全文获取类型
收费全文 | 7024篇 |
免费 | 316篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 132篇 |
妇产科学 | 65篇 |
基础医学 | 783篇 |
口腔科学 | 161篇 |
临床医学 | 433篇 |
内科学 | 1483篇 |
皮肤病学 | 203篇 |
神经病学 | 796篇 |
特种医学 | 419篇 |
外科学 | 1173篇 |
综合类 | 31篇 |
预防医学 | 254篇 |
眼科学 | 201篇 |
药学 | 654篇 |
中国医学 | 9篇 |
肿瘤学 | 527篇 |
出版年
2022年 | 77篇 |
2021年 | 110篇 |
2020年 | 66篇 |
2019年 | 86篇 |
2018年 | 89篇 |
2017年 | 90篇 |
2016年 | 99篇 |
2015年 | 126篇 |
2014年 | 156篇 |
2013年 | 191篇 |
2012年 | 286篇 |
2011年 | 353篇 |
2010年 | 203篇 |
2009年 | 168篇 |
2008年 | 310篇 |
2007年 | 300篇 |
2006年 | 316篇 |
2005年 | 303篇 |
2004年 | 327篇 |
2003年 | 355篇 |
2002年 | 330篇 |
2001年 | 249篇 |
2000年 | 280篇 |
1999年 | 242篇 |
1998年 | 106篇 |
1997年 | 89篇 |
1996年 | 59篇 |
1995年 | 60篇 |
1994年 | 55篇 |
1993年 | 61篇 |
1992年 | 182篇 |
1991年 | 170篇 |
1990年 | 157篇 |
1989年 | 144篇 |
1988年 | 135篇 |
1987年 | 118篇 |
1986年 | 107篇 |
1985年 | 117篇 |
1984年 | 83篇 |
1983年 | 58篇 |
1982年 | 33篇 |
1979年 | 58篇 |
1978年 | 34篇 |
1977年 | 37篇 |
1975年 | 31篇 |
1974年 | 41篇 |
1973年 | 31篇 |
1971年 | 29篇 |
1968年 | 29篇 |
1967年 | 28篇 |
排序方式: 共有7376条查询结果,搜索用时 17 毫秒
11.
Fuyumi Yamamoto Hiroshi Kasai Tadayoshi Bessho Myung-Hee Chung Hideo Inoue Eiko Ohtsuka Tomokatsu Hori Susumu Nishimura 《Cancer science》1992,83(4):351-357
Here we report the finding of enzymatic activity that specifically cleaves DNA containing 8-hydroxyguanine (oh8 Gua) residues in various mammalian cells. To detect this activity, we used a synthetic double-stranded DNA containing a single oh8 Gua at a defined position as the substrate, and analyzed the products of enzymatic digestion by polyacrylamide gel electrophoresis. Two cleavage sites near the oh8 Gua residue were detected with partially purified fractions from cow brain and rat liver, and also with preparations from all mammalian tissues examined. These results suggest that enzymatic activity for the removal of oh8 Gua from DNA is widely distributed in mammalian cells. 相似文献
12.
Jun Anabuki Masatoshi Hori Hiroshi Ozaki Iwao Kato Hideaki Karaki 《European journal of pharmacology》1990,190(3):373-379
The mechanism of the vasodilator effect of pinacidil was examined. Pinacidil (0.1–100 μM) inhibited the increases in cytosolic Ca2+ ([Ca2+]i) and muscle tension due to norepinephrine in rat aorta. In contrast, a Ca2+ channel blocker, verapamil, inhibited the norepinephrine-stimulated [Ca2+]i more strongly than the contraction. Higher concentrations of pinacidil (3–100 μM) inhibited the verapamil-insensitive portion of the contraction and [Ca2+]i. An inhibitor of ATP-sensitive K+ channels, glibenclamide, antagonized the inhibitory effect of low concentrations ( 10 pM) of pinacidol. Pinacidil did not change the contraction induced by Ca2+ in vascular smooth muscle permeabilized with Staphylococcus aureus -toxin. Norepinephrine (in the presence of GTP), 12-deoxyphorbol 13-isobutyrate (in the absence of GTP), and treatment with GTPγS potentiated the contraction of permeabilized smooth muscle induced by the addition of Ca2+. Pinacidil (100 μM) inhibited the potentiation due to GTPγS or noepinephrine but not to phorbol ester. These results suggest that pinacidil has dual effects on vascular smooth muscle contraction. At lower concentrations (>0.1 μM), it decreases [Ca2+]i, possibly by activating ATP-sensitive K+ channels. At higher concentrations (> 3 μM), it may additionally inhibit the receptor-mediated, GTP-binding protein-coupled phosphatidyl inositol turnover. 相似文献
13.
