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91.
It was previously reported that, during unfolding of creatine kinase in guanidinium chloride or urea solutions, inactivation occured before noticeable conformational change could be detected, suggesting that the conformation at the active site is more easily perturbed and, hence, more flexible than the molecule as a whole [Tsou (1986) Trends Biochem. Sci. 11 , 417–429]. In the present paper, the urea-gradient electrophoresis and the isoenzyme hybrid of creatine kinase has been studied. The results show that at low urea concentrations, creatine kinase is still in the dimeric state or only slightly dissociated. The dissociation and inactivation of creatine kinase during denaturation by urea are also compared. It was found that the enzyme was nearly inactivated in low urea concentrations before noticeable dissociation was detected. It therefore appears that in low urea concentrations, inactivation of creatine kinase is not due to the dissociation of the active dimer. The present result supports the hypothesis of the conformational flexibility of the active site in this enzyme. © Munksgaard 1996. 相似文献
92.
Effects of autotransfusion of mediastinal shed blood on biochemical markers of myocardial damage in coronary surgery 总被引:2,自引:0,他引:2
Pleym H Tjomsland O Asberg A Lydersen S Wahba A Bjella L Dale O Stenseth R 《Acta anaesthesiologica Scandinavica》2005,49(9):1248-1254
BACKGROUND: Previous studies have shown conflicting results regarding the effect of autotransfusion of mediastinal shed blood after coronary artery bypass grafting (CABG) on the serum levels of myocardial band (MB) isoenzymes of creatine kinase (CK-MB) and cardiac troponins. The effect of autotransfusion on serum levels of human heart fatty acid binding protein (H-FABP), another marker of myocardial necrosis, has not been studied. The aim of the present study was to investigate the effects of autotransfusion of mediastinal shed blood on the serum levels of CK-MB, cardiac troponin T (cTnT), and H-FABP after uncomplicated primary CABG. METHODS: Fifty patients were randomized to post-operative autotransfusion of mediastinal shed blood or no autotransfusion. Blood samples for the analysis of the biochemical markers of myocardial damage were drawn pre-operatively and 1, 4, 12, 24, 48, and 72 h after the termination of cardiopulmonary bypass. Samples from the mediastinal shed blood were collected after 1 and 4 h. RESULTS: The levels of the biochemical markers of myocardial injury were all markedly elevated in mediastinal shed blood. Autotransfusion did not significantly affect the serum levels of cTnT or H-FABP. However, during the early post-operative hours, there was a trend towards a higher level of cTnT and H-FABP in the autotransfusion group. During the first 24 h after surgery, the autotransfusion group had a significantly higher serum level of CK-MB. CONCLUSION: Post-operative autotransfusion of mediastinal shed blood may contribute to elevated serum levels of biochemical markers of myocardial injury. 相似文献
93.
94.
Badrising UA Maat-Schieman ML van Houwelingen JC van Doorn PA van Duinen SG van Engelen BG Faber CG Hoogendijk JE de Jager AE Koehler PJ de Visser M Verschuuren JJ Wintzen AR 《Journal of neurology》2005,252(12):1448-1454
The clinical features of
inclusion body myositis (IBM)
were of minor importance in the
design of consensus diagnostic
criteria, mainly because of controversial
views on the specificity of
signs and symptoms, although
some authors reported "typical"
signs. To re–assess the clinical spectrum
of IBM, a single investigator
using a standard protocol studied a
cohort of 64 patients cross–sectionally.
Symptom onset was before the
age of 50 years in 20% of cases.
Only a few patients (14 %) started
with weakness other than that of
quadriceps, finger flexor or pharyngeal
muscles. The sequence of
power loss was erratic, but onset of
symptoms with quadriceps weakness
predicted an earlier onset of
dysphagia in older patients (≥ 56
years) compared with younger
ones (< 56 years) (p = 0.02). Despite
widespread weakness patients had
favourable scores on three commonly
used function scales and
they kept their employment. Complete
wheel–chair dependency was
rare (3 %). A dominant characteristic
was the anatomical distribution
of afflicted muscles: ventral extremity
muscle groups were more
affected than dorsal muscle groups
and girdle muscles were least
affected, the latter preserving postural
stability. Ankylosis, especially
in extension of the fingers,was frequently
present. Together with the
sparing of intrinsic hand muscles it
was helpful in the preservation of
many skilful movements.
