49 research outputs found

    FATTY ACID COMPOSITION AND ANTIOXIDANT ACTIVITY OF CAMELLIA NINHII SEED OIL COLLECTED IN LAM DONG PROVINCE

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    The seed oil of Camellia ninhii was studied for the first time on its fatty acid composition by gas chromatography-mass spectrometry (GC-MS) and antioxidant activity by the DPPH method. The results show that unsaturated fatty acids account for the largest amount, especially oleic acid with 45.43% of the total sample analyzed. In addition, other fatty acids, palmitic, linoleic, pentadecanoic, and two aromatic acids, benzoic and cinnamic, were present. The sample of C. ninhii seed oil exhibited mild antioxidant activity against DPPH free radicals with IC50 = 0.94 mg/mL

    STRUCTURE, MICROSTRUCTURE, AND PIEZOELECTRIC PROPERTIES OF KNLNS-BNKZ LEAD-FREE CERAMICS UNDER THE EFFECT OF DIFFERENT SINTERING TEMPERATURES

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    Samples of 0.96(K0.48Na0.48Li0.04)(Nb0.95Sb0.05)O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 piezoelectric ceramic were fabricated with conventional ceramic techniques and sintered at different temperatures. The effect of sintering temperature (TS) on the structure, microstructure, and piezoelectric properties of the ceramics was studied in detail. The experimental results showed that with an increase of the TS temperature, the structure of the ceramics transformed from an orthorhombic-tetragonal mixed phase (O-T) at TS £ 1100 °C into a rhombohedral-tetragonal (R-T) mixed phase with a dense microstructure of uniform grain size at TS = 1110 °C. When TS was further increased (TS ³ 1120 °C), the ceramics showed only a rhombohedral phase (R). The ceramics showed the best electrical properties for TS = 1110 °C at which the rhombohedral and tetragonal (R-T) phases coexist. Specifically, the ceramic density reached its highest value (4.22 g/cm3), the electromechanical coupling coefficients kp and kt were 0.46 and 0.50, respectively, and the piezoelectric coefficient d33 was 245 pC/N.Samples of 0.96(K0.48Na0.48Li0.04)(Nb0.95Sb0.05)O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 piezoelectric ceramic were fabricated with conventional ceramic techniques and sintered at different temperatures. The effect of sintering temperature (TS) on the structure, microstructure, and piezoelectric properties of the ceramics was studied in detail. The experimental results showed that with an increase of the TS temperature, the structure of the ceramics transformed from an orthorhombic-tetragonal mixed phase (O-T) at TS £ 1100 °C into a rhombohedral-tetragonal (R-T) mixed phase with a dense microstructure of uniform grain size at TS = 1110 °C. When TS was further increased (TS ³ 1120 °C), the ceramics showed only a rhombohedral phase (R). The ceramics showed the best electrical properties for TS = 1110 °C at which the rhombohedral and tetragonal (R-T) phases coexist. Specifically, the ceramic density reached its highest value (4.22 g/cm3), the electromechanical coupling coefficients kp and kt were 0.46 and 0.50, respectively, and the piezoelectric coefficient d33 was 245 pC/N

    Sintering behavior and physical properties of Bi0.5(Na1–xKx)0.5SnO3 lead-free ceramics

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    In this study, Bi0.5(Na1–xKx)0.5SnO3 (BNKS) ceramics (x = 0, 0.1, 0.2, 0.3, and 0.4) were fabricated via ultrasound wave before milling. The time of ball milling decreased from 20 to 1 h. The X-ray diffraction patterns show that the BNKS has a single-phase structure. When the potassium content increases, the phase structure of the ceramics changes from rhombohedral to tetragonal. When sintered at 1100 °C and x = 0.2, the ceramics’ physical properties are the best with the mass density of 5.59 g/cm3, the electromechanical coupling constants kp of 0,31 and kt of 0.27, the remanent polarization of      11.9 µC/cm; the dielectric constant εr of 1131, and the highest dielectric constant emax of 4800

