全文获取类型
收费全文 | 1101篇 |
免费 | 70篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 436篇 |
金属工艺 | 6篇 |
机械仪表 | 25篇 |
建筑科学 | 37篇 |
矿业工程 | 1篇 |
能源动力 | 38篇 |
轻工业 | 291篇 |
水利工程 | 3篇 |
石油天然气 | 4篇 |
无线电 | 46篇 |
一般工业技术 | 168篇 |
冶金工业 | 15篇 |
原子能技术 | 2篇 |
自动化技术 | 95篇 |
出版年
2024年 | 3篇 |
2023年 | 12篇 |
2022年 | 89篇 |
2021年 | 98篇 |
2020年 | 33篇 |
2019年 | 35篇 |
2018年 | 38篇 |
2017年 | 39篇 |
2016年 | 43篇 |
2015年 | 40篇 |
2014年 | 51篇 |
2013年 | 72篇 |
2012年 | 70篇 |
2011年 | 76篇 |
2010年 | 78篇 |
2009年 | 62篇 |
2008年 | 55篇 |
2007年 | 44篇 |
2006年 | 38篇 |
2005年 | 27篇 |
2004年 | 23篇 |
2003年 | 22篇 |
2002年 | 28篇 |
2001年 | 11篇 |
2000年 | 5篇 |
1999年 | 9篇 |
1998年 | 16篇 |
1997年 | 7篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1961年 | 1篇 |
排序方式: 共有1171条查询结果,搜索用时 15 毫秒
991.
Blendi Ura Fulvio Celsi Luisa Zupin Giorgio Arrigoni Ilaria Battisti Bartolomea Gaita Domenico Leonardo Grasso Eva Orzan Raffaella Sagredini Egidio Barbi Sergio Crovella 《International journal of molecular sciences》2020,21(23)
Recurrent acute otitis media (RAOM) in children is clinically defined as the occurrence of at least three episodes of acute otitis media over a course of 6 months. A further common pathological condition of interest in the context of pediatric otolaryngology is adenotonsillar hypertrophy (ATH), a common cause of obstructive sleep apnea syndrome. Aimed at unraveling the differential modulation of proteins in the two pathologies and at understanding the possible pathways involved in their onset, we analyzed the proteomic profile of the adenoids from 14 RAOM and ATH patients by using two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). The 2-DE coupled with MS allowed us to identify 23 spots with significant (p-value < 0.05) changes in protein amount, recognizing proteins involved in neutrophil degranulation and glycolysis pathways. 相似文献
992.
Francesca Marini Francesca Giusti Francesco Tonelli Maria Luisa Brandi 《International journal of molecular sciences》2021,22(8)
Pancreatic neuroendocrine tumors (pNETs) are a rare group of cancers accounting for about 1–2% of all pancreatic neoplasms. About 10% of pNETs arise within endocrine tumor syndromes, such as Multiple Endocrine Neoplasia type 1 (MEN1). pNETs affect 30–80% of MEN1 patients, manifesting prevalently as multiple microadenomas. pNETs in patients with MEN1 are particularly difficult to treat due to differences in their growth potential, their multiplicity, the frequent requirement of extensive surgery, the high rate of post-operative recurrences, and the concomitant development of other tumors. MEN1 syndrome is caused by germinal heterozygote inactivating mutation of the MEN1 gene, encoding the menin tumor suppressor protein. MEN1-related pNETs develop following the complete loss of function of wild-type menin. Menin is a key regulator of endocrine cell plasticity and its loss in these cells is sufficient for tumor initiation. Somatic biallelic loss of wild-type menin in the neuroendocrine pancreas presumably alters the epigenetic control of gene expression, mediated by histone modifications and DNA hypermethylation, as a driver of MEN1-associated pNET tumorigenesis. In this light, epigenetic-based therapies aimed to correct the altered DNA methylation, and/or histone modifications might be a possible therapeutic strategy for MEN1 pNETs, for whom standard treatments fail. 相似文献
993.
Jos María Bastida Jos Ramn Gonzalez-Porras Jos Rivera María Luisa Lozano 《International journal of molecular sciences》2021,22(9)
In the last decade, improvements in genetic testing have revolutionized the molecular diagnosis of inherited thrombocytopenias (ITs), increasing the spectrum of knowledge of these rare, complex and heterogeneous disorders. In contrast, the therapeutic management of ITs has not evolved in the same way. Platelet transfusions have been the gold standard treatment for a long time. Thrombopoietin receptor agonists (TPO-RA) were approved for immune thrombocytopenia (ITP) ten years ago and there is evidence for the use of TPO-RA not only in other forms of ITP, but also in ITs. We have reviewed in the literature the existing evidence on the role of TPO-RAs in ITs from 2010 to February 2021. A total of 24 articles have been included, 4 clinical trials, 3 case series and 17 case reports. A total of 126 patients with ITs have received TPO-RA. The main diagnoses were Wiskott–Aldrich syndrome, MYH9-related disorder and ANKRD26-related thrombocytopenia. Most patients were enrolled in clinical trials and were treated for short periods of time with TPO-RA as bridging therapies towards surgical interventions, or other specific approaches, such as hematopoietic stem cell transplantation. Here, we have carried out an updated and comprehensive review about the efficacy and safety of TPO-RA in ITs. 相似文献
994.
