全文获取类型
收费全文 | 599篇 |
免费 | 38篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 318篇 |
金属工艺 | 4篇 |
机械仪表 | 11篇 |
建筑科学 | 23篇 |
矿业工程 | 1篇 |
能源动力 | 15篇 |
轻工业 | 84篇 |
水利工程 | 6篇 |
无线电 | 20篇 |
一般工业技术 | 92篇 |
冶金工业 | 9篇 |
原子能技术 | 4篇 |
自动化技术 | 47篇 |
出版年
2024年 | 4篇 |
2023年 | 25篇 |
2022年 | 118篇 |
2021年 | 107篇 |
2020年 | 32篇 |
2019年 | 25篇 |
2018年 | 32篇 |
2017年 | 22篇 |
2016年 | 25篇 |
2015年 | 21篇 |
2014年 | 24篇 |
2013年 | 35篇 |
2012年 | 20篇 |
2011年 | 34篇 |
2010年 | 17篇 |
2009年 | 21篇 |
2008年 | 15篇 |
2007年 | 8篇 |
2006年 | 13篇 |
2005年 | 7篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有637条查询结果,搜索用时 0 毫秒
61.
Anna Campanati Emanuela Martina Federico Diotallevi Giulia Radi Andrea Marani Davide Sartini Monica Emanuelli George Kontochristopoulos Dimitris Rigopoulos Stamatis Gregoriou Annamaria Offidani 《International journal of molecular sciences》2021,22(13)
Saliva is easy to access, non-invasive and a useful source of information useful for the diagnosis of serval inflammatory and immune-mediated diseases. Following the advent of genomic technologies and -omic research, studies based on saliva testing have rapidly increased and human salivary proteome has been partially characterized. As a proteomic protocol to analyze the whole saliva proteome is not currently available, the most common aim of the proteomic analysis is to discriminate between physiological and pathological conditions. The salivary proteome has been initially investigated in several diseases: oral squamous cell carcinoma and oral leukoplakia, chronic graft-versus-host disease, and Sjögren’s syndrome. Otherwise, salivary proteomics studies in the dermatological field are still in the initial phase, thus the aim of this review is to collect the best research evidence on the role of saliva proteomics analysis in immune-mediated skin diseases to understand the direction of research in this field. The results of PRISMA analysis reported herein suggest that human saliva analysis could provide significant data for the diagnosis and prognosis of several immune-mediated and inflammatory skin diseases in the next future. 相似文献
62.
Antonella Virgilio Daniela Benigno Annalisa Pecoraro Annapina Russo Giulia Russo Veronica Esposito Aldo Galeone 《International journal of molecular sciences》2021,22(13)
In this paper, we report our investigations on five analogues, prepared by replacing sequence thymidines with abasic sites (S) one at a time, in comparison to their natural counterpart in order to evaluate their antiproliferative potential and the involvement of the residues not belonging to the central core of stacked guanosines in biological activity. The collected NMR (Nuclear Magnetic Resonance), CD (Circular Dichroism), and PAGE (Polyacrylamide Gel Electrophoresis) data strongly suggest that all of them adopt G-quadruplex (G4) structures strictly similar to that of the parent aptamer with the ability to fold into a dimeric structure composed of two identical G-quadruplexes, each characterized by parallel strands, three all-anti-G-tetrads and four one-thymidine loops (one bulge and three propeller loops). Furthermore, their antiproliferative (MTT assay) and anti-motility (wound healing assay) properties against lung and colorectal cancer cells were tested. Although all of the oligodeoxynucleotides (ODNs) investigated here exhibited anti-proliferative activity, the unmodified T30175 aptamer showed the greatest effect on cell growth, suggesting that both its characteristic folding in dimeric form and its presence in the sequence of all thymidines are crucial elements for antiproliferative activity. This straightforward approach is suitable for understanding the critical requirements of the G-quadruplex structures that affect antiproliferative potential and suggests its application as a starting point to facilitate the reasonable development of G-quadruplexes with improved anticancer properties. T30175相似文献
63.
