Low G preconditioning reduces liver injury induced by high +Gz exposure in rats

AIM:To investigate the effect of repeated lower +Gzexposure on liver injury induced by high +Gz exposure in rats.METHODS:Sixty male Wister rats were randomly divided into a blank control group,a low G preconditioning group(LG)(exposed to +4 Gz/5 min per day for 3 d before +10 Gz/5 min exposure),and a +10 Gz/5 min group(10G)(n = 20 in each group).Blood specimens and liver tissue were harvested at 0 h and 6 h after +10 Gz/5 min exposure.Liver function was analyzed by measuring serum alanine transaminase(ALT) and aspartate aminotransferase(AST) levels,and liver injury was further assessed by histopathological observation.Malondialdehyde(MDA),superoxide dismutase(SOD) and Na+-K+-ATPase were determined in hepatic tissue.RESULTS:The group LG had lower ALT,AST,and MDA values at 0 h after exposure than those in group 10 G.SOD values and Na+-K+-ATPase activity in the LG group were higher than in group 10 G 0 h post-exposure.Hepatocyte injury was significantly less in group LG than in group 10 G on histopathological evaluation.CONCLUSION:It is suggested that repeated low +Gz exposure shows a protective effect on liver injury induced by high +Gz exposure in rats.

Characterizing the composition of intestinal microflora by 16S rRNA gene sequencing

BACKGROUND This study determined the composition and diversity of intestinal microflora in patients with colorectal adenoma(CRA),which may provide precedence for investigating the role of intestinal microflora in the pathogenesis of colorectal tumors,the composition of intestinal microflora closely related to CRA,and further validating the possibility of intestinal flora as a biomarker of CRA.AIM To study the relationship between intestinal microflora and CRA.METHODS This is a prospective control case study from October 2014 to June 2015 involving healthy volunteers and patients with advanced CRA.High-throughput sequencing and bioinformatics analysis were used to investigate the composition and diversity of intestinal microflora in 36 healthy subjects and 49 patients with advanced CRA.Endpoints measured were operational taxonomic units of intestinal flora,as well as their abundance and diversity(αandβtypes).RESULTS In this study,the age,gender,body mass index,as well as location between controls and patients had no significant differences.The mucosa-associated gut microbiota diversity and bacterial distribution in healthy controls and colorectal adenomas were similar.The operational taxonomic unit,abundance,andαandβdiversity were all reduced in patients with CRA compared to controls.At the phylum level,the composition of intestinal microflora was comparable between patients and controls,but the abundance of Proteobacteria was increased,and Firmicutes and Bacteroides were significantly decreased(P<0.05).The increase in Halomonadaceae and Shewanella algae,and reduction in Coprococcus and Bacteroides ovatus,could serve as biomarkers of CRA.High-throughput sequencing confirms the special characteristics and diversity of intestinal microflora in healthy controls and patients with CRA.CONCLUSION The diversity of intestinal microflora was decreased in patients with CRA.An increase in Halomonadaceae and Shewanella algae are markers of CRA.

Zircon U-Pb-Hf isotopic and geochemical characteristics of the Xierzi biotite monzogranite pluton,Linxi,Inner Mongolia and its tectonic implications

The opening, subduction and final closure of the Paleo-Asian Ocean led to the formation of the Central Asian Orogenic Belt. Controversy has long surrounded the timing of final closure of the Paleo-Asian Ocean. Here we present zircon U-Pb ages and petrological, geochemical and in situ Hf isotope data for the Xierzi biotite monzogranite pluton, Linxi, SE Inner Mongolia. U-Pb dating of zircon by LA-ICP-MS yields a middle Permian emplacement age(268.7 ± 2.3 Ma) for the Xierzi pluton that is dominated by biotite monzogranites with high SiO_2(71.2-72.8 wt.%),alkali(Na_2 O + K_2 O =8.05-8.44 wt.%), Al_2 O_3(14.4-15.2 wt.%) and Fe_2 O_3~T relative to low MgO contents, yielding Fe_2 O_3~T/MgO ratios of 2.87-3.44, and plotting within the high-K calc-alkaline field on a SiO_2 vs. K_2 O diagram. The aluminum saturation indexes(A/CNK) of the biotite monzogranites range from 1.06 to 1.19, corresponding to weakly to strongly peraluminous. They are enriched in rare earth elements(REE), high field strength elements(HFSEs; Zr,Hf). and large ion lithophile elements(LILEs; Rb, U, Th). The LREEs are enriched relative to the HREEs,with a distinct negative Eu anomaly in a chondrite-normalized REE diagram. Geochemically, the Xierzi biotite monzogranite is classified as an aluminous A-type granite, with all samples plotting within the A2-type granite field on a Y/Nb vs. Rb/Nb diagram. Zircon ε_(Hf)(t) values and two-stage modal ages of the zircons within the pluton range from +4.80 to +13.65 and from 983 to 418 Ma, respectively, indicating that the primary magma was generated through partial melting of felsic rocks from juvenile crust.Consequently, these results demonstrate that the Xierzi pluton formed under the post-orogenic extensional setting after arc-continent collision in the middle Permian.

