全文获取类型
收费全文 | 10082篇 |
免费 | 592篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 55篇 |
儿科学 | 195篇 |
妇产科学 | 139篇 |
基础医学 | 1500篇 |
口腔科学 | 189篇 |
临床医学 | 768篇 |
内科学 | 2875篇 |
皮肤病学 | 212篇 |
神经病学 | 526篇 |
特种医学 | 352篇 |
外科学 | 1571篇 |
综合类 | 41篇 |
预防医学 | 242篇 |
眼科学 | 126篇 |
药学 | 695篇 |
中国医学 | 44篇 |
肿瘤学 | 1201篇 |
出版年
2023年 | 40篇 |
2022年 | 108篇 |
2021年 | 182篇 |
2020年 | 82篇 |
2019年 | 134篇 |
2018年 | 189篇 |
2017年 | 126篇 |
2016年 | 178篇 |
2015年 | 195篇 |
2014年 | 257篇 |
2013年 | 292篇 |
2012年 | 495篇 |
2011年 | 514篇 |
2010年 | 300篇 |
2009年 | 274篇 |
2008年 | 482篇 |
2007年 | 519篇 |
2006年 | 507篇 |
2005年 | 554篇 |
2004年 | 539篇 |
2003年 | 599篇 |
2002年 | 508篇 |
2001年 | 296篇 |
2000年 | 332篇 |
1999年 | 330篇 |
1998年 | 162篇 |
1997年 | 126篇 |
1996年 | 120篇 |
1995年 | 92篇 |
1994年 | 98篇 |
1993年 | 126篇 |
1992年 | 214篇 |
1991年 | 212篇 |
1990年 | 207篇 |
1989年 | 186篇 |
1988年 | 166篇 |
1987年 | 127篇 |
1986年 | 115篇 |
1985年 | 111篇 |
1984年 | 89篇 |
1983年 | 64篇 |
1982年 | 33篇 |
1981年 | 42篇 |
1980年 | 33篇 |
1979年 | 50篇 |
1978年 | 30篇 |
1977年 | 31篇 |
1976年 | 27篇 |
1969年 | 24篇 |
1968年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
1.
2.
3.
Jun Agata Nobuyuki Ura Hideaki Yoshida Yasuyuki Shinshi Haruki Sasaki Masaya Hyakkoku Shinya Taniguchi Kazuaki Shimamoto 《Hypertension research》2006,29(11):865-874
Angiotensin II receptor blockers (ARBs) are widely used for the treatment of hypertension. It is believed that treatment with an ARB increases the level of plasma angiotensin II (Ang II) because of a lack of negative feedback on renin activity. However, Ichikawa (Hypertens Res 2001; 24: 641-646) reported that long-term treatment of hypertensive patients with olmesartan resulted in a reduction in plasma Ang II level, though the mechanism was not determined. It has been reported that angiotensin 1-7 (Ang-(1-7)) potentiates the effect of bradykinin and acts as an angiotensin-converting enzyme (ACE) inhibitor. It is known that ACE2, which was discovered as a novel ACE-related carboxypeptidase in 2000, hydrolyzes Ang I to Ang-(1-9) and also Ang II to Ang-(1-7). It has recently been reported that olmesartan increases plasma Ang-(1-7) through an increase in ACE2 expression in rats with myocardial infarction. We hypothesized that over-expression of ACE2 may be related to a reduction in Ang II level and the cardioprotective effect of olmesartan. Administration of 0.5 mg/kg/day of olmesartan for 4 weeks to 12-week-old stroke-prone spontaneously hypertensive rats (SHRSP) significantly reduced blood pressure and left ventricular weight compared to those in SHRSP given a vehicle. Co-administration of olmesartan and (D-Ala7)-Ang-(1-7), a selective Ang-(1-7) antagonist, partially inhibited the effect of olmesartan on blood pressure and left ventricular weight. Interestingly, co-administration of (D-Ala7)-Ang-(1-7) with olmesartan significantly increased the plasma Ang II level (453.2+/-113.8 pg/ml) compared to olmesartan alone (144.9+/-27.0 pg/ml, p<0.05). Moreover, olmesartan significantly increased the cardiac ACE2 expression level compared to that in Wistar Kyoto rats and SHRSP treated with a vehicle. Olmesartan significantly improved cardiovascular remodeling and cardiac nitrite/ nitrate content, but co-administration of olmesartan and (D-Ala7)-Ang-(1-7) partially reversed this anti-remodeling effect and the increase in nitrite/nitrate. These findings suggest that olmesartan may exhibit an ACE inhibitory action in addition to an Ang II receptor blocking action, prevent an increase in Ang II level, and protect cardiovascular remodeling through an increase in cardiac nitric oxide production and endogenous Ang-(1-7) via over-expression of ACE2. 相似文献
4.
