Ecotoxicological studies of CdS nanoparticles on photosynthetic microorganisms

The potential ecotoxicity of nanosized cadmium sulfide (CdS), synthesized by the polyol process, was investigated using common Anabaena flos-aquae cyanobacteria and Euglena gracilis euglenoid microalgae. The photosynthetic activities of these microorganisms, after addition of free Cd2+ ions and CdS nanoparticles, varied with the presence of tri-n-octylphosphine oxide (TOPO) used to protect surface particle to avoid toxicity and also to control particle size and shape during the synthesis. The nanoparticle concentration was varied from 10(-3) to 5 x 10(-4) M. It was observed that the cadmium concentration, the addition of TOPO protective agent and the particle dissolution process in the culture medium play an important role during the ecotoxicological tests. Viability tests were followed by PAM fluorimetry. Cd2+ ions were very toxic for Anabaena flos aquae. The same behavior was observed after contact with CdS and CdS-TOPO nanoparticles. However, for Euglena gracilis, the photosynthetic activity was stable for more than 1 month in the presence of Cd2+ ions. Moreover, it was observed that the toxicity varies with the concentration of CdS and CdS-TOPO nanoparticles, both kind of nanoparticles are toxic for this microorganism. Transmission electron microscopy (TEM) analyses of microorganisms ultrathin sections showed that polysaccharides produced by Anabaena flos-aquae, after contact with CdS and CdS-TOPO nanoparticles, protect the microalgae against particle internalization. Only some particles were observed inside the cells. Moreover, the nanoparticle internalization was observed after contact with all nanoparticles in the presence of Euglena gracilis by endocytosis. All nanoparticles are inside vesicles formed by the cells.     

Federal standards for community registration of juvenile sex offenders: An evaluation of risk prediction and future implications.

The enactment of the Adam Walsh Child Protection and Safety Act in 2006 is an extension of current protective legislation aimed at establishing stricter sanctions for community-released sexual offenders. What largely separates the Adam Walsh Act from previous registration and notification laws is the crossing of traditional jurisdictional boundaries between adult and juvenile courts at the federal level. This article addresses several key concerns relating to the application of these federal standards to adolescent offenders. In addition to a review of the extant literature, we present findings from an exploratory evaluation that examines the ability of the Adam Walsh Act's classification system to predict future offending among a sample of 112 adjudicated juvenile sex offenders over a 2-year outcome period. Results indicate that offenders who met criteria for registration did not reoffend (sexually or nonsexually) at a significantly higher rate than those who did not meet registration criteria. Implications regarding appropriate risk assessment and management of youth sexual offenders are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Telephone-administered cognitive behavioral therapy for veterans served by community-based outpatient clinics.

Objective: Multiple trials have found telephone-administered cognitive behavioral therapy (T-CBT) to be effective for the treatment of depression. The aim of this study was to evaluate T-CBT for the treatment of depression among veterans served by community-based outpatient clinics (CBOCs) outside of major urban areas. Method: Eighty-five veterans meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) criteria for major depressive disorder were randomized to receive 16 sessions of T-CBT over 20 weeks or treatment as usual through the CBOC. Veterans were assessed at baseline, 12 weeks, 20 weeks (posttreatment), and 6-month follow-up using the Hamilton Depression Rating Scale (Hamilton, 1960), the Patient Health Questionnaire–9 (Kroenke, Spitzer, & Williams, 2001), and a standardized psychiatric interview. Results: There were no significant Time × Treatment effects (ps > .20). Patients were compliant, with 38 (92.7%) completing at least 12 sessions, and 32 (78.0%) having no missed sessions whatsoever. Ratings of audiotaped sessions showed the therapists to be highly competent. Conclusions: This trial yielded negative results for an intervention that has been shown to be effective under other circumstances. We speculate that veterans served within the Veterans Affairs system are more refractory to treatment than other populations, and they may require a more rigorous intervention. Trial Registration: clinicaltrials.gov NCT00223652. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Different confidence–accuracy relationships for feature-based and familiarity-based memories.

