全文获取类型
收费全文 | 17339篇 |
免费 | 1829篇 |
国内免费 | 779篇 |
专业分类
耳鼻咽喉 | 185篇 |
儿科学 | 286篇 |
妇产科学 | 181篇 |
基础医学 | 1414篇 |
口腔科学 | 557篇 |
临床医学 | 2081篇 |
内科学 | 2017篇 |
皮肤病学 | 129篇 |
神经病学 | 608篇 |
特种医学 | 823篇 |
外科学 | 1867篇 |
综合类 | 3614篇 |
现状与发展 | 5篇 |
一般理论 | 2篇 |
预防医学 | 1832篇 |
眼科学 | 222篇 |
药学 | 2042篇 |
23篇 | |
中国医学 | 1172篇 |
肿瘤学 | 887篇 |
出版年
2024年 | 55篇 |
2023年 | 192篇 |
2022年 | 444篇 |
2021年 | 601篇 |
2020年 | 482篇 |
2019年 | 315篇 |
2018年 | 305篇 |
2017年 | 399篇 |
2016年 | 286篇 |
2015年 | 581篇 |
2014年 | 758篇 |
2013年 | 930篇 |
2012年 | 1333篇 |
2011年 | 1426篇 |
2010年 | 1258篇 |
2009年 | 1118篇 |
2008年 | 1233篇 |
2007年 | 1181篇 |
2006年 | 1064篇 |
2005年 | 877篇 |
2004年 | 646篇 |
2003年 | 635篇 |
2002年 | 460篇 |
2001年 | 430篇 |
2000年 | 407篇 |
1999年 | 194篇 |
1998年 | 91篇 |
1997年 | 98篇 |
1996年 | 105篇 |
1995年 | 89篇 |
1994年 | 78篇 |
1993年 | 71篇 |
1992年 | 150篇 |
1991年 | 134篇 |
1990年 | 117篇 |
1989年 | 138篇 |
1988年 | 129篇 |
1987年 | 107篇 |
1986年 | 81篇 |
1985年 | 88篇 |
1984年 | 73篇 |
1983年 | 51篇 |
1982年 | 42篇 |
1979年 | 48篇 |
1978年 | 52篇 |
1977年 | 41篇 |
1975年 | 45篇 |
1974年 | 40篇 |
1973年 | 38篇 |
1971年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的 探讨老年人颅脑损伤的发病因素和护理措施.方法 对1999~2003年在解放军总医院定点就医的一组老年人群(年均18 492人)共210例颅脑损伤患者发病时的身体状况,发病率及受伤特点,病程及治疗和护理等临床资料进行回顾性总结.该组老年人在建档案时已被分为2个亚组:超高龄组年龄限(平均年龄79.75岁,1 978例)和老年组年龄限(平均年龄69.42岁,16514例).以同期其他人群的脑损伤187例作为对照组,并进行2组回顾资料的比较.结果 按意向处理分析397例均进入结果分析.发病率及受伤特点:超高龄组发病率明显高于老年组,多为摔伤;老年组和对照组均为交通伤占主要伤因.治疗及病程:对照组和老年组中均有超过80%患者接受手术治疗,而超高龄组仅有53.40%的患者接受手术治疗.预后:各组的死亡率和重残比率均无明显差别.结论 老年人群的脑损伤致伤原因主要是摔伤,同时多患有单器官或多器官的疾病;老年人脑损伤占用医疗资源多,但经积极治疗和采取有效的护理措施,仍可获得较好的疗效;回顾性资料记载超高龄组是能够检索到的国内外老年人脑损伤平均年龄最高的一组,对超高龄脑损伤的相关分析是有临床借鉴意义的. 相似文献
2.
3.
4.
目的:探讨降低喉返神经损伤的方法。方法:2005年9月-2007年1月共有375例甲状腺手术患者,对其喉返神经损伤进行分析。结果:375例病人中有5例喉返神经损伤,其中甲状腺腺瘤3例,桥本甲状腺炎1例,甲状腺癌1例,损伤后立即行喉镜检查示声带处于外展位。给予营养神经治疗,15 d-3个月后完全恢复,喉镜检查示声带正常。结论:喉返神经损伤可以预防,关键是术者应熟悉喉返神经的解剖结构和变异,熟悉其与周围组织及血管的关系,要有手术区域的组织结构特别是喉返神经走行的“立体影像”。 相似文献
5.
The association of circulating endotoxin with the development of the adult respiratory distress syndrome 总被引:6,自引:0,他引:6
P E Parsons G S Worthen E E Moore R M Tate P M Henson 《The American review of respiratory disease》1989,140(2):294-301
Despite extensive investigation, the pathogenesis of the adult respiratory distress syndrome (ARDS) remains uncertain. As yet, there is no clear explanation of why some patients at risk for ARDS develop the syndrome, whereas others do not. Neutrophils and complement fragments have been implicated in the acute lung injury, but it is clear from published data that evidence of complement activation alone predicts neither the development nor the severity of ARDS. We investigated whether the combination of endotoxin, a leukocyte-priming agent, and complement fragments, leukocyte-stimulating agents, was associated with the development of ARDS. Ninety-eight patients were identified as being either at risk for the development of ARDS or having ARDS, and serial blood samples were obtained. There was no correlation between C5 fragments and the development of ARDS. C3 fragment levels were increased in 89% of the patients with ARDS, but they were also increased in 62% of patients at risk. Endotoxin was detected in 74% of the plasma samples obtained from patients at risk who subsequent developed ARDS and in 64% of the plasma samples obtained from the patients with ARDS. In contrast, only 22% of the plasma samples obtained from the patients at risk who did not develop ARDS had measurable endotoxin. We suggest that the combination of endotoxin and complement fragments may be one mechanism involved in the development of ARDS. 相似文献
6.
