Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage spaces.Traditional cross-plot analy...Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage spaces.Traditional cross-plot analysis and empirical formula methods for identifying reservoir types using geophysical logging data have high uncertainty and low efficiency,which cannot accurately reflect the nonlinear relationship between reservoir types and logging data.Recently,the kernel Fisher discriminant analysis(KFD),a kernel-based machine learning technique,attracts attention in many fields because of its strong nonlinear processing ability.However,the overall performance of KFD model may be limited as a single kernel function cannot simultaneously extrapolate and interpolate well,especially for highly complex data cases.To address this issue,in this study,a mixed kernel Fisher discriminant analysis(MKFD)model was established and applied to identify reservoir types of the deep Sinian carbonates in central Sichuan Basin,China.The MKFD model was trained and tested with 453 datasets from 7 coring wells,utilizing GR,CAL,DEN,AC,CNL and RT logs as input variables.The particle swarm optimization(PSO)was adopted for hyper-parameter optimization of MKFD model.To evaluate the model performance,prediction results of MKFD were compared with those of basic-kernel based KFD,RF and SVM models.Subsequently,the built MKFD model was applied in a blind well test,and a variable importance analysis was conducted.The comparison and blind test results demonstrated that MKFD outperformed traditional KFD,RF and SVM in the identification of reservoir types,which provided higher accuracy and stronger generalization.The MKFD can therefore be a reliable method for identifying reservoir types of deep carbonates.展开更多
Vessel Monitoring System(VMS) provides a new opportunity for quantified fishing research. Many approaches have been proposed to recognize fishing activities with VMS trajectories based on the types of fishing vessels....Vessel Monitoring System(VMS) provides a new opportunity for quantified fishing research. Many approaches have been proposed to recognize fishing activities with VMS trajectories based on the types of fishing vessels. However, one research problem is still calling for solutions, how to identify the fishing vessel type based on only VMS trajectories. This problem is important because it requires the fishing vessel type as a preliminary to recognize fishing activities from VMS trajectories. This paper proposes fishing vessel type identification scheme(FVID) based only on VMS trajectories. FVID exploits feature engineering and machine learning schemes of XGBoost as its two key blocks and classifies fishing vessels into nine types. The dataset contains all the fishing vessel trajectories in the East China Sea in March 2017, including 10031 pre-registered fishing vessels and 1350 unregistered vessels of unknown types. In order to verify type identification accuracy, we first conduct a 4-fold cross-validation on the trajectories of registered fishing vessels. The classification accuracy is 95.42%. We then apply FVID to the unregistered fishing vessels to identify their types. After classifying the unregistered fishing vessel types, their fishing activities are further recognized based upon their types. At last, we calculate and compare the fishing density distribution in the East China Sea before and after applying the unregistered fishing vessels, confirming the importance of type identification of unregistered fishing vessels.展开更多
[Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determinati...[Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determination of growth curve and correlation curve between OD 600 values and viable counts,drug susceptibility tests,pathogenicity analysis,and histopathological observations were carried out.[Results]The Streptococcus strain isolated from infected pigs was identified as Streptococcus suis type 2,which was named TA01 strain.TA01 strain reached the growth peak at 6-8 h post-incubation,and viable counts gradually declined after 8 h of incubation.The correlation equation between OD 600 values and viable counts is y=24.659 x-1.076 1,R^2=0.996 7.TA01 strain was sensitive to penicillin,erythromycin,florfenicol and oxacillin,and resistant to ciprofloxacin,polymyxin B and clindamycin.According to the results of pathogenicity analysis,all the mice in 3.6×10^9 cfu/mouse group died within 48,and these dead mice exhibited acute pyaemia septica.Based on the Reed-Muench formula,it was calculated that LD 50 of TA01 strain was 1.137×10^8 cfu/mouse.Pathological examination showed obvious blue-stained bacteria clusters,accompanied by neutrophil infiltration.[Conclusions]TA01 strain was a virulent strain of Streptococcus suis type 2.Compared with Streptococcus strains which were isolated and reported in China,TA01 strain exhibited strong virulence and rapid proliferation.展开更多
The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene,GlTop 2 was identified. It is a single copy gene with a 4476 bp long ORF without intron. The deduced amino...The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene,GlTop 2 was identified. It is a single copy gene with a 4476 bp long ORF without intron. The deduced amino acid sequence shows strong homology to eukaryotic DNA Top 2. However, some distortions were found, such as six insertions in the ATPase domain and the central domain, a -100 aa longer central domain; a ~200 aa shorter C-terminal domain containing rich charged residues. These features revealed by comparing with Top 2 of the host, human, might be helpful in exploiting drug selectivity for antigiardial therapy. Phylogenetic analysis of eukaryotic enzymes showed that kinetoplastids, plants, fungi, and animals were monophyletic groups, and the animal and fungi lineages shared a more recent common ancestor than either did with the plant lineage; microsporidia grouped with fungi. However, unlike many previous phylogenetic analyses, the ''amitochondriate'' G. lamblia was not the earliest branch but diverged after mitochondriate kinetoplastids in our trees. Both the finding of typical eukaryotic type IIA topoisomerase and the phylogenetic analysis suggest G, lamblia is not possibly as primitive as was regarded before and might diverge after the acquisition of mitochondria. This is consistent with the recent discovery of mitochondrial remnant organelles in G. lamblia.展开更多