    HIGH ORDER SLIDING MODE CONTROL WITH ANTI-SWAY BASED COMPENSATION ON ARTIFICIAL NEURAL NETWORK BY PSO ALGORITHM FOR OVERHEAD CRANE

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    This paper proposes a second order sliding mode controller combined with signal set calibrator for overhead crane tracking desired position and resisting disturbance. High order sliding mode controller ensures that the overhead crane tracks desired trajectory and resists disturbance. Neural network is trained by particle swarm optimization algorithm (PSO) to compensate anti-sway for load. The results on the computer simulation show that high order sliding mode controller with anti-sway compensation for overhead crane tracks desired trajectory and the swing of load that is smaller than high order sliding mode controller without anti-sway compensation

    KHẢ NĂNG LƯU TRỮ CACBON CỦA THẢM CỎ BIỂN TẠI ĐẦM LĂNG CÔ, TỈNH THỪA THIÊN HUẾ

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    Seagrass beds play an essential role in mitigating climate change by absorbing CO2 from the atmosphere and converting carbon into biomass through photosynthesis. We used remote sensing and GIS technology with field survey data to establish the distribution and above-ground dry biomass maps of seagrass beds in 2021. A Landsat 8 OLI satellite image was used in the interpretation process. An above-ground dry biomass map was established by building the regression function between the above-ground dry biomass and the reflectance spectrum of the image bands. The overall accuracy and the Kappa coefficient of the classification process were 95.5% and 0.94. At Lang Co Lagoon, the seagrass bed area in 2021 was about 36.18 ha, distributed primarily in the area between Lang Co Town and the north of the lagoon; and scattered in the north of the lagoon, Hoi Can, Hoi Dua, and Hoi Mit. In addition, the total carbon stock of seagrasses in Lang Co Lagoon was estimated at 5.54 tons, equivalent to 20.32 tons of CO2, in which the contribution of Halodule uninervis accounted for 61% of the total carbon stock.Thảm cỏ biển đóng vai trò quan trọng trong việc giảm thiểu biến đổi khí hậu thông qua việc hấp thụ CO2 từ khí quyển và chuyển cacbon thành sinh khối nhờ quá trình quang hợp. Chúng tôi đã sử dụng công nghệ viễn thám và GIS, kết hợp với dữ liệu khảo sát thực địa, để thành lập bản đồ phân bố và sinh khối khô trên mặt đất của hệ sinh thái thảm cỏ biển tại Đầm Lăng Cô vào năm 2021. Một ảnh vệ tinh Landsat 8 OLI đã được sử dụng trong quá trình giải đoán. Một bản đồ sinh khối khô trên mặt đất được thành lập thông qua việc xây dựng hàm hồi quy giữa sinh khối khô trên mặt đất và phổ phản xạ của các kênh ảnh Landsat. Độ chính xác tổng thể và hệ số Kappa là 95,5% và 0,94. Tại Đầm Lăng Cô, diện tích thảm cỏ biển năm 2021 chiếm khoảng 36,18 ha, phân bố chủ yếu ở các khu vực giao giữa Thị trấn Lăng Cô và phía Bắc của đầm; rải rác tại phía Bắc của đầm, Hói Cạn, Hói Dừa và Hói Mít. Ngoài ra, tổng trữ lượng cacbon của cỏ biển ở Đầm Lăng Cô là 5,54 tấn cacbon, tương đương với 20,32 tấn CO2; trong đó, sự đóng góp của loài Halodule uninervis chiếm 61% tổng trữ lượng cacbon

    Efficacy of Adding Oral Simvastatin to Topical Therapy for Treatment of Psoriasis: The Vietnamese Experience

