89 research outputs found

    Scanning Tunneling Microscopy and Fabrication of Nanometer Scale Structures at the Liquid-Gold Interface

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    The Scanning Tunneling Microscope (STM) can image gold surfaces covered with a variety of liquids. This paper reviews the results obtained using the STM to image gold surfaces covered with liquid. These results include the creation of 10 nm structures, images of the electrochemical process of electroplating, and the production of atomically flat Au (111) surfaces. We conclude that in the future STM will find further application in the area of nanostructure fabrication and electrochemistry. The trend in the field is toward greater control of the electrochemical environment

    College students and use of K2: an emerging drug of abuse in young persons

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    <p>Abstract</p> <p>Background</p> <p>K2 or "spice" has emerged as a popular legal alternative to marijuana among adolescents and young adults. However, no data has been published assessing prevalence of and associations with ever K2 use in any population. This study's aims were to examine prevalence of ever K2 use among a sample of college students, to determine characteristics of persons who use K2, and to access the association between K2 and other drug use.</p> <p>Findings</p> <p>Ever use of K2 was reported by 69 (8%) of the sample of 852 college students. Response rate was 36%. Bivariate and multivariate analyses assessed whether sociodemographic characteristics and other drug use were associated with ever use of K2. Ever use of K2 was reported by 69 (8%) of the sample. Among these 69 individuals, 61 (88%) had used a cigarette and 25 (36%) had used a hookah to smoke K2. In multivariate analyses, K2 use was more common in males (vs. females, adjusted Odds Ratio (aOR) = 2.0, 95% Confidence Interval (CI) = 1.2-3.5, <it>p </it>= 0.01) and 1<sup>st </sup>or 2<sup>nd </sup>year college students (vs. 3<sup>rd </sup>year or above, aOR = 2.4, 95% CI = 1.2-5.0, <it>p </it>= 0.02).</p> <p>Conclusions</p> <p>Ever use of K2 in this sample was higher than ever use of many other drugs of abuse that are commonly monitored in adolescents and young adults. Although DEA had banned five synthetic cannabinoids recently, clinicians and public health officials concerned with substance abuse in youth should be aware of and monitor the use of this drug in college students over time.</p

    User Experiences of Development of Dependence on the Synthetic Cannabinoids, 5f-AKB48 and 5F-PB-22, and Subsequent Withdrawal Syndromes

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    Emergence of synthetic cannabinoids (SCBs) in herbal smoking mixtures is a public health concern. New SCB’s such as 5f-AKB48 and 5F-PB-22 have been detected in French seizures and in sudden death post mortems in the US. The aim was to describe development of dependence on herbal smoking mixtures containing the SCB’s, 5f-AKB48 and 5F-PB-22 and subsequent withdrawal syndromes. Dependent users of herbal smoking mixtures known to contain the SCB’s 5f-AKB48 and 5F-PB-22 with an average Severity of Dependence Score (SDS) of 13 were interviewed using a structured guide (three males/three females). Narratives were analysed using the Empirical Phenomenological Psychological (EPP) five step method. Six themes with 68 categories emerged from the analysis. Themes are illustrated as 1) Networks and Product Availability; 2) Drivers and Motives for Use; 3) Effect and Pathways toward Dependence; 4) Poly Substance Use and Comparisons to Natural Cannabis; 5) Dependence and Withdrawal and 6) Self-detoxification Attempts. Two higher levels of abstraction above these theme-levels emerged from the data, with sole use of herbal smoking mixtures containing 5f-AKB48 and 5F-PB-22 centering on the interplay between intense cravings, compulsive all-consuming seeking, use and re-dose behaviours, and fear of the psychiatric and self-harms caused when in withdrawal. This is the first study describing dependence and withdrawal experiences in users dependent on 5f-AKB48 and 5F-PB-22. Given the potential for adverse psychiatric and physical consequences of dependent use, further development of specific clinical responses and clinical research around toxicity and withdrawal severity are warranted

    Phase I Hydroxylated Metabolites of the K2 Synthetic Cannabinoid JWH-018 Retain In Vitro and In Vivo Cannabinoid 1 Receptor Affinity and Activity

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    K2 products are synthetic cannabinoid-laced, marijuana-like drugs of abuse, use of which is often associated with clinical symptoms atypical of marijuana use, including hypertension, agitation, hallucinations, psychosis, seizures and panic attacks. JWH-018, a prevalent K2 synthetic cannabinoid, is structurally distinct from Δ(9)-THC, the main psychoactive ingredient in marijuana. Since even subtle structural differences can lead to differential metabolism, formation of novel, biologically active metabolites may be responsible for the distinct effects associated with K2 use. The present study proposes that K2's high adverse effect occurrence is due, at least in part, to distinct JWH-018 metabolite activity at the cannabinoid 1 receptor (CB1R).JWH-018, five potential monohydroxylated metabolites (M1-M5), and one carboxy metabolite (M6) were examined in mouse brain homogenates containing CB1Rs, first for CB1R affinity using a competition binding assay employing the cannabinoid receptor radioligand [(3)H]CP-55,940, and then for CB1R intrinsic efficacy using an [(35)S]GTPγS binding assay. JWH-018 and M1-M5 bound CB1Rs with high affinity, exhibiting K(i) values that were lower than or equivalent to Δ(9)-THC. These molecules also stimulated G-proteins with equal or greater efficacy relative to Δ(9)-THC, a CB1R partial agonist. Most importantly, JWH-018, M2, M3, and M5 produced full CB1R agonist levels of activation. CB1R-mediated activation was demonstrated by blockade with O-2050, a CB1R-selective neutral antagonist. Similar to Δ(9)-THC, JWH-018 and M1 produced a marked depression of locomotor activity and core body temperature in mice that were both blocked by the CB1R-preferring antagonist/inverse agonist AM251.Unlike metabolites of most drugs, the studied JWH-018 monohydroxylated compounds, but not the carboxy metabolite, retain in vitro and in vivo activity at CB1Rs. These observations, combined with higher CB1R affinity and activity relative to Δ(9)-THC, may contribute to the greater prevalence of adverse effects observed with JWH-018-containing products relative to cannabis

