102 research outputs found
The Effect of Indium Concentration on the Structure and Properties of Zirconium Based Intermetallics: First-Principles Calculations
The phase stability, mechanical, electronic, and thermodynamic properties of In-Zr compounds have been explored using the first-principles calculation based on density functional theory (DFT). The calculated formation enthalpies show that these compounds are all thermodynamically stable. Information on electronic structure indicates that they possess metallic characteristics and there is a common hybridization between In-p and Zr-d states near the Fermi level. Elastic properties have been taken into consideration. The calculated results on the ratio of the bulk to shear modulus (B/G) validate that InZr3 has the strongest deformation resistance. The increase of indium content results in the breakout of a linear decrease of the bulk modulus and Young’s modulus. The calculated theoretical hardness of α-In3Zr is higher than the other In-Zr compounds
Changes in the Material Characteristics of Maize Straw during the Pretreatment Process of Methanation
Pretreatment technology is important to the direct methanation of straw. This study used fresh water, four bacterium agents (stem rot agent, “result” microbe decomposition agent, straw pretreatment composite bacterium agent, and complex microorganism agent), biogas slurry, and two chemical reagents (sodium hydroxide and urea) as pretreatment promoters. Different treatments were performed, and the changes in the straw pH value, temperature, total solid (TS), volatile solid (VS), and carbon-nitrogen ratio (C/N ratio) under different pretreatment conditions were analyzed. The results showed that chemical promoters were more efficient than biological promoters in straw maturity. Pretreatment using sodium hydroxide induced the highest degree of straw maturity. However, its C/N ratio had to be reduced during fermentation. In contrast, the C/N ratio of the urea-pretreated straw was low and was easy to regulate when used as anaerobic digestion material. The biogas slurry pretreatment was followed by pretreatments using four different bacterium agents, among which the effect of the complex microorganism agent (BA4) was more efficient than the others. The current study is significant to the direct and efficient methanation of straw
Novel Reassortant Highly Pathogenic Avian Influenza (H5N5) Viruses in Domestic Ducks, China
In China, domestic ducks and wild birds often share the same water, in which influenza viruses replicate preferentially. Isolation of 2 novel reassortant highly pathogenic avian influenza (H5N5) viruses from apparently healthy domestic ducks highlights the role of these ducks as reassortment vessels. Such new subtypes of influenza viruses may pose a pandemic threat
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Rapamycin-Insensitive Up-Regulation of Adipocyte Phospholipase A2 in Tuberous Sclerosis and Lymphangioleiomyomatosis
Tuberous sclerosis syndrome (TSC) is an autosomal dominant tumor suppressor gene syndrome affecting multiple organs, including renal angiomyolipomas and pulmonary lymphangioleiomyomatosis (LAM). LAM is a female-predominant interstitial lung disease characterized by the progressive cyst formation and respiratory failure, which is also seen in sporadic patients without TSC. Mutations in TSC1 or TSC2 cause TSC, result in hyperactivation of mammalian target of rapamycin (mTOR), and are also seen in LAM cells in sporadic LAM. We recently reported that prostaglandin biosynthesis and cyclooxygenase-2 were deregulated in TSC and LAM. Phospholipase A2 (PLA2) is the rate-limiting enzyme that catalyzes the conversion of plasma membrane phospholipids into prostaglandins. In this study, we identified upregulation of adipocyte AdPLA2 (PLA2G16) in LAM nodule cells using publicly available expression data. We showed that the levels of AdPLA2 transcript and protein were higher in LAM lungs compared with control lungs. We then showed that TSC2 negatively regulates the expression of AdPLA2, and loss of TSC2 is associated with elevated production of prostaglandin E2 (PGE2) and prostacyclin (PGI2) in cell culture models. Mouse model studies also showed increased expression of AdPLA2 in xenograft tumors, estrogen-induced lung metastatic lesions of Tsc2 null leiomyoma-derived cells, and spontaneous renal cystadenomas from Tsc2+/− mice. Importantly, rapamycin treatment did not affect the expression of AdPLA2 and the production of PGE2 by TSC2-deficient mouse embryonic fibroblast (Tsc2−/−MEFs), rat uterine leiomyoma-derived ELT3 cells, and LAM patient-associated renal angiomyolipoma-derived “mesenchymal” cells. Furthermore, methyl arachidonyl fluorophosphate (MAFP), a potent irreversible PLA2 inhibitor, selectively suppressed the growth and induced apoptosis of TSC2-deficient LAM patient-derived cells relative to TSC2-addback cells. Our findings suggest that AdPLA2 plays an important role in promoting tumorigenesis and disease progression by modulating the production of prostaglandins and may serve as a potential therapeutic target in TSC and LAM
