Low temperature soldering technology based on superhydrophobic copper microlayer.

Cu-Cu soldering is realized under certain pressure and low temperature conditions by using a surface silver film to modify the copper microlayer structure, thus solving the problems of high thermal stress and signal delay aggravation caused by high temperature in the traditional reflow soldering process. The copper microlayer modified with silver film is obtained by electrodeposition. The surface substructure of the Cu microlayer is a nano cone-shaped protrusion. The diameter of the bottom of the cone is 500 nm∼1 µm, and the height of the cone is 1∼2 µm. The thickness of the silver film is about 320 nm, and the modification of the copper layer with silver film can effectively prevent the oxidation of the copper layer. Two silver-modified copper microlayers are placed in face-to-face contact as a soldering couple. A certain pressure and low temperature are applied to the contact area to realize the soldering and interconnection. The morphology of the soldered interface and the average shear strength of the soldered joints are analyzed by scanning electron microscopy, transmission electron microscopy and solder joint tester. It is found that under the optimal soldering parameters of soldering temperature 220 °C, soldering pressure 20 MPa and soldering time 20 min, the nano-conical projections of the Cu micrometer layer are inserted into each other to produce a physical blocking effect. The highly surface-meltable silver film effectively connects the surrounding copper layer as an intermediate buffer layer. The average shear strength of soldering joints is significantly increased. Heat treatment experiments have shown that the average shear strength can be effectively increased by heat treatment for an appropriate period of time. Prolonged exposure to heat has little effect on the average shear strength. With the special morphology of the copper microlayer structure and the nano-size effect of the silver layer, soldering can be done at low temperatures. The quality of the soldering interface is good and small soldering dimensions can be obtained.

Narrow linewidth laser based on a sidewall grating active distributed Bragg reflector.

We demonstrated a narrow linewidth semiconductor laser based on a deep-etched sidewall grating active distributed Bragg reflector (SG-ADBR). The coupling coefficients and reflectance were numerically simulated for deep-etched fifth-order SG-ADBR, and a reflectance of 0.86 with a bandwidth of 1.04 nm was obtained by the finite element method for a 500-period SG-ADBR. Then the fifth-order SG-ADBR lasers were fabricated using projection i-line lithography processes. Single-mode lasing at 1537.9 nm was obtained with a high side-mode suppression ratio (SMSR) of 65 dB, and a continuous tuning range of 10.3 nm was verified with SMSRs greater than 53 dB. Furthermore, the frequency noise power spectral density was characterized, from which a Lorentzian linewidth of 288 kHz was obtained.

ProNet DB: a proteome-wise database for protein surface property representations and RNA-binding profiles.

The rapid growth in the number of experimental and predicted protein structures and more complicated protein structures poses a significant challenge for computational biology in leveraging structural information and accurate representation of protein surface properties. Recently, AlphaFold2 released the comprehensive proteomes of various species, and protein surface property representation plays a crucial role in protein-molecule interaction predictions, including those involving proteins, nucleic acids and compounds. Here, we proposed the first extensive database, namely ProNet DB, that integrates multiple protein surface representations and RNA-binding landscape for 326 175 protein structures. This collection encompasses the 16 model organism proteomes from the AlphaFold Protein Structure Database and experimentally validated structures from the Protein Data Bank. For each protein, ProNet DB provides access to the original protein structures along with the detailed surface property representations encompassing hydrophobicity, charge distribution and hydrogen bonding potential as well as interactive features such as the interacting face and RNA-binding sites and preferences. To facilitate an intuitive interpretation of these properties and the RNA-binding landscape, ProNet DB incorporates visualization tools like Mol* and an Online 3D Viewer, allowing for the direct observation and analysis of these representations on protein surfaces. The availability of pre-computed features enables instantaneous access for users, significantly advancing computational biology research in areas such as molecular mechanism elucidation, geometry-based drug discovery and the development of novel therapeutic approaches. Database URL:  https://proj.cse.cuhk.edu.hk/aihlab/pronet/.

Deep Learning-Based construction of a Drug-Like compound database and its application in virtual screening of HsDHODH inhibitors.