IBM has a unique distribution
of muscle weakness. Ankylotic
contractures are common. We feel
that their joint impact on daily
functioning is characteristic for the
disease. 相似文献
95.
Postoperative 12-lead ECG predicts peri-operative myocardial ischaemia associated with myocardial cell damage 总被引:2,自引:0,他引:2
Böttiger BW Motsch J Teschendorf P Rehmert GC Gust R Zorn M Schweizer M Layug EL Snyder-Ramos SA Mangano DT Martin E 《Anaesthesia》2004,59(11):1083-1090
Peri-operative myocardial ischaemia is the single most important risk factor for an adverse cardiac outcome after non-cardiac surgery. The present study examines whether intermittent 12-lead ECG recordings can be used as an early warning tool to identify patients suffering from peri-operative myocardial ischaemia and subsequent myocardial cell damage. Fifty-five vascular surgery patients at risk for or with a history of coronary artery disease were monitored for peri-operative myocardial ischaemia using intermittent 12-lead ECG recordings taken pre-operatively and at 15 min, 20 h, 48 h, 72 h and 84 h postoperatively. The effectiveness of the 12-lead ECG was gauged by examining concordance with continuous 3-channel Holter monitoring and capturing peri-operative myocardial ischaemia by serial analyses of creatine kinase myocardial band isoenzyme and cardiac troponin T and I. The incidence of peri-operative myocardial ischaemia detected by 12-lead ECG was 44% and was identifiable in most patients (88%) 15 min after surgery. The incidence of peri-operative myocardial ischaemia detected by continuous monitoring was 53%, with the most severe episodes occurring intra-operatively and during emergence from anaesthesia. The concordance of the 12-lead method with continuous monitoring was 72%. The concordance of creatine kinase myocardial band isoenzyme activity with the 12-lead method was 71% and with Holter monitoring 57%. The concordance of mass concentration of creatine kinase myocardial band with 12-lead ECG recordings was 75%, and the corresponding value for Holter monitoring was 68%. The concordance of cardiac troponin T and I levels with the 12-lead method was 85% and 87%, respectively, and concordance with Holter monitoring was 72% and 66%, respectively. The postoperative 12-lead ECG identified peri-operative myocardial ischaemia associated with subsequent myocardial cell damage in most patients undergoing vascular surgery. 相似文献
96.
Tachikawa M Fukaya M Terasaki T Ohtsuki S Watanabe M 《The European journal of neuroscience》2004,20(1):144-160
The creatine/phosphocreatine shuttle system, as catalysed reversibly by creatine kinases, is thought to be essential for the storing and buffering of high phosphate-bound energy in tissues with high energy demand. In the present study, we aimed to clarify the cellular system of creatine biosynthesis and its energy metabolism in the mouse brain by immunohistochemistry for creatine biosynthetic enzyme S-adenosylmethionine:guanidinoacetate N-methyltransferase (GAMT), ubiquitous mitochondrial creatine kinase (uCK-Mi) and brain-type cytoplasmic creatine kinase (CK-B). GAMT was expressed highly in oligodendrocytes and olfactory ensheathing glia and moderately in astrocytes, whereas GAMT was very low in neurons and microglia. By contrast, uCK-Mi was expressed selectively in neurons and localized in their mitochondria in dendrites, cell bodies, axons and terminals. The distinct and almost complementary distribution of GAMT and uCK-Mi suggests that the creatine in neuronal mitochondria is derived not only from the circulation, but also from local glial cells associated with these neuronal elements. By contrast, CK-B was selective to astrocytes among glial populations, and was exclusive to inhibitory neurons among neuronal populations. Interestingly, these cells with high CK-B immunoreactivity are known to be highly resistant to acute energy loss, such as hypoxia and hypoglycemia. Considering that phosphocreatine generates ATP much faster than the processes of glycolysis and oxidative phosphorylation, the highly regulated cellular expressions of creatine biosynthetic and metabolic enzymes suggest that the creatine/phosphocreatine shuttle system plays a role in brain energy homeostasis through a novel neuron-glial relationship. 相似文献
97.
