ELF

ELF
  • 文章类型: Journal Article
    近年来,随着石油井筒数字化和智能化的提高,因此,在距离方面对无线通信技术的要求越来越严格,准确度,和便携性。因此,有必要依靠更先进、更高效的无线通信技术来满足行业的需求。然而,传统的通信技术,如电缆和光纤,在建筑上存在固有的缺点,数据解释,和成本。ELF电磁波具有远距离通信和较强的穿透能力,是复杂井筒条件下通信的理想解决方案,使它成为一个非常有效的选择。基于网络分裂理论,本文建立了分层介质中ELF电磁波通过套管传播的多边形多延迟不确定性耦合复杂网络模型,并设计了控制器,包括不同方向的磁场和电场强度的表达式,以及在不同媒介中的传播和分布特征。我们确定一般条件下ELF电磁波的最佳发射频率为12.7Hz。根据现场实验,我们验证了ELF电磁波可以在没有继电器的情况下在1500m内实现无线井筒通信。我们还分析了高温和高压环境下套管螺纹变形对ELF电磁波传播的影响。我们使用模拟实验来解决螺线管穿过套管和地层的电场和磁场之间的分布关系,以及发射和接收螺线管之间的耦合系数,并探讨不同的发射频率对信号传播效率的影响。理论和实验都验证了模型的正确性,并且还证明了使用ELF电磁波实现无线井筒通信的可靠性和连续性,为后续工程应用提供了理论依据和可行性。
    Over recent years, as digitalization and intelligence in oil wellbore have increased, so have the stricter requirements for wireless communication technology in terms of distance, accuracy, and portability. As a result, it\'s necessary to rely on more advanced and efficient wireless communication technologies to meet the industry\'s needs. However, traditional communication technologies such as cables and optical fibers have inherent shortcomings in construction, data interpretation, and cost. ELF electromagnetic waves are an ideal solution for communication in complex wellbore conditions due to long-distance communication and strong penetration capabilities, making it a highly effective option. Based on the theory of network splitting, this paper establishes a polygonal multiple-delays uncertainty coupled complex network model of ELF electromagnetic waves propagating through the casing in layered media and designs a controller, including expressions for the intensity of the magnetic and electric fields in different directions, and the propagation and distribution characteristics in different media. We determined that the optimal transmitting frequency of ELF electromagnetic waves under general conditions is 12.7 Hz. Based on field experiments, we verified that ELF electromagnetic waves can enable wireless wellbore communication within 1500 m without relays. We also analyzed the impact of casing thread deformation on ELF electromagnetic wave propagation due to high-temperature and high-pressure environments. We used simulation experiments to solve the distribution relationship between the electric and magnetic fields of the solenoids through casing and strata, as well as the coupling coefficients between the transmitting and receiving solenoids, and explore how different transmitting frequencies affect the efficiency of signal propagation. Both theories and experiments have verified the correctness of the model, and have also demonstrated the reliability and continuity of using ELF electromagnetic waves to achieve wireless wellbore communication, which provides a theoretical basis and feasibility for subsequent engineering applications.
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  • 文章类型: Journal Article
    在分子电子密度理论(MEDT)的背景下,本研究应用DFT模拟研究了异戊二烯(2)和R-香芹酮(1R)之间的Diels-Alder反应,有和没有路易斯酸(LA)催化。结果表明,香芹酮(1R)在极性过程中充当亲电试剂,异戊二烯(2)充当亲核试剂。LA催化增加香芹酮的亲电性,从而通过降低活化吉布斯自由能提高反应的反应性和选择性。Parr函数表明,C5=C6双键比C9=C10双键更具反应性,表明化学选择性。电子定位函数(ELF)的检查显示出高的区域和立体选择性,表明LA催化的DA反应的异步机制。此外,建议环加合物3具有很大的抗HIV潜力,因为在主要HIV-1蛋白(1A8O加5W4Q)中环加合物3和4的对接研究中,它表现出比叠氮胸苷(AZT)更低的结合能。
    Within the context of Molecular Electronic Density Theory (MEDT), this study investigates the Diels-Alder reaction among isoprene (2) and R-carvone (1R) applying DFT simulations, with and without Lewis acid (LA) catalysis. The results show that carvone (1R) acts as an electrophile and isoprene (2) as a nucleophile in a polar process. LA catalysis increases the electrophilicity of carvone, thereby improving the reactivity and selectivity of the reaction by reducing the activation Gibbs free energy. Parr functions reveal that the C5=C6 double bond is more reactive than the C9=C10 double bond, indicating chemoselectivity. The examination of the Electron Localization Function (ELF) reveals high regio- and stereoselectivity, indicating an asynchronous mechanism for the LA-catalyzed DA reaction. Furthermore, it is suggested that cycloadduct 3 has great anti-HIV potential because it exhibits lower binding energies than azidothymidine (AZT) in the docking studies of cycloadducts 3 and 4 amongst a primary HIV-1protein (1A8O plus 5W4Q).
