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1.
Hong Kong Med J ; 30(2): 188-190, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38651207
6.
Schizophr Bull ; 49(4): 1078-1087, 2023 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-36940411

RESUMO

BACKGROUND: Paranoia is higher in minority group individuals, especially those reporting intersecting aspects of difference. High negative and low positive self and other beliefs, and low social rank, are predictive of paranoia overtime; however, data are typically from majority group participants. This study examined whether social defeat or healthy cultural mistrust best characterizes paranoia in minority groups. STUDY DESIGN: Using cross-sectional, survey design, with a large (n = 2510) international sample, moderation analyses (PROCESS) examined whether self and other beliefs, and perceived social rank, operate similarly or differently in minority vs majority group participants. Specifically, we tested whether beliefs moderated the influence of minority group, and intersecting aspects of difference, on paranoia. STUDY RESULTS: Paranoia was consistently higher in participants from minority vs majority groups and level of paranoid thinking was significantly higher at each level of the intersectionality index. Negative self/other beliefs were associated with elevated paranoia in all participants. However, in support of the notion of healthy cultural mistrust, low social rank, and low positive self/other beliefs were significantly associated with paranoia in majority group participants but unrelated to paranoia in respective minority group members. CONCLUSIONS: Although mixed, our findings signal the need to consider healthy cultural mistrust when examining paranoia in minority groups and bring into question whether "paranoia" accurately describes the experiences of marginalized individuals, at least at low levels of severity. Further research on paranoia in minority groups is crucial to developing culturally appropriate ways of understanding people's experiences in the context of victimization, discrimination, and difference.


Assuntos
Vítimas de Crime , Grupos Minoritários , Humanos , Estudos Transversais , Enquadramento Interseccional , Transtornos Paranoides
7.
Psychol Med ; 53(6): 2652-2661, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-34879896

RESUMO

BACKGROUND: Globally, the corona virus disease 2019 (COVID-19) pandemic has created an interpersonally threatening context within which other people have become a source of possible threat. This study reports on the development and validation of a self-report measure of pandemic paranoia; that is, heightened levels of suspicion and mistrust towards others due to the COVID-19 pandemic. METHODS: An international consortium developed an initial set of 28 items for the Pandemic Paranoia Scale (PPS), which were completed by participants from the UK (n = 512), USA (n = 535), Germany (n = 516), Hong Kong (n = 454) and Australia (n = 502) using stratified quota sampling (for age, sex and educational attainment) through Qualtrics and translated for Germany and Hong Kong. RESULTS: Exploratory factor analysis in the UK sample suggested a 25-item, three-factor solution (persecutory threat; paranoid conspiracy and interpersonal mistrust). Confirmatory factor analysis (CFA) on the remaining combined sample showed sufficient model fit in this independent set of data. Measurement invariance analyses suggested configural and metric invariance, but no scalar invariance across cultures/languages. A second-order factor CFA on the whole sample indicated that the three factors showed large loadings on a common second-order pandemic paranoia factor. Analyses also supported the test-retest reliability and internal and convergent validity. CONCLUSION: The PPS offers an internationally validated and reliable method for assessing paranoia in the context of a pandemic. The PPS has the potential to enhance our understanding of the impact of the pandemic, the nature of paranoia and to assist in identifying and supporting people affected by pandemic-specific paranoia.


Assuntos
COVID-19 , Transtornos Paranoides , Humanos , Transtornos Paranoides/diagnóstico , Pandemias , Psicometria/métodos , Reprodutibilidade dos Testes , Tradução , Análise Fatorial , Inquéritos e Questionários
8.
J Dairy Sci ; 106(2): 990-1001, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36526456

