全文获取类型
收费全文 | 10088篇 |
免费 | 793篇 |
国内免费 | 105篇 |
专业分类
耳鼻咽喉 | 553篇 |
儿科学 | 149篇 |
妇产科学 | 92篇 |
基础医学 | 953篇 |
口腔科学 | 28篇 |
临床医学 | 1428篇 |
内科学 | 1201篇 |
皮肤病学 | 32篇 |
神经病学 | 214篇 |
特种医学 | 752篇 |
外科学 | 1429篇 |
综合类 | 1824篇 |
预防医学 | 518篇 |
眼科学 | 73篇 |
药学 | 766篇 |
9篇 | |
中国医学 | 125篇 |
肿瘤学 | 840篇 |
出版年
2024年 | 22篇 |
2023年 | 134篇 |
2022年 | 287篇 |
2021年 | 373篇 |
2020年 | 363篇 |
2019年 | 277篇 |
2018年 | 304篇 |
2017年 | 358篇 |
2016年 | 426篇 |
2015年 | 413篇 |
2014年 | 807篇 |
2013年 | 705篇 |
2012年 | 697篇 |
2011年 | 688篇 |
2010年 | 639篇 |
2009年 | 497篇 |
2008年 | 497篇 |
2007年 | 451篇 |
2006年 | 439篇 |
2005年 | 358篇 |
2004年 | 288篇 |
2003年 | 270篇 |
2002年 | 191篇 |
2001年 | 196篇 |
2000年 | 152篇 |
1999年 | 147篇 |
1998年 | 116篇 |
1997年 | 99篇 |
1996年 | 81篇 |
1995年 | 78篇 |
1994年 | 71篇 |
1993年 | 60篇 |
1992年 | 40篇 |
1991年 | 57篇 |
1990年 | 49篇 |
1989年 | 39篇 |
1988年 | 37篇 |
1987年 | 46篇 |
1986年 | 28篇 |
1985年 | 34篇 |
1984年 | 36篇 |
1983年 | 16篇 |
1982年 | 23篇 |
1981年 | 13篇 |
1980年 | 15篇 |
1979年 | 12篇 |
1978年 | 15篇 |
1977年 | 9篇 |
1975年 | 9篇 |
1974年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
61.
R. G. McMurray T. K. Eubank A. C. Hackney 《European journal of applied physiology》1995,72(1-2):121-126
The effects of resistance exercise on the nocturnal responses of cortisol (CO), testosterone (TEST), human growth hormone (hGH), and thyroid hormones (T3, T4) were examined in eight trained weight lifters. Each subject completed two trials using a counterbalanced design: a control, no exercise trial (CON) and a heavy resistance exercise session of three sets of six exercises to exhaustion (RE). The exercise session took place between 1900 and 2000 hours. Blood was sampled prior to and at 20-min intervals after RE. For both trials blood was sampled at hourly intervals from 2100 hours until 0700 hours. The hGH and CO concentrations were increased up to 40-min post-exercise (P < 0.05), but returned to resting levels 1 h post-exercise. Nocturnal hGH concentration was not affected by RE (P > 0.26) and peaked at 0200 hours and declined until 0700 hours. Similarly, the CO responses were similar between the trails (P > 0.14). This CO concentrations declined from 2200 hours until 0100 hours, then increased steadily until 0700 hours. The TEST concentrations during both trials rose steadily from 2200 hours until 0700 hours; however, the rise in TEST from 0500–0700 hours during RE was greater than during the CON trails (P = 0.059). The T3 concentrations were unchanged by exercise and were similar at all times between trails. The T4 concentrations were elevated for 20 min after RE; however nocturnal T4 concentrations were lower after RE than during CON. These results would suggest that bGH and CO may have limited nocturnal reactivity to resistance exercise. However, the nocturnal alterations of TEST and T4 after resistance exercise, although small, may have implications for muscle anabolism. 相似文献
62.
