[Physical activity level and its influence factors among residents in one suburb district of Beijing]

OBJECTIVE

To study the physical activity level and its influence factors among residents in one suburb of Beijing, so as to provide specific interventions for different people in different circumstances and to provide reference for health relevant policy-making in the future.

METHODS

In the study, 7 319 subjects aged 18 years or above were involved. The self-designed questionnaires based on Health Belief Model (HBM) had acceptable validity and reliability. The physical activity levels were calculated to classify sufficient or insufficient amount by a thousand-step equivalent greater than or equal to 6 or 10. Multiple variable Logistic regression was used to explore the influence factors of the physical activity among the residents.

RESULTS

The residents' median amount of physical activity in the suburb district of Beijing were 9.1 thousand-step equivalent with quartile of (3.8, 20.4). The percentages of the thousand-step equivalent greater than or equal to 6 or 10 were 63.7% and 47.7%, respectively. The median amounts of physical activity from work or household chores, transportation and recreation physical activities were 4.0, 1.0, 0.0 and the components of the total amount of physical activity from those were 61.7%, 18.3% and 20.1%, respectively. There were 8.6% residents whose life did notinvolve moderate or vigorous intensity activities. By using factor analysis, five factors were extracted from the scale based on the HBM; These factors together contributed to 63.7% of the sum of the squared loadings. The differences of physical activity levels on education level, age, gender, self-efficacy, cues, subjective and objective barriers were statistically significant (P<0.05).Those who were female, with older age, lower education level, higher self-efficacy, fewer cues, fewer subjective and objective barriers preferred to do more physical activities.

CONCLUSION

The physical activity levels among the residents in the suburb district of Beijing are moderate and high, and most amount of physical activities from work or household chores. Those who are male and whose ages are from 18 to 29 years and whose education levels are of university or above should be focused on intervention. Specific interventions should be developed for different people in different situations; More attention should be paid to improve the residents' self-efficacy and reduce the subjective and objective barriers of physical activity, and we also should actively advocate people to have more leisure exercise so as to improve the physical activity level among all residents.

Relationship between cytokine gene polymorphisms and acute rejection following liver transplantation

Acute rejection (AR) recurrence after liver transplantation (LT) is one of the major complications that leads to chronic graft dysfunction. It has been reported that the polymorphisms in some cytokine genes are associated with human liver allograft rejection. This study mainly investigated the associations between polymorphisms in the genes encoding interleukin-10 (IL10), transforming growth factor-b1 (TGFB1), and tumor necrosis factor-a (TNF), and the risk of AR recurrence. We enrolled 359 LT recipients; they were divided into two groups: an AR group (N = 165) and a non-AR group (N = 194) according to whether they experienced rejection within the first month following liver transplantation. After providing informed consent, blood was collected and DNA was extracted. The single nucleotide polymorphisms of IL10 (-1082, -819, and -592), TGFB1 (+869 and +915), and TNF (-308) were investigated according to the methods used in previous studies. A significant difference was observed in the distribution of allelic frequencies at position +869 in TGFB1 between the AR and non-AR groups (P = 0.000). However, no significant differences (P > 0.05) were found in the genotype distributions in IL10, TNF, and TGFB1 between the AR and non-AR groups. Our study suggests that the +869 gene polymorphism of TGFB1 is significantly associated with liver graft rejection, while the other gene polymorphisms investigated in IL10, TNF, and TGFB1 are probably not risk factors for AR in LT recipients.

Meta-analysis of the association between the rs7903146 polymorphism at the TCF7L2 locus and type 2 diabetes mellitus susceptibility

Type 2 diabetes mellitus (T2DM) is a chronic disease caused by genetic and environmental factors. T2DM has been associated with specific polymorphisms in the TCF7L2 gene. This study evaluates the relationship between the rs7903146 locus polymorphism of the TCF7L2 gene and T2DM susceptibility through meta-analysis; the overall aim is to provide a basis for evidence-based medicinal treatment of T2DM. Cohort and case-control studies from Medline, PubMed, EMBASE, CBM, CNKI, and academic conferences/dissertations that examined the correlation between T2DM and rs7903146 polymorphisms were evaluated. We determined whether the TCF7L2 rs7903146 locus was associated with T2DM susceptibility by comparing alleles and genotypes. The Stata 11.0 software was applied for meta-analysis, and a random-effects model was adopted for heterogeneity testing and odds ratio (OR) calculation. A fixed-effect model was used for quantitative analysis of the heterogeneity between different studies, and for calculating the percentage of variability I(2). A total of 10 studies related to the rs7903146 loci and T2DM susceptibility were enrolled; this included 3404 cases of T2DM patients and 6473 control cases. Meta-analysis showed that the T allele of rs7903146 was significantly correlated with the risk of T2DM, with both a dominant fixed-effect model (OR = 1.653, 95%CI = 1.416-1.653) and a co-dominant-fixed effect model (OR = 1.525, 95%CI = 1.350-1.723). Meta-analysis revealed that the T allele of rs7903146 was also correlated with T2DM susceptibility.

