全文获取类型
收费全文 | 2141篇 |
免费 | 107篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 10篇 |
妇产科学 | 23篇 |
基础医学 | 254篇 |
口腔科学 | 29篇 |
临床医学 | 133篇 |
内科学 | 592篇 |
皮肤病学 | 29篇 |
神经病学 | 184篇 |
特种医学 | 70篇 |
外科学 | 440篇 |
综合类 | 5篇 |
预防医学 | 44篇 |
眼科学 | 14篇 |
药学 | 229篇 |
中国医学 | 12篇 |
肿瘤学 | 186篇 |
出版年
2023年 | 18篇 |
2022年 | 31篇 |
2021年 | 39篇 |
2020年 | 42篇 |
2019年 | 38篇 |
2018年 | 40篇 |
2017年 | 35篇 |
2016年 | 32篇 |
2015年 | 38篇 |
2014年 | 52篇 |
2013年 | 72篇 |
2012年 | 105篇 |
2011年 | 102篇 |
2010年 | 56篇 |
2009年 | 48篇 |
2008年 | 97篇 |
2007年 | 103篇 |
2006年 | 119篇 |
2005年 | 148篇 |
2004年 | 165篇 |
2003年 | 142篇 |
2002年 | 160篇 |
2001年 | 47篇 |
2000年 | 55篇 |
1999年 | 49篇 |
1998年 | 45篇 |
1997年 | 32篇 |
1996年 | 30篇 |
1995年 | 35篇 |
1994年 | 21篇 |
1993年 | 21篇 |
1992年 | 19篇 |
1991年 | 18篇 |
1990年 | 22篇 |
1989年 | 24篇 |
1988年 | 19篇 |
1987年 | 14篇 |
1986年 | 15篇 |
1985年 | 27篇 |
1984年 | 11篇 |
1983年 | 13篇 |
1981年 | 6篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1972年 | 5篇 |
1968年 | 4篇 |
排序方式: 共有2263条查询结果,搜索用时 0 毫秒
1.
Ichiro Yasuda Takuji Iwashita Takaya Ohnishi Tsuyoshi Mukai Masamichi Enya Eiichi Tomita Hisataka Moriwaki 《Digestive endoscopy》2006,18(Z1):S92-S95
Endoscopic nasobiliary drainage (ENBD) is a well established mode of biliary decompression. Although ENBD is certainly an uncomfortable procedure with the potential risk of spontaneous dislocation or removal of the drainage catheter by disoriented patients, it has several advantages over endoscopic biliary drainage (EBD) using an indwelling stent. The current indications for ENBD are: (i) temporary drainage to treat obstructive jaundice and cholangitis caused by malignant or benign biliary stricture; (ii) urgent drainage to treat suppurative cholangitis primarily caused by common bile duct stones; (iii) temporary drainage after stone removal in patients with suspected incomplete clearance and/or with cholangitis; and (iv) biliary leaks that occur primarily after surgery, as well as other indications. Different types of nasobiliary catheters are currently available that have been designed with various diameters, shapes, and materials. However, the current catheters are not considered by most endoscopists to be sufficient. Further improvements are needed to achieve better drainage and better maneuverability. 相似文献
2.
Ryo Wakita Yuka Ohno Saori Yamazaki Hikaru Kohase Masahiro Umino 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2006,102(6):e28-e32
Two cases of vasovagal syncope (VVS) during venous access are reported. Both patients had a history of fainting episodes and experienced bradycardia with asystole, hypotension, and fainting. Pain and phobic stress during venous access triggered an increase in parasympathetic tone, resulting in bradycardia with asystole and hypotension in both cases. Hypotension and bradycardia likely caused cerebral hypoperfusion, leading to fainting. The intense parasympathetic tone triggered by somatic or emotional stress was likely responsible for directly depressing the sinus node, leading to asystole and bradycardia. Bradycardia with asystole progressing to syncope is a potentially fatal dysrhythmia in patients with cardiovascular disease or older patients with decreased cardiac function. Appropriate treatment for VVS includes the administration of intravenous fluids, vagolytics, ephedrine, and the rapid use of the Trendelenburg position. Intravenous fluids and atropine were used to treat the present patients. 相似文献
3.
