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251.
C MacAulay H Tezcan B Palcic 《Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology》1989,11(1):53-58
Multispectral images of stained cells enable the use of color differences to segment and/or to discriminate between image components, such as cell types and cellular subcomponents. When the spectral characteristics of the image components do not change over the area of a slide or from slide to slide, one can create a constant weighted linear combination of spectral images to generate one-dimensional or two-dimensional images that have the desired contrast between the image components that must be discriminated. However, when the spectral characteristics are not constant, i.e., when they vary from image to image, a constant weighted linear combination cannot be employed; instead, an appropriate solution must be found for each selected image. This is usually a time-consuming, manual procedure that cannot be employed in a fully automated process of discriminating and segmenting stained cells. This paper describes an algorithm that uses principal components decomposition basis vectors to generate a nonstatic weighted linear combination of color images that can be used by an automated system. This algorithm relies on a semiconstant relationship between the areas (sizes) of the image components that are to be discriminated and/or segmented. The technique has been successfully applied as an aid in the segmentation of images of stained cervical smears; the images were acquired with a three-chip CCD camera that generates three broad-band color images. 相似文献
252.
Aydin E Cumurcu T Ozugurlu F Ozyurt H Sahinoglu S Mendil D Hasdemir E 《Biological trace element research》2005,108(1-3):33-41
The purpose of this study was to investigate iron (Fe), zinc (Zn), and copper (Cu) levels of aqueous humor, lens, and serum
in nondiabetics and diabetics and to determine the effects of diabetes on Fe, Zn, and Cu contents in the lens. Fe, Zn, and
Cu contents of aqueous humor, lens, and serum samples of 19 patients (9 nondiabetic patients with a mean age of 62.3±5.4 yr,
and 10 diabetic patients with a mean age of 59.5±5.9 yr) were analyzed by atomic absorption spectrometry using a prospective
study design. The lens levels of Cu in diabetic patients were significantly higher compared with nondiabetic patients (p=0.02); however; there was no difference in the other elements (Zn, Fe; p=0.28, p=0.74, respectively). The levels of Fe, Zn, and Cu in the aqueous humor and serum of diabetic patients were not found to be
statistically significant when compared to nondiabetics (p=0.46, p=0.11, p=0.18, and p=0.22, p=0.43, p=0.72, respectively). These results demonstrate that increased Cu content of the lens presumably has a greater association
with the development of lens opacification in diabetics than Zn and Fe content. 相似文献
253.
254.
The ligand substitutions that occur during the folding of ferrocytochrome c [Fe(II)cyt c] have been monitored by transient absorption spectroscopy. The folding reaction was triggered by photoinduced electron transfer to unfolded Fe(III)cyt c in guanidine hydrochloride (GuHCl) solutions. Assignments of ligation states were made by reference to the spectra of the imidazole and methionine adducts of N-acetylated microperoxidase 8. At pH 7, the heme in unfolded Fe(II)cyt c is ligated by native His18 and HisX (X = 26, 33) residues. The native Met80 ligand displaces HisX only in the last stages of folding. The ferroheme is predominantly five-coordinate in acidic solution; it remains five-coordinate until the native methionine binds the heme to give the folded protein (the rate of the methionine binding step is 16 +/- 5 s-1 at pH 5, 3.2 M GuHCl). The evidence suggests that the substitution of histidine by methionine is strongly coupled to backbone folding. 相似文献
255.
Activation-induced cytidine deaminase (AID) deficiency causes the autosomal recessive form of the Hyper-IgM syndrome (HIGM2) 总被引:60,自引:0,他引:60
Revy P Muto T Levy Y Geissmann F Plebani A Sanal O Catalan N Forveille M Dufourcq-Labelouse R Gennery A Tezcan I Ersoy F Kayserili H Ugazio AG Brousse N Muramatsu M Notarangelo LD Kinoshita K Honjo T Fischer A Durandy A 《Cell》2000,102(5):565-575
The activation-induced cytidine deaminase (AID) gene, specifically expressed in germinal center B cells in mice, is a member of the cytidine deaminase family. We herein report mutations in the human counterpart of AID in patients with the autosomal recessive form of hyper-IgM syndrome (HIGM2). Three major abnormalities characterize AID deficiency: (1) the absence of immunoglobulin class switch recombination, (2) the lack of immunoglobulin somatic hypermutations, and (3) lymph node hyperplasia caused by the presence of giant germinal centers. The phenotype observed in HIGM2 patients (and in AID-/- mice) demonstrates the absolute requirement for AID in several crucial steps of B cell terminal differentiation necessary for efficient antibody responses. 相似文献
256.