Participants studied naturalistic pictures presented for varying brief durations and then received a recognition test on which they indicated whether each picture was old or new and rated their confidence. In 1 experiment they indicated whether each “old”/“new” response was based on memory for a specific feature in the picture or instead on the picture's general familiarity; in another experiment, we defined pictures that tended to elicit feature versus familiarity responses. Thus, feature/familiarity was a dependent variable in 1 experiment and an independent variable in the other. In both experiments feature-based responses were more accurate than those that were familiarity based, and confidence and accuracy increased with duration for both response types. However, when confidence was controlled for, mean accuracy was higher for familiarity-based than for feature-based responses. The theoretical implication is that confidence and accuracy arise from different underlying information. The applied implication is that confidence differences should not be taken as implying accuracy differences when the phenomenal basis of the memory reports differ. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Restraint use and seating position among child car passengers: an observational study in Shanghai

Child passenger restraint practices in China are poorly characterized and few direct observational studies have been performed. This study aims to describe child passenger restraint use and to investigate factors influencing the restraint practices. A cross-sectional observational study was conducted at toll-gates in Shanghai during an 11-day period in June in 2009. A pro-forma observation checklist was used to collect data related to restraint use by child passengers aged ≤12 years, restraint use by drivers, and the number of child passengers traveling in passenger cars registered in Shanghai. Adjusted risk ratios (RR) comparing those children who were properly rear seated with those in other positions (front seat, on adult's lap) and any restraint use with no restraint use were evaluated using multivariate binomial regression with robust variance estimation. Among 967 children observed, 44.1% of children were in suboptimal seating positions (i.e., 12.2% in the front seat and 31.9% in adult laps) and 93.9% were unrestrained. Children aged ≤4 years (RR: 0.35, 95% Confidence Interval: 0.28–0.44), and those who were the only child in a car (RR: 0.84, 95% confidence interval: 0.74–0.96) had a lower likelihood of being properly rear seated. Children traveling with unrestrained drivers (RR: 0.09, 95% confidence interval: 0.01–0.60) were less likely to be restrained. This study demonstrates low restraint use and common suboptimal seating positions for child passengers in China and relates these to driver restraint use. These findings support the need for targeted programs to improve child restraint practices in China.     

Portable microcoil NMR detection coupled to capillary electrophoresis

High-efficiency separation techniques, such as capillary electrophoresis (CE), coupled to a nondestructive nuclear magnetic resonance (NMR) spectrometer offer the ability to separate, chemically identify, and provide structural information on analytes in small sample volumes. Previous CE-NMR coupled systems utilized laboratory-scale NMR magnets and spectrometers, which require very long separation capillaries. New technological developments in electronics have reduced the size of the NMR system, and small 1-2 T permanent magnets provide the possibilities of a truly portable NMR. The microcoils used in portable and laboratory-scale NMR may offer the advantage of improved mass sensitivity because the limit of detection (LOD) is proportional to the coil diameter. In this work, CE is coupled with a portable, briefcase-sized NMR system that incorporates a microcoil probe and a 1.8 T permanent magnet to measure (19)F NMR spectra. Separations of fluorinated molecules are demonstrated with stopped- and continuous-flow NMR detection. The results demonstrate that coupling CE to a portable NMR instrument is feasible and can provide a low-cost method to obtain structural information on microliter samples. An LOD of 31.8 nmol for perfluorotributylamine with a resolution of 4 ppm has been achieved with this system.     

