96 research outputs found
Herba Epimedii: Anti-oxidative properties and its medical implications
Herba Epimedii is a Chinese herbal medicine with proven efficacy in treating cardiovascular diseases and osteoporosis, and in improving sexual and neurological functions. This efficacy is found to be related to the potent anti-oxidative ability of Herba Epimedii and its flavonoid components, with icarrin as the main effective constituent, along with polysaccharides and vitamin C. These ingredients have been proven to be effective against oxidative-stress related pathologies (cardiovascular diseases, Alzheimer's disease and inflammation) in animal rodent models and in vitro studies. Their antioxidative properties are found to be related to an inductive effect on endogenous freeradical scavenging enzymes such as catalase and glutathione peroxidase and the inherent electron-donating ability of flavonoids. © 2010 licensee MDPI, Basel, Switzerland.published_or_final_versio
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Expression of ABCA4 in the retinal pigment epithelium and its implications for Stargardt macular degeneration.
Recessive Stargardt disease (STGD1) is an inherited blinding disorder caused by mutations in the Abca4 gene. ABCA4 is a flippase in photoreceptor outer segments (OS) that translocates retinaldehyde conjugated to phosphatidylethanolamine across OS disc membranes. Loss of ABCA4 in Abca4 -/- mice and STGD1 patients causes buildup of lipofuscin in the retinal pigment epithelium (RPE) and degeneration of photoreceptors, leading to blindness. No effective treatment currently exists for STGD1. Here we show by several approaches that ABCA4 is additionally expressed in RPE cells. (i) By in situ hybridization analysis and by RNA-sequencing analysis, we show the Abca4 mRNA is expressed in human and mouse RPE cells. (ii) By quantitative immunoblotting, we show that the level of ABCA4 protein in homogenates of wild-type mouse RPE is about 1% of the level in neural retina homogenates. (iii) ABCA4 immunofluorescence is present in RPE cells of wild-type and Mertk -/- but not Abca4 -/- mouse retina sections, where it colocalizes with endolysosomal proteins. To elucidate the role of ABCA4 in RPE cells, we generated a line of genetically modified mice that express ABCA4 in RPE cells but not in photoreceptors. Mice from this line on the Abca4 -/- background showed partial rescue of photoreceptor degeneration and decreased lipofuscin accumulation compared with nontransgenic Abca4 -/- mice. We propose that ABCA4 functions to recycle retinaldehyde released during proteolysis of rhodopsin in RPE endolysosomes following daily phagocytosis of distal photoreceptor OS. ABCA4 deficiency in the RPE may play a role in the pathogenesis of STGD1
University Staff’s Perceptions of Community College Transfer Students’ Transition Experiences Within a “2+2” Pathway in an Asian Educational Context
Various countries have alternative pathway policies for 2-year community college graduates to articulate to 2-year university study, forming a “2+2” pathway. However, few studies have explored university staff members’ perceptions of this “2+2” transfer pathway and their understanding of transfer students’ (TSs) transition experiences. This descriptive qualitative study addressed this research gap. Forty-two academic and supporting staff participated in the focus group interviews. Specifically, the study explored the assets and challenges of the “2+2” pathway from the university staff perspective in Hong Kong. The articulation pathway and TSs are highly recognized for their prior learning, academic performances, and the value of the second chance. However, while the university staff were sympathetic to the challenges filling these transfer pathways, their offering of help was limited by government funding and policies restrictions. It is recommended that policies should be established at government and university levels to recognize and tackle TSs’ unique needs to alleviate their heavy workloads through better articulation between community college and university studies. Improving articulation will allow TSs time for social involvement in university life and thus enhance their mental well-being
Acute and subacute toxicity profiles of thymoquinone-loaded nanostructured lipid carrier in BALB/c mice
Herpes zoster related hospitalization after inactivated (CoronaVac) and mRNA (BNT162b2) SARS-CoV-2 vaccination: A self-controlled case series and nested case-control study
