34 research outputs found
Study on Construction Resource Optimization and Uncertain Risk of Urban Sewage Pipe Network
With considering sewage pipe network upgrading projects in the âvillagesâ in cities, the optimization of construction resources and the assessment of delay risks could be achieved. Based on the schedule-cost hypothetical theory, the mathematical model with constraint indicators was established to obtain the expression of optimal resource input, and conclude the method to analyze the schedule uncertainties. The analysis showed that cyclical footage of pipe could be regarded as a relatively fixed value, and the cost can be regarded as a function that depending on the number of working teams. The optimal number of teams and the optimal schedule occurred when the minimum total cost achieved. In the case of insufficient meteorological data, the Monte Carlo simulation method and uncertainty analysis method can be applied to assess the impact of rainfall on the total construction period, correspondingly the probability of such risk could be derived. The calculation showed that the risk of overdue completion varied significantly according to the construction starting time. It was necessary to take rainfall risk into consideration and make corresponding strategies and measures
Genome-wide functional annotation and structural verification of metabolic ORFeome of Chlamydomonas reinhardtii
<p>Abstract</p> <p>Background</p> <p>Recent advances in the field of metabolic engineering have been expedited by the availability of genome sequences and metabolic modelling approaches. The complete sequencing of the <it>C. reinhardtii</it> genome has made this unicellular alga a good candidate for metabolic engineering studies; however, the annotation of the relevant genes has not been validated and the much-needed metabolic ORFeome is currently unavailable. We describe our efforts on the functional annotation of the ORF models released by the Joint Genome Institute (JGI), prediction of their subcellular localizations, and experimental verification of their structural annotation at the genome scale.</p> <p>Results</p> <p>We assigned enzymatic functions to the translated JGI ORF models of <it>C. reinhardtii</it> by reciprocal BLAST searches of the putative proteome against the UniProt and AraCyc enzyme databases. The best match for each translated ORF was identified and the EC numbers were transferred onto the ORF models. Enzymatic functional assignment was extended to the paralogs of the ORFs by clustering ORFs using BLASTCLUST.</p> <p>In total, we assigned 911 enzymatic functions, including 886 EC numbers, to 1,427 transcripts. We further annotated the enzymatic ORFs by prediction of their subcellular localization. The majority of the ORFs are predicted to be compartmentalized in the cytosol and chloroplast. We verified the structure of the metabolism-related ORF models by reverse transcription-PCR of the functionally annotated ORFs. Following amplification and cloning, we carried out 454FLX and Sanger sequencing of the ORFs. Based on alignment of the 454FLX reads to the ORF predicted sequences, we obtained more than 90% coverage for more than 80% of the ORFs. In total, 1,087 ORF models were verified by 454 and Sanger sequencing methods. We obtained expression evidence for 98% of the metabolic ORFs in the algal cells grown under constant light in the presence of acetate.</p> <p>Conclusions</p> <p>We functionally annotated approximately 1,400 JGI predicted metabolic ORFs that can facilitate the reconstruction and refinement of a genome-scale metabolic network. The unveiling of the metabolic potential of this organism, along with structural verification of the relevant ORFs, facilitates the selection of metabolic engineering targets with applications in bioenergy and biopharmaceuticals. The ORF clones are a resource for downstream studies.</p
Edgetic perturbation models of human inherited disorders
