12,178 research outputs found
Paediatric preventative health care use by immigrants in Hong Kong: a pilot study
BACKGROUND: Over 14,000 children arrived in Hong Kong from Mainland China last year to join their recently immigrated parents. The aims of this pilot study were to explore immigrant parents' knowledge and perceptions of the accessibility of paediatric preventative health care services. METHOD: A descriptive survey was administered to parents. Participants (N=27) were grouped by their child's point of entry into the health care system. RESULTS: Most participants lacked knowledge about well-child care and health education. Participants whose children lived in Hong Kong for longer than one year used services for well-child care significantly more than those with shorter stays (χ2=4.50; p=0.03). The major barrier in accessing services was lack of knowledge. CONCLUSIONS: Although a preliminary study, the results suggest a population-based study is needed because lack of familiarity with available services was a reoccurring finding. A more comprehensive assessment of the learning needs of this population is needed so effective ways of familiarizing new immigrants and tracking these children can be developed.published_or_final_versio
The Prevalence and Risk Factors of Paternal Depression from the Antenatal to the Postpartum period and the Relationships between Antenatal and Postpartum Depression among Fathers in Hong Kong
Introduction. Despite the fact that maternal perinatal mental health problems have been extensively studied and addressed to be a significant health problem, the literature on paternal perinatal mental health problems is relatively scarce. The present study aims at determining the prevalence of paternal perinatal depression and identifying the risk factors and the relationship between antenatal and postpartum depression. Methodology. 622 expectant fathers were recruited from regional maternal clinics. The expectant fathers were assessed using standardized and validated psychological instruments on 3 time points including early pregnancy, late pregnancy, and six weeks postpartum. Results. Results showed that a significant proportion of expectant fathers manifested depressive symptoms during the perinatal period. Paternal antenatal depression could significantly predict higher level of paternal postpartum depression. Psychosocial risk factors were consistently associated with paternal depression in different time points. Conclusions. The present study points to the need for greater research and clinical attention to paternal depression given that it is a highly prevalent problem and could be detrimental to their spouse and children development. The present findings contribute to theoretical basis of the prevalence and risk factors of paternal perinatal depression and have implications of the design of effective identification, prevention, and interventions of these clinical problems.published_or_final_versio
Atom-by-Atom Substitution of Mn in GaAs and Visualization of their Hole-Mediated Interactions
The discovery of ferromagnetism in Mn doped GaAs [1] has ignited interest in
the development of semiconductor technologies based on electron spin and has
led to several proof-of-concept spintronic devices [2-4]. A major hurdle for
realistic applications of (Ga,Mn)As, or other dilute magnetic semiconductors,
remains their below room-temperature ferromagnetic transition temperature.
Enhancing ferromagnetism in semiconductors requires understanding the
mechanisms for interaction between magnetic dopants, such as Mn, and
identifying the circumstances in which ferromagnetic interactions are maximized
[5]. Here we report the use of a novel atom-by-atom substitution technique with
the scanning tunnelling microscope (STM) to perform the first controlled atomic
scale study of the interactions between isolated Mn acceptors mediated by the
electronic states of GaAs. High-resolution STM measurements are used to
visualize the GaAs electronic states that participate in the Mn-Mn interaction
and to quantify the interaction strengths as a function of relative position
and orientation. Our experimental findings, which can be explained using
tight-binding model calculations, reveal a strong dependence of ferromagnetic
interaction on crystallographic orientation. This anisotropic interaction can
potentially be exploited by growing oriented Ga1-xMnxAs structures to enhance
the ferromagnetic transition temperature beyond that achieved in randomly doped
samples. Our experimental methods also provide a realistic approach to create
precise arrangements of single spins as coupled quantum bits for memory or
information processing purposes
Antenatal anxiety in the first trimester: Risk factors and effects on anxiety and depression in the third trimester and 6-week postpartum