Enhanced segmentation of gastrointestinal polyps from capsule endoscopy images with artifacts using ensemble learning

BACKGROUND Endoscopy artifacts are widespread in real capsule endoscopy(CE)images but not in high-quality standard datasets.AIM To improve the segmentation performance of polyps from CE images with artifacts based on ensemble learning.METHODS We collected 277 polyp images with CE artifacts from 5760 h of videos from 480 patients at Guangzhou First People’s Hospital from January 2016 to December 2019.Two public high-quality standard external datasets were retrieved and used for the comparison experiments.For each dataset,we randomly segmented the data into training,validation,and testing sets for model training,selection,and testing.We compared the performance of the base models and the ensemble model in segmenting polyps from images with artifacts.RESULTS The performance of the semantic segmentation model was affected by artifacts in the sample images,which also affected the results of polyp detection by CE using a single model.The evaluation based on real datasets with artifacts and standard datasets showed that the ensemble model of all state-of-the-art models performed better than the best corresponding base learner on the real dataset with artifacts.Compared with the corresponding optimal base learners,the intersection over union(IoU)and dice of the ensemble learning model increased to different degrees,ranging from 0.08%to 7.01%and 0.61%to 4.93%,respectively.Moreover,in the standard datasets without artifacts,most of the ensemble models were slightly better than the base learner,as demonstrated by the IoU and dice increases ranging from-0.28%to 1.20%and-0.61%to 0.76%,respectively.CONCLUSION Ensemble learning can improve the segmentation accuracy of polyps from CE images with artifacts.Our results demonstrated an improvement in the detection rate of polyps with interference from artifacts.

Effect of rhBMP-2 sustained-release nanocapsules on the ectopic osteogenesis process in Sprague-Dawley rats

Objective:To explore the effect of sustained-release recombinant human bone morphogenetic protein-2(rhBMP-2) on ectopic osteogenesis in the muscle pouches of rats through preparing rhBMP-2 sustained-release capsules by wrapping morphogenesis protein bones-2(BMP-2)using chitosan nanoparticles,and compositing collagen materials.Methods:Twenty four SpragueDawley rats were randomly divided into four groups with six rats in each group,that is Group A(control group),Group B(only treated with collagen),Group C(rhBMP-2+collagen treated group) and Group D(rhBMP-2/cs+collagen treated group).The composite materials for each group were implanted in the bilateral peroneal muscle pouches in rats.The peroneal muscles were only separated without implanting any materials in control group.Rats were sacrificed 2 weeks and 4 weeks post treatment and samples were cut off for general observation,Micro CT scans and histological observation.Results:General observation showed no new bone formation in Groups A and B mice,while new bones were formed in Groups C and D mice.Two weeks after treatment Micro CT scans showed that The bone volume fraction(BVF),trabecular thickness(Tb. Th),bone mineral density(BMD) in Group C mice were all higher than that in Group D(P<0.05). At the fourth week,the BVK,Tb.Th and BMD were significantly higher than that at the second week(P<0.01).Conclusions:The slow-release effect of rhBMP-2/cs sustained-release capsules can significantly promote ectopic osteogenesis.Its bone formation effect is better than that of rhBMP-2 burst-release group.

Synergistic effect of RhBMP-2 and bFGF on ectopic osteogenesis in mice

Objective:To investigate the synergistic effect and mechanism of the combined application of recombinant human bone morphogenetic protein-2(rhBMP-2) and basic fibroblast growth factor(bFGF).Methods:24 KM male mice were randomly divided into 6 groups with 4 mice in each group,namely,Group A(control group),Group B(only treated with collagen),Group C(treated with2 ng bFGF+collagen).Group D(treated with 4μg rhBMP-2+collagen),Group E(treated with 4 μg rhBMP-2+2 ng bFGF+collagen) and Group F(treated with 4 μg rhBMP-2+4 ng bFGF+collagem.The composites were implanted into the intermuscular septum of hind legs mice:whereas in control group,intermuscular septum of mice was separated and no implantation was performed.General observation,detection of concentration of calcium content,micro computed tomography(Micro-CT).three-dimensional reconstruction scan.measurement of bone mineral density(BMD).bone volume fraction(BVF) and trabecular thickness(Tb.Th).as well as histological observation with HE staining and ALP and CD34 immumohistochemical staining were performed.Results:Ectopic osteogenesis was found in Groups D.F and F mice.The difference in concentration of calcium contents was statistically significant between Groups D and E(P<0.05),but insignificant between Groups E and F(P>0.05).Micro-CT and three-dimensional reconstruction revealed continuous newborn bone substance in external surface of ectopic bone formation,and the center of bone formation did not show obvious substantial filling by bone substance.The differences in BMD,BVF and Tb.Th were statistically significant between Groups D and E or F(P<0.01 or <0.05).HE staining showed that in Groups D.E and F.newborn bone substance was mainly located at the edge of ectopic bone formation,and the bone formation in Groups E and F was better than that in Group D.ALP and CD34 immumohistochemical staining revealed the positive expression mainly at the edge of ectopic bone formation,and area of positive expression in Groups E and F was larger than that in Groups D.Conclusions:rhBMP-2 possesses the capacity to induce ectopic osteogenesis independently,but bFGF does not have this ability;the combined application of rhBMP-2 and bFGF can enhance the synergetic effect on inducing ectopic osteogenesis.