Regulation of CD4⁺FOXP3⁺ T cells by CCL20/CCR6 axis in early unexplained recurrent miscarriage patients

Expression and function of CCR6/CCL20 in CD4(+)FOXP3(+) regulatory T cells (Tregs) was investigated in unexplained recurrent miscarriage (URM) patients. Flow cytometry, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, western blots, and Transwell migration assays were used to analyze the expression and function of regulatory T cells in peripheral blood (PB) and decidual samples of women with URM and of healthy controls. Proportions of CD4(+)FOXP3(+) T cells and CCR6(+)CD4(+)FOXP3(+) T cells were lower in URM patients than in healthy controls for both PB lymphocytes and decidual samples (P < 0.05). Expression levels of FOXP3 and CCR6 mRNA were lower in URM patients than in control subjects for PB and decidual samples (P < 0.05). CCL20 protein levels were lower in URM patients than in controls (P < 0.05). An effect of Treg migration was significantly blocked (by 89.13%) using a neutralizing anti-CCL20 antibody in vitro. Furthermore, CCL20-stimulated Tregs exhibited a 3.21-fold increase in migration and this was blocked using a neutralizing anti-CCL20 antibody. IL-10 concentration in culture supernatants of CD4(+)CD25(+)CD127(dim/-) Tregs of URM patients was significantly lower than that in controls. Anti-CCL20 antibody inhibited IL-10 and IL-4 expression but increased IFN-r and IL-17 levels when there was cell-cell contact between PB CD4(+)CD25(+) T cells and CD4(+)CD25(-) T cells. No difference was detected when cell-cell contact was prevented by a semi-permeable Transwell membrane. CCL20-CCR6 could drive immune activity of CD4(+)FOXP3(+) Tregs, followed by their migration to the feto-maternal microenvironment. These results elucidated the mechanism by which Tregs exert this suppressive effect.

Complex relation among Health Belief Model components in TB prevention and care

OBJECTIVES

This study aims to explore the relationships among components of the Health Belief Model, tuberculosis (TB) preventive behavior, and intention of seeking TB care.

STUDY DESIGN

Cross section study.

METHODS

Using convenience sampling, 1154 rural-to-urban migrant workers were selected between the ages of 18-50 years in six urban areas of three provinces in China. The survey was conducted by individual, face-to-face interviews with a standardized questionnaire. Lisrel 8.7 was used to conduct path analysis.

RESULTS

The knowledge and benefits components of the Health Belief Model predicted preventive behaviors: cover nose/mouth when coughing or sneezing (β = 0.24, 0.33 respectively), evade others' coughs (β = 0.13, 0.25) and also predicted seeking TB care (β = 0.27, 0.19). Susceptibility and severity also predicted seeking TB care (β = 0.12, 0.16). There were also important relationships among model components. Knowledge of TB predicted both susceptibility (β = 0.32-0.60) and severity (β = 0.41-0.45). Further, each of susceptibility (β = 0.30) and severity (β = 0.41) predicted perceived benefits of preventive care.

CONCLUSION

Thus, a path from knowledge, through severity and susceptibility, and then through benefits predicted prevention and TB care seeking behaviors.

Tenofovir disoproxil fumarate vs adefovir dipivoxil in Chinese patients with chronic hepatitis B after 48 weeks: a randomized controlled trial

Tenofovir disoproxil fumarate (TDF) has demonstrated long-term efficacy and a high barrier to resistance in multiple chronic hepatitis B (CHB) populations outside of China. This study aimed to evaluate the efficacy and safety of TDF compared with adefovir dipivoxil (ADV) in Chinese patients with CHB during 48 weeks of treatment (ClinicalTrial.gov number, NCT01300234). A Phase 3, multicentred, randomized, double-blind, controlled trial compared the efficacy and safety of TDF with ADV in Chinese patients with CHB. The primary endpoint was the proportion of patients with HBV DNA <400 copies/mL in each treatment group at Week 48, using an unpooled Z-test for superiority. Secondary endpoints included viral suppression, serologic response, histological improvement, normalization of alanine aminotransferase (ALT) levels and the emergence of resistance mutations. A total of 509 patients, 202 hepatitis B e antigen (HBeAg)-positive and 307 HBeAg-negative, with HBV DNA ≥10(5) copies/mL received either TDF 300 mg od or ADV 10 mg od. At Week 48, TDF demonstrated superior viral suppression compared with ADV in both HBeAg-positive (76.7% vs 18.2%, P < 0.0001) and HBeAg-negative (96.8% vs 71.2%, P < 0.0001) patients. The majority of patients in both treatment arms achieved ALT normalization (>85%). No resistance to TDF was observed. The frequency of adverse events was comparable between treatment arms (TDF 3.9% vs ADV 4.8%). In this double-blind, randomized, clinical trial, TDF demonstrated superiority over ADV with respect to viral suppression in Chinese patients with CHB at 48 weeks of treatment and without the development of resistance.

Exploring the nature of the liquid–liquid transition in silicon: a non-activated transformation

The dynamics of the HDL–LDL transformation in silicon shows that this process is actually a continuous transition.

Scaling of anomalous Hall effects in facing-target reactively sputtered Fe4N films

The scaling of the anomalous Hall effect in γ′-Fe₄N films is investigated systematically for the first time.

[Status analysis of patients with hypertension in 22 community health centers of Shenzhen Futian District]

OBJECTIVE

To investigate current situation of blood pressure control in patients with hypertension in 22 community health centers of Shenzhen Futian District, and to find out related factors which affect blood pressure control.

METHODS

In the study, 10 020 cases with essential hypertension that had been registered in 22 Community Health Centers were selected as cases for the survey. The questionnaires, physical examinations, and laboratory tests were used to obtain the patients' baseline data.

