以DMA、甘油与DMF为保护剂的鸡精液冷冻技术体系比较研究

为筛选出高效、更具推广价值的鸡精液冷冻技术体系,以湘黄鸡和湘东鸡冻后精子活力、受精率与孵化率为检测指标,比较二甲基乙酰胺(Dimethylacetamide,DMA)细管、甘油细管与N,N-二甲基甲酰胺(N,N-Dimethylformamide,DMF)细管精液冷冻技术体系效果。结果显示:①DMA方案最适液氮面冷冻距离为1 cm,冻后平均精子活力湘东鸡为0.23,湘黄鸡为0.33;甘油方案最适液氮面冷冻距离为5 cm,冻后平均精子活力湘东鸡为0.41,湘黄鸡为0.36。②湘东鸡DMF方案平均冻后精子活力为0.15,极显著低于甘油与DMA(P<0.01)。③通过5轮输精,甘油方案平均受精率为45.35%,孵化率为60.31%,均极显著高于其他两类方案(P<0.01)。④甘油方案,公鸡26周龄组冻前精子活力与冻后活力极显著高于50周龄组(P<0.01)。结果表明,甘油细管是目前鸡精液冷冻保存建设的首选方案,应用时可先进行冷冻速率的优化,且应尽可能选择青壮年公鸡。

DMF对原液着色与染色涤纶长丝的脱色影响探究

探究了N,N-二甲基甲酰胺(DMF)对原液着色涤纶与染色涤纶长丝的脱色影响。结果发现:当纤维样品与DMF的物料配比为1∶12,脱色时间为20 min,水浴脱色温度为95℃时,脱色效果较好;染色涤纶长丝受DMF脱色剂的影响相对较大,20组样品的脱色率为52.07%~91.83%;原液着色涤纶长丝受DMF脱色剂的影响相对较小,20组样品的脱色率为0.75%~26.41%。

10000 m^(3)闲置碳钢储槽储存DMF研究及应用

安阳九天精细化工有限责任公司2套甲胺/DMF装置当前DMF日产量已近400 t,但2台不锈钢储槽DMF储存量只有约2 000 t,产销存矛盾日益显现。基于现有工艺、设备条件及安化园区整体布局等要求,经分析与论证,新建1台5 000 m^(3)以上不锈钢储槽不具备实施条件且投资较高,于是拟改造1台闲置的10 000 m^(3)甲醇储槽(碳钢材质)用于DMF储存,并通过多次论证及完善形成碳钢储槽内部整体除油脱脂、酸洗钝化的最终改造方案。2021年10月底完成全部改造工作后,DMF储存能力达到11 000 t,碳钢储槽内DMF产品色度、铁离子含量、电导率均达到DMF优等品要求,开创了大型碳钢储槽储存DMF的先例,满足了DMF的产销存需求,助力了2套甲胺/DMF装置的长周期、稳定、高负荷运行。

Bio-Inspired Screwed Conduits from the Microfluidic Rope-Coiling Effect for Microvessels and Bronchioles

Tubular microfibers have recently attracted extensive interest for applications in tissue engineering.However,the fabrication of tubular fibers with intricate hierarchical structures remains a major challenge.Here,we present a novel one-step microfluidic spinning method to generate bio-inspired screwed conduits(BSCs).Based on the microfluidic rope-coiling effect,a viscous hydrogel precursor is first curved into a helix stream in the channel,and then consecutively packed as a hollow structured stream and gelated into a screwed conduit(SC)via ionic and covalent crosslinking.By taking advantage of the excellent fluid-controlling ability of microfluidics,various tubes with diverse structures are fabricated via simple control over fluid velocities and multiple microfluidic device designs.The perfusability and permeability results,as well as the encapsulation and culture of human umbilical vein endothelial cells(HUVECs),human pulmonary alveolar epithelial cells(HPAs),and myogenic cells(C2C12),demonstrate that these SCs have good perfusability and permeability and the ability to induce the formation of functional biostructures.These features support the uniqueness and potential applications of these BSCs as biomimetic blood vessels and bronchiole tissues in combination with tissue microstructures,with likely application possibilities in biomedical engineering.

