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

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

Thermo-kinetic understanding of the correlation between bainitic transformation and mechanical properties for bainitic steels

Phase transformations are feasible approaches for tailoring microstructures to achieve desired mechanical properties. However, the direct link between phase transformations and mechanical properties remains poorly studied. Here, using the theory of generalized stability (GS), we theoretically and experimentally correlate the bainitic transformation with the mechanical property of bainitic streels from a thermo-kinetic perspective. We established a quantitative relationship between the thermodynamic driving force and the yield strength, and explored the underlying physical correlation between the GS and the ductility. It is demonstrated that the thermodynamics-kinetics trade-off in the bainitic transformation inherently leads to the mutually exclusive relation between the yield strength and the uniform elongation. Specifically, a higher driving force generally results in an increased yield strength, while a larger GS tends to yield improved uniform elongation. Our findings provide fundamental insights into the relationship between the thermo-kinetics of bainitic transformation and mechanical properties, offering potential guidance for designing bainitic transformations to directly achieve superior mechanical performances

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

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

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 2–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 ± 0.61°C and fed with basal diet, while the 3 heat-stressed groups (A, B, and C groups) were housed at 30.5 ± 0.69°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), γ-glutamylcysteine synthetase (γ-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, γ-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, γ-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

Comparative Study of the Mechanical Properties and Fracture Mechanism of Ti-5111 Alloys with Three Typical Microstructures

In this work, Ti-5111 alloys with equiaxed, bimodal and lamellar microstructures were prepared by various heat treatment processes. The room-temperature tensile properties, deformation microstructure and fracture mechanism of the alloys with different microstructures were investigated. Furthermore, the mechanism by which the microstructure affects the mechanical properties of Ti-5111 alloys with three typical microstructures was confirmed. The Ti-5111 alloy with a bimodal microstructure has minimum grain size and a large number of αs/β phase boundaries, which are the primary reasons for its higher strength. Simultaneously, the excellent coordination in the deformation ability between the lamellar αs and β phases is what enables the alloy with a bimodal microstructure to have the most outstanding mechanical properties. Additionally, the presence of a grain boundary α phase and the parallel arrangement of a coarse αs phase are the main reasons for the inferior mechanical properties of the Ti-5111 alloy with a lamellar microstructure. The fracture mechanism of the alloy with an equiaxed microstructure is a mixed fracture mechanism including ductile fracture and destructive fracture. The fracture mechanisms of the Ti-5111 alloy with bimodal and lamellar microstructures are typical ductile fracture and cleavage fracture, respectively. These findings serve as a guide for the performance improvement and application of the Ti-5111 alloy

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

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 sarcoma–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

Effect of large deformation on microstructure and properties of copper alloy wire

Cu–Ag alloy wire with different deformations and Ag contents of 1%, 2%, and 4% are prepared using vacuum continuous casting technology combined with cold drawing and intermediate annealing processes. The evolution of microstructure, electrical properties, and mechanical properties of the Cu–Ag alloy wire is investigated, and a relationship model between wire diameter, Ag content, and alloy wire properties is established. The results showed that the directionally solidified billets exhibited good elongation and are suitable for drawing fine wire. As the Ag content increased, the twinning content inside the Cu–Ag alloy wire also increased significantly. It is found through Strain++ characterization that there is non-uniform deformation within the wire, and the tensile and compressive strains that exist interactively tend to aggregate within the twins. The properties of the Cu–Ag alloy wire with different diameters varied significantly at different stages of deformation, showing a pronounced size effect below 1 mm. With decreasing wire diameter or increasing Ag content, the DC resistance, resistivity, and tensile strength of the Cu–Ag alloy wire gradually increased, while the conductivity decreased. The effect of Ag content on elongation is not significant. Statistical analysis revealed that the established performance model had high predictive accuracy and could provide references for the optimization of production processes for Cu–Ag alloy wire