全文获取类型
收费全文 | 631篇 |
免费 | 32篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 20篇 |
化学工业 | 211篇 |
金属工艺 | 19篇 |
机械仪表 | 13篇 |
建筑科学 | 6篇 |
能源动力 | 39篇 |
轻工业 | 37篇 |
石油天然气 | 1篇 |
无线电 | 55篇 |
一般工业技术 | 83篇 |
冶金工业 | 112篇 |
原子能技术 | 12篇 |
自动化技术 | 56篇 |
出版年
2023年 | 13篇 |
2022年 | 24篇 |
2021年 | 40篇 |
2020年 | 21篇 |
2019年 | 17篇 |
2018年 | 26篇 |
2017年 | 19篇 |
2016年 | 33篇 |
2015年 | 14篇 |
2014年 | 28篇 |
2013年 | 37篇 |
2012年 | 27篇 |
2011年 | 39篇 |
2010年 | 25篇 |
2009年 | 24篇 |
2008年 | 16篇 |
2007年 | 17篇 |
2006年 | 9篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 12篇 |
2002年 | 6篇 |
2001年 | 9篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 35篇 |
1997年 | 16篇 |
1996年 | 20篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1979年 | 4篇 |
1977年 | 7篇 |
1976年 | 11篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有664条查询结果,搜索用时 203 毫秒
651.
Ryuichi Kondou Chenxi Wang Akitsu Shigetou Tadatomo Suga 《Microelectronics Reliability》2012,52(2):342-346
Direct wafer bonding of Si–Si and Si–SiN wafers was demonstrated using a nanoadhesion layer at room temperature. The two mating surfaces were cleaned by an Ar-ion beam and simultaneously deposited with ultrathin Fe layers (known as nanoadhesion layers). The ultrathin Fe layers imparted high bond strengths to Si–Si and Si–SiN bonds without heat treatment. Transmission electron microscopy revealed that the Si–Si and Si–SiN interfaces were tightly bonded and defect free. Moreover, the formation of crystalline iron silicide across the interface was found to enhance Si–Si wafer bonding. In addition to FeSi, an amorphous layer formed at the Si–SiN interface, resulting in a high bond strength at room temperature. 相似文献
652.
Kimata K Yamaguchi M Saito Y Hata H Miyake K Yamane T Nakagawa Y Yano A Ito K Kawarasaki Y 《Journal of Bioscience and Bioengineering》2012,113(2):154-159
Yeast's extracellular expression provides a cost-efficient means of producing industrially useful recombinant proteins. However, depending on the protein to be expressed, the production results in a poor yield, which is occasionally accompanied with loss of the expression plasmid and hence hampered growth of the host in the inducing medium. Here we propose an alternative approach, high cell-density expression, to improve the yield of a certain range of so-called difficult-to-express proteins. In this expression system, recombinant yeast cells resting in stationary phase (OD(660)=3-4) are suspended in a small aliquot of inducing medium to form a high cell-density culture (e.g., OD(660)=15). When applied to the yeast strains harboring Lentinula edodes laccase (Lcc1 or Lcc4) expressing plasmids, the high cell-density system allowed the host cells to synthesize elevated amounts of the laccase which resulted in >1000- to 6000-fold higher yield than those synthesized in a classical growth-associated manner. The resting cells required aerobic agitation for the maximum production. The production system also worked for other foreign enzymes but not for beta-galactosidase from Aspergillus oryzae or Escherichia coli, likely suggesting an involvement of chaperons that act on a certain range of secretory proteins. 相似文献
653.
Tsugumasa Toma Hiroshi Tateishi Kensaku Kawakami Taha F. S. Ali Masahiro Kamo Kazuaki Monde Yuta Nakashima Mikako Fujita Masami Otsuka 《International journal of molecular sciences》2022,23(9)
Cancer metastasis accounts for most of the mortality associated with solid tumors. However, antimetastatic drugs are not available on the market. One of the important biological events leading to metastasis is the epithelial to mesenchymal transition (EMT) induced by cytokines, namely transforming growth-factor-β (TGF-β). Although several classes of inhibitors targeting TGF-β and its receptor have been developed, they have shown profound clinical side effects. We focused on our synthetic compound, HPH-15, which has shown anti-fibrotic activity via the blockade of the TGF-β Smad-dependent signaling. In this study, 10 μM of HPH-15 was found to exhibit anti-cell migration and anti-EMT activities in non-small-cell lung cancer (NSCLC) cells. Although higher concentrations are required, the anti-EMT activity of HPH-15 has also been observed in 3D-cultured NSCLC cells. A mechanistic study showed that HPH-15 inhibits downstream TGF-β signaling. This downstream inhibition blocks the expression of cytokines such as TGF-β, leading to the next cycle of Smad-dependent and -independent signaling. HPH-15 has AMPK-activation activity, but a relationship between AMPK activation and anti-EMT/cell migration was not observed. Taken together, HPH-15 may lead to the development of antimetastatic drugs with a new mechanism of action. 相似文献
654.
