全文获取类型
收费全文 | 4099篇 |
免费 | 157篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 116篇 |
儿科学 | 85篇 |
妇产科学 | 40篇 |
基础医学 | 634篇 |
口腔科学 | 98篇 |
临床医学 | 252篇 |
内科学 | 925篇 |
皮肤病学 | 47篇 |
神经病学 | 414篇 |
特种医学 | 198篇 |
外科学 | 535篇 |
综合类 | 18篇 |
一般理论 | 1篇 |
预防医学 | 140篇 |
眼科学 | 22篇 |
药学 | 381篇 |
中国医学 | 12篇 |
肿瘤学 | 358篇 |
出版年
2023年 | 12篇 |
2022年 | 29篇 |
2021年 | 49篇 |
2020年 | 26篇 |
2019年 | 34篇 |
2018年 | 44篇 |
2017年 | 37篇 |
2016年 | 55篇 |
2015年 | 67篇 |
2014年 | 61篇 |
2013年 | 107篇 |
2012年 | 179篇 |
2011年 | 207篇 |
2010年 | 114篇 |
2009年 | 112篇 |
2008年 | 195篇 |
2007年 | 221篇 |
2006年 | 225篇 |
2005年 | 249篇 |
2004年 | 236篇 |
2003年 | 260篇 |
2002年 | 269篇 |
2001年 | 121篇 |
2000年 | 109篇 |
1999年 | 109篇 |
1998年 | 70篇 |
1997年 | 65篇 |
1996年 | 53篇 |
1995年 | 48篇 |
1994年 | 50篇 |
1993年 | 52篇 |
1992年 | 90篇 |
1991年 | 83篇 |
1990年 | 70篇 |
1989年 | 67篇 |
1988年 | 59篇 |
1987年 | 44篇 |
1986年 | 37篇 |
1985年 | 52篇 |
1984年 | 55篇 |
1983年 | 39篇 |
1982年 | 26篇 |
1981年 | 23篇 |
1980年 | 22篇 |
1979年 | 30篇 |
1978年 | 24篇 |
1977年 | 19篇 |
1976年 | 11篇 |
1966年 | 7篇 |
1957年 | 6篇 |
排序方式: 共有4276条查询结果,搜索用时 15 毫秒
81.
Renal handling of carnitine in children with carnitine deficiency and hyperammonemia associated with valproate therapy 总被引:6,自引:0,他引:6
Free and acylcarnitine in serum and urine samples were measured in five patients with hyperammonemia associated with anticonvulsant therapy including sodium valproate, of whom three had a Reye-like syndrome. All had considerable reduction in serum free carnitine and slight increase of acylcarnitine concentrations, suggesting increased conversion of free to acylcarnitine by valproate administration. Urinary excretion of both free and acylcarnitine was increased, accompanied by depressed reabsorption of free carnitine and decreased acylcarnitine/free carnitine clearance ratio. These results indicate a decreased threshold for free carnitine. The combination of these several factors may be responsible for carnitine deficiency in patients with hyperammonemia taking valproate. 相似文献
82.
In order to improve the solubility of sulfuric acid lignin (SL) in N,N-dimethylformamide (DMF), dry ball milling with excess amounts of additives such as l-tartaric acid was performed. Although the ball-milled SL without any additives was not soluble in DMF, when the SL was ball milled with an excessive amount of l-tartaric acid (the concentration of SL to be 0.1%), the dispersion and solubility of SL in DMF detected by the dynamic light scattering was greatly improved. Furthermore, the DMF solution showed clear photoluminescence, indicating that the distance between luminophores was modulated due to dispersion on the nanoscale. The structural analysis of the isolated lignin showed a decrease in molecular weight and the introduction of carboxylic acid groups. In other words, the introduction of hydrophilic functional groups into the lignin and simultaneously decrease in the molecular weight due to the cleavage of lignin linkages is considered to result in good dispersion in DMF on both the micro and macro scales. Similar effects were observed with the other chemicals containing several hydrophilic groups such as citric acid, d-glucose, and polyacrylic acid. Furthermore, this method is applicable to various lignins other than SL, and it is expected to utilize unused lignin resources.Ball milling with excess amounts of additives enhanced the solubility of poor solubility lignins in DMF. 相似文献
83.
84.
Haruo Makuuchi Akira Furuse Masahiro Endo Haruo Nakamura Hiroyuki Daida Mikio Watanabe Yasuo Ohashi Yasuyuki Hosoda Saichi Hosoda Hiroshi Yamaguchi Hisataka Yasui 《Circulation journal》2005,69(6):636-643
BACKGROUND: Although the anti-atherosclerotic effects of HMG-CoA reductase inhibitors are well known, their specific effect on saphenous vein grafts after coronary artery bypass graft (CABG) operation is not well documented and has not been studied in Japan, so the aim of the present prospective randomized controlled study involving 27 Japanese institutions was to investigate the effects of pravastatin on the progression of atherosclerosis in such grafts and native coronary arteries after CABG. METHODS AND RESULTS: A total of 303 patients who had undergone CABG were randomly assigned to either the pravastatin group (n =168) or the control group (n = 167). Paired coronary angiograms were obtained at baseline and at the end of 5-year follow-up in 182 (60%) patients. The low-density lipoprotein cholesterol concentration significantly decreased in the pravastatin group from 141.4 mg/dl to 113.7 mg/dl (-19.6%), compared with 141.1 mg/dl to 133.7 mg/dl (-5.2%) in the control group (p < 0.001). Although there was no significant difference in the quantitative coronary angiography measurements between the 2 groups, the global change score indicated a significant pravastatin-mediated reduction in plaque progression (p < 0.01). CONCLUSIONS: Pravastatin can potentially reduce atherosclerotic progression in both the bypass graft and native coronary arteries of patients after CABG. 相似文献
85.
