全文获取类型
收费全文 | 899739篇 |
免费 | 62445篇 |
国内免费 | 2334篇 |
专业分类
耳鼻咽喉 | 12477篇 |
儿科学 | 28677篇 |
妇产科学 | 26144篇 |
基础医学 | 126579篇 |
口腔科学 | 24687篇 |
临床医学 | 74753篇 |
内科学 | 183149篇 |
皮肤病学 | 18985篇 |
神经病学 | 71389篇 |
特种医学 | 36524篇 |
外国民族医学 | 336篇 |
外科学 | 142112篇 |
综合类 | 19030篇 |
一般理论 | 247篇 |
预防医学 | 64559篇 |
眼科学 | 20083篇 |
药学 | 63808篇 |
中国医学 | 1798篇 |
肿瘤学 | 49181篇 |
出版年
2018年 | 9048篇 |
2017年 | 7160篇 |
2016年 | 7675篇 |
2015年 | 8725篇 |
2014年 | 12371篇 |
2013年 | 19219篇 |
2012年 | 25663篇 |
2011年 | 27266篇 |
2010年 | 16580篇 |
2009年 | 15786篇 |
2008年 | 26134篇 |
2007年 | 27742篇 |
2006年 | 27931篇 |
2005年 | 27463篇 |
2004年 | 26307篇 |
2003年 | 25475篇 |
2002年 | 25057篇 |
2001年 | 41367篇 |
2000年 | 42562篇 |
1999年 | 36270篇 |
1998年 | 9969篇 |
1997年 | 9151篇 |
1996年 | 9082篇 |
1995年 | 8445篇 |
1994年 | 8081篇 |
1993年 | 7584篇 |
1992年 | 28202篇 |
1991年 | 26981篇 |
1990年 | 26409篇 |
1989年 | 25348篇 |
1988年 | 23556篇 |
1987年 | 23170篇 |
1986年 | 22252篇 |
1985年 | 21152篇 |
1984年 | 15806篇 |
1983年 | 13477篇 |
1982年 | 8087篇 |
1979年 | 14589篇 |
1978年 | 10208篇 |
1977年 | 8627篇 |
1976年 | 8148篇 |
1975年 | 8959篇 |
1974年 | 10697篇 |
1973年 | 10182篇 |
1972年 | 9661篇 |
1971年 | 8917篇 |
1970年 | 8584篇 |
1969年 | 8025篇 |
1968年 | 7684篇 |
1967年 | 7086篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
B Taillan G Barthelemy J P Routy F J Pedinielli F Zarrouk H Chardon A P Blanc 《Pathologie-biologie》1987,35(4):375-380
This article is concerned with a prospective study about the systematical, simultaneous and comparative assay of four biological markers (carcino-embryonic antigen, lactate dehydrogenase, gammaglutamyl transferase and phosphohexose isomerase). This study was conducted in a department of Hematology and oncology on 258 patients. The dosage of each marker separately does not appear to be of diagnostical interest because of a lack of sensibility and specificity. But when there is a positive statistical correlation between several makers, their simultaneous dosage may allow the diagnostic of cancer and sometimes the determination of its origin. 相似文献
993.
994.
995.
Gazzaniga P. P. Ferroni P. Mina C. Pulcinelli F. M. Rizzo P. A. 《The Italian Journal of Neurological Sciences》1987,8(6):561-566
148 patients with various forms of cerebrovascular disease (CVD) were studied by means of a multiparametric analysis ofin vitro platelet aggregation, based on the following six parameters: ADP and epinephrine primary and secondary aggregation thresholds
and percent maximum aggregation induced by optimal concentrations of ADP and epinephrine. These patients were assigned to
four study groups, according to clinical diagnosis supported by CT scan, of transient ischemic attack and reversible neurological
deficit (TIA-RIND), or completed stroke, in the presence or absence respectively of antiplatelet medical treatment at the
time of the study. A statistically significant increase of thein vitro platelet aggregation was found in 44.4% of the untreated TIA-RIND patients and in 33.9% of the untreated stroke patients.
