Search

To study the energy loss characteristics of a semi-open mixed-flow multiphase pump, an improved entropy generation theory considering the slip velocity was established to locate local areas with high energy loss. The relationships among local entropy generation, phase interface entropy generation, wall entropy generation, and unstable flow were analyzed for each component. The results showed that magnitude of interface entropy generation was similar to turbulent entropy generation and wall entropy generation, which could not be ignored. The interface entropy generation was mainly distributed at the leading edge, trailing edge, hub, and blade tip clearance. With an increased inlet gas volume fraction, the proportion of interfacial entropy production loss to total entropy production loss increased. As the inlet gas volume fraction increased to 30%, the interface entropy generation loss accounted for 70% of the local entropy generation loss at leading edge and 63% at trailing edge. The high interface entropy generation zone at the tip clearance region began to extend from the pressure side of the blade to the suction side of the blade. During the evolution of tip leakage vortex, the generation, unstable stretching, and breakup–regeneration stages were accompanied by a large loss of interface entropy generation. [ABSTRACT FROM AUTHOR]

Background: Changes in renal function in chronic hepatitis C (CHC) patients receiving direct-acting antivirals (DAAs) are controversial. The evolution of neutrophil gelatinase-associated lipocalin (NGAL) in these patients remains unclear. Methods: A total of 232 CHC patients receiving DAA at Dalin Tzu Chi Hospital from May 2016 to February 2019, were enrolled in this retrospective study. Grade 2/3 renal function deterioration, defined as a decrease in eGFR between 10% and 50% from baseline (BL) to 12 weeks after the end of treatment (P12), was investigated for its association with BL characteristics. The changes in renal function and NGAL levels were also analyzed at the SOF-base or nonSOF-base DAA. Results: Sixty-two patients (26.7%) had grade 2/3 renal function deterioration at P12 after DAA therapy. Univariate analysis showed that it was associated with age (P = 0.038). Multivariate analysis indicated that age (OR = 1.033, 95% CI: 1.004–1.064, P = 0.027), sex (male; OR = 2.039, 95% CI: 1.093–3.804, P = 0.025), ACEI/ARB use (OR = 2.493, 95% CI: 1.016–6.119, P = 0.046), and BL NGAL (OR = 1.033, 95% CI: 1.001–1.067, P = 0.046) positively correlated with grade 2/3 renal function deterioration. Furthermore, eGFR was decreased (P = 0.009) and NGAL was increased (P = 0.004) from BL to P12 in CHC patients receiving SOF-based DAA. Conclusions: Of the CHC patients receiving DAA therapy, 26.7% had grade 2/3 renal function deterioration at P12, and it was associated with older age, gender being male, ACEI/ARB use, and higher BL NGAL levels. In addition, NGAL might be a biomarker of nephrotoxicity at P12 in patients receiving SOF-based DAA. [ABSTRACT FROM AUTHOR]

The human microbiome exhibits a profound connection with the cancer development, progression, and therapeutic response, with particular emphasis on its components of the mycobiome, which are still in the early stages of research. In this review, we comprehensively summarize cancer‐related symbiotic and pathogenic fungal genera. The intricate mechanisms through which fungi impact cancer as an integral member of both gut and tissue‐resident microbiomes are further discussed. In addition, we shed light on the pivotal physiological roles of various nutrients, including cholesterol, carbohydrates, proteins and minerals, in facilitating the growth, reproduction, and invasive pathogenesis of the fungi. While our exploration of the interplay between nutrients and cancer, mediated by the mycobiome, is ongoing, the current findings have yet to yield conclusive results. Thus, delving into the relationship between nutrients and fungal pathogenesis in cancer development and progression would provide valuable insights into anticancer therapy and foster precision nutrition and individualized treatments that target fungi from bench to bedside. Highlights: Symbiotic and pathogenic fungi are crucial in modulating various processes of cancer.Dietary nutrients play essential physiological roles in growth, reproduction, and invasive pathogenesis of fungi.The interactions between nutrients and fungi in cancer development provide valuable insights into the application of fungi‐targeted strategies in precision nutrition for cancer prevention and treatment. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports an application of the grey relational analysis (GRA) to directly optimize laser cutting of a quad flat non-lead (QFN) strip using six performance characteristics. The most important performance characteristics include the cutting depth, the width of heat affected zone (HAZ), and the width of cutting line for both epoxy and Cu+epoxy materials along the cutting path. During the GRA, higher grades are obtained from any of the deeper (more complete) cutting depth, reduced widths of the HAZ and reduced widths of the cutting line. From nine experiments based on the orthogonal array of L9(34), a current of 29A, a frequency of 2kHz, and a cutting speed of 2mm/s were found to be the best parameters for laser cutting of a QFN strip with a thickness of 0.9mm. Moreover, the analysis of variance (ANOVA) is also employed to determine the contribution of each control parameter on the cutting quality characteristics. The three largest measured contributions on the cutting quality in decreasing order are the frequency, the current, and the cutting speed. Compared with the Taguchi optimization method, the GRA approach is significantly simpler because it directly assigns appropriate weighting factors to the required qualities. Finally, confirmation experiments are performed to ensure the robustness of the GRA predicted optimal configuration for laser cutting a QFN strip. [Copyright &y& Elsevier]

