Whether the Golgi protein 73 could be a diagnostic serological marker in hepatocellular carcinoma: a meta analysis.

BACKGROUND: The Value of Golgi protein 73 (GP73) in the diagnosis of Hepatocellular carcinoma (HCC) remains controversial, especially in its differentiation between HCC and cirrhosis. Besides, some papers showed that GP73 levels are correlated with liver fibrosis. This study conducts a meta-analysis to evaluate the value of GP73 in diagnosing HCC and differential diagnosing HCC from liver cirrhosis. METHODS: 36 studies with a sample size of 8314 cases concerning the accuracy of GP73 in the diagnosis of HCC were selected through a systematic review. Seven of these studies included a total of 438 HCC samples and 426 cirrhosis samples and calculated the sensitivity and specificity of GP73 for differential diagnosing HCC from cirrhosis. QUADAS (quality assessment of diagnostic accuracy studies) was used to evaluate the quality of literature. Statistical analyses were performed using StataSE16 software. RESULTS: The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and the area under the curve were 0.79(95%CI 0.74-0.83),0.85(95%CI 0.80-0.89),5.4(95%CI 3.8-7.5), 0.25(95%CI 0.20-0.31), 22(95%CI 13-35), and 0.88 for GP73 diagnosing HCC;0.74(95%CI 0.64-0.81),0.70(95%CI 0.49-0.85),2.40(95%CI 1.3-4.7),0.38(95%CI 0.23-0.61),6(95%CI 2-19), and 0.78 for GP73 differential diagnosing HCC from liver cirrhosis. CONCLUSION: The results suggest that GP73 has a high diagnostic value for HCC and a moderate value for differential diagnosis of HCC from liver cirrhosis.

Metagenomic analysis reveals the different characteristics of microbial communities inside and outside the karst tiankeng.

BACKGROUND: Karst tiankengs serve as a reservoir of biodiversity in the degraded karst landscape areas. However, the microbial diversity of karst tiankengs is poorly understood. Here, we investigated the composition and function of the microbial community in a karst tiankeng. RESULTS: We found that habitat differences inside and outside the karst tiankeng changed the composition and structure of the soil microbial communities, and the dominant phyla were Proteobacteria, Actinobacteria, Chloroflexi and Acidobacteria. The Shannon-Wiener diversity of microbial communities inside and outside the tiankeng was significantly different, and it was higher inside the tiankeng (IT). Venn and LEfSe analysis found that the soil microbial communities inside the tiankeng had 640 more endemic species and 39 more biomarker microbial clades than those identified outside of the tiankeng (OT)..Functional prediction indicated that soil microorganisms in outside the tiankeng had a high potential for carbohydrate metabolism, translation and amino acid metabolism. There were biomarker pathways associated with several of human diseases at both IT and OT sites. Except for auxiliary activities (AA), other CAZy classes had higher abundance at IT sites, which can readily convert litter and fix carbon and nitrogen, thereby supporting the development of underground forests. The differences in microbial communities were mainly related to the soil water content and soil total nitrogen. CONCLUSIONS: Our results provide a metagenomic overview of the karst tiankeng system and provide new insights into habitat conservation and biodiversity restoration in the area.

Synergistic Function between Phosphorus-Containing Flame Retardant and Multi-Walled Carbon Nanotubes towards Fire Safe Polystyrene Composites with Enhanced Electromagnetic Interference Shielding.

As a universal polymer material, polystyrene (PS) is widely applied in electrical devices and construction. Thus, it is necessary to improve the flame retardancy and electromagnetic shielding properties of PS material. In this work, PS/silicon-wrapped ammonium polyphosphate/Inorganic acid-treated multi-walled carbon nanotubes composites (PS/SiAPP/aMWCNT, abbreviated as PAC) were prepared via methods of filtration-induced assembly and hot-pressing. Morphology and structure characterization demonstrated that SiAPP and aMWCNT had good dispersion in PS and excellent compatibility with the PS matrix. Thermogravimetric analysis revealed that the addition of aMWCNT to PS improved its thermal stability and carbon-forming characteristics. The peak heat release rate, the peak carbon monoxide production rate, and the peak smoke production rate of the PAC10 composite decreased by 53.7%, 41.9%, and 45.5%, respectively, while its electromagnetic shielding effectiveness reached 12 dB. These enhancements were attributed to the reason that SiAPP and aMWCNT synergistically catalyzed the char generation and SiAPP produced free radical scavengers and numbers of incombustible gases, which could decrease the oxygen concentration and retard the combustion reaction. Therefore, the assembled PS/SiAPP/aMWCNT system provides a new pathway to improve the flame retardant and electromagnetic shielding properties of PS.

