全文获取类型
收费全文 | 3201篇 |
免费 | 156篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 93篇 |
妇产科学 | 21篇 |
基础医学 | 351篇 |
口腔科学 | 87篇 |
临床医学 | 219篇 |
内科学 | 1039篇 |
皮肤病学 | 17篇 |
神经病学 | 257篇 |
特种医学 | 80篇 |
外科学 | 593篇 |
综合类 | 4篇 |
预防医学 | 67篇 |
眼科学 | 26篇 |
药学 | 180篇 |
中国医学 | 9篇 |
肿瘤学 | 305篇 |
出版年
2023年 | 33篇 |
2022年 | 74篇 |
2021年 | 129篇 |
2020年 | 70篇 |
2019年 | 72篇 |
2018年 | 90篇 |
2017年 | 74篇 |
2016年 | 83篇 |
2015年 | 64篇 |
2014年 | 107篇 |
2013年 | 122篇 |
2012年 | 178篇 |
2011年 | 212篇 |
2010年 | 96篇 |
2009年 | 83篇 |
2008年 | 154篇 |
2007年 | 167篇 |
2006年 | 139篇 |
2005年 | 165篇 |
2004年 | 160篇 |
2003年 | 149篇 |
2002年 | 183篇 |
2001年 | 59篇 |
2000年 | 54篇 |
1999年 | 49篇 |
1998年 | 56篇 |
1997年 | 40篇 |
1996年 | 28篇 |
1995年 | 27篇 |
1994年 | 20篇 |
1993年 | 22篇 |
1992年 | 40篇 |
1991年 | 38篇 |
1990年 | 31篇 |
1989年 | 39篇 |
1988年 | 28篇 |
1987年 | 28篇 |
1986年 | 27篇 |
1985年 | 18篇 |
1984年 | 17篇 |
1983年 | 18篇 |
1982年 | 10篇 |
1981年 | 13篇 |
1980年 | 16篇 |
1979年 | 9篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 8篇 |
1974年 | 11篇 |
1972年 | 9篇 |
排序方式: 共有3380条查询结果,搜索用时 31 毫秒
11.
Yasuyuki Kato Satoru Miyamoto Hirokazu Minamimura Takumi Ishikawa Kensuke Ohue Yoshihiro Shimizu 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2005,53(1):46-48
In embryology, a persistent connection of the left superior vena cava to the left atrium rarely coexists with a coronary sinus.
We herein report an unusual case of persistent left superior vena cava terminating in a left atrium with normal coronary sinus,
which was revealed at the time of permanent pacemaker implantation after a second operation for recurrent left atrioventricular
valve regurgitation. Because this anomaly had gone undiagnosed at the first operation, we were unable to diagnose it prior
to the second operation, because the preoperative coronary angiogram clearly demonstrated a coronary sinus that was not dilated.
We would have repaired the anomaly using a patch or other procedure had it been diagnosed before the second operation in order
to prevent cyanosis or brain complications secondary to right-to-left shunting. One should always be on guard for this rare
condition. 相似文献
12.
Toshihiro Kawamura Hiroshi Motoyama Atsushi Yanaihara Takeshi Yorimitsu Akane Arichi Yasuhiro Karasawa Kahori Suga Kaoru Miya Seika Ishikawa Shiho Mizushima Makiko Kawamura 《Reproductive Medicine and Biology》2007,6(1):53-57
Aim: To compare the clinical outcomes of cryopreserved-thawed embryo transfer among patients with a normal menstrual cycle who had natural or hormone-replacement cycles.
Methods: From January 2004 to June 2006, cryopreserved embryos following conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) were thawed and transferred in a total of 720 natural cycles and 136 hormone-replacement cycles.
Results: Cryopreserved-thawed embryo transfer in patients who had a natural or hormone-replacement cycle resulted in clinical pregnancy in 43.1% and 40.4%, respectively; a rate of miscarriage of 14.5% and 23.6%, respectively; and a rate of ongoing pregnancy and delivery of 36.5% and 30.9%, respectively. None of these differences were statistically significant.
