首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2007篇
  免费   86篇
  国内免费   11篇
医药卫生   2104篇
  2023年   9篇
  2022年   24篇
  2021年   48篇
  2020年   27篇
  2019年   24篇
  2018年   32篇
  2017年   29篇
  2016年   35篇
  2015年   44篇
  2014年   63篇
  2013年   72篇
  2012年   118篇
  2011年   132篇
  2010年   71篇
  2009年   61篇
  2008年   152篇
  2007年   131篇
  2006年   112篇
  2005年   135篇
  2004年   143篇
  2003年   132篇
  2002年   117篇
  2001年   44篇
  2000年   30篇
  1999年   34篇
  1998年   37篇
  1997年   31篇
  1996年   22篇
  1995年   24篇
  1994年   27篇
  1993年   21篇
  1992年   15篇
  1991年   11篇
  1990年   19篇
  1989年   6篇
  1988年   9篇
  1987年   4篇
  1986年   3篇
  1985年   5篇
  1984年   4篇
  1983年   6篇
  1981年   3篇
  1980年   3篇
  1979年   3篇
  1978年   4篇
  1970年   3篇
  1969年   3篇
  1968年   3篇
  1967年   2篇
  1959年   2篇
排序方式: 共有2104条查询结果,搜索用时 15 毫秒
81.

Background

We retrospectively investigated prognostic factors to be used in selecting the patients with stage IV gastric cancer (GC) who have an unfavorable prognosis after palliative gastrectomy.

Methods

A total of 146 GC patients at stage IV who had undergone palliative gastrectomy were enrolled. Various clinicopathological parameters were evaluated for prognosis.

Results

Surgical morbidity and hospital mortality occurred in 35 (23.9 %) and 4 (2.7 %) patients, respectively. The overall 5-year survival rate and the median survival time were 11.2 % and 13.2 months, respectively. Of the 146 patients, 64 had uncomfortable symptoms associated with GC and 76 had no such symptoms. Of the 64 patients with uncomfortable symptoms, 60 (93.7 %) experienced relief of these symptoms after palliative surgery. Multivariate analysis for patients without uncomfortable symptoms associated with GC revealed that the number of incurable factors and serum SPan-1 level were independent prognostic factors.

