全文获取类型
收费全文 | 2819篇 |
免费 | 110篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 84篇 |
妇产科学 | 15篇 |
基础医学 | 182篇 |
口腔科学 | 9篇 |
临床医学 | 783篇 |
内科学 | 243篇 |
皮肤病学 | 8篇 |
神经病学 | 22篇 |
特种医学 | 42篇 |
外科学 | 59篇 |
综合类 | 532篇 |
预防医学 | 444篇 |
眼科学 | 104篇 |
药学 | 192篇 |
2篇 | |
中国医学 | 48篇 |
肿瘤学 | 183篇 |
出版年
2024年 | 5篇 |
2023年 | 21篇 |
2022年 | 52篇 |
2021年 | 83篇 |
2020年 | 77篇 |
2019年 | 123篇 |
2018年 | 83篇 |
2017年 | 97篇 |
2016年 | 114篇 |
2015年 | 156篇 |
2014年 | 227篇 |
2013年 | 166篇 |
2012年 | 223篇 |
2011年 | 221篇 |
2010年 | 146篇 |
2009年 | 132篇 |
2008年 | 142篇 |
2007年 | 157篇 |
2006年 | 105篇 |
2005年 | 91篇 |
2004年 | 70篇 |
2003年 | 60篇 |
2002年 | 45篇 |
2001年 | 22篇 |
2000年 | 26篇 |
1999年 | 19篇 |
1998年 | 16篇 |
1997年 | 19篇 |
1996年 | 12篇 |
1995年 | 13篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1990年 | 3篇 |
1989年 | 8篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 26篇 |
1984年 | 31篇 |
1983年 | 16篇 |
1982年 | 17篇 |
1981年 | 14篇 |
1980年 | 18篇 |
1979年 | 17篇 |
1978年 | 14篇 |
1977年 | 3篇 |
1976年 | 11篇 |
1975年 | 10篇 |
1974年 | 5篇 |
1973年 | 9篇 |
排序方式: 共有2954条查询结果,搜索用时 15 毫秒
1.
Seunghan Ha Minhee Lee Onseok Lee Gunwoo Lee Jeayoung Kim Jongsub Moon Mingi Kim Chilhwan Oh 《Skin research and technology》2009,15(2):200-213
Background/aims: The objective and quantitative assessment of the skin is important in medical and cosmeceutical research. Assessment of color is an important element for analyzing the surface of the skin, which is usually determined subjectively by a doctor or using color analysis devices. These devices, however, cannot provide correct color information because color is construed from the mean value of the observation region, and analysis of color distribution is impossible. The purpose of this paper is to develop an objective analysis method to permit skin color measurement of each pixel unit of an image and analyze the distribution of skin surface color. Methods: The Skin Color Distribution Analyzer (SCDA) is an analysis method newly developed at the Research Institute for Skin Image at Korea University. The SCDA system presented in this paper performed a novel form of quantitative and objective analysis of skin color distribution using each pixel color model parameter found in image wavelength information. In this paper, distribution analysis was conducted on normal skin and skin lesions and skin affected by artificially induced irritant contact dermatitis and pigmented nevous. The method selected a grade using a color model parameter. Twenty healthy Korean males participated in this study. A comparative study of the eight anatomical areas was performed, including the exposure and non‐exposure parts and the medial aspect and the lateral aspect of the forearm. A reliability test for the SCDA system was also conducted with a spectrometer (SPEC) using the color analysis method. Results: Each skin lesion was precisely segmented by grade and each parameter hada different statistical significance for results of analysis of distribution in pigmented nevous and the artificially induced irritant contact dermatitis. Parameters L*, b*, a*, and EI showed salient traits. Showed resemble measured result in the SCDA system and the SPEC of normal skin. The exposed site, in comparison with the non‐exposed site, showed a notable difference in the L* parameter and a significant statistical difference in the x and z parameters, except b*. The comparison of the medial and lateral aspects of the forearm showed a notable difference in the L* parameter and a significant statistical difference in the parameters except y and b*. In the reliability test result using the SCDA system and the SPEC, the SCDA system was highly reliabile in terms of the CV value in all color model parameters. Conclusions: The color distribution analysis method using the SCDA system has revealed an aspect that the existent method of medical research has not shown, and is considered to be more reliable than other methods. This method can provide better study findings because it can be applied to other fields in addition to the medical science field and the ripple effect is thought to be bigger in other science field too. 相似文献
2.
