全文获取类型
收费全文 | 957篇 |
免费 | 27篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 28篇 |
妇产科学 | 33篇 |
基础医学 | 95篇 |
口腔科学 | 21篇 |
临床医学 | 199篇 |
内科学 | 254篇 |
皮肤病学 | 45篇 |
神经病学 | 36篇 |
特种医学 | 11篇 |
外科学 | 101篇 |
综合类 | 20篇 |
一般理论 | 6篇 |
预防医学 | 51篇 |
眼科学 | 19篇 |
药学 | 58篇 |
肿瘤学 | 8篇 |
出版年
2016年 | 10篇 |
2015年 | 8篇 |
2014年 | 13篇 |
2013年 | 19篇 |
2012年 | 9篇 |
2010年 | 29篇 |
2009年 | 21篇 |
2008年 | 9篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 8篇 |
2003年 | 15篇 |
2001年 | 13篇 |
2000年 | 6篇 |
1999年 | 34篇 |
1998年 | 37篇 |
1997年 | 26篇 |
1996年 | 38篇 |
1995年 | 24篇 |
1994年 | 34篇 |
1993年 | 14篇 |
1992年 | 24篇 |
1991年 | 14篇 |
1990年 | 10篇 |
1989年 | 21篇 |
1988年 | 22篇 |
1987年 | 19篇 |
1986年 | 16篇 |
1985年 | 11篇 |
1984年 | 19篇 |
1983年 | 20篇 |
1982年 | 11篇 |
1981年 | 11篇 |
1980年 | 12篇 |
1979年 | 10篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1970年 | 7篇 |
1967年 | 11篇 |
1962年 | 7篇 |
1960年 | 5篇 |
1959年 | 32篇 |
1958年 | 34篇 |
1957年 | 41篇 |
1956年 | 45篇 |
1955年 | 47篇 |
1954年 | 51篇 |
1949年 | 8篇 |
1948年 | 15篇 |
1947年 | 4篇 |
排序方式: 共有987条查询结果,搜索用时 15 毫秒
1.
Taste sensitivity was evaluated by suprathreshold scaling of six concentrations each of sodium chloride, sucrose, citric acid, and quinine hydrochloride. Magnitude estimation was used as the method of scaling. The study group was composed of 22 males and 19 females were either patients (institutionalized) or staff members of the Jewish Institute for Geriatric Care. Data from each patient were used to compute individual slopes and Y-intercepts of the log to log transformations for each solution sequence. The mean age of the persons who were institutionalized was significantly higher than that of the staff members. In addition, the mean age of the females was 10 years older than that of the males. The older adult males seemed to have impaired taste function that resulted in significant decreases in total perceived intensity of several taste solutions. No significant differences were shown in taste ability between the relatively healthy younger staff member subjects and the older, more infirm, institutionalized subjects. 相似文献
2.
Introduction and Aims. Different self‐report methods tend to produce different estimates of alcohol consumption. The present study compares differences in rates and risk levels based on responses to a modified version of the Daily Drinking Questionnaire (m‐DDQ) and quantity‐frequency (QF) questions. Design and Methods. The sample comprised 2082 university students, 61% of whom were female and 39% male with a mean age of 23.5 years. An email containing an online link to a brief six‐question survey was emailed to students enrolled in participating faculties at the University of Wollongong, Australia. Current drinkers completed m‐DDQ and QF questions about alcohol consumption. Results. QF methods identified significantly lower estimates of consumption (Mean = 9.15, SD = 12.51) compared with m‐DDQ (Mean = 13.06, SD = 14.07). Allocation to risk categories based on the Australian Alcohol Guidelines were conducted for both the m‐DDQ and QF methods. Almost twice as many students were found to be drinking at levels considered risky using the m‐DDQ method compared with QF. In addition, the relative rank order of participants varied significantly between the two methods. Discussion and Conclusions. The m‐DDQ method identified higher rates of drinking and categorised almost twice as many individuals into risky categories of drinking compared with QF. Such variations have major implications for identification of risk groups in health promotion or prevention programs.[Utpala‐Kumar R, Deane FP. Rates of alcohol consumption and risk status among Australian university students vary by assessment questions. Drug Alcohol Rev 2009] 相似文献
3.
