Biological cell trapping and manipulation of a photonic nanojet by a specific microcone-shaped optical fiber tip.

Trapping and manipulating mesoscopic biological cells with high precision and flexibility are very important for numerous biomedical applications. In particular, a photonic nanojet based on a non-resonance focusing phenomenon can serve as a powerful tool for manipulating red blood cells and tumor cells in blood. In this study, we demonstrate an approach to trap and drive cells using a high-quality photonic nanojet which is produced by a specific microcone-shaped optical-fiber tip. The dynamic chemical etching method is used to fabricate optical-fiber probes with a microcone-shaped tip. Optical forces and potentials exerted on a red blood cell by a microcone-shaped fiber tips are analyzed based on finite-difference time-domain calculations. Optical trapping and driving experiments are done using breast cancer cells and red blood cells. Furthermore, a cell chain is formed by adjusting the magnitude of the optical force. The real-time backscattering intensities of multiple cells are detected, and highly sensitive trapping is achieved. This microcone-shaped optical fiber probe is potentially a powerful device for dynamic cell assembly, optical sorting, and the precise diagnosis of vascular diseases.

A Bibliometric Analysis of the Role of 3D Technology in Liver Cancer Resection.

BACKGROUND: Liver cancer resection is an effective but complex way to treat liver cancer, and complex anatomy is one of the reasons for the difficulty of surgery. The use of 3D technology can help surgeons cope with this dilemma. This article intends to conduct a bibliometric analysis of the role of 3D technology in liver cancer resection. METHODS: (TS = (3D) OR TS = (three-dimensional)) AND (TS = (((hepatic) OR (liver)) AND ((cancer) OR (tumor) OR (neoplasm)))) AND (TS = (excision) OR TS = (resection)) was used as a search strategy for data collection in the Web of Science (WoS) Core Collection. CiteSpace, Carrot2 and Microsoft Office Excel were used for data analysis. RESULTS: Three hundred and eighty-eight relevant articles were obtained. Their annual and journal distribution maps were produced. Countries/regions and institutions collaboration, author collaboration, references co-citations and their clusters and keywords co-occurrences and their clusters were constructed. Carrot2 cluster analysis was performed. CONCLUSIONS: There was an overall upward trend in the number of publications. China's contribution was greater, and the USA had greater influence. Southern Med Univ was the most influential institution. However, the cooperation between institutions still needs to be further strengthened. Surgical Endoscopy and Other Interventional Techniques was the most published journal. Couinaud C and Soyer P were the authors with the highest citations and centrality, respectively. "Liver planning software accurately predicts postoperative liver volume and measures early regeneration" was the most influential article. 3D printing, 3D CT and 3D reconstruction may be the mainstream of current research, and augmented reality (AR) may be a future hot spot.

The value of preoperative neutrophil/lymphocyte ratio in predicting the severity of cholecystolithiasis with cholecystitis in elderly patients.

BACKGROUND: This study aims to assess the effectiveness of neutrophil/lymphocyte ratio (NLR) and C-reactive protein (CRP) in diagnosing cholecystolithiasis with cholecystitis in elderly patients. Additionally, the study seeks to determine the predictive value of preoperative NLR in determining the severity of the condition in this population. METHODS: This study is a retrospective cohort study, including 160 elderly patients with cholecystolithiasis with cholecystitis (45 cases of simple cholecystitis, 58 cases of suppurative cholecystitis, 57 cases of gangrenous cholecystitis) and 60 cases of normal gallbladder histology. The study collected clinical data of the patients detected the preoperative CRP content, neutrophil, and lymphocyte levels through blood routine tests, and calculated the NLR value. The diagnostic value of NLR and CRP was determined by using the Receiver Operating Characteristic Curve (ROC), and the optimal value of preoperative NLR related to the severity of elderly patients with cholecystolithiasis with cholecystitis was identified. RESULTS: This study found that for elderly patients with cholecystolithiasis with cholecystitis, preoperative NLR and CRP levels can be used to distinguish the condition. The critical value for NLR was found to be 2.995 (95% CI, 0.9465-0.9853; P < 0.001) with an area under the ROC curve of 0.9659, while the critical value for CRP was 13.05 (95% CI, 0.9284-0.9830; P < 0.001) with an area under the ROC curve of 0.9557. Both NLR and CRP were found to have equivalent diagnostic abilities. Additionally, the study found that there were significant differences in neutrophil and lymphocyte levels in elderly patients with different severity levels, with NLR increasing as severity increased (P < 0.001). The study identified cut-off values for preoperative NLR that could distinguish Simple cholecystitis and Purulent cholecystitis, as well as Purulent cholecystitis and Gangrenous cholecystitis in elderly patients with cholecystolithiasis, with respective AUCs of 0.8441 (95% CI: 0.7642-0.9239; P < 0.001) and 0.7886(95% CI: 0.7050-0.8721, P < 0.001), sensitivities of 91.38% and 87.72%, and specificities of 73.33% and 63.79%. CONCLUSIONS: Preoperative NLR and CRP values can serve as indicators to detect cholecystolithiasis with cholecystitis in elderly patients. Additionally, NLR has been recognized as a potential tool to differentiate the severity of cholecystolithiasis with cholecystitis in the elderly population.

