全文获取类型
收费全文 | 150篇 |
免费 | 15篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 12篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 9篇 |
2017年 | 4篇 |
2016年 | 12篇 |
2015年 | 10篇 |
2014年 | 10篇 |
2013年 | 12篇 |
2012年 | 12篇 |
2011年 | 12篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 4篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1986年 | 3篇 |
1981年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1965年 | 1篇 |
1950年 | 1篇 |
排序方式: 共有165条查询结果,搜索用时 31 毫秒
141.
142.
Isolated uninucleate microspores of tomato,Lycopersicon esculentum
Mill, were cultured in defined, liquid nutritive media. The microspores developed to haploid embryoids with or without an attached
suspensor or into calli with compactly or loosely arranged cells. 相似文献
143.
Vipula K. Shukla Gulshan E. Stanbekova Sergey V. Shestakov Himadri B. Pakrasi 《Molecular microbiology》1992,6(7):947-956
The reaction center core of photosystem II, a multiprotein membrane bound complex, is composed of a heterodimer of two proteins, D1 and D2. A random mutagenesis technique was used to isolate a photosystem II deficient mutant, CP6t16, of the unicellular cyanobacterium, Synechocystis sp. PCC 6803. Nucleotide sequence analysis showed that the primary lesion in CP6t16 is an ochre mutation introducing a translational stop codon in the psbE gene, encoding the alpha-subunit of cytochrome b559, an integral component of the PSII complex. Analysis of the protein composition of CP6t16 thylakoid membranes isolated in the presence of serine protease inhibitors revealed that, in the absence of cytochrome b559, the D2 protein is also absent. However, the D1 protein is stably incorporated in these membranes, suggesting that the synthesis and integration of D1 are independent of those of D2 and cytochrome b559. 相似文献
144.
Microbial pretreatment of coals: A tool for solubilization of lignite in organic solvent – quinoline
A method was developed for the conversion of low rank coals to products soluble in an organic solvent (quinoline). A selected group of polynuclear aromatic-compound-degrading and lignin-degrading facultative pure cultures and enriched anaerobic mixed microbial cultures developed for this purpose were used separately as well as together under co-culture conditions for stepwise treatment of Neyveli lignite (NL). This aerobic-anaerobic co-metabolic (co-culture) biodegradation (AACB) process resulted in the enhancement of quinoline extractability of the lignite, thereby yielding clean coal substance (the extract). The residual lignite obtained after quinoline extraction was subjected to a second step of AACB fermentation treatment. This resulted in further extraction of lignite in quinoline. The conditions were optimised for AACB fermentation treatment. The two-step AACB fermentation process under optimum conditions, resulted in an overall enhancement of yield of extract from 18% for the original lignite sample to 56% for the treated sample. The changes in the filtrate were evaluated using UV spectra, those in the residue were evaluated using FTIR spectroscopy and UV-reflectance and those in the extract using proton NMR spectra of the chloroform soluble fraction. The results indicated a decreased absorption in the carbonyl region in the AACB-treated residue and also a decrease in the overall mineral matter in the lignite samples. The mechanism of the AACB fermentation process is discussed. The process affords biosolubilization of lignite in organic solvent (quinoline) under milder conditions along with a simultaneous removal of a part of the mineral matter present in the coal. Uses for the clean coal extract obtained are suggested. 相似文献
145.
Identification of microcephalin,a protein implicated in determining the size of the human brain 总被引:4,自引:0,他引:4 下载免费PDF全文
Jackson AP Eastwood H Bell SM Adu J Toomes C Carr IM Roberts E Hampshire DJ Crow YJ Mighell AJ Karbani G Jafri H Rashid Y Mueller RF Markham AF Woods CG 《American journal of human genetics》2002,71(1):136-142
Primary microcephaly (MIM 251200) is an autosomal recessive neurodevelopmental condition in which there is a global reduction in cerebral cortex volume, to a size comparable with that of early hominids. We previously mapped the MCPH1 locus, for primary microcephaly, to chromosome 8p23, and here we report that a gene within this interval, encoding a BRCA1 C-terminal domain-containing protein, is mutated in MCPH1 families sharing an ancestral 8p23 haplotype. This gene, microcephalin, is expressed in the developing cerebral cortex of the fetal brain. Further study of this and related genes may provide important new insights into neocortical development and evolution. 相似文献
146.
