首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   16篇
  免费   0篇
工业技术   16篇
  2022年   1篇
  2021年   2篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2012年   2篇
  2011年   1篇
  2009年   1篇
  2002年   1篇
  2001年   1篇
  1998年   2篇
  1997年   1篇
  1994年   1篇
排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
Tumor progression is a key aspect in oncology. Not even the overexpression of a powerful oncogenic stimulus such as platelet derived growth factor-B (PDGF-B) is sufficient per se to confer full malignancy to cells. In previous studies we showed that neural progenitors overexpressing PDGF-B need to undergo progression to acquire the capability to give rise to secondary tumor following transplant. By comparing the expression profile of PDGF-expressing cells before and after progression, we found that progressed tumors consistently downregulate the expression of the antiproliferative gene Btg2. We therefore tested whether the downregulation of Btg2 is sufficient and necessary for glioma progression with loss and gain of function experiments. Our results show that downregulation of Btg2 is not sufficient but is necessary for tumor progression since the re-introduction of Btg2 in fully progressed tumors dramatically impairs their gliomagenic potential. These results suggest an important role of Btg2 in glioma progression. Accordingly with this view, the analysis of public datasets of human gliomas showed that reduced level of Btg2 expression correlates with a significantly worse prognosis.  相似文献   
2.
3.
The miniaturization of energy storage units is pivotal for the development of next‐generation portable electronic devices. Micro‐supercapacitors (MSCs) hold great potential to work as on‐chip micro‐power sources and energy storage units complementing batteries and energy harvester systems. Scalable production of supercapacitor materials with cost‐effective and high‐throughput processing methods is crucial for the widespread application of MSCs. Here, wet‐jet milling exfoliation of graphite is reported to scale up the production of graphene as a supercapacitor material. The formulation of aqueous/alcohol‐based graphene inks allows metal‐free, flexible MSCs to be screen‐printed. These MSCs exhibit areal capacitance (Careal) values up to 1.324 mF cm?2 (5.296 mF cm?2 for a single electrode), corresponding to an outstanding volumetric capacitance (Cvol) of 0.490 F cm?3 (1.961 F cm?3 for a single electrode). The screen‐printed MSCs can operate up to a power density above 20 mW cm?2 at an energy density of 0.064 µWh cm?2. The devices exhibit excellent cycling stability over charge–discharge cycling (10 000 cycles), bending cycling (100 cycles at a bending radius of 1 cm) and folding (up to angles of 180°). Moreover, ethylene vinyl acetate‐encapsulated MSCs retain their electrochemical properties after a home‐laundry cycle, providing waterproof and washable properties for prospective application in wearable electronics.  相似文献   
4.
We carried out a pilot nonrandomized phase II study to compare the neo-adjuvant chemotherapic regimen with cisplatin, 5-FU and vinorelbine with the same combination plus s.c. IL 2 in advanced head and neck squamous cell carcinoma (HNSCC). The primary goals of the trial were to evaluate the feasibility and response rates of the two regimens. The study design consisted of a patient's assignment to either of the two following arms: Arm A: Cisplatin 80 mg/m2 i.v. on day 1; 5-FU 600 mg/m2 i.v. on days 2-5; and vinorelbine 20 mg/m2 i.v. on days 2 and 8, Arm B: the same chemotherapic regimen plus recombinant IL 2 (Proleukin, Eurocetus) 9 MIU s.c. daily from day 9 to 13 and from day 16 to 20 for every cycle. From March 1993 to November 1993 twenty three patients with Stage III-IV HNSCC were enrolled in the study. Patients could be evaluated for response to treatment if they had received at least 2 complete cycles of therapy. The overall response rate (ORR) was 63% in Arm A and 100% in Arm B. The differences for ORR and CR rates were statistically significant in favor of Arm B. The analysis for each of the three drugs included in the chemotherapy schedule shows that both the actually received average dose-intensity and the actually delivered average cumulative doses/patient were higher for Arm B (chemo-plus IL 2 therapy) (approximately 80% of programmed dose-intensity) than for Arm A (approximately 70% of programmed dose-intensity). Both the actually received average dose-intensity and the actually delivered average cumulative doses/patient for IL 2 were more than 80%. In both arms the most frequent side effects were myelosuppression, phlebitis and electrolyte disturbances. There were 2 toxic deaths, 1 in Arm A and 1 in Arm B, both for hematologic toxicity. Our "pilot" study suggests that the combination of cisplatin, 5-FU, vinorelbine plus IL 2 is a highly active, but rather toxic, neo-adjuvant treatment in advanced HNSCC with very high ORR and CR rates.  相似文献   
5.
