全文获取类型
收费全文 | 11241篇 |
免费 | 486篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 258篇 |
儿科学 | 480篇 |
妇产科学 | 385篇 |
基础医学 | 1009篇 |
口腔科学 | 406篇 |
临床医学 | 926篇 |
内科学 | 2629篇 |
皮肤病学 | 185篇 |
神经病学 | 679篇 |
特种医学 | 503篇 |
外科学 | 2253篇 |
综合类 | 253篇 |
一般理论 | 3篇 |
预防医学 | 451篇 |
眼科学 | 245篇 |
药学 | 618篇 |
中国医学 | 36篇 |
肿瘤学 | 485篇 |
出版年
2024年 | 7篇 |
2023年 | 107篇 |
2022年 | 230篇 |
2021年 | 390篇 |
2020年 | 202篇 |
2019年 | 274篇 |
2018年 | 322篇 |
2017年 | 236篇 |
2016年 | 366篇 |
2015年 | 423篇 |
2014年 | 528篇 |
2013年 | 609篇 |
2012年 | 774篇 |
2011年 | 779篇 |
2010年 | 467篇 |
2009年 | 409篇 |
2008年 | 768篇 |
2007年 | 868篇 |
2006年 | 849篇 |
2005年 | 779篇 |
2004年 | 663篇 |
2003年 | 538篇 |
2002年 | 476篇 |
2001年 | 86篇 |
2000年 | 79篇 |
1999年 | 66篇 |
1998年 | 60篇 |
1997年 | 41篇 |
1996年 | 51篇 |
1995年 | 29篇 |
1994年 | 21篇 |
1993年 | 22篇 |
1992年 | 23篇 |
1991年 | 20篇 |
1990年 | 24篇 |
1989年 | 31篇 |
1988年 | 20篇 |
1987年 | 19篇 |
1986年 | 18篇 |
1985年 | 18篇 |
1984年 | 8篇 |
1983年 | 11篇 |
1982年 | 6篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1974年 | 5篇 |
1973年 | 9篇 |
1972年 | 7篇 |
1971年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
41.
42.
Ali Yildiz Ekrem Islamoglu Mustafa Yuksel Ibrahim Erol Kaan Karamik Tuncay Cakir Mutlu Ates Murat Savas 《Current Urology》2021,15(2):111
Background:To evaluate the changes in penile sensation by electrophysiological tests in patients who underwent radical prostatectomy (RP) and to demonstrate the role of dorsal penile nerve injury in postoperative erectile dysfunction.Materials and methods:Twenty-six volunteer patients who were eligible for RP were included in the study. Preoperative penile sensory electromyography and the International Index of Erectile Function-5 (IIEF-5) questionnaire were done for each patient. Erectile function assessment and electrophysiological evaluation of penile sensation were repeated at postoperative 3rd and 6th months.Results:Postoperative IIEF-5 scores and electromyography values were significantly lower than preoperative findings (p < 0.05). The IIEF-5 scores in the nerve sparing-RP (NS-RP) group were significantly higher than the non-nerve sparing-RP (NNS-RP) group in the postoperative period. Nerve conduction velocity values in the NS-RP group were also higher than the NNS-RP group at the postoperative 3rd and 6th months. However, these changes were not statistically significant (p > 0.05).Conclusions:Patients who underwent RP have decreased penile sensation due to cavernous nerve damage and a possible dorsal penile nerve injury. The decrease of penile sensation may be associated with postoperative erectile dysfunction. 相似文献
43.
