全文获取类型
收费全文 | 3961篇 |
免费 | 244篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 78篇 |
妇产科学 | 50篇 |
基础医学 | 550篇 |
口腔科学 | 121篇 |
临床医学 | 305篇 |
内科学 | 1076篇 |
皮肤病学 | 75篇 |
神经病学 | 300篇 |
特种医学 | 136篇 |
外科学 | 516篇 |
综合类 | 17篇 |
一般理论 | 1篇 |
预防医学 | 156篇 |
眼科学 | 62篇 |
药学 | 359篇 |
中国医学 | 16篇 |
肿瘤学 | 381篇 |
出版年
2023年 | 17篇 |
2022年 | 36篇 |
2021年 | 99篇 |
2020年 | 73篇 |
2019年 | 78篇 |
2018年 | 94篇 |
2017年 | 59篇 |
2016年 | 57篇 |
2015年 | 105篇 |
2014年 | 110篇 |
2013年 | 148篇 |
2012年 | 262篇 |
2011年 | 244篇 |
2010年 | 128篇 |
2009年 | 107篇 |
2008年 | 212篇 |
2007年 | 232篇 |
2006年 | 240篇 |
2005年 | 223篇 |
2004年 | 213篇 |
2003年 | 198篇 |
2002年 | 167篇 |
2001年 | 72篇 |
2000年 | 91篇 |
1999年 | 89篇 |
1998年 | 63篇 |
1997年 | 44篇 |
1996年 | 35篇 |
1995年 | 37篇 |
1994年 | 33篇 |
1993年 | 34篇 |
1992年 | 68篇 |
1991年 | 52篇 |
1990年 | 58篇 |
1989年 | 53篇 |
1988年 | 36篇 |
1987年 | 43篇 |
1986年 | 36篇 |
1985年 | 41篇 |
1984年 | 29篇 |
1983年 | 20篇 |
1982年 | 12篇 |
1981年 | 12篇 |
1979年 | 20篇 |
1978年 | 20篇 |
1977年 | 13篇 |
1974年 | 9篇 |
1973年 | 12篇 |
1971年 | 16篇 |
1970年 | 19篇 |
排序方式: 共有4222条查询结果,搜索用时 15 毫秒
1.
Rebecca L. King Albert C. Yan Debora R. Sekiguchi John K. Choi 《Journal of cutaneous pathology》2015,42(12):1012-1017
Reactive lymphoid infiltrates of the skin composed predominantly of gamma‐delta (γδ) T cells are not well described in the literature. Herein we report a case of an otherwise healthy 4‐year‐old male who presented with a waxing and waning papular rash characterized by small, discrete crusted papules spread across his trunk, face and extremities. Clinical evaluation revealed no evidence of systemic disease. Microscopic examination revealed a dermal, perivascular infiltrate of highly atypical lymphocytes with a γδ T cell phenotype, worrisome for primary cutaneous γδ T cell lymphoma. The clinical course, however, was that of a reactive condition and prompted consideration of a diagnosis of pityriasis lichenoides et varioliformis acuta (PLEVA) and lymphomatoid papulosis (LyP). In many ways, this case defies current classification schemes and seems to expand the spectrum of reactive γδ T cell infiltrates of the skin. 相似文献
2.
Shingo Hashimoto Masaki Katsurada Rie Muramatsu Kumiko Asai Kenichiro Tanaka Kensuke Hayashi Yoshiaki Kibe Koichiro Nakajima Yukiko Hattori Hiromitsu Iwata Jun-etsu Mizoe Hiroyuki Ogino Yuta Shibamoto 《Practical radiation oncology》2019,9(2):e149-e155
Purpose
Suppression of respiratory movement of the liver would be desirable for high-precision radiation therapy for liver tumors. We aimed to investigate the effect of our original device-free compressed shell fixation method and breathing instruction on suppression of respiratory movement. The characteristics of liver motion based on the movement of a fiducial marker were also analyzed.Methods and Materials
First, respiratory amplitudes of the liver with the device-free compressed shell were analyzed from the data of 146 patients. The effect of this shell fixing method on liver movement was evaluated. Second, as another cohort study with 166 patients, interfractional internal motion of the liver for patients fixed in the shell was calculated using the fiducial marker coordinate data of images for position setting before daily irradiation. Third, in another 12 patients, intrafractional internal motion was calculated from the fiducial marker coordinate data using x-ray images before and after irradiation.Results
The median respiratory movement without the shell, after fixing with the shell, and after instructing on the breathing method with the shell was 14.2 (interquartile range, 10.7-19.8), 11.5 (8.6-17.5), and 10.4 mm (7.3-15.8), respectively. Systematic and random errors of interfractional internal motion were all ≤2 mm in the left-right and anteroposterior directions and 3.7 and 3.0 mm, respectively, in the craniocaudal direction. Systematic and random errors of intrafractional internal motion were all ≤1.3 mm in the left-right and anteroposterior directions and 0.8 and 2.4 mm, respectively, in the craniocaudal direction.Conclusions
The device-free compressed shell fixation method was effective in suppressing the respiratory movement of the liver. Irradiation position matching using the fiducial marker can correct the interfractional internal motion on each day, which would contribute to the reduction of the margin to be given around the target. 相似文献3.
4.