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  • 文章类型: Journal Article
    我们的工作的目的是使用FIB-4评分评估初级保健肝纤维化的筛查,自动计算。当FIB-4≥1.3时,它被定义为阳性,并进行ELF测试。当ELF测试≥9.8表明晚期纤维化时,确认FIB-4阳性。在包括的3427名患者中,869(25%)的FIB-4评分为阳性,784(22.5%)在中间(FIB-4:1.3-2.67),和85(2.5%)在纤维化的高风险(FIB-4>2.67)。通过ELF测试确认了509(59%)的FIB-4阳性。65岁以上患者的确认百分比明显更高(83vs.57%),FIB-4>2.67(80vs.56%),BMI>25(47vs.37%),和糖尿病(24vs.14%),p=0.001)。在没有已知肝病的患者中(92%),该医生在27%的病例中确定了病因:主要是NAFLD和酒精.在初级保健中,有25%的患者在FIB-4上怀疑肝纤维化。ELF测试,作为第二行执行,改善肝纤维化的筛查,特别是FIB-4中间结果。FIB-4阳性测试允许医生识别肝脏疾病,提供及时干预的机会。临床试验注册:SI18.00832.201865-MS04-IDRCB2018-A01571-54。
    The objective of our work was to evaluate the screening of hepatic fibrosis in primary care using the FIB-4 score, automatically calculated. When the FIB-4 was ≥ 1.3, it was defined as positive, and ELF Test was performed. FIB-4 positivity was confirmed when ELF Test was ≥ 9.8 indicating an advanced fibrosis. Among the 3427 patients included, 869 (25%) had a positive FIB-4 score, 784 (22.5%) at intermediate (FIB-4: 1.3-2.67), and 85 (2.5%) at high risk of fibrosis (FIB-4 > 2.67). 509 (59%) of the FIB-4 positive were confirmed by the ELF Test. The percentage of confirmation was significantly higher in patients over 65 years (83 vs. 57%), with FIB-4 > 2.67 (80 vs. 56%), BMI > 25 (47 vs. 37%), and diabetes (24 vs. 14%), p = 0.001). In patients without known liver disease (92%), the practitioner identified a cause of disease in 27% of cases: mainly NAFLD and alcohol. Liver fibrosis was suspected on FIB-4 in 25% of patients in primary care. The ELF Test, performed as a second-line, improves the screening of liver fibrosis, particularly for FIB-4 intermediate results. A positive FIB-4 test allows physicians to recognize a liver disease, providing an opportunity for timely intervention.Clinical trial registration: Comité de protection des personnes du sud-ouest et outre-mer SI18.00832.201865-MS04-IDRCB 2018-A01571-54.
