The 121 mining method of longwall mining first proposed in England has been widely used around the world.This method requires excavation of two mining roadways and reservation of one coal pillar to mine one working fa...The 121 mining method of longwall mining first proposed in England has been widely used around the world.This method requires excavation of two mining roadways and reservation of one coal pillar to mine one working face.Due to considerable excavation of roadway,the mining roadway is generally destroyed during coal mining.The stress concentration in the coal pillar can cause large deformation of surrounding rocks,rockbursts and other disasters,and subsequently a large volume of coal pillar resources will be wasted.To improve the coal recovery rate and reduce excavation of the mining roadway,the 111 mining method of longwall mining was proposed in the former Soviet Union based on the 121 mining method.The 111 mining method requires excavation of one mining roadway and setting one filling body to replace the coal pillar while maintaining another mining roadway to mine one working face.However,because the stress transfer structure of roadway and working face roof has not changed,the problem of stress concentration in the surrounding rocks of roadway has not been well solved.To solve the above problems,the conventional concept utilizing high-strength support to resist the mining pressure for the 121 and 111 mining methods should be updated.The idea is to utilize mining pressure and expansion characteristics of the collapsed rock mass in the goaf to automatically form roadways,avoiding roadway excavation and waste of coal pillar.Based on the basic principles of mining rock mechanics,the“equilibrium mining”theory and the“short cantilever beam”mechanical model are proposed.Key technologies,such as roof directional presplitting technology,negative Poisson’s ratio(NPR)high-prestress constant-resistance support technology,and gangue blocking support technology,are developed following the“equilibrium mining”theory.Accordingly,the 110 and N00 mining methods of an automatically formed roadway(AFR)by roof cutting and pressure releasing without pillars are proposed.The mining methods have been applied to a large nu展开更多
The aim of this study was to compare the structure of gut microbiota in Parkinson's disease(PD) patients and healthy controls;and to explore correlations between gut microbiota and PD clinical features. We analyze...The aim of this study was to compare the structure of gut microbiota in Parkinson's disease(PD) patients and healthy controls;and to explore correlations between gut microbiota and PD clinical features. We analyzed fecal bacterial composition of 24 PD patients and 14 healthy volunteers by using 16 S rRNA sequencing. There were significant differences between PD and healthy controls, as well as among different PD stages. The putative cellulose degrading bacteria from the genera Blautia(P=0.018),Faecalibacterium(P=0.048) and Ruminococcus(P=0.019) were significantly decreased in PD compared to healthy controls.The putative pathobionts from the genera Escherichia-Shigella(P=0.038), Streptococcus(P=0.01), Proteus(P=0.022), and Enterococcus(P=0.006) were significantly increased in PD subjects. Correlation analysis indicated that disease severity and PD duration negatively correlated with the putative cellulose degraders, and positively correlated with the putative pathobionts. The results suggest that structural changes of gut microbiota in PD are characterized by the decreases of putative cellulose degraders and the increases of putative pathobionts, which may potentially reduce the production of short chain fatty acids, and produce more endotoxins and neurotoxins; and these changes is potentially associated with the development of PD pathology.展开更多
The mammalian gut is inhabited by a massive and complicated microbial community, in which the hostachieves a stable symbiotic environment through the interdependence, coordination, reciprocal constraintsand participat...The mammalian gut is inhabited by a massive and complicated microbial community, in which the hostachieves a stable symbiotic environment through the interdependence, coordination, reciprocal constraintsand participation in an immune response. The interaction between the host gut and themicrobiota is essential for maintaining and achieving the homeostasis of the organism. Consequently, guthomeostasis is pivotal in safeguarding the growth and development and potential productive performanceof the host. As metabolites of microorganisms, short chain fatty acids are not only the preferredenergy metabolic feedstock for host intestinal epithelial cells, but also exert vital effects on antioxidantsand the regulation of intestinal community homeostasis. Herein, we summarize the effects of intestinalmicroorganisms on the host gut and the mechanisms of action of short chain fatty acids on the fourintestinal barriers of the organism, which will shed light on the manipulation of the intestinal communityto achieve precise nutrition for specific individuals and provide a novel perspective for theprevention and treatment of diseases.展开更多
车载网VANET是一种应用于智能交通系统的新型无线移动自组织网络(mobile ad hoc network,MANET).随着车辆以及移动ad hoc网络技术的发展,车载网已经成为一个新兴的研究领域.针对VANET中车辆行驶的特征,提出一种拓扑相对稳定的车辆分簇算...车载网VANET是一种应用于智能交通系统的新型无线移动自组织网络(mobile ad hoc network,MANET).随着车辆以及移动ad hoc网络技术的发展,车载网已经成为一个新兴的研究领域.针对VANET中车辆行驶的特征,提出一种拓扑相对稳定的车辆分簇算法.在此算法基础上,根据专用短程通信(dedicated short range communication,DSRC)标准中控制信道(control channel,CCH)和服务信道(service channel,SCH)的分配,考虑车辆间的无线通信干扰和不同应用的QoS需求,提出一种基于分簇的多信道混合型MAC协议,簇内通信采用非竞争的TDMA机制,簇间通信采用基于竞争的CSMA?CA机制,相邻簇采用不同的服务信道.模拟实验表明,提出的MAC协议在同时满足实时应用的延迟需求和非实时应用的吞吐量方面,优于现有协议.展开更多
AIM: To study the interplay between butyrate concentration and butyrate-producing bacteria in fecal samples of ulcerative colitis (UC) patients vs control individuals. METHODS: Fecal samples were collected from 14 con...AIM: To study the interplay between butyrate concentration and butyrate-producing bacteria in fecal samples of ulcerative colitis (UC) patients vs control individuals. METHODS: Fecal samples were collected from 14 control individuals (hemorrhoid patients only) and 26 UC patients (severe: n = 12, moderate: n = 6, remission: n = 8), recruited by the gastroenterologist at the Department of Gastroenterology, All India Institute of Medical Sciences, New Delhi, India. Disease activity in UC patients was determined by clinical colitis activity index. We employed fluorescent in situ hybridization in combination with flow cytometry to enumerate the clostridium cluster population targeted by 16S rRNA gene probe. Major butyrate-producing species within this cluster were quantified to see if any change existed in control vs UC patients with different disease