Mechanical transmission of dengue virus by Aedes aegypti may influence disease transmission dynamics during outbreaks

BACKGROUND

Dengue virus outbreaks are increasing in number and severity worldwide. Viral transmission is assumed to require a minimum time period of viral replication within the mosquito midgut. It is unknown if alternative transmission periods not requiring replication are possible.

METHODS

We used a mouse model of dengue virus transmission to investigate the potential of mechanical transmission of dengue virus. We investigated minimal viral titres necessary for development of symptoms in bitten mice and used resulting parameters to inform a new model of dengue virus transmission within a susceptible population.

FINDINGS

Naïve mice bitten by mosquitoes immediately after they took partial blood meals from dengue infected mice showed symptoms of dengue virus, followed by mortality. Incorporation of mechanical transmission into mathematical models of dengue virus transmission suggest that this supplemental transmission route could result in larger outbreaks which peak sooner.

INTERPRETATION

The potential of dengue transmission routes independent of midgut viral replication has implications for vector control strategies that target mosquito lifespan and suggest the possibility of similar mechanical transmission routes in other disease-carrying mosquitoes.

FUNDING

This study was funded by grants from the National Health Research Institutes, Taiwan (04D2-MMMOST02), the Human Frontier Science Program (RGP0033/2021), the National Institutes of Health (1R01AI143698-01A1, R01AI151004 and DP2AI152071) and the Ministry of Science and Technology, Taiwan (MOST104-2321-B-400-016).

CLEC5A mediates Zika virus-induced testicular damage

BACKGROUND

Zika virus (ZIKV) infection is clinically known to induce testicular swelling, termed orchitis, and potentially impact male sterility, but the underlying mechanisms remain unclear. Previous reports suggested that C-type lectins play important roles in mediating virus-induced inflammatory reactions and pathogenesis. We thus investigated whether C-type lectins modulate ZIKV-induced testicular damage.

METHODS

C-type lectin domain family 5 member A (CLEC5A) knockout mice were generated in a STAT1-deficient immunocompromised background (denoted clec5a^-/-stat1^-/-) to enable testing of the role played by CLEC5A after ZIKV infection in a mosquito-to-mouse disease model. Following ZIKV infection, mice were subjected to an array of analyses to evaluate testicular damage, including ZIKV infectivity and neutrophil infiltration estimation via quantitative RT-PCR or histology and immunohistochemistry, inflammatory cytokine and testosterone detection, and spermatozoon counting. Furthermore, DNAX-activating proteins for 12 kDa (DAP12) knockout mice (dap12^-/-stat1^-/-) were generated and used to evaluate ZIKV infectivity, inflammation, and spermatozoa function in order to investigate the potential mechanisms engaged by CLEC5A.

RESULTS

Compared to experiments conducted in ZIKV-infected stat1^-/- mice, infected clec5a^-/-stat1^-/- mice showed reductions in testicular ZIKV titer, local inflammation and apoptosis in testis and epididymis, neutrophil invasion, and sperm count and motility. CLEC5A, a myeloid pattern recognition receptor, therefore appears involved in the pathogenesis of ZIKV-induced orchitis and oligospermia. Furthermore, DAP12 expression was found to be decreased in the testis and epididymis tissues of clec5a^-/-stat1^-/- mice. As for CLEC5A deficient mice, ZIKV-infected DAP12-deficient mice also showed reductions in testicular ZIKV titer and local inflammation, as well as improved spermatozoa function, as compared to controls. CLEC5A-associated DAP12 signaling appears to in part regulate ZIKV-induced testicular damage.

CONCLUSIONS

Our analyses reveal a critical role for CLEC5A in ZIKV-induced proinflammatory responses, as CLEC5A enables leukocytes to infiltrate past the blood-testis barrier and induce testicular and epididymal tissue damage. CLEC5A is thus a potential therapeutic target for the prevention of injuries to male reproductive organs in ZIKV patients.

Limonitum Ameliorates Castor Oil-Induced Diarrhoea in Mice by Modulating Gut Microbiota

Diarrhoea is a common clinical condition; its pathogenesis is strongly associated with gut microbiota dysbiosis. Limonitum is a well-known traditional Chinese medicine that exerts appreciable benefits regarding the amelioration of diarrhoea. However, the mechanism through which Limonitum ameliorates diarrhoea remains unclear. Here, the efficacy and underlying mechanism of Limonitum decoction (LD) regarding diarrhoea were explored from the aspect of gut microbiota. Castor oil (CO) was used to induce diarrhoea in mice, which were then used to evaluate the effects of LD regarding the timing of the first defecation, diarrhoea stool rate, degree of diarrhoea, diarrhoea score, intestinal propulsive rate, and weight of intestinal contents. The concentrations of short-chain fatty acids (SCFAs), including acetic, propionic, isobutyric, butyric and valeric acids, were analysed by gas chromatography-mass spectrometry (GC-MS). The 16S rRNA high-throughput sequencing technology was applied to evaluate changes in the gut microbiota under exposure to LD. LD was found to effectively ameliorate the symptoms of diarrhoea, and the diversity and relative abundance of gut microbiota were restored to normal levels following LD treatment. Additionally, LD significantly restored the observed reductions in SCFAs. These results provide strong evidence that LD can sufficiently ameliorate diarrhoea in mice by regulating their gut microbiota. The findings presented here highlight that Limonitum may constitute a prospective remedy for diarrhoea.

[A preliminary investigation on a deep learning convolutional neural networks based pulmonary tuberculosis CT diagnostic model]

Objective: To evaluate the clinical value of a pulmonary tuberculosis CT diagnostic model based on deep learning convolutional neural networks (CNN). Methods: From March 2017 to March 2018,a total of 1 764 patients with positive sputum for tuberculous bacterium and had received high-resolution chest CT scan in radiology department of Hebei province chest hospital were enrolled. Among them, 937 were male, and 827 were female, aging from 17-73 years (average 38.4). A total of 20 139 CT images (17 kinds of image features) classified by 4 radiologists were used as training dataset to create a tuberculosis CT CNN diagnostic model. The top 5 image features in training set were: infiltrative pulmonary tuberculosis, cavitary pulmonary tuberculosis, pleural thickening, caseous pneumonia and pleural effusion. A total of 302 images were randomly selected from the marked images as testing dataset. The diagnosis of 2 senior radiologists was taken as "golden standard". The differences of sensitivity and accuracy in CT diagnosis between the CNN diagnostic model and the radiologists were compared. The classification error types and numbers of the CNN diagnostic model were recorded. FROC(free response operating characteristic curve)curve was drawn and the highest diagnostic efficiency of the model was measured. Results: The diagnostic accuracy of infiltrative pulmonary tuberculosis, cavitary pulmonary tuberculosis, pleural thickening, caseous pneumonia and pleural effusion by the CNN diagnostic model were 95.33%(10 982/11 520), 73.68%(2 151/2 920), 73.07%(1 128/1544), 83.33%(1 020/1225)and 94.11%(814/865), respectively. The overall diagnostic sensitivity and accuracy of the CNN model were 95.49%(339/355)and 90.40%(339/375), respectively, and the corresponding values ​​of radiologists were 93.80%(348/371)and 92.80%(348/375), respectively, and there was no statistical difference between the CNN model and the radiologists(sensitivity χ²=1.022,P=0.312;accuracy χ²=1.404,P=0.236). FROC curve showed that when sensitivity of the CNN model was 78% and FPI value was 2.48, it reached the highest diagnostic efficiency. The classification error of CNN diagnostic models was mainly confusion of fiber stripe components, cavitary pulmonary tuberculosis, caseous pneumonia and infiltrative pulmonary tuberculosis. Conclusions: The CNN-based pulmonary tuberculosis CT diagnostic model exhibited high sensitivity and accuracy (95.49% and 90.40% respectively). It could assist radiologists in CT diagnosis of pulmonary tuberculosis and deserve further clinical application.

