全文获取类型
收费全文 | 4416篇 |
免费 | 188篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 21篇 |
综合类 | 8篇 |
化学工业 | 1204篇 |
金属工艺 | 44篇 |
机械仪表 | 46篇 |
建筑科学 | 187篇 |
矿业工程 | 14篇 |
能源动力 | 67篇 |
轻工业 | 727篇 |
水利工程 | 27篇 |
石油天然气 | 9篇 |
无线电 | 123篇 |
一般工业技术 | 486篇 |
冶金工业 | 1105篇 |
原子能技术 | 24篇 |
自动化技术 | 517篇 |
出版年
2023年 | 27篇 |
2022年 | 189篇 |
2021年 | 203篇 |
2020年 | 82篇 |
2019年 | 98篇 |
2018年 | 108篇 |
2017年 | 84篇 |
2016年 | 100篇 |
2015年 | 95篇 |
2014年 | 136篇 |
2013年 | 261篇 |
2012年 | 173篇 |
2011年 | 227篇 |
2010年 | 191篇 |
2009年 | 156篇 |
2008年 | 215篇 |
2007年 | 193篇 |
2006年 | 149篇 |
2005年 | 134篇 |
2004年 | 120篇 |
2003年 | 96篇 |
2002年 | 121篇 |
2001年 | 72篇 |
2000年 | 67篇 |
1999年 | 85篇 |
1998年 | 84篇 |
1997年 | 56篇 |
1996年 | 78篇 |
1995年 | 50篇 |
1994年 | 59篇 |
1993年 | 54篇 |
1992年 | 61篇 |
1990年 | 51篇 |
1989年 | 69篇 |
1988年 | 45篇 |
1987年 | 52篇 |
1986年 | 55篇 |
1985年 | 53篇 |
1984年 | 58篇 |
1983年 | 45篇 |
1982年 | 30篇 |
1981年 | 47篇 |
1980年 | 26篇 |
1979年 | 23篇 |
1978年 | 22篇 |
1977年 | 23篇 |
1976年 | 30篇 |
1975年 | 26篇 |
1973年 | 16篇 |
1970年 | 17篇 |
排序方式: 共有4609条查询结果,搜索用时 15 毫秒
941.
Damian Kaniowski Katarzyna Kulik Justyna Suwara Katarzyna Ebenryter-Olbiska Barbara Nawrot 《International journal of molecular sciences》2022,23(20)
Boron cluster-conjugated antisense oligonucleotides (B-ASOs) have already been developed as therapeutic agents with “two faces”, namely as potential antisense inhibitors of gene expression and as boron carriers for boron neutron capture therapy (BNCT). The previously observed high antisense activity of some B-ASOs targeting the epidermal growth factor receptor (EGFR) could not be rationally assigned to the positioning of the boron cluster unit: 1,2-dicarba-closo-dodecaborane (0), [(3,3′-Iron-1,2,1′,2′-dicarbollide) (1-), FESAN], and dodecaborate (2-) in the ASO chain and its structure or charge. For further understanding of this observation, we performed systematic studies on the efficiency of RNase H against a series of B-ASOs models. The results of kinetic analysis showed that pyrimidine-enriched B-ASO oligomers activated RNase H more efficiently than non-modified ASO. The presence of a single FESAN unit at a specific position of the B-ASO increased the kinetics of enzymatic hydrolysis of complementary RNA more than 30-fold compared with unmodified duplex ASO/RNA. Moreover, the rate of RNA hydrolysis enhanced with the increase in the negative charge of the boron cluster in the B-ASO chain. In conclusion, a “smart” strategy using ASOs conjugated with boron clusters is a milestone for the development of more efficient antisense therapeutic nucleic acids as inhibitors of gene expression. 相似文献
942.
