The development and application of pseudoviruses: assessment of SARS-CoV-2 pseudoviruses.

Although most Coronavirus disease (COVID-19) patients can recover fully, the disease remains a significant cause of morbidity and mortality. In addition to the consequences of acute infection, a proportion of the population experiences long-term adverse effects associated with SARS-CoV-2. Therefore, it is still critical to comprehend the virus's characteristics and how it interacts with its host to develop effective drugs and vaccines against COVID-19. SARS-CoV-2 pseudovirus, a replication-deficient recombinant glycoprotein chimeric viral particle, enables investigations of highly pathogenic viruses to be conducted without the constraint of high-level biosafety facilities, considerably advancing virology and being extensively employed in the study of SARS-CoV-2. This review summarizes three methods of establishing SARS-CoV-2 pseudovirus and current knowledge in vaccine development, neutralizing antibody research, and antiviral drug screening, as well as recent progress in virus entry mechanism and susceptible cell screening. We also discuss the potential advantages and disadvantages.

B1 inhomogeneity-corrected T1 mapping and quantitative magnetization transfer imaging via simultaneously estimating Bloch-Siegert shift and magnetization transfer effects.

PURPOSE: To introduce a method of inducing Bloch-Siegert shift and magnetization Transfer Simultaneously (BTS) and demonstrate its utilization for measuring binary spin-bath model parameters free pool spin-lattice relaxation ( T 1 F $$ {T}_1^{\mathrm{F}} $$ ), macromolecular fraction ( f $$ f $$ ), magnetization exchange rate ( k F $$ {k}_{\mathrm{F}} $$ ) and local transmit field ( B 1 + $$ {B}_1^{+} $$ ). THEORY AND METHODS: Bloch-Siegert shift and magnetization transfer is simultaneously induced through the application of off-resonance irradiation in between excitation and acquisition of an RF-spoiled gradient-echo scheme. Applying the binary spin-bath model, an analytical signal equation is derived and verified through Bloch simulations. Monte Carlo simulations were performed to analyze the method's performance. The estimation of the binary spin-bath parameters with B 1 + $$ {B}_1^{+} $$ compensation was further investigated through experiments, both ex vivo and in vivo. RESULTS: Comparing BTS with existing methods, simulations showed that existing methods can significantly bias T 1 $$ {T}_1 $$ estimation when not accounting for transmit B 1 $$ {B}_1 $$ heterogeneity and MT effects that are present. Phantom experiments further showed that the degree of this bias increases with increasing macromolecular proton fraction. Multi-parameter fit results from an in vivo brain study generated values in agreement with previous literature. Based on these studies, we confirmed that BTS is a robust method for estimating the binary spin-bath parameters in macromolecule-rich environments, even in the presence of B 1 + $$ {B}_1^{+} $$ inhomogeneity. CONCLUSION: A method of estimating Bloch-Siegert shift and magnetization transfer effect has been developed and validated. Both simulations and experiments confirmed that BTS can estimate spin-bath parameters ( T 1 F $$ {T}_1^{\mathrm{F}} $$ , f $$ f $$ , k F $$ {k}_{\mathrm{F}} $$ ) that are free from B 1 + $$ {B}_1^{+} $$ bias.

The optimal spatial delineation method for the service level of urban park green space from the perspective of opportunity equity.

Urban park green spaces (UPGS) constitute a vital component of urban ecosystems, and the unequal distribution of UPGS can significantly impact the well-being of residents. Therefore, investigating the spatial delineation methods of UPGS service levels from the perspective of opportunity equity contributes to enhancing people's quality of life and promoting social harmony. Taking the Yingze District of Taiyuan City as an example, this study uses a modified accessibility measurement method of UPGS with the smallest clustered unit (building) as the service demand point and the UPGS entrance/exit as the service provision point, to establish a micro-scale evaluation framework for spatial equity considering the service radius and service quality of UPGS. The findings are as follows: after setting different service radius for UPGS at different levels, additional areas not covered by UPGS service were identified compared to setting the same service radius uniformly, which could prevent these areas from being overlooked in urban plans. After considering the quality of UPGS services, additional areas with low and high UPGS service levels were identified. Accurate spatial delineation of UPGS service level can avoid wasting public resources by including areas with high service levels in the scope of new UPGS requirements, while areas with low service levels lose opportunities for consideration in future urban infrastructure planning. This study emphasizes the residents' demand for both the quantity and quality of UPGS, facilitating an accurate assessment of whether urban residents can enjoy UPGS, the number of UPGS options available to them, and evaluate the quality of UPGS services experienced. Overall, this research provides new insights for evaluating the spatial equity of urban public facilities.

How do corruption and energy efficiency affect the carbon emission performance of China's industrial sectors?

Existing research on the relationship among corruption, energy efficiency, and industrial carbon emissions is limited, while incorporating them into one analytical framework might provide new insights for the mechanism between corruption and industrial carbon emissions. Using the provincial panel data in China's industry from 2005 to 2015, this study applies the System Generalized Method of Moments (SYS-GMM) to explore the impacts of corruption and energy efficiency on industrial carbon emissions. The results indicate that under current economic development status, the effects of corruption and energy efficiency on industrial carbon emissions are divergent; i.e., corruption can enhance carbon emissions, whereas energy efficiency facilitates carbon emission reduction. Energy efficiency plays a mediating role in the relationship between corruption and carbon emissions for both the whole sample and the sub-samples. In other words, corruption aggravates industrial carbon emissions through lowering energy efficiency. Additionally, for the eastern region in China, there is an inverted U-shaped curve relationship between corruption and carbon emissions, as well as a U-shaped curve relationship between energy efficiency and carbon emissions. For the other regions, there is little sign of nonlinearity. Based on the results, policy implications regarding carbon emissions curbing are proposed.