Transgenic Expression of Human C-Type Lectin Protein CLEC18A Reduces Dengue Virus Type 2 Infectivity in Aedes aegypti

The C-type lectins, one family of lectins featuring carbohydrate binding domains which participate in a variety of bioprocesses in both humans and mosquitoes, including immune response, are known to target DENV. A human C-type lectin protein CLEC18A in particular shows extensive glycan binding abilities and correlates with type-I interferon expression, making CLEC18A a potential player in innate immune responses to DENV infection; this potential may provide additional regulatory point in improving mosquito immunity. Here, we established for the first time a transgenic Aedes aegypti line that expresses human CLEC18A. This expression enhanced the Toll immune pathway responses to DENV infection. Furthermore, viral genome and virus titers were reduced by 70% in the midgut of transgenic mosquitoes. We found significant changes in the composition of the midgut microbiome in CLEC18A expressing mosquitoes, which may result from the Toll pathway enhancement and contribute to DENV inhibition. Transgenic mosquito lines offer a compelling option for studying DENV pathogenesis, and our analyses indicate that modifying the mosquito immune system via expression of a human immune gene can significantly reduce DENV infection.

Ethnic Disparities in Dental Caries among Adolescents in China

Comprehensive research on ethnic disparities in dental caries in China is limited. The aims of this cross-sectional study were to compare the levels of dental caries in adolescents between the Han ethnic group and ethnic minority groups in China and to explore the risk indicators for dental caries within ethnic subgroups. Data from the Fourth National Oral Health Survey in 2015, which covered all 31 province-level administrative divisions in mainland China, were used. The dental caries status in the permanent dentition of adolescents aged 12, 13, 14, and 15 y was measured using the decayed, missing, and filled teeth (DFMT) score, and sociodemographic characteristics and oral health-related behaviors were also collected. A total of 118,601 adolescents were included, with ethnic minority groups accounting for 13.15%. Of the Han and minority groups, the standardized prevalence of dental caries experience was 40.58% and 47.67%, and the mean DMFT scores were 0.97 and 1.28, respectively. According to the multivariate zero-inflated negative binomial regression analysis, the caries status of minorities was more severe than Han adolescents (adjusted prevalence rate ratio [PRR], 1.14; 95% confidence interval [CI], 1.10-1.18). This disparity was greater among adolescents who lived in rural areas, had mid-level economic status, and frequently consumed sugary beverages. After propensity score matchings, Uygur (PRR, 1.44; 95% CI, 1.25-1.67), Tibetan (PRR, 1.39; 95% CI, 1.3-1.48), and Yi (PRR, 1.24; 95% CI, 1.04-1.48) adolescents were significantly more likely to have caries than Han adolescents. Subgroup analyses revealed that gender, age, location of residence, economic status, region, consumption of sweet snacks and sugary beverages, and dental visit pattern were significantly associated with dental caries within ethnic minorities.

Releasing Intracellular NS1 from Mosquito Cells for the Detection of Dengue Virus-Infected Mosquitoes

Dengue virus (DENV), the pathogen that causes dengue fever, is mainly transmitted by Aedes aegypti. Surveillance of infected mosquitoes is a major component of integrated mosquito control methods for reducing the risk of vector-born disease outbreaks. However, a specialized rapid test for DENV detection in mosquitoes is not currently available. Utilizing immunoblotting, we found that the secretion of NS1 from both a DENV-infected mosquito cell line and mosquito bodies was below the detection threshold. However, when Triton X-100 was used to lyse infected mosquitoes, intracellular NS1 was released, and could then be effectively detected by the NS1 rapid test. The distribution of DENV NS1 in intrathoracically infected mosquitoes was different from that of orally infected mosquitoes. Next, we performed sensitivity tests by bisecting mosquitoes longitudinally; one half of each mosquito was subjected to the NS1 rapid test while the other half was used for qPCR confirmation. This modified test had a sensitivity of nearly 90% from five days post-infection onwards, while DENV had escaped from the midgut barrier. This adapted test offers a valuable, easy-to-use tool for mosquito surveillance, which is a crucial component of DENV disease control.

Loss of the Drosophila branched-chain α-ketoacid dehydrogenase complex results in neuronal dysfunction

Maple syrup urine disease (MSUD) is an inherited error in the metabolism of branched-chain amino acids (BCAAs) caused by a severe deficiency of the branched-chain α-ketoacid dehydrogenase (BCKDH) complex, which ultimately leads to neurological disorders. The limited therapies, including protein-restricted diets and liver transplants, are not as effective as they could be for the treatment of MSUD due to the current lack of molecular insights into the disease pathogenesis. To address this issue, we developed a Drosophila model of MSUD by knocking out the dDBT gene, an ortholog of the human gene encoding the dihydrolipoamide branched chain transacylase (DBT) subunit of BCKDH. The homozygous dDBT mutant larvae recapitulate an array of MSUD phenotypes, including aberrant BCAA accumulation, developmental defects, poor mobile behavior and disrupted L-glutamate homeostasis. Moreover, the dDBT mutation causes neuronal apoptosis during the developmental progression of larval brains. The genetic and functional evidence generated by in vivo depletion of dDBT expression in the eye indicates severe impairment of retinal rhabdomeres. Further, the dDBT mutant shows elevated oxidative stress and higher lipid peroxidation accumulation in the larval brain. Therefore, we conclude from in vivo evidence that the loss of dDBT results in oxidative brain damage that may lead to neuronal cell death and contribute to aspects of MSUD pathology. Importantly, when the dDBT mutants were administrated with Metformin, the aberrances in BCAA levels and motor behavior were ameliorated. This intriguing outcome strongly merits the use of the dDBT mutant as a platform for developing MSUD therapies.This article has an associated First Person interview with the joint first authors of the paper.

A torque type full tensor gravity gradiometer based on a flexure-strip suspension

Full tensor gravity gradiometers based on accelerometer pair combination are widely employed in earth resource explorations using gravity gradient measurements. However, the extremely high requirements of accelerometer dynamic range and the scale factor consistency of accelerometer pairs are the two main limitations to further improve their performances. In order to overcome these two extreme challenges, the torque type gravity gradiometer based on the Etövös torsion balance pendulum is re-considered. In this paper, an improved torque type full tensor gravity gradiometer with a flexure-strip suspension is proposed, which balances the mechanical sensitivity and the response time. The proposed gradiometer can be used to measure the full tensor gravity gradient by observing angle variations at three azimuths. The principle and feasibility of the torque type full tensor gravity gradiometer based on a flexure-strip suspension are introduced, and the main noise sources including mechanical thermal noise, position sensing noise, and readout noise are analyzed. A prototype gravity gradiometer with a designed resolution of 2 E/Hz^1/2 at 0.1 Hz is constructed (1 E = 10^-9/s²), and the experimental results indicate that its resolution comes to 3 E/Hz^1/2 at 0.1 Hz, which is mainly limited by the seismic noise. This type of gravity gradiometer can be further improved due to its high potential resolution and independence of matching combination requirement, which allows it to be applied in next generation gravity resource exploration.

Intestinal microbial dysbiosis aggravates the progression of Alzheimer's disease in Drosophila

Neuroinflammation caused by local deposits of Aβ₄₂ in the brain is key for the pathogenesis and progression of Alzheimer’s disease. However, inflammation in the brain is not always a response to local primary insults. Gut microbiota dysbiosis, which is recently emerging as a risk factor for psychiatric disorders, can also initiate a brain inflammatory response. It still remains unclear however, whether enteric dysbiosis also contributes to Alzheimer’s disease. Here we show that in a Drosophila Alzheimer’s disease model, enterobacteria infection exacerbated progression of Alzheimer’s disease by promoting immune hemocyte recruitment to the brain, thereby provoking TNF-JNK mediated neurodegeneration. Genetic depletion of hemocytes attenuates neuroinflammation and alleviated neurodegeneration. We further found that enteric infection increases the motility of the hemocytes, making them more readily attracted to the brain with an elevated oxidative stress status. This work highlights the importance of gut–brain crosstalk as a fundamental regulatory system in modulating Alzheimer’s disease neurodegeneration.

Emerging evidence suggests that gut microbiota influences immune function in the brain and may play a role in neurological diseases. Here, the authors offer in vivo evidence from a Drosophila model that supports a role for gut microbiota in modulating the progression of Alzheimer’s disease.

