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The inferior creep ductility of Inconel 718 (IN718) fabricated by selective laser melting (SLM), which is unable to meet aerospace material specification (≥4%), limits its engineering application. Despite persistent optimization efforts in the SLM process and post-heat treatment, this issue remains unresolved. This study involved SLM fabrication of the modified IN718 with trace amounts of LaB6 and/or P, followed by homogenization and double aging heat treatment. The addition of trace LaB6 notably influenced the recrystallized grain structure and carbide precipitation at grain boundaries, while trace P addition had minimal impact. All samples exhibited similar γ′ and γ″ strengthening precipitates. Creep tests conducted at 650°C/690 MPa revealed that the individual modification of LaB6 showed limited improvement in creep performance and P showed no improvement, but the combined addition of LaB6 and P led to a substantial enhancement in creep performance, especially reaching as high as 8.6% creep strain. This remarkable improvement in creep ductility is unlikely to arise from the altered grain structure and grain boundary precipitates induced by LaB6 but predominantly arises from the synergistic effect of P and B in enhancing resistance to crack propagation during the third stage of creep.

BackgroundEffective prevention is key to addressing the increasing prevalence and mortality of Alzheimer’s disease. Assessing the causal relationship between modifiable entertainment activity factors and the risk of Alzheimer’s disease is important for developing public health measures, but establishing causal relationships in epidemiological data may be challenging.MethodsThis study using the two-sample Mendelian randomization analysis aimed to investigate the causal effect of entertainment activity factors on the risk of Alzheimer’s disease. Summary statistics from publicly available genome-wide association studies were used to analyze 14 modifiable entertainment activity. The inverse variance weighted random effects method as the primary analytical method to estimate causal effects was used. Additionally performed MR-Egger, weighted median and weighted model methods to assess the robustness of the results. The reliability of our findings was validated through systematic sensitivity analyses and tests for heterogeneity.ResultsWe found significant correlation between time spent using computer (odds ratio 0.998; 95% confidence interval 0.996–0.999; p = 0.013) and Alzheimer’s disease, compared to other studied entertainment activities that had no significant causal relationship with Alzheimer’s disease.ConclusionOur findings support the hypothesis that increased computer use may reduce the risk of Alzheimer’s disease, providing potential strategic directions for the prevention of neurodegenerative diseases.

Objective To explore the the potential risks of antiretroviral therapy(ART) drugs on blood safety among blood donors in Shenzhen. Methods High pressure liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was used to measure ART drugs concentrations in the plasma of regular blood donors (negative control group, n=86) and anti-HIV positive individuals (experimental group, n=98, detected from approximately 440 000 blood donors during 2019—2023). The baseline plasma concentrations of ART drugs in the negative control group were clarified, and the impact of ART drugs on blood safety was analyzed. Results The baseline concentrations of ART drugs were not detected in 86 samples of negative control group. Four positive ART drugs samples were detected in 1∶2 pooled plasma samples of 98 anti-HIV positive blood donors plasma in the resolution test. The ART positive rate of anti-HIV positive donors was 4.08%, with tenofovir, lamivudine and efavirenz detected in three blood donors and lamivudine, lopinavir, ritonavir and zidovudine detected in one blood donor. Conclusion ART drugs were found among anti-HIV positive blood donors in Shenzhen. Additional research is needed to investigate the motivation of these specific donors, so as to ascertain the groups most susceptible to potential risks, and guarantee blood safety.

