全文获取类型
收费全文 | 3202篇 |
免费 | 154篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 93篇 |
妇产科学 | 21篇 |
基础医学 | 351篇 |
口腔科学 | 87篇 |
临床医学 | 219篇 |
内科学 | 1039篇 |
皮肤病学 | 17篇 |
神经病学 | 257篇 |
特种医学 | 80篇 |
外科学 | 593篇 |
综合类 | 4篇 |
预防医学 | 67篇 |
眼科学 | 26篇 |
药学 | 180篇 |
中国医学 | 9篇 |
肿瘤学 | 305篇 |
出版年
2023年 | 33篇 |
2022年 | 74篇 |
2021年 | 129篇 |
2020年 | 70篇 |
2019年 | 72篇 |
2018年 | 90篇 |
2017年 | 74篇 |
2016年 | 83篇 |
2015年 | 64篇 |
2014年 | 107篇 |
2013年 | 122篇 |
2012年 | 178篇 |
2011年 | 212篇 |
2010年 | 96篇 |
2009年 | 83篇 |
2008年 | 154篇 |
2007年 | 167篇 |
2006年 | 139篇 |
2005年 | 165篇 |
2004年 | 160篇 |
2003年 | 149篇 |
2002年 | 183篇 |
2001年 | 59篇 |
2000年 | 54篇 |
1999年 | 49篇 |
1998年 | 56篇 |
1997年 | 40篇 |
1996年 | 28篇 |
1995年 | 27篇 |
1994年 | 20篇 |
1993年 | 22篇 |
1992年 | 40篇 |
1991年 | 38篇 |
1990年 | 31篇 |
1989年 | 39篇 |
1988年 | 28篇 |
1987年 | 28篇 |
1986年 | 27篇 |
1985年 | 18篇 |
1984年 | 17篇 |
1983年 | 18篇 |
1982年 | 10篇 |
1981年 | 13篇 |
1980年 | 16篇 |
1979年 | 9篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 8篇 |
1974年 | 11篇 |
1972年 | 9篇 |
排序方式: 共有3380条查询结果,搜索用时 15 毫秒
91.
92.
Tomoyuki Akiyama Masahiko Inamori Hiroshi Iida Hironori Mawatari Hiroki Endo Kunihiro Hosono Kyoko Yoneda Koji Fujita Masato Yoneda Hirokazu Takahashi Ayumu Goto Yasunobu Abe Noritoshi Kobayashi Kensuke Kubota Satoru Saito Atsushi Nakajima 《BMC gastroenterology》2008,8(1):1-6
Background
The precise role of capsule endoscopy in the diagnostic algorithm of obscure gastrointestinal bleeding has yet to be determined. Despite the higher diagnostic yield of capsule endoscopy, the actual impact on clinical outcome remains poorly defined. The aim of this study was to evaluate the follow-up results of patients with obscure gastrointestinal bleeding to determine which management strategies after capsule endoscopy reduced rebleeding.Methods
All patients in whom the cause of obscure gastrointestinal bleeding was investigated between May 2004 and March 2007 were studied retrospectively. We evaluated the clinical outcome of patients with obscure gastrointestinal bleeding after capsule endoscopy using the rebleeding rate as the primary outcome.Results
Seventy-seven patients with obscure gastrointestinal bleeding underwent capsule endoscopy. Capsule endoscopy identified clinically significant findings that were thought to be the sources of obscure gastrointestinal bleeding in 58.4% of the patients. The overall rebleeding rate was 36.4%. The rebleeding rate was significantly higher among patients with insignificant findings than among those with significant findings (p = 0.036). Among the patients in whom capsule endoscopy produced significant findings, the rebleeding rate of the patients who underwent therapeutic interventions was significantly lower than that in those who did not undergo intervention (9.5% vs 40.0%, p = 0.046).Conclusion
Follow-up and further aggressive interventions are necessary for patients with obscure gastrointestinal bleeding and significant capsule endoscopy findings to reduce the chance of rebleeding. 相似文献93.
