118 research outputs found
NEW SPECTROSCOPIC TECHNIQUES FOR STUDYING THE ORIGIN OF PHOSPHORESCENCE.
No full textM.A. El-Sayed has been an Alfred P. Sloan Fellow. M.A. El-Sayed, D.S. Tinti and D.V. Owens, Chem, Phys. Letters, in press. D.S. Tinti, M.A. El-Sayed, A.H. Maki and C.B. Harris, Chem. Phys. Letters, in press. The yz plane is parallel to the molecular plane with the z-axis being the long molecular axis.Author Institution: Department of Chemistry, University of California at Los AngelesAt temperatures for which the electron spin-lattice relaxation times between the zero-field levels of the lowest triplet state are comparable to or longer than the phosphorescence lifetimes, the relative intensity of the different vibronic bands in the phosphorescence spectrum and the observed decays are sensitive to changes in application of magnetic and saturation of the zero-field transitions with microwave From the changes in the spectrum and in the decays upon applying these perturbations, the zero-field level(s) responsible for the intensity of each vibronic band can be determined, as well as the complete description of the spin-orbit coupling scheme. The above techniques are demonstrated for 2,3-dichloroquinoxaline in a durene host crystal. The intersystem crossing route in the guest molecule is established to be . By means of optical-detection of the zero-field transitions, the usual spin Hamiltonian parameters for the lowest triplet state of 2,3-dichloroquinoxaline are found to be
Alcohol and illegal drug use behaviors and prescription opioids use: How do nonmedical and medical users compare, and does motive to use really matter?
No full textBackground-Aims: This study compares illegal drug and alcohol use behaviors between medical and nonmedical users of prescription opioids (PO) and nonmedical users with distinct motives to use. Method: An ethically approved cross-sectional study (2010) was conducted on a representative sample of private university students (n = 570), using a self-filled anonymous questionnaire. Results: About 25percent reported using PO only medically and 15percent nonmedically. The prevalence of alcohol and illegal drug use was consistently higher among nonmedical than medical PO users. Adjusting for age and gender, lifetime medical users of PO were more likely to use marijuana only (OR = 1.8, 95percent CI: 1.1, 2.8), while nonmedical users were at higher odds of using marijuana, ecstasy, cocaine-crack, and alcohol problematically. Compared to nonusers, students who took PO nonmedically for nontherapeutic reasons were more likely to use various illegal drugs, but nonmedical users who took PO to relieve pain-help in sleep were only more likely to use marijuana (OR = 2.5, 95percent CI: 1.1, 5.4) and alcohol (e.g. alcohol abuse; OR = 3.8, 95percent CI: = 1.4, 10.1). Conclusion: Youth who use PO nonmedically to self-treat have a different alcohol and illegal drug-using profile than those who take it for nontherapeutic reasons. © 2013 S. Karger AG, Basel.[Anonymous], 2007, MEAS TRANSP IMPR GOO; Becker WC, 2008, DRUG ALCOHOL DEPEN, V94, P38, DOI 10.1016-j.drugalcdep.2007.09.018; Blanco C, 2007, DRUG ALCOHOL DEPEN, V90, P252, DOI 10.1016-j.drugalcdep.2007.04.005; Boyd CJ, 2006, DRUG ALCOHOL DEPEN, V81, P37, DOI 10.1016-j.drugalcdep.2005.05.017; Boyd CJ, 2009, J ADOLESCENT HEALTH, V45, P543, DOI 10.1016-j.jadohealth.2009.03.023; Brands B, 2010, CAN FAM PHYSICIAN, V56, P256; Catalano RF, 2010, ADDICT BEHAV, V36, P79; Compton WM, 2006, DRUG ALCOHOL DEPEN, V81, P103, DOI 10.1016-j.drugalcdep.2005.05.009; Cone EJ, 2004, J ANAL TOXICOL, V28, P616; Fischer B, 2010, CAN J PSYCHIAT, V55, P606; Fredheim OMS, 2010, PEDIATR ANESTH, V20, P537, DOI 10.1111-j.1460-9592.2010.03310.x; Garnier LM, 2009, AM J DRUG ALCOHOL AB, V35, P334, DOI 10.1080-00952990903075059; Ghandour LA, 2011, DRUG ALCOHOL DEPEN, V121, P101; Gilson AM, 2004, J PAIN SYMPTOM MANAG, V28, P176, DOI 10.1016-j.jpainsymman.2004.01.003; Hamunen K, 2009, EUR J PAIN, V13, P954, DOI 10.1016-j.ejpain.2008.11.006; Harrison L., 1997, VALIDITY SELF REPORT, V167, P17; Haydon