[ Objective] In order to make out differences between drug resistance spectrum types of different animal sources of Salmonella. [ Meth- otis] Selenite cystine broth, Salmonella- Shigella genus agar medium, CHROMagar S...[ Objective] In order to make out differences between drug resistance spectrum types of different animal sources of Salmonella. [ Meth- otis] Selenite cystine broth, Salmonella- Shigella genus agar medium, CHROMagar Salmonella chromogenic culture, Reveal Salmonella detection kit and molecular biology methods were used for isolation and identification of Salmonella from different animal feces samples. Antibacterialantimi- crobial susceptibility tests of 17 kinds of drugs such as enrofloxacin, apramycin and florfenicol were done on isolated strains with broth microdilution method, and test data was analysed with WHOnet 5.4 software. [ Results ] 699 feces samples from different animals were separated, and 53 strains of Salmonella were achieved with separation rate of 7.58%, among which those of yak, poultry, and pet sources were respectively 4.33%, 9.06% and 8.37%. [ Condusions] Separation rates and drug resistance spectrum types of different animal origin Salmonella varied greatly, among which separation rates and drug resistance spectrum types of yak source Salmonella were the lowest, there was little difference between separation rates of poultry and dog source Salmonella, however there were large differences on drug resistance spectrum types.展开更多
In September 2011, an infectious disease suspected to be postweaning multisystemic wasting syndrome (PMWS) broke out in some pig farm in Taizhou. The inguinal lymph node, liver and lung tissues were collected and gr...In September 2011, an infectious disease suspected to be postweaning multisystemic wasting syndrome (PMWS) broke out in some pig farm in Taizhou. The inguinal lymph node, liver and lung tissues were collected and grinded into tissue suspension. The suspension was subjected to PCR detection, and the positive product was sequenced. The suspension of positive samples was filtered with 0.22 μm filter membrane, and the filtrate was inoculated onto PK15 cells. After five generations of blind passages, the cell viral liquid was collected and extracted for DNA, which was subjected to PCR detection and indirect immunofluorescence. The results showed that the isolate was porcine circovirus type 2 (PCV2) and designated as TAIZ110926. The target sequence was committed to NCBI with a serial number: KF039888.展开更多
The results of geological research show that those phenomena such as surface geology,geomorphology,deep geophysical field,and time-space distribution of seismicities can be usedas the main seismogeological indicators ...The results of geological research show that those phenomena such as surface geology,geomorphology,deep geophysical field,and time-space distribution of seismicities can be usedas the main seismogeological indicators to identify the newly-generated seismic rupture zone(NSRZ).According to their formation and evolution process,the NSRZs can be divided intothree types:pre-rupture-isolated,quasi-rupture-discontinuous and major-rupture-connected.In a pre-rupture-isolated NSRZ,the seismicity is dominated by medium-small earthquakes.In a quasi-rupture-discontinuous NSRZ,the frequency and intensity of strong earthquakesincrease and there may even be the largest earthquake to occur.A major-rupture-connectedNSRZ is the segment where rupture has entered the mature stage;in such a zone,theintensity and duration of seismic activity depend on the constitutive condition and regionalstress field in the zone.展开更多
The current study tested the gas component and carbon isotopic composition of gas samples from 6 oilgas fields at the northern margin of Qaidam Basin, and established a chart to quantitatively identify the mixing rati...The current study tested the gas component and carbon isotopic composition of gas samples from 6 oilgas fields at the northern margin of Qaidam Basin, and established a chart to quantitatively identify the mixing ratio of source-mixed gas. Besides, this research quantitatively investigated the natural gas generated by different types of organic matter. The results show that different ratios of source-mixed gas exist in the 6 oil-gas fields at the northern margin of Qaidam Basin. Among them, Mabei has the highest mixing ratio of coal-type gas, followed by Nanbaxian, Mahai, Lenghu-4, Lenghu-3 and Lenghu-5, with the ratios of coal-type gas 91%, 87%, 83%, 66%, 55% and 36%, respectively. Lenghu-3 and Lenghu-4 oil-gas fields were mainly filled by coal-type gas earlier. For Lenghu-3, the gas was mainly generated from low matured source rocks in lower Jurassic Series of Lengxi sub-sag. For Lenghu-4, the gas was mainly generated from humus-mature source rocks in lower Jurassic Series of the northern slope of Kunteyi sub-sag. Gas in Lenghu-5 was mainly later filled oil-type gas, which was generated from high matured sapropelics in lower Jurassic Series of Kunteyi sub-sag. Earlier filled coal-type gas was the main part of Mahai, Nanbaxian and Mabei oil-gas fields. Gas source of Mahai was mainly generated from high mature humics in lower Jurassic Series of Yibei sub-sag; for Nanbaxian, the gas was mainly generated from high matured humics in middle-lower Jurassic Series of Saishiteng sub-sag; for Mabei, the gas was mainly generated from humus-mature source rocks in middle Jurassic Series of Yuqia sub-sag.展开更多
