全文获取类型
收费全文 | 1769篇 |
免费 | 99篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 31篇 |
妇产科学 | 7篇 |
基础医学 | 215篇 |
口腔科学 | 21篇 |
临床医学 | 102篇 |
内科学 | 477篇 |
皮肤病学 | 2篇 |
神经病学 | 115篇 |
特种医学 | 48篇 |
外科学 | 390篇 |
综合类 | 6篇 |
预防医学 | 33篇 |
眼科学 | 39篇 |
药学 | 147篇 |
中国医学 | 7篇 |
肿瘤学 | 228篇 |
出版年
2023年 | 19篇 |
2022年 | 41篇 |
2021年 | 72篇 |
2020年 | 35篇 |
2019年 | 31篇 |
2018年 | 50篇 |
2017年 | 29篇 |
2016年 | 46篇 |
2015年 | 49篇 |
2014年 | 58篇 |
2013年 | 61篇 |
2012年 | 92篇 |
2011年 | 103篇 |
2010年 | 56篇 |
2009年 | 38篇 |
2008年 | 90篇 |
2007年 | 92篇 |
2006年 | 75篇 |
2005年 | 83篇 |
2004年 | 78篇 |
2003年 | 101篇 |
2002年 | 88篇 |
2001年 | 52篇 |
2000年 | 43篇 |
1999年 | 38篇 |
1998年 | 32篇 |
1997年 | 18篇 |
1996年 | 19篇 |
1995年 | 14篇 |
1994年 | 17篇 |
1993年 | 10篇 |
1992年 | 19篇 |
1991年 | 19篇 |
1990年 | 16篇 |
1989年 | 15篇 |
1988年 | 15篇 |
1987年 | 21篇 |
1986年 | 20篇 |
1985年 | 21篇 |
1984年 | 29篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1975年 | 10篇 |
1974年 | 6篇 |
1972年 | 5篇 |
1971年 | 4篇 |
排序方式: 共有1886条查询结果,搜索用时 10 毫秒
1.
Tetsuya Ozeki Shuji Beppu Takuto Mizoe Yuuki Takashima Hiroshi Yuasa Hiroaki Okada 《Journal of controlled release》2005,107(3):387-394
In this study, we used a novel 4-fluid nozzle spray drier to prepare composite microparticles of a water-insoluble drug, flurbiprofen (FP), and a water-soluble drug, sodium salicylate (SS), for the purpose of improving the water solubility of FP. An ethanol solution of FP and an aqueous SS solution were simultaneously introduced through different liquid passages in the 4-fluid nozzle spray drier and then spray-dried. Quantitative elemental analysis suggested that the FP/SS ratio in each composite microparticle was nearly the same as the formulation ratio. We also found that SS and FP exist in a low crystallinity state in the composite particles. Release of FP from dissolved composite microparticles was markedly improved because of an increase in the effective surface area following rapid dissolution of SS. This study shows that it is possible to prepare FP-SS composite microparticles using a 4-fluid nozzle spray drier in single process and that this can improve the ability of FP to dissolve in water. 相似文献
2.
M Beppu J F Codington R D Lasky R W Jeanloz 《Journal of the National Cancer Institute》1987,78(6):1169-1175
Fetal tissues from time-pregnant female A/J mice of 16- and 19-day pregnancies and from neonates 1 day after birth, as well as from fetal cells in culture, absorbed significant amounts of anti-epiglycanin antibody. Detergent-solubilized glycoproteins, with epiglycanin activity, from fetal tissues and cells were separated by polyacrylamide gel electrophoresis, and the protein bands electroblotted onto a nitrocellulose gel. After the antigens were labeled with rabbit anti-epiglycanin antiserum and [125I]epiglycanin, autoradiography revealed two major bands containing the antigenic determinant at Mr 90,000 and 82,000. Bands of similar molecular weights, but with no demonstrated immunologic cross-reactivity, were observed by fluorography, if intact cells prior to solubilization were labeled by galactose oxidase followed by sodium borotritiide. Immunoreactive epiglycanin activity could be destroyed by Pronase, endo-N-acetyl-alpha-D-galactosaminidase (Diplococcus pneumoniae), or periodate oxidation. Activity was enhanced with neuraminidase. The spleen, liver, or erythrocytes from adult A/J mice did not possess the antigen, but incubation of adult spleen or liver with neuraminidase (Vibrio cholerae) exposed the epitope. 相似文献
3.
4.
The fungistatic antibiotics trichostatins (TS) A and C were isolated from culture broth of Streptomyces platensis No. 145 and were found to be potent inducers of differentiation in murine erythroleukemia (Friend and RV133) cells at concentrations of 1.5 X 10(-8) M for TSA and 5 X 10(-7) M for TSC. Differentiation induced by TS was cooperatively enhanced by UV irradiation but not by treatment with dimethyl sulfoxide. This enhanced activity was completely inhibited by adding cycloheximide to the culture medium 2 h after exposure to TS, suggesting that TS are dimethyl sulfoxide-type inducers of erythroid differentiation. No inhibitory effect of TS was observed on macromolecular synthesis in cultured cells. 相似文献
5.
Goichi Yotsumoto Koki Tanaka Naoki Ishizaki Akira Ikoma Sumihiro Kawashima Akira Taira 《Surgery today》1997,27(7):657-660
We report herein a case of spontaneous subcapsular hepatic hemorrhage which occurred in a 33-year-old woman 1 day after she
had been delivered of her second child by cesarean section following an uneventful pregnancy. She complained of right upper
quadrant pain on the 1st postoperative day, and computed tomography (CT) showed subcapsular low-density masses in both liver
lobes, while extravasation was demonstrated by CO2 intraarterial digital subtraction angiography (IADSA). The hemorrhage was successfully controlled by transcatheter arterial
embolization (TAE). However, on the 3rd day after TAE, an exploratory laparotomy was performed to establish an exact diagnosis
to explain the persistent abdominal pain and abnormal liver function tests. Subcapsular hematomas in both lobes were confirmed
and no visible laceration was present. The patient recovered gradually by spontaneous absorption of the hematomas and was
discharged on the 22nd postoperative day. Spontaneous hepatic hemorrhage associated with pregnancy is a very rare complication,
and establishing a correct diagnosis and initiating appropriate therapy are essential for this life-threatening disease. 相似文献
6.