A novel closed reduction technique for treating femoral shaft fractures with intramedullary nails, haemostatic forceps and the lever principle.

BACKGROUND: Faster, easier, more economical and more effective versions of the minimally invasive reduction procedure for femoral shaft fractures need to be developed for use by orthopaedic surgeons. In this study, a fracture table was used to restore limb length, and long, curved haemostatic forceps and the lever principle were utilized to achieve minimally invasive reduction and intramedullary nail fixation of femoral shaft fractures. METHODS: A retrospective analysis involving 20 patients with femoral shaft fractures reduced with a fracture table; long, curved haemostatic forceps; and the lever principle was conducted. The operative effect was evaluated on the basis of the operative time, reduction time, fluoroscopy time, and intraoperative blood loss. RESULTS: All 20 cases were reduced in a closed fashion, and no conversions to open reduction were needed. The average operative time and fracture reduction time for all patients were 69.1 ± 13.5 min (range, 50-100 min) and 6.7 ± 1.9 min (range, 3-10 min), respectively. The fluoroscopy exposure time during the reduction process was 5-15 s, with an average time of 8.7 ± 2.7 s. The average intraoperative blood loss was 73.5 ± 22.5 mL (range, 50-150 mL). The patients exhibited excellent alignment in the injured limb after intramedullary nailing. Seventeen patients successfully completed a follow-up after fracture healing. The healing time ranged from 4 to 6 months. CONCLUSIONS: Displaced femoral shaft fractures in adults can be treated by a labour-saving lever technique involving fragments, 2 haemostatic forceps and soft tissue envelope-assisted closed reduction and intramedullary nail fixation. This technique is easy to perform; reduces blood loss, the fluoroscopy time and the surgical time for intraoperative reduction; and leads to excellent fracture healing.

Effect of Community-Acquired Pneumonia on Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

Community-acquired pneumonia (CAP) is a major contributor to hospitalization for acute exacerbations of chronic obstructive pulmonary disease (AECOPD). The clinical manifestations of AECOPD with and without CAP are confusing. The difference in the survival or readmission rate of AECOPD with or without CAP remains controversial. A prospective cohort study was conducted to evaluate the clinical and laboratory characteristics and in-hospital outcomes of patients who were consecutively hospitalized due to AECOPD from May 2015 to December 2019. Grouping was based on chest computed tomography findings. Multivariable logistic regression was used to explore the predictors for early identification between CAP exacerbations and non-CAP exacerbations. Kaplan-Meier analysis was used to compare the cumulative survival rate and readmission rate for a 12-month follow-up between the two groups. A total of 378 patients with AECOPD were enrolled, including 200 patients with CAP and 178 patients without CAP. The presence of pleuritic pain, usage of ICS, and elevated levels of C-reactive protein and procalcitonin on admission were the predictors for the early discrimination between AECOPD with and without CAP. During a 1-year follow-up, the cumulative survival rate was lower in patients with AECOPD with CAP than in those with AECOPD without CAP (13.0% vs. 3.37%; HR: 4.099; 95% CI, 2.049-8.199; p < 0.001), but the readmission rate was similar in both groups. Patients with first-time exacerbation due to CAP were more likely to experience subsequent pneumonic exacerbation. CAP is frequent among patients hospitalized for AECOPD and associated with increased mortality and successive pneumonic exacerbation.

Self-adapting extraction of cropland phenological transitions of rotation agroecosystems using dynamically fused NDVI images.