RESULTS

The mean blood pressure (median) levels were 142/86 mmHg (1 mmHg=0.133 kPa). Those of the males were higher than those of the females (142/86 mmHg vs. 140/85 mmHg, ZSBP=-6.14,ZDBP=-9.93,P<0.001), the systolic blood pressure increased with age. The overall blood pressure control rate was 40.2%. The blood control rates were different with different gender, body mass index (BMI) and waist circumference. The majority of the patients took single antihypertensive drug, and the proportion accounted to 54.4%. Regression analysis showed that gender, age, hyperlipidemia, smoking, and waist circumference were the main factors that affected blood pressure control.

CONCLUSION

The blood control rate was low in these communities. Patients with high blood pressure often merge a variety of factors that affect blood pressure control, and at the same time of antihypertensive therapy for the patients, we should pay attention to the control of these factors.

Monitoring of atherosclerosis evolution by detection of inflammatory states of aortae in a rabbit model using 18F-FDG -PET/CT

AIM

In vivo dynamic evaluation of atherosclerosis could be clinically significant in the prevention of cardiovascular events. We aimed to monitor Fluorine-18 fluorodeoxyglucose (18F-FDG) uptake in different stages of atherosclerosis, and investigate the feasibility of detecting vulnerable plaques using positron emission tomography/computed tomography (PET/CT) angiography.

METHODS

Twenty-two male NZW rabbits were divided into two groups: atherosclerosis group (group A, N.=11) and atherosclerosis and statin group (group S, N.=11). The rabbits underwent two pharmacological triggerings to induce thrombus at the 18th week. In vivo PET/CT scans were performed on four time points: before cholesterol diet (baseline, N.=6), at 8th week (the middle-of-feeding, N.=4), at 18th week (the end-of-feeding, N.=22) and after triggering (post-triggering, N.=15). 18F-FDG uptake by the aorta was expressed as maximal standardized uptake value (SUVmax) and mean SUV (SUVmean). SUVs were measured on serial 7.5 mm arterial segments.

RESULTS

SUVmean and SUVmax were 0.449±0.108 and 0.550±0.132 at baseline, 0.694±0.117 and 0.754±0.129 at the middle-of-feeding, 0.788±0.121 and 0.861±0.139 in group A, and 0.651±0.194 and 0.736±0.243 in group S at the end-of feeding before triggering. SUVmean and SUVmax were 1.128±0.420 and 1.302±0.489 in thrombosis group, 0.774±0.159 and 0.859±0.191 in non-thrombosis group after triggering. Thrombus were identified in 10 of 22 rabbits (45.5%): 8 of 11 (72.3%) in group A, and 2 of 11 (18.2%) in group S (P<0.001).

CONCLUSION

The inflammatory states of atherosclerosis and vulnerable plaque can be detected by quantitative analysis of 18F-FDG uptake. PET/CT may be used for predicting thrombosis events in patients with atherosclerotic disease.

Integrating carbon nanotubes into silicon by means of vertical carbon nanotube field-effect transistors

Single-walled carbon nanotubes have been integrated into silicon for use in vertical carbon nanotube field-effect transistors (CNTFETs). A unique feature of these devices is that a silicon substrate and a metal contact are used as the source and drain for the vertical transistors, respectively. These CNTFETs show very different characteristics from those fabricated with two metal contacts. Surprisingly, the transfer characteristics of the vertical CNTFETs can be either ambipolar or unipolar (p-type or n-type) depending on the sign of the drain voltage. Furthermore, the p-type/n-type character of the devices is defined by the doping type of the silicon substrate used in the fabrication process. A semiclassical model is used to simulate the performance of these CNTFETs by taking the conductance change of the Si contact under the gate voltage into consideration. The calculation results are consistent with the experimental observations.

Effects of curcumin on hippocampal expression of NgR and axonal regeneration in Aβ-induced cognitive disorder rats

Curcumin has been widely used for the prevention and treatment of Alzheimer's disease (AD), but its mechanism is still not clear. Inhibitory factors of axonal regeneration have been shown to cause a series of pathophysiological changes in the early period of AD. In this study, the co-receptor (Nogo receptor; NgR) of three axonal growth-inhibitory proteins was examined, and effects of curcumin on spatial learning and memory abilities and hippocampal axonal growth were investigated in amyloid β-protein (Aβ)1-40-induced AD rats. Results showed that the expression of NgR in the AD group significantly increased and the number of axonal protein-positive fibers significantly reduced. The spatial learning and memory abilities of AD rats were significantly improved in the curcumin group. Furthermore, hippocampal expressions of NgR mRNA and protein decreased, and the expression of axonal protein significantly increased. There was a negative correlation between the expression of NgR and axonal growth. Together, these results suggested that curcumin could improve the spatial learning and memory abilities of AD rats. The mechanism might be related with its lowering of hippocampal NgR expression and promoting axonal regeneration.

