Search

Pseudoalteromonas, with a ubiquitous distribution, is one of the most abundant marine bacterial genera. It is especially abundant in the deep sea and polar seas, where it has been found to have a broad metabolic capacity and unique co-existence strategies with other organisms. However, only a few Pseudoalteromonas phages have so far been isolated and investigated and their genomic diversity and distribution patterns are still unclear. Here, the genomes, taxonomic features and distribution patterns of Pseudoalteromonas phages are systematically analyzed, based on the microbial and viral genomes and metagenome datasets. A total of 143 complete or nearly complete Pseudoalteromonas-associated phage genomes (PSAPGs) were identified, including 34 Pseudoalteromonas phage isolates, 24 proviruses, and 85 Pseudoalteromonas-associated uncultured viral genomes (UViGs); these were assigned to 47 viral clusters at the genus level. Many integrated proviruses (n = 24) and filamentous phages were detected (n = 32), suggesting the prevalence of viral lysogenic life cycle in Pseudoalteromonas. PSAPGs encoded 66 types of 249 potential auxiliary metabolic genes (AMGs) relating to peptidases and nucleotide metabolism. They may also participate in marine biogeochemical cycles through the manipulation of the metabolism of their hosts, especially in the phosphorus and sulfur cycles. Siphoviral and filamentous PSAPGs were the predominant viral lineages found in polar areas, while some myoviral and siphoviral PSAPGs encoding transposase were more abundant in the deep sea. This study has expanded our understanding of the taxonomy, phylogenetic and ecological scope of marine Pseudoalteromonas phages and deepens our knowledge of viral impacts on Pseudoalteromonas. It will provide a baseline for the study of interactions between phages and Pseudoalteromonas in the ocean.

Nuclear decoupling and softening are the main cellular mechanisms to resist mechanical stress-induced nuclear/DNA damage, however, its molecular mechanisms remain much unknown. Our recent study of Hutchinson-Gilford progeria syndrome (HGPS) disease revealed the role of nuclear membrane protein Sun2 in mediating nuclear damages and cellular senescence in progeria cells. However, the potential role of Sun2 in mechanical stress-induced nuclear damage and its correlation with nuclear decoupling and softening is still not clear. By applying cyclic mechanical stretch to mesenchymal stromal cells (MSCs) of WT and Zmpset24−/− mice (Z24−/−, a model for HGPS), we observed much increased nuclear damage in Z24−/− MSCs, which also featured elevated Sun2 expression, RhoA activation, F-actin polymerization and nuclear stiffness, indicating the compromised nuclear decoupling capacity. Suppression of Sun2 with siRNA effectively reduced nuclear/DNA damages caused by mechanical stretch, which was mediated by increased nuclear decoupling and softening, and consequently improved nuclear deformability. Our results reveal that Sun2 is greatly involved in mediating mechanical stress-induced nuclear damage by regulating nuclear mechanical properties, and Sun2 suppression can be a novel therapeutic target for treating progeria aging or aging-related diseases.

We aimed to identify the molecular biomarkers of MDD disease progression to uncover potential mechanisms of major depressive disorder (MDD). In this study, three microarray data sets, GSE44593, GSE12654, and GSE54563, were cited from the Gene Expression Omnibus database for performance evaluation. To perform molecular functional enrichment analyses, differentially expressed genes (DEGs) were identified, and a protein–protein interaction network was configured using the Search Tool for the Retrieval of Interacting Genes/Proteins and Cytoscape. To assess multi-purpose functions and pathways, such as signal transduction, plasma membrane, protein binding, and cancer pathways, a total of 220 DEGs, including 143 upregulated and 77 downregulated genes, were selected. Additionally, six central genes were observed, including electron transport system variant transcription factor 6, FMS-related receptor tyrosine kinase 3, carnosine synthetase 1, solute carrier family 22 member 13, prostaglandin endoperoxide synthetase 2, and protein serine kinase H1, which had a significant impact on cell proliferation, extracellular exosome, protein binding, and hypoxia-inducible factor 1 signaling pathway. This study enhances our understanding of the molecular mechanism of the occurrence and progression of MDD and provides candidate targets for its diagnosis and treatment.

