Increased transgene expression mediated by recombinant adeno-associated virus in human neuroglia cells under microgravity conditions

The space environment has the special characteristics of radiation, noise particularity and weightlessness, all of which have adverse effects on astronauts’ muscles, bones, neurons and immune system. Some reports have shown that chemotherapy and radiotherapy can increase the activity of the recombinant adeno-associated virus (AAV) which is widely used in gene therapy. In this paper, recombinant AAV2 (rAAV2) was first packaged with the enhanced green fluorescence protein (eGFP) gene and used to infect neuroglia cells including the U87 and U251 cell lines, under microgravity conditions; it was then detected by fluorescence microscopy and flow cytometry. The results show that microgravity affects the adhesion ability of cells, promotes transgene expression induced by rAAV2 and causes changes of viral infection receptors at different time points. These findings broaden the current understanding of the microgravity effects on rAAV, with significant implications in gene therapy and the mechanisms of increased virus pathogenicity under space microgravity.

Genome-Wide Association Study for Adult-Plant Resistance to Stripe Rust in Chinese Wheat Landraces (Triticum aestivum L.) From the Yellow and Huai River Valleys

Stripe rust (also known as yellow rust), caused by the pathogen Puccinia striiformis f. sp. tritici (Pst), is a common and serious fungal disease of wheat (Triticum aestivum L.) worldwide. To identify effective stripe rust resistance loci, a genome-wide association study was performed using 152 wheat landraces from the Yellow and Huai River Valleys in China based on Diversity Arrays Technology and simple sequence repeat markers. Phenotypic evaluation of the degree of resistance to stripe rust at the adult-plant stage under field conditions was carried out in five environments. In total, 19 accessions displayed stable, high degrees of resistance to stripe rust development when exposed to mixed races of Pst at the adult-plant stage in multi-environment field assessments. A marker–trait association analysis indicated that 51 loci were significantly associated with adult-plant resistance to stripe rust. These loci included 40 quantitative trait loci (QTL) regions for adult-plant resistance. Twenty identified resistance QTL were linked closely to previously reported yellow rust resistance genes or QTL regions, which were distributed across chromosomes 1B, 1D, 2A, 2B, 3A, 3B, 4A, 4B, 5B, 6B, 7A, 7B, and 7D. Six multi-trait QTL were detected on chromosomes 1B, 1D, 2B, 3A, 3B, and 7D. Twenty QTL were mapped to chromosomes 1D, 2A, 2D, 4B, 5B, 6A, 6B, 6D, 7A, 7B, and 7D, distant from previously identified yellow rust resistance genes. Consequently, these QTL are potentially novel loci for stripe rust resistance. Among the 20 potentially novel QTL, five (QDS.sicau-2A, QIT.sicau-4B, QDS.sicau-4B.2, QDS.sicau-6A.3, and QYr.sicau-7D) were associated with field responses at the adult-plant stage in at least two environments, and may have large effects on stripe rust resistance. The novel effective QTL for adult-plant resistance to stripe rust will improve understanding of the genetic mechanisms that control the spread of stripe rust, and will aid in the molecular marker-assisted selection-based breeding of wheat for stripe rust resistance

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Serendipity in human information behavior: a systematic review

Purpose: Serendipitous information discovery has become a unique and important approach to discovering and obtaining information, which has aroused a growing interest for serendipity in human information behavior. Despite numerous publications, few have systematically provided an overview of current state of serendipity research. Consequently, researchers and practitioners are less able to make effective use of existing achievements, which limits them from making advancements in this domain. Against this backdrop, we performed a systematic literature review to explore the world of serendipity and to recapitulate the current states of different research topics. Design/methodology/approach: Guided by a prior designed review protocol, this paper conducted both automatic and manual search for available studies published from January 1990 to December 2020 on seven databases. A total of 207 serendipity studies closely related to human information behavior form the literature pool. Findings: We provide an overview of distinct aspects of serendipity, that is research topics, potential benefits, related concepts, theoretical models, contextual factors and data collection methods. Based on these findings, this review reveals limitations and gaps in the current serendipity research and proposes an agenda for future research directions. Originality/value: By analyzing current serendipity research, developing a knowledge framework and providing a research agenda, this review is of significance for researchers who want to find new research questions or re-align current work, for beginners who need to quickly understand serendipity, and for practitioners who seek to cultivate serendipity in information environments