Objective To analyze the results of different methods for reactive samples screened by the enzyme linked immunosorbent assay (ELISA) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in blood donors. Methods From March to April 2020, a total of 8 632 blood samples in Shenzhen were screened for SARS-CoV-2 total antibodies (TAb, including IgG, IgM, IgA) in plasma using ELISA(PC group), the antibody reactivity samples and their follow up plasma samples (FC group), and samples of disease control group(DC group) from January to April 2020 were detected using the following methods: 1) ELISA method for detecting IgG, IgM, and (or without detection) TAb; 2) pseudovirus neutralizing antibody test(pVNT); 3) western blot (WB) of SARS-CoV-2 antibody. The negative control group(NC group) from February to April 2020 performed ELISA and WB testing. Results Among the 34 total antibody positive samples, 2 were positive for pVNT test, and the total antibody, IgG and WB in the initial screening and tracking testing were positive. Thereafter, it was determined to be confirmed positive. The other 2 cases were positive for pVNT test, while the samples with positive WB results were in the follow-up stage. The TAb, IgG, and pVNT results did not conform to the dynamic evolution of antibodies, and cannot be determined as confirmed positive. Conclusion The infection status of antibody reactivity samples screened by SARS-CoV-2 ELISA can be judged by the logic of pVNT, WB and the dynamic change of antibody.

Objective To establish a magnetic bead enrichment strategy for the detection of human immunodeficiency virus deoxyribonucleic acid (HIV DNA) in peripheral blood, and to verify the improvement of the sensitivity of this method for the detection of HIV DNA in HIV infected patients after early antiretrovital treatment (ART). Methods Peripheral whole blood was collected at 4 timepoints in one ART HIV window period (WP) patient. Peripheral blood mononuclear cells (PBMCs) were isolated on a Ficoll gradient. CD4+ T lymphocytes were enriched from total PBMCs by negative sorting. HIV DNA concentration in magnetic beads enriched group and whole blood group was detected by HIV DNA detection kit. Results CD4+ T cells were isolated by magnetic beads and identified by FCM for purity at (96.4 ± 2.6)%. The viability was (95.9 ± 2.9)%, as demonstrated by trypan blue staining. The person on continued ART treatment in this study had significantly greater reduction in HIV viral load and undetectable HIV plasma RNA at follow up timepoint 4. No HIV DNA was detected in the whole blood group at all 4 timepoints. The quantitative results of HIV DNA in the CD4+ T lymphocyte group of the magnetic bead enrichment group were 73.4, 429.3, 137.1, 449.9 copies/106 CD4+ T cell′s respectively. Conclusion The magnetic bead enrichment method can be more sensitive in detecting the limit low copy HIV DNA in blood samples, and provide early confirmatory data for HIV WP infection and breakthrough infection after ART treatment.

Objective To analyze the SARS-CoV-2 detection results among blood donors in different periods of COVID-19 pandemic control in Shenzhen and assess the antibody levels and infection status of blood donors in different periods, so as to provide reference for subsequent blood testing strategies. Methods A total of 4 768 plasma samples of blood donors were subjected to pooled testing by nucleic acid testing(NAT) with 8 samples per pool. Additionally, these samples were subjected to a 1000-fold dilution, and the detection of SARS-CoV-2 total antibody was performed by enzyme-linked immunosorbent assay (ELISA). The 4 768 plasma samples were collected from blood donors at different time points in Shenzhen, with inquiries made to determine whether donors during the COVID-19 pandemic were in the convalescence. The antibody positive rates in blood screening samples during different periods of the pandemic and samples from individuals in the convalescence of COVID-19 infection were analyzed. Furthermore, the antibody levels were examined for differences based on gender, age, and blood type. Results All 4 768 plasma samples from blood donors were negative by NAT, while 2 342 samples were detected positive by the SARS-CoV-2 total antibody detection, with a positive rate of 49.1%. These samples from four periods (September 30 to October 3, 2022; November 3 to 6, 2022; December 27 to 31, 2022; January 6 to 18, 2023) were subjected to a 1 000-fold dilution for COVID-19 antibody detection, and the positive rates were 21.3%, 15.8%, 65.9%, and 93.9%, respectively. Conclusion The prevalence of COVID-19 antibodies among blood donors in Shenzhen during different periods of the pandemic varied significantly. There was no difference in antibody prevalence among different genders and blood types, while younger individuals exhibited a higher prevalence of antibodies. The risk of COVID-19 transmission through blood transfusion was found to be extremely low.