4.
FRANK ESPERSEN NIELS FRIMODT-MLLER VIBEKE THAMDRUP ROSDAHL OVE JESSEN VIGGO FABER KIRSTEN ROSENDAL 《Journal of internal medicine》1987,222(5):465-470
ABSTRACT. A total of 6 253 cases of Staphylococcus aureus bacteremia, including 274 (4.4%) endocarditis cases, were registered in Denmark in the period 1975–1984. Patients with hematological malignancies and/or agranulocytosis accounted for 479 of the bacteremia cases. The incidence of endocarditis in this group of patients was only 0.4% as compared to 4.7% in other patients with staphylococcal bacteremia (p<0.01). The lower incidence of endocarditis complicating bacteremia in these patients may justify a shorter course of therapy than usually recommended for suspected endocarditis. Patients with hematological malignancies and other patients with agranulocytosis had a higher mortality (49 and 46%, respectively) than other patients with S. aureus bacteremia (33%). The highest mortality was found in patients with multiple myeloma (71%, p<0.01), the lowest in patients with acute lymphocytic leukemia (28%, p<0.01). The higher mortality in these patients may indicate that empiric antibiotic regimens in granulocytopenic patients should include a specific anti-staphylococcal agent. 相似文献
5.
Novel polyanionic proteins were designed to increase the rate of heparin cofactor II (HC) inhibition of α-thrombin, an essential protease in the coagulation cascade. Two α-helical coiled-coil proteins, a 62-residue dimer containing 8 Glu residues (E8C) and a 104-residue dimer containing 14 Glu residues (E14C), plus two 31-residue control peptides containing 8 Glu residues each (E8A and E8B), were chemically synthesized, structurally characterized and enzymatically assayed. Circular dichroic spectrophotometry indicated that both E8C and E14C formed stable two-chain α-helical coiled coils at pH 7 and 25 °C. The control peptides were only partially α-helical. E14C remained folded at 90 °C but E8C was half unfolded at 49 °C. Coiled-coil proteins E8C and E14C maximally accelerated by 35- and 33-fold, respectively, the rate of HC inhibition of α-thrombin. None of these compounds accelerated antithrombin inhibition of α-thrombin, and neither control peptide accelerated HC inhibition of α-thrombin. Acceleration of the HC inhibition of α-thrombin showed bimodal dependence on the concentration of the polyanionic protein, which is consistent with formation of a HC-coiled-coil-thrombin ternary complex. The results suggest that antithrombotic polyanionic α-helical coiled-coil proteins can be designed and synthesized and that the occurrence of secondary structure can be correlated with biologcal activity. © Munksgaard 1995. 相似文献
6.
CHRISTOPH STELLBRINK KLAUS-PETER KUNZE PETER HANRATH 《Pacing and clinical electrophysiology : PACE》1995,18(9):1717-1720
STELLBRINK, C., et al .: Preexcitation in Hypertrophic Cardiomyopathy: A Case of a Fasciculoventricular Mahaim Fiber . A patient with hypertrophic cardiomyopathy (HCM) who presented with preexcitation pattern on the surface ECG suggestive of the Wolff-Parkinson-White (WPW) syndrome is described. Intracardiac electrophysiological study revealed a fixed anomalous QRS complex and a short fixed His-ventricular interval indicating a fasciculoventricular Mahaim fiber. As this specific form of accessory connection does not cause reentrant tachycardias, no treatment was required. It is important to distinguish this entity from atriofascicular or nodoventricular Mahaim fibers or the WPW syndrome in patients with HCM showing a preexcitation pattern in the surface ECG, as these may cause life-threatening arrhythmias in this patient population. 相似文献
7.