Effect of Ta content on formation mechanism of passivation film and corrosion resistance in ZrTiNbAl-system alloy

The formation mechanism of passivation film and corrosion resistance of (40-x)Zr-30Ti-20Nb-10Al-xTa (x=0, 2, 4, atom fraction/%, the same below, referred to as Tax alloy) high entropy alloy in a 0.3mol/L LiOH solution were investigated by potentiodynamic polarization, electrochemical impedance technique, Mott-Schottky analysis and potentiostatic polarization. The results show that the addition of appropriate amount of Ta (2%) helps to form a compact oxide film, which improves the corrosion resistance, while the excessive amount of Ta (4%) decreases the corrosion resistance due to the increase of oxygen vacancy concentration. The corrosion current density of the Ta2 alloy is 49.66 nA/cm2, which is less than the Ta0 and Ta4 alloys of 201.40, 70.16 nA/cm2. The concentration of oxygen vacancy point defect in the passivation film of the Ta2 alloy is 9.79×1018 cm-3, which is less than 2.13×1019, 2.05×1019 cm-3 in the Ta0 and Ta4 alloys, with the most compact passive film structure. The passivation film of the alloy is a stable n-type composed of ZrO2, Nb2O5, TiO2, Al2O3 and Ta2O5. Among them, the oxide content of ZrO2, Nb2O5 and TiO2 in the oxide film of the Ta2 alloy is the highest, which delays the dissolution rate of the primary oxide film and protects the matrix from further dissolution, with the best corrosion resistance

Examining the Effects of Health Belief and Affection on Continued Teleconsultation Use in the Post-COVID-19 Era: Evidence from China

The COVID-19 pandemic has led to a high demand for teleconsultation to protect doctors and patients from infection while maintaining healthcare services. As public mobility is no longer strictly restricted in the post-COVID-19 era, the number of teleconsultation users has declined. However, promoting continued teleconsultation use still matters as it not only helps manage public health crisis during recurrent outbreaks, but also helps solve long-term challenges rooted in healthcare system. Against this backdrop, we proposed a research model based on protection motivation theory and expectation-confirmation model to examine post-acceptance of teleconsultation from the perspectives of health belief and affection. We conducted an online survey on Chinese teleconsultation users and found that health belief and affection significantly influenced continuance intention of teleconsultation. Providing richer perspectives, this study advances the understanding of user post-acceptance of teleconsultation, and provides guidance for its sustained use in post-COVID-19 era

Comparative Study of 5-Aminolevulinic Acid-Mediated Photodynamic Therapy and the Loop Electrosurgical Excision Procedure for the Treatment of Cervical High-Grade Squamous Intraepithelial Lesions

The loop electrosurgical excision procedure (LEEP) is a common treatment for cervical intraepithelial neoplasia (CIN). Photodynamic therapy (PDT) mediated by 5-aminolevulinic acid (ALA) is a non-invasive modality that has been used for treating precancerous diseases and HPV infections. This comparative study evaluated the efficacy and safety of ALA PDT and the LEEP in the treatment of cervical high-grade squamous intraepithelial lesions (HSILs). Patient records were reviewed and HSIL patients with HPV infections (24–51 years old) who underwent PDT or LEEP treatment were selected. Efficacy was analyzed blindly based on HPV-DNA, cytology, and colposcopy-directed biopsy obtained at 6 months after treatment. Treatment-related discomfort and side effects were also analyzed. Cure rates of 88.1% and 70.0% were achieved for the PDT group and LEEP group (p p < 0.05), respectively. The overall lesion remission rate of the PDT group was 19% higher than that of the LEEP group. The incidence of side effects was much lower in the PDT group. These results show that ALA PDT is a feasible non-invasive treatment for cervical HSIL