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971.
972.
Constant Anatole Pieme Guru Kumar Santosh Emmanuel Mouafo Tekwu Tülin Askun Hatice Aydeniz Jeanne Yonkeu Ngogang Shashi Bhushan Ajit Kumar Saxena 《Biological research》2014,47(1)
Background
Zanthoxylum heitzii is a spice used to prepare several dishes and to treat tumors, syphilis, malaria, cardiac palpitations, urogenital infections in the west region of Cameroon, but the antitumor mechanisms and chemical composition are not yet investigated.This study was aimed to determine the antiproliferative effects of four extracts from the fruits and barks of Zanthoxyllum heitzii (Rutaceae) on apoptosis in human promyelocytic cells, their mechanisms and the chemical composition. The 3-(4, 5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the fifty percent inhibition (IC50) concentration of the cell lines after treatment. The effect on morphology was observed using a light or fluorescence microscopy. The rate of apoptosis and the cell cycle were measured using flow cytometry (FCM). The phytochemical analysis of the extract was carried with HPLC/MS methods.Results
The phytochemical analysis of the extracts indicated the presence of four known polyphenols (Syringic acid, Juglon, Luteolin and Myricetin) in both fruits and barks of Z. heitzii but in different quantities. Syringic acid and Myricetin concentrations were between 17-21 fold higher in the fruits than the stem bark. Rhamnetin (393.35 μg/mL) and Oleuropein (63.10 μg/mL) were identified only in the stem barks of Z. heitzii. Among the four extracts tested for cytotoxicity properties, only the methanol extract of fruits and barks significantly inhibited cell proliferation of HL-60 cells with IC50 value of 20 μg/mL and 12 μg/mL respectively. HL-60 cells treated with Z. heitzii extracts significantly produced reactive oxygen species (ROS) with concurrent loss of mitochondrial membrane potential (MMP). Modifications in the DNA distribution and enhanced of G1/G0 phase cell cycle arrest were observed in a concentration dependent manner.Conclusions
Polyphenols from Z. heitzii plant exert inhibitory effect on HL-60 cells through the reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential and cell cycle destabilization. 相似文献973.
Objective
To assess whether increased awareness and diagnosis of obstructive sleep apnoea syndrome (OSAS) and national guidance on tonsillectomy for recurrent tonsillitis have influenced the socio-demographic profile of children who underwent tonsillectomy over the last decade.Method
Retrospective time-trends study of Hospital Episodes Statistics data. We examined the age, sex and deprivation level, alongside OSAS diagnoses, among children aged <16 years who underwent (adeno)tonsillectomy in England between 2001/2 and 2011/12.Results
Among children aged <16 years, there were 29,697 and 27,732 (adeno)tonsillectomies performed in 2001/2 and 2011/12, respectively. The median age at (adeno)tonsillectomy decreased from 7 (IQR: 5–11) to 5 (IQR: 4–9) years over the decade. (Adeno)tonsillectomy rates among children aged 4–15 years decreased by 14% from 350 (95%CI: 346–354) in 2001/2 to 300 (95%CI: 296–303) per 100,000 children in 2011/12. However, (adeno)tonsillectomy rates among children aged <4 years increased by 58% from 135 (95%CI: 131–140) to 213 (95%CI 208–219) per 100,000 children in 2001/2 and 2011/2, respectively. OSAS diagnoses among children aged <4 years who underwent surgery increased from 18% to 39% between these study years and the proportion of children aged <4 years with OSAS from the most deprived areas increased from 5% to 12%, respectively.Conclusions
(Adeno)tonsillectomy rates declined among children aged 4–15 years, which reflects national guidelines recommending the restriction of the operation to children with more severe recurrent throat infections. However, (adeno)tonsillectomy rates among pre-school children substantially increased over the past decade and one in five children undergoing the operation was aged <4 years in 2011/12.The increase in surgery rates in younger children is likely to have been driven by increased awareness and detection of OSAS, particularly among children from the most deprived areas. 相似文献974.