Chlamydia psittaci exposure in pet birds

Chlamydia psittaci is a zoonotic pathogen with a wide range of avian hosts and may be transmitted to humans and cause severe disease. To assess the risk of psittacosis posed by pet birds, the seroprevalence of Chlamydia psittaci antibodies in 360 Eurasian siskins (Carduelis spinus), 289 oriental skylarks (Alauda arvensis) and 36 black-tailed grosbeaks (Coccothraustes migratorius) in Gansu province, north-western China was detected by an indirect haemagglutination assay. Twenty-seven out of 289 (9.34 %) Alauda arvensis, 45 out of 360 (12.50 %) Carduelis spinus and 2 out of 36 (5.56 %) Coccothraustes migratorius were positive for Chlamydia psittaci infection at a cut-off dilution of 1 : 16. The prevalence of Chlamydia psittaci was higher in Carduelis spinus (12.5 %) than in Alauda arvensis (9.34 %) and Coccothraustes migratorius (5.56 %); however, the differences were not statistically significant (P>0.05). Statistical analysis indicated that Chlamydia psittaci seroprevalence in adult pet birds (12.4 %, 67/540) was significantly higher than that in juvenile pet birds (4.83 %, 7/145) (P<0.01). There was no statistical difference in Chlamydia psittaci seroprevalence between male (12.4 %) and female (8.27 %) birds. To our knowledge, this is the first report indicating the seroprevalence of Chlamydia psittaci exposure in pet birds in China. Our results indicate that close contact with pet birds poses the risk of zoonotic transmission of Chlamydia psittaci.

High performance of Ge@C nanocables as the anode for lithium ion batteries

Germanium is a promising high-capacity anode material for lithium ion batteries.

Simultaneous Quantification of Six Major Flavonoids From Fructus sophorae by LC-ESI-MS/MS and Statistical Analysis

A new, sensitive and selective high-performance liquid chromatography–tandem mass spectrometric method has been developed for the determination of six major flavonoids including sophoricoside, genistin, genistein, rutin, quercetin, kaempferol in Fructus sophorae. Principal component analysis and hierarchical clustering analysis were used to classify and differentiate these samples. Chromatographic separation was performed on a C₁₈ column with linear gradient elution of methanol and 0.05% acetic acid (v/v) at a flow rate of 0.8 ml/min. The detection was accomplished in the negative mode using multiple-reaction monitoring. The total run time was 8.0 min. Full validation of the assay was carried out including linearity, precision, accuracy, recovery, limit of detection and limit of quantification. The validated method was successfully applied to the simultaneous determination of these active components in Fructus sophorae. The results demonstrated that the quantitative difference in content of six active compounds was useful for chemotaxonomy of many samples from different sources and the standardization and differentiation of many similar samples. Simultaneous quantification of bioactive components by high-performance liquid chromatography–tandem mass spectrometric method coupled with chemometric techniques would be a well-acceptable strategy to comprehensively control the quality of Fructus sophorae.

Complementary laboratory indices for predicting the disease status of patients with hepatitis B virus infection

To identify complementary laboratory indices for determining the disease status of patients with hepatitis B virus. Subjects were divided into six groups: hepatitis B virus carrier, mild chronic hepatitis B, moderate chronic hepatitis B, severe chronic hepatitis B, fulminant hepatitis B and healthy controls. Serum alanine aminotransferase, total bilirubin and direct bilirubin were measured by an automatic analyser. The levels of T-cell immunoglobulin domain and mucin-domain-containing molecule-3, macrophage inflammatory protein 2, neutrophil gelatinase-associated lipocalin and inducible nitric oxide synthase were measured by ELISA. T-cell immunoglobulin domain, mucin-domain-containing molecule-3, macrophage inflammatory protein 2 and inducible nitric oxide synthase levels were significantly higher in patients with severe chronic hepatitis B compared with those in patients with mild and moderate chronic hepatitis B or fulminant hepatitis B (P < 0.05). When normal or abnormal alanine aminotransferase was present, significant differences between macrophage inflammatory protein 2 and T-cell immunoglobulin domain and mucin-domain-containing molecule-3 levels between patients with mild, moderate, severe chronic hepatitis B or fulminant hepatitis B were observed (P < 0.05). Our results suggest that T-cell immunoglobulin domain and mucin-domain-containing molecule-3 and macrophage inflammatory protein 2 could serve as alanine aminotransferase, direct bilirubin or total bilirubin complementary indices for determining the status of patients with hepatitis B.

Effects of polymorphisms in the bovine growth differentiation factor 9 gene on sperm quality in Holstein bulls

Members of the transforming growth factor-β (TGFβ) superfamily are critical regulators of germ cell development that act as extracellular ligands of the signal transduction pathways regulating proliferation, differentiation, apoptosis, and other aspects of cell behavior. Growth differentiation factor 9 (GDF9) is a member of the TGFβ superfamily that plays a critical role in ovarian follicular development and ovulation rate in females; however, its role in the testis has not been well elucidated. Therefore, in this study we investigated the effects of GDF9 mutations on the quality of fresh and frozen semen of Holstein bulls. Two reported single nucleotide polymorphisms of GDF9, A485TA and A625C, were analyzed in 129 Holstein bulls. Analysis of variance revealed that the A485T polymorphism had significant effects on the acrosome integrity rate (P < 0.05), whereas the A625T polymorphism was significantly associated with sperm concentration (P < 0.05). In addition, a significant additive effect on sperm concentration was detected for the A485T polymorphism (P < 0.05), whereas the polymorphisms A485TA and A625C had significant dominant effects on acrosome integrity rate and sperm motility in frozen semen, respectively (P < 0.05). This study is the first to show a significant association of GDF9 with sperm quality traits, and the results implied that GDF9 is involved in the initiation or maintenance of spermatogenesis; however, further verification is needed.

