分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: This paper focuses on the enhancement of thermal stability of Ag-Al2O3 nanocermet films by means of alloying of Ag nanoparticles with Al element. The optical analysis demonstrated the AgAl embedded Al2 O3 cermet films (namely, AgAl-Al2O3) possess excellent thermal tolerance even at 500◦C for 260h under nitrogen ambient. The evolution of microstructural and chemical properties of Al2O3/AgAl-Al2O3/Al2O3 stack layers during the annealing process was comprehensively investigated, in order to grasp the thermal stability mechanism. It is believed that the enhanced thermal stability was ascribed to the formation of fresh alumina as capping layer riveted on the Ag nanoparticles surfaces, which acted as the pinning points to prevent silver element from migrating so as to maintain the expected optical properties.
分类: 生物学 >> 生态学 提交时间: 2017-11-17
摘要: From the (a)CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China, and Guangzhou Medical University, Guangzhou 511436, China, (b)CAS Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cells and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China, (c)Laboratory of RNA, Chromatin, and Human Disease, CAS Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cells and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China, (d)Cardiology Division, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China, (e)Hong Kong-Guangdong Stem Cell and Regenerative Medicine Research Centre, The University of Hong Kong and Guangzhou Institutes of Biomedicine and Health, Hong Kong SAR, China, (f)Department of Ophthalmology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China, (g)State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Guangdong Provincial Research Center for Liver Fibrosis, Department of Infectious Diseases and Hepatology Unit, Nanfang Hospital and (h)Biomedical Research Center, Southern Medical University, Guangzhou 510515, China, (i)Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, (j)National Institute for Health Research (NIHR) Birmingham Liver Biomedical Research Unit and Centre for Liver Research, and (k)Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom, (l)Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council (MRC) Building, Cambridge CB2 0XY, United Kingdom, mDepartment of Clinical Biochemistry Unit, Queen Mary Hospital, Hong Kong SAR, China, (n)Department of Medicine, University of Hong Kong-Shenzhen Hospital, Shenzhen 518053, Guangdong, China, and (o)Laboratory of Metabolism and Cell Fate, CAS Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cells and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, Guangdong, China
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Polypropylene and calcium carbonate were prepared by melt extrusion in a twin screw extruder or cast- ing in a kneader extruder. The dispersion of CaCO3 particles in PP was analysed through the observation of impact-fracture surface, polished surface, cross-section surface and film using scanning electron microscopy (SEM), focused ion beam (FIB) and optical transmission microscopy (OTM). Only basic infor- mation on particle dispersion was obtained from the investigation of fracture surfaces by SEM and the FIB cross-sections by virtue of the ambiguous phase contrast and the limited area observed. However, the SEM images from polished-surfaces and the film images observed in OTM show the different particle dispersion in different samples. The derived Particle Size Distribution (PSD) curves from OTM images explain the difference of impact strength, demonstrating the relationship between particle dispersion and mechanical properties.
分类: 生物学 >> 生态学 提交时间: 2017-11-17
摘要: Background: The adapter proteins Appl1 (adaptor protein containing pleckstrin homology domain, phosphotyrosine domain, and leucine zipper motif 1) and Appl2 are highly homologous and involved in several signaling pathways. While previous studies have shown that Appl1 plays a pivotal role in adiponectin signaling and insulin secretion, the physiological functions of Appl2 are largely unknown. Results: In the present study, the role of Appl2 in sepsis shock was investigated by using Appl2 knockout (KO) mice. When challenged with lipopolysaccharides (LPS), Appl2 KO mice exhibited more severe symptoms of endotoxin shock, accompanied by increased production of proinflammatory cytokines. In comparison with the wild-type control, deletion of Appl2 led to higher levels of TNF-alpha and IL-1 beta in primary macrophages. In addition, phosphorylation of Akt and its downstream effector NF-kappa B was significantly enhanced. By co-immunoprecipitation, we found that Appl2 and Appl1 interacted with each other and formed a complex with PI3K regulatory subunit p85 alpha, which is an upstream regulator of Akt. Consistent with these results, deletion of Appl1 in macrophages exhibited characteristics of reduced Akt activation and decreased the production of TNF alpha and IL-1 beta when challenged by LPS. Conclusions: Results of the present study demonstrated that Appl2 is a critical negative regulator of innate immune response via inhibition of PI3K/Akt/NF-kappa B signaling pathway by forming a complex with Appl1 and PI3K.Conclusions: Results of the present study demonstrated that Appl2 is a critical negative regulator of innate immune response via inhibition of PI3K/Akt/NF-kappa B signaling pathway by forming a complex with Appl1 and PI3K.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: SnCdxTe materials were synthesized by the zone-melting method for this thermoelectric performance study. The X-ray diffraction results show that the lattice parameter decreases with increasing x, following Vegard's law of rock-salt structure SnTe and CdTe. Besides, the room temperature Seebeck coefficients of the SnCdxTe system are enhanced to >60 mV K 1, larger than those of Cd-doped SnTe synthesized by spark plasma sintering. A large power factor of $25 mW cm 1 K 1 is achieved in SnCd0.12Te at 820 K, which rivals those of high performance PbTe-based materials. As a result, the highest ZT of $1.03 at 820 K was achieved for SnCd0.12Te.