全文获取类型
收费全文 | 71篇 |
免费 | 4篇 |
出版年
2021年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 1篇 |
2011年 | 3篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 3篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1977年 | 1篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有75条查询结果,搜索用时 15 毫秒
21.
Kirton CM Wang T Dockray GJ 《American journal of physiology. Gastrointestinal and liver physiology》2002,283(3):G787-G793
Recent studies suggest that gastrin regulates parietal cell maturation. We asked whether it also regulates parietal cell life span and migration along the gland. Dividing cells were labeled with 5'-bromo-2'-deoxyuridine (BrdU), and parietal cells were identified by staining with Dolichos biflorus lectin. Cells positive for D. biflorus lectin and BrdU were reliably identified 10-30 days after BrdU injection in mice in which the gastrin gene had been deleted by homologous recombination (Gas-KO) and wild-type (C57BL/6) mice. The time course of labeling was similar in the two groups. The distribution of BrdU-labeled parietal cells in wild-type mice was consistent with migration to the base of the gland, but in Gas-KO mice, a higher proportion of BrdU-labeled cells was found more superficially 20 and 30 days after BrdU injection. Conversely, in transgenic mice overexpressing gastrin, BrdU-labeled parietal cells accounted for a higher proportion of the labeled pool in the base of the gland 10 days after BrdU injection. Gastrin, therefore, stimulates movement of parietal cells along the gland axis but does not influence their life span. 相似文献
22.
A system of suspending traps from a movable balloon was developed and tested on pollinating and wood boring Coleoptera in
a tropical rainforest canopy in Pasoh Forest Reserve, Peninsular Malaysia. The balloons, 2.5 m in diameter, were filled with
helium gas for levitation and moored in different directions by three pieces of thin rope. Traps in which benzyl acetate and
ethanol were used as attractants for the pollinators and wood borers, respectively, were suspended from the balloon at different
heights. The trapping results show that the balloon system can be used for studying canopy insects and their vertical distribution
on a spatial and temporal scale. 相似文献
23.
Kirton RS Taberner AJ Nielsen PM Young AA Loiselle DS 《American journal of physiology. Heart and circulatory physiology》2005,288(4):H1662-H1667
Studies of the passive mechanical properties of cardiac tissue have traditionally been conducted at subphysiological temperatures and various concentrations of extracellular Ca(2+) ([Ca(2+)](o)). More recently, the negative inotropic agent 2,3-butanedione monoxime (BDM) has been used. However, there remains a lack of data regarding the influence of temperature, Ca(2+), and BDM on the passive mechanical properties of cardiac tissue. We have used the dynamic stiffness technique, a sensitive measurement of cross-bridge activity, in which minute (approximately 0.2% of muscle length) sinusoidal perturbations are applied at various frequencies (0.2-100 Hz) to quiescent, viable right ventricular rat trabeculae at two temperatures (20 degrees C and 26 degrees C) and at two [Ca(2+)](o) (0.5 and 1.25 mM) in the presence and absence of BDM (20 mM). The stiffness spectra (amplitude and phase) were sensitive to temperature and [Ca(2+)](o) in the absence of BDM but insensitive in the presence of BDM. From the index of cross-bridge cycling (the ratio of high- to low-frequency stiffness amplitude), we infer that BDM inhibits a small degree of spontaneous sarcomere activity, thereby allowing the true passive properties of trabeculae to be determined. In the absence of BDM, the extent of spontaneous sarcomere activity decreases with increasing temperature. We caution that the measured mechanical properties of passive cardiac tissue are critically dependent on the experimental conditions under which they are measured. Experiments must be performed at sufficiently high temperatures (>25 degrees C) to ensure a low resting concentration of intracellular Ca(2+) or in the presence of an inhibitor of cross-bridge cycling. 相似文献
24.
