全文获取类型
收费全文 | 931879篇 |
免费 | 66830篇 |
国内免费 | 1343篇 |
专业分类
耳鼻咽喉 | 12965篇 |
儿科学 | 24363篇 |
妇产科学 | 23239篇 |
基础医学 | 132985篇 |
口腔科学 | 28247篇 |
临床医学 | 80573篇 |
内科学 | 183424篇 |
皮肤病学 | 19233篇 |
神经病学 | 72180篇 |
特种医学 | 36814篇 |
外国民族医学 | 79篇 |
外科学 | 152143篇 |
综合类 | 18046篇 |
现状与发展 | 1篇 |
一般理论 | 234篇 |
预防医学 | 61755篇 |
眼科学 | 21309篇 |
药学 | 72568篇 |
3篇 | |
中国医学 | 2162篇 |
肿瘤学 | 57729篇 |
出版年
2018年 | 8984篇 |
2017年 | 7038篇 |
2016年 | 7764篇 |
2015年 | 8870篇 |
2014年 | 11998篇 |
2013年 | 17511篇 |
2012年 | 24113篇 |
2011年 | 25062篇 |
2010年 | 14819篇 |
2009年 | 14284篇 |
2008年 | 24615篇 |
2007年 | 25710篇 |
2006年 | 26495篇 |
2005年 | 25453篇 |
2004年 | 24584篇 |
2003年 | 23647篇 |
2002年 | 23184篇 |
2001年 | 54741篇 |
2000年 | 56552篇 |
1999年 | 46965篇 |
1998年 | 10741篇 |
1997年 | 9469篇 |
1996年 | 9598篇 |
1995年 | 8930篇 |
1994年 | 8280篇 |
1993年 | 7598篇 |
1992年 | 35498篇 |
1991年 | 33922篇 |
1990年 | 32751篇 |
1989年 | 31877篇 |
1988年 | 29001篇 |
1987年 | 28255篇 |
1986年 | 26291篇 |
1985年 | 25148篇 |
1984年 | 17835篇 |
1983年 | 15146篇 |
1982年 | 7797篇 |
1981年 | 6773篇 |
1979年 | 15783篇 |
1978年 | 10599篇 |
1977年 | 9053篇 |
1976年 | 7873篇 |
1975年 | 8628篇 |
1974年 | 10467篇 |
1973年 | 9860篇 |
1972年 | 9357篇 |
1971年 | 8852篇 |
1970年 | 8426篇 |
1969年 | 7924篇 |
1968年 | 7200篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Patients with head injury may experience olfactory dysfunction. Unfortunately, little is known about changes in the olfactory neuroepithelium caused by intracranial olfactory nerve injury and hemorrhage. We performed olfactory nerve section or bulbectomy in 53 Mongolian gerbils and subjected the olfactory neuroepithelium to immunohistochemical analysis. A decrease or disappearance of the antiserum to an olfactory marker protein containing olfactory receptor neurons was evident in the sectioned group. Degeneration of the olfactory neuroepithelium contralateral to olfactory nerve injury was also noted in animals with perineural hemorrhage. These findings suggest that olfactory dysfunction may occur not only with nerve injury but also secondary to intracranial hemorrhage. 相似文献
982.
P. T. Wakode P. L. Joshi M. N. Mahore 《Indian journal of otolaryngology and head and neck surgery》1989,41(4):138-140
Nasal Cytogram is a simple, economical and reliable investigation. Although its utility was recognised as early s1927, it has not gained much popularity. Here an attempt is madeto assess the efficacy of nasal cytology in the light of histology, to diagnose various nasal conditions.127 cases of common rhinological problem were studied at Govt. Medical College, Nagpur. This investigation was found to be simple,
reliable & economical. 相似文献
983.
F T McDermott G Whelan D J St John G L Barnes R Elliott R Herrmann G T Schmidt R A Smallwood 《The Medical journal of Australia》1987,146(10):525, 528-525, 529
Information on the relative incidence of Crohn's disease and ulcerative colitis was obtained by a prospective investigation at six Melbourne teaching hospitals. One hundred and eleven patients who presented with chronic inflammatory bowel diseases between 1980-1981 were admitted to the study. Forty (36%) patients were diagnosed as having Crohn's disease and 63 (57%) patients as having ulcerative colitis. The type of chronic inflammatory bowel disease could not be determined in eight (7%) patients. These findings suggest that the relative frequency of Crohn's disease and ulcerative colitis in Melbourne hospitals is within the range that is reported for northern Europe and the United States. 相似文献
984.
985.
A monoclonal antibody (MoAb, SK-930) of the IgG2a subclass to human pancreatic carcinoma cells (MIA-PaCa 2) was obtained by hybridization of spleen cells from immunized Balb/c mice with murine myeloma cells. SK-930 was investigated for reacting in indirect immunofluorescence on FACS against a panel comprising 12 types of different origin. SK-930 reacted with seven out of 11 tumor cells and with one PBL. Immunoperoxidase techniques (ABC method) showed that SK-930 antigen was present on pancreatic adenocarcinoma cells, but could not be detected on normal pancreatic tissue. Immunoprecipitation experiments and SDS-PAGE analysis revealed that SK-930 recognized 134K dalton peptide on tumor cells. These results suggest that SK-930 reacts with a novel pancreatic cancer-associated antigen. 相似文献
986.