David A. Gates  David Anderson  S. Anderson  M. Zarnstorff  Donald A. Spong  Harold Weitzner  G. H. Neilson  D. Ruzic  D. Andruczyk  J. H. Harris  H. Mynick  C. C. Hegna  O. Schmitz  J. N. Talmadge  D. Curreli  D. Maurer  A. H. Boozer  S. Knowlton  J. P. Allain  D. Ennis  G. Wurden  A. Reiman  J. D. Lore  Matt Landreman  J. P. Freidberg  S. R. Hudson  M. Porkolab  D. Demers  J. Terry  E. Edlund  S. A. Lazerson  N. Pablant  R. Fonck  F. Volpe  J. Canik  R. Granetz  A. Ware  J. D. Hanson  S. Kumar  C. Deng  K. Likin  A. Cerfon  A. Ram  A. Hassam  S. Prager  C. Paz-Soldan  M. J. Pueschel  I. Joseph  A. H. Glasser 《Journal of Fusion Energy》2018,37(1):51-94
This document is the product of a stellarator community workshop, organized by the National Stellarator Coordinating Committee and referred to as Stellcon, that was held in Cambridge, Massachusetts in February 2016, hosted by MIT. The workshop was widely advertised, and was attended by 40 scientists from 12 different institutions including national labs, universities and private industry, as well as a representative from the Department of Energy. The final section of this document describes areas of community wide consensus that were developed as a result of the discussions held at that workshop. Areas where further study would be helpful to generate a consensus path forward for the US stellarator program are also discussed. The program outlined in this document is directly responsive to many of the strategic priorities of FES as articulated in “Fusion Energy Sciences: A Ten-Year Perspective (2015–2025)” [1]. The natural disruption immunity of the stellarator directly addresses “Elimination of transient events that can be deleterious to toroidal fusion plasma confinement devices” an area of critical importance for the US fusion energy sciences enterprise over the next decade. Another critical area of research “Strengthening our partnerships with international research facilities,” is being significantly advanced on the W7-X stellarator in Germany and serves as a test-bed for development of successful international collaboration on ITER. This report also outlines how materials science as it relates to plasma and fusion sciences, another critical research area, can be carried out effectively in a stellarator. Additionally, significant advances along two of the Research Directions outlined in the report; “Burning Plasma Science: Foundations—Next-generation research capabilities”, and “Burning Plasma Science: Long pulse—Sustainment of Long-Pulse Plasma Equilibria” are proposed.  相似文献   
6.
Layered semiconductors of the IIIA–VIA group have attracted considerable attention in (opto)electronic applications thanks to their atomically thin structures and their thickness‐dependent optical and electronic properties, which promise ultrafast response and high sensitivity. In particular, 2D indium selenide (InSe) has emerged as a promising candidate for the realization of thin‐film field effect transistors and phototransistors due to its high intrinsic mobility (>102 cm2 V?1 s?1) and the direct optical transitions in an energy range suitable for visible and near‐infrared light detection. A key requirement for the exploitation of large‐scale (opto)electronic applications relies on the development of low‐cost and industrially relevant 2D material production processes, such as liquid phase exfoliation, combined with the availability of high‐throughput device fabrication methods. Here, a β polymorph of indium selenide (β‐InSe) is exfoliated in isopropanol and spray‐coated InSe‐based photodetectors are demonstrated, exhibiting high responsivity to visible light (maximum value of 274 A W?1 under blue excitation 455 nm) and fast response time (15 ms). The devices show a gate‐dependent conduction with an n‐channel transistor behavior. Overall, this study establishes that liquid phase exfoliated β‐InSe is a valid candidate for printed high‐performance photodetectors, which is critical for the development of industrial‐scale 2D material‐based optoelectronic devices.  相似文献   
7.
