Evaluation of a school-based HIV/AIDS peer-led prevention programme: the first intervention trial for children of migrant workers in China

The effectiveness of a peer-led education intervention in HIV/AIDS prevention was assessed in the Chinese children of migrant workers. A prospective study was conducted in 12 junior high schools for migrant children. Among the intervention group, a peer-education-based HIV/AIDS prevention was implemented for three months. The results during the baseline survey indicated that the level of knowledge on HIV/AIDS was lower in children of migrant workers. After three months of peer-led intervention, compared with the control group, students in the intervention group positively increased their HIV/AIDS-related knowledge, modified their attitude and improved their protection self-efficacy. Compared with attitude, intervention was more effective in the improvement of knowledge and protection self-efficacy, especially knowledge. The findings suggest that peer-led education was an effective method in improving knowledge, attitude and protection self-efficacy in Chinese children of migrant workers. Heightened concerns targeting the group students were particularly necessary, given their lower level of related knowledge and vulnerability to HIV infection.

Simulating the ES-SAGD Process With Solvent Mixture in Athabasca Reservoirs

Abstract

The ES-SAGD process was developed to improve the energy and oil drainage efficiency of the SAGD process. The idea of the ES-SAGD process is to co-inject solvent with steam and the co-injected solvent mixes with the bitumen to further reduce the viscosity of the heated bitumen along the boundary of the steam chamber thus enhances the oil recovery. Practically, the co-injected solvent will be a solvent mixture (such as diluent /naphtha) because of its availability and reduced cost than a pure hydrocarbon. This paper reports the results of an ES-SAGD lab test conducted with steam and diluent co-injection using Athabasca bitumen. To simulate the ES-SAGD test, a pseudo-component scheme to represent the complex solvent mixture in the numerical model is derived, based on the diluent composition and measured PVT data. The behaviours and effects of the co-injected solvent in the ES-SAGD process are analyzed through detailed history matching of the ES-SAGD test. Numerical sensitivity analyses are also performed to investigate the effects of some key parameters in the numerical approach.

Introduction

The Steam Assisted Gravity Drainage (SAGD)(1) and the Vapour Extraction (VAPEX)(2), combined with the horizontal well technology, are being developed to recover the enormous heavy oil and bitumen resources in Western Canada. The SAGD process has been successfully field-tested and is in the early stage of commercial-scale application, while the VAPEX process is still at the piloting stage. Both processes have their advantages and disadvantages. The advantage of the SAGD process is its high oil production rate. However, the high production rate of the SAGD process is associated with intensive energy consumption and CO2 emissions from burning natural gas to generate steam, and costly post-production water treatment. The VAPEX process, on the other hand, has the advantage of lower energy consumption and water usage, and therefore less CO2 emission and water treatment cost. However, the major drawbacks of the VAPEX process are its relatively lower oil production rate and the additional cost of solvent.

Sterol regulatory element-binding protein-1c knockdown protected INS-1E cells from lipotoxicity

OBJECTIVE

The reduction in insulin secretory capacity and beta-cell mass has been attributed, at least partially, to lipotoxicity, which may contribute to the development of type 2 diabetes. Chronic free fatty acids (FFA) exposure impairs pancreatic beta-cell function and induces beta-cell apoptosis. This study is to elucidate the underlying molecular mechanisms.

RESEARCH DESIGN AND METHODS

We exposed INS-1E pancreatic beta-cell line to palmitate or oleate, and measured the glucose stimulated insulin secretion (GSIS). The effect of FFA on sterol regulatory element-binding protein (SREBP)-1c lipogenic pathway, and expression of genes involved in beta-cell functions, including AMPK (AMP-activated protein kinase), UCP-2 (uncoupling protein-2), IRS-2 (insulin receptor substrate-2), PDX-1 (pancreatic duodenal homeobox-1), GLUT-2 (glucose transporter-2) and B cell lymphoma/leukaemia-2 (Bcl-2) were investigated. Apoptosis of these exposed cells was determined by MitoCapture, Annexin V-Cy3 or terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. Cell lipid accumulation was measured by oil red O staining or TG extraction. Also SREBP-1c expression knockdown were used.

RESULTS

FFA treatment resulted in SREBP-1c overexpression, impaired GSIS, lipid accumulation, apoptosis of INS-1E cells. In addition, the expression of lipogenic genes and UCP-2 were upregulated, but AMPK, IRS-2, PDX-1, GLUT-2 and Bcl-2 were downregulated in the exposed cells. However, these lipotoxic effects of FFA were largely prevented by induction of a SREBP-1c small interfering RNA.

CONCLUSIONS

These data suggest a strong correlation between FFA treatment and SREBP-1c activation in INS-1E cells. SREBP-1c might be a major factor responsible for beta-cell lipotoxicity, and SREBP-1c knockdown could protect INS-1E cells from lipotoxicity, which is implicating a therapeutic potential for treating diabetes related to lipotoxicity.