Remote sensing can be used to monitor cropland phenological characteristics; however, tradeoffs between the spatial and temporal resolutions of cloudless satellite images limit the accuracy of their retrieval. In this study, an improved enhanced spatial and temporal adaptive reflectance fusion model (ESTARFM) was applied to human-dominated Xiong'an New Area to develop a self-adapting algorithm automating the extraction of main phenological transition points (greenup, maturity, senescence, and dormancy). The analyses of cropland phenological characteristics were performed utilizing the Softmax classification method. By examining three different phases of fusion images, it was found that the improved ESTARFM was more accurate than the original ESTARFM (correlation coefficient > 0.76; relative root mean square error < 0.25; structural similarity index > 0.79). The reconstructed normalized difference vegetation indexes were consistent with that acquired by the Moderate Resolution Imaging Spectroradiometer (average discrepancy: 0.1136, median absolute deviation: 0.0110). The greenup, maturity, senescence, and dormancy points were monitored in 5-day resolution and 50-day length on a 30-m grid scale, and their average day of year (DOY) were 67, 119, 127, and 166 for wheat; 173, 224, 232, and 283 for single-season corn; and 189, 227, 232, and 285 for rotation corn, respectively. The corresponding median absolute deviations were 2, 3, 2, and 2 days for wheat; 2, 5, 3, and 4 days for single-season corn; and 2, 5, 2, and 2 days for rotation corn, respectively, while all coefficients of variation did not exceed 6%. The proposed self-adapting approach can be used for identifying the planting modes at grid level in rotation agroecosystems and cropland phenological dynamics on a global or regional scale.

BMP9-regulated angiogenic signaling plays an important role in the osteogenic differentiation of mesenchymal progenitor cells.

Mesenchymal stromal progenitor cells (MSCs) are multipotent progenitors that can be isolated from numerous tissues. MSCs can undergo osteogenic differentiation under proper stimuli. We have recently demonstrated that bone morphogenetic protein 9 (BMP9) is one of the most osteogenic BMPs. As one of the least studied BMPs, BMP9 has been shown to regulate angiogenesis in endothelial cells. However, it is unclear whether BMP9-regulated angiogenic signaling plays any important role in the BMP9-initiated osteogenic pathway in MSCs. Here, we investigate the functional role of hypoxia-inducible factor 1α (HIF1α)-mediated angiogenic signaling in BMP9-regulated osteogenic differentiation of MSCs. We find that BMP9 induces HIF1α expression in MSCs through Smad1/5/8 signaling. Exogenous expression of HIF1α potentiates BMP9-induced osteogenic differentiation of MSCs both in vitro and in vivo. siRNA-mediated silencing of HIF1α or HIF1α inhibitor CAY10585 profoundly blunts BMP9-induced osteogenic signaling in MSCs. HIF1α expression regulated by cobalt-induced hypoxia also recapitulates the synergistic effect between HIF1α and BMP9 in osteogenic differentiation. Mechanistically, HIF1α is shown to exert its synergistic effect with BMP9 by inducing both angiogenic signaling and osteogenic signaling in MSCs. Thus, our findings should not only expand our understanding of the molecular basis behind BMP9-regulated osteoblastic lineage-specific differentiation, but also provide an opportunity to harness the BMP9-induced synergy between osteogenic and angiogenic signaling pathways in regenerative medicine.

The serum glucan level and pathological changes of antifungal treatment for lower respiratory tract infection of Candida albicans.

Due to the fact that Candida albicans colonizes in the upper respiratory tracts of healthy people, whether or not its isolation from airway secretions is sufficient to warrant treatment remains controversial. The animal models of immunosuppressive rats with pulmonary candidiasis were established by the intratracheal inoculating suspensions of C. albicans, and the animals were divided into the following three groups: (1) antifungal treatment group, (2) saline control group, and (3) blank control group. We noted the following in our studies: (1) The fungal load of the saline control group gradually increased such that it was higher than those of the antifungal treated group and was significant from the fourth day of treatment (P < 0.01). (2) The serum (1,3)-ß-D-glucan (BG) in the saline control group also gradually increased so that it was significantly higher than found with the treated group by the sixth day of treatment (P < 0.05), and in fact, the rank of pulmonary colony count and BG in the two groups at different time points showed an almost perfect linear correlation. (3) The median survival period of the rats in the antifungal treated group and saline control group was 15 and 8 days respectively, no rats died in the blank control group. (4) The lung lesions from the saline control group gradually became more aggravated than those in the antifungal treated group; no significant pathological changes were found in the blank control group. Antifungal treatment (micafungin) is capable of efficaciously decreasing the lung fungal burden, and continuous monitoring of BG is useful for the evaluation of therapeutic effect of antifungals. Infection of C. albicans with associated pathological damage implies the need for antifungal therapy.