[Study on age and white matter neuronal integrity in healthy volunteers based on automating fiber-tract quantification]

Objective: To analyze age-related change in cerebral matter tract, especially fractional anisotropy, based on automating fiber-tract quantification(AFQ). Methods: A total of 64 years old normal persons and 43 young volunteers were enrolled respectively from the Affiliated Drum Tower Hospital of Nanjing University Medical School and community from January 2015 to June 2016.All of them underwent MRI scan, which included DTI and 3D T(1)WI sequence .All cases were divided into 3 groups according to their ages, the young group 20-35 years old, the middle old group 60-75 years old, the old group 76-90 years old.AFQ was used to identify 20 major white matter tracts in brains of all subjects and make measurements at anatomically equivalent locations along their trajectories. Results: The FA change trend of each fiber was similar among three groups. The old and the middle old group had different FA value in both sides of inferior fronto-occipital fasciculus(left t=-2.73, right t=-6.12, P<0.05), thalamic radiation(left t=-4.79, right t=-19.61, P<0.05), arcuate(left t=10.53, right t=-2.72, P<0.05), callosum forceps(genu t=-2.66, splenium t=28.64, P<0.05), cingulum(left t=-4.53, right t=-2.22, P<0.05)and right corticospinal tract(t=3.10, P<0.05), among which each location of callosum forceps minor was different between the old group and the young group, and this area decreased in the middle group. The old group had different FA value in both sides of uncinate fasciculus(left t=-4.52, right t=-4.53, P<0.05), left corticospinal tract(t=-2.19, P<0.05)and right inferior longitudinal fasciculus(t=11.12, P<0.05). Compared to the young group, there was no statistical difference in the FA of both superior longitudinal fasciculus and left inferior longitudinal fasciculus in the old and the middle old group. Conclusion: AFQ has an impact on the further specific study of the age-related white matter tract.

[Change of white matter neuronal integrity associated with spatial navigation impairment in mild cognitive impairment]

Objective: To analyze the correlation between white matter integrity and spatial navigation impairment in patients with mild cognitive impairment (MCI). Methods: A total of 27 MCI subjects and 24 healthy controls were enrolled from the Affiliated Drum Tower Hospital of Nanjing University Medical School from May 2015 to February 2016, who underwent 3.0 T MRI scan and 2D-computer version spatial navigation test.DTI preprocessing and tract-based spatial statistics (TBSS) were performed by PANDA.Two sample t-test and partial correlation coefficients were performed to investigate the correlation of white matter impairments and spatial navigation decline. Results: Relative to controls, MCI showed worse egocentric navigation (t=-2.202, P<0.05). Decreased FA in superior longitudinal fasciculus (left t=2.95, right t=2.95, P<0.05), inferior longitudinal fasciculus and inferior fronto-occipital fasciculus (left t=2.66, right t=2.96, P<0.05), corpus callosum (t=2.09, P<0.05), cingulum (left t=2.76, right t=2.41, P<0.05), fornix (t=4.83, P<0.05), and corticospinal tract (left t=2.33, right t=2.26, P<0.05), were found in the MCI subjects.The decreased FA value of superior longitudinal fasciculus (left r=-0.354, right r=-0.347, P<0.05), inferior longitudinal fasciculus (left r=-0.338, right r=-0.336, P<0.05), cingulum (left r=-0.395, right r=-0.370, P<0.05), right corticospinal tract (r=-0.362, P<0.05) and fornix (r=-0.369, P<0.05) were correlated with increased ego average total error.Allo average total error were negative correlated with FA value of superior longitudinal fasciculus (left r=-0.329, right r=-0.350, P<0.05), inferior longitudinal fasciculus (left r=-0.349, right r=-0.378, P<0.05), splenium of corpus callosum (r=-0.364, P<0.05) and cingulum (left r=-0.340, right r=-0.406, P<0.05). Conclusion: This study implicated the potential white matter structural basis of spatial navigation impairment and will have an impact on the further study of the neurobiological mechanisms of human spatial navigation ability.

Effects of Pre-Existing Liver Disease on Acute Pain Management Using Patient-Controlled Analgesia Fentanyl With Parecoxib After Major Liver Resection: A Retrospective, Pragmatic Study

BACKGROUND

The aim of this study was to compare the outcomes of pain management with the use of patient-controlled analgesia (PCA) fentanyl with IV parecoxib between patients with healthy liver with patients with diseased liver undergoing major liver resection.

METHODS

Patients with healthy liver undergoing partial hepatectomy as liver donors for liver transplantation (group 1) and patients with liver cirrhosis (Child's criteria A) undergoing major liver resection for hepatoma (group 2) were identified retrospectively. Both groups routinely received post-operative IV PCA fentanyl and a single dose of parecoxib 40 mg. They were followed up for 3 days or until PCA fentanyl was discontinued post-operatively. Daily Visual Analog Scale, PCA fentanyl usage, rescue attempts, and common drug side effects were collected and analyzed with the use of SPSS version 20.

RESULTS

One hundred one patients were included in the study: 54 in group 1, and 47 in group 2. There were no statistical differences between the two groups in terms of the daily and total fentanyl usage, VAS resting, and incidence of itchiness. The rate of rescue analgesia on post-operative day (POD) 1 was lower in group 2, with a value of P = .045. VAS dynamics were better on POD 1 and 2 for group 2, with P = .05 and P = .012, respectively.

CONCLUSIONS

We found that combining a single dose of IV parecoxib 40 mg with PCA fentanyl is an easy and effective method of acute pain control after major liver resection. We propose the careful usage of post-operative fentanyl and parecoxib in patients with diseased liver, given the difference in effect as compared with healthy liver.

The level of mercury contamination in mariculture sites at the estuary of Pearl River and the potential health risk

In the present study, the Hg contamination in mariculture sites located at the estuary of Pearl River was to investigate with an attempt to analyse associated health risks of dietary exposure to both total mercury (THg) and methyl mercury (MeHg) in cultured fish and shellfish. The highest total mercury concentration (7.037 ± 0.556 ng L^-1) of seawater was observed at Zhuhai Estuary. The Hg concentrations of sediment in Guishan Island were significantly higher (p < 0.05) than in Daya Bay (away from the Pearl River). Besides, the both THg and MeHg levels in sediment at mariculture sites were higher (p < 0.05) than corresponding reference sites. It was attributed to the fact that mariculture activities increased Hg loading and promoted MeHg production. The vertical distribution of Hg in sediment cores demonstrated that mercury methylation mostly occurred at the sediment-water interface. Results of health risk assessments showed that fish consumption would impose a higher risk to children but less to adults, while shellfish produced in the studied area was safe for consumption.

Correlation Between Changes in End-Tidal Carbon Dioxide Concentration and Cardiac Output During Inferior Vena Cava Clamping and Unclamping in Living-donor Liver Transplantation

BACKGROUND

To test the hypothesis that low end-tidal carbon dioxide tension encountered during anhepatic phase in liver transplantation is related to hemodynamic status rather than ventilatory status, and can be used to predict the change in cardiac output during anhepatic phase.

METHODS

We retrospectively analyzed and compared data, included end-tidal carbon dioxide tension (ETCO2), arterial blood pressure, heart rate, central venous pressure, cardiac output, cardiac index, and stroke volume, before and after inferior vena cava clamping, and 0, 5, 10, 30 minutes during the anhepatic, and 5 minutes after the release of IVC cross clamp during the reperfusion phase, with paired Student t test, repeated measurement, and linear regression. P < .05 was regarded as significant.

RESULTS

The cardiac output and ETCO2 decrease significantly after clamping the inferior vena cava and increase concomitantly after unclamping. There is a positive correlation between the changes in % in cardiac output and ETCO2 (Pearson coefficient r = 0.741).

CONCLUSION

The changes in ETCO2 can be used to predict the changes of the cardiac output in % when cardiac output monitoring is not available. Before unclamping of the IVC, mild hyperventilation is suggested to prevent excessive increase in PaCO2.

[Effectiveness research of medicated γ intrauterine device and medicated genefix intrauterine device inserted immediately after abortion]

OBJECTIVE

To compare the effectiveness of medicated γ intrauterine device (IUD) and medicated genefix IUD inserted immediately after abortion.