activity. This observed change was further validated by quantitative polymerase chain reaction. In addition to this,we carried out gas chromatography to evaluate the changes in concentration of major short chain fatty acids (SCFAs), namely acetate, n -butyrate, iso -butyrate, in the above samples. Student t test and Graph pad prism-6 were used to compare the data statistically. RESULTS: There was a significant decrease of Clostridium coccoides (control, 25.69% ± 1.62% vs severe, 9.8% ± 2.4%, P = 0.0001) and Clostridium leptum clusters (control, 13.74% ± 1.05% vs severe, 6.2% ± 1.8%, P = 0.0001) in fecal samples of UC patients. Furthermore, we demonstrated that some butyrateproducing members of the clostridial cluster, like Fecalibacterium prausnitzii (control, 11.66% ± 1.55% vs severe, 6.01% ± 1.6%, P = 0.0001) and Roseburia intestinalis (control, 14.48% ± 1.52% vs severe, 9% ± 1.83%, P = 0.02) were differentially present in patients with different disease activity. In addition, we also demonstrated decreased concentrations of fecal SCFAs, especially of n -butyrate (control, 24.32 ± 1.86 mmol/μL vs severe, 12.74 ± 2.75 mmol/μL, P = 0.003), iso -butyrate (cont展开更多
: The present study is aimed to investigate the mechanism of the biochemical genetic in short-seasoned cotton (Gossypium hirsutum L.) (SSC). Ten cultivars from two types of SSC were selected, five SSC with no prematur...: The present study is aimed to investigate the mechanism of the biochemical genetic in short-seasoned cotton (Gossypium hirsutum L.) (SSC). Ten cultivars from two types of SSC were selected, five SSC with no premature senescence crossed with five SSC with premature senescence. The parents, F1, and F2 from the reciprocal crosses were field tested in replication in 2001 and 2002. The results indicated that the activities of protective enzymes of the antioxidant system, such as catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), were higher in the early maturing SSC with premature senescence compared with activities in the SSC parental cultivars that showed premature senescence, whereas the malondialdehyde (MD A) content in former group was lower than that in latter group. Various genetic variances and heritabilities for these biochemical traits and auxin (IAA), abscisic acid (ABA), and chlorophyll (Chl a+b) contents were also estimated. Significant additive variance for CAT, POD, ABA, and IAA existed, whereas CAT specific activity and SOD activity were largely controlled by dominant effects. Both maternal and dominant variances played equally predominant roles in the specific activity of POD and SOD, MDA, and soluble portents. The relative contribution of the various genetic components to the phenotypic variation varied in the boll-setting period.展开更多
BACKGROUND: Survivin is known to be overexpressed in various human malignancies, including pancreatic cancer, and mediates cancer cell proliferation and tumor growth, so the regulation of this molecule could be a new ...BACKGROUND: Survivin is known to be overexpressed in various human malignancies, including pancreatic cancer, and mediates cancer cell proliferation and tumor growth, so the regulation of this molecule could be a new strategy for treating pancreatic cancer. In this study, short hairpin RNAs (shRNAs) specific to survivin were introduced into human pancreatic cancer Patu8988 cells to investigate the inhibitory effects on survivin expression and cell proliferation in vitro and in vivo. METHODS: Three kinds of shRNA specific to the survivin gene were designed and cloned into eukaryotic expression plasmid pGenesil-1 vector. Subsequently the recombinant plasmids were transfected into human pancreatic cancer Patu8988 cells with lipfectamine (TM) 2000 reagent. The mRNA and protein expressions of survivin in the transiently transfected Patu8988 cells were determined by RT-PCR, flow cytometry, and Western blotting analysis. The proliferation inhibition rates of stably transfected Patu8988 cells were determined by MTT assay. The antitumor activities of the three kinds of survivin-shRNA plasmids were evaluated in BALB/c nude mice inoculated with Patu8988 cells and bearing human pancreatic cancer. RESULTS: The three survivin-shRNA plasmids named pGenesil-1-survivin-1, pGenesil-1-survivin-2 and pGenesil-1-survivin-1+2 (with double interfering RNA sites) were successfully constructed, and were confirmed by restriction enzyme cutting and sequencing. At 48 hours after transfection, the expression of survivin mRNA and protein was inhibited in Patu8988 cells transfected with pGenesil-1-survivin-1, pGenesil-1-survivin-2, and pGenesil-1-survivin-1+2 when compared with that of either pGenesil-1-NC (with scrambled small interfering RNA) transfected cells or control cells (P<0.05). The MTT results showed that the proliferation rates of Patu8988 cells stably transfected with survivin-shRNA plasmids were reduced when compared with that of either pGenesil-1-NC transfected cells or control cells (P<0.01). Furthermore, when Patu8988 cells st展开更多
Objective To evaluate the clinical impact of whole body diffusion weighted imaging （WB-DWI） on diagnosis and staging of malignant lymphoma. Methods Thirty-one patients with suspected lymphadenopathy were enrolled. ...Objective To evaluate the clinical impact of whole body diffusion weighted imaging （WB-DWI） on diagnosis and staging of malignant lymphoma. Methods Thirty-one patients with suspected lymphadenopathy were enrolled. WB-DWI was performed by using short TI inversion recovery echo-planar imaging sequence with free breathing and built-in body coil. Axial T2- weighted imaging images of the same location were used as reference. The results of WB-DWI were compared with pathological results and other imaging modalities. The mean apparent diffusion coefficient （ADC） values of different kinds of lymph nodes were compared. Results WB-DWI was positive in all 18 cases with lymphoma, 5 cases with metastatic lymph nodes and 4 of 8 eases with benign lymphadenopathy. The mean ADC value of lymphomatous, metastatic and benign lymph nodes was （0.87 ± 0.17） × 10^3, （0.98± 0.09） × 10^3 and （1.20 ± 0.10） × 10^3 mm^2/s. There was significant difference in ADC value between benign lymph nodes and other two groups （P 〈 0.01）. The sensitivity, specificity and accuracy of WB-DWI in diagnosis of lymphoma were 100% （18/18）, 30.8% （4/13） and 71.0% （22/31）. When an ADC value of 1.08 × 10^-3 mm^2/s was used as the threshold value for differentiating malignant from benign lymph nodes, the best results were obtained with sensitivity of 87.8% and specificity of 91.3%. Sixteen of eighteen cases （88.9%） of lymphoma were accurately staged in accordance with clinical staging. Conclusions WB-DWI is a sensitive, but less specific technique for diagnosis of lymphoma. It is difficult to differentiate lymphnmatous from metastatic lymph nodes using WB-DWI. However, it is a valuable imaging modality for staging of patients with malignant lymphoma.展开更多