Azza Farag Mostafa Hammam Nada Alnaidany Eman Badr Mustafa Elshaib Aliaa El-Swah Wafaa Shehata 《The Journal of clinical and aesthetic dermatology》2021,14(2):14
BACKGROUND: Melasma is a chronic hypermelanotic disorder that is challenging to treat; no single effective therapeutic agent for it has been discovered. Methimazole, an oral antithyroid drug, has a skin depigmenting effect when used topically. OBJECTIVE: We sought to evaluate the efficacy and safety of methimazole, applied during microneedling sessions and additional topical use in between sessions, for the treatment of melasma. METHODS: This split-face study included 30 Egyptian patients with melasma, each of whom received 12 microneedling sessions once per week for 12 weeks followed by topical methimazole on the right side of face and placebo on the left side. In between the sessions, topical methimazole 5% cream was applied twice per day on the right side and placebo on the left side. Assessments were performed using the Hemi-melasma Area and Severity Index (hemi-MASI) percentage of improvement, patient satisfaction, dermoscopy, and thyroid-stimulating hormone (TSH) serum levels. RESULTS: There were significant clinical and dermoscopic improvements; hemi-MASI scores on the methimazole-treated right sides were decreased (p<0.001). The percent of hemi-MASI score improvement was significantly associated with the malar pattern (p=0.031) and epidermal type (p=0.04) of melasma. About 70 percent of our studied patients reported being satisfied with their treatment response (7% excellent, 33% good, 30% fair). No significant local or systemic side effects were observed. Pre- and posttreatment serum TSH levels were within the normal range in all treated cases. CONCLUSIONS: Methimazole has the potential to be a safe and promising therapeutic agent for the treatment of melasma via dermapen-delivered microneedling sessions with topical use in between sessions. 相似文献
44.
Christian Rehme Carolin Burchert Mustafa Tosun Tibor Szarvas Nadine Nagy Herbert Ruebben Boris Hadaschik Christian Niedworok 《Translational andrology and urology》2021,10(1):87
BackgroundTo evaluate whether stone extraction with a loop ureteral catheter (LUC) in distal ureteral stones is associated with a higher frequency of ureteral strictures compared to treatment with primary ureteroscopic stone removal (p-URS) or ureteroscopic laser lithotripsy (l-URS).MethodsFive hundred and forty-seven consecutive patients were primarily endourologically treated for distal ureteral stones in our department between 2005 and 2019 and included in the study protocol. Data was retrospectively obtained from the patients’ charts and medical reports as well as from office-based urologists. Data analysis was performed using Fisher’s exact test, Mann-Whitney test or Student’s t-test as appropriate. A level of P<0.05 was assigned statistical significance.ResultsFour hundred and twelve patients were treated by URS (p-URS n=304, l-URS n=108) and another 135 by LUC stone extraction. Median follow-up was 41 [2–159] months. There was no difference between the groups concerning age, gender, proportion of patients with ureteral stenting, operating time, hospitalization or readmission rates. The number of ureteric strictures was small in all procedures [n=3 (1.0%) in p-URS, n=2 (1.9%) in l-URS and n=2 (1.5%) in LUC] and there was no difference between the groups concerning this serious complication (p-URS vs. LUC: P=0.6465; l-URS vs. LUC: P=0.9999).ConclusionsIn small distal stones, LUC stone extraction still is an alternative to URS procedures in stone management with comparable results concerning postinterventional ureteral strictures. In experienced hands, it still has its value in accurately selected patients. 相似文献
45.
