全文获取类型
收费全文 | 8049篇 |
免费 | 514篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 195篇 |
妇产科学 | 95篇 |
基础医学 | 1257篇 |
口腔科学 | 161篇 |
临床医学 | 553篇 |
内科学 | 1873篇 |
皮肤病学 | 199篇 |
神经病学 | 891篇 |
特种医学 | 285篇 |
外科学 | 917篇 |
综合类 | 18篇 |
预防医学 | 313篇 |
眼科学 | 229篇 |
药学 | 638篇 |
中国医学 | 59篇 |
肿瘤学 | 889篇 |
出版年
2023年 | 60篇 |
2022年 | 113篇 |
2021年 | 225篇 |
2020年 | 106篇 |
2019年 | 117篇 |
2018年 | 199篇 |
2017年 | 162篇 |
2016年 | 187篇 |
2015年 | 182篇 |
2014年 | 272篇 |
2013年 | 309篇 |
2012年 | 453篇 |
2011年 | 558篇 |
2010年 | 322篇 |
2009年 | 265篇 |
2008年 | 474篇 |
2007年 | 530篇 |
2006年 | 501篇 |
2005年 | 555篇 |
2004年 | 474篇 |
2003年 | 453篇 |
2002年 | 459篇 |
2001年 | 156篇 |
2000年 | 131篇 |
1999年 | 140篇 |
1998年 | 93篇 |
1997年 | 72篇 |
1996年 | 71篇 |
1995年 | 55篇 |
1994年 | 62篇 |
1993年 | 43篇 |
1992年 | 63篇 |
1991年 | 82篇 |
1990年 | 71篇 |
1989年 | 69篇 |
1988年 | 67篇 |
1987年 | 61篇 |
1986年 | 69篇 |
1985年 | 55篇 |
1984年 | 51篇 |
1983年 | 41篇 |
1982年 | 15篇 |
1981年 | 17篇 |
1980年 | 16篇 |
1979年 | 26篇 |
1978年 | 13篇 |
1977年 | 12篇 |
1976年 | 12篇 |
1973年 | 14篇 |
1969年 | 10篇 |
排序方式: 共有8632条查询结果,搜索用时 15 毫秒
101.
102.
Dietary zinc deficiency decreases glutathione S-transferase expression in the rat olfactory epithelium 总被引:3,自引:0,他引:3
Zinc deficiency leads to olfactory and gustatory dysfunction, but little is known about the underlying molecular mechanism of this phenomenon. We examined the effect of dietary zinc deficiency on the rat olfactory epithelium. Immunoreactivities of glutathione S-transferase (GST) mu, neuron-specific enolase (NSE) and proliferating cell nuclear antigen (PCNA), and in situ hybridization of GST mu mRNA in the olfactory epithelia were examined under different dietary zinc intake conditions. Adult male rats were fed a zinc-deficient (ZD) diet (0.5 mg zinc/kg diet), whereas control rats, including pair-fed (PF) and zinc-adequate (ad libitum consumption, AL) groups, were fed a zinc-adequate diet (58 mg zinc/kg diet) for 7 wk. We also examined the effect of zinc replacement (ZR) by subsequently feeding half of the ZD group a zinc-adequate diet for 5 wk after the initial 7-wk deprivation. No significant differences in immunoreactivity for NSE in olfactory epithelial receptor cells or for PCNA in basal cells were noted among groups. Intense GST mu immunoreactivity and hybridization signals were observed in olfactory supporting cells of AL, PF and ZR groups, but very minimal or no such signal was noted in ZD rats. Our findings indicated that zinc deficiency reduces GST mu expression in the supporting cells of rat olfactory epithelia but does not affect receptor cell proliferation or maintenance. 相似文献
103.
