Microwave-assisted synthesis of layered basic zinc acetate nanosheets and their thermal decomposition into nanocrystalline ZnO

We have developed a low-cost technique using a conventional microwave oven to grow layered basic zinc acetate (LBZA) nanosheets (NSs) from a zinc acetate, zinc nitrate and HMTA solution in only 2 min. The as-grown crystals and their pyrolytic decomposition into ZnO nanocrystalline NSs are characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD) and photoluminescence (PL). SEM and AFM measurements show that the LBZA NSs have typical lateral dimensions of 1 to 5 μm and thickness of 20 to 100 nm. Annealing in air from 200°C to 1,000°C results in the formation of ZnO nanocrystalline NSs, with a nanocrystallite size ranging from 16 nm at 200°C to 104 nm at 1,000°C, as determined by SEM. SEM shows evidence of sintering at 600°C. PL shows that the shape of the visible band is greatly affected by the annealing temperature and that the exciton band to defect band intensity ratio is maximum at 400°C and decreases by a factor of 15 after annealing at 600°C. The shape and thickness of the ZnO nanocrystalline NSs are the same as LBZA NSs. This structure provides a high surface-to-volume ratio of interconnected nanoparticles that is favorable for applications requiring high specific area and low resistivity such as gas sensing and dye-sensitized solar cells (DSCs). We show that resistive gas sensors fabricated with the ZnO NSs showed a response of 1.12 and 1.65 to 12.5 ppm and 200 ppm of CO at 350°C in dry air, respectively, and that DSCs also fabricated from the material had an overall efficiency of 1.3%

Experimental and theoretical optical properties of methylammonium lead halide perovskites

The optical constants from the ellipsometry of single crystals of CH3NH3PbX3(X = I, Br, Cl) are interpreted with high levelab initioQSGW calculations.</p

Physical activity for cancer survivors: meta-analysis of randomised controlled trials

Objective To systematically evaluate the effects of physical activity in adult patients after completion of main treatment related to cancer

The fitness of African malaria vectors in the presence and limitation of host behaviour

&lt;p&gt;Background Host responses are important sources of selection upon the host species range of ectoparasites and phytophagous insects. However little is known about the role of host responses in defining the host species range of malaria vectors. This study aimed to estimate the relative importance of host behaviour to the feeding success and fitness of African malaria vectors, and assess its ability to predict their known host species preferences in nature.&lt;/p&gt; &lt;p&gt;Methods Paired evaluations of the feeding success and fitness of African vectors Anopheles arabiensis and Anopheles gambiae s.s in the presence and limitation of host behaviour were conducted in a semi-field system (SFS) at Ifakara Health Institute, Tanzania. In one set of trials, mosquitoes were released within the SFS and allowed to forage overnight on a host that was free to exhibit natural behaviour in response to insect biting. In the other, mosquitoes were allowed to feed directly on from the skin surface of immobile hosts. The feeding success and subsequent fitness of vectors under these conditions were investigated on 6 host types (humans, calves, chickens, cows, dogs and goats) to assess whether physical movements of preferred host species (cattle for An. arabiensis, humans for An. gambiae s.s.) were less effective at preventing mosquito bites than those of common alternatives.&lt;/p&gt; &lt;p&gt;Results Anopheles arabiensis generally had greater feeding success when applied directly to host skin than when foraging on unrestricted hosts (in five of six host species). However, An. gambiae s.s obtained blood meals from free and restrained hosts with similar success from most host types (four out of six). Overall, the blood meal size, oviposition rate, fecundity and post-feeding survival of mosquito vectors were significantly higher after feeding on hosts free to exhibit behaviour, than those who were immobilized during feeding trials.&lt;/p&gt; &lt;p&gt;Conclusions Allowing hosts to move freely during exposure to mosquitoes was associated with moderate reductions in mosquito feeding success, but no detrimental impact to the subsequent fitness of mosquitoes that were able to feed upon them. This suggests that physical defensive behaviours exhibited by common host species including humans do not impose substantial fitness costs on African malaria vectors.&lt;/p&gt

Effectiveness of a single-session early psychological intervention for children after road traffic accidents: a randomised controlled trial

BACKGROUND: Road traffic accidents (RTAs) are the leading health threat to children in Europe, resulting in 355,000 injuries annually. Because children can suffer significant and long-term mental health problems following RTAs, there is considerable interest in the development of early psychological interventions. To date, the research in this field is scarce, and currently no evidence-based recommendations can be made. METHODS: To evaluate the effectiveness of a single-session early psychological intervention, 99 children age 7-16 were randomly assigned to an intervention or control group. The manualised intervention was provided to the child and at least one parent around 10 days after the child's involvement in an RTA. It included reconstruction of the accident using drawings and accident-related toys, and psychoeducation. All of the children were interviewed at 10 days, 2 months and 6 months after the accident. Parents filled in questionnaires. Standardised instruments were used to assess acute stress disorder (ASD), posttraumatic stress disorder (PTSD), depressive symptoms and behavioural problems. RESULTS: The children of the two study groups showed no significant differences concerning posttraumatic symptoms and other outcome variables at 2 or at 6 months. Interestingly, analyses showed a significant intervention x age-group effect, indicating that for preadolescent children the intervention was effective in decreasing depressive symptoms and behavioural problems. CONCLUSIONS: This study is the first to show a beneficial effect of a single-session early psychological intervention after RTA in preadolescent children. Therefore, an age-specific approach in an early stage after RTAs may be a promising way for further research. Younger children can benefit from the intervention evaluated here. However, these results have to be interpreted with caution, because of small subgroup sizes. Future studies are needed to examine specific approaches for children and adolescents. Also, the intervention evaluated here needs to be studied in other groups of traumatised children. TRIAL REGISTRATION: Clinical Trial Registry: ClinicalTrials.gov: NCT00296842

Short-Term Memory Maintenance of Object Locations during Active Navigation: Which Working Memory Subsystem Is Essential?

