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1.
Public Health ; 198: 315-323, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34507138

RESUMEN

OBJECTIVES: This study aimed to evaluate associations between mental distress and COVID-19-related changes in behavioral outcomes and potential modifiers (age, gender, educational attainment) of such associations. STUDY DESIGN: This was a cross-sectional study. METHODS: An online survey using anonymous network sampling was conducted in China from April to May 2020 using a 74-item questionnaire. A national sample of 10,545 adults in 31 provinces provided data on sociodemographic characteristics, COVID-19-related mental distress, and changes in behavioral outcomes. Structural equation models were used for data analyses. RESULTS: After adjusting for covariates, greater mental distress was associated with increased smoking (odds ratio [OR] = 1.42, 95% confidence interval [CI]: 1.20-1.68 and OR = 1.54, 95% CI: 1.31-1.82 per one standard deviation [SD] increase in mental distress) and alcohol consumption (OR = 1.67, 95% CI: 1.45-1.92 and OR = 1.47, 95% CI: 1.24-1.75 per one SD increase in mental distress) among current smokers and drinkers and with both increased and decreased physical activity (ORs ranged from 1.32 to 1.56). Underweight adults were more likely to lose body weight (≥1 kg; OR = 1.63, 95% CI: 1.30-2.04), whereas overweight adults were more likely to gain weight (OR = 1.61, 95% CI: 1.46-1.78) by the same amount. Association between mental distress and change in physical activity was stronger in adults aged ≥40 years (ORs ranged from 1.43 to 2.05) and those with high education (ORs ranged from 1.43 to 1.77). Mental distress was associated with increased smoking in males (OR = 1.60, 95% CI: 1.37-1.87) but not females (OR = 1.11, 95% CI: 0.82-1.51). CONCLUSIONS: Greater mental distress was associated with some positive and negative changes in behavioral outcomes during the pandemic. These findings inform the design of tailored public health interventions aimed to mitigate long-term negative consequences of mental distress on outcomes.


Asunto(s)
COVID-19 , Pandemias , Adulto , China/epidemiología , Estudios Transversales , Humanos , Masculino , SARS-CoV-2
2.
Phys Rev Lett ; 124(20): 203001, 2020 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-32501042

RESUMEN

The x-ray absorption spectrum of N_{2}^{+} in the K-edge region has been measured by irradiation of ions stored in a cryogenic radio frequency ion trap with synchrotron radiation. We interpret the experimental results with the help of restricted active space multiconfiguration theory. Spectroscopic constants of the 1σ_{u}^{-1} ^{2}Σ_{u}^{+} state, and the two 1σ_{u}^{-1}3σ_{g}^{-1}1π_{g} ^{2}Π_{u} states are determined from the measurements. The charge of the ground state together with spin coupling involving several open shells give rise to double excitations and configuration mixing, and a complete breakdown of the orbital picture for higher lying core-excited states.

6.
J Chem Phys ; 145(19): 194302, 2016 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-27875883

RESUMEN

The Φ9/24 ground state of the Ni2+ diatomic molecular cation is determined experimentally from temperature and magnetic-field-dependent x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap, where an electronic and rotational temperature of 7.4±0.2 K was reached by buffer gas cooling of the molecular ion. The contribution of the spin dipole operator to the x-ray magnetic circular dichroism spin sum rule amounts to 7Tz=0.17±0.06µB per atom, approximately 11% of the spin magnetic moment. We find that, in general, homonuclear diatomic molecular cations of 3d transition metals seem to adopt maximum spin magnetic moments in their electronic ground states.

7.
Phys Rev Lett ; 114(8): 087202, 2015 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-25768776

RESUMEN

The magnetic moment of a single impurity atom in a finite free electron gas is studied in a combined x-ray magnetic circular dichroism spectroscopy, charge transfer multiplet calculation, and density functional theory study of size-selected free chromium-doped gold clusters. The observed size dependence of the local magnetic moment can be understood as a transition from a local moment to a mixed valence regime. This shows that the Anderson impurity model essentially describes finite systems even though the discrete density of states introduces a significant deviation from a bulk metal, and the free electron gas is only formed by less than 10 electrons. Electronic shell closure in the gold host minimizes the interaction of localized impurity states with the confined free electron gas and preserves the magnetic moment of 5 µ_{B} fully in CrAu_{2}^{+} and almost fully in CrAu_{6}^{+}. Even for open-shell species, large local moments are observed that scale with the energy gap of the gold cluster. This indicates that an energy gap in the free electron gas stabilizes the local magnetic moment of the impurity atom.

