Performance-control-orientated hybrid metal additive manufacturing technologies:state of the art,challenges,and future trends

Metal additive manufacturing(AM)technologies have made significant progress in the basic theoretical field since their invention in the 1970s.However,performance instability during continuous processing,such as thermal history,residual stress accumulation,and columnar grain epitaxial growth,consistently hinders their broad application in standardized industrial production.To overcome these challenges,performance-control-oriented hybrid AM(HAM)technologies have been introduced.These technologies,by leveraging external auxiliary processes,aim to regulate microstructural evolution and mechanical properties during metal AM.This paper provides a systematic and detailed review of performance-control-oriented HAM technology,which is categorized into two main groups:energy field-assisted AM(EFed AM,e.g.ultrasonic,electromagnetic,and heat)technologies and interlayer plastic deformation-assisted AM(IPDed AM,e.g.laser shock peening,rolling,ultrasonic peening,and friction stir process)technologies.This review covers the influence of external energy fields on the melting,flow,and solidification behavior of materials,and the regulatory effects of interlayer plastic deformation on grain refinement,nucleation,and recrystallization.Furthermore,the role of performance-control-oriented HAM technologies in managing residual stress conversion,metallurgical defect closure,mechanical property improvement,and anisotropy regulation is thoroughly reviewed and discussed.The review concludes with an analysis of future development trends in EFed AM and IPDed AM technologies.

Detection of Embryo Sex Chromosome by Dual Color Fluorescent In-Situ Hybridization

In order to evaluate the effects of sex chromosomal mosaicism on the accuracy of single-cell gender diagnosis, sex chromosomes of 21 normal fertilized embryos were detected by dual color fluorescent in-situ hybridization (FISH). The results showed that 4 embryos had sex chromosomal mosaicism (19%) and the remaining 17 showed uniformly XX or XY signals in all blastomeres. In conclusion, identification of sex by dual color FISH analysis of a single cell was accurate and efficient , and sex chromosomal mosaicism would not affect preimplantation gender diagnosis.

In-situ magnetic field enhanced performances in ferromagnetic FeCo_(2)O_(4) nanofibers-based rechargeable Zinc-air batteries

Field-assisted electrocatalytic reactions are demonstrated to be sufficient strategies in enhancing the electrocatalyst activities for oxygen evolution reaction(OER).Here,we report the in-situ magnetic field enhanced electrocatalytic activity in ferromagnetic FeCo_(2)O_(4)nanofibers.Our results demonstrate that the overpotential of FeCo_(2)O_(4)nanofibers at 10 mA cm^(-2)shows a left-shift of 40 mV for the OER by applying an external magnetic field,and no obvious change has been observed in the non-ferromagnetic-order Co3O4nanofibers.Calculation results indicate that there are more overlaps between the density of states for Co3d and O 2p by applying an external magnetic field.Accordingly,the spin hybridization of 3d-2p and the kinetics of spin charge transfer are optimized in ferromagnetic FeCo_(2)O_(4),which can promote the adsorption of oxygen-intermediates and electron transfer,significantly improving its electrocatalytic efficiency.What’s more,the maximum power density of the FeCo_(2)O_(4)nanofibers based Zn-air battery(ZAB)increases from 97.3 mW cm^(-2)to 108.2 mW cm^(-2)by applying an external magnetic field,providing a new idea for the application of magnetic cathode electrocatalysts in ZABs.

Matrix Induced Synthesis of Eu^(3+) Doped Zn_3(PO_4)_2 and LaPO_4 Phosphors by in-Situ Composing Hybrid Precursors

Using rare earth and zinc coordination polymers with aromatic carboxylic acids as the precursors, composing with the polyethylene glycol (PEG) as the dispersing media, micro crystalline phosphors Zn_3(PO_4)_2∶Eu 3+ and LaPO_4∶Eu 3+ were synthesized by in-situ co-precipitation method. X-ray diffraction and scanning electronic micrograph were used to characterize the resultant samples, whose particle size are in the range of micrometer. The emission spectra of Zn_3(PO_4)_2∶Eu 3+ (λ_ ex=245 nm) and LaPO_4∶Eu 3+ (λ_ ex=390 nm) shows that the emission for Eu 3+ in Zn_3(PO_4)_2 is dominated by the 5D_0→7F_1 (592 nm) magnetic-dipole transition,While the dominant emission for Eu 3+ in LaPO_4 is the typical hypersensitive transition 5D_0→7F_2 (618 nm).

