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1.
To trace evolution of canine parvovirus-2 (CPV-2), a total of 201 stool samples were collected from dogs with diarrhea in Heilongjiang province of northeast China from May 2014 to April 2015. The presence of CPV-2 in the samples was determined by PCR amplification of the VP2 gene (568 bp) of CPV-2. The results revealed that 95 samples (47.26%) were positive for CPV-2, and they showed 98.8%–100% nucleotide identity and 97.6%–100% amino acid identity. Of 95 CPV-2-positive samples, types new2a (Ser297Ala), new2b (Ser297Ala), and 2c accounted for 64.21%, 21.05%, and 14.74%, respectively. The positive rate of CPV-2 and the distribution of the new2a, new2b and 2c types exhibited differences among regions, seasons, and ages. Immunized dogs accounted for 48.42% of 95 CPV-2-positive samples. Coinfections with canine coronavirus, canine kobuvirus, and canine bocavirus were identified. Phylogenetic analysis revealed that the identified new2a, new2b, and CPV-2c strains in our study exhibited a close relationship with most of the CPV-2 strains from China; type new2a strains exhibited high variability, forming three subgroups; type new2b and CPV-2c strains formed one group with reference strains from China. Of 95 CPV-2 strains, Tyr324Ile and Thr440Ala substitutions accounted for 100% and 64.21%, respectively; all type new2b strains exhibited the Thr440Ala substitution, while the unique Gln370Arg substitution was found in all type 2c strains. Recombination analysis using entire VP2 gene indicated possible recombination events between the identified CPV-2 strains and reference strains from China. Our data revealed the co-circulation of new CPV-2a, new CPV-2b, and rare CPV-2c, as well as potential recombination events among Chinese CPV-2 strains.  相似文献   

2.
中国大风子科(Flacourtiaceae)研究资料   总被引:5,自引:0,他引:5  
赖书绅 《植物研究》1994,14(3):221-230
本文介绍了中国大风子科(Flacourtiaceac)的研究历史和2个新种、7个新变种和2个新变型及2个新组合、2个新组、2个新分布、2个新亚族。  相似文献   

3.
P. F. Lasko  M. L. Pardue 《Genetics》1988,120(2):495-502
The region of the second chromosome of Drosophila melanogaster defined by Df(2R)vgB was screened for recessive lethal and visible mutations. Fifty-eight new recessive alleles fall into 17 complementation groups. Many new vg alleles were also isolated in a screen for new vg deficiencies. The breakpoints of the new vg deficiencies were nonrandomly distributed. The distal breakpoints of twelve of 20 deficiencies overlapping Df(2R)vgB are genetically identical to that of Df(2R)vgD, coinciding with the position of a complex, pleiotropic locus, l(2)49Ea-Psc-Su(z)2.  相似文献   

4.
对颚毛虫兆属Crossodonthina Yosii, 1954做了简要介绍,提供了该属的鉴别特征,记述了采自中国湖南省东安县舜皇山的颚毛虫兆属1新种——周氏颚毛疣虫兆Crossodonthina choui,这是该属在华中地区(湖南)的新记录。新种的正模标本(♂)和2个副模标本(2♂)保存在中南林业科技大学生命科学与技术学院昆虫标本室。  相似文献   

5.
An oligohalobic peritrichous ciliate, Epistylis chlorelligerum Shen, 1980, was collected from a ditch in Hangzhou, China. The morphology, oral infraciliature, and morphogenesis of the species were studied using living and protargol-impregnated specimens. Zooids of E. chlorelligerum are 160-230 × 50-60 μm in vivo, and characterized by green-colored endoplasm containing symbiotic algae. The oral infraciliature presents a well-developed filamentous reticulum linked to the circular fiber of the cytostome; the outer two rows of P3 extend adstomally over P1 and usually enfold it. During binary fission, one daughter cell inherits most part of the old buccal apparatus and the reorganized haplokinety and germinal kinety (Hk' and G'), and new buccal apparatus of the other daughter cell is mostly developed from the original germinal kinety (G) and haplokinety (Hk): new peniculi 2, 3 (2P2, 2P3), new haplokinety (2Hk), and new germinal kinety (2G) are formed from G, while the new peniculus 1 (2P1) and its peristomial extention (2Pk) originate from Hk. The epistomial membrane can be observed until the two sets of buccal apparatus begin to separate from each other.  相似文献   