E, 2005, CAN J PUBLIC HEALTH, V96, P459; International Narcotics Control Board, 2010, REP INT NARC CONTR B; Jessor R., 1987, ALCOHOL DRUGS DRIVIN, V3, P1; Johnston L. D., 2010, MONITORING FUTURE NA, VII; Karam Elie G, 2010, J Med Liban, V58, P76; Karam EG, 2003, SUBSTANCE USE MISUSE; Kendler KS, 2003, ARCH GEN PSYCHIAT, V60, P929, DOI 10.1001-archpsyc.60.9.929; Khantzian EJ, 1997, HARVARD REV PSYCHIAT, V4, P231, DOI 10.3109-10673229709030550; Kroutil LA, 2006, DRUG ALCOHOL DEPEN, V84, P135, DOI 10.1016-j.drugalcdep.2005.12.011; Martins SS, 2009, DRUG ALCOHOL DEPEN, V103, P16, DOI 10.1016-j.drugalcdep.2009.01.019; Martins SS, 2012, PSYCHOL MED, V42, P1261, DOI 10.1017-S0033291711002145; McCabe SE, 2011, ARCH PEDIAT ADOL MED, V165, P729, DOI 10.1001-archpediatrics.2011.114; McCabe SE, 2006, J PSYCHOACTIVE DRUGS, V38, P43; McCabe SE, 2009, ARCH PEDIAT ADOL MED, V163, P739, DOI 10.1001-archpediatrics.2009.120; McCabe SE, 2005, ADDICT BEHAV, V30, P1342, DOI 10.1016-j.addbeh.2005.01.012; McCabe SE, 2009, DRUG ALCOHOL DEPEN, V102, P63, DOI 10.1016-j.drugalcdep.2009.01.007; McCabe SE, 2005, DRUG ALCOHOL DEPEN, V77, P37, DOI 10.1016-j.drugalcdep.2004.07.005; McCabe SE, 2005, ADDICT BEHAV, V30, P789, DOI 10.1016-j.addbeh.2004.08.024; McCabe SE, 2007, ADDICT BEHAV, V32, P562, DOI 10.1016-j.addbeh.2006.05.022; McCabe SE, 2006, J AM COLL HEALTH, V54, P269, DOI 10.3200-JACH.54.5.269-278; Solberg KE, 2008, LANCET, V372, P1137, DOI 10.1016-S0140-6736(08)61463-4; Sung HE, 2005, J ADOLESCENT HEALTH, V37, P44, DOI 10.1016-j.jadohealth.2005.02.013; Zacny J, 2003, DRUG ALCOHOL DEPEN, V69, P215, DOI 10.1016-S0376-8716(03)00003-6; Zacny JP, 2008, J PAIN, V9, P473, DOI 10.1016-j.jpain.2007.12.008; Zarocostas J, 2007, BRIT MED J, V334, P444, DOI 10.1136-bmj.39140.394410.DB24
Prevalence and patterns of commonly abused psychoactive prescription drugs in a sample of university students from Lebanon: An opportunity for cross-cultural comparisons
No full textBackground: Concerns about psychoactive prescription drug abuse among youth are growing worldwide, but the majority of published studies remain from the US and Canada impeding cross-cultural comparisons. This study examines the prevalence, sources, motivations and substance-use correlates of commonly abused medications among youth from Lebanon. Methods: An IRB-approved cross-sectional study was conducted (May 2010) at the American University of Beirut. Proportionate cluster sampling was used to generate a representative sample of AUB students (n=570). A self-filled anonymous questionnaire was administered. Results: Lifetime medical and nonmedical prevalence of medications were (respectively): pain (36.9percent, 15.1percent), anxiety (8.3percent, 4.6percent), sleeping (6.5percent, 5.8percent) and stimulants (2.6percent, 3.5percent). Gender differences were not observed. Lebanese were least likely to report non-medical use. Nonmedical users mostly used the drugs for their intended purpose (e.g., sleeping to help in sleep, stimulants to increase alertness). Parents and pharmacists (without a doctor's prescription) were the top two sources of all medications, except for stimulants (friends predominated). Diversion was observed in about 20percent of the medical users. Lifetime marijuana users and past year alcohol abusers were three times as likely to use any prescription drug nonmedically. Conclusions: In Lebanon, as in Western cultures, a considerable proportion of youth may be self-medicating. The absence of medical supervision coupled with motivations such as to get high renders this issue a high priority on the national youth agenda. Besides larger more comprehensive surveys, the findings signal the immediate need to reinforce relevant policies, and raise awareness among youth, parents, health professionals and other stakeholders. © 2011 Elsevier Ireland Ltd.