AIM: To investigate the individual and the combined effects of glutamine, dietary fiber, and growth hormone on the structural adaptation of the remnant small bowel. METHODS: Forty-two adult male Sprague-Dawley rats un...AIM: To investigate the individual and the combined effects of glutamine, dietary fiber, and growth hormone on the structural adaptation of the remnant small bowel. METHODS: Forty-two adult male Sprague-Dawley rats underwent 85% mid-small bowel resection and received total parenteral nutrition (TPN) support during the first three postoperational days.From the 4th postoperational day, animals were randomly assigned to receive 7 different treatments for 8 days: TPNcon group, receiving TPN and enteral 20 g x L(-1) glycine perfusion; TPN+Gln group, receiving TPN and enteral 20 g x L(-1) glutamine perfusion; ENcon group, receiving enteral nutrition (EN) fortified with 20 g x L(-1) glycine; EN+Gln group, enteral nutrition fortified with 20 g x L(-1) glutamine; EN+Fib group, enteral nutrition and 2 g x d(-1) oral soybean fiber; EN+GH group, enteral nutrition and subcutaneous growth hormone (GH) (0.3 IU) injection twice daily; and ENint group, glutamine-enriched EN, oral soybean fiber, and subcutaneous GH injection. RESULTS: Enteral glutamine perfusion during TPN increased the small intestinal villus height (jejunal villus height 250 microm +/- 29 microm in TPNcon vs 330 microm +/- 54 microm in TPN+Gln, ileal villus height 260 microm +/- 28 microm in TPNcon vs 330 microm +/- 22 microm in TPN+Gln, P【0.05) and mucosa thickness (jejunal mucosa thickness 360 microm +/- 32 microm in TPNcon vs 460 microm +/- 65 microm in TPN+Gln, ileal mucosa thickness 400 microm +/- 25 microm in TPNcon vs 490 microm +/- 11 microm in TPN+Gln,P【 0.05) in comparison with the TPNcon group. Either fiber supplementation or GH administration improved body mass gain (end body weight 270 g +/- 3.6g in EN+Fib, 265.7 g +/- 3.3 g in EN+GH, vs 257 g +/- 3.3 g in ENcon, P【 0.05), elevated plasma insulin-like growth factor (IGF-I) level (880 microg x L(-1). 52 microg x L-(-1) in EN+Fib,1200 microg x L(-1). 96 microg x L-(-1) in EN +/- GH, vs 620 microg x L(-1).43 microg x L-(-1) in ENcon, P【 0.05), and increased the villus height (jejunum 560 mi展开更多
The intestinal tract is colonized soon after birth with a variety of ingested environmental and maternal microflora. This process is influenced by many factors including mode of delivery, diet, environment, and the us...The intestinal tract is colonized soon after birth with a variety of ingested environmental and maternal microflora. This process is influenced by many factors including mode of delivery, diet, environment, and the use of antibiotics. Normal intestinal microflora provides protection against infection, ensures tolerance to foods, and contributes to nutrient digestion and energy harvest. In addition, enteral feeding and colonization with the normal commensal flora are necessary for the maintenance of intestinal barrier function and play a vital role in the regulation of intestinal barrier function. Intestinal commensal microorganisms also provide signals that foster normal immune system development and influence the ensuing immune responses. There is increasingly recognition that alterations of the microbial gut flora and associated changes in intestinal barrier function may be related to certain diseases of the gastrointestinal tract. This review summarizes recent advances in understanding the complex ecosystem of intestinal microbiota and its role in regulating intestinal barrier function and a few common pediatric diseases. Disruption in the establishment of a stable normal gut microflora may contribute to the pathogenesis of diseases including inflammatory bowel disease, nosocomial infection, and neonatal necrotizing enterocolitis.展开更多
Under the background of the energy saving and emission reduction, more and more attention has been placed on investigating the energy efficiency of ships. The added resistance has been noted for being crucial in predi...Under the background of the energy saving and emission reduction, more and more attention has been placed on investigating the energy efficiency of ships. The added resistance has been noted for being crucial in predicting the decrease of speed on a ship operating at sea. Furthermore, it is also significant to investigate the added resistance for a ship functioning in short waves of large modern ships. The researcher presents an estimation formula for the calculation of an added resistance study in short waves derived from the reflection law. An improved method has been proposed to calculate the added resistance due to ship motions, which applies the radiated energy theory along with the strip method. This procedure is based on an extended integral equation （EIE） method, which was used for solving the hydrodynamic coefficients without effects of the irregular frequency. Next, a combined method was recommended for the estimation of added resistance for a ship in the whole wave length range. The comparison data with other experiments indicate the method presented in the paper provides satisfactory results for large blunt ship.展开更多
RNA interference (RNAi) is an evolutionally conserved gene silencing mechanism present in a variety of eukaryotic species. RNAi uses short double-stranded RNA (dsRNA) to trigger degradation or translation repression o...RNA interference (RNAi) is an evolutionally conserved gene silencing mechanism present in a variety of eukaryotic species. RNAi uses short double-stranded RNA (dsRNA) to trigger degradation or translation repression of homologous RNA targets in a sequence-specific manner. This system can be induced effectively in vitro and in vivo by direct application of small interfering RNAs (siRNAs), or by expression of short hairpin RNA (shRNA) with non-viral and viral vectors. To date, RNAi has been extensively used as a novel and effective tool for functional genomic studies, and has displayed great potential in treating human diseases, including human genetic and acquired disorders such as cancer and viral infections. In the present review, we focus on the recent development in the use of RNAi in the prevention and treatment of viral infections. The mechanisms, strategies, hurdles and prospects of employing RNAi in the pharmaceutical industry are also discussed.展开更多