The phalloidin sensitivity of hepatocytes resulting in the formation of cytoplasmic blebs was examined with cells isolated from 73- to 74-week-old and 99- to 100-week-old F344/DuCrj rats of both sexes by a collagenase perfusion method. The cells isolated from aged rats were less sensitive to the toxin than those obtained from 10- to 14-week-old rats. The decrease in the sensitivity was more marked in males than in females, and it appeared at an earlier age in the former than in the latter. Phalloidin consumption experiments showed decreases in the cellular uptake of the toxin in aged rats, and these were more marked in males than in females. The low cellular uptake of the toxin seemed to play an important role in the low sensitivity of the cells in aged rats. Although histological and histochemical examinations showed the development of foci of altered hepatocytes in the aged rat liver, the foci were estimated to account for less than 1.5% of liver tissues. Thus, the decrease in the sensitivity of the cells isolated from whole liver tissues might mainly be attributed to the decrease in the sensitivity of otherwise normal-looking hepatocytes. 相似文献
987.
988.
Differentiation of blast cells from a Down's syndrome patient with transient myeloproliferative disorder 总被引:2,自引:0,他引:2
Suda J; Eguchi M; Akiyama Y; Iwama Y; Furukawa T; Sato Y; Miura Y; Suda T; Saito M 《Blood》1987,69(2):508-512
A male neonate with Down's syndrome and congenital myeloproliferative disorder was studied. His blood picture showed the unique coexistence of leukocytosis with matured cells and a large number of blast cells. The in vitro proliferation and differentiation of blast cells into various lineages in the presence of phytohemagglutinin-stimulated leukocyte conditioned medium (PHA-LCM) was examined by using a liquid culture and a methylcellulose culture system. The differentiation of blast cells into myeloid cells was confirmed by specific cytochemical stainings, electron microscopy, and an immunologic study. No specific factors in the plasma of the patient promoted the proliferation or differentiation of blast cells. The cellular composition of colonies grown in methylcellulose culture from single blast cells was studied by a micromanipulation technique. High plating efficiency was observed. Of 136 cultures, 78 showed colony growth. Half of the blast cells were colony-forming cells that could proliferate and differentiate into basophils, neutrophils, eosinophils, macrophages, and erythrocytes in the presence of PHA-LCM. Using the blast cells with a high differentiation capacity to the basophil pathway, we studied the effect of recombinant granulocyte-macrophage colony-stimulating factor (GM- CSF). Recombinant GM-CSF support neutrophils, eosinophils, and macrophages but not typical basophils. These findings of the cell differentiation of blast cells into various kinds of cells in vitro were in agreement with the finding of neutrophilia, eosinophilia, basophilia, and thrombocythemia in this patient. 相似文献
989.
G.
berg B. Simonsson B. Smedmyr T. H. Ttterman P. Venge 《European journal of haematology》1987,38(4):356-362
Bone-marrow regeneration after chemo- and radiotherapy-induced aplasia can be monitored by serum levels of myeloperoxidase (MPO), lysozyme (LYS) and lactoferrin (LF). In 10 patients with leukemia, serum measurements were performed before and after bone-marrow transplantation. Bone-marrow regeneration was suggested by increments in serum MPO and LYS 5 and 4 days prior to the increase in mononuclear cells (Mono) and 10 and 9 d before the increase in polymorphonuclear leukocytes (PMN) in the peripheral blood. LF started to rise 4.5 d before detectable circulating PMNs. 2 patients with early relapses of leukemia post transplantation are shown to display atypical patterns of serum MPO and LYS. We conclude that serum measurements of MPO, LYS and LF may be used as early and sensitive means to monitor bone-marrow activity during hematological regeneration. However, the findings also strongly support the earlier proposal that MPO alone may be used to reflect myeloid activity in the bone-marrow in general. 相似文献
990.
Aldosterone production by suspensions of adrenal glomerulosa cells obtained from young and old cows was measured. Basal steroidogenesis was lower in cells from old cows, as were the responses to angiotensin II (AII), potassium, ACTH and dibutyryl cyclic AMP. Receptors for AII and aldosterone production from added progesterone were the same in old and young cells. Synthesis of pregnenolone from endogenous precursor, the 'early pathway' of aldosteronogenesis, was lower in old cells than in young. AII-stimulated incorporation of 32P into phosphatidylinositol and the change in 45Ca2+ flux induced by AII were diminished in old cells. Overall protein synthesis, measured by 3H leucine incorporation, was lower in old cells than young, but was not affected by AII in either. Diminished responsiveness of adrenal glomerulosa cells from old animals results from a change in postreceptor events that affect the early pathway of aldosteronogenesis. 相似文献