1,415 research outputs found

    Quark mass density- and temperature- dependent model for strange quark matter

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    It is found that the radius of a stable strangelet decreases as the temperature increases in a quark mass density-dependent model. To overcome this difficulty, we extend this model to a quark mass density- and temperature- dependent model in which the vacuum energy density at zero baryon density limit B depends on temperature. An ansatz is introduced and the regions for the best choice of the parameters are studied.Comment: 5 pages, 4 figure

    Geographical, meteorological and vectorial factors related to malaria re-emergence in Huang-Huai River of central China

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    <p/> <p>Background</p> <p>Malaria still represents a significant public health problem in China, and the cases dramatically increased in the areas along the Huang-Huai River of central China after 2001. Considering spatial aggregation of malaria cases and specific vectors, the geographical, meteorological and vectorial factors were analysed to determine the key factors related to malaria re-emergence in these particular areas.</p> <p>Methods</p> <p>The geographic information of 357 malaria cases and 603 water bodies in 113 villages were collected to analyse the relationship between the residence of malaria cases and water body. Spearman rank correlation, multiple regression, curve fitting and trend analysis were used to explain the relationship between the meteorological factors and malaria incidence. Entomological investigation was conducted in two sites to get the vectorial capacity and the basic reproductive rate to determine whether the effect of vector lead to malaria re-emergence.</p> <p>Results</p> <p>The distances from household of cases to the nearest water-body was positive-skew distributed, the median was 60.9 m and 74% malaria cases were inhabited in the extent of 60 m near the water body, and the risk rate of people live there attacked by malaria was higher than others(<it>OR </it>= 1.6, 95%<it>CI </it>(1.042, 2.463), <it>P </it>< 0.05). The annual average temperature and rainfall may have close relationship with annual incidence. The average monthly temperature and rainfall were the key factors, and the correlation coefficients are 0.501 and 0.304(<it>P </it>< 0.01), respectively. Moreover, 75.3% changes of monthly malaria incidence contributed to the average monthly temperature (T<sub>mean</sub>), the average temperature of last two months(T<sub>mean01</sub>) and the average rainfall of current month (R<sub>mean</sub>) and the regression equation was Y = -2.085 + 0.839I<sub>1 </sub>+ 0.998T<sub>mean0 </sub>- 0.86T<sub>mean01 </sub>+ 0.16R<sub>mean0</sub>. All the collected mosquitoes were <it>Anopheles sinensis</it>. The vectorial capacity and the basic reproductive rate of <it>An. sinensis </it>in two sites were 0.6969, 0.4983 and 2.1604, 1.5447, respectively.</p> <p>Conclusion</p> <p>The spatial distribution between malaria cases and water-body, the changing of meteorological factors, and increasing vectorial capacity and basic reproductive rate of <it>An. sinensis </it>leaded to malaria re-emergence in these areas.</p

    Evaluating residual acceleration noise for TianQin gravitational waves observatory with an empirical magnetic field model

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    TianQin (TQ) project plans to deploy three satellites in space around the Earth to measure the displacement change of test masses caused by gravitational waves via laser interferometry. The requirement of the acceleration noise of the test mass is on the order of 10−15  m s−2 Hz−1/210^{-15}~\,{\rm m}\,{\rm s}^{-2}\,{\rm Hz}^{-1/2} in the sensitive frequency range of TQ, %the extremely precise acceleration measurement requirements make it necessary to investigate acceleration noise due to space magnetic fields. which is so stringent that the acceleration noise caused by the interaction of the space magnetic field with the test mass needs to be investigated. In this work, by using the Tsyganenko model, a data-based empirical space magnetic field model, we obtain the magnetic field distribution around TQ's orbit spanning two solar cycles in 23 years from 1998 to 2020. With the obtained space magnetic field, we derive the distribution and amplitude spectral densities (ASDs) of the acceleration noise of TQ in 23 years. Our results reveal that the average values of the ratio of the acceleration noise cauesd by the space magnetic field to the requirements of TQ at 1 mHz (R1mHzR_{\rm 1mHz}) and 6 mHz (R6mHzR_{\rm 6mHz}) are 0.123±\pm0.052 and 0.027±\pm0.013, respectively. The occurence probabilities of R1mHz>0.2R_{\rm 1mHz}>0.2 and >0.3>0.3 are only 7.9% and 1.2%, respectively, and R6mHzR_{\rm 6mHz} never exceeds 0.2.Comment: 13 pages, 10 figures, Published in PR

    Discordance between Liver Biopsy and FibroScan® in Assessing Liver Fibrosis in Chronic Hepatitis B: Risk Factors and Influence of Necroinflammation

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    BACKGROUND: Few studies have investigated predictors of discordance between liver biopsy (LB) and liver stiffness measurement (LSM) using FibroScan®. We assessed predictors of discordance between LB and LSM in chronic hepatitis B (CHB) and investigated the effects of necroinflammatory activity. METHODS: In total, 150 patients (107 men, 43 women) were prospectively enrolled. Only LSM with ≥ 10 valid measurements was considered reliable. Liver fibrosis was evaluated using the Laennec system. LB specimens <15 mm in length were considered ineligible. Reference cutoff LSM values to determine discordance were calculated from our cohort (6.0 kPa for ≥ F2, 7.5 kPa for ≥ F3, and 9.4 kPa for F4). RESULTS: A discordance, defined as a discordance of at least two stages between LB and LSM, was identified in 21 (14.0%) patients. In multivariate analyses, fibrosis stages F3-4 and F4 showed independent negative associations with discordance (P = 0.002; hazard ratio [HR], 0.073; 95% confidence interval [CI], 0.014-0.390 for F3-4 and P = 0.014; HR, 0.067; 95% CI, 0.008-0.574 for F4). LSM values were not significantly different between maximal activity grades 1-2 and 3-4 in F1 and F2 fibrosis stages, whereas LSM values were significantly higher in maximal activity grade 3-4 than 1-2 in F3 and F4 fibrosis stage (median 8.6 vs. 11.3 kPa in F3, P = 0.049; median 11.9 vs. 19.2 kPa in F4, P = 0.009). CONCLUSION: Advanced fibrosis stage (F3-4) or cirrhosis (F4) showed a negative correlation with discordance between LB and LSM in patients with CHB, and maximal activity grade 3-4 significantly influenced LSM values in F3 and F4

