全文获取类型
收费全文 | 22699篇 |
免费 | 1048篇 |
国内免费 | 104篇 |
专业分类
耳鼻咽喉 | 137篇 |
儿科学 | 357篇 |
妇产科学 | 269篇 |
基础医学 | 2677篇 |
口腔科学 | 648篇 |
临床医学 | 1462篇 |
内科学 | 5491篇 |
皮肤病学 | 382篇 |
神经病学 | 1739篇 |
特种医学 | 1102篇 |
外科学 | 4051篇 |
综合类 | 107篇 |
一般理论 | 1篇 |
预防医学 | 780篇 |
眼科学 | 595篇 |
药学 | 1646篇 |
中国医学 | 24篇 |
肿瘤学 | 2383篇 |
出版年
2023年 | 90篇 |
2022年 | 207篇 |
2021年 | 357篇 |
2020年 | 217篇 |
2019年 | 300篇 |
2018年 | 364篇 |
2017年 | 277篇 |
2016年 | 362篇 |
2015年 | 362篇 |
2014年 | 463篇 |
2013年 | 629篇 |
2012年 | 996篇 |
2011年 | 1103篇 |
2010年 | 628篇 |
2009年 | 536篇 |
2008年 | 988篇 |
2007年 | 1099篇 |
2006年 | 1130篇 |
2005年 | 1099篇 |
2004年 | 1067篇 |
2003年 | 957篇 |
2002年 | 1009篇 |
2001年 | 909篇 |
2000年 | 924篇 |
1999年 | 801篇 |
1998年 | 312篇 |
1997年 | 231篇 |
1996年 | 252篇 |
1995年 | 172篇 |
1994年 | 173篇 |
1993年 | 140篇 |
1992年 | 536篇 |
1991年 | 501篇 |
1990年 | 486篇 |
1989年 | 470篇 |
1988年 | 426篇 |
1987年 | 410篇 |
1986年 | 410篇 |
1985年 | 391篇 |
1984年 | 236篇 |
1983年 | 187篇 |
1982年 | 98篇 |
1979年 | 185篇 |
1978年 | 114篇 |
1977年 | 107篇 |
1975年 | 92篇 |
1973年 | 97篇 |
1972年 | 93篇 |
1970年 | 109篇 |
1969年 | 93篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
K Baba M Yajima N Ohyama T Iwamoto T Osada T Inoue T Shinagawa 《Hinyokika kiyo. Acta urologica Japonica》1990,36(12):1467-1470
Metastatic tumor of the penis is uncommon and only 95 cases have been reported in Japan. A 70-year-old man, who had squamous cell carcinoma of the lower pharynx, complained of urethral induration. Biopsy was performed and pathological diagnosis was metastatic tumor of penis originating from the lower pharynx. Although partial response in tumor size was noted by irradiation therapy, the patient died of multiple metastases in the 4th month after the diagnosis. This case is the first report of metastatic penile tumor originating from the lower pharynx. 相似文献
62.
Effects of repeated exposure to Fenitrothion (Sumithion) powder on erythrocyte membrane acetylcholinesterase (AChE) and plasma cholinesterase (PChE) were studied. Rats (Wistar, male) were exposed to fenitrothion powder for 2 hrs/day, 5 days/week for up to 3 months. The suppression of AChE and PChE increased as the exposure period and exposure concentration increased, although no suppression of AChE was found after a single 4-hr exposure. The persistence of AChE inhibition after the termination of exposure increased with the increase of the exposure period and was longer than that of PChE. Therefore, the AChE activity seems to be useful in examining the response to the repeated exposure to fenitrothion powder. 相似文献
63.
Seventeen specimens of orbital fatty tissue taken from cases of dysthyroid ophthalmopathy at the time of operation were observed by light and electron microscopy, and also by immunohistochemical staining. The pathological changes observed were infiltration of the chronic inflammatory cells, deposit of fibrin, sclerosis of vascular wall, occlusion of the vascular lumen, and accumulation of hydrophilic mucopolysaccharide. Immunoglobulin G was detected in fat cells and lymphocytes, and some of the infiltrating lymphocytes were determined to be T cells, by immunohistochemistry. These findings suggested that the pathology of the dysthyroid ophthalmopathy was closely related to the chronic inflammation induced by the immune reaction. The exophthalmos was considered to occur due to edema secondary to chronic inflammation and accumulation of the mucopolysaccharides. 相似文献
64.
65.
The same iron pot in which their father had boiled lead with mercury (from a glass thermometer) for the purpose of alchemy, was also used for cooking in the kitchen. Although his wife had died of mercury poisoning, and his 14-year-old and 11-year-old daughters were found to excrete 322 and 455 micrograms/l mercury in the urine, respectively, (1-10 micrograms/l in controls), he stubbornly refused to give permission for them to be examined further. Nine months later, the daughters were permitted to be sent to our clinical ward. While the blood level of mercury had already come down to near normal, its excessive deposition in hair, kidneys and other parts of the body as well as its excessive urinary excretion, were still persistent (beyond tenfold the normal). According to our measurement values, mercury ranged from 14 to 49 micrograms/g in every 1-cm-piece of 10 cm hair of the elder sister, and ranged from 21 to 85 micrograms/g in 14 cm hair from the younger sister. About a 75% decrease in mercury deposition was estimated during these 9 months, based on the speculation of 1.5 cm/month hair-lengthening. 相似文献
66.