RESUMO

The objective of this study was to evaluate the effects of dietary replacement of magnesium oxide (MgO) with calcium-magnesium hydroxide [CaMg(OH)2] and its interaction with ruminal buffer (sodium sesquicarbonate) supplementation on production, Ca and Mg balance, and overall physiological response of mid-lactation Holstein dairy cows. Sixty cows averaging 40.5 ± 7.0 kg of milk/d were used. Treatments were assigned following a 2 × 2 factorial arrangement: (1) MgO, (2) MgO + buffer, (3) CaMg(OH)2, or (4) CaMg(OH)2 + buffer. Diets were formulated to have 16.5% of crude protein, 1.82 Mcal/kg of net energy for lactation, 0.67% Ca, 0.39% P, and 0.25% Mg, all on a dry matter (DM) basis. Treatments were individually top dressed. Milk production, composition, and DM intake were evaluated. A subsample of 20 cows were randomly selected for the evaluation of Ca and Mg balance, blood gases, and electrolytes. Ruminal fluid was also collected for evaluation of pH and Ca and Mg solubility. Effects of Mg source, buffer, and the interaction Mg source × buffer were analyzed through orthogonal contrasts. An interaction of Mg source × buffer was found for DM intake and feed efficiency, in which cows fed CaMg(OH)2 had a similar feed efficiency regardless of ruminal buffer inclusion; however, when cows were fed MgO, the inclusion of buffer reduced feed efficiency. No effects on body weight and milk yield were observed. Buffer addition tended to increase the concentrations of fat, protein, and solids-not-fat, without affecting the yields of these milk components. Magnesium source and buffer did not affect ruminal fluid, blood, urine, or fecal pH; however, buffer supplementation increased urinary pH. Treatment with CaMg(OH)2 increased blood concentration of HCO3-, total CO2, and base excess compared with cows fed MgO. No differences were observed in the ruminal solubility of Ca and Mg or on milk or urinary Ca and Mg excretion. Greater plasma Mg concentration was observed for animals fed MgO compared with cows fed CaMg(OH)2; however, both sources were above the threshold recommended in the literature for dairy cows. Also, a reduction in fecal Mg excretion was observed in animals fed CaMg(OH)2. In summary, we provide evidence that CaMg(OH)2 could replace MgO without affecting performance, overall physiological response, or Ca and Mg balance of mid-lactating dairy Holstein cows.


Assuntos
Lactação , Magnésio , Feminino , Bovinos , Animais , Lactação/fisiologia , Magnésio/análise , Cálcio/metabolismo , Óxido de Magnésio/farmacologia , Leite/química , Dieta/veterinária , Cálcio da Dieta/análise , Rúmen/metabolismo , Ração Animal/análise , Digestão
9.
J Hosp Infect ; 123: 52-60, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35196559

RESUMO

BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) infections are rampant in hospitals and residential care homes for the elderly (RCHEs). AIM: To analyse the prevalence of MRSA colonization among residents and staff, and degree of environmental contamination and air dispersal of MRSA in RCHEs. METHODS: Epidemiological and genetic analysis by whole-genome sequencing (WGS) in 12 RCHEs in Hong Kong. FINDINGS: During the COVID-19 pandemic (from September to October 2021), 48.7% (380/781) of RCHE residents were found to harbour MRSA at any body site, and 8.5% (8/213) of staff were nasal MRSA carriers. Among 239 environmental samples, MRSA was found in 39.0% (16/41) of randomly selected resident rooms and 31.3% (62/198) of common areas. The common areas accessible by residents had significantly higher MRSA contamination rates than those that were not accessible by residents (37.2%, 46/121 vs. 22.1%, 17/177, P=0.028). Of 124 air samples, nine (7.3%) were MRSA-positive from four RCHEs. Air dispersal of MRSA was significantly associated with operating indoor fans in RCHEs (100%, 4/4 vs. 0%, 0/8, P=0.002). WGS of MRSA isolates collected from residents, staff and environmental and air samples showed that ST 1047 (CC1) lineage 1 constituted 43.1% (66/153) of all MRSA isolates. A distinctive predominant genetic lineage of MRSA in each RCHE was observed, suggestive of intra-RCHE transmission rather than clonal acquisition from the catchment hospital. CONCLUSION: MRSA control in RCHEs is no less important than in hospitals. Air dispersal of MRSA may be an important mechanism of dissemination in RCHEs with operating indoor fans.