Green Approach for <i>In-Situ</i>Growth of CdS Nanorods in Low Band Gap Polymer Network for Hybrid Solar Cell Applications

In-situ growth of CdS nanorods (NRs) has been demonstrated via solvothermal, in a low band gap polymer, poly [[4,8-bis[(2-ethylhexyl)oxy] benzo [1,2-b:4,5-b’] dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno [3,4-b] thiophenediyl]] (PTB7). It is a high yielding, green approach as it removes use of volatile and hazardous chemicals such as pyridine as ligand which are conventionally used to synthesize precursors of CdS (NRs). Moreover the solvothermal process is a zero emission process being a close vessel synthesis and hence no material leaching into the atmosphere during the synthesis. The PTB7:CdS nanocomposite has been characterized by SEM, XRD, FTIR, UV-visible spectroscopy techniques. The photoluminescence (PL) spectroscopy study of PTB7 with CdS NRs has shown significant PL quenching by the incorporation of CdS NRs in PTB7;this shows that CdS NRs are efficient electron acceptors with the PTB7. The PTB7:CdS is used as active layer in the fabrication of hybrid solar cells (HSC) as donor-acceptor combination in the bulk heterojunction (BHJ) geometry. The HSCs fabricated using this active layer without any additional supporting fullerene based electron acceptor has given power conversion efficiency of above 1%.

Characterization of progenies of Triticum aestivum- Psathyrostachys juncea derivatives by using genomic in-situ hybridization

Using genomic in-situ hybridization (GISH) technique, 7 translocation-addition lines, 6 transloca-tion and translocation-addition lines, 2 ditelosomic addition lines and 1 translocation line were identified from Triticum aestivum L.-Psathyrostachys juncea (Fisch. ) Nevski intergeneric hybrids, of which translocation-addition and translocation and translocation-addition lines were not found in other reports. No substitutions and disomic additions were detected in the hybrids and breakages occurred in all P. juncea chromosomes studied. Results have shown that the improved GISH technique is a rapid and economical method for use in this field.

Aptamer-induced in-situ growth of acetylcholinesterase-Cu_(3)(PO_(4))_(2)hybrid nanoflowers for electrochemical detection of organophosphorus inhibitors

Enzyme-inorganic hybrid nanoflowers(HNFs)have shown excellent sensing capabilities due to their large specific surface area as well as the simplicity and mildness of the preparation process.However,coupling HNFs to electrodes to fabricate a uniform and controllable enzymatic electrochemical sensing interface remains a challenge.Here,we proposed an aptamer-induced insitu fabrication strategy for preparing an HNF-based electrochemical sensor with ideal performance.Central to this strategy is the introduction of acetylcholinesterase(AChE)-specific binding aptamer(Apt),which induces the in-situ growth of AChE-copper phosphate(Cu_(3)(PO_(4))_(2))HNFs on the surface of carbon paper(CP).In addition,a dense gold nanoparticle(AuNP)layer was electrodeposited on the CP for anchoring Apt and further extending the electroactive surface area.The prepared AChECu_(3)(PO_(4))_(2)HNF/Apt/AuNP/CP biosensor exhibited a wide detection range from 1 to 107 pM for the four organophosphorus inhibitors,including isocarbophos,dichlorvos,methamidophos,and parathion,with detection limits down to 0.016,0.028,0.071,and 0.113 pM,respectively.With the reactivation of pralidoxime chloride,the electrode can still recover 98.1%of the response after five times of repeated use.In real sample detection,the biosensor achieved high recoveries from 96.45%to 100.13%.The detection target may be extendable to other AChE inhibitors(e.g.,drugs for Alzheimer’s disease).This study demonstrates for the first time the feasibility of using aptamers as an inducer to fabricate an electrochemical enzyme sensing interface in-situ.This strategy can be used to fabricate other enzyme-based biosensors and therefore has broader applications.

Manipulating the ionic nanophase of Nafion by in-situ precise hybridization with polymer quantum dot towards highly enhanced fuel cell performances

Hierarchical-structure materials hold great promise for numerous applied domains such as fuel cell,sensor,and optic.However,the developments are significantly impeded by the lack of efficient strategy permitting precise and efficient decoration of specific confined space.Here,an in-situ precise hybridization strategy is proposed to efficiently manipulate the nanostructure of membrane nanochannels.Typically,Nafion ionic nanochannels are impregnated with precursors via heat swelling,followed by microwave-assisted condensation to form polymer quantum dot network.The formation of polymer quantum dot network significantly improves the stability and functionality of ionic nanophase(i.e.,ionic nanochannel).This helps hybrid membrane achieving enhanced proton conduction and methanol barrier properties,resulting in over ten times increase in proton/methanol selectivity.These then impart prominent device performances for both hydrogen and methanol fuel cells with the elevation of~100%.Importantly,such function manipulation of ionic nanochannels is achieved with fully maintaining function of backbone nanophase.Besides,the regulation of physical topology and chemical environment of ionic nanochannel also brings optimization of gas and ion separation properties.This facile and versatile strategy may open up a new avenue for decorating confined space of many hierarchical-structure materials.