Conclusions: Patients with a normal menstrual cycle who have natural or hormone-replacement cycles can be expected to have comparable clinical outcomes with cryopreserved-thawed embryo transfer. (Reprod Med Biol 2007; 6 : 53–57) 相似文献
Methods: From January 2004 to June 2006, cryopreserved embryos following conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) were thawed and transferred in a total of 720 natural cycles and 136 hormone-replacement cycles.
Results: Cryopreserved-thawed embryo transfer in patients who had a natural or hormone-replacement cycle resulted in clinical pregnancy in 43.1% and 40.4%, respectively; a rate of miscarriage of 14.5% and 23.6%, respectively; and a rate of ongoing pregnancy and delivery of 36.5% and 30.9%, respectively. None of these differences were statistically significant.
Conclusions: Patients with a normal menstrual cycle who have natural or hormone-replacement cycles can be expected to have comparable clinical outcomes with cryopreserved-thawed embryo transfer. (Reprod Med Biol 2007; 6 : 53–57) 相似文献
13.
E Ohshima H Takami H Sato S Mohri H Obase I Miki A Ishii S Shirakura A Karasawa K Kubo 《Journal of medicinal chemistry》1992,35(18):3402-3413
A series of 11-[2-(1-benzimidazolyl)ethylidene]-6,11-dihydrodibenz[b,e]oxep in-2- carboxylic acid derivatives and related compounds were synthesized and found to be potent TXA2/PGH2 receptor antagonists. Each compound synthesized was tested for its ability to displace [3H]U-46619 binding from guinea pig platelet TXA2/PGH2 receptors. Structure-activity relationship studies revealed that the following key elements were required for enhanced activities: (1) an (E)-2-(1-benzimidazolyl)ethylidene side chain in the 11-position of the dibenzoxepin ring system and (2) a carboxyl group in the 2-position of the dibenzoxepin ring system. The studies also indicated that the TXA2/PGH2 receptor binding affinities of this series of compounds in guinea pig platelet were poorly correlated with those in human platelet. Introduction of substituent(s) to the benzimidazole moiety was effective and sodium (E)-11-[2-(5,6-dimethyl-1-benzimidazolyl)ethylidene]- 6,11-dihydrodibenz[b,e]oxepin-2-carboxylate monohydrate (57) recorded the highest affinity for human platelet TXA2/PGH2 receptor with a K(i) value of 1.2 +/- 0.14 nM. It demonstrated potent inhibitory effects on U-46619-induced guinea pig platelet aggregation (in vitro and ex vivo) and human platelet aggregation (in vitro). Compound 57, now designated as KW-3635, is a novel, orally active, and specific TXA2/PGH2 receptor antagonist with neither TXA2/PGH2 receptor agonistic nor TXA2 synthase inhibitory effects. It is now under clinical evaluation. 相似文献
14.
Masahiko Kawaguchi Masakazu Kuro Hisatoshi Ohsumi Toshito Nakajima Yoshihiro Kuriyama Jun Karasawa 《Journal of anesthesia》1994,8(1):60-63
We assessed the local cerebral blood flow (LCBF) in 40 patients under fentanyl-diazepam anesthesia. The measurement of LCBF
was made using 50%–70% stable xenon with 20 min of inhalation interval and a shuttle method for computed tomography imaging.
All patients were anesthetized with 5.95±1.76 μg·kg−1 fentanyl and 0.22±0.07 mg·kg−1 diazepam under mechanical ventilation during CBF measurement. The values and distribution of LCBF on non-affected hemisphere
appeared to be unaltered by fentanyldiazepam anesthesia. We also assessed the cerebral carbon dioxide reactivity in 6 patients.
The cerebral carbon dioxide reactivity, expressed as percentage change in LCBF per unit change in arterial carbon dioxide
partial pressure, was 5.39±1.07, and there were no significant differences of reactivity among regions studied. In conclusion,
we showed reference values of LCBF and carbon dioxide reactivity, measured by stable xenon-enhanced computed tomography, in
patients under fentanyl-diazepam anesthesia. Carbon dioxide reactivity was preserved in all regions including gray matter,
white matter, and basal ganglia. 相似文献
15.