Reconstruction of soft-tissue defects of the calcaneal region and the heel is very demanding and necessitates, as a rule, a sensate and thin flap. The ideal characteristics of a sensate and thin layer of flap should be combined with a reliable blood supply and minimal morbidity at the donor site. The authors report an updated review of their experience with the use of island modifications of the lateral calcaneal artery skin flap-the lateral calcaneal island flap, the lateral calcaneal V-Y advancement flap, and the bilobed-shaped lateral calcaneal island advancement flap-for the reconstruction of small and medium-sized tissue defects over the exposed calcaneal tendons and calcaneal bones of 18 patients. All of the procedures were performed under spinal or epidural anesthesia. There were no problems associated with flap viability, but the authors have seen necrosis of undermined skin between the lateral malleolus and calcaneal tendon in two cases and a partial loss of skin graft in one case. In this article, the authors discuss some advantages and disadvantages of the use of a lateral calcaneal island flap and its modifications. 相似文献
257.
Scorzonera ahmet‐duranii sp. nov. (Asteraceae) from southwest Anatolia,and its phylogenetic position
Serdar Makbul Kamil Coskuncelebi Mutlu Gültepe Seda Okur Murat Erdem Güzel 《Nordic Journal of Botany》2012,30(1):2-11
Scorzonera ahmet‐duranii S. Makbul & Coskuncelebi sp. nov. (Asteraceae) is described and illustrated as a new species endemic to Turkey. It is morphologically similar to S. semicana DC., but differs by its rootstock, deeply undulating basal leaves and glabrous achenes. Additionally, the size and micro‐morphological properties of achenes and some anatomical traits of the leaf and stem are helpful in distinguishing these closely related taxa. A phylogenetic analysis based on nrDNA ITS sequence data showed that S. semicana is the sister species of the new taxon presented in this study. 相似文献
258.
Our aim was to investigate parameters of iron and copper status and oxidative stress and antioxidant function in women with healthy pregnancy, mild and severe preeclampsia with a view to exploring the possible contribution of these parameters to the aetiology. Thirty healthy, 30 mild preeclamptic and 30 severe preeclamptic pregnant women were included. Serum and placental lipid peroxides, and serum vitamin E and total carotene levels were measured by colorimetric assay. Cholesterol, copper, iron, total iron binding capacity (TIBC), ceruloplasmin and transferrin concentrations were measured by commercially available procedures. Data were analysed statistically using one-way analysis of variance and Pearson correlation test. Logistic regression procedures were used to calculate odds ratios. Lipid peroxides in serum and placental tissue, and iron, copper and ceruloplasmin levels in serum were significantly increased, and transferrin, TIBC, vitamin E/total cholesterol and total carotene/total cholesterol ratios in serum were significantly decreased especially in women with severe preeclampsia. Significant correlations were detected between serum iron and lipid peroxides in serum and placental tissue and between serum iron and vitamin E/total cholesterol in severe preeclamptic pregnancy. Furthermore, there were significant correlations between serum malondialdehyde and ceruloplasmin and vitamin E/total cholesterol in women with severe preeclampsia, and changes in serum and placental lipid peroxides and serum iron concentrations were significantly associated with preeclampsia. In conclusion, ischaemic placental tissue may be a primary source of potentially toxic iron in preeclampsia and the released iron species may contribute to the aetiology and would exacerbate lipid peroxidation and endothelial cell injury, which may be abated by antioxidant supplementation. 相似文献
259.
Arpacı Abdullah Doğan Serdar Erdoğan Hazal Fatma El Çiğdem Cura Sibel Elmacıoğlu 《Molecular biology reports》2021,48(3):2025-2033
Molecular Biology Reports - Familial Mediterranean Fever (FMF), which is an autosomal recessive disease characterized by recurrent self-limiting fever, peritonitis, pleuritis, arthritis and... 相似文献
260.
Collecting representative sets of cancer microRNAs (miRs) from the literature we show that their corresponding families are enriched in sets of highly interacting miR families. Targeting cancer genes on a statistically significant level, such cancer miR families strongly intervene with signaling pathways that harbor numerous cancer genes. Clustering miR family-specific profiles of pathway intervention, we found that different miR families share similar interaction patterns. Resembling corresponding patterns of cancer miRs families, such interaction patterns may indicate a miR family’s potential role in cancer. As we find that the number of targeted cancer genes is a naïve proxy for a cancer miR family, we design a simple method to predict candidate miR families based on gene-specific interaction profiles. Assessing the impact of miR families to distinguish between (non-)cancer genes, we predict a set of 84 potential candidate families, including 75% of initially collected cancer miR families. Further confirming their relevance, predicted cancer miR families are significantly indicated in increasing, non-random numbers of tumor types. 相似文献