The process of virtual screening relies heavily on the databases, but it is disadvantageous to conduct virtual screening based on commercial databases with patent-protected compounds, high compound toxicity and side effects. Therefore, this paper utilizes generative recurrent neural networks (RNN) containing long short-term memory (LSTM) cells to learn the properties of drug compounds in the DrugBank, aiming to obtain a new and virtual screening compounds database with drug-like properties. Ultimately, a compounds database consisting of 26,316 compounds is obtained by this method. To evaluate the potential of this compounds database, a series of tests are performed, including chemical space, ADME properties, compound fragmentation, and synthesizability analysis. As a result, it is proved that the database is equipped with good drug-like properties and a relatively new backbone, its potential in virtual screening is further tested. Finally, a series of seedling compounds with completely new backbones are obtained through docking and binding free energy calculations.

Interfacial reaction of Sn-1.5Ag-2.0Zn low-silver lead-free solder with oriented copper.

High density packaging technology reduces the pad size and the number of grains contained in the pad. When the polycrystalline pad turns into a single crystal pad, the grain orientation has an important impact on the formation of the intermetallic compound (IMC) at the interface. The growth of IMC at the interface between the solder and the single-crystal copper substrate is investigated by selecting the prospective Sn-1.5Ag-2Zn as the solder alloy. Sn-1.5Ag-2.0Zn lead-free solder joints soldered with single crystal (111) copper substrate and polycrystalline red copper substrate are reflowed at 250 °C for 5 min. Samples are subsequently aged at 160 °C. The uneven scallop like Cu6Sn5 IMC layer grows rapidly when the alloy solder contacts with the copper substrate. The Cu6Sn5 grain size formed on the surface of single crystal copper is larger than that of polycrystalline copper. Single crystal copper has no grain boundary to block atomic diffusion, which affects grain nucleation and growth. The growth rate of Cu6Sn5 formed by alloy solder and the single crystal (111) copper solder joint after aging treatment at 160 °C for 20 h is about twice that of the polycrystalline copper solder joint. Then it grows slowly with the increase of aging treatment time. The thick layer Cu6Sn5 breaks due to crack diffusion after 600 h of aging treatment, and the thickness of IMC remains at 3.5 µm. Cu5Zn8 generated at the solder and polycrystalline copper solder joint during aging treatment acts as a barrier layer, preventing the solder from contacting the copper substrate and inhibiting the formation of Cu6Sn5. Cu5Zn8 is broken and decomposed after 300 h of aging treatment, and Cu6Sn5 grows rapidly after the barrier layer disappeared. The thickness of Cu6Sn5 is about 2.8 µm. The thickness of IMC of solder joint on single crystal copper is 0.7 µm more than that on polycrystalline copper. After aging treatment, the IMC formed at the interface between alloy solder and single crystal copper has better compactness and basically no pores, while there are obvious pores between IMC grains at the interface between alloy solder and polycrystalline copper, which can predict that the soldering quality of the interface between alloy solder and single crystal copper is better. This will provide application prospects for solder joint interface reliability research.

Predictive value of coagulation function, alpha-fetoprotein and placental growth factor in patients with perilous placenta previa.

OBJECTIVE: To analyze the predictive value of coagulation function, alpha-fetoprotein (AFP) and placental growth factor (PIGF) for postpartum hemorrhage in patients with perilous placenta previa (PPP). METHODS: The clinical data of 104 PPP patients were retrospectively analyzed. The patients were divided into a hemorrhage group (n=68) and a non-hemorrhage group (n=36). A total of 55 healthy pregnant women were recruited as controls. The coagulation function, AFP and PIGF were compared between the three groups. Multivariate logistic regression was performed to determine independent risk factors for hemorrhage. RESULTS: PT, TT, APTT, FIB and AFP were significantly higher while PIGF was lower in the PPP group than the control group (all P<0.05). Placental adhesion (OR 3.924, 95% CI 1.389-11.083, P=0.01), anterior placenta (OR 4.583, 95% CI 1.589-13.22, P=0.005), AFP (OR 0.208, 95% CI 0.068-0.635, P=0.006) and PIGF (OR 3.963, 95% CI 1.385-11.34, P=0.01) were independent risk factors for hemorrhage. CONCLUSION: Coagulation function, AFP and PIGF could predict postpartum hemorrhage in PPP patients.

