This study investigates the trunnion crack of a 50 MW hydraulic turbine in the generator guide bearing. The crack area has been examined metallographically and the fixing method for the the trunnion crack has been explained. Result of the study shows that the reason for the formation of the bearing trunnion crack can be the thermal stresses that occur during the mounting of the bearing trunnion to the turbine shaft and the material fatigue that occurs during the operation of the hydraulic turbine.
Quantifying the influences of factors on Normalized Difference Vegetation Index (NDVI) changes is critical to understanding the functions of terrestrial ecosystems. However, identification of the causes responsible for vegetation changes is still limited. We applied the Geographic Detector to quantify the individual and interactive influences of human and natural factors on the change in the vegetation NDVI,and determined the optimal characteristics of factors that are beneficial to vegetation growth. Our results show that vegetation cover for 2000 and 2015 is in good condition, and regions with NDVI > 0.6 showed a significant transformation, whereas areas with mid-high vegetation or lower and areas with high vegetation increased and decreased, respectively. Vegetation cover changes were mainly in the upper reaches of the Minjiang River and its tributaries. We illustrated that the elevation, annual average temperature, and soil type can satisfactorily account for the vegetation changes with explanatory powers of 60%, 52% and 39% or larger, respectively. Land use types and distance from the road had enhanced influences in the NDVI changes with explanatory powers of less than 16% and 12%, respectively. We proposed that there are interactive effects between the impact factors on vegetation NDVI, and the synergistic effects of the impact factors showed mutual enhancement and nonlinear enhancement. The interaction between the two factors strengthens the influence of each individual factor on the vegetation changes. This study provides important references that policymakers can use to intervene and promote vegetation change for ecological protection and vegetation restoration, while alleviating environmental degradation.
Objective: To study the pregnancy outcomes of vaginal delivery and neonatal prognosis during the epidemic of COVID-19, and to summarize the management of vaginal delivery. Design: Retrospective review of medical records Setting: Zhongnan Hospital of Wuhan University, Wuhan, China Sample: Pregnant women (n=63) with vaginal delivery from January 20 to March 02, 2020 Methods: Retrospectively analyzed the outcomes of vaginal delivery in 10 pregnant women with clinical diagnosis of COVID-19 and 53 pregnant women without COVID-19 from January 20 to March 02, 2020. The related laboratory tests, imaging tests and the SARS-CoV-2 nucleic acid tests results were also analyzed in neonates delivered by pregnant woman with clinical diagnosis of COVID-19. Main Outcome Measures: Delivery outcomes and neonatal outcomes Results: (1) There were no significant differences in gestational weeks, postpartum hemorrhage (245±49.72ml vs 237±85.99ml), and perineal resection rates (10% vs 7.55%) between the two groups. (2) There were no significant differences in birth weight of neonates(3283±449g vs 3274±456g) and neonatal asphyxia between the two groups. Results of the blood routine, throat swabs test for nucleic acid of SARS-CoV-2 and chest radiograph of neonates delivered by pregnant woman with clinical diagnosis of COVID-19 showed no signs of the SARS-CoV-2 infection. Conclusions: Pregnant women with mild COVID-19 can delivery vaginally without exacerbation of COVID-19 and without increasing the risk of SARS-CoV-2 infection in the neonates. Keywords: COVID-19；outcomes of vaginal delivery；neonatal prognosis；management Tweetable abstract：Pregnant women with mild COVID-19 can try vaginal delivery
This paper presents the optimum exponent of Barlat-Lian (1989) yield function which defines the yield surface shape for different materials under plane stress condition. The predictions of the optimum exponents of Barlat-Lian (1989) yield function are derived and then compared with the experimental data for these materials to allow a better representation of the plastic behavior of the orthotropic sheet metals. The results show that contrary to what it was supposed to be up to now the optimum exponent of Barlat-Lian could be have different values for verity of face and body centered cubic types of materials case by case.