The achievement of fine equiaxed β grain with conventional intragranular (α-Ti+β-Ti) microstructure in additive manufacturing titanium alloy remains a big challenge. We conquer this challenge by synergistically controlling β-grains during both solidification and subsequent thermal-cycles of laser directed energy deposition (DED), and a solution + quenching heat-treatment. Both the strength and plasticity of heat-treated Ti6Al4V3Ni0.05B are superior to those reported new DED titanium alloy and comparable to that of DED Ti6Al4V, because of the fine-equiaxed β-grains with intragranular (α-Ti+β-Ti) microstructure. These findings provide new insight into the grain structure control and the composition design of AM titanium alloy.

Understanding the dynamics of grain boundaries and their melting behaviour is important for controlling the mechanical properties of materials. Now, experiments show that grain boundaries can be superheated, and that they melt via a nucleation mechanism.

Objective To assess three severe acute respiratorysyndrome coronavirus 2 (SARS-CoV-2) enzyme linked immunosorbent assays (ELISA) and one pseudotype lentivirus-based neutralization test (ppNAT) in detecting the convalescent plasma antibody levles from COVID-19. Methods 30 COVID-19 convalescent plasma samples were screened for antibodies against SARS-CoV-2 using three kinds of SARS-CoV-2 ELISA reagents and one ppNAT test in Shenzhen. The controls consisted of plasma samples from 32 healthy blood donors in February 2019. The diagnostic efficacy analysis of various SARS-CoV-2 ELISA reagents was performed using real-time fluorescent Polymerase Chain Reaction (RT-PCR). We also analyzed correlation between different immunological reagents and the age, gender, hospitalization, and severity of illness. Results The positive yielding rate of ppNAT and three kinds of IgG ELISA was higher than that of IgM ELISA. The positive yielding rates of three kinds of IgG ELISA were 100%(30/30), 93.33%(28/30), and 96.67%(29/30) respectively, while the yielding rates in control group were all 0. The positive yielding rate of three IgM ELISAs were 93.33%(28/30), 70%(21/30)and 46.67% (14/30). All the cases from negative control group were negative for IgG and IgM. Pearson correlation coefficient was calculated; there was a strong correlation between ELISA reagent 2 IgG and ELISA reagent 3 IgG (r=0.765, P0.05). Conclusion In the convalescent plasma with nucleic acid confirmed covid-19, the yielding rates of different IgM antibodies varied greatly. Antibody levels were influenced by age to some extent.

Objective To evaluate the performance and clinical application of a high-throughput nucleic acid blood screening detection system for SARS-CoV-2, so as to provide basis and technical means for its application in detection of plasma from recovered COVID-19 patients. Methods The SARS-CoV-2 nucleic acid was detected by real-time fluorescence quantitative PCR, and the sensitivity, precision, anti-interference and other parameters were evaluated. Blood donor samples collected during COVID-19 epidemic period were screened using the detection system to evaluate its applicability. Results The detection limits of gene N and ORF 1ab were 3.98 copies/mL and 9.38 copies/mL, respectively. The CV of high and low concentration samples were both less than 5%. Hemoglobin at 500 mg/dL and triglyceride at 3g/dL had little effect on the results. The detection system can effectively prevent carryover, thus avoiding false positive results. The SARS-CoV-2 nucleic acid blood screening was carried out in a total of 39 306 blood samples, and all samples were negative. Conclusion The established method can meet the needs of SARS-CoV-2 nucleic acid screening therefore ensure the safe application of plasma from recovered COVID-19 patients.

