Genomic instability is the hallmark of various cancers with the increasing accumulation of DNA damage. The application of radiotherapy and chemotherapy in cancer treatment is typically based on this ...property of cancers. However, the adverse effects including normal tissues injury are also accompanied by the radiotherapy and chemotherapy. Targeted cancer therapy has the potential to suppress cancer cells' DNA damage response through tailoring therapy to cancer patients lacking specific DNA damage response functions. Obviously, understanding the broader role of DNA damage repair in cancers has became a basic and attractive strategy for targeted cancer therapy, in particular, raising novel hypothesis or theory in this field on the basis of previous scientists' findings would be important for future promising druggable emerging targets. In this review, we first illustrate the timeline steps for the understanding the roles of DNA damage repair in the promotion of cancer and cancer therapy developed, then we summarize the mechanisms regarding DNA damage repair associated with targeted cancer therapy, highlighting the specific proteins behind targeting DNA damage repair that initiate functioning abnormally duo to extrinsic harm by environmental DNA damage factors, also, the DNA damage baseline drift leads to the harmful intrinsic targeted cancer therapy. In addition, clinical therapeutic drugs for DNA damage and repair including therapeutic effects, as well as the strategy and scheme of relative clinical trials were intensive discussed. Based on this background, we suggest two hypotheses, namely "environmental gear selection" to describe DNA damage repair pathway evolution, and "DNA damage baseline drift", which may play a magnified role in mediating repair during cancer treatment. This two new hypothesis would shed new light on targeted cancer therapy, provide a much better or more comprehensive holistic view and also promote the development of new research direction and new overcoming strategies for patients.
Nanomaterials in Superlubricity Zhai, Wenzheng; Zhou, Kun
Advanced functional materials,
07/2019, Letnik:
29, Številka:
28
Journal Article
Recenzirano
The vanishing friction, known as superlubricity, is potentially a significant performance indicator in the development of nanostructured materials and has become increasingly important for realizing ...energy saving and extending the life of mechanical components. Herein, a systematic review of recent progress in nanomaterials for achieving the superlubric state is provided, beginning with a brief introduction of nanostructured materials in superlubricity and its wide potential applications. Subsequently, a detailed discussion of experimental and simulation works on the different spatial structures of nanomaterials associated with size effects ranging from 0D to 3D nanostructures is given, with an emphasis on solid and liquid superlubricity. Finally, this work concludes with perspectives on the challenges and future directions for developing nanomaterials in the field of superlubricity.
Superlubricity is a state of ultralow friction and has attracted increasing interest in numerous potential applications of nanomaterials. A timely review offers possible solutions to lubrication challenges in a variety of nanotechnologies including water transport control, micro/nano‐electromechanical systems, biomedical engineering, atomic force microscopy, and other electronic devices for which maintaining their functional stability is pivotal.
Radiotherapy is one of the most common countermeasures for treating a wide range of tumors. However, the radioresistance of cancer cells is still a major limitation for radiotherapy applications. ...Efforts are continuously ongoing to explore sensitizing targets and develop radiosensitizers for improving the outcomes of radiotherapy. DNA double-strand breaks are the most lethal lesions induced by ionizing radiation and can trigger a series of cellular DNA damage responses (DDRs), including those helping cells recover from radiation injuries, such as the activation of DNA damage sensing and early transduction pathways, cell cycle arrest, and DNA repair. Obviously, these protective DDRs confer tumor radioresistance. Targeting DDR signaling pathways has become an attractive strategy for overcoming tumor radioresistance, and some important advances and breakthroughs have already been achieved in recent years. On the basis of comprehensively reviewing the DDR signal pathways, we provide an update on the novel and promising druggable targets emerging from DDR pathways that can be exploited for radiosensitization. We further discuss recent advances identified from preclinical studies, current clinical trials, and clinical application of chemical inhibitors targeting key DDR proteins, including DNA-PKcs (DNA-dependent protein kinase, catalytic subunit), ATM/ATR (ataxia-telangiectasia mutated and Rad3-related), the MRN (MRE11-RAD50-NBS1) complex, the PARP (polyADP-ribose polymerase) family, MDC1, Wee1, LIG4 (ligase IV), CDK1, BRCA1 (BRCA1 C terminal), CHK1, and HIF-1 (hypoxia-inducible factor-1). Challenges for ionizing radiation-induced signal transduction and targeted therapy are also discussed based on recent achievements in the biological field of radiotherapy.
