126 research outputs found

    Symmetry and tendency judgment of Ms ≥ 8.0 strong earthquakes in Chile

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    Abstract:The Ms ≥8.0 strong earthquakes occurring in Chile since 1800 were analyzed using the ternary, quaternary, and quinary commensurability methods and the butterfly structure diagram, and it was believed that the earthquake signal in Chile in 2014 is relatively strong, a large earthquake is likely to occur in Chile in 2014. An analysis of spatial epicenter migrations showed that the longitudinal and latitudinal epicenter migrations have symmetry and synchronism, and there were five obvious northward migrations and four southward migrations. The symmetry axis of the longitudinal migrations is at about 71. 7° W and that of the latitudinal migrations is at about 30° S; these spatial symmetry axes are located at the subduction zone on the western margin of South America, where two major plates (the Nazca Plate and the South American Plate) converge

    Experimental evidence of colloids and nanoparticles presence from 25 waste leachates.

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    International audienceThe potential colloids release from a large panel of 25 solid industrial and municipal waste leachates, contaminated soil, contaminated sediments and landfill leachates was studied. Standardized leaching, cascade filtrations and measurement of element concentrations in the microfiltrate (MF) and ultrafiltrate (UF) fraction were used to easily detect colloids potentially released by waste. Precautions against CO(2) capture by alkaline leachates, or bacterial re-growth in leachates from wastes containing organic matter should be taken. Most of the colloidal particles were visible by transmission electron microscopy with energy dispersion spectrometry (TEM-EDS) if their elemental MF concentration is greater than 200 μgl(-1). If the samples are dried during the preparation for microscopy, neoformation of particles can occur from the soluble part of the element. Size distribution analysis measured by photon correlation spectroscopy (PCS) were frequently unvalid, particularly due to polydispersity and/or too low concentrations in the leachates. A low sensitivity device is required, and further improvement is desirable in that field. For some waste leachates, particles had a zeta potential strong enough to remain in suspension. Mn, As, Co, Pb, Sn, Zn had always a colloidal form (MF concentration/UF concentration>1.5) and total organic carbon (TOC), Fe, P, Ba, Cr, Cu, Ni are partly colloidal for more than half of the samples). Nearly all the micro-pollutants (As, Ba, Co, Cr, Cu, Mo, Ni, Pb, Sb, Sn, V and Zn) were found at least once in colloidal form greater than 100 μgl(-1). In particular, the colloidal forms of Zn were always by far more concentrated than its dissolved form. The TEM-EDS method showed various particles, including manufactured nanoparticles (organic polymer, TiO(2), particles with Sr, La, Ce, Nd). All the waste had at least one element detected as colloidal. The solid waste leachates contained significant amount of colloids different in elemental composition from natural ones. The majority of the elements were in colloidal form for wastes of packaging (3), a steel slag, a sludge from hydrometallurgy, composts (2), a dredged sediment (#18), an As contaminated soil and two active landfill leachates. These results showed that cascade filtration and ICP elemental analysis seems valid methods in this field, and that electronic microscopy with elemental detection allows to identify particles. Particles can be formed from dissolved elements during TEM sample preparation and cross-checking with MF and UF composition by ICP is useful. The colloidal fraction of leachate of waste seems to be a significant source term, and should be taken into account in studies of emission and transfer of contaminants in the environment. Standardized cross-filtration method could be amended for the presence of colloids in waste leachates

    NHERF1, a novel GPER associated protein, increases stability and activation of GPER in ER-positive breast cancer

