全文获取类型
收费全文 | 203640篇 |
免费 | 3065篇 |
国内免费 | 130篇 |
专业分类
耳鼻咽喉 | 1547篇 |
儿科学 | 7219篇 |
妇产科学 | 4068篇 |
基础医学 | 20090篇 |
口腔科学 | 2354篇 |
临床医学 | 15332篇 |
内科学 | 36585篇 |
皮肤病学 | 1126篇 |
神经病学 | 19095篇 |
特种医学 | 9808篇 |
外科学 | 32684篇 |
综合类 | 2817篇 |
一般理论 | 18篇 |
预防医学 | 20112篇 |
眼科学 | 3400篇 |
药学 | 11458篇 |
1篇 | |
中国医学 | 758篇 |
肿瘤学 | 18363篇 |
出版年
2023年 | 139篇 |
2022年 | 282篇 |
2021年 | 626篇 |
2020年 | 354篇 |
2019年 | 544篇 |
2018年 | 22544篇 |
2017年 | 17778篇 |
2016年 | 19942篇 |
2015年 | 1548篇 |
2014年 | 1673篇 |
2013年 | 2108篇 |
2012年 | 8786篇 |
2011年 | 22922篇 |
2010年 | 19956篇 |
2009年 | 12560篇 |
2008年 | 21153篇 |
2007年 | 23364篇 |
2006年 | 2299篇 |
2005年 | 3841篇 |
2004年 | 4964篇 |
2003年 | 5851篇 |
2002年 | 3966篇 |
2001年 | 963篇 |
2000年 | 1027篇 |
1999年 | 668篇 |
1998年 | 511篇 |
1997年 | 490篇 |
1996年 | 369篇 |
1995年 | 335篇 |
1994年 | 297篇 |
1993年 | 216篇 |
1992年 | 324篇 |
1991年 | 339篇 |
1990年 | 334篇 |
1989年 | 259篇 |
1988年 | 245篇 |
1987年 | 196篇 |
1986年 | 181篇 |
1985年 | 184篇 |
1984年 | 188篇 |
1983年 | 188篇 |
1982年 | 210篇 |
1981年 | 163篇 |
1980年 | 210篇 |
1979年 | 116篇 |
1978年 | 146篇 |
1977年 | 116篇 |
1976年 | 124篇 |
1974年 | 107篇 |
1973年 | 84篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
BACKGROUND: The skin of patients with atopic dermatitis (AD) exhibits a striking susceptibility to colonization and infection by Staphylococcus aureus. The exotoxins secreted by S. aureus can act as superantigens and classic allergens, inducing the production of functionally relevant specific IgE antibodies. The aim of this study was to compare the levels and positive rates of serum staphylococcal enterotoxin A (SEA)- and staphylococcal enterotoxin B (SEB)-specific IgE between atopic children with and without AD. METHODS: Sixty children with AD, 55 children with respiratory allergy without AD, and 24 nonatopic healthy children were studied. The levels and positive rates of serum SEA- and SEB-specific IgE were compared among three groups. The correlation between the levels or positive rates of serum SEA/SEB-specific IgE and the severity of AD or the presence of previous skin infections was studied. RESULTS: The children with AD had significantly higher levels and positive rates of serum SEA- and SEB-specific IgE than the atopic children without AD (P < 0.001) and the nonatopic children (P < 0.001). There was no significant difference in the levels and positive rates of serum SEA- and SEB-specific IgE between the atopic children without AD and the nonatopic children. With or without adjustment for the potential confounding effect of total serum IgE levels, the levels and positive rates of serum SEA- and SEB-specific IgE were significantly correlated with severity of AD (P <0.005), but they were not significantly different between AD children with and without previous skin infections. CONCLUSIONS: SEA and SEB may contribute to chronic inflammation and exacerbation of AD through the IgE-mediated immune response. 相似文献
992.
993.
Distributed computing can be applied to CT or MRI scanner image acquisition, printing, and archiving by interfacing the scanner with a computer network. Also on the network must be a computer workstation that has image management software to capture the images sent over the network by the scanner. This software must also allow the radiology staff to print and archive the images. Several benefits are realized by this network configuration. First, the scanner console is solely used for scanning patients; delays are not encountered because the console is being used for printing and archiving images. Also, the workstation printing software can be developed so that useful features not available at the scanner console can be incorporated. Finally, sophisticated archiving strategies can be implemented at the workstation. We have developed a network image management station at the Fox Chase Cancer Center using a reduced instruction set computer (RISC) workstation. Hardware and software is utilized to convert all scanner image data to the American College of Radiology-National Electrical Manufacturers Association format. All workstation software is developed using the open X-Windows standard. Digital audio tape is used for image archiving. 相似文献
994.