Cellular functions are mediated through complex systems of macromolecules and metabolites linked through biochemical and physical interactions, represented in interactome models as ânodes' and âedges', respectively. Better understanding of genotype-to-phenotype relationships in human disease will require modeling of how disease-causing mutations affect systems or interactome properties. Here we investigate how perturbations of interactome networks may differ between complete loss of gene products (ânode removal') and interaction-specific or edge-specific (âedgetic') alterations. Global computational analyses of âŒ50 000 known causative mutations in human Mendelian disorders revealed clear separations of mutations probably corresponding to those of node removal versus edgetic perturbations. Experimental characterization of mutant alleles in various disorders identified diverse edgetic interaction profiles of mutant proteins, which correlated with distinct structural properties of disease proteins and disease mechanisms. Edgetic perturbations seem to confer distinct functional consequences from node removal because a large fraction of cases in which a single gene is linked to multiple disorders can be modeled by distinguishing edgetic network perturbations. Edgetic network perturbation models might improve both the understanding of dissemination of disease alleles in human populations and the development of molecular therapeutic strategies
Human Adipose Mesenchymal Stem Cells Show More Efficient Angiogenesis Promotion on Endothelial Colony-Forming Cells than Umbilical Cord and Endometrium
Angiogenesis is a complicated process in which perivascular cells play important roles. Multipotent mesenchymal stem/stromal cells (MSCs) from distinct tissues have been proved to be proangiogenic and share functional properties and gene expression profiles with perivascular cells. However, different tissues derived MSCs may exhibit different potential for clinical applications. Accordingly, comparative studies on different MSCs are essential. Here, we characterized MSCs from adipose (ADSCs), umbilical cord (UCMSCs), and endometrium (EMSCs) in terms of the surface antigen expression, differentiation ability, and the ability of angiogenesis promotion on endothelial colony-forming cells (ECFCs) both in vitro and in vivo. No significant differences in immunophenotype and differentiation were observed. In addition, three types of MSCs all located around tubular-like structures formed by ECFCs in coculture system on matrigel. But ECFCs seeded on ADSCs monolayer formed more organized capillary-like network than that on UCMSCs or EMSCs. When suspended with ECFCs in matrigel and implanted into nude mice, ADSCs promoted more functional vessel formation after 7 days. Moreover, in murine hindlimb ischemia model, cotransplantation of ECFCs with ADSCs was significantly superior to UCMSCs and EMSCs in promoting perfusion recovery and limb salvage. Furthermore, ADSC-conditioned medium (CM) contained more proangiogenic factors (such as vascular endothelial growth factor-A, platelet-derived growth factor BB, and basic fibroblast growth factor) and less inhibitory factor (such as thrombospondin-1), when compared with UCMSC-CM and EMSC-CM. And ADSC-CM more durably stabilized the vascular-like structures formed by ECFCs on matrigel and promoted ECFCs migration more efficiently. In summary, MSCs from adipose show significantly efficient promotion on angiogenesis both in vitro and in vivo than UCMSCs and EMSCs. Hence, ADSCs may be recommended as a more suitable source for treating hindlimb ischemia
Rapid evolution of T2/S-RNase genes in Fragaria linked to multiple transitions from self-incompatibility to self-compatibility
The T2/RNase gene family is widespread in eukaryotes, and particular members of this family play critical roles in the gametophytic self-incompatibility (GSI) system in plants. Wild diploid strawberry (Fragaria) species have diversified their sexual systems via self-incompatible and self-compatible traits, yet how these traits evolved in Fragaria remains elusive. By integrating the published and de novo assembled genomes and the newly generated RNA-seq data, members of the RNase T2 gene family were systematically identified in six Fragaria species, including three self-incompatible species (Fragaria nipponica, Fragaria nubicola, and Fragaria viridis) and three self-compatible species (Fragaria nilgerrensis, Fragaria vesca, and Fragaria iinumae). In total, 115 RNase T2 genes were identified in the six Fragaria genomes and can be classified into three classes (IâIII) according to phylogenetic analysis. The identified RNase T2 genes could be divided into 22 homologous gene sets according to amino acid sequence similarity and phylogenetic and syntenic relationships. We found that extensive gene loss and pseudogenization coupled with small-scale duplications mainly accounted for variations in the RNase T2 gene numbers in Fragaria. Multiple copies of homologous genes were mainly