45 research outputs found

    Effects of Bonding Parameters on Free Air Ball Properties and Bonded Strength of Ag-10Au-3.6Pd Alloy Bonding Wire

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    Free air ball (FAB) and bonded strength were performed on an Ag-10Au-3.6Pd alloy bonding wire (diameter of 0.025 mm) for different electronic flame-off (EFO) currents, times and bonding parameters. The effects of the EFO and bonding parameters on the characteristics of the FAB as well as the bonded strength were investigated using scanning electron microscopy. The results showed that, for a constant EFO time, the FAB of the Ag-10Au-3.6Pd alloy bonding wire transitioned from a pointed defined ball to an oval one, then to a perfectly shaped one, and finally to a golf ball with an increase in the EFO current. On the other hand, when the EFO current was constant and the EFO time was increased, the FAB changed from a small ball to a perfect one, then to a large one, and finally to a golf ball. The FAB exhibited the optimal geometry at an EFO current of 0.030 A and EFO time of 0.8 ms. Further, in the case of the Ag-10Au-3.6Pd alloy bonding wire, for an EFO current of 0.030 A, the FAB diameter exhibited a nonlinear relationship with the EFO time, which could be expressed by a quadratic function. Finally, the bonded strength decreased when the bonding power and force were excessively high, causing the ball bond to overflow. This led to the formation of neck cracks and decrease in the bonded strength. On the other hand, the bonded strength was insufficiently when the bonding power and force were small. The bonded strength was of the desired level when the bonding power and force were 70 mW and 0.60 N (for the ball bonded) and 95 mW and 0.85 N (for the wedge bonded), respectively

    The Impact of Air Pollution on Intestinal Microbiome of Asthmatic Children: A Panel Study

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    Air pollution could impact on the alteration of intestinal microbiome. Maturation of intestinal microbiome in early life played an important role in the development of allergic diseases, including asthma. Recent studies presented an increase in the evidence of association between the shift of gut microbiota and asthma. This article is aimed at exploring whether the alteration in the intestinal microbiome triggered by a short wave of air pollution could influence the colonization of bacteria that have been related to the immunological mechanisms of the asthma attack. The impact of air pollution on intestinal microbiome was assessed by longitudinal comparison. Fecal samples were collected twice for twenty-one children in clean and smog days, respectively, including eleven asthmatic children and ten healthy children. Intestinal bacteria were discriminated by using the method of 16S rRNA gene sequence. The results showed that the composition of intestinal microbiome changed between clean and smog days among all children (PERMANOVA, P=0.03). During smog days, Bifidobacteriaceae, Erysipelotrichaceae, and Clostridium sensu stricto 1 decreased, and Streptococcaceae, Porphyromonadaceae, Rikenellaceae, Bacteroidales S24-7 group, and Bacteroides increased in asthmatic children (Wilcoxon test, P<0.05), while Fusicatenibacter decreased and Rikenellaceae and Terrisporobacter increased in healthy children (Wilcoxon test, P<0.05). After controlling for food consumption, the relative abundance of some bacteria belonging to Firmicutes negatively associated with concentration of PM2.5, PM10, NO2, and SO2 (multiple linear regression, P<0.05). This study demonstrated that short wave of air pollution had an impact on the intestinal microbiome of asthmatic children. Intestinal bacteria, which have been related to immunological mechanisms of asthma attack, were also found to be associated with air pollution. This finding suggested that a short wave of air pollution may trigger asthma by impacting on intestinal bacteria

    Effect of phloretin on growth performance, serum biochemical parameters and antioxidant profile in heat-stressed broilers

