全文获取类型
收费全文 | 34676篇 |
免费 | 1570篇 |
国内免费 | 196篇 |
专业分类
耳鼻咽喉 | 408篇 |
儿科学 | 589篇 |
妇产科学 | 610篇 |
基础医学 | 4230篇 |
口腔科学 | 808篇 |
临床医学 | 2391篇 |
内科学 | 9625篇 |
皮肤病学 | 589篇 |
神经病学 | 2515篇 |
特种医学 | 1007篇 |
外科学 | 5802篇 |
综合类 | 161篇 |
一般理论 | 1篇 |
预防医学 | 1033篇 |
眼科学 | 488篇 |
药学 | 2154篇 |
中国医学 | 91篇 |
肿瘤学 | 3940篇 |
出版年
2023年 | 179篇 |
2022年 | 327篇 |
2021年 | 605篇 |
2020年 | 336篇 |
2019年 | 426篇 |
2018年 | 626篇 |
2017年 | 453篇 |
2016年 | 564篇 |
2015年 | 598篇 |
2014年 | 841篇 |
2013年 | 1003篇 |
2012年 | 1629篇 |
2011年 | 1779篇 |
2010年 | 993篇 |
2009年 | 859篇 |
2008年 | 1738篇 |
2007年 | 1859篇 |
2006年 | 1748篇 |
2005年 | 1760篇 |
2004年 | 1771篇 |
2003年 | 1781篇 |
2002年 | 1772篇 |
2001年 | 1017篇 |
2000年 | 1021篇 |
1999年 | 946篇 |
1998年 | 468篇 |
1997年 | 349篇 |
1996年 | 349篇 |
1995年 | 322篇 |
1994年 | 291篇 |
1993年 | 233篇 |
1992年 | 691篇 |
1991年 | 721篇 |
1990年 | 593篇 |
1989年 | 603篇 |
1988年 | 579篇 |
1987年 | 535篇 |
1986年 | 464篇 |
1985年 | 478篇 |
1984年 | 375篇 |
1983年 | 280篇 |
1982年 | 147篇 |
1981年 | 135篇 |
1979年 | 262篇 |
1978年 | 149篇 |
1977年 | 150篇 |
1974年 | 137篇 |
1972年 | 143篇 |
1969年 | 144篇 |
1967年 | 135篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Y Shiokawa M Nobunaga T Saito T Sakita T Miwa K Nakamura A Gunji K Aoki 《Ryūmachi》1991,31(5):554-571
52.
Chihaya Maesawa Gen Tamura Yasushi Suzuki Kaoru Ishida Kazuyoshi Saito Ryoichi Satodate 《Cancer science》1992,83(12):1253-1256
For the rapid and sensitive detection of p53 gene mutations in esophageal endoscopic biopsy specimens, we combined cell sorting with the polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) analysis. Mutations in exons 5–8 of the p53 gene were investigated by FCR-SSCF analysis using 103 sorted nuclei obtained from each endoscopic biopsy specimen of 16 patients with esophageal cancer. DNAs extracted from their respective surgical specimens were investigated by a conventional method of PCR-SSCP analysis. Mutations in the biopsy specimens were detected in 6 of the 12 aneuploid tumors but in none of the 4 diploid tumors. After tumor cell enrichment by cell sorting, one mutation in exon 8 became apparent, which could not be detected from the surgical specimen by a conventional method of PCR-SSCP analysis. This method should improve the sensitivity of detecting p53 gene mutations, and provides additional information concerning the DNA ploidy pattern in the tumors. 相似文献
53.
Susumu Ishikawa M.D. Akio Ohtaki M.D. Toru Takahashi M.D. Tetsuya Koyano M.D. Yutaka Hasegawa M.D. Satoshi Ohki M.D. Yukitaka Isa M.D. Kennichi Arai M.D. Fumio Kunimoto M.D. Yasuo Morishita M.D. 《Journal of cardiac surgery》1997,12(3):176-179
A bstract The purpose of this study was to assess the efficacy of nasal mask bi-level positive airway pressure (BiPAP) support in managing respiratory failure following cardiovascular surgery. A total of 20 patients requiring postoperative prolonged respiratory support of 72 hours or longer were studied. BiPAP support was used for eight patients (BiPAP group); the other 12 patients were managed using ordinary oxygen mask treatment (control group). The mean age of the BiPAP group and control group was 65 and 58 years of age, respectively. The mean period of postoperative endotracheal intubation of the BiPAP group and control group was 12 ± 5 days and 7 ± 1 days, respectively. Reintubation was necessary in two patients of the control group. The BiPAP group patients required no reintubation. BiPAP support was discontinued within 48 hours in 6 out of 8 patients. The respiratory rates of control group increased (p < 0.1) 24 hours after extubation, however, the respiratory rates of the BiPAP group remained unchanged. The values of the respiratory index of the BiPAP group improved significantly (p < 0.01) after BiPAP management (from 1.5 ± 0.2 to 0.9 ± 0.2). The values of the control group, however, remained unchanged. A-aDO2 and Qs/Qt decreased (p < 0.1) in the BiPAP group. There were no significant differences in central venous pressure or circulatory status between the two groups. In conclusion, BiPAP support is a noninvasive management technique for postoperative respiratory failure and may also prevent prolonged endotracheal intubation. 相似文献
54.