Abdolrahman Amiri Rahmat Allah Fatahian Dehkordi Mohamad Saeed Heidarnejad Mohsen Jafarian Dehkordi 《Biological trace element research》2018,181(2):258-264
This research was carried out to evaluate the antidiabetic effects of zinc oxide nanoparticles (ZnO NPs) and thiamine following experimental diabetes. Fifty-six 6-week-old female mice were used and divided into seven groups of eight animals. Diabetes was induced in fasted mice by using intraperitoneal (IP) injection of alloxan (180 mg/kg). Groups included (I) non-diabetic control, (II) thiamine (30 mg/l, IP), (III) alloxan-induced diabetic mice, (IV) diabetes + ZnO NPs (0.1 mg/kg IP), (V) diabetes + ZnO NPs (0.5 mg/kg IP), (VI) diabetes + ZnO NPs (0.1 mg/kg IP) + thiamine (30 mg/l, IP), and (VII) diabetes + ZnO NPs (0.5 mg/kg IP) + thiamine (30 mg/l, IP). Coincident with pancreas recovery, in diabetic treated mice (groups IV to VII), the mean islet volume, islets per square micrometer, and volume density of the pancreas had increased than in alloxan-induced diabetic mice. ZnO NPs and thiamine induced a decreasing blood glucose, lower serum triglyceride (TG), LDL, and total cholesterol (TC) levels in alloxan-induced diabetic mice treated with ZnO NPs and thiamine, simultaneously increasing HDL as well. In conclusion, ZnO NPs and thiamine are potent antidiabetic factors, and that, these compound supplementation possesses hypoglycemic properties and have effect on serum lipid parameters in diabetes mice. 相似文献
147.
Shahram Darabi Ali Noori-Zadeh Farzad Rajaei Hojjat Allah Abbaszadeh Salar Bakhtiyari Navid Ahmady Roozbahany 《Neurochemical research》2018,43(12):2313-2323
Parkinson’s disease is the second most common neurodegenerative disease that occurs due to cellular autophagy deficiency and the accumulation of alpha-synuclein in the dopaminergic neurons of the substantia nigra pars compacta (SNc) of the brainstem. The SMER28 (also known as 6-Bromo-N-prop-2-enylquinazolin-4-amine) is an autophagy inducer. In this study, the neuroprotective effects of SMER28 were evaluated on autophagy induction, antioxidant system activation, and microgliosis attenuation. The Parkinson’s disease model was developed in the male Wistar rats by injection of 6-OHDA into the left striatum. Apomorphine-induced behavior assessment test and SNc cell counting were performed to investigate the neuroprotective effects of SMER28. This study examined the pharmacological roles of SMER28, especially by focusing on the autophagy (p62/ SQSTM1 and LC3II/LC3I ratio where LC3 is microtubule-associated protein 1A/1B-light chain 3), inhibiting free radicals, and activating the antioxidant system. The levels of malondialdehyde (MDA), reactive oxygen species (ROS), glutathione (GSH), GSH/glutathione peroxidase (GPX), superoxide dismutase (SOD) activity and nuclear factor-erythroid 2-related factor-2 (Nrf2) were measured to evaluate the antioxidant activity of SMER28. Moreover, Iba-1 (ionized calcium binding adaptor molecule, indicating microgliosis) and tyrosine hydroxylase immunoreactivities were evaluated in the SNc. In the behavioral assessment, SMER28 (50 µg/kg) attenuated damages to the SNc dopaminergic neurons, characterized by improved motor function. The tissue observations revealed that SMER28 prevented the destruction of SNc neurons and attenuated microgliosis as well. It also reduced MDA and ROS production and increased GSH, GPX, SOD, and Nrf2 activities by inducing autophagy (decreasing p62 and increasing LC3II/LC3I ratio). Consequently, possibly with further studies, it can be considered as a drug for neurodegenerative diseases with proteinopathy etiology. 相似文献
148.