With the explosion of online communication and publication, texts become obtainable via forums, chat messages, blogs, book reviews and movie reviews. Usually, these texts are much short and noisy without sufficient st...With the explosion of online communication and publication, texts become obtainable via forums, chat messages, blogs, book reviews and movie reviews. Usually, these texts are much short and noisy without sufficient statistical signals and enough information for a good semantic analysis. Traditional natural language processing methods such as Bow-of-Word (BOW) based probabilistic latent semantic models fail to achieve high performance due to the short text environment. Recent researches have focused on the correlations between words, i.e., term dependencies, which could be helpful for mining latent semantics hidden in short texts and help people to understand them. Long short-term memory (LSTM) network can capture term dependencies and is able to remember the information for long periods of time. LSTM has been widely used and has obtained promising results in variants of problems of understanding latent semantics of texts. At the same time, by analyzing the texts, we find that a number of keywords contribute greatly to the semantics of the texts. In this paper, we establish a keyword vocabulary and propose an LSTM-based model that is sensitive to the words in the vocabulary; hence, the keywords leverage the semantics of the full document. The proposed model is evaluated in a short-text sentiment analysis task on two datasets: IMDB and SemEval-2016, respectively. Experimental results demonstrate that our model outperforms the baseline LSTM by 1%similar to 2% in terms of accuracy and is effective with significant performance enhancement over several non-recurrent neural network latent semantic models (especially in dealing with short texts). We also incorporate the idea into a variant of LSTM named the gated recurrent unit (GRU) model and achieve good performance, which proves that our method is general enough to improve different deep learning models.展开更多
In recent years,high-fat diet(HFD)has been widely applied in aquaculture,which reduces the intestinal health of cultured fish.The current study evaluated the protective effects of nano-selenium(nano-Se)on intestinal h...In recent years,high-fat diet(HFD)has been widely applied in aquaculture,which reduces the intestinal health of cultured fish.The current study evaluated the protective effects of nano-selenium(nano-Se)on intestinal health of juvenile grass carp(Ctenopharyngodon idella)fed with HFD.A total of 135 experimental fish were fed with a regular diet(Con),a HFD(HFD)and a HFD containing nano-Se at 0.6 mg/kg(HSe)for 10 weeks.The results showed that dietary nano-Se significantly improved the survival rate and feed efficiency which were reduced by HFD in juvenile grass carp(P<0.05).Also,nano-Se(0.6 mg/kg)supplement alleviated intestinal damage caused by the HFD,thus maintaining the integrity of the intestine.Moreover,it significantly up-regulated the expression of genes related to tight junction(ZO-1,claudin-3 and occludin),anti-oxidization(GPx4a and GPx4b),and the protein of ZO-1 in the intestine of juvenile grass carp,which were depressed by the HFD(P<0.05).Furthermore,nano-Se supplementation significantly suppressed the expressions of genes related to the inflammation,including inflammatory cytokines(IL-8,IL-1β,IFN-γ,TNF-αand IL-6),signaling molecules(TLR4,p38 MAPK and NF-kB p65),and protein expression of NF-kB p65 and TNF-αin the intestine of juvenile grass carp which were induced by the HFD(P<0.05).Besides,dietary nano-Se normalized the intestinal microbiota imbalance of juvenile grass carp caused by the HFD through increasing the abundance of the beneficial bacteria,e.g.,Fusobacteria.Finally,dietary nano-Se increased the production of short chain fatty acids(SCFA)in the intestine,especially for butyric acid and caproic acid,which were negatively related to the increase of intestinal permeability and inflammation.In summary,supply of nano-Se(0.6 mg/kg)in HFD could effectively alleviate intestinal injury of juvenile grass carp by improving intestinal barrier function and reducing intestinal inflammation and oxidative stress.These positive effects may be due to the regulation of nano-Se on intestinal microbiota and th展开更多
External short circuit(ESC)of lithium-ion batteries is one of the common and severe electrical failures in electric vehicles.In this study,a novel thermal modelis developed to capture the temperature behavior of batte...External short circuit(ESC)of lithium-ion batteries is one of the common and severe electrical failures in electric vehicles.In this study,a novel thermal modelis developed to capture the temperature behavior of batteries under ESC conditions.Experiments were systematically performed under different battery initial state of charge and ambient temperatures.Based on the experimental results,we employed an extreme learming machine(ELM)-based thermal(ELMT)model to depict battery temperature behavior under ESC,where a lumped-state thermal model was used to replace the activation function of conventional ELMs.To demonstrate the effectiveness of the proposed model,wecompared the ELMT model with a multi-lumped-state thermal(MLT)model parameterized by thegenetic algorithm using the experimental data from various sets of battery cells.It is shown that the ELMT model can achieve higher computa-tional efficiency than the MLT model and better fitting and prediction accuracy,where the average root mean squared error(RMSE)of the fitting is 0.65℃ for the ELMT model and 3.95℃ for the MLT model,and the RMES of the prediction under new data set is 3.97℃ for the ELMT model and 6.11℃ for the MLT model.展开更多
Social media websites allow users to exchange short texts such as tweets via microblogs and user status in friendship networks. Their limited length, pervasive abbrevi- ations, and coined acronyms and words exacerbate...Social media websites allow users to exchange short texts such as tweets via microblogs and user status in friendship networks. Their limited length, pervasive abbrevi- ations, and coined acronyms and words exacerbate the prob- lems of synonymy and polysemy, and bring about new chal- lenges to data mining applications such as text clustering and classification. To address these issues, we dissect some poten- tial causes and devise an efficient approach that enriches data representation by employing machine translation to increase the number of features from different languages. Then we propose a novel framework which performs multi-language knowledge integration and feature reduction simultaneously through matrix factorization techniques. The proposed ap- proach is evaluated extensively in terms of effectiveness on two social media datasets from Facebook and Twitter. With its significant performance improvement, we further investi- gate potential factors that contribute to the improved perfor- mance.展开更多