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  • 文章类型: Journal Article
    本文探讨了C5${_5}$环状分子中可能存在的五月价键结构。为此,我们使用量子化学工具来阐明线性内化学键的可能排列和性质,循环,和仅由五个碳原子形成的三维结构。虽然线性结构显然是最稳定的,获得了二维和三维结构的局部最小值。使用本地化-离域矩阵方法,我们表征了最小线性结构和环状结构。有趣的是,线性结构是离子键和共价键的结合,尽管四个距离几乎相同,当使用密度泛函理论时。对于循环C5${_5}$,五角键合排列出现了一个重要的路易斯结构,这表明了一种不寻常的形式构型,其特征是五个交叉的C-C键。我们的计算表明,环状C5${_5}$方案中的这种五位数排列也存在于更已知的环戊二烯基分子中。
    This article explores the possible presence of a pentacle valence bond structure in C 5 ${_5 }$ cyclic molecules. At this end, we have used quantum chemistry tools to elucidate the possible arrangement and the nature of chemical bonds within linear, cyclic, and three-dimensional structures only formed by five carbon atoms. While the linear structure is clearly the most stable one, local minima were obtained for both bi- and three-dimensional structures. Using the localization-delocalization matrices approach, we characterize both the minimum linear structure and the cyclic ones. Interestingly, the linear structure is a combination of ionic and covalent bonds, albeit the four distances are almost identical, when using Density Functional Theory. For cyclic C 5 ${_5 }$ , the pentacle bonding arrangement emerges as a significant Lewis structure, indicative of an unusual formal configuration characterized by five intersecting C-C bonds. Our calculations show that this pentacle arrangement in cyclic C 5 ${_5 }$ scheme is also present in the more known cyclo-pentadienyl molecule.
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  • 文章类型: Journal Article
    分子电子密度理论(MEDT)用于检查(E)-N-((二甲基氨基)亚甲基)苯并硫酰胺(1)和(S)-3-丙烯酰基-4-苯基恶唑烷-2-酮(2)在B3LYP/6-311++G(d,P)设计水平。Parr功能和能量研究清楚地表明,该反应是区域选择性和立体选择性的,与实验结果完全一致。通过从键演化理论(BET)和电子局域函数(ELF)方面评估化学机理,它沿着反应路径传播电子密度的各种变化,揭示了具有高度异步过渡状态结构的单步机制。此外,与Nirmatrelvir相比,我们对SARS-CoV-2主要蛋白酶(6LU7)中的化合物P1,P2,P3和P4进行了对接研究。我们的发现证实了产品P4可以作为一种有效的抗病毒药物。
    The molecular electron density theory (MEDT) was employed to examine the [4 + 2] cycloaddition reaction between (E)-N-((dimethylamino)methylene)benzothioamide (1) and (S)-3-acryloyl-4-phenyloxazolidin-2-one (2) at the B3LYP/6-311++G(d,p) design level. Parr functions and energy studies clearly show that this reaction is regio- and stereoselective, in perfect agreement with experimental results. By evaluating the chemical mechanism in terms of bond evolution theory (BET) and electron localization function (ELF), which divulges a variety of variations in the electron density along the reaction path, a single-step mechanism with highly asynchronous transition states structures was revealed. Additionally, we conducted a docking study on compounds P1, P2, P3, and P4 in the SARS-CoV-2 main protease (6LU7) in comparison to Nirmatrelvir. Our findings provide confirmation that product P4 may serve as a potent antiviral drug.