To address the problem of identifying multiple types of additives in lubricating oil,a method based on midinfrared spectral band selection using the eXtreme Gradient Boosting(XGBoost)algorithm combined with the ant co...To address the problem of identifying multiple types of additives in lubricating oil,a method based on midinfrared spectral band selection using the eXtreme Gradient Boosting(XGBoost)algorithm combined with the ant colony optimization(ACO)algorithm is proposed.The XGBoost algorithm was used to train and test three additives,T534(alkyl diphenylamine),T308(isooctyl acid thiophospholipid octadecylamine),and T306(trimethylphenol phosphate),separately,in order to screen for the optimal combination of spectral bands for each additive.The ACO algorithm was used to optimize the parameters of the XGBoost algorithm to improve the identification accuracy.During this process,the support vector machine(SVM)and hybrid bat algorithms(HBA)were included as a comparison,generating four models:ACO-XGBoost,ACO-SVM,HBA-XGboost,and HBA-SVM.The results showed that all four models could identify the three additives efficiently,with the ACO-XGBoost model achieving 100%recognition of all three additives.In addition,the generalizability of the ACO-XGBoost model was further demonstrated by predicting a lubricating oil containing the three additives prepared in our laboratory and a collected sample of commercial oil currently in use。展开更多
[Objective] This study aimed to investigate the genetic variation of porcine circovirus type 2 (PCV2) in China. [Method] The strain was isolated from infected samples by cel passage and preliminarily identified by P...[Objective] This study aimed to investigate the genetic variation of porcine circovirus type 2 (PCV2) in China. [Method] The strain was isolated from infected samples by cel passage and preliminarily identified by PCR and IFA. Ful-length genome of the isolated strain was obtained by specific amplification for homology and phylogenetic analysis. [Result] A PCV2 strain was successful y isolated and named 201105ZJ, which could proliferate in PK15 cel lines. Specific fragments could be amplified by specific PCR assay. According to results of IFA assay, specif-ic immunofluorescence was observed; the TCID50 was low (102.67); the ful-length genome sequence of the isolated strain was 1 768 bp, sharing 94.1%-96.8% ho-mology with 13 reference strains; to be specific, the isolated strain exhibited the highest homology of 96.8% with AF055392PCV2a; the isolated strain 201105ZJ and reference strain AF055392 belonged to genotype PCV2a, exhibiting a distant genetic relationship with genotype PCV2c. [Conclusion] Characteristics of genetic variation of PCV2 isolate 201105ZJ provided theoretical basis for vaccine development, investi-gation of PCV2 pathogenesis, and prevention and control of porcine circovirus-as-sociated diseases (PCVAD) in East China.展开更多
Human adenoviruses (HAdVs), especially HAdV-B3, -E4 and -B7, are associated with Acute Respiratory Disease in Chinese children, and occasionally in adults. In order to establish and document the profiles of the respir...Human adenoviruses (HAdVs), especially HAdV-B3, -E4 and -B7, are associated with Acute Respiratory Disease in Chinese children, and occasionally in adults. In order to establish and document the profiles of the respiratory adenovirus pathogen among children in Guangzhou, Southern China, a rapid, simple and practical method for identification and typing of respiratory adenoviruses was developed and evaluated. One pair of universal PCR primers was designed according to the conserved region of the hexon gene, which can detect not only HAdV-B3, -E4 and -B7, but also HAdV-B14, -F40 and -F41, with a specific 300bp PCR product. Three pairs of type-specific PCR primers were also designed according to the hypervariable regions of the hexon gene to type HAdV-B3, -E4 and -B7 by three independent PCR reactions, making it easy to optimize the PCR conditions. By using this method, one hundred throat swab specimens collected during Oct 2010 to Dec 2011 and suspected of being positive for adenoviral infection were identified and typed for adenoviruses. Of these samples, fifty-five were adenovirus-positive. The most common HAdV type was HAdV-B3, identified in 92.7% of samples, which is not only consistent with the data reported in 2004-2006, but also consistent with the recent report in Hangzhou, eastern China, indicating that HAdV-B3 has been circulating in Guangzhou, and maybe in eastern China, for many years. The method for the respiratory adenovirus identification and typing we developed is rapid, simple and practical, which has a potential in the real-time surveillance of circulating adenovirus strains and also to provide etiological evidence for the adenovirus-relative disease control and prevention in China.展开更多
Great volumes of shallow-buried (〈2,000 m) natural gases which are mainly composed of biogases and low-mature gases have been found in the Mesozoic-Cenozoic sedimentary basins in China. Many shallow gas reservoirs ...Great volumes of shallow-buried (〈2,000 m) natural gases which are mainly composed of biogases and low-mature gases have been found in the Mesozoic-Cenozoic sedimentary basins in China. Many shallow gas reservoirs in China are characterized by coexistence of biogas and low-mature gas, so identifying the genetic types of shallow gases is important for exploration and development in sedimentary basins. In this paper, we study the gas geochemistry characteristics and distribution in different basins, and classify the shallow gas into two genetic types, biogas and low-mature gas. The biogases are subdivided further into two subtypes by their sources, the source rock-derived biogas and hydrocarbon-derived biogas. Based on the burial history of the source rocks, the source rock-derived biogases are divided into primary and secondary biogas. The former is generated from the source rocks in the primary burial stage, and the latter is from uplifted source rocks or those in a secondary burial stage. In addition, the identifying parameters of each type of shallow gas are given. Based on the analysis above, the distributions of each type of shallow gas are studied. The primary biogases generated from source rocks are mostly distributed in Quaternary basins or modem deltas. Most of them migrate in watersoluble or diffused mode, and their migration distance is short. Reservoir and caprock assemblages play an important role in primary biogas accumulation. The secondary biogases are distributed in a basin with secondary burial history. The oil-degraded biogases are distributed near heavy oil pools. The low-mature gases are widely distributed in shallow-buried reservoirs in the Meso-Cenozoic basins.展开更多
