124 research outputs found

    THE ANALYSIS OF FLUID DYNAMICS OF WAVE POWER STATION WITH WELLS TURBIN BY CFD

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    Natural energy such as wind, wave and other natural vibrations is one of the high potential renewable energy sources. The Wells turbine is based on the use of bidirectional turbines, which act as axial-flow self-rectifying turbines that employs a symmetrical blade profile and rotating unidirectionally in reciprocating airflows generated by the air chamber to extract energy from vibrations. These topics have been extensively studied both numerically and experimentally such as research on the parameters of the effects of structure, angle of attack, blade shape, etc. In this paper, numerical simulation is carried out using commercially available tool Fluent for fluid dynamics analysis and focus on oscillating predictions, with particular attention to the behavior of the flow. Based on the Numerical Wave Tank (NWT) model is simulated in a two dimensional used in this model, which is constructed mainly based on the spatially averaged Navier Stokes equation with the k-ε model for simulating the turbulence and modeled with Volume of Fluid (VOF). Axial-flow turbines system and future development as well as the proposed limitations will be discussed in detail

    TẠO DÒNG VÀ BIỂU HIỆN PROTEIN hGM-CSF TRÊN TẾ BÀO CHO K1

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    GM-CSF (granulocyte-macrophage colony stimulating factor) is a cytokine with wide effects, not only on hematopoietic precursor cells, dendritic cells, but also on smooth muscle cells, epithelial cells and even neurons. Although, it does not play role in hGM-CSF biological functions, glycosylation enhances the protein in vivo stability. Therapeutic drugs containing recombinant hGM-CSF are mostly produced in Escherichia coli or Saccharomyces cerevisiae, which do not have post-translation modification mechanisms similar to those of humans. In this present study, the gene encoding for human (h)GM-CSF was transfected into the Chinese Ovary Cell (CHO)-K1 and expression of the protein was evaluated. Firstly, gene was inserted into the open reading frame after early promoter CMV at EcoRI and XhoI restriction sites. Recombinant vectors are screened by colony PCR, restriction enzyme digestion and sequencing. The recombinant vector was termed pcDNA-hGM and was transfected into CHO-K1 cells using cationic lipid method. Transformants was selected and maintained using antibiotic Geneticin. The results showed that the gene encoding for hGM-CSF was indeed cloned into pcDNA3.1+ vector at EcoRI and XhoI restriction sites. The conditioned medium collected from CHO‑K1/pcDNA-hGM stimulated the proliferation of TF-1, an hGM-CSF-dependent cell line. In summary, the recombinant vector pcDNA-hGM was cloned and the recombinant cell line CHO‑K1/pcDNA-hGM expressed active hGM-CSF. This is the first research on expression hGM-CSF in CHO-K1 cell line and providing evidence for further investigation on isolation and purification of hGM-CSF afterward.Nhân tố kích thích tạo cụm bạch cầu hạt và đại thực bào người (hGM-CSF, human granulocyte-macrophage colony stimulating factor) là một cytokine có phổ tác dụng rộng trong cơ thể, từ các tế bào tiền thân tạo máu, tế bào tua, đến tế bào cơ trơn, tế bào biểu mô và cả một số tế bào thần kinh. Sự glycosyl hóa, dù không đóng vai trò trong tương tác với thụ thể nhưng có tác dụng làm tăng độ bền cho hGM-CSF ở điều kiện in vivo. Những sản phẩm hGM-CSF tái tổ hợp sử dụng rộng rãi hiện nay chủ yếu được sản xuất từ Echerichia coli và Saccharomyces cerevisiae, những loại tế bào chủ không có bộ máy biến đổi sau dịch mã giống người. Trong nghiên cứu này, gene hgm-csf mã hóa cho protein hGM‑CSF được chuyển vào trong tế bào buồng trứng chuột hamster Trung Quốc (CHO-K1 cells) và đánh giá khả năng biểu hiện protein. Trước tiên, gene được chèn vào plasmid pcDNA3.1+ đúng khung đọc mở ngay sau promoter CMV tại vị trí EcoRI và XhoI. Plasmid tái tổ hợp được sàng lọc bằng PCR khuẩn lạc với cặp mồi đặc hiệu, cắt giới hạn và giải trình tự. Plasmid tái tổ hợp sau quá trình kiểm tra được đặt tên pcDNA-hGM. Sau đó, plasmid tái tổ hợp đưa vào tế bào CHO-K1 bằng phương pháp biến nạp sử dụng cationic lipid và nuôi chọn lọc bằng kháng sinh Geneticin. Kết quả cho thấy gene hgm-csf đã được dòng hoá vào plasmid pcDNA3.1+ tại vị trí EcoRI và XhoI. Dịch môi trường nuôi tế bào CHO-K1/ pcDNA‑hGM cho thấy khả năng kích thích sự tăng sinh của dòng tế bào TF-1, dòng tế bào sống phụ thuộc hGM-CSF. Như vậy, plasmid tái tổ hợp pcDNA-hGM đã được cấu trúc thành công và dòng tế bào mang gene tái tổ hợp CHO‑K1/pcDNA-hGM biểu hiện protein hGM‑CSF có hoạt tính. Đây là nghiên cứu đầu tiên về biểu hiện hGM-CSF trên tế bào CHO-K1 ở Việt Nam và là cơ sở cho bước khảo sát các điều kiện thu nhận và tinh chế hGM-CSF tiếp sau