BACKGROUND: Stimulation of immunity by vaccination may elicit adverse events. There is currently inconclusive evidence on the relationship between herpes zoster related hospitalization and COVID-19 vaccination. This study aimed to evaluate the effect of inactivated virus (CoronaVac, Sinovac) and mRNA (BNT162b2, BioNTech/Fosun Pharma) COVID-19 vaccine on the risk of herpes zoster related hospitalization. METHODS: Self-controlled case series (SCCS) analysis was conducted using the data from the electronic health records in Hospital Authority and COVID-19 vaccination records in the Department of Health in Hong Kong. We conducted the SCCS analysis including patients with a first primary diagnosis of herpes zoster in the hospital inpatient setting between February 23 and July 31, 2021. A confirmatory analysis by nested case-control method was also conducted. Each herpes zoster case was randomly matched with ten controls according to sex, age, Charlson comorbidity index, and date of hospital admission. Conditional Poisson regression and logistic regression models were used to assess the potential excess rates of herpes zoster after vaccination. FINDINGS: From February 23 to July 31, 2021, a total of 16 and 27 patients were identified with a first primary hospital diagnosis of herpes zoster within 28 days after CoronaVac and BNT162b2 vaccinations. The incidence of herpes zoster was 7.9 (95% Confidence interval [CI]: 5.2–11.5) for CoronaVac and 7.1 (95% CI: 4.1–11.5) for BNT162b2 per 1,000,000 doses administered. In SCCS analysis, CoronaVac vaccination was associated with significantly higher risk of herpes zoster within 14 days after first dose (adjusted incidence rate ratio [aIRR]=2.67, 95% CI: 1.08–6.59) but not in other periods afterwards compared to the baseline period. Regarding BNT162b2 vaccination, a significantly increased risk of herpes zoster was observed after first dose up to 14 days after second dose (0-13 days after first dose: aIRR=5.23, 95% CI: 1.61–17.03; 14–27 days after first dose: aIRR=5.82, 95% CI: 1.62–20.91; 0-13 days after second dose: aIRR=5.14, 95% CI: 1.29–20.47). Using these relative rates, we estimated that there has been an excess of approximately 5 and 7 cases of hospitalization as a result of herpes zoster after every 1,000,000 doses of CoronaVac and BNT162b2 vaccination, respectively. The findings in the nested case control analysis showed similar results. INTERPRETATION: We identified an increased risk of herpes zoster related hospitalization after CoronaVac and BNT162b2 vaccinations. However, the absolute risks of such adverse event after CoronaVac and BNT162b2 vaccinations were very low. In locations where COVID-19 is prevalent, the protective effects on COVID-19 from vaccinations will greatly outweigh the potential side effects of vaccination. FUNDING: The project was funded by Research Grant from the Food and Health Bureau, The Government of the Hong Kong Special Administrative Region (Ref. No.COVID19F01). FTTL (Francisco Tsz Tsun Lai) and ICKW (Ian Chi Kei Wong)’s posts were partly funded by D(2)4H; hence this work was partly supported by AIR@InnoHK administered by Innovation and Technology Commission
Association between the risk of seizure and COVID-19 vaccinations: A self-controlled case-series study
OBJECTIVE: The risk of seizure following BNT162b2 and CoronaVac vaccinations has been sparsely investigated. This study aimed to evaluate this association. METHOD: Patients who had their first seizure-related hospitalization between February 23, 2021 and January 31, 2022 were identified in Hong Kong. All seizure episodes happening on the day of vaccination (day 0) were excluded since clinicians validated that most of the cases on day 0 were syncopal episodes. Within-individual comparison using a modified self-controlled case series analysis was applied to estimate the incidence rate ratio (IRR) with 95% confidence intervals (CI) of seizure using conditional Poisson regression. RESULTS: We identified 1656 individuals who had their first seizure-related hospitalization (BNT162b2: 426; CoronaVac: 263; unvaccinated: 967) within the observation period. The incidence of seizure was 1.04 (95% CI: 0.80-1.33) and 1.11 (95% CI: 0.80-1.50) per 100,000 doses of BNT162b2 and CoronaVac administered respectively. 16 and 17 individuals received second dose after having first seizure within 28 days after first dose of BNT162b2 and CoronaVac vaccinations, respectively. None had recurrent seizures after the second dose. There was no increased risk during day 1-6 after the first (BNT162b2: IRR=1.39, 95% CI=0.75-2.58; CoronaVac: IRR=1.19, 95% CI=0.50-2.83) and second doses (BNT162b2: IRR=1.36, 95% CI 0.72-2.57; CoronaVac: IRR=0.71, 95% CI=0.22-2.30) of vaccinations. During 7-13, 14-20- and 21-27-days post-vaccination, no association was observed for both vaccines. SIGNIFICANCE: The findings demonstrated no increased risk of seizure following BNT162b2 and CoronaVac vaccinations. Future studies will be warranted to evaluate the risk of seizure following COVID-19 vaccinations in different populations with subsequent doses to ensure the generalizability
Effect of fertility health awareness strategies on fertility knowledge and childbearing in young married couples (FertStart): study protocol for an effectiveness-implementation hybrid type I multicentre three-arm parallel group open-label randomised clinical trial
Introduction Birth rates have been declining in many advanced societies including Singapore. We designed two interventions with vastly different resource requirements, which include fertility education, personalised fertility information and a behavioural change component targeting modifiable psychological constructs to modify fertility awareness and childbearing intentions. We aim to evaluate the effect of these two interventions on knowledge, attitudes and practice around childbearing compared with a control group among young married couples in Singapore and understand the implementation factors in the setting of an effectiveness-implementation hybrid type 1 three-arm randomised trial.