Ultrasound-guided superficial cervical plexus block combined with clavipectoral fascial plane block or interscalene brachial plexus block in clavicle surgery: a single-centre, double-blind, randomized controlled trial.

The sensory innervation of the clavicle is complex, and the best regional block technology for clavicular surgery has yet to be determined. The purpose of this study was to compare the application of ultrasound-guided superficial cervical plexus block combined with clavipectoral fascial plane block verses interscalene brachial plexus block in clavicular surgery. Fifty patients undergoing internal fixation surgery for elective clavicle fractures were randomly divided into two groups (n = 25 for each group): group I and group II. Superficial cervical plexus block combined with clavipectoral fascial plane block was used in group I, and superficial cervical plexus block combined with interscalene brachial plexus block was used in group II. The primary outcome measure was the duration of analgesia. The duration of analgesia in group I was significantly longer than that in group II (P < 0.05). The modified Bromage scale function score in group II was lower than that in group I (P < 0.01). There was no significant difference in the skin acupuncture pain score 30 min after block and visual analog scale (VAS) scores at 6 and 12 h after surgery. However, the 24 h VAS score in group I was lower than that in group II (P < 0.05). The incidence of diaphragmatic paralysis was significantly increased in group II (P < 0.01). Ultrasound-guided superficial cervical plexus block combined with clavipectoral fascial plane block can be used for clavicular surgery. It has a long postoperative analgesia time, can retain the motor function of the involved upper limb and does not cause hemidiaphragmatic paresis.Clinical trial number and registry URL: Clinical Trials.gov; Trial registration number: ChiCTR2000039383; Date of registration: 25 October 2020.

The association between time in the glucose target range and abnormal ankle-brachial index: a cross-sectional analysis.

BACKGROUND: Time in range (TIR), a novel proxy measure of glucose control, is found closely related to diabetic microangiopathy and some other chronic complications, but the correlation between TIR and lower limb angiopathy has not been studied yet. Our purpose is to explore the relationship between TIR and abnormal ankle-brachial index(ABI) in type 2 diabetes. METHODS: We retrospectively collected patients' information from the database and performed cross-sectional analysis. A total of 405 type 2 diabetes patients were enrolled in this study. ABI was measured and patients were stratified into low, normal, and high groups according to ≤ 0.9, > 0.9 and < 1.3, ≥ 1.3 ABI values. All patients underwent continuous glucose monitoring(CGM), and TIR was defined as the percentage of time in which glucose was in the range of 3.9-10 mmol/L during a 24-h period. Correlations between TIR and abnormal ABI were analyzed using Spearman analysis. And logistic regression was used to explore whether TIR is an independent risk factor for abnormal ABI. RESULTS: The overall prevalence of abnormal ABI was 20.2% (low 4.9% and high 15.3%). TIR was lower in patients with abnormal ABI values (P = 0.009). The prevalence of abnormal ABI decreased with increasing quartiles of TIR (P = 0.026). Abnormal ABI was negatively correlated with TIR and positively correlated with hypertension, age, diabetes duration, UREA, Scr, ACR, TAR, MBG, and M values (P < 0.05). The logistic regression revealed a significant association between TIR and abnormal ABI, while HbA1C and blood glucose variability measures had no explicit correlation with abnormal ABI. Additionally, there was a significant difference in LDL between the low and high ABI groups (P = 0.009), and in Scr between normal and low groups (P = 0.007). And there were significant differences in TIR (P = 0.003), age (P = 0.023), UREA (P = 0.006), ACR (P = 0.004), TAR (P = 0.015), and MBG (P = 0.014) between normal and high ABI groups, and in diabetes duration between both normal and low (P = 0.023) and normal and high (P = 0.006) groups. CONCLUSIONS: In type 2 diabetes patients, abnormal ABI is associated with lower TIR, and the correlation is stronger than that with HbA1C. Therefore, the role of TIR should be emphasized in the evaluation of lower limb vascular diseases.