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  • 文章类型: Journal Article
    使用B3LYP/6-31G通过DFT方法进行嘧啶基偶氮染料的理论计算(d,P)基础设置。通过计算最小能量,基于相同的基础集对分子进行优化。FMO,计算DOS和GCRD的动力学稳定性和所选化合物的化学反应性。研究了MEP表面以定位亲核和亲电攻击区。对嘧啶基偶氮染料的能隙进行了仔细研究。就PED分配而言,在最突出的区域研究了振动光谱学。同样,在不同溶剂介质中使用TD-DFT方法计算UV-Vis吸收技术。通过电子定位函数(ELF)和局部轨道定位器(LOL)检查分子中每个原子的电子结构。使用降低的密度梯度分析探索非共价相互作用。实验和理论数据的结合使我们能够将结构修饰与观察到的光物理性质相关联,促进设计具有定制特性的偶氮染料。这项工作有助于对偶氮染料的基本理解,并为开发具有增强的光物理和电子性能的新材料奠定了基础。
    Theoretical computations of pyrimidine-based azo dyes were performed by the DFT approach using the B3LYP/6 - 31G(d,p) basis set. The molecules were optimized based on the same basis set by calculating the minimum energy. FMOs, DOS and GCRD were computed for kinetic stability and chemical reactivity of the selected compounds. The MEP surface was studied to locate nucleophilic and electrophilic attack zones. The energy gap was carefully studied for pyrimidine-based azo dyes. Vibrational spectroscopy was studied in the most prominent regions with respect to PED assignments. Similarly, the UV-Vis absorption technique was calculated using the TD-DFT approach in different solvent media. The electronic structure of each atom in a molecule was examined via the electron localization function (ELF) and localized orbital locator (LOL). Non-covalent interactions were explored using reduced density gradient analysis. The combination of experimental and theoretical data allowed us to correlate the structural modifications with the observed photophysical properties, facilitating the design of azo dyes with tailored characteristics. This work contributes to the fundamental understanding of azo dyes and offers a foundation for the development of new materials with enhanced photophysical and electronic properties.
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  • 文章类型: Journal Article
    在过去的15年中,非侵入性纤维化测试(NIT)的开发和验证改变了肝病学的临床实践。代谢相关脂肪变性肝病(MASLD),以前称为非酒精性脂肪性肝病(NAFLD),是西方国家最常见的肝病,多达三分之一的未选择的成年人口受到影响。在这篇文章中,我们回顾了NIT在MASLD诊断和分期中的应用。我们讨论它们在脂肪变性诊断中的应用,脂肪性肝炎和纤维化,并严格评估最近发表的数据。这些NIT包括各种方法,如血清标志物FIB-4,pro-C3和ELF,成像技术,如Fibroscan®和MRE,并结合了敏捷3+和敏捷4等分数,为医疗保健提供者提供了一系列选择。此外,这些非侵入性测试也是有价值的预后工具,允许更好的风险评估和改善患者管理,特别是在预测肝脏相关事件和总死亡率方面。
    The development and validation of non-invasive fibrosis tests (NITs) has changed clinical practice in Hepatology over the last 15 years. Metabolic associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is the most prevalent liver disease in western countries, with up to a third of the unselected adult population affected. In this article, we review the use of NITs in the diagnosis and staging of MASLD. We discuss their use in the diagnosis of steatosis, steatohepatitis and fibrosis and critically evaluate recently published data. These NITs include a variety of approaches, such as serum markers like FIB-4, pro-C3 and ELF, imaging techniques like Fibroscan® and MRE, and combined scores like Agile 3+ and Agile 4, offering a range of options for healthcare providers. Furthermore, these non-invasive tests also serve as valuable prognostic tools, allowing for better risk assessment and improved patient management, particularly in predicting liver-related events and overall mortality.
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  • 文章类型: Journal Article
    目的:2型糖尿病(T2DM)患者的纤维化-4(FIB-4)指数和非酒精性脂肪性肝病(NAFLD)纤维化评分(NFS)的诊断表现较差。我们确定了增强肝纤维化(ELF)测试在T2DM患者中的有用性。
    方法:共纳入1,228例经活检证实的NAFLD患者。与FIB-4指数和NFS相比,评估了ELF测试在有或没有T2DM的参与者中预测晚期纤维化的诊断性能。
    结果:总体而言,预测晚期纤维化的ELF测试曲线下面积(0.828)大于FIB-4指数(0.727)和NFS(0.733).在T2DM患者中,ELF测试的诊断性能(曲线下面积0.820)也优于FIB-4指数(0.698)和NFS(0.700)。由于每个非侵入性测试的截止值较低,ELF测试在该人群中提供了可接受的假阴性率(截止值9.8,6.7%),与FIB-4指数(1.30,14.5%)和NFS(-1.455,12.4%)不同。在倾向得分匹配后,避免包括年龄在内的选择偏差,性别,身体质量指数,以及晚期纤维化的患病率,具有低截止值的ELF测试显示高灵敏度(≥91.4%)和高阴性预测值(≥96.8%),无论是否存在T2DM。
    结论:ELF测试在预测有或没有T2DM的个体的晚期纤维化中的高诊断性能可以满足对糖尿病和NAFLD患者肝纤维化的准确评估的未满足的医学需求。
    OBJECTIVE: The diagnostic performance of the Fibrosis-4 (FIB-4) index and nonalcoholic fatty liver disease (NAFLD) fibrosis score (NFS) is poor in patients with type 2 diabetes mellitus (T2DM). We determined the usefulness of the Enhanced Liver Fibrosis (ELF) test in patients with T2DM.