Objective: Anxiety is common among pregnant women. However, research attention in the area of reproductive mental health has mainly focused on postpartum depression in past decades. Given adverse outcomes of antenatal anxiety, there is an urgent need to fill the research gaps. The objectives of the present study were to determine the prevalence of antenatal anxiety symptoms and examine the risk factors and effects of anxiety symptoms in early pregnancy on anxiety and depressive symptoms in later pregnancy and early postpartum period. Methodology: A prospective longitudinal design with quantitative approach was adopted. A consecutive sample of 1470 Chinese pregnant women from hospitals in Hong Kong was invited to participate in the study and was assessed using standardized instruments on 3 time points including first and third trimesters of pregnancy and 6-week postpartum. Results: The results showed that 17.7% of pregnant women manifested anxiety symptoms in the first trimester of pregnancy. Single mothers, younger mothers, mothers who smoked before pregnancy and mothers who received low education level reported significantly higher levels of anxiety symptoms in the first trimester. Unwanted pregnancy, low self esteem, low marital satisfaction and perceived low social support were significant psychosocial risk factors for anxiety symptoms in the first trimester. Anxiety symptoms in the first trimester were independent predictors for anxiety symptoms in the third trimester ( QUOTE β = 0.26, t = 5.74, p < 0.001), however anxiety symptoms in the first trimester no longer significantly predicted anxiety and depressive symptoms in 6 weeks postpartum after adjusting for the effects of potential confounders. Discussions: The present study points to the need for greater research and clinical attention to antenatal anxiety given that antenatal anxiety is a prevalent problem and has serious impacts on maternal well-being. Such findings also contribute to the understanding of maternal anxiety and have implications for the design of effective identification, prevention and treatment of these significant clinical problemspublished_or_final_versio
Family conflict and lower morning cortisol in adolescents and adults: modulation of puberty
published_or_final_versio
Rupture by damage accumulation in rocks
The deformation of rocks is associated with microcracks nucleation and
propagation, i.e. damage. The accumulation of damage and its spatial
localization lead to the creation of a macroscale discontinuity, so-called
"fault" in geological terms, and to the failure of the material, i.e. a
dramatic decrease of the mechanical properties as strength and modulus. The
damage process can be studied both statically by direct observation of thin
sections and dynamically by recording acoustic waves emitted by crack
propagation (acoustic emission). Here we first review such observations
concerning geological objects over scales ranging from the laboratory sample
scale (dm) to seismically active faults (km), including cliffs and rock masses
(Dm, hm). These observations reveal complex patterns in both space (fractal
properties of damage structures as roughness and gouge), time (clustering,
particular trends when the failure approaches) and energy domains (power-law
distributions of energy release bursts). We use a numerical model based on
progressive damage within an elastic interaction framework which allows us to
simulate these observations. This study shows that the failure in rocks can be
the result of damage accumulation
The regulatory subunit of PKA-I remains partially structured and undergoes β-aggregation upon thermal denaturation
Background: The regulatory subunit (R) of cAMP-dependent protein kinase (PKA) is a modular flexible protein that responds with large conformational changes to the binding of the effector cAMP. Considering its highly dynamic nature, the protein is rather stable. We studied the thermal denaturation of full-length RIα and a truncated RIα(92-381) that contains the tandem cyclic nucleotide binding (CNB) domains A and B. Methodology/Principal Findings: As revealed by circular dichroism (CD) and differential scanning calorimetry, both RIα proteins contain significant residual structure in the heat-denatured state. As evidenced by CD, the predominantly α-helical spectrum at 25°C with double negative peaks at 209 and 222 nm changes to a spectrum with a single negative peak at 212-216 nm, characteristic of β-structure. A similar α→β transition occurs at higher temperature in the presence of cAMP. Thioflavin T fluorescence and atomic force microscopy studies support the notion that the structural transition is associated with cross-β-intermolecular aggregation and formation of non-fibrillar oligomers. Conclusions/Significance: Thermal denaturation of RIα leads to partial loss of native packing with exposure of aggregation-prone motifs, such as the B' helices in the phosphate-binding cassettes of both CNB domains. The topology of the β-sandwiches in these domains favors inter-molecular β-aggregation, which is suppressed in the ligand-bound states of RIα under physiological conditions. Moreover, our results reveal that the CNB domains persist as structural cores through heat-denaturation. © 2011 Dao et al
Challenges in monitoring and managing engineered slopes in a changing climate
Geotechnical asset owners need to know which parts of their asset network are vulnerable to climate
change induced failure in order to optimise future investment. Protecting these vulnerable slopes requires monitoring
systems capable of identifying and alerting to asset operators changes in the internal conditions that precede failure.