    Growth and quality of hydroponic cultivated spinach (Spinacia oleracea L.) affected by the light intensity of red and blue LEDs

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    This study aimed to evaluate the effect of four light intensities (90, 140, 190 and 240 μmol m-2 s-1) provided by red-blue LED light (spectrum ratio: R660/B450 = 4/1) on the growth and quality of hydroponic cultivated spinach. The results showed that when the light intensity increased, plant height, leaf number, root length, leaf width, shoot fresh weight, shoot dry weight, root fresh weight and root dry weight were increased but specific leaf weight and shoot-to-root ratio did not increase. The highest values of growth parameters were observed under 190 μmol m-2 s-1 treatment, while the lowest values were observed under 90 μmol m-2 s-1 treatment. At higher light intensities, K+, oxalic acid and nitrate contents tended to decrease but not Ca2+ content. Meanwhile, the highest values of Fe2+, crude fiber, soluble-solids, total polyphenol and vitamin C contents were observed under 190 μmol m-2 s-1 treatment, but 190 μmol m-2 s-1 treatment showed the lowest organic acid content. Our results indicated that among all experimental lighting treatments, 190 μmol m-2 s-1 light intensity showed the best effect on the growth and quality of hydroponic cultivated spinach

    CRL4A-FBXW5-mediated degradation of DLC1 Rho GTPase-activating protein tumor suppressor promotes non-small cell lung cancer cell growth

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    The DLC1 tumor suppressor gene is commonly lost in cancer by genomic deletion or epigenetic silencing, leading to loss of gene transcription. DLC1 encodes a GTPase-activating protein for the RhoA small GTPase, and DLC1 loss of expression results in aberrant RhoA activation and signaling. Unexpectedly, we found that a subset of non-small cell lung cancer patient tumors and cell lines retained DLC1 mRNA but not protein expression. We determined that the CUL4A–DDB1–FBXW5 E3 ubiquitin ligase complex is responsible for loss of DLC1 protein expression. Suppression of FBXW5 function restored DLC1-dependent lung cancer cell growth suppression. Our observations identify a mechanism for posttranslational loss of DLC1 function in cancer and substrate for CRL4A-FBXW5–driven cancer growth

    Electrochemical aptasensor for human osteopontin detection using a DNA aptamer selected by SELEX

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    A DNA aptamer with affinity and specificity for human osteopontin (OPN), a potential breast cancer biomarker, was selected using the SELEX process, considering its homology rate and the stability of its secondary structures. This aptamer exhibited a satisfactory affinity towards OPN, showing dissociation constants lower than 2.5 nM. It was further used to develop a simple, label-free electrochemical aptasensor against OPN. The aptasensor showed good sensitivity towards OPN in standard solutions, being the square wave voltammetry (SWV), compared to the cyclic voltammetry, the most sensitive technique with detection and quantification limits of 1.4 ± 0.4 nM and 4.2 ± 1.1 nM, respectively. It showed good reproducibility and acceptable selectivity, exhibiting low signal interferences from other proteins, as thrombin, with 2.610 times lower current signals-off than for OPN. The aptasensor also successfully detected OPN in spiked synthetic human plasma. Using SWV, detection and quantification limits (1.3 ± 0.1 and 3.9 ± 0.4 nM) within the OPN plasma levels reported for patients with breast cancer (0.44.5 nM) or with metastatic or recurrent breast cancer (0.98.4 nM) were found. Moreover, preliminary assays, using a sample of human plasma, showed that the aptasensor and the standard ELISA method quantified similar OPN levels (2.2 ± 0.7 and 1.7 ± 0.1 nM, respectively). Thus, our aptasensor coupled with SWV represents a promising alternative for the detection of relevant breast cancer biomarkers.The authors acknowledge the financial support from the Strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), and from project BioTecNorte (project number NORTE-01-0145-FEDER-000004). This work was also financially supported by Project POCI-01–0145-FEDER-006984 – Associate Laboratory LSRE-LCM and by Project UID/QUI/00616/2013 – CQ-VR both funded by FEDER - Fundo Europeu de Desenvolvimento Regional through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundação para a Ciência e a Tecnologia, Portugal. S. Meirinho also acknowledges the research grant provided by Project UID/EQU/50020/2013.info:eu-repo/semantics/publishedVersio