Conclusions

Patients with stage IV GC who had multiple incurable factors and a high level of serum SPan-1 might not be candidates for palliative gastrectomy for the purpose of prognostic benefit.  相似文献   
82.
Cold atmospheric plasma has already been shown to decrease the bacterial load in chronic wounds. However, until now it is not yet known if plasma treatment can also improve wound healing. We aimed to assess the impact of cold atmospheric argon plasma on the process of donor site healing. Forty patients with skin graft donor sites on the upper leg were enrolled in our study. The wound sites were divided into two equally sized areas that were randomly assigned to receive either plasma treatment or placebo (argon gas) for 2 minutes. Donor site healing was evaluated independently by two blinded dermatologists, who compared the wound areas with regard to reepithelialization, blood crusts, fibrin layers, and wound surroundings. From the second treatment day onwards, donor site wound areas treated with plasma (n = 34) showed significantly improved healing compared with placebo‐treated areas (day 1, p = 0.25; day 2, p = 0.011; day 3, p < 0.001; day 4, p < 0.001; day 5, p = 0.004; day 6, p = 0.008; day 7, p = 0.031). Positive effects were observed in terms of improved reepithelialization and fewer fibrin layers and blood crusts, whereas wound surroundings were always normal, independent of the type of treatment. Wound infection did not occur in any of the patients, and no relevant side effects were observed. Both types of treatment were well tolerated. The mechanisms contributing to these clinically observed effects should be further investigated.  相似文献   
83.
84.
Di-2-ethylhexyl phthalate (DEHP) is the most commonly used phthalate for the production of flexible polyvinyl chloride. Recent studies in humans reported a widespread DEHP exposure, raising concerns in infants whose metabolic and excretory systems are immature. DEHP is a potential endocrine-disrupting chemical, but the effects of postnatal DEHP exposure on neuronal development are unclear. The dentate gyrus (DG) is critical in the consolidation of information from short- to long-term memory, as well as spatial learning. We evaluated neurodevelopmental toxicity due to neonatal DEHP exposure by assessing neurogenesis in the DG. Newborn mice were orally administered DEHP from postnatal day (PND) 12 to 25. We performed immunostaining using neuronal markers at different stages to assess whether DEHP exposure affects neurons at specific differentiation stages at PND 26 and PND 110. We found that in mice, postnatal DEHP exposure led to a decrease in the number of Type-1, -2a, -2b, and -3 neural progenitor cells, as well as granule cells in the hippocampal DG at PND 26. Further, the results showed that neural progenitor cell proliferation and differentiation were also reduced in the hippocampal DG of the DEHP-exposed mice. However, no effect on memory and learning was observed. Overall, our results suggest that neurodevelopmental toxicity due to postnatal DEHP exposure might affect postnatal DG morphogenesis.  相似文献   
85.
86.
Bisphenol A (BPA), 4‐nonylphenol (NP) and butyl benzyl phthalate (BBP), termed endocrine‐disrupting chemicals, are known to mimic estrogen activity. The effects of these chemicals on 17β‐estradiol (E2) metabolism in vivo in rats were examined. Male and female rats were given NP (250 mg kg–1 day–1), BPA (250 μg kg–1 day–1) or BBP (500 mg kg–1 day–1) by gavage for 14 days, followed by a single intraperitoneal injection of E2 (5 mg kg–1) on the final day. The urinary excretion over 72 hours of 2‐hydroxyestrone 1‐N‐acetylcysteine thioether, 2‐hydroxyestrone 4‐N‐acetylcysteine thioether, 4‐hydroxyestrone 2‐N‐acetylcysteine thioether, 2‐hydroxy‐17β‐estradiol (2‐OHE2), 2‐hydroxyestrone (2‐OHE1), 4‐hydroxy‐17β‐estradiol, 4‐hydroxyestrone, 15α‐hydroxyestriol (E4), 15α‐hydroxy‐17β‐estradiol and 15α‐hydroxyestrone was measured. Increases in urinary excretion of 2‐OHE1 and decreases in E4 were observed in males treated with NP or BBP. Decreases in urinary excretion of 2‐OHE2 and E4 were observed in males treated with BPA. Decreases in urinary excretion of 2‐OHE1 and 2‐OHE2 were observed in females treated with BBP. Normalized liver and weights were increased in both sexes treated with NP or BBP. Histologic observations revealed marked changes in the distal tubules and collecting ducts in the kidneys of rats exposed to NP and BBP, and hypertrophy in the hepatocytes of the centrilobular zone of the liver. No BPA‐related effects on organ weight and on liver or kidney histopathology were found. These results suggest that the 14 day oral dosing of NP and BBP disrupted E2 metabolism, resulting from marked morphological and functional alterations in the liver and kidneys. In addition, BPA could induce metabolic and endocrine disruption.  相似文献   
87.
88.
A 55-year-old man was admitted to our hospital because of myelopathy. He had a history of chronic renal failure due to polycystic kidney disease at the age of 39, being treated by hemodialysis for 9 years with several blood transfusions for the treatment of renal anemia. After cadaver renal transplantation at the age of 48, he discontinued hemodialysis. At 50 years of age, he had pulmonary tuberculosis and tuberculous arthritis of the left elbow joint. He has experienced difficulty in walking since he was 48 years old, with mild dysuria. Gait disturbance gradually aggravated after that, and urinary retention was observed. When he was 55 years old, being human T-cell lymphotropic virus type-1 (HTLV-1)-positive in the serum and cerebrospinal fluid, he was diagnosed as having HTLV-1-associated myelopathy (HAM). As active steroid therapy was unapplicable because of the history of pulmonary tuberculosis and immunosuppression for transplanted kidney, a series of plasma exchanges (PE) was performed with fresh frozen plasma as a replacement fluid. After PE, dyskinesia of the left leg and dysuria subjectively and objectively improved. These results suggest that PE seems to be one of the therapeutic tools for the treatment of HAM.  相似文献   
89.
An all-solution-processed transparent tin oxide (SnO2)-based humidity sensor was directly prepared on borosilicate glass (SnO2–G) and a flexible polyethylene terephthalate (SnO2–PET) substrate without using a template. The entire process included film deposition by a spin-spray process at 90 °C and subsequent hot water treatment (HWT) at 100 °C. The resistivity of the films dramatically decreased and had semiconductor characteristics after the HWT, even though the as-prepared SnO2–G and SnO2–PET samples were insulators. Based on the results, the variation of the resistivity could be attributed to the formation of a hydroxyl layer on the crystallized SnO2 surface. With the help of the HWT on the SnO2 films, the formation of tin hydroxyl derivatives provided mobile protons, which led to the variation of the electrical properties of SnO2 at ambient conditions with different humidities. The sensitivity of the SnO2–G-HWT and SnO2–PET-HWT at 95% relative humidity (RH) was 35.2 and 3.5 times higher, respectively, than that at 5% RH. Both the sensitivity of the SnO2–G-HWT and SnO2–PET-HWT samples showed a good uptrend corresponding to the increase of RH at 20 ± 1 °C, and the response/recovery time of SnO2–G-HWT and SnO2–PET-HWT was 51/38 s and 69/47 s in the % RH range of 30–70% at 20 ± 1 °C, respectively.

An all-solution-processed transparent tin oxide (SnO2)-based humidity sensor was directly prepared on borosilicate glass (SnO2–G) and a flexible polyethylene terephthalate (SnO2–PET) substrate without using a template.  相似文献   
90.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号