[Genetic characteristics of hantavirus detected in rodents in Shenzhen].

Objective: To study the molecular epidemiological characteristics and genotypes of hantavirus carried by rodents in Shenzhen. Methods: Rodents were captured, and their lung samples were collected and grinded for RNA extraction. The hantavirus positive samples were classified by real-time fluorescence PCR. Rat lung nucleic acid samples were selected to amplify the nucleotide sequences of partial M fragments (G2 segment) and S fragments by reverse transcription-nested polymerase chain reaction (RT-nested PCR). The PCR products were then sequenced and homology and phylogenetic tree analyses were conducted. Results: A total of 200 rodents were captured, including 189 Rattus norvegicus, 9 Rattus flavipectus and 2 Mus musculus. The positive rate of hantavirus was 21.0% (42/200), all of the isolates were seoul virus (SEOV) strains. The positive rate of hantavirus in Bao'an district was highest (45.7%), and the difference in detection rate among districts were significant (χ2=25.60,P<0.05). A total of 25 G2 segment sequences and S fragment sequences of SEOV were obtained by virus gene sequencing, and their nucleotide homology was 95.3%-100.0% and 97.6%-100.0%, respectively. Compared with other reference sequences of S2 subtype, the nucleotide homology between the sample sequence and the reference sequence from Guangzhou was high. Analysis on nucleotide homology and phylogenetic tree showed that hantavirus carried by the rodents captured in Shenzhen belonged to SEOV S2 subtype. Analysis on amino acid variation sites revealed that there was a variation in the nucleocapsid protein encoded by S gene from Alanine to Threonine at the 973 position of BA-111. Conclusion: Hantavirus carried by rodents in Shenzhen belongs to S2 subtype of Seoul virus, which have little variation compared with the hantavirus strains obtained in other years in Shenzhen and surrounding provinces.

A highly distorted ultraelastic chemically complex Elinvar alloy.

The development of high-performance ultraelastic metals with superb strength, a large elastic strain limit and temperature-insensitive elastic modulus (Elinvar effect) are important for various industrial applications, from actuators and medical devices to high-precision instruments1,2. The elastic strain limit of bulk crystalline metals is usually less than 1 per cent, owing to dislocation easy gliding. Shape memory alloys3-including gum metals4,5 and strain glass alloys6,7-may attain an elastic strain limit up to several per cent, although this is the result of pseudo-elasticity and is accompanied by large energy dissipation3. Recently, chemically complex alloys, such as 'high-entropy' alloys8, have attracted tremendous research interest owing to their promising properties9-15. In this work we report on a chemically complex alloy with a large atomic size misfit usually unaffordable in conventional alloys. The alloy exhibits a high elastic strain limit (approximately 2 per cent) and a very low internal friction (less than 2 × 10-4) at room temperature. More interestingly, this alloy exhibits an extraordinary Elinvar effect, maintaining near-constant elastic modulus between room temperature and 627 degrees Celsius (900 kelvin), which is, to our knowledge, unmatched by the existing alloys hitherto reported.

Metabolomics and its application in the mechanism analysis on diabetic bone metabolic abnormality.

OBJECTIVE: This study is aimed at analysing the endogenous metabolites profiling of patients with diabetic osteoporosis, so as to provide the reference for pathogenesis research of diabetic osteoporosis. PATIENTS AND METHODS: The 1H-NMR metabolomics technology, combined with pattern recognition analysis and SIMCA-P 12.0 statistical analysis, were employed to identify the metabolites differences between diabetic patients with disordered bone metabolism (research group) and healthy volunteers (normal group) in this study. RESULTS: Compared with normal group, the results show that in research group, the levels of O-acetyl glycoprotein, proline, 1-methyl histidine, tricarboxylic acid cycle (TCA cycle) product (citric acid and α-ketoglutaric acid) decline, while the levels of branched chain amino acids (leucine, isoleucine, valine), glucose, choline, creatine, inositol, glutamine, aspartic acid, alanine, glycine, and citrulline increase. CONCLUSIONS: There are disordered metabolic pathways and imbalanced bone synthetic materials and regulatory substances in diabetic patients with bone metabolic abnormality. These metabolic abnormalities could be the specific indicators in early diagnosis of diabetic osteoporosis.

Weight status, cardiorespiratory fitness and high blood pressure relationship among 5-12-year-old Chinese primary school children.