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    G protein-coupled estrogen receptor (GPER) plays an important role in mediating the effects of estradiol. High levels of GPER have been implicated to associate with the malignant progress of invasive breast cancer (IBC). However, the mechanisms by which GPER protein levels were regulated remain unclear. In this study, PDZ protein Na+/H+ exchanger regulatory factor (NHERF1) was found to interact with GPER in breast cancer cells. This interaction was mediated by the PDZ2 domain of NHERF1 and the carboxyl terminal PDZ binding motif of GPER. NHERF1 was demonstrated to facilitate GPER expression at post-transcriptional level and improve GPER protein stability by inhibiting the receptor degradation via ubiquitin-proteasome pathway in a GPER/NHERF1 interaction-dependent manner. In addition, GPER protein levels are positively associated with NHERF1 protein levels in a panel of estrogen receptor (ER)-positive breast cancer cells. Furthermore, analysis of clinical IBC data from The Cancer Genome Atlas (TCGA) showed no significant difference in GPER mRNA levels between ER-positive IBC and normal breast tissues. However, gene set enrichment analysis (GSEA) showed that GPER signaling is ultra-activated in ER-positive IBC when compared with normal and its activation is positively associated with NHERF1 mRNA levels. Taken together, our findings identify NHERF1 as a new binding partner for GPER and its overexpression promotes protein stability and activation of GPER in ER-positive IBC. Our data indicate that regulation of GPER stability by NHERF1 may contribute to GPER-mediated carcinogenesis in ER-positive IBC

    Intestinal segment and vitamin D3 concentration affect gene expression levels of calcium and phosphorus transporters in broiler chickens

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    Two experiments were conducted in this research. Experiment 1 investigated the spatial expression characteristics of calcium (Ca) and phosphorus (P) transporters in the duodenum, jejunum, and ileum of 21-day-old broilers provided with adequate nutrient feed. Experiment 2 evaluated the effects of dietary vitamin D3 (VD3) concentration (0, 125, 250, 500, 1,000, and 2,000 IU/kg) on growth performance, bone development, and gene expression levels of intestinal Ca and P transporters in 1–21-day-old broilers provided with the negative control diet without supplemental VD3. Results in experiment 1 showed that the mRNA levels of calcium-binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), plasma membrane calcium ATPase 1b (PMCA1b), and IIb sodium-phosphate cotransporter (NaPi-IIb) were the highest in the broiler duodenum. By contrast, the mRNA levels of inorganic phosphate transporter 1 (PiT-1) and 2 (PiT-2) were the highest in the ileum. Results in experiment 2 showed that adding 125 IU/kg VD3 increased body weight gain (BWG), feed intake (FI), bone weight, and percentage and weight of Ca and P in the tibia and femur of 1–21-day-old broilers compared with the negative control diet (p < 0.05). The rise in dietary VD3 levels from 125 to 1,000 IU/kg further increased the BWG, FI, and weights of the bone, ash, Ca, and P (p < 0.05). No difference in growth rate and leg bone quality was noted in the broilers provided with 1,000 and 2,000 IU/kg VD3 (p > 0.05). Supplementation with 125–2,000 IU/kg VD3 increased the mRNA abundances of intestinal Ca and P transporters to varying degrees. The mRNA level of CaBP-D28k increased by 536, 1,161, and 28 folds in the duodenum, jejunum, and ileum, respectively, after adding 1,000 IU/kg VD3. The mRNA levels of other Ca and P transporters (PMCA1b, NCX1, NaPi-IIb, PiT-1, and PiT-2) increased by 0.57–1.74 folds by adding 1,000–2,000 IU/kg VD3. These data suggest that intestinal Ca and P transporters are mainly expressed in the duodenum of broilers. Moreover, the addition of VD3 stimulates the two mineral transporter transcription in broiler intestines

    Low-Temperature, Highly Selective, Gas-Phase Oxidation of Benzyl Alcohol over Mesoporous K-Cu-TiO2 with Stable Copper(I) Oxidation State

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    通讯作者地址: Fan, J (通讯作者), Zhejiang Univ, Dept Chem, Key Lab Appl Chem Zhejiang Prov, Hangzhou 310027, Zhejiang Peoples R China 地址: 1. Zhejiang Univ, Dept Chem, Key Lab Appl Chem Zhejiang Prov, Hangzhou 310027, Zhejiang Peoples R China 2. Univ Calif Santa Barbara, Dept Chem & Biochem, Santa Barbara, CA 93106 USA 电子邮件地址: [email protected], [email protected] newly developed mesoporous mixed metal oxide (K-Cu-TiO2) catalyst is capable of highly selective, gas-phase benzyl alcoholbenzaldehyde transformation at excellent yields (>99%) under surprisingly low temperatures (203 degrees C, bp of benzyl alcohol). The tow-temperature reaction conditions and integration of K and Cu(I) components into the TiO2 matrix are of vital importance for the stabilization of an active Cu(I) oxidation state and resultant stable, excellent catalytic performance.National Science Foundations of China 20873122 J0830413 National Science Foundation DMR 02-3372