Current monitoring systems are heavily reliant on point sensors which can be difficult to interpret across slope scale.
This paper presents challenges to producing such a system and research being carried out to address some of these
using electrical resistance tomography (ERT). Experimental results show that whilst it is possible to measure soil
water content indirectly via resistivity the relationship between resistivity and water content will change over time for
a given slope. If geotechnical parameters such as pore water pressure are to be estimated using this method then ERT
systems will require integrating with more conventional geotechnical instrumentation to ensure correct representative
information is provided. The paper also presents examples of how such data can be processed and communicated to
asset owners for the purposes of asset management
Mindfulness-based interventions in epilepsy: a systematic review
Mindfulness based interventions (MBIs) are increasingly used to help patients cope with physical and mental long-term conditions (LTCs). Epilepsy is associated with a range of mental and physical comorbidities that have a detrimental effect on quality of life (QOL), but it is not clear whether MBIs can help. We systematically reviewed the literature to determine the effectiveness of MBIs in people with epilepsy. Medline, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, Allied and Complimentary Medicine Database, and PsychInfo were searched in March 2016. These databases were searched using a combination of subject headings where available and keywords in the title and abstracts. We also searched the reference lists of related reviews. Study quality was assessed using the Cochrane Collaboration risk of bias tool. Three randomised controlled trials (RCTs) with a total of 231 participants were included. The interventions were tested in the USA (n = 171) and China (Hong Kong) (n = 60). Significant improvements were reported in depression symptoms, quality of life, anxiety, and depression knowledge and skills. Two of the included studies were assessed as being at unclear/high risk of bias - with randomisation and allocation procedures, as well as adverse events and reasons for drop-outs poorly reported. There was no reporting on intervention costs/benefits or how they affected health service utilisation. This systematic review found limited evidence for the effectiveness of MBIs in epilepsy, however preliminary evidence suggests it may lead to some improvement in anxiety, depression and quality of life. Further trials with larger sample sizes, active control groups and longer follow-ups are needed before the evidence for MBIs in epilepsy can be conclusively determined
Inhibition of the tyrosine phosphatase SHP-2 suppresses angiogenesis in vitro and in vivo
Endothelial cell survival is indispensable to maintain endothelial integrity and initiate new vessel formation. We investigated the role of SHP-2 in endothelial cell survival and angiogenesis in vitro as well as in vivo. SHP-2 function in cultured human umbilical vein and human dermal microvascular endothelial cells was inhibited by either silencing the protein expression with antisense-oligodesoxynucleotides or treatment with a pharmacological inhibitor (PtpI IV). SHP-2 inhibition impaired capillary-like structure formation (p < 0.01; n = 8) in vitro as well as new vessel growth ex vivo (p < 0.05; n = 10) and in vivo in the chicken chorioallantoic membrane (p < 0.01, n = 4). Additionally, SHP-2 knock-down abrogated fibroblast growth factor 2 (FGF-2)-dependent endothelial proliferation measured by MTT reduction ( p ! 0.01; n = 12). The inhibitory effect of SHP-2 knock-down on vessel growth was mediated by increased endothelial apoptosis ( annexin V staining, p ! 0.05, n = 9), which was associated with reduced FGF-2-induced phosphorylation of phosphatidylinositol 3-kinase (PI3-K), Akt and extracellular regulated kinase 1/2 (ERK1/2) and involved diminished ERK1/2 phosphorylation after PI3-K inhibition (n=3). These results suggest that SHP-2 regulates endothelial cell survival through PI3-K-Akt and mitogen-activated protein kinase pathways thereby strongly affecting new vessel formation. Thus, SHP-2 exhibits a pivotal role in angiogenesis and may represent an interesting target for therapeutic approaches controlling vessel growth. Copyright (C) 2007 S. Karger AG, Basel
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