噬菌体展示外源多肽的免疫原性研究

利用噬菌体展示技术将丝状噬菌体fd基因 8克隆入 pKK2 2 3-3质粒中 .将白色念珠菌特异表位基因插入到修饰后的质粒载体中 ,并制备了杂合噬菌体 .利用纯化的该表位抗原PA免疫小鼠 ,结果表明该噬菌体 -表位抗原PA在有无佐剂存在的情况下均产生抗体 ,用ELISA方法采用双波长 (4 50 / 6 30nm)检测抗体 ,其在有无佐剂存在的情况下光密度值无明显差别 .免疫后小鼠脾淋巴细胞在有无佐剂的情况下均产生明显增殖 ,未见明显的毒副作用 ,具有良好的安全性 .该方法产生的抗体与传统的合成多肽相比具有方法简便、低价高效等特点 .它将成为生产高效低价疫苗的有效途径 .该噬菌体 -表位抗原PA为真菌疫苗的研制打下基础 .

噬菌体展示肿瘤异性抗原表位的初步免疫活性研究

利用噬菌体展示技术将丝噬菌体(fd)基因8克隆入pKK233-3质粒中,将人的恶性黑色素瘤的抗原表位基因插入到修饰后的质粒载体中,制备了含有抗原表位的杂合噬菌体.利用纯化的表位抗原免疫小鼠,用间接ELISA方法采用双波长(450/630nm)动态检测抗体.结果表明,噬菌体-表位抗原刺激小鼠产生了抗体.抗体的含量随时间不断增加,到4周时达到高峰.小鼠脾淋巴细胞转化实验表明噬菌体-表位抗原产生了明显的淋巴细胞增殖反应,为研制肿瘤疫苗奠定了基础.

蛋白质组学及其在植物研究中的应用

蛋白质组研究将生命活动直接化和具体化,将基因功能整体化、动态化、定量化,是后基因组计划的一个重要组成部分.为全面准确了解和揭示植物生命活动规律,对其在分子水平上的研究工作应将基因组研究和蛋白质组研究并列开展,为植物各领域的研究提供更可靠的理论依据.综述了蛋白质组学的研究意义、重要研究体系及在植物研究中的应用,同时展望了未来的蛋白质组学.

噬菌体展示技术筛选与白介素-32相互作用的蛋白

目的利用T7噬菌体展示技术筛选与白介素-32(interleukin-32,IL-32)相互作用的蛋白。方法构建IL-32α的原核表达重组质粒,表达并纯化重组IL-32α蛋白(recombinant IL-32α,rIL-32α);以纯化后的rIL-32α作为靶蛋白,应用T7噬菌体展示技术对人肝细胞cDNA文库进行筛选;对筛选到的阳性克隆进行DNA测序及计算机辅助分析;利用哺乳动物双杂交实验和免疫共沉淀实验对筛选到的阳性克隆进行验证。结果成功表达并亲和纯化了rIL-32α蛋白;经过5轮筛选,投入和产出的噬菌体滴度比值达到稳定;同源性分析初步确定9个与IL-32α蛋白相互作用的蛋白;进一步实验证实IL-32α与这9个蛋白片段能发生相互作用。结论利用T7噬菌体展示技术成功筛选到9个与IL-32α相互作用的蛋白,我们的发现为深入揭示IL-32的生物学功能奠定了研究基础。

蛋白质组学研究进展

蛋白质组学是在后基因组时代出现的一个新的研究领域,它是对机体、组织或细胞的全部蛋白质的表达和功能模式进行研究.简要介绍蛋白质组学的概念、研究内容并对近年来蛋白质组学主要研究技术进行了介绍.

中国美利奴绵羊MHC ClassⅡb区349I12 BAC克隆插入片段基因组成与结构分析

利用已测序的中国美利奴绵羊细菌人工染色体(BAC)文库MHC区段阳性克隆插入片段制备探针,筛选中国美利奴绵羊(新疆军垦型)混合组织cDNA文库,以期获得该MHC片段的基因组成与结构信息。用中国美利奴绵羊MHC ClassⅡb区域内的349I12 BAC克隆,BsaJⅠ酶切后制备α-32P放射性探针,以噬菌斑原位杂交筛选正常中国美利奴绵羊cDNA文库,并将分离所得的cDNA阳性克隆测序后进行基因结构分析。以349I12 BAC克隆制备探针经过两轮的噬菌斑原位杂交筛选,获得19个cDNA阳性克隆,经测序、比对等进一步分析确定获得17条不同序列,其中7条序列与免疫相关。绵羊20号染色体上的MHC区段包含表达序列,且多为断裂基因,对其基因结构的分析将有助于相应基因功能及调控方面的研究。