COLMAN R. D.; FRANK M.; LOUGHNAN B. A.; COHEN D. G.; CATTERMOLE R. 《British journal of anaesthesia》1988,61(6):720-729
Twenty patients who underwent elective Caesarean section receivedranitidine 150 mg by mouth 814 h, and 50 mg i.m. 90 min,before surgery. Intraoperative gastric aspiration resulted incontents with a pH > 2.5 and volume < 25 ml in all patients(mean pH 6.5 (SD 0.8); mean volume 9.0 (SD 7.2) ml). Sixty patientsin labour, who received ranitidine 50 mg i.m. 6-hourly, underwentemergency surgery. Half of this group received, in addition,a single preinduction dose of either 15 or 30 ml of sodium citrate0.3 mol litre-1. A further 30 patients who remained unmedicatedduring labour and required emergency surgery received a preinductiondose of 15 or 30 ml of sodium citrate 0.3 mol litre-1 alone.Ranitidine medication resulted in a mean aspirated gastric volumeof 31.4 (26.6) ml and pH of 5.3 (2.1); five of 30 patients hada pH < 2.5. The addition of sodium citrate 0.3 mol litre-1resulted in gastric pH > 2.5 in all patients and a mean gastricvolume of 43.2 (38.3) ml. The group who received only sodiumcitrate 0.3 mol litre-1 had a mean pH of 5.3 (1.1) and a meanvolume 122.7 (98.2) ml. 相似文献
8.
ALEKSANDRA MISICKA ANDRZEJ W. LIPKOWSKI ROBERT HORVATH PEG DAVIS FRANK PORRECA HENRY I. YAMAMURA VICTOR J. HRUBY 《Chemical biology & drug design》1994,44(1):80-84
Further efforts to correlate the topography of the bioactive structures of DPDPE and the deltorphins, two δ-opioid receptor active peptide families, are reported. A number of DPLPE-deltorphin chimeric peptides have been synthesized in which the C-terminal dipeptide δ-address of the deltorphins (-Val-GlyNH2, -Nle-GlyNH2) have been linked to the highly δ-opioid selective cyclic peptides DPDPE or DPLPE. These studies demonstrate that a major structural feature determining high potency of hybrid analogues is the chirality of the amino acid residue in position 5. The radioligand binding assays have revealed a decrease in potency (compared to DPDPE) at §-receptors when the C-terminal dipeptides were added to DPDPE. On the other hand, chimeric peptides of DPLPE with these same C-terminal dipeptides retained high δ-selectivity and affinity. Similar results were obtained using the mouse vas deferens (MVD) and guinea pig ileum (GPI) bioassays. The importance of the hydrophilicity of amino acids in positions 2 and 5 for δ-selectivity is consistent with the previous finding for DPLPE and DPDPE. On the other hand, the replacement of phenylalanine-4 with p-chlorophenylalanine-4 did not increase δ-selectivity as in DPDPE. These findings suggest that the δ-receptor interacts with hybridized enkephalins and deltorphins somewhat differently than with DPDPE. 相似文献
9.