The added resistance of KVLCC2 in short and regular head waves has been studied theoretically and experimentally. Model tests are performed to determine how well the asymptotic formula （Faltinsen et al. 1980） predic...The added resistance of KVLCC2 in short and regular head waves has been studied theoretically and experimentally. Model tests are performed to determine how well the asymptotic formula （Faltinsen et al. 1980） predicts the typical level of added resistance in short waves. Because the asymptotic formula neglects the effects of ship motions, it is combined with theoretical methods to calculate the added resistance in long waves using an function to predict the added resistance in the intermediate wavelength region where both ship motions and wave reflection are important. A unique feature of this experiment is that the ship model is divided into three segments to explore the added resistance distribution with respect to hull segment. This paper discusses the sensitivity of experimental results to the quality of the incident regular head waves. Moreover, a novel procedure for analyzing added resistance is described. Finally, the experimentally determined added resistance of KVLCC2 is compared with theoretical results. It is shown that the added resistance from the combined theoretical methods agrees well with experimental results in both the intermediate and short wave regions. The use of hull segments shows that added resistance is concentrated primarily at the bow.展开更多
基金This work was supported by the Natural Science Foundation of China(Grant Nos.52074164 and 42077267)the Major Scientific and Technological Innovation Project of Shandong Province,China(Grant No.2019SDZY04)。
文摘The 121 mining method of longwall mining first proposed in England has been widely used around the world.This method requires excavation of two mining roadways and reservation of one coal pillar to mine one working face.Due to considerable excavation of roadway,the mining roadway is generally destroyed during coal mining.The stress concentration in the coal pillar can cause large deformation of surrounding rocks,rockbursts and other disasters,and subsequently a large volume of coal pillar resources will be wasted.To improve the coal recovery rate and reduce excavation of the mining roadway,the 111 mining method of longwall mining was proposed in the former Soviet Union based on the 121 mining method.The 111 mining method requires excavation of one mining roadway and setting one filling body to replace the coal pillar while maintaining another mining roadway to mine one working face.However,because the stress transfer structure of roadway and working face roof has not changed,the problem of stress concentration in the surrounding rocks of roadway has not been well solved.To solve the above problems,the conventional concept utilizing high-strength support to resist the mining pressure for the 121 and 111 mining methods should be updated.The idea is to utilize mining pressure and expansion characteristics of the collapsed rock mass in the goaf to automatically form roadways,avoiding roadway excavation and waste of coal pillar.Based on the basic principles of mining rock mechanics,the“equilibrium mining”theory and the“short cantilever beam”mechanical model are proposed.Key technologies,such as roof directional presplitting technology,negative Poisson’s ratio(NPR)high-prestress constant-resistance support technology,and gangue blocking support technology,are developed following the“equilibrium mining”theory.Accordingly,the 110 and N00 mining methods of an automatically formed roadway(AFR)by roof cutting and pressure releasing without pillars are proposed.The mining methods have been applied to a large nu
基金supported by Future Life Sciences International Ltd.(NSBJ01032014,http://ffsi.jpl)
文摘The aim of this study was to compare the structure of gut microbiota in Parkinson's disease(PD) patients and healthy controls;and to explore correlations between gut microbiota and PD clinical features. We analyzed fecal bacterial composition of 24 PD patients and 14 healthy volunteers by using 16 S rRNA sequencing. There were significant differences between PD and healthy controls, as well as among different PD stages. The putative cellulose degrading bacteria from the genera Blautia(P=0.018),Faecalibacterium(P=0.048) and Ruminococcus(P=0.019) were significantly decreased in PD compared to healthy controls.The putative pathobionts from the genera Escherichia-Shigella(P=0.038), Streptococcus(P=0.01), Proteus(P=0.022), and Enterococcus(P=0.006) were significantly increased in PD subjects. Correlation analysis indicated that disease severity and PD duration negatively correlated with the putative cellulose degraders, and positively correlated with the putative pathobionts. The results suggest that structural changes of gut microbiota in PD are characterized by the decreases of putative cellulose degraders and the increases of putative pathobionts, which may potentially reduce the production of short chain fatty acids, and produce more endotoxins and neurotoxins; and these changes is potentially associated with the development of PD pathology.
基金the National Natural Science Foundation of China(31772612)the Beijing Natural Science Foundation(6202019).
文摘The mammalian gut is inhabited by a massive and complicated microbial community, in which the hostachieves a stable symbiotic environment through the interdependence, coordination, reciprocal constraintsand participation in an immune response. The interaction between the host gut and themicrobiota is essential for maintaining and achieving the homeostasis of the organism. Consequently, guthomeostasis is pivotal in safeguarding the growth and development and potential productive performanceof the host. As metabolites of microorganisms, short chain fatty acids are not only the preferredenergy metabolic feedstock for host intestinal epithelial cells, but also exert vital effects on antioxidantsand the regulation of intestinal community homeostasis. Herein, we summarize the effects of intestinalmicroorganisms on the host gut and the mechanisms of action of short chain fatty acids on the fourintestinal barriers of the organism, which will shed light on the manipulation of the intestinal communityto achieve precise nutrition for specific individuals and provide a novel perspective for theprevention and treatment of diseases.
文摘车载网VANET是一种应用于智能交通系统的新型无线移动自组织网络(mobile ad hoc network,MANET).随着车辆以及移动ad hoc网络技术的发展,车载网已经成为一个新兴的研究领域.针对VANET中车辆行驶的特征,提出一种拓扑相对稳定的车辆分簇算法.在此算法基础上,根据专用短程通信(dedicated short range communication,DSRC)标准中控制信道(control channel,CCH)和服务信道(service channel,SCH)的分配,考虑车辆间的无线通信干扰和不同应用的QoS需求,提出一种基于分簇的多信道混合型MAC协议,簇内通信采用非竞争的TDMA机制,簇间通信采用基于竞争的CSMA?CA机制,相邻簇采用不同的服务信道.模拟实验表明,提出的MAC协议在同时满足实时应用的延迟需求和非实时应用的吞吐量方面,优于现有协议.