    HIV Detection and Delayed Diagnosis: A Time Series Analysis in China

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    Background: Insufficient HIV detection and late presentation to antiretroviral therapy (ART) pose significant public health challenges. In China, universal access to HIV testing is available now. Under this background, we aim to analyze the trends of HIV detection and the prevalence of delayed HIV diagnosis (DHD) in order to provide evidence for HIV prevention and treatment in China. Methods: Data of HIV tests in Hangzhou city between 2007 and 2018 were collected from the Chinese National HIV/AIDS Comprehensive Response Information Management System (CRIMS). Descriptive statistics were used to describe the characteristics of HIV testing and detection and the prevalence of DHD among newly diagnosed HIV cases. Non-parametric tests were employed to examine the prevalence of DHD among newly diagnosed HIV cases. Moreover, logistic regression models were employed to explore the influencing factors of DHD. Results: Testing rates doubled from 14.1% in 2007–2010 to 28.2% in 2016–2018. The total positive rate of HIV tests was 5.3 per 10,000. Preoperative testing was the predominant pathway for HIV tests, accounting for 41.9%, followed by testing for health screening, maternal examination and other patients, accounting for 18.4%, 13.2% and 11.8%, respectively. Meanwhile, the predominant pathway for HIV case detection was also preoperative testing, accounting for 29.1%, followed by testing for other patients, testing at STD clinics and VCT, with the proportions of 18.8%, 15.8% and 13.6%, respectively. MSM (men who have sex with men) contact was the main transmission route, accounting for 55.3%, followed by heterosexual contact, accounting for 41.6%. Overall, DHD occurred in 29.0% of the newly diagnosed cases, and this rate had not improved over the years. A higher prevalence of DHD was found in those diagnosed through a pre-test for receiving blood/products [OR (95%CI): 5.42(2.95–9.97)], detection of other patients [OR (95%CI): 2.08(1.64–2.63)], preoperative testing [OR (95%CI): 1.83(1.44–2.32)] and spouse or sexual partner testing in positive person [OR (95%CI): 1.93(1.34–2.78)] compared with those diagnosed at a VCT clinic. Heterosexuals [OR (95%CI): 1.20(1.06–1.36)] had a higher risk of DHD than MSM. Diagnosis at a CDC [OR (95%CI): 0.68(0.55–0.83)] and community health centers [OR (95%CI): 0.54(0.39–0.75)] had a lower risk of DHD than in hospitals. Older age, males, being single/divorced or widowed and floating population were also associated with DHD. Conclusions: In China, DHD had not improved in the last 10 years, although HIV testing had been expanded. Therefore, it is important for continued efforts to promote early diagnosis of HIV to prevent transmission, morbidity and early mortality in HIV infection

    Tetrakis(μ-2-phenylquinoline-4-carboxylato-κ2O:O′)bis[(methanol-κO)copper(II)]

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    The title complex, [Cu2(C16H10NO2)4(CH3OH)2], consists of centrosymmetric wheel-shaped dinuclear neutral molecules in which each CuII atom is coordinated in a slightly distorted square-pyramidal geometry by four O atoms of carboxylate groups from different ligands at the basal plane and an O atom of a methanol molecule at the axial position. In the crystal, the dinuclear complex molecules are linked into one-dimensional supramolecular columns parallel to the b axis by O—H...N hydrogen bonds and π–π stacking interactions [centroid–centroid distance = 3.7259 (11) Å]

    Evaluating spatial-temporal dynamics of net primary productivity of different forest types in northeastern China based on improved FORCCHN.