Usman Sayeed Gulshan Wadhwa Qazi Mohd. Sajid Jamal Mohammad A. Kamal Salman Akhtar Mohd. Haris Siddiqui M. Salman Khan 《Saudi Journal of Biological Sciences》2018,25(8):1546-1551
Japanese encephalitis (JE), a viral disease has seen a drastic and fatal enlargement in the northern states of India in the current decade. The better and exact cure for the disease is still in waiting. For the cause an in silico strategy in the development of the peptide vaccine has been taken here for the study. A computational approach to find out the Major Histocompatibility Complex (MHC) binding peptide has been implemented. The prediction analysis identified MHC class I (using propred I) and MHC class II (using propred) binding peptides at an expectable percent predicted IC (50) threshold values. These predicted Human leukocyte antigen [HLA] allele binding peptides were further analyzed for potential conserved region using an Immune Epitope Database and Analysis Resource (IEDB). This analysis shows that HLA-DRB1*0101, HLA-DRB3*0101, HLA-DRB1*0401, HLA-DRB1*0102 and HLA-DRB1*07:01% of class II (in genotype 2) and HLA-A*0101, HLA-A*02, HLA-A*0301, HLA-A*2402, HLA-B*0702 and HLA-B*4402% of HLA I (in genotype 3) bound peptides are conserved. The predicted peptides MHC class I are ILDSNGDIIGLY, FVMDEAHFTDPA, KTRKILPQIIK, RLMSPNRVPNYNLF, APTRVVAAEMAEAL, YENVFHTLW and MHC class II molecule are TTGVYRIMARGILGT, NYNLFVMDEAHFTDP, AAAIFMTATPPGTTD, GDTTTGVYRIMARGI and FGEVGAVSL found to be top ranking with potential super antigenic property by binding to all HLA. Out of these the predicted peptide FVMDEAHFTDPA for allele HLA-A*02:01 in MHC class I and NYNLFVMDEAHFTDP for allele HLA-DRB3*01:01 in MHC class II was observed to be most potent and can be further proposed as a significant vaccine in the process. The reported results revealed that the immune-informatics techniques implemented in the development of small size peptide is useful in the development of vaccines against the Japanese encephalitis virus (JEV). 相似文献
149.
Mst. Ara Gulshan Shigeyoshi Matsumura Tsunehiko Higuchi Naoki Umezawa 《Bioscience, biotechnology, and biochemistry》2018,82(8):1404-1407
Polyamines are a promising class of molecules that can modulate RNA enzyme activities. To analyze the effects of the number of amine moieties systematically, we employed four polyamines sharing dimethylene units to connect amine moieties. As a model RNA enzyme, we used a structurally unstable group I ribozyme, which was activated most and least efficiently by tetraethylenepentamine and diethylenetriamine respectively. 相似文献
150.
Shaheen Nourinejhad Zarghani Masoud Shams‐Bakhsh Nemat Sokhandan Bashir Thierry Wetzel 《Journal of Phytopathology》2013,161(6):419-425
Grapevine fanleaf virus (GFLV) is the major causal agent of the grapevine degeneration disease. To characterize the genomic RNA2 segment from Iranian isolates of GFLV, leaf samples were collected from infected vineyards in different locations with a long history of vine cultivation. Four isolates were selected for cloning and sequencing on the basis of the restriction profiles of RT‐PCR products. The sequencing data revealed that the RNA2 of the Iranian GFLV isolates were the shortest compared with that of all previously described GFLV isolates. The sizes were 3730 nucleotides (nt) for Shir‐Amin and Urmia isolates and 3749 nt for Takestan and Bonab isolates (excluding the poly (A) tail), due to deletion events in both 5′ and 3′ non‐coding regions. In the phylogenetic tree based on the full‐length nucleotide sequences of GFLV RNA2, all the GFLV isolates clustered into two groups with the exception of the Hungarian isolate (GHu). The Iranian isolates grouped as a distinct cluster. Recombination analyses showed that GFLV‐NW (Germany), GFLV‐F13 (reference isolate), GFLV isolate Shir‐Amin (Iran) and Arabis mosaic virus isolate Lv were recombinant isolates and one of their parents belonged to the same lineage as the Iranian isolates. These findings suggest that these isolates originated from a common ancestor. 相似文献