Kazutoshi Hori Kunio Uematsu Hitoshi Yasoshima Aklhiko Yamada Kazunari Sakurai Munehiko Ohya 《Pathology international》1997,47(9):592-599
Testicular seminoma with elevated serum human chorionic gonadotropin level (hCG-positive seminoma) is regarded as more malignant than marker-negative seminoma, although Its prognosis is still unclear. To clarify the malignant potential of seminoma with hCG production, the serum levels of the beta subunit of hCG (β-hCG) and lactic acid dehydrogenase (LDH) were examined in 35 and 40 patients, respectively, and the Immunohistochemical expression of β-hCG examined in 45 tumors. The elevation of the LDH serum level correlated to the Invasive status, metestatic status and poor outcome, while that of the serum β-hCG level correlated only to the metastatic status. Immunohistochemical expression of β-hCG was observed in syncytiotrophoblastic giant cells in 11 tumors and a few mononuclear seminoma cells In 36 tumors. Expression was not associated with the malignancy potential, except where the expression In mononuclear cells Inversely correlated to the invasive status. These results suggest that most seminomas produce a slight amount of hCG; that an elevated hCG serum level Indicates the pressnce of metastatic tumors and mainly reflects an increase in tumor volume but not in cellular malignancy potential; and that the LDH serum level, rather than hCG, is more useful as a prognostic indicator for patients with seminoma. 相似文献
14.
Y Noguchi H Washida H Watanabe S Sasaki M Kato T Hori 《Hinyokika kiyo. Acta urologica Japonica》1990,36(1):59-61
Acute focal bacterial nephritis refers to a renal mass caused by acute focal infection. We report a case of acute focal bacterial nephritis, herein. The case was in a 56-year-old woman, who was hospitalized with the chief complaint of left flank pain, chills and fever. Intravenous pyelography suggested the presence of a mass in the upper pole of the left kidney. Ultrasonography showed a hypoechoic mass, CT scan revealed a round, low density mass. Antibiotic therapy resulted in resolution of symptoms, and a follow-up CT scan and ultrasonography showed complete resolution of the renal mass. 相似文献
15.
Although propylene oxide, which is similar in chemical structure to ethylene oxide, is expected to produce neuropathy, there is no convincing evidence of the degeneration of the peripheral nervous system. To determine the exposure concentration of propylene oxide necessary to produce neuropathy in male Wistar rats, we subjected them to repeated exposures of propylene oxide at concentrations of 500, 750, 1000, 1500 and 2000 ppm. The test rats were subjected to a single 6 hour exposure of propylene oxide at a concentration of 1500 parts per million 5 times a week for 3 weeks. They developed a significant decrease in body weight, abnormal posture of the hindlegs and axonal degeneration of myelinated fibers in the peroneal and sural nerves, the nerves to the soleus muscle, and in the fasciculus gracilis of the spinal cord. Therefore, it was concluded that propylene oxide induces neuropathy in rats characterized by axonal degeneration, similar to that produced by ethylene oxide, and that the exposure to the higher concentration of propylene oxide is more necessary to produce neuropathy than in the case of ethylene oxide neuropathy in rats. 相似文献
16.