Takahiro Narishige Kensuke Egashira M.D. Yutaka Akatsuka Teisuke Takahashi Akira Takeshita 《Cardiovascular and interventional radiology》1993,16(6):343-347
The effects of an intracoronary administration of iomeprol, a new nonionic tri-iodinated water-soluble contrast medium, on
coronary circulation were compared to those of iopamidol and those of nitroglycerin in 6 chronically instrumented conscious
dogs. A pair of 10 MHz piezoelectric crystals and an electromagnetic flow probe were placed on the left circumflex coronary
artery (LCCA) to measure the epicardial coronary diameter (CD) and coronary blood flow (CBF). Polyethylene tubing for drug
administration was inserted into the LCCA proximal to the sonomicrometers. Iomeprol at the dose of 1 ml and 3 ml/min for 1
min significantly increased CD by 0.6±0.1% and 1.4±0.3%, respectively and CBF by 44.5±9% and 70±10%, respectively. Iopamidol
at the same rates also significantly increased CD by 0.8±0.1% and 1.5±0.3% and CBF by 50±11% and 82±14%, respectively. There
was no statistically significant difference between iomeprol-and iopamidol-induced increases in CD and CBF. However, the duration
of the increase in CD was significantly shorter (p<0.05) after iomeprol than after iopamidol. Nitroglycerin (10 μg/kg) significantly increased CD by 4.5±1% and CBF by 105±10%.
The increases in CD and CBF in response to iopamidol and iomeprol were significantly smaller (p<0.01) than to nitroglycerin. We conclude that vasodilating effects of iomeprol and iopamidol on the large epicardial coronary
artery and coronary blood flow are comparable in conscious dogs and significantly lower than after nitroglycerin in the doses
used by us.
This study was supported by a grant from the EI-ZA1 Pharmaceutical Co., Tokyo, Japan. 相似文献
16.
Kazuro Sugi Kouichi Nawata Kazuhiro Ueda Yoshikazu Kaneda Sumihiko Nawata Atsunori Oga Kensuke Esato 《Surgery today》1997,27(7):666-668
We report herein the case of a 70-year-old man in whom a chest wall implantation of adenocarcinoma of the lung at the drainage
tube site was found 4 months after a right lower lobectomy with mediastinal lymph node dissection had been performed for adenocarcinoma
of the right lower lobe. The lesion was successfully treated by tumor extirpation. We believe that tumor seeding to the chest
wall occurred at the time of thoracotomy. To prevent such tumor seeding, the pleural cavity should be washed out routinely
with a massive volume of physiological saline solution prior to closure of the chest wall. 相似文献
17.
T. Tamura M. Matsubara K. Hasegawa K. Ohmori A. Karasawa 《Clinical and experimental allergy》2005,35(1):97-103
BACKGROUND: Olopatadine hydrochloride (olopatadine; Allelock) is one of the second-generation antihistamines that are treated for allergic disorders such as rhinitis, urticaria and eczema dermatitis. Olopatadine has recently been shown to have inhibitory effects on the chronic contact hypersensitivity induced by repeated application of oxazolone in mice. Although topical steroids have widely been prescribed for atopic dermatitis, a relapse often occurs within several days after discontinuation of their prolonged use. OBJECTIVES: We investigated the possible efficacy of olopatadine against the relapse after discontinuation of prolonged use of topical prednisolone in the Balb/c mice with oxazolone-induced chronic contact hypersensitivity. METHODS: Mice with the chronic contact hypersensitivity induced by repeated application of oxazolone were treated with olopatadine as a sequential therapeutic agent. The effects of olopatadine were quantified by measurements of ear-swelling, and levels of cytokines and histamine in the lesioned ear. Results Topical prednisolone (0.05 mg/ear/day) significantly inhibited the increases in ear swelling and production of IL-1beta, IL-4, IL-18, granulocyte-macrophage colony-stimulating factor (GM-CSF) and histamine. However, after discontinuation of the treatment with topical prednisolone, the inflammation relapsed and the IL-4 level exceeded the control one. The sequential treatment with olopatadine (10 mg/kg/day) after discontinuation of the treatment with topical prednisolone alone, or topical prednisolone with olopatadine, significantly inhibited the increases in ear swelling and levels of IL-1beta, IL-4, IL-18, GM-CSF, nerve growth factor and histamine. CONCLUSIONS: These results indicate that olopatadine is an antihistamine agent having inhibitory activities against the rebound phenomenon following the discontinuation of topical steroid therapy. Olopatadine is thus expected to be a sequential therapeutic agent after discontinuation of the chronic treatment with a topical steroid. 相似文献
18.
