138 research outputs found

    Differential permittivity sensor using microstrip terminated cross-shaped resonator structure for material characterization

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    A differential planar microwave resonator permittivity sensor for material characterization is proposed in this paper. The sensor is based on asymmetric terminated cross-shaped resonator (TCSR) to provide multi-band notch frequency characteristics, allowing permittivity measurement of a small dielectric material under test (MUT) with a single resonator. Differential sensing is robust against varying ambient factors that cause frequency variations in the measurements. The dielectric properties of the MUT can be measured from the difference in notch frequencies with the reference material. To illustrate the technique, a tri-band sensor is prototyped using the proposed resonator configuration to measure the permittivity of both solid and liquid samples. The empirical equations for the determination of the MUT permittivity in relation to the notch frequencies have been derived. The sensor operates at 0.97, 1.69, and 2.91 GHz with an average sensitivity of 1.18, 4.45, and 1.22 MHz, respectively. The measured results are in a good agreement with the theoretical analysis

    Association of Genetic Variants Related to Combined Exposure to Higher Body Mass Index and Waist-to-Hip Ratio on Lifelong Cardiovascular Risk in UK Biobank

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    OBJECTIVE: This study examines the individual and combined association of body mass index (BMI) and 7 waist-to-hip ratio (WHR) with cardiovascular diseases (CVD) risk using genetic scores of the 8 obesity measurements as proxies. DESIGN: A 2×2 factorial analysis approach was applied, with participants divided into four groups of lifetime exposure to low BMI and WHR, high BMI, high WHR, and high BMI and WHR based on weighted genetic risk scores. The difference in CVD risk across groups was evaluated using multivariable logistic regression. SETTING: Cohort study. PARTICIPANTS: A total of 408,003 participants were included from the prospective observational UK Biobank study. RESULTS: A total of 58,429 of CVD events were recorded. Compared to the low BMI and WHR genetic scores group, higher BMI or higher WHR genetic scores were associated with an increase in CVD risk (high BMI: odds ratio (OR), 1.07; 95%CI, 1.04-1.10; high WHR: OR, 1.12; 95%CI, 1.09-1.16). A weak additive effect on CVD risk was found between BMI and WHR (high BMI and WHR: OR, 1.16; 95%CI, 1.12-1.19). Subgroup analysis showed similar patterns between different sex, age (<65, ≥65 years old), smoking status, Townsend deprivation index, fasting glucose level and medication uses, but lower systolic blood pressure was associated with higher CVD risk in obese participants. CONCLUSIONS: High BMI or WHR were associated with increased CVD risk, and their effects are weakly additive. Even though there were overlapping of effect, both BMI and WHR are important in assessing the CVD risk in the general population

    Potential enhancement of post-stroke angiogenic response by targeting the oligomeric aggregation of p53 protein

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    Tumor suppressor gene p53 and its aggregate have been found to be involved in many angiogenesis-related pathways. We explored the possible p53 aggregation formation mechanisms commonly occur after ischemic stroke, such as hypoxia and the presence of reactive oxygen species (ROS). The angiogenic pathways involving p53 mainly occur in nucleus or cytoplasm, with one exception that occurs in mitochondria. Considering the high mitochondrial density in brain and endothelial cells, we proposed that the cyclophilin D (CypD)-dependent vascular endothelial cell (VECs) necrosis pathway occurring in the mitochondria is one of the major factors that affects angiogenesis. Hence, targeting p53 aggregation, a key intermediate in the pathway, could be an alternative therapeutic target for post-stroke management

    Proximity-induced quasi-one-dimensional superconducting quantum anomalous Hall state: a promising scalable top-down approach towards localized Majorana modes

