首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   49篇
  免费   5篇
  54篇
  2020年   1篇
  2018年   1篇
  2017年   1篇
  2015年   1篇
  2014年   1篇
  2013年   10篇
  2012年   5篇
  2011年   2篇
  2010年   4篇
  2008年   2篇
  2007年   1篇
  2006年   3篇
  2005年   2篇
  2004年   2篇
  2003年   2篇
  2002年   1篇
  2001年   1篇
  2000年   3篇
  1999年   1篇
  1998年   1篇
  1995年   1篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1978年   1篇
  1972年   1篇
  1968年   1篇
  1949年   1篇
排序方式: 共有54条查询结果,搜索用时 15 毫秒
41.
The immense potency of nutritional components of human breast milk and importance of breastfeeding is known worldwide. Recent researches had identified stem cells as integral component of human breast milk. Nevertheless, there is little proof of evidence on the stem cell constituents of breast milk. It is imperative to explore the cellular constituents of human breast milk, including of stem cells, to open new avenue in child’s development and regeneration. Thus, we aimed at identifying the cellular constituents of human breast milk by phenotypic characterisation of diverse cell surface markers of hematopoietic stem cells (CD 34, CD 133, CD 117), mesenchymal stem cells (CD 90, CD 105, CD 73), myoepithelial cells (CD 29, CD 44), Immune cells (CD 209, CD 86, CD 83, CD 14, CD 13, HLADR, CD 45), as well as cell adhesion molecules (CD 31, CD 54, CD 166, CD 106, CD 49d), and other markers (ABCG2, CD140b) using flowcytometry. We found a lower expression of CD 34 (13.07 ± 2.0 %), CD 90 (7.79 ± 0.8 %) and CD 73 (2.19 ± 0.41 %), indicating scanty hematopoietic and mesenchymal stem cell population in human breast milk. On contrary, myoepithelial progenitors, cell adhesion molecules, immune cells and growth factors were identified as the major constituents of breast milk. Overall, this study illuminates the benefits of breast feeding as breast milk encompasses heterogeneous cellular components that benefits child’s growth, immunity and development. However, further research on these constituents of human breast milk will widen their applicability in treatment of neonatal disorders.  相似文献   
42.
Transfer RNA (tRNA) structure, modifications and functions are evolutionary and established in bacteria, archaea and eukaryotes. Typically the tRNA modifications are indispensable for its stability and are required for decoding the mRNA into amino acids for protein synthesis. A conserved methylation has been located on the anticodon loop specifically at the 37th position and it is next to the anticodon bases. This modification is called as m1G37 and it is catalyzed by tRNA (m1G37) methyltransferase (TrmD). It is deciphered that G37 positions occur on few additional amino acids specific tRNA subsets in bacteria. Furthermore, Archaea and Eukaryotes have more number of tRNA subsets which contains G37 position next to the anticodon and the G residue are located at different positions such as G36, G37, G38, 39, and G40. In eight bacterial species, G (guanosine) residues are presents at the 37th and 38th position except three tRNA subsets having G residues at 36th and 39th positions. Therefore we propose that m1G37 modification may be feasible at 36th, 37th, 38th, 39th and 40th positions next to the anticodon of tRNAs. Collectively, methylation at G residues close to the anticodon may be possible at different positions and without restriction of anticodon 3rd base A, C, U or G.  相似文献   
43.
The present study, deal about the antibiosis activity of soil bacteria, isolated from 10 different locations of rhizosphere and diverse cultivation at Kochi, Kerala, India. The bacteria were isolated by standard serial dilution plate techniques. Morphological characterization of the isolate was done by Gram’s staining and found that all of them gram positive. Isolated bacteria were tested against 6 human pathogens viz., Escherichia coli, Enterococcus sp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Acinetobacter sp. Primary screening was carried out by perpendicular streaking and seed overlay method. Based on the result of primary screening most potential isolates of S1A1 and S7A3 were selected for secondary screening. Both the isolates showed positive results against Enterococcus sp. and S.aureus. The maximum antagonistic activity of 20.98 and 27.08?mm zone of inhibition was recorded at S1A1 against Enterococcus sp. and S. aureus respectively, at 180?µl concentration. Molecular identification was carried out by 16S rRNA sequence. The 16S rRNA was amplified from the DNA samples by using PCR. The amplified 16S rRNA PCR products were purified and sequenced. The sequences were subjected to NCBI BLAST. The isolates S1A1 and S7A3 BLAST results showed 99% and 95% respectively, similarity with the available database sequence of Bacillus amyloliquefaciens. The sequences were deposited in GenBank and the accession numbers KY864390 (S1A1) and KY880975 (S7A3) were obtained.  相似文献   
44.