The goal of the present study was to examine the extent to which working memory supports the maintenance of object locations during active spatial navigation. Participants were required to navigate a virtual environment and to encode the location of a target object. In the subsequent maintenance period they performed one of three secondary tasks that were designed to selectively load visual, verbal or spatial working memory subsystems. Thereafter participants re-entered the environment and navigated back to the remembered location of the target. We found that while navigation performance in participants with high navigational ability was impaired only by the spatial secondary task, navigation performance in participants with poor navigational ability was impaired equally by spatial and verbal secondary tasks. The visual secondary task had no effect on navigation performance. Our results extend current knowledge by showing that the differential engagement of working memory subsystems is determined by navigational ability

Allosteric “beta-blocker” isolated from a DNA-encoded small molecule library

The present study reports the discovery of a small-molecule negative allosteric modulator for the β2-adrenergic receptor (β2AR) via in vitro affinity-based iterative selection of highly diverse DNA-encoded small-molecule libraries. Characterization of the compound demonstrates its selectivity for the β2AR and that it negatively modulates a wide range of receptor functions. More importantly, our findings establish a generally applicable, proof-of-concept strategy for screening DNA-encoded small-molecule libraries against purified G-protein–coupled receptors (GPCRs), which holds great potential for discovering therapeutic molecules

Predicting high-grade cancer at ten-core prostate biopsy using four kallikrein markers measured in blood in the ProtecT study

BACKGROUND: Many men with elevated prostate-specific antigen (PSA) levels in serum do not have aggressive prostate cancer and undergo unnecessary biopsy. Retrospective studies using cryopreserved serum suggest that four kallikrein markers can predict biopsy outcome. METHODS: Free, intact and total PSA, and kallikrein-related peptidase 2 were measured in cryopreserved blood from 6129 men with elevated PSA (≥3.0ng/mL) participating in the prospective, randomized trial Prostate Testing for Cancer and Treatment. Marker levels from 4765 men providing anticoagulated plasma were incorporated into statistical models to predict any-grade and high-grade (Gleason score ≥7) prostate cancer at 10-core biopsy. The models were corrected for optimism by 10-fold cross validation and independently validated using markers measured in serum from 1364 men. All statistical tests were two-sided. RESULTS: The four kallikreins enhanced prostate cancer detection compared with PSA and age alone. Area under the curve (AUC) for the four kallikreins was 0.719 (95% confidence interval [CI] = 0.704 to 0.734) vs 0.634 (95% CI = 0.617 to 0.651, P < .001) for PSA and age alone for any-grade cancer, and 0.820 (95% CI = 0.802 to 0.838) vs 0.738 (95% CI = 0.716 to 0.761) for high-grade cancer. Using a 6% risk of high-grade cancer as an illustrative cutoff, for 1000 biopsied men with PSA levels of 3.0ng/mL or higher, the model would reduce the need for biopsy in 428 men, detect 119 high-grade cancers, and delay diagnosis of 14 of 133 high-grade cancers. Models exhibited excellent discrimination on independent validation among men with only serum samples available for analysis. CONCLUSIONS: A statistical model based on kallikrein markers was validated in a large prospective study and reduces unnecessary biopsies while delaying diagnosis of high-grade cancers in few men

Surgical and medical second trimester abortion in South Africa: A cross-sectional study

<p>Abstract</p> <p>Background</p> <p>A high percentage of abortions performed in South Africa are in the second trimester. However, little research focuses on women's experiences seeking second trimester abortion or the efficacy and safety of these services.</p> <p>The objectives are to document clinical and acceptability outcomes of second trimester medical and surgical abortion as performed at public hospitals in the Western Cape Province.</p> <p>Methods</p> <p>We performed a cross-sectional study of women undergoing abortion at 12.1-20.9 weeks at five hospitals in Western Cape Province, South Africa in 2008. Two hundred and twenty women underwent D&E with misoprostol cervical priming, and 84 underwent induction with misoprostol alone. Information was obtained about the procedure and immediate complications, and women were interviewed after recovery.</p> <p>Results</p> <p>Median gestational age at abortion was earlier for D&E clients compared to induction (16.0 weeks vs. 18.1 weeks, p < 0.001). D&E clients reported shorter intervals between first clinic visit and abortion (median 17 vs. 30 days, p < 0.001). D&E was more effective than induction (99.5% vs. 50.0% of cases completed on-site without unplanned surgical procedure, p < 0.001). Although immediate complications were similar (43.8% D&E vs. 52.4% induction), all three major complications occurred with induction. Early fetal expulsion occurred in 43.3% of D&E cases. While D&E clients reported higher pain levels and emotional discomfort, most women were satisfied with their experience.</p> <p>Conclusions</p> <p>As currently performed in South Africa, second trimester abortions by D&E were more effective than induction procedures, required shorter hospital stay, had fewer major immediate complications and were associated with shorter delays accessing care. Both services can be improved by implementing evidence-based protocols.</p