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41.
The palpation and enucleation of occult insulinomas (less than 15 mm) can be a difficult surgical problem even with good arteriographic localization. In the authors' limited experience, confirmation of arteriographic findings by pancreatic venous sampling provided little additional localizing information. However, if arteriography is negative or equivocal, venous sampling can indicate the segment of pancreas to be "blindly" resected if the adenoma is not palpable. Venous sampling may be misleading in polyendocrine syndromes because of the frequency of multiple adenomas and variable hormone production. 相似文献
42.
The isomers of 3,4-methylenedioxyamphetamine (MDA) functioned as discriminative stimuli in rats trained to discriminate either (-) MDA (1.25mg/kg) or (+) MDA (1.25mg/kg) from saline. Dose- and time-response curves indicated that drug lever selection occurred at doses of at least 1.00mg/kg of (-) MDA and 0.75mg/kg of (+) MDA and that drug-appropriate responding for both isomers was maintained for at least 90min. Cross-substitution was observed between the MDA isomers; both (+) and (-) 3,4-methylenedioxymethamphetamine (MDMA) also substituted completely for (+) and (-) MDA. The hallucinogens (+)-lysergic acid diethylamide (LSD) and (+/-)-2,5-dimethoxy-4-methylamphetamine (DOM), substituted for (-) MDA; neither mescaline nor (+) amphetamine or cocaine had (-) MDA-like effects. LSD also substituted for (+) MDA; DOM, mescaline, (+) amphetamine and cocaine failed to have (+) MDA-like effects. The (-) but not the (+) MDA cue was blocked by the 5-HT(2) antagonist pirenpirone; the dopamine (DA) antagonists SCH-23390 and (-) sulpiride had no effect on either the (-) or (+) MDA cues. When animals were trained to discriminate LSD (0.16mg/kg) or (+) amphetamine (1.0mg/kg) from saline, neither (-) MDA nor (+) MDA substituted completely. These results indicate that: (1) the stimulus effects of the isomers of MDA and MDMA are similar; (2) (-) MDA may be more hallucinogenic (or more accurately, LSD- or DOM-like) than (+) MDA; (3) neither (+) nor (-) MDA has potent amphetamine-like effects; and (4) the effects of (-) MDA may be more serotonergic than those of (+) MDA. 相似文献
43.
44.
Giap BT Jong CN Ricker JH Cullen NK Zafonte RD 《The Journal of head trauma rehabilitation》2000,15(3):875-894
Cognitive deficits following insults to the central nervous system-particularly those involving the hippocampus and related structures-are often persistent and severely debilitating. Progress has been made in establishing the role of the hippocampus in integrating information in the formation of memory necessary for subsequent recollection of information. The present article will review anatomic, physiological, and functional aspects of the hippocampus in reference to learning and memory. Both animal and human hippocampal pathophysiological processes will be explored. Adaptive and maladaptive central nervous system responses will be reviewed, with a special emphasis on neurogenesis. Ideally, physiological and cellular compensatory responses ought to parallel clinical observation. However, this association is not clearly established. Finally, the current understanding of neuromodulatory mechanisms (although quite preliminary) will also be discussed. 相似文献
45.
Functional neuroimaging and quantitative electroencephalography in adult traumatic head injury: clinical applications and interpretive cautions 总被引:3,自引:0,他引:3
Functional neuroimaging and quantitative electroencephalographic procedures are being used increasingly in brain injury research and clinical care. These procedures are also seeing increased use in the context of forensic evaluations, particularly in cases of mild head trauma. This article provides an overview of the use of procedures such as positron emission tomography, single photon emission computed tomography, and quantitative electroencephalogram in adults. Also discussed are the clinical limitations of each procedure within the context of myriad interpretive confounds that can interfere with accurate differential diagnosis of mild head trauma. 相似文献
46.
47.
