首页 | 本学科首页   官方微博 | 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   2543篇
  免费   158篇
  国内免费   23篇
耳鼻咽喉   4篇
儿科学   48篇
妇产科学   63篇
基础医学   345篇
口腔科学   58篇
临床医学   204篇
内科学   758篇
皮肤病学   65篇
神经病学   223篇
特种医学   67篇
外科学   403篇
综合类   13篇
预防医学   88篇
眼科学   45篇
药学   127篇
中国医学   6篇
肿瘤学   207篇
  2023年   13篇
  2022年   23篇
  2021年   37篇
  2020年   22篇
  2019年   44篇
  2018年   43篇
  2017年   43篇
  2016年   57篇
  2015年   52篇
  2014年   56篇
  2013年   56篇
  2012年   88篇
  2011年   121篇
  2010年   68篇
  2009年   70篇
  2008年   111篇
  2007年   100篇
  2006年   116篇
  2005年   120篇
  2004年   115篇
  2003年   85篇
  2002年   100篇
  2001年   92篇
  2000年   107篇
  1999年   76篇
  1998年   34篇
  1997年   24篇
  1996年   27篇
  1995年   14篇
  1994年   25篇
  1993年   26篇
  1992年   75篇
  1991年   76篇
  1990年   51篇
  1989年   70篇
  1988年   53篇
  1987年   57篇
  1986年   55篇
  1985年   58篇
  1984年   30篇
  1983年   32篇
  1982年   11篇
  1979年   23篇
  1978年   22篇
  1977年   22篇
  1972年   10篇
  1969年   18篇
  1968年   21篇
  1967年   9篇
  1966年   10篇
排序方式: 共有2724条查询结果,搜索用时 15 毫秒
91.
92.
ROS1‐rearranged lung adenocarcinoma has been recently identified. We report a case of ROS1‐rearranged lung adenocarcinoma with special emphasis on cytological findings. Here, we report a case of young woman with ROS1‐rearranged lung adenocarcinoma diagnosed by cytology and discuss the clinical, cytological, and molecular findings. Cytologically, the tumor consisted of small tight clusters of cells with high nuclear/cytoplasmic ratio. Nuclei were enlarged and small nucleoli were occasionally observed. Signet‐ring cells were focally identified. Neoplastic cells were positive for ROS1 immunocytochemistry. Subsequently, the translocation of ROS1 gene was confirmed in a histological specimen. In conclusion, the specific histology of adenocarcinoma on cytological materials should promote testing for ROS1 immunohistochemistry. Immunocytochemical detection of ROS1 protein helps identify patients suitable for molecular targeted therapy.  相似文献   
93.
94.
AIM: To assess each layer of the optical coherence tomography (OCT) image of the esophageal wall with reference to the histological structure, METHODS: Resected specimens of fresh pig esophagus was used as a model for the esophageal wall. We injected cyanoacrylate adhesive into the specimens to create a marker, and scanned them using a miniature OCT probe. The localization of these markers was assessed in the OCT images. Then we compared the OCT-imaged morphology with the corresponding histological section, guided by the cyanoacrylate adhesive markers. We prepared a second set of experiments using nylon sutures as markers. RESULTS: The OCT image of the esophageal specimen has a clear five-layered morphology. First, it consisted of a relatively less reflective layer; second, a more reflective layer; third, a less reflective layer; fourth, a more reflective layer; and fifth, a less reflective layer. Comparing the OCT images with marked histological sections showed that the first layer corresponded to stratified squamous epithelium; the second to lamina propria; the third to muscularis mucosa; fourth, submucosa; and fifth, muscularis propria with deeper structures of the esophageal wa CONCLUSION: We demonstrated that the OCT image of the normal esophageal wall showed a five- layered morphology, which corresponds to histological esophageal wall components.  相似文献   
95.
Hayashi T, Sentani K, Oue N, Anami K, Sakamoto N, Ohara S, Teishima J, Noguchi T, Nakayama H, Taniyama K, Matsubara A & Yasui W
(2011) Histopathology 59 , 710–721
Desmocollin 2 is a new immunohistochemical marker indicative of squamous differentiation in urothelial carcinoma Aims: Urothelial carcinoma (UC) with squamous differentiation tends to present at higher stages than pure UC. To distinguish UC with squamous differentiation from pure UC, a sensitive and specific marker is needed. Desmocollin 2 (DSC2) is a protein localized in desmosomal junctions of stratified epithelium, but little is known about its biological significance in bladder cancer. We examined the utility of DSC2 as a diagnostic marker. Methods and results: We analysed the immunohistochemical characteristics of DSC2, and studied the relationship of DSC2 expression with the expression of the known markers uroplakin III (UPIII), cytokeratin (CK)7, CK20, epidermal growth factor receptor (EGFR), and p53. DSC2 staining was detected in 24 of 25 (96%) cases of UC with squamous differentiation, but in none of 85 (0%) cases of pure UC. DSC2 staining was detected only in areas of squamous differentiation. DSC2 expression was mutually exclusive of UPIII expression, and was correlated with EGFR expression. Furthermore, DSC2 expression was correlated with higher stage (P = 0.0314) and poor prognosis (P = 0.0477). Conclusions: DSC2 staining offers high sensitivity (96%) and high specificity (100%) for the detection of squamous differentiation in UC. DSC2 is a useful immunohistochemical marker for separation of UC with squamous differentiation from pure UC.  相似文献   
96.