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) can integrate viral DNA into host cell chromosomes to establish a long-term stable latent reservoir, which is a major obstacle to cure HIV-1 infection. The characteristics of the HIV-1 latent reservoir have not been fully understood. Here, we identified 126 upregulated plasma membrane proteins in HIV-1 latently infected cells by a label-free liquid chromatography-tandem mass spectrometry analysis. The higher levels of CD98 expression in multiple HIV-1 latently infected cell lines and primary CD4+ T cells compared to uninfected cells were further confirmed by quantitative reverse transcription PCR (RT-qPCR) and flow cytometry analyses. In addition, CD98high CD4+ T cells displayed hyper-permissiveness to HIV-1 infection and possessed distinct immune phenotypic profiles associated with Th17 and peripheral follicular T helper (pTFH) characteristics. Notably, the CD98high resting memory CD4+ T cells harbored significantly higher cell-associated viral RNA and intact provirus than CD98low counterparts in HIV-1-infected individuals receiving combined antiretroviral therapy. Furthermore, CD98high CD4+ T cells exhibited a robust proliferative capacity and significantly contributed to the clonal expansion of the HIV-1 latent reservoir. Our study demonstrates that CD98 can be used as a novel biomarker of HIV-1 latently infected cells to indicate the effect of various strategies to reduce the viral reservoir. IMPORTANCE Identification of cellular biomarkers is the crucial challenge to eradicate the HIV-1 latent reservoir. In our study, we identified CD98 as a novel plasma membrane biomarker for HIV-1 permissiveness and latent infection. Importantly, CD98high CD4+ T cells exhibited a hyper-permissiveness to HIV-1 infection and significantly contributed to the clonal expansion of the HIV-1 latent reservoir. CD98 could be targeted to develop therapeutic strategies to reduce the HIV-1 latent reservoir in further research.

In this study, a new p-y model is proposed for the seismic loading prediction of pile foundations using the Beam on Nonlinear Winkler Foundation (BNWF) method. It matches the desired modulus reduction curve by identifying three parameters in a hyperbolic function and a linear function using a genetic algorithm (GA), and the desired damping curve by applying the Ishihara-Yoshida rule that controls the unloading–reloading curves iteratively through the three parameters. The rate effect is integrated into the proposed PySimple5 model for clay by exerting influence on the ultimate capacity and maximum material damping through a power function, while the pore pressure effect is reflected in the proposed Pyliq5 model for sand by relating the ultimate capacity to the mean effective stress. For a single pile in non-liquefiable soil, the predicted superstructure acceleration and pile bending moment by PySimple5 agree well with those from centrifuge tests for different soil shear strain levels, while the equivalent linear and PySimple1 models underestimate them for soil shear strain levels higher than 1%. For a pile in liquefiable soil, PyLiq5 shows a reasonable agreement with the centrifuge tests in terms of the superstructure acceleration and pile bending moment by considering the pore pressure effect.

Here, the authors determine seroprevalence of antibodies to SARS-CoV-2 in healthy blood donors in the cities of Wuhan, Shenzhen, and Shijiazhuang in China between January and April 2020. The age- and sex-standardized SARS-CoV-2 seroprevalence among 18–60 year-old adults is, with 2.66%, the highest in Wuhan.

Abstract Background Human T-cell lymphotropic virus (HTLV) remains a major safety concern for blood supplies. Despite many HTLV positive cases being reported in southeastern China, the detection of HTLV has not been prioritized in routine blood screening. Additionally, data on the prevalence of HTLV infection among blood donors is also limited. The objective of this study was to investigate the prevalence of HTLV among blood donors in three Chinese provinces through their representative blood centers, to evaluate the feasibility of chemiluminescence immunoassay (CLIA) for blood screening. Methods From November 2018 to March 2019, blood plasma samples were collected from Hebei, Changsha, and Shenzhen blood centers and were screened for the HTLV-1/2 antibody using a CLIA and enzyme-linked immunosorbent assay (ELISA). This was followed by confirmatory tests using INNO-LIA HTLV I/II. Results A total of 59,929 blood donations were collected and screened for HTLV-1/2. The reactive rate of CLIA and ELISA among donations in the Shenzhen blood center (0.0943%, 27/28,621) was higher than Hebei (0.0248%, 4/16,144), and Changsha (0.0198%, 3/15,164) (p