Ichiro Inoue Yuichi Inubushi Takahiro Sato Kensuke Tono Tetsuo Katayama Takashi Kameshima Kanade Ogawa Tadashi Togashi Shigeki Owada Yoshiyuki Amemiya Takashi Tanaka Toru Hara Makina Yabashi 《Proceedings of the National Academy of Sciences of the United States of America》2016,113(6):1492-1497
Resolution in the X-ray structure determination of noncrystalline samples has been limited to several tens of nanometers, because deep X-ray irradiation required for enhanced resolution causes radiation damage to samples. However, theoretical studies predict that the femtosecond (fs) durations of X-ray free-electron laser (XFEL) pulses make it possible to record scattering signals before the initiation of X-ray damage processes; thus, an ultraintense X-ray beam can be used beyond the conventional limit of radiation dose. Here, we verify this scenario by directly observing femtosecond X-ray damage processes in diamond irradiated with extraordinarily intense (∼1019 W/cm2) XFEL pulses. An X-ray pump–probe diffraction scheme was developed in this study; tightly focused double–5-fs XFEL pulses with time separations ranging from sub-fs to 80 fs were used to excite (i.e., pump) the diamond and characterize (i.e., probe) the temporal changes of the crystalline structures through Bragg reflection. It was found that the pump and probe diffraction intensities remain almost constant for shorter time separations of the double pulse, whereas the probe diffraction intensities decreased after 20 fs following pump pulse irradiation due to the X-ray–induced atomic displacement. This result indicates that sub-10-fs XFEL pulses enable conductions of damageless structural determinations and supports the validity of the theoretical predictions of ultraintense X-ray–matter interactions. The X-ray pump–probe scheme demonstrated here would be effective for understanding ultraintense X-ray–matter interactions, which will greatly stimulate advanced XFEL applications, such as atomic structure determination of a single molecule and generation of exotic matters with high energy densities.Since W. C. Röntgen discovered X-rays emitted from vacuum tube equipment in 1895, scientists have continuously endeavored to develop brighter X-ray sources throughout the 20th century. One of the most remarkable breakthroughs was the emergence of synchrotron light sources, which were much more brilliant than the early lab-based X-ray sources. Such dramatic increase in X-ray brilliance provided a pathway to obtain high-quality X-ray scattering data. This, in turn, enabled one to solve the structures of complex systems such as proteins, functional units of living organisms, and viruses. However, the increase in the brilliance is also accompanied by a severe problem of X-ray radiation damage to the samples being examined (1). X-rays ionize atoms and generate highly activated radicals that break chemical bonds and cause changes in the structures of the samples. To achieve structure determination precisely, a sufficient scattering signal should be recorded before the samples are severely damaged. Radiation damage was considered to be an intrinsic problem associated with X-ray scattering experiments, which imposed a fundamental limit on the resolution in X-ray structure determination (2).The recent advent of X-ray free-electron lasers (XFELs) (3–5), which emit ultraintense X-ray pulses with durations of several femtoseconds, may totally avoid the problem of radiation damage. The irradiation of intense XFEL pulses generates highly ionized atoms, and the strong Coulomb repulsive force leads to evaporation of the samples. Meanwhile, it has been predicted theoretically (6) that atoms do not change their positions before the termination of the femtosecond X-ray pulse owing to inertia, thus enabling the use of X-ray radiations beyond the conventional X-ray dose limit. This innovative concept, called a “diffraction-before-destruction” scheme (6, 7), has paved a clear way to high-resolution structure determinations of weak scattering objects, including nanometer-sized protein crystals (8), noncrystalline biological particles (9), and damage-sensitive protein crystals (10).Despite the potential impact of XFELs, detailed understanding of the ultrafast XFEL damage processes has been missing. As a pioneering work, Barty et al. (11) measured the diffraction intensities of protein nanocrystals by changing the XFEL pulse durations from 70 to 300 fs at intensities of ∼1017 W/cm2. They found that the diffraction intensities greatly decrease for longer durations, clearly indicating sign of structural damage, i.e., X-ray–induced atomic displacements within the XFEL pulse durations. For further understanding of ultraintense X-ray interactions with matter, we need to directly measure the temporal changes of the structural damage. In particular, measuring the ignition time of the atomic displacements is crucial for realizing advanced applications with greatly intense XFELs. Although improving our knowledge of the X-ray damage processes is essential for all aspects of XFEL science, the experimental verifications have been missing because of the extreme difficulty in observation with ultrahigh resolutions in space (ångstrom) and time (femtosecond).As a new approach to investigate the femtosecond X-ray damage processes, we here propose an X-ray–X-ray pump–probe experiment using double X-ray pulses; a pump X-ray pulse excites a sample and a probe X-ray pulse with a well-controlled time delay characterizes the change in the sample. In this approach, it is highly useful to exploit two-color double pulses with tunable temporal separations (12–15), which have been developed at SPring-8 Angstrom Compact free-electron LAser (SACLA) (4) and Linac Coherent Light Source (3). In this article, we measured the X-ray damage processes of diamond by using an X-ray–X-ray pump–probe diffraction experiment at SACLA. As the carbon–carbon bond is one of the most fundamental bonds in biomolecules, our results should provide a benchmark for XFEL-induced damage to practical samples. 相似文献
94.