A series of 17 novel tetra substituted thiophenes was designed, synthesized, and screened for anti-inflammatory activity in carrageenin induced rat paw edema model, an acute in vivo model. The lead molecule selected was Tenidap, a dual COX/LOX inhibitor. Compounds I (43%), III (60%), IV (60%), and VIII (64%) showed moderate to good anti-inflammatory activity. The best candidate among the whole series was VIII, which gave 64% protection to the inflamed paw. The side chain of candidate VIII had resemblance to that of Romazarit, a DMARD, which was withdrawn due to its toxicity profile. A probable reason for the metabolic stability of the proposed side chain not having the possibility of generating peroxy type radicals or acrylic acid moieties, unlike Romazarit, is discussed. The biological activity exhibited by the three designed series was in the order of methyl amino series > ethyl amino series > carbethoxy amino series. The –(CO)–CH2–COOR side chain at the fifth position as in candidate VIII, the methyl amino group at the second position, and the ester at the third position of the thiophene can be considered as a three-point pharmacophore for designing better anti-inflammatory agents. The present study is a classical example of the exploitation of an analogue based drug design, which culminated in the development of good anti-inflammatory agents that have the potential of becoming dual inhibitors.  相似文献   
45.
ACUA: a software tool for automated codon usage analysis   总被引:1,自引:0,他引:1  
Currently available codon usage analysis tools lack intuitive graphical user interface and are limited to inbuilt calculations. ACUA (Automated Codon Usage Tool) has been developed to perform high throughput sequence analysis aiding statistical profiling of codon usage. The results of ACUA are presented in a spreadsheet with all perquisite codon usage data required for statistical analysis, displayed in a graphical interface. The package is also capable of on-click sequence retrieval from the results interface, and this feature is unique to ACUA. AVAILABILITY: The package is available for non-commercial purposes and can be downloaded from: http://www.bioinsilico.com/acua.  相似文献   
46.
Modeling protein loops using a phi i + 1, psi i dimer database.   总被引:1,自引:1,他引:0       下载免费PDF全文
We present an automated method for modeling backbones of protein loops. The method samples a database of phi i + 1 and psi i angles constructed from a nonredundant version of the Protein Data Bank (PDB). The dihedral angles phi i + 1 and psi i completely define the backbone conformation of a dimer when standard bond lengths, bond angles, and a trans planar peptide configuration are used. For the 400 possible dimers resulting from 20 natural amino acids, a list of allowed phi i + 1, psi i pairs for each dimer is created by pooling all such pairs from the loop segments of each protein in the nonredundant version of the PDB. Starting from the N-terminus of the loop sequence, conformations are generated by assigning randomly selected pairs of phi i + 1, psi i for each dimer from the respective pool using standard bond lengths, bond angles, and a trans peptide configuration. We use this database to simulate protein loops of lengths varying from 5 to 11 amino acids in five proteins of known three-dimensional structures. Typically, 10,000-50,000 models are simulated for each protein loop and are evaluated for stereochemical consistency. Depending on the length and sequence of a given loop, 50-80% of the models generated have no stereochemical strain in the backbone atoms. We demonstrate that, when simulated loops are extended to include flanking residues from homologous segments, only very few loops from an ensemble of sterically allowed conformations orient the flanking segments consistent with the protein topology. The presence of near-native backbone conformations for loops from five different proteins suggests the completeness of the dimeric database for use in modeling loops of homologous proteins. Here, we take advantage of this observation to design a method that filters near-native loop conformations from an ensemble of sterically allowed conformations. We demonstrate that our method eliminates the need for a loop-closure algorithm and hence allows for the use of topological constraints of the homologous proteins or disulfide constraints to filter near-native loop conformations.  相似文献   
47.