Isolation and characterization of propagable cell lines (HUNC) from the androgen-sensitive Dunning R3327H rat prostatic adenocarcinoma 总被引:1,自引:0,他引:1
Presnell SC; Borchert KM; Glover WJ; Gregory CW; Mohler JL; Smith GJ 《Carcinogenesis》1998,19(4):585-590
The Dunning H rat prostate tumor (R3327H) is a widely used experimental
model of human prostatic adenocarcinoma (CaP). The Dunning H tumor has been
characterized as androgen-sensitive, androgen-receptor (AR) positive,
prostate-specific antigen and prostatic acid phosphatase (PAP) positive. To
date, the tumor has been maintained by serial passage in vivo because of
the lack of an in vitro cell line that retains the characteristics of the
in vivo tumor. The objective of the present study was to establish a
propagable cell line from R3327H adenocarcinoma that maintained androgen
sensitivity and expression of AR, PSA and PAP. Tissue harvested from an in
vivo R3327H tumor was dissociated with collagenase and placed into
Richter's improved media (with supplements). A cytokeratin-positive
epithelial cell line (HUNC- E) and a vimentin-positive stromal cell line
(HUNC-S) were generated from the primary culture, subcultured continuously
for >300 days, and passaged >50 times. Survival of the HUNC-E cell
line in vitro depended on several media supplements, including
nicotinamide, insulin, transferrin, selenium and epidermal growth factor
(EGF). HUNC-E cells expressed AR and produced PSA and PAP throughout the
culture period, as confirmed by immunocytochemistry and Western blot
analyses. Addition of 14 nM testosterone (T) or dihydrotestosterone (DHT)
to HUNC-E cells, stimulated DNA synthesis as well as anchorage-independent
growth and PSA production, which demonstrated the androgen-sensitive nature
of the cells in vitro. When HUNC-E and HUNC-S cells were combined in a 3:1
ratio and introduced subcutaneously into syngeneic male hosts, tumors
formed in 2/3 animals with an average latency of 7 months. RT-PCR and
immunocytochemical characterization of the HUNC cell lines revealed that
the cells expressed several growth factors and their cognate receptors,
including HGF, TGF-alpha and the TGF-betas, indicating the establishment of
potential autocrine loops in the neoplastic cells. The HUNC-E and HUNC-S
CaP cell lines, which retain the characteristics of the epithelial and
stromal components of the in vivo R3327H tumor, will allow a more thorough
and informative molecular and biological analysis of prostatic
adenocarcinoma.
相似文献
48.
Previous work has shown that sustained increased and decreased cell
proliferation, induced by dietary zinc deficiency and caloric restriction
respectively, influence the course of N- nitrosomethylbenzylamine
(NMBA)-induced esophageal carcinogenesis in rats. The present study
considered whether the increased cell proliferation and esophageal tumor
incidence induced by zinc deficiency are reversed upon zinc replenishment.
Weanling rats were maintained initially on a deficient diet containing 4
p.p.m. zinc. After 5 weeks, carcinogen-treated animals were given six
intragastric doses of NMBA (2 mg/kg twice weekly). Controls were untreated.
After the second NMBA dose, the rats were divided into three dietary
groups. One group was continued on the deficient diet, while the other two
groups were switched to diets containing either 75 or 200 p.p.m. zinc, with
half of the members in each group fed ad libitum and half pair-fed with
deficient rats. NMBA-untreated controls were similarly replenished. At
various time points, esophageal cell proliferation was assessed in five
animals from each group by immunohistochemical detection of cells in S
phase, with in vivo 5-bromo-2'deoxyuridine labeling. At 11 weeks after the
first dose, esophageal tumor incidence was greatly reduced, from 100% in
the deficient group to 26 and 14% respectively in the replenished groups
fed ad libitum 75 and 200 p.p.m. zinc and to 14 and 11% respectively in the
replenished groups pair-fed 75 and 200 p.p.m. zinc. In addition, the number
of tumors per esophagus was reduced from 9.93 +/- 4.25 in deficient rats,
to a range of 0.11 +/- 0.31-0.30 +/- 0.54 in replenished animals. Following
zinc replenishment, esophageal cell proliferation, as measured by labeling
index (LI), the number of labeled cells and the total number of cells, was
markedly decreased in NMBA-untreated and -treated esophagi as compared with
those in corresponding deficient esophagi. Thus, the esophageal cell
proliferation induced by zinc deficiency is reversed by zinc replenishment
and replenished animals have a markedly lower incidence of esophageal
tumors.
相似文献
49.
P. A. Keenan Joseph H. Ricker Laurie A. Lindamer C. Colleen Jiron Mark W. Jacobson 《The Clinical neuropsychologist》2013,27(4):455-458
Abstract Eighty-two normal subjects, aged 16 to 95, were administered the California Verbal Learning Test, and the WAIS-R Vocabulary subtest. A set of hierarchical multiple regression equations (with age entered on the first step and Vocabulary on the second step) were calculated for CVLT performance variables. Significant incremental gains in R2 (p < .01) were found between Vocabulary scores and most CVLT recall variables. Education, in spite of having a significant correlation with Vocabulary, was a poor predictor of CVLT performance. Results indicated that age and Vocabulary together accounted for up to 31% of the variance in select CVLT performance variables; Vocabulary alone accounted for up to 13% of additional variance in select CVLT scores beyond the effects of age. Norms based on vocabulary scores or a similar estimate of verbal IQ may increase this test's sensitivity. 相似文献
50.