Shuichiro Uchiyama Kazuo Chijiiwa Masahide Hiyoshi Motoaki Nagano Jiro Ohuchida Koki Nagaike Masahiro Kai Kazuhiro Kondo 《Journal of gastrointestinal surgery》2007,11(11):1570-1572
Mucin-producing tumor in the bile duct is referred to clinically as mucin-producing bile duct tumor (MPBT). Intraductal papillary
neoplasm of the biliary tract that resembles an intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a rare category
of MPBT and is not well characterized. We, herein, report a case of MPBT of the caudate lobe of the liver that showed papillary
growth and communicated with the bile duct of the caudate lobe and protruded into the common hepatic duct. Histologically,
MPBT cells showed papillary overgrowth with abundant mucinous secretions, resembling an IPMN of the pancreas. The MPBT cells
showed the same immunostaining pattern as that of cells from IPMN of the pancreas. 相似文献
7.
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
8.
Opioid supplements are often required in total intravenous anesthesia (TIVA). Most ϰ-opiate receptors are found in the spinal
cord, wherea μ-opiate receptors are widespread throughout the brain and spinal cord. Buprenorphine has a strong μ-action with
a minute ϰ-action, while eptazocine stimulates ϰ-receptors only. From these, epidural eptazocine is expected to exert strong
spinal analgesia by ϰ-stimulation without μ-action, which produces circulatory and respiratory depression. Therefore, the
clinical effects of epidural opioids on circulation, respiration, and analgesia were compared. Continuous epidural administration
of eptazocine or buprenorphine was combined with TIVA in patients scheduled for elective abdominal surgery. Epidural opioid
administration was continued throughout and for 72h after anesthesia. A significant analgesic effect (P<0.01) of epidural eptazocine without circulatory and respiratory depression was observed. With epidural buprenorphine, circulatory
and respiratory depression during and immediately after anesthesia were significant (P<0.05). These results suggest that medullary μ-stimulation by an epidural opioid induces circulatory (hypervagotonicity and
hypervagosensitivity) and respiratory depression, while ϰ-stimulation produces only minimal effects on circulatory and respiratory
systems. 相似文献
9.
H King C Finch A Collins G Koki L F King P Heywood P Zimmet 《The Medical journal of Australia》1989,151(4):204-210
That Melanesians of non-Austronesian genetic ancestry may be relatively resistant to glucose intolerance was supported by the results of a study of two semitraditional non-Austronesian villages in the Papua New Guinean highlands in 1983, in which an absence of diabetes and a high degree of glucose tolerance and insulin sensitivity were observed. The second of this series of surveys was conducted in 1985 in three non-traditional communities: a periurban, non-Austronesian village in the highlands, and rural and periurban Austronesian villages in coastal locations. Although an absence of diabetes was demonstrated once again in the highlanders, these periurban subjects showed an unexpectedly high insulin response which may be a precursor of glucose intolerance. The notion that highland communities that are living in non-traditional circumstances in Papua New Guinea presently are in "metabolic transition" towards diabetes and other non-communicable diseases, if correct, is of importance to the public health of the nation. In the periurban, coastal-dwelling Austronesians, diabetes with severe hyperglycaemia was demonstrated, and there was some evidence of a secular trend towards increasing glucose intolerance. The two-hour plasma glucose concentrations were shown to be associated with obesity, modernity and Seventh-Day Adventist religious persuasion. However, important and unexplained differences in glucose tolerance remained between rural and periurban coastal dwellers after taking these factors into account. 相似文献
10.
Yamaguchi U Hasegawa T Hirose T Chuman H Kawai A Ito Y Beppu Y 《Journal of clinical pathology》2003,56(11):826-830
BACKGROUND: A small number of malignant peripheral nerve sheath tumours (MPNSTs) are low grade, and the nature of these low grade tumours has never been systematically assessed. AIMS: To describe the clinicopathological, immunohistochemical, and ultrastructural features of low grade MPNST and to discuss the main differential diagnoses. METHODS: Four cases of low grade MPNST were studied, including one coexistent with neurofibromatosis type 1. The tumours were analysed with respect to nuclear atypia, cellularity, nuclear enlargement, hyperchromasia, mitotic rate, and necrosis. Immunohistochemistry was performed by standard techniques, and an ultrastructural study was performed on one tumour. RESULTS: The ages of the patients ranged from 32 to 72 years (mean, 58). Two were male and two were female. Three tumours occurred in the deep tissue, including one in the retroperitoneum, and one was located in the dermal and subcutaneous tissue. The maximum diameters of the tumours ranged from 3.5 to 8.0 cm. Microscopically, all tumours showed moderate hypercellularity, an increased nuclear to cytoplasmic ratio, and hyperchromasia, but exhibited varied growth patterns, including those that were atypical neurofibroma-like, low grade fibromyxoid sarcoma-like, low grade epithelioid, and haemangiopericytoma-like. All tumours showed immunoreactivity for S-100 protein and vimentin. CONCLUSIONS: These findings suggest that careful clinical and histological evaluation, along with S-100 protein immunostaining, are essential for the accurate diagnosis of low grade MPNST. 相似文献