Vernica Palma-Barqueros Nuria Revilla Ana Snchez Ana Zamora Cnovas Agustín Rodriguez-Aln Ana Marín-Quílez Jos Ramn Gonzlez-Porras Vicente Vicente María Luisa Lozano Jos María Bastida Jos Rivera 《International journal of molecular sciences》2021,22(9)
Platelets play a major role in hemostasis as ppwell as in many other physiological and pathological processes. Accordingly, production of about 1011 platelet per day as well as appropriate survival and functions are life essential events. Inherited platelet disorders (IPDs), affecting either platelet count or platelet functions, comprise a heterogenous group of about sixty rare diseases caused by molecular anomalies in many culprit genes. Their clinical relevance is highly variable according to the specific disease and even within the same type, ranging from almost negligible to life-threatening. Mucocutaneous bleeding diathesis (epistaxis, gum bleeding, purpura, menorrhagia), but also multisystemic disorders and/or malignancy comprise the clinical spectrum of IPDs. The early and accurate diagnosis of IPDs and a close patient medical follow-up is of great importance. A genotype–phenotype relationship in many IPDs makes a molecular diagnosis especially relevant to proper clinical management. Genetic diagnosis of IPDs has been greatly facilitated by the introduction of high throughput sequencing (HTS) techniques into mainstream investigation practice in these diseases. However, there are still unsolved ethical concerns on general genetic investigations. Patients should be informed and comprehend the potential implications of their genetic analysis. Unlike the progress in diagnosis, there have been no major advances in the clinical management of IPDs. Educational and preventive measures, few hemostatic drugs, platelet transfusions, thrombopoietin receptor agonists, and in life-threatening IPDs, allogeneic hematopoietic stem cell transplantation are therapeutic possibilities. Gene therapy may be a future option. Regular follow-up by a specialized hematology service with multidisciplinary support especially for syndromic IPDs is mandatory. 相似文献
995.
Luisa Chocarro Ester Blanco Miren Zuazo Hugo Arasanz Ana Bocanegra Leticia Fernndez-Rubio Pilar Morente Gonzalo Fernndez-Hinojal Miriam Echaide Maider Garnica Pablo Ramos Ruth Vera Grazyna Kochan David Escors 《International journal of molecular sciences》2021,22(10)
Lymphocyte activation gene 3 (LAG-3) is a cell surface inhibitory receptor with multiple biological activities over T cell activation and effector functions. LAG-3 plays a regulatory role in immunity and emerged some time ago as an inhibitory immune checkpoint molecule comparable to PD-1 and CTLA-4 and a potential target for enhancing anti-cancer immune responses. LAG-3 is the third inhibitory receptor to be exploited in human anti-cancer immunotherapies, and it is considered a potential next-generation cancer immunotherapy target in human therapy, right next to PD-1 and CTLA-4. Unlike PD-1 and CTLA-4, the exact mechanisms of action of LAG-3 and its relationship with other immune checkpoint molecules remain poorly understood. This is partly caused by the presence of non-conventional signaling motifs in its intracellular domain that are different from other conventional immunoregulatory signaling motifs but with similar inhibitory activities. Here we summarize the current understanding of LAG-3 signaling and its role in LAG-3 functions, from its mechanisms of action to clinical applications. 相似文献
996.
Screening for Effects of Phytochemical Variability on Cytoplasmic Protein Synthesis Pattern of Crop Plants 总被引:1,自引:0,他引:1
Crop plants have to cope with phytochemical variability along with other environmental stresses. Allelochemicals affect several cellular processes. We tested the effect of toxic aqueous leachates from Sicyos deppei, Acacia sedillense, Sebastiania adenophora, and Lantana camara on the radicle growth and cytoplasmic protein synthesis patterns of Zea mays (maize), Phaseolus vulgaris (bean), Cucurbita pepo (squash), and Lycopersicon esculentum (tomato). 2D-PAGE and gel scan densitometry analysis were used to detect differences in cytoplasmic root protein pattern expression. High-, medium-, and low-molecular-weight cytoplasmic proteins were affected by the different aqueous leachates. Crop plant responses were diverse, but in general, an increase in protein synthesis was observed in the treated roots. Maize was the least affected, but both the radicle growth and also the protein pattern of tomato were severely inhibited by all allelopathic plants. The changes observed in protein expression may indicate a biochemical alteration at the cellular level of the tested crop plants. 相似文献
997.
