首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1893篇
  免费   65篇
  国内免费   2篇
耳鼻咽喉   13篇
儿科学   54篇
妇产科学   50篇
基础医学   241篇
口腔科学   33篇
临床医学   111篇
内科学   399篇
皮肤病学   69篇
神经病学   119篇
特种医学   70篇
外科学   356篇
综合类   9篇
预防医学   82篇
眼科学   82篇
药学   116篇
中国医学   3篇
肿瘤学   153篇
  2023年   10篇
  2022年   22篇
  2021年   26篇
  2020年   13篇
  2019年   24篇
  2018年   21篇
  2017年   26篇
  2016年   33篇
  2015年   21篇
  2014年   32篇
  2013年   40篇
  2012年   68篇
  2011年   78篇
  2010年   58篇
  2009年   53篇
  2008年   73篇
  2007年   82篇
  2006年   71篇
  2005年   86篇
  2004年   74篇
  2003年   73篇
  2002年   65篇
  2001年   80篇
  2000年   74篇
  1999年   72篇
  1998年   28篇
  1997年   22篇
  1996年   19篇
  1995年   11篇
  1994年   13篇
  1993年   14篇
  1992年   67篇
  1991年   48篇
  1990年   36篇
  1989年   62篇
  1988年   61篇
  1987年   51篇
  1986年   36篇
  1985年   38篇
  1984年   23篇
  1983年   17篇
  1982年   15篇
  1979年   12篇
  1978年   10篇
  1977年   15篇
  1976年   9篇
  1974年   8篇
  1973年   8篇
  1972年   10篇
  1970年   8篇
排序方式: 共有1960条查询结果,搜索用时 15 毫秒
51.
The occurrence of a collision tumor in the stomach, consisting of adenocarcinoma and malignant lymphoma, is extremely rare. We report herein the case of a patient who had undergone a pancreatoduodenectomy for bile duct cancer 5 year earlier, in whom an ulcerating tumor of the remnant stomach developed and grew rapidly within 5 months. Surgical exploration revealed a tumor in the remnant stomach, multiple liver metastases, and multiple lymph node metastases. Total resection of the remnant stomach was performed, and pathological examination revealed a collision tumor consisting of adenocarcinoma and malignant lymphoma. The patient died of liver metastases and lymph node metastases 7 months after his second operation. The coexistence of both adenocarcinoma and malignant lymphoma of the remnant stomach and the etiology of this unusual combination, never previously reported, is discussed. Received: December 20, 1999 / Accepted: November 20, 2000  相似文献   
52.
Endometriosis extending into the thoracic cage or the lung might induce defect of the tissue and show catamenial symptoms, such as pneumothorax or hemothorax. These events usually occur 48 to 72 hours after menstruation. A 37-year-old woman with ten year history of recurrent catamenial pneumothorax was scheduled for removal of ovarian cyst. Since intermittent positive pressure ventilation or pneumoperitoneum might induce pneumothorax, we selected epidural anesthesia for laparotomy. Epidural cannulations were performed at Th 9/10 and L 4/5 interspaces. After administration of 2% mepivacaine (400 mg) and fentanyl (0.1 mg), the block extended from Th 6 to S 5. The surgery was done without any complication. In this case epidural anesthesia for laparotomy was useful for the patient with catamenial pneumothorax.  相似文献   
53.
Although excitotoxic and oxidative stress play important roles in spinal neuron death, the exact mechanisms are not fully understood. We examined cell damage of primary culture of 11-day-old rat spinal cord by addition of glutamate, nitric oxide (NO) or peroxynitrite (PN) with detection of caspase-3, terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end labeling (TUNEL) or 72kDa heat shock protein (HSP72). With addition of glutamate, NOC18 (a slow NO releaser) or PN, immu-noreactivity for caspase-3 became stronger in the cytoplasm of large motor neurons in the ventral horn at 6 to 24h. TUNEL positive nuclei were found in spinal large motor neurons from 24 h, and the positive cell proportion greatly increased at 48 h in contrast to the vehicle. On the other hand, the immunoreactivity of HSP72 in the ventral horn was already positive at 0 h, and gradually decreased in the course of time with glutamate, NOC18 or PN than vehicle treatment. In the dorsal horn, the proportion of caspase-3 positive small neurons greatly increased at 6 to 48 h after addition of glutamate. The present results suggest that both excitotoxic and oxidative stress play important role in the apoptotic pathway in cultured rat spinal neurons.  相似文献   
54.
