Synergistic Effect of Au Interband Transition on Graphene Oxide/ZnO Heterostructure: Experimental Analysis with FDTD Simulation.

We furnish a comprehensive study on light-induced carrier generation due to the synergistic contribution of Au interband transition and graphene oxide (GO)/ZnO heterostructure. Plasmonic gold nanoparticles (Au_nps) are incorporated as a substructure sandwiched between GO and ZnO, assisting in additional photo-induced charge carrier generation. GO is prepared by a single-step plasma-enhanced chemical vapor deposition process. The GO/ZnO heterostructure having an active working area of 0.25 cm2 is created to unleash the pyroelectric property of ZnO, and subsequently, Au_np is introduced at the interface of GO/ZnO. Here, the interband transition of Au_np and its capability for charge carrier generation combined with the excitonic charge carrier generation of the highly crystalline non-centrosymmetric hexagonal wurtzite ZnO enhances the photoresponse. Furthermore, the interaction of Au_np with ZnO and its spatial electric field intensity distribution is demonstrated by finite difference time domain simulation which indicate toward an efficient carrier generation at the interface of Au_np and ZnO. The fabricated heterostructure has an active working wavelength in the UV-A region with the highest responsivity at 375 nm of the electromagnetic spectrum. The ultrafast response time (∼29 µs) of the device is due to the pyro-phototronic effect of the GO/ZnO heterostructure enhanced by the interband transition of Au. In the comparative study of the Au_np-enriched GO/ZnO heterostructure device with a GO/ZnO device, the former shows better performance. Both the devices work in the self-powered mode as well as the photoconductive mode, but with a higher on-off current ratio in the photoconductive mode. Hence, this work helps in properly understanding photo-induced charge generation in a Au interband transition enriched GO/ZnO heterostructure.

Influencing the Electron Density of Nanosized Au Colloids via Immobilization on MgO to Stimulate Surface Reaction Activities.

Heterogenization of colloidal gold on MgO is demonstrated to facilitate its catalytic surface reactivity. We show that the electron density on Au influenced by its immobilization on MgO along with the ensued metal-support interaction is one of the key parameters to obtain high activity. As elucidated by X-ray absorption spectroscopic (X-ray photoelectron spectroscopy, X-ray absorption near-edge structure, and extended X-ray absorption fine structure) studies, the presence of well-dispersed nanosized Au on MgO is observed to result in an enhancement in the electron density of Au. The consequence of this electron-rich gold on the catalytic activity is then investigated using the nitroarene reduction as a model reaction with a detailed kinetic study. The kinetic study is an attempt to use a true heterogeneous system rather than the usually studied quasi-homogeneous systems. The results obtained reveal that the Au/MgO catalyst has a surface rate constant of ∼1.39 × 10-3 mol m-2 s-1, which is significantly higher than those of the reported catalysts. While it validates the higher catalytic activity with a TOF of 9456 h-1 observed for Au/MgO, the increased adsorption constant for 4-nitrophenol on Au/MgO further reflects the efficacy of MgO as the support. This not only allows effective heterogenization of the Au nanoparticles keeping the catalyst stable under the reaction conditions and being reused several times but also renders a capability in reduction of other nitro group-containing substrates. Therefore, the results are believed to be of importance in designing heterogeneous catalysts utilizing the distinctive properties of the nanosized colloids and tuning their surface reactivity as well.

A randomized controlled trial of buprenorphine for probationers and parolees: Bridging the gap into treatment.

BACKGROUND: Buprenorphine can be effective in a variety of community substance use treatment settings outside of methadone programs, including outpatient programs and medical practices. In these settings, it has been found to be effective in reducing opioid use and retaining patients in treatment. Despite its effectiveness and safety, it is rarely provided to individuals with opioid use disorders in probation and parole settings. METHODS: Male and female individuals under probation or parole supervision (N = 320) with histories of opioid use disorder will be enrolled in this randomized controlled trial. Participants will be randomized to one of two study arms: Buprenorphine Bridge Treatment (BBT): Participants will begin buprenorphine using the MedicaSafe dispensing device immediately after an on-site intake at a community supervision office and continue such treatment until they are transitioned to a community program; or Treatment as Usual (TAU): Participants will receive a referral to buprenorphine pharmacotherapy treatment in the community. Treatment outcomes will be: (a) illicit opioid oral saliva drug test results; and (b) treatment adherence (i. entered community based treatment; ii. number of days receiving opioid treatment). RESULTS: We describe the background and rationale for the study, its aims, hypotheses, and study design. CONCLUSIONS: If shown to increase compliance rates with conditions of probation and parole, buprenorphine treatment co-located at community supervision field offices could have a major impact on delivery of buprenorphine treatment to the criminal justice population. The public health impact of the proposed study would be widespread because this intervention could be implemented throughout areas of the US.

