全文获取类型
收费全文 | 11644篇 |
免费 | 1031篇 |
国内免费 | 139篇 |
专业分类
耳鼻咽喉 | 602篇 |
儿科学 | 164篇 |
妇产科学 | 98篇 |
基础医学 | 1087篇 |
口腔科学 | 39篇 |
临床医学 | 1674篇 |
内科学 | 1421篇 |
皮肤病学 | 91篇 |
神经病学 | 230篇 |
特种医学 | 969篇 |
外科学 | 1582篇 |
综合类 | 2104篇 |
预防医学 | 583篇 |
眼科学 | 96篇 |
药学 | 826篇 |
14篇 | |
中国医学 | 181篇 |
肿瘤学 | 1053篇 |
出版年
2024年 | 47篇 |
2023年 | 194篇 |
2022年 | 441篇 |
2021年 | 516篇 |
2020年 | 504篇 |
2019年 | 356篇 |
2018年 | 390篇 |
2017年 | 435篇 |
2016年 | 498篇 |
2015年 | 466篇 |
2014年 | 926篇 |
2013年 | 789篇 |
2012年 | 776篇 |
2011年 | 768篇 |
2010年 | 690篇 |
2009年 | 555篇 |
2008年 | 559篇 |
2007年 | 512篇 |
2006年 | 489篇 |
2005年 | 402篇 |
2004年 | 319篇 |
2003年 | 307篇 |
2002年 | 212篇 |
2001年 | 207篇 |
2000年 | 170篇 |
1999年 | 159篇 |
1998年 | 125篇 |
1997年 | 112篇 |
1996年 | 94篇 |
1995年 | 85篇 |
1994年 | 80篇 |
1993年 | 73篇 |
1992年 | 47篇 |
1991年 | 64篇 |
1990年 | 52篇 |
1989年 | 42篇 |
1988年 | 41篇 |
1987年 | 48篇 |
1986年 | 34篇 |
1985年 | 39篇 |
1984年 | 42篇 |
1983年 | 17篇 |
1982年 | 27篇 |
1981年 | 15篇 |
1980年 | 17篇 |
1979年 | 13篇 |
1978年 | 17篇 |
1977年 | 10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 0 毫秒
51.
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
52.
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
53.
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
54.
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
55.
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
56.
Ryohei Katoh Koichi Suzuki Akihiro Hemmi Akira Kawaoi 《Virchows Archiv : an international journal of pathology》1993,422(4):301-306
To elucidate the significance and nature of calcium oxalate crystals in the thyroid, we studied these crystals clinicopathologically and immunohistochemically in 182 normal thyroids from patients autopsied within 5 h of death. Under polarized light, calcium oxalate crystals showed brilliant birefringence and were invariably found within the colloid. The crystals were found in 73.1% of all cases but were more prevalent and denser in older individuals, with the highest prevalence (85.2%) being observed in those over 70 years of age. No crystals were seen in those under 10 years of age. Although underlying diseases seemed to have little influence, post-mortem delay apparently affected the prevalence and density of occurrence since the crystals tended to disappear with hours after death. An immunohistochemical study using anti-thyroid hormone antibodies revealed that the crystals were within negatively or weakly stained colloid and were not common in strongly stained colloid. These findings support the hypothesis that the occurrence of calcium oxalate crystals in normal human thyroid is associated with a low functional state of the thyroid follicles. 相似文献
57.
Iris (Lisch) nodules in neurofibromatosis 总被引:3,自引:0,他引:3
A group of 30 patients ranging from 4 to 56 years of age with the peripheral form of neurofibromatosis were evaluated for the presence of iris (Lisch) nodules. These nodules were observed in 73% of our cases and their presence was directly related to the severity of the skin manifestations of the disease. It is concluded that Lisch nodules are pathognomonic for neurofibromatosis and thus, their presence should be looked for in all suspected cases. 相似文献
58.