Junya Miyahara Naoki Shirakawa Yuta Setoguchi Masami Tsubota Kento Kuroiwa Jiro Kitagawa 《Journal of Superconductivity and Novel Magnetism》2018,31(11):3559-3564
The Hill plot is a well-known criterion of the f-electron element interatomic threshold distance separating the nonmagnetic state from the magnetic state in actinides and lanthanides. We have reinvestigated the Hill plot of Ce compounds using the commercial crystallographic database CRYSTMET, focusing on a relationship between the Ce-Ce distance and the magnetic ordering temperature because a Ce compound with no other magnetic elements rarely has a magnetic ordering temperature that is higher than 20 K. The Hill plot of approximately 730 compounds has revealed that a Ce compound, particularly a ferromagnet, showing a high magnetic ordering temperature would require a short Ce-Ce distance with a suppression of the valence instability of the Ce ion. From the study, we developed interest in Ce2AuP3 with a Curie temperature of 31 K. The ferromagnetic nature of this material has been examined in terms of a doping effect, which suggests a possible increase in magnetic anisotropy energy. 相似文献
655.
Masashi Okada Yurika Nakagawa-Saito Yuta Mitobe Asuka Sugai Keita Togashi Shuhei Suzuki Chifumi Kitanaka 《International journal of molecular sciences》2022,23(15)
Glioma stem cells (GSCs), the cancer stem cells of glioblastoma multiforme (GBM), contribute to the malignancy of GBM due to their resistance to therapy and tumorigenic potential; therefore, the development of GSC-targeted therapies is urgently needed to improve the poor prognosis of GBM patients. The molecular mechanisms maintaining GSCs need to be elucidated in more detail for the development of GSC-targeted therapy. In comparison with patient-derived GSCs and their differentiated counterparts, we herein demonstrated for the first time that phospholipase C (PLC)ε was highly expressed in GSCs, in contrast to other PLC isoforms. A broad-spectrum PLC inhibitor suppressed the viability of GSCs, but not their stemness. Nevertheless, the knockdown of PLCε suppressed the survival of GSCs and induced cell death. The stem cell capacity of residual viable cells was also suppressed. Moreover, the survival of mice that were transplanted with PLCε knockdown-GSCs was longer than the control group. PLCε maintained the stemness of GSCs via the activation of JNK. The present study demonstrated for the first time that PLCε plays a critical role in maintaining the survival, stemness, and tumor initiation capacity of GSCs. Our study suggested that PLCε is a promising anti-GSC therapeutic target. 相似文献
656.
Takahiro Imanishi Yuta Fujiwara Yoshinari Sawama Yasunari Monguchi Hironao Sajiki 《Advanced Synthesis \u0026amp; Catalysis》2012,354(5):771-776
Geminal‐dichloromethyl derivatives could be efficiently synthesized by the highly chemoselective platinum on carbon‐catalyzed mono‐dechlorination of trichloromethyl substrates in dimethylacetamide (DMA) as a specific solvent at 25 °C under a hydrogen atmosphere. 相似文献
657.
Shan Min Chin Giacomo Reina Ngoc Do Quyen Chau Tanguy Chabrol Didier Wion Ali Bouamrani Emmanuel Gay Yuta Nishina Alberto Bianco François Berger 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(18):2208227
Peritumoral brain invasion is the main target to cure glioblastoma. Chemoradiotherapy and targeted therapies fail to combat peritumoral relapse. Brain inaccessibility and tumor heterogeneity explain this failure, combined with overlooking the peritumor microenvironment. Reduce graphene oxide (rGO) provides a unique opportunity to modulate the local brain microenvironment. Multimodal graphene impacts are reported on glioblastoma cells in vitro but fail when translated in vivo because of low diffusion. This issue is solved by developing a new rGO formulation involving ultramixing during the functionalization with polyethyleneimine (PEI) leading to the formation of highly water-stable rGO-PEI. Wide mice brain diffusion and biocompatibility are demonstrated. Using an invasive GL261 model, an anti-invasive effect is observed. A major unexpected modification of the peritumoral area is also observed with the neutralization of gliosis. In vitro, mechanistic investigations are performed using primary astrocytes and cytokine array. The result suggests that direct contact of rGO-PEIUT neutralizes astrogliosis, decreasing several proinflammatory cytokines that would explain a bystander tumor anti-invasive effect. rGO also significantly downregulates several proinvasive/protumoral cytokines at the tumor cell level. The results open the way to a new microenvironment anti-invasive nanotherapy using a new graphene nanomaterial that is optimized for in vivo brain delivery. 相似文献
658.