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    ABSTRACT: The objective of this work was to evaluate the effect of phloretin on growth performance, serum biochemical parameters, antioxidant profile, glutathione (GSH)-related enzymes, nuclear factor erythroid 2ā€“related 2 (Nrf2) and heat shock protein 70 (HSP70) in heat-stressed broilers. A total of 240, 22-day-old Arbor Acres broilers were divided into 4 groups. The control group was housed at 23.0 Ā± 0.61Ā°C and fed with basal diet, while the 3 heat-stressed groups (A, B, and C groups) were housed at 30.5 Ā± 0.69Ā°C and fed with basal diet containing 0, 100, and 200 mg/kg phloretin, respectively. Serum was taken form 42-day-old broilers. Results showed that heat stress decreased (P < 0.05) the final body weight (FBW), body weight gain (BWG), feed intake (FI), serum total protein (TP), triglyceride (TG), triiodothyronine (T3), thyroxine (T4), GSH, catalase (CAT), and total antioxidant capacity (T-AOC) levels, but increased (P < 0.05) the feed-to-gain ratio (FGR) and serum malondialdehyde (MDA) levels in broilers compared with that in the control group. Among the heat-stressed groups, supplementary 200 mg/kg phloretin increased (P < 0.05) the FBW, BWG, FI, serum TP, TG, T4, GSH, CAT, and T-AOC levels, and decreased (P < 0.05) the FGR and serum MDA in broilers. There were significant decreases (P < 0.05) in the glutathione peroxidase (GSH-Px), Ī³-glutamylcysteine synthetase (Ī³-GCS), and Nrf2, but significant increases (P < 0.05) in the HSP70 of the broiler serum after heat stress treatment. Among the heat-stressed groups, supplementary 200 mg/kg phloretin increased (P < 0.05) the GSH-Px, Ī³-GCS, and Nrf2 levels, but decreased (P < 0.05) the serum HSP70 level in the heat-stressed broilers. Under high temperature condition, FBW, BWG, FI, FGR, serum TP, TG, T4, MDA, GSH, CAT, T-AOC, GSH-Px, Ī³-GCS, Nrf2 and HSP70 were linearly affected by inclusion of phloretin. These results indicated that phloretin may improve growth performance, serum parameters, and antioxidant profiles through regulated GSH-related enzymes, Nrf2 and HSP70 in heat-stressed broilers

    Unveiling the mechanisms of nephrotoxicity caused by nephrotoxic compounds using toxicological network analysis

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    Billions of people worldwide have experienced irreversible kidney injuries, which is mainly attributed to the complexity of drug-induced nephrotoxicity. Consequently, there is an urgent need for uncovering the mechanisms of nephrotoxicity caused by compounds. In the present study, a network-based methodology was applied to explore the mechanisms of nephrotoxicity induced by specific compounds. Initially, a total of 42 nephrotoxic compounds and 60 kinds of syndromes associated with nephrotoxicity were collected from public resources. Afterward, network localization and separation algorithms were used to map the targets of compounds and diseases into the human interactome. By doing so, 199 statistically significant nephrotoxic networks displaying the interaction between compound targets and disease genes were obtained, which played pivotal roles in compounds-induced nephrotoxicity. Subsequently, enrichment analysis pinpointed core Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways that highlight commonalities in nephrotoxicity induced by nephrotoxic compounds. It was found that nephrotoxic compounds primarily induce nephrotoxicity by mediating the advanced glycosylation end products-receptor for advanced glycosylation end products signaling pathway in diabetic complications, human cytomegalovirus infection, lipid and atherosclerosis, Kaposi sarcomaā€“associated herpesvirus infection, apoptosis, and the phosphatidylinositol 3-kinase-Akt pathways. These results provide valuable insights for preventing drug-induced nephrotoxicity. Furthermore, the approaches we used are also helpful in conducting research on other kinds of toxicities

    Thermal and arc erosion behavior of CuCr contact material based on large plastic deformation treatment

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    CuCr alloys are the main contact materials used in medium-voltage and high-current vacuum interrupters. In this paper, the effect of large plastic deformation on microstructure and the transverse/longitudinal thermal conductivity of CuCr30 contact material were studied. The results show that the morphology of Cr particles in CuCr30 changes from dendritic to oriented fibrous after large plastic deformation, and the longitudinal thermal conductivity of CuCr30 contact material is about 1.5 times higher than its transverse thermal conductivity. During the electrical contacting process, the mass loss of the extruded CuCr30 contact material is lower than that of as-cast CuCr30 contact material, which is directly related to the significantly higher longitudinal thermal conductivity of the extruded CuCr30 contact material. The enhancement of longitudinal thermal conductivity is beneficial to reduce the mass loss of the contact material and improve the arc erosion resistance of the contact material. The mass loss of the cathode with higher longitudinal thermal conductivity is significantly lower than that of the anode contact in extruded CuCr30 contact material

