免疫检查点抑制剂治疗错配修复缺陷/微卫星高度不稳定型胃癌的研究进展

错配修复缺陷/微卫星高度不稳定型(mismatch repair-deficient/microsatellite instability-high,dMMR/MSI-H)胃癌是胃癌的一个特殊分子亚型,其因独特的免疫微环境和高突变负荷对免疫检查点抑制剂(immune checkpoint inhibitors,ICIs)高度敏感。ICIs治疗dMMR/MSI-H胃癌在多项临床研究中展现出较好的效果,但仍存在原发耐药与继发耐药的挑战。如何在这一特殊分子亚型的胃癌中选择合适的ICIs和克服耐药性是临床上亟需解决的问题。本文对ICIs的作用机制,及其治疗dMMR/MSI-H胃癌的研究进展和存在的耐药性挑战进行综述,以期为临床治疗提供参考。

Advanced smart biomaterials and constructs for hard tissue engineering and regeneration

Hard tissue repair and regeneration cost hundreds of billions of dollars annually worldwide, and the need has substantially increased as the population has aged. Hard tissues include bone and tooth structures that contain calcium phosphate minerals.Smart biomaterial-based tissue engineering and regenerative medicine methods have the exciting potential to meet this urgent need. Smart biomaterials and constructs refer to biomaterials and constructs that possess instructive/inductive or triggering/stimulating effects on cells and tissues by engineering the material’s responsiveness to internal or external stimuli or have intelligently tailored properties and functions that can promote tissue repair and regeneration. The smart material-based approaches include smart scaffolds and stem cell constructs for bone tissue engineering; smart drug delivery systems to enhance bone regeneration; smart dental resins that respond to pH to protect tooth structures; smart pH-sensitive dental materials to selectively inhibit acid-producing bacteria; smart polymers to modulate biofilm species away from a pathogenic composition and shift towards a healthy composition; and smart materials to suppress biofilms and avoid drug resistance. These smart biomaterials can not only deliver and guide stem cells to improve tissue regeneration and deliver drugs and bioactive agents with spatially and temporarily controlled releases but can also modulate/suppress biofilms and combat infections in wound sites. The new generation of smart biomaterials provides exciting potential and is a promising opportunity to substantially enhance hard tissue engineering and regenerative medicine efficacy.

Scheduling optimization for upstream dataflows in edge computing

Edge computing can alleviate the problem of insufficient computational resources for the user equipment,improve the network processing environment,and promote the user experience.Edge computing is well known as a prospective method for the development of the Internet of Things(IoT).However,with the development of smart terminals,much more time is required for scheduling the terminal high-intensity upstream dataflow in the edge server than for scheduling that in the downstream dataflow.In this paper,we study the scheduling strategy for upstream dataflows in edge computing networks and introduce a three-tier edge computing network architecture.We propose a Time-Slicing Self-Adaptive Scheduling(TSAS)algorithm based on the hierarchical queue,which can reduce the queuing delay of the dataflow,improve the timeliness of dataflow processing and achieve an efficient and reasonable performance of dataflow scheduling.The experimental results show that the TSAS algorithm can reduce latency,minimize energy consumption,and increase system throughput.

压气机叶片加工偏差的不确定性效应研究进展

压气机叶片的复杂三维构型及薄壁结构导致其加工难度极大,在加工制造过程中叶片几何偏差的不确定性问题十分突出。随着压气机的气动负荷不断攀升、几何尺寸不断缩减,其工作环境及内部流动特征愈加恶劣和复杂。苛刻的工作环境放大了加工偏差的不确定性影响,这导致同批出厂的压气机气动性能分散度大以及服役过程中性能衰减剧烈的问题频发,带来性能不达标甚至故障问题。为此,近年来国内外针对压气机叶片加工偏差的不确定性量化问题已经开展了大量的研究工作。本文从压气机叶片加工偏差的几何建模、概率模型表征、不确定性量化方法及不确定性影响等方面综述了本领域的研究进展,总结了压气机叶片加工偏差不确定性量化面临的关键问题及研究展望。