METHODS

A multicenter clinical trail was performed for the study from Mar. 2012 to Jan. 2013. Totally 840 women who volunteered to participate were randomly allocated to γ-group (medicated γ IUD) or genefix-group (medicated genefix IUD) immediately after abortion. While 464 abortion women who had not used IUD or steroids contraceptive methods were chosen as control group. The effectiveness of the IUD were followed up for 1 year. All women were required to record the number of vaginal bleeding days and blood volume of vaginal bleeding within 3 months after abortion.

RESULTS

At the 12(th) month, the expulsion was the most common reason for termination. The expulsion rates of genefix-group and γ-group were 2.48/100 women years and 3.12/100 women years, respectively (P>0.05). For the expulsion reasons, IUD moving down could account for more than seventy percent. The removal rate for IUD usage of two IUD groups were almost equal (3.91/100 women years verus 4.35/100 women years), the differences were not statistically significant (P>0.05). At the 90(th) day after abortion, comparing with control group, the bleeding and (or) spotting days of genefix-group and γ-group extended by 3.9 and 2.6 days respectively, the differences had statistical significance between the three groups (P<0.05). Among the bleeding and (or) spotting days, spotting days prolonged significantly. At the 12(t)h month, spotting days of genefix-group and γ-group were (9.2±5.9) days and (8.5±4.6) days respectively, more than (5.2±4.0) days of control group. The differences had statistical significance between IUD with control group (P<0.05), and had not between the two kinds of IUD (P>0.05).

CONCLUSION

The insertion of medicated genefix IUD and medicated γ IUD immediately after abortion is safe, feasible, has slight side effects and could be effective contraception.

Magnetic and superconducting phase diagram of the half-Heusler topological semimetal HoPdBi

We report a study of the magnetic and electronic properties of the non-centrosymmetric half-Heusler antiferromagnet HoPdBi (TN = 2.0 K). Magnetotransport measurements show HoPdBi has a semimetallic behavior with a carrier concentration n = 3.7 × 10(18) cm(-3) extracted from the Shubnikov-de Haas effect. The magnetic phase diagram in the field-temperature plane has been determined by transport, magnetization, and thermal expansion measurements: magnetic order is suppressed at BM ~ 3.6 T for T --> 0. Superconductivity with Tc ~ 1.9 K is found in the antiferromagnetic phase. Ac-susceptibility measurements provide solid evidence for bulk superconductivity below Tc = 0.75 K with a screening signal close to a volume fraction of 100%. The upper critical field shows an unusual linear temperature variation with Bc2(T --> 0) = 1.1 T. We also report electronic structure calculations that classify HoPdBi as a new topological semimetal, with a non-trivial band inversion of 0.25 eV.

Establishment of a novel, eco-friendly transgenic pig model using porcine pancreatic amylase promoter-driven fungal cellulase transgenes

Competition between humans and livestock for cereal and legume grains makes it challenging to provide economical feeds to livestock animals. Recent increases in corn and soybean prices have had a significant impact on the cost of feed for pig producers. The utilization of byproducts and alternative ingredients in pig diets has the potential to reduce feed costs. Moreover, unlike ruminants, pigs have limited ability to utilize diets with high fiber content because they lack endogenous enzymes capable of breaking down nonstarch polysaccharides into simple sugars. Here, we investigated the feasibility of a transgenic strategy in which expression of the fungal cellulase transgene was driven by the porcine pancreatic amylase promoter in pigs. A 2,488 bp 5'-flanking region of the porcine pancreatic amylase gene was cloned by the genomic walking technique, and its structural features were characterized. Using GFP as a reporter, we found that this region contained promoter activity and had the potential to control heterologous gene expression. Transgenic pigs were generated by pronuclear microinjection. Founders and offspring were identified by PCR and Southern blot analyses. Cellulase mRNA and protein showed tissue-specific expression in the pancreas of F1 generation pigs. Cellulolytic enzyme activity was also identified in the pancreas of transgenic pigs. These results demonstrated the establishment of a tissue-specific promoter of the porcine pancreatic amylase gene. Transgenic pigs expressing exogenous cellulase may represent a way to increase the intake of low-cost, fiber-rich feeds.

Design and validation of a high-voltage levitation circuit for electrostatic accelerometers

A simple high-voltage circuit with a voltage range of 0 to 900 V and an open-loop bandwidth of 11 kHz is realized by using an operational amplifier and a MOSFET combination. The circuit is used for the levitation of a test mass of 71 g, suspended below the top-electrodes with a gap distance of 57 μm, so that the performance of an electrostatic accelerometer can be tested on the ground. The translation noise of the accelerometer, limited by seismic noise, is about 4 × 10(-8) m/s(2)/Hz(1/2) at 0.1 Hz, while the high-voltage coupling noise is one-order of magnitude lower.

Do arbuscular mycorrhizal fungi affect arsenic accumulation and speciation in rice with different radial oxygen loss?

The effects of arbuscular mycorrhizal fungi (AMF) on the temporal variation of arsenic (As) speciation and accumulation in two paddy rice cultivars (TD 71 and Xiushui 11) with different degrees of radial oxygen loss (ROL) at three growth periods (day 7, day 35, day 63 after flooding the soil) were investigated in soil, spiked with and without 30 mg As kg(-1). The results showed that TD 71 with high ROL colonized by Glomus intraradices led to higher root colonization rates than Xiushui 11 at three growth periods, both in soil with or without 30 mg As kg(-1) (p<0.05). Mycorrhizal inoculation led to elevated (p<0.05) root ratios of arsenite (As(III)) conc./arsenate (As(V)) conc. (concentration) in TD 71 with high ROL at three growth periods in As contaminated flooding soils. Furthermore, the ratios of As(III) conc./As(V) conc. in roots of TD71 were significantly more than Xiushui 11 when colonized by AMF at three growth periods in 30 mg As kg(-1) soil (p<0.05). Therefore, rice with high ROL can favor AM fungal infection and enhance root ratio of As(III) conc./As(V) conc. in the presence of AMF.

Arsenic uptake in upland rice inoculated with a combination or single arbuscular mycorrhizal fungi

A pot trial was conducted to investigate the role of arbuscular mycorrhizal fungi (AMF) on arsenic (As) uptake of upland rice (Oryza sativa L.) cultivar, Zhonghan 221; where the following 3 species of Glomus geosporum (Gg), G. mosseae (Gm) and G. versiforme (Gv) were applied as single or combined inoculations. In general, Gm significantly enhanced (p<0.05) total As concentration in Zhonghan 221 when compared to the non mycorrhizal (NM) treatment. The treatment inoculated with Gg + Gm increased total phosphorus (P) uptake and decreased total As uptake in the ingestible rice parts (husks and grains). In terms of AMF colonization rates, Gm had significantly higher (p<0.05) average values of 57.3% and 66.6% when grown in As0 and As40 soils, respectively, in comparison to that of Gg and Gv, and finally dropped to 3.63% when grown in As80 soil. There was a significant difference (p<0.05) between single AMF species (Gg or Gv) and AMF mixture treatments (Gg + Gv, Gg + Gm, Gv + Gm and Gg + Gv + Gm) in terms of total As concentrations in rice. No significant correlation between AMF colonization rates and As uptake in grains (r = 0.150, p > 0.01) and total P (r = 0.002, p > 0.01) were observed.

Dietary intake of PBDEs of residents at two major electronic waste recycling sites in China

The dietary intake of polybrominated diphenyl ether (PBDE) of local residents from 2 major electronic waste (e-waste) processing sites (Guiyu, Guangdong Province and Taizhou, Zhejiang Province) in China was investigated. Seventy-four food items were collected from these sites, divided into 9 food groups (freshwater fish, marine fish, shellfish, pork, poultry, chicken offal, egg, vegetables and cereals), and examined for residual PBDE concentrations. Out of all food items examined, the freshwater bighead carp (Aristichthys nobilis) contained extremely high (11,400±254 ng/g wet wt.) concentrations of PBDE, the highest concentrations amongst published data concerning PBDE detected in freshwater fish. Food consumption data obtained through semi-quantitative food intake questionnaires showed that Guiyu residents had a PBDE dietary intake of 931±772 ng/kg bw/day, of which BDE-47 (584 ng/kg bw/day) exceeded the US EPA's reference dose (100 ng/kg/day). Taizhou (44.7±26.3 ng/kg bw/day) and Lin'an (1.94±0.86 ng/kg bw/day) residents exhibited lower readings. The main dietary source of PBDEs in Guiyu and Taizhou residents was seafood (88-98%) and pork (41%) in Lin'an. The present results indicated that health risks arising from PBDE dietary exposure are of significance in terms of public health and food safety to local residents of e-waste processing sites.