Influence of contact height on the performance of vertically aligned carbon nanotube field-effect transistors

Vertically aligned carbon nanotube field-effect transistors (CNTFETs) have been experimentally demonstrated (J. Li et al., Carbon, 2012, 50, 4628-4632). The source and drain contact heights in vertical CNTFETs could be much higher than in flat CNTFETs if the fabrication process is not optimized. To understand the impact of contact height on transistor performance, we use a semi-classical method to calculate the characteristics of CNTFETs with different contact heights. The results show that the drain current decreases with increasing contact height and saturates at a value governed by the thickness of the oxide. The current reduction caused by the increased contact height becomes more significant when the gate oxide is thicker. The higher the drain voltage, the larger the current reduction. It becomes even worse when the band gap of the carbon nanotube is larger. The current can differ by a factor of more than five between the CNTEFTs with low and high contact heights when the oxide thickness is 50 nm. In addition, the influence of the contact height is limited by the channel length. The contact height plays a minor role when the channel length is less than 100 nm.

Determination of passive-sampled sulphur dioxide in ambient air as sulphate ion by flow injection analysis with an in-line reaction column

A modified FIA method was developed for the determination of sulphur dioxide (SO(2)) in ambient air collected by a passive sampler. SO(2) was oxidized by hydrogen peroxide and determined as sulphate ion in solution. Barium-dimethylsulfoazo-III complex was used as spectrophotometric reagent. A BaSO(4)-immobilized in-line reaction column was introduced into the flow system to increase the sensitivity and reproducibility. An in-line cation exchange column was used to eliminate triethanolamine, which was used as the absorbent reagent in the passive sampler. Sulphate ions can be analyzed in the range of 0.08-10.00 mg l(-1) with the R.S.D. less than 1.6% at the rate of 15 samples h(-1). It was satisfactory to apply this method to the analysis of sulphur dioxide in ambient air and the results agreed with those obtained by ion chromatography.

Doping monolayer graphene with single atom substitutions

Functionalized graphene has been extensively studied with the aim of tailoring properties for gas sensors, superconductors, supercapacitors, nanoelectronics, and spintronics. A bottleneck is the capability to control the carrier type and density by doping. We demonstrate that a two-step process is an efficient way to dope graphene: create vacancies by high-energy atom/ion bombardment and fill these vacancies with desired dopants. Different elements (Pt, Co, and In) have been successfully doped in the single-atom form. The high binding energy of the metal-vacancy complex ensures its stability and is consistent with in situ observation by an aberration-corrected and monochromated transmission electron microscope.

Correlation of assessment of plasma cells by flow cytometry and detection of cytogenomic abnormalities by fluorescence in situ hybridization in plasma cell neoplasms

INTRODUCTION

Increased monoclonal plasma cell count (PCC) in bone marrow (BM) is an indicator of a plasma cell neoplasm (PCN). Assessing PCC in BM by morphologic evaluation (ME) and flow cytometry (FC) is important in diagnosing PCN. Also important is fluorescence in situ hybridization (FISH) to detect cytogenomic abnormalities (CAs) in PCN. Owing to FC's short turnaround time, FC-assessed PCC is often used as empirical reference for further FISH study. However, correlation of FC-assessed PCs with FISH-detected CAs has not been well studied. The purpose of this study was to validate this correlation on BM aspirates from patients with PCN.

METHODS

We reviewed 224 cases of newly diagnosed PCN identified from our Lab-database. Both FC and FISH had been performed on BM aspirates from these cases, of which 178 had been assessed by ME. The original findings from the 224 cases were also reviewed.

RESULTS

Using a cut-off of 3% PCs assessed by FC as an indicator for further FISH analysis, 20 (17%) FISH-detectable PCN cases were missed; 30% of the missed cases carried high-risk CAs and/or were highly progressive PCN.

CONCLUSION

In PCN cases, an FC-assessed 3% PCC in BM aspirates should not be used as a cut-off for further FISH testing.

Rice planting systems, global warming and outbreaks of Nilaparvata lugens (Stål)

Brown Planthopper (BPH, Nilaparvata lugens (Stål)) is one of the most serious pests of rice in both temperate and tropical regions of East and South Asia and has become especially problematic over the past few years. In order to analyze the effect of the change of rice cropping system on the population dynamics of BPH, field surveys of the occurrence and distribution of BPH were performed and other relevant data, including light trap data and ovary dissection data were collected in nearly 40 Chinese counties encompassing six provinces (or municipalities), including Hainan, Guangxi, Anhui, Shanghai, Fujian and Guangdong from April to October in 2007.The mixed planting areas of single- and double-cropping rice in China include Hubei, South and Central Anhui, North Hunan, and North Jiangxi. In these areas, double-cropping rice has now been greatly reduced and single-cropping rice has been rapidly increasing since 1997. The surveys revealed that when the immigration peak of BPH occurred in June and July, the single-cropping rice was at the tillering to booting stage and fit for BPH, but early rice had already matured and most of late rice had not yet been transplanted. BPH immigrants from southern rice areas prefer to inhabit and breed in single-cropping rice paddies. Moreover, farming activities between early rice and late rice interrupted the continuous growth of BPH populations in double-cropping rice paddies. As a result, in comparison with data collected 30 years ago, the spatiotemporal dynamics and migration patterns of BPH have dramatically changed in the lower-middle reaches of the Yangtze River. In the mixed planting areas, due to their high suitability, the BPH population in single-cropping rice grew so quickly that it caused serious local damage and there was mass emigration of macropterous progeny to the Yangtze River Delta in late August and early September.Global warming may also affect BPH populations, where results suggest steadily warmer autumns have occurred from the 1990s on, with such conditions gradually the norm. The combination of 'cooler summer' and 'warmer autumn' are conditions known to promote outbreaks of BPH in the lower-middle reaches of the Yangtze River. Immigrant BPH arrivals in late August and September now cause serious damage to late-maturing mid-season rice and late rice in the lower-middle reaches of the Yangtze River.