Research progress of circRNA as a biomarker of osteoporosis.

Osteoporosis, as a chronic metabolic bone disease, has the characteristic of insidious disease progression, which often leads to relatively delayed disease diagnosis. Therefore, early screening for osteoporosis has become a major public health challenge. The latest research indicates that circRNA is widely involved in the regulation of bone metabolism and is closely related to the occurrence and development of osteoporosis. Based on its high degree of sequence conservation and stability, circRNA has the potential to become a new clinical biomarker. The study of biomarkers is generally based on body fluid samples or adjacent tissue samples, with blood being the most commonly used, which can be divided into sources such as serum, plasma, peripheral blood monocytes, and plasma exosomes. Therefore, this article aims to review the research status of circRNA as a biomarker of osteoporosis.

Cross-talk between EGF and BMP9 signalling pathways regulates the osteogenic differentiation of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are multipotent progenitors, which give rise to several lineages, including bone, cartilage and fat. Epidermal growth factor (EGF) stimulates cell growth, proliferation and differentiation. EGF acts by binding with high affinity to epidermal growth factor receptor (EGFR) on the cell surface and stimulating the intrinsic protein tyrosine kinase activity of its receptor, which initiates a signal transduction cascade causing a variety of biochemical changes within the cell and regulating cell proliferation and differentiation. We have identified BMP9 as one of the most osteogenic BMPs in MSCs. In this study, we investigate if EGF signalling cross-talks with BMP9 and regulates BMP9-induced osteogenic differentiation. We find that EGF potentiates BMP9-induced early and late osteogenic markers of MSCs in vitro, which can be effectively blunted by EGFR inhibitors Gefitinib and Erlotinib or receptor tyrosine kinase inhibitors AG-1478 and AG-494 in a dose- and time-dependent manner. Furthermore, EGF significantly augments BMP9-induced bone formation in the cultured mouse foetal limb explants. In vivo stem cell implantation experiment reveals that exogenous expression of EGF in MSCs can effectively potentiate BMP9-induced ectopic bone formation, yielding larger and more mature bone masses. Interestingly, we find that, while EGF can induce BMP9 expression in MSCs, EGFR expression is directly up-regulated by BMP9 through Smad1/5/8 signalling pathway. Thus, the cross-talk between EGF and BMP9 signalling pathways in MSCs may underline their important roles in regulating osteogenic differentiation. Harnessing the synergy between BMP9 and EGF should be beneficial for enhancing osteogenesis in regenerative medicine.

Inhibition of histone deacetylases potentiates BMP9-induced osteogenic signaling in mouse mesenchymal stem cells.

BACKGROUND/AIMS: We have demonstrated that bone morphogenetic protein 9 (BMP9) is one of the most potent BMPs in regulating osteoblast differentiation of mesenchymal stem cells (MSCs) although the molecular mechanism underlying BMP9-induced osteogenesis remains to be fully elucidated. It is known that epigenetic regulations play an important role in regulating the stem cell potency and lineage commitment. Here, we investigate if the inhibition of histone deacetylases (Hdacs) affects BMP9-induced osteogenic differentiation of MSCs. METHODS: Using the Hdac inhibitor trichostatin A (TSA), we assess that TSA enhances BMP9-mediated osteogenic markers and matrix mineralization in MSCs, and bone formation in mouse embryonic limb explants. RESULTS: We find that the endogenous expression of most of the 11 Hdacs is readily detectable in MSCs. BMP9 is shown to induce most Hdacs in MSCs. We demonstrate that TSA potentiates BMP9-induced early osteogenic marker alkaline phosphatase (ALP) activity in MSCs, as well as late osteogenic markers osteopontin (OPN) and osteocalcin (OCN) and matrix mineralization. Fetal limb explant culture studies reveal that TSA potentiates BMP9-induced endochondral bone formation, possibly by expanding hypertrophic chondrocyte zone of growth plate. CONCLUSION: Our findings strongly suggest histone deacetylases may play an important role in fine-tuning BMP9-mediated osteogenic signaling through a negative feedback network in MSCs. Thus, Hdac inhibitors may be used as novel therapeutics for bone fracture healing.