Cardiorespiratory fitness (CRF) and adiposity contribute to high blood pressure (HBP) in adults and children. However, their relative importance as risk factors is unknown. We examined the relationships between weight status, CRF and HBP among Chinese primary school children. A cross-sectional study was conducted with 4926 school children aged 5-12 years. CRF was estimated from a modified Cooper test, body mass index z-scores and weight categories were calculated from objective height and weight measurements and BP was measured using an electronic sphygmomanometer. HBP was defined as >95th percentile based on reference cutoffs for Chinese boys and girls. Generalised Linear Mixed models, adjusting for age, pubertal status and height, were developed for boys and girls to explore the independent and combined associations between fitness, weight status and HBP. Seven hundred and fifty-two (15.3%) children had HBP, with a higher prevalence in obese (40.5% and 45.9% in boys and girls, respectively) and overweight (27.6% and 30.2% in boys and girls, respectively) compared with non-overweight (9.0% and 13.8% in boys and girls, respectively) children. HBP prevalence was lower in boys with higher CRF (odds ratio (OR) for the highest vs lowest CRF quartile in boys 0.64; 95% confidence interval (CI) 0.46-0.89). This association was not seen in girls. With weight status and CRF in the same model, weight status, but not CRF, remained significantly associated with HBP (obesity in boys: OR 4.19; 95% CI 2.63-6.67; in girls: OR 2.49; 95% CI 1.19-5.19). The interaction effect for CRF and weight status was non-significant. Overweight/obesity was significantly associated with HBP among children. There was no evidence of modification of this relationship by CRF.

Composition- and temperature-dependent liquid structures in Al-Cu alloys: an ab initio molecular dynamics and x-ray diffraction study.

The composition- and temperature-dependent liquid structures in eight Alrich-Cu binary alloys (from hypoeutectic Al93Cu7 to hypereutectic Al70Cu30) have been experimentally and computationally studied by x-ray diffraction (XRD) experiments and ab initio molecular dynamics (AIMD) simulations. The remarkable agreements of structure factors for all liquid Alrich-Cu alloys obtained from high-temperature high-energy XRD measurements and AIMD simulations have been achieved, which consolidates the analyses of structural evolutions in Alrich-Cu liquids during the cooling processing by AIMD simulations. The heat capacity of liquid Alrich-Cu alloys continuously increases and presents no abnormal peak when reducing the temperature, which differs from the reported prediction for 55-atom Alrich-Cu nanoliquids. The diffusivities of Al and Cu undergo an increasing deviation from Arrhenius behavior by tuning Cu concentration from 7 to 30 atomic percentages, correlated to the local ordering in these liquids by means of coordination number, bond-angle distribution, Honeycutt-Andersen index, bond-orientational order and Voronoi tessellation analyses. Upon cooling, the microstructure of the liquid Alrich-Cu alloys inclines to form Al2Cu crystal-like local atomic ordering, especially in the hypereutectic liquids. The favorable short-range ordering between Cu and Al atoms could cause the non-Arrhenius diffusion behavior.

Evolution of atomic structure in Al75Cu25 liquid from experimental and ab initio molecular dynamics simulation studies.

X-ray diffraction and electrostatic levitation measurements, together with the ab initio molecular dynamics simulation of liquid Al(75)Cu(25) alloy have been performed from 800 to 1600 K. Experimental and ab initio molecular dynamics simulation results match well with each other. No abnormal changes were experimentally detected in the specific heat capacity over total hemispheric emissivity and density curves in the studied temperature range for a bulk liquid Al(75)Cu(25) alloy measured by the electrostatic levitation technique. The structure factors gained by the ab initio molecular dynamics simulation precisely coincide with the experimental data. The atomic structure analyzed by the Honeycutt-Andersen index and Voronoi tessellation methods shows that icosahedral-like atomic clusters prevail in the liquid Al(75)Cu(25) alloy and the atomic clusters evolve continuously. All results obtained here suggest that no liquid-liquid transition appears in the bulk liquid Al(75)Cu(25) alloy in the studied temperature range.

The study of the tumor stem cell properties of CD133+CD44+ cells in the human lung adenocarcinoma cell line A549.

We studied the tumor stem cell properties of the CD133+CD44+ subpopulation in the human lung adenocarcinoma cell line A549. A549 cells were classified into subpopulations based on differential expression patterns for CD133 and CD44. Cells from different subpopulations were cultured and subcutaneously injected into 32 nude mice. Our results as following, (1) The majority of A549 cells died, whereas only about 4.11% of cells divided and proliferated to form cell clones. (2) The expression of CD133 and CD44 in proliferative cancer cells was statistically significantly different from that in normal A549 cells (p < 0.001). (3) Cell proliferation in group A (CD133+CD44+) was the fastest among all groups. Cell proliferation in A549 cells was slower than in group A but faster than in groups B (CD133-CD44-), C (CD133-CD44+), and D (CD133+CD44-). (4) The tumorigenic capacity in cells from group A was significantly higher than that in cells from groups B (p<0.001), C (p<0.001) and D (p<0.04). In conclusion, CD133+CD44+ cells in the adenocarcinoma cell line A549 have expressive significant cancer stem cell properties with continuous proliferative capacity and differentiation potential.