    METHODS: A total of 1228 patients with biopsy-proven NAFLD were enrolled. The diagnostic performance of the ELF test for predicting advanced fibrosis in participants with or without T2DM was evaluated in comparison with the FIB-4 index and NFS.
    RESULTS: Overall, the area under the curve of the ELF test for predicting advanced fibrosis was greater (0.828) than that of the FIB-4 index (0.727) and NFS (0.733). The diagnostic performance of the ELF test (area under the curve, 0.820) was also superior to that of the FIB-4 index (0.698) and NFS (0.700) in patients with T2DM. With the low cutoff values for each noninvasive test, the ELF test provided an acceptable false negative rate (cutoff value 9.8, 6.7%) in this population, unlike the FIB-4 index (1.30, 14.5%) and NFS (-1.455, 12.4%). After propensity score matching to avoid selection bias including age, sex, body mass index, and the prevalence of advanced fibrosis, the ELF test with a low cutoff value showed a high sensitivity (≥91.4%) and a high negative predictive value (≥96.8%), irrespective of the presence or absence of T2DM.
    CONCLUSIONS: The high diagnostic performance of the ELF test for predicting advanced fibrosis in individuals with or without T2DM could address an unmet medical need for accurate assessment of liver fibrosis in patients with diabetes and NAFLD.
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  • 文章类型: Journal Article
    非酒精性脂肪性肝病(NAFLD)是慢性肝病的主要原因,肝纤维化是病态的最强预测因子。我们旨在评估包含纤维化4(FIB-4)和增强肝纤维化(ELF)评分的顺序算法的性能,以识别处于晚期纤维化风险的患者。这项横断面研究包括一个基于医院的队列与活检证实的NAFLD(n=140)和两个来自不同临床环境的初级保健队列:2型糖尿病(T2D)随访(n=141)和慢性肝病(CLD)初始研究(n=138)。进行Logistic回归分析以评估基于FIB-4和ELF生物标志物的肝纤维化诊断模型。在活检证实的队列中,顺序算法在预测阶段F3-4中检索到以下准确性参数:灵敏度(85%),特异性(73%),阴性预测值(79%)和阳性预测值(81%)。在T2D和CLD队列中,共有28%的患者被分类为F3-4期.此外,在T2D队列中所有F3-4分类的患者中,80%的人被诊断为肝病,44%的人被转诊为二级保健。同样,在CLD队列中所有F3-4分类的患者中,71%的人被诊断为肝病,44%的人被转诊为二级保健。这些结果表明,该算法作为初级保健肝纤维化分层工具的潜在效用,需要更新转诊方案以检测高风险F3-4。FIB-4和ELF序贯测量是在有代谢危险因素的人群中优先考虑F3-4高风险患者的有效策略。
    Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease, and liver fibrosis is the strongest predictor of morbimortality. We aimed to assess the performance of a sequential algorithm encompassing the Fibrosis 4 (FIB-4) and Enhanced Liver Fibrosis (ELF) scores for identifying patients at risk of advanced fibrosis. This cross-sectional study included one hospital-based cohort with biopsy-proven NAFLD (n = 140) and two primary care cohorts from different clinical settings: Type 2 Diabetes (T2D) follow-up (n = 141) and chronic liver disease (CLD) initial study (n = 138). Logistic regression analysis was performed to assess liver fibrosis diagnosis models based on FIB-4 and ELF biomarkers. The sequential algorithm retrieved the following accuracy parameters in predicting stages F3-4 in the biopsy-confirmed cohort: sensitivity (85%), specificity (73%), negative predictive value (79%) and positive predictive value (81%). In both T2D and CLD cohorts, a total of 28% of patients were classified as stages F3-4. Furthermore, of all F3-4 classified patients in the T2D cohort, 80% had a diagnosis of liver disease and 44% were referred to secondary care. Likewise, of all F3-4 classified patients in the CLD cohort, 71% had a diagnosis of liver disease and 44% were referred to secondary care. These results suggest the potential utility of this algorithm as a liver fibrosis stratifying tool in primary care, where updating referral protocols to detect high-risk F3-4 is needed. FIB-4 and ELF sequential measurement is an efficient strategy to prioritize patients with high risk of F3-4 in populations with metabolic risk factors.
