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991.
Alpha(v)beta3 and alpha(v)beta5 integrin expression in meningiomas   总被引:12,自引:0,他引:12  
OBJECTIVE: Integrins are emerging as alternative receptors capable of mediating several biological functions, such as cell-matrix and cell-cell adhesion, cell migration, signal transduction, and angiogenesis. Two alpha(v) integrins, i.e., alpha(v)beta3 and alpha(v)beta5, play critical roles in mediating these activities, particularly in tumors. No data are available on the expression of these integrins in meningiomas. METHODS: Using Western blot and immunohistochemical analyses with LM609 and PG32, two monoclonal antibodies capable of recognizing the functional integrin heterodimer, we evaluated the expression of alpha(v)beta3 and alpha(v)beta5 integrins in a series of 34 meningiomas of different histological subtypes and grades. We studied their expression in tumor cells and vasculature, as well as the expression of their related angiogenic factors (fibroblast growth factor 2 and vascular endothelial growth factor) and the alpha(v)beta3 ligand vitronectin. RESULTS: Alpha(v)beta3 and alpha(v)beta5 integrins were expressed by neoplastic vasculature and cells. Alpha(v)beta3 and alpha(v)beta5 expression was associated and correlated with that of their respective growth factors (fibroblast growth factor 2 and vascular endothelial growth factor) and microvessel counts and densities. Alpha(v)beta3 was more strongly expressed than alpha(v)beta5 in two cases of histologically benign meningiomas with aggressive clinical behavior. Alpha(v)beta3 expression was associated with that of its related ligand vitronectin and was also evident in small vessels of brain tissue closely surrounding meningiomas. CONCLUSION: Our data demonstrate the expression of alpha(v)beta3 and alpha(v)beta5 integrins in meningioma cells and vasculature. Our findings suggest a role for both of these integrins, and particularly alpha(v)beta3, in meningioma angiogenesis.  相似文献   
992.
The analgesic and central depressor effects of the dichloromethanol extract of Schinus molle L. were analysed in in vivo models. This extract showed low acute toxicity, CNS depressor activity and analgesic effect. Following further fractionation, the hexane/dichloromethane (75/25) fraction showed the most interesting results. Thus, this fraction caused a total inhibition of motor activity and significantly reduced the threshold of pain to chemical stimulus. © 1997 John Wiley & Sons, Ltd.  相似文献   
993.
This is Part 2 of a three-part review and deals with tumorigenic cell lines. Several immortalized and malignant adult human prostatic epithelial cell lines have been recently developed. The three most widely used carcinoma cell lines—DU-145, PC-3, and LNCaP—developed between 1977 and 1980, have greatly contributed to our current understanding of prostate cancer. Before a cell line can be accepted as having prostatic epithelial origin, some basic characteristics must be established. Expression of specific cytokeratins but absence of desmin and factor VIII should be first determined to establish epithelial origin. Responsiveness to androgens and expression of androgen receptor and prostate-specific antigen should be examined under stringent culture conditions to establish prostatic epithelial origin. Response to growth factors and expression of their receptors facilitates further characterization of cell behavior. Cell lines immortalized by human papillomaviruses (HPVs) are of special interest because HPVs are involved in a variety of anogenital cancers and may also play a role in prostate carcinogenesis. Malignant transformation of HPV-18 immortalized cells with the ras oncogene provides cell systems for investigating the multistep process of carcinogenesis. Each cell line has some unique characteristics, whether it arose directly from a carcinoma or resulted from immortalization with Simian virus 40 (SV40) or HPV, or was transformed in vitro by oncogenes. Comparisons of these characteristics should facilitate elucidation of the mechanisms involved in the initiation, promotion, and progression of prostate cancer. These cell lines will further serve as useful models for investigating tumor progression, invasion, metastasis, new therapeutic strategies, drug resistance, and its reversal and chemoprevention. The nontumorigenic cell lines were discussed in Part 1 [1]. This review summarizes the characteristics of several currently available tumorigenic, adult human prostatic epithelial cell lines. Prostate 30:58–64, 1997 © 1997 Wiley-Liss, Inc.  相似文献   
994.