The Role of Chitooligosaccharidolytic ß-N-Acetylglucosamindase in the Molting and Wing Development of the Silkworm Bombyx mori.

The insect glycoside hydrolase family 20 ß-N-acetylhexosaminidases (HEXs) are key enzymes involved in chitin degradation. In this study, nine HEX genes in Bombyx mori were identified by genome-wide analysis. Bioinformatic analysis based on the transcriptome database indicated that each gene had a distinct expression pattern. qRT-PCR was performed to detect the expression pattern of the chitooligosaccharidolytic ß-N-acetylglucosaminidase (BmChiNAG). BmChiNAG was highly expressed in chitin-rich tissues, such as the epidermis. In the wing disc and epidermis, BmChiNAG has the highest expression level during the wandering stage. CRISPR/Cas9-mediated BmChiNAG deletion was used to study the function. In the BmChiNAG-knockout line, 39.2% of female heterozygotes had small and curly wings. The ultrastructure of a cross-section showed that the lack of BmChiNAG affected the stratification of the wing membrane and the formation of the correct wing vein structure. The molting process of the homozygotes was severely hindered during the larva to pupa transition. Epidermal sections showed that the endocuticle of the pupa was not degraded in the mutant. These results indicate that BmChiNAG is involved in chitin catabolism and plays an important role in the molting and wing development of the silkworm, which highlights the potential of BmChiNAG as a pest control target.

Whole-genome resequencing reveals loci under selection during silkworm improvement.

Breeding or genetic improvement refers to the process of artificial selection following domestication; as such, it has had a major influence on modern agriculture and animal production. Improvement generally focuses on traits that greatly affect the economic performance. Therefore, understanding the genetic basis underlying improvement will contribute to the identification of genes controlling economic traits and will facilitate future crop and animal breeding. However, genome-wide study of the molecular basis underlying improvement remains rare. The silkworm is a unique, entirely domesticated economically important invertebrate; genetic improvement has had a huge effect on the silkworm regarding silk-related traits. Herein, we performed whole-genomic sequencing on local and genetically improved silkworm lines to identify the genomic regions under strong selection in silkworm breeding/improvement. By genomic-wide selective sweeping analysis, we identified 24 genomic regions with strong selection signals, eight of which contained 13 candidate genes underlying silkworm breeding. Interestingly, six of these genes were annotated with functions related to neural signal response. Among the six genes, BGIBMGA004050 encodes silkworm CREB-regulated_transcription_coactivator_1 (BmCRTC1), which was reported to be involved in energy-sensing pathways. These results suggested that improvement may have affected the nervous system of the silkworm. This research will provide new insights into the genetic basis underlying the genetic improvement of silkworms and possibly of other species.

Effect of urban underlying surface on PM2.5 vertical distribution based on UAV in Xi'an, China.

Fine particulate matter (PM2.5) has become a significant issue of ecological environment. However, few studies have explored the vertical distribution of PM2.5 in cities. The objectives of this paper are to reveal the vertical distribution regular pattern of PM2.5 over urban underlying surfaces near the ground with a hexacopter-type unmanned aerial vehicle (UAV) in winter. Results showed that the maximum vertical gradient of PM2.5 near the ground was typically the greatest in the morning as the stable atmospheric conditions. Moreover, regression model illustrated that relative humidity had the greatest impact on the vertical profile of PM2.5 compared to air temperature and altitude as hygroscopic of PM2.5 aerosols. Curve model shown that vertical profile of PM2.5 over the surfaces of water and green space first increased slowly and then declined, besides, the highest concentration inflection of PM2.5 above the water body (23.7 m) is higher than the green space (14.3 m). Thus, suggesting residents living vertical of 10-30 m from the ground around large water bodies and green spaces should not open windows for ventilation in the morning. Therefore, this study provides insights into the vertical distributions of PM2.5 over different underlying surfaces and should be of reference value to urban planners for designing urban spaces to optimize atmosphere environment to provide a healthy living environment.