High endemicity of alveolar echinococcosis in Yili Prefecture, Xinjiang Autonomous Region, the People’s Republic of China: infection status in different ethnic communities and in small mammals
Alveolar echinococcosis (AE) is a neglected zoonosis caused by the larval stage of the fox/dog tapeworm Echinococcus multilocularis. In this study, we collected data on 286 AE cases reported from Yili Prefecture, Xinjiang Autonomous Region, the People’s Republic of China from 1989 to 2015 with an annual incidence (AI) of 0.41/100,000. Among the patients, 73.08% were diagnosed in the last 11 years. The incidence (0.51–1.22 cases/100,000 residents) was higher in the high-altitude mountainous areas than those in low level areas (0.19–0.29/100,000 residents). In term of ethnic group, the AI of AE in Mongolian (2.06/100,000 residents) and Kazak (0.93/100,000) groups had higher incidence than the other ethnic groups, indicating sheep-farming activity is a risk for infection given that sheep farming is mainly practiced by these two groups in the prefecture. A total of 1411 small mammals were captured with 9.14% infected with E. multilocularis metacestodes. Microtus obscurus was the dominant species captured in the mountainous pasture areas with 15.01% infection rate, whereas Mus musculus and Apodemus sylvaticus were the dominant small mammals in the low altitude areas. Only 0.40% of A. sylvaticus were infected with E. multilocularis. These findings show that Yili Prefecture is a highly endemic area for AE and that the high-altitude pasture areas favorable for M. obscurus may play an important role in its transmission in this region
Wielding the sword: President Xi’s new anti-corruption campaign
A state achieves legitimacy through multiple sources, one of which is the effectiveness of its governance. Generations of scholars since Hobbes have identified the maintenance of peace and order as core functions of a legitimate state. In the modern world, economic prosperity, social stability and effective control of corruption often provide adequate compensation for a deficit of democracy. Corruption closely correlates with legitimacy. While a perceived pervasive, endemic corruption undermines the legitimacy of a regime, a successful anti-corruption campaign can allow a regime to recover from a crisis of legitimacy (Gilley 2009; Seligson and Booth 2009). This is the rationale behind the periodical campaigns against corruption that have been conducted by the Chinese Communist Party (‘Party’ or ‘CCP’) (Manion 2004; Wedeman 2012). Political leaders in China have found it expedient to use anti-corruption campaigns to remove their political foes, to rein in the bureaucracy and to restore public confidence in their ability to rule. Through anti-corruption campaigns, emerging political leaders consolidate their political power, secure loyalty from political factions and regional political forces, and enhance their legitimacy in the eyes of the general public. In an authoritarian state that experiences a high level of corruption, an anti-corruption campaign is a delicate political battle that addresses two significant concerns. The first concern is to orchestrate the campaign so that it is regime-reinforcing instead of regime-undermining. To remain credible, the regime must demonstrate its willingness and capacity to punish corrupt officials at the highest levels.preprin
Neutrino Physics with JUNO
The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purposeunderground liquid scintillator detector, was proposed with the determinationof the neutrino mass hierarchy as a primary physics goal. It is also capable ofobserving neutrinos from terrestrial and extra-terrestrial sources, includingsupernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos,atmospheric neutrinos, solar neutrinos, as well as exotic searches such asnucleon decays, dark matter, sterile neutrinos, etc. We present the physicsmotivations and the anticipated performance of the JUNO detector for variousproposed measurements. By detecting reactor antineutrinos from two power plantsat 53-km distance, JUNO will determine the neutrino mass hierarchy at a 3-4sigma significance with six years of running. The measurement of antineutrinospectrum will also lead to the precise determination of three out of the sixoscillation parameters to an accuracy of better than 1\%. Neutrino burst from atypical core-collapse supernova at 10 kpc would lead to ~5000inverse-beta-decay events and ~2000 all-flavor neutrino-proton elasticscattering events in JUNO. Detection of DSNB would provide valuable informationon the cosmic star-formation rate and the average core-collapsed neutrinoenergy spectrum. Geo-neutrinos can be detected in JUNO with a rate of ~400events per year, significantly improving the statistics of existing geoneutrinosamples. The JUNO detector is sensitive to several exotic searches, e.g. protondecay via the decay channel. The JUNO detector will providea unique facility to address many outstanding crucial questions in particle andastrophysics. It holds the great potential for further advancing our quest tounderstanding the fundamental properties of neutrinos, one of the buildingblocks of our Universe
Panax ginseng abuse exhibits a pro-inflammatory effect by activating the NF-κB pathway