Y Aoyama K Ishida K Hori A Sakaguchi M Kudoh Y Yoshida 《Biochemical pharmacology》1992,44(9):1701-1705
AFK-108 (1-[2-(2,4-dichlorophenyl)-2-((2E)-3,7-dimethylocta-2,6- dienyloxy)ethyl]-1H-imidazole) is a new imidazole derivative characterized by a geranyl substituent showing strong antifungal activity. Azole antifungal agents are known to be potent inhibitors of lanosterol 14 alpha-demethylase (P450(14)DM) of fungi. The role of the geranyl group of AFK-108 on interaction of AFK-108 with the target was studied by using Saccharomyces cerevisiae P450(14)DM as the model enzyme. AFK-108 and some of its derivatives bound to oxidized P450(14)DM with one-to-one stoichiometry and inhibited the demethylase activity. AFK-108 derivatives having the longer farnesyl or the shorter prenyl group showed lower affinity than AFK-108 for the enzyme. AFK-108 caused 100% inhibition at the equivalent concentration to P450(14)DM in the reaction mixture (0.07 microM), while the farnesyl derivative inhibited the activity by 60% at the same concentration. AFK-108 interfered with the binding of CO to the ferrous P450(14)DM. However, the interfering effect of the prenyl derivative was lower than that of AFK-108. Another AFK-108 derivative having the saturated 3,7-dimethyloctyl group was also a weaker inhibitor than AFK-108. These experiments suggest that the geranyl group of AFK-108 interacts with the substrate binding site of P450(14)DM that recognises the side chain of the substrate. AFK-108 is the first example of an azole derivative interacting with the side chain recognising region of the substrate binding site of P450(14)DM. 相似文献
17.
Nobuaki Miyazono M.D. Hiroki Inoue Akira Hori Ichiroh Kanetsuki Jurio Shimada Masayuki Nakajo 《Cardiovascular and interventional radiology》1994,17(1):36-37
We present a 44-year-old woman in whom a bronchialto-coronary artery communication via the conus branch was discovered after distal bronchial artery embolization with gelatin sponge for hemoptysis. If this bronchial-to-coronary artery anastomosis, not visible prior to embolization, had been inadvertently embolized, the patient could have developed a myocardial infarction. To reduce the likelihood of a serious complication, the possibility of this anastomosis should be kept in mind and angiography should be repeated before attempting proximal bronchial artery embolization. 相似文献
18.
We investigated populations of the infiltrating cells in Bowen's disease (BD) and squamous cell carcinoma (SCC), both of which arose in the same patient, using the Avidin-Biotin-peroxidase complex method with eight monoclonal antibodies. T lymphocytes were most predominant among infiltrating cells; NK cells, B cells, and monocytes were rarely seen in either BD or SCC. Analysis of subsets of the infiltrating T lymphocytes revealed that the number of suppressor/cytotoxic (s/c) T cells was twice that of helper/inducer (h/i) T cells in BD, while the number of s/c T cells was lower than that of h/i T cells in SCC. The immunohistochemical results in the present case differed from those of predominant infiltration of h/i T cells and of s/c T cells in three other reports of BD and SCC. These results suggest that the population of the cellular infiltrates may be modulated by the nature of tumors and by the immuno-competent state of the hosts. 相似文献
19.
S Maeshima H Nakamura M Nishikawa T Murakami T Mitani T Marukawa S Hori T Kozuka M Irimoto 《Clinical imaging》1992,16(2):121-124
Tumors in the area of the adrenal were detected by chance in two patients who underwent a regular physical check-up. On arteriography the tumors were found to be fed by the adrenal artery. The diagnosis was retroperitoneal schwannoma, but in both patients it was difficult to differentiate the schwannoma from an adrenal tumor preoperatively. 相似文献
20.
A Sakai T Hori T Okuda T Matsubara K Saitoh M Yajima S Nishio 《Japanese journal of pharmacology》1989,51(3):450-454
TRK-100 (0.03, 0.1 and 0.3 mg/kg, p.o.), a chemically stable analogue of prostacyclin, dose-dependently prevented blood coagulation and glomerular fibrin deposition which were enhanced by 4 hr infusion of endotoxin (100 mg/kg) in rats. In addition, TRK-100 suppressed the generation of endotoxin-induced tissue thromboplastin like activity in cultured human endothelial cells. 相似文献