Jinping Zhang Jia Wang Lan Pang Guorui Xie Thomas Welte Vandana Saxena Jason Wicker Brian Mann Lynn Soong Alan Barrett Willi Born Rebecca O'Brien Tian Wang 《PloS one》2014,9(9)
γδ T cells express several different toll-like receptor (TLR)s. The role of MyD88- dependent TLR signaling in TCR activation of murine γδ T cells is incompletely defined. Here, we report that Pam3CSK4 (PAM, TLR2 agonist) and CL097 (TLR7 agonist), but not lipopolysaccharide (TLR4 agonist), increased CD69 expression and Th1-type cytokine production upon anti-CD3 stimulation of γδ T cells from young adult mice (6-to 10-week-old). However, these agonists alone did not induce γδ T cell activation. Additionally, we noted that neither PAM nor CL097 synergized with anti-CD3 in inducing CD69 expression on γδ T cells of aged mice (21-to 22-month-old). Compared to young γδ T cells, PAM and CL097 increased Th-1 type cytokine production with a lower magnitude from anti-CD3- stimulated, aged γδ T cells. Vγ1+ and Vγ4+ cells are two subpopulations of splenic γδ T cells. PAM had similar effects in anti-CD3-activated control and Vγ4+ subset- depleted γδ T cells; whereas CL097 induced more IFN-γ production from Vγ4+ subset-depleted γδ T cells than from the control group. Finally, we studied the role of MyD88-dependent TLRs in γδ T cell activation during West Nile virus (WNV) infection. γδ T cell, in particular, Vγ1+ subset expansion was significantly reduced in both MyD88- and TLR7- deficient mice. Treatment with TLR7 agonist induced more Vγ1+ cell expansion in wild-type mice during WNV infection. In summary, these results suggest that MyD88-dependent TLRs provide co-stimulatory signals during TCR activation of γδ T cells and these have differential effects on distinct subsets. 相似文献
975.
Geoffrey Berguet Jan Hendrickx Celine Sabatel Miklos Laczik Sharon Squazzo Ignacio Mazon Pelaez Rini Saxena Helene Pendeville Dominique Poncelet 《Journal of visualized experiments : JoVE》2014,(94)
Chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq) is a technique of choice for studying protein-DNA interactions. ChIP-seq has been used for mapping protein-DNA interactions and allocating histones modifications. The procedure is tedious and time consuming, and one of the major limitations is the requirement for high amounts of starting material, usually millions of cells. Automation of chromatin immunoprecipitation assays is possible when the procedure is based on the use of magnetic beads. Successful automated protocols of chromatin immunoprecipitation and library preparation have been specifically designed on a commercially available robotic liquid handling system dedicated mainly to automate epigenetic assays. First, validation of automated ChIP-seq assays using antibodies directed against various histone modifications was shown, followed by optimization of the automated protocols to perform chromatin immunoprecipitation and library preparation starting with low cell numbers. The goal of these experiments is to provide a valuable tool for future epigenetic analysis of specific cell types, sub-populations, and biopsy samples. 相似文献
976.
977.
Sunita Yadav Smita Gupta Chandrabose Selvaraj Pawan Kumar Doharey Anita Verma Sanjeev Kumar Singh Jitendra Kumar Saxena 《PloS one》2014,9(9)
Filarial parasites modulate effective immune response of their host by releasing a variety of immunomodulatory molecules, which help in the long persistence of the parasite within the host. The present study was aimed to characterize an immunomodulatory protein of Brugia malayi and its interaction with the host immune component at the structural and functional level. Our findings showed that Brugia malayi Calreticulin (BmCRT) is responsible for the prevention of classical complement pathway activation via its interaction with the first component C1q of the human host. This was confirmed by inhibition of C1q dependent lysis of immunoglobulin-sensitized Red Blood Cells (S-RBCs). This is possibly the first report which predicts CRT-C1q interaction on the structural content of proteins to explain how BmCRT inhibits this pathway. The molecular docking of BmCRT-C1q complex indicated that C1qB chain (IgG/M and CRP binding sites on C1q) played a major role in the interaction with conserved and non-conserved regions of N and P domain of BmCRT. Out of 37 amino acids of BmCRT involved in the interaction, nine amino acids (Pro126, Glu132, His147, Arg151, His153, Met154, Lys156, Ala196 and Lys212) are absent in human CRT. Both ELISA and in silico analysis showed the significant role of Ca+2 in BmCRT-HuC1q complex formation and deactivation of C1r2–C1s2. Molecular dynamics studies of BmCRT-HuC1q complex showed a deviation from ∼0.4 nm to ∼1.0 nm. CD analyses indicated that BmCRT is composed of 49.6% α helix, 9.6% β sheet and 43.6% random coil. These findings provided valuable information on the architecture and chemistry of BmCRT-C1q interaction and supported the hypothesis that BmCRT binds with huC1q at their targets (IgG/M, CRP) binding sites. This interaction enables the parasite to interfere with the initial stage of host complement activation, which might be helpful in parasites establishment. These results might be utilized for help in blocking the C1q/CRT interaction and preventing parasite infection. 相似文献
978.
