A review of carbon-based thermal interface materials: mechanisms, thermal measurements and thermal properties.
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•Various carbon-based thermal interface materials were reviewed, ranging ...from one-dimensional carbon nanotubes, two-dimensional graphene films, to three-dimensional graphene foams, graphene aerogels, vertical graphene and other 3D graphene.•Thermal measurements for bulk and nanoscale materials were discussed to offer a guidance for improving the precision of the results.•The challenges for carbon-based thermal interface materials were discussed, including how to decrease the overall thermal resistance of thermal interface materials, the potential applications from micro to macro devices and the prerequisites for industrial application.
With the development of electronic technologies, electronic devices become smaller, while their power density increases dramatically. The resulting excessive heat requires excellent heat dissipation to ensure great performance of the devices. A good thermal interface material (TIM), with excellent bulk thermal conductivity and proper elastic modulus, which can fill the gap between contact surfaces, is of great importance to improve overall performance of thermal management in the electronic devices. Carbon-based materials, such as carbon nanotubes (CNTs) and graphene (Gr), have attracted great attentions, due to their intrinsic high thermal conductivity. In this paper, carbon-based TIMs are reviewed, as well as the thermal conducting mechanisms and techniques to measure thermal properties for materials. The unique three-dimensional network of 3D-Gr provides not only high thermal conductivity, but also excellent mechanical properties, which makes it more competitive as TIM than CNTs and Gr. Furthermore, there is currently no universal characterization techniques, which are suitable to measure thermal properties of all TIMs. Hence, special attention must be paid to select a proper technique based on the measuring principle, in order to obtain accurate results. An outlook of the future challenges of the thermal interface materials is proposed at the end of the paper.
Abstract
The prison system of the People’s Republic of China (PRC) has been viewed by some scholars as effective in achieving the primary target of Chinese imprisonment: rehabilitation. This article ...aims to redress this argument. Drawing on interviews undertaken with 30 female parolees/ex-prisoners and 10 prison officers, this article argues that the Jifen Kaohe System in prison, which is strongly imprinted with Foucault’s theory of ‘disciplinary power’, is ineffective and is unable to make accurate judgements on the achievement of prisoners’ rehabilitation at selected women’s prisons. This article suggests that Foucault’s disciplinary power is theoretically problematic in producing a ‘new person’, not the least of its unawareness of contextualized culture, values and situations, and women’s agency in prison.
Exosomes: An emerging factor in atherosclerosis Wang, Yanan; Xie, Yingyu; Zhang, Ao ...
Biomedicine & pharmacotherapy,
July 2019, 2019-Jul, 2019-07-00, 20190701, 2019-07-01, Letnik:
115
Journal Article
Recenzirano
Odprti dostop
Atherosclerosis is the main reason for morbidity and death caused by cardiovascular disease which leads to approximately 20% of total death around the world. Exosomes secreted by the cells is a kind ...of extracellular vesicles with lipid bilayer structure, containing a variety of cell specific lipid, nucleic acid and protein, involved in intercellular communication, plays an important role in different physiological and pathological process. In recent years, with the deepening of research, the role of exosomes in cardiovascular diseases has received extensive attention. This review summarizes the roles of exosomes and exosome-derived from microRNAs, proteins and DNA as biomarkers in the development of atherosclerosis, and explores the mechanism of exosome-mediated intercellular crosstalk in atherosclerosis, providing potential roles for diagnosis and treatment.
The first example of transition metal-catalyzed meta-selective CAr–H nitration of arenes is described. With the use of Ru3(CO)12 as the catalyst and Cu(NO3)2·3H2O as the nitro source, a wide ...spectrum of arenes bearing diversified N-heterocycles or oximido as the directing groups were nitrated with meta-selectivity exclusively. Mechanism studies have demonstrated the formation of a new 18e-octahedral ruthenium species as a key ortho-CAr–H metalated intermediate, which may be responsible for the subsequent meta-selective electrophilic aromatic substitution (SEAr). Moreover, this approach provides a fast-track strategy for atom/step economical synthesis of many useful pharmaceutical molecules.
Semiconducting molybdenum ditelluride (2H‐MoTe2), a fast‐emerging 2D material with an appropriate band gap and decent carrier mobility, is configured as field‐effect transistors and is the focus of ...substantial research interest, showing hole‐dominated ambipolar characteristics. Here, carrier modulation of ambipolar few‐layer MoTe2 transistors is demonstrated utilizing magnesium oxide (MgO) surface charge transfer doping. By carefully adjusting the thickness of MgO film and the number of MoTe2 layers, the carrier polarity of MoTe2 transistors from p‐type to n‐type can be reversely controlled. The electron mobility of MoTe2 is significantly enhanced from 0.1 to 20 cm2 V−1 s−1 after 37 nm MgO film doping, indicating a greatly improved electron transport. The effective carrier modulation enables to achieve high‐performance complementary inverters with high DC gain of >25 and photodetectors based on few‐layer MoTe2 flakes. The results present an important advance toward the realization of electronic and optoelectronic devices based on 2D transition‐metal dichalcogenide semiconductors.
The MoTe2 transistors are electron doped by magnesium oxide (MgO) surface charge transfer doping. The electron mobility of MoTe2 is significantly enhanced from 0.1 to 20 cm2 V−1 s−1 after 37 nm MgO doping. The effective carrier modulation enables to achieve high‐performance complementary inverters with high DC gain of >25 and photodetectors based on few‐layer MoTe2 flakes.
