There is limited information is known about the composition difference of the gut microbiota in patients with constipation and healthy controls. Here, the faecal 16S rRNA fastq sequence data of ...microbiota from the publicly available American Gut Project (AGP) were analysed. The tendency score matching (PSM) method was used to match in a 1:1 manner to control for confounding factors age, gender, body mass index (BMI), and country. A total of 524 participants including 262 patients with constipation and 262 healthy controls were included in this analysis. The richness and evenness of the gut microbiota in the constipation group were significantly lower than those in the control group. The dominant genera in the constipation group include Escherichia_Shigella, Pseudomonas, and Citrobacter. The dominant genera in the control group include Faecalibacterium, Prevotella, Roseburia, Clostridium_XlVa, and Blautia. The abundance of three butyrate production-related pathways were significantly higher in the constipation group than in the control groups. There was no significant difference in the diversity and gut microbiota composition in patients with constipation at different ages. In conclusion, patients with constipation showed gut microbiota and butyrate metabolism dysbiosis. This dysbiosis might provide a reference for the diagnosis and clinical therapy of diseases.
Purple passion fruit (Passiflora edulis Sims) is a perennial climbing vine native to South America that is grown worldwide as an edible tropical fruit with excellent nutritional value and high ...economic value (Zibadi et al. 2007). With the increasing expansion of the plantation area in China, considerable economic loss caused by collar rot has attracted wide attention. From 2018-2020, collar rot resulted in the death of many plants of P. edulis 'Mantianxing', a commercial cultivar in China, in southwest China's Yunnan province. The disease spread quickly, and field incidence reached more than 50%. Stem rot symptoms were observed at the base of the stem, about 5-10 cm from the ground, resulting in wilting, defoliation, and death of plants. Representative symptomatic samples were collected from the base of five plants, surface disinfested for 30 seconds with 75% ethanol and 15 min with 10% hypochlorite, washed three times with sterile distilled water, then transferred to potato dextrose agar (PDA) dishes. After 2 days in the dark at 28℃, emerging fungal colonies were purified on new PDA dishes cultured at 28℃ for 7 days. The mycelia were flocculent. The color of the surface and the reverse colony was white and cream, respectively. On synthetic nutrient agar (SNA) medium, microconidia were oval, ellipsoidal or reniform, 0- or 1-septate, and 6.7-23.1 μm in length (n>30); macroconidia were straight to slightly curved, 3- or 5-septate, and 30.8-53.9 μm in length (n>30). Genomic DNA, extracted from six isolates, was amplified with three pairs of primers, ITS1 and ITS4 (White et al. 1990) , EF1-728F and EF1-986R (Carbone and Kohn 1999), and fRPB2-5F and fRPB2-7cR (Liu et al. 1999). The amplicons from all six isolates were sequenced and identical sequences obtained. The sequence of one representative isolate was uploaded to NCBI (National Center for Biotechnology Information) and analyzed with BLASTn in the Fusarium MLST database (https://fusarium.mycobank.org). The sequence of the internal transcribed spacer 1 (ITS1) region (GenBank MN944550) showed 99.1% (449/453 bp) identity to Fusarium solani strain NRRL 53667 (syn: Neocosmospora solani, GenBank MH582405). The sequence of the translation elongation factor-1 (EF-1) gene (GenBank MN938933) showed 97.8% identity (263/269 bp) to F. solani strain NRRL 32828 (GenBank DQ247135). The sequence of the second largest subunit of RNA polymerase Ⅱ (RPB2) gene (GenBank MW002686) showed 98.7% identity (810/821 bp) to F. solani strain NRRL 43441 (GenBank MH582407). Based on a multilocus phylogenetic analysis of the ITS1, EF-1 and RPB2 sequences, coupled with the morphological characteristics, the isolate (designated as NsPed1) was considered to be Neocosmospora solani (syn: Fusarium solani) (Crespo et al. 2019). Subsequently, three-month-old healthy seedlings and 45-day-old cuttings of P. edulis 'Mantianxing' plants were inoculated with the isolate NsPed1 to test its pathogenicity. Stems were wounded, approximately 1-2 mm deep, in the collar region of plants at 2 cm above the soil. A disk (9 mm in diameter) of NsPed1-colonized PDA was placed on the wound. Sterile PDA served as controls. All plants were kept in a growth chamber with 28-30°C, 60% relative humidity, and 16/8-h light/dark photoperiod. Fifteen plants were used for each treatment and replicated three times. Two weeks after inoculation, the stems of the inoculated plants turned brown with a lesion, 2-5 cm in length, and the leaves wilted. These symptoms were similar to those of the diseased plants in the field. The control plants were asymptomatic. N. solani NsPed1 was re-isolated from the infected plants, satisfying Koch's postulates. Taken together, N. solani NsPed1 was identified as the causal pathogen of collar rot in P. edulis 'Mantianxing'. Knowledge of the causal organism of collar rot in purple passion fruit will lead to improved measures to prevent and control the disease in China and other countries.