Assuntos
COVID-19 , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Idoso , COVID-19/epidemiologia , Portador Sadio/epidemiologia , Humanos , Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Pandemias , Infecções Estafilocócicas/epidemiologia
10.
J Hosp Infect ; 121: 65-74, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34953945

RESUMO

BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) has become endemic in many healthcare settings. AIM: To analyse the incidence, risk factors, outcomes, and genomic relatedness of patients with newly diagnosed gastrointestinal colonization of MRSA. METHODS: Epidemiology and genetic analysis by whole-genome sequencing (WGS) in a hospital network in Hong Kong. FINDINGS: Between October 1st, 2015 and December 31st, 2018, a total of 919 (2.7%) of 34,667 patients had newly diagnosed gastrointestinal MRSA colonization by admission screening. The incidence was 0.67 ± 0.32 per 1000 patient-days per quarter. Including patients with gastrointestinal MRSA colonization, the overall burden of MRSA increased by 59.2%, with an addition of 4727 MRSA patient-days during the study period. Patients referred from residential care home for the elderly, with history of hospitalization in the past six months, and consumption of fluoroquinolones, cephalosporins, and proton-pump inhibitors in the preceding six months were found to be independent risk factors by multivariate analysis in the case-control analysis. The median survival of cases was significantly shorter than that of controls (860 vs 1507 days, P < 0.001). Of 919 patients, 127 (13.8%) developed symptomatic MRSA infection in a median of 112 days. Of 19 patients with paired MRSA faecal and blood culture isolates subjected to WGS, clonality was found in 16 (84.2%) pairs of MRSA isolates. MRSA ST45 constituted 44.7% (17/38) of MRSA isolates. CONCLUSION: Gastrointestinal MRSA colonization may contribute to adverse clinical outcomes and pose an unrecognized burden upon hospital infection control.


Assuntos
Infecção Hospitalar , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Idoso , Infecção Hospitalar/epidemiologia , Humanos , Meticilina , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Fatores de Risco , Infecções Estafilocócicas/epidemiologia
11.
J Hosp Infect ; 116: 78-86, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34403765

RESUMO

AIM: To describe the nosocomial transmission of Air, multidrug-resistant, Acinetobacter baumannii, nosocomial, COVID-19 Acinetobacter baumannii (MRAB) in an open-cubicle neurology ward with low ceiling height, where MRAB isolates collected from air, commonly shared items, non-reachable high-level surfaces and patients were analysed epidemiologically and genetically by whole-genome sequencing. This is the first study to understand the genetic relatedness of air, environmental and clinical isolates of MRAB in the outbreak setting. FINDINGS: Of 11 highly care-dependent patients with 363 MRAB colonization days during COVID-19 pandemic, 10 (90.9%) and nine (81.8%) had cutaneous and gastrointestinal colonization, respectively. Of 160 environmental and air samples, 31 (19.4%) were MRAB-positive. The proportion of MRAB-contaminated commonly shared items was significantly lower in cohort than in non-cohort patient care (0/10, 0% vs 12/18, 66.7%; P<0.001). Air dispersal of MRAB was consistently detected during but not before diaper change in the cohort cubicle by 25-min air sampling (4/4,100% vs 0/4, 0%; P=0.029). The settle plate method revealed MRAB in two samples during diaper change. The proportion of MRAB-contaminated exhaust air grills was significantly higher when the cohort cubicle was occupied by six MRAB patients than when fewer than six patients were cared for in the cubicle (5/9, 55.6% vs 0/18, 0%; P=0.002). The proportion of MRAB-contaminated non-reachable high-level surfaces was also significantly higher when there were three or more MRAB patients in the cohort cubicle (8/31, 25.8% vs 0/24, 0%; P=0.016). Whole-genome sequencing revealed clonality of air, environment, and patients' isolates, suggestive of air dispersal of MRAB. CONCLUSIONS: Our findings support the view that patient cohorting in enclosed cubicles with partitions and a closed door is preferred if single rooms are not available.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , COVID-19 , Infecção Hospitalar , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Farmacorresistência Bacteriana Múltipla , Humanos , Testes de Sensibilidade Microbiana , Pandemias , SARS-CoV-2
12.
Obstet Med ; 14(2): 105-108, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34394720

RESUMO

Acute kidney injury in women during pregnancy and the puerperium is often ascribed to hypertensive complications of pregnancy, especially pre-eclampsia. However, rarer causes, including atypical hemolytic uremic syndrome (aHUS) can be triggered by pregnancy. We present a case of a woman with post-partum acute kidney injury due to aHUS, which was successfully treated with the C5a inhibitor eculizumab. We also present a summary of the evaluation and management of thrombotic microangiopathy in pregnancy.