This paper presents an overview of petrophysical research and exploration achievements of low resistivity pay (LRP) zone by well logs in China. It includes geological characteristics and characteristics of well log ...This paper presents an overview of petrophysical research and exploration achievements of low resistivity pay (LRP) zone by well logs in China. It includes geological characteristics and characteristics of well log response of the low resistivity pay zones discovered and evaluated in recent years, as well as the problems in recognizing and evaluating low resistivity pay zones by well logs. The research areas mainly include the Neogene formations in the Bohai Bay Basin, the Triassic formations in the northern Tarim Basin and the Cretaceous formations in the Junggar Basin, The petrophysical research concerning recognition and evaluation of the low resistivity pays, based on their genetic types, is introduced in this paper.展开更多
Natural gas has been discovered in many anticlines in the southern margin of the Junggar Basin. However, the geochemical characteristics of natural gas in different anticlines haven’t been compared systematically, pa...Natural gas has been discovered in many anticlines in the southern margin of the Junggar Basin. However, the geochemical characteristics of natural gas in different anticlines haven’t been compared systematically, particularly, the type and source of natural gas discovered recently in Well Gaotan-1 at the Gaoquan anticline remain unclear. The gas composition characteristics and carbon and hydrogen isotope compositions in different anticlines were compared and sorted systematically to identify genetic types and source of the natural gas. The results show that most of the gas samples are wet gas, and a few are dry gas;the gas samples from the western and middle parts have relatively heavier carbon isotope composition and lighter hydrogen isotope composition, while the gas samples from the eastern part of southern basin have lighter carbon and hydrogen isotope compositions. The natural gas in the southern margin is thermogenic gas generated by freshwater-brackish water sedimentary organic matter, which can be divided into three types, coal-derived gas, mixed gas and oil-associated gas, in which coal-derived gas and mixed gas take dominance. The Jurassic coal measures is the main natural gas source rock in the southern margin, and the Permian lacustrine and the Upper Triassic lacustrine-limnetic facies source rocks are also important natural gas source rocks. The natural gas in the western part of the southern margin is derived from the Jurassic coal measures and the Permian lacustrine source rock, while the natural gas in the middle part of the southern margin is mainly derived from the Jurassic coal measures, partly from the Permian and/or the Upper Triassic source rocks, and the natural gas in the eastern part of the southern margin is originated from the Permian lacustrine source rock. The natural gas in the Qingshuihe oil and gas reservoir of Well Gaotan-1 is a mixture of coal-derived gas and oil-associated gas, of which the Jurassic and Permian source rocks contribute about half each.展开更多
Identifying the origin of body fluids left at a crime scene can give a significant insight into crime scene reconstruction by supporting a link between sample donors and actual criminal acts.However,the conventional b...Identifying the origin of body fluids left at a crime scene can give a significant insight into crime scene reconstruction by supporting a link between sample donors and actual criminal acts.However,the conventional body fluid identification methods are prone to various limitations,such as time consumption,intensive labor,nonparallel manner,varying degrees of sensitivity and limited specificity.Recently,the analysis of cell-specific messenger RNA expression(mRNA profiling)has been proposed to supplant conventional methods for body fluid identification.Since 2011,the collaborative exercises have been organized by the European DNA Profiling Group(EDNAP)in order to evaluate the robustness and reproducibility of mRNA profiling for body fluid identification.The major advantages of mRNA profiling,compared to the conventional methods,include higher sensitivity,greater specificity,the ability of detecting several body fluids in one multiplex reaction,and compatibility with current DNA extraction and analysis procedure.In the current review,we provided an overview of the present knowledge and detection methodologies of mRNA profiling for forensic body fluid identification and discussed its possible practical application to forensic casework.展开更多
基金supported by the National Natural Science Foundation of China(No.U21B2062)the Natural Science Foundation of Hubei Province(No.2023AFB307)。
文摘Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage spaces.Traditional cross-plot analysis and empirical formula methods for identifying reservoir types using geophysical logging data have high uncertainty and low efficiency,which cannot accurately reflect the nonlinear relationship between reservoir types and logging data.Recently,the kernel Fisher discriminant analysis(KFD),a kernel-based machine learning technique,attracts attention in many fields because of its strong nonlinear processing ability.However,the overall performance of KFD model may be limited as a single kernel function cannot simultaneously extrapolate and interpolate well,especially for highly complex data cases.To address this issue,in this study,a mixed kernel Fisher discriminant analysis(MKFD)model was established and applied to identify reservoir types of the deep Sinian carbonates in central Sichuan Basin,China.The MKFD model was trained and tested with 453 datasets from 7 coring wells,utilizing GR,CAL,DEN,AC,CNL and RT logs as input variables.The particle swarm optimization(PSO)was adopted for hyper-parameter optimization of MKFD model.To evaluate the model performance,prediction results of MKFD were compared with those of basic-kernel based KFD,RF and SVM models.Subsequently,the built MKFD model was applied in a blind well test,and a variable importance analysis was conducted.The comparison and blind test results demonstrated that MKFD outperformed traditional KFD,RF and SVM in the identification of reservoir types,which provided higher accuracy and stronger generalization.The MKFD can therefore be a reliable method for identifying reservoir types of deep carbonates.