Maria Infantino Aris Tsalouchos Edda Russo Selene Laudicina Valentina Grossi Barbara Lari Maurizio Benucci Lorenzo Stacchini Amedeo Amedei Patrizia Casprini Danilo Villalta Pietro Claudio Dattolo Mariangela Manfredi 《International journal of molecular sciences》2022,23(20)
The vulnerable population of kidney transplant recipients (KTRs) are low responders to COVID-19 vaccines, so specific immune surveillance is needed. The interferon-gamma (IFN-γ) release assay (IGRA) is effective in assessing T cell-mediated immunity. We assessed SARS-CoV-2-directed T cell responses in KTRs with absent antibody production after a third dose of the mRNA-1273 vaccine, using two different IGRAs. A cohort of 57 KTRs, who were actively followed up, received a third dose of the mRNA-1273 vaccine. After the evaluation of humoral immunity to SARS-CoV-2, 14 seronegative patients were tested with two commercial IGRAs (SD Biosensor and Euroimmun). Out of 14 patients, one and three samples were positive by IGRAs with Euroimmun and SD Biosensor, respectively. The overall agreement between the two assays was 85.7% (κ = 0.444). In addition, multivariate linear regression analysis showed no statistically significant association between the IFN-γ concentration, and the independent variables analyzed (age, gender, years since transplant, total lymphocytes cells/mcl, CD3+ cells/mcl, CD3+ CD4+ cells/mcl, CD3+ CD8+ cells/mcl, CD19+ cells/mcl, CD3-CD16+CD56+ cells/mcl) (p > 0.01). In a vulnerable setting, assessing cellular immune response to complement the humoral response may be advantageous. Since the two commercial IGRAs showed a good agreement on negative samples, the three discordant samples highlight the need for further investigations. 相似文献
943.
Marina Martello Vincenza Solli Rosalinda Termini Ajsi Kanapari Daniel Remondini Enrica Borsi Andrea Poletti Silvia Armuzzi Barbara Taurisano Ilaria Vigliotta Gaia Mazzocchetti Elena Zamagni Alessandra Merlotti Paola Tacchetti Lucia Pantani Serena Rocchi Ilaria Rizzello Katia Mancuso Michele Cavo Carolina Terragna 《International journal of molecular sciences》2022,23(20)
DNA microarrays and RNA-based sequencing approaches are considered important discovery tools in clinical medicine. However, cross-platform reproducibility studies undertaken so far have highlighted that microarrays are not able to accurately measure gene expression, particularly when they are expressed at low levels. Here, we consider the employment of a digital PCR assay (ddPCR) to validate a gene signature previously identified by gene expression profile. This signature included ten Hedgehog (HH) pathways’ genes able to stratify multiple myeloma (MM) patients according to their self-renewal status. Results show that the designed assay is able to validate gene expression data, both in a retrospective as well as in a prospective cohort. In addition, the plasma cells’ differentiation status determined by ddPCR was further confirmed by other techniques, such as flow cytometry, allowing the identification of patients with immature plasma cells’ phenotype (i.e., expressing CD19+/CD81+ markers) upregulating HH genes, as compared to others, whose plasma cells lose the expression of these markers and were more differentiated. To our knowledge, this is the first technical report of gene expression data validation by ddPCR instead of classical qPCR. This approach permitted the identification of a Maturation Index through the integration of molecular and phenotypic data, able to possibly define upfront the differentiation status of MM patients that would be clinically relevant in the future. 相似文献
944.
945.
Barbara Infante Silvia Mercuri Andrea Dello Strologo Rossana Franzin Valeria Catalano Dario Troise Emanuela Cataldo Paola Pontrelli Carlo Alfieri Valentina Binda Giulia Frontini Giuseppe Stefano Netti Elena Ranieri Loreto Gesualdo Giuseppe Castellano Giovanni Stallone 《International journal of molecular sciences》2022,23(24)
Systemic lupus erythematosus (SLE) is a chronic, systemic autoimmune disease with a wide range of clinical expressions. The kidney is often affected, usually within 5 years of the onset of SLE, and lupus nephropathy (LN) carries a high risk for increased morbidity. The clinical heterogeneity of the disease is accompanied by complex disturbances affecting the immune system with inflammation and tissue damage due to loss of tolerance to nuclear antigens and the deposition of immune complexes in tissues. Several studies have reported that in human SLE, there is an important role of the Type-I-interferons (INF) system suggested by the upregulation of INF-inducible genes observed in serial gene expression microarray studies. This review aims to describe the transduction pathways of Type-I-interferons, in particular INFα, and its immune-regulatory function in the pathogenesis of SLE and, in particular, in LN. In addition, recent novelties concerning biologic therapy in LN will be discussed. 相似文献
946.