P. ginseng (Panax ginseng C. A. Meyer) is a well-known traditional medicine that has been used for thousands of years to treat diseases. However, “ginseng abuse syndrome” (GAS) often occurs due to an inappropriate use such as high-dose or long-term usage of ginseng; information about what causes GAS and how GAS occurs is still lacking. In this study, the critical components that potentially caused GAS were screened through a step-by-step separation strategy, the pro-inflammatory effects of different extracts on messenger RNA (mRNA) or protein expression levels were evaluated in RAW 264.7 macrophages through quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot, respectively. It was found that high-molecular water-soluble substances (HWSS) significantly increased the expression of cytokines (cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and interleukin 6 (IL-6)) and cyclooxygenase 2 (COX-2) protein; gel filtration chromatography fraction 1 (GFC-F1) further purified from HWSS showed prominent pro-inflammatory effects by increasing the transcription of cytokines (COX-2, iNOS, tumor necrosis factor alpha (TNF-α), and interleukin 1β (IL-1β)) as well as the expression of COX-2 and iNOS protein. Moreover, GFC-F1 activated nuclear factor-kappa B (NF-кB) (p65 and inhibitor of nuclear factor-kappa B alpha (IκB-α)) and the p38/MAPK (mitogen-activated protein kinase) signaling pathways. On the other hand, the inhibitor of the NF-κB pathway (pyrrolidine dithiocarbamate (PDTC)) reduced GFC-F1-induced nitric oxide (NO) production, while the inhibitors of the MAPK pathways did not. Taken together, GFC-F1 is the potential composition that caused GAS through the production of inflammatory cytokines by activating the NF-кB pathway
Comparative Transcriptome Analysis Reveals Hormone Signaling Genes Involved in the Launch of Culm-Shape Differentiation in Dendrocalamus sinicus
Dendrocalamus sinicus is a sympodial bamboo species endemic to Yunnan Province, China, and is the strongest bamboo species in the world. However, there is substantial variation in the basal culm shape, i.e., straight culm (SC) and bent culm (BC), among different D. sinicus as a result of genetic and growth factors. This study performed a comparative transcriptomic analysis of bamboo shoots of two variants at the early, mid-, and late shoot-development stages to examine the molecular basis of this variation. In total, 98,479 unigenes were annotated, of which 13,495 were differentially expressed in pairwise comparisons of the six libraries. More differentially expressed genes (DEGs) were involved in SC than in BC culm development. The DEGs between BC and SC were assigned to 108 metabolic pathways. The 1064 DEGs in early development might mainly control the launch of culm-shape differentiation. Sixty genes encoding components of hormone signaling pathways were differentially expressed between BC5 and SC5, indicating complex hormonal regulation of culm differentiation. The AUX/IAA, ARF, PP2C, SnRK2, and ABF genes involved in auxin and abscisic acid signaling played key roles. These results help us to understand the molecular mechanism of culm variation and other aspects of culm development in D. sinicus
Effects of anabolic steroids on chronic obstructive pulmonary disease: a meta-analysis of randomised controlled trials.
BACKGROUND: Anabolic steroids are known to improve body composition and muscle strength in healthy people. However, whether anabolic steroids improve the physical condition and function in patients with chronic obstructive pulmonary disease (COPD) remains undetermined. A meta-analysis was conducted to review the current evidence regarding the effects of anabolic steroids on COPD patients. METHODS: A comprehensive literature search of PubMed and EMBASE was performed to identify randomised controlled trials that examine the effects of anabolic steroids on COPD patients. Weighted mean differences (WMDs) with 95% confidence intervals were calculated to determine differences between anabolic steroid administration and control conditions. RESULTS: Eight eligible studies involving 273 COPD patients were identified in this meta-analysis. Significant improvements were found in body weight (0.956 kg), fat-free mass (1.606 kg), St. George's Respiratory Questionnaire total score (-6.336) and symptom score (-12.148). The apparent improvements in maximal inspiratory pressure (2.740 cmH2O) and maximal expiratory pressure (12.679 cmH2O) were not significant. The effects on handgrip strength, forced expiratory volume in one second (FEV1), predicted FEV1 percent, PaO2, PaCO2 and six-min walk distance were negative, with WMDs of -0.245 kg, -0.096 L/sec, -1.996% of predicted, -1.648 cmHg, -0.039 cmHg and -16.102 meters, respectively. CONCLUSIONS: Limited evidence available from the published literature suggests that the benefit of anabolic steroids on COPD patients cannot be denied. However, further studies are needed to identify the specific benefits and adverse effects of anabolic steroids on COPD patients and to determine the optimal populations and regimes of anabolic steroids in COPD patients
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