generated from tandem and segmental duplication events. Furthermore, we newly identified five S-RNase genes in three self-incompatible Fragaria genomes, including two in F. nipponica, two in F. viridis, and one in F. nubicola, which fit for typical features of a pistil determinant, including highly pistil-specific expression, highly polymorphic proteins and alkaline isoelectric point (pI), while no S-RNase genes were found in all three self-compatible Fragaria species. Surprisingly, these T2/S-RNase genes contain at least one large intron (>10 kb). This study revealed that the rapid evolution of T2/S-RNase genes within the Fragaria genus could be associated with its sexual mode, and repeated evolution of the self-compatible traits in Fragaria was convergent via losses of S-RNase
Study on instability mechanism of KCl/PHPA drilling waste fluid
The KCl/PHPA waste drilling fluid is produced during drilling operations in Bohai Oilfield, China, which cannot be directly used or discharged, it needs to be flocculated. In order to know the aggregation mechanism of colloidal particles in KCl/PHPA drilling fluid, the calculation method of zeta potential and the relationship between the stability of waste fluid and zeta potential are discussed in detail in this article. The process of decreasing the zeta potential of waste fluid due to the addition of cationic polyacrylamide is called instability. The process in which unstable particles aggregate into larger particles is called coagulation, and the process in which unstable particles aggregate into large flocs is called flocculation. According to the types of treatment agents in KCl/PHPA waste drilling fluid, the structure and energy changes formed between low-viscosity polyanionic cellulose, partially hydrolyzed polyacrylamide, xanthan gum, starch, and water molecules are constructed. The energy of the four treatment agent systems decreased by 21.4â67.5% after the cationic polyacrylamide was added. The reduction of system energy reduced the repulsive force between colloidal particles in the waste fluid and promoted the agglomeration of colloidal particles. The agglomeration mechanism of waste liquid particles was obtained
Surface and bulk reconstruction of CoW sulfides during pH-universal electrocatalytic hydrogen evolution
Electrocatalytic water splitting is an efficient means of producing energy carriers, such as H2. The hydrogen evolution reaction (HER) requires high-efficiency electrocatalysts. Understanding the active site structures of the HER electrocatalysts is essential for the rational design and development of water splitting devices. In this study, porous CoW sulfides were employed as model electrocatalysts for pH-universal HER. Multiple characterization studies, such as X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and operando X-ray diffraction, were systematically used to investigate the reconstruction of the active species at the surface and in the bulk. The results show that during the HER, the structural transformation of the species CoW sulfides is strongly dependent on the pH of the electrolyte. Electrolytes of varying pH lead to varied reconstruction and influence the true catalytically active species responsible for the HER. The surface and the bulk of the electrocatalysts transform to different oxides/hydroxides when subjected to the HER. This is the first time that the pH-dependent bulk and surface structural evolution in the HER has been revealed. This study reveals the reconstruction and potential active site evolution of mixed-metal sulfides for the HER. We believe that the present study not only provides an idealized âpre-catalystâ for pH-universal highly-efficient HER, but also provides a thorough understanding about the identification of the real active sites and the mechanism of the structural evolution of the electrocatalysts during hydrogen evolution
MetalâOrganic Framework-Derived NickelâCobalt Sulfide on Ultrathin Mxene Nanosheets for Electrocatalytic Oxygen Evolution
Water oxidation is
the key process for many sustainable energy technologies containing
artificial photosynthesis and metalâair batteries. Engineering
inexpensive yet active electrocatalysts for water oxidation is mandatory
for the cost-effective generation of solar fuels. Herein, we propose
a novel hierarchical porous NiâCo-mixed metal sulfide (denoted
as NiCoS) on Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene via a metalâorganic framework (MOF)-based approach.
