全文获取类型
收费全文 | 2653篇 |
免费 | 108篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 73篇 |
儿科学 | 58篇 |
妇产科学 | 27篇 |
基础医学 | 377篇 |
口腔科学 | 51篇 |
临床医学 | 159篇 |
内科学 | 591篇 |
皮肤病学 | 7篇 |
神经病学 | 297篇 |
特种医学 | 151篇 |
外科学 | 447篇 |
综合类 | 5篇 |
一般理论 | 1篇 |
预防医学 | 111篇 |
眼科学 | 5篇 |
药学 | 176篇 |
中国医学 | 5篇 |
肿瘤学 | 231篇 |
出版年
2022年 | 12篇 |
2021年 | 28篇 |
2020年 | 17篇 |
2019年 | 28篇 |
2018年 | 28篇 |
2017年 | 29篇 |
2016年 | 49篇 |
2015年 | 47篇 |
2014年 | 51篇 |
2013年 | 85篇 |
2012年 | 136篇 |
2011年 | 154篇 |
2010年 | 90篇 |
2009年 | 85篇 |
2008年 | 141篇 |
2007年 | 150篇 |
2006年 | 153篇 |
2005年 | 166篇 |
2004年 | 159篇 |
2003年 | 178篇 |
2002年 | 188篇 |
2001年 | 39篇 |
2000年 | 17篇 |
1999年 | 35篇 |
1998年 | 55篇 |
1997年 | 51篇 |
1996年 | 43篇 |
1995年 | 28篇 |
1994年 | 34篇 |
1993年 | 36篇 |
1992年 | 43篇 |
1991年 | 38篇 |
1990年 | 35篇 |
1989年 | 29篇 |
1988年 | 33篇 |
1987年 | 30篇 |
1986年 | 17篇 |
1985年 | 26篇 |
1984年 | 29篇 |
1983年 | 19篇 |
1982年 | 14篇 |
1981年 | 18篇 |
1980年 | 18篇 |
1979年 | 9篇 |
1978年 | 15篇 |
1977年 | 16篇 |
1974年 | 9篇 |
1973年 | 5篇 |
1970年 | 6篇 |
1957年 | 6篇 |
排序方式: 共有2772条查询结果,搜索用时 15 毫秒
101.
We measured the thickness of the substantia innominata using magnetic resonance imaging in 122 patients with Alzheimer's disease (AD), 31 patients with dementia with Lewy bodies (DLB) and 34 patients with vascular dementia (VaD), and examined the correlates of cognitive response to donepezil. Although all dementia groups showed significant atrophy of the substantia innominata compared to 28 age-matched controls, atrophy was greater in the DLB group, but less in the VaD group than the AD group. Mini-Mental State Examination score changes at 12 weeks after donepezil administration inversely and significantly correlated with the thickness of the substantia innominata in patients with AD (n=103, r=-0.43, p<0.0001) and in patients with DLB (n=24, r=-0.57, p<0.01), but not in patients with VaD (n=12, r=-0.22, p>0.1). There may be some differences in cholinergic impairment among AD, DLB and VaD, reflecting cholinergic neuropathology. Clinical response to cholinergic therapy may be partly attributable to damaged cholinergic neurons in AD and DLB, but not in VaD, suggesting differences in the therapeutic implication of cholinergic system degeneration. 相似文献
102.
Suzuki T Matsuzaki T Hagiwara H Aoki T Takata K 《ACTA HISTOCHEMICA ET CYTOCHEMICA》2007,40(5):131-137
Tremendous progress in recent computer-controlled systems for fluorescence and laser-confocal microscopy has provided us with powerful tools to visualize and analyze molecular events in the cells. Various fluorescent staining and labeling techniques have also been developed to be used with these powerful instruments. Fluorescent proteins such as green fluorescent protein (GFP) allow us to directly label particular proteins of interest in living cells. This technique has been extended over a large area of cell biology, and a variety of fluorescent protein-derived techniques have been developed to visualize the functions and conditions of the molecules within living cells. In this review, we summarize the techniques for fluorescent staining and labeling for recent fluorescence microscopy. 相似文献
103.