Genetic polymorphisms, growth performance, hematological parameters, serum enzymes, and reproductive characteristics in phenotypically normal Landrace boars produced by somatic cell nuclear transfer

Understanding the performances of cloned pigs and their offspring is critical to evaluate the practical applications of somatic cell nuclear transfer. In this study, genetic polymorphism, growth performance, hematological parameters, and reproduction characteristics of cloned Landrace boars were compared with those of controls. In addition, the growth performance of clone offspring was also evaluated. A total of 479 reconstructed embryos were transferred to five recipient pigs and resulted in the delivery of 14 piglets (overall cloning of 2.9%) from two litters. Analyses of microsatellite markers and polymorphisms of the specific genes confirmed that the 14 clones were genetically identical to the nuclear donor and maintained the desirable genotypes. Growth performance of five healthy, phenotypically normal cloned boars from one litter and eight of their male offspring did not differ from age, breed, and management-matched controls. Although some significant differences were observed between cloned and control boars in hematological and serum enzymes, most of these parameters were within the normal range. Cloned boars had less (P < 0.05) normal sperm in the ejaculated boars than in control boars (71.4% vs. 77.9%, respectively), but sperm production (ejaculate volume, sperm concentration, and total sperm) did not differ between these groups. In addition, use of frozen-thawed semen from cloned boars for insemination produced results that seemed comparable to a control. In conclusion, the present study reported that somatic cell nuclear transfer is effective in reproducing preferred genetic traits and has potential applications to conserve elite bloodlines in a routine pig breeding program.

Infection-induced intestinal oxidative stress triggers organ-to-organ immunological communication in Drosophila

Local infections can trigger immune responses in distant organs, and this interorgan immunological crosstalk helps maintain immune homeostasis. We find that enterobacterial infection or chemically and genetically stimulating reactive oxygen species (ROS)-induced stress responses in the Drosophila gut triggers global antimicrobial peptide (AMP) responses in the fat body, a major immune organ in flies. ROS stress induces nitric oxide (NO) production in the gut, which triggers production of the AMP Diptericin, but not Drosomycin, in the fat body. Hemocytes serve as a signaling relay for communication between intestinal ROS/NO signaling and fat body AMP responses. The induction of AMP responses requires Rel/NF-κB activation within the fat body. Although Rel-mediated Drosomycin induction is repressed by the AP-1 transcription factor, this repressor activity is inhibited by intestinal ROS. Thus, intestinal ROS signaling plays an important role in initiating gut-to-fat body immunological communication in Drosophila.

High resolution space quartz-flexure accelerometer based on capacitive sensing and electrostatic control technology

High precision accelerometer plays an important role in space scientific and technical applications. A quartz-flexure accelerometer operating in low frequency range, having a resolution of better than 1 ng/Hz(1/2), has been designed based on advanced capacitive sensing and electrostatic control technologies. A high precision capacitance displacement transducer with a resolution of better than 2 × 10(-6) pF/Hz(1/2) above 0.1 Hz, is used to measure the motion of the proof mass, and the mechanical stiffness of the spring oscillator is compensated by adjusting the voltage between the proof mass and the electrodes to induce a proper negative electrostatic stiffness, which increases the mechanical sensitivity and also suppresses the position measurement noise down to 3 × 10(-10) g/Hz(1/2) at 0.1 Hz. A high resolution analog-to-digital converter is used to directly readout the feedback voltage applied on the electrodes in order to suppress the action noise to 4 × 10(-10) g/Hz(1/2) at 0.1 Hz. A prototype of the quartz-flexure accelerometer has been developed and tested, and the preliminary experimental result shows that its resolution comes to about 8 ng/Hz(1/2) at 0.1 Hz, which is mainly limited by its mechanical thermal noise due to low quality factor.

A human health risk assessment of mercury species in soil and food around compact fluorescent lamp factories in Zhejiang Province, PR China

This study investigated total mercury (THg) and methylmercury (MeHg) contamination in a major production center of compact fluorescent lamps (CFLs) located in Gaohong, Zhejiang Province, China. This was a result of the growing concern associated with the release of mercury into the environment from such components. The results of the study included the following mean concentrations for THg and MeHg of 157±11 (61-518)ng/gdw and 0.28±0.07 (0.07-0.67)ng/gdw in agricultural soil, respectively, and 18.6±6.5 (3.2-47.8)ng/gww and 0.11±0.03 (0.02-0.37)ng/gww in vegetable samples, respectively. A significant correlation was observed between THg in vegetables and corresponding soil samples (r=0.64, p<0.01). THg and MeHg in sediment samples had respective concentrations ranging from 28 to 1019ng/gdw and 0.11 to 3.15ng/gdw. Mud skipper bought from the local market contained the highest Hg (THg: 170±45ng/gww, MeHg: 143±37ng/gww) amongst all fish species (THg: 14-170; MeHg: 11-143ng/gww) of the study. The risk assessment indicated that fish consumption should not result in a MeHg EDI exceeding the RfD (0.1μg/kgbw/d) for both adults and children, when MeHg bioaccessibility is taken into account.

Uptake kinetics of different arsenic species in lowland and upland rice colonized with Glomus intraradices

The effect of Glomus intraradices on four As species (arsenate; arsenite; dimethylarsinic acid, DMA; and monomethylarsonic acid, MMA) uptake by lowland rice and upland rice were investigated based on two experiments: (1) high (0-0.05 mM) and low (0-2.5mM) - affinity uptake kinetics of four As species in the short-term, and (2) As speciation in rice treated with 1mM arsenate, arsenite, DMA or MMA solutions. The results showed that mycorrhizal roots of two rice cultivars reduced the arsenate uptake significantly (P<0.001) in low-affinity uptake system, and decreased the uptake of arsenite and MMA noticeably (P<0.05) in high or low-affinity uptake systems. The four As species influx have significant differences (P<0.05) between two rice varieties in low-affinity uptake systems. In the arsenate treatment, the ratio of arsenate/arsenite reduced in shoots while increased in roots because of G. intraradices presence.

Inconsistency and comprehensiveness of risk assessments for heavy metals in urban surface sediments

Numerous indices have been developed to assess environmental risk of heavy metals in surface sediments, including the total content based geoaccumulation index (I(geo)), exchangeable fraction based risk assessment code (RAC), and biological toxicity test based sediment quality guidelines (SQGs). In this study, the three indices were applied to freshwater surface sediments from 10 sections along an urbanization gradient of the Grand Canal, China to assess the environmental risks of heavy metals (Cu, Pb, Zn, Cd, and Cr) and to understand discrepancies of risk assessment indices and urbanization effects regarding heavy metal contamination. Results showed that Cd, Zn, and Pb were the most enriched metals in urban sections assessed by I(geo) and over 95% of the samples exceeded the Zn and Pb thresholds of the effect range low (ERL) of SQGs. According to RAC, Cu, Zn, Cd, and Cr had high risks of adversely affecting the water quality of the Grand Canal due to their remarkable portions of exchangeable fraction in surface sediment. However, Pb showed a relative low risk, and was largely bounded to Fe/Mn oxides in the urban surface sediments. Obviously, the three assessment indices were not consistent with each other in terms of predicting environmental risks attributed to heavy metals in the freshwater surface sediments of this study. It is recommended that risk assessment by SQGs should be revised according to availability and site specificity. However, the combination of the three indices gave us a comprehensive understanding of heavy metal risks in the urban surface sediments of the Grand Canal.

Can arbuscular mycorrhizal fungi improve grain yield, As uptake and tolerance of rice grown under aerobic conditions?