基金partially supported by National Key R&D Program (No. 2016YFC 1401900)the National Natural Science Foundation of China (Nos. 61379127, 61379128, 61572448)+1 种基金the Fundamental Research Funds for the Central Universities (No. 201713016)Qingdao National Laboratory for Marine Science and Technology Open Research Project (No. QNLM2016ORP 0405)
文摘Vessel Monitoring System(VMS) provides a new opportunity for quantified fishing research. Many approaches have been proposed to recognize fishing activities with VMS trajectories based on the types of fishing vessels. However, one research problem is still calling for solutions, how to identify the fishing vessel type based on only VMS trajectories. This problem is important because it requires the fishing vessel type as a preliminary to recognize fishing activities from VMS trajectories. This paper proposes fishing vessel type identification scheme(FVID) based only on VMS trajectories. FVID exploits feature engineering and machine learning schemes of XGBoost as its two key blocks and classifies fishing vessels into nine types. The dataset contains all the fishing vessel trajectories in the East China Sea in March 2017, including 10031 pre-registered fishing vessels and 1350 unregistered vessels of unknown types. In order to verify type identification accuracy, we first conduct a 4-fold cross-validation on the trajectories of registered fishing vessels. The classification accuracy is 95.42%. We then apply FVID to the unregistered fishing vessels to identify their types. After classifying the unregistered fishing vessel types, their fishing activities are further recognized based upon their types. At last, we calculate and compare the fishing density distribution in the East China Sea before and after applying the unregistered fishing vessels, confirming the importance of type identification of unregistered fishing vessels.
基金Supported by National Key Basic Research Program of China(973 Program)(2017YFD0500605)
文摘[Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determination of growth curve and correlation curve between OD 600 values and viable counts,drug susceptibility tests,pathogenicity analysis,and histopathological observations were carried out.[Results]The Streptococcus strain isolated from infected pigs was identified as Streptococcus suis type 2,which was named TA01 strain.TA01 strain reached the growth peak at 6-8 h post-incubation,and viable counts gradually declined after 8 h of incubation.The correlation equation between OD 600 values and viable counts is y=24.659 x-1.076 1,R^2=0.996 7.TA01 strain was sensitive to penicillin,erythromycin,florfenicol and oxacillin,and resistant to ciprofloxacin,polymyxin B and clindamycin.According to the results of pathogenicity analysis,all the mice in 3.6×10^9 cfu/mouse group died within 48,and these dead mice exhibited acute pyaemia septica.Based on the Reed-Muench formula,it was calculated that LD 50 of TA01 strain was 1.137×10^8 cfu/mouse.Pathological examination showed obvious blue-stained bacteria clusters,accompanied by neutrophil infiltration.[Conclusions]TA01 strain was a virulent strain of Streptococcus suis type 2.Compared with Streptococcus strains which were isolated and reported in China,TA01 strain exhibited strong virulence and rapid proliferation.
基金supported by Grants (30070362, 30170135,30021004) the National Natural Science Foundationof China and Grants (KSCX2-SW-101C, STZ-00-23)the Chinese Academy of Sciences.
文摘The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene,GlTop 2 was identified. It is a single copy gene with a 4476 bp long ORF without intron. The deduced amino acid sequence shows strong homology to eukaryotic DNA Top 2. However, some distortions were found, such as six insertions in the ATPase domain and the central domain, a -100 aa longer central domain; a ~200 aa shorter C-terminal domain containing rich charged residues. These features revealed by comparing with Top 2 of the host, human, might be helpful in exploiting drug selectivity for antigiardial therapy. Phylogenetic analysis of eukaryotic enzymes showed that kinetoplastids, plants, fungi, and animals were monophyletic groups, and the animal and fungi lineages shared a more recent common ancestor than either did with the plant lineage; microsporidia grouped with fungi. However, unlike many previous phylogenetic analyses, the ''amitochondriate'' G. lamblia was not the earliest branch but diverged after mitochondriate kinetoplastids in our trees. Both the finding of typical eukaryotic type IIA topoisomerase and the phylogenetic analysis suggest G, lamblia is not possibly as primitive as was regarded before and might diverge after the acquisition of mitochondria. This is consistent with the recent discovery of mitochondrial remnant organelles in G. lamblia.