8.
J Chem Phys ; 143(24): 244318, 2015 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-26723682

RESUMEN

The (6)Π electronic ground state of the Co2 (+) diatomic molecular cation has been assigned experimentally by x-ray absorption and x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap. Three candidates, (6)Φ, (8)Φ, and (8)Γ, for the electronic ground state of Fe2 (+) have been identified. These states carry sizable orbital angular momenta that disagree with theoretical predictions from multireference configuration interaction and density functional theory. Our results show that the ground states of neutral and cationic diatomic molecules of 3d transition elements cannot generally be assumed to be connected by a one-electron process.

9.
J Chem Phys ; 142(23): 234301, 2015 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-26093553

RESUMEN

The electronic structure and magnetic moments of free Mn2 (+) and Mn3 (+) are characterized by 2p x-ray absorption and x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap that is coupled to a synchrotron radiation beamline. Our results directly show that localized magnetic moments of 5 µB are created by 3d(5)((6)S) states at each ionic core, which are coupled ferromagnetically to form molecular high-spin states via indirect exchange that is mediated in both cases by a delocalized valence electron in a singly occupied 4s derived antibonding molecular orbital with an unpaired spin. This leads to total magnetic moments of 11 µB for Mn2 (+) and 16 µB for Mn3 (+), with no contribution of orbital angular momentum.

10.
Health Educ Res ; 30(5): 706-18, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26336905

RESUMEN

The impact of influenza on elderly can be severe and fatal. Influenza vaccination (IV) has been shown to be effective in reducing influenza-related complications, but the IV uptake among elderly in Hong Kong remains low. This study investigated the prevalence and factors associated with IV among Chinese elderly in Hong Kong using the Health Belief Model (HBM). A total of 1101 Chinese elderly aged over 65 was randomly selected and completed a phone interview. Background information, experience of and intention to receive IV and IV-related knowledge and perceptions based on the HBM were measured. Results showed that 48.5 and 49.5% of the participants have ever been vaccinated and intended to receive IV, respectively. Female gender, having chronic disease, and participating in community activities were significantly associated with previous IV. Knowledge of the fact that IV is required every year, lower perceived side effect, IV price lower than HK$150, and recommendations from health care providers was associated with both previous IV and intention to be vaccinated in the next year. Interventions promoting IV among elderly should disseminate knowledge regarding the necessity of IV and correct misconceptions about the side effects of IV.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/prevención & control , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Hong Kong , Humanos , Masculino , Factores de Riesgo
12.
AIDS Behav ; 18(10): 1934-44, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24452496

RESUMEN

Condom use is often equated to safer sex. The prevalence of condom use during sex work among female sex workers (FSW) in China is high. Condom use, however, co-exists with condom failure and improper use and hence risk of HIV transmission. In a cross-sectional study, we interviewed 195 FSW in Shenzhen, China. The prevalence of condom use in the last episode of sex work was 97.4 %, However, respectively 53.8 and 86.2 % had experienced at least one condition of condom failure that may lead to genital contact (wearing condoms after penetration, condom breakage/slippage, condoms removed by clients) and at least one condition of improper condom use (not removing air from the tip of the condom, not pulling it down to the root of penis and not choosing good quality condoms). Factors of individual level (e.g. never choosing high quality condoms for sex work), inter-personal level (e.g. agreement to have unprotected sex if fond of clients or paid more) and environmental/structural level (e.g. non-availability of condoms) were associated with various types of condom failure and improper use. Although HIV prevention interventions have increased prevalence of condom use among FSW, the risk of HIV transmission may still be high as "unsafe" sex due to condom failure and improper use is prevalent. Interventions promoting safer sex need to address such issues and take socio-ecological factors into account. Condom use during sex work is not equivalent to well protected sex as the protective effects could be compromised by frequent condom failure and improper use.