Identification, expression, and artificial selection of silkworm epigenetic modification enzymes.

BACKGROUND: Understanding the genetic basis of phenotype variations during domestication and breeding is of great interest. Epigenetics and epigenetic modification enzymes (EMEs) may play a role in phenotypic variations; however, no comprehensive study has been performed to date. Domesticated silkworm (Bombyx mori) may be utilized as a model in determining how EMEs influence domestication traits. RESULTS: We identified 44 EMEs in the genome of silkworm (Bombyx mori) using homology searching. Phylogenetic analysis showed that genes in a subfamily among different animals were well clustered, and the expression pattern of EMEs is constant among Bombyx mori, Drosophila melanogaster, and Mus musculus. These are most highly expressed in brain, early embryo, and internal genitalia. By gene-related selective sweeping, we identified five BmEMEs under artificial selection during the domestication and breeding of silkworm. Among these selected genes, BmSuv4-20 and BmDNMT2 harbor selective mutations in their upstream regions that alter transcription factor-binding sites. Furthermore, these two genes are expressed higher in the testis and ovary of domesticated silkworm compared to wild silkworms, and correlations between their expression pattern and meiosis of the sperm and ova were observed. CONCLUSIONS: The domestication of silkworm has induced artificial selection on epigenetic modification markers that may have led to phenotypic changes during domestication. We present a novel perspective to understand the genetic basis underlying animal domestication and breeding.

2,3,5,6-Tetramethylpyrazine improves diet-induced whole-body insulin resistance via suppressing white adipose tissue lipolysis in mice.

Ectopic lipid accumulation in skeletal muscle and liver arises when nutrient storage systems are exposed to chronic energy surplus, leading to whole-body insulin resistance and metabolic disorders. One recent study has shown 2,3,5,6-tetramethylpyrazine (TMP), highly enriched in roasted foodstuffs, such as cocoa and peanuts, significantly decreases blood lipids levels and ameliorates ApoE-defect induced atherosclerosis suggesting a potent role of TMP in lipid dysregulation improvement. Here, we evaluated the impact of TMP treatment on high fat diet (HFD)-induced insulin resistance. Using hyperinsulinemic-euglycemic mouse clamp, we demonstrated 4-week TMP treatment improved whole-body insulin resistance in HFD-fed mice through suppressing lipolysis in white adipose tissue associated with reduced triglyceride in liver and improved glucose uptake in skeletal muscle. Collectively, our work provides proof-of-concept data to support the development of white adipose tissue-targeted medicine for the treatment of metabolic disorder.

Thickness-Dependent In-Plane Polarization and Structural Phase Transition in van der Waals Ferroelectric CuInP2 S6.

van der Waals (vdW) layered materials have rather weaker interlayer bonding than the intralayer bonding, therefore the exfoliation along the stacking direction enables the achievement of monolayer or few layers vdW materials with emerging novel physical properties and functionalities. The ferroelectricity in vdW materials recently attracts renewed interest for the potential use in high-density storage devices. With the thickness becoming thinner, the competition between the surface energy, depolarization field, and interfacial chemical bonds may give rise to the modification of ferroelectricity and crystalline structure, which has limited investigations. In this work, combining the piezoresponse force microscope scanning, contact resonance imaging, the existence of the intrinsic in-plane polarization in vdW ferroelectrics CuInP2 S6 single crystals is reported, whereas below a critical thickness between 90 and 100 nm, the in-plane polarization disappears. The Young's modulus also shows an abrupt stiffness at the critical thickness. Based on the density functional theory calculations, these behaviors are ascribed to a structural phase transition from monoclinic to trigonal structure, which is further verified by transmission electron microscope technique. These findings demonstrate the foundational importance of structural phase transition for enhancing the rich functionality and broad utility of vdW ferroelectrics.