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    BACKGROUND: Psoriasis, the prevalence of which ranges from 2% to 3% of the general population, has been recently recognised as not only a chronic inflammatory skin disorder but also an immunometabolic systemic disease. Dyslipidemia is one of the most important comorbidities of psoriasis. Statins, frequently used as anti-hyperlipidemic agents, may be beneficial in the treatment of several autoimmune diseases, including psoriasis, due to their anti-inflammatory and immunomodulatory characteristics. Hence, we hypothesised that using this medication was not only beneficial for reducing hyperlipidemia but also improving psoriatic conditions. AIM: We conducted a study to determine the prevalence of dyslipidemia in psoriatic patients as well as whether the addition of statins (simvastatin prescribed forms) to standard topical antipsoriatic treatment can improve skin lesions in psoriatic patients. METHODS: A group of 128 psoriatic patients and 128 healthy controls who were matched with the patients regarding ethnicity, age, and sex were enrolled, and their lipid concentrations were determined. Furthermore, sixty patients were randomly selected from the former group and divided into two treatment subgroups to evaluate the effect of statins on the severity of psoriasis using the PASI score. RESULTS: We found that the rate of dyslipidemia in the patient group was significantly higher than in the healthy group (53.9% versus 21.9%, p < 0.001), particularly the triglyceride concentration (1.86 ± 1.17 versus 1.43 ± 0.79 mg/dL, p < 0.001). Also, the PASI score reduction in the simvastatin-treated subgroup was significantly different from that in the placebo-treated one after eight weeks of therapy (8.63 ± 4.78 versus 5.34 ± 3.59, p < 0.01). CONCLUSION: This study showed that simvastatin might play a role in controlling hyperlipidemia and in turn decrease the PASI score in psoriatic patients

    Antioxidant and in vitro antidiabetic activities of Peperomia pellucida (L.) Kunth extract

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    Peperomia pellucida (L.) is commonly used as a herbal plant. Its effectiveness in treating inflammatory diseases, digestive disorders, and cancer in tropical and subtropical countries was introduced, especially in field of folk medicine. However, this plant species has not been studied widely in Vietnam, especially for its biological activities. This study was done to determine the antioxidant capacity of P. pellucida by using in vitro and in vivo methods, as well as its inhibitory ability to α-amylase enzyme activity. The total polyphenolic and flavonoid contents of P. pellucida extract were reported to be 359.91±0.77 mg GAE/g and 200.28±1.23 mg QE/g extract, respectively. The results showed the in vitro antioxidant activity of P. pellucida extract in four methods, including DPPH, and ABTS.+, RP and TAC, had EC50 values of 730.34 μg/mL, 84.33 μg/mL, 95.28 μg/mL, respectively, and Abs0.5 value of 114.73 μg/mL. Under H2O2-induced oxidative stress, fruit flies that were raised in the feed medium supplemented with a concentration of 1 mg/mL of P. pellucida extract showed their average survival time, 50% survival time, and 10% survival time at 1.6 times, 1.8 times, and 1.62 times, respectively, higher than those of the control treatment. The ability to inhibit the α-amylase activity in P. pellucida extract was determined with an EC50 value of 115.32±2.65 μg/mL compared with the commercial drug of 18.67±0, 01 μg/mL. The research results showed that P. pellucida is a potential species in the study of natural compounds with antioxidant and antidiabetic activities

    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 Role of Medical Interpretation on Breast and Cervical Cancer Screening Among Asian American and Pacific Islander Women

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    We examined whether the impact of medical interpretation services was associated with the receipt of a mammogram, clinical breast exam, and Pap smear. We conducted a large cross-sectional study involving four Asian American and Pacific Islander (AAPI) communities with high proportions of individuals with limited English proficiency (LEP). Participants were recruited from community clinics, churches and temples, supermarkets, and other community gathering sites in Northern and Southern California. Among those that responded, 98% completed the survey rendering a total of 1,708 AAPI women. In a series of multivariate logistic regression models, it was found that women who typically used a medical interpreter had a greater odds of having received a mammogram (odds ratio [OR] = 1.85; 95% confidence interval [CI] = 1.21, 2.83), clinical breast exam (OR = 3.03; 95% CI = 1.82, 5.03), and a Pap smear (OR = 2.34; 95% CI = 1.38, 3.97) than those who did not usually use an interpreter. The study provides support for increasing language access in healthcare settings. In particular, medical interpreters may help increase the utilization of breast and cervical cancer screening among LEP AAPI women
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