Histochemical analyses of type II brain 4.1/4.1B/KIAA0987, a member of the protein 4.1 family, were carried out in rat brain. In situ hybridization (ISH) showed that type II brain 4.1 mRNA is expressed in a variety of neuronal cells. In particular, type II brain 4.1 mRNA was actively transcribed in the cells of the mesencephalon and the brainstem, which have large myelinated nerve fibers. Expression of type II brain 4.1 mRNA was not observed at least in glial cells distributed in nerve fiber tracts. In immunohistochemical studies using anti-type II brain 4.1-specific antibody, the major immunosignals appeared as brilliant pairs of dots along nerve fibers. Such immunosignals were detected throughout the brain, but were highly concentrated in nerve fiber tracts. These data suggested that type II brain 4.1 is predominantly localized to neuronal paranodes. Detailed analysis concentrating on the nodal region indicated that type II brain 4.1 is present at the paranodal membrane but not in the axoplasm. Weaker type II brain 4.1-specific immunosignals were observed along the internodal membrane of myelinated axons and in the cytoplasm of some neuronal cells. Finally, comparative immunohistochemical studies using antibodies against the other three protein 4.1 family members, type I brain 4.1/4.1N/KIAA0338, erythroid type 4.1 (4.1R) and 4.1G, demonstrated that each of these proteins is distributed in a unique pattern in the cerebellum. Our results are the first to show that type II brain 4.1 is the only member of the protein 4.1 family localized to neuronal paranodes.  相似文献   
97.
PURPOSE: The study goal was to evaluate the clinical usefulness of intravenous EEG recording by placing wire electrodes in the cavernous sinus (CS) and the superior petrosal sinus (SPS) in patients with intractable temporal lobe epilepsy (TLE), with special emphasis on the ictal recording. METHODS: We placed Seeker Lite-10 guide wire as electrodes in the bilateral CS, SPS, or both to simultaneously record both ictal and interictal EEGs with the scalp EEG in five patients with TLE. In addition, in one patient, we averaged interictal scalp and intravascular EEG time-locked to the epileptiform discharge recorded from the CS/SPS-EEG to further delineate the relationship of the spikes between scalp and intravenous recording. RESULTS: In four of five patients, clinically useful recording was obtained to determine ictal focus. We recorded habitual seizures in three patients, and the detailed characteristics of ictal epileptiform discharges were shown. The averaged waveform of interictal epileptiform discharges clarified the spike distribution in the scalp EEGs, which was otherwise undetectable in the single trace. All of the patients completed the intravenous EEG monitoring without any neurological or psychological problems. CONCLUSIONS: The CS/SPS-EEG is a relatively noninvasive method that is useful for the detection of ictal focus and its spreading pattern and thus for the selection of surgical candidate among patients with intractable TLE. Although the number of seizures detected during the short monitoring period may be limited, due to the advantages of its safety and simplicity, it is worth trying for potential surgical candidates before more invasive examinations are applied. A further study with a larger number of patients is needed to estimate its practical risk.  相似文献   
98.
We have examined satellite glial cell (SGC) proliferation in trigeminal ganglia following chronic constriction injury of the infraorbital nerve. Using BrdU labeling combined with immunohistochemistry for SGC specific proteins we positively confirmed proliferating cells to be SGCs. Proliferation peaks at approximately 4 days after injury and dividing SGCs are preferentially located around neurons that are immunopositive for ATF‐3, a marker of nerve injury. After nerve injury there is an increase GFAP expression in SGCs associated with both ATF‐3 immunopositive and immunonegative neurons throughout the ganglia. SGCs also express the non‐glial proteins, CD45 and CD163, which label resident macrophages and circulating leukocytes, respectively. In addition to SGCs, we found some Schwann cells, endothelial cells, resident macrophages, and circulating leukocytes were BrdU immunopositive. GLIA 2013;61:2000–2008  相似文献   
99.
100.
BACKGROUND AND PURPOSE: Symptomatic progression is frequently observed in lacunar infarcts. The exact mechanisms of this phenomenon have not yet been clarified. SUMMARY OF CASES: We report 2 patients with lenticulostriate artery infarcts that presented with skip lesions that were restricted to gray matter. One of the patients subsequently developed symptomatic deterioration; the other experienced no further neurological events. CONCLUSIONS: A possible mechanism of differential vulnerability to ischemia of gray and white matter is considered. White matter may have a longer therapeutic time window for neuroprotective treatment than gray matter.  相似文献   
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