基金funded by 12th Five-Year Technology Support Program-key pastoral areas production of ecological life protection technology integration and demonstration topics-comprehensive prevention and control technology integration,innovation and application of cattle and sheep key epidemic disease(2012BAD13B06)Veterinary Medicine Discipline Program of Southwest University for Nationalities(2011XWD-S0906)
文摘[ Objective] In order to make out differences between drug resistance spectrum types of different animal sources of Salmonella. [ Meth- otis] Selenite cystine broth, Salmonella- Shigella genus agar medium, CHROMagar Salmonella chromogenic culture, Reveal Salmonella detection kit and molecular biology methods were used for isolation and identification of Salmonella from different animal feces samples. Antibacterialantimi- crobial susceptibility tests of 17 kinds of drugs such as enrofloxacin, apramycin and florfenicol were done on isolated strains with broth microdilution method, and test data was analysed with WHOnet 5.4 software. [ Results ] 699 feces samples from different animals were separated, and 53 strains of Salmonella were achieved with separation rate of 7.58%, among which those of yak, poultry, and pet sources were respectively 4.33%, 9.06% and 8.37%. [ Condusions] Separation rates and drug resistance spectrum types of different animal origin Salmonella varied greatly, among which separation rates and drug resistance spectrum types of yak source Salmonella were the lowest, there was little difference between separation rates of poultry and dog source Salmonella, however there were large differences on drug resistance spectrum types.
基金Supported by Key Project of Jiangsu Agri-animal Husbandry Vocational College(ZD201104)College Students'Innovation and Enterpreneurship Training Program of Jiangsu Province(201312806014Y)Special Fund for Fenghuang talents in Jiangsu Agri-animal Husbandry Vocational College
文摘In September 2011, an infectious disease suspected to be postweaning multisystemic wasting syndrome (PMWS) broke out in some pig farm in Taizhou. The inguinal lymph node, liver and lung tissues were collected and grinded into tissue suspension. The suspension was subjected to PCR detection, and the positive product was sequenced. The suspension of positive samples was filtered with 0.22 μm filter membrane, and the filtrate was inoculated onto PK15 cells. After five generations of blind passages, the cell viral liquid was collected and extracted for DNA, which was subjected to PCR detection and indirect immunofluorescence. The results showed that the isolate was porcine circovirus type 2 (PCV2) and designated as TAIZ110926. The target sequence was committed to NCBI with a serial number: KF039888.
基金This project was sponsored by the Nationnal Science Foundation(496742149),China.
文摘The results of geological research show that those phenomena such as surface geology,geomorphology,deep geophysical field,and time-space distribution of seismicities can be usedas the main seismogeological indicators to identify the newly-generated seismic rupture zone(NSRZ).According to their formation and evolution process,the NSRZs can be divided intothree types:pre-rupture-isolated,quasi-rupture-discontinuous and major-rupture-connected.In a pre-rupture-isolated NSRZ,the seismicity is dominated by medium-small earthquakes.In a quasi-rupture-discontinuous NSRZ,the frequency and intensity of strong earthquakesincrease and there may even be the largest earthquake to occur.A major-rupture-connectedNSRZ is the segment where rupture has entered the mature stage;in such a zone,theintensity and duration of seismic activity depend on the constitutive condition and regionalstress field in the zone.
基金Financial support from the National Natural Science Foundation of China (No. 40730422)the Priority Academic Program Development of Jiangsu Higher Education Institutions of Chinadata provided by Jurassic Project Department in Research Institute of Petroleum Exploration and Development of China are gratefully acknowledged
文摘The current study tested the gas component and carbon isotopic composition of gas samples from 6 oilgas fields at the northern margin of Qaidam Basin, and established a chart to quantitatively identify the mixing ratio of source-mixed gas. Besides, this research quantitatively investigated the natural gas generated by different types of organic matter. The results show that different ratios of source-mixed gas exist in the 6 oil-gas fields at the northern margin of Qaidam Basin. Among them, Mabei has the highest mixing ratio of coal-type gas, followed by Nanbaxian, Mahai, Lenghu-4, Lenghu-3 and Lenghu-5, with the ratios of coal-type gas 91%, 87%, 83%, 66%, 55% and 36%, respectively. Lenghu-3 and Lenghu-4 oil-gas fields were mainly filled by coal-type gas earlier. For Lenghu-3, the gas was mainly generated from low matured source rocks in lower Jurassic Series of Lengxi sub-sag. For Lenghu-4, the gas was mainly generated from humus-mature source rocks in lower Jurassic Series of the northern slope of Kunteyi sub-sag. Gas in Lenghu-5 was mainly later filled oil-type gas, which was generated from high matured sapropelics in lower Jurassic Series of Kunteyi sub-sag. Earlier filled coal-type gas was the main part of Mahai, Nanbaxian and Mabei oil-gas fields. Gas source of Mahai was mainly generated from high mature humics in lower Jurassic Series of Yibei sub-sag; for Nanbaxian, the gas was mainly generated from high matured humics in middle-lower Jurassic Series of Saishiteng sub-sag; for Mabei, the gas was mainly generated from humus-mature source rocks in middle Jurassic Series of Yuqia sub-sag.