基金Supported by Council of Scientific and Industrial Research,New Delhi Government of India
文摘AIM: To study the interplay between butyrate concentration and butyrate-producing bacteria in fecal samples of ulcerative colitis (UC) patients vs control individuals. METHODS: Fecal samples were collected from 14 control individuals (hemorrhoid patients only) and 26 UC patients (severe: n = 12, moderate: n = 6, remission: n = 8), recruited by the gastroenterologist at the Department of Gastroenterology, All India Institute of Medical Sciences, New Delhi, India. Disease activity in UC patients was determined by clinical colitis activity index. We employed fluorescent in situ hybridization in combination with flow cytometry to enumerate the clostridium cluster population targeted by 16S rRNA gene probe. Major butyrate-producing species within this cluster were quantified to see if any change existed in control vs UC patients with different disease activity. This observed change was further validated by quantitative polymerase chain reaction. In addition to this,we carried out gas chromatography to evaluate the changes in concentration of major short chain fatty acids (SCFAs), namely acetate, n -butyrate, iso -butyrate, in the above samples. Student t test and Graph pad prism-6 were used to compare the data statistically. RESULTS: There was a significant decrease of Clostridium coccoides (control, 25.69% ± 1.62% vs severe, 9.8% ± 2.4%, P = 0.0001) and Clostridium leptum clusters (control, 13.74% ± 1.05% vs severe, 6.2% ± 1.8%, P = 0.0001) in fecal samples of UC patients. Furthermore, we demonstrated that some butyrateproducing members of the clostridial cluster, like Fecalibacterium prausnitzii (control, 11.66% ± 1.55% vs severe, 6.01% ± 1.6%, P = 0.0001) and Roseburia intestinalis (control, 14.48% ± 1.52% vs severe, 9% ± 1.83%, P = 0.02) were differentially present in patients with different disease activity. In addition, we also demonstrated decreased concentrations of fecal SCFAs, especially of n -butyrate (control, 24.32 ± 1.86 mmol/μL vs severe, 12.74 ± 2.75 mmol/μL, P = 0.003), iso -butyrate (cont
文摘: The present study is aimed to investigate the mechanism of the biochemical genetic in short-seasoned cotton (Gossypium hirsutum L.) (SSC). Ten cultivars from two types of SSC were selected, five SSC with no premature senescence crossed with five SSC with premature senescence. The parents, F1, and F2 from the reciprocal crosses were field tested in replication in 2001 and 2002. The results indicated that the activities of protective enzymes of the antioxidant system, such as catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), were higher in the early maturing SSC with premature senescence compared with activities in the SSC parental cultivars that showed premature senescence, whereas the malondialdehyde (MD A) content in former group was lower than that in latter group. Various genetic variances and heritabilities for these biochemical traits and auxin (IAA), abscisic acid (ABA), and chlorophyll (Chl a+b) contents were also estimated. Significant additive variance for CAT, POD, ABA, and IAA existed, whereas CAT specific activity and SOD activity were largely controlled by dominant effects. Both maternal and dominant variances played equally predominant roles in the specific activity of POD and SOD, MDA, and soluble portents. The relative contribution of the various genetic components to the phenotypic variation varied in the boll-setting period.
基金supported by grants from the Social Bureau Foundation of Suzhou (SZD0614)the Foundation of Health Bureau of Jiangsu Province (Z200622)
文摘BACKGROUND: Survivin is known to be overexpressed in various human malignancies, including pancreatic cancer, and mediates cancer cell proliferation and tumor growth, so the regulation of this molecule could be a new strategy for treating pancreatic cancer. In this study, short hairpin RNAs (shRNAs) specific to survivin were introduced into human pancreatic cancer Patu8988 cells to investigate the inhibitory effects on survivin expression and cell proliferation in vitro and in vivo. METHODS: Three kinds of shRNA specific to the survivin gene were designed and cloned into eukaryotic expression plasmid pGenesil-1 vector. Subsequently the recombinant plasmids were transfected into human pancreatic cancer Patu8988 cells with lipfectamine (TM) 2000 reagent. The mRNA and protein expressions of survivin in the transiently transfected Patu8988 cells were determined by RT-PCR, flow cytometry, and Western blotting analysis. The proliferation inhibition rates of stably transfected Patu8988 cells were determined by MTT assay. The antitumor activities of the three kinds of survivin-shRNA plasmids were evaluated in BALB/c nude mice inoculated with Patu8988 cells and bearing human pancreatic cancer. RESULTS: The three survivin-shRNA plasmids named pGenesil-1-survivin-1, pGenesil-1-survivin-2 and pGenesil-1-survivin-1+2 (with double interfering RNA sites) were successfully constructed, and were confirmed by restriction enzyme cutting and sequencing. At 48 hours after transfection, the expression of survivin mRNA and protein was inhibited in Patu8988 cells transfected with pGenesil-1-survivin-1, pGenesil-1-survivin-2, and pGenesil-1-survivin-1+2 when compared with that of either pGenesil-1-NC (with scrambled small interfering RNA) transfected cells or control cells (P<0.05). The MTT results showed that the proliferation rates of Patu8988 cells stably transfected with survivin-shRNA plasmids were reduced when compared with that of either pGenesil-1-NC transfected cells or control cells (P<0.01). Furthermore, when Patu8988 cells st
文摘Objective To evaluate the clinical impact of whole body diffusion weighted imaging （WB-DWI） on diagnosis and staging of malignant lymphoma. Methods Thirty-one patients with suspected lymphadenopathy were enrolled. WB-DWI was performed by using short TI inversion recovery echo-planar imaging sequence with free breathing and built-in body coil. Axial T2- weighted imaging images of the same location were used as reference. The results of WB-DWI were compared with pathological results and other imaging modalities. The mean apparent diffusion coefficient （ADC） values of different kinds of lymph nodes were compared. Results WB-DWI was positive in all 18 cases with lymphoma, 5 cases with metastatic lymph nodes and 4 of 8 eases with benign lymphadenopathy. The mean ADC value of lymphomatous, metastatic and benign lymph nodes was （0.87 ± 0.17） × 10^3, （0.98± 0.09） × 10^3 and （1.20 ± 0.10） × 10^3 mm^2/s. There was significant difference in ADC value between benign lymph nodes and other two groups （P 〈 0.01）. The sensitivity, specificity and accuracy of WB-DWI in diagnosis of lymphoma were 100% （18/18）, 30.8% （4/13） and 71.0% （22/31）. When an ADC value of 1.08 × 10^-3 mm^2/s was used as the threshold value for differentiating malignant from benign lymph nodes, the best results were obtained with sensitivity of 87.8% and specificity of 91.3%. Sixteen of eighteen cases （88.9%） of lymphoma were accurately staged in accordance with clinical staging. Conclusions WB-DWI is a sensitive, but less specific technique for diagnosis of lymphoma. It is difficult to differentiate lymphnmatous from metastatic lymph nodes using WB-DWI. However, it is a valuable imaging modality for staging of patients with malignant lymphoma.