Kunio Okuda Toshiro Nakashima Masahiko Okudaira Masayoshi Kage Yoshibumi Aida Masao Omata Hirotaka Musha Shunji Futagawa Mitsuo Sugiura Haruo Kameda 《Liver international》1981,1(4):255-263
ABSTRACT— Hepatic venograms made in 40 authentic cases of idiopathic portal hypertension (Banti's syndrome) were compared with 13 normal venograms and venograms obtained in 88 cases of cirrhosis, and analyzed in the light of the pathological changes seen in 16 postmortem liver specimens. There were frequent anastomoses between hepatic vein radicles, approximation of middle-size branches to the liver surface, reduction in the angles between the main hepatic vein and its tributaries, and difficulty in opacifying portal vein branches in wedged retrograde portography. These angiographic alterations were corroborated by gross pathological findings which comprised displacement of middle-size hepatic vein branches closer to the liver surface and their approximation among themselves, and seem to be accounted for by the disappearance of liver parenchyma secondary to the peripheral portal circulatory failure. 相似文献
86.
87.
88.
Kikuchi S Matsuzaki H Kondo K Ohtani Y Ihara A Hiki Y Kakita A Kuwao S 《Hepato-gastroenterology》2000,47(33):669-671
BACKGROUND/AIMS: We present herein the three-dimensional reconstruction of colorectal tumors, with particular reference to growth pattern into each layer of the colorectal wall, and measurement of tumor volume and surface area. METHODOLOGY: Conventional tissue section images of colorectal tumors were analyzed using a computer graphics analysis program. The two-dimensional extent of invasion by each tumor into each layer of intestinal wall were determined from the images of each section. Based on data from multiple sections, tumor and surrounding normal tissue layers were reconstructed three-dimensionally, and volume and surface area of the tumors were determined. RESULTS: Using this technique, three-dimensional morphology of tumor and tumor progression into colorectal wall could be determined. Volume and surface area of the colon tumor were 4871 mm3 and 1741 mm2, respectively. Volume and surface area of the rectal tumor were 1090 mm3 and 877 mm2, respectively. CONCLUSIONS: This technique may provide a new approach for pathological analysis of colorectal carcinoma. 相似文献
89.
Misaki Kageyama Hideharu Hagiya Yasutaka Ueda Katsuki Ohtani Yasuo Fukumori Norimitsu Inoue Nobutaka Wakamiya Nanoka Yoneda Keigo Kimura Motonori Nagasawa Futoshi Nakagami Isao Nishi Ken Sugimoto Hiromi Rakugi 《Medicine》2021,100(13)
Rationale:Complement deficiency are known to be predisposed to disseminated gonococcal infection (DGI). We herein present a case of DGI involving a Japanese man who latently had a complement 7 deficiency with compound heterozygous variants.Patient concerns:A previously healthy 51-year-old Japanese man complained of sudden-onset high fever. Physical examination revealed various skin lesions including red papules on his trunk and extremities, an impetigo-like pustule on left forearm, and tendinitis of his right forefinger.Diagnosis:Blood culture testing detected gram-negative cocci, which was confirmed to be Neisseria gonorrhoeae based on mass spectrometry and a pathogen-specific PCR test.Interventions:Screening tests for underlying immunocompromised factors uncovered that complement activities (CH50) was undetectable. With a suspicion of a congenital complement deficiency, genetic analysis revealed rare single nucleotide variants in complement 7 (C7), including c.281-1G>T and a novel variant c.1454C>T (p.A485V). CH50 was normally recovered by adding purified human C7 to the patient''s serum, supporting that the patient has C7 deficiency with compound heterozygous variants.Outcomes:Under a diagnosis of DGI, the patient underwent an antibiotic treatment with cefotaxime for a week and was discharged without any sequela.Lessons:DGI is a rare sexually-transmitted infection that potentially induces systemic complications. Complement immunity usually defeats N. gonorrhoeae and prevents the organism from causing DGI. This case highlighted the importance of suspecting a complement deficiency when a person develops DGI. 相似文献
90.
Yukiko Ohno Yuji Okura Mahmoud M Ramadan Koji Taneda Keisuke Suzuki Manabu Tomita Kazuhisa Hao Shinpei Kimura Makoto Hoyano Wataru Mitsuma Komei Tanaka Takeshi Kashimura Masahiro Ito Satoru Hirono Haruo Hanawa Makoto Kodama Yoshifusa Aizawa 《Circulation journal》2008,72(9):1436-1442
Background The impact of isolated diastolic dysfunction (IDD) and systolic dysfunction (SD) on health-related quality of life (HRQOL) is unknown. Methods and Results To evaluate HRQOL in patients with IDD and SD under treatment, information on outpatients aged 60-84 years was extracted from the records of 4,500 consecutive individuals who underwent echocardiographic examination at Sado General Hospital. The medical records of these patients were reviewed and a questionnaire, including the Medical Outcome Study Short Form 36, was mailed to 71 IDD and 99 SD patients; answers were obtained from 66 and 91 patients, respectively. The HRQOL of patients with cardiac dysfunction was impaired even when echocardiographic parameters improved with treatment. Patients with IDD showed an impairment of HRQOL similar to those with SD. Compared with males, female patients had a larger and more significant reduction in the physical and mental components of the HRQOL score. These scores correlated positively with exercise capacity in patients with IDD or SD. Conclusions Impaired HRQOL, in both its mental and physical components, is a serious problem for IDD and SD patients under treatment. Because exercise intolerance may underlie the reduced HRQOL, improving exercise capacity could be an important target for managing outpatients with heart failure. (Circ J 2008; 72: 1436 - 1442). 相似文献