全文获取类型
收费全文 | 359篇 |
免费 | 17篇 |
出版年
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 12篇 |
2013年 | 23篇 |
2012年 | 26篇 |
2011年 | 15篇 |
2010年 | 11篇 |
2009年 | 12篇 |
2008年 | 16篇 |
2007年 | 20篇 |
2006年 | 12篇 |
2005年 | 25篇 |
2004年 | 22篇 |
2003年 | 14篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 11篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 6篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1970年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有376条查询结果,搜索用时 15 毫秒
1.
2.
M S Jawahar S Sivasubramanian V K Vijayan C V Ramakrishnan C N Paramasivan V Selvakumar S Paul S P Tripathy R Prabhakar 《BMJ (Clinical research ed.)》1990,301(6748):359-362
OBJECTIVE--To assess the efficacy of a short course chemotherapy regimen for treating tuberculosis of the lymph nodes in children. DESIGN--Open, collaborative, outpatient clinical trial. SETTING--Outpatient department of the Tuberculosis Research Centre, paediatric surgery departments of the Institute of Child Health and Hospital for Children and the Government Stanley Hospital, Madras, South India. PATIENTS--Children aged 1-12 years with extensive, multiple site, superficial tuberculous lymphadenitis confirmed by biopsy (histopathology or culture). INTERVENTIONS--Patients were treated with a fully supervised intermittent chemotherapy regimen consisting of streptomycin, rifampicin, isoniazid, and pyrazinamide three times a week for two months followed by streptomycin and isoniazid twice a week for four months on an outpatient basis. Surgery was limited to biopsy of nodes for diagnosis and assessment. MAIN OUTCOME MEASURES--Response to chemotherapy was assessed by regression of lymph nodes and healing of sinuses and abscesses during treatment and follow up. Compliance with treatment and frequency of adverse reactions were also estimated. RESULTS--197 Patients were admitted to the study and 168 into the analysis. The regimen was well tolerated and compliance was good with 101 (60%) patients receiving the prescribed chemotherapy within 15 days of the stipulated period of six months. Those whose chemotherapy extended beyond that period received the same total number of doses. Clinical response was favourable in most patients at the end of treatment. Sinuses and abscesses healed rapidly. Residual lymphadenopathy (exceeding 10 mm diameter) was present in 50 (30%) patients at the end of treatment; these nodes were biopsied. Fresh nodes, increase in size of nodes, and sinuses and abscesses occurred both during treatment and follow up. After 36 months of follow up after treatment only 5 (3%) patients required retreatment for tuberculosis. CONCLUSION--Tuberculous lymphadenitis in children can be successfully treated with a short course chemotherapy regimen of six months. 相似文献
3.
Systemic administration of Neurotensin, a tridecapeptide, in immature rats treated with estradiol benzoate significantly enhances uterine DNA synthesis as reflected by the incorporation of 3H-thymidine. The peptide may have a direct action on the uterus. Substance P, a related peptide, had no effect on uterine DNA synthesis. 相似文献
4.
t-Buthyoxycarbonyl-L -alanyl-α-aminiosobutyryl-L -alanyl-α-aminoisobutyryl-α-aminoisobutyric acid methyl ester (t-Boc-L -Ala-Aib-L -Ala-Aib-Aib-OMe), C24H43N5O8, an end-protected pentapeptide with a sequence corresponding to the 6th through the 10th residues in suzukacillin, crystallizes in the orthorhombic space group P212121 with a = 11.671, b = 14.534, c = 17.906 Å and z = 4. The molecule exists as a right-handed 310-helix with a pitch of 6.026 Å. The helix is stabilized by three 4 → 1 hydrogen bonds with the NH groups of Ala(3), Aib(4), and Aib(5) hydrogen bonding to the carbonyl oxygens of t-Boc, Ala(1), and Aib(2), respectively. The helical molecules arrange themselves in a head-to-tail fashion along the a direction in such a way that the NH groups of Ala(1) and Aib(2) hydrogen bond to the carbonyl oxygens of Aib(4) and Aib(5), respectively, of a translationally related molecule. The helical columns thus formed close-pack nearly hexagonally to form the crystal. 相似文献
5.
6.
Modulation of catecholamine storage and release by the pituitary-interrenal axis in the rainbow trout,Oncorhynchus mykiss 总被引:2,自引:0,他引:2
S. G. Reid M. M. Vijayan S. F. Perry 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1996,165(8):665-676
This study examined the effects of pituitary-interrenal hormones on catecholamine storage and release in the rainbow trout Oncorhynchus mykiss. An extract of trout pituitary elicited the release of adrenaline, but not noradrenaline, using an in situ perfusion preparation. A variety of doses of adrenocorticotropic hormone (2–2000 mU) caused the release of both catecholamines in situ which was unaffected by pre-treatment with the ganglion blocker, hexamethonium, or the serotonergic receptor antagonist, methysergide, but was abolished in calcium-free media. Intra-arterial injections of adrenocorticotrophic hormone in vivo caused an elevation of plasma adrenaline but not noradrenaline levels. Injections of cortisol in situ did not elicit catecholamine release. Trout given an intraperitoneal implant of cortisol (50 mg·kg-1 body weight) had significantly higher plasma cortisol concentrations when compared to controls after 7 days of implantation. Increases in the levels of stored catecholamines were observed in various regions of the kidney and posterior cardinal vein following 3 and 7 days of cortisol treatment. The ability of the chromaffin cells to release catecholamines in response to cholinergic stimulation was assessed in situ after 7 days of treatment. Basal (non-stimulated) adrenaline outflowing perfusate levels were greater in the cortisol-treated fish. Cortisol treatment increased the responsiveness of the catecholamine release process to low doses of the cholinoceptor agonist carbachol. Three or 7 days of cortisol treatment did not alter the in vitro activity of the enzyme phenylethanolamine-N-methyl-transferase. The results of this study demonstrate that interactions within the pituitary-adrenal axis can influence both catecholamine storage and release in the rainbow trout.Abbreviations
ACTH
adrenocorticotropic hormone
-
AK
anterior third of the kidney
-
APCV
anterior third of the PCV
-
HPLC
high performance liquid chromatography
-
MK
middle third of the kidney
-
M1
maximum value
-
MPCV
middle third of the PCV
-
MS222
ethyl-aminobenzoate
-
P1
pre value
-
PCA
perchloric acid
-
PCV
posterior cardinal vein
-
PK
posterior third of the kidney
-
PNMT
phenylethanolamine-N-methyltransferase
-
PPCV
posterior third of the PCV
-
rbc
red blood cells
-
SEM
standard error of the mean
-
TK
total kidney (i.e. the sum of the AK, MK, and PK)
-
TPCV
total PCV (i.e. the sum of the APCV, MPCV and PPCV) 相似文献
7.