Abstract: In this paper, a multiple regression analysis (MRA) and an artificial neural network (ANN) were employed to build a predicting model for cutting Quad Flat Non-lead (QFN) packages by using a Diode Pumped Solid State Laser (DPSSL) System. The predicting model includes three input variables of the current, the frequency and the cutting speed, and six cutting qualities of depths of the cutting line, widths of heat affected zone (HAZ) and cutting line for epoxy and for copper-compounded epoxy. After the training process from 27 sets of training data including input data and its output qualities, the average training error is 0.822% by using a back-propagation (BP) neural network with Levenberg–Marquardt (LM) algorithm, which leads to the best results. The testing accuracy is then verified with extra 14 sets of experimental data and the average predicting error is 1.512%. The results show that the ANN model has the predicting ability to estimate the laser-cutting qualities of QFN packages. Finally, a genetic algorithm (GA) is applied to find the optimal cutting parameters that lead to least HAZ width and fast cutting speed with complete cutting. The optimal combination found is the current of 29A, the frequency of 2.7kHz and the cutting speed of 3.49mm/s. The GA is helpful to determine the ideal laser-cutting parameters in order to meet the desired cutting qualities and to avoid unnecessary adjustments in the subsequent cutting process. [Copyright &y& Elsevier]

Abstract: This paper reports the study of optimal laser parameters for cutting QFN (Quad Flat No-lead) packages by using a diode pumped solid-state laser system (DPSSL). The QFN cutting path includes two different materials, which are the encapsulated epoxy and a copper lead frame substrate. The Taguchi''s experimental method with orthogonal array of L9(34) is employed to obtain optimal combinatorial parameters. A quantified mechanism was proposed for examining the laser cutting quality of a QFN package. The influences of the various factors such as laser current, laser frequency, and cutting speed on the laser cutting quality is also examined. From the experimental results, the factors on the cutting quality in the order of decreasing significance are found to be (a) laser frequency, (b) cutting speed, and (c) laser driving current. The optimal parameters were obtained at the laser frequency of 2kHz, the cutting speed of 2mm/s, and the driving current of 29A. Besides identifying this sequence of dominance, matrix experiment also determines the best level for each control factor. The verification experiment confirms that the application of laser cutting technology to QFN is very successfully by using the optimal laser parameters predicted from matrix experiments. [Copyright &y& Elsevier]

Abstract: Dopamine- and cAMP-regulated phosphoprotein of relative molecular mass 32kDa (DARPP-32) plays a pivotal role in the signal transduction of several neurotransmitters and neuromodulators that are implicated in the pathophysiology of a variety of neuropsychiatric disorders. A postmortem study reported a significantly reduced DARPP-32 expression in the dorsolateral prefrontal cortex (DLPFC) of patients with schizophrenia, suggesting possible involvement of DARPP-32 in the pathophysiology of schizophrenia. Hence, DARPP-32 was considered as a candidate gene for schizophrenia in this study. We first systemically searched for mutations in the DARPP-32 gene in 50 Han Chinese patients with schizophrenia from Taiwan. Five molecular variants were identified, including a C-to-G substitution (g.-2036C>G) in the putative core promoter that obliterated a predictive AP-2 transcription factor binding site, a G deletion in the untranslated exon 2 (g.1238delG), a G-to-A and an A-to-G substitutions in intron 2 (IVS2+31G>A) and intron 6 (IVS6+32A>G), respectively, and a three-base pair deletion of AGA in exon 6 that resulted in deletion of a glutamate at codon 135 (E135del). Further SNP- and haplotype-based association study in 249 patients and 273 control subjects, however, did not detect association of these markers with schizophrenia. Hence, our results suggest that the reduced DARPP-32 protein in patients with schizophrenia is unlikely caused by mutations in the DARPP-32 gene itself and the DARPP-32 gene is also unlikely a major susceptibility gene for schizophrenia. Nevertheless, the identification of these molecular variants should help the study of gene regulation and structure–function relationship of DARPP-32, and the association study of DARPP-32 gene with other neuropsychiatric disorders. [Copyright &y& Elsevier]