Astrocytes play a crucial role in regulating sleep–wake behavior, and adenosine signaling is generally thought to be involved. Here we show multiple lines of evidence supporting that modulation of the sleep–wake behavior by astrocyte Ca2+ activity could occur without adenosine signaling. In the basal forebrain and the brainstem, two brain regions that are known to be essential for sleep–wake regulation, chemogenetically-induced astrocyte Ca2+ elevation significantly modulated the sleep–wake cycle. Although astrocyte Ca2+ level positively correlated with the amount of extracellular adenosine, as revealed by a genetically encoded adenosine sensor, we found no detectable change in adenosine level after suppressing astrocyte Ca2+ elevation, and transgenic mice lacking one of the major extracellular ATP-adenosine conversion enzymes showed similar extracellular adenosine level and astrocyte Ca2+-induced sleep modulation. Furthermore, astrocyte Ca2+ is dependent primarily on local neuronal activity, causing brain region-specific regulation of the sleep–wake cycle. Thus, neural activity-dependent astrocyte activity could regulate the sleep–wake behavior independent of adenosine signaling.

As one of the most important coal-producing provinces of China, Shanxi Province has been concerned about soil potentially toxic elements (PTEs) contamination in recent years. The study aimed to determine the status and sources of PTEs contamination and evaluate the quality of the soil ecology. This study investigated the degree of 13 PTEs contamination. The sources and contributions of PTEs were traced by the absolute principal component score followed by a multiple linear regression model (APCS-MLR). And the status of the soil ecosystem was verified by evaluating the soil nematode community around the coal mining areas in Jinzhong. The results showed that the mean PTEs concentration of 5 trace elements were higher than the background values of Shanxi, and safe to considerable was indicated by the pollution and ecological risk values. Soil Hg was the most contaminated element, followed by Cd. The distribution of PTEs was determined by coal mining activities (44.72%) followed by agricultural practice (32.37%) and coal transportation (21.37%). The nematode genera Acrobeloides (4.01%), Aphelenchus (20.30%), Meloidogyne (11.95%) and Aporcelaimus (2.74%) could be regarded as bioindicators of soil PTEs contamination by their tolerance. Concentrations of soil Cr, Mn, Ti and Cd showed remarkable influences on the total nematode abundance, maturity index, enrichment index, structural index, Shannon-Wiener diversity index and Pielou index of soil nematode. It is an appropriate method to evaluate the status of soil PTEs contamination combining the response of a single nematode genus and the nematode community evaluation index.

The cerebral cortex is spontaneously active during sleep, yet it is unclear how this global cortical activity is spatiotemporally organized, and whether such activity not only reflects sleep states but also contributes to sleep state switching. Here we report that cortex-wide calcium imaging in mice revealed distinct sleep stage-dependent spatiotemporal patterns of global cortical activity, and modulation of such patterns could regulate sleep state switching. In particular, elevated activation in the occipital cortical regions (including the retrosplenial cortex and visual areas) became dominant during rapid-eye-movement (REM) sleep. Furthermore, such pontogeniculooccipital (PGO) wave-like activity was associated with transitions to REM sleep, and optogenetic inhibition of occipital activity strongly promoted deep sleep by suppressing the NREM-to-REM transition. Thus, whereas subcortical networks are critical for initiating and maintaining sleep and wakefulness states, distinct global cortical activity also plays an active role in controlling sleep states.

