全文获取类型
收费全文 | 1626篇 |
免费 | 83篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 41篇 |
妇产科学 | 37篇 |
基础医学 | 224篇 |
口腔科学 | 36篇 |
临床医学 | 117篇 |
内科学 | 437篇 |
皮肤病学 | 41篇 |
神经病学 | 201篇 |
特种医学 | 50篇 |
外科学 | 107篇 |
综合类 | 11篇 |
一般理论 | 1篇 |
预防医学 | 93篇 |
眼科学 | 39篇 |
药学 | 125篇 |
肿瘤学 | 146篇 |
出版年
2023年 | 14篇 |
2022年 | 12篇 |
2021年 | 27篇 |
2020年 | 20篇 |
2019年 | 14篇 |
2018年 | 25篇 |
2017年 | 31篇 |
2016年 | 33篇 |
2015年 | 31篇 |
2014年 | 45篇 |
2013年 | 74篇 |
2012年 | 104篇 |
2011年 | 90篇 |
2010年 | 64篇 |
2009年 | 46篇 |
2008年 | 103篇 |
2007年 | 89篇 |
2006年 | 115篇 |
2005年 | 107篇 |
2004年 | 124篇 |
2003年 | 120篇 |
2002年 | 101篇 |
2001年 | 34篇 |
2000年 | 30篇 |
1999年 | 28篇 |
1998年 | 21篇 |
1997年 | 21篇 |
1996年 | 9篇 |
1995年 | 12篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 19篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 19篇 |
1988年 | 15篇 |
1987年 | 19篇 |
1986年 | 9篇 |
1985年 | 3篇 |
1984年 | 12篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1972年 | 3篇 |
1964年 | 1篇 |
排序方式: 共有1716条查询结果,搜索用时 31 毫秒
1.
2.
Masahiro Yamauchi Hiroko Kusano Etsuko Saito Takeshi Iwata Masashi Nakakura Yasuki Kato Takaaki Uochi Shiro Akinaga Noboru Aoki 《Journal of controlled release》2006,114(2):268-275
Previously, we demonstrated that wrapping dextran fluorescein anionic/cationic lipid complexes with neutral lipids produced a stable formulation that markedly increased the duration of the compound in plasma after intravenous administration to rats. The improved drug-delivery properties of the wrapped liposomes (WL) relative to other formulations suggested that this technology could offer important advantages for the administration of other polyanionic drugs, including antisense oligodeoxynucleotides (ODN). In the present study, we investigated the value of WL for formulating fluorescence-labeled phosphorothioated ODN (F-ODN). WL encapsulating F-ODN/cationic lipid complexes were prepared efficiently using similar methodology to that used in our earlier study. Studies confirmed that these WL were stable in vitro. Following intravenous administration to mice, free F-ODN and naked F-ODN/cationic lipid complexes were rapidly eliminated whereas administration of the WL resulted in high blood concentrations of drug that were maintained for several hours. Additional studies were conducted in mice that were inoculated with tumor cells (Caki-1 xenograft model, human kidney); in these experiments, intravenous administration of WL delivered 13 times more F-ODN to the tumor site than achieved after injection of free F-ODN. 相似文献
3.
Summary Histological, ultrastructural and morphometrical observations on Clarke's column were carried out in 18 patients with sporadic amyotrophic lateral sclerosis (ALS) and 15 age-matched control subjects. Of the 18 ALS patients 6 had been on a respirator before death. Bunina bodies were found in the neuronal cytoplasm in 7 of the 12 non-respirator-supported ALS patients and in 3 of the 6 respirator-supported patients. The number of spheroids was significantly higher in the non-respirator-supported patients (P<0.01) than in the control subjects; however, the number in the respirator-supported patients was about equal to that in the controls. The number of neurons in Clarke's column in the non-respirator-supported ALS patients was not reduced, but in the respirator-supported patients they tended to disappear with time after respiratory support. These findings suggest that Clarke's column neurons are also involved primarily in the disease process in sporadic ALS. However, they may begin to disappear only after the patients require respiratory support.Supported in part by a research grant for CNS degenerative diseases from the Ministry of Health and Welfare, Japan 相似文献
4.
5.
6.
Etsuko Odawara 《The American journal of occupational therapy》2005,59(3):325-334
The purposes of this paper are two. The first purpose is to contribute to cultural competence in occupational therapy practice. The second is to contribute to occupational therapy literature about culture and cultural analysis related to practice. This paper introduces a cultural analysis of stories about the therapeutic process with two Japanese therapists and their Japanese patients. Two therapeutic situations, including therapists' and their patients' experiences, are interpreted by the author, a Japanese occupational therapist, as critical incidents for reflection to improve culture general competence. The stories illustrate the patients' perception of life with illness and, particularly, the emergence of their cultural values within the therapy process. The analyses focus on how an understanding of the patients' illness experience is integrated into the therapy process and how the therapeutic interventions reflect the culture. In one case, the therapeutic occupation of cooking links to the meaning found in the traditional Japanese woman's role. In the second case, the therapist-patient relationship, based on local rather than western social relationships, promoted the patient's engagement in meaningful occupations. Reflection on these stories, which illustrate an alternative cultural view of occupations and therapeutic relationships, may assist occupational therapists in the development of improved level of cultural competence. 相似文献
7.