High incidence of nitrosamine-induced tumorigenesis in mice lacking DNA repair methyltransferase 总被引:12,自引:4,他引:8
Iwakuma T; Sakumi K; Nakatsuru Y; Kawate H; Igarashi H; Shiraishi A; Tsuzuki T; Ishikawa T; Sekiguchi M 《Carcinogenesis》1997,18(8):1631-1635
The enzyme O6-methylguanine-DNA methyltransferase repairs alkylation-
induced DNA damage, O6-methylguanine and O4-methylthymine, the former being
formed more frequently. Previously, by means of gene targeting, we
generated mice in which alleles for methyltransferase were disrupted. We
now use these mouse lines, which are totally deficient in methyltransferase
activity, to examine protective effects of the enzyme against tumor
formation. In gene-targeted female mice given an i.p. injection of 5 mg/kg
of dimethylnitrosamine, a larger number of liver and lung tumors occurred,
as compared with normal female mice treated in the same manner. In male
mice given a lower dose of carcinogen, the difference between normal and
gene-targeted mice was statistically insignificant although more tumors did
form in the gene-targeted mice. Methyltransferase apparently afforded
protection from nitrosamine- induced tumorigenesis.
相似文献
5.
6.
Yasuhiro Sano Shigeharu Yamashiro Asuka Komano Hisashi Maruko Hiroshi Sekiguchi Yasuo Takayama Ryoji Sekioka Kouichiro Tsuge Isaac Ohsawa Mieko Kanamori-Kataoka Yasuo Seto Akiyoshi Satoh 《Forensic Toxicology》2007,25(2):76-79
We previously reported that the Guardian Bio-Threat Alert (BTA) system could detect (detection limit: about 0.1 μg/ml) staphylococcal
enterotoxin B (SEB), botulinum toxins (BTX) A and B, and ricin, with no interference by white-powdered materials or colored
matrices. In this study, the capability of the BTA system was further assessed. With 10 min of preheating at 60°C, all toxins
could be detected, but with preheating at 80°C, BTX A and B and ricin became undetectable. About 20% SEB could be detected
after heating at 80°C, but this detection ability was completely removed after heating at 100°C. The effects of chemicals
usually used for decontamination, such as sodium hypochlorite, hydrogen peroxide, formaldehyde, and sodium nitrite, on the
detectability of SEB, BTX A, or ricin in the BTA system were also tested. The concentrations giving 50% line intensity for
SEB, BTX A, and ricin were 3.1, 11, and 15 μM for sodium hypochlorite and 88, 210, and 60 mM for formaldehyde, respectively.
The addition of hydrogen peroxide or sodium nitrite did not decrease the detectability even when used at high concentrations. 相似文献
7.
8.
Shinichiro Maeshima Jun Tanemura Aiko Osawa Miho Kawarada Eri Sekiguchi Toru Itakura 《Brain and nerve》2006,58(3):207-211
To investigate the usefulness of the frontal assessment battery (FAB) as a brief assessment for diagnosis in patients with dementia, we examined cognitive function using the FAB, Mini-mental state examination (MMSE), Kana-hiroi test, and Raven's colored progressive matrices (RCPM). Subjects were 82 senile patients having amnesia as a complaint including 28 Alzheimer's disease (AD), 14 frontotemporal dementia (FTD), 17 vascular dementia (VD), 13 mild cognitive impairment (MCI), and 10 healthy persons. We discussed the difference of scores in different types of dementia. In the FAB, the scores of healthy persons and MCI were much higher compared with the scores of all types of dementia. There were high correlation between FAB and MMSE, Kana-hiroi test, and RCPM. Although some subjects showed normal score in MMSE and/or RCPM, they showed low score in FAB. Based on this, FAB is efficient for the differential diagnosis of dementia as brief screening tool. 相似文献
9.
Temporal evolution of internal memory states in a terrestrial mollusk, Limax flavus, was studied using cooling-induced retrograde amnesia. The slug was conditioned to avoid carrot odor by temporally correlated presentation of carrot juice and a bitter-taste stimulus of quinidine sulfate. We could induce retrograde amnesia by cooling of the conditioned slug immediately after the training trial. Thus, we studied the memory states in the slug using the retrograde amnesia according to strategies used in the studies of memory states in mammals or insects. In the early process of memory acquisition, at least two distinctive memory states were observed, short-term memory and long-term memory (LTM). For LTM, two states were also observed. One was a reactivated state of LTM, which was sensitive to the cooling used to induce the amnesia. The other was a so-called resting state of LTM, which was insensitive to cooling. A few days after memory acquisition, further evolution was observed in that the amnesia could not be induced even if the memory trace was reactivated. The results obtained in Limax flavus was comparable with those obtained in a variety of animals. 相似文献
10.
Shinichiro Kitada Kumiko Kato Alan J. Wein Robert M. Levin 《Neurourology and urodynamics》1989,8(3):255-262
We were able to produce two highly reproducible experimental models (in the rabbit) that demonstrated a high degree of reflex bladder contractile activity. In one model, a somatovesical reflex was induced by touching or pinching the perineal area. This reflex may be organized through a neurogenic reflex at the spinal level. In another model, rhythmic bladder contractions were produced by distal urethral constriction in the absence of bladder distension. These rhythmic contractions were thought to be due to a supraspinal reflex. In both types of contractile reflexes, intravenous administration of hexamethonium inhibited the reflex contractile activity virtually completely, intravenous atropine inhibited over 90% of the induced contractile activity, thus suggesting that these contractions were mediated reflexly through cholinergic stimulation. These two models of reflex bladder contractions should be useful for the study of hyperreflexic bladders. 相似文献