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991.
Basic fibroblast growth factor prolongs the proliferation of rat cortical progenitor cells in vitro without altering their cell cycle parameters 总被引:12,自引:0,他引:12
Cavanagh JF; Mione MC; Pappas IS; Parnavelas JG 《Cerebral cortex (New York, N.Y. : 1991)》1997,7(4):293-302
Basic fibroblast growth factor (bFGF) has been shown to influence the
survival, proliferation and differentiation of a variety of cell types in
the nervous system. In this investigation we have examined the action of
bFGF on: (i) the rate of proliferation; (ii) cell cycle parameters; (iii)
the maintenance of cell division; (iv) the recruitment of quiescent cells;
and (v) the degree of differentiation of cortical progenitor cells in
cultures prepared from E16 rat embryos. The proliferation rate (labelling
index) of cortical progenitor cells doubled in the presence of bFGF over 48
h. However, the lengths of the cell cycle phases were unchanged. Clones
marked with a recombinant retrovirus on the first day in vitro (DIV) grew
significantly larger in the presence of bFGF. Furthermore, many of the
clones examined in control cultures had ceased to divide after a maximum of
four cell cycles, whereas almost all clonally related cells were still
dividing in the presence of bFGF 4 days later, i.e. for at least six cell
cycles. Basic FGF also stimulated the division of quiescent progenitor
cells, which otherwise would have differentiated or undergone cell death.
The degree of neuronal and glial differentiation was studied after 5 DIV
using MAP-2 and GFAP immunocytochemistry. In the presence of bFGF, the
percentage of MAP-2-labelled cells was less than half that of control
cultures, whereas the number of cells immunoreactive for nestin (a marker
of progenitor cells) remained very high. Cells immunoreactive for GFAP were
present in bFGF-treated cultures, yet were extremely rare in control
conditions. These experiments show that bFGF, a potent mitogen for cortical
progenitor cells, has no effects on the parameters of their cell cycle but
extends their proliferative capability, promotes their survival and delays
their differentiation into neurons.
相似文献
992.
Role of leucocytes in free radical production during myocardial revascularisation. 总被引:2,自引:1,他引:1
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E. De Vecchi R. Paroni M. G. Pala G. Di Credico V. Agape C. Gobbi P. A. Bonini G. Paolini A. Grossi 《Heart (British Cardiac Society)》1997,77(5):449-455
OBJECTIVE: To evaluate the role of leucocytes in free radical production in patients with depressed or normal ejection fraction undergoing coronary bypass. DESIGN: Two randomised control trials. SETTING: Tertiary care centre. PATIENTS AND INTERVENTIONS: In the first study, 22 patients with ejection fractions of < or = 40% received blood cardioplegic reperfusion with (n = 11) or without (n = 11) leucocyte depletion. In the second study, 22 patients with ejection fractions > or = 45% received either leucocyte depleted (n = 11) or blood cardioplegia (n = 11). MAIN OUTCOME MEASURES: Glutathione, hypoxanthine, and lipid peroxidation products were measured in coronary sinus blood and plasma before aortic cross clamping and at 0, 15, and 30 minutes after unclamping. Haemodynamic variables and creatine kinase MB isoenzymes were monitored on the first postoperative day. Comparison between treatments was performed on difference (delta) between measurements at time 0 and at baseline, and on slopes obtained by fitting measurements after unclamping with a linear regression model. RESULTS: At unclamping no difference in delta for plasma glutathione redox ratio (oxidised/total glutathione, %) was observed between treated and control groups with low ejection fraction (delta = 16 (SD 8.39) and 24 (7.0) redox ratio %, respectively). Baseline value recovery rate (redox ratio %/min) was significantly faster in treated v control patients (slope -0.912 (0.380) v -0.158 (0.200), P < 0.005, respectively). Cardiac index showed a trend to greater improvement in the treated group (slope 0.04 (0.03) v 0.003 (0.002) 1/min/m2/h, P < 0.02, treated v controls, respectively). In patients with normal ejection fraction, leucocyte depletion did not result in significant improvement v controls. CONCLUSIONS: Leucocyte depletion seems to provide benefit only in patients with left ventricular dysfunction. 相似文献
993.
994.