Background and purpose: Amphetamine use disorder is a serious health concern, but surprisingly little is known about the vulnerability to the moderate and compulsive use of this psychostimulant and its underlying mechanisms. Previous research showed that inherited serotonin transporter (SERT) down-regulation increases the motor response to cocaine, as well as moderate and compulsive intake of this psychostimulant. Here we sought to investigate whether these findings generalize to amphetamine and the underlying mechanisms in the nucleus accumbens. Experimental Approach: In serotonin transporter knockout (SERT−/−) and wild-type control (SERT+/+) rats we assessed the locomotor response to acute amphetamine (AMPH) and intravenous AMPH self-administration under short access (ShA: 1 hr daily sessions) and long access (LgA: 6 hr daily sessions) conditions. 24 hrs after AMPH self-administration we analysed the expression of glutamate system components in the nucleus accumbens shell and core. Key results: We found that SERT−/− animals displayed an increased AMPH-induced locomotor response and increased AMPH self-administration under LgA, but not ShA conditions. Further, we observed changes in the vesicular and glial glutamate transporters, NMDA and AMPA receptor subunits and their respective postsynaptic scaffolding proteins as function of serotonin transporter genotype, AMPH exposure (baseline, ShA and LgA) and nucleus accumbens sub region. Conclusion and implications: We demonstrate that SERT gene deletion increases the psychomotor and reinforcing effects of AMPH, and that the latter is potentially mediated, at least in part, by homeostatic changes in the glutamatergic synapse of the nucleus accumbens shell and/or core.
Background and purposes Preeclampsia(PE) is associated with abnormal function of various factors in placentas. 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) is abundantly expressed in placenta and controls the local availability of glucocorticoids. We aimed to elucidate the role of 11β-HSD2 in the pathogenesis of PE. Experimental approach Pregnant rats were administrated with 11β-HSD2 inhibitor carbenoxolone (CBX) subcutaneously or by placenta-targeted delivery system. The blood pressure, renal and placental morphology, placental blood flow and circulatory levels of fms-like tyrosine kinase 1 (sFlt1) and placental growth factor (PlGF) were subsequently examined. Cultured human trophoblasts were used to investigate the role of 11β-HSD2 in migration and invasion function and sFlt1 release in vitro. Key results Subcutaneous administration and placenta-targeted delivery of CBX resulted in the hallmark of PE-like features including hypertension, proteinuria, renal damages, elevated circulatory sFlt1 level and increased sFlt1/ PlGF in pregnant rats. These animals displayed reduced trophoblast invasion in uterus, impaired spiral artery remodeling and reduced placental blood flow. In vitro study showed that 11β-HSD2 dysfunction inhibited migration and invasion of the extravillous trophoblasts and promoted sFlt1 release in syncytiotrophoblasts. Mechanically, sFlt1 release induced by 11β-HSD2 dysfunction is mediated by enhancement of a disintegrin and metalloprotease (ADAM)17 transcription in placenta.
BACKGROUND AND PURPOSE In this study, we compared the different effect of Dimethyl-2-ketoglutarate (DMKG) on energy metabolism, autophagy, and apoptosis between parental and doxorubicin-resistant liver cancer cell lines. EXPERIMENTAL APPROACH In the energy metabolism section, cell viability, adenosine triphosphate (ATP) level, doxorubicin (DOX) content, energy metabolism phenotype, and enzymes expression were measured. In the autophagy part, autophagy vesicles were observed, enzymes expression and cell viability were detected. Apoptosis rate and expression of enzymes were detected in the apoptosis part. KEY RESULTS DMKG can directly act on ATP synthase and prolyl hydroxylase, affecting the cellular oxidative phosphorylation and glycolysis levels, respectively, in both SMMC-7721 and SMMC-7721/DOX cells. However, its practical effects depend on the function of the mitochondrial malate-aspartate shuttle. Furthermore, ATP-reduced cell autophagy had partial anti-apoptotic effects in SMMC-7721 cells, which is an important reason for the weak inhibition of cell viability observed at low doses of DMKG. In contrast, DMKG showed no significant effect on autophagy but a high cell death rate in SMMC-7721/DOX cells. Induced high expression levels of p-AMPK, p-mTOR, and Bcl-2 could inhibit DMKG-induced apoptosis in SMMC-7721 cells. However, activation of Caspase-3 was the most important molecular effect that was observed in relation to the DMKG-induced apoptosis in SMMC-7721/DOX cells. CONCLUSIONS AND IMPLICATIONS These results suggest that inhibition of energy metabolism can reduce the effects of autophagy in DOX resistant cells, which could improve the therapeutic outcomes and reverse the resistance to chemotherapeutic drugs. This article provides a new idea and method for reversing tumor resistance.
