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Spectrophotometric Determination of Thiosulfate in Desulfurization Solutions by Decoloration of Methylene Blue Published on: May 1, 2023 Xiuxiu Zhao, Ming Xu, Chunying Ma, Yingying Ma, Xianji Ma Spectroscopy, May 2023, Volume 38, Issue 5 Pages: 19–22,34 This article proposes a method for the determination of thiosulfate by decoloring spectrophotometry with methylene blue as an oxidant. Methylene blue has redox properties. Its oxidized form is blue, and its reduced form is colorless. Thiosulfate is a medium-strength reducing agent. In an acidic medium, the two can undergo redox reactions to reduce methylene blue and cause the solution to exhibit a fading reaction within a certain range, and the degree of fading is proportional to the amount of thiosulfate added. This method measures the change in absorbance (AU) at a fixed wavelength of 664 nm, and ΔAU has a linear relationship with the content of thiosulfate. The linear range is 0–0.3 mmol/L. From this curve, the content of thiosulfate in the desulfurization solution can be accurately measured. This method is not interfered with by other secondary salts in the desulfurization solution during the thiosulfate determination process, and has high sensitivity. The color change can be observed by the naked eye to judge whether there is thiosulfate in the solution. This method is simple to perform and is an improved method for the determination of thiosulfate in a desulfurization solution.

Viruses are important components of the human body. Growing evidence suggests that they are engaged in the physiology and disease status of the host. Even though the vaginal microbiome is involved in human papillomavirus (HPV) infection and cervical cancer (CC) progression, little is known about the role of the vaginal virome. In this pilot exploratory study, using unbiased viral metagenomics, we aim to investigate the vaginal eukaryotic virome in women with different levels of cervical lesions, and examine their associations with different cervical disease status. An altered eukaryotic virome was observed in women with different levels of lesions and Lactobacillus profiles. Anelloviruses and papillomaviruses are the most commonly detected eukaryotic viruses of the vaginal virome. Higher abundance and richness of anelloviruses and papillomaviruses were associated with low-grade squamous intraepithelial lesion (LSIL) and CC. Besides, higher anellovirus abundance was also associated with lactobacillus-depleted microbiome profiles and bacterial community state (CST) type IV. Furthermore, increased correlations between Anelloviridae and Papillomaviridae occurred in the women with increased cervical disease severity level from LSIL to CC. These data suggest underlying interactions between different microbes as well as the host physiology. Higher abundance and diversity of both anelloviruses and papillomaviruses shared by LSIL and CC suggest that anellovirus may be used as a potential adjunct biomarker to predict the risk of HPV persistent infection and/or CC. Future studies need to focus on the clinical relevance of anellovirus abundance with cervical disease status, and the evaluation of their potential as a new adjunct biomarker for the prediction and prognoses of CC.

Regulation of the energy transfer between Eu2+ and Mn2+ ions, and the photoluminescence properties with pressure.

The pressure-induced structural transformation and irreversible amorphization contribute to 1.2–2.6 times upconversion luminescence enhancement in Ln3+ codoped LiYF4 and LiLuF4.

We consider a new class of spatio-temporal models with sparse autoregressive coefficient matrices and exogenous variable. To estimate the model, we first profile the exogenous variable out of the response. This leads to a profiled model structure. Next, to overcome endogeneity issue, we propose a class of generalized methods of moment (GMM) estimators to estimate the autoregressive coefficient matrices. A novel bagging-based estimator is further developed to conquer the over-determined issue which also occurs in Chang et al. (2015) and Dou et al. (2016). An adaptive forward–backward greedy algorithm is proposed to learn the sparse structure of the autoregressive coefficient matrices. A new BIC-type selection criteria is further developed to conduct variable selection for GMM estimators. Asymptotic properties are further studied. The proposed methodology is illustrated with extensive simulation studies. A social network dataset is analyzed for illustration purpose.