目的建立滑膜炎颗粒剂中原儿茶醛的含量测定方法质量。方法采用高效液相色谱法对方中原儿茶醛进行含量测定。结果高效液相色谱法测定结果表明原儿茶醛在0.1005~1.005μg范围内呈线性关系,平均加样回收率为99.22%;RSD为0.72%。结论本法简便,重现性好、结果可靠,可作为控制滑膜炎颗粒剂的质量方法。 相似文献
7.
Breuer J.; Moniz C.; Baldwin D.; Parsons V. 《Nephrology, dialysis, transplantation》1987,2(5):347-350
The effect of oral magnesium carbonate aluminium hydroxide onserum ionised calcium, total calcium, aluminium and magnesium,was assessed in 31 patients with chronic renal failure, duringand after one haemodialysis. The behaviour of ionised calcium and total calcium was the samein both groups. Each showed a slight fall during dialysis, whichwas not significant. Serum total calcium was 0.20.3 mmol/l(0.81.2 mg/dl) greater throughout the period of dialysisin the group taking aluminium hydroxide. Serum magnesium andaluminium were both lower in the group treated with magnesiumcarbonate. In the group taking magnesium carbonate, serum magnesium concentrationsfell markedly during dialysis, but otherwise were maintainedwithin the reference range by the use of a magnesium-free dialysate.These results show the effectiveness of magnesium carbonateoral phosphate-binding agents and zero magnesium dialysate inreducing serum aluminium without affecting the behaviour ofserum calcium fractions during dialysis. 相似文献
8.
C. L. Parsons 《World journal of urology》1994,12(1):38-42
Summary Investigations into the antibacterial defense mechanisms of the urinary tract revealed an important function for cell surface glycosaminoglycans (GAG), that of a generalized antiadherent activity. This activity was found to prevent bacterial, protein, and ionic adherence to the cell membrane. A model was developed to explain mechanically the activity of sulfated polysaccharides at the bladder surface. The model predicted injurious effects of quaternary amines and also that the mucus would be the so-called blood-urine barrier. It also led to the hypothesis that exogenous polysaccharides may be important in treating bladder disease such as infection and interstitial cystitis. For the first clinical test of these concepts, a polysaccharide was employed in several double-blind studies and was shown to ameliorate significantly the symptoms of interstitial cystitis. These discoveries suggest new methods to manipulate the microenvironment between the transitional cell surface and the urine, leading to novel therapies in regulating disease of the genitourinary tract. They also stress the importance of understanding the mechanisms by which GAGs exert their effect in the urinary tract and how they are produced, maintained, and even inactivated (e.g., by urinary substances such as protamine).Supported by the Medical Research Service of the Veterans Administration, Urological Research and Education Foundation, and by National Institutes of Health grant R01DK39239. 相似文献
9.
Darren S Parsons David A Reaveley Darrell V Pavitt Madhukar Misra Edwina A Brown 《Nephrology, dialysis, transplantation》2003,18(9):1848-1853
BACKGROUND: Studies have reported an increase in median Lipoprotein (Lp) (a) in patients with high molecular weight (HMW) apolipoprotein (apo) (a) isoforms and renal impairment. Some studies identify Lp (a) levels as a risk factor for vascular disease in renal failure whilst others have demonstrated an association with apo (a) isoform type and vascular disease. METHODS: A total of 239 patients at end-stage renal failure (ESRF) were studied prior to the initiation of dialysis. Blood was taken for Lp (a) levels and apo (a) isoforms. Clinical vascular disease (CVD) was assessed on the basis of clinical history and Rose questionnaire. The control group for Lp (a) levels consisted of 228 healthy volunteers. RESULTS: Despite a higher median Lp (a) level in those with HMW isoforms, 30% of patients had Lp (a) levels <10 mg/dl. Overall, 49% patients were identified as having CVD. Diabetes, smoking history and Lp (a) levels were significantly associated with CVD in logistic regression analysis, although when patients with low molecular weight (LMW) and HMW isoforms were analysed separately, Lp (a) levels were not significantly associated with CVD in those with LMW isoforms. The rates of CVD in those with HMW isoform and low Lp (a) levels were significantly lower than those with HMW isoforms and elevated Lp (a) levels, 34 vs 57% (P < 0.01). CONCLUSIONS: Although median Lp (a) levels in those patients at ESRF with HMW isoforms are higher than controls, in a third of such patients Lp (a) levels remain relatively low. These patients have lower rates of CVD than those with high levels of Lp (a). 相似文献
10.
C Piérard-Franchimont P Paquet P Quatresooz GE Piérard 《Journal of the European Academy of Dermatology and Venereology》2007,21(5):657-661
BACKGROUND: The observation of photo-exposed skin under ultraviolet light reveals a mosaic pattern of varying intensity in epidermal melanization. Several patterns of mosaic subclinical melanoderma (MSM) have been described using a specially designed CCD camera and the ultraviolet light-enhanced visualization (ULEV) method. Vitamin D(3) and its analogues influence the biology of keratinocytes and melanocytes. OBJECTIVE: To assess the effect of calcipotriol on MSM. METHODS: This randomized split-face study was conducted in 27 men to compare the effect of once daily applications of 5% calcipotriol cream or a moisturizing cream on the heterogeneity of facial MSM. Computerized image analysis of video images was used at 1-month intervals before and during a 2-month treatment, as well as during a 3-month follow-up. RESULTS: At both sites, the average melanin content of the epidermis showed no significant change over time. However, the mottled appearance was smoothened at the calcipotriol site, whereas it was increased at the site receiving the moisturizer. CONCLUSION: The decreased heterogeneity in MSM after calcipotriol applications suggests a control of the epidermal melanocyte unit by the vitamin D(3) derivative. 相似文献