Giulia Della Pelle Andrea Delgado Lpez Marina Salord Fiol Nina Kostevek 《International journal of molecular sciences》2021,22(13)
Cyanine fluorescent dyes are attractive diagnostic or therapeutic agents due to their excellent optical properties. However, in free form, their use in biological applications is limited due to the short circulation time, instability, and toxicity. Therefore, their encapsulation into nano-carriers might help overcome the above-mentioned issues. In addition to indocyanine green (ICG), which is clinically approved and therefore the most widely used fluorescent dye, we tested the structurally similar and cheaper alternative called IR-820. Both dyes were encapsulated into liposomes. However, due to the synthetic origin of liposomes, they can induce an immunogenic response. To address this challenge, we proposed to use erythrocyte membrane vesicles (EMVs) as “new era” nano-carriers for cyanine dyes. The optical properties of both dyes were investigated in different biological relevant media. Then, the temperature stability and photo-stability of dyes in free form and encapsulated into liposomes and EMVs were evaluated. Nano-carriers efficiently protected dyes from thermal degradation, as well as from photo-induced degradation. Finally, a hemotoxicity study revealed that EMVs seem less hemotoxic dye carriers than clinically approved liposomes. Herein, we showed that EMVs exhibit great potential as nano-carriers for dyes with improved stability and hemocompatibility without losing excellent optical properties. 相似文献
64.
Benedetta Angeloni Rachele Bigi Gianmarco Bellucci Rosella Mechelli Chiara Ballerini Carmela Romano Emanuele Morena Giulia Pellicciari Roberta Reni Virginia Rinaldi Maria Chiara Buscarinu Silvia Romano Giovanni Ristori Marco Salvetti 《International journal of molecular sciences》2021,22(7)
Multiple sclerosis is a complex, multifactorial, dysimmune disease prevalent in women. Its etiopathogenesis is extremely intricate, since each risk factor behaves as a variable that is interconnected with others. In order to understand these interactions, sex must be considered as a determining element, either in a protective or pathological sense, and not as one of many variables. In particular, sex seems to highly influence immune response at chromosomal, epigenetic, and hormonal levels. Environmental and genetic risk factors cannot be considered without sex, since sex-based immunological differences deeply affect disease onset, course, and prognosis. Understanding the mechanisms underlying sex-based differences is necessary in order to develop a more effective and personalized therapeutic approach. 相似文献
65.
Marcello Candelli Laura Franza Giulia Pignataro Veronica Ojetti Marcello Covino Andrea Piccioni Antonio Gasbarrini Francesco Franceschi 《International journal of molecular sciences》2021,22(12)
Lipopolysaccharides (LPSs) are bacterial surface glycolipids, produced by Gram-negative bacteria. LPS is known to determine acute inflammatory reactions, particularly in the context of sepsis. However, LPS can also trigger chronic inflammation. In this case, the source of LPS is not an external infection, but rather an increase in endogenous production, which is usually sustained by gut microbiota (GM), and LPS contained in food. The first site in which LPS can exert its inflammatory action is the gut: both GM and gut-associated lymphoid tissue (GALT) are influenced by LPS and shift towards an inflammatory pattern. The changes in GM and GALT induced by LPS are quite similar to the ones seen in IBD: GM loses diversity, while GALT T regulatory (Tregs) lymphocytes are reduced in number, with an increase in Th17 and Th1 lymphocytes. Additionally, the innate immune system is triggered, through the activation of toll-like receptor (TLR)-4, while the epithelium is directly damaged, further triggering inflammation. In this review, we will discuss the importance of the crosstalk between LPS, GM, and GALT, and discuss the possible implications. 相似文献
66.
Ownership, Investment Policies and Funding Choices of Italian Water Utilities: An Empirical Analysis
Nowadays, the efficient management of water has become the focus of vast debate, both in the academic literature and in the practical and regulatory field. Due to the growing importance and scarcity of water resources, it has become crucial to better understand how to improve the organizational efficiency of water utilities. By adopting an accounting perspective and using statistical methods, this paper analyzes whether and to what extent investment and financial strategies differ among clusters of water utilities with different ownership structures. The paper focuses on the Italian water industry, a context considered particularly appropriate due to the coexistence of utilities with different ownership structures. The main results of the paper show that ownership affects the level of investment as well as the financial structure and costs of water utilities. The evidence provided by this study should encourage national governments and regulatory authorities to select water utilities with the greatest investment potential measured in terms of financial efficiency and effectiveness. 相似文献
67.
