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71.
Mark D. Savellano Nicci Owusu‐Brackett Ji Son Tanay Ganga Nadia L. Leung Dagmar H. Savellano 《Photochemistry and photobiology》2013,89(3):687-697
A novel pyropheophorbide‐a (PPa) derivative, Ac‐sPPp, was developed in our lab for targeted photodynamic therapy (PDT) and combination therapies. Its versatile peptide moiety, high water‐solubility, amphiphilicity, and micellar aggregation allow efficient coupling to targeting moieties and convenient mixing with other therapeutics. Photosensitizer immunoconjugate (PIC) targeted PDT, using Ac‐sPPp conjugated to therapeutic anti‐epidermal growth factor receptor (EGFR) antibody cetuximab, and PDT + chemotherapy combination treatment, using Ac‐sPPp mixed with stealth liposomal doxorubicin (Doxil), were investigated as promising strategies for potentiating PDT and improving target specificity. Passively targeted PDT with Ac‐sPPp only or surfactant‐solubilized PPa was also investigated for comparison. The A‐431 human vulvar squamous cell carcinoma, xenografted in nude mice, was chosen as a tumor model because of its high EGFR expression and sensitivity to liposomal doxorubicin in vitro. Fluorescence imaging and PDT experiments showed that Ac‐sPPp formulations circulated far longer and provided superior tumor contrast and superior tumor control compared to PPa. Strong PDT vascular effects were observed by laser Doppler imaging regardless of whether Ac‐sPPp was passively or actively targeted. Passively targeted Ac‐sPPp PDT gave equivalent or better tumor control than PIC‐targeted PDT or PDT + Doxil combination therapy, and when treatments were repeated, it also yielded the highest cure rate. 相似文献
72.
73.
Sana Jahanshahi‐Anbuhi Kevin Pennings Vincent Leung Dr. Meng Liu Carmen Carrasquilla Dr. Balamurali Kannan Prof. Dr. Yingfu Li Prof. Dr. Robert Pelton Prof. Dr. John D. Brennan Prof. Dr. Carlos D. M. Filipe 《Angewandte Chemie (International ed. in English)》2014,53(24):6155-6158
A simple and inexpensive method is reported for the long‐term stabilization of enzymes and other unstable reagents in premeasured quantities in water‐soluble tablets (cast, not compressed) made with pullulan, a nonionic polysaccharide that forms an oxygen impermeable solid upon drying. The pullulan tablets dissolve in aqueous solutions in seconds, thereby facilitating the easy execution of bioassays at remote sites with no need for special reagent handling and liquid pipetting. This approach is modular in nature, thus allowing the creation of individual tablets for enzymes and their substrates. Proof‐of‐principle demonstrations include a Taq polymerase tablet for DNA amplification through PCR and a pesticide assay kit consisting of separate tablets for acetylcholinesterase and its chromogenic substrate, indoxyl acetate, both of which are highly unstable. The encapsulated reagents remain stable at room temperature for months, thus enabling the room‐temperature shipping and storage of bioassay components. 相似文献
74.
Dr. Ming-Yu Wu Jong-Kai Leung Li Liu Dr. Chuen Kam Dr. Kelvin Yuen Kwong Chan Prof. Dr. Ronald A. Li Prof. Dr. Shun Feng Dr. Sijie Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(26):10413-10417
The chromosome periphery (CP) is a complex network that covers the outer surface of chromosomes. It acts as a carrier of nucleolar components, helps maintain chromosome structure, and plays an important role in mitosis. Current methods for fluorescence imaging of CP largely rely on immunostaining. We herein report a small-molecule fluorescent probe, ID-IQ , which possesses aggregation-induced emission (AIE) property, for CP imaging. By labelling the CP, ID-IQ sharply highlighted the chromosome boundaries, which enabled rapid segmentation of touching and overlapping chromosomes, direct identification of the centromere, and clear visualization of chromosome morphology. ID-IQ staining was also compatible with fluorescence in situ hybridization and could assist the precise location of the gene in designated chromosome. Altogether, this study provides a versatile cytogenetic tool for improved chromosome analysis, which greatly benefits the clinical diagnostic testing and genomic research. 相似文献
75.