Preoperative therapy effects, resected margin and local radicality were investigated in 40 cases of soft tissue sarcoma in which preoperative therapy (mainly radiation therapy) had been given. The results indicated that there was no effect upon prognosis due to postponement of surgery in order to perform preoperative treatment. In cases in which radiation therapy was used for preoperative treatment, even when a surgical margin resulted with in a tumor, no recurrence was found. However, histologically there was concern that some portion of the living tumor cell in marginal area of the tumor might have remained. Thus, at the present stage in cases having undergone initial treatment, radiation limited to the specific area of the resected margin causing non-curative margin should be given. If combined with preoperative radiation therapy, surgical intervention involving "wide margin" can be considered radical. On the other hand, cases having undergone surgery before and receiving preoperative therapy that show good response nevertheless show numerous recurrences. These recurrences, however, invariably occur outside of the irradiated area, and may be attributed to the fact that tumor cell dissemination from the earlier surgery was not within the radiation field. Hence, it was considered that the area for radiation in the case of a recurrence should extend well beyond the scar area.  相似文献   
55.
Familial occurrence of differentiated, nonmedullary thyroid carcinoma in 23 patients from 11 families is reported. Five patients were male and 18 were female. The familial relationship of patients was parent and child in 12 cases from 6 families, and siblings in 11 cases from 5 families. Carcinoma of other organs was noted in other members in 8 families. Histological examination revealed 18 papillary, 2 follicular, and 2 anaplastic carcinomas (the 2 anaplastic carcinomas were considered to be transformed from preexisting differentiated carcinoma). In 1 case, the histological type was unknown. The average diameter of the primary lesion was 29.9 mm. Cervical lymph node metastasis was found in 77.8% and local recurrence in 28.6% of the patients. Solid and invasive growth was dominant. On HLA typing, phenotypes of B7 and DR1 were significantly redominant in familial patients compared with nonfamilial patients and normal Japanese. Moreover, the haplotype of B7-Cw7-DR1 was observed in 5 of 13 patients tested. It is suggested from these observations that some types of differentiated, nonmedullary thyroid carcinoma may show familial occurrence and that they may have common factors with regard to the genetic and immunologic basis of the disease.
Resumen Se informa la ocurrencia familiar de carcinoma bien diferenciado, no medular, de tiroides en 23 pacientes provenientes de 11 familias, 5 hombres y 18 mujeres. La relación familiar fue padre e hijo en 12 casos de 6 familias, y hermanos en 11 casos de 5 familias. Se observé la presencia de carcinoma de otros órganos en otros miembros de 8 familias. El examen histopatológico reveló 18 carcinomas papilares, 2 foliculares, y 2 anaplásicos (los 2 fueron considerados como transformación de carcinomas diferenciados preexistentes). En un caso no fue conocido el tipo histológico. El diámetro promedio de la lesión primaria fue 29.9 mm. Se hallaron metástasis en ganglios cervicales en 77.8% de los pacientes y recurrencia local en 28.6%. El crecimiento sólido e invasivo apareció como característica dominante. En la tipificación HLA aparecieron como significativamente predominantes los fenotipos de B7 y DR1 en pacientes familiares en comparación con pacientes no familiares y japoneses normales. Por otra parte, el halotipo de B7-CW7-DR1 fue observado en 5 de 13 pacientes investigados.Como resultado de estas observationes se sugiere que algunos tipos de carcinomas diferenciados, no medulares, pueden demostrar ocurrencia familiar y que pueden poseer factores comunes relacionados con las bases genéticas e inmunológicas de la enfermedad.