BACKGROUND: The systemic hypotension during human sepsis has been ascribed to increased production of nitric oxide (NO). Therefore, inhibitors of NO synthesis have been used in the treatment of hypotension in patients with septic shock. In addition, NO production may inhibit the synthesis and vasoconstrictor effects of endothelin-1 (ET-1). In this study, we tested whether ET-1 contributed to the vasopressor action of the NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) in patients with severe septic shock. METHODS AND RESULTS: Compared with healthy volunteers, patients with septic shock had increased plasma levels of nitrite/nitrate (37+/-5 [SEM] versus 12+/-5 mmol/L, P<0.01), the stable end products of NO metabolism, and ET-1 (45+/-7 versus 3+/-2 pg/mL, P<0.001). Plasma ET-1 concentration was not related to plasma nitrite/nitrate concentration or blood pressure. Continuous infusion of L-NAME (1 mg. kg-1. h-1 IV) for 12 hours increased mean arterial pressure by 43+/-5% and systemic vascular resistance by 64+/-10% (both P<0.01). The increase in blood pressure and systemic vascular resistance correlated positively with the level of ET-1 (both P<0. 005) but not with plasma nitrite/nitrate level. L-NAME infusion did not result in significant changes in the plasma concentrations of ET-1 or nitrite/nitrate. CONCLUSIONS: NO and ET-1 may both play a role in the cardiovascular derangements of human sepsis. Although L-NAME does not increase ET-1 concentration in patients with septic shock, the vasopressor response induced by L-NAME depends on the plasma level of ET-1. These findings may indicate that inhibitors of NO synthesis unmask a tonic pressor response of ET-1 in human septic shock.  相似文献   
995.
The function of cortical circuits depends critically on the balance between excitation and inhibition. This balance reflects not only the relative numbers of excitatory and inhibitory synapses but also their relative strengths. Recent studies of excitatory synapses in visual and somatosensory cortices have emphasized that synaptic strength is not a fixed quantity but is a dynamic variable that reflects recent presynaptic activity. Here, we compare the dynamics of synaptic transmission at excitatory and inhibitory synapses onto visual cortical pyramidal neurons. We find that inhibitory synapses show less overall depression than excitatory synapses and that the kinetics of recovery from depression also differ between the two classes of synapse. When excitatory and inhibitory synapses are stimulated concurrently, this differential depression produces a time- and frequency-dependent shift in the reversal potential of the composite postsynaptic current. These results indicate that the balance between excitation and inhibition can change dynamically as a function of activity.  相似文献   
996.
997.
肿瘤细胞株和癌组织角蛋白19、20 mRNA表达及临床意义   总被引:16,自引:0,他引:16  
目的 建立利用角蛋白检测外周血中循环癌细胞的方法 ,探讨角蛋白 19、2 0 (K19、K2 0 )在不同肿瘤细胞株和肿瘤组织中的表达。方法 采用定量逆转录多聚酶链反应 (RT PCR)方法检测11个肺癌、食管癌、膀胱癌、大肠癌肿瘤细胞株和 33例相对应的癌组织中特异性K19、K2 0mRNA的表达。结果  4种肿瘤细胞株及 33例相对应的癌组织均表达K19mRNA ,但表达量有明显差别。同种癌组织之间K19mRNA的表达量相差在 1.7~ 10倍之间 ,表达量最低者仅为阳性对照的 12 %以下。肺癌和食管癌细胞株和癌组织中均未见K2 0mRNA的表达。 6例膀胱癌组织中 ,仅有 1例呈阳性 ;5例肠癌组织中 ,4例呈阳性 ,表达量为阳性对照的 41%~ 77%。膀胱癌细胞株EJ1和肠癌细胞株SW480未见K2 0mRNA的表达。结论 K19、K2 0可作为检测外周血中循环癌细胞的生物标志物。但个别癌组织中K19、K2 0的表达低下 ,有可能导致检测出现假阴性结果。  相似文献   
998.
This study investigated 40 growing patients with Angle‐Class II, division 1, treated with either a functional regulator (FR) or cervical headgear (HG) over a period of approximately 1 year. The objective was to evaluate dentoalveolar and skeletal reactions.
Both appliances significantly (p<0.001) improved distocclusion and reduced the overjet. Cephalometric analyses revealed that the effects of these two appliances on the skeleton differed. Also, in the FR group, the inclination of incisors was (p<0.05) altered as well as the maxillary plane angle and the Wits‐appraisal (p<0.05). The HG group showed a significant (p<0.001) reduction in both SNA and ANB angles. Both appliances appear to be sufficient for improvement in patients with Class II, division 1 occlusion, with the HG showing an additional skeletal effect in the maxilla.  相似文献   
999.
1000.
OBJECTIVE: To determine the clinical significance of continuous flow in the long saphenous vein in limbs with venous ulceration. DESIGN: Retrospective review. PATIENTS AND METHODS: Review of 1608 consecutive limbs undergoing colour duplex scanning for venous disease over a 43 month period. RESULTS: Continuous flow in the long saphenous vein is seen in 8% of limbs with venous ulceration and in 37% of limbs with deep venous obstruction. Sixty-six per cent of ulcerated limbs with continuous flow in the long saphenous vein had deep venous obstruction, 27% had deep venous reflux with cellulitis and 7% had lymphoedema in addition to venous ulceration. CONCLUSION: Continuous flow in the long saphenous vein in patients with venous ulceration should alert the clinician to the possibility of deep venous obstruction. Such limbs should be treated by compression bandaging with extreme caution.  相似文献   
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