Photoreduction of CO2 into reusable carbon forms is considered as a promising approach to address the crisis of energy from fossil fuels and reduce excessive CO2 emission. Recently, metal–organic ...frameworks (MOFs) have attracted much attention as CO2 photoreduction‐related catalysts, owing to their unique electronic band structures, excellent CO2 adsorption capacities, and tailorable light‐absorption abilities. Recent advances on the design, synthesis, and CO2 reduction applications of MOF‐based photocatalysts are discussed here, beginning with the introduction of the characteristics of high‐efficiency photocatalysts and structural advantages of MOFs. The roles of MOFs in CO2 photoreduction systems as photocatalysts, photocatalytic hosts, and cocatalysts are analyzed. Detailed discussions focus on two constituents of pure MOFs (metal clusters such as Ti–O, Zr–O, and Fe–O clusters and functional organic linkers such as amino‐modified, photosensitizer‐functionalized, and electron‐rich conjugated linkers) and three types of MOF‐based composites (metal–MOF, semiconductor–MOF, and photosensitizer–MOF composites). The constituents, CO2 adsorption capacities, absorption edges, and photocatalytic activities of these photocatalysts are highlighted to provide fundamental guidance to rational design of efficient MOF‐based photocatalyst materials for CO2 reduction. A perspective of future research directions, critical challenges to be met, and potential solutions in this research field concludes the discussion.
Photocatalyst materials based on metal–organic frameworks (MOFs) have great potential for carbon dioxide (CO2) reduction due to their tailorable light‐absorption ability, unique pore texture, and excellent CO2 adsorption capacity. A comprehensive review of recent advances in the design, synthesis, and CO2 photoreduction applications of MOF‐based photocatalysts is presented to offer valuable insights toward the exploitation of new‐generation photocatalyst materials.
Fe–N–C single-atom catalysts (SACs) exhibit high activity for oxygen reduction reaction (ORR). However, it remains controversial how the active center mediates catalysis, and the predicted potential ...deviates from experimental results, hindering development of ideal SACs. Here, using first-principles calculations, we present a microkinetic model for ORR on Fe–N–C SACs, disclosing a self-adjusting mechanism induced by its intrinsic intermediate. The modeling results show that the single-atom Fe site of the FeN4 center of Fe–N–C is covered with an intermediate OH* from 0.28 to 1.00 V. Remarkably, such OH* becomes part of the active moiety, Fe(OH)N4, and can optimize intermediate bindings on the Fe site, exhibiting a theoretical half-wave potential of ∼0.88 V. Partial current density analysis reveals the dominating associative path over the dissociative ones. In addition, ORR on Mn–N–C and Co–N–C SACs is unveiled. This work demonstrates the necessity of assessing the effect of intrinsic intermediates in single-atom catalysis and provides practical guidance for rational design of high-performance SACs.
We present FaceWarehouse, a database of 3D facial expressions for visual computing applications. We use Kinect, an off-the-shelf RGBD camera, to capture 150 individuals aged 7-80 from various ethnic ...backgrounds. For each person, we captured the RGBD data of her different expressions, including the neutral expression and 19 other expressions such as mouth-opening, smile, kiss, etc. For every RGBD raw data record, a set of facial feature points on the color image such as eye corners, mouth contour, and the nose tip are automatically localized, and manually adjusted if better accuracy is required. We then deform a template facial mesh to fit the depth data as closely as possible while matching the feature points on the color image to their corresponding points on the mesh. Starting from these fitted face meshes, we construct a set of individual-specific expression blendshapes for each person. These meshes with consistent topology are assembled as a rank-3 tensor to build a bilinear face model with two attributes: identity and expression. Compared with previous 3D facial databases, for every person in our database, there is a much richer matching collection of expressions, enabling depiction of most human facial actions. We demonstrate the potential of FaceWarehouse for visual computing with four applications: facial image manipulation, face component transfer, real-time performance-based facial image animation, and facial animation retargeting from video to image.