Comparison of tailpipe carbonyls and volatile organic compounds emissions from in-use gasoline/CNG bi-fuel vehicles

Ground-level ozone contamination has been globally an urban air quality issue,particularly for China,which has recently made significant progress in purifying its sky.Unregulated exhaust emissions from motor vehicles,predominantly carbonyls and volatile organic compounds(VOCs),are among the leading contributors to ozone formation.In this chassislevel study,the unregulated emissions from five China-5 certified gasoline/CNG bi-fuel taxis,along with their ozone forming potential(OFP),were evaluated.It is found that carbonyls and VOCs were mainly emitted during the starting phase no matter the engine was cold or hot.Compared to gasoline,CNG fueling reduced VOCs emissions on a large scale,especially in the starting phase,but had elevated carbonyls.On a fleet average,CNG fueling derived 15%and 46%less OFP than gasoline in cold-and hot-start tests,respectively.VOCs contributed to over 90%of the total OFP of the exhaust.In terms of alleviating ground-level ozone contamination,CNG is a feasible alternative to gasoline on light-duty vehicles.

Influence of leading edge with real manufacturing error on aerodynamic performance of high subsonic compressor cascades

To investigate the influence of real leading-edge manufacturing error on aerodynamic performance of high subsonic compressor blades,a family of leading-edge manufacturing error data were obtained from measured compressor cascades.Considering the limited samples,the leadingedge angle and leading-edge radius distribution forms were evaluated by Shapiro-Wilk test and quantile–quantile plot.Their statistical characteristics provided can be introduced to later related researches.The parameterization design method B-spline and Bezier are adopted to create geometry models with manufacturing error based on leading-edge angle and leading-edge radius.The influence of real manufacturing error is quantified and analyzed by self-developed non-intrusive polynomial chaos and Sobol’indices.The mechanism of leading-edge manufacturing error on aerodynamic performance is discussed.The results show that the total pressure loss coefficient is sensitive to the leading-edge manufacturing error compared with the static pressure ratio,especially at high incidence.Specifically,manufacturing error of the leading edge will influence the local flow acceleration and subsequently cause fluctuation of the downstream flow.The aerodynamic performance is sensitive to the manufacturing error of leading-edge radius at the design and negative incidences,while it is sensitive to the manufacturing error of leading-edge angle under the operation conditions with high incidences.

Decision Support System for Adaptive Restoration Control of Transmission System

The power system restoration control has a higher uncertainty level than the preventive control of cascading failures. In order to ensure the feasibility of the decision support system of restoration control, a decision support framework for adaptive restoration control of transmission system is proposed, which can support the coordinated restoration of multiple partitions, coordinated restoration of units and loads, and coordination of multi-partition decision-making process and actual restoration process. The proposed framework is divided into two layers, global coordination layer and partition optimization layer. The upper layer partitions the transmission system according to the power outage scenario, constantly and dynamically adjusts the partitions during the restoration process, and optimizes the time-space decision-making of inter-partition connectivity. For each partition, the lower layer pre-selects restoration targets according to the estimated restoration income, optimizes the corresponding restoration paths, and evaluates the restoration plans according to the expected net income per unit of power consumption. During the restoration process, if the restoration operation such as energizing the outage branch fails, the current restoration plan will be adaptively switched to the sub-optimal one or re-optimized if necessary. The framework includes two operation modes, i.e., the on-line operation mode and training simulation mode, and provides an information interaction interface for collaborative restoration with related distribution systems. The effectiveness and adaptability of the proposed framework is demonstrated by simulations using the modified IEEE 118-bus system.

