37 research outputs found

    Analysis of Electromagnetic Parameters of Hybrid Externally Excited Synchronous Motors for Electric Vehicle Applications

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    This paper presents two different approaches to improve the electromagnetic torque and output power of the hybrid Externally Excited Synchronous Motor (EESM) applied to Electric Vehicles (EVs). An analytical approach is first considered to define the main parameters of the proposed machine. Based on the obtained results from the analytical model, the hybrid EESM is designed with different rotor shapes and step-skewing magnet segments to reduce the total losses and improve torque ripple. Then, Finite Element Analysis (FEA) is applied to compute and simulate electromagnetic parameters, such as the magnetic flux density, mean torque, and output power. The development of these two approaches is validated on an actual EESM machine and the agreement with the theory is shown

    Direct Observation of Exceptional Points in Photonic Crystal by Cross-Polarization Imaging in Momentum Space

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    This study explores exceptional points (EPs) in photonic crystals (PhCs) and introduces a novel method for their single-shot observation. Exceptional points are spectral singularities found in non-Hermitian systems, such as leaky PhC slabs. However, directly observing EPs in PhC systems using regular reflectivity spectroscopy is a considerable challenge due to interference between guided resonances and background signals. In this work, we present a simple, nondestructive technique that employs crossed polarizations to directly observe EPs in momentum-resolved resonant scattering. This approach effectively suppresses the background signal, enabling exclusive probing of the guided resonances where EPs manifest. Our results demonstrate the formation of EPs in both energy-momentum mapping and isofrequency imaging. All experimental findings align seamlessly with numerical simulations and analytical models. Our approach holds great potential as a robust tool for studying non-Hermitian physics in PhC platform

    NGHIÊN CỨU THÀNH PHẦN VÀ HÀM LƯỢNG CÁC LỚP CHẤT LIPID, PHOSPHOLIPID, AXIT BÉO, VÀ PHOSPHATIDYLCHOLINE LOÀI SAN HÔ MỀM CAPNELLA SP.

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    The total lipid content of the soft coral Capnella sp. contained 1.44 ± 0.10% of the fresh weight. In the fatty acid content, the tetracosapolyenoic fatty acids 24:5n-6 and 24:6n-3, which were the typical markers for the soft corals (the eight compartment coral), and the fatty acids that marked for symbiotic microorganism including 18:5n-3, 18:2n-6, 18:3n-6, 18:4n-3, 20:4n-3 were presented. The result of the lipid composition analysis showed that the total lipid contained polar lipid, sterol, free fatty acid, triacylglycerol, monoalkyldiacylglycerol, hydrocarbon and wax. Of these, the polar lipid displayed the highest content with 21.14 ± 1.17% of the total lipid. The phospholipid composition of the soft coral Capnella sp. contained the characteristic phospholipid subclasses of the animals of the phylum Cnidaria, including phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, and ceramide aminoethylphosphonate (phosphonolipid, CAEP). Of these, phosphatidylcholine exhibited the highest content with 35.53 ± 1.46% of the total phospholipid. This is the first time that the content and composition of the molecular types of the phosphatidylcholine from a Vietnamese soft coral species have been investigated and reported. By using modern mass spectrometry IT TOF LC-MS, the presence of 13 molecular types have been precisely identified, which PC 18:0e/20:4 and PC 16:0e/20:4 were the two ingredients displaying the highest content.Hàm lượng lipid tổng của mẫu san hô mềm Capnella sp. chiếm 1,44 ± 0,10% so với trọng lượng mẫu tươi. Trong thành phần axit béo có mặt các axit béo tetracosapolyenoic 24:5n-6 và 24:6n-3 là axit béo đánh dấu điển hình cho san hô mềm (san hô tám ngăn) và các axit béo đánh dấu cho vi sinh vật cộng sinh như 18:5n-3, 18:2n-6, 18:3n-6, 18:4n-3, 20:4n-3. Kết quả phân tích lớp chất lipid cho thấy trong lipid tổng có mặt các lớp chất lipid chính là lipid phân cực, sterol, axit béo tự do, triacylglycerol, monoalkyldiacylglycerol, hydrocacbon và sáp, trong đó lipid phân cực chiếm hàm lượng cao nhất (21,14 ± 1,17% hàm lượng lipid tổng). Thành phần phospholipid của san hô mềm Capnella sp. có mặt các phân lớp phospholipid đặc trưng của động vật ngành Cnidarian là phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, phosphonolipid là ceramide aminoethylphosphonate, trong đó phosphatidylcholine chiếm hàm lượng cao nhất (35,53 ± 1,46% tổng phospholipid). Đây là lần đầu tiên ở Việt Nam, thành phần và hàm lượng các dạng phân tử trong lớp chất phosphatidylcholine từ loài san hô mềm của Việt Nam được nghiên cứu và công bố, kết quả đã xác định được sự có mặt của 13 dạng phân tử bằng phương pháp phổ khối hiện đại LC-MS IT TOF với độ chính xác cao. Hai dạng phân tử chiếm hàm lượng cao nhất là PC 18:0e/20:4 và PC 16:0e/20:4