BACKGROUND: The purpose of this study was to determine the effects of systemic infusions of nitroglycerin and sodium nitroprusside on flow distribution and wall shear stress in the microcirculation. METHODS: With university approval, the cremaster muscle of 28 anesthetized (70 mg/kg pentobarbital given intraperitoneally) hamsters (Harlan Sprague Dawley: Syrian; weight, 121+/-11 g [mean +/- SDD) was observed using in vivo fluorescence microscopy. Arteriolar diameter, erythrocyte flux, and velocity were measured for a feed arteriole and its sequential branches. Observations were made during control (mean arterial pressure, 88+/-4 mm Hg) and after 30 min of intravenous delivery of sodium nitroprusside or nitroglycerin, titrated to decrease mean arterial pressure by 20 mm Hg. RESULTS: Sodium nitroprusside significantly dilated select upstream portions of the network (23+/-2.6 to 29+/-2.6 microm); no arterioles were dilated with nitroglycerin. Erythrocyte flux into the feed (i.e., inflow into the arteriolar network) and into the sequential branches (i.e., distribution within the network) were evaluated. With nitroglycerin, inflow decreased significantly from 1,560+/-335 to 855+/-171 cells/s, and flux into the branches decreased evenly. With sodium nitroprusside, inflow increased significantly to 2,600+/-918 cells/s, yet cells were "stolen" from upstream branches (a decrease from 425+/-67 to 309+/-87 cells/s in the first branch). Excess flow passed into a downstream "thorough-fare channel," significantly increasing flux from 347+/-111 to 761+/-246 cells/s. Wall shear stress decreased uniformly with nitroglycerin infusion, with a decrease in the feed from 8.8+/-2.5 to 6+/-1.7 dyn/cm2. With sodium nitroprusside, variable changes occurred that were location specific within the network. For instance, at the inflow point to the network, wall shear stress changed from 8.3+/-2.5 to 4.2+/-3.3 dyn/cm2. CONCLUSIONS: Nitroglycerin infusion promoted homogeneity of flow. Sodium nitroprusside significantly increased the heterogeneity of flow within this arteriolar network; an anatomic location for steal induced by sodium nitroprusside is identified. 相似文献
46.
Electrical stimulation of ovine trachealis smooth muscle and bronchial ring segments induced neurogenic and monophasic atropine-sensitive contractions. Pretreatment of the tissues with capsaicin (100 microM) significantly reduced these contractions indicating a possible contribution of a peptidergic neurotransmitter to the contractions. The effect of capsaicin on electrically induced contractions was significantly inhibited by capsazepin indicating an action on vanilloid receptors. In both preparations, electrically induced contractions were not modified by tachykinin NK(1)- and NK(2)-receptor antagonists singly and in combination. It was therefore concluded that a component of the atropine-sensitive electrically induced contractions of ovine airways smooth muscles involved the release of a peptide neurotransmitter which is probably not a tachykinin. However, an action of capsaicin on prejunctional vanilloid receptors located on cholinergic nerves cannot be ruled out. 相似文献
47.
Giant or huge colloid cysts of the third ventricle up to of more than 3 cm in diameter are extremely rare. The patient presented with symptoms of increased intracranial pressure, including headache, vomiting, and papilledema. Computerized tomographic (CT) scan revealed a hypodense, huge colloid cyst of the third ventricle associated with calcification in the cyst wall. Both hypodensity and calcification are uncommon roentgenological findings for colloid cysts of the third ventricle. The patient was operated on by the transcortical/transventricular approach and the colloid cyst was completely excised. 相似文献
48.
N M Elsayed A D Hacker K Kuehn M G Mustafa G N Schrauzer 《Toxicology and applied pharmacology》1983,71(3):398-406
We examined the influence of dietary selenium (Se) on the pulmonary biochemical response to ozone (O3) exposure. For 11 weeks, weanling female strain A/St mice were fed a test diet containing Se either at 0 ppm (-Se) or 1 ppm (+Se). Each diet contained 55 ppm vitamin E (vit E). Mice from each dietary group were exposed to 0.8 +/- 0.05 ppm (1568 +/- 98 micrograms/m3) O3 continuously for 5 days. After O3 exposure, they were killed along with a matched number of unexposed controls, and their lungs were analyzed for various biochemical parameters. The Se contents of lung tissue and whole blood were determined, and the levels were seven- to eightfold higher in +Se mice than in -Se mice, reflecting the Se intake of the animals. In unexposed control mice, Se deficiency caused a decline in glutathione peroxidase (GP) activity relative to +Se group. After O3 exposure, the GP activity in the -Se group was associated with a lack of stimulation of glutathione reductase (GR) activity and the pentose phosphate cycle (PPC) as assessed by measuring glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) activities. In contrast, the +Se group after O3 exposure exhibited increases in all four enzyme activities. Other parameters, e.g., lung weight, total lung protein, DNA and nonprotein sulfhydryl contents, and O2 consumption, were not affected by dietary Se in the presence or absence of O3 exposure. The data indicate that dietary Se alters the GP activity, which in turn influences the GR and PPC activities in the lung evidently through a reduced demand for NADPH. The level of vit E in the lung was found to be twofold higher in the -Se group than in the +Se group, suggesting a compensatory relationship between Se and vit E in the lung. With O3 exposure, both Se and vit E contents further increased in the lungs of each dietary group. It is plausible that Se and vit E under oxidant stress are "mobilized" to the lung from other body sites. 相似文献
49.