    Associations of obesity and malnutrition with cardiac remodeling and cardiovascular outcomes in Asian adults:A cohort study

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    BackgroundObesity, a known risk factor for cardiovascular disease and heart failure (HF), is associated with adverse cardiac remodeling in the general population. Little is known about how nutritional status modifies the relationship between obesity and outcomes. We aimed to investigate the association of obesity and nutritional status with clinical characteristics, echocardiographic changes, and clinical outcomes in the general community.Methods and findingsWe examined 5,300 consecutive asymptomatic Asian participants who were prospectively recruited in a cardiovascular health screening program (mean age 49.6 ± 11.4 years, 64.8% male) between June 2009 to December 2012. Clinical and echocardiographic characteristics were described in participants, stratified by combined subgroups of obesity and nutritional status. Obesity was indexed by body mass index (BMI) (low, ≤25 kg/m2 [lean]; high, >25 kg/m2 [obese]) (WHO-recommended Asian cutoffs). Nutritional status was defined primarily by serum albumin (SA) concentration (low, ConclusionsIn our cohort study among asymptomatic community-based adults in Taiwan, we found that obese individuals with poor nutritional status have the highest comorbidity burden, the most adverse cardiac remodeling, and the least favorable composite outcome

    Overexpression of LCMR1 is significantly associated with clinical stage in human NSCLC

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    <p>Abstract</p> <p>Background</p> <p>Lung cancer is one of the most common human cancers and the leading cause of cancer death worldwide. The identification of lung cancer associated genes is essential for lung cancer diagnosis and treatment.</p> <p>Methods</p> <p>Differential Display-PCR technique was used to achieve the novel cDNA, which were then verified by real-time PCR. Northern blot was utilized to observe the expression of LCMR1 in different human tissues. 84 cases human NSCLC tissues and normal counterparts were analyzed for the expression of LCMR1 by immunohistochemistry.</p> <p>Results</p> <p>A novel 778-bp cDNA fragment from human large cell lung carcinoma cell lines 95C and 95D was obtained, and named <it>LCMR1 </it>(Lung Cancer Metastasis Related protein 1). LCMR1 was differentially expressed in different human tissues. LCMR1 was strongly overexpressed in NSCLC and its expression was significantly associated with clinical stage.</p> <p>Conclusion</p> <p>Our data indicated that <it>LCMR1</it>, strongly overexpressed in NSCLC, might have applications in the clinical diagnosis and treatment of lung cancer.</p

    Incidence of oral cancer in relation to nickel and arsenic concentrations in farm soils of patients' residential areas in Taiwan

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    <p>Abstract</p> <p>Background</p> <p>To explore if exposures to specific heavy metals in the environment is a new risk factor of oral cancer, one of the fastest growing malignancies in Taiwan, in addition to the two established risk factors, cigarette smoking and betel quid chewing.</p> <p>Methods</p> <p>This is an observational study utilized the age-standardized incidence rates of oral cancer in the 316 townships and precincts of Taiwan, local prevalence rates of cigarette smoking and betel quid chewing, demographic factors, socio-economic conditions, and concentrations in farm soils of the eight kinds of heavy metal. Spatial regression and GIS (Geographic Information System) were used. The registration contained 22,083 patients, who were diagnosed with oral cancer between 1982 and 2002. The concentrations of metal in the soils were retrieved from a nation-wide survey in the 1980s.</p> <p>Results</p> <p>The incidence rate of oral cancer is geographically related to the concentrations of arsenic and nickel in the patients' residential areas, with the prevalence of cigarette smoking and betel quid chewing as controlled variables.</p> <p>Conclusions</p> <p>Beside the two established risk factors, cigarette smoking and betel quid chewing, arsenic and nickel in farm soils may be new risk factors for oral cancer. These two kinds of metal may involve in the development of oral cancer. Further studies are required to understand the pathways via which metal in the farm soils exerts its effects on human health.</p

    Discrete π-Stacks from Self-Assembled Perylenediimide Analogues.

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    The formation of well-defined finite-sized aggregates represents an attractive goal in supramolecular chemistry. In particular, construction of discrete π-stacked dye assemblies remains a challenge. Reported here is the design and synthesis of a novel type of discrete π-stacked aggregate from two comparable perylenediimide (PDI) dyads (PEP and PBP). The criss-cross PEP-PBP dimers in solution and (PBP-PEP)-(PEP-PBP) tetramers in the solid state are well elucidated using single-crystal X-ray diffraction, dynamic light scattering, and diffusion-ordered NMR spectroscopy. Extensive π-π stacking between the PDI units of PEP and PBP as well as repulsive interactions of swallow-tailed alkyl substituents are responsible for the selective formation of discrete dimer and tetramer stacks. Our results reveal a new approach to preparing discrete π stacks that are appealing for making assemblies with well-defined optoelectronic properties
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