Magnetostratigraphy and paleoenvironmental record of late Cenozoic sediments in the Taiyuan Basin,North China

The Taiyuan Basin is of importance for intraplate tectonic deformation in North China and contains Cenozoic strata with a maximum thickness of 3800 m.A~853.5-m-deep borehole(ZK01)with an overall core recovery rate of 85.09%was drilled at Yuci(37°35'37?N,112°39'47?E)in the central Taiyuan Basin,to obtain high-resolution records of paleomagnetism,paleoclimatic and paleoenvironmental conditions,and depositional environment of the sediments.The obtained magnetic polarity sequence consists of 13 normal and 12 reverse zones,which correspond to C1n-C4An.2n of the geomagnetic polarity time scale.Magnetostratigraphic data show that the evolution of ZK01 core covers the interval from 8.1 Ma to the present,and the bottoms of Pliocene,Quaternary,and Middle Pleistocene were identified in Taiyuan Basin,with a sedimentary accumulation rate ranging from 62.5 m/Ma to 175.9 m/Ma.Geochemical data reveal that the source rocks in the study area underwent intense weathering and the sediments mainly formed in a semi-arid and oxygen-rich conditions.In addition,paleoclimatic changes occurred at~7 Ma,3.8 Ma,and 1.7 Ma,which can be closely related to the tectonic uplift of the Loess Plateau and Tibetan Plateau,as well as the variations in the Asian monsoon and associated regional and global climatic change.

Knowledge modeling based on interval-valued fuzzy rough set and similarity inference: prediction of welding distortion

Knowledge-based modeling is a trend in complex system modeling technology. To extract the process knowledge from an information system, an approach of knowledge modeling based on interval-valued fuzzy rough set is presented in this paper, in which attribute reduction is a key to obtain the simplified knowledge model. Through defining dependency and inclusion functions, algorithms for attribute reduction and rule extraction are obtained. The approximation inference plays an important role in the development of the fuzzy system. To improve the inference mechanism, we provide a method of similaritybased inference in an interval-valued fuzzy environment. Combining the conventional compositional rule of inference with similarity based approximate reasoning, an inference result is deduced via rule translation, similarity matching, relation modification, and projection operation. This approach is applied to the problem of predicting welding distortion in marine structures, and the experimental results validate the effectiveness of the proposed methods of knowledge modeling and similarity-based inference.

Novel N-(pyrimidin-4-yl)thiazol-2-amine derivatives as dual-action hypoglycemic agents that activate GK and PPARc

A series of novel N-(pyrimidin-4-yl)thiazol-2-amine derivatives have been synthesized and evaluated as glucokinase(GK)activators.Ethyl 2-(6-(4-(2-hydroxyethyl)piperazin-1-yl)-2-methylpyrimidin-4-yl-amino)thiazole-5-carboxylate was found to be a potent dual-acting hypoglycemic agent activating both GK and PPARg.When given orally to normal mice,the compound demonstrated significant efficacy in decreasing the glucose level after oral glucose loading.

Synthesis and in vitro cytotoxic activities of sorafenib derivatives

A series of novel sorafenib derivatives have been designed and synthesized.The cytotoxic activities of these compounds were tested in three tumor cell lines.Most of the compounds showed potent antiproliferative activity against the tested cell lines with IC50= 0–20 mmol/L.Some compounds demonstrated competitive antiproliferative activities to sorafenib against all three cancer cell lines.Among them,compound 5g demonstrated significant inhibitory activity against A549,ACHN and MDAMB-231 cell lines with IC50values of 1.29,1.99,3.11 mmol/L,respectively.

An adaptive smoothed particle hydrodynamics for metal cutting simulation

Normally large amounts of particles are required to accurately simulate the metal cutting process,which consumes a lot of computing time and storage.Adaptive techniques can help decrease the number of particles,hence reducing the runtime.This paper presents a novel adaptive smoothed particle hydrodynamics(SPH)method for the metal cutting simulation.The spatial resolution changes adaptively according to the distance to the tool tip by the particle splitting and merging.More particles are selected in the region where the workpiece and the tool are in contact.Since the contact region constantly changes during the cutting process,two quadrilateral frames are adopted in the adaptive algorithm to dynamically change the distribution of particles.One frame for the refinement,the other for the coarsening.These frames move at the same speed as the tool.To test the computational efficiency,the metal cutting process is simulated by using SPH with three different adaptive approaches.Numerical results show that the proposed adaptive algorithm with dynamic refinement and coarsening can significantly optimize the runtime.