67.
Human central and peripheral nerve cell tumors were examined in detail using antibodies to calcineurin, glial fibrillary acidic protein (GFAP) and neuron-specific enolase (NSE). Forty-eight formalin-fixed and paraffin-embedded specimens of human neuronal tumors, including 27 medulloblastomas, were examined. Calcineurin-positive cells were found in all peripheral nerve cell tumors and the two gangliogliomas, whereas 20 of the 27 medulloblastomas and one of the two cerebral neuroblastomas did not contain calcineurin-positive cells. Differentiation of cells along the neuronal lines was positively correlated with calcineurin immunoreactivity. NSE-positive cells were found in all of the tumors with the exception of the one cerebral neuroblastoma. NSE immunoreactivity was not invariably consistent with calcineurin immunoreactivity and non-neuronal cells were often positive. Calcineurin-positive cells were all devoid of GFAP, but NSE-positive cells expressed GFAP in some tumors. GFAP-immunoreactive cells were found only in central nerve cell tumors, and not in peripheral tumors. In addition, GFAP-positive cells in some tumors such as retinoblastoma and medulloblastoma morphologically revealed not only neoplastic but also reactive astrocytic features. 相似文献
68.
Relationship between tumor DNA ploidy and regional lymph node changes in lung cancer. 总被引:1,自引:0,他引:1
Seventy-four patients with lung cancer, resected consecutively from April 1989 to August 1990, were divided into (1) 21 with diploid tumors having a single G0/G1 peak and a coefficient of variation (CV) of 4.9 or less, (2) 18 with peridiploid tumors having a single G0/G1 peak and a CV at 5.0 or more, and (3) 35 with aneuploid tumors having multiple G0/G1 peaks. Aneuploid tumors had higher frequencies of lymphatic invasion and metastasis to the mediastinal lymph nodes. To evaluate the relationship between ploidy tumor status and immunologic competence of the regional lymph nodes, histologic findings and the proportion of killer T-lymphocytes were examined in the dissected lymph nodes. Aneuploid tumors had significantly lower proportions of paracortical hyperplasia and killer T-lymphocytes than did diploid and peridiploid ones in the nonmetastatic lymph nodes of N0 and N1 disease. These findings suggest the possibility that a decline in the antitumor competence of these lymph nodes could cause metastasis to the nodes. The recurrence rates were 19% in diploid, 33% in peridiploid, and 54% in aneuploid tumors, and the 2-year survival rates were 87%, 78%, and 44%, respectively. Peridiploid tumors showed intermediate values between diploid and aneuploid in terms of immunologic competence, recurrence rate, and survival. They were assumed to have a different proportion of aneuploid cells than the other two. 相似文献
69.
K Pak C J Kim H Inoue Y Wakabayashi J Watanabe Y Arai T Konishi T Tomoyoshi H Sako K Okino 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1990,81(10):1500-1505
To study the hemodialysis period following cadaveric renal transplantation, we reviewed 18 consecutive cadaver donor kidney pairs of which one kidney was transplanted at Shiga University of Medical Science (SUMS) while the contralateral kidney was transplanted at Kyoto Prefectural Medical University (KPMU) between January 1983 and September 1988. Of these 18 pairs, graft function was satisfactory and the recipient was free from hemodialysis in 13 pairs. However, the postoperative hemodialysis periods were different between the two centers. To clarify the factors causing this difference, recipient factors, such as age, HLA matching, total ischemic time of the graft (TIT), immunosuppression, onset of diuresis and postoperative complications were studied. There were no significant differences in age, HLA matching, or immunosuppression. TIT of cases at SUMS was significantly longer than that of cases at KPMU. The postoperative hemodialysis period at SUMS was 25.8 days and that at KPMU was 17.8 days, however, the difference was not statistically significant. The results of this study indicate that TIT seems to be a major factor relating to delayed graft function in cadaveric renal transplantation. 相似文献
70.
Y Iwai A Hakuba J Katsuyama Y Nagata S Nishimura K Abe T Asakura Y Inoue 《No shinkei geka. Neurological surgery》1990,18(1):71-75
Ectopic pituitary adenomas are very rare and only 17 cases have been reported. In this paper we present a case of large pituitary adenoma originating in the suprasellar region. A 26-year-old man was admitted to our clinic with a chief complaint of headaches. Neurological examination revealed slight disorientation and bilateral choked disk. Hormonal study revealed that the serum prolactin level was 3300ng/ml and serum growth hormone level was 29.5ng/ml. Computed tomography showed a large mass in the suprasellar region extending upward to the third ventricle and backward to the pons. T1-weighted MR imaging revealed that the intensity of the mass was the same as that of the cerebral cortex and the pituitary gland was showing high intensity in the pituitary fossa. The tumor was radically removed via the transpetrosal transtentorial approach. Histologically, the tumor was a prolactin-growth hormones producing pituitary adenoma. The literature was reviewed and the origin of the tumor was discussed. 相似文献