Yusuke Sato Diego M Marzese Katsuya Ohta Sharon K Huang Myung Shin Sim Kelly Chong Dave SB Hoon 《Epigenetics》2013,8(10):1043-1052
Regenerating gene 1A (REG1A) plays an important role in tissue regeneration and in cell proliferation in epithelium origin tumors; however, its role in melanoma has not been explored in details. The objective of this study was to identify whether REG1A is expressed in cutaneous melanoma and if REG1A expression status can predict prognosis in cutaneous melanoma patients with metastasis. We also determined whether epigenetic regulation of the promoter region regulates REG1A expression. AJCC stage III cutaneous melanoma specimens with clinically well annotated stage III lymph node melanoma metastasis tissue microarray were assessed by IHC. MALDI-TOF-mass spectrometry and HM450K array were used to identify REG1A promoter region CpG site methylation. Chemotherapeutic agent response by melanoma cells as related to REG1A protein expression was assessed. Post-surgery melanoma patients followed by adjuvant chemotherapy with high REG1A expression had a significantly better prognosis (disease-specific survival) compared with patients with low REG1A expression (log rank test; p = 0.0013). The demethylating reagent 5-Aza-2′-deoxycytidine activated REG1A promoter region resulting in enhanced REG1A mRNA and protein expression in melanoma cell lines. Promoter region CpG methylation was shown to regulate REG1A expression in melanoma cells. Moreover, melanoma lines with high REG1A mRNA expression were more susceptible to Dacarbazine and Cisplatin, as compared with those with low REG1A mRNA expression. In conclusion, REG1A expression status may be useful as a biomarker in melanoma patients for sensitivity to these chemotherapeutic agents. The epigenetic regulation of the REG1A promoter region may offer a potential therapeutic approach to improve chemotherapy for metastatic melanoma patients. 相似文献
25.
Robert A Terkeltaub H Ralph Schumacher John D Carter Herbert SB Baraf Robert R Evans Jian Wang Shirletta King-Davis Steven P Weinstein 《Arthritis research & therapy》2013,15(1):R25
Introduction
In phase-3 clinical trials, the interleukin (IL-1) blocker, rilonacept (IL-1 Trap), demonstrated efficacy for gout flare prevention during initiation of urate-lowering therapy. This trial evaluated rilonacept added to a standard-of-care, indomethacin, for treatment of acute gout flares.Methods
Adults, aged 18-70 years, with gout presenting within 48 hours of flare onset and having at least moderate pain as well as swelling and tenderness in the index joint were randomized to subcutaneous (SC) rilonacept 320 mg at baseline plus oral indomethacin 50 mg TID for 3 days followed by 25 mg TID for up to 9 days (n = 74); SC placebo at baseline plus oral indomethacin as above (n = 76); or SC rilonacept 320 mg at baseline plus oral placebo (n = 75). The primary efficacy endpoint was change in pain in the index joint (patient-reported using a Likert scale (0 = none; 4 = extreme)) from baseline to the average of values at 24, 48 and 72 hours (composite time point) for rilonacept plus indomethacin versus indomethacin alone. Comparison of rilonacept monotherapy with indomethacin monotherapy was dependent on demonstration of significance for the primary endpoint. Safety evaluation included clinical laboratory and adverse event (AE) assessments.Results
Patient characteristics were comparable among the groups; the population was predominantly male (94.1%), white (75.7%), with mean ± SD age of 50.3 ± 10.6 years. All treatment groups reported within-group pain reductions from baseline (P < 0.0001). Although primary endpoint pain reduction was greater with rilonacept plus indomethacin (-1.55 ± 0.92) relative to indomethacin alone (-1.40 ± 0.96), the difference was not statistically significant (P = 0.33), so formal comparison between monotherapy groups was not performed. Pain reduction over the 72-hour period with rilonacept alone (-0.69 ± 0.97) was less than that in the other groups, but pain reduction was similar among groups at 72 hours. Treatment with rilonacept was well-tolerated with no reported serious AEs related to rilonacept. Across all groups, the most frequent AEs were headache and dizziness.Conclusions
Although generally well-tolerated, rilonacept in combination with indomethacin and rilonacept alone did not provide additional pain relief over 72 hours relative to indomethacin alone in patients with acute gout flare.Trial registration
ClinicalTrials.gov registration number . NCT00855920相似文献26.
27.