Application of FIB-SEM Techniques for the Advanced Characterization of Earth and Planetary Materials.

Advanced microanalytical techniques such as high-resolution transmission electron microscopy (HRTEM), atom probe tomography (APT), and synchrotron-based scanning transmission X-ray microscopy (STXM) enable one to characterize the structure and chemical and isotopic compositions of natural materials down towards the atomic scale. Dual focused ion beam-scanning electron microscopy (FIB-SEM) is a powerful tool for site-specific sample preparation and subsequent analysis by TEM, APT, and STXM to the highest energy and spatial resolutions. FIB-SEM also works as a stand-alone technique for three-dimensional (3D) tomography. In this review, we will outline the principles and challenges when using FIB-SEM for the advanced characterization of natural materials in the Earth and Planetary Sciences. More specifically, we aim to highlight the state-of-the-art applications of FIB-SEM using examples including (a) traditional FIB ultrathin sample preparation of small particles in the study of space weathering of lunar soil grains, (b) migration of Pb isotopes in zircons by FIB-based APT, (c) coordinated synchrotron-based STXM characterization of extraterrestrial organic material in carbonaceous chondrite, and finally (d) FIB-based 3D tomography of oil shale pores by slice and view methods. Dual beam FIB-SEM is a powerful analytical platform, the scope of which, for technological development and adaptation, is vast and exciting in the field of Earth and Planetary Sciences. For example, dual beam FIB-SEM will be a vital technique for the characterization of fine-grained asteroid and lunar samples returned to the Earth in the near future.

Postpartum assessment of the beta cell function and insulin resistance for Chinese women with previous gestational diabetes mellitus.

Gestational diabetes mellitus (GDM) imparts a high risk of developing postpartum diabetes and is considered to be an early stage of type 2 diabetes mellitus (T2DM). In this study, a 75-g oral glucose tolerance test was performed on 472 women with GDM at 6-8 weeks after delivery. The clinical and metabolic characteristics were compared between the patients with normal glucose tolerance (NGT) and abnormal glucose metabolism (AGM). These data were then compared between pre-diabetic and diabetic patients. A total of 37.7% of the women with GDM continued to have abnormal glucose levels after delivery. Compared with the women who reverted to normal, HOMA-IR was significantly higher in AGM. A multiple stepwise regression analysis revealed that age, the postpartum body mass index (BMI), low density lipoprotein-cholesterol (LDL-C), 2 h glucose load plasma glucose (2 h PG), triglycerides (TG), hemoglobin A1c (HbA1c), 1 h glucose load plasma insulin (INS) level, and 2 h INS level were independent risk factors for the development of insulin resistance after delivery. This study has identified a high prevalence of AGM after GDM. Insulin resistance appears to be the major contributor. Any treatment to reduce the postpartum BMI and lipids level may be beneficial to decrease insulin resistance.

Assessment of FAE1 polymorphisms in three Brassica species using EcoTILLING and their association with differences in seed erucic acid contents.

BACKGROUND: FAE1 (fatty acid elongase1) is the key gene in the control of erucic acid synthesis in seeds of Brassica species. Due to oil with low erucic acid (LEA) content is essential for human health and not enough LEA resource could be available, thus new LEA genetic resources are being sought for Brassica breeding. EcoTILLING, a powerful genotyping method, can readily be used to identify polymorphisms in Brassica. RESULTS: Seven B. rapa, nine B. oleracea and 101 B. napus accessions were collected for identification of FAE1 polymorphisms. Three polymorphisms were detected in the two FAE1 paralogues of B. napus using EcoTILLING and were found to be strongly associated with differences in the erucic acid contents of seeds. In genomic FAE1 sequences obtained from seven B. rapa accessions, one SNP in the coding region was deduced to cause loss of gene function. Molecular evolution analysis of FAE1 homologues showed that the relationship between the Brassica A and C genomes is closer than that between the A/C genomes and Arabidopsis genome. Alignment of the coding sequences of these FAE1 homologues indicated that 18 SNPs differed between the A and C genomes and could be used as genome-specific markers in Brassica. CONCLUSION: This study showed the applicability of EcoTILLING for detecting gene polymorphisms in Brassica. The association between B. napus FAE1 polymorphisms and the erucic acid contents of seeds may provide useful guidance for LEA breeding. The discovery of the LEA resource in B. rapa can be exploited in Brasscia cultivation.

The clinical value of serum connective tissue growth factor in the assessment of liver fibrosis.

To explore the relation between connective tissue growth factor (CTGF) in serum and the severity of liver fibrosis, and to determine the clinical value of CTGF in the assessment of liver fibrosis, serum CTGF was tested utilizing enzyme-linked immunosorbent assay (ELISA). The correlation between serum CTGF concentration and fibrosis stage was assessed. The diagnostic performance of CTGF was assessed by comparing the area under the receiver operating characteristic (ROC) curves (AUC) with a panel of fibrosis markers. The correlation coefficient was 0.689 (P < 0.001) between the levels of serum CTGF and fibrosis stages and the AUC of CTGF was 0.841 (95% confidence interval [CI] 0.762-0.920) in distinguishing mild fibrosis from significant fibrosis. The present data revealed that serum CTGF was significantly correlated with the stage of liver fibrosis, suggested that serum CTGF was an indicator for the stage of liver fibrosis, and shown evidence that serum CTGF could be used as a valuable marker for assessing liver fibrosis.