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441.
442.
Phase fluctuation chromatography (PFC) involves injection of a semidilute solution of a copolymer for separation by the chemical composition. It is considered that PFC utilizes naturally occurring spatial fluctuations of composition in the semidilute solution of the multi‐component polymer to enhance segregation by a selective surface. We conducted PFC for semidilute solutions of poly(styrene‐co‐acrylonitrile) in various solvents that have a different solubility for the constituent monomeric units. Heterogeneity in the semidilute solution was studied by using dynamic light scattering (DLS). In selective solvents, DLS autocorrelation functions had a slow mode ascribed to composition fluctuations in addition to a fast cooperative diffusion mode. PFC of these solutions produced fractions with a broad span in the styrene content. The early eluent was enriched with components preferred by the solvent regardless of the surface. The resolution was better when the surface moieties repelled components preferred by the solvent. As the solvent selectivity decreased, the solution became more uniform, losing the heterogeneity mode in the autocorrelation functions. Then the separation by PFC became worse and more dependent on the surface preference. The surface‐controlled partitioning was effective only when the solvent selectivity was low. We thus find that when the solvent is selective, the heterogeneous solution is segregated according to the preference of the mobile phase rather than to the preference of the pore surface.  相似文献   
443.
Embryonic stem (ES) cells have a potential to differentiate into various progenitor cells. Here we investigated the differentiation capacity of mouse ES cells into hepatocytes both in vitro and in vivo. During the culture of embryoid bodies (EBs) derived from ES cells, albumin (ALB) messenger RNA (mRNA) was expressed within 12 days after removal of leukemia inhibitory factor, and alpha-fetoprotein (AFP) mRNA was observed within 9 days without additional exogenous growth factors. In ES cells and early EBs, by contrast, neither ALB mRNA nor AFP mRNA was observed. ALB protein was first detected at day 15 and the level increased with the culture period. The differentiation of EBs facilitated the synthesis of urea with the culture period, whereas early EBs and ES cells produced no urea. These results suggest that cultured EBs contain hepatocytes capable of producing ALB and urea. ES cells and the isolated cells from EBs were transplanted through portal vein to the liver after 30% partial hepatectomy of female mice pretreated with 2-acetylaminofluorene. Four weeks after transplantation with isolated cells from day-9 EBs, ES-derived cells containing Y-chromosome in the liver were positive for ALB (0.2% of total liver cells), whereas teratoma was found in mice transplanted with ES cells or EBs up to day 6. The incidence of teratoma was decreased with the culture duration and no teratoma was observed in the liver transplanted with isolated cells from day-9 EBs. In conclusion, our in vitro and in vivo experiments revealed that cultured EBs contain functional hepatocytes or hepatocyte-like cells.  相似文献   
444.
Matsui  M.  Tanji  N.  Teraoka  T.  Yokoyama  M.  Ikeda  M. 《International urology and nephrology》1999,31(6):737-741
We studied the biochemical markers of bone metabolism and bone mineral density (BMD) in 43 male haemodialysis patients. We measured serum levels of carboxyterminal parathyroid hormone (PTH-c), carboxyterminal propeptide of human type I procollagen, calcitonin, intact osteocalcin, cross-linked carboxyterminal telopeptide of human type I collagen, and alkaline phosphatase. We divided all patients into 2 groups (group A and B), those with serum PTH-c levels of 7.5 ng/ml or higher, and those with levels lower than 7.5 ng/ml, respectively. In group A, the levels of markers for bone formation and for bone resorption were notably elevated, while BMD was not significantly decreased. The level of serum markers for bone metabolism appears to be more sensitive than BMD for the clinical assessment of secondary hyperparathyroidism.  相似文献   
445.
Bilateral xanthogranulomas arising from both choroid plexues were found in a 6-year-old child with epileptic seizures and psychomotor retardation. Both masses were surgically removed without adding any neurological deficits. The xanthogranulomas were fairly large, and the posterior part of both lateral ventricles were slightly dilated, but clinical symptoms and the location of the xanthogranulomas could not be clearly correlated in this case.  相似文献   
446.
