• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 870
  • 347
  • 70
  • 65
  • 49
  • 27
  • 27
  • 17
  • 12
  • 11
  • 11
  • 9
  • 6
  • 6
  • 4
  • Tagged with
  • 1857
  • 475
  • 409
  • 391
  • 199
  • 162
  • 139
  • 138
  • 136
  • 120
  • 117
  • 114
  • 110
  • 107
  • 105
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
471

Smoking Behaviors Before and After Implementation of a Smoke-Free Legislation in Guangzhou, China

Ye, Xiaohua, Chen, Sidong, Yao, Zhenjiang, Gao, Yanhui, Xu, Ya, Zhou, Shudong, Zhu, Zhengwei, Wang, Liang, Yang, Yi 29 September 2015 (has links)
Background: According to the partial smoke-free legislation implemented on 1 September 2010 in Guangzhou, China, smoke-free did not cover all indoor areas. Some places have a full smoking ban (100 % smoke-free), other places have a partial smoking ban, and homes have no ban. This study aimed to compare the smoking behaviors before and after implementation of a smoke-free legislation. Method: A repeated cross-sectional survey was conducted on smoking-related behaviors with a total of 4,900 respondents before, and 5,135 respondents after the legislation was instituted. For each wave of the survey, a three-stage stratified sampling process was used to obtain a representative sample. Pearson's Chi-square test was used to determine differences of smoking prevalence and quit ratio between the two samples. Logistic regression models were used to examine the associations of a smoke-free legislation with smoking behaviors. Results: The overall daily smoking rate declined significantly from 20.8 % to 18.2 % (p∈<∈0.05), especially among those aged 15-24 years. The quit ratios increased significantly (from 14.5 % to 17.9 %), but remained low among 15-44 year olds. The overall self-reported smoking behaviors in locations with a full smoking ban decreased significantly from 36.4 % to 24.3 % with the greater drops occurring in cultural venues, public transport vehicles, and government offices. Smoking in places with partial smoking bans remained high (89.6 % vs. 90.4 %), although a slight decrease was observed in some of these areas. The implementation of a smoke-free legislation did not lead to more smoking in homes (91.0 % vs 89.4 %), but smoking in homes remained high. Conclusions: These findings highlight the urgent need for a comprehensive smoke-free legislation covering all public places in Guangzhou, simultaneously educational interventions and campaigns promoting voluntary changes in home smoking need to occur.
472

Breastfeeding Initiation in a Rural Sample: Predictive Factors and the Role of Smoking

Bailey, Beth A., Wright, Heather N. 01 February 2011 (has links)
The study objective was to identify demographic, medical, and health behavior factors that predict breastfeeding initiation in a rural population with low breastfeeding rates. Participants were 2323 women who experienced consecutive deliveries at 2 hospitals, with data obtained through detailed chart review. Only half the women initiated breastfeeding, which was significantly associated with higher levels of education, private insurance, nonsmoking and non-drug-using status, and primiparity, after controlling for confounders. Follow-up analyses revealed that smoking status was the strongest predictor of failure to breastfeed, with nonsmokers nearly twice as likely to breastfeed as smokers and with those who had smoked a pack per day or more the least likely to breastfeed. Findings reveal many factors placing women at risk for not breastfeeding and suggest that intervention efforts should encourage a combination of smoking cessation and breastfeeding while emphasizing that breastfeeding is not contraindicated even if the mother continues to smoke.
473

Muscarinic and Nicotinic Responses in the Developing Pedunculopontine Nucleus (PPN)

Good, Cameron H., Bay, Kevin D., Buchanan, Roger, Skinner, Robert D., Garcia-Rill, Edgar 19 January 2007 (has links)
The pedunculopontine nucleus (PPN), the cholinergic arm of the reticular activating system (RAS), is known to modulate waking and rapid eye movement (REM) sleep. REM sleep decreases between 10 and 30 days postnatally in the rat, with the majority occurring between 12 and 21 days. We investigated the possibility that changes in the cholinergic, muscarinic and/or nicotinic, input to PPN neurons could explain at least part of the developmental decrease in REM sleep. We recorded intracellularly from PPN neurons in 12-21 day rat brainstem slices maintained in artificial cerebrospinal fluid (aCSF) and found that application of the nicotinic agonist 1,1-dimethyl-4-phenyl-piperazinium iodide (DMPP) depolarized PPN neurons early in development, then hyperpolarized PPN neurons by day 21. Most of the effects of DMPP persisted following application of the sodium channel blocker tetrodotoxin (TTX), and in the presence of glutamatergic, serotonergic, noradrenergic and GABAergic antagonists, but were blocked by the nicotinic antagonist mecamylamine (MEC). The mixed muscarinic agonist carbachol (CAR) hyperpolarized all type II (A current) PPN cells and depolarized all type I (low threshold spike-LTS current) and type III (A + LTS current) PPN cells, but did not change effects during the period known for the developmental decrease in REM sleep. The effects of CAR persisted in the presence of TTX but were mostly blocked by the muscarinic antagonist atropine (ATR), and the remainder by MEC. We conclude that, while the nicotinic inputs to the PPN may help modulate the developmental decrease in REM sleep, the muscarinic inputs appear to modulate different types of cells differentially.
474

Central Nicotinic Cholinergic Systems: A Role in the Cognitive Dysfunction in Attention-Deficit/Hyperactivity Disorder?