SHARON E. ALBERS M.D. L. FRANK GLASS M.D. NEIL A. FENSKE M.D. 《International journal of dermatology》1994,33(9):645-644
A 32-year-old black woman presented with the complained of a l-year history of asymptomatic “dark areas” on her face and neck. New lesions developed throughout this time and, once present, slowly increased in size and persisted. She denied systemic symptoms, including arthralgias and myalgias. Her occupation as a real estate agent involved frequent outdoor work. The family history was noncontributory. On physical examination there were multiple hyperpig-mented round-to-oval macules and papules measuring from 0.5 to 2.0 cm in diameter and located over the photoexposed lateral aspects of the face and neck (Figs. 1 and 2). New lesions were papules characterized by a subtle, raised “thread-like” border (Fig. 1, arrow). Older lesions were mac-ular, some with a slightly atrophic, hypopigmented center (Fig. 1, Flesh-colored polygonal papules were present in the V-shaped area on the anterior neck (Fig. 2). The remainder of the cutaneous examination, including the oral mucosa, was unremarkable. Histopathologic examination of a flesh-colored papule viewed on low power revealed a bandlike lymphohistiocytic infiltrate that focally obscured the dermoepidermal junction. Numerous homogenous eosinophilic bodies (Civatte bodies, cytoid bodies, apoptotic cells) and scattered melanophages were identified. In addition, there was epidermal hyperplasia, overlying orthokeratosis, and V-shaped hyper-granulosis. The rete was jagged and possessed a slightly eosinophilic hue (Fig. 3). Hyperpigmented, oval macules had a more patchy lichenoid infiltrate, less epidermal hyperplasia, but possessed a greater number of melanophages in the papillary dermis than new lesions. Periodic acid-Schiff (PAS) stained sections of either type of specimen were negative for basement membrane thickening and also negative for dermal mucin using the colloidal iron reagent. No deposits of immunoglobulin or complement were identified at the dermoepidermal junction by direct immunofluorescence microscopy, but numerous immunoglobulin-coated cytoid bodies were present. Laboratory testing was significant for a negative antinu-clear antibody (ANA) reaction and RPR. A complete blood cell count, results of serum chemistry, and the angiotensin converting enzyme level were within normal limits. Chest roentgenogram revealed no active cardiopulmonary disease. Based on the distinctive histopathology and the impressive, characteristic clinical presentation, the diagnosis of lichen planus subtropicus was made. Therapy with hydroxy-chloroquine 200 mg per day, topical hydrocortisone valerate 0.2% cream b.i.d. to inflammatory lesions, 3% hydroquinone solution b.i.d. to hyperpigmented lesions, and photoprotection were initiated. Partial resolution of the lichenoid lesions has occurred, new lesions have ceased to appear, and the hyperpigmentation has slightly improved. 相似文献
10.
Seong‐II BIN Shing‐Sheng WU Xiaofeng ZENG Alan MOORE Nicole FRANK 《International journal of rheumatic diseases》2007,10(3):190-197
Aim: The aim of the current study was to assess the efficacy, safety, and tolerability of lumiracoxib 200 mg once daily (o.d.) in relieving osteoarthritis (OA) knee pain in patients in China, Taiwan, and South Korea. Methods: Patients of either sex (aged ≥ 18 years) with symptomatic, primary OA of the knee for ≥ 3 months were eligible for inclusion if they had OA pain intensity of ≥ 40 mm (100 mm visual analogue scale [VAS]) in the target knee joint during the previous 24 h. Patients were required to undergo regular non‐steroidal anti‐inflammatory drug therapy for ≥ 6 weeks. After 3–7 days of screening, patients were randomized (1 : 1) to receive either lumiracoxib 200 mg o.d. or celecoxib 200 mg o.d. The primary efficacy comparison between the study groups was overall OA pain intensity (VAS) in the target knee after 6 weeks of treatment. Results: The mean overall OA pain intensity (VAS) in the target knee after 6 weeks decreased from 60.6 mm to 35.7 mm and 60.5 mm to 36.1 mm in the lumiracoxib and celecoxib groups, respectively. Both study groups showed similar results in terms of improvement in both patient's and physician's global assessment of disease activity and functional health status. The percentage of adverse events (AEs) in the lumiracoxib and celecoxib groups (40.3% and 37.9%, respectively) was similar, as was the proportion of treatment‐related AEs (21.0% and 18.2%, respectively). Conclusions: Lumiracoxib 200 mg o.d. provided effective and well‐tolerated pain relief similar to that achieved with celecoxib 200 mg o.d. in knee OA patients. 相似文献