DNA-dependent protein kinase (DNA-PK) is an important nuclear enzyme which consists of a catalytic subunit known as DNA-PKcs and a regulatory component identified as the Ku autoantigen. In the present study, we surveyed 312 patients in a search for this specificity. 10 sera immunoprecipitated a large polypeptide which exactly comigrated with DNA-PKcs in SDS-PAGE. Immunoblot analysis demonstrated that this polypeptide was recognizable by a rabbit antiserum specific for DNA-PKcs. Although the patient sera did not bind to biochemically purified DNA-PKcs in immunoblots or ELISA, they were able to deplete DNA-PK catalytic activity from extracts of HeLa cells in a dose-dependent manner. We conclude that these antibodies should be useful probes for studies which aim to define the role of DNA-PK in cells. Since six sera simultaneously contained antibodies to the Ku protein, these studies suggest that relatively intact forms of DNA-PK complex act as autoantigenic particles in selected patients.  相似文献   
447.
Summary The selection of gluteus maximus musculocutaneous flaps and the appropriate designs of such flaps are described. These flaps are based on either the superior gluteal pedicle or the inferior gluteal pedicle. Knowledge of the pedicle's position in relation to the skin surface is essential for correct design of the flap. We have treated 34 cases of sacral decubitus ulcer in which we have accomplished reconstruction with various types of gluteus maximus musculocutaneous flaps. Four representative cases are presented. Requests for reprints: A. Yanai, M.D.  相似文献   
448.
Cyclosporin (CYA) is now recognized as an effective immunosuppressant to lead to a marked improvement in graft survival in organ transplant recipients. Although the incidence of infection in the CYA group has been decreased compared with that in the azathioprine group, infectious diseases in 400 kidney transplant recipients treated with CYA were noted in our single center. Treatment strategy for infectious diseases: Antibiotics and/or gamma-Globulin were administered to all recipients with bacterial infections. Aciclovir was added in recipients with herpes simplex virus (HSV) infection or varicella zoster virus (VZV) infection. Human interferon-beta (HuIFN-beta) was used in recipients who had life-threatening viral infection, especially cytomegalovirus (CMV) pneumonitis. Glycyrrhizin was used for acute hemorrhagic cystitis and nephropathy due to adenovirus (AV). Trimethoprim sulfamethoxazole and/or pentamidine were added in recipients complicated with Pneumocystis carinii (Pc) pneumonitis or in order to prevent Pc pneumonitis. Infectious diseases: One hundred and six recipients had infectious diseases 129 times in this series, seventy-six percent of all infections occurred during the first 4 months after the transplantation. Urinary tract infection (UTI), herpes zoster and pulmonary infection were the most common infectious diseases, occurring in 28.7%, 24.0% and 23.2%, respectively. Septicemia or bacteremia developed in 9 recipients, secondary to UTI in 8 and to surgical wound infection in one. Sixty-one symptomatic viral infections occurred in 57 recipients. A total of 5 recipients (1.3%) died of interstitial pneumonitis. Infectious organisms: Viral and bacterial infections were most common, occurring in 47.3% and 41.9%, respectively. Viral species detected in these recipients with the frequency were HSV 14 times, CMV 9 times, VZV 31 times and AV 7 times. 1) The incidence of viral infections in kidney transplant recipients treated with CYA is relatively high compared to bacterial infections. 2) HuIFN-beta therapy is effective in the treatment of serious opportunistic herpes virus infections, especially CMV pneumonitis. 3) Glycyrrhizin therapy is effective in the treatment of acute hemorrhagic cystitis and nephropathy due to AV and hepatic dysfunction. 4) Aerosolised pentamidine therapy is very useful for prophylaxis of Pc pneumonitis.  相似文献   
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