The validity of the Cognitive Coping Strategy Inventory (CCSI; Butler et al., 1989) was tested in a prospective fashion. Subjects were randomly assigned to one of three conditions. Some were matched to a strategy for which they received a high CCSI score, some were mismatched to a strategy for which they received a low CCSI score, and some were given a choice of strategies. Those subjects using a matched strategy obtained better threshold and tolerance times on the cold pressor than subjects who used a mismatched strategy. Despite clear differences in exposure to the cold pressor these conditions did not differ from each other in self-reported levels of pain. It was concluded that the CCSI appears to be a valid and useful tool for selecting a coping strategy to help particular individuals manage acute pain. Though the CCSI is relatively easy to administer and score, the comparative costs and benefits of using it must be weighed against the somewhat more efficient approach of simply offering the subject a choice of treatments. Subjects given a choice of strategies performed as well as subjects matched to a strategy on the basis of CCSI scores. 相似文献
50.
Fumihiko Kawamoto Nobuo Kido Takamasa Hanaichi Mustafa B. A. Djamgoz Robert E. Sinden 《Parasitology research》1992,78(4):277-284
Ionic regulation in the induction of exflagellation ofPlasmodium berghei was investigated by culturing the parasites in various isotonic media. Of the salts tested, NaHCO3 exhibited the highest activity in inducing exflagellation, whereas KHCO3 showed no activity. In the absence of HCO
3
–
, media containing monovalent cation (Na+, K+, Cs+, Rd+, choline+, lysine+, arginine+) and Cl– also induced exflagellation, but their activities were lower than that of NaHCO3. Anions of Br– or NO
3
–
could be substituted with Cl–, whereas other anions such as I–, NO
2
–
, SO
4
2–
, SCN–, H2PO
4
–
, or HPO
4
2–
failed to induce exflagellation, as did tetramethylammonium-Cl, CaCl2, MgSO4, MgCl2 and sucrose as well. These results suggest that the induction of exflagellation requires the presence of Na+ and HCO
3
–
or monovalent, membrane-permeable cation and Cl– in the medium. Measurements of the efflux of H[14C]O
3
–
or Cl– indicated that these anions were released from the cells into the NaCl or the NaHCO3 medium, respectively, probably by exchange in HCO
3
–
/Cl–. Determination of intracellular ionic concentrations by electron microscopic X-ray microanalysis of cryopreserved specimens revealed that in the NaHCO3 medium, external Na+ (and probably HCO
3
–
) enters the gametocytes by exchange with internal Cl– (and probably H+), whereas in Cl–-containing media, external unspecified cation and Cl– influx by exchange, probably with H+ and HCO
3
–
. It is therefore suggested that two separate ion exchangers, i.e., Na+-dependent HCO
3
–
(in)/Cl–(out) and nonspecific monovalent-cation-dependent Cl–(in)/HCO
3
–
(out) exchangers, are involved in the induction of gametogenesis inP. berghei. Furthermore, the presence of both classes of anion in the medium enhanced exflagellation activity and increased Na+ uptake more than did the NaCl or NaHCO3 medium alone. The apparent synergistic enhancement by two contraactive anion exchangers is consistent with a recycling model of pHi regulation, in which HCO
3
–
and Cl– are exchanged between the cells and the media, resulting in the acceleration of monovalent cation/H+ exchange.This work was supported by a Grant-in-Aid (No. 01570212) from the Ministry of Education, Science and Culture, Japan and the Ohyama Health Foundation, Japan (to FK), and in part by the Medical Research Council, United Kingdom (to RES) 相似文献