Chunman Li Xiaomin Luo Shan Zhao Gavin KY Siu Yongheng Liang Hsiao Chang Chan Ayano Satoh Sidney SB Yu 《The EMBO journal》2017,36(4):441-457
The transport protein particle (TRAPP) was initially identified as a vesicle tethering factor in yeast and as a guanine nucleotide exchange factor (GEF) for Ypt1/Rab1. In mammals, structures and functions of various TRAPP complexes are beginning to be understood. We found that mammalian TRAPPII was a GEF for both Rab18 and Rab1. Inactivation of TRAPPII‐specific subunits by various methods including siRNA depletion and CRISPR–Cas9‐mediated deletion reduced lipolysis and resulted in aberrantly large lipid droplets. Recruitment of Rab18 onto lipid droplet (LD) surface was defective in TRAPPII‐deleted cells, but the localization of Rab1 on Golgi was not affected. COPI regulates LD homeostasis. We found that the previously documented interaction between TRAPPII and COPI was also required for the recruitment of Rab18 to the LD. We hypothesize that the interaction between COPI and TRAPPII helps bring TRAPPII onto LD surface, and TRAPPII, in turn, activates Rab18 and recruits it on the LD surface to facilitate its functions in LD homeostasis. 相似文献
28.
Evidence for independent recruitment of zeta-crystallin/quinone reductase (CRYZ) as a crystallin in camelids and hystricomorph rodents 总被引:3,自引:2,他引:1
Zeta-crystallin/quinone reductase (CRYZ) is an NADPH oxidoreductase
expressed at very high levels in the lenses of two groups of mammals:
camelids and some hystricomorph rodents. It is also expressed at very low
levels in all other species tested. Comparative analysis of the mechanisms
mediating the high expression of this enzyme/crystallin in the lens of the
Ilama (Lama guanacoe) and the guinea pig (Cavia porcellus) provided
evidence for independent recruitment of this enzyme as a lens crystallin in
both species and allowed us to elucidate for the first time the mechanism
of lens recruitment of an enzyme- crystallin. The data presented here show
that in both species such recruitment most likely occurred through the
generation of new lens promoters from nonfunctional intron sequences by the
accumulation of point mutations and/or small deletions and insertions.
These results further support the idea that recruitment of CRYZ resulted
from an adaptive process in which the high expression of CRYZ in the lens
provides some selective advantage rather than from a purely neutral
evolutionary process.
相似文献
29.
Evidence of independent gene duplications during the evolution of archaeal and eukaryotic family B DNA polymerases 总被引:1,自引:0,他引:1
Eukaryotes and archaea both possess multiple genes coding for family B DNA
polymerases. In animals and fungi, three family B DNA polymerases, alpha,
delta, and epsilon, are responsible for replication of nuclear DNA. We used
a PCR-based approach to amplify and sequence phylogenetically conserved
regions of these three DNA polymerases from Giardia intestinalis and
Trichomonas vaginalis, representatives of early-diverging eukaryotic
lineages. Phylogenetic analysis of eukaryotic and archaeal paralogs
suggests that the gene duplications that gave rise to the three replicative
paralogs occurred before the divergence of the earliest eukaryotic
lineages, and that all eukaryotes are likely to possess these paralogs. One
eukaryotic paralog, epsilon, consistently branches within archaeal
sequences to the exclusion of other eukaryotic paralogs, suggesting that an
epsilon-like family B DNA polymerase was ancestral to both archaea and
eukaryotes. Because crenarchaeote and euryarchaeote paralogs do not form
monophyletic groups in phylogenetic analysis, it is possible that archaeal
family B paralogs themselves evolved by a series of gene duplications
independent of the gene duplications that gave rise to eukaryotic paralogs.
相似文献
30.
F.A. Kimball S.E. Porteus K.T. Kirton R.D. Frielink D.M. Creasy A.D. Dayan 《Prostaglandins & other lipid mediators》1979,18(3):377-385
Intravenous injection of 600 μg PGE2 or PGI2 significantly increased serum LH and prolactin levels in estradiol treated ovariectomized rats. There was no effect on serum FSH concentration. PGE2 and PGI2 stimulated LH release in a non-dose dependent manner, while prolactin levels were positively correlated with the dose administered following PGI2 treatment. 6-keto-PGF1α at a comparable dose had no effect on pituitary hormone levels. Subcutaneous administration of 1 mg/kg or 60 mg/kg PGI2 for seven days significantly depressed serum LH level both in male and female rats. These doses had no effect on serum FSH or prolactin levels. 相似文献