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: The recent emergence of liquid crystals of atomically thin two- dimensional (2D) materials not only has allowed us to explore novel phenomena of macroscopically aligned 2D nanomaterials but also has provided a route toward their controlled assembly into three-dimensional functional macrostructures. Using flow- induced mechanical alignment, we prepared flakes of graphene oxide (GO) in different orientational orders and demonstrated that GO liquid crystals (LC) can be used as rewritable media for reflec- tive displays without polarizing optics. With a wire or stick as a pen, we can make the surface of GO LC reflective and bright, and we can then manually draw lines, curves, and any patterns with dark appearance. The contrast between bright and dark features is due to anisotropic optical responses of ordered GO flakes. Since optical anisotropy is an intrinsic property of 2D structures, our observations and demonstration represent one of many potential applications of macroscopically aligned 2D nanomaterials.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: A new facile scalable method has been developed to synthesize silicon oxycarbide (SiOC)/carbon nanohybrids using difunctional dental methacrylate monomers as solvent and carbon source and the silane coupling agent as the precursor for SiOC. The content (from 100% to 40% by mass) and structure (ratio of disor- dered carbon over ordered carbon) of the free carbon matrix have been systematically tuned by varying the mass ratio of methacryloxy- propyltrimethoxysilane (MPTMS) over the total mass of the resin monomers from 0.0 to 6.0. Compared to the bare carbon anode, the introduction of MPTMS significantly improves the electrochemical performance as a lithium-ion battery anode. The initial and cycled discharge/charge capacities of the SiOC/C nanohybrid anodes reach maximum with the MPTMS ratio of 0.50, which displays very good rate performance as well. Detailed structures and electrochemical performance as lithium-ion battery anodes have been systematically investigated. The structure−property correlation and corresponding mechanism have been discussed.
分类: 生物学 >> 生态学 提交时间: 2017-11-17
摘要: A novel dipeptidyl peptidase IV inhibitor hit (5, IC50 = 0.86 mu M) was structurally derived from our recently disclosed preclinical candidate 4 by replacing the cyanobenzyl with a butynyl based on pharmacophore hybridization. A hit-to-lead optimization effort was then initiated to improve its potency. Most N-substituted analogs exhibited good in vitro activity, and compound 180 (IC50 = 1.55 nM) was identified to be a potent dipeptidyl peptidase IV inhibitor with a significantly improved pharmacokinetic properties (bioavailablity: 41% vs 82.9%; T-1/2: 2 h vs 4.9 h). (C) 2013 Elsevier Ltd. All rights reserved.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Detection of malignant cells from malignant effusion is crucial to establish or adjust therapies of patients with cancer. The conventional qualitative detection in malignant pleuroperitoneal effusion is cytological analysis, which is time-consuming and complicated. Therefore, a faster and more convenient detection strategy is urgently needed. In this study, we report a rapid method to detect malignant cells from malignant pleuroperitoneal effusion (hydrothorax and ascites) of patients using IR-808, a tumor-targeted near-infrared (NIR) fluorescent heptamethine dye (tNRI dye), which exhibited superior labeling efficacy without specific conjugation to biomarkers. The targeted imaging performance toward malignant cells using IR-808 was confirmed by comparing with normal cells, and the fluorescence stability assay of IR- 808 in malignant effusion was performed from 1 h to 48 h. In order to save time and dose, the incubation time and concentration were optimized to 10 min and 5 mM, which were used to detect malignant cells from 28 clinical samples of malignant pleuroperitoneal effusion. The results revealed that IR-808 could be internalized selectively by malignant cells of samples, and these malignant cells could be easily distinguished from normal cells under a fluorescence microscope. The positive rates between cytological analysis and the IR-808 staining method were 86% (24/28) and 79% (22/28), respectively. An excellent concordance level (Kappa 1⁄4 0.752, P < 0.001) was observed between the two methods. Our results indicated that IR-808, a new NIR fluorescent heptamethine dye with unique optical imaging and tumor targeting properties, could provide a fast and simple way to detect a broad spectrum of malignant cells from malignant pleuroperitoneal effusion in patients.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Electrochemical cycling stabilities were compared for undoped and Al/Co dual-doped spinel LiMn2O4 synthesized by solid state reactions. We observed the suppression of particle fracture in Al/Co dual- doped LiMn2O4 during charge/discharge cycling and its distinguishable particle morphology with respect to the undoped material. Systematic first-principles calculations were performed on undoped, Al or Co single-doped, and Al/Co dual-doped LiMn2O4 to investigate their structural differences at the atomistic level. We reveal that while Jahn–Teller distortion associated with the Mn3+O6 octahedron is the origin of the lattice strain, the networking — i.e. the distribution of mixed valence Mn ions — is much more important to release the lattice strain, and thus to alleviating particle cracking. The calculations showed that the lattice mismatching between Li+ intercalation and deintercalation of LiMn2O4 can be significantly reduced by dual-doping, and therefore also the volumetric shrinkage during delithiation. This may account for the near disappearance of cracks on the surface of Al/Co–LiMn2O4 after 350 cycles, while some obvious cracks have developed in undoped LiMn2O4 at similar particle size even after 50 cycles. Corre- spondingly, Al/Co dual-doped LiMn2O4 showed a good cycling stability with a capacity retention of 84.1% after 350 cycles at a rate of 1C, 8% higher than the undoped phase.