MB Andresdottir KJ Assmann RA Koene JF Wetzels 《American journal of kidney diseases》1998,32(4):582-588
In renal transplant recipients with type I membranoproliferative glomerulonephritis (MPGN), the posttransplantation course can be complicated by a recurrence of the original disease. However, it is well known that a recurrence of type I MPGN and chronic transplant glomerulopathy (CTG) cannot easily be distinguished. It has been suggested that the two entities can be differentiated by using electron microscopy (EM) and immunofluorescence (IF) techniques. However, studies are lacking that compare biopsy specimens from patients with either a recurrence of type I MPGN or CTG. We have studied renal biopsy specimens from 10 patients with CTG and compared the ultrastructural and IF findings with biopsy specimens from 12 patients with a possible recurrence of type I MPGN. All the patients with CTG showed an electron-lucent zone of finely flocculent material in the subendothelial space, whereas all patients with a recurrence of type I MPGN showed subendothelial electron-dense deposits on EM. On IF, all patients with CTG showed Immunoglobulin M (IgM) with greater intensity than C3. For the patients with recurrent type I MPGN, the opposite was true. Eleven specimens showed C3 deposits with greater intensity than IgM, and in one patient, C3 and IgM were found in equal intensity. In conclusion, when IF and EM studies are available, CTG and recurrence of type I MPGN can reliably be distinguished. 相似文献
995.
Griveau JF; Grizard G; Boucher D; Le Lannou D 《Human reproduction (Oxford, England)》1998,13(11):3108-3113
Oxygen radical generation is known to be detrimental to sperm function. An
example of a reactive oxygen species-associated male pathology is
oligozoospermia in which fertilization and pregnancy rates are low in
in-vitro fertilization (IVF) programmes. As the extent of the modifications
induced by reactive oxygen species (ROS) depends on several factors,
notably from oxygen tension in the incubation medium, the aim of this study
was to examine the influence of a low (5%) rather than atmospheric (20%)
oxygen tension in the incubator gas phase on the function of
Percoll-selected spermatozoa from ejaculates of oligozoospermic patients
and normozoospermic fertile donors. After incubation for several hours in a
gas phase of either 5% CO2/90% N2/5% O2 or 5% CO2/95% air (20% O2), none of
the parameters investigated, e.g. movement characteristics, potential of
spermatozoa to acquire hyperactivated motility, to undergo the acrosome
reaction when challenged with a calcium ionophore and to fuse with
zona-free hamster oocytes, was significantly different between the two
oxygen tensions in fertile donors. In contrast, among oligozoospermic
patients, the motility parameters, the percentage of hyperactivated
motility and of induced-acrosome reaction were significantly improved under
a gas phase of 5% O2 compared with those observed under an atmosphere of
20% O2 (P < 0.05). Exposure to 5% rather than 20% oxygen tension also
induced a significant increase in the percentage of penetration of
zona-free hamster eggs after capacitation for 17 h, but no difference was
found in the mean number of bound spermatozoa per oocyte. After incubation
for 24 h, a significantly higher survival rate was observed under 5%
compared with 20% oxygen tension. These results show that the use of a low
oxygen tension rather than air might improve spermatozoan competence of
oligozoospermic patients during IVF programmes.
相似文献
996.
Detection of mass lesions with MR colonography: preliminary report 总被引:13,自引:1,他引:12
997.
以Rev依赖性凋亡增强HIV-1gp160的抗原性 总被引:1,自引:0,他引:1
目的 检测Rev(HIV的调控基因 )依赖性肿瘤坏死因子受体 (TNFR 1)和gp16 0双重表达质粒pDM12 8 TNFR 1(pT12 8)的凋亡诱导功能。方法 采用基因枪转导及流式细胞仪检测新质粒的表达功能。结果 新结构具有特异的选择性表达作用。当Rev存在时 ,能间接表达TNFR 1,明显诱导HeLa细胞凋亡 ,使绿荧光细胞百分率非常显著地低于阴性对照 (P <0 .0 1)。等质量转染时 ,TNFR 1表达量少于Hup6 0TNFR 1的pDC30 2 (pT6 0 ) ,故间接表达不及单纯pT6 0的直接表达 ,绿荧光细胞百分率显著高于pT6 0转染组 (P <0 .0 1)。培养 40h ,才有明显杀伤功能并接近单纯pT6 0 ,差异无显著性 (P>0 .0 1)。单纯pT12 8不能直接表达TNFR 1,绿荧光细胞百分率非常显著地高于单纯pT6 0转染组 (P<0 .0 1) ,接近阴性对照 ,培养 40h时差异无显著性 (P >0 .0 1)。当AD8或pMD +pRnv存在并表达Rev时 ,pT12 8均能表达TNFR 1,杀伤HeLa细胞 ,绿荧光细胞百分率非常显著地低于阴性对照 (P <0 .0 1)。pT12 8与pRev或AD8转染人正常的角质生成细胞时 ,能表达TNFR 1,诱导细胞凋亡。培养 72h后 ,阴性对照和单纯pT12 8组的绿荧光角质生成细胞数皆显著地超过pT12 8+pRev和pT12 8+pAD8组 (P <0 .0 1)。结论 pT12 8可调控的凋亡诱导保证了HIVDNA疫苗足量的抗原表 相似文献
998.