Opioid Use Disorders.

Opioid use and addiction in adolescents and young adults is a health problem of epidemic proportions, with devastating consequences for youth and their families. Opioid overdose is a life-threatening emergency that should be treated with naloxone, and respiratory support if necessary. Overdose should always be an opportunity to initiate addiction treatment. Detoxification is often a necessary, but never sufficient, component of treatment for OUDs. Treatment for OUDs is effective but treatment capacity is alarmingly limited and under-developed. Emerging consensus supports the incorporation of relapse prevention medications such as buprenorphine and extended release naltrexone into comprehensive psychosocial treatment including counseling and family involvement.

Self-Powered Broadband Photodetector using Plasmonic Titanium Nitride.

We report the demonstration of plasmonic titanium nitride (TiN) for fabrication of an efficient hybrid photodetector. A novel synthesis method based on plasma nanotechnology is utilized for producing air stable plasma polymerized aniline-TiN (PPA-TiN) nanocomposite and its integration in photodetector geometry. The device performs as a self-powered detector that responds to ultraviolet and visible light at zero bias. The photodetector has the advantage of broadband absorption and outcomes an enhanced photoresponse including high responsivity and detectivity under low light conditions. This work opens up a new direction for plasmonic TiN-based hybrid nanocomposite and its exploitation in optoelectronic applications including imaging, light-wave communication and wire-free route for artificial vision.

Plasmonic Hot Hole Generation by Interband Transition in Gold-Polyaniline.

Studies on hot carrier science and technology associated with various types of nanostructures are dominating today's nanotechnology research. Here we report a novel synthesis of polyaniline-gold (PAni-Au) nanocomposite thin films with gold nanostructures (AuNs) of desired shape and size uniformly incorporated in the polymer matrix. According to shape as well as size variation of AuNs, two tunable plasmonic UV-Visible absorption bands are observed in each of the nanocomposites. Plasmonic devices are fabricated using PAni-Au nanocomposite having different UV-Visible plasmon absorption bands. However, all the devices show strong photoelectrical responses in the blue region (400-500 nm) of the visible spectrum. The d-band to sp-band (d-sp) transition of electrons in AuNs produces hot holes that are the only carriers in the material responsible for photocurrent generation in the device. This work provides an experimental evidence of novel plasmonic hot hole generation process that was still a prediction.

Assembly of multiple components in a hybrid microcapsule: designing a magnetically separable Pd catalyst for selective hydrogenation.

In analogy to the role of long-chain polyamines in biosilicification, poly-L-lysine facilitates the assembly of nanocomponents to design multifunctional microcapsule structures. The method is demonstrated by the fabrication of a magnetically separable catalyst that accommodates Pd nanoparticles (NPs) as active catalyst, Fe3O4 NPs as magnetic component for easy recovery of the catalyst, and silica NPs to impart stability and selectivity to the catalyst. In addition, polyamines embedded inside the microcapsule prevent the agglomeration of Pd NPs and thus result in efficient catalytic activity in hydrogenation reactions, and the hydrophilic silica surface results in selectivity in reactions depending on the polarity of substrates.

Triglyceride/high-density lipoprotein cholesterol ratio: a surrogate to predict insulin resistance and low-density lipoprotein cholesterol particle size in nondiabetic patients with schizophrenia.