With the development of deep learning network models, the automatic segmentation of medical images is becoming increasingly popular. Left ventricular cavity segmentation is an important step in the diagnosis of cardiac disease, but post-processing segmentation is a time-consuming and challenging task. That is why a fully automated segmentation method can assist specialists in increasing their efficiency. Inspired by the power of deep neural networks, a multi-scale multi-skip connection network (MMNet) model is proposed to fully automate the left ventricular segmentation of cardiac magnetic resonance imaging (MRI) images; this model is simple and efficient and has high segmentation accuracy without pre-detecting left ventricular localization. MMNet redesigns the classic encoder and decoder to take advantage of multi-scale feature information, effectively solving the problem of difficult segmentation due to blurred left ventricular edge information and the low accuracy of end-systolic segmentation of the cardiac area. In the model encoding stage, a multi-scale feature fusion module applying dilated convolution is proposed to obtain richer semantic information from different perceptual fields. The decoding stage reconstructs the full-size skip connection structure to make full use of the feature information obtained from different layers for contextual semantic information fusion. At the same time, a pre-activation module is used before each weighting layer to prevent overfitting phenomena from arising. The experimental results demonstrate that the proposed model has better segmentation performance than advanced benchmark models. Ablation experiments show that the proposed modules are effective at improving segmentation results. Therefore, MMNet is a promising approach for the left ventricular fully automated segmentation.

In the manufacturing process of LED chips, the accuracy of the LED chip visual localization system affects the quality of LED chip production directly. There are many errors that have impacts on positioning system accuracy. Therefore, the identification and compensation of the critical errors is key to efficiently improving the precision of the system. Based on this fact, an error analysis method and an error compensation strategy are proposed in this paper. The first step was to measure the relevant error sources that may affect the localization system. Then error model of localization system was established, and the validity of this error model was verified by comparing simulated and actual positioning results. In addition, the impact factors of each error source on localization system accuracy were obtained using the error transfer theory. According to the error analysis results, an efficient error compensation strategy was proposed, which could compensate the errors in order of impact factors, and judge whether the error compensation method is optimal. Finally, the experimental results proved that the proposed error analysis method was valid and the error compensation strategy could efficiently enhance the positioning accuracy to meet the industrial application requirements.

Background Silencing of the periostin gene (POSTN) can inhibit the biological process of several different cancers, and this inhibition may be related to down-regulation of PI3K/AKT signaling. However, the effect of POSTN on the progression, proliferation, and invasion of osteosarcoma (OS) remain unclear. Methods We used the Gene Expression Omnibus (GEO) database to screen datasets on in situ OS and lung metastases to identify core genes and potential pathways. We used additional bioinformatics tools to identify protein–protein interactions (PPIs) and gene networks, and selected the top seven genes whose expression had the strongest correlations with other genes. Results The results indicated that POSTN was a major hub gene. Subsequent analysis of gene expression profiles showed that POSTN was highly expressed in 262 cases with sarcoma and expression was closely related to poor prognosis. We also performed enrichment analysis to identify differentially expressed genes and used real-time PCR, western blotting, and immunohistochemistry analyses to measure POSTN expression in cells and tissues. Transfection of a POSTN-shRNA plasmid into cultured OS cells (Saos-2) effectively inhibited the proliferation, invasion, and migration of these cells. Taken together, our results suggest that POSTN may play a role in promoting the proliferation and metastasis of OS by activation of the PI3K/Akt signaling pathway. Conclusions Our results provide a preliminary characterization of the mechanism by which POSTN may regulate the migration and invasion of OS cells and also provide a theoretical basis for identifying biomarkers that have potential use for the diagnosis and treatment of OS.

