To meet the requirement of big data era and neuromorphic computations, nonvolatile memory with fast speed, high density, and low power consumption is urgently needed. As an emerging technology, ...phase‐change memory is a promising candidate to solve this problem. However, the drawback of the high power consumption hinders their applications. Most recently, a new phase‐change material of (GeTe)x/(Sb2Te3)yn superlattice attracts intensive attentions owing to its ultralow power consumption comparing with conventional phase‐change memory devices. Many studies on this new material have been reported. However, there still lacks a comprehensive and unified understanding of its atomic picture and working mechanism. This article at first summarizes the broad applications for phase‐change materials. Then, the major progresses of phase‐change superlattices to understand the microscopic structure and working principles for data storage are discussed. Strategies on material optimizations to further enhance device performances are proposed. Finally, an outlook on new applications with these advanced superlattice materials is suggested.
The phase‐change superlattice is an advanced functional material that is suitable for nonvolatile memory with ultralow power consumption, high density, and fast speed. It is a promising candidate for the big data and artificial‐intelligence applications. The major progresses in the field are reviewed including its microscopic picture, working principles, and optimizations. Outlooks on its future development and applications are proposed.
Pure spin current is expected to be utilized for designing energy-saving devices. Using first-principles calculations in combination with a non-equilibrium Green's function method, the spin-dependent ...thermoelectric transport properties of metallocene dimer-based molecular junctions are investigated. The results show that spin-polarized currents can be achieved when a temperature difference is applied in molecular structures. It is found that the spin-polarized transport properties are different when transition metals in the dimers are different. It is interesting that a negative differential thermoelectric resistance and a perfect spin filtering effect can be found in chromocene dimer-based and manganocene dimer-based molecular junctions. Moreover, one key finding is that a pure spin current can be obtained in a cobaltocene dimer-based molecular junction, in which the spin-dependent Seebeck coefficient is larger than the charge Seebeck coefficient. These interesting results indicate that metallocene dimer-based molecular junctions have potential applications in future thermal spintronic and spin thermoelectric devices.
Thermally driven magnetic-molecular junctions can be designed as pure spin current generators, spin thermoelectric devices or thermal-spin converters.
Objective To evaluate the efficacy and safety of different antidepressants and anticonvulsants in the treatment of central poststroke pain (CPSP) by network meta-analysis and provide an ...evidence-based foundation for clinical practice. Methods PubMed, Cochrane Library, EMBASE, CNKI, APA PsycINFO, Wanfang, VIP and other databases were searched by computer to find clinical randomized controlled studies (RCTs) on drug treatment of CPSP. The retrieval time limit was from the establishment of each database to July 2022. The quality of the included RCTs was evaluated using the bias risk assessment tool recommended by Cochrane. Stata 14.0 was used for network meta-analysis. Results A total of 13 RCTs, 1040 patients and 9 drugs were finally included. The results of the network meta-analysis showed that the effectiveness ranking as rated by the visual analog scale (VAS) was gabapentin > pregabalin > fluoxetine > lamotrigine > duloxetine > serqulin > amitriptyline > carbamazepine > vitamin B. Ranking according to the numerical rating scale (NRS) was pregabalin > gabapentin > carbamazepine. Ranking derived from the Hamilton depression scale (HAMD) was pregabalin > duloxetine > gabapentin > amitriptyline. Conclusion All nine drugs can relieve the pain of CPSP patients to different degrees; among them pregabalin and gabapentin have the most significant effect, and gabapentin and pregabalin also have the most adverse reactions. In the future, more multicenter, large sample, double-blind clinical randomized controlled trials need to be carried out to supplement and demonstrate the results of this study.
Enantioenriched indole derivatives are widely found in natural products, pharmaceuticals and bioactive compounds. Therefore, developing efficient methods for the synthesis of enantioenriched indole ...derivatives has become an important goal in the community of organic chemistry. To this end, chemists have designed and developed a variety of indole-containing platform molecules and their related catalytic asymmetric reactions. Among these approaches, vinylindoles have proved to be versatile platform molecules for accessing enantioenriched indole derivatives via catalytic asymmetric reactions, especially organocatalytic asymmetric reactions. Based on this approach, a plethora of chiral indole derivatives have been synthesized with optical purity and structural complexity. This review summarizes advances in vinylindole-based organocatalytic asymmetric reactions since 2008 and includes the applications of some methodologies in the total synthesis of natural products. In addition, this review points out the remaining challenges in this research area to be confronted by organic chemists, which will shed light on the future development of this area.