F. Ide K. Mishima H. Yamada I. Saito A. Tanaka K. Kusama 《Journal of oral pathology & medicine》2007,36(8):505-510
BACKGROUND: Nevic corpuscle (NC), a stacked lamellar structure reminiscent of Meissner corpuscle, is frequently observed in dermal melanocytic nevi. Although the heading 'neurotized' is classically used for these nevi, the exact neural nature of NC has been a topic of considerable debate. Neurotized nevi have received little attention in the dental literature, and there was no information on NC in oral melanocytic nevi. METHODS: Six cases of oral intramucosal nevi with a significant number of NC (two completely and four partially neurotized nevi) were examined immunohistochemically and ultrastructurally. RESULTS: NC was composed of closely piled laminar cells devoid of visible melanin. NC and associated spindle nevus cells were immunopositive for S-100 protein but negative for HMB-45, myelin basic protein and epithelial membrane antigen. Within NC, no reactivity for neurofilament protein, protein gene product 9.5 or peripherin was evident. Numerous CD34-positive dendritic cells were located between nevus cells and often encircled NC. Ultrastructurally, NC consisted of concentrically layered elongated cells with a slender lamellated cytoplasm rich in thin filaments and pinocytotic vesicles. Their cytoplasmic processes were focally covered by external basal lamina and continuous to spindle nevus cells. Occasional NC cells contained a few melanosomes. There was no interposed axon in NC. CONCLUSIONS: Despite the close resemblance to Meissner corpuscle, NC showed no axonal supply. NC cells lacked terminal Schwannian differentiation and appeared to be modified melanocytes with some perineurial ultrastructural characteristics. The presence of CD34-positive cells, presumably corresponding to endoneurial fibroblasts, further supports an organizational relationship of NC and peripheral nerve sheath elements. 相似文献
55.
M Ishii O Abe H Okura N Okazaki T Kawai Y Saito N Sawabu Y Takamizawa T Takeuchi H Niitani 《Gan to kagaku ryoho. Cancer & chemotherapy》1987,14(8):2548-2555
The CA-50 enzyme immunoassay kit (EIA kit) that has been developed with the use of C-50 monoclonal antibody prepared by L. Lindholm et al. was evaluated for diagnosis of human cancer. The levels of CA-50 in the sera were determined using this kit supplied from Mitsui Pharmaceuticals, Inc. Co. in 759 healthy donors, 728 patients with benign disease and 1,263 untreated patients with cancer. A CA-50 concentration of 40 U/ml of serum was used as the cut-off value. Patients with pancreatic cancer and patients with bile duct cancer had high positive incidence of 75% and 68%, respectively, compared with a low positive incidence of under 40% in patients with other cancers. On the other hand, positive rates in patients with benign disease were as low as 13%. Comparison of the serum levels of CA-50 with CA19-9 in the same samples did not exhibit complete positive correlation in patients with pancreatic cancer, patients with bile duct cancer and patients with liver cancer. These findings indicated that C-50 antibody reacted with two epitopes of CA19-9 and sialosyllactotetraose. From the above results, the usefulness of CA-50 as a tumor marker for pancreatic cancer and bile duct cancer was recognized with this EIA kit. 相似文献
56.
Katsuyoshi Hori Maroh Suzuki Shigeru Tanda Sachiko Saito Mika Shinozaki Qiu-Hang Zhang 《Cancer science》1991,82(11):1309-1316
To elucidate the significance of angiotensin II (AID-induced hypertension chemotherapy, changes of tissue blood flow both in normal subcutis and in tumors (AH109A, LY80) were measured with the hydrogen gas clearance method. A newly-developed anesthetic machine was used to keep the animals' condition constant. Tissue blood flow in normal subcutis and tumors always fluctuated with time under normotension. The nature and the rate of fluctuation in tumor Wood flow were almost identical in two different types of tumors. However, the fluctuation of blood flow in tumor and that in normal subcutis were almost always inversely related when blood flows in these different tissues were measured simultaneously, i.e., when tissue blood flow in normal subcutis decreased, tumor blood flow increased, and vice versa. The findings supported the idea that the connection mode between the tumor vascular bed and normal vascular bed is a parallel circuit. Vascular resistance in the normal vascular bed under All-induced hypertension seemed to be greater than that under normotension, because the All-increased tumor blood flow always exceeded the maximum tumor blood flow under normotension. Due to the fluctuations of tumor blood flow, no-flow or low-flow areas, resistant to delivery of anti-cancer drugs, moved sporadically within the tumor under the normotensive condition. However, good conditions for drug delivery to tumor tissue were induced by All-induced hypertension. 相似文献
57.