Background A major challenge of prospective cohort studies is attrition in follow-up surveys. This study investigated attrition in a prospective cohort comprised of medical graduates in China. We described status of attrition, identified participants with higher possibility of attrition, and examined if attrition affect the estimation of the key outcome measures. Methods The cohort study recruited 3,620 new medical graduates from four medical universities in central and western China between 2015 and 2019. Online follow-up surveys were conducted on an annual basis. Follow-up status was defined as complete (meaning that the participant completed all the follow-up surveys) and incomplete, while incomplete follow-up was further divided into ‘always-out’, ‘rejoin’ and ‘other’. Multivariable logistic and linear regressions were used to examine factors predicting attrition and the influence on the outcome measures of career development. Results 2364 (65.3%) participants completed all follow-up surveys. For those with incomplete follow-up, 520 (14.4%) were ‘always-out’, 276 (7.6%) rejoined in the 2020 survey. Willingness to participate in residency training (OR=0.80, 95%CI[0.66 - 0.98]) and willingness to provide sensitive information in the baseline survey predicted a lower rate of attrition (providing scores for university entrance exam OR=0.82, 95%CI[0.69 - 0.97]]; providing contact information (OR=0.46, 95%CI[0.32 - 0.66]); providing household income (OR=0.60, 95%CI[0.43 - 0.84]). Participants with compulsory rural service (OR=1.52, 95%CI[1.05 - 2.19]) and those providing university entrance scores (OR=1.64, 95%CI[1.15-2.33)) were more likely to rejoin in the follow-up survey. These factors associated with follow-up status did not have significant impact on key outcome measures of career development. Conclusions Graduates who were unwilling to participate in residency training or not providing sensitive information should be targeted early in the cohort study to reduce attrition. More information about the study should be provided to those graduates early to facilitate their understanding of the meaning in participation. On the contrary, medical graduates with compulsory rural service and those who provided university entrance scores were more likely to rejoin in the cohort. The research team should invest more effort in contacting those graduates and returned them to the cohort.

As the core ingredient for spin polarization, the equilibrium spin distribution function that eliminates the collision terms is derived from the detailed balance principle. The kinetic theory for interacting fermionic systems is applied to the Nambu–Jona-Lasinio model at quark level. Under the semi-classical expansion with respect to $$\hbar $$ ħ , the kinetic equations for the vector and axial-vector distribution functions are obtained with collision terms. For an initially unpolarized system, spin polarization can be generated at the first order of $$\hbar $$ ħ from the coupling between the vector and axial-vector charges. Different from the classical transport theory, the collision terms in a quantum theory vanish only in global equilibrium with Killing condition.

Amphioxus belongs to the subphylum cephalochordata, an extant representative of the most basal chordates, whose regulation of endocrine system remains ambiguous. Here we clearly demonstrated the existence of a functional orexin neuropeptide in amphioxus, which is able to interact with orexin receptor, activate both PKC and PKA pathways, decrease leptin expression, and stimulate lipogenesis. We also showed the transcription level of amphioxus orexin was affected by fasting or temperature, indicating a role of this gene in the regulation of energy balance. In addition, the expression of the amphioxus orexin was detected at cerebral vesicle, which has been proposed to be a homolog of the vertebrate brain. These data collectively suggest that a functional orexin neuropeptide has already emerged in amphioxus, which provide insights into the evolutionary origin of orexin in chordate and the functional homology between the cerebral vesicle and vertebrate brain.

Purposes to study the effect of titanium particles on MLO-Y4 and the effects of osteocytes alterations on osteoblasts. Methods cultured MLO-Y4 osteocytes were exposed to different concentrations of titanium (Ti) particles, cell viability was measured using the Cell Counting Kit-8 (CCK-8) assay, apoptosis of MLO-Y4 cells was evaluated by flow cytometry, Real-time PCR quantification of mRNA expression of SOST, at the same time with Western Blot detection sclerosteosis protein expression levels.MC3T3-E1 cells culture with MLO-Y4 cells exposed to different concentrations of titanium (Ti) particles in vitro, in order to detection of osteoblast osteogenetic activity. Results Our results showed that Ti particles inhibited cell viability of MLO-Y4 osteocytes in a dose-dependent manner. Incubation with Ti particles caused apoptosis of MLO-Y4cells.Treatment with Ti particles significantly increased expression of the osteocytic marker SOST/sclerostin. Furthermore, treatment of MLO-Y4 cells with Ti particles produced a dose-dependent decrease in ALP activity and decreased mineralization of MC3T3-E1 cells through direct cell-cell contact. Conclusions Titanium particles damage osteocytes and inhibit osteoblast differentiation.