OBJECTIVE: Insulin resistance, changes in lipid parameters, and cardiometabolic adverse events have been reported in some patients during clinical trials of antipsychotic agents. The present study examined whether the triglyceride/high-density lipoprotein (HDL) ratio can be used as a better surrogate than other conventional lipid measures (low-density lipoprotein [LDL], HDL, triglyceride) in predicting insulin resistance and LDL particle size in nondiabetic patients with schizophrenia. METHOD: Outpatients 18 to 75 years old diagnosed with schizophrenia or schizoaffective disorder (DSM-IV criteria) and receiving olanzapine, risperidone, or typical antipsychotics participated in a multicenter, cross-sectional study. Fasting blood samples were obtained to determine the levels of glucose, insulin, lipids, and lipid particle size. The study was conducted from July 2001 to March 2002. RESULTS: In the sample of 206 patients, significant correlations were found between various lipid measures (LDL, HDL, triglyceride, and triglyceride/HDL ratio) and the homeostasis model of assessment of insulin resistance (P < .05). However, stepwise multiple regression analysis suggested that the triglyceride/HDL ratio is a stronger predictor of insulin resistance and of LDL particle size than other conventional lipoprotein measures after other potential confounding variables, including age, gender, race, family history of diabetes, body mass index, and antipsychotic agent, were taken into consideration (P < .001). Further, logistic regression analysis indicated that the triglyceride/HDL ratio and male gender predict the existence of a small LDL particle size pattern (pattern B LDL phenotype), with a sensitivity of 75.9% and a specificity of 85.4%. CONCLUSIONS: The triglyceride/HDL ratio, a simple, readily available and inexpensive measure, can be a useful surrogate to identify those with insulin resistance as well as those with more atherogenic small LDL particles in nondiabetic patients with schizophrenia.

Dietary saturated fat intake and glucose metabolism impairments in nondiabetic, nonobese patients with schizophrenia on clozapine or risperidone.

BACKGROUND: High dietary saturated fat (SF) intake is strongly linked to metabolic disturbances. The goal of this study was to understand the relationship between clozapine and risperidone with glucose and lipid metabolism and dietary fat intake in patients with schizophrenia. METHODS: Thirty-one clozapine-treated patients and 15 risperidone-treated patients were assessed using a 4-day dietary record, an IV glucose tolerance test, and lipid profiles. RESULTS: Clozapine-treated patients consumed a significantly higher percentage of SF than did risperidone-treated patients (13.7% +/- 3.4% vs 10.6% +/- 3.0 % of total energy; P = .007). Compared with the risperidone group, the clozapine group also had a significantly higher percentage of total fat in their diet (36% +/- 6.7% vs 30.9% +/- 5.7% of total energy; P = .007). Similarly, the clozapine group had a significant impairment in insulin sensitivity index (SI), glucose effectiveness (SG), and disposition index (DI) compared with the risperidone group (P < .05). Pearson correlation analysis of both groups showed that dietary SF was significantly correlated with impairment in glucose homeostasis (SG: r = -0.43; P = .004; DI: r = -0.35; P = .02). CONCLUSION: Abnormal glucose homeostasis in atypical clozapine-treated patients with schizophrenia may be associated with or aggravated by high dietary SF consumption.

Waist circumference is the best anthropometric predictor for insulin resistance in nondiabetic patients with schizophrenia treated with clozapine but not olanzapine.

OBJECTIVE: The goal of this study was to evaluate which anthropometric measure (human body measurement) best predicts insulin resistance measured by the insulin sensitivity index (SI) and the homeostasis model of assessment of insulin resistance (HOMA-IR) in nondiabetic patients with schizophrenia treated with clozapine or olanzapine. METHODS: We conducted a cross-sectional study of nondiabetic subjects with schizophrenia being treated with olanzapine or clozapine using a frequently sampled intravenous glucose tolerance test, nutritional assessment, and anthropometric measures, to assess the relationship between anthropometric measures and insulin resistance. RESULTS: No difference was found between the groups treated with clozapine and olanzapine in age, gender, race, body mass index (BMI), waist circumference (WC), lipid levels, HOMA-IR, or SI. The disposition index (SI x the acute insulin response to glucose), which measures how the body compensates for insulin resistance to maintain a normal glucose level, was significantly lower in the group treated with clozapine than in the group treated with olanzapine (1067+/-1390 vs. 2521+/-2805; P=0.013), suggesting that the subjects treated with clozapine had a reduced compensatory response to IR compared with the subjects treated with olanzapine. In the clozapine group, both higher WC and BMI were significantly associated with elevated HOMA-IR and lower SI; however, WC was a stronger correlate of IR than BMI, as measured by SI (-0.50 vs. -0.40). In the olanzapine group, neither WC nor BMI was significantly associated with any measure of glucose metabolism. CONCLUSIONS: In this study, WC was the single best anthropometric surrogate for predicting IR in patients treated with clozapine but not olanzapine. The results suggest that WC may be a valuable screening tool for predicting IR in patients with schizophrenia being treated with clozapine who are at relatively higher risk of developing the metabolic syndrome, type 2 diabetes mellitus, and associated cardiovascular disease.