The development of new target ion source systems for the selective production of exotic species (SPES) facility is currently in progress at Legnaro National Laboratories. In this context, the study of ion sources and their performance in terms of ionization efficiency and transversal emittance is a crucial point in order to maximize the available yields, particularly for short-lived isotopes. In this work, preliminary off-line ionization efficiency and emittance measurements for the SPES surface and plasma ion sources are presented. The plasma source emittance measurements are supported by dedicated numerical calculations.  相似文献   
8.
The high arsenic content of the flotation concentrate obtained from a gold-bearing enargite ore for pyrometallurgical processing strongly diminishes its market value. An investigation has been carried out for selectively leaching arsenic from enargite–luzonite minerals using alkaline Na2S solutions. By suitably adjusting the main reaction conditions almost 98% arsenic was leached, as well as part of the gold, particularly with high Na2S concentrations. Copper was not lost from the solid phase in which the enargite is converted into a new species with the chemical formula Cu1.5S.  相似文献   
9.
Selective electrochemically activated biofunctionalization of In(2)O(3) nanowires (NWs) has been achieved, using monolayer coatings of p-dimethoxybenzene derivatives. Monolayer coatings of 4-(2,5-dimethoxyphenyl)butyl-phosphonic acid (DMP-PA) were deposited on planar indium-tin oxide (ITO) electrodes and In(2)O(3) NWs. The electrochemical behavior of the monolayer coating was first studied using ITO electrodes, as a model system for In(2)O(3) nanowires. When a potential of 950 mV vs a Ag/AgCl reference electrode is applied to an ITO electrode coated with DMP-PA in PBS buffer, the p-dimethoxyphenyl groups are converted to p-benzoquinone (BQ). The electrochemically formed benzoquinone groups react readily with alkyl thiol groups via a Michael addition. The reaction strategy optimized on ITO was applied to an In(2)O(3) NW mat sample coated with DMP-PA. Applying a potential of 950 mV to metal electrodes deposited on NWs converts the DMP-PA NW coating to BQ-PA, which reacts with a thiol-terminated 20-base oligonucleotide. These NWs showed strong fluorescence response after paring with the dye labeled compliment, demonstrating that the probe was bound to the NW surface and that it remained active toward hybridization with its compliment. The unactivated DMP-PA coated NWs showed no response, demonstrating the selective electrochemical functionalization of NWs and the potential of using them in multiplex sensing. We also compared the p-dimethoxybenzene derivative to the conventional hydroquinone analog. The results show that the former can largely enhance the selectivity during the functionalization of both ITO and In(2)O(3) NWs.  相似文献   
10.
A photometric method is proposed that allows the determination of phenolase activity in olive fruits, olive pastes, and virgin olive oil. The method can also be used to quantify partially purified phenolase from olives, and is based on the coupling between 4-methyl-o-benzoquinone, the reaction product of phenolase toward its substrate 4-methylcatechol, and the aromatic amine 4-amino-N,N-diethylaniline. The deep-blue adduct arising from this reaction has been characterized by means of nuclear magnetic resonance and mass spectrometric techniques and identified as 4-(4′-diethylaminophenylimino)-2-hydroxy-5-methyl-cyclohexa-2,5-dienone. This compound shows an absorption band, centered (in dichloromethane) at 617 nm, with an ε of 11,080 M−1cm−1. The main advantage of the proposed method resides in the high absorption coefficient of the adduct and its ultraviolet/visible absorption pattern, with a λmax in a spectral region void of significant interferences by the pigments that ultimately will probably be present in the extracts to be tested by this proposed method. The method has proven to be sensitive, specific, and reliable. This paper is dedicated to the memory of Professor Francesco Corongiu, Dean of the Faculty of Sciences, University of Cagliari, prematurely deceased one year ago.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号