Lorenzo M. Donini Luciano Scavone Claudia Savina Cecilia Coletti Maddalena Paolini Settimio Tempera Barbara Neri Maria Rosaria De Felice Alessandro Pinto Carlo Cannella 《Mediterranean journal of nutrition and metabolism》2009,2(3):187-195
Background
For an “in the field” estimate of visceral adiposity, simple, inexpensive, non-invasive and highly repetitive methods are needed. The anthropometric measurement most commonly used as an indicator for visceral fat deposits is waist circumference (W). Nevertheless, there are some doubts with regard to the anatomic landmark points where the evaluation needs to be carried out. Sagittal abdominal diameter (SAD) is another anthropometric measurement that has been proposed for the estimation of visceral fat. 相似文献999.
Methotrexate for the treatment of refractory Crohn's disease. 总被引:4,自引:2,他引:2
Lemann M Chamiot-Prieur C Mesnard B Halphen M Messing B Rambaud JC Gendre JP Colombel JF Modigliani R 《Alimentary pharmacology & therapeutics》1996,10(3):309-314
BACKGROUND: Previous studies suggested that methotrexate has beneficial effects in patients with Crohn's disease. We report our experience with this agent in patients with chronic active Crohn's disease who previously failed to improve with conventional treatment, including azathioprine in most cases. METHODS: Between June 1988 and June 1992, 39 patients with refractory Crohn's disease were treated with methotrexate. In patients with active disease, clinical remission was defined by a Harvey-Bradshaw index of less than 4. For patients also taking corticosteroids, the dates of remission and complete steroid withdrawal were recorded. For patients who achieved clinical remission, and those in clinical remission when methotrexate was started, the relapse rate on methotrexate therapy was noted. RESULTS: In the 37 patients with active disease at methotrexate initiation, the probability of remission was 72% at 3 months. The probability of remission and steroid withdrawal was 42% at 12 months. In patients on clinical remission, the probability of relapse on methotrexate was 58% at 12 months. Twenty-two patients experienced side-effects, but these only warranted methotrexate discontinuation in four cases. CONCLUSIONS: Methotrexate appears effective in most patients with refractory Crohn's disease and its short-term toxicity is acceptable, but the long-term benefit seems more limited. 相似文献
1000.
Immunocytochemical localization of the Menkes copper transport protein (ATP7A) to the trans-Golgi network 总被引:3,自引:1,他引:2
We have generated polyclonal antibodies against the amino-terminal third of
the Menkes protein (ATP7A; MNK) by immunizing rabbits with a
histidine-tagged MNK fusion construct containing metal-binding domains 1-4.
The purified antibodies were used in Western analysis of cell lysates and
in indirect immunofluorescence experiments on cultured cells. On Western
blots, the antibodies recognized the approximately 165 kDa MNK protein in
CHO cells and human fibroblasts. No MNK signal could be detected in
fibroblasts from a patient with Menkes disease or in Hep3B hepatocellular
carcinoma cells, confirming the specificity of the antibodies.
Immunocytochemical analysis of CHO cells and human fibroblasts showed a
distinct perinuclear signal corresponding to the pattern of the Golgi
complex. This staining pattern was similar to that of alpha-mannosidase II
which is a known resident enzyme of the Golgi complex. Using brefeldin A, a
fungal inhibitor of protein secretion, we further demonstrated that the MNK
protein is localized to the trans- Golgi network. This data provides direct
evidence for a subcellular localization of the MNK protein which is similar
to the proposed vacuolar localization of Ccc2p, the yeast homolog of MNK
and WND (ATP7B), the Wilson disease gene product. In light of the proposed
role of MNK both in subcellular copper trafficking and in copper efflux,
these data suggest a model for how these two processes are linked and
represent an important step in the functional analysis of the MNK protein.
相似文献