    THỰC TRẠNG NĂNG LỰC KIẾN THỨC CÁN BỘ ĐỊA CHÍNH CẤP XÃ TRONG QUẢN LÝ ĐẤT ĐAI TẠI HUYỆN A LƯỚI, TỈNH THỪA THIÊN HUẾ

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    Cadastral officials play an important role in land management at the local level. Therefore, this study aims to investigate the knowledge capacity of cadastral officials in A Luoi district. We used secondary and primary data by interviewing 171 people, including cadastral officials, commune leaders, district level staff and households. In parallel, we used the 5-point Likert scale (from 1-5, corresponding to the level of competence of cadastral officials from very poor to very good) for analysis. The results show that the knowledge capacity of the cadastral officials is only average, with a score of 3.4. In particular, 4 out of a total of 4 knowledge capacities in law, procedures, time and authority implementation of cadastral officials in conciliation and land dispute resolution are at an average level. In contrast, 3 out of a total of 4 knowledge capacities in conditions for issuance of land use rights certificate, procedures, and authority implementation of cadastral officials in issuance of land use rights certificate are at a good level, and 1 knowledge capacity in law is at an average level. The research results highlighted reasons and proposed some solutions to improve the knowledge capacity of cadastral officials in the study area.Cán bộ địa chính (CBĐC) cấp xã là lực lượng nòng cốt trong công tác quản lý đất đai tại địa phương. Do vậy, nghiên cứu này nhằm đánh giá năng lực kiến thức của CBĐC cấp xã trong quản lý đất đai tại huyện A Lưới. Nghiên cứu sử dụng số liệu thứ cấp và sơ cấp thông qua phỏng vấn 171 người: cán bộ cấp huyện, lãnh đạo xã, CBĐC cấp xã, và người dân để phân tích. Đồng thời, sử dụng thang đo Likert 5 mức độ (từ 1–5, tương ứng rất chưa tốt – rất tốt) để đánh giá năng lực kiến thức. Kết quả cho thấy, năng lực kiến thức CBĐC chỉ ở mức trung bình với số điểm bình quân là 3,4. Trong đó, thủ tục hoà giải, giải quyết tranh chấp đất đai có 4/4 tiêu chí về năng lực kiến thức pháp luật; trình tự thủ tục; thời gian và thẩm quyền thực hiện của CBĐC đều ở mức độ trung bình. Trái lại, thủ tục đăng ký đất đai, cấp GCN, lập và quản lý HSĐC, 3 tiêu chí kiến thức về điều kiện; trình tự và thẩm quyền thực hiện ở mức tốt, 1 tiêu chí kiến thức pháp luật bị đánh giá ở mức trung bình. Kết quả nghiên cứu đã chỉ ra các nguyên nhân và đề xuất một số giải pháp góp phần nâng cao năng lực kiến thức của CBĐC cấp xã tại địa phương

    Evaluation of awake prone positioning effectiveness in moderate to severe COVID-19

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    Evidence mainly from high income countries suggests that lying in the prone position may be beneficial in patients with COVID-19 even if they are not receiving invasive ventilation. Studies indicate that increased duration of prone position may be associated with improved outcomes, but achieving this requires additional staff time and resources. Our study aims to support prolonged (≥ 8hours/day) awake prone positioning in patients with moderate to severe COVID-19 disease in Vietnam. We use a specialist team to support prone positioning of patients and wearable devices to assist monitoring vital signs and prone position and an electronic data registry to capture routine clinical data

    Awareness and preparedness of healthcare workers against the first wave of the COVID-19 pandemic: A cross-sectional survey across 57 countries.