Carlo Capella Cesare Bordi Guido Monga Roberto Buffa Paolo Fontana Silvana Bonfanti Gianni Bussolati Enrico Solcia 《Virchows Archiv : an international journal of pathology》1978,377(2):111-128
Summary 10 cases of thyroid medullary carcinoma (TMC) have been studied ultrastructurally and histochemically. Well differentiated calcitonin-producing C cells were present in all tumours, being prevalent in 9 cases. 5-Hydroxytryptamine (5HT) storing cells were found in two cases, somatostatin immunoreactive cells in at least 5 cases and ACTH-immunoreactive cells in 4 cases. Ultrastructurally, at least 3 types of apparently non-C cells were observed. Type 1 cells with large, poorly osmiophilic granules resembling those of gastroenteropancreatic D cells, were present in 6 cases; they appeared to correlate well with somatostatin immunoreactive cells. Type 2 cells with large osmiophilic granules were found in 5 cases; they resembled ACTH-MSH cells of the human pituitary and may correspond to the ACTH-immunoreactive cells of light microscopy. Type 3 cells with small granules and an unknown function were found in 6 cases, always in scarce number. It is concluded that TMC, although mainly made up of C cells, usually contains large proportions of other endocrine cell types.Supported in part by grant N. 75.00630.04 from the Italian National Research Council (C.N.R.). P.F. is a fellow of the Fondazione Anna Villa Rusconi, Varese 相似文献
63.
The objective was to investigate glucose-6-phosphate dehydrogenase (G6PD) activity in monolayer cultures of thyroid epithelial cells and to examine whether inhibition of nitric oxide synthase affects activity of G6PD or oxygen sensitivity of the assay. Primary cultures without TSH addition prior to experiments demonstrated a TSH-dependent increase in G6PD activity. G6PD activity was higher in F12 medium than in a serum-free physiological medium. Secondary cultures grown in F12 medium demonstrated a diminished activity of G6PD and a lack of response to TSH. In the serum-free physiological medium, G6PD activity was comparable to that found in primary cultures and a response to high concentrations of TSH was maintained. In primary cultures grown in F12 medium devoid of TSH, G6PD activity decreased dose-dependently when nitric oxide synthase activity was inhibited. The oxygen sensitivity of the assay was comparable to that reported previously in malignant cells and correlated with the activity of G6PD in primary cultures. We suggest that thyroid epithelial cells may be an appropriate system to investigate oxygen sensitivity of the G6PD assay as the cells demonstrate a reduced oxygen sensitivity which can be influenced by culture conditions. 相似文献
64.
血清抗甲状腺球蛋白抗体和抗甲状腺过氧化物酶抗体检测在甲状腺疾病诊断及甲亢预后判断中的价值 总被引:1,自引:0,他引:1
采用放免法检测甲状豚疾病患者抗甲状腺球蛋白抗体(TGAb)和抗甲状腺过氧化物酶抗体(TPOAb)、并对部分Graves病患者停药后随诊一年的结果进行分析。结果显示:(1)自身免疫性甲状腺疾病患者TGAb和TPOAb活性及阳性率明显高于非AITD,尤以桥本甲状腺炎为然。(2)GD治疗前及停药时TGAb和TPOAb均阴性者与均阳性者停药一年内的复发率分别为0.583和0.231。(3)TGAb和TPOAb均阴性,而停药时甲状腺刺激抗体(TSAb)阳性者,停药时GD复发的机率最大(0.909),提示TGAb和TPOAb检测在AITD诊断,鉴别诊断以及GD预后判断中具有重要的临床意义。 相似文献
65.
Tohru Yashiro Motohiko Aiba Takao Obara Yoshihide Fujimoto Akira Hirayama 《Pathology international》1988,38(3):371-381
A case of primary plasmacytoma of the thyroid gland which occurred in a 63-year-old woman is reported. Histologic and ultramicroscopic examination revealed that the excised thyroid tumor was plasmacytoma superimposed on lymphocytic thyroiditis. Immunohistological study showed that the tumor cells produced intracytoplasmic immunoglobulin (IgG-kappa). Electropho-retic and immunoelectrophoretic studies disclosed the presence of monoclonal immunoglobulin (IgG-kappa) in samples of the patient's serum which had been obtained preoperatively. After completion of irradiation therapy to the neck following tumor removal, the serum monoclonal immunoglobulin disappeared. The patient is currently alive and well without any evidence of the tumor three years after surgery. 相似文献
66.
Yamashita H Noguchi Y Noguchi S Yamashita H Uchino S Watanabe S Ogawa T Murakami T 《Endocrine pathology》2005,16(1):41-48
Risk factors for distant metastasis were studied in 82 patients with follicular thyroid carcinoma (FTC). Metastases to either
the lung or bone existing at the time of presentation were confirmed by I-131 radio-iodine uptake in 10 patients. FTC with
an insular component was found in eight patients. Univariate analysis of 14 possible risk factors showed 7 to be statistically
significant: insular component, poorly differentiated carcinoma, trabecular component, serum thyroglobulin level before surgery,
patient age at the time of presentation, solid component, and vascular invasion (ranked by p values). After further analysis of the interrelation of the factors and of the logistic regression curves, we concluded that
presence of an insular component and patient age were the only independent risk factors. Distant metastasis was not detected
in any of the 27 patients ≤49 yr old. Among the 55 older patients (≥50 yr old), 5 of the 49 (10%) without an insular component
and 5 of the 6 (83%) with an insular component had distant metastasis. The remaining older patient with an insular component
but without distant metastasis showed a gradual increase in thyroglobulin levels after total thyroidectomy. 相似文献
67.