Background and purpose. The purpose of this study was to evaluate the effects of CBD on the behavioural and gene expression changes induced by a new animal model of spontaneous cocaine withdrawal. Experimental approach. Six hours after cessation of progressive increase of cocaine administration for 12 days (15 mg·kg-1·day-1 to 60 mg·kg-1·day-1, i.p.), spontaneous cocaine withdrawal was evaluated in male mice. The effects of CBD (10, 20 and 40 mg·kg-1, i.p.) were evaluated on cocaine withdrawal-induced alterations in motor activity, somatic signs and anxiety-like behaviour. Furthermore, gene expression changes in dopamine transporter (DAT) and tyrosine hydroxylase (TH) in the ventral tegmental area, and in cannabinoid receptors 1 (CNR1) and 2 (CNR2) in the nucleus accumbens were analysed by real-time PCR. Key results. Mice exposed to the spontaneous cocaine withdrawal model showed increased motor activity, somatic withdrawal signs and high anxiety-like behaviour. Interestingly, the administration of CBD normalized motor and somatic signs disturbances and induced an anxiolytic effect. Moreover, the administration of CBD blocked the increase of DAT and TH gene expression in mice exposed to the cocaine withdrawal. In addition, the administration of CBD modulated the cocaine withdrawal-induced decrease of CNR1 and induced an additional up-regulation of CNR2 gene expression. Conclusions and implications. These results show behavioural and gene expression alterations in mice exposed to a new model of spontaneous cocaine withdrawal. Interestingly, CBD alleviates cocaine withdrawal-induced behavioural and gene expression alterations suggesting potential for the management of cocaine withdrawal.
Rationale, aims and objectives :Over the past decades, thrombophilia testing in patients with venous thrombo-embolism (VTE) has increased tremendously. However, the role of inherited thrombophilia (IT) in prediction the risk of recurrence remains controversial. Consequently, it is still unclear whether thrombophilia testing influences decisions regarding duration of anticoagulation in clinical practices. The aim of this study was to evaluate the impact if IT on VTE treatment decisions and on predicting the risk of recurrence. Methods : A retrospective longitudinal study (January 2011-Decembre 2016) including 190 patients with confirmed VTE referred from internal medicine department for inherited thrombophilia screening was carried out. Results : The mean age patients was 40.2 years and the sex ratio (M/F) was 0.78. IT was confirmed in 27.5% of patients. A long term anticoagulation was decided in 51.6% of patients with IT. There was no significant difference in the duration of anticoagulation between patients with or without IT. VTE recurrence was recorded in 26 (13.7 %) patients. The 24 years cumulative incidence of recurrence was 9% in patients with IT and 14% in those without. IT was not associated with increased risk of recurrence after treatment withdrawal (Hazard ratio=1.31 IC(0.47-3.63); p=0.6). Conclusion : In clinical practice, IT did not influence anticoagulation duration and was not associated with a higher VTE risk of recurrence. It seems to be less relevant for decision making than presumed.
The ab initio molecular dynamics simulations are performed to study the atomic structures of Co92-xBxTa8 (x = 30, 32.5, 35, 37.5, at.%) glassy alloys. The result shows that the local packing of B-centered clusters is more efficient than that for Co- and Ta-centered clusters. It is also found that B-centered clusters are the primary structure-forming clusters. The Kasper polyhedra with a Voronoi index of <0 3 6 0> and <0 2 8 0> are dominant in B-centered clusters. Specially, the <0 3 6 0> clusters can form a robust network structure, which plays a key role in mechanical properties. Such a network structure has a higher activation barrier for structural rearrangement and a better resist to plastic flow. Thus, the increase in the fraction of <0 3 6 0> with B content would result in an increase in yield strength as well as a sharp decrease in compression plasticity.