Bovine viral diarrhea virus (BVDV) is the etiologic agent of bovine viral diarrhea-mucosal disease, one of the most important viral diseases of cattle, leading to numerous losses to the cattle rearing industry worldwide. The pathogenicity of BVDV is extremely complex, and many underlying mechanisms involved in BVDV-host interactions are poorly understood, especially how BVDV utilizes host metabolism pathway for efficient viral replication and spread. In our previous study, using an integrative analysis of transcriptomics and proteomics, we found that DHCR24 (3β-hydroxysteroid-Δ24 reductase), a key enzyme in regulating cholesterol synthesis, was significantly upregulated at both gene and protein levels in the BVDV-infected bovine cells, indicating that cholesterol is important for BVDV replication. In the present study, the effects of DHCR24-mediated cholesterol synthesis on BVDV replication was explored. Our results showed that overexpression of the DHCR24 effectively promoted cholesterol synthesis, as well as BVDV replication, while acute cholesterol depletion in the bovine cells by treating cells with methyl-β-cyclodextrin (MβCD) obviously inhibited BVDV replication. In addition, knockdown of DHCR24 (gene silencing with siRNA targeting DHCR24, siDHCR24) or chemical inhibition (treating bovine cells with U18666A, an inhibitor of DHCR24 activity and cholesterol synthesis) significantly suppressed BVDV replication, whereas supplementation with exogenous cholesterol to the siDHCR24-transfected or U18666A-treated bovine cells remarkably restored viral replication. We further confirmed that BVDV nonstructural protein NS5A contributed to the augmentation of DHCR24 expression. Conclusively, augmentation of the DHCR24 induced by BVDV infection plays an important role in BVDV replication via promoting cholesterol production. IMPORTANCE Bovine viral diarrhea virus (BVDV), an important pathogen of cattle, is the causative agent of bovine viral diarrhea-mucosal disease, which causes extensive economic losses in both cow- and beef-rearing industry worldwide. The molecular interactions between BVDV and its host are extremely complex. In our previous study, we found that an essential host factor 3β-hydroxysteroid-δ24 reductase (DHCR24), a key enzyme involved in cholesterol synthesis, was significantly upregulated at both gene and protein levels in BVDV-infected bovine cells. Here, we experimentally explored the function of the DHCR24-mediated cholesterol synthesis in regulating BVDV replication. We elucidated that the augmentation of the DHCR24 induced by BVDV infection played a significant role in viral replication via promoting cholesterol synthesis. Our data provide evidence that BVDV utilizes a host metabolism pathway to facilitate its replication and spread.

The purpose of this review is to examine the effects of automated writing evaluation (AWE) feedback on students’ English writing performance. We systematically reviewed studies that have empirically focused on this purpose. This review uses several combinations of key words to search in the databases of JSTOR, SSCI, and ERIC for peer-reviewed articles published from 2005 to April 2020. The systematic review produced 22 eligible studies categorized as within-group and between group studies based on Stevenson and Phakiti’s (2014) categorization. The results indicated that AWE feedback might be helpful for student writing under certain conditions. Specifically, the feedback was helpful when it was provided for one single group of students. The feedback was also helpful when the writing performance of a group of students receiving the feedback was compared to the writing performance of the other group of students receiving no such feedback. Moreover, AWE feedback should be continuously offered to help students benefit most from it. This review is an update about the effects of AWE feedback on student writing and may serve as a guide for researchers and instructional practitioners through informing them of the latest research on AWE feedback.

