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101.
吲唑衍生物的合成及其生物活性的研究   总被引:1,自引:1,他引:1  
丁自荣  张永钦 《合成化学》1997,5(2):175-178
报道了10种吲唑衍射生物合成及其初步生物活性的测定结果,结构经^1HNMR,IR元素分析等证实。  相似文献   
102.
ComputerHandlingofChemicalandBiologicalDataofTraditionalChineseMedicinesCHEChun-taoa**,PaulR.CarlieraandOpheliaC.W.Leeb(aDepa...  相似文献   
103.
Current cell-based bone tissue regeneration strategies cannot cover large bone defects. K-carrageenan is a highly hydrophilic and biocompatible seaweed-derived sulfated polysaccharide, that has been proposed as a promising candidate for tissue engineering applications. Whether κ-carrageenan can be used to enhance bone regeneration is still unclear. In this study, we aimed to investigate whether κ-carrageenan has osteogenic potential by testing its effect on pre-osteoblast proliferation and osteogenic differentiation in vitro. Treatment with κ-carrageenan (0.5 and 2 mg/mL) increased both MC3T3-E1 pre-osteoblast adhesion and spreading at 1 h. K-carrageenan (0.125–2 mg/mL) dose-dependently increased pre-osteoblast proliferation and metabolic activity, with a maximum effect at 2 mg/mL at day three. K-carrageenan (0.5 and 2 mg/mL) increased osteogenic differentiation, as shown by enhanced alkaline phosphatase activity (1.8-fold increase at 2 mg/mL) at day four, and matrix mineralization (6.2-fold increase at 2 mg/mL) at day 21. K-carrageenan enhanced osteogenic gene expression (Opn, Dmp1, and Mepe) at day 14 and 21. In conclusion, κ-carrageenan promoted MC3T3-E1 pre-osteoblast adhesion and spreading, metabolic activity, proliferation, and osteogenic differentiation, suggesting that κ-carrageenan is a potential osteogenic inductive factor for clinical application to enhance bone regeneration.  相似文献   
104.
Background: Platelet-rich fibrin (PRF) has gained popularity in craniofacial surgery, as it provides an excellent reservoir of autologous growth factors (GFs) that are essential for bone regeneration. However, the low elastic modulus, short-term clinical application, poor storage potential and limitations in emergency therapy use restrict its more widespread clinical application. This study fabricates lyophilised PRF (Ly-PRF), evaluates its physical and biological properties, and explores its application for craniofacial tissue engineering purposes. Material and methods: A lyophilisation method was applied, and the outcome was evaluated and compared with traditionally prepared PRF. We investigated how lyophilisation affected PRF’s physical characteristics and biological properties by determining: (1) the physical and morphological architecture of Ly-PRF using SEM, and (2) the kinetic release of PDGF-AB using ELISA. Results: Ly-PRF exhibited a dense and homogeneous interconnected 3D fibrin network. Moreover, clusters of morphologically consistent cells of platelets and leukocytes were apparent within Ly-PRF, along with evidence of PDGF-AB release in accordance with previously reports. Conclusions: The protocol established in this study for Ly-PRF preparation demonstrated versatility, and provides a biomaterial with growth factor release for potential use as a craniofacial bioscaffold.  相似文献   
105.
Impaired wound healing is a major medical challenge, especially in diabetics. Over the centuries, the main goal of tissue engineering and regenerative medicine has been to invent biomaterials that accelerate the wound healing process. In this context, keratin-derived biomaterial is a promising candidate due to its biocompatibility and biodegradability. In this study, we evaluated an insoluble fraction of keratin containing casomorphin as a wound dressing in a full-thickness surgical skin wound model in mice (n = 20) with iatrogenically induced diabetes. Casomorphin, an opioid peptide with analgesic properties, was incorporated into keratin and shown to be slowly released from the dressing. An in vitro study showed that keratin-casomorphin dressing is biocompatible, non-toxic, and supports cell growth. In vivo experiments demonstrated that keratin-casomorphin dressing significantly (p < 0.05) accelerates the whole process of skin wound healing to the its final stage. Wounds covered with keratin-casomorphin dressing underwent reepithelization faster, ending up with a thicker epidermis than control wounds, as confirmed by histopathological and immunohistochemical examinations. This investigated dressing stimulated macrophages infiltration, which favors tissue remodeling and regeneration, unlike in the control wounds in which neutrophils predominated. Additionally, in dressed wounds, the number of microhemorrhages was significantly decreased (p < 0.05) as compared with control wounds. The dressing was naturally incorporated into regenerating tissue during the wound healing process. Applied keratin dressing favored reconstruction of more regular skin structure and assured better cosmetic outcome in terms of scar formation and appearance. Our results have shown that insoluble keratin wound dressing containing casomorphin supports skin wound healing in diabetic mice.  相似文献   
106.