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    BACKGROUND: Since the COVID-19 pandemic began, there have been concerns related to the preparedness of healthcare workers (HCWs). This study aimed to describe the level of awareness and preparedness of hospital HCWs at the time of the first wave. METHODS: This multinational, multicenter, cross-sectional survey was conducted among hospital HCWs from February to May 2020. We used a hierarchical logistic regression multivariate analysis to adjust the influence of variables based on awareness and preparedness. We then used association rule mining to identify relationships between HCW confidence in handling suspected COVID-19 patients and prior COVID-19 case-management training. RESULTS: We surveyed 24,653 HCWs from 371 hospitals across 57 countries and received 17,302 responses from 70.2% HCWs overall. The median COVID-19 preparedness score was 11.0 (interquartile range [IQR] = 6.0-14.0) and the median awareness score was 29.6 (IQR = 26.6-32.6). HCWs at COVID-19 designated facilities with previous outbreak experience, or HCWs who were trained for dealing with the SARS-CoV-2 outbreak, had significantly higher levels of preparedness and awareness (p<0.001). Association rule mining suggests that nurses and doctors who had a 'great-extent-of-confidence' in handling suspected COVID-19 patients had participated in COVID-19 training courses. Male participants (mean difference = 0.34; 95% CI = 0.22, 0.46; p<0.001) and nurses (mean difference = 0.67; 95% CI = 0.53, 0.81; p<0.001) had higher preparedness scores compared to women participants and doctors. INTERPRETATION: There was an unsurprising high level of awareness and preparedness among HCWs who participated in COVID-19 training courses. However, disparity existed along the lines of gender and type of HCW. It is unknown whether the difference in COVID-19 preparedness that we detected early in the pandemic may have translated into disproportionate SARS-CoV-2 burden of disease by gender or HCW type

    Effectiveness of perindopril/amlodipine fixed-dose combination in the treatment of hypertension: a systematic review

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    Background: Uncontrolled blood pressure is a major risk factor for cardiovascular diseases. Fixed-dose combination (FDC) therapy offers a promising approach to addressing this challenge by providing a convenient single-tablet solution that enhances the effectiveness of blood pressure control. In our systematic review, we assess the effectiveness of perindopril/amlodipine FDC in managing blood pressure.Methods: We conducted a comprehensive search across four primary electronic databases, namely, PubMed, Virtual Health Library (VHL), Global Health Library (GHL), and Google Scholar, as of 8 February 2022. Additionally, we performed a manual search to find relevant articles. The quality of the selected articles was evaluated using the Study Quality Assessment Tools (SQAT) checklist from the National Institute of Health and the ROB2 tool from Cochrane.Results: Our systematic review included 17 eligible articles. The findings show that the use of perindopril/amlodipine FDC significantly lowers blood pressure and enhances the quality of blood pressure control. Compared to the comparison group, the perindopril/amlodipine combination tablet resulted in a higher rate of blood pressure response and normalization. Importantly, perindopril/amlodipine FDC contributes to improved patient adherence with minimal side effects. However, studies conducted to date have not provided assessments of the cost-effectiveness of perindopril/amlodipine FDC.Conclusion: In summary, our analysis confirms the effectiveness of perindopril/amlodipine FDC in lowering blood pressure, with combination therapy outperforming monotherapy and placebo. Although mild adverse reactions were observed in a small subset of participants, cost-effectiveness assessments for this treatment remain lacking in the literature

    The global, regional, and national burden of oesophageal cancer and its attributable risk factors in 195 countries and territories, 1990-2017: A systematic analysis for the global burden of disease study 2017