Establishment and characterization of the reversibly immortalized mouse fetal heart progenitors.

OBJECTIVE: Progenitor cell-based cardiomyocyte regeneration holds great promise of repairing an injured heart. Although cardiomyogenic differentiation has been reported for a variety of progenitor cell types, the biological factors that regulate effective cardiomyogenesis remain largely undefined. Primary cardiomyogenic progenitors (CPs) have a limited life span in culture, hampering the CPs' in vitro and in vivo studies. The objective of this study is to investigate if primary CPs isolated from fetal mouse heart can be reversibly immortalized with SV40 large T and maintain long-term cell proliferation without compromising cardiomyogenic differentiation potential. METHODS: Primary cardiomyocytes were isolated from mouse E15.5 fetal heart, and immortalized retrovirally with the expression of SV40 large T antigen flanked with loxP sites. Expression of cardiomyogenic markers were determined by quantitative RT-PCR and immunofluorescence staining. The immortalization phenotype was reversed by using an adenovirus-mediated expression of the Cre reconbinase. Cardiomyogenic differentiation induced by retinoids or dexamethasone was assessed by an α-myosin heavy chain (MyHC) promoter-driven reporter. RESULTS: We demonstrate that the CPs derived from mouse E15.5 fetal heart can be efficiently immortalized by SV40 T antigen. The conditionally immortalized CPs (iCP15 clones) exhibit an increased proliferative activity and are able to maintain long-term proliferation, which can be reversed by Cre recombinase. The iCP15 cells express cardiomyogenic markers and retain differentiation potential as they can undergo terminal differentiate into cardiomyctes under appropriate differentiation conditions although the iCP15 clones represent a large repertoire of CPs at various differentiation stages. The removal of SV40 large T increases the iCPs' differentiation potential. Thus, the iCPs not only maintain long-term cell proliferative activity but also retain cardiomyogenic differentiation potential. CONCLUSIONS: Our results suggest that the reported reversible SV40 T antigen-mediated immortalization represents an efficient approach for establishing long-term culture of primary cardiomyogenic progenitors for basic and translational research.

Spatiotemporal responses of habitat quality to land use changes in the source area of Pearl River, China.

Habitat quality assessment provides an effective interface for exploring the mechanisms linking land use change and biodiversity. We used InVEST model to assess the spatial and temporal variations of habitat quality in the Pearl River source area from 2000 to 2020, and to examine the impacts of land use change on habitat quality. The results showed that during the study period, construction land had the largest change, with an area increase of 321.48 km2, and the area of grassland decreased most significantly. Habitat quality in the Pearl River source area was generally at a high level, with a small downward trend. The low value areas were concentrated in the town centers and main agricultural production areas, while habitat quality was high in the mountainous areas in the south and north region. The cold spots of habitat quality change had the most significant aggregation effect in the Quzhan Basin along the Nanpan River. The number of hot spots was small and scattered. Among the various types of nature reserves, habitat quality of Jiache Nature Reserve in Huize County was the lowest, and that of Zhujiangyuan Nature Reserve had a slight decreasing trend, mainly due to the transformation of grassland to cropland. The contribution of habitat quality degradation driven by land function change was 5.6 times as that of improvement. The encroachment of urban and rural construction space into grassland ecological space and agricultural production space was the dominant factor driving the reduction of habitat quality in the Pearl River source area. The contribution of construction land expansion decreased from 69.9% (2000-2010) to 46.7% (2010-2020). The expansion of construction land was the main cause for the degradation of habitat quality. The degradation threat from arable land expansion overtook the traffic network construction as the secondary threat source from 2010 to 2020. It was necessary to increase control of nature reserves in the Pearl River source area and to implement land use regulation strictly to guarantee no net loss and integrity of the ecosystem.