Human telomerase RNA gene (TERC) gain and polysomy of chromosome 3 in cervicovaginal liquid-based pap preparations: a fluorescence in situ hybridization study

PURPOSE. This study investigated human telomerase RNA gene (TERC) gain and polysomy of chromosome 3 in cervicovaginal liquid-based pap preparations in Guilin, China, and assessed the relationship between FISH findings and clinical diagnoses. METHODS. Slides prepared from 63 liquid-based preparations with cytologic diagnoses of negative for squamous intraepithelial lesion or malignancy (NILM n = 9), atypical squamous cells of undetermined significance (ASCUS, n = 18), low-grade squamous intraepithelial lesion (LSIL, n = 14), high-grade squamous intraepithelial lesion (HSIL, n = 9), and cervical squamous cell carcinoma (SCCA, n = 13) were analyzed for TERC gain and polysomy of chromosome 3 using a commercially available two-color FISH probe. The results of the cytologic analysis and those of concurrent or subsequent biopsies, when available, were compared with the FISH findings. The Mann-Whitney test was used to assess associations between FISH findings and diagnoses. RESULTS. TERC gain and polysomy of chromosome 3 were significantly associated with the cytologic diagnosis (p? 0.001). Patients with HSIL or SCCA cytology diagnoses had a significantly higher percentage of cells with TERC gain and polysomy of chromosome 3 than did patients with NILM, ASCUS or LSIL cytologic diagnoses. Those abnormal cases with CIN1 histological diagnosis had a significantly lower percentage of cells with TERC gain and polysomy of chromosome 3 than did patients with a CIN2, CIN3 and SCCA histological diagnosis. CONCLUSIONS. TERC gain and polysomy of chromosome 3 may be important associated genetic events in cervical intraepithelial neoplasia and carcinoma. FISH is a potential tool for the diagnoses of uterine cervix disease.

Oxidation and corrosion behaviors of Mg-based nanoparticles

Various Mg-based nanoparticles were prepared by evaporating bulk magnesium in the atmospheres of Ar, Ar+N2 and CH4, respectively. The formations, phases, morphologies, thermal properties and corrosion behaviors of these kinds of nanocomposite particles were investigated by means of X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), thermogravimetric-differential thermal analysis (TG/DTA) and potentiodynamic polarisation scan (PPS). It is shown that the Mg-based nanoparticles produced in Ar and Ar+N2 atmospheres have hexangular crystal habits with particles' sizes ranging from 50 to 400 nm, while the nanoparticles produced in CH4 atmosphere have amorphous carbon out layers with particles' sizes among 20-100 nm. TG/DTA results show that two-steps oxidation process can be confirmed for all samples, which may be attributed to the oxidations of out layer and core of nanoparticle. The CH4 atmosphere-prepared nanoparticles exhibit better corrosion resistance properties due to its peculiar carbon doping.

Low-temperature nitridation of Fe nanoparticles precursor

Nitridation of Fe nanoparticle precursor was performed in a NH3 atmosphere at the temperatures of 473 K and 673 K for one hour. Fe nanoparticles precursor had a typical spherical shape with iron oxides shell and alpha-Fe core, which was obtained by an arc-discharge method. Up to date, the nitriding temperature of 473 K in present work was the lowest by thermal ammonolysis method because of the characteristics of the nano-sized particles. The resultant product after nitridation was a mixture of iron-nitrides (gamma'-Fe4N and epsilon-Fe3N) nanoparticles with homogeneous dispersion. The nitriding mechanism, oxidizing behaviors and magnetic properties of iron-nitride nanoparticles were measured and discussed.

HIV/AIDS education effects on behaviour among senior high school students in a medium-sized city in China

Few studies have examined the long-term effects of peer-led HIV prevention in Chinese adolescents. A two-year follow-up study was conducted among senior high school students in a medium-sized city of Fujian Province, from 1 March 2006 to 30 April 2008. In all, 3068 students from 14 schools were invited in March 2006, and 893 students in five schools were followed up. Data were collected at baseline, right after intervention (one month later) and two years later by a self-administered questionnaire. In the intervention group, the average knowledge score including reproductive health and HIV/AIDS/sexually transmitted diseases rose from 4.30 to 7.06 one month later (P < 0.01) and to 7.08 two years later (P < 0.01). There was no significant difference between the average knowledge score after one month and two years (P > 0.05). Sustained increases were found in the attitude scores towards people living with HIV/AIDS (PLWH) and intention of condom use after intervention. The study indicates that peer-led HIV prevention education succeeds in improving and sustaining HIV/AIDS-related knowledge and some behaviour intentions. Future research should focus on strategies to sustain long-term behaviour change.

Normal range values for thromboelastography in healthy adult volunteers

Thromboelastography (TEG) provides a functional evaluation of coagulation. It has characteristics of an ideal coagulation test for trauma, but is not frequently used, partially due to lack of both standardized techniques and normal values. We determined normal values for our population, compared them to those of the manufacturer and evaluated the effect of gender, age, blood type, and ethnicity. The technique was standardized using citrated blood, kaolin and was performed on a Haemoscope 5000 device. Volunteers were interviewed and excluded if pregnant, on anticoagulants or having a bleeding disorder. The TEG parameters analyzed were R, K, alpha, MA, LY30, and coagulation index. All volunteers outside the manufacturer's normal range underwent extensive coagulation investigations. Reference ranges for 95% for 118 healthy volunteers were R: 3.8-9.8 min, K: 0.7-3.4 min, alpha: 47.8-77.7 degrees, MA: 49.7-72.7 mm, LY30: -2.3-5.77%, coagulation index: -5.1-3.6. Most values were significantly different from those of the manufacturer, which would have diagnosed coagulopathy in 10 volunteers, for whom additional investigation revealed no disease (81% specificity). Healthy women were significantly more hypercoagulable than men. Aging was not associated with hypercoagulability and East Asian ethnicity was not with hypocoagulability. In our population, the manufacturer's normal values for citrated blood-kaolin had a specificity of 81% and would incorrectly identify 8.5% of the healthy volunteers as coagulopathic. This study supports the manufacturer's recommendation that each institution should determine its own normal values before adopting TEG, a procedure which may be impractical. Consideration should be given to a multi-institutional study to establish wide standard values for TEG.