Identification and genetic characterization of a recently identified enterovirus C116 in China.

Enterovirus C116 (EV-C116) is a new member of the enterovirus C group which is closely associated with several infectious diseases. Although sporadic studies have detected EV-C116 in clinical samples worldwide, there is currently limited information available. In this study, two EV-C-positive fecal specimens were detected in apparently healthy children, which harbored low abundance, through meta-transcriptome sequencing. Based on the prototypes of several EV-Cs, two lineages were observed. Lineage 1 included many types that could not cause EV-like cytopathic effect in cell culture. Three genogroups of EV-C116 were divided in the maximum likelihood tree, and the two strains in this study (XZ2 and XZ113) formed two different lineages, suggesting that EV-C116 still diffuses worldwide. Obvious inter-type recombination events were observed in the XZ2 strain, with CVA22 identified as a minor donor. However, another strain (XZ113) underwent different recombination situations, highlighting the importance of recombination in the formation of EV-Cs biodiversity. The EV-C116 strains could propagate in rhabdomyosarcoma cell cultures at low titer; however, EV-like cytopathic effects were not observed. HEp-2, L20B, VERO, and 293T cell lines did not provide an appropriate environment for EV-C116 growth. These results challenge the traditional recognition of the uncultured nature of EV-C116 strains and explain the difficulty of clinical detection.

The Effects of Occupation, Education and Dwelling Place on Attitudes towards Animal Welfare in China.

Attitudes to animal welfare are not understood well in China, the country with the highest output of farm animals in the world. We surveyed attitudes of the public around China using a team of researchers to conduct individual interviews, with 1301 respondents in total. Contrary to results obtained in several other countries, high school leavers were more concerned about animal welfare than those who had obtained a university degree. We speculate that this may reflect the labour market currently existing in China, with limited opportunities for graduates. Scientists were less supportive, and artists more supportive, of good animal welfare. Urban dwellers were more concerned about animal welfare than rural residents, with village residents in the middle, which confirmed our theory that such a difference prevails in developing countries, where a large proportion of the rural population are involved in agriculture. It is concluded that education level, occupation and living place all have pronounced influences on attitudes to animal welfare in China, some of which follow international trends.

UiO-66 nanoparticles combat influenza A virus in mice by activating the RIG-I-like receptor signaling pathway.

The Influenza A virus (IAV) is a zoonotic pathogen that infects humans and various animal species. Infection with IAV can cause fever, anorexia, and dyspnea and is often accompanied by pneumonia characterized by an excessive release of cytokines (i.e., cytokine storm). Nanodrug delivery systems and nanoparticles are a novel approach to address IAV infections. Herein, UiO-66 nanoparticles (NPs) are synthesized using a high-temperature melting reaction. The in vitro and in vivo optimal concentrations of UiO-66 NPs for antiviral activity are 200 µg mL-1 and 60 mg kg-1, respectively. Transcriptome analysis revealed that UiO-66 NPs can activate the RIG-I-like receptor signaling pathway, thereby enhancing the downstream type I interferon antiviral effect. These NPs suppress inflammation-related pathways, including the FOXO, HIF, and AMPK signaling pathways. The inhibitory effect of UiO-66 NPs on the adsorption and entry of IAV into A549 cells is significant. This study presents novel findings that demonstrate the effective inhibition of IAV adsorption and entry into cells via UiO-66 NPs and highlights their ability to activate the cellular RIG-I-like receptor signaling pathway, thereby exerting an anti-IAV effect in vitro or in mice. These results provide valuable insights into the mechanism of action of UiO-66 NPs against IAV and substantial data for advancing innovative antiviral nanomedicine.

Anti-Cariogenic Effects of S. cerevisiae and S. boulardii in S. mutans-C. albicans Cross-Kingdom In Vitro Models.