Identification and effect of Zf-AD-containing C2H2 zinc finger genes on BmNPV replication in the silkworm (Bombyx mori).

Zf-AD-containing C2H2 zinc -finger genes (ZAD) are uniquely present and have lineage-specific expansion in arthropods. Arthropods are also the hosts of Baculoviruses. We studied the possible relationship between the lineage-specific expansion of ZAD genes and arthropod-Baculovirus co-evolution. We used the silkworm (Bombyx mori) as a model. We identified 73 ZAD genes (BmZAD) in the silkworm. Sequence-based similarity analysis showed that nine clusters involving 28 BmZADs may have undergone species-specific expansion in the silkworm. Expression pattern analysis showed that the BmZADs were divided into five groups. Group I comprised 10 genes with high expression in multiple tissues, suggesting that BmZADs may play roles in the development of various tissues. We identified six BmZADs that could be induced by the Nucleopolyhedrovirus (BmNPV). Among them, BmZAD69 expression is capable of responding to BmNPV infection, and the ZAD domain is indispensable for the function of BmZAD69 in BmNPV replication. We also detected a 3 bp deletion at 1.7 kb upstream of BmZAD69, which may make it more sensitive to BmNPV infection, and thus elevate the BmNPV resistance in Qiufeng_N, a strain with strong virus resistance. These data suggest that BmZADs may be involved in BmNPV infection and that ZAD genes may play a role in arthropod-Baculovirus co-evolution.

Trends in age of smoking initiation among the Chinese population born between 1950 and 1997.

OBJECTIVES: Smoking prevalence has significantly increased among Chinese adolescences in the past decades. The aim of our study is to investigate the trends and changing patterns in age of smoking initiation among the Chinese population. STUDY DESIGN: Pooled data from the 2006-2015 China Health and Nutrition Survey was used for analysis. A total of 10,032 adults aged ≥18 years who were born between 1950 and 1997 were separated into five birth cohorts (1950-1959, 1960-1969, 1970-1979, 1980-1989 and 1990-1997). METHODS: Age-specific (10-24 years) smoking initiation rates were calculated by gender, educational level and urbanisation. The multiple logistic models were used for estimates of changes in smoking initiation age. RESULTS: The mean age of smoking initiation decreased substantially from 22.0 years (95% confidence interval [CI]: 21.2-22.7) to 17.5 years (95% CI: 16.2-19.1) over five generations. A large decrease was seen in the initiation age group of 15-24 years in the 1980s cohort (15-19 years: odds ratio [OR] = 0.57; 95% CI: 0.19-0.97; 20-24 years: OR = 0.45; 95% CI: 0.18-0.82); a significant decrease was also found in the 1990s cohort (15-19 years: OR = 0.47; 95% CI: 0.11-0.94; 20-24 years old: OR = 0.34; 95% CI: 0.14-0.85). The peak age of smoking initiation changed from 20 years old to 18 years old over the five generations. CONCLUSIONS: The age of smoking initiation has decreased rapidly in the Chinese population in the past decades. Chinese adolescents are becoming the main target group for the tobacco marketing industry, and national legislations are urgently required.

Effects and interaction of meteorological factors on influenza: Based on the surveillance data in Shaoyang, China.

BACKGROUND: Previous studies have demonstrated that meteorological factors influence the incidence of influenza. However, little is known regarding the interactions of meteorological factors on the risk of influenza in China. OBJECTIVE: The study aimed to evaluate the associations between meteorological factors and influenza in Shaoyang of southern China, and explore the interaction of temperature with humidity and rainfall. METHODS: Weekly meteorological data and disease surveillance data of influenza in Shaoyang were collected from 2009 to 2012. According to the incubation period and infectious period of influenza virus, the maximum lag period was set as 3 weeks. A generalized additive model was conducted to evaluate the effect of meteorological factors on the weekly number of influenza cases and a stratification model was applied to investigate the interaction. RESULTS: During the study period, the total number of influenza cases that were notified in the study area was 2506, with peak times occurring from December to March. After controlling for the confounders, each 5 °C decrease in minimum temperature was related to 8% (95%CI: 1-15%) increase in the number of influenza cases at a 1-week lag. There was an interaction between minimum temperature and relative humidity and the risk of influenza was higher in cold and less humid conditions than other conditions. The interaction between minimum temperature and rainfall was not statistically significant in our study. CONCLUSIONS: The study suggests that minimum temperature is inversely associated with influenza in the study area of China, and the effect can be modified by relative humidity. Meteorological variables could be integrated in current public health surveillance system to better prepare for the risks of influenza.