Pathologic anxiety, marked by inappropriate apprehension and/or fear, causes patients to seek help. Anxiety is associated with a wide variety of physical illnesses, and these must be initially considered when making a diagnosis. Similarly, anxiety associated with a wide variety of psychiatric syndromes must also be considered. Finally, the possibility of transient situational anxiety is ever present. Once it is determined that a primary anxiety disorder exists, then the presence or absence of phobias, panic attacks, and chronic "free-floating" anxiety will fully characterize the disorder. With an accurate diagnosis in hand, a multifaceted treatment approach can be designed. Effective treatments now exist for phobic and panic disorders, and more effective treatment for chronic generalized anxiety may be forthcoming. 相似文献
995.
N Tsai Z X Gao C L Xu K Zhu G B Yin H Z Shi Y C Jia 《Annales médico-psychologiques》1987,145(7):595-597
The concept and taxonomy of periodic psychosis still remains in controversy for the past 100 years. In China, it was first reported by Ji, and thereafter various rinds of terminology and views were given by different authors. In the presentation, clinical investigation and follow up were carried out in 62 cases. In many of these cases, the so-called "periodic psychosis" or "phasophrenia" was early clinical features of schizophrenia or manic-depression. In those cases with apparent symptoms and signs of diencephalic function, differential diagnosis should be carried out from organic brain syndrome. In a small number of cases, their clinical manifestations, conforming to previous diagnostic criteria, might be an uncommon syndrome. It was concluded by the authors that until now periodic could be considered only as a clinical syndrome rather than a disease entity. 相似文献
996.
DeWayne Roberts Taisheng Lee Evangelos Parganas Lee Wiggins Jack Yalowich Richard Ashmun 《Cancer chemotherapy and pharmacology》1987,19(2):123-130
Summary Resistance to teniposide (VM-26) by VM-26 selected resistant L1210 cells in culture was attributed to alterations in the flux of VM-26 across the plasma membrane and to functions of homogeneously staining regions that appeared on one or more chromosomes. In the present study, electrophoresis of membrane-cytosol fractions of these resistant sublines demonstrated a protein band, Mr 22 kd, that was not evident in similar fractions of drugsensitive L1210 cells or three revertant sublines. The distribution of this protein among various cellular fractions could be altered by manipulation of the concentration of calcium ions. A representative subline, LIa5 M, was observed to have vesicles that reacted with Sudan black B stain, an indication of altered lipid metabolism. The LIa5 M subline was cross-resistant to etoposide, vincristine, doxorubicin, amsacrine, and actinomycin D. Concentrations of VM-26 that inhibited cell division to the same extent caused an accumulation of fewer cells in the G2 stage of cell division in LIa5 M cultures than in L1210 cultures. These observations indicate that the LIa5 M subline expressed multiple drug resistance, as well as changes in the expression of cytotoxicity to VM-26.This investigation was supported by Research Project Grant CA 35319, by Cancer Center Support (CORE) Grant CA 21765 from the National Cancer Institute, and by the American Lebanese Syrian Associated Charities.Recipient of research support from a training grant, American Cancer Society Grant IN-85-06, to the University of Tennessee Center for the Health Sciences 相似文献
997.