Yoshie Nakanishi Junichi Kodama Keizo Tokumo Noriko Seki Yasunari Miyagi Mitsuo Yoshinouchi Hiroyuki Okuda Takafumi Kudo 《International journal of clinical oncology / Japan Society of Clinical Oncology》1997,2(4):219-223
Background The object of this study is to clarify the association of an angiogenic factor, PD-ECGF (platelet-derived endothelial cell
growth factor/thymidine phosphorylase), with clinicopathologic factors, in this case tumor angiogenesis, in epithelial ovarian
cancers.
Methods Tumor specimens were obtained at the time of surgery from the primary lesion in 60 patients with epithelial ovarian cancer.
Histologic cell types were assigned to tumors according to the World Health Organization classification: 26 were classified
as serous adenocarcinoma, 15 as endometrioid adenocarcinoma, 9 as mucinous adenocarcinoma, 9 as clear cell carcinoma, and
1 as undifferentiated carcinoma. Surgical staging was based on the international Federation of Gynecology and Obstetrics (FIGO)
staging system: 16 were stage I, 6 were stage II, 34 were stage III, and 4 were stage IV. Expression of PD-ECGF was evaluated
by immunohistochemical staining. Microvessel density was assessed by immunostaining for factor VIII-related antigen in the
most neovascularized area.
Results Stroma cells stained more strongly than cancer cells (80% vs. 33%). The immunopositivity of PD-ECGF in stroma cells was higher
in cases of advanced cancer. Expression of PD-ECGF in mucinous adenocarcinomas was significantly higher than that in serous
adenocarcinomas, while PD-ECGF expression in clear cell carcinomas was significantly lower. The microvessel density in the
cases with marked PD-ECGF-positive stroma cells was significantly higher than that in the cases with absent/minimal PD-ECGF-positive
stroma cells (P<0.05).
Conclusion The expression of PD-ECGF may play a crucial role in the promotion of angiogenesis in epithelial ovarian cancers. 相似文献
104.
Patients with head and neck cancers that produce a high concentration of granulocyte colony-stimulating factor (G-CSF) or
patients with esophageal squamous cell carcinomas who have elevated serum interleukin-6 (IL-6) concentrations have been found
previously to be at significant risk for tumor invasion to adjacent organs as well as frequent metastases. This suggests that
G-CSF and Il-6 enhance the invasiveness and metastatic potential of cancer cells. We studied the in vitro invasiveness of
head and neck cancer cell lines with and without recombinant human G-CSF (rhG-CSF) and human IL-6 (hIL-6) in an extracellular
matrix membrane system. The degree of invasiveness was affected by incubating cells with hIL-6, but not by pre-incubating
the cell-matrix with hIL-6. The maximum concentration of hIL-6 for enhanced invasiveness was approximately 5,000 u/ml. In
addition, rhG-CSF enhanced the invasiveness of tumor cells that produced large amounts of G-CSF. The present study also suggests
that tumor cells tend to invade and metastasize in an environment rich in hIL-6.
Received: 3 November 1997 / Accepted: 1 April 1998 相似文献
105.
Minoru Hojo Naoko Momotani Noriko Ikeda Akihiko Ueda Kuniko Uno Takashi Ishikita Akira Ishiguro Toshikazu Shimbo 《Pediatrics international》1998,40(5):483-485
Abstract We report here a case of neonatal hyperthyroidism born to a mother, whose pregnancy was complicated by poorly controlled Graves' disease. The patient demonstrated exophthalmos and marked goiter at birth, indicating the existence of thyrotoxicosis in utero. The mother's Graves' disease was well controlled in the third trimester, resulting in a slightly lower level of free thyroxine (FT4 ) in the umbilical cord blood serum; however, thyroid-stimulating hormone (TSH) was undetectable. Thyroid-stimulating hormone remained undetectable for 2 months, while FT4 levels varied in the course. This case suggests that severe and prolonged thyrotoxicosis in utero, due to poor control of pregnancy with Graves' disease, might induce unresponsiveness of the hypothalamo-pituitary system in the newborn. 相似文献
106.
107.