    Ventricular Dysrhythmias Associated with Poisoning and Drug Overdose: A 10-Year Review of Statewide Poison Control Center Data from California

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    Background: Ventricular dysrhythmias are a serious consequence associated with drug overdose and chemical poisoning. The risk factors for the type of ventricular dysrhythmia and the outcomes by drug class are not well documented. Objective: The aim of this study was to determine the most common drugs and chemicals associated with ventricular dysrhythmias and their outcomes. Methods: We reviewed all human exposures reported to a statewide poison control system between 2002 and 2011 that had a documented ventricular dysrhythmia. Cases were differentiated into two groups by type of arrhythmia: (1) ventricular fibrillation and/or tachycardia (VT/VF); and (2) torsade de pointes (TdP). Results: Among the 300 potential cases identified, 148 cases met the inclusion criteria. Of these, 132 cases (89&nbsp;%) experienced an episode of VT or VF, while the remaining 16 cases (11&nbsp;%) had an episode of TdP. The most commonly involved therapeutic classes of drugs associated with VT/VF were antidepressants (33/132, 25&nbsp;%), stimulants (33/132, 25&nbsp;%), and diphenhydramine (16/132, 12.1&nbsp;%). Those associated with TdP were antidepressants (4/16, 25&nbsp;%), methadone (4/16, 25&nbsp;%), and antiarrhythmics (3/16, 18.75&nbsp;%). Drug exposures with the greatest risk of death in association with VT/VF were antidepressant exposure [odds ratio (OR) 1.71; 95&nbsp;% confidence interval (CI) 0.705–4.181] and antiarrhythmic exposure (OR 1.75; 95&nbsp;% CI 0.304–10.05), but neither association was statistically significant. Drug exposures with a statistically significant risk for TdP included methadone and antiarrhythmic drugs. Conclusions: Antidepressants and stimulants were the most common drugs associated with ventricular dysrhythmias. Patients with suspected poisonings by medications with a high risk of ventricular dysrhythmia warrant prompt ECG monitoring

    The Effect of the FDA VVarning on the Use of Droperidol by U.S. Emergency Physicians

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    Objectives: To determine if emergency physicians' (EP) use droperidol has changed since the United States Food and Drug Administration (FDA) warning of December 2001 concerning QT interval prolongation, torsade de pointes, and sudden death; and to query EP opinions regarding droperidol before and after the FDA warning and regarding potential alternative drugs.Methods: An internet-based survey was designed with questions regarding droperidol use in the emergency department (ED). Data collected included EP demographics, use of droperidol before and after the FDA warning, use of alternative drugs, and incidence of arrhythmias. A representative sample of EPs were contacted by e-mail and asked to complete the survey.Results: A total of 2,000 e-mails resulted in 506 (25%) completed surveys. There was no second mailing. Responders' average years practicing was 12.6 +_ 9.2. EP responders worked in private/community (n=278, 55%), academic/county (n=187, 37%), and HMO (n=41,8%) hospitals. The majority (n=455, 90%) used droperidol and were aware of the FDA warning (n=460, 91%). Droperidol was no longer available at 122 (24%) of the respondents' EDs as a result of the FDA warning. Prior to the FDA warning, EPs who had used droperidol used it as an antiemetic (n=408, 90%), for control of agitation (n=330, 73%), for treatment of headache (n=247, 54%), and for treatment of vertigo (n=106, 23%). After the FDA warning, 387 (85%) of EPs reported their use of droperidol had decreased or ceased altogether, and 68 (15%) always obtained an electrocardiogram prior to administration. Of those who used droperidol for agitation, 137 (42%) felt there were no other drugs with greater efficacy. Haloperidol was the most cited alternative agent (n=160, 79%) followed by benzodiazepines (n=223, 68%). Of those who used droperidol for antiemesis, 116 (28%) felt there were no other drugs with greater efficacy than droperidol; promethazine was the most cited alternative agent (n=26O, 64%). Two (0.4%) EPs reported arrhythmias in patients who received droperidol. Only 37 (8%) EPs reported they were unconcerned with potential loss of droperidol from the market.Conclusion: Based on this survey, EP use of droperidol has decreased dramatically as a result of the FDA warning. However, EPs believe that there are few or no alternative antiemetic drugs that have an improved adverse effect profile
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