提交时间: 2017-05-02
摘要: The structural transitions of Ti3AlC2 induced by ion irradiation were investigated over a wide fluence range by transmission electron microscopy. No amorphization occurs even at the highest dose of 31 dpa, indicating a great tolerance to irradiation-induc
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: A novel non-conjugated small-molecule electrolyte was invented as a cathode interlayer in PTB7:PC71BM- based polymer solar cells (PSCs). We discovered a significant synergy effect for improving the device efficiency between methanol treatment and the interlayer. The methanol treatment mainly contributed to the open-circuit voltage, while the interlayer primarily enhanced the short-circuit current and fill factor. Under the effective synergy effect, power conversion efficiencies (PCEs) of PTB7:PC71BM-based PSCs were largely improved from 3.89% to 9.79% for conventional PSCs and from 7.34% to 9.10% for inverted PSCs. Our findings create a new path of interfacial modification for highly efficient PSCs.
提交时间: 2017-05-02
摘要: The flexural strength reliability of bulk metallic glasses [BMGs] plates is analyzed using Weibull statistics. The Weibull modulus [m] and characteristic strength [sigma[0]] of the Zr48Cu45Al7 BMG are 34 and 2630 MPa, respectively, which are much higher t
提交时间: 2017-05-02
摘要: White TiO2 nanoparticles [NPs] have been widely used for cancer photodynamic therapy based on their ultraviolet light-triggered properties. To date, biomedical applications using white TiO2 NPs have been limited, since ultraviolet light is a well-known mu
提交时间: 2017-05-02
摘要: This study demonstrates that uniform materials of reduced graphene oxide/polydopamine composite thin film can serve as a highly sensitive and ultrafast responsive actuator driven by water gradients absorption-induced in situ formation of bilayer structures in swelling difference along the lateral uniform thin film
提交时间: 2017-05-02
摘要: Template-free synthesis of TiO2 architectures with controlled morphology evolution has been developed through solvothermal reaction in 1,4-dioxane. By simply varying the molar ratio of the concentrated HCl over Titanium isopropoxide [TTIP] from 0 to 5.0,
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Tin telluride (SnTe) has recently attracted much attention as a promising thermoelectric material. In this work, SnTe is alloyed with additional Pb, and the high density crystalline ingots of SnPbxTe (x 1⁄4 0, 0.02, 0.04, and 0.06) have been synthesized by a zone-melting method. Through this method, SnPbxTe samples show larger power factors than those prepared by other methods, and a maximum value of 30.5 mW cm 1 K 2 at 823 K has been reached in p-type SnPb0.02Te, which is the highest value reported so far. As a result, a promising figure of merit ZT of $0.81 has been obtained at 823 K.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: In this paper, Ga-doped ZnO (GZO) thin films are deposited on glass substrates by radio frequency magnetron sputtering for low loss plasmonic applications. The effects of Ga2O3 content in the target and substrate temperature on the electrical, structural and optical properties of GZO films are investigated. Film with the highest carrier concen- tration of 7.0 × 1020 cm− 3 was obtained at a Ga2O3 content of 5 wt% in the target under room temperature deposi- tion. With increasing deposition temperature, the lowest electrical resistivity of 3.8 × 10− 4 Ω cm was acquired at a deposition temperature of 200 °C. The values of plasmonic resonances wavelength could be changed from 1.35 to 2.39 μm by adjusting the carrier concentration. Material absorption losses in these GZO films are 10 times lower than that of conventional Ag films at telecommunication wavelengths. These results make GZO a promising low-loss plasmonic material operating at telecommunication wavelengths.
提交时间: 2017-05-02
摘要: We report an approach to improve the electric resistivity of Nd-Fe-B die-upset magnets without sacrificing their magnetic properties very much. NdF3 fine powders were segmentally added in the die filling with MQU-F powders and then were die-upset for magn
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Two novel conjugated donoreacceptor polymers were synthesized by combining anthracene donor and benzothiadiazole acceptor with two different side chains (conjugated and non-conjugated). Their ab- sorption spectroscopy, thermogravimetric analysis, electrochemical cyclic voltammetry, theoretical prediction, surface morphology, and photovoltaic performance were investigated. The resultant two- dimensional configuration showed good optical and electrochemical properties. By selectively intro- ducing branched conjugated side chains and non-conjugated linear side chains on the polymer back- bone, the highest occupied molecular orbital levels are low lying which results in an increased open circuit voltage for polymer solar cells. The open circuit voltage of 1.02 V in this work was among the highest value for anthracene-based polymer solar cells ever. Our results suggest a good way to regulate the molecular energy levels by selecting appropriate side chains.