Asunto(s)
Condones/estadística & datos numéricos , Falla de Equipo/estadística & datos numéricos , Infecciones por VIH/prevención & control , Trabajadores Sexuales/estadística & datos numéricos , Abuso de Sustancias por Vía Intravenosa/epidemiología , Sexo Inseguro/estadística & datos numéricos , Adolescente , Adulto , China/epidemiología , Estudios Transversales , Femenino , Infecciones por VIH/psicología , Infecciones por VIH/transmisión , Conocimientos, Actitudes y Práctica en Salud , Humanos , Intención , Masculino , Prevalencia , Factores de Riesgo , Trabajadores Sexuales/psicología , Parejas Sexuales/psicología , Abuso de Sustancias por Vía Intravenosa/psicología , Sexo Inseguro/prevención & control , Sexo Inseguro/psicología
14.
Epidemiol Infect ; 141(2): 377-89, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22717154

RESUMEN

Chronic disease patients are at high risk of developing serious influenza-related complications. This study investigated the prevalence of seasonal influenza vaccination (IV) and associated factors in such patients. A random sample of 704 Chinese adults with chronic disease was anonymously interviewed by telephone; 35·8% of them had ever taken up IV and 22·7% did so during the last flu season. The most frequently mentioned facilitator was recommendation made by a healthcare worker (HCW). Knowledge that IV is required annually, perceived severe health impacts of influenza, and recommendation made by a HCW were positively associated with previous IV and intention to take up IV in the next year, while perceived side-effects was inversely associated with previous IV and intention to take up IV. The coverage of IV in this study population was low. HCWs should clarify IV-related health beliefs in chronic disease patients and actively advise them to take up IV.


Asunto(s)
Enfermedad Crónica , Conocimientos, Actitudes y Práctica en Salud , Vacunas contra la Influenza , Gripe Humana/epidemiología , Aceptación de la Atención de Salud , Adulto , Estudios Transversales , Recolección de Datos , Femenino , Hong Kong/epidemiología , Humanos , Gripe Humana/inmunología , Gripe Humana/prevención & control , Modelos Logísticos , Masculino , Persona de Mediana Edad , Prevalencia , Estaciones del Año
15.
Phys Rev Lett ; 108(5): 057201, 2012 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-22400954

RESUMEN

Magnetic spin and orbital moments of size-selected free iron cluster ions Fe{n}{+} (n=3-20) have been determined via x-ray magnetic circular dichroism spectroscopy. Iron atoms within the clusters exhibit ferromagnetic coupling except for Fe{13}{+}, where the central atom is coupled antiferromagnetically to the atoms in the surrounding shell. Even in very small clusters, the orbital magnetic moment is strongly quenched and reduced to 5%-25% of its atomic value while the spin magnetic moment remains at 60%-90%. This demonstrates that the formation of bonds quenches orbital angular momenta in homonuclear iron clusters already for coordination numbers much smaller than those of the bulk.

16.
Epidemiol Infect ; 139(1): 80-90, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20800008

RESUMEN

To investigate the changes in community responsiveness during the pre-community-outbreak phase of the H1N1 epidemic in Hong Kong, a pooled sample of 999 adults was interviewed in three surveys (S1, S2, S3) from 7 May to 6 June 2009. Over time, fewer people felt confident in staying free from H1N1 infection in the following year (S1, 63·3%; S3, 46%; P<0·001). The level of distress due to H1N1 remained modest throughout the study period. People's confidence in the government's ability to control a large-scale H1N1 outbreak declined slightly at the third survey (S1, 80·5%; S3, 73·8%; P=0·025). Across the three surveys, respondents remained vigilant with frequent adoption of preventive measures (e.g. wearing face masks in public areas when suffering from influenza-like symptoms and frequent hand-washing). The public was generally supportive of the Hong Kong government although misconceptions regarding the disease were common. Provision of evidence-based public-health education is still warranted as the disease outbreak unfolds.


Asunto(s)
Epidemias , Conocimientos, Actitudes y Práctica en Salud , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/epidemiología , Gripe Humana/psicología , Adolescente , Adulto , Recolección de Datos , Femenino , Hong Kong/epidemiología , Humanos , Gripe Humana/prevención & control , Masculino , Persona de Mediana Edad , Factores de Riesgo , Encuestas y Cuestionarios , Adulto Joven
17.
J Chem Phys ; 134(4): 041102, 2011 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-21280677

RESUMEN

A method to determine band gaps of size-selected and isolated nanoparticles by combination of valence band and core-level photoionization spectroscopy is presented. This approach is widely applicable and provides a convenient alternative to current standard techniques for the determination of band gaps by optical or photoelectron spectroscopy. A first application to vanadium doped silicon clusters confirms a striking size-dependence of their highest occupied-lowest unoccupied molecular orbital gaps.