Carbon dioxide has attracted considerable attention owing to its physics and abundant polymorphs. Despite decades of extensive experiments and theoretical simulations, the structure and properties of carbon dioxide under extreme pressures and temperatures are yet to be properly understood. Particularly, the intermediate phase IV of solid carbon dioxide, which separates the molecular phases at low pressures from the non-molecular phases at high pressures, has not been fully investigated, and its structure remains controversial. Here, based on the second-order Møller−Plesset perturbation (MP2) theory and the embedded fragment method, we study the crystal structure, equation of state, and Raman spectra of solid carbon dioxide phase IV at high pressures and temperatures. We demonstrate that the solid carbon dioxide phase IV is a molecular structure that remains in a molecular state rather than the bent state shown in other literatures, which is consistent with the experimental work by Datchi et al. and denies the observed results by Park et al. The proposed work is of great significance in determining the structure of the high-pressure phases of carbon dioxide and further exploring the new phase of molecular crystals.
Respiratory infections in general and rhinovirus (RV) infection specifically are the main reason for asthma exacerbation in children. Here we found increased level of Programmed cell death protein 1 ligand (PD-L1) mRNA in total blood cells isolated from pre-school children with virus-induced asthma, with lower FEV1% and with high serum levels of the C-Reactive-Protein (CRP). These data indicate that, in the presence of infection in the airways of preschool children, worse asthma is associated with induced PD-L1 mRNA expression. Further, the activation of regulatory elements that induce IFNβ, a cytokine that is involved in immunity of infections, was found to be associated with better lung function in asthmatic children. Finally, IFN-beta released by peripheral blood Mononuclear cells (PBMC) was found associated with an induced expression of PD-L1mRNA in control but no asthmatic children. These data suggest that improving peripheral blood IFN type I expression in PBMCs in pediatric asthma could improve disease exacerbation because suppressing PDL1 expression in blood cells.
Coronaviruses are a large group of viruses which are found in avian and mammalian species. It has been reported that, the identification and characterization of a novel coronavirus (2019-nCoV) which caused a pandemic of acute respiratory syndrome in humans in Wuhan, China. By 26 January 2020 it has caused 2,050 laboratory-confirmed infections with 56 fatal cases. Furthermore, it was found that 2019-nCoV is 96% identical at the whole-genome level to a bat coronavirus.The new coronavirus SARS-CoV-2 binds with human respiratory cells in order to hijack them to produce more viruses. The new virus attaches to a receptor on respiratory cells called angiotensin-converting ACE2. The most abundant protein in coronavirus is the nucleocapsid protein.
In-crop soil waterlogging caused by extreme rainfall events, high ground water tables, excessive irrigation and lateral ground water flow inhibit potential grain yields. However, the extent to which yield is influenced by the timing and duration of waterlogging relative to crop phenology is unknown. To investigate this, we conducted various waterlogging treatments on a range of modern barley genotypes varying in their waterlogging tolerance, with tolerance conferred through aerenchyma formation under oxygen deficit conditions. Results showed that yield was reduced by 35% in W1 (waterlogging at Zadoks stage (ZS) 12.5 for one month) to 52% in WL3 (waterlogging at ZS 15 for two months) due to fewer spikes/m2 and kernels/spike. Two weeks waterlogging at ear emergency stage had the greatest impact on yield (70% reduction) due to its effect on spikelet fertility and grain filling. Phenology was delayed 1-8 ZS at the end of waterlogging treatments, with the waterlogging-susceptible cultivar Franklin showing the greatest delays, and waterlogging tolerant genotypes capable of AF (Macquarie+, TAMF169) having the least delays (0-4 ZS). Genotypes with the AF QTL (Macquarie+) showed a slight and nonsignificant yield reduction compared with unwaterlogged controls and mitigated around 23% yield loss under early phenological waterlogging stress.
The average lifespan of HIV-infected subjects remains shorter compared to uninfected individuals. Immunosenescence may be responsible for this difference despite effective antiretroviral therapy (ART) with successful viral suppression. Here, we evaluated the effects of HIV and ART exposure on T cell aging in male homosexual HIV subjects. CD4+ T cell activation (HLA-DR+) and senescence (CD57+) markers were analyzed by flow cytometry, and telomere length was quantified by real-time PCR. Specifically, we observed an increase in activation and senescence markers on total CD4+ T cell populations in HIV-infected subjects. We also observed a reduction in senescence markers on terminally differentiated memory T(TemRA) cells and activation markers on central memory T(TCM), effector memory T(TEM), and TemRA cells in ART-treated HIV subjects. Furthermore, we also observed an extension of telomere length in memory CD4+ T cells, rather than naive CD4+ T cells, after viral control by ART. Our results indicate that HIV-infected patients exhibit a premature T cell aging phenotype with accelerated immune senescence. Partial recovery of immune senescence and differentiation aberrances is achieved in CD4+ T cells in HIV patients on ART. Overall, these results suggest that HIV infection, rather than ART exposure, influences the T cell aging process.