The effects of arbuscular mycorrhizal fungi (AMF) -Glomus intraradices and G. geosporum on arsenic (As) and phosphorus (P) uptake by lowland (Guangyinzhan) and upland rice (Handao 502) were investigated in soil, spiked with and without 60 mg As kg(-1). In As-contaminated soil, Guangyinzhan inoculated with G. intraradices or Handao 502 inoculated with G. geosporum enhanced As tolerance, grain P content, grain yield. However, Guangyinzhan inoculated with G. geosporum or Handao 502 inoculated with G. intraradices decreased grain P content, grain yield and the molar ratio of grain P/As content, and increased the As concentration and the ratio of grain/straw As concentration. These results show that rice/AMF combinations had significant (p < 0.05) effects on grain As concentration, grain yield and grain P uptake. The variation in the transfer and uptake of As and P reflected strong functional diversity in AM (arbuscular mycorrhizal) symbioses.

Responses of bioaugmented ryegrass to PAH soil contamination

The physiological and biochemical responses of ryegrass (Lolium multiflorum) to PAH induced stress in soils contaminated with phenanthrene and pyene were investigated, in the presence of PAH-degrading bacteria (Acinetobacteria junii) or arbuscular mycorrhizal fungi (AM fungi, Glomus mossae). The parameters monitored included chlorophyll content, chlorophyll a/b ratio, soluble-carbohydrate content, soluble-protein, malondialdehyde and electrolyte leakage, and superoxide dismutase (SOD) and peroxidase (POD) activities. Ryegrass showed good resistance and acclimation to PAH stress in soil, however, PAH contamination resulted in adverse effects such as damage of photosynthetic function and acceleration of shoot senescence. At PAH level of 100 mg kg(-1), chlorophyll contents were 14% lower than control (no PAH). Activities of SOD and POD were more sensitive indicators of PAH stress as compared to other parameters. However, all parameters showed trends based on either the bioaugmentation of the plants or PAH treatment level. It was concluded that the inoculation of AMF and PAH-degrading bacteria, especially the former, have a positive effect on alleviation of PAH toxicity to ryegrass plants. Furthermore, the inoculation of AMF increased the shoot and biomass of ryegrass by 11-19% and 18-78%, respectively. Bioaugmented ryegrass plants show promise as a host plants in the phytoremediation of PAH contaminated soils.

Phenanthrene and pyrene uptake by arbuscular mycorrhizal maize and their dissipation in soil

Polycyclic aromatic hydrocarbons (PAHs) commonly found in soils can be degraded in rhizosphere, but may also be taken up by plants. The effects of arbuscular mycorrhizal (AM) fungi on uptake of phenanthrene (PHE) and pyrene (PYR) in maize and on their dissipation in soil were investigated using the three-compartmentalized rhizoboxes. Inoculation of Glomus mosseae significantly (p<0.01) increased PHE and PYR concentrations in maize roots and significantly (p<0.05) enhanced PYR translocation from roots to stems in the soil treatments of the PHE+PYR spiked-soils added into the central compartment of the rhizoboxes. There was a significant (p<0.05) dissipation gradient of PHE and PYR observed away from the maize roots, with the highest dissipation rates recorded in rhizosphere zone in the central compartments of the rhizoboxes, followed by near rhizosphere zone and bulk soil zone in the outer compartments. However, G. mosseae only exerted minimal impacts on dissipation of PHE and PYR in the rhizosphere. The present study suggested that the hyphae and extraradical mycelium of AM fungi could play important roles in the uptake and translocation of PHE and PYR in plants. The present results indicated that there is a potential for the use of AM fungi and plant for remediating PAHs contaminated soils.

Enhanced dissipation of PAHs from soil using mycorrhizal ryegrass and PAH-degrading bacteria

The major aim of this experiment was to test the effects of a multi-component bioremediation system consisting of ryegrass (Lolium multiflorum), polycyclic aromatic hydrocarbons (PAHs)-degrading bacteria (Acinetobacter sp.), and arbuscular mycorrhizal fungi (Glomus mosseae) for cleaning up PAHs contaminated soil. Higher dissipation rates were observed in combination treatments: i.e., bacteria+ryegrass (BR), mycorrhizae+ryegrass (MR), and bacteria+mycorrhizae+ryegrass (BMR); than bacteria (B) and ryegrass (R) alone. The growth of ryegrass significantly (p<0.05) increased soil peroxidase activities, leading to enhanced dissipation of phenanthrene (PHE) and pyrene (PYR) from soil. Interactions between ryegrass with the two microbes further enhanced the dissipation of PHE and PYR. Mycorrhizal ryegrass (MR) significantly enhanced the dissipation of PYR from soil, PYR accumulation by ryegrass roots and soil peroxidase activities under lower PHE and PYR levels (0 and 50+50 mg kg(-1)). The present results highlighted the contribution of mycorrhiza and PAH-degrading bacteria in phytoremediation of PAH contaminated soil, however more detailed studies are needed.

Dissipation gradients of phenanthrene and pyrene in the Rice rhizosphere

An experiment was conducted to reveal the effects of rice cultivation as well as polycyclic aromatic carbohydrates (PAHs) degrading bacterium (Acinetobacter sp.) on the dissipation gradients of two PAHs (PHE and PYR) in the rhizosphere. The results showed that the presence of rice root and bacteria significantly accelerated the dissipation rate of PHE and PYR. The root exudates contributed to the formation of dissipation gradients of PHE and PYR along the vertical direction of roots, with a higher dissipation rate in the rhizosphere and near rhizosphere zone than the soil far away the rhizosphere.

Porcine peroxisome proliferator-activated receptor delta mediates the lipolytic effects of dietary fish oil to reduce body fat deposition

Peroxisome proliferator-activated receptor delta promotes fatty acid catabolism and energy expenditure in skeletal muscle and adipose tissues. A ligand for PPARdelta is required to activate PPARdelta function. Polyunsaturated fatty acids are potential ligands for PPARdelta activation. The current experiment was designed to determine the potential for PUFA, particularly from dietary fish oil, to activate porcine PPARdelta in vivo. Transgenic mice were generated to overexpress porcine PPARdelta in the adipose tissue. Mice were fed a high-saturated fat (13% beef tallow), or high-unsaturated fat (13% fish oil) diet, or a diet containing 4 mg/kg of a PPARdelta ligand (L165041) for 4 mo. Compared with beef tallow feeding, fish oil feeding reduced fat mass and decreased (P < 0.05) plasma triacylglycerol and FFA concentrations in the transgenic mice. Adipose tissue expression of genes involved in adipogenesis (i.e., lipoprotein lipase and adipocyte fatty acid-binding protein) was decreased in transgenic mice fed fish oil or the PPARdelta ligand. In the same mice, expression of the lipolytic gene, hormone-sensitive lipase was increased (P < 0.05). Fish oil feeding also stimulated expression of genes participating in fatty acid oxidation in the liver of transgenic mice compared with wild-type mice. Overall, these results indicate that PUFA may serve as natural and effective regulators of lipid catabolism in vivo and many of these effects may be generated from activation of PPARdelta.

Adsorption kinetics of Pb and Cd by two plant growth promoting rhizobacteria

A bench study was carried out to characterize the kinetics of two plant growth promoting rhizobacteria (PGPR) Azotobacter chroococcum and Bacillus megaterium to adsorb heavy metals from solution. Adsorption of Pb(2+) and Cd(2+) by bacterial cells was processed quickly with an equilibration achieved within 5 min. The adsorptions were fitted well with Freundlich and Langmuir isotherm models. The comparison of isotherm parameters indicated that A. chroococcum had a stronger capacity to bind metal ions than B. megaterium, with an average increase of 59.8% for Pb(2+) and 75.6% for Cd(2+), respectively. Both bacteria had a stronger affinity to Pb(2+) than Cd(2+) since Pb(2+) was more easily bound with the phosphoryl groups on the cell surface than Cd(2+). This demonstrated that the presence of bacteria in the rhizosphere may result in the reduction of mobile ions in soil solution.