Giulia Bernardini Maurizio Comanducci Stefania Bambini Giovanni Renzone Andrea Scaloni Giovanna Morelli Mark Achtman Giulio Ratti Annalisa Santucci 《Proteomics. Clinical applications》2009,3(10):1251-1254
We previously described the first reference map for the proteome of one strain of serogroup A Neisseria meningitidis (MenA), a major cause of epidemic meningitis in humans. As a preliminary finding, in that work we noted that 2‐DE protein maps of closely related MenA isolates from different epidemics spreads could be easily compared to detect minor differences and that 2‐DE phenotypes attributable to the well‐known epidemiological marker tbpB agreed with the genoclouds model of MenA epidemiological variation during pandemic waves. We explored here the possibility that an extended comparative study of 2‐DE maps of isolates representative of the nine genoclouds described by Achtman and collaborators could be used to discriminate between strains otherwise undistinguishable. We showed the example of 14 proteins with different 2‐DE spot patterns in different genoclouds that could be considered as putative tracers for alike‐strains discrimination. We introduce the novel concept that comparative proteomics can be useful in identifying new epidemiological markers for N. meningitidis. 相似文献
68.
Sinico Michele; Parovel Giulia; Casco Clara; Anstis Stuart 《Canadian Metallurgical Quarterly》2009,35(4):948
We show that human observers strongly underestimate a linear or circular trajectory that a luminous spot follows in the dark. At slow speeds, observers are relatively accurate, but, as the speed increases, the size of the path is progressively underestimated, by up to 35%. The underestimation imposes little memory load and does not require tracking of the trajectory. Most importantly, we found that underestimation occurred only when successive motion vectors changed in direction. This suggests a perceptual rather than representational origin of the illusion, related to vector-sum integration over time of neural motion signals in different directions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
Simone Belluco Giulia Simonato Mario Pietrobelli Antonia Ricci 《Critical reviews in food science and nutrition》2018,58(18):3085-3096
ABSTRACTBackground: Toxoplasmosis is a zoonotic disease causing severe symptoms in pregnant women and immunocompromised individuals. On average, worldwide, around 30% of people are seropositive. The oral transmission route is of great significance and food, particularly meat, is an important transmission vehicle for T. gondii. However, the role of different food matrices is debated. Objectives: The aim of this review was to assess the risk of humans developing acute T. gondii infection via the foodborne route. Study eligibility criteria: Case-control studies including acute cases of T. gondii infection were included after literature searches, without time limits, in several databases. All studies estimating the risk of acquiring T. gondii infection after consumption of specific food categories were included. Results: Three risk factors proved to be significantly associated with acute T. gondii infection in humans: consumption of raw/undercooked meat, Odds Ratio (OR) 3.44 (1.29–9.16), consumption of raw/undercooked beef, OR 2.22 (1.57–3.12), and consumption of raw/undercooked sheep meat, OR 3.85 (1.85–8.00). Consumption of raw/undercooked pork, raw eggs, and unpasteurized milk proved to be non-significant risk factors. Limitations: Limitations in the present review and meta-analysis are due to the low number of case-control studies available for analysis and the lack of a search strategy targeting gray literature. Conclusion: Consumption of raw/undercooked beef and sheep meat are important risk factors for T. gondii infection. Their consumption should be avoided in order to prevent toxoplasmosis, particularly by those in at-risk categories, including pregnant women. The review protocol is registered in PROSPERO database (CRD42016043295). 相似文献
70.
De Petris G 《Accounts of chemical research》2002,35(5):305-312
Recent mass spectrometric studies of species and processes relevant to the chemistry of atmospheres are reported. New species have been detected, including HO(3); a stratospheric reservoir of OH radicals; the [H(2)O(+)O(2)(-)] charge transfer complex, central to the atmospheric photonucleation theory; and the OSOSO oxide and its cation, likely present in the Io's atmosphere. As to ionic processes, a new route to tropospheric N(2)O in air ionized by lightning and coronas is reported, as well as the complex chemistry promoted by ionization of ozone/freon and ozone/carbonyl sulfide mixtures and the formation of O(5)(+), relevant to the problem of (18)O excess in stratospheric ozone. 相似文献