Wanhe Wang Ke‐Jia Wu Kasipandi Vellaisamy Chung‐Hang Leung Dik‐Lung Ma 《Angewandte Chemie (International ed. in English)》2020,59(41):17897-17902
Gastrin‐releasing peptide receptor (GRPr) plays proliferative and inflammatory roles in living systems. Here, we report a highly selective GRPr antagonist (JMV594)‐tethered iridium(III) complex for probing GRPr in living cancer cells and immune cells. This probe exhibited desirable photophysical properties and also displayed negligible cytotoxicity, overcoming the inherent toxicity of the iridium(III) complex. Its long emission lifetime enabled its luminescence signal to be readily distinguished from the interfering fluorescence of organic dyes by using a time‐resolved technique. This probe selectively visualized living cancer cells via specific binding to GRPr, while it also modulated the function of GRPr on TNF‐α secretion in immune cells. To our knowledge, this is the first peptide‐conjugated iridium(III) complex developed as a GRPr bioimaging probe and modulator of GRPr activity. This theranostic agent shows great potential at unmasking the diverse roles of GRPr in living systems. 相似文献
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77.
Peter Jaein Choi Petr Tomek Moana Tercel Jhannes Reynisson Thomas In Hyeup Park Elizabeth Alexandra Cooper William Alexander Denny Jiney Jose Euphemia Leung 《Molecules (Basel, Switzerland)》2022,27(3)
The CDK4/6 inhibitor palbociclib, combined with endocrine therapy, has been shown to be effective in postmenopausal women with estrogen receptor-positive, HER2-negative advanced or metastatic breast cancer. However, palbociclib is not as effective in the highly aggressive, triple-negative breast cancer that lacks sensitivity to chemotherapy or endocrine therapy. We hypothesized that conjugation of the near-infrared dye MHI-148 with palbociclib can produce a potential theranostic in triple-negative, as well as estrogen receptor-positive, breast cancer cells. In our study, the conjugate was found to have enhanced activity in all mammalian cell lines tested in vitro. However, the conjugate was cytotoxic and did not induce G1 cell cycle arrest in breast cancer cells, suggesting its mechanism of action differs from the parent compound palbociclib. The study highlights the importance of investigating the mechanism of conjugates of near-infrared dyes to therapeutic compounds, as conjugation can potentially result in a change of mechanism or target, with an enhanced cytotoxic effect in this case. 相似文献
78.
Louis M. Leung W. H. Chan Sew Koo Leung 《Journal of polymer science. Part A, Polymer chemistry》1993,31(7):1799-1806
A series of aliphatic and aromatic polytrithiocarbonates was prepared using a novel “one-pot” synthesis procedure employing a phase-transfer catalyst. The starting reagents were either an aliphatic or an aromatic dihalide and an excessive amount of carbon disulfide. The effects of the phase-transfer catalyst and reaction conditions on yield were studied. The structure and composition of the polymers and reaction side-products were determined from infrared, ultraviolet, 1H-NMR spectra, and elemental analyses. The polymers were further characterized by viscosity measurement and thermal analysis. © 1993 John Wiley & Sons, Inc. 相似文献
79.
80.
X. B. Zeng A. W. N. Leung X. S. Xia H. P. Yu D. Q. Bai J. Y. Xiang Y. Jiang C. S. Xu 《Laser Physics》2010,20(6):1500-1503
In the present study, we have successfully set up a novel blue light source with the power density of 9 mW/cm2 and the wavelength of 435.8 nm and then the novel light source was used to investigate the effect of light radiation on curcumin-induced
cell death. The cytotoxicity was investigated 24 h after the treatment of curcumin and blue light radiation together using
MTT reduction assay. Nuclear chromatin was observed using a fluorescent microscopy with Hoechst33258 staining. The results
showed blue light radiation could significantly enhance the cytotoxicity of curcumin on the MCF-7 cells and apoptosis induction.
These findings demonstrated that blue light radiation could enhance curcumin-induced cell death of breast cancer cells, suggesting
light radiation may be an efficient enhancer of curcumin in the management of breast cancer. 相似文献