基金Supported partially by the MedicalHealth Research Foundation of PLA, No. 980015
文摘AIM: To investigate the individual and the combined effects of glutamine, dietary fiber, and growth hormone on the structural adaptation of the remnant small bowel. METHODS: Forty-two adult male Sprague-Dawley rats underwent 85% mid-small bowel resection and received total parenteral nutrition (TPN) support during the first three postoperational days.From the 4th postoperational day, animals were randomly assigned to receive 7 different treatments for 8 days: TPNcon group, receiving TPN and enteral 20 g x L(-1) glycine perfusion; TPN+Gln group, receiving TPN and enteral 20 g x L(-1) glutamine perfusion; ENcon group, receiving enteral nutrition (EN) fortified with 20 g x L(-1) glycine; EN+Gln group, enteral nutrition fortified with 20 g x L(-1) glutamine; EN+Fib group, enteral nutrition and 2 g x d(-1) oral soybean fiber; EN+GH group, enteral nutrition and subcutaneous growth hormone (GH) (0.3 IU) injection twice daily; and ENint group, glutamine-enriched EN, oral soybean fiber, and subcutaneous GH injection. RESULTS: Enteral glutamine perfusion during TPN increased the small intestinal villus height (jejunal villus height 250 microm +/- 29 microm in TPNcon vs 330 microm +/- 54 microm in TPN+Gln, ileal villus height 260 microm +/- 28 microm in TPNcon vs 330 microm +/- 22 microm in TPN+Gln, P【0.05) and mucosa thickness (jejunal mucosa thickness 360 microm +/- 32 microm in TPNcon vs 460 microm +/- 65 microm in TPN+Gln, ileal mucosa thickness 400 microm +/- 25 microm in TPNcon vs 490 microm +/- 11 microm in TPN+Gln,P【 0.05) in comparison with the TPNcon group. Either fiber supplementation or GH administration improved body mass gain (end body weight 270 g +/- 3.6g in EN+Fib, 265.7 g +/- 3.3 g in EN+GH, vs 257 g +/- 3.3 g in ENcon, P【 0.05), elevated plasma insulin-like growth factor (IGF-I) level (880 microg x L(-1). 52 microg x L-(-1) in EN+Fib,1200 microg x L(-1). 96 microg x L-(-1) in EN +/- GH, vs 620 microg x L(-1).43 microg x L-(-1) in ENcon, P【 0.05), and increased the villus height (jejunum 560 mi
基金Supported by In part by Zhejiang Provincial Natural Science Foundation,No.LY12H04005 and LY13H040011
文摘The intestinal tract is colonized soon after birth with a variety of ingested environmental and maternal microflora. This process is influenced by many factors including mode of delivery, diet, environment, and the use of antibiotics. Normal intestinal microflora provides protection against infection, ensures tolerance to foods, and contributes to nutrient digestion and energy harvest. In addition, enteral feeding and colonization with the normal commensal flora are necessary for the maintenance of intestinal barrier function and play a vital role in the regulation of intestinal barrier function. Intestinal commensal microorganisms also provide signals that foster normal immune system development and influence the ensuing immune responses. There is increasingly recognition that alterations of the microbial gut flora and associated changes in intestinal barrier function may be related to certain diseases of the gastrointestinal tract. This review summarizes recent advances in understanding the complex ecosystem of intestinal microbiota and its role in regulating intestinal barrier function and a few common pediatric diseases. Disruption in the establishment of a stable normal gut microflora may contribute to the pathogenesis of diseases including inflammatory bowel disease, nosocomial infection, and neonatal necrotizing enterocolitis.
基金Supported by the National Natural Science Foundation of China under Grant No.51079032 the Outstanding Youth Science Foundation of Heilongjiang Province,No.200908
文摘Under the background of the energy saving and emission reduction, more and more attention has been placed on investigating the energy efficiency of ships. The added resistance has been noted for being crucial in predicting the decrease of speed on a ship operating at sea. Furthermore, it is also significant to investigate the added resistance for a ship functioning in short waves of large modern ships. The researcher presents an estimation formula for the calculation of an added resistance study in short waves derived from the reflection law. An improved method has been proposed to calculate the added resistance due to ship motions, which applies the radiated energy theory along with the strip method. This procedure is based on an extended integral equation （EIE） method, which was used for solving the hydrodynamic coefficients without effects of the irregular frequency. Next, a combined method was recommended for the estimation of added resistance for a ship in the whole wave length range. The comparison data with other experiments indicate the method presented in the paper provides satisfactory results for large blunt ship.
基金RFCID, No 01030152, RGC, CUHK4428/06M, ITF ITS091/03 of Hong Kong Government, and Faculty Direct Fund of the Chinese University of Hong Kong
文摘RNA interference (RNAi) is an evolutionally conserved gene silencing mechanism present in a variety of eukaryotic species. RNAi uses short double-stranded RNA (dsRNA) to trigger degradation or translation repression of homologous RNA targets in a sequence-specific manner. This system can be induced effectively in vitro and in vivo by direct application of small interfering RNAs (siRNAs), or by expression of short hairpin RNA (shRNA) with non-viral and viral vectors. To date, RNAi has been extensively used as a novel and effective tool for functional genomic studies, and has displayed great potential in treating human diseases, including human genetic and acquired disorders such as cancer and viral infections. In the present review, we focus on the recent development in the use of RNAi in the prevention and treatment of viral infections. The mechanisms, strategies, hurdles and prospects of employing RNAi in the pharmaceutical industry are also discussed.