Active smoking and secondhand smoke increase breast cancer risk: the report of the Canadian Expert Panel on Tobacco Smoke and Breast Cancer Risk (2009)

Four authoritative reviews of active smoking and breast cancer have been published since 2000, but only one considered data after 2002 and conclusions varied. Three reviews of secondhand smoke (SHS) and breast cancer (2004-2006) each came to different conclusions. With 30 new studies since 2002, further review was deemed desirable. An Expert Panel was convened by four Canadian agencies, the Ontario Tobacco Research Unit, the Public Health Agency of Canada, Physicians for a Smoke-Free Canada and the Canadian Partnership Against Cancer to comprehensively examine the weight of evidence from epidemiological and toxicological studies and understanding of biological mechanisms regarding the relationship between tobacco smoke and breast cancer. This article summarises the panel's full report (http://www.otru.org/pdf/special/expert_panel_tobacco_breast_cancer.pdf). There are 20 known or suspected mammary carcinogens in tobacco smoke, and recognised biological mechanisms that explain how exposure to these carcinogens could lead to breast cancer. Results from the nine cohort studies reporting exposure metrics more detailed than ever/never and ex/current smoker show that early age of smoking commencement, higher pack-years and longer duration of smoking increase breast cancer risk 15% to 40%. Three meta-analyses report 35% to 50% increases in breast cancer risk for long-term smokers with N-acetyltransferase 2 gene (NAT2) slow acetylation genotypes. The active smoking evidence bolsters support for three meta-analyses that each reported about a 65% increase in premenopausal breast cancer risk among never smokers exposed to SHS. The Panel concluded that: 1) the association between active smoking and breast cancer is consistent with causality and 2) the association between SHS and breast cancer among younger, primarily premenopausal women who have never smoked is consistent with causality.     

Apoptosis-inducing activity of hydroxylated polymethoxyflavones and polymethoxyflavones from orange peel in human breast cancer cells

Sweet orange (Citrus sinensis L.) peel is a rich resource of flavonoids, especially polymethoxyflavones (PMFs). Citrus flavonoids exert a broad spectrum of biological activity, including antiproliferative and proapoptotic effects in cancer cells. We have recently shown that individual PMFs from orange peel induce Ca(2+)-mediated apoptosis in human breast cancer cells and that hydroxylation of PMFs is critical for enhancing their proapoptotic activity. Here, we report that the fraction of orange peel extract containing a mixture of non-hydroxylated PMFs (75.1%) and hydroxylated PMFs (5.44%) and the fraction containing only hydroxylated PMFs (97.2%) induce apoptosis in those cells as well. Treatment of MCF-7 breast cancer cells with these fractions inhibited growth and induced apoptosis associated with an increase in the basal level of intracellular Ca(2+). Effective concentrations of the hydroxylated PMFs fraction in inhibiting growth, inducing apoptosis, and increasing intracellular Ca(2+) were lower than those of the non-hydroxylated PMFs fraction. Our results strongly imply that bioactive PMFs from orange peel exert proapoptotic activity in human breast cancer cells, which depends on their ability to induce an increase in intracellular Ca(2+ )and thus, activate Ca(2+)-dependent apoptotic proteases.     

Hydrogenation of Citral Over IrAu/TiO2 Catalysts. Effect of the Preparation Method

Hydrogenation of citral over Ir/TiO₂ and IrAu/TiO₂ catalysts was studied. Catalysts were prepared by deposition?Cprecipitation with urea (Ir/TiO₂) and sequential incorporation of the metals using a combined DPU-incipient wetness impregnation approach (IrAu/TiO₂). Samples were reduced in H₂ at 573 K (LT) and 773 K (HT). These materials were characterized by transmission electron microscopy (HAADF), TPR and CO adsorption followed by DRIFT. The liquid phase hydrogenation of citral was studied in a Parr type batch reactor at 363 K and a H₂ pressure of 0.62 MPa. An Ir/TiO₂ catalyst prepared by wet impregnation was used as reference catalyst. High selectivity to unsaturated alcohols was found, the only reaction products were geraniol and nerol for Ir/TiO₂ DPU and IrAu/TiO₂ catalysts. The IrAu/TiO₂ (HT) catalyst showed the higher conversion levels.     

Oxidative biodegradation of single- and multi-walled carbon nanotubes

In this study we compare the biodegradation of both single-walled (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) using two different oxidative conditions. In particular, we demonstrate that oxidized multi-walled carbon nanotubes are highly degraded, although not to completeness when treated with horseradish peroxidase (HRP) in the presence of hydrogen peroxide.