Matsukawa T.; Hanagata K.; Ozaki M.; Iwashita H.; Koshimizu M.; Kumazawa T. 《British journal of anaesthesia》1997,78(4):396-399
We tested the hypothesis that premedication with i.m. midazolam decreases
core temperature dose-dependently. We studied six male volunteers, in
random order, on 3 days: (1) no midazolam administration (control day), (2)
midazolam 0.025 mg kg-1 i.m., (3) midazolam 0.075 mg kg-1 i.m. On the first
day, subjects were maintained alert during a 30- min control period. On the
second and third days, midazolam 0.025 or 0.075 mg kg-1 was administered
i.m. Core temperatures were measured at the right tympanic membrane. Four
adhesive skin surface probes were fixed on the chest, upper right arm,
lateral calf and thigh. Finger tip perfusion was evaluated using forearm
minus fingertip and calf minus toe, skin surface temperature gradients.
Thirty minutes after midazolam i.m., the level of sedation in the
volunteers was assessed. Peripheral venous blood was obtained immediately
after the assessment of the level of sedation. Tympanic membrane
temperatures after administration of midazolam 0.075 mg kg-1 i.m. were
significantly lower than those on the control and midazolam 0.025 mg kg-1
i.m. days at 20 and 30 min. The decreases in tympanic membrane temperatures
at 30 min after midazolam i.m. became larger as the volunteers were more
deeply sedated. i.m. midazolam produced a concentration-dependent decrease
in tympanic membrane temperature at 30 min after midazolam 0.025 and 0.075
mg kg-1 i.m. We conclude that midazolam impaired tonic thermoregulatory
vasoconstriction, allowing core-to-peripheral heat redistribution in a
dose-dependent manner after i.m. administration.
相似文献
4.
Mariko Hosono H. Kobayashi Ryota Fujimoto Kazushige Tsutsui Yoshihiko Kotoura Tadao Tsuboyama Hikaru Hayashi Takashi Nakamura Junji Konishi 《Skeletal radiology》1997,26(9):525-528
Objective. To clarify the MRI features of parasymphyseal insufficiency fractures of the os pubis. Design and patients. MRI was performed in four postmenopausal women with parasymphyseal insufficiency fractures. The diagnosis was confirmed with
plain films in every patient. T1-weighted and T2-weighted images were obtained in four patients using a 1.5-T unit. Postcontrast
T1-weighted imaging was also done in three patients. Results and conclusions. MRI of pubic parasymphyseal insufficiency fracture characteristically demonstrates a hyperintense mass lesion with a hypointense
rim on T2-weighted imaging, showing peripheral and septal enhancement after contrast administration. It is important to have
this entity in mind in patients with osteoporosis, especially in patients with a history of pelvic irradiation for malignant
disease, so as not to misinterpret it as a chondroid tumor or bone metastasis. 相似文献
5.
6.
Intracellular recordings of electrical activity were made from circular smooth muscle cells in small segments of tissue isolated from the guinea-pig stomach antrum. Every cell that was impaled exhibited a rhythmic generation of slow potentials. Experiments were carried out to test the effects of three different concentrations (1, 10 and 100 nM) of phorbol 12, 13-dibutyrate (PDBu) on these slow potentials and on the responses produced by acetylcholine (ACh), in the presence of nifedipine and N(omega)-nitro-L-arginine (nitroarginine), known inhibitors of L-type Ca-channels and nitric oxide synthase, respectively. The resting membrane potential was -62 +/- 7 mV, while the frequency and amplitude of the slow potentials were 1.6 +/- 0.1 cycle per min (cpm) and 33 +/- 1 mV, respectively. Application of 1 nM PDBu increased the frequency of slow potentials, with no significant change in the membrane potential and amplitude of slow potentials. At a concentration of 100 nM, PDBu depolarized the membrane by about 6 mV, and either decreased the amplitude and frequency of the slow potentials or abolished them. The amplitude and frequency of the slow potentials were not significantly changed in the presence of 10 nM PDBu. In the presence of chelerythrine (1-2 microM), a known inhibitor of protein kinase C (PKC), the increase in frequency of slow potentials by 1 nM PDBu and depolarization produced by 100 nM PDBu were not elicited. The increase in frequency of slow potentials by 100 nM ACh was inhibited by PDBu, in a concentration-dependent manner, and ACh-responses were abolished in the presence of 100 nM PDBu. These results indicate that PDBu has dual actions on the spontaneous activity of antral circular muscle, with low concentrations increasing and high concentrations inhibiting the frequency of the slow potentials. The former may be produced by activation of protein kinase C (PKC). As the ACh-induced excitation of slow potentials is inhibited by PDBu, a possible causal relationship between the inhibition and over-activation of PKC is considered. 相似文献
7.