Glibenclamide (GBC) improves neurological outcome after cardiac arrest (CA) in rats. In this study, we sought to elucidate the mechanism responsible for the neuroprotective effects of GBC by using a high-field MRI system. Male Sprague–Dawley rats were subjected to 10-min asphyxial CA followed by cardiopulmonary resuscitation (CPR). Diffusion-weighted imaging (DWI) as well as conventional T2-weighted imaging was conducted prior to CA and at 24, 48, and 72 h after resuscitation. Afterward, histological examination was performed. Twelve rats were randomized to receive GBC (n = 6) or vehicle (n = 6) at 15 min after return of spontaneous circulation, while four rats were set as sham control. Rats that underwent CA/CPR and received vehicle exhibited distinct neurological deficit, which was alleviated by GBC treatment. Marked water diffusion abnormality as demonstrated by hyperintense DWI in vulnerable regions of the brain was detected after CA/CPR, with the most prominent hyperintense DWI observed in the hippocampal CA1 region at 72 h. Consistently, histological examination revealed neuronal swelling, dendritic injury, and activation of astrocytes and microglia in the hippocampal CA1 region in vehicle-treated rats. Correlation analysis revealed that the ADC values in the hippocampus were significantly correlated with the histological findings (all p

Positioning accuracy of chip directly impacts on the quality and efficiency of LED chip production. The purpose of this paper is to improve the chip positioning accuracy by improving the camera calibration algorithm of LED chip visual positioning system. Firstly, by making the error analysis for the visual positioning system, the systematic errors of each parts of the system are obtained, and the relationship between chip positioning error and chip position distribution in image is found. Then, according to the result of error analysis and the characteristics of the chip positioning process, an improved calibration algorithm is proposed to improve the chip positioning accuracy. This improved algorithm solves the calibration parameters in two steps, which highlights the main cause of errors in calibration process and meets the requirements of chip positioning. Finally, the experiment results show that the proposed algorithm can improve the chip positioning accuracy obviously, and has good stability and robustness.

Background Echinococcosis has led to considerable social and economic losses in China, particularly in the endemic communities of the eastern Tibetan Plateau. In China, human cases of Echinococcus granulosus (sensu stricto), E. canadensis and E. multilocularis infections have been described, but no E. ortleppi (G5) infections in humans or animals have been reported. Results A case of E. ortleppi infection in a human from Guangxi, which is a non-endemic echinococcosis area in China, is described. A 17 × 12 × 20 cm (diameter) cyst was observed in the liver of the patient, and Echinococcus larvae were collected from the cyst. A morphological examination indicated that the larvae were E. ortleppi, and amplification and analysis of the nicotinamide adenine dinucleotide hydrogenase dehydrogenase subunit 1 (nad1) and cytochrome c oxidase subunit 1 (cox1) genes showed that the larvae had 99–100% homology with the corresponding E. ortleppi sequences on GenBank. Conclusions To our knowledge, this report describes the first identification of a human E. ortleppi infection in China. Our data broaden the geographical distribution of this rarely reported species of Echinococcus.