Conventional oxygen‐dependent photodynamic therapy (PDT) has faced severe challenges because of the non‐specificity of most available photosensitizers (PSs) and the hypoxic nature of tumor tissues. ...Here, an O2 self‐sufficient cell‐like biomimetic nanoplatform (CAT‐PS‐ZIF@Mem) consisting of the cancer cell membrane (Mem) and a cytoskeleton‐like porous zeolitic imidazolate framework (ZIF‐8) with the embedded catalase (CAT) protein molecules and Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4, defined as PS) is developed. Because of the immunological response and homologous targeting abilities of the cancer cell membrane, CAT‐PS‐ZIF@Mem is selectively accumulated at the tumor site and taken up effectively by tumor cells after intravenous injection. After the intracellular H2O2 penetration into the framework, it is catalyzed by CAT to produce O2 at the hypoxic tumor site, facilitating the generation of toxic 1O2 for highly effective PDT in vivo under near‐infrared irradiation. By integrating the immune escape, cell homologous recognition, and O2 self‐sufficiency, this cell‐like biomimetic nanoplatform demonstrates highly specific and efficient PDT against hypoxic tumor cells with much reduced side‐effect on normal tissues.
An O2 self‐sufficient cell‐like biomimetic nanoplatform based on zeolitic imidazolate framework (ZIF‐8) is developed for effective photodynamic therapy (PDT). In vitro and in vivo investigations confirm that this cell‐like PDT agent possesses immune escape, homologous targeting, and O2 self‐sufficient capabilities for highly specific PDT against hypoxic tumor cells.
The diverse expression pattern of CD36 reflects its multiple cellular functions. However, the roles of CD36 in colorectal cancer (CRC) remain unknown. Here, we discover that CD36 expression is ...progressively decreased from adenomas to carcinomas. CD36 loss predicts poor survival of CRC patients. In CRC cells, CD36 acts as a tumor suppressor and inhibits aerobic glycolysis in vitro and in vivo. Mechanically, CD36-Glypcian 4 (GPC4) interaction could promote the proteasome-dependent ubiquitination of GPC4, followed by inhibition of β-catenin/c-myc signaling and suppression of downstream glycolytic target genes GLUT1, HK2, PKM2 and LDHA. Moreover, disruption of CD36 in inflammation-induced CRC model as well as Apc
mice model significantly increased colorectal tumorigenesis. Our results reveal a CD36-GPC4-β-catenin-c-myc signaling axis that regulates glycolysis in CRC development and may provide an intervention strategy for CRC prevention.
A novel adaptive smoothing approach is proposed for noise removal and feature preservation where two distinct measures are simultaneously adopted to detect discontinuities in an image. Inhomogeneity ...underlying an image is employed as a multiscale measure to detect contextual discontinuities for feature preservation and control of the smoothing speed, while local spatial gradient is used for detection of variable local discontinuities during smoothing. Unlike previous adaptive smoothing approaches, two discontinuity measures are combined in our algorithm for synergy in preserving nontrivial features, which leads to a constrained anisotropic diffusion process that inhomogeneity offers intrinsic constraints for selective smoothing. Thanks to the use of intrinsic constraints, our smoothing scheme is insensitive to termination times and the resultant images in a wide range of iterations are applicable to achieve nearly identical results for various early vision tasks. Our algorithm is formally analyzed and related to anisotropic diffusion. Comparative results indicate that our algorithm yields favorable smoothing results, and its application in extraction of hydrographic objects demonstrates its usefulness as a tool for early vision.
The purpose of this study was to develop and test a senior technology acceptance model (STAM) aimed at understanding the acceptance of gerontechnology by older Hong Kong Chinese people. The proposed ...STAM extended previous technology acceptance models and theories by adding age-related health and ability characteristics of older people. The proposed STAM was empirically tested using a cross-sectional questionnaire survey with a sample of 1012 seniors aged 55 and over in Hong Kong. The result showed that STAM was strongly supported and could explain 68% of the variance in the use of gerontechnology. For older Hong Kong Chinese, individual attributes, which include age, gender, education, gerontechnology self-efficacy and anxiety, and health and ability characteristics, as well as facilitating conditions explicitly and directly affected technology acceptance. These were better predictors of gerontechnology usage behaviour (UB) than the conventionally used attitudinal factors (usefulness and ease of use).
Practitioner Summary: Previous studies have not given much consideration to age-related health and associated abilities when examining acceptance of technology by the ageing population. By encompassing conventional technology acceptance constructs together with age-related health and ability characteristics, the present study was able to identify more factors affecting gerontechnology acceptance by older Hong Kong Chinese.
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