Résumé On a étudié les caratéristiques du cancer de la thyroïde, dans sa variété différenciée non médullaire, survenu chez 23 patients provenant de 11 familles. Cinq patients étaient des hommes, 18 des femmes. La relation familiale était parent/enfant dans 12 cas provenant de 6 familles, et frère/soeur dans 11 cas provenant de 5 familles. Des membres de 8 autres familles présentaient un cancer d'un autre organe. Il y avait 18 cancers papillaires, 2 cancers folliculaires, et 2 cancers anaplasiques (on a considéré que les 2 cancers anaplasiques étaient des transformations à partir de cancers différenciés préexistants). Dans un cas, le type histologique était inconnu. Le diamètre moyen de la lésion primitive était de 29.9 mm. On a retrouvé des métastases ganglionnaires cervicales chez 77.8% des patients et une récidive locale chez 28.6%. Les tumeurs étaient principalement solides et invasives. Par rapport aux cancéreux non familiaux et à la population japonaise normale, il y avait plus de phénotypes B7 et DR1 au système HLA. L'haplotype B7-CW7-DR1 était observé chez 5 des 13 patients testés.On suggère que certains types de cancer différenciés, non médullaires, ayant des facteurs communs génétiques et immunologiques, peuvent survenir dans une même famille.


Presented at the International Association of Endocrine Surgeons in Sydney, Australia, September, 1987.  相似文献   
56.
"Trichohyalin" is a 220-kD protein found in trichohyalin granules that are present as major differentiation products in the medulla and inner root sheath cells of human hair follicles. It was unclear whether this protein served as an intermediate filament precursor in the inner root sheath or as an intermediate-filament-associated (matrix) protein. We have produced a panel of monoclonal antibodies (AE15-17) to this protein and used them to trace its fate during inner root sheath differentiation. These studies have allowed us to define three immunologically distinct forms of this trichohyalin protein. They are 1) the AE15-positive form, which is found throughout all trichohyalin granules; 2) the AE16-positive form, which is localized as discrete punctae on the surface of trichohyalin granules; and 3) the AE17-positive, intermediate-filament-bound form, which associates with the inner root sheath filaments with a regular, 400-nm periodicity. From these results we suggest that the 220-kD trichohyalin protein is an intermediate-filament-associated protein that may play a role in the lateral aggregation, precise alignment, and stabilization of inner root sheath filament bundles.  相似文献   
57.
Mutations in the ERBB2kinase domain have been reported in non-small cell lung cancer (NSCLC). Here, we describe a detailed search for ERBB2 gene mutations in tumors derived from NSCLC patients. Tumor specimens from 223 patients who underwent resection for NSCLC were examined for the presence of mutations in exons 19 and 20 of the ERBB2gene. Correlations were then made between the expression of these mutations and the clinical characteristics of the patients from which they were derived as well as the tumor's pathological features. ERBB2mutations were observed in four of the above tumors (1.8%), all of which were adenocarcinomas. All ERBB2mutations were in-frame insertions that occurred in exon 20. The patients from whom these tumors were derived were nonsmokers. Three of the tumors were of the papillary subtype, and one was a mixed subtype that consisted of acinar, papillary, and solid components. None of the tumors had a bronchio-alveolar component nor did they have epidermal growth factor receptoror K-rascodon 12 mutations. In conclusion, patients with these tumors tended to be nonsmokers who had clinical features similar to those of lung cancer patients whose tumors expressed epidermal growth factor receptormutations, although their tumors showed slightly different pathological features.  相似文献   
58.
59.
Congenital cystic adenomatoid malformation (CCAM) is a congenital pulmonary anomaly, which may lead to fetal hydrops, pulmonary hypoplasia, and fetal or neonatal death. Recently, diagnosis and surgery for fetus have been improved. We experienced a case of CCAM, classified in Stocker class I, with a single cyst of about 5 cm in diameter. A 32 year-old pregnant woman had a fetus diagnosed as CCAM at 25 th gestational week. The thoraco-amniotic shunt placement using a modified double pig tail catheter was performed at 27 th gestational week under general anesthesia with 1% isoflurane in oxygen 2 l x min(-1) and nitrous oxide 4 l x min(-1), and 100 microg of fentanyl. Fetal movement was suppressed during surgery. This fetal therapy was effective and the cyst disappeared after surgery. The baby was delivered with caesarian section under spinal anesthesia with 0.5% bupivacaine 2.5 ml. On the next day, right lung lobectomy was accomplished under general anesthesia with fentanyl 0.2 mg and pancuronium 6.0 mg. Anesthesia with isoflurane, nitrous oxide, and fentanyl was useful for the fetal surgery of thoraco-amniotic shunt placement. Consequently, caesarian section and lung lobectomy were completed successfully.  相似文献   
60.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号