Karst tiankeng shapes the differential composition and structure of bacterial and fungal communities in karst land.

Karst tiankeng are important biodiversity conservation reservoirs. However, the unique habitats of karst tiankeng affect microbial community structure remained poorly understood. In this study, we collected soil samples from karst tiankeng (TK) and karst land (KL) and subjected to high-throughput sequencing. Based on the classification of the total, abundance, and rare taxa for bacteria and fungi, a multivariate statistical analysis was carried out. The results revealed that bacterial community Shannon diversity and Pielou's evenness were highest in TK. The rare taxa were ubiquitous in all soil samples, while the higher Shannon diversity of the abundant taxa of TK may be related to the habitat preferences of species and niche differentiation. The community composition of bacterial and fungal sub-communities exhibited significant dissimilarity between TK and KL. The redundancy analysis further demonstrated that abundant taxa were environmentally more constrained than rare taxa. The bacterial and fungal networks of KL were more complex than TK. The keystones of the network transforms may suggest their significant role in the ecological function of the karst tiankeng ecosystem. This study represents the first reports of the characteristics of bacterial and fungal communities in karst tiankeng.

The Relationship Between Prognostic Nutritional Indexes and the Clinical Outcomes of Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

Purpose: Nutritional status is related to the clinical outcomes of patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The aim of this study was to investigate the association between nutritional status, measured by the prognostic nutritional index (PNI), and adverse hospitalization outcomes in patients with AECOPD. Methods: Consecutive AECOPD patients admitted to the First Affiliated Hospital of Sun Yat-sen University between January 1, 2015 to October 31, 2021 were enrolled. We collected the clinical characteristics and laboratory data of patients. Multivariable logistic regression models were developed to assess the relationship between the baseline PNI and adverse hospitalization outcomes. A generalized additive model (GAM) was used to identify any non-linear relationship. In addition, we performed a subgroup analysis to tested the robustness of the results. Results: A total of 385 AECOPD patients were involved in this retrospective cohort study. Based on the tertiles of PNI, patients in the lower tertiles of PNI showed more worse outcome incidence (30 [23.6%] versus 17 [13.2%] versus 8 [6.2%]; p < 0.001). Multivariable logistic regression analysis revealed that the PNI were independently associated with adverse hospitalization outcomes after adjustment for confounding factors (Odds ratio [OR] = 0.94, 95% CI: 0.91 to 0.97, P < 0.0001). After adjusting for confounders, smooth curve fitting showed a saturation effect, suggesting that the relationship between the PNI and adverse hospitalization outcomes was nonlinear. Two-piecewise linear regression model suggested that the incidence of adverse hospitalization outcomes significantly decreased with PNI level up to the inflection point (PNI = 42), and PNI was not associated with adverse hospitalization outcome after that point. Conclusion: Decreased PNI levels at admission were determined to be associated with adverse hospitalization outcomes in patients with AECOPD. The results obtained in this study may potentially assist clinicians optimize risk evaluations and clinical management processes.

Slope aspect affects the soil microbial communities in karst tiankeng negative landforms.

BACKGROUND: Karst tiankeng is a large-scale negative surface terrain, and slope aspects affect the soil conditions, vegetation and microbial flora in the tiankeng. However, the influence of the slope aspect on the soil microbial community in tiankeng has not been elucidated. METHODS: In this study, metagenomic sequencing technology was used to analyze the soil microbial community structure and functional potentials on the shady and sunny slopes of karst tiankeng. RESULTS: The Shannon-Wiener diversity of microbial communities on shady slope (SHS) was significantly higher than that on sunny slope (SUS). Although the composition of dominant phyla on shady slope (SHS) and sunny slope (SUS) was similar, there were significant differences in beta-diversity. The linear discriminate analysis (LDA) results showed that biomarkers mainly belongs to Actinobacteria, Chloroflexi and Proteobacteria. Functional pathways and CAZy (Carbohydrate-Active Enzymes) genes also had a remarkable response to slope aspect change. LEfSe results indicated several biomarker pathways in sunny slope involved in human disease. Moreover, the abundance of CAZy genes was higher in shady slope and had stronger ability in decomposing litter. The microbial communities were mainly correlation with the vegetation characteristics (species richness and coverage) and soil properties (SOC and pH). CONCLUSIONS: These results indicate slope aspect has a pronounced influence on microbial community composition, structure and function at karst tiankeng. In the future, the conservation of karst tiankeng biodiversity should pay more attention to topographical factors.