Peter Bright-Asare Stephen J. Sontag Ronald J. Gould Douglas L. Brand Walter M Roufail 《Digestive diseases and sciences》1986,31(2):63S-67S
This study was undertaken to evaluate the efficacy of misoprostol taken twice daily for the healing of duodenal ulcer. Three hundred thirty patients with endoscopically proven duodenal ulcer participated in a multicenter, double-blind, controlled trial comparing placebo with misoprostol 200 μg and 400 μg twice daily for up to four weeks. Patient characteristics were similar in all three treatment groups. Ulcers were between 0.3 cm and 2.0 cm in length. Healing was determined by endoscopy at two weeks; if ulcers were not healed, endoscopy was repeated at four weeks. All patients were given Al(OH)3 antacid (up to 54 meq a day) to be used as needed for pain. Healing rates at four weeks for a total of 280 evaluable patients in the three treatment groups were as follows: misoprostol 400 μg bid, 65.4%; misoprostol 200 μg bid, 52.9%; and placebo, 42.2%. Misoprostol 400 μg bid was superior to placebo (P=0.002) in healing ulcers. However, the healing rate for misoprostol 200 μg bid did not differ significantly from placebo. The percentage of nonsmokers who healed at four weeks was higher than that of smokers in both misoprostoltreatment groups, although the difference was not analyzed for statistical significance. There were no differences in antacid consumption or pain relief among the three experimental groups during the study. Diarrhea was the most common side effect but was mild and self-limiting, occurring in 8.9%, 5.9%, and 1.8% of the misoprostol 400 μg, 200 μg, and placebo groups, respectively. These results indicate that misoprostol 400 μg, 200 μg, and for four weeks is effective and safe for the treatment of duodenal ulcers. 相似文献
998.
999.
Hira Shakoor Jack Feehan Vasso Apostolopoulos Carine Platat Ayesha Salem Al Dhaheri Habiba I. Ali Leila Cheikh Ismail Marijan Bosevski Lily Stojanovska 《Nutrients》2021,13(3)
Functional and nutraceutical foods provide an alternative way to improve immune function to aid in the management of various diseases. Traditionally, many medicinal products have been derived from natural compounds with healing properties. With the development of research into nutraceuticals, it is becoming apparent that many of the beneficial properties of these compounds are at least partly due to the presence of polyphenols. There is evidence that dietary polyphenols can influence dendritic cells, have an immunomodulatory effect on macrophages, increase proliferation of B cells, T cells and suppress Type 1 T helper (Th1), Th2, Th17 and Th9 cells. Polyphenols reduce inflammation by suppressing the pro-inflammatory cytokines in inflammatory bowel disease by inducing Treg cells in the intestine, inhibition of tumor necrosis factor-alpha (TNF-α) and induction of apoptosis, decreasing DNA damage. Polyphenols have a potential role in prevention/treatment of auto-immune diseases like type 1 diabetes, rheumatoid arthritis and multiple sclerosis by regulating signaling pathways, suppressing inflammation and limiting demyelination. In addition, polyphenols cause immunomodulatory effects against allergic reaction and autoimmune disease by inhibition of autoimmune T cell proliferation and downregulation of pro-inflammatory cytokines (interleukin-6 (IL-6), IL-1, interferon-γ (IFN-γ)). Herein, we summarize the immunomodulatory effects of polyphenols and the underlying mechanisms involved in the stimulation of immune responses. 相似文献
1000.
Jiun-Chi Huang Ya-Chin Huang Pei-Yu Wu Wen-Hsien Lee Yi-Chun Tsai Yi-Ping Chen Szu-Chia Chen Ho-Ming Su Yi-Wen Chiu Jer-Ming Chang 《Nutrients》2021,13(6)
Diastolic dysfunction is an emerging challenge among hemodialysis (HD) patients, and the associations between serum zinc with echocardiographic parameters and diastolic function remain uncertain. A total of 185 maintenance HD patients were stratified by the tertiles of serum zinc level to compare their clinical characteristics and echocardiography. Correlations of serum zinc levels with echocardiographic parameters were examined using Pearson’s analysis. Univariate and multivariate logistic regression analyses were performed to investigate the determinants of E/e’ ratio >15 and left atrial volume index (LAVI) > 34 mL/m2, both indicators of diastolic dysfunction. Patients belonging to the first tertile of serum zinc level had a significantly higher E/e’ ratio and LAVI. Serum zinc levels were negatively correlated with E (r = −0.204, p = 0.005), E/e’ ratio (r = −0.217, p = 0.003), and LAVI (r = −0.197, p = 0.007). In a multivariate analysis, older age, diabetes, coronary artery disease, and lower serum zinc levels (OR = 0.974, 95% CI = 0.950–0.999, p = 0.039) were significantly associated with E/e’ ratio >15. Furthermore, diabetes and lower serum zinc levels (OR = 0.978, 95% CI = 0.958–0.999, p = 0.041) were significantly associated with LAVI >34 mL/m2. Reduced serum zinc level was significantly associated with diastolic dysfunction among HD patients. Further prospective studies are warranted to investigate whether zinc supplementation can attenuate cardiac dysfunction in maintenance HD patients. 相似文献