18.
Public Health ; 125(5): 275-82, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21419466

RESUMEN

OBJECTIVES: To investigate the prevalence and factors associated with uptake of voluntary counselling and testing (VCT) for human immunodeficiency virus (HIV) among men who have sex with men (MSM) in Hong Kong. STUDY DESIGN: Cross-sectional study. METHODS: A total of 389 MSM were recruited from gay venues. An additional 188 MSM were recruited through the Internet. Data were collected via face-to-face interviews using a self-administered anonymous questionnaire or via an electronic questionnaire accessible via local gay-friendly websites. The associations between independent and dependent variables (VCT uptake in lifetime and in last 12 months) were examined by logistic regression models. RESULTS: The prevalence rates for lifetime and 12-month uptake of VCT were 56.5% and 39.4%, respectively. Adjusting for significant background variables, all cognitive variables (attitudes, subjective norms, perceived control and behavioural intention) that were derived from the Theory of Planned Behaviours (TPB) were significantly associated with both lifetime and 12-month uptake of VCT [adjusted odds ratio (AOR) 0.56-4.71, P < 0.05]. Perceived fear of contracting HIV and perceived discrimination towards local MSM were associated with a lower likelihood of 12-month uptake of VCT (AOR 0.63, P < 0.05) and lifetime uptake (AOR 0.65, P < 0.05). In the summary models, variables derived from the TPB (subjective norms, perceived control and behavioural intention) were independently associated with lifetime and 12-month uptake of VCT (OR 0.64-2.78, P < 0.05; OR 2.39-3.21, P < 0.05, respectively). Fear of contracting HIV was associated with VCT uptake in the last 12 months (OR 0.55, P < 0.05). CONCLUSIONS: Psychological factors are associated with VCT uptake. The TPB and other health behavioural theories should be taken into account when designing VCT promotion campaigns.


Asunto(s)
Consejo/estadística & datos numéricos , Infecciones por VIH/diagnóstico , Homosexualidad , Tamizaje Masivo/estadística & datos numéricos , Cooperación del Paciente , Adulto , Actitud Frente a la Salud , Infecciones por VIH/epidemiología , Infecciones por VIH/psicología , Infecciones por VIH/terapia , Conductas Relacionadas con la Salud , Hong Kong/epidemiología , Humanos , Masculino , Prevalencia , Adulto Joven
19.
Public Health ; 125(5): 260-5, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21658537

RESUMEN

A large-scale national survey was conducted in 2008 across 61 cities throughout China, covering over 18,000 men who have sex with men (MSM). The prevalence of human immunodeficiency virus (HIV) was 4.9% and incidence ranged from 2.6 to 5.4 per 100 person-years. The prevalence of sexually transmitted diseases ranged from 2.0% to 29.9% among MSM in different parts of China. Syphilis status, recruitment of sexual partners mainly from gay saunas, duration of MSM experience, and unprotected sex with regular male sex partners and multiple male sex partners predicted HIV seroconversion. The prevalence of consistent condom use was low during anal sex, ranging from 29.4% to 37.3%. Within this context, this paper considers the factors surrounding HIV prevention activity, and identifies a number of public health challenges which need to be considered if optimum outcomes are to be achieved. HIV prevention targeting MSM is a delayed response. The high risk associated with gay saunas and the need for steady condom supply at these venues needs urgent consideration. In addition, approximately one-third of MSM in China reported bisexual behavior, which may be attributed to sociocultural reasons and stigma against MSM. Female sex partners of MSM are seldom aware of their exposure to high risk of HIV transmission. Finally, the primitive nature of non-government organizations for HIV prevention and issues around their sustainability pose another serious challenge for the future of HIV prevention campaigns targeting MSM in China.


Asunto(s)
Infecciones por VIH/epidemiología , Infecciones por VIH/transmisión , Homosexualidad , Bisexualidad/etnología , China/epidemiología , Condones/estadística & datos numéricos , Infecciones por VIH/etnología , Infecciones por VIH/prevención & control , Homosexualidad/etnología , Humanos , Masculino , Organizaciones , Prevalencia , Salud Pública , Asunción de Riesgos , Enfermedades de Transmisión Sexual/epidemiología
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