Aripiprazole added to overweight and obese olanzapine-treated schizophrenia patients.

Olanzapine treatment has been associated with clinically meaningful weight increases, hypertriglyceridemia, insulin resistance, and diabetes mellitus. There are few options for olanzapine responders who fail other antipsychotic agents. Aripiprazole is a potent (high-affinity) partial agonist at D2 and 5-HT1A receptors and a potent antagonist at 5-HT2A receptor and is associated with less weight gain than olanzapine. We report the results of a 10-week placebo-controlled, double-blind crossover study that examined 15 mg/d aripiprazole's effects on weight, lipids, glucose metabolism, and psychopathology in overweight and obese schizophrenia and schizoaffective disorder subjects treated with a stable dose of olanzapine. During the 4 weeks of aripiprazole treatment, there were significant decreases in weight (P = 0.003) and body mass index (P = 0.004) compared with placebo. Total serum cholesterol (P = 0.208), high-density lipoprotein cholesterol (HDL-C; P = 0.99), HDL-2 (P = 0.08), HDL-3 (P = 0.495), and low-density lipoprotein cholesterol (P = 0.665) did not change significantly comparing aripiprazole treatment to placebo treatment. However, total serum triglycerides (P = 0.001), total very low-density lipoprotein cholesterol (VLDL-C; P = 0.01), and VLDL-1C and VLDL-2C (P = 0.012) decreased significantly during the aripiprazole treatment phase. The VLDL-3C tended lower during aripiprazole, but the decrease was not significant (P = 0.062). There was a decrease in C-reactive protein comparing aripiprazole treatment to placebo, although it did not reach significance (P = 0.087). The addition of aripiprazole to a stable dose of olanzapine was well tolerated and resulted in significant improvements on several outcome measures that predict risk for medical morbidity.

Ziprasidone as an adjuvant for clozapine- or olanzapine-associated medical morbidity in chronic schizophrenia.

OBJECTIVE: This study sought to examine the effect of ziprasidone on olanzapine or clozapine-associated medical morbidity such as insulin resistance, diabetes mellitus (DM) and impaired fasting glucose, obesity, and hyperlipidemia in patients with schizophrenia or schizoaffective disorder. METHOD: This was a 6-week, open label trial of ziprasidone 160 mg/day added to a stable dose of olanzapine or clozapine in 21 schizophrenia or schizoaffective patients with DM, impaired fasting glucose, or insulin resistance. RESULTS: Ten olanzapine-treated subjects and 11 clozapine-treated subjects were enrolled in the study. There were no significant differences between the two groups at baseline for age, gender, education, ethnicity, BMI, cholesterol levels, or fasting glucose. At week 6, there were no significant changes in weight, BMI, cholesterol levels, or fasting glucose. There was no significant difference in psychotic, negative, or depressive symptoms. QTc significantly increased at week 2 but not at week 6. CONCLUSIONS: The addition of 160 mg/day of ziprasidone was well tolerated but did not produce significant improvement in fasting glucose, insulin resistance, hyperlipidemia or lead to weight loss in olanzapine- or clozapine-treated subjects with schizophrenia or schizoaffective disorder.

Sibutramine: current status as an anti-obesity drug and its future perspectives.

BACKGROUND: Obesity has become a global epidemic with recent estimates of > 400 million obese adults. Despite this, there are few safe and effective pharmacological interventions for obesity. Sibutramine is a weight loss agent, for use as an adjuvant to a comprehensive program of calorie restriction, exercise and behavioral therapy. OBJECTIVE: The goal of this article is to review the available literature of pharmacological interventions for obesity and specifically to examine data with sibutramine for the short term on safety and efficacy for weight loss. METHODS: The literature on sibutramine was reviewed after a PubMed and Medline search in March 2008. All randomized clinical trails were reviewed. RESULTS/CONCLUSIONS: Sibutramine appears to be safe and effective in producing clinically significant weight loss for up to 1 year. Longer prospective clinical studies with sibutramine are needed to evaluate its safety (effect on blood pressure) and ability to maintain weight loss, improve metabolic profiles and reduce the risk of cardiovascular diseases.