生化自动分析仪在进行噪音核查和反应限核查之前,均已完成线性核查,已确定线性反应区,从吸光度-时间回归线计算出每分钟吸光度变化速度(△A/min)。在此基础上进行噪音核查(Noise Check)和反应限核查(Reaction Limit Check)。 相似文献
3.
H. Iwata T. Otoshi N. Takada T. Murai S. Tamano T. Watanabe Y. Katsura S. Fukushima 《Urological research》1995,23(1):27-32
A series of 8 rat and 16 mouse invasive bladder carcinomas were investigated for the presence of silverstained nucleolar organizer regions (AgNORs) to clarify whether this parameter is applicable to the estimation of their invasive character. With regard to number of AgNORs per cell, neither rat nor mouse carcinomas showed any difference between invasive and noninvasive sites within the same tumor. However, the frequency of cancer cells bearing bizarre dots, irregular in size and shape, was significantly higher at sites of actual invasion. Quantitative data generated using an image analyzer revealed significantly lower values for NOR roundness and significantly larger NOR size in invasive sites than in noninvasive sites in all groups. Double staining for the proliferation marker proliferating cell nuclear antigen (PCNA) and AgNORs was performed on eight rat carcinomas and a close correlation between the two was confirmed. Thus the number of AgNORs in PCNA-positive cells was significantly greater than in PCNA-negative cells. Furthermore, a particularly strong correlation was observed for incidences of PCNA-positive cells and bizarre dots (P<0.01). The quantitative data also demonstrated significant differences in size and shape of dots. It is concluded that AgNORs have diagnostic value for the invasive character of bladder carcinomas. 相似文献
4.
5.
Atsuo Furuhashi M.D. Yasutaka Akasaki M.D. Masayasu Sato M.D. Koho Miyoshi M.D. 《Psychiatry and clinical neurosciences》1994,48(3):645-653
Abstract: The behavioral effects of ceroid-lipofuscin accumulation, induced by intraperitoneal administration of acetyl-ethyl-tetramethyl-tetralin (AETT) in Wistar rats for 3 months, were examined in the present studies. A significant increase in neuronal ceroid-lipofuscin was demonstrated neuropathologically as well as morphometrically. Although the AETT-intoxicated rats showed neither alteration of locomotor activity nor shock sensitivity, a significant impairment of learning ability, especially an acquisition trial in passive avoidance tests, was observed. Results of the present studies indicate the possibility that a diffuse lipofuscin accumulation causes a learning impairment in rats. The results also imply the possibility of a significant role of age-related lipofuscin accumulation in the dementing processes of human especially in the elderly. 相似文献
6.
C. Ferrero-Vacher I. Sudaka D. Jambou D. Vanhaeke F. Fischer J. Bayle 《Hematology and Cell Therapy》1997,39(3):149-158
An evaluation of the new automated hematology analyzer was performed in comparison with the Coulter STKS on 1,694 blood samples coming from the different departments of Nice University Hospital. The Cobas Vega showed very satisfactory results in terms of repeatability, reproducibility and linearity. Correlation with the STKS was excellent with the exception of the following parameters: red blood cell distribution index and the absolute values for eosinophils and basophils. Two qualities were particularly appreciable: absence of leukocyte carryover, and stability of the complete blood count and leukocyte differential count over a long period. Analysis of qualitative flags showed that the overall blood smear review rate was 47% for the Cobas Vega, not forgetting that optical microscopy detects 37% of all abnormalities. The STKS’s review rate was 49.5%. Flags commonly concerned the granulocytic lineage, 61% for the STKS and 48% for the Vega, with a false positive rate of 43.4% for the STKS compared with 22% for the Vega. The opposite phenomenon was observed with the flag for atypical lymphocytes which represented 11% of flags for the STKS and 25.6% for the Vega, with a false positive rate of 25.5% for the STKS and 34% for the Cobas Vega. This may be explained by the fact that lymphocyte abnormalities sometimes generated “granulocytic” flags on the STKS. Studies of the false negative rate carried out using light microscopy on 505 blood samples without flags on either system, detected the presence of a slight myelemia, and a few hyperbasophilic lymphocytes or plasmocytes in 18.6% of all cases. Finally, the Cobas Vega’s practicality was greatly appreciated and there was no trouble with breakdowns throughout the whole period of its use. 相似文献
7.