Identifying different types of flood-sensitive diarrheal diseases from 2006 to 2010 in Guangxi, China.

Floods may influence different types of diarrheal diseases and epidemiological studies of pathogen-specific diarrhea due to floods in China are still needed. In addition, few studies have been conducted to quantify the lag and cumulative risk of diarrheal disease due to floods in Guangxi, China. Our study aimed to identify different types of diarrheal diseases that were sensitive to floods and to quantify their lag and cumulative impact. A matched analysis based on time series data of floods and infectious disease from 2006 to 2010 was conducted in Guangxi, China. Each flood day was treated as an independent unit in our study. A simplified assumption that each day of the flood confers the same risk was adopted before analysis. Each flood day was matched to a non-flood day by city and time. Log-linear mixed-effects regression models were used to quantify the association between different types of diarrheal diseases and floods. Lag and cumulative effects were also calculated to get delayed and overall effects. A total of 45,131 diarrhea cases were notified in the study area over the study period. After controlling for the long-term trend, seasonality, and meteorological factors, floods caused a significantly increased risk of total diarrheal diseases. The RR was highest at lag 2 days (RR=1.24, 95% CI: 1.11-1.40). Floods caused a significantly increased risk in bacillary dysentery and in other infectious diarrhea, but not in typhoid fever and paratyphoid fever. Floods were significantly associated with total diarrheal diseases and other infectious diarrhea for both cumulative lag 0-7 and 0-14 days. Our study provides strong evidence of a positive association between floods and diarrheal diseases including bacillary dysentery and other infectious diarrhea in study area. Public health interventions should be taken to prevent a potential risk of these flood-sensitive diarrheal diseases according to the different lag period after floods.

Photoassisted Construction of Holey Defective g-C3 N4 Photocatalysts for Efficient Visible-Light-Driven H2 O2 Production.

Holey defective g-C3 N4 photocatalysts, which are easily prepared via a novel photoassisted heating process, are reported. The photoassisted treatment not only helps to create abundant holes, endowing g-C3 N4 with more exposed catalytic active sites and crossplane diffusion channels to shorten the diffusion distance of both reactants from the surface to bulk and charge carriers from the bulk to surface, but also introduces nitrogen vacancies in the tri-s-triazine repeating units of g-C3 N4 , inducing the narrowing of intrinsic bandgap and the formation of defect states within bandgap to extend the visible-light absorption range and suppress the radiative electron-hole recombination. As a result, the holey defective g-C3 N4 photocatalysts show much higher photocatalytic activity for H2 O2 production with optimized enhancement up to ten times higher than pristine bulk g-C3 N4 . The newly developed synthetic strategy adopted here enables the sufficient utilization of solar energy and shows rather promising for the modification of other materials for efficient energy-related applications.

Association between floods and typhoid fever in Yongzhou, China: Effects and vulnerable groups.

BACKGROUND: Little information about the effects of floods on typhoid fever is available in previous studies. This study aimed to examine the relationships between floods and typhoid fever and to identify the vulnerable groups in Yongzhou, China. METHODS: Weekly typhoid fever data, flood data and meteorological data during the flood season (April to September) from 2005 to 2012 were collected for this study. A Poisson generalized linear model combined with a distributed lag non-linear model was conducted to quantify the lagged and cumulative effects of floods on typhoid fever, considering the confounding effects of long-term trend, seasonality, and meteorological variables. The model was also used to calculate risk ratios of floods for weekly typhoid fever cases among various subpopulations. RESULTS: After adjusting for long-term trend, seasonality, and meteorological variables, floods were associated with an increased number of typhoid fever cases with a risk ratio of 1.46 (95% CI: 1.10-1.92) at 1-week lag and a cumulative risk ratio of 1.76 (95% CI: 1.21-2.57) at lag 0-1 weeks. Males, people aged 0-4 years old, people aged 15-64 years old, farmers, and children appeared to be more vulnerable than the others. CONCLUSIONS: Our study indicates that floods could significantly increase the risks of typhoid fever with lag effects of 1 week in the study areas. Precautionary measures should be taken with a focus on the identified vulnerable groups in order to control the transmission of typhoid fever associated with floods.