[Anonymous], 2007, MEAS TRANSP IMPR GOO; Blanco C, 2007, DRUG ALCOHOL DEPEN, V90, P252, DOI 10.1016-j.drugalcdep.2007.04.005; Boyd CJ, 2007, ARCH PEDIAT ADOL MED, V161, P276, DOI 10.1001-archpedi.161.3.276; Boyd CJ, 2009, J ADOLESCENT HEALTH, V45, P543, DOI 10.1016-j.jadohealth.2009.03.023; Brands B, 2010, CAN FAM PHYSICIAN, V56, P256; Catalano RF, 2010, ADDICT BEHAV, V36, P79; Compton WM, 2006, DRUG ALCOHOL DEPEN, V81, P103, DOI 10.1016-j.drugalcdep.2005.05.009; Cotto JH, 2010, GENDER MED, V7, P402, DOI 10.1016-j.genm.2010.09.004; Dib JG, 2004, AM J HEALTH-SYST PH, V61, P794; El-Aneed A, 2009, J SUBST USE, V14, P75, DOI 10.1080-14659890802446087; Figueiras A, 2000, EUR J EPIDEMIOL, V16, P19, DOI 10.1023-A:1007608702063; Fischer B, 2008, J PAIN, V9, P490, DOI 10.1016-j.jpain.2008.03.002; Friedman RA, 2006, NEW ENGL J MED, V354, P1448, DOI 10.1056-NEJMp068010; Garnier LM, 2009, AM J DRUG ALCOHOL AB, V35, P334, DOI 10.1080-00952990903075059; Goldsworthy RC, 2008, AM J PUBLIC HEALTH, V98, P1115, DOI 10.2105-AJPH.2007.123257; Harrison L, 1997, NIDA Res Monogr, V167, P17; Haydon E, 2005, CAN J PUBLIC HEALTH, V96, P459; Hurwitz W, 2005, PAIN MED, V6, P152, DOI 10.1111-j.1526-4637.2005.05024.x; Johnston L.D., 2008, MONITORING FUTURE NA, P77; Johnston LD, 2009, J ADOLESCENT HEALTH, V45, P539, DOI 10.1016-j.jadohealth.2009.09.004; Johnston L D, 1997, NIDA Res Monogr, V167, P59; Karam E, 2000, EUR ADDICT RES, V6, P189, DOI 10.1159-000052045; Karam EG, 2003, SUBSTANCE USE MISUSE; Kheir N, 2008, AM J PHARM EDUC, V72; Kroutil LA, 2006, DRUG ALCOHOL DEPEN, V84, P135, DOI 10.1016-j.drugalcdep.2005.12.011; Kuehn BM, 2007, JAMA-J AM MED ASSOC, V297, P1306, DOI 10.1001-jama.297.12.1306; Kuehn BM, 2006, JAMA-J AM MED ASSOC, V295, P612, DOI 10.1001-jama.295.6.612; Levine SB, 2009, J ADOLESCENT HEALTH, V44, P407, DOI 10.1016-j.jadohealth.2008.08.010; McCabe SE, 2009, ARCH PEDIAT ADOL MED, V163, P739, DOI 10.1001-archpediatrics.2009.120; McCabe SE, 2005, ADDICT BEHAV, V30, P1342, DOI 10.1016-j.addbeh.2005.01.012; McCabe SE, 2005, DRUG ALCOHOL DEPEN, V77, P37, DOI 10.1016-j.drugalcdep.2004.07.005; McCabe SE, 2005, ADDICT BEHAV, V30, P789, DOI 10.1016-j.addbeh.2004.08.024; McCabe SE, 2007, ADDICT BEHAV, V32, P562, DOI 10.1016-j.addbeh.2006.05.022; McCabe SE, 2006, J AM COLL HEALTH, V54, P269, DOI 10.3200-JACH.54.5.269-278; McCauley JL, 2010, J CHILD PSYCHOL PSYC, V51, P84, DOI 10.1111-j.1469-7610.2009.02134.x; Nassar N T, 1973, J Med Liban, V26, P215; Simoni-Wastila L, 2008, J ADDICT MED, V2, P31, DOI 10.1097-ADM.0b013e31815b5590; Solberg KE, 2008, LANCET, V372, P1137, DOI 10.1016-S0140-6736(08)61463-4; Volkow N. D., 2005, NIH PUB; Zarocostas J, 2007, BRIT MED J, V334, P444, DOI 10.1136-bmj.39140.394410.DB7111
HEAVY ATOM EFFECT ON THE POLARIZATION OF THE PHOSPHORESCENCE SPECTRUM OF CONDENSED AROMATIC HYDROCARBONS
No full textD.S. McClure, J. Chem. Phys. 17, 905 (1949).Author Institution: Department of Chemistry, University of California“It is known that the phosphorescence lifetime of the halonaphthalenes decreases as the atomic number of the halogen atom . This was to an increase in the spin orbit perturbation (which gives rise to the observed emission). The purpose of this work is to examine the exact mechanism by which the halogen enhances the spin orbit perturbation in these molecules. A comparison of the polarization results of the phosphorescence of naphthalene -halonaphthalenes and -halonaphthalenes clearly shows that the halogen does not merely enhance the perturbation which is already present in the parent hydrocarbon, but rather introduces new strong perturbing states of its own. Possible spin-orbit vibronic schemes which explain the observed results will be discussed together with results on other related systems.
Spectroscopic determination of the most probable intersystem crossing route in phosphorescing molecules
No full textAssignment of the lowest triplet state of benzene using phosphorescence-microwave double resonance (PMDR) techniques
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Optical detection of electron-electron double resonance (EEDOR) in zero field of the triplet state
No full textTreatment of “acute” hepatitis C virus in human immunodeficiency virus-infected men with short-course sofosbuvir/ledipasvir
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