Biomimetic Erythrocyte-Like Particles from Microfluidic Electrospray for Tissue Engineering

Microparticles have demonstrated value for regenerative medicine.Attempts in this field tend to focus on the development of intelligent multifunctional microparticles for tissue regeneration.Here,inspired by erythrocytes-associated self-repairing process in damaged tissue,we present novel biomimetic erythrocyte-like microparticles(ELMPs).These ELMPs,which are composed of extracellular matrix-like hybrid hydrogels and the functional additives of black phosphorus,hemoglobin,and growth factors(GFs),are generated by using a microfluidic electrospray.As the resultant ELMPs have the capacity for oxygen delivery and near-infrared-responsive release of both GFs and oxygen,they would have excellent biocompatibility and multifunctional performance when serving as microscaffolds for cell adhesion,stimulating angiogenesis,and adjusting the release profile of cargoes.Based on these features,we demonstrate that the ELMPs can stably overlap to fill a wound and realize controllable cargo release to achieve the desired curative effect of tissue regeneration.Thus,we consider our biomimetic ELMPs with discoid morphology and cargo-delivery capacity to be ideal for tissue engineering.

Functional microfluidics:theory,microfabrication,and applications

Microfluidic devices are composed of microchannels with a diameter ranging from ten to a few hundred micrometers.Thus,quite a small(10-9–10-18l)amount of liquid can be manipulated by such a precise system.In the past three decades,significant progress in materials science,microfabrication,and various applications has boosted the development of promising functional microfluidic devices.In this review,the recent progress on novel microfluidic devices with various functions and applications is presented.First,the theory and numerical methods for studying the performance of microfluidic devices are briefly introduced.Then,materials and fabrication methods of functional microfluidic devices are summarized.Next,the recent significant advances in applications of microfluidic devices are highlighted,including heat sinks,clean water production,chemical reactions,sensors,biomedicine,capillaric circuits,wearable electronic devices,and microrobotics.Finally,perspectives on the challenges and future developments of functional microfluidic devices are presented.This review aims to inspire researchers from various fields engineering,materials,chemistry,mathematics,physics,and more—to collaborate and drive forward the development and applications of functional microfluidic devices,specifically for achieving carbon neutrality.

Simulation and fabrication of in vitro microfluidic microelectrode array chip for patterned culture and electrophysiological detection of neurons

To enable the detection and modulation of modularized neural networks in vitro,this study proposes a microfluidic microelectrode array chip for the cultivation,compartmentalization,and control of neural cells.The chip was designed based on the specific structure of neurons and the requirements for detection and modulation.Finite-element analysis of the chip’s flow field was conducted using the COMSOL Multiphysics software,and the simulation results show that the liquid within the chip can flow smoothly,ensuring stable flow fields that facilitate the uniform growth of neurons within the microfluidic channels.By employing MEMS technology in combination with nanomaterial modification techniques,the microfluidic microelectrode array chip was fabricated successfully.Primary hippocampal neurons were cultured on the chip,forming a well-defined neural network.Spontaneous electrical activity of the detected neurons was recorded,exhibiting a 23.7%increase in amplitude compared to neuronal discharges detected on an open-field microelectrode array.This study provides a platform for the precise detection and modulation of patterned neuronal growth in vitro,potentially serving as a novel tool in neuroscience research.

High-throughput microfluidic production of carbon capture microcapsules:fundamentals,applications,and perspectives

In the last three decades,carbon dioxide(CO_(2)) emissions have shown a significant increase from various sources.To address this pressing issue,the importance of reducing CO_(2) emissions has grown,leading to increased attention toward carbon capture,utilization,and storage strategies.Among these strategies,monodisperse microcapsules,produced by using droplet microfluidics,have emerged as promising tools for carbon capture,offering a potential solution to mitigate CO_(2) emissions.However,the limited yield of microcapsules due to the inherent low flow rate in droplet microfluidics remains a challenge.In this comprehensive review,the high-throughput production of carbon capture microcapsules using droplet microfluidics is focused on.Specifically,the detailed insights into microfluidic chip fabrication technologies,the microfluidic generation of emulsion droplets,along with the associated hydrodynamic considerations,and the generation of carbon capture microcapsules through droplet microfluidics are provided.This review highlights the substantial potential of droplet microfluidics as a promising technique for large-scale carbon capture microcapsule production,which could play a significant role in achieving carbon neutralization and emission reduction goals.