Background The chemotherapy-resistance of triple-negative breast cancer (TNBC) remains a major challenge. The Nek2B kinase and β-catenin serve as crucial regulators of mitotic processes. The aim of this study was to test the correlation between Nek2B and TNBC chemotherapy sensitivity, and to determine the regulation of Nek2B on β-catenin and wnt/β-catenin signal pathway. Methods Gene Expression Omnibus(GEO) databases were used to gather gene exprsssion data of TNBC patients who undergoing chemotherapy. The co-expression of Nek2B and β-catenin in TNBC surgical sections and cells were analysed by immunohistochemistry, Q-RT-PCR, Western-blot and immunofluorescent staining. The impact of the expression of Nek2B and β-catenin in prognosis was also assessed using the Kaplan-Meier curves. CCK8 assay was used to detect the IC50 value of TNBC cell line. The endogenous binding capacity of Nek2B and β-catenin and phosphorylation of β-catenin by Nek2B were detected using co-immunoprecipitation (CO-IP). Chromatin immune-precipitation (ChIP) analysis and Luciferase Assays were used to evaluate the binding ability of the Nek2B, β-catenin and TCF4 complex with LEF-1 promoter. Nek2B-siRNA and Nek2B plasmid were injected into nude mice, and tumorigenesis was monitored. Results We found that overexpression of Nek2B and β-catenin in TNBC samples, was associated with patients poor prognosis. Patients with positive Nek2B expression were less sensitive to paclitaxel-containing neoadjuvant chemotherapy. Interestingly, in a panel of established TNBC cell line, Nek2B and β-catenin were highly expressed in cells exhibiting paclitaxel resistance. Our data also suggest that β-catenin binded to and was phosphorylated by Nek2B, and was in a complex with TCF4. Nek2B mainly regulates the expression of β-catenin in TNBC nucleus. Nek2B, β-catenin and TCF4 can be binded with the WRE functional area of LEF-1 promoter. Nek2B can activite wnt signaling pathway and wnt downstream target genes. The tumors treated by Nek2B siRNA associated with paclitaxel were the smallest in nude mouse, and Nek2B can regulate the expression of β-catenin and wnt downstream target genes in vivo. Conclusion Our study suggested that Nek2B can bind to β-catenin and the co-expression correlated with TNBC patients poor prognosis. It appears that Nek2B and β-catenin might synergize to promote chemotherapy resistance.

Separation of Ni2+ from ammonia/ammonium chloride solution using a flat-sheet supported liquid membrane (SLM) impregnated with Acorga M5640 in kerosene was investigated. The fundamental experimental variables influencing Ni2+ transport, such as ammonia concentration, carrier concentration, H2SO4 concentration in the stripping solution, stirring speed, and initial Ni2+ concentration were studied. Almost all of Ni2+ was transported from the feed to the stripping phase after 18 h of operation with a permeability coefficient of 9.28 × 10−6 m s−1 under optimum conditions: stirring speed of 1000 rpm in both phases, 20 vol.% Acorga M5640 as the carrier, 1.70 mmol L−1 Ni2+ in the feed phase and 0.10 mol L−1 H2SO4 in the stripping phase. The flux value of Ni2+ was 15.82 × 10−6 mol m−2 s−1. Additionally, the influences of temperature and ultrasound on flux were examined, and results indicated that higher temperature and ultrasonic assistance improved transport of Ni2+ through the SLM. Selective separation of nickel from cobalt in an ammonia/ammonium chloride solution was also achieved through SLM. The stability of the SLM was examined on a continuous run mode and satisfactory stability of the nickel permeation was observed for 84 h (7 runs).

Drilling is used in a very large variety of applications, which is one of the most complex manufacturing processes and is a semi-enclosed cutting process. The use of titanium alloy Ti6Al4V in engineering applications has increased in recent years, and in many of these applications drilling is one of the most critical stages in the manufacturing process. Critical issues in drilling of Ti6Al4V are often associated with large drilling forces and short life. Understanding and predicting the drilling forces occurring during drilling of Ti6Al4V would allow extending the currently used optimization methods and proposing new tool geometries and tool materials. The current paper introduces an improved mechanistic model for predicting the drilling force distribution along the main cutting edge and chisel edge of a drill, which considered the effect of feed rate. Based on the definitions of working angles, the equivalent model of drilling is developed. The effect of feed rate on the working rake angle was also investigated. Then, the drilling force model in the main cutting edge is developed based on the oblique cutting model. However, there are two different equivalent regions in chisel edge; here the drilling force model is developed based on orthogonal cutting model and plastic extrusion model, respectively. A special drilling forces distribution experiments are carried out in drilling Ti6Al4V. Good agreement between the measured and predicted drilling forces is found.