Morita I Nakagaki H Yoshii S Tsuboi S Hayashizaki J Igo J Mizuno K Sheiham A 《Journal of clinical periodontology》2007,34(11):952-956
AIM: The objective was to assess whether there was a social gradient in periodontal status by job classification in Japanese male workers. MATERIAL AND METHODS: Study participants were 15,803 Japanese male workers aged 20-69 years. There were seven groups classified by jobs. Oral examinations were conducted using community periodontal index (CPI). RESULTS: The percentages of sextants with a CPI score of 3 or 4 of professionals were significantly lower than for other job classes. The gradient also existed for the percentage of sextants with CPI score 4. After adjusting for age, a history of diabetes mellitus and smoking status, those lower on the gradient, namely, drivers, service occupations, salespersons and managers were 2.0, 1.5, 1.4 and 1.4, times, respectively more likely to have one or more sextants with CPI score 3 or 4 compared with professionals. Odds ratios of having more than one or more sextants with CPI score 4 after adjusting for age, clinical history of diabetes mellitus and smoking status for drivers, service occupations, salespersons and managers were 2.1, 1.5, 1.5 and 1.2, respectively, compared with professionals. CONCLUSIONS: There was a gradient in periodontal status by job classification. Professional and office workers had better periodontal status than salespersons, service occupations and drivers. 相似文献
104.
Hiroki Sato Mitsugu Uematsu Wakaba Endo Tojo Nakayama Tomoko Kobayashi Naomi Hino-Fukuyo Osamu Sakamoto Haruo Shintaku Shigeo Kure 《Brain & development》2014
Autosomal recessive guanosine triphosphate cyclohydrolase I (GTPCH) deficiency is an inborn error of tetrahydrobiopterin (BH4) synthesis from GTP. GTPCH deficiency causes severe reduction of BH4, resulting in hyperphenylalaninemia (HPA) and decreased dopamine and serotonin synthesis. Without treatment, a patient with GTPCH deficiency develops complex neurological dysfunctions, including dystonia and developmental delays. The first Japanese patient with GTPCH deficiency was discovered by HPA during asymptomatic newborn screening. The phenylalanine level at the age of 5 days was 1273 μmol/L (cutoff value, 180.0 μmol/L). The high serum phenylalanine level was decreased to normal after adequate BH4 oral supplementation. Serum and urinary pteridine examination revealed very low levels of neopterin and biopterin. Sequence analysis of GCH1 revealed compound heterozygous point mutations, including a novel point mutation (p.R235W). Replacement therapy with BH4 and L-dopa/carbidopa were started at the age of 1 month, and 5-hydroxytryptophan (5-HTP) was started at the age of 5 months. At 10 months of age, the patient showed slight dystonia but no obvious developmental delay. Cerebrospinal fluid should be examined to determine the appropriate dosage of supplement drugs. In conclusion, it is important to control the serum phenylalanine level and perform early replacement of neurotransmitters to prevent neurological dysfunction. 相似文献
105.
Dr. Manabu Yamamura M.D. Masaharu Nishi M.D. Haruo Furubayashi M.D. Koshiro Hioki M.D. Masakatsu Yamamoto M.D. 《Diseases of the colon and rectum》1985,28(5):347-352
A case of generalized peritonitis, secondary to a perforation of the rectosigmoid colon during barium-enema roentgenography,
is presented. The patient required immediate surgical intervention with the prime importance of the treatment being removal
of as much of the contaminating materials as possible. This was done successfully with irrigation and wiping, using urokinase
solution. Peritoneal lavage with urokinase solution was also carried out in the early postoperative period. Fluid replacement
with careful monitoring of fluid and electrolyte balance is essential before, during, and after the surgical procedure. Adequate
antibiotic therapy and careful respiratory and nutritional support are also important. 相似文献
106.