基金the Beijing Natural Science Foundation(Grant No.2232066)the Open Project Foundation of State Key Laboratory of Solid Lubrication(Grant LSL-2212).
文摘To address the problem of identifying multiple types of additives in lubricating oil,a method based on midinfrared spectral band selection using the eXtreme Gradient Boosting(XGBoost)algorithm combined with the ant colony optimization(ACO)algorithm is proposed.The XGBoost algorithm was used to train and test three additives,T534(alkyl diphenylamine),T308(isooctyl acid thiophospholipid octadecylamine),and T306(trimethylphenol phosphate),separately,in order to screen for the optimal combination of spectral bands for each additive.The ACO algorithm was used to optimize the parameters of the XGBoost algorithm to improve the identification accuracy.During this process,the support vector machine(SVM)and hybrid bat algorithms(HBA)were included as a comparison,generating four models:ACO-XGBoost,ACO-SVM,HBA-XGboost,and HBA-SVM.The results showed that all four models could identify the three additives efficiently,with the ACO-XGBoost model achieving 100%recognition of all three additives.In addition,the generalizability of the ACO-XGBoost model was further demonstrated by predicting a lubricating oil containing the three additives prepared in our laboratory and a collected sample of commercial oil currently in use。
基金Supported by National Natural Science Foundation of China(31302071)Special Fund for Agro-scientific Research in the Public Interest(201303046)+1 种基金Independent Innovation Project of Jiangsu Province[CX(13)3065]Project of the Fourth Period of "333" High-level Personnel Training Program of Jiangsu Province(BRA2012194)~~
文摘[Objective] This study aimed to investigate the genetic variation of porcine circovirus type 2 (PCV2) in China. [Method] The strain was isolated from infected samples by cel passage and preliminarily identified by PCR and IFA. Ful-length genome of the isolated strain was obtained by specific amplification for homology and phylogenetic analysis. [Result] A PCV2 strain was successful y isolated and named 201105ZJ, which could proliferate in PK15 cel lines. Specific fragments could be amplified by specific PCR assay. According to results of IFA assay, specif-ic immunofluorescence was observed; the TCID50 was low (102.67); the ful-length genome sequence of the isolated strain was 1 768 bp, sharing 94.1%-96.8% ho-mology with 13 reference strains; to be specific, the isolated strain exhibited the highest homology of 96.8% with AF055392PCV2a; the isolated strain 201105ZJ and reference strain AF055392 belonged to genotype PCV2a, exhibiting a distant genetic relationship with genotype PCV2c. [Conclusion] Characteristics of genetic variation of PCV2 isolate 201105ZJ provided theoretical basis for vaccine development, investi-gation of PCV2 pathogenesis, and prevention and control of porcine circovirus-as-sociated diseases (PCVAD) in East China.
基金supported by National Natural Science Foundation of China (31100133)Natural Science Foundation of Guangdong Province (S2012010009261)+2 种基金Guangdong College Students' Innovative Experimental Project(1212111023)Extracurricular Research Activities of Southern Medical University (2010kw076)School of Public Health and Tropical Medicine (GWXS20110102)
文摘Human adenoviruses (HAdVs), especially HAdV-B3, -E4 and -B7, are associated with Acute Respiratory Disease in Chinese children, and occasionally in adults. In order to establish and document the profiles of the respiratory adenovirus pathogen among children in Guangzhou, Southern China, a rapid, simple and practical method for identification and typing of respiratory adenoviruses was developed and evaluated. One pair of universal PCR primers was designed according to the conserved region of the hexon gene, which can detect not only HAdV-B3, -E4 and -B7, but also HAdV-B14, -F40 and -F41, with a specific 300bp PCR product. Three pairs of type-specific PCR primers were also designed according to the hypervariable regions of the hexon gene to type HAdV-B3, -E4 and -B7 by three independent PCR reactions, making it easy to optimize the PCR conditions. By using this method, one hundred throat swab specimens collected during Oct 2010 to Dec 2011 and suspected of being positive for adenoviral infection were identified and typed for adenoviruses. Of these samples, fifty-five were adenovirus-positive. The most common HAdV type was HAdV-B3, identified in 92.7% of samples, which is not only consistent with the data reported in 2004-2006, but also consistent with the recent report in Hangzhou, eastern China, indicating that HAdV-B3 has been circulating in Guangzhou, and maybe in eastern China, for many years. The method for the respiratory adenovirus identification and typing we developed is rapid, simple and practical, which has a potential in the real-time surveillance of circulating adenovirus strains and also to provide etiological evidence for the adenovirus-relative disease control and prevention in China.