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    © 2020 The Author(s). Background Oesophageal cancer is a common and often fatal cancer that has two main histological subtypes: oesophageal squamous cell carcinoma and oesophageal adenocarcinoma. Updated statistics on the incidence and mortality of oesophageal cancer, and on the disability-adjusted life-years (DALYs) caused by the disease, can assist policy makers in allocating resources for prevention, treatment, and care of oesophageal cancer. We report the latest estimates of these statistics for 195 countries and territories between 1990 and 2017, by age, sex, and Socio-demographic Index (SDI), using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD). Methods We used data from vital registration systems, vital registration-samples, verbal autopsy records, and cancer registries, combined with relevant modelling, to estimate the mortality, incidence, and burden of oesophageal cancer from 1990 to 2017. Mortality-to-incidence ratios (MIRs) were estimated and fed into a Cause of Death Ensemble model (CODEm) including risk factors. MIRs were used for mortality and non-fatal modelling. Estimates of DALYs attributable to the main risk factors of oesophageal cancer available in GBD were also calculated. The proportion of oesophageal squamous cell carcinoma to all oesophageal cancers was extracted by use of publicly available data, and its variation was examined against SDI, the Healthcare Access and Quality (HAQ) Index, and available risk factors in GBD that are specific for oesophageal squamous cell carcinoma (eg, unimproved water source and indoor air pollution) and for oesophageal adenocarcinoma (gastro-oesophageal reflux disease). Findings There were 473 000 (95% uncertainty interval [95% UI] 459 000-485 000) new cases of oesophageal cancer and 436 000 (425 000-448 000) deaths due to oesophageal cancer in 2017. Age-standardised incidence was 5.9 (5.7-6.1) per 100 000 population and age-standardised mortality was 5.5 (5.3-5.6) per 100 000. Oesophageal cancer caused 9.78 million (9.53-10.03) DALYs, with an age-standardised rate of 120 (117-123) per 100 000 population. Between 1990 and 2017, age-standardised incidence decreased by 22.0% (18.6-25.2), mortality decreased by 29.0% (25.8-32.0), and DALYs decreased by 33.4% (30.4-36.1) globally. However, as a result of population growth and ageing, the total number of new cases increased by 52.3% (45.9-58.9), from 310 000 (300 000-322 000) to 473 000 (459 000-485 000); the number of deaths increased by 40.0% (34.1-46.3), from 311 000 (301 000-323 000) to 436 000 (425 000-448 000); and total DALYs increased by 27.4% (22.1-33.1), from 7.68 million (7.42-7.97) to 9.78 million (9.53-10.03). At the national level, China had the highest number of incident cases (235 000 [223 000-246 000]), deaths (213 000 [203 000-223 000]), and DALYs (4.46 million [4.25-4.69]) in 2017. The highest national-level agestandardised incidence rates in 2017 were observed in Malawi (23.0 [19.4-26.5] per 100 000 population) and Mongolia (18.5 [16.4-20.8] per 100 000). In 2017, age-standardised incidence was 2.7 times higher, mortality 2.9 times higher, and DALYs 3.0 times higher in males than in females. In 2017, a substantial proportion of oesophageal cancer DALYs were attributable to known risk factors: tobacco smoking (39.0% [35.5-42.2]), alcohol consumption (33.8% [27.3-39.9]), high BMI (19.5% [6.3-36.0]), a diet low in fruits (19.1% [4.2-34.6]), and use of chewing tobacco (7.5% [5.2-9.6]). Countries with a low SDI and HAQ Index and high levels of indoor air pollution had a higher proportion of oesophageal squamous cell carcinoma to all oesophageal cancer cases than did countries with a high SDI and HAQ Index and with low levels of indoor air pollution. Interpretation Despite reductions in age-standardised incidence and mortality rates, oesophageal cancer remains a major cause of cancer mortality and burden across the world. Oesophageal cancer is a highly fatal disease, requiring increased primary prevention efforts and, possibly, screening in some high-risk areas. Substantial variation exists in age-standardised incidence rates across regions and countries, for reasons that are unclear

    Global injury morbidity and mortality from 1990 to 2017 : results from the Global Burden of Disease Study 2017

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    Correction:Background Past research in population health trends has shown that injuries form a substantial burden of population health loss. Regular updates to injury burden assessments are critical. We report Global Burden of Disease (GBD) 2017 Study estimates on morbidity and mortality for all injuries. Methods We reviewed results for injuries from the GBD 2017 study. GBD 2017 measured injury-specific mortality and years of life lost (YLLs) using the Cause of Death Ensemble model. To measure non-fatal injuries, GBD 2017 modelled injury-specific incidence and converted this to prevalence and years lived with disability (YLDs). YLLs and YLDs were summed to calculate disability-adjusted life years (DALYs). Findings In 1990, there were 4 260 493 (4 085 700 to 4 396 138) injury deaths, which increased to 4 484 722 (4 332 010 to 4 585 554) deaths in 2017, while age-standardised mortality decreased from 1079 (1073 to 1086) to 738 (730 to 745) per 100 000. In 1990, there were 354 064 302 (95% uncertainty interval: 338 174 876 to 371 610 802) new cases of injury globally, which increased to 520 710 288 (493 430 247 to 547 988 635) new cases in 2017. During this time, age-standardised incidence decreased non-significantly from 6824 (6534 to 7147) to 6763 (6412 to 7118) per 100 000. Between 1990 and 2017, age-standardised DALYs decreased from 4947 (4655 to 5233) per 100 000 to 3267 (3058 to 3505). Interpretation Injuries are an important cause of health loss globally, though mortality has declined between 1990 and 2017. Future research in injury burden should focus on prevention in high-burden populations, improving data collection and ensuring access to medical care.Peer reviewe
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