Shigeru Imai Shouichi Uchiyama Toshiki Suzuki Atsushi Arita Kazuaki Yoshida Hidebumi Kodama Takaya Sato Koho Akimaru Tetsuo Shibuya Haruo Kameda 《Journal of gastroenterology》1995,30(4):547-550
A very rare case of adenomyoma of the common hepatic duct is described. A 54-year-old woman was admitted with impending obstructive jaundice secondary to adenomyoma of the common hepatic duct. Our impression, formulated from her clinical presentation, endoscopic investigations, and biochemical and radiological findings, was a cancer of the proximal common hepatic duct. The patient was treated successfully by combination surgical resection and hepaticojejunostomy. Despite our obtaining an intraoperative frozen section, final histological examination was required to confirm the diagnosis. The patient remains well 16 months postoperatively. A survey of the world literature revealed that this is the second report of adenomyoma occurring in the common hepatic duct. 相似文献
107.
John K. Vyden Koichi Nagasawa Babeth Rabinowitz William W. Parmley Haruo Tomoda Eliot Corday H.J.C. Swan 《The American journal of cardiology》1974,34(6):677-686
Methylprednisolone sodium succinate, 50 mg/kg body weight, was given as an intravenous bolus injection to 15 dogs with acute myocardial infarction and the results were compared with data in control animals. Methylprednisolone was thought to improve the critical oxygen balance of the infarcted heart by two mechanisms: (1) by diminishing heart rate, afterload and preload in the initial 15 minutes after its administration and thereby decreasing the oxygen need of the heart, and (2) by increasing coronary arterial blood flow. Both mechanisms were believed to contribute to the increase in cardiac output, efficiency and ventricular performance. This improvement in performance was presumably not due to a positive inotropic effect, since studies in isolated heart muscle showed no effect of methylprednisolone on contractility. Regional circulations other than the coronary circulation seemed to be little affected by administration of methylprednisolone except for blood pressure-related increases in superior mesenteric and femoral arterial blood flow. 相似文献
108.
Delayed Removal of N-Terminal Methionine from Nascent Globin Chains in Sickle-Cell Anemia Reticulocytes
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Haruo Suzuki Harvey A. Itano 《Proceedings of the National Academy of Sciences of the United States of America》1973,70(7):2059-2063
Synthetic αT1 and βT1, the N-terminal tryptic peptides of α-chain and β-chain of hemoglobin, and MetαT1 and MetβT1, peptides in which N-terminal methionyl residues are peptide-bonded to αT1 and βT1, were prepared by the solid-state method of Merrifield. These synthetic peptides were used to establish conditions for chromatographic purification and analysis. When tryptic digests of nascent globin chains from rabbit and sickle-cell anemia reticulocytes incubated with 35S- and 3H-labeled amino acids were analyzed, radioactivity not present in tryptic digests of labeled hemoglobin appeared at the elution positions of MetαT1 and MetβT1. The fraction of nascent chains with N-terminal methionine was higher in sickle-cell anemia reticulocytes than in rabbit reticulocytes. If rate of peptide-chain elongation in polysomes is uniform, nascent human chains must attain a greater length before removal of the initial methionyl residue. Length of nascent chain at time of removal was calculated from two independent sets of data, one obtained from [35S]methionine incorporation into MetαT1, MetβT1, αT5, and βT5, and the other obtained from [3H]lysine and [3H]valine incorporation into MetβT1 and βT1. 相似文献
109.
110.
Hanawa H Ma Y Mikolajczak SA Charles ML Yoshida T Yoshida R Strathdee CA Litchfield DW Ochi A 《Blood》2002,99(6):2138-2145
We have characterized a splice variant (isoform) of the human CD28 T cell costimulatory receptor. The nucleotide sequence of this CD28 isoform was identical to that of CD28 in the signal peptide, the transmembrane domain, and the cytoplasmic tail, but it was missing a large segment of the extracellular ligand-binding domain, which is encoded by the second exon. This isoform (CD28i), whose message level exceeded 25% of CD28, was a transmembrane homodimer. CD28i was found noncovalently associated with CD28 and was tyrosine-phosphorylated/PI3-kinase-complexed following the crosslinking of CD28, and the CD28 costimulatory signal was enhanced in T cells expressing CD28i. These data demonstrate that CD28i, via noncovalent association with CD28, plays a role as a costimulatory signal amplifier in human T cells. 相似文献