Shigella dysentery caused 65% of all cases of acute renal failure (ARF) seen in children treated at the Christian Medical College Hospital, Vellore, during the 33 months ending September 1977. In the 40 children with ARF secondary to shigella dysentery, haematological findings suggested that they were suffering from the haemolytic-uraemic syndrome, and glomerular hypercellularity and fibrin deposition were present in all 12 patients whose renal histology could be studied. Peritoneal dialysis was the main element of treatment: 43% of children who underwent dialysis improved, compared with only 25% of those who did not undergo dialysis. The haemolytic-uraemic syndrome precipitated by bacillary dystentery is therefore the most important cause of ARF in children aged under 5 years in Tamil Nadu and the adjoining area of Andhra Pradesh.  相似文献   
48.
Sets of tetrasubstituted thiophene esters 4a-4g, 5a-5f and 6a-6e were synthesized by reaction of 1-(alpha-Carbomethoxy-beta-aminothiocrotonoyl)-aryl/aroyl amines (3) with 3-(bromoacetyl)coumarin, 1,4-dibromodiacetyl and chloroacetone respectively. The compound 3 were synthesized by nucleophilic addition of aryl/aroylisothiocyanate and enamine (2). The synthesized targeted compounds (4a-4g, 5a-5f and 6a-6e) were evaluated for their in vivo anti-inflammatory activity in carrageenin-induced rat hind paw oedema model at three graded doses employed at 10, 20 and 40 mg/kg body weight using mefanamic acid, ibuprofen and in vivo analgesic activity in acetic acid induced writhing response model at 10 mg/kg dose using ibuprofen as standard drug. The compounds 4a-4f, 5c, 5f, 6c and 6e were evaluated for their in vitro antioxidant nitric oxide radical scavenging assay at the concentrations of 5, 10, 15, 20, 25, 30 and 35 microg/mL using ascorbic acid as standard drug. Among all the targeted compounds 4c showed maximum anti-inflammatory activity of 71% protection at 10 mg/kg and 77% protection at 20 mg/kg to inflamed paw and analgesic activity of 56% inhibition and also maximum in vitro nitric oxide radical scavenging activity having IC(50) value 31.59 microg/mL.  相似文献   
49.
A series of novel tetra substituted thiophenes were synthesized, characterized, and evaluated for their anti-inflammatory activity in carrageenin induced rat paw edema model-an acute in vivo model. Compounds V1, V3, V11, V12, V17, and V18 showed good anti-inflammatory activity, indicating the importance of oxime moiety in modulating the activity. The structure-activity relationship studies explore "the aliphatic oxime esters" attached via a ketone bridge to fifth position of the thiophene, and indicate that this feature may enhance the anti-inflammatory activity as compared to aromatic oximes. Since free radicals are implicated in various inflammatory disorders, the free radical scavenging activity of some of the synthesized candidates was assessed using 1,1-diphenyl-2-picryl hydrazyl assay. The oxime containing analogs exhibited weak to moderate activity as free radical scavengers in DPPH assay. A plausible reasoning for its free radical scavenging ability is discussed. All the compounds were also screened in nitro blue tetrazolium model, to assess them as superoxide anion radical scavengers. A direct correlation between anti-inflammatory activity and free radical scavenging activity was not seen. The results disclose a new class of anti-inflammatory agents designed and synthesized for the first time wherein the utility of aliphatic oxime esters in modulating the anti-inflammatory activity profile is apparent. This will give us potential anti-inflammatory leads.  相似文献   
50.
Recent scientific explorations in search of novel sources for autologous transplantation transpired an alternative source of MSCs (mesenchymal stem cells) derived from omentum fat. The scarcity of experimental evidences probing into the biosafety concerns of omentum fat‐derived MSC under prolonged culture conditions limits its applicability as an efficient tool in regenerative medicine. This study, thus, aims to optimize human omentum fat‐derived MSC in four different media [DMEM (Dulbecco's modified Eagle's medium) LG (low glucose), DMEM KO (knock out), α‐MEM (α‐minimal essential media) and DMEM F12] in the facets of phenotypic characterization, growth kinetics, differentiation and karyotyping under prolonged culture. The cells exhibited a similarity in expression profile for the majority of markers with evidential variations in certain markers. The relevance of omentum fat‐derived MSCs became evident from its triumphant differentiation potential and karyotypic stability substantiated even at later passage. The results obtained from growth curve and PDT (population doubling time) lead to optimization of appropriate media for omentum fat‐derived stem cell research, thereby bringing omentum fat into the forefront of regenerative medicine.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号