13.
Br J Dermatol ; 185(2): 405-411, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33314029

RESUMO

BACKGROUND: Clinical and histological diagnosis of Sézary syndrome (SS) and mycosis fungoides (MF) is challenging in clinical routine. OBJECTIVES: We investigated five blood markers previously described for SS (T-plastin, Twist, KIR3DL2, NKp46 and Tox) in a prospective validation cohort of patients. METHODS: We included 447 patients in this study and 107 patients were followed up for prognosis. The markers were analysed by reverse transcriptase quantitative real-time polymerase chain reaction (RT-qPCR) on peripheral blood leucocytes and CD4+ T cells in a cohort of consecutive patients with early MF, erythrodermic MF and SS and compared with patients presenting with benign inflammatory dermatoses (BID) and erythrodermic BID. The markers were assessed in parallel to gold standard values such as CD4/CD8 ratio, loss of CD7 and CD26 membrane expression and CD4 absolute values. Sensitivity and specificity were analysed by receiver operator characteristic curves. The prognostic value of selected markers was analysed on a subset of patients. This study was conducted in one centre. RESULTS: We defined cut-off values for each marker. T-plastin, Twist and KIR3DL2 had the best validity. SS may be overrepresented. The combination of T-plastin and Twist was able to differentiate between erythrodermic MF or BID and SS. The additional analysis of KIR3DL2 may be useful to predict the prognosis. CONCLUSIONS: We propose T-plastin, Twist and KIR3DL2 measured by RT-qPCR as new diagnostic markers for Sézary syndrome.


Assuntos
Micose Fungoide , Síndrome de Sézary , Neoplasias Cutâneas , Biomarcadores , Humanos , Micose Fungoide/diagnóstico , Prognóstico , Síndrome de Sézary/diagnóstico , Neoplasias Cutâneas/diagnóstico
14.
BMJ Simul Technol Enhanc Learn ; 7(6): 501-509, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35520980

RESUMO

Introduction: In early 2020, our hospital responded with high alertness when novel coronavirus SARS-CoV-2 appeared. A hospital-based training programme was rapidly arranged to prepare staff for the imminent threat. Objective: We developed a hospital-wide multidisciplinary infection control training programme on endotracheal intubation for healthcare workers to minimise nosocomial spread of COVID-19 during this high-stress and time-sensitive risky procedure. Methodology: Major stakeholders (Quality & Safety Department, Infection Control Team, Central Nursing Division, high-risk clinical departments and hospital training centre) formed a training programme task group. This group was tasked with developing high-fidelity scenario-based simulation training curriculum for COVID-19 endotracheal intubation with standard workflow and infection control practice. This group then implemented and evaluated the training programme for its effectiveness. Results: 101 training classes of 2-hour session were conducted from 5 February to 18 March 2020, involving 1415 hospital staff (~81% of target participants with training needs) either inside the hospital training centre or as in situ simulation training (intensive care unit or accident and emergency department). Learners' satisfaction was reflected by overall positive response percentage at 90%. Opinions of participating staff were incorporated into the standard airway management and infection control practice for endotracheal intubation of adult patients with COVID-19. Thirty-five patients with COVID-19 were intubated with the current workflow and guideline without any nosocomial transmission. Conclusion: An early planned and well-structured multidisciplinary hospital-wide simulation training programme was organised expeditiously to provide extensive staff coverage. The insight and experience gained from this project is valuable for future infectious disease challenges.