Noriko Hosoya Kiyoshi Miyagawa Kinuko Mitani Yoshio Yazaki Hisamaru Hirai 《Cancer science》1998,89(8):821-824
The WT1 tumor suppressor gene was examined for mutations in a panel of 44 patients with myelo-dysplastic syndromes (MDS) including acute myelogenous leukemias (AML) secondary to MDS, using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis and sequencing analysis. A WT1 mutation was detected in one out of 17 cases of AML secondary to MDS. This mutation exists upstream of the zinc finger region and is predicted to produce a truncated WT1 protein lacking the zinc finger region. No mutations were detected in 27 MDS patients who had not progressed to AML. This is the first report of analysis for WT1 mutations in a large number of MDS patients, suggesting that WT1 mutations are uncommon in MDS. Abnormalities in this gene may, however, contribute to a small proportion of cases showing progression from MDS into AML. 相似文献
108.
为了检测妇女绝经后发生骨量减少的相关指标进而倡导依据生活方式的特点对绝经后妇女骨质疏松的发生采取相应的预防和护理方针,我们对日本乡村的绝经后妇女(末次月经后六个月或更长时间算起)进行了为期4a的随访。我们运用双能X线骨密度仪(DXA)对腰椎骨密度(BMD)进行检测并对各种变量,包括年龄、绝经时的年龄、骨折史、日常摄奶量以及吸烟习惯进行多元分析,结果表明这些因素对于腰椎骨密度(BMD)的恢复是不相关联的。
在这些变量中,骨折史被证明对于相关人群是最具危险性的,这些对象有高比例的骨量减少(6.6%),其次是不规律的摄奶(13.6%)和吸烟(9.3%)。在护理中使用的作用于足跟骨的检测骨密度的设备被证实与作用于腰椎的DXA设备可以相互替代。依据这些结果,针对居住在日本乡村的绝经后妇女制订了相应的预防骨质疏松的方针。这些卫生指导方针依据特定区域的生活方式而制定并可适用于其他的人群和区域。在本文中,作者列出了不同的有助于预防绝经后妇女出现骨质疏松的方法并进行了调查。 相似文献
109.
Nationwide survey on complementary and alternative medicine in cancer patients in Japan. 总被引:1,自引:0,他引:1
Ichinosuke Hyodo Noriko Amano Kenji Eguchi Masaru Narabayashi Jiro Imanishi Midori Hirai Tomohito Nakano Shigemitsu Takashima 《Journal of clinical oncology》2005,23(12):2645-2654
PURPOSE: To determine the prevalence of use of complementary and alternative medicine (CAM) by patients with cancer in Japan, and to compare the characteristics of CAM users and CAM nonusers. PATIENTS AND METHODS: A questionnaire on cancer CAM and the Hospital Anxiety and Depression Scale were delivered to 6,607 patients who were treated in 16 cancer centers and 40 palliative care units. RESULTS: There were 3,461 available replies for a response rate of 52.4%. The prevalence of CAM use was 44.6% (1,382 of 3,100) in cancer patients and 25.5% (92 of 361) in noncancer patients with benign tumors. Multiple logistic regression analysis determined that history of chemotherapy, institute (palliative care units), higher education, an altered outlook on life after cancer diagnosis, primary cancer site, and younger age were strongly associated with CAM use in cancer patients. Most of the CAM users with cancer (96.2%) used products such as mushrooms, herbs, and shark cartilage. The motivation for most CAM use was recommendation from family members or friends (77.7%) rather than personal choice (23.3%). Positive effects were experienced by 24.3% of CAM users with cancer, although all of them received conventional cancer therapy concurrently. Adverse reactions were reported by 5.3% of cancer patients. CAM products were used without sufficient information by 57.3% of users with cancer and without a consultation with a doctor by 60.7% of users. CONCLUSION: This survey revealed a high prevalence of CAM use among cancer patients, without sufficient information or consultation with their physicians. Oncologists should not ignore the CAM products used by their patients because of a lack of proven efficacy and safety. 相似文献
110.