Risk assessment of PCDD/Fs levels in human tissues related to major food items based on chemical analyses and micro-EROD assay

Nine groups of food items (freshwater fish, marine fish, pork, chicken, chicken eggs, leafy, non-leafy vegetables, rice and flour) and three types of human samples (human milk, maternal serum and cord serum) were collected for the analysis of PCDD/Fs. Results of chemical analysis revealed PCDD/Fs concentrations (pg g(-1) fat) in the following ascending order: pork (0.289 pg g(-1) fat), grass carp (Ctenopharyngodon idellus) (freshwater fish) (0.407), golden thread (Nemipterus virgatus) (marine fish) (0.511), chicken (0.529), mandarin fish (Siniperca kneri) (marine fish) (0.535), chicken egg (0.552), and snubnose pompano (Trachinotus blochii) (marine fish) (1.219). The results of micro-EROD assay showed relatively higher PCDD/Fs levels in fish (2.65 pg g(-1) fat) when compared with pork (0.47), eggs (0.33), chicken (0.13), flour (0.07), vegetables (0.05 pg g(-1) wet wt) and rice (0.05). The estimated average daily intake of PCDD/Fs of 3.51 pg EROD-TEQ/kg bw/day was within the range of WHO Tolerable Daily Intake (1-4 pg WHO-TEQ/kg bw/day) and was higher than the Provisional Tolerable Daily Intake (PMTL) (70 pg for dioxins and dioxin-like PCBs) recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) [Joint FAO/WHO Expert Committee on Food Additives (JECFA), Summary and conclusions of the fifty-seventh meeting, JECFA, 2001.]. Nevertheless, the current findings were significantly lower than the TDI (14 pg WHO-TEQ/kg/bw/day) recommended by the Scientific Committee on Food of the Europe Commission [European Scientific Committee on Food (EU SCF), Opinions on the SCF on the risk assessment of dioxins and dioxin-like PCBs in food, 2000.]. However, it should be noted that micro-EROD assay overestimates the PCDD/Fs levels by 2 to 7 folds which may also amplify the PCDD/Fs levels accordingly. Although the levels of PCDD/Fs obtained from micro-EROD assay were much higher than those obtained by chemical analysis by 2 to 7 folds, it provides a cost-effective and rapid screening of dioxin levels in food and human samples.

Variation in arsenic, lead and zinc tolerance and accumulation in six populations of Pteris vittata L. from China

Arsenic, Pb and Zn tolerance and accumulation were investigated in six populations of Pteris vittata collected from As-contaminated and uncontaminated sites in southeast China compared with Pteris semipinnata (a non-As hyperaccumulator) in hydroponics and on As-contaminated soils. The results showed that both metallicolous and nonmetallicolous population of P. vittata possessed high-level As tolerance, and that the former exhibited higher As tolerance (but not Pb and Zn tolerance) than the latter. In hydroponic culture, nonmetallicolous population clearly showed significantly higher As concentrations in fronds than those in metallicolous populations. In pot trials, As concentrations in fronds of nonmetallicolous population ranged from 1060 to 1639 mg kg(-1), about 2.6- to 5.4-folds as those in metallicolous populations. It was concluded that As tolerance in P. vittata resulted from both constitutive and adaptive traits, Pb and Zn tolerances were constitutive properties, and that nonmetallicolous population possesses more effective As hyperaccumulation than metallicolous populations.

Chemical and ecotoxicological analyses of sediments and elutriates of contaminated rivers due to e-waste recycling activities using a diverse battery of bioassays

A multi-trophic, multi-exposure phase assessment approach was applied to characterize the toxicity of sediments collected from two rivers in Guiyu, China, an e-waste recycling centre. Elutriate toxicity tests (bacterium Vibrio fischeri and microalga Selenastrum capricornutum) and whole sediment toxicity test (crustacean Heterocypris incongruens) showed that most sediments exhibited acute toxicity, due to elevated heavy metals and PAHs levels, and low pH caused by uncontrolled acid discharge. The survival rates of crustaceans were negatively (p < 0.05) correlated with total PAHs in sediments (411-1755 mg kg(-1)); EC50s of V. fischeri on the elutriates were significantly correlated with elutriate pH (p < 0.01). Significant (p < 0.05) correlations between the induction of hepatic metallothionein in tilapia (Oreochromis mossambicus) and metal concentrations (Cu, Zn, Pb) in sediments were also observed, when fish were fed with diets containing sediment. The results showed that uncontrolled e-waste recycling activities may bring adverse effects to local aquatic ecosystem.

The effects of residual tetracycline on soil enzymatic activities and plant growth

A pot trial was carried out to investigate the adverse effects of tetracycline (TC) on soil microbial communities, microbial activities, and the growth of ryegrass (Lolium perenne L). The results showed that the presence of TC significantly disturbed the structure of microbial communities and inhibited soil microbial activities in terms of urease, acid phosphatase and dehydrogenase (p < 0.05). Plant biomass was adversely influenced by TC, especially the roots with a reduction of 40% when compared with the control. Furthermore, TC decreased the assimilation of phosphorus by the plant although the concentration of phosphorus was increased by 20% due to decreased plant biomass. TC seemed to increase the concentration of dissolved organic carbon (by 20%) in soil. The findings implied that the agricultural use of animal manure or fishpond sediment containing considerable amounts of antibiotics may give rise to ecological risks.

Two mifepristone doses and two intervals of misoprostol administration for termination of early pregnancy: a randomised factorial controlled equivalence trial

OBJECTIVE

To compare the efficacy of 100 mg and 200 mg of mifepristone and 24- and 48-hour intervals to administration of 800 microg vaginal misoprostol for termination of early pregnancy.

DESIGN

Placebo-controlled, randomized, equivalence trial, stratified by centre.

SETTING

13 departments of obstetrics and gynecology in nine countries.

POPULATION

2,181 women with 63 days or less gestation requesting medical abortion.

METHODS

Two-sided 95% CI for the risk differences of failure to complete abortion were calculated and compared with 5% equivalence margin between two doses of mifepristone and two intervals to misoprostol administration. Proportions of women with adverse effects were compared between the regimens using standard testes for proportions.

OUTCOME MEASURES

Rates of complete abortion without surgical intervention and adverse effects associated with the regimens.

RESULTS

Efficacy outcome was analysed for 2,126 women (97.5%) excluding 55 lost to follow up. Both mifepristone doses were found to be similar in efficacy. The rate of complete abortion was 92.0% for women assigned 100 mg of mifepristone and 93.2% for women assigned 200 mg of mifepristone (difference 1.2%, 95% CI: -1.0 to 3.5). Equivalence was also evident for the two intervals of administration: the rate of complete abortion was 93.5% for 24-hour interval and 91.7% for the 48-hour interval (difference -1.8%, 95% CI: -4.0 to 0.5). Interaction between doses and interval to misoprostol administration was not significant (P = 0.92). Adverse effects related to treatments did not differ between the groups.

CONCLUSIONS

Both the 100 and 200 mg doses of mifepristone and the 24- and 48-hour intervals have a similar efficacy to achieve complete abortion in early pregnancy when mifepristone is followed by 800 micrograms of vaginally administered misoprostol.

Identification of physical parameters controlling the dominance of algal species in a subtropical reservoir

Eutrophication is a serious problem of water resource management in Taiwan. The occurrence of annoying algal species as well as abnormally abundant algal mass threatens the quality of water supply. The growth and decline of a specific phytoplankton species are affected by environmental factors, including light, nutrients, temperature, etc. There have been many investigations on the effects of individual factors on the abundance and composition of algal populations. However, many analyses on the effects of environmental factors, especially the concentration of nutrients, on phytoplankton failed to identify the controlling factors on the dynamic change of the phytoplankton species. This study used statistical methods to isolate the effect of seasons on the phytoplankton growth and searched for the relationships between the nutrient concentrations and the abundance of different algal species in Feitsui Reservoir based on the data obtained from 1995 to 2003. We found that the dynamic change of dominance of some species of phytoplankton was strongly related to the seasonal factors. The controlling factors of the survival of an algal species were the settling and mobility of the phytoplankton, the mixing depth and the vertical mixing strength of the water bodies. According to our preliminary findings, the influence of physical factors, varying seasonally, outweighs the influence of nutrients on the algal species composition in Feitsui Reservoir in Taiwan.