    Stepwise Reduction and In Situ Loading of Coreā€Shelled Pt@Cu Nanocrystals on TiO2ā€“NTs for Highly Active Hydrogen Evolution

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    Abstract A flexible and mild fabricating protocol, i.e., stepwise reduction and in situ loading route, is proposed to modulate ordered growing and dispersive depositing of Pt@Cu bimetal layered nanostructure on titanium dioxide nanotubes (TiO2ā€NTs) via reasonably regulating addition sequence and dosage for the reactants and additives. Comprehensive characterizations demonstrate that most of the Cu coreā€Pt shell nanocrystals with a mean size of 10 nm evenly disperse on the surface of TiO2ā€NTs, and a small number of nanocrystals permeate into the nanotubes. In comparison to TiO2ā€NTs, the specific surface area declines after loading bimetals, with the pore size distribution shifting from micropores to mesopores. The catalytic activity of the Pt@Cu(x)/TiO2 for hydrolytic hydrogen evolution presents an increasing tendency as the bimetal loadings rise, each surpassing that of the bare bimetal nanocrystals. The H2 generating rate gradually rises with temperature increment. The AB hydrolysis catalyzed by Pt@Cu(9%)/TiO2 at the given temperatures (293ā€“313 K) is affirmed as a firstā€order reaction, with apparent activation energy of 28.43 kJ molāˆ’1 and TOF value of 107.27 mināˆ’1. The catalyst Pt@Cu(9%)/TiO2 unfolds exceptionally high stability, remaining 91% initial catalytic activity after five cycling use

    Effect of Ceramic Capillary Parameters on Bonded Morphology and Strength

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    The effects of the geometry parameters of a ceramic cleaver on the morphology of ball and second bonded points were studied using an automatic wire bonder, push pull tester, scanning electron microscope, ceramic capillary with different geometric parameters and &phi;25.4 &mu;mAg-5Au bonding alloy wire, etc. The result shows that when the inner hole diameter (IHD) of the ceramic capillary is 1.3 times the diameter of the alloy wire (33 &mu;m), the neck morphology of the ball bonded point (first bonded point) meet the requirements. The neck of the ball bonded point appeared to fracture when the IHD is 26 &mu;m; The neck of the ball bonded point appeared as an irregular shape when the IHD is 41 &mu;m. When the inner cutting angle diameter (ICAD) is 64 &mu;m, the size of the mashed ball diameter (MBD) is qualified. When the ICAD is 51 &mu;m, the MBD is too large and mashed ball overflows the pad. When the ICAD is 76 &mu;m, the ball bonded point is too high. When the inner cutting bevel angle (ICBA) is 100&deg;, the MBD size meets the requirements of the pad. When the ICBA was reduced to 70&deg;, the ball bonded point is eccentric. When the ICBA was increased to 120&deg;, the MBD is too large and is connected to the adjacent pad contact. The size of the fish tail of the second bonded point (second bonded point) changed in the same direction as the tip diameter (TD) changes. When the TD is 178 &mu;m, the fish tail shape is regular and symmetrical. When the working face angle (WFA) is 8&deg; and the outer circular radius (OCR) is equal to the diameter of the alloy wire (25.4 &mu;m), the fish tail shape is regular. When the WFA is higher than 11&deg; or the OCR is higher than 30 &mu;m, the fish tail will appear as virtual welding, and when the WFA is less than 4&deg;, the fish tail of the second bonded point will break due to thinning. When the OCR is less than 20 &mu;m, the fish tail of the second bonded point is too long and causes a short circuit
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