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    In this work, ~100 nm wide quantum anomalous Hall insulator (QAHI) nanoribbons are etched from a two-dimensional QAHI film. One part of the nanoribbon is covered with superconducting Nb, while the other part is connected to an Au lead via two-dimensional QAHI regions. Andreev reflection spectroscopy measurements were performed, and multiple in-gap conductance peaks were observed in three different devices. In the presence of an increasing magnetic field perpendicular to the QAHI film, the multiple in-gap peak structure evolves into a single zero-bias conductance peak (ZBCP). Theoretical simulations suggest that the measurements are consistent with the scenario that the increasing magnetic field drives the nanoribbons from a multi-channel occupied regime to a single channel occupied regime, and that the ZBCP may be induced by zero energy Majorana modes as previously predicted [24]. Although further experiments are needed to clarify the nature of the ZBCP, we provide initial evidence that quasi-1D QAHI nanoribbon/superconductor heterostructures are new and promising platforms for realizing zero-energy Majorana modes

    A brief cognitive-behavioral psycho-education (B-CBE) program for managing stress and anxiety of main family caregivers of patients in the intensive care unit

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    © 2016 by the authors; licensee MDPI, Basel, Switzerland. Having a loved one in the intensive care unit (ICU) is a stressful event, which may cause a high level of anxiety to the family members. This could threaten their wellbeing and ability to support the patients in, or after discharge from, the ICU. To investigate the outcomes of a brief cognitive-behavioral psycho-education program (B-CBE) to manage stress and anxiety of the main family caregivers (MFCs), a pragmatic quasi-experimental study involving 45 participants (treatment group: 24; control group: 21) was conducted in an ICU. The Depression and Anxiety Stress Scale and the Critical Care Family Need Inventory were used to evaluate the primary outcomes on stress and anxiety, and satisfaction with family needs. The treatment group reported significantly better improvement in the information satisfaction score compared to the control group (p < 0.05; η 2 = 0.09). Overall main effects were observed on the stress (p < 0.01; η 2 = 0.20), anxiety (p < 0.01; η 2 = 0.18), depression (p < 0.05; η 2 = 0.13), support satisfaction (p < 0.05; η 2 = 0.13), and comfort satisfaction (p < 0.05; η 2 = 0.11) scores. The experience of this study suggest that MFCs are in great need of additional support like B-CBE to manage their stress and anxiety. Given the brevity of B-CBE, it is practical for critical care nurses to deliver and MFCs to take within the industrious context of an ICU. More studies are needed to investigate these types of brief psychological interventions.published_or_final_versio

    Adaptation and psychometric evaluation of the Chinese version of the functional assessment of chronic illness therapy spiritual well-being scale among Chinese childhood cancer patients in China

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    BackgroundSpiritual well-being is a strength for childhood cancer patients to cope with cancer. The availability of a valid and reliable instrument for assessing spiritual well-being is crucial. This study translated and adapted the Functional Assessment of Chronic Illness Therapy Spiritual Well-being scale (FACIT-Sp) for Chinese childhood cancer patients and examined the psychometric properties and factor structure in this population.MethodsThis was a methodological study. The FACIT-Sp was translated into Chinese. Adaptation was based on our qualitative study. For psychometric evaluation, a convenience sample of 412 were recruited based on the suggested sample size for the exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Childhood cancer patients were included if they aged 8–17 years, with parental consent to participate, able to communicate that they were being treated for cancer, and able to communicate and read Chinese. Participants answered the Chinese version of the adapted FACIT-Sp, the Center for Epidemiology Studies Depression Scale for Children (CES-DC), and the Pediatric Quality of Life Inventory 3.0 Cancer Module (PedsQL). Content validity, convergent validity, internal consistency and test–retest reliability were examined. Both EFA and CFA assessed the structural validity of the adapted FACIT-Sp.ResultsThe content validity index values for items ranged 0.8–1.0 and that for the scale was 0.84, indicating appropriate content validity. The scale had good internal consistency, with a Cronbach’s alpha of 0.815. The FACIT-Sp scores positively correlated with the CES-DC scores, and negatively correlated with PedsQL scores, suggesting that the Chinese version of the adapted FACIT-Sp had reasonable convergent validity. EFA yielded a four-factor (meaning, peace, faith, and connection with others) model. The CFA results revealed that the four-factor model achieved a better fit than the original three-factor model (Chi-Square Mean/Degree of Freedom = 2.240 vs. 3.557, Comparative Fit Index = 0.953 vs. 0.916, Goodness of Fit Index = 0.909 vs. 0.884, Root Mean Square Error of Approximation = 0.078 vs. 0.112).ConclusionThe Chinese version of the adapted FACIT-Sp is a reliable and valid instrument for assessing spiritual well-being among Chinese childhood cancer patients. This instrument can be applied in clinical settings for routine assessment