Density functional study on the hole doping of single-layer SnS2 with metal element X (X = Li, Mg, and Al).

The effects of metal element X-doping on the electronic and optical properties of single-layer SnS2 were investigated using density functional theory. The results show that the doping is energetically more favorable under S-rich conditions than under Sn-rich conditions. For Li and Mg doping, there is the existence of ionic bonding between the dopants and adjacent S atoms, and the systems exhibit magnetic ground states. However, covalent bonding character is observed in Al-doped single-layer SnS2, and the system exhibits non-magnetic ground states. The optical properties show that the optical absorptions are anisotropic for all doping cases. The X doping not only results in a red shift of the absorption edges, but also enhances the effective utilization in the near-infrared light region. Additionally, Li-doped single-layer SnS2 is active for overall water splitting under visible light radiation whereas Mg and Al-doped SnS2 are only suitable for oxygen evolution.

N-Glycosylation of Human R-Spondin 1 Is Required for Efficient Secretion and Stability but Not for Its Heparin Binding Ability.

R-spondin 1 (Rspo1) plays an essential role in stem cell biology by potentiating Wnt signaling activity. Despite the fact that Rspo1 holds therapeutic potential for a number of diseases, its biogenesis is not fully elucidated. All Rspo proteins feature two amino-terminal furin-like repeats, which are responsible for Wnt signal potentiation, and a thrombospondin type 1 (TSR1) domain that can provide affinity towards heparan sulfate proteoglycans. Using chemical inhibitors, deglycosylase and site-directed mutagenesis, we found that human Rspo1 and Rspo3 are both N-glycosylated at N137, a site near the C-terminus of the furin repeat 2 domain, and Rspo2 is N-glycosylated at N160, a position near the N-terminus of TSR1 domain. Elimination of N-glycosylation at these sites affects their accumulation in media but have no effect on the ability towards heparin. Introduction of the N-glycosylation site to Rspo2 mutant at the position homologous to N137 in Rspo1 restored full glycosylation and rescued the accumulation defect of nonglycosylated Rspo2 mutant in media. Similar effect can be observed in the N137 Rspo1 or Rspo3 mutant engineered with Rspo2 N-glycosylation site. The results highlight the importance of N-glycosylation at these two positions in efficient folding and secretion of Rspo family. Finally, we further showed that human Rspo1 is subjected to endoplasmic reticulum (ER) quality control in N-glycan-dependent manner. While N-glycan of Rspo1 plays a role in its intracellular stability, it had little effect on secreted Rspo1. Our findings provide evidence for the critical role of N-glycosylation in the biogenesis of Rspo1.

An ESRG-interacting protein, COXII, is involved in pro-apoptosis of human embryonic stem cells.

Human embryonic stem cells(hESC) posses very promising application perspective in clinical transplant therapies for their characteristics of self-renewal and pluripotency. So efforts focusing on the mechanisms of the two characteristics are extremely important. ESRG, first identified by our group, is a candidate stemness gene of hESC for its much higher expression level in hESC comparing to that in 7-day embryoid bodies(EBs). Here, the proteins interacted with ESRG and its functions in hESC were explored. Yeast two-hybrid (Y2H) screening system was adopted to explore the interacting proteins of ESRG. Then Co-IP was performed to confirm the interactions between candidate proteins and ESRG. At last, the functions of validated interacting protein were explored by RNA interference(RNAi) and Western blot(WB). There were no autonomous activation and toxicity in the Y2H system, which verified its availability. Four candidate proteins, AAMP, DDT, GNB2L1 and COXII, were discovered, and the interaction between ESRG and COXII was ultimately confirmed. The expression of COXII in hESC was suppressed by siRNA, and the inhibited mitochondrial apoptosis was observed in hESC with downregulated COXII expression. Our work first validated the interaction between ESRG and COXII, and demonstrated that COXII serves as a pro-apoptotic protein in hESC. The results implied that ESRG may play an important role in regulating the apoptosis of hESC by interacting with COXII, and thus contribute a lot to the maintenance of hESC characteristics.