Shiro Akinaga Tadashi Ashizawa Katsushige Gomi Hiroe Ohno Makoto Morimoto Chikara Murakata Masami Okabe 《Cancer chemotherapy and pharmacology》1992,29(4):266-272
Summary Novel derivatives of K-252a, (8R*,9S*,11S*)-(–)-9-hydroxy-9-methoxycarbonyl-8-methyl-2,3,9,10-tetrahydro-8, 11-epoxy-1H,8H,11H-2,7b,11a-triazadibenzo [a,g]-cycloocta[cde]trinden-1-one, an inhibitor of protein kinases and calmodulin-dependent phosphodiesterase, were synthesized and evaluated for their antitumor activity in vitro and in vivo. Of ten derivatives tested, four were active against the P388 murine leukemia i. p.-i. p. system, although K-252a was inactive. Among these derivatives, KT6124 was selected for further biological evaluation studies because its efficacy was the highest. KT6124 was also active against sarcoma 180 and B16 melanoma. It exerted a relatively broad spectrum of antiproliferative activity against 20 human tumor cell lines in vitro. To determine the mechanism(s) of action underlying the antitumor activity of KT6124, we tested the drug for inhibition of protein kinases, including Ca2+-and phospholipid-dependent protein kinase (PKC), in intact A431 human epidermoid carcinoma cells in comparison with the PKC-inhibitory activity of K-252a. KT6124 did not antagonize the action of phorbol 12-myristate 13-acetate (PMA) in A431 cells, whereas K-252a did, suggesting that KT6124 may not act on protein kinases in the cells. The interaction of KT6124 with DNA in living cells was examined by the alkaline elution method. KT6124 apparantly exhibited DNA scission both dose-and time-dependently in the target cells. The DNA breakage was dependent on proteinase K treatment, suggesting its possible interaction with DNA-related enzyme(s). These results indicate that KT6124 exerts antitumor activity by acting on DNA or on DNA-related enzyme(s) in tumor cells rather than via the inhibition of protein kinases. 相似文献
5.
Laparoscopic cholecystectomy and time-course changes in renal function 总被引:13,自引:3,他引:10
Y. Miki K. Iwase W. Kamiike E. Taniguchi K. Sakaguchi J. Sumimura H. Matsuda I. Nagai 《Surgical endoscopy》1997,11(8):838-841
Background: Recently, the retraction method has been used to reduce intraabdominal pressure (IAP) during laparoscopic surgery. The purpose
of this study was to determine the serial changes in renal function during laparoscopic cholecystectomy (LC) using the retraction
method.
Methods: Urine output, effective renal plasma flow (ERPF), and glomerular filtration rate (GFR) were measured serially in seven patients
who underwent LC with 12 mmHg pneumoperitoneum (High-IAP group) and five who underwent LC using the retraction method with
4 mmHg pneumoperitoneum (Low-IAP group).
Results: Urine output, ERPF, and GFR were decreased during pneumoperitoneum in the High-IAP group, whereas no significant changes
in any of these parameters were observed in the Low-IAP group.
Conclusions: Our findings demonstrate that reduction of IAP to 4 mmHg using the retraction method prevents the transient renal dysfunction
caused by prolonged 12 mmHg pneumoperitoneum during LC, suggesting that the retraction method reduces the risk of perioperative
renal dysfunction during laparoscopic surgery.
Received: 26 March 1996/Accepted: 27 July 1996 相似文献
6.
Isolated ultrafiltration, hemodialysis & peritoneal dialysis (Tx) were recently used in the treatment of intractable heart failure (HF). We examined the relation between the response of HF to Tx and the residual kidney functions. Tx was carried out in 17 patients (Pts) with HF who did not respond to aggressive medical treatment. Ten Pts (R) responded to Tx and 7 Pts (N) did not. Serum urea nitrogen (UN), creatinine (Cr), uric acid (UA), sodium (Na), potassium (K), and chloride (Cl) concentrations on admission and before Tx were not different between R and N. Urine UN, Cr, Na, K, and Cl on admission and before Tx were also not significantly different. Fractional sodium excretions (FENa), renal failure indices (RFI), and urine/plasma Cr ratios (U/P Cr) on admission were 2.0 +/- 1.6, 2.7 +/- 2.2, and 30.5 +/- 20.0 in R and 5.9 +/- 4.2, 8.2 +/- 6.0 and 11.5 +/- 3.8 in N. They were significantly different (p less than 0.05). However, these did not differ before and after Tx. These data show that FENa, RFI and U/P Cr might be useful indices in predicting the responsiveness of intractable HF to Tx. 相似文献
7.