Antitumor activity of orally administered streptococcal preparation, OK-432 on murine solid tumors and its absorption from the gut 总被引:1,自引:0,他引:1
Y Nio T Shiraishi T Tsuchitani T Tobe Y Sugawara M Saito H Kamiyama 《In vivo (Athens, Greece)》1989,3(5):307-313
OK-432 is an immunopotentiator which is normally administered by injection. In the present study, the antitumor activity of orally administered OK-432 on various solid tumors and the absorption of OK-432 from the gut were studied. Orally administered OK-432 inhibited the growth of Meth-A and BAMC-1 fibrosarcomas which had been subcutaneously transplanted in BALB/c mice. Autoradiograms of mice which had been administered 14C-labelled OK-432 orally demonstrated the absorption of OK-432 from the gut, and about 6% of orally administered OK-432 was absorbed 24 hrs after its administration. Moreover, an immunofluorescent study using an anti-OK-432 antibody revealed specific fluorescence in the mesenteric lymph node of mice which had been orally administered with OK-432. These results suggest that oral administration of OK-432 may be a beneficial immunotherapy. 相似文献
58.
The pharmacokinetic properties of lenampicillin (KBT-1585), a new ampicillin ester, were investigated in 41 healthy volunteers. The maximum concentration of ampicillin in serum after oral administration of 400 mg of lenampicillin was 6.5 micrograms/ml at 0.70 h, and that after a equimolar dosage of ampicillin was 2.9 micrograms/ml at 0.87 h. 相似文献
59.
T. Saito 《European journal of pediatrics》1987,146(3):261-265
The presenting symptoms of Wilson disease and its natural history as related to age are described based on 283 cases collected in Japan. The disease presented with a variety of signs and symptoms; the most frequent were in order of frequency jaundice, dysarthria, clumsiness, tremor, drooling, gait disturbance, malaise and arthralgia. The mean age at onset of the disease was 12.0 years. Hepatic and osteoarthral symptoms developed early and neurological symptoms late. Fifty-eight cases develolped neurological symptoms only, 28 cases had hepatic symptoms only, and in 26 cases hepatic mortality rate was observed in hepatic, hepato-haematological and hepato-renal cases mainly due to acute hepatic failure resulting in death only a few weeks after onset. Cases having only neurological symptoms showed a more favourable prognosis with a longer survival. 相似文献
60.
Differential expression of the beta I- and beta II-PKC subspecies in the postnatal developing rat brain; an immunocytochemical study. 总被引:1,自引:0,他引:1
Differential expression of protein kinase C subspecies, beta I- and beta II-PKC, derived from a single gene by alternative splicing was evidenced in the postnatal developing rat brain. Immunoblot analysis of the PKC subspecies in the whole developing brain showed that beta I-PKC was present at birth and then gradually increased, while beta II-PKC was not present at birth or on postnatal day 3, then increased rapidly from day 7 to the maximum value seen in the adult brain. Under light microscopy, beta I-PKC immunoreactivities seen at birth were the most intense in the brainstem and intense in the diagonal bundle and globus pallidus. beta I-PKC immunoreactivities in these neurons weakened from day 7 and disappeared in the adult brain, while in the cerebral cortex, triangular septal nucleus and pontine nucleus beta I-PKC immunoreactivities were week at birth and then gradually increased. beta II-PKC immunoreactivities were first visible in neurons on day 7 and increased progressively. beta I- and beta II-PKCs were not co-localized in a neuron, as far as examined. The immunoreactivities of beta I-PKC at birth were localized in growth cone-like structures as well as in the dendrites and perikarya. Similarly, alpha-PKC was also present at birth in the growth cone-like structure. Immunoblot analysis revealed that beta I-PKC was present at birth in the growth cone-rich fraction from the hindbrain but not in that from the forebrain, while alpha-PKC was found in the growth cone-rich fraction from both the forebrain and the hindbrain. beta II- and gamma-PKC were not detected in the growth cone-rich fraction from either forebrain or hindbrain. These findings suggest that beta I- and beta II-PKC play a role in different stages of development and in different neurons; both beta-subspecies may be involved in postnatal developing neuronal functions while only beta I-PKC plays functional roles in the growth cone, in the prenatal developmental stage. 相似文献