Benefiting from the unique structure and strong interfacial interaction
between NiCoS and Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> sheets, the hybrid guarantees an enhanced active surface area
with prominent charge-transfer conductivity and thus a superior activity
toward oxygen evolution reactions (OERs). Impressively, the hierarchical
NiCoS in the hybrid is converted to nickel/cobalt oxyhydroxideâNiCoS
assembly (denoted as NiCoOOHâNiCoS) by OER measurement, where
NiCoOOH on the surface is confirmed as the intrinsic active species
for the consequent water oxidation. The hybrid material is further
applied to an air cathode for a rechargeable zincâair battery,
which exhibits low charging/discharging overpotential and long-term
stability. Our work underscores the tuned structure and electrocatalytic
OER performance of MOF derivatives by the versatility of MXenes and
provides insight into the structureâactivity relationship for
noble metal-free catalysts
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Induction of apoptosis by an oleanolic acid derivative in SMMC-7721 human hepatocellular carcinoma cells is associated with mitochondrial dysfunction
The aim of the present study was to investigate the effects of an oleanolic acid derivative, a novel antitumor drug, on the growth of SMMC-7721 human hepatocellular carcinoma cells and the underlying mechanism. An MTT assay was performed to determine the cytotoxicity of the oleanolic acid derivative. Cell membrane integrity was assessed using fluorescence microscopy to assess the uptake of annexin V-FITC/propidium iodide (PI). Western blotting was used to detect the apoptosis-associated proteins B cell lymphoma-2 (Bcl-2), Bax, caspase-9 and caspase-3. A spectrophotometer was used to analyze the intracellular adenosine triphosphate (ATP) expression level. The loss of mitochondrial membrane potential was detected by performing the JC-1 assay. ELISA was used to evaluate the content of cytochrome c (Cyt-C). The oleanolic acid derivative reduced the cell viability of SMMC-7721 cells in a dose- and time-dependent manner. The half maximal inhibitory concentration values of the oleanolic acid derivative in SMMC-7721 cells at 24, 48 and 72 h were 26.80, 11.85, and 6.66 ”M, respectively. The antiapoptotic-protein Bcl-2 was downregulated, and the proapoptotic protein Bax was upregulated following treatment with the oleanolic acid derivative for 48 h. The oleanolic acid derivative induced the cleavage of caspase-9 and caspase-3 as well as promoted annexin V-FITC/PI uptake in SMMC-7721 cells. Furthermore, treatment of SMMC-7721 cells with the oleanolic acid derivative induced a reduction of the intracellular ATP expression level, loss of ÎΚm and Cyt-C release from the mitochondria. The oleanolic acid derivative induced apoptosis in SMMC-7721 human cells. Mitochondrial dysfunction was involved in the anticancer effects of this derivative on SMMC-7721 human cells
The status of emotional labour and its influence on job burnout among village doctors during the COVID-19 pandemic in China: a cross-sectional study
Abstract Background Village doctors in China are not only the gatekeepers of rural residents' health but also the net bottom of the medical security system. However, emotional labour is increasingly threatening the stability of the rural primary medical system. In addition, the ongoing coronavirus disease 2019 (COVID-19) pandemic has further exposed the vulnerability of human resources in China's rural health system. This study aims to evaluate the current situation of emotional labour among village doctors and explore the impact of emotional labour on job burnout during the COVID-19 pandemic in China. Methods A cross-sectional survey was conducted in December 2021 in Shandong Province. We used structured questionnaires to collect data, including sociodemographic characteristics, emotional labour, and job burnout. Data were analysed by t test, analysis of variance (ANOVA), Pearson correlation analysis, and hierarchical multiple linear regression. Results A total of 1,093 village doctors from Shandong Province participated in the study. More than half of the participants were male (62.40%) and were between 41 and 50 years old (53.43%). The total mean score of emotional labour was 3.17â±â0.67, of which the surface acting (SA) score was 2.28â±â0.90, and the deep acting (DA) score was 3.91â±â0.93. There were significant differences in SA according to gender and work content (Pâ<â0.05) and in DA according to gender, age, education level, and work content (Pâ<â0.05). Pearson correlation analysis showed that SA was positively correlated with job burnout (Pâ<â0.001), and DA was negatively correlated with job burnout (Pâ<â0.001). Hierarchical multiple linear regression analysis revealed that 29% of the variance in job burnout is attributable to SA (ÎČâ=â0.530, Pâ<â0.001) and DA (ÎČâ=â-0.154, Pâ<â0.001). Conclusion Village doctors in Shandong Province performed moderate levels of emotional labour during the COVID-19 pandemic. SA had a significant positive effect on job burnout, while DA had a significant negative effect on job burnout among village doctors. Administrators should enhance training on emotional labour for village doctors to play a positive role in alleviating their job burnout