8.
Akihiro Shindo Yasumasa Kokubo Akira Taniguchi Manami Kuze Shigeki Kuzuhara 《Clinical neurology》2007,47(2-3):116-118
A 30-year-old woman was admitted to Mie University Hospital for recurrence of sudden visual field defect with photopsia in the right eye. She had experienced the same episodes at the age of 15, 20, 25 and 28 years old. A diagnosis of retrobulbar optic neuritis had been made at each episode, but corticosteroid therapy failed to resolve the symptoms. Neurologic examination on admission was unremarkable except for the visual field defect of the right eye. Brain MRIs with and without gadolinium enhancement were normal. On ophthalmologic examination, visual acuity was normal, but the Mariotte blind spot of the right eye was expanded. Ophthalmoscopic examination, visual evoked potential, flicker electro-oculogram and Hess test were normal. Multifocal electroretinogram (ERG) revealed reduction in the inferior temporal response of the right eye that corresponded to the expansion of the Mariotte blind spot These findings were consistent with conditions of acute zonal occult outer retinopathy (AZOOR). The visual symptoms of AZOOR thus resemble those of retrobulbar optic neuritis and findings of multifocal ERG were useful to differentiate them. AZOOR is a newly established condition, and it is necessary to pay more attention to AZOOR on the differential diagnoses of acute-onset mono ocular visual disturbances. 相似文献
9.
A Miura Y Ukai T Matsuzaki N Taniguchi S Hayashi S Kano Y Kimura K Kimura H Enomoto 《Arzneimittel-Forschung》1986,36(9):1323-1328
The effects of methyl 2,6-dimethyl-4-(2-nitrophenyl)-5-(2-oxo-1,3,2-dioxaphosphorinan-2- yl)-1,4- dihydropyridine 3-carboxylate (DHP-218), a new dihydropyridine calcium antagonist, on vascular smooth muscles, cardiac muscles and [3H]-nitrendipine binding to the cardiac muscle and brain membranes were investigated in vitro. Vascular smooth muscles: Calcium-induced contraction of the rat aorta in high K+ solution was inhibited by DHP-218 with the pA2 value of 9.11. The IC50 value for the inhibitory effects of this compound in high K+-induced and phenylephrine-induced contraction was 6.3 nmol/l and 66 nmol/l, respectively. Vasodilatory effects of this drug on various blood vessels of rabbits contracted by high K+ appeared to a similar extent. The onset of the vasodilatory effect was very slow and the recovery rate of vasodilatory response after washout with the bathing solution containing high K+ or phenylephrine was also very slow. Cardiac muscles: Negative chronotropic and inotropic actions were observed at concentrations more than 30 and 100 nmol/l, respectively. Duration of the plateau phase of normal action potential was shortened and the amplitude and duration of slow action potential were reduced at concentrations more than 1 mumol/l. Very high vasculoselectivity was observed. Displacement of [3H]-nitrendipine binding: The pattern of displacement of [3H]-nitrendipine binding by DHP-218 was very similar to that of other 1,4-dihydropyridines but this compound was about 70 times less potent than nifedipine in [3H]-nitrendipine displacement capacity. These results indicate that DHP-218 has specific vasodilatory action due to calcium antagonism, but association and dissociation rates with tissue and receptors were different from those of nifedipine. 相似文献
10.
Yuji Maruyama Shigeo Yamauchi Hidetsugu Ogasawara Hajime Imura Masami Ochi Kazuo Shimizu 《Annals of thoracic and cardiovascular surgery》2006,12(1):60-62
Surgical treatment for subacute pulmonary arterial thromboembolism has previously been considered to be inappropriate. We undertook a pulmonary arterial thrombectomy and removal of a floating right heart thrombus in a patient who had been symptomatic for over a month. The pulmonary arterial pressure, which had been equal to the systemic pressure preoperatively, decreased gradually and almost normalized one month postoperatively. Pulmonary perfusion scintigraphy revealed a dramatic improvement and the patient returned to normal life activities. 相似文献