Furukawa H Doh-ura K Sasaki K Iwaki T 《Laboratory investigation; a journal of technical methods and pathology》2004,84(7):828-835
Prion protein (PrP) is known to accumulate in some non-neuronal tissues under conditions unrelated to prion diseases. The biochemical and biological nature of such accumulated PrP molecules, however, has not been fully evaluated. In this study, we established experimental myopathy in hamsters by long-term administration of chloroquine, and we examined the nature of the PrP molecules that accumulated. PrP accumulation was immunohistochemically demonstrated in autophagic vacuoles in degenerated muscle fibers, and this was accompanied by the accumulation of other molecules related to the neuropathogenesis of prion diseases such as clathrin, cathepsin B, heparan sulfate, and apolipoprotein J. Accumulated PrP molecules were partially insoluble in detergent solution and were slightly less sensitive to proteinase K digestion than normal cellular PrP. Muscle homogenates containing these PrP molecules did not cause disease in inoculated hamsters. The findings indicate that the PrP molecules that accumulated in muscle fibers have distinct biochemical and biological properties. Therefore, experimental chloroquine myopathy is a novel and useful model to investigate the mechanism of deposition of PrP in non-neuronal tissues and might provide new insights in the pathogenesis of prion diseases. 相似文献
19.
Parathyroid hormone related peptide (PTHrP) was discovered as a causative factor of humoral hypercalcemia of malignancy (HHM). The present study elucidates the histopathological characters of incisor lesions in the HHM rat model. Nude rats were implanted with PTHrP-expressing tumor (LC-6) cells, maintained for 12 weeks, after which the mandibular incisors were collected. Incisor fractures were observed grossly. Microscopically, hypercalcified dentin, dentin niche with osteodentin, and thinning of dentin were observed. Hypercalcified dentin was observed as a basophilic line of calcified dentin without associated odontoblastic changes, whereas dentin niche and thinning of dentin occurred with osteodentin and loss of cell height, respectively. In contrast with hypercalcified dentin, which was distributed throughout the dentin, dentin niche and thinning of dentin were localized to the labial area of the apical and middle region, and to the labial and lingual areas of the middle and incisal region, respectively. These results suggest that hypercalcemia affected the entire calcification process resulting in hypercalcified dentin, and that high PTHrP concentrations affected selective populations of odontoblasts resulting in formation of dentin niche and thinning of dentin. The localization of dentin niche and thinning of dentin also suggest that PTHrP may also be involved odontoblastic development in the rat. 相似文献
20.
Clostridium sordellii phospholipase C: gene cloning and comparison of enzymatic and biological activities with those of Clostridium perfringens and Clostridium bifermentans phospholipase C
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Karasawa T Wang X Maegawa T Michiwa Y Kita H Miwa K Nakamura S 《Infection and immunity》2003,71(2):641-646
The gene encoding Clostridium sordellii phospholipase C (Csp) was cloned and expressed as a histidine-tagged (His-tag) protein, and the protein was purified to compare its enzymatic and biological activities with those of Clostridium perfringens phospholipase C (Cpa) and Clostridium bifermentans phospholipase C (Cbp). Csp was found to consist of 371 amino acid residues in the mature form and to be more homologous to Cbp than to Cpa. The egg yolk phospholipid hydrolysis activity of the His-tag Csp was about one-third of that of His-tag Cpa, but the hemolytic activity was less than 1% of that of His-tag Cpa. His-tag Csp was nontoxic to mice. Immunization of mice with His-tag Cbp or His-tag Csp did not provide effective protection against the lethal activity of His-tag Cpa. These results indicate that Csp possesses similar molecular properties to Cbp and suggest that comparative analysis of toxic and nontoxic clostridial phospholipases is helpful for characterization of the toxic properties of clostridial phospholipases. 相似文献