全文获取类型
收费全文 | 61652篇 |
免费 | 4020篇 |
国内免费 | 1068篇 |
学科分类
医药卫生 | 66740篇 |
出版年
2023年 | 508篇 |
2022年 | 894篇 |
2021年 | 2079篇 |
2020年 | 1358篇 |
2019年 | 1508篇 |
2018年 | 1669篇 |
2017年 | 1408篇 |
2016年 | 1519篇 |
2015年 | 1862篇 |
2014年 | 2455篇 |
2013年 | 3074篇 |
2012年 | 4118篇 |
2011年 | 4198篇 |
2010年 | 2456篇 |
2009年 | 2338篇 |
2008年 | 3577篇 |
2007年 | 3680篇 |
2006年 | 3360篇 |
2005年 | 3217篇 |
2004年 | 3003篇 |
2003年 | 2572篇 |
2002年 | 2288篇 |
2001年 | 1528篇 |
2000年 | 1420篇 |
1999年 | 1348篇 |
1998年 | 587篇 |
1997年 | 458篇 |
1996年 | 447篇 |
1995年 | 367篇 |
1994年 | 330篇 |
1993年 | 287篇 |
1992年 | 720篇 |
1991年 | 624篇 |
1990年 | 583篇 |
1989年 | 574篇 |
1988年 | 484篇 |
1987年 | 448篇 |
1986年 | 435篇 |
1985年 | 346篇 |
1984年 | 286篇 |
1983年 | 237篇 |
1982年 | 136篇 |
1981年 | 111篇 |
1979年 | 218篇 |
1978年 | 137篇 |
1977年 | 119篇 |
1974年 | 126篇 |
1973年 | 128篇 |
1972年 | 129篇 |
1971年 | 113篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Nutritional follow-up after total gastrectomy 总被引:1,自引:0,他引:1
103.
104.
甘肃省1995年共报告15岁以下儿童急性弛缓性麻痹(AFP)病例90例,发病率为1.32/10万。省脊髓灰质炎(脊灰)实验室收到AFP病例的粪便标本共79例,占88%;双份合格粪便标本采集率为68%(61/90);粪便标本7天内送省脊灰实验室的占65%(52/79)收到粪便标本后7天内分离培养的占89%(70/79);分离培养结果及时报告率为87%(69/79)。病毒分离阳性率13.92%(11/79),其中脊灰病毒(PV)Ⅱ型5株,Ⅲ型1株,非脊灰肠道病毒(NPEV)5株。收到AFP病例密切接触者粪便标本3l8份,病毒分离阳性率5.66%(18/318),其中PVⅡ型8株,NPEV10株。全部送检粪便标本NPEV分离率3.78%(15/397)。所分离的PV均为疫苗株,且Ⅱ型居多。 相似文献
105.
Daily nutrient intake represents a modifiable determinant of nutritional status in chronic haemodialysis patients. 总被引:2,自引:0,他引:2
Vincenzo Bellizzi Biagio R Di Iorio Vincenzo Terracciano Roberto Minutolo Carmela Iodice Luca De Nicola Giuseppe Conte 《Nephrology, dialysis, transplantation》2003,18(9):1874-1881
BACKGROUND: In maintenance haemodialysis patients, daily food intake is changeable; however, its relationship with nutritional status is unexplored. This study aimed to evaluate the isolated, long-term effect of daily nutrient intake on nutritional status in haemodialysis patients. METHODS: We performed a prospective 1-year controlled study in 27 chronic haemodialysis patients, without recognized risk factors for malnutrition. Each day for 1 week, four times in the year, we measured protein nitrogen appearance, and assessed dietary protein (DPI) and energy (DEI) intake from dietary diaries. We compared the nutritional outcome of patients spontaneously reducing nutrient intake below the threshold of 0.8 g/kg body weight/day for DPI and 25 kcal/kg body weight/day for DEI during the week (LOW, n = 8), with controls at adequate nutrient intake (CON, n = 19). An interventional 6-month study was then carried out in LOW to verify the cause-effect relationship. RESULTS: All patients showed a day-by-day reduction of whole nutrient intake during interdialytic period, which was mostly relevant in the third interdialytic day (L3). During the 1-year study, even in the presence of adequate dialysis dose and normal inflammatory indexes, body weight (68.0 +/- 5.5 to 65.8 +/- 5.9 kg), serum albumin (3.96 +/- 0.07 to 3.66 +/- 0.06 g/dl) and creatinine (9.2 +/- 1.1 to 8.1 +/- 0.7 mg/dl) significantly decreased in LOW but not in CON. Diaries evidenced in LOW a reduced number of meals at L3 that was explained by the fear of excessive interdialytic weight gain. During the interventional study, daily DPI and DEI increased at L3; this was associated with a significant increment of body weight, and serum albumin and creatinine levels. CONCLUSIONS: In maintenance haemodialysis patients the persistent, marked reduction of daily nutrient intake, even if limited to a single day of the week, is an independent determinant of reversible impairment of nutritional status. 相似文献
106.
Ultrafiltration and solute transport during 60-min peritoneal dialyses of normal rabbits with intraperitoneal administration of phosphatidylcholine were compared to control values. The ultrafiltration rate of 0.27 mL/Kg/min did not increase when phosphatidylcholine was added. This agent had no effect on the ultrafiltration coefficient, sodium mass transport or solute clearances. Previously reported beneficial results with this agent could be due to repletion of a deficiency or an effect of the organic solvent. More studies of safety and efficacy of phosphatidylcholine are warranted before widespread clinical use. 相似文献
107.
Sir, We are writing to provide some clarifications on the EditorialComment by Drüeke et al. [1]. We would have been happyto provide these very same clarifications had we been fairlyinvited to do so before the publication of the article. First of all, we would like to 相似文献
108.
109.
110.
目的分析对比不同时期军队疗养员消化性溃疡(PU)的患病情况。方法采用相同的病史采集和问卷调查法,以胃镜检查资料为确诊手段,对1990年和2005年两个年度的疗养员进行消化性溃疡流行病学调查。结果1990年军队疗养员消化性溃疡的患病率为158/1168人(13.53%);2005年为56/1239人(4.52%),二者相比有显著性差异P〈0.01。结论由于保健意识、生活方式和药物治疗的干预,十五年间,军队疗养员消化性溃疡的发病率显著下降。 相似文献