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    An improved individual-based forest ecosystem carbon budget model for China (FORCCHN) was applied to investigate the spatial-temporal dynamics of net primary productivity of different forest types in northeastern China. In this study, the forests of northeastern China were categorized into four ecological types according to their habitats and generic characteristics (evergreen broadleaf forest, deciduous broadleaf forest, evergreen needleleaf forest and deciduous needleleaf forest). The results showed that distribution and change of forest NPP in northeastern China were related to the different forest types. From 1981 to 2002, among the forest types in northeastern China, per unit area NPP and total NPP of deciduous broadleaf forest were the highest, with the values of 729.4 gC/(m(2)•yr) and 106.0 TgC/yr, respectively, followed by mixed broadleaf- needleleaf forest, deciduous needleleaf forest and evergreen needleleaf forest. From 1981 to 2002, per unit area NPP and total NPP of different forest types in northeastern China exhibited significant trends of interannual increase, and rapid increase was found between the 1980s and 1990s. The contribution of the different forest type's NPP to total NPP in northeastern China was clearly different. The greatest was deciduous broadleaf forest, followed by mixed broadleaf- needleleaf forest and deciduous needleleaf forest. The smallest was evergreen needleleaf forest. Spatial difference in NPP between different forest types was remarkable. High NPP values of deciduous needleleaf forest, mixed broadleaf- needleleaf forest and deciduous broadleaf forest were found in the Daxing'anling region, the southeastern of Xiaoxing'anling and Jilin province, and the Changbai Mountain, respectively. However, no regional differences were found for evergreen needleleaf NPP. This study provided not only an estimation NPP of different forest types in northeastern China but also a useful methodology for estimating forest carbon storage at regional and global levels

    The Effects of Internet Exposure on Sexual Risk Behavior Among Sexually Experienced Male College Students in China: Cross-sectional Study

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    BackgroundAs a young subgroup, college students have become the main users of mobile social networks. Considering that people can indiscriminately access explicit sexual content on the internet, coupled with the increase of HIV infections in male college students, the role of the internet in meeting sexual partners and its correlation to risky sexual behavior has become an important topic. ObjectiveThe aim of this study is to explore the effects of internet exposure on sexual partners and sexual risk behavior among sexually experienced male college students. MethodsAn institution-based cross-sectional study design was used to collect data through a paper-based questionnaire administered to male college students recruited from colleges and gay organizations in Hangzhou, Zhejiang Province, China. A total of 1045 sexually experienced male students were incorporated in our analysis, with the following information collected: sociodemographic characteristics, sexual intercourse–related behaviors, and sexually transmitted disease (STD) knowledge. Mann-Whitney U and Kruskal-Wallis tests were used to examine differences regarding basic characteristics and sexual risk behaviors between male college students who meet sexual partners via the internet and those who do not. Sequential logistic regression models were employed to examine the influence of meeting sexual partners via the internet on risky sexual behaviors after controlling for other factors. ResultsThe mean age of the sexually experienced male students was 21.6 (SD 2.0) years. The likelihood of risky sexual behavior was varied, yet it was the highest for those who aim to meet paid sexual partners (145/192, 75.5% to 19/22, 86.4%), followed by those seeking partners for love or romance (258/435, 59.3%). Compared to non-internet partner seekers, internet partner seekers tended to have more casual intercourse (292/542, 53.9% versus 51/503, 10.1%), paid intercourse (32/542, 5.9% versus 12/503, 2.4%), and intercourse with same-sex partners (349/542, 64.4% versus 41/503, 8.2%); they were also more likely to use psychoactive drugs (125/349, 35.8% versus 5/41, 12.2%) and have more than 2 partners. With the increase of HIV and STD knowledge, the probability of having unprotected intercourse decreased for non-internet partner seekers. However, it increased for internet partner seekers with a rising HIV knowledge score. Sequential logistic regression showed that meeting sexual partners on the internet was statistically associated with sexual risk behaviors with multiple sexual partners (odds ratio 4.434; P<.001). ConclusionsMeeting sexual partners via the internet is a common behavior among sexually experienced male college students, and those who meet partners on the internet exhibited higher levels of risky sexual behaviors although they had sufficient HIV and STD knowledge; this is especially true for students who aimed to find partners for sexual intercourse. Thus, more attention should be paid to young adults to address the risky sexual behaviors that may contribute to STD spread among this population
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