Despite the well-documented health benefits of the probiotic Saccharomyces, its application in oral health has not been comprehensively assessed. Dental caries is a transmissible disease initiated by acid production of cariogenic bacteria and yeast, such as Streptococcus mutans and Candida albicans, on tooth enamel and followed by subsequent enamel demineralization. Here, we investigated the effect of two Saccharomyces strains (Saccharomyces boulardii and Saccharomyces cerevisiae) on S. mutans-C. albicans cross-kingdom interactions using a cariogenic planktonic model. Viable cells, pH changes, and gene expression were measured. S. cerevisiae and S. boulardii inhibited the growth of C. albicans in dual- and multi-species conditions at 4, 6, and 20 h. Saccharomyces also inhibited C. albicans hyphal formation. Furthermore, Saccharomyces reduced the acidity of the culture medium, which usually plummeted below pH 5 when S. mutans and C. albicans were present in the model. The presence of Saccharomyces maintained the culture medium above 6 even after overnight incubation, demonstrating a protective potential against dental enamel demineralization. S. boulardii significantly down-regulated S. mutans atpD and eno gene expression. Overall, our results shed light on a new promising candidate, Saccharomyces, for dental caries prevention due to its potential to create a less cariogenic environment marked by a neutral pH and reduced growth of C. albicans.

Characterization of sucrose nonfermenting-1-related protein kinase 2 (SnRK2) gene family in Haynaldia villosa demonstrated SnRK2.9-V enhances drought and salt stress tolerance of common wheat.

BACKGROUND: The sucrose nonfermenting-1-related protein kinase 2 (SnRK2) plays a crucial role in responses to diverse biotic/abiotic stresses. Currently, there are reports on these genes in Haynaldia villosa, a diploid wild relative of wheat. RESULTS: To understand the evolution of SnRK2-V family genes and their roles in various stress conditions, we performed genome-wide identification of the SnRK2-V gene family in H. villosa. Ten SnRK2-V genes were identified and characterized for their structures, functions and spatial expressions. Analysis of gene exon/intron structure further revealed the presence of evolutionary paths and replication events of SnRK2-V gene family in the H. villosa. In addition, the features of gene structure, the chromosomal location, subcellular localization of the gene family were investigated and the phylogenetic relationship were determined using computational approaches. Analysis of cis-regulatory elements of SnRK2-V gene members revealed their close correlation with different phytohormone signals. The expression profiling revealed that ten SnRK2-V genes expressed at least one tissue (leave, stem, root, or grain), or in response to at least one of the biotic (stripe rust or powdery mildew) or abiotic (drought or salt) stresses. Moreover, SnRK2.9-V was up-regulated in H. villosa under the drought and salt stress and overexpressing of SnRK2.9-V in wheat enhanced drought and salt tolerances via enhancing the genes expression of antioxidant enzymes, revealing a potential value of SnRK2.9-V in wheat improvement for salt tolerance. CONCLUSION: Our present study provides a basic genome-wide overview of SnRK2-V genes in H. villosa and demonstrates the potential use of SnRK2.9-V in enhancing the drought and salt tolerances in common wheat.

Small Extracellular Vesicles Released from miR-211-5p-Overexpressed Bone Marrow Mesenchymal Stem Cells Ameliorate Spinal Cord Injuries in Rats.

Spinal cord injury (SCI) has become one of the common and serious diseases affecting patients' motor functions. The small extracellular vesicles secreted by bone marrow mesenchymal stem cells (BMSCs) have shown a promising prospect for the treatment of neurological diseases. BMSCs were collected from rat bones. Osteogenic and adipogenic differentiation of BMSCs was further determined. Small extracellular vesicles were obtained by high-speed centrifugation. Dual-luciferase reporter assay was performed to demonstrate the targeting of miR-211-5p to the cyclooxygenase 2 (COX2) mRNA. qRT-PCR and Western blot assay were used for the detection of the mRNA and protein expression. ELISA was performed to estimate the levels of proinflammatory factors in spinal cord tissues. Our results showed that miR-211-5p targeted COX2 mRNA and regulated the protein expression of COX2 in BMSCs. Extracellular vesicles released from miR-211-5p-overexpressed BMSCs ameliorated SCI-induced motor dysfunction and motor evoked potential impairments. Extracellular vesicles released from miR-211-5p-overexpressed BMSCs ameliorated SCI-induced COX2 expression and related inflammatory responses. In conclusion, small extracellular vesicles released from miR-211-5p-overexpressed BMSCs ameliorate spinal cord injuries in rats.