Site-specific multi-stage CVD of large-scale arrays of ultrafine ZnO nanorods

Multi-stage growth of ZnO nanorod arrays has been carried out by Au-assisted chemical vapor deposition (CVD) in order to better understand and more precisely control the growth behaviors. It is evidenced that Au-catalyzed vapor-liquid-solid (VLS) growth only dominates the initial site-specific nucleation of the nanorods, while the subsequent growth is governed by a vapor-solid (VS) epitaxy mechanism. The sequential VLS and VS behaviors permit the fabrication of large-scale highly ordered arrays of ZnO nanorods with precisely tunable diameters and embedded junctions by controlling reactant concentration and nanorod top morphology. Based on the above results, two routes to fabricate ultrafine ZnO nanorod arrays are proposed and stepwise nanorod arrays with ultrafine top segment (~10 nm in diameter) have been achieved. Temperature-dependent photoluminescence (PL) and spatial resolved PL were carried out on the nanorod arrays and on individual nanorods, indicating high quality optical properties and tunable light emission along the length of the stepwise nanorods.

Testing temperature-induced proteomic changes in the plant-associated bacterium Pseudomonas fluorescens SBW25

Traits used by bacteria to enhance ecological performance in natural environments are not well understood. Recognizing that the saprophytic plant-colonizing bacterium Pseudomonas fluorescens SBW25 experiences temperatures in its natural environment significantly cooler than the 28°C routinely used in the laboratory, we identified proteins differentially expressed between 28°C and the more environmentally relevant temperature of 14°C. Of 2102 protein isoforms, 32 were temperature responsive and identified by mass spectrometry. Seven of these (OmpR, MucD, GuaD, OsmY and three of unknown function, Tee1, Tee2 and Tee3) were selected for genetic and ecological analyses. In each instance, changes in protein expression with temperature were mirrored by parallel transcriptional changes. The fitness contribution of the genes encoding each of the seven proteins was larger at 14°C than 28°C and included two cases of trade-offs (enhanced fitness at one temperature and reduced fitness at the other -mucD and tee2 deletions). The relationship between the fitness effects of genes in vitro and in vivo was variable, but two temperature-responsive genes -osmY and mucD- contribute substantially to the ability of P. fluorescens to colonize the plant environment.

Giant magnetic-field-induced strains in polycrystalline Ni-Mn-Ga foams

The magnetic shape-memory alloy Ni-Mn-Ga shows, in monocrystalline form, a reversible magnetic-field-induced strain (MFIS) up to 10%. This strain, which is produced by twin boundaries moving solely by internal stresses generated by magnetic anisotropy energy, can be used in actuators, sensors and energy-harvesting devices. Compared with monocrystalline Ni-Mn-Ga, fine-grained Ni-Mn-Ga is much easier to process but shows near-zero MFIS because twin boundary motion is inhibited by constraints imposed by grain boundaries. Recently, we showed that partial removal of these constraints, by introducing pores with sizes similar to grains, resulted in MFIS values of 0.12% in polycrystalline Ni-Mn-Ga foams, close to those of the best commercial magnetostrictive materials. Here, we demonstrate that introducing pores smaller than the grain size further reduces constraints and markedly increases MFIS to 2.0-8.7%. These strains, which remain stable over >200,000 cycles, are much larger than those of any polycrystalline, active material.

Optimization of Xhhh strain biodegradation with metal ions for pharmaceautical wastewater treatment

Effects of three ions, Mn2+, Cu2+ and Zn2+ on biological treatment of pharmaceutical wastewaterby a functional strain Xhhh were investigated. Through orthogonal tests, Cu2+ was determined to be the most important factor influencing Xhhh biodegradation performance. Biodegradation kinetic experiments demonstrated that with Cu+ concentration at about 200 mg l(-1), the maximum of specific growth rate and specific degradation rate were obtained to be 0.033 and 0.075 d(-1), respectively. The optimal levels of Mn2+ (5.00 mg I(-1)), Cu2+ (2.00 mg l(-1)) and Zn2+ (5.00 mg l(-1)) were achieved based on experimental results of their effects on the activities of manganese peroxidase and lignin peroxidase, and biodegradation kinetic parameters. Among three types of biodegradation kinetic models (Monod, Tessier and Contois), Tessier model was found most reasonable for kinetics description of Xhhh growth (R2 = 0.995) and pollutants degradation (R2 = 0.970) in the case of metals optimization. Both kinetics evaluation and experimental results demonstrated that optimization with the three metals made a great contribution to Xhhh growth and COD removal for pharmaceutical wastewater treatment.

Preliminary risk assessment of trace metal pollution in surface water from Yangtze River in Nanjing Section, China

In order to investigate the contamination levels of trace metals, surface water samples were collected from six regions along Yangtze River in Nanjing Section. The concentrations of trace metals (As, B, Ba, Be, Cd, Cr, Cu, Fe, Pb, Li, Mn, Mo, Ni, Sb, Se, Sn, Sr, V and Zn) were determined using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Total concentrations of the metals in the water samples ranged from 825.1 to 950.4 microg/L. The result was compared with international water quality guidelines. Seven metals levels were above the permissible limit as prescribed by guidelines. A preliminary risk assessment was then carried out to determine the human health risk via calculating Hazard Quotient and carcinogenic risk of the metals. Hazard Quotients of all metals were lower than unity, except As. The carcinogenic risk of As and Cd was higher than 10(-6), suggesting that those two metals have potential adverse effects on local residents.