Abstract Background Pinellia ternata is a Chinese traditional medicinal herb, used to cure diseases including insomnia, eclampsia and cervical carcinoma, for hundreds of years. Non-self-recognition in multicellular organisms can initiate the innate immunity to avoid the invasion of pathogens. A design for pathogen independent, heterosis based, fresh resistance can be generated in F1 hybrid was proposed. Results By library functional screening, we found that P. ternata genes, named as ptHR375 and ptHR941, were identified with the potential to trigger a hypersensitive response in Nicotiana benthamiana. Significant induction of ROS and Callose deposition in N. benthamiana leaves along with activation of pathogenesis-related genes viz.; PR-1a, PR-5, PDF1.2, NPR1, PAL, RBOHB and ERF1 and antioxidant enzymes was observed. After transformation into N. benthamiana, expression of pathogenesis related genes was significantly up-regulated to generate high level of resistance against Phytophthora capsici without affecting the normal seed germination and morphological characters of the transformed N. benthamiana. UPLC-QTOF-MS analysis of ptHR375 transformed N. benthamiana revealed the induction of Oxytetracycline, Cuelure, Allantoin, Diethylstilbestrol and 1,2-Benzisothiazol-3(2H)-one as bioactive compounds. Here we also proved that F1 hybrids, produced by crossing of the ptHR375 and ptHR941 transformed and non-transformed N. benthamiana, show significant high levels of PR-gene expressions and pathogen resistance. Conclusions Heterologous plant genes can activate disease resistance in another plant species and furthermore, by generating F1 hybrids, fresh pathogen independent plant immunity can be obtained. It is also concluded that ptHR375 and ptHR941 play their role in SA and JA/ET defense pathways to activate the resistance against invading pathogens.

The mechanical anisotropy of laser directed energy deposition (L-DED) titanium alloys using laser solid forming (LSF) is significantly deteriorated owing to the coarse prior β columnar grains and continuous grain boundary α-laths (αGB). The influence mechanisms of trace boron (up to 0.25 wt%) on the microstructure, tensile properties and anisotropy of Ti6Al4V manufactured by LSF were investigated. The sizes of β grains and α phases both decreased with increasing boron content. Compared with the Ti6Al4V deposit, when the addition of boron was 0.08 wt%, the average width of β grains was reduced by about one order of magnitude owing to the growth restricting effect caused by boron and Zener pinning by TiB. Besides, the average length and aspect ratio of α-laths were reduced by 43% and 33%, respectively, owing to the refinement of β grains and the heterogeneous nucleation of α phases on TiB particles. With an increase in boron content, the strength anisotropy gradually decreased for the disappearance of αGB, the elongation anisotropy initially increased and then significantly decreased for the poor deformation compatibility between the TiB and the matrix. A better combination of strength and elongation could be obtained with the addition of 0.08 wt% boron to Ti6Al4V. Keywords: Laser deposition, Titanium alloys, Microstructure, Mechanical properties, Anisotropy

Anodization has been widely used to synthesize nanostructured TiO2 films with promising photocatalytic performance for solar hydrogen production and pollution removal. However, it usually takes a few hours to obtain the right nanostructures even on a small scale (e.g., 10 mm × 20 mm). In order to attract interest for industrial applications, fast and large-scale fabrication is highly desirable. Herein, we demonstrate a fast and large-scale (e.g., 300 mm × 360 mm) synthesis of pine-cone TiO2 nanostructures within two min. The formation mechanism of pine-cone TiO2 is proposed. The pine-cone TiO2 possesses a strong solar absorption, and exhibits high photocatalytic activities in photo-oxidizing organic pollutants in wastewater and producing hydrogen from water under natural sunlight. Thus, this study demonstrates a promising method for fabricating TiO2 films towards practical photocatalytic applications.