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1.
The cell movements of gastrulation were analyzed in embryos of the spider Zygiella x-notata, using time-lapse video, cell tracing, and improved histology. Cells are internalized near the center of the germ disc in three distinct phases. First, cumulus mesenchyme cells ingress and migrate as a group beneath the superficial layer. Second, mass internalization through a blastopore yields a diffusely organized deep layer. Third, superficial cells accumulate at the center of the germ disc to form the caudal bud. The floor is internalized, and the caudal bud moves over the nascent dorsal field to form the caudal lobe. This pattern of gastrulation differs from the canonical pattern described in the historical literature: (1) the cumulus of Z. x-notata is completely formed before any other cells internalize; and (2) the caudal lobe is formed by means of the caudal bud, which is a locus of cell internalization.  相似文献   
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Chaw CS  Tan CW  Yang YY  Wang L  Moochhala S 《Biomaterials》2003,24(7):1271-1277
Physostigmine is an anti-cholinesterase used for the pretreatment of a poisoning caused by highly toxic organophosphorus neurotoxins. The aim of this study is to design a polymeric microparticle system for sustained release of physostigmine. In this paper, we have attempted to encapsulate physostigmine in microparticles made from poly(D,L-lactide-co-glycolide) (PLGA) with various contents of glycolide and poly(D,L-lactide) (PLA) using spray-drying and single emulsion techniques. It was found that during the single emulsion process, most of the physostigmine molecules were lost in the external aqueous phase. However, more than 90% encapsulation efficiency of physostigmine was obtained using the spray-drying technique. SEM micrographs revealed that spherical microparticles containing physostigmine with a smooth surface were yielded with PLA, PLGA 50:50, RG 502 (PLGA 50:50 with a lower molecular weight) and PLGA 65:35 but PLGA 85:15, PLGA 75:25 and PLGA 50:50 with a high concentration produced microparticles with irregular shapes. An increased inlet temperature yielded a higher physostigmine release rate from the PLA microparticles. Physostigmine release from the microparticles showed a biphasic pattern, characterized by an initial burst release followed by a sustained release for PLGA 65:35, PLGA 50:50 and RG 502 or a non-detectable release for PLGA 85:15, PLGA 75:25 and PLA. A sustained-release of physostigmine with a low initial burst over 1 week was achieved from RG 502 microparticles, which would be used as an injectable dosage form in our further animal studies.  相似文献   
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Clinical Autonomic Research - Comparison of hemodynamic profiles and pain scores in diabetic patients undergoing diabetic foot surgery receiving peripheral nerve block (PNB) or spinal anesthesia...  相似文献   
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OBJECTIVE: Passive retrospective cohorts composed of persons who have tested 2 or more times for a sexually transmitted infection (STI) of interest during clinical visits have been used to estimate STI incidence. We hypothesized that the analytic period of a passive cohort might affect the estimate of STI incidence, with shorter periods yielding higher estimates of incidences of infection. STUDY: We analyzed data collected from women, 12 to 24 years of age, tested for chlamydia 2 or more times at 6 sites in San Francisco between January 1997 and December 2000. Incidence was calculated for 10 different analytic periods. RESULTS: The calculated incidence of chlamydial infection during 1997 was 16.8 (95% confidence interval [CI], 10.9-24.0) per 1000 person-months of follow up. The calculated incidence dropped markedly as the analytic period lengthened, with the incidence estimated to be 9.7 (95% CI, 8.6-10.9) using a study period of 4 years (1997-2000). Estimates of incidence were similar when using the same analytic period, regardless of calendar year, and there was a similar decline in estimated incidence using longer analytic periods. CONCLUSIONS: Estimates of STI incidence based on passive cohort data may have limited epidemiologic value because incidence measures may be highly dependent on the analytic period.  相似文献   
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Background  

Adenine nucleotide translocase (ANT) is located in the inner mitochondrial membrane and catalyzes the exchange of mitochondrial ATP for cytosolic ADP. ANT has been known to be a major component of the permeability transition pore complex of mitochondria and contributes to mitochondria-mediated apoptosis. Human ANT has four isoforms (ANT1, ANT2, ANT3, and ANT4), and the expression of the ANT isoforms is variable depending on the tissue and cell type, developmental stage, and proliferation status. Among the isoforms, ANT1 is highly expressed in terminally-differentiated tissues, but expressed in low levels in proliferating cells, such as cancer cells. In particular, over-expression of ANT1 induces apoptosis in cultured tumor cells.  相似文献   
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Primary scarring alopecia (PSA) is caused by irreversible damage to the hair epithelial stem cells that reside in hair follicles. There is limited published work regarding PSA amongst the Asian population. The aim of this study was to evaluate the clinical features and to characterize the subtypes of PSA in southern Taiwan. In this retrospective case series, we reviewed 89 patients with pathology‐confirmed PSA. The data was collected from National Cheng Kung University Hospital between 1988 through 2016. The clinical and histological data were reviewed, and the patients were characterized into different subtypes of PSA based on the clinical features and histological findings. We noted seven different subtypes of PSA. The most common type was dissecting cellulitis (DC) (30.3%), followed by lichen planopilaris (LPP) (23.5%), central centrifugal cicatricial alopecia (CCCA) (12.4%) and acne keloidalis nuchae (AKN) (12.4%). The other subtypes include folliculitis decalvans (FD), discoid lupus erythematosus (DLE) and pseudopelade of Brocq (PPB). Interestingly, FD, DC and AKN were more common in males, while CCCA, LPP, DLE and PPB had a female predominance. The mean age of patients with DLE, DC and AKN were younger, while patients with CCCA, LPP, PPB and FD tend to be older. The pattern of hair loss was more likely to be unifocal‐ragged border in CCCA and DLE, multifocal‐interconnected in LPP and FD, and multifocal‐separated in DC. The pathogenesis of PSA may be influenced by sex, age and genetic background. It is important to identify the hair loss pattern to differentiate the subtypes of PSA.  相似文献   
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Three-dimensional (3-D) extracellular matrices (ECM) allow complex biochemical and biophysical interactions between cells and matrices. Unlike 2-D systems, 3-D models provide a better representation of the micro and local environments in living tissues for facilitating the physiological study of cell migration. Here, we report a microfluidic device based on polydimethylsiloxane (PDMS) for monitoring 3-D cell migration across ECM-coated microgaps with real-time light microscopy. We tracked the migration of the invasive MDA-MB-231 (mammary carcinoma) cells and mapped out their migration paths. It enabled us to quantify the percentage of migrated cells as well as migration information of individual cells. This wide spectrum of data acquisition is vital for elucidating the migration capabilities of different type of cells and to understand the basic mechanism involved in cancer metastasis.  相似文献   
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