Variability and genetic basis for migratory behaviour in a spring population of the aphid, Aphis gossypii Glover in the Yangtze River Valley of China

The population dynamics, development of gonads, takeoff and flight behaviour of Aphis gossypii Glover were investigated in order to test whether there was variation of migratory ability in the spring population. Field surveys showed that not all the aphids overwintering on hibiscus migrated to the secondary host plants, and the host-alternating and host-specific life-cycle forms coexisted in Nanjing, China. Substantial variation in flight capacity of winged individuals, development of gonads and takeoff behaviour were found within the spring population. The frequency distribution of flight duration and the number of ovarioles per individual alatae exhibited two peaks, representing the migratory and sedentary genotypes, respectively. Significant response to directional selection on takeoff behaviour demonstrated the additive genetic component of this variation. Selection for 'takeoff' individuals caused a significant increase in takeoff angle from 39.8 degrees in the first selection to 68.7 degrees in the fifth; and, hence, screened out the migratory genotype (M), while selection for the sedentary individuals increased the rate of non-takeoffs significantly, and screened out the sedentary genotype (S). The reciprocal cross, M(female) x S(male), produced hybrid offspring performing significantly steeper takeoff angles compared with those from the cross S(female) x M(male), suggesting the presence of a maternal effect. On the other hand, takeoff rate was ranked as M(female) x S(male)=S(female) x M(male)>M>S, involving no sex-linkage and maternal effect. The coexistence of host-alternating and host-specific life-cycle forms of A. gossypii on the primary host has, as deduced from the present studies, a genetic basis.

Intrinsic anisotropy of degree of transport spin polarization in typical ferromagnets

A general approach is presented for investigation of the anisotropy of the degree of transport spin polarization (P) in ferromagnets both in the ballistic regime, P(1,i), and in the diffusive regime, P(2,i), as a function of crystal direction. The validity of this approach is confirmed by the benchmark calculation for the isotropic P. By this approach, we have investigated the anisotropy of P in bcc Fe, fcc Co, fcc Ni and hcp Co. For cubic structures, P(1,i) shows a small but appreciable anisotropy, due to the difference in the electronic orbital extension for spin-up and spin-down conduction bands. However, P(2,i) shows an isotropic feature for the cubic structure, as a result of the combination of its dependence on the square of electron velocity and the lattice symmetry. On the other hand, for hcp Co, both P(1,i) and P(2,i) show a very strong anisotropy. The large anisotropy of P(1,i) and P(2,i) in hcp Co is mainly attributed to the anisotropy of spin-down ballistic (diffusive) conductance.

A novel Delta12-fatty acid desaturase gene from methylotrophic yeast Pichia pastoris GS115

The methylotrophic yeast Pichia pastoris GS115, a widely used strain in production of various heterologous proteins, especially membrane-bound enzymes, can also produce linoleic and linolenic acids, which indicates the existence of membrane-bound Delta12 and Delta15-fatty acid desaturases. This paper describes the cloning and functional characterization of a novel Delta12-fatty acid desaturase gene from this methylotrophic yeast. The open reading frame of the gene (named Pp-FAD12) is 1263 bp in size and encodes a 420-amino-acid peptide. The deduced Pp-FAD12 protein shows high identity (50-67%) with Delta12-fatty acid desaturases from other fungi. It also shows a high identity (57%) with Delta15-fatty acid desaturase (named Sk-FAD15) from Saccharomyces kluyveri. Expression of Pp-FAD12 in polyunsaturated fatty acids non-producing yeast Saccharomyces cerevisiae demonstrated that its product converted oleic acid (18 : 1) to linoleic acid (18 : 2). This result suggests that Pp-FAD12 encodes a novel Delta12-fatty acid desaturase in P. pastoris GS115. This is the first report about the cloning and functional characterization of Delta12-fatty acid desaturase gene in methylotrophic yeast.

Location and phylogenetic analysis of the region immediately upstream of the granulin gene of the Clostera anachoreta granulovirus

The region immediately upstream of the granulin gene from Clostera anachoreta granulovirus (ClanGV) was identified from hybridization experiments and sequenced. The sequence of 5122nt EcoRI restriction fragment was presented and compared with the equivalent area in other GVs. Database searches showed that this region contained three open reading frames (ORFs) similar to the baculovirus genes (egt, fgf and me53, respectively) and four ORFs unique to ClanGV genome. Phylogenetic trees of the baculovirus genes egt and me53 were constructed. These analyses indicated that ClanGV genes may be more closely related to CfGV, CpGV, ClGV, PoGV and AoGV than to PxGV and XcGV.