S Tseleni-Balafouta A Kyroudi-Voulgari P Paizi-Biza N X Papacharalampous 《Diagnostic cytopathology》1989,5(4):362-365
This study assessed the morphological criteria for the diagnosis of various types of lymphocytic thyroiditis in fine-needle aspirates. Of 950 aspirates, 121 revealed lymphocytic thyroiditis, including Hashimoto's thyroiditis (partly confirmed by serological or histological examination) and focal thyroiditis adjacent to neoplasms. The diagnosis of Hashimoto's thyroiditis was easy when the aspirated material was adequate and contained oxyphilic cells; in the fibrous type, diagnosis was rather difficult. Focal thyroiditis may be confused with Hashimoto's thyroiditis, especially when adjacent to neoplasm. Surgical exploration should be performed in cases of severe lymphocytic thyroiditis revealed by fine-needle aspiration with repeatedly negative antibody titers in order to exclude neoplasm. 相似文献
59.
Diffuse sclerosing variant of papillary thyroid carcinoma: A clinicopathologic and immunophenotypic analysis of 22 cases 总被引:3,自引:0,他引:3
Background: The diffuse sclerosing variant of papillary thyroid carcinoma (DSV-PTC) is an uncommon tumor making up about 2% of all papillary
thyroid carcinomas. Previous studies have not comprehensively evaluated these tumors in a large series of patients.
Design: Twenty-two cases of DSV-PTC diagnosed between 1970 and 2000 were identified in the files of the AFIP. Histologic and immunohistochemical
features were evaluated and patient follow-up was obtained.
Results: The tumors affected 14 females and 8 males, aged 6 to 49 yr (mean, 18 yr), with males presenting at a mean older age than
females (24 vs 14 yr). Symptoms included an enlarging mass in the thyroid, present for a mean of 9.5 mo. While a dominant
tumor was identified in a single lobe, bilateral disease was common (n=16). The dominant mass ranged in size from 1.7 to 5.8 cm in diameter (mean, 3.8 cm). Histologically, all cases demonstrated
a papillary carcinoma (conventional, solid, or follicular pattern) diffusely involving the gland. Extrathyroidal extension,
lymphocytic thyroiditis, squamous metaplasia, increased fibrosis/sclerosis, and psammoma bodies were present to a variable
degree. Both the papillary carcinoma and squamous metaplasia cells were strongly immunoreactive with CK19, thyroglobulin,
and TTF-1. An increased number of S-100 protein immunoreactive dendritic cells were recognized. p53 was increased (>15%) in
the tumor cells in 12 patients, while Ki-67 was increased in the tumor cells in two patients. Perithyroidal and cervical lymph
node metastasis occurred in 18 (82%) patients. All metastases demonstrated histologic features similar to the primary. Complete
resection (thyroidectomy in 18 patients) with lymph node dissection, yielded a 95% 5-yr survival without evidence of disease.
One patient died of disease after a malignant transformation of the squamous metaplasia into squamous cell carcinoma.
Conclusions: The recognition of DSV-PTC can be made with the following features: classic to solid foci of PTC, lymphocytic thyroiditis,
squamous metaplasia, increased fibrosis, and innumerable psammoma bodies. DSV-PTC is more biologically aggressive than conventional
PTC, but the patients’ survival is not significantly different. This diagnosis should lead the clinician to aggressively manage
these patients (thyroidectomy and lymph node dissection) in an effort to achieve an excellent long-term clinical outcome. 相似文献
60.
A case of mixed medullary follicular carcinoma of the thyroid is reported. Grossly, the tumor was a solid, grayish white, well circumscribed mass without lymph node metastasis. Microscopically, the tumor showed both medullary and follicular areas. The follicular areas occupied discrete portions of the tumor, and were considered to be neoplastic. Tumor cells in the medullary area were polyhedral or spindle-shaped. There was no amyloid deposition within the tumor. Immunohistochemically, tumor cells in the medullary area were positive for calcitonin and negative for thyroglobulin. Some cells lining the follicles were positive for thyroglobulin. By electron microscopy, two types of tumor cell were observed. One type contained numerous cytoplasmic secretory granules, whereas the other type had few granules and showed a prominent rough endoplasmic reticulum. These findings suggested that this mixed medullary follicular carcinoma of the thyroid presented neoplastic changes within a common cell lineage. 相似文献