Docosahexaenoic acid regulates adipogenic genes in myoblasts via porcine peroxisome proliferator-activated receptor gamma

The nuclear transcription factor peroxisome proliferator-activated receptor gamma (PPARgamma) triggers adipocyte differentiation by regulating lipogenic genes. A ligand for PPARgamma is necessary to activate PPARgamma function. Fatty acids are potential ligands for PPARgamma activation. The current experiment was designed to determine the potential for individual fatty acids to activate porcine PPARgamma ectopically expressed in myoblasts. The expression of adipocyte fatty acid binding protein (aP2) and adiponectin in myoblasts stably expressing porcine PPARgamma was increased when docosahexaenoic acid (DHA) was added to the adipogenic medium. The response was positively related to DHA concentration and suggests that DHA may bind to and activate porcine PPARgamma, leading to increased expression of aP2 and adiponectin. The conditioned media collected from myoblasts expressing PPARgamma between d 3 and 6 or between d 6 and 9, but not DHA itself, activated the aP2 gene promoter-driven luciferase activity. These results suggest that a metabolite of DHA is the ligand binding to and activating porcine PPARgamma. The metabolite and pathway for its production are currently unknown.

Interaction of higher plant (jute), electrofused bacteria and mycorrhiza on anthracene biodegradation

The interaction of bacteria, mycorrhiza and jute (Corchotus capsulari, a higher plant) to reduce anthracene in different concentrations of spiked soils was investigated. Dominant indigenous bacterium (Pseudomonas sp.) isolated in the rhizosphere of jute was electrofused with anthracene degraders (Sphingomonas paucimobilis and Pseudomonas aeruginosa) which were able to produce different types of biosurfactants. The highest population (56 x 10(5)CFU/g) was found in the planted soil with the inoculation of mixtures of electrofused anthracene degraders after 7 days. The growth of anthracene degraders in the spiked soil was improved by gene transfer from indigenous bacteria. After 35 days, enhanced anthracene removals were observed in inoculated soils planted with jute (65.5-75.2%) compared with unplanted soil without inoculation (12.5%). The interaction of jute and electrofused S. paucimobilis enabled the greatest reduction of soil anthracene with or without the addition of P. aeruginosa. Mycorrhizal colonization was not significantly inhibited by anthracene in soils up to 150 mg/kg. Inoculation of jute with Glomus mosseae and Glomus intraradices improved plant growth and enhanced anthracene removal in the presence of electrofused S. paucimobilis.

Physiological and biochemical responses of rice (Oryza sativa L.) to phenanthrene and pyrene

Phenanthrene (Phe) and pyrene (Pyr) are two typical polycyclic aromatic hydrocarbons (PAHs) found in contaminated soil. This study investigated physiological and biochemical responses of rice (Oryza sativa L.) to PAH stress after they were planted in soils contaminated with Phe and Pyr, in the presence or absence of a PAH-degrading bacteria (Acinetobacteria sp.). A number of parameters including biomass and water, chlorophyll and chlorophyll a/b ratio, electrolyte leakage, activities of superoxide dismutase (SOD) and peroxidase, and soluble carbohydrate and soluble protein contents were monitored. Results show that rice plants have good resistance and tolerance to lower levels of PAHs stress, while adding high levels of PAHs to soils resulted in adverse effects on rice plants such as a reduction in biomass and damage to photosynthetic function. Water content and SOD activities were the most sensitive indicators of PAH stress among the observed parameters. Inoculation with PAH-degrading bacteria promoted growth and photosynthesis of rice.

Ectopic expression of porcine peroxisome proliferator-activated receptor δ regulates adipogenesis in mouse myoblasts1

Peroxisome proliferator-activated receptor gamma (PPARgamma) plays a critical role in regulating adipogenesis. The expression of peroxisome proliferator-activated receptor delta (PPARdelta) precedes that of PPARgamma during adipocyte differentiation in rodents. The current experiment was designed to study the function of porcine PPARdelta and the interaction of PPARdelta and PPARgamma in adipocyte differentiation. Inhibition of myogenesis was observed in mouse myoblasts expressing porcine PPARdelta, similar to myoblasts expressing PPARgamma. Treatment of myoblasts expressing PPARdelta with ligands for both PPARdelta and PPARgamma enhanced lipogenesis and adipogenesis to a greater extent than treatment with a PPARgamma ligand alone, suggesting that both genes were involved in regulating lipogenesis and adipogenesis. The ability to transdifferentiate myoblasts into adipocytes was decreased in myoblasts coexpressing PPARdelta with either wild type or mutated PPARgamma (Ser 112 was mutated to Ala; the mutated PPARgamma is more active than the wild type) compared with myoblasts expressing PPARgamma alone. Adipocyte differentiation in myoblasts coexpressing PPARdelta and mutated PPARgamma was greater than in myoblasts coexpressing PPARdelta and wild type PPARgamma, confirming that Ser 112 is important for the function of PPARgamma. Taken together, our results demonstrate that overexpression of PPARdelta inhibits myotube formation and also enhances adipocyte differentiation. However, the complexity and interaction of PPARdelta and PPARgamma in adipogenesis are not clearly understood.

Metal accumulation and arbuscular mycorrhizal status in metallicolous and nonmetallicolous populations of Pteris vittata L. and Sedum alfredii Hance

Although Pteris vittata L. and Sedum alfredii Hance have been identified as an As hyperaccumulator and a Zn/Cd hyperaccumulator, respectively, for a few years, variations in metal accumulation among populations and their arbuscular mycorrhizal (AM) status have not been fully explored. Six populations of P. vittata and four populations of S. alfredii from southeast China were investigated. Up to 1,373 As, 680 Pb, 376 Zn, 4.8 Cd, 169 Cu mg kg(-1) in fronds of P. vittata and 358 As, 2,290 Pb, 23,403 Zn, 708 Cd, 342 Cu mg kg(-1 )in shoots of S. alfredii were detected. Constitutive properties of As and Zn hyperaccumulation in metallicolous populations of P. vittata and S. alfredii, respectively, were confirmed. However, Cd hyperaccumulation in S. alfredii varied among populations. The two hyperaccumulators varied in efficiency in taking up other heavy metals. Different metal tolerance strategies adopted by the two hyperaccumulators varied among plant species and metal species. Low to moderate levels of AM colonization in P. vittata (4.2-12.8%) and S. alfredii (8.5-45.8%) were observed at uncontaminated and metal-contaminated sites. The relationship between metal concentrations and AM colonization in the two hyperacumulators was also examined. The abundance of AM fungal spores ranged from 16 to 190 spores per 25 g soil. Glomus microaggregatum, Glomus mosseae, Glomus brohultii and Glomus geosporum were the most common species associated with both P. vittata and S. alfredii. To our knowledge, this is the first report of AM fungal status in rhizosphere of P. vittata and S. alfredii.

Export of toxic chemicals - a review of the case of uncontrolled electronic-waste recycling

This paper reviews the concentrations of persistent organic pollutants such as flame retardants (PBDEs), dioxins/furans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals/metalloid concentrations of different environmental media at Guiyu, a traditional rice-growing village located in southeastern Guangdong Province (PR China), which has turned into an intensive electronic-waste (e-waste) recycling site. Incomplete combustion of e-waste in open air and dumping of processed materials are the major sources of various toxic chemicals. By comparing with existing data available in other areas and also guidelines adopted in different countries, it is obvious that the environment is highly contaminated by these toxic chemicals derived from the recycling processes. For example, the monthly concentration of the sum of 22 PBDE congeners contained in PM(2.5) (16.8ngm(-3)) of air samples at Guiyu was 100 times higher than published data. In order to safeguard the environment and human health, detailed investigations are urgently needed, especially on tracking the exposure pathways of different toxic chemicals which may affect the workers and local residents especially mothers, infants and children.

Visual evoked potentials estimation by adaptive noise cancellation with neural-network-based fuzzy inference system

Visual Evoked potentials (VEPs) are time-varying signals typically buried in relatively large background noise known as the electroencephalogram (EEG). An adaptive noise cancellation with neural-network-based fuzzy inference system was used and the NNFIS was carefully designed to model the VEP signal. An advantage of the method in this paper is that no reference signal is required. The NNFIS based on Takagi and Sugeno's fuzzy model has the advantage of being linear-in-parameter, which is able to closely fit any function mapping and can track the dynamic behavior of VEP in a real-time fashion. 4 sets of simulated data indicate that the proposed method is appropriate to estimate VEP. A total of 150 trials are processed to demonstrate the superior performance of the proposed method.