    Antimalarial and antitumour activities of the steroidal quinone-methide celastrol and its combinations with artemiside, artemisone and methylene blue

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    Artemisinin, isolated from the traditional Chinese medicinal plant qīng hāo 青蒿 (Artemisia annua) and its derivatives are used for treatment of malaria. With treatment failures now being recorded for the derivatives and companion drugs used in artemisinin combination therapies new drug combinations are urgently required. The amino-artemisinins artemiside and artemisone display optimal efficacies in vitro against asexual and sexual blood stages of the malaria parasite Plasmodium falciparum and are active against tumour cell lines. In continuing the evolution of combinations of the amino-artemisinins with new drugs, we examine the triterpenoid quinone methide celastrol isolated from the traditional Chinese medicinal plant léi gōng téng 雷公藤 (Tripterygium wilfordii). This compound is redox active, and has attracted considerable attention because of potent biological activities against manifold targets. We report that celastrol displays good IC50 activities ranging from 0.50–0.82 µM against drug-sensitive and resistant asexual blood stage Pf, and 1.16 and 0.28 µM respectively against immature and late stage Pf NF54 gametocytes. The combinations of celastrol with each of artemisone and methylene blue against asexual blood stage Pf are additive. Given that celastrol displays promising antitumour properties, we examined its activities alone and in combinations with amino-artemisinins against human liver HepG2 and other cell lines. IC50 values of the aminoartemisinins and celastrol against HepG2 cancer cells ranged from 0.55–0.94 µM. Whereas the amino-artemisinins displayed notable selectivities (SI > 171) with respect to normal human hepatocytes, in contrast, celastrol displayed no selectivity (SI < 1). The combinations of celastrol with artemiside or artemisone against HepG2 cells are synergistic. Given the promise of celastrol, judiciously designed formulations or structural modifications are recommended for mitigating its toxicity.https://www.frontiersin.org/journals/pharmacologyBiochemistr

    Diversidade e Estrutura Genéticas de Bryconamericus aff. Iheringii (Characiformes: Characidae) na Área de Influência do Reservatório da Itaipu

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    Trabalho de Conclusão de Curso apresentado ao Instituto Latino-Americano de Ciências da Vida e Natureza da Universidade Federal da Integração Latino-Americana, como requisito parcial à obtenção do título de Bacharel em Ciências Biológicas – Ecologia e Biodiversidade.A diversidade genética é necessária para que as populações evoluam e se adaptem às mudanças ambientais, e comumente, está distribuída em um padrão dentro e entre populações que é referido como estrutura genética. O isolamento e a existência de poucos caminhos migratórios entre águas doces implicam na estruturação genética, principalmente, para peixes que possuem baixa mobilidade. Peixes de pequeno porte (≤ 15 cm de comprimento), que habitam riachos, representam, no mínimo 50% de toda a ictiofauna sul-americana e apresentam um alto grau de endemismo, devido, em parte, à sua baixa capacidade de deslocamento. Neste contexto, o presente trabalho objetivou avaliar a diversidade e a estrutura genéticas do caracídeo Bryconamericus aff. iheringii na área de influência do reservatório da Itaipu Binacional. Para isto, foram analisados 47 espécimes, 23 coletados em riachos da margem direita (Paraguai) e 24 coletados em riachos da margem esquerda (Brasil) do reservatório da Itaipu. Para acessar sua diversidade genética, foi empregado o marcador molecular D-loop, sendo estimado o número de haplótipos, os índices de diversidade haplotípica e nucleotídica e o nível de estruturação entre as diferentes amostras. B. aff. iheringii apresentou níveis de diversidade genética dentro do padrão relatado para a espécie, com moderados (amostras do Paraguai) a altos (amostras do Brasil) níveis de diversidade, o que se deve, sobretudo, ao fato de que quase todos os riachos paraguaios analisados são de uma única microbacia, enquanto os riachos brasileiros são de quatro microbacias diferentes. As populações não parecem ter respondido a eventos drásticos recentes, pois mesmo as presentes em regiões sob a pressão de atividades agrícolas, mostram variações no DNA mitocondrial. Foram encontrados altos níveis de estruturação genética entre o conjunto de amostras paraguaio e brasileiro e entre as microbacias dentro de cada país, o que se deve, principalmente, aos processos de colonização destas drenagens, os quais possivelmente envolvem fundadores com diferentes linhagens haplotípicas. Além disso, parece plausível que o rio Paraná (reservatório da Itaipu) funciona como uma barreira ao fluxo gênico entre as diferentes margens e entre suas microbacias. Deste modo, a identificação de linhagens é de grande importância, pois a manutenção da diversidade genética de uma espécie depende de sua preservação. Considerando a importância de estudos genético-populacionais para a conservação de espécies, espera-se que este trabalho possa servir como base para futuros estudos mais amplos com peixes de riachos