Poloxamer188 (PL188), as one of the most commonly used pharmaceutical excipients, has unique physicochemical properties and good biocompatibility, and so is playing an increasingly extensive role in the field of medicine. Currently, there are few studies on the tissue distribution of PL188 in vivo. In this study, the LC-MS method based on MSALL technique of quadrupole time of flight mass spectrometry for absolute quantitative analysis of poloxamer 188 in biological substrates was established for the first time. The tissue distribution of poloxamer188 in SD rats were studied using the established quantitative analysis method. To explore the distribution of PL188 in organs and tissues, PL188 was administered via rat tail vein at a dose of 5 mg/kg. Eight kinds of tissues including heart, liver, spleen, lung, kidney, stomach, muscle and brain of rats were collected at 0.25 h, 1 h and 4 h after administration. Tissue distributions showed the highest level was observed in kidney, then in stomach, which indicated PL188 mainly bioaccumulated in the kidney. This study can provide references for the further study of PL188.  相似文献   
107.
Matrix‐assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) is a molecular imaging technology uniquely capable of untargeted measurement of proteins, lipids, and metabolites while retaining spatial information about their location in situ. This powerful combination of capabilities has the potential to bring a wealth of knowledge to the field of molecular histology. Translation of this innovative research tool into clinical laboratories requires the development of reliable sample preparation protocols for the analysis of proteins from formalin‐fixed paraffin‐embedded (FFPE) tissues, the standard preservation process in clinical pathology. Although ideal for stained tissue analysis by microscopy, the FFPE process cross‐links, disrupts, or can remove proteins from the tissue, making analysis of the protein content challenging. To date, reported approaches differ widely in process and efficacy. This tutorial presents a strategy derived from systematic testing and optimization of key parameters, for reproducible in situ tryptic digestion of proteins in FFPE tissue and subsequent MALDI IMS analysis. The approach describes a generalized method for FFPE tissues originating from virtually any source.  相似文献   
108.
In the present research, chitosan/collagen and chitosan/collagen/nano-hydroxyapatite (nHAP) hydrogel nanocomposites were prepared using naturally extracted chitosan from Persian Gulf shrimp wastes and rat tail-tendon collagen. Freeze-gelation method was used to prepare highly porous scaffolds. The morphology, chemical structure, water retainability, and thermal properties were characterized using SEM, FTIR, water content experiment, simultaneous thermal analysis (STA), respectively. Atomic force microscopy (AFM) nanoindentation and unconfined compression test were used to assess different feature of the mechanical properties of the hydrogels. The obtained results were so promising that the prepared nanocomposites can be considered as a potential candidate for cartilage tissue engineering.  相似文献   
109.
The Development of Modern Pesticides   总被引:1,自引:0,他引:1  
IntroductionAt present,over80 0 different compounds areavailable for being used as pesticides[1] oragrochemicals[2 ] . Insecticides,fungicides,andherbicides constitute the largest groups but othertypes that are listed include acaricides,additives,algicides,attractants,bactericides,growthregulators,molluscicides,nematicides,repellents,rodenticides,safeners,soil sterilants,synergists,and wood protectants.The worldwide consumptionof pesticides is indicated by the level of sales in thelast decade …  相似文献   
110.
Utilization of carbohydrates by radiation processing   总被引:2,自引:0,他引:2  
Upgrading and utilization of carbohydrates such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated for recycling these bio-resources and reducing the environmental pollution. These carbohydrates were easily degraded by irradiation and various kinds of biological activities such as anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction, etc. were induced. On the other hand, some carbohydrate derivatives, carboxymethylcellulose and carboxymethylstarch, could be crosslinked under certain radiation condition and produce the biodegradable hydrogel for medical and agricultural use.  相似文献   
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