Potter, Alexandra, Newhouse, Paul A., Bucci, David J. 15 December 2006 (has links)
Theories of the neurobiological basis of Attention-Deficit/Hyperactivity Disorder (ADHD) have largely focused on dysregulation of central dopaminergic function. However, other neurotransmitter systems may be implicated in specific cognitive deficits in ADHD. Interest in the potential involvement of nicotinic cholinergic systems in ADHD has arisen in part from the observation that adolescents and adults with ADHD smoke cigarettes at significantly higher rates than people without this disorder. In addition, several studies report that nicotine alleviates ADHD symptoms, and recent neuro-genetics studies indicate that cholinergic systems may be altered in persons with ADHD. In this review, we describe the evidence for a role of central nicotinic cholinergic systems in cognitive deficits in ADHD. We also propose mechanisms by which alterations in cholinergic function may contribute directly and/or indirectly to these deficits. Finally, we identify specific paradigms and models to guide future investigations into the specific involvement of nicotinic cholinergic systems in ADHD, possibly leading to the development of more effective pharmacotherapies for ADHD.
475

Self-efficacy modulates the neural correlates of craving in male smokers and ex-smokers: an fMRI study / 自己効力感は喫煙渇望における神経相関を変化させる:男性の喫煙者と禁煙維持者を対象のfMRI(機能的磁気共鳴映像装置)研究

Ono, Miki 23 January 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20796号 / 医博第4296号 / 新制||医||1025(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 中山 健夫, 教授 富樫 かおり, 教授 鈴木 実 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
476

Smoking Thirties: How Tobacco & BMI Shape the Subgingival Microbiome

Kasabreh, Najla January 2019 (has links)
No description available.
477

Assisting teachers through curriculum change: teachers' use of support materials for teaching about smoking-related matters

Khoali, Thabo Johannes 08 August 2013 (has links)
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, South Africain fulfilment of the requirements for the degree of Doctor of Philosophy, October 2013. / Unable to load abstract.
478

Analysis of Electronic Cigarettes Contaminants, Effectiveness of Nicotine Concentration Tests, and Statistical Overview of the Usage of Electronic Cigarettes

Alam, Harris 01 January 2021 (has links)
Electronic cigarettes are a recent trend that has spark interest in young adults and teens. Due to the recent growth of electronic cigarette companies and their low manufacturing costs, this has allowed the entry-level price point to be drastically low allowing for teens and adults to become users. These products deliver an addictive dose of nicotine and, in the last years, have caused unexpected pulmonary complications that have often resulted in hospitalization. This project is a three-part study that aims to identify contaminants, nicotine concentration, and the psychological reasoning behind vaping. The first part of the study is a statistical overview of the population of students that do smoke and the psychological reason for them starting. This study focuses on the students at University of Central Florida. The second part is the utilization of analytical methods to determine the nicotine concentration and identify any contaminants found in electronic cigarette liquids. This part utilizes gas chromatography-mass spectrometry (GCMS). Additionally, all chemicals that are identified using the GCMS are thoroughly reviewed to determine its usefulness in the electronic cigarette liquid and its effect on the human body. Acid-base titrations are used by many companies and by avid "DIY" vape users to determine the nicotine concentration in the liquid that has been manufactured. This method is very inaccurate and can only give a rough estimate of the nicotine concentration. The third part uses acid-base titrations to determine the nicotine concentration of the electronic cigarette liquids and compare them to the analytic data found in the previous test that utilizes gas chromatography.
479

The relationship of tobacco smoking to scholarship in high school.

Lombard, William Robert 01 January 1942 (has links) (PDF)
No description available.
480

Failure of Chronic Cigarette Smoke Exposure to Alter Plasma Lipoproteins of Stumptailed Macaques (Macaca Arctoides)

Raymond, Thomas L., DeLucia, Anthony J., Bryant, Lester R. 01 January 1982 (has links)
Twenty-one 8-14 kg adult male stumptailed macaques, Macaca arctoides, were fed a standard laboratory diet and divided into 3 groups. The high-dose group and low-dose group were exposed to cigarette smoke at the human equivalent of 3 packs and 1 pack per day, respectively, 7 days per week, for 3-5 years. Eight animals served as cage and sham controls. Peak blood carboxyhemoglobin (COHb) levels measured immediately after smoking showed levels of 0.5 ± 0.1%, 3.6 ± 1.0%, and 5.7 ± 2.8% for. sham controls, low, and high dose smokers, respectively. Hemoglobin and hematocrit values were 2-7% higher (N.S. to P < 0.05) for smoking groups, presumably as a consequence of chronically elevated COHb levels. No significant differences were seen in total plasma cholesterol and lipoprotein cholesterol concentration measured at four intervals over a period of one year. We conclude from these data that, while fed a low fat diet, chronic cigarette smoke inhalation fails to alter plasma lipoprotein levels in this animal model.

Page generated in 0.0587 seconds