Evolution of the SARS-CoV-2 Omicron Variants: Genetic Impact on Viral Fitness.

Over the last three years, the pandemic of COVID-19 has had a significant impact on people's lives and the global economy. The incessant emergence of variant strains has compounded the challenges associated with the management of COVID-19. As the predominant variant from late 2021 to the present, Omicron and its sublineages, through continuous evolution, have demonstrated iterative viral fitness. The comprehensive elucidation of the biological implications that catalyzed this evolution remains incomplete. In accordance with extant research evidence, we provide a comprehensive review of subvariants of Omicron, delineating alterations in immune evasion, cellular infectivity, and the cross-species transmission potential. This review seeks to clarify the underpinnings of biology within the evolution of SARS-CoV-2, thereby providing a foundation for strategic considerations in the post-pandemic era of COVID-19.

The Effects of Housing on Growth, Immune Function and Antioxidant Status of Young Female Lambs in Cold Conditions.

Cold conditions in northern China during winter may reduce sheep growth and affect their health, especially if they are young, unless housing is provided. We allocated 45 two-month-old female lambs to be housed in an enclosed building, a polytunnel, or kept outdoors, for 28 days. The daily weight gain and scalp and ear skin temperature of outdoor lambs were less than those of lambs that were housed in either a house or polytunnel; however, rectal temperature was unaffected by treatment. There was a progressive change in blood composition over time, and by the end of the experiment, outdoor lambs had reduced total antioxidant capacity (T-AOC), catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) and increased malondialdehyde compared to those in the house or polytunnel. In relation to immune responses in the lambs' serum, in the polytunnel, immunoglobulin A (IgA), tumor necrosis factor-α (TNF-α) and interleukin-4 (IL-4) were higher and immunoglobulin G (IgG) lower compared with the concentrations in lambs that were outdoors. Over the course of the experiment, genes expressing heat shock proteins and antioxidant enzymes increased in lambs in the outdoor treatment, whereas they decreased in lambs in the indoor treatments. It is concluded that although there were no treatment effects on core body temperature, the trends for progressive changes in blood composition and gene expression indicate that the outdoor lambs were not physiologically stable; hence, they should not be kept outdoors in these environmental conditions for long periods.

Using scanning electron microscopy and molecular data to discover a new species from old herbarium collections: The case of Phlomoideshenryi (Lamiaceae, Lamioideae).

Phlomoides is one of the largest genera of Lamiaceae with approximately 150-170 species distributed mainly in Eurasia. In this study, we describe and illustrate a new species, P.henryi, which was previously misidentified as P.bracteosa, from Yunnan Province, southwest China. Molecular phylogenetic analyses revealed that P.henryi is found within a clade in which most species lack basal leaves. In this clade, the new species is morphologically distinct from P.rotata in having an obvious stem and, from the rest, by having transparent to white trichomes inside the upper corolla lip. In addition, micro-features of trichomes on the calyx and leaf epidermis can differentiate the new species from other species grouped in the same clade and a key, based on trichome morphology for these species, is provided. The findings demonstrate that the use of scanning electron microscopy can reveal inconspicuous morphological affinities amongst morphologically similar species and play an important role in the taxonomic study of the genus Phlomoides.

Predictive visual field outcomes after optic chiasm decompressive surgery by retinal vessels parameters using optical coherence tomography angiography.