95.
Shinichi Kako Yoshinobu Kanda Makoto Onizuka Nobuyuki Aotsuka Kensuke Usuki Takayoshi Tachibana Takeshi Kobayashi Jun Kato Shingo Yano Hiroaki Shimizu Katsuhiro Shono Masatsugu Tanaka Shokichi Tsukamoto Takehiko Mori Etsuko Yamazaki Yuho Najima Akira Hangaishi Takumi Hoshino Reiko Watanabe Kenji Matsumoto Shinichiro Okamoto for Kanto Study Group for Cell Therapy 《American journal of hematology》2020,95(3):251-257
The optimal pre-transplant conditioning for aplastic anemia (AA) remains unclear. We performed a prospective study on allogeneic transplantation from a related or unrelated donor for adult patients with AA. We assessed whether reduced-dose cyclophosphamide (CY) could decrease toxicity while maintaining engraftment, and low-dose thymoglobulin could safely prevent graft-vs-host disease (GVHD). The pre-transplant conditioning regimen consisted of fludarabine 120 mg/m2, CY 100 mg/kg, and thymoglobulin 2.5 mg/kg with or without 2 Gy of total body irradiation. Twenty-seven patients with a median age of 36 years were analyzed. Sixteen patients received graft from related donors. The stem cell source was bone marrow in 26 patients. All of the patients but one, who died early, achieved neutrophil engraftment at a median of 19 days. Mixed chimerism was observed in six and five patients at days 30 and 90, respectively. Only one patient experienced secondary engraftment failure with complete donor-type chimerism. None of the patients developed severe acute GVHD. The cumulative incidence of chronic GVHD was 37.7% at 1 year. The overall survival rate was 96.3% at 1 year and 3 years. A high EB virus-DNA load was detected in one patient at days 60. No one developed EBV-lymphoproliferative disorder within a year. The results suggest that the conditioning regimen in this study was safe and effective. However, relatively high incidence of chronic GVHD needs further improvement. 相似文献
96.
Yuzo Fujino Tatsuya Kawasaki Hirofumi Kawamata Aiko Tamura Kensuke Shiga Hirokazu Oyamada 《Internal medicine (Tokyo, Japan)》2020,59(22):2955
Arterial and venous thrombi can coexist without preexisting conditions, such as malignant disease, thrombotic predisposition, or arteriovenous shunt. We herein report a case of acute cerebral infarction and pulmonary thromboembolism in the absence of underlying disease. A 71-year-old woman presented with left hemiplegia. On an examination, her oxygen saturation was 91% on ambient air despite the absence of chest symptoms and clear lung fields on a chest radiograph. The patient was finally diagnosed with acute cerebral infarction caused by large artery atherosclerosis and acute pulmonary thromboembolism due to deep vein thrombosis, consequent to immobilization for three days after the onset of cerebral infarction. 相似文献
97.
Hironori Ochi Ryuichi Ohno Mitsuaki Kubota Ryo Hanyu Kensuke Sakai Yu Sugawara Fumihiro Mukasa Kazuo Kaneko 《International journal of surgery case reports》2014,5(12):1178-1182
INTRODUCTION
Low back pain is common during pregnancy. However, the incidence of symptomatic lumbar disc herniation during pregnancy is very rare. We report a case of lumbar disc herniation underwent discectomy just after cesarean delivery in the third trimester of pregnancy.PRESENTATION OF CASE
A 33-year-old woman presented at 32 weeks gestation. She had a low back pain and the left-sided leg pain below the knee. At 34 weeks gestation, she had severe weakness of the left extension halluces longus, left ankle dorsiflexion. MRI showed a large disc herniation at L4/5 expanded to the spinal canal more. The cesarean delivery was performed in the supine position. The patient was then turned to a prone position, and a left L4/5 discectomy was performed. But the day after surgery, she had a severe low back pain and the right leg pain below the knee. MRI showed a disc herniation at L4/5 on the right side of the spinal canal. At 6 days after the first surgery, a right L4/5 discectomy was performed. In the immediate postoperative period, the patient experienced complete relief of the right leg pain.DISCUSSION
It is necessary to cooperate with a pediatrician, an obstetrician, and an anethesiologists. For obtaining the best outcome on mother and child, it is important to discuss in advance to be able to respond quickly for changeable situation.CONCLUSION
It is necessary to conduct the operation under pregnancy in consideration of the great influence on mother and child. 相似文献98.
