全文获取类型
收费全文 | 3187篇 |
免费 | 187篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 65篇 |
妇产科学 | 62篇 |
基础医学 | 523篇 |
口腔科学 | 77篇 |
临床医学 | 199篇 |
内科学 | 653篇 |
皮肤病学 | 101篇 |
神经病学 | 233篇 |
特种医学 | 219篇 |
外科学 | 292篇 |
综合类 | 15篇 |
一般理论 | 1篇 |
预防医学 | 202篇 |
眼科学 | 98篇 |
药学 | 322篇 |
中国医学 | 6篇 |
肿瘤学 | 291篇 |
出版年
2024年 | 1篇 |
2023年 | 15篇 |
2022年 | 36篇 |
2021年 | 104篇 |
2020年 | 55篇 |
2019年 | 72篇 |
2018年 | 94篇 |
2017年 | 76篇 |
2016年 | 91篇 |
2015年 | 79篇 |
2014年 | 116篇 |
2013年 | 161篇 |
2012年 | 233篇 |
2011年 | 287篇 |
2010年 | 175篇 |
2009年 | 136篇 |
2008年 | 215篇 |
2007年 | 271篇 |
2006年 | 243篇 |
2005年 | 233篇 |
2004年 | 184篇 |
2003年 | 150篇 |
2002年 | 177篇 |
2001年 | 13篇 |
2000年 | 17篇 |
1999年 | 25篇 |
1998年 | 23篇 |
1997年 | 22篇 |
1996年 | 20篇 |
1995年 | 16篇 |
1994年 | 9篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有3393条查询结果,搜索用时 15 毫秒
991.
Ohmori K Ebihara S Kuriyama S Ugajin T Ogata M Hozawa A Matsui T Tsubono Y Arai H Sasaki H Tsuji I 《Annals of epidemiology》2005,15(1):80-84
PURPOSE: To examine the association between body mass index (BMI) and the plasma level of a lipid peroxidation biomarker in a large sample of elderly healthy Asian population. This cross-sectional study included 1150 community-dwelling Japanese aged 70 years or older in 2002. METHODS: We measured the lipid peroxidation biomarker 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) using the ELISA method. We also measured the weight and height and calculated the BMI as weight (kg)/height (m)2. RESULTS: After adjustment for potential confounders, the mean +/- SE plasma 8-iso-PGF(2alpha) level was significantly higher in subjects with higher BMI: 21.1 +/- 0.8 pg/ml in those with BMI of 30.0 or more; 20.5 +/- 0.3 pg/ml in those with BMI between 25.0 and 29.9; 20.0 +/- 0.2 pg/ml in those with BMI between 18.5 and 24.9; and 19.0 +/- 0.7 pg/ml in those with BMI of less than 18.5 (p for trend = 0.011). CONCLUSIONS: Our results demonstrated that in the healthy Asian population, there was a modest but significant relationship between BMI and the plasma lipid peroxidation level. 相似文献
992.
Nishikawa Y Minenaka Y Ichimura M Tatsumi K Nadamoto T Urabe K 《Journal of nutritional science and vitaminology》2005,51(3):135-141
Astaxanthin (Asx), one of the carotenoids, is a red pigment in fish and Crustaceans, and possesses stronger reduction properties than conventional carotenoids, like beta-carotene. However, little is known about the biochemical properties and physiological functions of astaxanthin. The effects of astaxanthin and vitamin C on stressed rats were studied physiologically and biochemically. beta-Carotene and three kinds of astaxanthins, which were extracted from Haematococcus and Phaffia, and synthesized chemically, were used in these experiments. These rats given astaxanthins or beta-carotene had stress induced on the 12th day by immersing the rats in chest-level water at 20 degrees C for 24 h after fasting for 24 h. Rats given astaxanthins or beta-carotene prior to stressing were appreciably protected against the evolution of gastric ulcerations in relation to control rats. Ulcer indexes in particular were smaller with the rat group fed astaxanthin extracted from Haematococcus than the other groups. Next, the effects of Asx and/or vitamin C on the protection of evolution of gastric ulcer in stressed rats were persued by the same methods as described above. The results showed that rats given Asx or vitamin C were appreciably protected against the evolution of gastric ulcerations in relation to control rats. The effects were more intense, especially in rats simultaneously supplied Asx and vitamin C than in rats taking either Asx or vitamin C. It was suggested that the simultaneous supplementation of food substances with astaxanthin and vitamin C would supply enough antioxidants to offset stress-related injuries. 相似文献
993.