Peanut (Arachis hypogea L.) bacterial wilt (BW) is a devastating disease caused by Ralstonia solanacearum that results in severe yield and quality losses. Plant defensins are short cysteine-rich peptides with antimicrobial activity. The role of defensin genes (AhDef) in peanut is unclear. A genome-wide investigation of AhDef genes was undertaken, and 12 identified AhDef genes were classified into two groups containing the gamma-thionin domain formed by four disulfide pairs: Cys1-Cys8, Cys2-Cys5, Cys3-Cys6, and Cys4-Cys7. In silico analysis revealed that AhDef genes showed highly conserved architectural features and contained cis-elements associated with phytohormone signaling and defense responses. A highly resistant cultivar, H108 (R) and a susceptible accession, H107 (S) were tested by R. solanacearum inoculation. H108 (R) showed fewer symptoms than H107 (S) owing to inhibition of bacterial reproduction and spread in the vascular bundles of roots and stems. In a transcriptomic expression profile, AhDef genes, particularly AhDef1.6 and AhDef2.2, were up-regulated in H108 (R) compared with H107 (S) under R. solanacearum infection and phytohormone treatment. Subcellular localization showed that the AhDef1.6 and AhDef2.2 proteins were both expressed specifically on the plasma membrane. Overexpression of protein fusion AhDef2.2-YFP in Nicotiana benthamiana and peanut leaves increased resistance to R. solanacearum, suggesting its role in response to BW infection. AhDef2.2 may be valuable for peanut resistance breeding.

Objective: To investigate the infection status of high-risk human papillomavirus (HR-HPV) E6/E7 mRNA in patients with a cytological diagnosis of "atypical squamous cells of undetermined significance" (ASCUS) and to analyze the pathogenic rate of different high-risk HPV subtypes combined with biopsy pathological results to provide a more accurate basis for managing ASCUS patients. Methods A total of 1387 patients with ASCUS and HPV E6/E7 mRNA positivity who were referred for colposcopy were retrospectively analyzed. They were divided into HPV16+, 18/45+ and other HR-HPV+ groups premenopausal and postmenopausal groups. The pathological results of the biopsy were divided into the LSIL- group (including normal and low-grade squamous intraepithelial lesions) and the HSIL+ group (including high-grade squamous intraepithelial lesions and higher lesions). SPSS was used for the analysis. Results The age group 31-40 years had the highest level of HPV16+, and HPV18/45+ was the highest in the 41-50 years group. The detection rates of HSIL+ in the HPV16+, HPV18/45+, HPV 16/18/45+ and Other HR-HPV+ groups were 48.4%, 18.8%, 43.9% and 15.0%, respectively. The infection rates of HPV16/18/45 in postmenopausal and premenopausal women were 42.4% and 34.3%, respectively. In the HPV18/45 group, the incidence of HSIL+ was 30.0% in postmenopausal women and 15.0% in premenopausal women (P < 0.01). In the HPV 16+ and Other HR-HPV+ groups, the incidence of HSIL+ in postmenopausal patients was not significantly different from that in premenopausal patients. The incidence of cervical cancer in postmenopausal patients is significantly higher than that in premenopausal patients. Conclusions Colposcopy referral or further biopsy is recommended for all ASCUS patients with HPV16/18/45E6/E7 mRNA positivity and postmenopausal patients with HR-HPVE6/E7 mRNA positivity. For premenopausal ASCUS patients with other HR-HPV E6/E7 mRNA positivity, colposcopy should be performed if possible, depending on the specific situation, to achieve early detection and diagnosis.