It is a great challenge to improve the strength of disc superalloys without great loss of plasticity together since the microstructures benefiting the strength always do not avail the plasticity. ...Interestingly, this study shows that the trade-off relationship between strength and plasticity can be broken through decreasing stacking fault energy (SFE) in newly developed Ni-Co based disc superalloys. Axial tensile tests in the temperature range of 25 to 725 °C were carried out in these alloys with Co content ranging from 5% to 23% (wt.%). It is found that the ultimate tensile strength (UTS) and uniform elongation (UE) are improved synchronously when microtwinning is activated by decreasing the SFE at 650 and 725 °C. In contrast, only UTS is improved when stacking fault (SF) dominates the plastic deformation at 25 and 400 °C. These results may be helpful for designing advanced disc superalloys with relatively excellent strength and plasticity simultaneously.
The traditional way to study Sources–Receptor Relationships (SRRs) of wet deposition is based on sensitivity simulation, which has weakness in dealing with the non-linear secondary formation ...pollutants (e.g. ozone and nitrate). An on-line source tracking method has been developed in the Nested Air Quality Prediction Modeling System (NAQPMS) coupled with cloud-process module for the first time. The new model can not only quantify the total volume of the sulfate, nitrate and ammonium wet deposition with more accuracy, but also trace these acidic species to their emitted precursors. Compared with previous studies, our result clearly shows: (1) East China and Central China, which are the two primary export regions, have 15–30% and 10% effect on wet deposition in other areas, respectively; (2) Besides the above two regions, the total acid deposition in Southwestern and Northeastern China have reached or exceeded the critical loads under their own environmental conditions.
•We updated NAQPMS model so that it can trace the secondary formation species at real time.•We modeled the acidic deposition and the SRRs based on the updated NAQPMS.•Eastern and Central China are the highest export regions in wet deposition of acidic substances.•The total acidic deposition in Southwestern and Northeastern China exceeded the critical loads.
The wet deposition of acidify substances and their SRRs over China have been studied using the updated NAQPMS.
In the present work, we carried out an experimental analysis on the thermal performance of a windowed volumetric solar receiver (WVSR). A prototype was designed and tested in a dish concentrator ...system. Three silicon carbide (SiC) absorber slabs with different typical pore structures were tested. A unified theoretical model adequately considering the overall heat transfer processes for the WVSR is first put forward. The key component, a windowed cavity incorporated with the irradiated surface of the absorber was modeled in a coupled radiative-convection boundary condition, which detailedly concerning the porous surface structure of the absorber under local thermal non-equilibrium conditions. Model authentication was achieved by comparing the experimental and theoretical results. The maximum temperature of the outlet air was over 1003 K, and the best thermal efficiency (solar to thermal) obtained was 63.61%. The maximum deviations in the results were 9.4% and 2.3% for the temperature of the back wall and the outlet air, respectively. In terms of the thermal efficiency, the maximum deviation was 5.35%. These results demonstrate the feasibility of our model applied to describe the overall transport process from solar to thermal energy in a receiver.
•A prototype test is presented on a windowed volumetric solar receiver (WVSR).•A uniform theoretical heat transfer model for WVSR is first put forward.•Boundary condition coupling the porous absorber surface and window is developed.•Model validation is finished by comparing the experimental and numerical results.
Functional gradient material (FGM) is an innovative material possessing gradient properties using different premixed proportions of two or multiple metallic powders. In the present work, novel FGMs ...of Ti6Al4V/316L composites with different premixed proportions were successfully fabricated by laser melting deposition (LMD). The microstructure and phase evolution were characterized by means of optical microscopy (OM), X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Subsequently, the effects of different Ti6Al4V/316L proportions on micro-hardness, tensile and wear properties were systematically investigated. The results showed that the grain refinement process had experienced three following stages of cellular crystal, columnar crystal and equiaxed crystal with increasing the 316L content. Finally, the LMD-processed FGM specimen with a premixed proportion, 85 wt % Ti6Al4V/15 wt % 316L, is achieved, and exhibits the optimal wear resistance.