Luisa Barbieri Anna Corradi Isabella Lancellotti Antonio Pedro Novaes De Oliveira Orestes Estevam Alarcon 《Journal of the American Ceramic Society》2002,85(3):670-674
The nucleation and growth of diopside Ca(Mg,Al)(Si,Al)2 O6 crystals on the free surface of a 24 wt% MgO, 14 wt% CaO, 9 wt% Al2 O3 , and 53 wt% SiO2 glass, with a 2 wt% addition of steel fly ash, were investigated through DTA, XRD, SEM, and optical microscopy. Crystallization was complete at ∼920°C with an activation energy of 589 kJ/mol. Samples with polished free surfaces were nucleated at selected temperatures in the range of 730° to 820°C, and then heat-treated at 870°C for 15 min for crystal growth. Nucleation was predominantly observed at the surface, and the number of diopside crystals per unit of area and the mechanism of crystallization were determined. It was concluded that nucleation reaches a maximum at 750°C, corresponding to an average density of diopside crystals of 8.4 × 106 nuclei/cm2 , and that between 900° and 1100°C, a uniformly crystallized layer is formed at an exponential rate. The crystallized volume fraction increased significantly in the 880°–890°C growth range, and remained almost constant at higher temperatures. In the 860°–910°C range, the size of the diopside crystals formed in the samples nucleated at the temperature of the maximum nucleation rate, and linearly increased, reaching values between 1.0 and 3.0 μm at 870° and at 910°C, respectively. 相似文献
998.
A covalent organic/inorganic hybrid proton exchange polymeric membrane: synthesis and characterization 总被引:1,自引:0,他引:1
Commercial polyetheretherketone (Victrex PEEK) was sulfonated up to 90% degree of sulfonation (DS), then reacted with SiCl4 to obtain a hybrid polymer. The product was characterized by 29Si NMR and ATR/FTIR spectroscopies demonstrating the formation of covalent bonds between the organic and inorganic components. No dispersed inorganic silicon was present in the product as evidenced by the lack of any resonance at δ<−100 ppm. Despite the high DS the physicochemical properties of the hybrid were suitable for the preparation of membranes exhibiting high and stable conductivity values (10−2 S/cm), hence suitable for application as ion exchange membrane. 相似文献
999.
Different synthetic pathways leading to polythiophenes (PTs) containing units derived from methyl N-(tert-butoxycarbonyl)-S-3-thienyl-l-cysteinate (1) and methyl N-(tert-butoxycarbonyl)-S-(2-thien-3-ylethyl)-l-cysteinate (2) were investigated. The oxidative coupling with FeCl3 applied to N-deprotected monomer 1 generates a chemically fleeting PT, whereas when applied to N-deprotected monomer 2 generates a mixture of oligomers. Two co-polymers bearing cysteine moieties, poly{[methyl N-(tert-butoxycarbonyl)-S-3-thienyl-l-cysteinate]-co-thiophene} (co-PT1) and poly{[methyl N-(tert-butoxycarbonyl)-S-(2-thien-3-ylethyl)-l-cysteinate]-co-thiophene} (co-PT2), were eventually synthesized through Stille coupling of 2,5-bis(trimethylstannyl)thiophene and 2,5-dibromo derivative of compound 1 and through the post-functionalization with protected cysteine of a tosylate co-polymer, poly{[2-(3-thienyl)ethyl 4-methylbenzenesulfonate]-co-thiophene} (co-PTTs). UV-vis, CD, NMR and GPC analyses evidenced that these polymers are able to form chiral self-assembling structures, due to the formation of a hydrogen bond network and to π-stacks, not only in the solid state but also in solution. 相似文献
1000.
Sonia Calligaris Gianmichele Arrighetti Luisa Barba Maria Cristina Nicoli 《Journal of the American Oil Chemists' Society》2008,85(7):591-598
The influence of the oxidation level on the phase transition behavior of sunflower oil was evaluated by differential scanning calorimetry (DSC) and synchrotron X-ray diffraction (XRD) at both small and wide angles. The crystallization was monitored at a cooling/heating rate of 2 °C/min from 20 to ?80 °C and vice versa applying both techniques. The triacylglycerols organize in two double-chain length structures: α 2L (61.87 Å) and β′ 2L (82.89 Å). The crystalline structure changes upon oxidation. In particular, the intensity of the XRD peak associated with the double-chain structure of β′, as well as its crystallization and melting enthalpy, significantly decreases as the oxidation level increases. 相似文献