With the continuous development of immunotherapy, researchers have paid more attention to the specific immune regulatory mechanisms of various immune responses in different diseases. As a novel and ...vital innate immune signal pathway, the cGAS-STING signal pathway activated by nucleic acid substances, interplays with other immune responses, by which it participates in regulating cancer, autoimmune and inflammatory diseases, microbial and parasitic infectious diseases, and other diseases. With the exception of its role in innate immunity, the growing list of researches demonstrated expanding roles of the cGAS-STING signal pathway in bridging the innate immunity (macrophage polarization) with the adaptive immunity (T lymphocytes differentiation). Macrophages and T lymphocytes are the most representative cells of innate immunity and adaptive immunity, respectively. Their polarization or differentiation are involved in the pathogenesis and progression of various diseases. Here we mainly summarized recent advanced discoveries of how the cGAS-STING signal pathway regulated macrophages polarization and T lymphocytes differentiation in various diseases and vaccine applications, providing a promising direction for the development and clinical application of immunotherapeutic strategies for related diseases.
Objectives/Hypothesis
Using network meta‐analysis, we aimed to compare the efficacy and safety of Epley and Semont maneuvers as treatment options for posterior canal benign paroxysmal positional ...vertigo.
Study Design
Network meta‐analysis.
Methods
Randomized controlled studies with a Jadad score ≥ 3 that used an Epley or Semont maneuver in posterior canal benign paroxysmal positional vertigo patients were analyzed in this project. The following efficacy outcomes included 1‐week recovery rate and end of study recovery rate. Recurrence rate was used to assess the safety of each treatment.
Results
Of 589 articles, 12 studies that enrolled 999 posterior canal benign paroxysmal positional vertigo patients were selected. The pooled analysis revealed that the Epley maneuver was as efficacious as the Semont maneuver, in both the 1‐week recovery rate and end of study recovery rate (odds ratio OR = 1.8, 95% confidence interval CI = 0.48‐7.00; OR = 1.8, 95% CI = 0.47‐7.20), and had a similar recurrence rate (OR = 1.00, 95% CI = 0.33‐4.4). These two techniques were both better than sham‐controlled treatment in the two efficacy indicators. No difference was observed in recurrence rate for treatments.
Conclusions
The Epley maneuver was similar to the Semont maneuver in both efficacy and safety for posterior canal benign paroxysmal positional vertigo in short‐term effects, and both were superior to the sham‐controlled treatment.
Level of Evidence
NA Laryngoscope, 126:951–955, 2016
Many double-stranded DNA viruses, such as Epstein-Barr virus, can establish persistent infection, but the underlying virus-host interactions remain poorly understood. Here we report that in human ...airway epithelial cells Epstein-Barr virus induces TRIM29, a member of the TRIM family of proteins, to inhibit innate immune activation. Knockdown of TRIM29 in airway epithelial cells enhances type I interferon production, and in human nasopharyngeal carcinoma cells results in almost complete Epstein-Barr virus clearance. TRIM29 is also highly induced by cytosolic double-stranded DNA in myeloid dendritic cells. TRIM29
mice have lower adenovirus titers in the lung, and are resistant to lethal herpes simplex virus-1 infection due to enhanced production of type I interferon. Mechanistically, TRIM29 induces K48-linked ubiquitination of Stimulator of interferon genes, a key adaptor in double-stranded DNA-sensing pathway, followed by its rapid degradation. These data demonstrate that Epstein-Barr virus and possible other double-stranded DNA viruses use TRIM29 to suppress local innate immunity, leading to the persistence of DNA virus infections.Proteins of the TRIM family have regulatory functions in immune signaling, often via ubiquitination of target proteins. Here, the authors show that TRIM29 is induced upon infection with DNA viruses, resulting in degradation of STING, decreased interferon signaling and increased pathogenicity in mice.
The influences of anionic surfactant SDS (sodium dodecylsulfate) and cationic surfactant CTAB (hexadecyl trimethyl ammonium bromide) on electrodeposition of Cu-TiO2 composite coatings by jet ...electrodeposition were studied. The maximum TiO2 content in the composite coatings was 8.94 wt % at optimum concentration of 50 mg/L for SDS and the maximum TiO2 content was 11.45 wt % at optimum concentration of 30 mg/L for CTAB, while the maximum TiO2 content was 7.25 wt% without any surfactant. The coatings deposited with either SDS or CTAB became more homogeneous. XRD analysis showed that both SDS and CTAB decreased the grain sizes of deposited coatings. The preferred orientations for composite coatings with SDS and CTAB were (111) plane and (220) plane respectively. With optimum addition of SDS (50 mg/L) and CTAB (30 mg/L) in the electrolyte, both hardness and wear resistant of the composite coatings was obviously enhanced due to second phase strengthening and grain refinement strengthening.
•Cu-TiO2 composite coatings were prepared by Jet electrodeposition.•SDS can slightly increase TiO2 content.•CTAB can significantly increase TiO2 content.•The maximum TiO2 content was 11.45 wt% when optimum CTAB was added.•With high TiO2 content, the composite coatings show enhanced wear performance.
A novel and efficient C–H activation approach for the direct 3,3-difluoroallylation of 2-pyridones and indoles is herein reported using a manganese(I) complex as the catalyst. A broad range of ...substrates with diverse functional groups were tolerated. Moreover, late-stage C–H functionalization of bioactive molecules was achieved in good yield.
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