15.
East Asian Arch Psychiatry ; 29(1): 3-9, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31237250

RESUMO

BACKGROUND: Hypervigilance to threat is a mechanism contributing to generalised anxiety disorder (GAD). Although attentional bias modification training (ABMT) is designed to reduce attention to threat, its use as a mechanistically focused psychological intervention for GAD has not been examined. We aimed to investigate the effect of a brief ABMT on reducing anxiety, worry, and attentional bias in outpatients with GAD, and to determine the association between change in attentional bias and changes in anxiety and worry. METHODS: This was a parallel-group, double-blind, randomised controlled trial. Patients with GAD who had no changes after medication treatment for the past 8 weeks were randomly allocated to either the treatment or control group to receive 4 weekly sessions of ABMT or sham ABMT, respectively, in addition to standard care. Anxiety was measured using the Hamilton Anxiety Rating Scale and the State-Trait Anxiety Inventory - trait anxiety subscale. Pathological worry was measured using the Penn State Worry Questionnaire. Attentional bias was measured using the bias score. RESULTS: A total of 33 participants were allocated to the treatment (n = 17) or control (n = 16) groups. Both groups reported a significant reduction in levels of anxiety and worry after intervention, but the reduction was not greater after ABMT than sham ABMT. There was no significant change in attentional bias after ABMT; change in attentional bias was not correlated to changes in anxiety and worry. CONCLUSION: The efficacy of the brief ABMT as a mechanistically focused treatment for GAD was not supported. The small sample size and short duration of treatment may have rendered the results inconclusive.


Assuntos
Transtornos de Ansiedade/fisiopatologia , Transtornos de Ansiedade/terapia , Viés de Atenção/fisiologia , Psicoterapia Breve/métodos , Adulto , Transtornos de Ansiedade/psicologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
16.
Int J Med Inform ; 114: 27-34, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29673600

RESUMO

INTRODUCTION: In view of the popularity of Internet usage in Hong Kong, an interactive web-based drug information platform entitled "Ask My Pharmacist - Online University Led drug Enquiry Platform" (AMPOULE) was launched in 2009 to better serve the needs of drug information in Hong Kong. This paper aimed to evaluate the utility of AMPOULE in improving drug-related knowledge among the public and to reassess the needs of the general public in Hong Kong. METHODS: All enquiries sent via AMPOULE were reviewed. Demographic data, nature of questions and types of drug class covered were analyzed. The workload of pharmacists was examined with respect to the preparation time needed for the enquiry, the lag days to reply and also the timing of enquiry recipient. RESULTS: 2122 enquiries were received from 2009 to 2017. Most enquirers were from Hong Kong (56.6%) and female gender (49.2%). 13% of the concerned subjects were aged over 61-year-old. The most frequent types of questions and medications covered were "Drug Ingredients and Indications" (28.0%) and Adverse Drug Reactions (26.8%) and "Cardiovascular Medication" (21.9%) respectively but these varied in different age groups or enquirer groups. The median time for preparation was 40.0 min (IQR: 25-65 min) while the median time lag was found to be 2.5 days (IQR: 1.0-5.0 days). The number of enquiries received was evenly distributed throughout the day except during 1:00 am to 9:00 am and 7:00 pm to 8:00 pm. CONCLUSION: AMPOULE has demonstrated that an online platform providing patient-oriented drug information service through the Internet is promising and further promotion is warranted. Current data suggested that the need of different age groups and enquirer groups are different and should therefore be individualized.


Assuntos
Serviços de Informação sobre Medicamentos/normas , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Determinação de Necessidades de Cuidados de Saúde , Sistemas On-Line , Farmacêuticos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Hong Kong , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
Eur Psychiatry ; 45: 139-153, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28763680

RESUMO

BACKGROUND: Dysfunctions in metacognition have been reported in individuals with anxiety disorders. Although recent studies have examined metacognition in other disorders, how dysfunctional metacognition compares across disorders is not clear. This review aimed to ascertain the importance of dysfunctional metacognition in various psychopathologies, and to identify similarities and differences in metacognitive profiles across disorders. METHODS: Forty-seven studies were selected from 586 articles published between 1990 and August 2015, including a total sample of 3772 patients and 3376 healthy individuals. Studies that measured metacognition using the Meta-Cognitions Questionnaire (MCQ) and its variants were included. We conducted five meta-analyses including 49 to 55 effect sizes, comparing psychiatric patients to healthy individuals on respective metacognitive dimensions of the MCQ. RESULTS: We found elevated metacognitive dysfunctions in patients, as a group, on all MCQ dimensions. Group effects were large and robust for the two negative beliefs (i.e., beliefs about the uncontrollability and danger of thoughts, and beliefs about the need to control thoughts), and moderate and unstable for the positive beliefs. Patients showed decreased cognitive confidence and heightened cognitive self-consciousness on moderate to large levels. Moderator analyses revealed that negative beliefs about uncontrollability and danger of thoughts were most prevalent in generalized anxiety disorder, whereas heightened cognitive self-consciousness was more characteristic in obsessive-compulsive disorder. Generalized anxiety disorder, obsessive-compulsive disorder and eating disorders manifested more similar metacognitive profiles than other disorders. CONCLUSIONS: Our findings supported dysfunctional metacognition as common processes across psychopathologies, with certain dimensions being more prevalent in particular disorders.