This study dealt with the potential of fermented milk products as a source of functional casein phosphopeptides (CPPs) using plain yogurts and Camembert cheeses. The CPPs were prepared by tryptic digestion from four commercially available plain yogurts (P1-P4), five Camembert cheeses (C1-C5), and raw milk. From portions with a 1-g protein content of the plain yogurts, the Camembert cheeses, and the raw milk, 171 mg, 139 mg, and 146 mg of CPPs were obtained, respectively. The Camembert cheeses retained high amounts of organic phosphorus (32 microg) per 1 mg CPPs compared to the raw milk (15 microg) and plain yogurts (16 microg). Reverse-phase high-performance liquid chromatographic analysis showed that the elution patterns and retention times of the three major peaks of CPPs from P1 and C1 were similar to those from raw milk. Moreover, CPPs from P1 and C1 showed a mitogenic effect, while CPPs from C1 showed an IgA-enhancing effect in mouse spleen cell cultures. These results suggest that fermented milk products such as plain yogurts and Camembert cheeses generate functional CPPs in the body and exert beneficial effects on the immune system. 相似文献
994.
Ogawa T Hoshina K Haginaka J Honda C Tanimoto T Uchida T 《Journal of pharmaceutical sciences》2005,94(2):353-362
The purpose of the present study was to examine the possibility of using molecularly imprinted polymers (MIPs) to screen for bitterness-suppressing agents. Quinine was selected as the bitter substance standard. L-arginine (L-Arg), L-ornithine (L-Orn), L-lysine (L-Lys), and L-citrulline (L-Ctr) were tested as bitterness suppressant candidates. In a high-performance liquid chromatography study using a uniformly sized MIP for cinchonidine, which has a very similar structure to quinine, the retention factor (k) of quinine was significantly shortened by the addition of L-Arg or L-Orn to the mobile phase, whereas slight or no decrease was observed when L-Ctr and L-Lys were added. The abilities of these amino acids to decrease the k of quinine were ranked in the following order: L-Arg = (L-Orn >(L-Ctr >(L-Lys. A linear relationship between the reciprocal of k and the concentration of the amino acids indicated a single competitive model at a single site. The magnitude of the association constants obtained seemed to be directly related to the inhibitory effect of the test substances on the affinity of quinine for the receptor site. Nuclear magnetic resonance and molecular modeling studies suggested a one-to-two hydrogen-bonding-based complex formation of one quinine molecule with two methacrylic acid molecules (Q-2MAA) in chloroform. In the molecular modeling studies, the N--N distance of the quinine molecule in the assumed Q-2MAA complex was calculated to be 5.12 angstroms, similar to the N - N distances of the two amino acid complexes (L-Arg-2MAA, L-Orn-2MAA), which were 4.84 and 5.30 angstroms, respectively. This suggests that L-Arg and L-Orn may compete with the quinine molecule in the cinchonidine-imprinted space. Finally, the results of human gustatory sensation tests correlated well with the MIP data. The proposed method using MIPs seems to have a potential for screening bitterness-suppressing agents for quinine. 相似文献
995.
996.
Inoue K Takano H Yanagisawa R Ichinose T Sadakane K Yoshino S Yamaki K Uchiyama K Yoshikawa T 《Clinical and experimental pharmacology & physiology》2005,32(3):230-232
1. Previously, we have demonstrated that 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) enhances acute lung injury induced by lipopolysaccharide (LPS) in mice. The enhancement in acute lung injury by 15d-PGJ2 was concomitant with the enhanced expression of several pro-inflammatory cytokines in the lung. However, other underlying mechanisms of this enhancement remain to be elucidated. The present study investigated the effects of 15d-PGJ2 on the expression of Toll-like receptor (TLR) 4 and 2 in the lung in the absence or presence of LPS. 2. In the present study, ICR mice were divided into four experimental groups that received (intratracheally) vehicle, LPS (125 microg/kg), 15d-PGJ2 (1 mg/kg) or 15d-PGJ2 + LPS. The mRNA expression of both TLR4 and 2 in the lung was evaluated 4 h after intratracheal administration. 3. 15-Deoxy-Delta12,14-prostaglandin J2 enhanced the mRNA expression of both TLR4 and 2 in the presence of LPS. 4. These results suggest that the enhancing effects of 15d-PGJ2 on LPS-induced acute lung injury may be explained, at least in part, by its effect on the lung expression of TLR4 and 2. 相似文献
997.