    Fundamental issues, mechanisms and models of flow boiling heat transfer in microscale channels

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    This paper presents state-of-the-art review on the fundamental and frontier research of flow boiling heat transfer, mechanisms and prediction methods including models and correlations for heat transfer in microscale channels. First, fundamental issues of current research on flow boiling in microscale channels are addressed. These mainly include the criteria for macroscale and microscale channels. Then, studies on flow boiling heat transfer behaviours and mechanisms in microscale channels are presented. Next, the available correlations and models of flow boiling heat transfer in microscale channels are reviewed and analysed. Comparisons of 12 correlations with a database covering a wide range of test parameters and 8 fluids are presented. It shows that all correlations poorly agree to the database. No generalized model or correlation is able to predict all flow boiling heat transfer data. Furthermore, comparisons of the mechanistic flow boiling heat transfer models based on flow patterns including the Thome et al. three-zone heat transfer model for evaporation in microchannel and the flow pattern based model combining the Thome et al. three zone heat transfer models with the Cioncolini-Thome annular flow model for both macro- and microchannel to the database are presented. It shows that the flow pattern based model combining the three zone model with the annular flow model gives better prediction than the three zone heat transfer model alone. The flow pattern based heat transfer model favourably agrees with the experimental database collected from the literature. According to the comparison and analysis, suggestions have been given for improving the prediction methods in the future. Next, flow patterned based phenomenological models and their applications to microscale channels are presented. Finally, as an important topic, unstable and transient flow boiling phenomena in microscale channels are briefed and recommendations for future research are given. According to this comprehensive review and analysis of the current research on the fundamental issues of flow boiling, mechanisms and prediction methods in microscale channels, the future research needs have been identified and recommended. In general, systematic and accurate experimental data of flow boiling heat transfer in microscale channels are still needed although a large amount of work has been done over the past decades. The channel size effect on the flow boiling behaviours should be systematically investigated. Heat transfer mechanisms in microscale channels should be further understood and related to the corresponding flow patterns. Furthermore, effort should be made to develop and improve generalized mechanistic prediction methods and theoretical models for flow boiling heat transfer in microscale channels according to the physical phenomena/mechanisms and the corresponding flow structures. The effects of the channel size and a wide range of test conditions and fluid types should be considered in develop new methods. Furthermore, systematic experimental, analytical and modeling studies on unstable and transient flow boiling heat transfer in microscale channels should be conducted to understand the physical mechanisms and theoretical models

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

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    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

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    Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

    Evacetrapib and Cardiovascular Outcomes in High-Risk Vascular Disease

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    BACKGROUND: The cholesteryl ester transfer protein inhibitor evacetrapib substantially raises the high-density lipoprotein (HDL) cholesterol level, reduces the low-density lipoprotein (LDL) cholesterol level, and enhances cellular cholesterol efflux capacity. We sought to determine the effect of evacetrapib on major adverse cardiovascular outcomes in patients with high-risk vascular disease. METHODS: In a multicenter, randomized, double-blind, placebo-controlled phase 3 trial, we enrolled 12,092 patients who had at least one of the following conditions: an acute coronary syndrome within the previous 30 to 365 days, cerebrovascular atherosclerotic disease, peripheral vascular arterial disease, or diabetes mellitus with coronary artery disease. Patients were randomly assigned to receive either evacetrapib at a dose of 130 mg or matching placebo, administered daily, in addition to standard medical therapy. The primary efficacy end point was the first occurrence of any component of the composite of death from cardiovascular causes, myocardial infarction, stroke, coronary revascularization, or hospitalization for unstable angina. RESULTS: At 3 months, a 31.1% decrease in the mean LDL cholesterol level was observed with evacetrapib versus a 6.0% increase with placebo, and a 133.2% increase in the mean HDL cholesterol level was seen with evacetrapib versus a 1.6% increase with placebo. After 1363 of the planned 1670 primary end-point events had occurred, the data and safety monitoring board recommended that the trial be terminated early because of a lack of efficacy. After a median of 26 months of evacetrapib or placebo, a primary end-point event occurred in 12.9% of the patients in the evacetrapib group and in 12.8% of those in the placebo group (hazard ratio, 1.01; 95% confidence interval, 0.91 to 1.11; P=0.91). CONCLUSIONS: Although the cholesteryl ester transfer protein inhibitor evacetrapib had favorable effects on established lipid biomarkers, treatment with evacetrapib did not result in a lower rate of cardiovascular events than placebo among patients with high-risk vascular disease. (Funded by Eli Lilly; ACCELERATE ClinicalTrials.gov number, NCT01687998 .)

    Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

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    BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)
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