Kei Kawana Katsuyuki Adachi Satoko Kojima Ayumi Taguchi Kensuke Tomio Aki Yamashita Haruka Nishida Kazunori Nagasaka Takahide Arimoto Terufumi Yokoyama Osamu Wada-Hiraike Katsutoshi Oda Tomomitsu Sewaki Yutaka Osuga Tomoyuki Fujii 《Vaccine》2014
Background
Cervical intraepithelial neoplasia grade 3 (CIN3) is a mucosal precancerous lesion caused by high-risk human papillomavirus (HPV). Induction of immunological clearance of CIN3 by targeting HPV antigens is a promising strategy for CIN3 therapy. No successful HPV therapeutic vaccine has been developed.Methods
We evaluated the safety and clinical efficacy of an attenuated Lactobacillus casei expressing modified full-length HPV16 E7 protein in patients with HPV16-associated CIN3. Ten patients were vaccinated orally during dose optimization studies (1, 2, 4, or 6 capsules/day) at weeks 1, 2, 4, and 8 (Step 1). Seven additional participants were only tested using the optimized vaccine formulation (Step 2), giving a total of 10 patients who received optimized vaccination. Cervical lymphocytes (CxLs) and peripheral blood mononuclear cells (PBMCs) were collected and E7 specific interferon-γ-producing cells were counted (E7 cell-mediated immune responses: E7-CMI) by ELISPOT assay. All patients were re-evaluated 9 weeks after initial vaccine exposure using cytology and biopsy to assess pathological efficacy.Results
No patient experienced an adverse event. E7-CMI in both CxLs and PBMCs was negligible at baseline. All patients using 4–6 capsules/day showed increased E7-CMI in CxLs, whereas patients using 1–2 capsules/day did not. No patient demonstrated an increase in E7-CMI in their PBMCs. In comparison between patients of cohorts, E7-CMI at week 9 (9 wk) in patients on 4 capsules/day was significantly higher than those in patients on 1, 2, or 6 capsules/day. Most patients (70%) taking the optimized dose experienced a pathological down-grade to CIN2 at week 9 of treatment. E7-CMI in CxLs correlated directly with the pathological down-grade.Conclusions
Oral administration of an E7-expressing Lactobacillus-based vaccine can elicit E7-specific mucosal immunity in the uterine cervical lesions. We are the first to report a correlation between mucosal E7-CMI in the cervix and clinical response after immunotherapy in human mucosal neoplasia. 相似文献99.
Ryo Wada MD PhD Masaya Shinohara MD PhD Tadashi Fujino MD PhD Shingo Matsumoto MD PhD Shintaro Yao MD PhD Kensuke Yano MD Shintaro Dobashi MD PhD Katsuya Akitsu MD PhD Hideki Koike MD PhD Hiroshi Ohara MD PhD Toshio Kinoshita MD PhD Hitomi Yuzawa MD PhD Rine Nakanishi MD PhD Takanori Ikeda MD PhD 《Pacing and clinical electrophysiology : PACE》2023,46(1):73-83
100.
Dai Keino Kensuke Kondoh Shunsuke Murata Ryo Ohyama Mizuho Morimoto Shinji Muto Miho Fukuda Munechika Wakisaka Hiroaki Kitagawa Akitoshi Kinoshita 《Pediatric transplantation》2014,18(2):E52-E56
A 15‐yr‐old boy presented with an anterior mediastinal mass, multiple lung metastases and obstruction of the left brachiocephalic vein, the superior vena cava and the subclavian vein. Tumor biopsy by CT guidance confirmed a diagnosis of GCT. Five courses of BEP therapy were performed, and CT of the chest revealed reduction in the anterior mediastinal mass and disappearance of the multiple lung metastases. We performed the anterior mediastinal mass extraction followed by adjuvant chemotherapy consisting of ICE and TIP. However, the AFP levels became elevated soon after. Abnormal accumulation was observed in the right upper lung by DW‐MRI. After the operation, two courses of TI chemotherapy and two courses of HDCT followed by auto‐PBSCT were performed. He was complicated with auditory disorder and renal dysfunction. Although HDCT followed by auto‐PBSCT was effective for the relapsed primary mediastinal GCT, a treatment strategy avoiding late complications is warranted. 相似文献