6.
Deletion of the cytochrome c2 gene in the purple bacterium Rhodobacter sphaeroides renders it incapable of phototrophic growth (strain cycA65). However, suppressor mutants which restore the ability to grow phototrophically are obtained at relatively high frequency (1-10 in 10(7)). We examined two such suppressors (strains cycA65R5 and cycA65R7) and found the expected complement of electron transfer proteins minus cytochrome c2: SHP, c', c551.5, and c554. Instead of cytochrome c2 which elutes from DEAE-cellulose between SHP and cytochrome c', at about 50 mM ionic strength in wild-type extracts, we found a new high redox potential cytochrome c in the mutants which elutes with cytochrome c551.5 at about 150 mM ionic strength. The new cytochrome is more acidic than cytochrome c2, but is about the same size or slightly smaller (13,500 Da). The redox potential of the new cytochrome from strain cycA65R7 (294 mV) is about 70 mV lower than that of cytochrome c2. The 280 nm absorbance of the new cytochrome is smaller than that of cytochrome c2, which suggests that there is less tryptophan (the latter has two residues). In vitro kinetics of reduction by lumiflavin and FMN semiquinones show that the reactivity of the new cytochrome is similar to that of cytochrome c2, and that there is a relatively large positive charge (+2.6) at the site of reduction, despite the overall negative charge of the protein. This behavior is characteristic of cytochromes c2 and unlike the majority of bacterial cytochromes examined. Fourteen out of twenty-four of the N-terminal amino acids of the new cytochrome are identical to the sequence of cytochrome c2. The N-termini of the cycA65R5 and cycA65R7 cytochromes were the same. The kinetics and sequence data indicate that the new protein may be a cytochrome c2 isozyme, which is not detectable in wild-type cells under photosynthetic growth conditions. We propose the name iso-2 cytochrome c2 for the new cytochrome produced in the suppressor strains.  相似文献   

7.
Bioassay-guided fractionation of an EtOAc-soluble extract of the stem bark of Erythrina addisoniae (Leguminosae), using an in vitro PTP1B inhibitory assay, resulted in the isolation of three new (1-3) and three known (4-6) 2-arylbenzofuran derivatives. The new compounds were identified as 2-[2',4'-dihydroxy-3'-(3-methylbut-2-enyl)phenyl]-6-hydroxybenzofuran (1), 2-[2'-methoxy-4'-hydroxy-5'-(3-methylbut-2-enyl)phenyl]-6-hydroxybenzofuran (2), and 2-(2'-methoxy-4'-hydroxyphenyl)-5-(3-methylbut-2-enyl)-6-hydroxybenzofuran (3). The new 2-arylbenzofurans 1-3 inhibited PTP1B activity with IC(50) values ranging from 13.6+/-1.1 to 17.5+/-1.2 microM in vitro assay. On the basis of the data obtained, 2-arylbenzofurans with prenyl group may be considered as a new class of PTP1B inhibitors.  相似文献   

8.
A new chemiluminescence assay was developed for the quantitative determination of linamarin, a cyanogenic glucoside present in cassava. The assay involved hydrolysis of linamarin by a specific enzyme, linamarase, to release glucose, which was then quantitated by a chemiluminescence system consisting of glucose oxidase-peroxidase-luminol. The new assay was more sensitive than the conventional spectrophotometric method for quantitating linamarin in cassava extracts. However, the following agents were found to interfere with the new assay: Vanadate, Mg2+, and Cu2+, were inhibitory to the luminescence of the H2O2-peroxidase-luminol system used in the coupling reaction, whereas EDTA and EGTA activated the system. In addition, Hg2+, which inhibits glucose oxidase, and Tris ion, which inhibits linamarase, both interfered with the new assay.  相似文献   

9.
The induction of 2-amino-Delta(2)-thiazoline-4-carboxylic acid hydrolase (ATCase) and N-carbamoylcysteine amidohydrolase (NCCase), both of which are involved in the conversion step of 2-amino-Delta(2)-thiazoline carboxylic acid (ATC) to cysteine, was studied with Pseudomonas putida AJ3865. We found that L-ATC induced L-ATCase and L-NCCase, but that D-ATC induced only L-NCCase, whereas L- or D-NCC and thiazoline derivatives did not induce both enzymes. The bacterium showed neither D-ATCase nor D-NCCase activities, indicating that the role of L-ATC and D-ATC was different in the enzyme induction. We also found new inducers, d- and l-methionine, S-methyl-L-cysteine, cysteic acid, and 2-aminoethane sulfonic acid. However, the induction level of both enzymes by new inducers was much lower than those by L-ATC and D-ATC. Furthermore, the induction rate of both enzymes was synergistically increased only under a combination of D,L-ATC and new inducers. S-Compounds, however, such as new inducers except S-methyl-L-cysteine, inhibited both enzyme activities. This is the first report on the new inducers, synergistic induction, and the new inhibitors of L-ATCase and L-NCCase.  相似文献   