卡那霉素链霉菌噬菌体SKJ 1——温和性噬菌体

从土壤中分离出一株卡那霉素链霉菌噬菌体ＳＫＪ１，该噬菌体在卡那霉素链霉菌及林肯链霉菌菌苔上产生混浊的噬菌斑。从噬斑中长出的菌落后代对ＳＫＪ１噬菌体的感染产生了抗性。单株传代未风自发释放游离噬菌体。紫外线照射亦未发现诱导现象。抗性菌株经１０μｇ／ｍｌ丝裂霉素Ｃ处理后，其中一株能释放出约５．９×１０＾３ｐｆｕ／ｍｌ游离噬菌体颗粒，推测这些抗性菌株可能是溶源性菌株。

利用BAC克隆混合型探针筛选中国美利奴细毛羊cDNA文库

采用Taq酶进行快速标记细菌人工染色体(Bacterial artificial chromosome,BAC)克隆酶切片段,对制备好的混合型探针进行检测。通过噬菌体原位杂交的方法,筛选中国美利奴细毛羊cDNA文库。结果杂交筛选获得了3个cDNA阳性克隆,经过测序比对,分析了主要组织相容性复合体(Major histocompatibility complex,MHC)基因的组成。

中国美利奴绵羊55L9 BAC克隆基因的筛选与序列的初步分析

利用绵羊55L9 BAC(细菌人造染色体)克隆制备探针,采用噬菌斑原位杂交方法,从中国美利奴细毛羊cDNA文库中筛选与免疫相关的基因,并对筛选得到的候选基因进行测序及软件分析。初步筛出12个候选阳性克隆。经过测序和比对,推测有8个独立的序列可能与绵羊的免疫及疾病相关,其中2个基因可以在已提交的BAC序列中定位。

蛋白质相互作用研究的常用方法进展及比较

如今蛋白质间的相互作用已成为生命科学领域研究的重点,而各种蛋白质间相互作用的研究方法的飞速发展成为蛋白质研究的重点。本综述中将着眼于酵母双杂交方法新进发展与Sos系统、噬菌体展示、GST-pull down、免疫共沉淀、串联亲和纯化等蛋白质相互作用研究方法做一比较分析。以便在未来的研究中,根据不同方法的优缺点选择合适的研究技术。

Hybrid memristor-CMOS neurons for in-situ learning in fully hardware memristive spiking neural networks

Spiking neural network,inspired by the human brain,consisting of spiking neurons and plastic synapses,is a promising solution for highly efficient data processing in neuromorphic computing.Recently,memristor-based neurons and synapses are becoming intriguing candidates to build spiking neural networks in hardware,owing to the close resemblance between their device dynamics and the biological counterparts.However,the functionalities of memristor-based neurons are currently very limited,and a hardware demonstration of fully memristor-based spiking neural networks supporting in-situ learning is very challenging.Here,a hybrid spiking neuron combining a memristor with simple digital circuits is designed and implemented in hardware to enhance neuron functions.The hybrid neuron with memristive dynamics not only realizes the basic leaky integrate-and-fire neuron function but also enables the in-situ tuning of the connected synaptic weights.Finally,a fully hardware spiking neural network with the hybrid neurons and memristive synapses is experimentally demonstrated for the first time,and in-situ Hebbian learning is achieved with this network.This work opens up a way towards the implementation of spiking neurons,supporting in-situ learning for future neuromorphic computing systems.

In-situ electrochemical activation designed hybrid electrocatalysts for water electrolysis

Developing transition metal-based electrocatalysts with rich active sites for water electrolysis plays important roles in renewable energy fields. So far, some strategies including designing nanostructures, incorporating conductive support or foreign elements have been adopted to develop efficient electrocat- alysts. Herein, we summarize recent progresses and propose in-situ electrochemical activation as a new pretreating technique for enhanced catalytic performances. The activation techniques mainly comprise facile electrochemical processes such as anodic oxidation, cathodic reduction, etching, lithium-assisted tuning and counter electrode electro-dissolution. During these electrochemicaI treatments, the catalyst surfaces are modified from bulk phase, which can tune local electronic structures, create more active spe- cies. enlarge surface area and thus improve the catalytic performances. Meanwhile, this technique can couple the atomic, electronic structures with electrocatalysis mechanisms for water splitting. Compared to traditional chemical treatment, the in-situ electrochemical activation techniques have superior advantages such as facile operation, mild environment, variable control, high efficiency and flex- ibility. This review may provide guidance for improving water electrolysis efficiencies and hold promis- ing for application in many other energy-conversion fields such as supercapacitors, fuel cells and batteries.