Tomomi Iwashita Kazuo Kitazawa Jun-Ichi Koyama Hisashi Nagashima Toru Koyama Yuichiro Tanaka Kazuhiro Hongo Hiroshi Okudera Kazufumi Okamoto 《Journal of clinical neuroscience》2007,14(1):68-71
A patient with cerebral deep sinus thrombosis, which was not diagnosed on the first examination, is reported. A 46-year-old woman presented with headache and vomiting. Neurological examination and a brain computed tomography (CT) scan showed no obvious abnormal findings. The patient suffered disturbed consciousness on the day after the examination, and was admitted to our emergency centre. A CT scan and magnetic resonance imaging revealed an ischaemic lesion in the left basal ganglia, suggesting deep sinus occlusion. Anticoagulant therapy was administered. One day after admission, a CT scan showed a haematoma and severe brain swelling in the same region. Cerebral angiography demonstrated a straight sinus occlusion. Intracranial pressure was not controlled with hypothermia, and the patient died 25 days after admission. Review of the initial CT scan revealed subtle, early findings of deep venous thrombosis that were missed on first examination. 相似文献
8.
Jun Maeda Mitsunori Ohta Hirohisa Hirabayashi Hikaru Matsuda 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2005,53(4):196-198
We present a case of lung cancer that showed false positive accumulation in an 18F fluorodeoxyglucose positron emission tomography (FDG-PET) scan following induction chemotherapy for suspected metastasis
and progression of malignancy. A 66-year-old man was diagnosed with squamous cell carcinoma in the lung, classified as clinical
stage IIIA (T2N2M0), and underwent induction chemotherapy. An FDG-PET scan prior to chemotherapy demonstrated accumulation
only in the tumor, whereas following treatment it revealed a strong accumulation not only in the tumor, but also in the supraclavicular
lymph nodes, which indicated lymph node metastasis. The patient underwent a biopsy of the right supraclavicular lymph node
and mediastinoscopy, after which all dissected lymph nodes showed sarcoid reactions and no tumor cells were found pathologically.
We concluded that when evaluating the effect of induction chemotherapy for malignancy, a sarcoid reaction might lead to the
false positive accumulation of FDG. 相似文献
9.
Hikaru Tanaka Naofumi Uesato Koki Shigenobu 《Naunyn-Schmiedeberg's archives of pharmacology》1995,351(4):391-397
Chronotropic and inotropic effects of histamine were examined in isolated atrial and ventricular preparations from embryonic and hatched chicken hearts. Histamine produced positive chronotropic and inotropic responses both in embryonic and hatched hearts. The responses to histamine in middle embryonic myocardia, which were observed in the micromolar range, were antagonized by H2 antagonists but not by H1, H3 antagonists and propranolol. Isobutylmethylxantine, an inhibitor of phosphodiesterase, produced a leftward shift of the concentration-response curve for the chronotropic effect of histamine in the embryo. The responses to histamine in myocardia from hatched chicks, which were observed in the milimolar range, appeared concurrently with the responses to tyramine during development and were antagonized by beta adrenoceptor antagonists but not by any of the histamine antagonists. The positive inotropic response to histamine in hatched ventricular preparations were greatly attenuated by reserpine pretreatment or in the presence of desipramine. Thus, we demonstrated that exogenously applied histamine produces positive chronotropic and inotropic responses in developing chicken hearts and that the mechanisms are different between embryonic and hatched chicks: direct action on H2 receptors in the embryonic heart and release of norepinephrine from sympathetic nerve terminals in hatched hearts. 相似文献
10.
Tokio Yamaguchi Masahiko Miyata Wataru Kamiike Yasushi Kobayashi Hikaru Matsuda 《Surgery today》1997,27(5):420-428
To clarify the histological status of the pancreas tail after pancreatoduodenectomy (PD), fibrosis, islets of Langerhans,
and A, B, and D cells were examined histometrically in surgical cases of pancreatic cancer. The same investigations were also
performed during an autopsy examination of the pancreas tail of survivors of surgery who had received either PD or total pancreatectomy
with segmental autotransplantation (SAT). In the surgical cases, fibrosis and the islet percentage compared with nonpancreatic
cancer cases were significantly higher while the B cell ratio was significantly lower. In addition, in pancreatic cancer patients,
the fibrosis and islet ratio in the group with a blocked pancreatic duct were higher while the B cell ratio was lower than
in the group with an open pancreatic duct. A direct relationship between the islet ratio and the degree of fibrosis, and an
inverse relationship between the B cell ratio and the degree of fibrosis, were thus found. From the autopsy cases, the fibrosis
progressed and the islet ratio increased following PD, but after SAT only the islet ratio increased compared to the time of
surgery. The progression of fibrosis after PD thus suggests the presence of some problems in both the surgical method and
postoperative management. 相似文献