ABX MICROS 60-OT型血细胞分析仪的性能评价 总被引:1,自引:0,他引:1
目的 评价ABXMICROS 60 -OT(以下简称ABX -60 )血细胞分析仪的分析性能 ,推广临床应用。 方法 用EDTA -K2静脉抗凝血标本连续测定和每天随机插入常规标本测定及稀释法分别测定ABX -60的精密度 ,携带污染率和线性性能 ,并与COULTERJT -IR结果进行比较。 结果 ABX -60的批内和批间精密度的变异系数均 <5 ,病人标本测定携带污染率均≤ 0 4% ,对白细胞、红细胞、血红蛋白、血小板测定结果与COULTERJT -IR比较有良好的相关性。 结论 ABX -60是一种较为理想的中档血细胞分析仪 ,适合中心型单位使用。 相似文献
8.
Comparative study of two computerized semen motility analyzers 总被引:1,自引:0,他引:1
Semen analysis is one of the primary tests carried out to investigate the infertile male. Subjective evaluation of semen is often prone to observer bias and error. To eliminate this, a number of computerized semen analyzers have recently been introduced into the market and we have evaluated two of the more popular models, the Cell Soft Semen Analyzer and the Hamilton Thorn Motility Analyzer (HTM 2000). The Cell Soft identifies sperm on the basis of user defined values for cell size and luminosity whereas the Hamilton Thorn identifies sperm by motility, and then applies the computer-calculated average size and luminosity of all moving objects to non moving sperm cells. Semen samples from 25 normal donors and 25 subfertile patients were analyzed using these two models of computerized semen analyzers, and also by an experienced technician using both the Makler chamber and the hemocytometer. The results obtained from the two automated analyzers were compared with those obtained by subjective evaluation. Variation in sperm count and motility were analyzed according to the sperm density. Four groups, less than 30 million/ml with debris, less than 30 million/ml, 30-50 million/ml, and greater than 50 million/ml were studied. The majority of patients fit into the first two groups. We observed that the HTM 2000 is superior to the Cell Soft in evaluating sperm count within the patient population group. For our donor population with an average sperm count of greater than 85 million/ml both systems provide extremely accurate counts.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
9.
目的评价美国强生VITROS250全自动干化学分析仪器。方法运用相关统计学方法对VITROS250全自动干化学分析仪的精密度、相关性、抗胆红素干扰方面进行分析。结果VITROS250全自动干化学分析仪精密度高,回收率高,相关性好,抗干扰能力强。结论VITROS250全自动干化学分析仪适用于临床实验诊断中心(检验科)急诊化验室生化项目的检测。 相似文献
10.
目的 观察大黄提取液对脱矿釉质中钙溶出量的影响.方法 用不同浓度的大黄提取液和去离子水处理牙面后进行脱矿,ASCA生化分析仪对釉质脱矿后的脱矿液进行钙离子浓度的检测.结果 2 mg/ml和4 mg/ml大黄提取液处理后釉质钙溶出量<去离了水(P<0.01)、<1 mg/ml大黄提取液组(P<0.05),>2%氟化钠组但差异无统计学意义(P>0.05).1 mg/ml大黄提取液处理后釉质钙溶出量>2%氟化钠组(P<0.01),<去离子水组但差异无统计学意义(P>0.05).结论 2mg/ ml和4 mg/ml大黄提取液具有抑制脱矿釉质中钙溶出作用:2mg/ml大黄提取液为抑制钙溶出的起始有效浓度. 相似文献