Mikamo H Tanaka K Watanabe K Saheki H Sawamura H Miwa M Ishigo S Asano Y Terachi M Suematsu H Hashido H Matsubara S Yamaoka K Matsukawa Y Miyasato M Ichikawa E 《The Japanese journal of antibiotics》2005,58(3):290-302
We analyzed Haemophilus influenzae isolates in Gifu prefecture between May 2003 and August 2003. We conducted molecular-level epidemiological studies for 313 strains using PCR to identify resistant genes in H. influenzae. Our four sets of primers are as follows: (i) p6 gene of P6 membrane protein, (ii) TEM-1 type beta-lactamase gene (bla), (iii) normal PBP 3 gene (ftsl), and (iv) mutational ftsl gene detected in beta-lactamase-nonproducing ampicillin (ABPC) resistant H. influenzae (BLNAR). H. influenzae strains were classified into 6 types based on PCR: (i) beta-lactamase-nonproducing ABPC-susceptible strains (BLNAS; n = 85) with no any resistant genes, (ii) TEM-1 type beta-lactamase-producing ABPC resistant strains (BLPAR; n = 6), (iii) beta-lactamase-nonproducing and low-level ABPC-resistant strains (Low-BLNAR; n = 77) possessing Asn-526 --> Lys-526 amino acid substitution, (iv) BLNAR strains (n = 138) possessing Asn-526 --> Lys-526 and 3 amino acids substitutions detected around the Ser-Ser-Asn conserved motif, (v) beta-lactamase-producing amoxicillin-clavulanate resistant strains (BLPACR-I; n = 3) possessing TEM-1 and Low-BLNAR resistant genes, and (vi) beta-lactamase-producing amoxicillin-clavulanate resistant strains (BLPACR-II; n = 4) possessing TEM-1 and BLNAR resistant genes. Amoxicillin (AMPC) MIC90s in Low-BLNAR was 4 microg/mL and in BLNAR was 16 microg/mL. In oral cephalosporins, cefditoren MIC90 was the most excellent with 0.5 microg/mL against BLNAR. The prevalence of H. influenzae type b isolates in Matsubara Otorhinolaryngology Clinic was 66.7%. Selection of appropriate antimicrobial agents should be performed to prevent resistant microorganisms. Also, the vaccination for H. influenzae type b would be strongly recommended in near future. 相似文献
998.
Plasma adrenomedullin and carotid atherosclerosis in atherothrombotic ischemic stroke 总被引:2,自引:0,他引:2
Hosomi N Ohyama H Takahashi T Shinomiya K Naya T Ban CR Osaka K Kohno M Koziol JA 《Journal of hypertension》2004,22(10):1945-1951
OBJECTIVE: Adrenomedullin is known to exert anti-atherosclerotic actions by inhibiting proliferation and migration of smooth muscle cells in vitro. Here we examine the relationship between the plasma concentration of adrenomedullin and ultrasonographic characteristics of carotid arteries both in ischemic stroke and in the absence of cerebrovascular disease. METHODS: We studied 61 patients with atherothrombotic ischemic stroke in the chronic phase and 50 patients without any cerebrovascular disease. Intima-media thickness and vascular lumen diameters were evaluated by carotid ultrasonography. Plasma mature-adrenomedullin was determined by radioimmunoassay. RESULTS: Plasma mature-adrenomedullin in the patients with atherothrombotic ischemic stroke in the chronic phase (2.01 +/- 0.58 fmol/ml) was significantly higher than that in the patients without any cerebrovascular disease (1.24 +/- 0.18 fmol/ml, P < 0.001). With multiple regression analysis, plasma mature-adrenomedullin was found to be predicted by: stroke status (atherothrombotic ischemic stroke versus no cerebrovascular disease), diabetes status (yes/no), left ventricular ejection fraction, internal carotid artery intima-media thickness, and common carotid artery pressure strain elastic modulus (R = 0.79; F5,105 = 85.39, P < 0.0001). CONCLUSION: Plasma mature-adrenomedullin showed significantly positive associations with carotid atherosclerosis and atherothrombotic ischemic stroke, independent of systolic blood pressure. 相似文献
999.
Liver metastases of a minute rectal carcinoid less than 5mm in diameter: a case report 总被引:3,自引:0,他引:3
Tsuboi K Shimura T Suzuki H Mochiki E Haga N Masuda N Soda M Yamamoto H Asao T Kuwano H 《Hepato-gastroenterology》2004,51(59):1330-1332
We report a case of liver metastases of a minute rectal carcinoid less than 5mm in diameter, which was found during the postoperative follow-up course of a stomach cancer patient. For the early stomach cancer, laparoscope-assisted distal gastrectomy with lymph node dissection was performed on August 26, 1998. Later, abdominal CT revealed space-occupying lesions in the liver (S2). Metastatic tumors of the stomach cancer were suspected, but further examination revealed that the lesions were metastatic tumors due to a rectal carcinoid tumor. Ten months later, metastatic carcinoid tumors were found in the liver (S1, S5, S6, S7, S8). Subsegmentectomy of the liver (S7) and microwave coagulation therapy (S1, S5, S6, S8) were performed. Carcinoid tumors metastatic to the lymph nodes, liver, and other areas have been reported, but all were larger than 20mm in diameter. In this case, the primary tumor was less than 5mm in diameter, which is extremely rare. This patient was successfully treated with lateral segmentectomy, subsegmentectomy (S7), microwave coagulation therapy of the liver, and transanal extirpation. She is presently in a good condition and has had no recurrence of the carcinoid tumor from ten months after the last hepatectomy. 相似文献
1000.