10.
Convenient enzymatic transformation of the phenylpropanoid caffeic acid (1) with polyphenol oxidase originating from pear afforded three new oxidized metabolites, caffeoxynic acid (2), caffeicinic acid (3), and isocaffeicinic acid (4), along with, 7,8-erythro-caffeicin (5) and phellinsin A (6). The structures of the three new caffeic acid oxidation products were elucidated on the basis of spectroscopic methods. The new products 2 and 3 exhibited significantly enhanced inhibitory activity against cyclooxygenase-2 (COX-2) when compared to parent caffeic acid.  相似文献   

11.
Compound YS 035 [NN-bis-(3,4-dimethoxyphenethyl)-N-methylamine] is a new synthetic compound capable of inhibiting Ca2+ uptake by different cells. The inhibition of Ca2+ uptake by muscle cells isolated from chicken embryo is dose-dependent in the compound YS 035 concentration range 10-30 microM. The new compound also inhibits Ca2+ entry into rat brain synaptosomes and less effectively into baby-hamster kidney cells. Compound YS 035 partially inhibits the slow Ca2+ release induced by Ruthenium Red and the rapid Na+-dependent efflux from heart mitochondria. The inhibition of the Na+/Ca2+ exchange appears to be of a non-competitive type with an apparent Ki of 28 microM. The new Ca2+ antagonist totally inhibits the Ca2+ efflux from liver mitochondria induced by Ruthenium Red, but it does not affect the release induced by uncoupler, respiratory inhibitor or chelator, nor the mitochondrial ATP synthesis and membrane potential. The properties shown by the new compound indicate it to be a Ca2+ antagonist and a useful tool for studies on the mitochondrial Ca2+ transport.  相似文献   

12.
二氧化硫生物学研究进展:从毒理学到生理学   总被引:1,自引:0,他引:1  
Meng ZQ  Li JL 《生理学报》2011,63(6):593-600
本文以作者20余年的系列研究为基础,对二氧化硫(SO2)生物学研究进展进行了综述.首先,总结近年来SO2的毒理学作用及其机制的研究;其次,评述SO2作为一种新型气体信号分子的生理学作用及SO2供体方面的最新研究进展;最后介绍SO2的病理生理学作用的研究进展.  相似文献   

13.
中国毛茛属新分类群及其核型   总被引:6,自引:1,他引:6  
新种R.shuichengensis L,Liao有两种核型类型,即基本型2n=2x=16=4m+2sm+10st(2SAT);杂合型2n=2x=16=4m+2sm+9st(1SAT)+1t(1SAT),其核型和近缘种R.trigonus Hand.- Mazz.核型相似,但其随体染色体短臂比后者更小而不同。新变种R.silerifolius var.dolicanthus L. Liao核型(2n=2x=16=4m+2sm+10st(2SAT)与原变种Var.silerifolius不同。根据形态和染色体的特征,我们认为本文中两个新分类群和R.Trigonus是国产毛茛组中x=8至x=7的过渡类群。  相似文献   

14.
R Rothstein  R Wu 《Gene》1981,15(2-3):167-176
The construction of two new derivatives of the bacteriophage cloning vector M13mp2 is described. One derivative, mWJ22, contains a new HindIII site while the other, mWJ43, contains a new BamHI site. These new sites were both introduced at the EcoRI site at amino acid five of the 145 amino acid-long fragment of Escherichia coli beta-galactosidase within the phage. The new restriction sites do not disrupt the blue color detection system of M13mp2; therefore insertion of cloned fragments results in colorless plaques on indicator plates for the new derivatives.  相似文献   

15.
The Hardness (Ha) locus controls grain texture and affects many end-use properties of wheat (Triticum aestivum L.). The Ha locus is functionally comprised of the Puroindoline a and b genes, Pina and Pinb, respectively. The lack of Pin allelic diversity is a major factor limiting Ha functional analyses and wheat quality improvement. In order to create new Ha alleles, a 630 member M(2) population was produced in the soft white spring cultivar Alpowa using ethylmethane sulfonate mutagenesis. The M(2) population was screened to identify new alleles of Pina and Pinb. Eighteen new Pin alleles, including eight missense alleles, were identified. F(2) populations for four of the new Pin alleles were developed after crossing each back to non-mutant Alpowa. Grain hardness was then measured on F(2:3) seeds and the impact of each allele on grain hardness was quantified. The tested mutations were responsible for between 28 and 94% of the grain hardness variation and seed weight and vigor of all mutation lines was restored among the F(2) populations. Selection of new Pin alleles following direct phenotyping or direct sequencing is a successful approach to identify new Ha alleles useful in improving wheat product quality and understanding Ha locus function.  相似文献   