The present study investigates the effect of cannulation and chronic'black-box' confinement, as well as epinephrine administration (4–0 μg kg−1 ), on the degree and time-course of alterations in trout ( Oncorhynchus mykiss ) catecholamine and cortisol concentrations. Plasma cortisol concentrations in seawater trout acclimated to 3–6° C reached 104 ng ml−1 1 day after cannulation/confinement and remained elevated above resting levels (8 ng ml−1 ) until 6 days post-confinement. Although plasma epinephrine and norepinephrine generally declined over the period of confinement (day 1 approx. 12 nM; day 7 approx. 6 nM), norepinephrine titres were usually higher and more variable. Epinephrine injection caused elevations in plasma epinephrine levels but not in norepinephrine levels; epinephrine titres reaching 107 ± 26 nM (range 65–238 nM) at 2 min post-injection and returning to pre-injection levels by 30 min post-injection. Plasma cortisol increased by 20 ng ml−1 following epinephrine administration. Based on the time-course for post-confinement alterations in plasma cortisol, it appears that up to a week may be required before cannulated fish are completely acclimated to 'black-box' confinement. The findings suggest that meaningful results from experiments utilizing epinephrine injection and 'black-box confinement are contingent upon: (1) knowledge of circulating epinephrine levels shortly after injection (i.e. within 2 min post-injection); and (2) an experimental design that takes into account the elevated cortisol titres that are inherent with cannulation/confinement and epinephrine injection. 相似文献
8.
9.
Conscious ovariectomized (OVX) rats bearing a cannula implanted in the 3rd ventricle were injected with 2 μl of 0.9% NaCl containing varying doses of synthetic gastrin and plasma gonadotropin, GH and TSH levels were measured by RIA in jugular blood samples drawn through an indwelling silastic catheter. Control injections of saline iv or into the 3rd ventricle did not modify plasma hormone levels. Intraventricular injection of 1 or 5 μg gastrin produced significant suppression of plasma LH and prolactin (Prl) levels within 5 min of injection. Injection of 1 μg gastrin had no effect on plasma GH, but increasing the dose to 5 μg induced a progressive elevation, which reached peak levels at 60 min. By contrast, TSH levels were lowered by both doses of gastrin within 5 min of injection and the lowering persisted for 60 min. Intravenous injection of gastrin had no effect on plasma gonadotropin, GH and TSH, but induced an elevation in Prl levels. incubation of hemipituitaries with gastrin failed to modify gonadotropin, GH or Prl but slightly inhibited TSH release at the highest dose of 5 μg gastrin. The results indicate that synthetic gastrin can alter pituitary hormone release in unrestrained OVX rats and implicate a hypothalamic site of action for the peptide to alter release of a gonadotropin, Prl and GH. Its effect on TSH release may be mediated both via hypothalamic neurons and by a direct action on pituitary thyrotrophs. 相似文献
10.
R Banerjee V Dhanaraj S K Mahanta A Surolia M Vijayan 《Journal of molecular biology》1991,221(3):773-776
Four new crystal forms of the anti-T lectin from jackfruit (Artocarpus integrifolia) have been prepared and characterized. Three of them, two monoclinic (P21, a = 59.4 A, b = 83.3 A, c = 63.5 A, beta = 107.7 degrees; C2, a = 106.1 A, b = 53.9 A, c = 128.0 A, beta = 95.0 A) and one orthorhombic (C222(1), a = 98.1 A, b = 67.3 A, c = 95.1 A) were grown with 2-methylpentan-2,4-diol (MPD) as the precipitant while the fourth, an hexagonal form (P6(1)22, a = b = 129.6 A, c = 157.9 A), was obtained in the presence of methyl-alpha-D-galactopyranoside with polyethylene glycol 4000 as the precipitant. The reported relative molecular mass (Mr) of the lectin was found to be inconsistent with the solvent content of the crystals estimated using measured densities. The Mr was redetermined using size-exclusion chromatography in the presence of methyl-alpha-D-galactopyranoside and Ferguson-plot analysis of mobilities in polyacrylamide gel electrophoresis. The redetermined Mr (66,000) is consistent with the measured crystal densities. The orthorhombic and the hexagonal forms, which have one half molecule and one molecule, respectively, in the asymmetric unit, are suitable for high-resolution X-ray analysis. 相似文献