文摘With the explosion of online communication and publication, texts become obtainable via forums, chat messages, blogs, book reviews and movie reviews. Usually, these texts are much short and noisy without sufficient statistical signals and enough information for a good semantic analysis. Traditional natural language processing methods such as Bow-of-Word (BOW) based probabilistic latent semantic models fail to achieve high performance due to the short text environment. Recent researches have focused on the correlations between words, i.e., term dependencies, which could be helpful for mining latent semantics hidden in short texts and help people to understand them. Long short-term memory (LSTM) network can capture term dependencies and is able to remember the information for long periods of time. LSTM has been widely used and has obtained promising results in variants of problems of understanding latent semantics of texts. At the same time, by analyzing the texts, we find that a number of keywords contribute greatly to the semantics of the texts. In this paper, we establish a keyword vocabulary and propose an LSTM-based model that is sensitive to the words in the vocabulary; hence, the keywords leverage the semantics of the full document. The proposed model is evaluated in a short-text sentiment analysis task on two datasets: IMDB and SemEval-2016, respectively. Experimental results demonstrate that our model outperforms the baseline LSTM by 1%similar to 2% in terms of accuracy and is effective with significant performance enhancement over several non-recurrent neural network latent semantic models (especially in dealing with short texts). We also incorporate the idea into a variant of LSTM named the gated recurrent unit (GRU) model and achieve good performance, which proves that our method is general enough to improve different deep learning models.
基金This research was funded by the National Key Research and Development Program of China(Project No.2019YFD0901002)Northwest A&F University Young Talent Training Program(2452018030)+2 种基金Science and Technology Research Program of China Se-enriched Research Institute(2018FXZX02-05)Postdoctoral Science Foundation of China(2016M600821)Technical Innovation Guidance Project,Innovation Capability Support Program and Key Research and Development Project of Shaanxi Province(2019QYPY-124,2018TD-021&2018NY-008).
文摘In recent years,high-fat diet(HFD)has been widely applied in aquaculture,which reduces the intestinal health of cultured fish.The current study evaluated the protective effects of nano-selenium(nano-Se)on intestinal health of juvenile grass carp(Ctenopharyngodon idella)fed with HFD.A total of 135 experimental fish were fed with a regular diet(Con),a HFD(HFD)and a HFD containing nano-Se at 0.6 mg/kg(HSe)for 10 weeks.The results showed that dietary nano-Se significantly improved the survival rate and feed efficiency which were reduced by HFD in juvenile grass carp(P<0.05).Also,nano-Se(0.6 mg/kg)supplement alleviated intestinal damage caused by the HFD,thus maintaining the integrity of the intestine.Moreover,it significantly up-regulated the expression of genes related to tight junction(ZO-1,claudin-3 and occludin),anti-oxidization(GPx4a and GPx4b),and the protein of ZO-1 in the intestine of juvenile grass carp,which were depressed by the HFD(P<0.05).Furthermore,nano-Se supplementation significantly suppressed the expressions of genes related to the inflammation,including inflammatory cytokines(IL-8,IL-1β,IFN-γ,TNF-αand IL-6),signaling molecules(TLR4,p38 MAPK and NF-kB p65),and protein expression of NF-kB p65 and TNF-αin the intestine of juvenile grass carp which were induced by the HFD(P<0.05).Besides,dietary nano-Se normalized the intestinal microbiota imbalance of juvenile grass carp caused by the HFD through increasing the abundance of the beneficial bacteria,e.g.,Fusobacteria.Finally,dietary nano-Se increased the production of short chain fatty acids(SCFA)in the intestine,especially for butyric acid and caproic acid,which were negatively related to the increase of intestinal permeability and inflammation.In summary,supply of nano-Se(0.6 mg/kg)in HFD could effectively alleviate intestinal injury of juvenile grass carp by improving intestinal barrier function and reducing intestinal inflammation and oxidative stress.These positive effects may be due to the regulation of nano-Se on intestinal microbiota and th
基金support by the National Key Researchand Development Program of China(2018YFBO104100).
文摘External short circuit(ESC)of lithium-ion batteries is one of the common and severe electrical failures in electric vehicles.In this study,a novel thermal modelis developed to capture the temperature behavior of batteries under ESC conditions.Experiments were systematically performed under different battery initial state of charge and ambient temperatures.Based on the experimental results,we employed an extreme learming machine(ELM)-based thermal(ELMT)model to depict battery temperature behavior under ESC,where a lumped-state thermal model was used to replace the activation function of conventional ELMs.To demonstrate the effectiveness of the proposed model,wecompared the ELMT model with a multi-lumped-state thermal(MLT)model parameterized by thegenetic algorithm using the experimental data from various sets of battery cells.It is shown that the ELMT model can achieve higher computa-tional efficiency than the MLT model and better fitting and prediction accuracy,where the average root mean squared error(RMSE)of the fitting is 0.65℃ for the ELMT model and 3.95℃ for the MLT model,and the RMES of the prediction under new data set is 3.97℃ for the ELMT model and 6.11℃ for the MLT model.
文摘Social media websites allow users to exchange short texts such as tweets via microblogs and user status in friendship networks. Their limited length, pervasive abbrevi- ations, and coined acronyms and words exacerbate the prob- lems of synonymy and polysemy, and bring about new chal- lenges to data mining applications such as text clustering and classification. To address these issues, we dissect some poten- tial causes and devise an efficient approach that enriches data representation by employing machine translation to increase the number of features from different languages. Then we propose a novel framework which performs multi-language knowledge integration and feature reduction simultaneously through matrix factorization techniques. The proposed ap- proach is evaluated extensively in terms of effectiveness on two social media datasets from Facebook and Twitter. With its significant performance improvement, we further investi- gate potential factors that contribute to the improved perfor- mance.
基金part of the research project SeaPro, which is sponsored by Rolls-Royce Marine and the Research Council of Norway
文摘The added resistance of KVLCC2 in short and regular head waves has been studied theoretically and experimentally. Model tests are performed to determine how well the asymptotic formula （Faltinsen et al. 1980） predicts the typical level of added resistance in short waves. Because the asymptotic formula neglects the effects of ship motions, it is combined with theoretical methods to calculate the added resistance in long waves using an function to predict the added resistance in the intermediate wavelength region where both ship motions and wave reflection are important. A unique feature of this experiment is that the ship model is divided into three segments to explore the added resistance distribution with respect to hull segment. This paper discusses the sensitivity of experimental results to the quality of the incident regular head waves. Moreover, a novel procedure for analyzing added resistance is described. Finally, the experimentally determined added resistance of KVLCC2 is compared with theoretical results. It is shown that the added resistance from the combined theoretical methods agrees well with experimental results in both the intermediate and short wave regions. The use of hull segments shows that added resistance is concentrated primarily at the bow.