Geographic or ethnic differences in the incidence of thyroid carcinoma, as well as in the histologic distribution of thyroid
carcinoma between Japan and Western countries, have been described but are still unclear. The recent establishment of histologic
criteria for the diagnosis of thyroid carcinoma by the WHO committee has facilitated the comparison of clinicopathological
data of patients with thyroid carcinoma all over the world. The aim of the present review article is to clarify the epidemiological
and clinicopathological differences of thyroid carcinoma between Japan and Western countries. We found recently no significant
differences in the incidence, mortality, and histologic distribution of thyroid carcinoma between Japan and Western countries;
this was contrary to our expectation. This is likely attributable to westernization of the Japanese diet, standardized medical
levels, and international standardization of histologic criteria of thyroid carcinoma. 相似文献
68.
Seiji Shibuya Yoshihiro Wakayama Masahiko Inoue Makoto Murahasi Hiroaki Oniki 《Medical Electron Microscopy》1998,31(3):135-141
To examine the influence of thyroid hormone on the skeletal muscle plasma membrane, we analyzed the changes in ultrastructural architecture and membrane area complexed with digitonin of muscle plasma membrane in myopathic patients with hypo-and hyperthyroidism by the conventional freeze-fracture (F-F) technique and F-F cytochemistry using the sterol-specific ligand digitonin. The densities of flask-shaped invaginations, which are mainly thought to correspond to caveolae, intramembranous particles, and orthogonal arrays, and the changes of digitoninreacted membrane areas in the muscle plasma membranes in three patients with hypothyroid myopathy and one patient with both myasthenia gravis and hyperthyroidism were compared with those in age-matched controls. In the conventional F-F study, the muscle plasma membrane of hypothyroid patients showed increased invagination density, whereas that of the hyperthyroid patient was normal ultrastructurally. In the F-F cytochemistry study, however, the ratio of digitonin-reacted membrane areas versus fractured membrane areas was not different between hypothyroid patients and controls, whereas that of the hyperthyroid patient was lowered in comparison with that of control. These results suggest that thyroid hormone may alter the biochemical properties and ultrastructural architecture of muscle plasma membrane.This study was presented at the 29th annual meeting of the Clinical Electron Microscopy Society of Japan, Sapporo, October 2–3, 1997 相似文献
69.
Gianluca Taccagni Clara Sambade Jahn Nesland Maria Rosa Terreni Manuel Sobrinho-Simões 《Virchows Archiv : an international journal of pathology》1993,422(6):491-497
We describe three cases of solitary fibrous tumour (SFT) arising from thyroid stroma. Grossly, the tumours were clearly delimited but only partly encapsulated. The following histomorphological growth patterns were observed: bundles of cells in storiform configuration; non-structured bundles; prevalence of fibrous matrix; highly cellular, non-structured; prevalence of loose, non-structured extracellular substance; cellular proliferation and vascular spaces in a haemangiopericytic configuration and a lipomatous component. Immunohistochemical investigation demonstrated intense, diffuse vimentin positivity and focal, less intense actin positivity in all three cases. At electron microscopy we observed a primitive cell of mesenchymal type, with cytoplasm poor in organelles and rich in filaments; this cell sometimes presented differentiation characteristics. SFT is at present the most correct term for the lesions presented here despite some morphological characteristics which differ from cases reported in the literature. 相似文献
70.
实验用Wistar大鼠125只。随机分成五组。动物实验期为20周。结果显示:单纯低碘或单纯高锂的大鼠均表现为增生性甲状腺肿的组织学改变及血清T_4降低、T_3升高;前者甲状腺上皮细胞增生较后者显著,后者甲状腺滤泡腔内胶质含量较多。低碘合并高锂摄入的大鼠,其甲状腺病变较单纯低碘或单纯高锂大鼠严重,并呈明显的胶性甲状腺肿组织学改变,血清T_4降低、T_3正常。可见高锂不仅有致甲肿作用,而且当它与低碘并存时,将加重甲状腺的病变,并使其向胶性甲状腺肿发展。 相似文献