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•Effects of phase transformation on the microstructure were investigated.•The tensile properties of specimens with different powder mixture were discussed.•Effects of different content of 316L on wear resistance were revealed.•Relationship between the content of 316L and micro-hardness was characterized.•The specimen with best mechanical properties was achieved.
Background. Seven persons in one family living in eastern China developed fever and thrombocytopenia during May 2007, but the initial investigation failed to identify an infectious etiology. In ...December 2009, a novel bunyavirus (designated severe fever with thrombocytopenia syndrome bunyavirus SFTSV) was identified as the cause of illness in patients with similar clinical manifestations in China. We reexamined this family cluster for SFTSV infection. Methods. We analyzed epidemiological and clinical data for the index patient and 6 secondary patients. We tested stored blood specimens from the 6 secondary patients using real time reverse transcription polymerase chain reaction (RT-PCR), viral culture, genetic sequencing, micro-neutralization assay (MNA), and indirect immunofluorescence assay (IFA). Results. An 80-year-old woman with fever, leucopenia, and thrombocytopenia died on 27 April 2007. Between 3 and 7 May 2007, another 6 patients from her family were admitted to a local county hospital with fever and other similar symptoms. Serum specimens collected in 2007 from these 6 patients were positive for SFTS viral RNA through RT-PCR and for antibody to SFTSV through MNA and IFA. SFTSV was isolated from 1 preserved serum specimen. The only shared characteristic between secondary patients was personal contact with the index patient; none reported exposure to suspected animals or vectors. Conclusions. Clinical and laboratory evidence confirmed that the patients of fever and thrombocytopenia occurring in a family cluster in eastern China in 2007 were caused by a newly recognized bunyavirus, SFTSV. Epidemiological investigation strongly suggests that infection of secondary patients was transmitted to family members by personal contact.
The combined and individual hydrological impacts of climate variation and urbanization have been extensively discussed over the past few decades, yet little is known about the relative impact of ...each. In this paper we took one of the most developed regions worldwide, Yangtze River Delta, as an example to analyse the long-term relative impacts of precipitation and urbanization change on water level alterations, based on precipitation, water level series, and annual impervious area data from 1960 to 2015. Abrupt changes detection in the water level series divided the data into the pre-impact period (1960–1988) and impacted period (1989–2015), and relative impacts of precipitation and urbanization on the water level increase from pre-impacted to impacted period, as well as their spatial and seasonal variations were estimated with the elasticity method. The results indicated that the urbanization change showed no distinct influence on the water level rise in the pre-impact period, while the precipitation played distinct roles only during summer months in the impacted period; the precipitation dominated two thirds of the water level rise in flood season, and in non-flood season the urbanization controlled the two thirds of the water level rise; spatially, the water level variations in old and new urban area were dominated by precipitation and urbanization process respectively; compared with precipitation amount, the water level correlated more strongly to the contribution ratio of precipitation. The results would provide a good reference for flood control and water resource management in the river basin, especially in the economically developed areas.
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•Pre-impact (1960–1988) and impacted period (1989–2015)•Urbanization contributed in impacted period, precipitation contributed from Apr to Nov.•Flood season: precipitation contributed two thirds of water level rise.•Non-flood season: urbanization contributed two thirds of water level rise.•Spatially, western basin dominated by precipitation, eastern basin controlled by urbanization.
•Fine and coarse columnar dendritic microstructure of as-deposited IN718 superalloy are respectively obtained.•The influence of the average widths of columnar grains of LSF IN718 superalloy is ...studied.•The tensile microstructure of as-deposited IN718 superalloy is proposed.
The present work studies the influence of various parameters on the as-deposited Inconel 718 (IN718) superalloy using laser solid forming method. The microstructure and mechanical properties of IN718 superalloys were analysed. Fine and coarse columnar dendritic microstructure of as-deposited IN718 superalloy are respectively obtained at different laser power and laser beam diameter. The average widths of columnar grains of LSF IN718 superalloy enlarge with increasing laser power and laser beam diameter. The formation of Nb and Mo rich Laves phase in the inter-dendritic regions is found. The highest yield strength and ultimate tensile strength is about 729MPa and 936MPa, respectively.
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