The human α7 neuronal nicotinic receptor subunit gene has been considered as a candidate gene for P50 sensory gating deficit in schizophrenic patients. Because P50 sensory gating deficit is a common neurophysiological dysfunction in patients with schizophrenia and schizophrenia spectrum disorders, it is conceivable to hypothesize that the human α7 neuronal nicotinic receptor subunit gene might be a susceptible gene for schizophrenia. Researchers have reported that mutations in the protein-coding sequences of the human α7 neuronal nicotinic receptor subunit gene are very rare. Therefore, we searched for mutations at the promoter region of the human α7 neuronal nicotinic receptor subunit gene and performed a genetic association study in 249 unrelated Han Chinese schizophrenic patients and 273 non-psychotic subjects from Taiwan. Two molecular variants were identified and designated g.-213G>A and g.-324A>G, respectively. The g.-213G>A variant was found to obliterate a putative NF-1 transcription factor binding site using computer analysis. One out of 249 patients was detected to be a heterozygote for this variant, but none of 273 control subjects was. The g.-324A>G variant was also very rare in both patients and control subjects, only one heterozygote of this variant was identified in 249 patients and 273 control subjects, respectively. Hence, in this study, we did not find mutations in the human α7 neuronal nicotinic receptor subunit gene that are associated with schizophrenia in our population. [Copyright &y& Elsevier]

The intrinsic characteristics of multiphase flow inevitably result in vibrations within the pipe structure. The evolution of vibration characteristics is crucial for monitoring the stability of the multiphase flow pipelines. However, under high liquid velocity condition, the influence of flow pattern on the gas–liquid two-phase flow-induced vibration (GTFIV) of the pipe remains unclear. In this paper, the vibration signals in the horizontal pipe under different flow patterns at high liquid velocity are measured by a vibration test system. Synchronously, images inside the pipe are captured to illustrate the flow mechanism. The results show that the α stable distribution model holds higher fitting accuracy than the standard normal distribution for the GTFIV. The random behavior of small-scale bubbles determines the structural richness of the GTFIV. The multifractal characteristics of the GTFIV are strongly dependent on the flow pattern. The formation of the gas plug leads to significant unevenness in the fractal structure of the GTFIV. The multifractal strength of the GTFIV gradually increases as the flow pattern transforms from dispersed bubble flow to slug flow. Some multifractal spectrum parameters of the vibration signal can be applied for the identification of flow patterns in the pipe. [ABSTRACT FROM AUTHOR]

The flow in mixed-flow pumps under gas–liquid operating conditions is complex, involving special phenomena such as secondary flow and bubble breakup and coalescence. As a result, its pressure fluctuation characteristic is far different from that under pure water conditions. In this work, the energy performance, pressure fluctuation characteristics, and flow pattern under different inlet gas volume fractions (IGVFs) are studied through a visualization test in a mixed-flow pump. The air pocket forms easily close to the suction side of diffuser vanes, where two pressure fluctuation monitoring points are set up. The pressure increment decreases continuously when the IGVF increases, and the flow pattern shows a transition from bubble, condensed bubble, and air pocket to separated flow. Moreover, the pressure fluctuation amplitude and peak-to-peak values increase. The main frequency under different IGVFs is maintained as the blade passing frequency. When the IGVF increases to 15%, the peak-to-peak amplitude at P1 reaches the maximum, which is 2.24 times that of the pure water condition. Some amplitudes at one frequency fluctuate at different times when the IGVF is higher than 10%. The findings contribute theoretical support in improving the stability of multiphase pumps. [ABSTRACT FROM AUTHOR]

A serpentine aneurysm is defined as a thrombosed giant aneurysm with internal channel, which mimics a giant arteriovenous malformation on angiography. We report a case of serpentine aneurysm and its radiological characters. [ABSTRACT FROM AUTHOR]

Thermal convection is one of the basic modes (thermal convection, thermal conduction, thermal radiation) of heat transfer, and it belongs to the thermo-fluid mechanics. With the development and progress of science and technology, as well as the cross accommodation of disciplines, new contents and challenges arise in the thermal convection. For instance, along with the increasing energy consumption all over the world, the enhanced energy transport has attracted more and more attentions, which is inseparable from the development of thermal convection. As a classical model of natural convection, the Rayleigh-Bénard (RB) convection has been investigated for more than 100 years and numerous research findings have been obtained. However, it is still one of the most notable subjects, particularly the complex flow and heat transport problems of the stabilizing-destabilizing flow. This review, therefore, focuses on the RB convection researches, as well as natural convection of other configurations, under the influence of various complicating factors, including thermal radiation, magnetic field, rotation and electrical field. The flow and transport characteristics, especially the heat transfer, are summarized and analyzed. Although these factors usually show a stabilizing effect, like the delay of the onset of instabilities, it is quite surprising that there is a counterintuitive but significant flux enhancement within the specific strength range. Finally, some topics of future work are prospected briefly, such as the multi-fields coupling problem, the ultimate regime with additional field effects and the unifying view on strengthening mechanism of stabilizing effects. [ABSTRACT FROM AUTHOR]