16.
Two new species of Paraorygmatobothrium Ruhnke, 1994, P. janineae n. sp. and P. kirstenae n. sp., are described from the spiral intestine of 2 shark species of the Family Hemigaleidae: Hemigaleus microstoma and Hemipristis elongata. The 2 new cestode species differ from other members of Paraorygmatobothrium in vitelline follicle distribution and possession of a cephalic peduncle. The 2 new species differ from 1 another in total length, maximum width, scolex size, number of proglottids per strobila, and number of testes per proglottid. The generic diagnosis of Paraorygmatobothrium is emended to include the new species. The results of this study extend the distribution of Paraorygmatobothrium to include the carcharhinid shark family Hemigaleidae.  相似文献   

17.
Data were collected on sexual interactions before and after a male takeover of a one-male unit (OMU) of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in the Qinling Mountains, China. The original unit consisted of an adult male, 2 adult and 2 subadult females, 2 female juveniles and a single infant. Following the takeover, the new resident male copulated with 1 adult female, which was not lactating. Subsequent to the disappearance of her infant, the second (lactating female) entered breeding condition and began to solicit copulation with the new resident male. The subadult females also engaged in matings with the new male. The new resident male was observed mating, on 3 occasions, with females in 2 other OMUs. These are the first observations of sexual behaviour in free-ranging Sichuan snub-nosed monkeys after an OMU takeover. Sexual interactions play an important role in establishing relationships between the new male and resident females in the OMU.  相似文献   

18.
The input and fate of new C in two forest soils under elevated CO2   总被引:2,自引:0,他引:2  
The aim of this study was to estimate (i) the influence of different soil types on the net input of new C into soils under CO2 enrichment and (ii) the stability and fate of these new C inputs in soils. We exposed young beech–spruce model ecosystems on an acidic loam and calcareous sand for 4 years to elevated CO2. The added CO2 was depleted in 13C, allowing to trace new C inputs in the plant–soil system. We measured CO2‐derived new C in soil C pools fractionated into particle sizes and monitored respiration as well as leaching of this new C during incubation for 1 year. Soil type played a crucial role in the partitioning of C. The net input of new C into soils under elevated CO2 was about 75% greater in the acidic loam than in the calcareous sand, despite a 100% and a 45% greater above‐ and below‐ground biomass on the calcareous sand. This was most likely caused by a higher turnover of C in the calcareous sand as indicated by 30% higher losses of new C from the calcareous sand than from the acidic loam during incubation. Therefore, soil properties determining stabilization of soil C were apparently more important for the accumulation of C in soils than tree productivity. Soil fractionation revealed that about 60% of the CO2‐derived new soil C was incorporated into sand fractions. Low natural 13C abundance and wide C/N ratios show that sand fractions comprise little decomposed organic matter. Consistently, incubation indicated that new soil C was preferentially respired as CO2. During the first month, evolved CO2 consisted to 40–55% of new C, whereas the fraction of new C in bulk soil C was 15–23% only. Leaching of DOC accounted for 8–23% of the total losses of new soil C. The overall effects of CO2 enrichment on soil C were small in both soils, although tree growth increased significantly on the calcareous sand. Our results suggest that the potential of soils for C sequestration is limited, because only a small fraction of new C inputs into soils will become long‐term soil C.  相似文献   

19.
2 型糖尿病(T2DM)是一种代谢障碍性疾病。传统抗糖尿病药物具有不同程度的副作用,如低血糖、胃肠道反应、体重增加、 心血管风险等,因此开发作用于新靶点和新作用机制的T2DM 治疗新药成为当前研究的热点。目前基于新靶点设计的糖尿病治疗新药有 些已上市,且获得良好的降糖效果,但大部分药物仍处于临床或临床前研究阶段,其疗效和安全性有待进一步临床验证。综述传统抗糖 尿病药物、T2DM 药物新靶点及基于新靶点设计的抗糖尿病新药的研究进展。  相似文献   

20.
A new acetophenone glycoside and two new naphthalide glycosides have been isolated from the bark of Turkish Rhamnus libanoticus together with 7-hydroxy-5-methoxyphthalide 7-O-β-D-glucoside. The structures of the new compounds were elucidated by spectroscopic methods as 2,6-dihydroxy-4-methoxyacetophenone 2-O-β- rutinoside, 8,9-dihydroxy-6-methoxynaphthalide 8-O-β-rutinoside, 8,9-dihydroxy-6-methoxynaphthalide 8-O-/3b-D glucoside, respectively.  相似文献   

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