Elbieta mudzka Klaudia Lustyk Monika Guch-Lutwin Barbara Mordyl Alicja Zakrzewska-Sito Pawe Mierzejewski Jolanta Jakowska Marcin Koaczkowski Jacek Sapa Karolina Pytka 《International journal of molecular sciences》2022,23(24)
Schizophrenia is a chronic mental illness, which remains difficult to treat. A high resistance to the available therapies, their insufficient efficacy, and numerous side effects are the reasons why there is an urgent need to develop new antipsychotics. This study aimed to assess the antipsychotic-like effects of JJGW08, a novel arylpiperazine alkyl derivative of salicylamide, in rodents. First, considering the JJGW08 receptor profile, we investigated the compound’s intrinsic activity towards dopamine D2 and serotonin 5-HT1A, 5-HT2A, and 5-HT7 receptors using functional assays. Next, we assessed the effect of JJGW08 on MK-801- and amphetamine-induced hyperlocomotion, its risk of inducing catalepsy and impairing motor coordination, as well as the anxiolytic-like effects in the four-plate and marble burying tests in mice. Finally, we investigated the antipsychotic-like properties of JJGW08 in rats using MK-801-induced hyperlocomotion and prepulse inhibition tests. We found that JJGW08 showed antagonistic properties at dopamine D2 and serotonin 5-HT1A, 5-HT2A, and 5-HT7 receptors. However, the effect on the 5-HT2A and 5-HT7 receptors was very weak. Moreover, the tested compound showed an antipsychotic-like effect in MK-801- and amphetamine-induced hyperlocomotion but not in a prepulse inhibition test in rats. Notably, JJGW08 demonstrated anxiolytic-like properties in both behavioral tests. Importantly, the compound did not induce catalepsy or motor coordination impairment in mice at antipsychotic-like doses. Our study suggests it is worth searching for new potential antipsychotics among arylpiperazine alkyl derivatives of salicylamide. 相似文献
947.
Paola Zanetta Diletta Francesca Squarzanti Alessia di Coste Roberta Rolla Paolo Aluffi Valletti Massimiliano Garzaro Valeria DellEra Angela Amoruso Marco Pane Barbara Azzimonti 《International journal of molecular sciences》2022,23(24)
The human oral pathobionts Aggregatibacter actinomycetemcomitans, Streptococcus mitis and Streptococcus mutans, in dysbiosis-promoting conditions, lead to oral infections, which also represent a threat to human systemic health. This scenario may be worsened by antibiotic misuse, which favours multi-drug resistance, making the research on pathogen containment strategies more than crucial. Therefore, we aimed to in vitro select the most promising probiotic strains against oral pathogen growth, viability, biofilm formation, and co-aggregation capacity, employing both the viable probiotics and their cell-free supernatants (CFSs). Interestingly, we also assessed probiotic efficacy against the three-pathogen co-culture, mimicking an environment similar to that in vivo. Overall, the results showed that Lactobacillus CFSs performed better than the Bifidobacterium, highlighting Limosilactobacillus reuteri LRE11, Lacticaseibacillus rhamnosus LR04, Lacticaseibacillus casei LC04, and Limosilactobacillus fermentum LF26 as the most effective strains, opening the chance to deeper investigation of their action and CFS composition. Altogether, the methodologies presented in this study can be used for probiotic efficacy screenings, in order to better focus the research on a viable probiotic, or on its postbiotics, suitable in case of infections. 相似文献
948.
Arthur E. Currier 《Journal of the American Ceramic Society》1943,26(2):67-71
A study of six brands of silicate of soda used in a typical ceramic casting slip discloses the effect of the Na2O to SiO2 ratio on hydrometer readings, pH, viscosity, casting rate, water retention, drying shrinkage, dry strength, firing shrinkage, fired strength, and fired absorption. The effect of varying the amount of electrolyte both above and below that required for complete deflocculation is also reported. 相似文献
949.
Arthur E. Currier 《Journal of the American Ceramic Society》1947,30(11):335-338
A procedure is developed for determining leachable lead in lead frits. The procedure is sufficiently simple for use by control laboratories whereby duplicate results can be obtained. It is based on leaching the lead at 40°± 0.5°C. from frit (-180, +200-mesh particles) with 0.137 N HCl and precipitating the lead as PbCrO4. 相似文献
950.
Clean Technologies and Environmental Policy - The article discusses the impact of the lithotype of lignite on the suitability for gasification in CO2 atmosphere. The research was aimed at... 相似文献