Methods and analysis We will randomise 1200 young married couples to no intervention (control), Fertility Health Screening group (FHS) or Fertility Awareness Tools (FAT) in a 7:5:5 ratio. Couples in FHS will undergo an anti-Mullerian hormone test and semen analysis, a doctor’s consultation to explain the results and standardised reproductive counselling by a trained nurse. Couples in FAT will watch a standardised video, complete an adapted fertility status awareness (FertiSTAT) tool and receive an educational brochure. The attitudes, fertility knowledge and efforts to achieve pregnancy of all couples will be assessed at baseline and 6 months post-randomisation. Birth statistics will be tracked using administrative records at 2 and 3 years. The primary outcome is the change in the woman’s self-reported intended age at first birth between baseline and 6 months post-randomisation. In addition, implementation outcomes and cost-effectiveness of the two interventions will be assessed
A brain-computer interface based cognitive training system for healthy elderly: A randomized control pilot study for usability and preliminary efficacy
10.1371/journal.pone.0079419PLoS ONE811-POLN
A Brief Mindfulness-Based Family Psychoeducation Intervention for Chinese Young Adults With First Episode Psychosis: A Study Protocol
Family psychoeducation (FPE) has been recommended as a major component in the treatment of psychosis. Many previous studies have implemented an intensive program design that often only emphasized improvements in patients’ illness outcomes but the benefits for caregivers were limited. There have been calls for a time-limited but cost-effective FPE program to mitigate the looming reality of the suffering of people with psychosis and their families. A Brief Mindfulness-Based Family Psychoeducation for psychosis program is developed to reduce caregivers’ burden and promote young adult’s recovery. A randomized controlled trial will be conducted to compare this intervention with an ordinary FPE intervention. Both arms will involve six sessions, with a total contact time of 12 h. 300 caregivers of young adults who have experienced first episode psychosis within last 3 years will be recruited. Program effectiveness will be assessed by comparing outcomes measuring the caregivers’ burden, mental health symptoms, positive well-being, and the young adult’s mental health symptoms during the study and at 9-month post-randomization. The role of expressed emotions, interpersonal mindfulness, and non-attachment in mediating these outcomes will be explored. An additional qualitative approach Photovoice is selected to explore the complex family experiences and the benefits of mindfulness from the caregivers’ personal perspectives.Trial Registration: The trial is registered with the United States Clinical Trials Registry (ClinicalTrials.gov): NCT03688009
Graphene Schottky diodes: an experimental review of the rectifying graphene/semiconductor heterojunction
In the past decade graphene has been one of the most studied material for
several unique and excellent properties. Due to its two dimensional nature,
physical and chemical properties and ease of manipulation, graphene offers the
possibility of integration with the exiting semiconductor technology for
next-generation electronic and sensing devices. In this context, the
understanding of the graphene/semiconductor interface is of great importance
since it can constitute a versatile standalone device as well as the
building-block of more advanced electronic systems. Since graphene was brought
to the attention of the scientific community in 2004, the device research has
been focused on the more complex graphene transistors, while the
graphene/semiconductor junction, despite its importance, has started to be the
subject of systematic investigation only recently. As a result, a thorough
understanding of the physics and the potentialities of this device is still
missing. The studies of the past few years have demonstrated that graphene can
form junctions with 3D or 2D semiconducting materials which have rectifying
characteristics and behave as excellent Schottky diodes. The main novelty of
these devices is the tunable Schottky barrier height, a feature which makes the
graphene/semiconductor junction a great platform for the study of interface
transport mechanisms as well as for applications in photo-detection, high-speed
communications, solar cells, chemical and biological sensing, etc. In this
paper, we review the state-of-the art of the research on graphene/semiconductor
junctions, the attempts towards a modeling and the most promising applications.Comment: 85 pages. Review articl
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