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  • 文章类型: Journal Article
    2-氨基噻吩衍生物,合成了2-氨基-4-甲基噻吩-3-甲酸乙酯(EAMC),characterized,并进行了量子化学研究。通过不同的光谱方法如NMR(1H-NMR和13C-NMR)进行了实验研究,FT-IR,和紫外可见。B3LYP方法和6-311++G(d,p)基集用于优化分子结构和计算正常振动模式的波数以及其他各种重要参数。将计算的键长和角度与实验键长和键角参数进行比较。优化后的粘结参数与实验粘结参数吻合良好。VEDA成功完成了完整的势能分配分配。HOMO/LUMO能隙强调分子内发生的充分电荷转移。通过NBO分析对供体-受体互连进行了研究。进行MEP表面分析以定性地证明分子中的电荷分布和反应面积。通过ELF图分析了电子的相对定位程度。福井功能分析显示了不同取代基攻击的可能位点。通过使用TD-DFT方法和PCM溶剂模型,紫外可见光谱(气体,甲醇,DMSO)和最大吸收波长进行了计算,并与实验数据进行了比较。通过Hirshfeld表面分析分析了晶体中的3D和2D分子间相互作用,指纹图谱显示EAMC晶体通过H--H/H--H/C--H键的形成而稳定。用分子上的7种不同的蛋白质受体进行分子对接,以找到最佳的配体-蛋白质相互作用。还进行了分子动力学模拟和MMGBSA计算以发现配体与蛋白质的最佳结合。由RamaswamyH.Sarma沟通。
    2-aminothiophenes derivative, Ethyl-2-amino-4-methyl thiophene-3-carboxylate (EAMC) has been synthesized, characterized, and investigated quantum chemically. It was experimentally investigated by different spectroscopic methods like- NMR (1H-NMR and 13C-NMR), FT-IR, and UV-Visible. B3LYP method and 6-311++G(d,p) basis set were employed for optimization of molecular structure and calculation of wave numbers of normal modes of vibrations and various other important parameters. Calculated bond lengths and angles were compared with the experimental bond lengths and Bond Angle Parameters. Optimized bond parameters and experimental bond parameters were found in good agreement. Complete potential energy distribution assignments were done successfully by VEDA. The HOMO/LUMO energy gap emphasizes adequate charge transfer happening within the molecule. A study of donor-acceptor interconnections was done via NBO analysis. MEP surface analysis was done to demonstrate charge distribution and reactive areas qualitatively in the molecule. The degree of relative localization of electrons was analyzed via ELF Diagram. The Fukui function analysis showed possible sites for attacks by different substituents. By using the TD-DFT method and PCM solvent model, the UV-Vis spectrum (gas, methanol, DMSO) and the maximum absorption wavelength was computed and compared with experimental data. 3D and 2D intermolecular interactions in the crystal were analyzed via Hirshfeld surface analysis and fingerprint plots reveal that the EAMC crystal was stabilized by H--H/H--H/C--H bond formation. The molecular docking was done with 7 different protein receptors on the molecule to find the best ligand-protein interactions. Molecular dynamic simulations and MMGBSA calculations were also carried out to find out the best binding of the ligand with the protein.Communicated by Ramaswamy H. Sarma.
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