文摘Great volumes of shallow-buried (〈2,000 m) natural gases which are mainly composed of biogases and low-mature gases have been found in the Mesozoic-Cenozoic sedimentary basins in China. Many shallow gas reservoirs in China are characterized by coexistence of biogas and low-mature gas, so identifying the genetic types of shallow gases is important for exploration and development in sedimentary basins. In this paper, we study the gas geochemistry characteristics and distribution in different basins, and classify the shallow gas into two genetic types, biogas and low-mature gas. The biogases are subdivided further into two subtypes by their sources, the source rock-derived biogas and hydrocarbon-derived biogas. Based on the burial history of the source rocks, the source rock-derived biogases are divided into primary and secondary biogas. The former is generated from the source rocks in the primary burial stage, and the latter is from uplifted source rocks or those in a secondary burial stage. In addition, the identifying parameters of each type of shallow gas are given. Based on the analysis above, the distributions of each type of shallow gas are studied. The primary biogases generated from source rocks are mostly distributed in Quaternary basins or modem deltas. Most of them migrate in watersoluble or diffused mode, and their migration distance is short. Reservoir and caprock assemblages play an important role in primary biogas accumulation. The secondary biogases are distributed in a basin with secondary burial history. The oil-degraded biogases are distributed near heavy oil pools. The low-mature gases are widely distributed in shallow-buried reservoirs in the Meso-Cenozoic basins.
基金Supported by CNPC Innovation Foundation,Research Projects of PetroChina,Xinjiang and Tarim Oil Companies
文摘This paper presents an overview of petrophysical research and exploration achievements of low resistivity pay (LRP) zone by well logs in China. It includes geological characteristics and characteristics of well log response of the low resistivity pay zones discovered and evaluated in recent years, as well as the problems in recognizing and evaluating low resistivity pay zones by well logs. The research areas mainly include the Neogene formations in the Bohai Bay Basin, the Triassic formations in the northern Tarim Basin and the Cretaceous formations in the Junggar Basin, The petrophysical research concerning recognition and evaluation of the low resistivity pays, based on their genetic types, is introduced in this paper.
基金Supported by the PetroChina Science and Technology Project(06-01A-01-02,2016A-0202)
文摘Natural gas has been discovered in many anticlines in the southern margin of the Junggar Basin. However, the geochemical characteristics of natural gas in different anticlines haven’t been compared systematically, particularly, the type and source of natural gas discovered recently in Well Gaotan-1 at the Gaoquan anticline remain unclear. The gas composition characteristics and carbon and hydrogen isotope compositions in different anticlines were compared and sorted systematically to identify genetic types and source of the natural gas. The results show that most of the gas samples are wet gas, and a few are dry gas;the gas samples from the western and middle parts have relatively heavier carbon isotope composition and lighter hydrogen isotope composition, while the gas samples from the eastern part of southern basin have lighter carbon and hydrogen isotope compositions. The natural gas in the southern margin is thermogenic gas generated by freshwater-brackish water sedimentary organic matter, which can be divided into three types, coal-derived gas, mixed gas and oil-associated gas, in which coal-derived gas and mixed gas take dominance. The Jurassic coal measures is the main natural gas source rock in the southern margin, and the Permian lacustrine and the Upper Triassic lacustrine-limnetic facies source rocks are also important natural gas source rocks. The natural gas in the western part of the southern margin is derived from the Jurassic coal measures and the Permian lacustrine source rock, while the natural gas in the middle part of the southern margin is mainly derived from the Jurassic coal measures, partly from the Permian and/or the Upper Triassic source rocks, and the natural gas in the eastern part of the southern margin is originated from the Permian lacustrine source rock. The natural gas in the Qingshuihe oil and gas reservoir of Well Gaotan-1 is a mixture of coal-derived gas and oil-associated gas, of which the Jurassic and Permian source rocks contribute about half each.
基金supported by the grants from the National Key Technology Research&Development Program of the Ministry of Science and Technology of People’s Republic of China(2012BAK16B01)the National Natural Science Foundation of Peo-ple’s Republic of China(No.81222041,81172908)
文摘Identifying the origin of body fluids left at a crime scene can give a significant insight into crime scene reconstruction by supporting a link between sample donors and actual criminal acts.However,the conventional body fluid identification methods are prone to various limitations,such as time consumption,intensive labor,nonparallel manner,varying degrees of sensitivity and limited specificity.Recently,the analysis of cell-specific messenger RNA expression(mRNA profiling)has been proposed to supplant conventional methods for body fluid identification.Since 2011,the collaborative exercises have been organized by the European DNA Profiling Group(EDNAP)in order to evaluate the robustness and reproducibility of mRNA profiling for body fluid identification.The major advantages of mRNA profiling,compared to the conventional methods,include higher sensitivity,greater specificity,the ability of detecting several body fluids in one multiplex reaction,and compatibility with current DNA extraction and analysis procedure.In the current review,we provided an overview of the present knowledge and detection methodologies of mRNA profiling for forensic body fluid identification and discussed its possible practical application to forensic casework.