AIM: To evaluate the predictive value of superficial retinal capillary plexus (SRCP) and radial peripapillary capillary (RPC) for visual field recovery after optic cross decompression and compare them with peripapillary nerve fiber layer (pRNFL) and ganglion cell complex (GCC). METHODS: This prospective longitudinal observational study included patients with chiasmal compression due to sellar region mass scheduled for decompressive surgery. Generalized estimating equations were used to compare retinal vessel density and retinal layer thickness pre- and post-operatively and with healthy controls. Logistic regression models were used to assess the relationship between preoperative GCC, pRNFL, SRCP, and RPC parameters and visual field recovery after surgery. RESULTS: The study included 43 eyes of 24 patients and 48 eyes of 24 healthy controls. Preoperative RPC and SRCP vessel density and pRNFL and GCC thickness were lower than healthy controls and higher than postoperative values. The best predictive GCC and pRNFL models were based on the superior GCC [area under the curve (AUC)=0.866] and the tempo-inferior pRNFL (AUC=0.824), and the best predictive SRCP and RPC models were based on the nasal SRCP (AUC=0.718) and tempo-inferior RPC (AUC=0.825). There was no statistical difference in the predictive value of the superior GCC, tempo-inferior pRNFL, and tempo-inferior RPC (all P>0.05). CONCLUSION: Compression of the optic chiasm by tumors in the saddle area can reduce retinal thickness and blood perfusion. This reduction persists despite the recovery of the visual field after decompression surgery. GCC, pRNFL, and RPC can be used as sensitive predictors of visual field recovery after decompression surgery.

Multigenerational paternal obesity enhances the susceptibility to male subfertility in offspring via Wt1 N6-methyladenosine modification.

There is strong evidence that obesity is a risk factor for poor semen quality. However, the effects of multigenerational paternal obesity on the susceptibility to cadmium (a reproductive toxicant)-induced spermatogenesis disorders in offspring remain unknown. Here, we show that, in mice, spermatogenesis and retinoic acid levels become progressively lower as the number of generations exposed to a high-fat diet increase. Furthermore, exposing several generations of mice to a high fat diet results in a decrease in the expression of Wt1, a transcription factor upstream of the enzymes that synthesize retinoic acid. These effects can be rescued by injecting adeno-associated virus 9-Wt1 into the mouse testes of the offspring. Additionally, multigenerational paternal high-fat diet progressively increases METTL3 and Wt1 N6-methyladenosine levels in the testes of offspring mice. Mechanistically, treating the fathers with STM2457, a METTL3 inhibitor, restores obesity-reduced sperm count, and decreases Wt1 N6-methyladenosine level in the mouse testes of the offspring. A case-controlled study shows that human donors who are overweight or obese exhibit elevated N6-methyladenosine levels in sperm and decreased sperm concentration. Collectively, these results indicate that multigenerational paternal obesity enhances the susceptibility of the offspring to spermatogenesis disorders by increasing METTL3-mediated Wt1 N6-methyladenosine modification.

Effects of glutaraldehyde and povidone-iodine on apoptosis of grass carp liver and hepatocytes.

Since disinfectants are used all over the world to treat illnesses in people and other animals, they pose a major risk to human health. The comprehensive effects of disinfectant treatments on fish liver, especially the impacts on oxidative stress, toxicological effects, transcriptome profiles, and apoptosis, have not yet been fully analyzed. In the current investigation, healthy grass carp were exposed to 80 µg/L glutaraldehyde or 50 µg/L povidone-iodine for 30 days. First, the findings of enzyme activity tests demonstrated that the administration of glutaraldehyde could considerably increase oxidative stress by lowering T-SOD, CAT, and GPx and raising MDA. Furthermore, KEGG research revealed that exposure to glutaraldehyde and povidone-iodine stimulated the PPAR signal pathway. To further elucidate the transcriptome results, the relative expressions of related DEGs in the PPAR signal pathway were verified. Glutaraldehyde induced apoptosis in liver tissue of grass carp; however, it activated cytotoxicity and apoptosis in grass carp hepatocytes when exposed to glutaraldehyde or povidone-iodine. According to the current study, disinfectants can cause the impairment of the immune system, oxidative stress, and attenuation of the PPAR signal pathway in the liver of grass carp, making them detrimental as dietary supplements for grass carp, particularly in the aquaculture sector.