Dr. Shinya Matsuda Dr. Yuta Tsunematsu Takuma Matsushita Yuji Ogata Shihomi Hachiya Dr. Shinji Kishimoto Dr. Noriyuki Miyoshi Prof. Dr. Kenji Watanabe 《Chembiochem : a European journal of chemical biology》2022,23(4):e202100645
Biosynthetic genes are not only responsible for the formation of bioactive substances but also suited for other applications including gene therapy. To test the feasibility of human cells producing antibiotics in situ when provided with a heterologous biosynthetic gene, we focused on cytochrome P450, the class of enzymes important in conferring bioactivity to natural product precursors. We selected Fma-P450 that plays a central role in the fumagillin antimicrobial biosynthesis in Aspergillus fumigatus to examine fungal metabolite production by HeLa cells that express fma-P450 heterologously. Here we show that HeLa cells harboring fma-P450 can biosynthesize 5-hydroxyl-β-trans-bergamoten and cytotoxic 5-epi-demethoxyfumagillol when supplemented with the nontoxic precursor β-trans-bergamotene. While the production level was insufficient to effect cell death, we demonstrate that programming human cells to autogenerate antibiotics by introducing a heterologous biosynthetic gene is feasible. 相似文献
659.
Dr. Tatsuya Ikenoue Dr. Miki Oono Dr. Masatomo So Dr. Hodaka Yamakado Prof. Toshiaki Arata Prof. Ryosuke Takahashi Prof. Yasushi Kawata Prof. Hiroaki Suga 《Chembiochem : a European journal of chemical biology》2023,24(12):e202300320
There is considerable interest in drug discovery targeting the aggregation of α-synuclein (αSyn) since this molecular process is closely associated with Parkinson's disease. However, inhibiting αSyn aggregation remains a major challenge because of its highly dynamic nature which makes it difficult to form a stable binding complex with a drug molecule. Here, by exploiting Random non-standard Peptides Integrated Discovery (RaPID) system, we identified a macrocyclic peptide, BD1, that could interact with immobilized αSyn and inhibit the formation of fibrils. Furthermore, improving the solubility of BD1 suppresses the co-aggregation with αSyn fibrils while it kinetically inhibits more effectively without change in their morphology. We also revealed the molecular mechanism of kinetic inhibition, where peptides bind to fibril ends of αSyn, thereby preventing further growth of fibrils. These results suggest that our approach for generating non-standard macrocyclic peptides is a promising approach for developing potential therapeutics against neurodegeneration. 相似文献
660.
Shuhei Takatsuka Takeshi Kubota Yuta Kurashina Hiroaki Onoe 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(7):2204139
Gene therapy using adeno-associated virus (AAV) has potential as a radical treatment modality for genetic diseases such as sensorineural deafness. To establish clinical applications, it is necessary to avoid immune response to AAV by controlled release system of AAV. Here, a near-infrared (NIR)-triggered on-demand AAV release system using alginate hydrogel microbeads with a heat transducer is proposed. By using a centrifuge-based microdroplet shooting device, the microbeads encapsulating AAV with Fe3O4 microparticles (Fe3O4-MPs) as a heat transducer are fabricated. Fe3O4-MPs generated heat by NIR enhanced the diffusion speed of the AAV, resulting in the AAV being released from the microbeads. By irradiating the microbeads encapsulating fluorescent polystyrene nanoparticles (FP-NPs) (viral model) with NIR, the fluorescence intensity decreased only for FP-NPs with a diameter of 20 nm and not for 100 or 200 nm, confirming that this system can release virus with a diameter of several tens of nanometers. By irradiating NIR to the AAV-encapsulating microbeads with Fe3O4-MPs, the AAV is released on demand, and gene transfection to cells by AAV is confirmed without loss of viral activity. The NIR-triggered AAV release system proposed in this study increases the number of alternatives for the method of drug release in gene therapy. 相似文献