Scenario-based Unit Commitment Optimization for Power System with Large-scale Wind Power Participating in Primary Frequency Regulation

Continuous increase of wind power penetration brings high randomness to power system,and also leads to serious shortage of primary frequency regulation(PFR)reserve for power system whose reserve capacity is typically provided by conventional units.Considering large-scale wind power participating in PFR,this paper proposes a unit commitment optimization model with respect to coordination of steady state and transient state.In addition to traditional operation costs,losses of wind farm de-loaded operation,environmental benefits and transient frequency safety costs in high-risk stochastic scenarios are also considered in the model.Besides,the model makes full use of interruptible loads on demand side as one of the PFR reserve sources.A selection method for high-risk scenarios is also proposed to improve the calculation efficiency.Finally,this paper proposes an inner-outer iterative optimization method for the model solution.The method is validated by the New England 10-machine system,and the results show that the optimization model can guarantee both the safety of transient frequency and the economy of system operation.

Intelligent H_(2)S release coating for regulating vascular remodeling

Coronary atherosclerotic lesions exhibit a low-pH chronic inflammatory response.Due to insufficient drug release control,drug-eluting stent intervention can lead to delayed endothelialization,advanced thrombosis,and unprecise treatment.In this study,hyaluronic acid and chitosan were used to prepare pH-responsive self-assembling films.The hydrogen sulfide(H2S)releasing aspirin derivative ACS14 was used as drug in the film.The film regulates the release of the drug adjusted to the microenvironment of the lesion,and the drug balances the vascular function by releasing the regulating gas H2S,which comparably to NO promotes the self-healing capacity of blood vessels.Drug releasing profiles of the films at different pH,and other biological effects on blood vessels were evaluated through blood compatibility,cellular,and implantation experiments.This novel method of self-assembled films which H2S in an amount,which is adjusted to the condition of the lesion provides a new concept for the treatment of cardiovascular diseases.

Decision Support System for Adaptive Restoration Control of Distribution System

Aiming at the high-dimensional uncertainties of restoration process, an optimization model for distribution system restoration control is proposed considering expected restoration benefits, expected restoration costs, and security risks of the overall restoration scheme. In the proposed model, the effect of security control on restoration process is actively analyzed considering the security control costs of preventive, emergency, and correction controls. A two-layer decision support framework for distribution system restoration decision support system(DRDSS) is also designed. The upper layer of the proposed framework generates the pre-adjustment schemes of operation mode for energized power grid by load transfer and selects the optimal pre-adjustment scheme and the corresponding partitioning scheme based on the partition adjustment results of each pre-adjustment scheme. In addition, it optimizes the spatial-temporal decision-making of the inter-partition connectivity. For each partition, the lower layer of the proposed framework pre-selects the units and loads to be restored according to the pre-evaluated restoration income, generates the table of alternative restoration scheme for coping with uncertain events through simulation and deduction, and evaluates the risk and benefit of each scheme.For the uncertain events in the actual restoration process, the current restoration scheme can be adaptively switched to a sub-optimal scheme or re-optimized if necessary. Meanwhile, the proposed framework provides an information interaction interface for collaborative restoration with the related transmission system. A 123-node test system is built to evaluate the effectiveness and adaptability of the proposed model and framework.

Polarization microwave-induced thermoacoustic imaging for quantitative characterization of deep biological tissue microstructures

Polarization optical imaging can be used to characterize anisotropy in biological tissue microstructures and has been demonstrated to be a powerful tool for clinical diagnosis. However, the approach is limited by an inability to image targets deeper than ~1 mm due to strong optical scattering in biological tissues. As such, we propose a novel polarization microwave-induced thermoacoustic imaging(P-MTAI) technique to noninvasively detect variations in deep tissue by exploiting the thermoacoustic signals induced by four pulsed microwaves of varying polarization orientations. The proposed P-MTAI method overcomes the penetration limits of conventional polarization optical imaging and provides submillimeter resolution over depths of several centimeters. As part of the paper, the structural characteristics of tissues were quantified using a new parameter, the degree of microwave absorption anisotropy. P-MTAI was also applied to the noninvasive detection of morphological changes in cardiomyocytes as they transitioned from ordered to disordered states, providing a potential indication of myocardial infarction.