Kagayaki Kuroda Daisuke Kokuryo Etsuko Kumamoto Kyohei Suzuki Yuichiro Matsuoka Bilgin Keserci 《Magnetic resonance in medicine》2006,56(4):835-843
Referenceless, or self-reference, thermometry is a technique for mapping temperature differences in the region of interest (ROI) using the baseline phase estimated by extrapolating the field in the surrounding region for estimation (RFE) and subtracting the estimated baseline from the measured field. In the present work a self-reference technique based on complex field estimation using 2D polynomials comprising complex-valued coefficients was proposed and optimized. Numerical simulations with a Gaussian-profiled phase distribution demonstrated that the ROI radius had to be 2.3-2.5 times the standard deviation (SD) of the Gaussian function in order to keep the error below 8% of the peak phase change. The area ratio between the ROI and the RFE had to be larger than 2.0 to maintain the error level. Based on the simulations, and phantom and volunteer experiments, the complex-based method with independently optimized polynomial orders for the two spatial dimensions was compared with the phase-based method using the similar-order optimization strategy. The complex-based method appeared to be useful when phase unwrapping was not removed. Otherwise, the phase-based method yielded equivalent results with less polynomial orders. 相似文献
8.
John Evans Pablo Bringas Jr. Masanori Nakamura Etsuko Nakamura Valentino Santos Professor Harold C. Slavkin 《Calcified tissue international》1988,42(4):220-230
Summary Biomineralization was investigated using embryonic mouse mandibular first molars (M1) cultured in the presence or absence of fetal calf serum. Metabolic features including cell division and Ca2+ and phosphate incorporation into dentine and enamel extracellular matrices were analyzed. The relative timing and magnitude
of DNA synthesis for serumless cultures was comparable toin vivo controls. Isotopic calcium and phosphate incorporation into the mineral phase of dentine and enamel matrices, in the absence
of serum, fluctuated during development. Molar tooth morphogenesis, cytodifferentiation, and extracellular matrix formation
approximated late crown-stage development in serumless cultures. Von Kossa histochemical staining indicated calcium phosphate
salt formation in serumless cultures. Analysis of anhydrous fixation-prepared enamel and dentine representing serumless cultured
explants indicated that crystal size and orientation were comparable toin vivo enamel and dentine. In contrast, serum-supplemented cultures showed atypical crystal size and orientation. Calcium/phosphorous
(Ca/P) ratio values for serumless cultures after 21 days showed Ca/P enamel values of 2.03 (SD±0.04, p<0.025) and dentine
values of 1.89 (SD±0.01, p<0.025). Electron diffraction patterns of enamel and dentine formed in serumless cultures were principally
those of highly-ordered crystalline hydroxyapatite. Our results suggest that tissue-specific dentine and enamel biomineralization
is regulated by endogenous factors intrinsic to the developmental program of embryonic tooth organs during serumless culture. 相似文献
9.
Noriyuki Kimura Toshihide Kumamoto Hidetsugu Ueyama Hideo Horinouchi Eisaku Ohama 《Neuropathology》2007,27(6):522-530
We examined the role of the 20S proteasome in pathologic changes, including abnormal aggregation of phosphorylated neurofilaments, of spinal motor nerve cells from aluminum‐treated rabbits. Immunohistochemistry for the 20S proteasome revealed that many lumbar spinal motor neurons without intracytoplasmic neurofilamentous inclusions or with small inclusions were more intensely stained in aluminum‐treated rabbits than in controls, whereas the immunoreactivity was greatly decreased in some enlarged neurons containing large neurofilamentous inclusions. Proteasome activity in whole spinal cord extracts was significantly increased in aluminum‐treated rabbits compared with controls. Furthermore, Western blot analysis indicated that the 20S proteasome degraded non‐phosphorylated high molecular weight neurofilament (neurofilament‐H) protein in vitro. These results suggest that aluminum does not inhibit 20S proteasome activity, and the 20S proteasome degrades neurofilament‐H protein. We propose that abnormal aggregation of phosphorylated neurofilaments is induced directly by aluminum, and is not induced by the proteasome inhibition in the aluminum‐treated rabbits. Proteasome activation might be involved in intracellular proteolysis, especially in the earlier stages of motor neuron degeneration in aluminum‐treated rabbits. 相似文献
10.
This report describes an experimental model of chronic tonsillar herniation and its effects on the spinal cord. In ten rats, a small piece of chemically induced mammary cancer was transplanted to the supraoccipital bone. In all cases, the transplanted cancers grew into the posterior fossa, destroying the supraoccipital bone and compressing the cerebellum extradurally. In six of the ten rats, tonsillar herniation was observed at 8–14 weeks after transplantation. Transdural infiltration of the tumor cells was not apparent in any animal. In those rats with tonsillar herniation (n=6), the spinal cord from the C5 to the T8 segments showed enlargement of the central canal without exception. Histological examination revealed the following changes: stretching and thinning of the ependymal cells; swelling of the astrocytic processes; and extracellular edema, predominantly in the dorsal gray matter, but also in the ventral inner portion of the dorsal column. In the control group (n=4) and those rats without tonsillar herniation (n=4), such histological changes of the spinal cord were not observed. Although the lesions can not be regarded as representing mature syringomyelia, they most likely constitute an earlier evolutionary stage. 相似文献