Effects of carbon dioxide on the searching behaviour of the root-feeding clover weevil Sitona lepidus (Coleoptera: Curculionidae)

The respiratory emission of CO2 from roots is frequently proposed as an attractant that allows soil-dwelling insects to locate host plant roots, but this role has recently become less certain. CO2 is emitted from many sources other than roots, so does not necessarily indicate the presence of host plants, and because of the high density of roots in the upper soil layers, spatial gradients may not always be perceptible by soil-dwelling insects. The role of CO2 in host location was investigated using the clover root weevil Sitona lepidus Gyllenhall and its host plant white clover (Trifolium repens L.) as a model system. Rhizochamber experiments showed that CO2 concentrations were approximately 1000 ppm around the roots of white clover, but significantly decreased with increasing distance from roots. In behavioural experiments, no evidence was found for any attraction by S. lepidus larvae to point emissions of CO2, regardless of emission rates. Fewer than 15% of larvae were attracted to point emissions of CO2, compared with a control response of 17%. However, fractal analysis of movement paths in constant CO2 concentrations demonstrated that searching by S. lepidus larvae significantly intensified when they experienced CO2 concentrations similar to those found around the roots of white clover (i.e. 1000 ppm). It is suggested that respiratory emissions of CO2 may act as a 'search trigger' for S. lepidus, whereby it induces larvae to search a smaller area more intensively, in order to detect location cues that are more specific to their host plant.

The origin of the non-monotonic field dependence of the blocking temperature in magnetic nanoparticles

The dependence of the peak temperature (T(P)) of the zero-field-cooled (ZFC) magnetization curves on the field in a magnetic nanoparticle system was studied using a diluted magnetic fluid composed of FePt nanoparticles. We found that the peak temperature increases with increasing applied field below 3 kOe; it then decreases when the applied field is increased further. We attribute the non-monotonic field dependence of the peak temperature to the anisotropic energy barrier distribution of the particles and to the slow decrease of high-field magnetization above the blocking temperature. Numerical simulations, based on magnetic dynamics, agree well with our experimental results.

A novel Delta12-fatty acid desaturase gene from methylotrophic yeast Pichia pastoris GS115

The methylotrophic yeast Pichia pastoris GS115, a widely used strain in production of various heterologous proteins, especially membrane-bound enzymes, can also produce linoleic and linolenic acids, which indicates the existence of membrane-bound Delta12 and Delta15-fatty acid desaturases. This paper describes the cloning and functional characterization of a novel Delta12-fatty acid desaturase gene from this methylotrophic yeast. The open reading frame of the gene (named Pp-FAD12) is 1263 bp in size and encodes a 420-amino-acid peptide. The deduced Pp-FAD12 protein shows high identity (50-67%) with Delta12-fatty acid desaturases from other fungi. It also shows a high identity (57%) with Delta15-fatty acid desaturase (named Sk-FAD15) from Saccharomyces kluyveri. Expression of Pp-FAD12 in polyunsaturated fatty acids non-producing yeast Saccharomyces cerevisiae demonstrated that its product converted oleic acid (18 : 1) to linoleic acid (18 : 2). This result suggests that Pp-FAD12 encodes a novel Delta12-fatty acid desaturase in P. pastoris GS115. This is the first report about the cloning and functional characterization of Delta12-fatty acid desaturase gene in methylotrophic yeast.

Characterization and partial genome sequence analysis of Clostera anachoreta granulovirus

The morphological and biological properties as well as partial genomic sequencing of a granulovirus isolated from Clostera anachoreta (Lepidoptera: Notodontidae), C. anachoreta granulovirus (ClanGV), were carried out. The ovoidal occlusion bodies were 337 nm x 170 nm in size, and each granule contained one single rod-shape virion, with a mean size of 250 nm x 46 nm. Granulin had a molecular weight of approximately 30 kDa. ClanGV genome size was estimated as 104.34 kb based on the restriction fragments. The restriction pattern of the ClanGV genome was different from other GVs. A restriction fragment genomic library of ClanGV genome was constructed. The library consisted of nine SalI fragments, seven HindIII fragments and seven EcoRI fragments. One 4.8 kb fragment of the genome, digested by SalI, was sequenced and analyzed. This region was composed of eight unknown ORFs, two baculoviruses homologous gene (vp1054 and lef10) and partial sequence of lef-8. The unknown ORFs included three unique to ClanGV, the other five ORFs were related to baculoviruses. The ORFs, located within this restriction fragment, were compared to homologues in other GVs. The results indicated that ClanGV, CpGV, ClGV, AoGV and PoGV had similar arrangement and orientation of the homologous ORFs. Phylogenetic analysis of VP1054 proteins from 20 baculoviruses indicated that ClanGV was more closely related to CpGV, ClGV, AoGV and PoGV than to other baculoviruses.

Molecular epidemiology of Mycobacterium tuberculosis in China: a nationwide random survey in 2000

OBJECTIVE

To determine the contribution of the Mycobacterium tuberculosis (TB) Beijing genotype to the population structure of M. tuberculosis complex in China.

DESIGN

Genotypes of 441 mycobacterial isolates were determined by spoligotyping and IS6110 restriction fragment length polymorphism (RFLP). The isolates were from a nationwide random survey for the epidemiology of TB conducted in 2000, and the drug susceptibility patterns and epidemiological data were known.

RESULT

A total of 408 samples contained M. tuberculosis as determined by spoligotyping. Of the M. tuberculosis strains, 64.9% (265/408) were of the Beijing genotype. Using the chi-squared test, no statistically significant differences were observed in the proportion of Beijing genotype TB in patients of different sex, age or living in different areas of the country, but a significant difference was observed with multidrug-resistant (MDR) TB: 77.8% (42/ 54) of MDR isolates were of the Beijing genotype vs. 60.2% (213/354) of the drug-susceptible isolates. In the multivariate logistic regression model, the Beijing genotype was significantly associated with region and not with MDR.

CONCLUSION

The M. tuberculosis Beijing genotype has prevailed in China for at least five decades and is associated with region.