An improved daily standardized precipitation index dataset for mainland China from 1961 to 2018.

The standardized precipitation index (SPI), one of the most commonly used drought indicators, is widely used in the research areas of drought analysis and drought prediction in different fields such as meteorology, agriculture, and hydrology. However, its main disadvantage is the relatively coarse time resolution of one month. To improve the time resolution of SPI to identify flash droughts, we have refined the traditional SPI calculation method and developed a new multi-scale daily SPI dataset based on data from 484 meteorological stations in mainland China from 1961 to 2018. SPI data from three different sites (located in Henan, Yunnan, and Fujian Provinces) at the three-month timescale were analyzed by comparing with historically recorded drought events. We found that the new multi-scale daily SPI can effectively capture drought events in different periods and locations and identify the specific start and end times of drought events. In short, our SPI dataset appears reasonable and capable of facilitating drought research in different fields.

The characterization of microbial communities and associations in karst tiankeng.

The karst tiankeng is a special and grand negative terrain on the surface, that maintains a unique ecosystem. However, knowledge about bacterial and fungal communities in karst tiankengs is still limited. Therefore, soil samples from five karst tiankengs were collected and subjected to high-throughput sequencing of 16S rRNA and ITS genes, and multivariate statistical analysis. The results showed abundant and diversified bacterial and fungal communities in karst tiankeng. The bacterial communities were dominated by Proteobacteria and Acidobacteria, and the fungal communities were dominated by Ascomycota and Basidiomycota. Statistical analysis revealed significant differences in bacterial and fungal communities among the five karst tiankengs, which may indicate that the distribution of bacterial and fungal communities was driven by separate karst tiankengs. The co-occurrence network structure was characterized by highly modularized assembly patterns and more positive interactions. The keystone taxa were mainly involved in nutrient cycling and energy metabolism. The null model analysis results showed that the stochastic process, especially dispersal limitation, tended to be more important in controlling the development of bacterial and fungal communities in karst tiankeng. The bacterial community structure was significantly associated with soil properties (SWC, TN, AN, and BD), while the fungal community structure was significantly associated with soil properties (SWC and TP) and plant diversity. These results can expand our knowledge of the karst tiankeng microbiome.

Development of a Predictive Model for Mortality in Hospitalized Patients With COVID-19.

INTRODUCTION: Early identification of patients with novel corona virus disease 2019 (COVID-19) who may be at high mortality risk is of great importance. METHODS: In this retrospective study, we included all patients with COVID-19 at Huanggang Central Hospital from January 23 to March 5, 2020. Data on clinical characteristics and outcomes were compared between survivors and nonsurvivors. Univariable and multivariable logistic regression were used to explore risk factors associated with in-hospital death. A nomogram was established based on the risk factors selected by multivariable analysis. RESULTS: A total of 150 patients were enrolled, including 31 nonsurvivors and 119 survivors. The multivariable logistic analysis indicated that increasing the odds of in-hospital death associated with higher Sequential Organ Failure Assessment score (odds ratio [OR], 3.077; 95% confidence interval [CI]: 1.848-5.122; P < 0.001), diabetes (OR, 10.474; 95% CI: 1.554-70.617; P = 0.016), and lactate dehydrogenase greater than 245 U/L (OR, 13.169; 95% CI: 2.934-59.105; P = 0.001) on admission. A nomogram was established based on the results of the multivariable analysis. The AUC of the nomogram was 0.970 (95% CI: 0.947-0.992), showing good accuracy in predicting the risk of in-hospital death. CONCLUSIONS: This finding would facilitate the early identification of patients with COVID-19 who have a high-risk for fatal outcome.