Background: Cladribine (CdA), an oral prodrug approved for the treatment of relapsing multiple sclerosis, selectively depletes lymphocytes. CdA passes the blood-brain barrier suggesting a potential effect on CNS resident cells. Objective: We examined, if CdA modifies the phenotype and function of naïve and activated primary mouse microglia, when applied in different concentrations including 0.1-1 µM that putatively overlaps human CSF concentrations. Methods: Primary microglia cultures without stimulation or in the presence of proinflammatory lipopolysaccharide (LPS) or anti-inflammatory IL-4 were co-treated with different concentrations of CdA for 24 hours. Viability was assessed by MTT assay. Phagocytotic ability and morphology were examined by flow cytometry, and random migration by IncuCyte Zoom and TrackMate. Change in gene expression was examined by qPCR, and protein secretion by Meso Scale Discovery. Results: LPS and IL-4 upregulated deoxycytidine kinase (DCK) expression. Only activated microglia were affected by CdA, and this was unrelated to viability. CdA 0.1-1 µM significantly reduced granularity, phagocytotic ability and random migration of activated microglia. CdA 10 µM increased the IL-4-induced gene expression of Arg1 and LPS-induced expression of IL-1beta, TNF, iNOS, and Arg1, but protein secretion remained unaffected. CdA 10 µM potentiated the increased expression of anti-inflammatory TNFR2 but not TNFR1 induced by LPS. Conclusion: Microglia acquire a less activated phenotype when treated with 0.1–1 µM CdA that putatively overlaps human CSF concentrations. This may be related to the upregulated gene expression of DCK upon activation and suggests a potential alternative mechanism of CdA with direct effect on CNS resident cells.
COVID-19 pandemic disease spread by SARS-COV-2 single-strand structure RNA virus belongs to the 7th generation of the coronavirus family. Following an unusual replication mechanism, its extreme ease of transmissibility has put many counties under lockdown. With a cure for the infection uncertain in the near future, the pressure currently lies in the current healthcare infrastructure, policies, government activities, and behaviour of the people to contain the virus. This research seeks to understand the spreading patterns of the COVID-19 virus through exponential growth modelling and identifies countries that have showed an initial sign of containment until 26th March 2020. Post identification of countries that have shown an initial sign of containment, predictive supervised machine learning models were built with infrastructure, environment, policies, and infection related independent variables. For the purpose, COVID-19 infection data across 42 countries were used. Logistic regression results shows a positive significant relationship of healthcare infrastructure and lockdown policies on the sign of early containment in countries. Machine learning models based on logistic regression, decision tree, random forest, and support vector machines were developed and are seen to have accuracies between 76.2% to 92.9% to predict early sign of infection containment. Other policies and activities taken by countries to contain the infection are also discussed.
Microwave assisted hydrodistillation (MAHD) and conventional hydrodistillation techniques were compared in the extraction of essential oils from Amomum subulatum seeds. The time required for MAHD method (70 min) is lesser than that for HD method (4 hr). There is a slight increase in the yield of extracted oil in MAHD method (3.35%) compared to HD (3%). GC-MS results show that MAHD extracted essential oil was wealthier in oxygenated compounds. 1, 8-Cineole was found to be a major compound in case of both the essential oil, followed by α-pinene. In MAHD the percentage of the major oxygenated monoterpene (1, 8- cineol) slightly increases from 88% to 89% as compared to hydrodistillation. Contrarily to this, the percentage of monoterpene hydrocarbon were decreased in MAHD than HD extracted oil. MAHD and HD extracted oils show good antibacterial activities against gram-negative and gram-positive bacteria. MAHD extracted oil shows better antibacterial activity than HD extracted against both gram positive and gram-negative bacteria. 2, 2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging antioxidant activities show that MAHD extract has better inhibition percentage than HD extract, and the IC50 value of MAHD was less than HD extracted oil.