Supermolecule β-cyclodextrin was used to assist CsPbBr 3 film fabrication. In situ growth of nanocrystals was effectively confined through strong interactions between perovskite Pb 2+ ions and β-CD ...hydroxyl groups, producing a compact and smooth film. The quantum efficiency achieved was 85.3% with a moisture resistance over months, exceeding the record of perovskite films.
We present a fully automatic approach to real-time facial tracking and animation with a single video camera. Our approach does not need any calibration for each individual user. It learns a generic ...regressor from public image datasets, which can be applied to any user and arbitrary video cameras to infer accurate 2D facial landmarks as well as the 3D facial shape from 2D video frames. The inferred 2D landmarks are then used to adapt the camera matrix and the user identity to better match the facial expressions of the current user. The regression and adaptation are performed in an alternating manner. With more and more facial expressions observed in the video, the whole process converges quickly with accurate facial tracking and animation. In experiments, our approach demonstrates a level of robustness and accuracy on par with state-of-the-art techniques that require a time-consuming calibration step for each individual user, while running at 28 fps on average. We consider our approach to be an attractive solution for wide deployment in consumer-level applications.
We present the first real-time high-fidelity facial capture method. The core idea is to enhance a global real-time face tracker, which provides a low-resolution face mesh, with local regressors that ...add in medium-scale details, such as expression wrinkles. Our main observation is that although wrinkles appear in different scales and at different locations on the face, they are locally very self-similar and their visual appearance is a direct consequence of their local shape. We therefore train local regressors from high-resolution capture data in order to predict the local geometry from local appearance at runtime. We propose an automatic way to detect and align the local patches required to train the regressors and run them efficiently in real-time. Our formulation is particularly designed to enhance the low-resolution global tracker with exactly the missing expression frequencies, avoiding superimposing spatial frequencies in the result. Our system is generic and can be applied to any real-time tracker that uses a global prior, e.g. blend-shapes. Once trained, our online capture approach can be applied to any new user without additional training, resulting in high-fidelity facial performance reconstruction with person-specific wrinkle details from a monocular video camera in real-time.
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As one of the most important categories in the additive manufacturing (AM) field, powder-based techniques, such as selective laser sintering, electron beam melting and selective laser ...melting, utilize laser or electronic beams to selectively fuse polymeric, metallic, ceramic or composite powders layer-by-layer into desired products according to their computer-aided design models. With unique mechanical, thermal, electrical, biocompatible and fire-retardant properties, polymeric composite materials for powder-based AM have been attracting intensive research interests because of their potential for a wide variety of functional applications in aerospace, automobile, marine and offshore, medical and many other industries.
This article provides a comprehensive review of the recent progress on polymeric composite materials, their powder preparation for AM, and functionalities and applications of their printed products. It begins with the introduction of thermoplastic polymers that have been used as the main matrices of the polymeric composites and various composite reinforcements such as metallic, ceramic, carbon-based fillers and polymer blends for strengthening and functionality purposes. Discussion is then made on the processes for manufacturing such polymeric composites into powder form, which include shear pulverization, solution-based methods and melt compounding methods, with a focus on their advantages, limitations and challenges in terms of their productivity and processibility as well as powder printability. Thereafter, the properties and functionalities of the printed products and their various intriguing applications particularly in biomedical (anatomical models, tissue engineering and drug delivery), aerospace, automobile, military, energy and environmental, acoustic devices and sports equipment are highlighted. Finally, this review is concluded with an outlook on polymeric composites for powder-based AM, new opportunities, major challenges and possible solutions.
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