Accurate estimation of wind speed at wind turbine hub height is of significance for wind energy assessment and exploitation. Nevertheless, the traditional power law method (PLM) generally estimates the hub-height wind speed by assuming a constant exponent between surface and hub-height wind speed. This inevitably leads to significant uncertainties in estimating the wind speed profile especially under unstable conditions. To minimize the uncertainties, we here use a machine learning algorithm known as random forest (RF) to estimate the wind speed at hub heights such as at 120 m (WS120), 160 m (WS160), and 200 m (WS200). These heights go beyond the traditional wind mast limit of 100–120 m. The radar wind profiler and surface synoptic observations at the Qingdao station from May 2018 to August 2020 are used as key inputs to develop the RF model. A deep analysis of the RF model construction has been performed to ensure its applicability. Afterwards, the RF model and the PLM model are used to retrieve WS120, WS160, and WS200. The comparison analyses from both RF and PLM models are performed against radiosonde wind measurements. At 120 m, the RF model shows a relatively higher correlation coefficient R of 0.93 and a smaller RMSE of 1.09 m s−1, compared with the R of 0.89 and RMSE of 1.50 m s−1 for the PLM. Notably, the metrics used to determine the performance of the model decline sharply with height for the PLM model, as opposed to the stable variation for the RF model. This suggests the RF model exhibits advantages over the traditional PLM model. This is because the RF model considers well the factors such as surface friction and heat transfer. The diurnal and seasonal variations in WS120, WS160, and WS200 from RF are then analyzed. The hourly WS120 is large during daytime from 09:00 to 16:00 local solar time (LST) and reach a peak at 14:00 LST. The seasonal WS120 is large in spring and winter and is low in summer and autumn. The diurnal and seasonal variations in WS160 and WS200 are similar to those of WS120. Finally, we investigated the absolute percentage error (APE) of wind power density between the RF and PLM models at different heights. In the vertical direction, the APE is gradually increased as the height increases. Overall, the PLM algorithm has some limitations in estimating wind speed at hub height. The RF model, which combines more observations or auxiliary data, is more suitable for the hub-height wind speed estimation. These findings obtained here have great implications for development and utilization in the wind energy industry in the future.

Aim Previously, we found that diabetes-related liver dysfunction is due to activation of the 5-HT2A receptor (5-HT2AR) and increased synthesis and degradation of 5-HT. Here, we investigated the role of 5-HT in the development of atherosclerosis. Methods The study was conducted using high-fat diet-fed male ApoE－/－ mice, THP-1 cell-derived macrophages, and HUVECs. Protein expression and biochemical indexes were determined by Western blotting and quantitative analysis kit, respectively. The following staining methods were used: oil red O staining (showing atherosclerotic plaques and intracellular lipid droplets), immunohistochemistry (showing the expression of 5-HT2AR, 5-HT synthase, and CD68 in the aortic wall), and fluorescent probe staining (showing intracellular ROS). Results In addition to improving hepatic steatosis, insulin resistance, and dyslipidemia, co-treatment with a 5-HT synthesis inhibitor and a 5-HT2AR antagonist significantly suppressed the formation of atherosclerotic plaques and macrophage infiltration in the aorta of ApoE－/－ mice in a synergistic manner. Macrophages and HUVECs exposed to oxLDL or palmitic acid in vitro showed that activated 5-HT2AR regulated TG synthesis and oxLDL uptake by activating PKCe, resulting in formation of lipid droplets and even foam cells; ROS production was due to the increase of both intracellular 5-HT synthesis and mitochondrial MAO-A-catalyzed 5-HT degradation, which leads to the activation of NF-κB and the release of the inflammatory cytokines TNF-α and IL-1β from macrophages and HUVECs as well as MCP-1 release from HUVECs. Conclusion Similar to hepatic steatosis, the pathogenesis of lipid-induced atherosclerosis is associated with activation of intracellular 5-HT2AR, 5-HT synthesis, and 5-HT degradation.

A series of novel Sr5YTi3Nb7O30:xEu3+ (x = 0.05–0.40) red-emitting phosphors were firstly synthesized using the high-temperature solid-state method. The X-ray diffraction (XRD) patterns demonstrate that the phosphors are pure phase with the space group P4bm of tetragonal system. Under the 395 nm excitation wavelength, the red emission of Sr5YTi3Nb7O30:Eu3+ phosphor is considered to be dominated by the 5D0→7F2 transition at 613 nm. The asymmetry ratios (R/O) of Sr5YTi3Nb7O30:xEu3+ (x = 0.05–0.40) phosphors are identified as 2.64–2.78, which contribute to the high color purity (99.5%–99.8%). The phosphor has good thermal stability with 0.17 eV of activation energy. The Commission International de L'Eclairage (CIE) coordinates of the w-LED nearly overlap with the standard white light (0.333, 0.333), the Ra is as high as 90. Meanwhile, the features of fingerprint are simultaneously distinguished at three levels on aluminum foil by Sr5YTi3Nb7O30:0.30Eu3+ phosphor. In addition, the latent fingerprint on various nonporous substrates (stainless steel, glass, and plastic surfaces) were identified. In summary, the phosphor is feasible to apply in the w-LEDs and latent fingerprint detection.