Assuntos
Controle Interno-Externo , Metacognição , Transtorno Obsessivo-Compulsivo/psicologia , Índice de Gravidade de Doença , Adulto , Ansiedade/psicologia , Transtornos de Ansiedade/psicologia , Feminino , Humanos , Masculino
18.
Br J Dermatol ; 177(5): 1322-1336, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28403520

RESUMO

BACKGROUND: Male androgenetic alopecia (AGA) is the most common form of hair loss in men. It is characterized by a distinct pattern of progressive hair loss starting from the frontal area and the vertex of the scalp. Although several genetic risk loci have been identified, relevant genes for AGA remain to be defined. OBJECTIVES: To identify biomarkers associated with AGA. METHODS: Molecular biomarkers associated with premature AGA were identified through gene expression analysis using cDNA generated from scalp vertex biopsies of hairless or bald men with premature AGA, and healthy volunteers. RESULTS: This monocentric study reveals that genes encoding mast cell granule enzymes, inflammatory mediators and immunoglobulin-associated immune mediators were significantly overexpressed in AGA. In contrast, underexpressed genes appear to be associated with the Wnt/ß-catenin and bone morphogenic protein/transforming growth factor-ß signalling pathways. Although involvement of these pathways in hair follicle regeneration is well described, functional interpretation of the transcriptomic data highlights different events that account for their inhibition. In particular, one of these events depends on the dysregulated expression of proopiomelanocortin, as confirmed by polymerase chain reaction and immunohistochemistry. In addition, lower expression of CYP27B1 in patients with AGA supports the notion that changes in vitamin D metabolism contributes to hair loss. CONCLUSIONS: This study provides compelling evidence for distinct molecular events contributing to alopecia that may pave the way for new therapeutic approaches.


Assuntos
Alopecia/genética , Transdução de Sinais/genética , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/metabolismo , Adulto , Análise de Variância , Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Estudos de Casos e Controles , Cateninas/genética , DNA Complementar/genética , Regulação para Baixo/genética , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Marcadores Genéticos , Folículo Piloso/metabolismo , Humanos , Masculino , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Regulação para Cima/genética , Vitamina D/genética , Vitamina D/metabolismo , Via de Sinalização Wnt/genética
19.
Sci Total Environ ; 592: 584-592, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28320524

RESUMO

In this study, natural organic matter (NOM) characteristics were investigated over three years of monthly monitoring to determine the effect of seasonal variations on NOM levels from source to tap. Liquid chromatography with organic carbon detection (LC-OCD) was used to determine NOM characteristics and the level of reduction of biodegradable dissolved organic carbon (BDOC). The average dissolved organic matter concentration in the source water (Lake Paldang, Korea) was not significantly different between summer and winter. However, the distribution of NOM components, such as biopolymers, building blocks, low molecular weight (MW) neutrals and acids, identified by LC-OCD, varied seasonally. While high MW NOM was preferentially removed by coagulation/sedimentation/rapid sand filtration (CSR), no seasonal effects were observed on the removal of high MW NOM. CSR and biological activated carbon (BAC) filtration showed a better efficiency of BDOC removal in winter and summer, respectively. High concentrations of chlorine used in the treatment plants in summer resulted in 10% higher DOC concentrations during disinfection. Overall NOM removal efficiencies from source to tap were 45% and 35% for summer and winter, respectively. Principal component analysis also indicated that seasonal variations (principal component 1) showed the strongest positive correlation with the overall performance of water treatment. The long-term monitoring of drinking water treatment processes showed that seasonal variations were important factors affecting NOM characteristics during water treatment.


Assuntos
Carbono/análise , Água Potável/química , Estações do Ano , Purificação da Água , Carvão Vegetal , Filtração , República da Coreia
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