    「回首.動情.傳承」長者生命故事計劃

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    嶺南大學亞太老年學研究中心獲華人永遠墳場管理委員會(「華永會」)資助為期一年的「回首.動情.傳承」長者生命故事計劃(「計劃」)。此計劃旨在讓青年人認識長者生命經驗,學習克服困難與挫折以提升抗逆力,建立正向人生觀。 近年,主流媒體經常批評年輕人的負面人生觀,例如:「躺平主義」、「享樂主義」、「犬儒心態」等,亦不時看到青年人輕生的新聞。我們曾在大學內處理過不少受情緒困擾及企圖自殺的個案,與學生深入交流後,發現他們面對着沉重的學業壓力、財政困難或複雜的家庭關係,內心充滿掙扎不安。 此計劃讓嶺大學生與長者導師進行深度的對談,透過了解長者走過的路、他們經歷過的挫折和教訓,給予年輕人生命的啟示。如果我們以旅遊比喻人生,長者就像環遊世界的資深背包客,即使大家遊覽不同的地點、觀賞過不同的風景,他們總能夠分享一些旅遊的心得,讓新手遊客走少一點冤枉路,或領悟到旅遊的樂趣和意義。長者亦可以藉由敍述人生片段回顧他們生命中的故事,學習接納過去,增加自我認同感。青年人創作生命教育書冊,將長者積極的人生觀傳給年輕一代,並藉此鼓勵其他長者豁達地度過餘年。 我們於2022年初招募嶺南大學學生接受「生命故事敍述」培訓,內容包括:本港的人口老化現象、敍述治療理論、與長者溝通的技巧及模擬實踐練習等,以裝備同學的知識和技巧。本中心再向屯門、元朗區的長者機構發邀請信,誠邀長者擔任生命導師接受訪問。 嶺大安排同學以兩人一組的小隊形式,於2022年6至7月期間前往長者中心、日間護理中心、嶺南大學或長者家中,與十二位長者進行深入訪談。訪談結束後,同學根據訪談的內容,為長者書寫他們獨特的生命故事。例如在人離鄉賤的異國環境下,努力打拼事業的Alfred;堅持不懈持續進修的淑芹和馮春林;即使沒機會求學,仍憑一雙巧手闖出一片天的譚惠;在文化大革命的漩渦中,憑着熱忱而改變命運的蘭英;還有為家人無私奉獻的鳳群、歐婆婆、雅芳及細女;離鄉別井勇闖異地的阿美和阿水;即使被家人賣去做「妹仔」,仍能以「阿Q精神」面對的諒餘。 為保障長者的私隱權益,本書內所有刊登之故事皆經過受訪者或社工審閱,部份受訪者選擇以化名的形式來分享自己的故事,我們亦移除了部份敏感的個人資料。https://commons.ln.edu.hk/apias_guide/1008/thumbnail.jp
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