The vertical distribution of fine particles with a diameter

Eu-doped SrS red-emitting phosphors show superior thermal quenching resistance and luminescent intensity when the energy transfer from Ce3+ to Eu2+ is boosted.

Vertical distributions of temperature and humidity are two essential factors for understanding of atmospheric structure, extreme weather events, and regional and global climate. The ground-based MicroWave Radiometer (MWR), which acts as a passive sensor and operate continuously under all weather conditions, has an irreplaceable role in measuring the vertical information of the temperature and water content in the atmosphere. In this paper, we proposed a four-layer Back-Propagation Neural Network (BPNN) method to retrieve temperature and Relative Humidity (RH) profiles from the bright temperature measured by the MWR. In contrast to the traditional BPNN, this method has greater advantages in dealing with the problems of over-fitting, gradient disappearance, and gradient explosion in vertical atmospheric retrieval. By adding dropout layers, it can also help to describe the non-linear relationships for RH profiles. Results showed that the performance of the four-layer BPNN method was better than the quadratic regression method (QR, provided by MWR manufacturer) under both cloud and cloud-free conditions. Compared with measurements of radiosonde data, root-mean-square error of temperature and RH, BPNN achieves 1.88 K and 19.30 % under cloud conditions and 2.03 K and 15.10 % under cloud-free conditions, respectively. Whereas, the corresponding values by using QR method were only 3.07 K and 24.28 % under cloud conditions and 4.14 K and 18.96 % under cloud-free conditions, respectively. Temperature and RH profiles retrieval with high precision have increased the efficiency of the MWR observations and provided data foundation for further atmospheric climate research.

Changes of aerosol loadings and properties are of importance to understand atmospheric environment and climate change. This study investigates the characteristics and the long-term trends of aerosols of different sizes and types in Asia from 2000 to 2020, by considering multi-source aerosol data, novel analysis method and perspective, all this groundwork promote the acquisition of new discoveries that are different from the past. The geometric mean aggregation method is applied, and serial auto-correlation is considered to avoid overestimation of trend significance. Among regions in Asia, high values of aerosol optical depth (AOD) are mainly concentrated in East Asia (EA) and South Asia (SA), closely related to population density. The AOD in EA showed the most significant negative trend with a value of -5.28×10-4 per year, mainly owing to decreases in organic carbon (OC), black carbon (BC), and dust aerosols. It is also worth noting that this observed large-scale decrease in OC and BC is a unique and significant phenomenon to region of EA, and mainly around China. By contrast, the aerosol concentrations in SA generally show a positive trend, with an increase value of AOD of 1.25×10-3 per year. This increase is mainly due to large emission of fine-mode aerosols, such as OC and sulphate aerosol. Additionally, the high aerosol loading in north SA has lower AOD variability comparing with that of East China plain, revealing a relatively more persistent air pollution situation. Over the whole Asia region, the characteristics of percentage changes in different type AOD are increases in BC (6.23 %) and OC (17.09 %) AOD with a decrease in dust (-5.51 %), sulphate (-3.07 %), and sea salt (-9.80 %) AOD. Except for anthropogenic emission, the large increase in the percentage of OC is also owing to wild fires found in Northern Asia in the summer. Whereas, the different size AOD only shows slight changes in Asia, that small-size AOD decreases (-3.34 %), and the total AOD did not show a significant change, suggesting that, from a trend perspective, decreases in aerosol in recent years have mostly been offsetting earlier increases in anthropogenic emission over Asia. To summarize, the above findings analyse the comprehensive characteristics of aerosol distributions and reappraise the long-term trends of different aerosol parameters, which will greatly enhance the understandings of regional and global aerosol environment and climatology, as well as fill in the gaps and break through the limitation of past knowledge.