Ultra-fast and low-cost fabrication of transparent paper

Transparent paper is a kind of promising and environmentally friendly material.In this study,we show that transparent paper can be fabricated in an ultra-fast and low-cost way.This low-cost top-down method only takes three steps of cell separation,lignin removal,and cold pressing to obtain a high-quality transparent paper.The fabrication time is further reduced,and the resulted transparent paper shows high transparency up to 90.3%.The application as a substrate material for transparent and flexible electronic devices is demonstrated by emulating the printed circuit on the prepared transparent paper.This top-down method will greatly promote the market-oriented applications of transparent paper as an environment friendly material.

Regulating f orbital of Tb electronic reservoir to activate stepwise and dual-directional sulfur conversion reaction

The sluggish kinetics in multistep sulfur redox reaction with different energy requirements for each step,is considered as the crucial handicap of lithium–sulfur(Li–S)batteries.Designing an electron reservoir,which can dynamically release electron to/accept electron from sulfur species during dis-charge/charge,is the ideal strategy for realizing stepwise and dual-directional polysulfide electrocatalysis.Herein,a single Tb^(3+/4+)oxide with moderate unfilled f orbital is synthetized as an electron reservoir to optimize polysulfide adsorption via Tb–S and N…Li bonds,reduce activation energy barrier,expe-dite electron/Li+transport,and selectively catalyze both long-chain and short-chain polysulfide conversions during charge and discharge.As a result,Tb electron reservoir enables stable operation of low-capacity decay(0.087%over 500 cycles at 1 C),high sulfur loading(5.2 mg cm^(2))and electrolyte-starved(7.5μL mg^(-1))Li–S batteries.This work could unlock the potential of f orbital engineering for high-energy battery systems.

Novel dental implant modifications with two-staged double benefits for preventing infection and promoting osseointegration in vivo and in vitro

Peri-implantitis are a major problem causing implant failure these days.Accordingly,anti-infection during the early stage and subsequent promotion of osseointegration are two main key factors to solve this issue.Micro-arc oxidation(MAO)treatment is a way to form an oxidation film on the surface of metallic materials.The method shows good osteogenic properties but weak antibacterial effect.Therefore,we developed combined strategies to combat severe peri-implantitis,which included the use of a novel compound,PD,comprising dendrimers poly(amidoamine)(PAMAM)loading dimethylaminododecyl methacrylate(DMADDM)as well as MAO treatment.Here,we explored the chemical properties of the novel compound PD,and proved that this compound was successfully synthesized,with the loading efficiency and encapsulation efficiency of 23.91%and 31.42%,respectively.We further report the two-stage double benefits capability of PD+MAO:(1)in the first stage,PD+MAO could decrease the adherence and development of biofilms by releasing DMADDM in the highly infected first stage after implant surgery both in vitro and in vivo;(2)in the second stage,PD+MAO indicated mighty anti-infection and osteoconductive characteristics in a rat model of peri-implantitis in vivo.This study first reports the two-staged,double benefits of PD+MAO,and demonstrates its potential in clinical applications for inhibiting peri-implantitis,especially in patients with severe infection risk.

A Note on Quadratically Parametrized Surfaces

Let f0, f1, f2, f3 be linearly independent homogeneous quadratic forms in the standard Z-graded ring R ：= K[s, t, u], and gcd（f0, f1, f2, f3） = 1. This defines a rational map Ф ： P2 → P3. The Rees algebra Rees（I） = R I I2 … of the ideal I = （f0, fl, f2, fs） is the graded R-algebra which can be described as the image of an R-algebra homomorphism h ： R[x, y, z, w] → Rees（I）. This paper discusses the free resolutions of I, and the structure of ker（h）.