979.
The hydrolysis of triglycerides in plasma lipoproteins is mediated by lipoprotein lipase (LPL) that is bound to vascular endothelial cells. The specific endothelial cell surface protein(s) with which LPL associates has not been characterized. To identify this LPL binding protein(s), radioiodinated cell surface proteins from cultured bovine aortic endothelial cells were chromatographed using bovine LPL-Sepharose. A single radioiodinated protein of apparent molecular mass 220 kDa was specifically retained by the gel and eluted with 0.4 M NaCl. A LPL-binding protein of similar size was obtained after metabolic labeling of the cellular proteoglycans with 35SO4, indicating that the 220-kDa protein is a proteoglycan. After heparitinase or nitrous acid treatments the molecular mass of the LPL-binding protein decreased to approximately 50 kDa, suggesting that it contains heparin sulfate chains. A 220-kDa protein from the basal cell surface was also identified using LPL-Sepharose chromatography. 125I-LPL was cross-linked to the endothelial cell surface using ethylene glycobis (succinimidylsuccinate). A single ligand-receptor complex, approximately 350 kDa, was obtained. Heparin and unlabeled LPL decreased the cross-linking of radioiodinated LPL to the cell surface receptor. To examine whether the receptor mediates the internalization of cross-linked 125I-LPL, cells containing 125I-LPL complexed to the surface were incubated at either 37 or at 4 degrees C. The amount of 125I-LPL internalized by the cells was 74% greater at 37 degrees C than at 4 degrees C. This suggested that LPL cross-linked to the receptor was internalized in a temperature-dependent manner. Thus, a 220-kDa heparan sulfate proteoglycan functions as an endothelial cell surface receptor for LPL. 相似文献
980.
We have characterized the mutations in 1050 carriers of the β-thalassemia gene and analyzed their regional distribution in
India. The majority of β-thalassemia carriers were migrants from Pakistan and their pattern of mutations differed from the
rest. The frequency of the 619-bp deletion was 33.3% among the migrants from Pakistan, 8–17% in the northern states, and less
than 5% in the other states. Among non-migrant subjects, the predominant mutation was IVS-I-5 (G→C), varying from 85% in the
southern states and 66–70% in the eastern states to 47–60% in the northern states. The mutation IVS-I-1 (G→T) was observed
at high frequency among the migrants from Pakistan (26.2%), but with very low/ zero frequency in the other states. Mutations
at codons 8/9 (+G) and codons 41/42 (–CTTT) were distributed in all regions of India with a frequency varying from 3% to 15%.
Only eight of 12 published rare mutations were observed in subjects from different parts of India. Mutations of codon 5 (–CT)
and codons 47/48 (+ATCT) were found exclusively in migrants from Pakistan, and mutation –88 (C→T) was detected only in subjects
from Punjab, Haryana, and Uttar Pradesh. Using the amplification refractory mutation system technique, mutations were successfully
identified in 98.2% of subjects. Overall, 91.8% of the subjects had one of the five commonest mutations [IVS-I-5 (G→C), 34.1%;
619-bp deletion, 21.0%; IVS-I-1 (G→T) 15.8%; codons 8/9 (+G), 12.1%, and codons 41/42 (–CTTT), 8.7%], 5.9% of the subjects
had a less common mutation, while 1.8% of the carriers remained uncharacterized. The application of this knowledge has helped
to successfully establish a program of genetic counselling and prenatal diagnosis of β-thalassemia in order to reduce the
burden of this disease in India.
Received: 15 October 1996 / Accepted: 18 February 1997 相似文献