capsules and more susceptibility to pH, and cps2B inactivation resulted in complete absence of capsular polysaccharides. These two mutants both exhibited increased adhesion and invasion to Hep-2 cells and improved sensibility to phagocytosis. Not only do they retain the capability of inducing the release of host pro-inflammatory cytokines, but also result in the faster secretion of IL-8. Easier cleaning up of the mutant strains in whole blood is consistent with virulence attenuation seen with experimental infections of both mice and SPF-piglets. Therefore we concluded that altered architecture of S. suis surface attenuates its virulence.

[Capsular saliva acid of Streptococcus suis 2 influences virulence and host inflammatory responses].

OBJECTIVE: We clarified the pathogenic influence of the absence of Streptococcus suis type 2 capsular saliva acid on BLAB/c mice. METHODS: The virulence of the experimental strains were compared; the distribution of strains in vivo was determined by quantitative plating. Histopathological analysis was used to qualitatively compare the different pathogenicity of wild strain and knockout strains. ELISA was used to test the levels of cytokine in whole blood cells for the stimulation of strains. RESULTS: The virulence of mutant strains was significantly reduced, and when the genes were restored, toxicity levels were recovered to that of the wild type strain. The distribution in blood and in the brain between wild strain and knock out strains has significant difference, and Streptococcus suis type 2 strains can cause different degrees of brain damage. During the in vitro test, the mutant strains can stimulate the whole blood cells to secrete higher levels of MCP-1 and IL-6. CONCLUSION: Capsular saliva acid affects bacterial virulence and host cell inflammation response. As an important virulence factor of Streptococcus suis type 2, it can damage the blood brain barrier and cause meningitis.