However this last group showed a higher percentage of very marked hyperaggregation. Differences between the two treated study
groups and controls were not signicant. No difference was found in collagen-and ristocetin-induced aggregation between the
patient groups and the controls.
Sommario 148 pazienti con varie forme di malattia cerebrovascolare, sono stati studiati con analisi multiparametriche dell'aggregazione piastrinica in vitro sulla base dei seguenti sei parametri: le soglie di aggregazione primaria e secondaria e l'aggregazione massima percentuale indotta da ADP ed Epinefrina. Questi pazienti sono stati suddivisi in 4 gruppi di studio in accordo con la diagnosi clinica confortata dai dati della TAC e cioè: TIA, RIND, o rammollimento in presenza o in assenza rispettivamente di un trattamento antiaggregante nel momento dello studio. è stato trovato un aumento statisticamente significativo dell'aggregazione in vitro delle piastrine nel 44.4% dei casi TIA, RIND non trattati e nel 33,9% dei casi di rammollimento non trattati. Quest'ultimo gruppo, però, ha dimostrato una più alta percentuale di iperaggregazione molto marcata. Le differenze tra i 2 gruppi di studio trattati con antiaggreganti e i controlli non erano significative. Inoltre nessuna differenza è stata riscontrata tra i gruppi e i controlli nell'aggregazione indotta da collageno e ristocetina.相似文献
996.
The in vitro exposure of rat bronchial smooth muscle to the acetylcholinesterase inhibitor soman (0-[1,1,2-trimethylpropyl]-methylphosphonofluoridate) reduced the potassium (51 mM) evoked release of 3H-acetylcholine (3H-ACh). Exposure to 1.0 and 100 microM soman for 15 min inhibited the acetylcholinesterase (AChE) activity completely and reduced the potassium evoked release by 23.1% and 34.4% respectively. In the presence of scopolamine (0.3 microM), however, there was a large enhancement (87.0%) of potassium evoked release during soman inhibited (100%) AChE-activity. Furthermore, soman (1.0 microM) did not reduce the spontaneous release of 3H-ACh. The results indicate that the presynaptic effect of soman is due to the enhanced concentration of ACh following AChE-activity inhibition in the synaptic region. This induces a stimulation of presynaptic muscarinic receptors and thereby modulation of the ACh release only during evoked release. 相似文献
997.
E Damiani M T Cattaneo C Sessa E Zucca F Cavalli A Bertolini A Libretti R Beretta 《Tumori》1987,73(5):487-491
Urinary excretion of N-acetyl-beta-glucosaminidase (NAG) is an early marker of nephrotoxicity. NAG activity was assayed by the fluorimetric method of Leaback and Walker in 17 patients treated (22 courses) with carboplatin (CBDCA, 220-550 mg/m2) before infusion and 24, 48, 72 and 96 h after. Increased excretion of NAG, a sensitive index of renal tubular damage, was observed following 10 of the 22 courses. A transient increase in plasma creatinine and/or abnormal proteinuria was observed in 6 cases. Impaired renal function prior to therapy seems to be a predisposing factor to the nephrotoxicity. 相似文献
998.
Lin Shang-ze林尚泽and Wang Gui-fa王贵发Department of Otorhinolarrjngology Affiliated Hospital of GuiyangMedical College Guiyang 《中华医学杂志(英文版)》1986,99(7):602-603
Since the beginning of this century, trans-
naso-sphenoidal resection of the pituitary fossa
tumors has been widely used clinically. It has
more merits than other operative approaches
used before. In China it has been adopted by
both ENT doctors and neurosurgeons since 1959.1
In order to afford some relevant anatomical
data, we measured 137 adult sagittal plane
skulls with distinct landmarks. 相似文献
999.
1000.