Serum neuron-specific enolase, prolactin, and creatine kinase after epileptic and psychogenic non-epileptic seizures 总被引:1,自引:0,他引:1
PURPOSE: To evaluate the discriminative power of serial, simultaneous determinations of serum neuron-specific enolase (NSE), prolactin (PRL) and creatine kinase (CK) in differentiating psychogenic non-epileptic seizures (PNES) from epileptic seizures (ES). METHODS: Prospective measurement of the three markers after 44 single seizures (32 ES and 12 PNES) during continuous video-EEG monitoring at seven different sampling points. RESULTS: Patients with ES had a significantly greater increase in PRL at 10, 20, 30 min, 1 and 6 h. The sensitivity for elevated NSE and CK was low. PRL showed a higher sensitivity. However, the corresponding positive predictive value was lower than in CK and NSE. Additionally, PRL had the lowest specificity of all parameters. CONCLUSIONS: The limited discriminative power of PRL, CK, and NSE calls into question if these markers are helpful in differentiating PNES and ES. 相似文献
98.
高温高湿环境下犬肢体火器伤后血清组织释放酶含量变化的实验研究 总被引:8,自引:0,他引:8
将12只犬随机分为高温高湿组和常温常湿组,分别于火器伤后0、2、4、6、8、12、24h抽取外周血检测碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)、肌酸激酶(CK)等指标。结果显示,ALP、LDH、CK含量随时间变化呈逐渐增高,其中CK含量变化较ALP、LDH明显;高温高湿组较常温常湿组变化提前且各酶含量升高显著。表明组织释放酶含量与局部组织损伤程度一致;CK含量对组织损伤的反应更敏感;高温高湿环境因素与火器伤因素同时作用后机体变化更为显著,组织损伤更为严重。 相似文献
99.
Laakso MP Hiltunen Y Könönen M Kivipelto M Koivisto A Hallikainen M Soininen H 《Journal of neural transmission (Vienna, Austria : 1996)》2003,110(3):267-275
Summary. Apolipoprotein E (ApoE) genotype has been shown to influence results in neuroimaging studies using a number of various imaging
modalities. No in vivo data exists on whether or not there are ApoE-related changes observable by proton magnetic resonance
spectroscopy (MRS). In this study we measured absolute peak areas of proton MR spectra obtained from the occipital cortex
in 22 non-demented elderly with (n = 8) or without (n = 14) the ApoE ε4 allele. No statistically significant differences were
found in levels of N-acetyl aspartate, myo-inositol, or choline containing compounds between the groups. Instead, compared
with the non-carriers, the levels of creatine were significantly lower in the ε4 carriers, suggesting increased metabolic
demands in the brain of the ε4 carriers. The levels of creatine also correlated significantly with age and performance on
the Mini-Mental State Examination test in the ε4 carriers, but not in the non-carriers. These findings may be of significant
clinical interest as potential indicator of incipient AD, and also from therapeutical point of view given the potential neuroprotective
effects of creatine.
Received February 18, 2002; accepted August 5, 2002 Published online December 9, 2002
Acknowledgements This study was supported by the Research Council for Health of the Academy of Finland, the Finnish Neurology Foundation,
the Instrumentarium Research Foundation, and the Farmos Research Foundation.
Authors' address: M. Laakso, Department of Neurology, Bldg. 5, Kuopio University Hospital, P.O.Box 1777, 70211 Kuopio, Finland,
e-mail: mikko.laakso@uku.fi
Abbreviations AD Alzheimer's disease, ApoE apolipoprotein E, MI myo-inositol, MMSE Mini-Mental State Examination, MRI magnetic resonance imaging, MRS magnetic resonance spectroscopy, NAA N-acetyl aspartate. 相似文献
100.
目的探讨急性毒鼠强中毒血清肌酸激酶及肌钙蛋白I变化的原因和意义。方法测定48例急性毒鼠强中毒血清肌酸激酶(CK、CK-MB)及肌钙蛋白I,同时以癫痫病人和急性心肌梗死患者作对照。结果中毒患者血清肌酸激酶变化与癫痫病人肌酸激酶变化差异无显著性(P>0.05),而血清肌钙蛋白I在中毒患者与急性心肌梗死患者的变化比较差异有显著性(P<0.01)。结论急性毒鼠强中毒血清心肌酶升高可能为骨骼肌损伤所致,而非心肌直接损伤。 相似文献