Femtosecond laser-induced nanoparticle implantation into flexible substrate for sensitive and reusable microfluidics SERS detection

Surface-enhanced Raman spectroscopy(SERS)microfluidic system,which enables rapid detection of chemical and biological analytes,offers an effective platform to monitor various food contaminants and disease diagnoses.The efficacy of SERS microfluidic systems is greatly dependent on the sensitivity and reusability of SERS detection substrates to ensure repeated use for prolonged periods.This study proposed a novel process of femtosecond laser nanoparticle array(NPA)implantation to achieve homogeneous forward transfer of gold NPA on a flexible polymer film and accurately integrated it within microfluidic chips for SERS detection.The implanted Au-NPA strips show a remarkable electromagnetic field enhancement with the factor of 9×108 during SERS detection of malachite green(MG)solution,achieving a detection limit lower than 10 ppt,far better than most laser-prepared SERS substrates.Furthermore,Au-NPA strips show excellent reusability after several physical and chemical cleaning,because of the robust embedment of laser-implanted NPA in flexible substrates.To demonstrate the performance of Au-NPA,a SERS microfluidic system is built to monitor the online oxidation reaction between MG/NaClO reactants,which helps infer the reaction path.The proposed method of nanoparticle implantation is more effective than the direct laser structuring technique.It provides better performance for SERS detection,robustness of detection,and substrate flexibility and has a wider range of applications for microfluidic systems without any negative impact.

A novel integrated microfluidic chip for on-demand electrostatic droplet charging and sorting

On-demand droplet sorting is extensively applied for the efficient manipulation and genome-wide analysis of individual cells.However,state-of-the-art microfluidic chips for droplet sorting still suffer from low sorting speeds,sample loss,and labor-intensive preparation procedures.Here,we demonstrate the development of a novel microfluidic chip that integrates droplet generation,on-demand electrostatic droplet charging,and high-throughput sorting.The charging electrode is a copper wire buried above the nozzle of the microchannel,and the deflecting electrode is the phosphate buffered saline in the microchannel,which greatly simplifies the structure and fabrication process of the chip.Moreover,this chip is capable of high-frequency droplet generation and sorting,with a frequency of 11.757 kHz in the drop state.The chip completes the selective charging process via electrostatic induction during droplet generation.On-demand charged microdroplets can arbitrarilymove to specific exit channels in a three-dimensional(3D)-deflected electric field,which can be controlled according to user requirements,and the flux of droplet deflection is thereby significantly enhanced.Furthermore,a lossless modification strategy is presented to improve the accuracy of droplet deflection or harvest rate from 97.49% to 99.38% by monitoring the frequency of droplet generation in real time and feeding it back to the charging signal.This chip has great potential for quantitative processing and analysis of single cells for elucidating cell-to-cell variations.

Micro-nano-fabrication of green functional materials by multiphase microfluidics for environmental and energy applications

Multiphase microfluidic has emerged as a powerful platform to produce novel materials with tailor-designed functionalities,as microfluidic fabrication provides precise controls over the size,component,and structure of resultant materials.Recently,functional materials with well-defined micro-/nanostructures fabricated by microfluidics find important applications as environmental and energy materials.This review first illustrated in detail how different structures or shapes of droplet and jet templates are formed by typical configurations of microfluidic channel networks and multiphase flow systems.Subsequently,recent progresses on several representative energy and environmental applications,such as water purification,water collecting and energy storage,were overviewed.Finally,it is envisioned that integrating microfluidics and other novel materials will play increasing important role in contributing environmental remediation and energy storage in near future.

Microfluidic-oriented synthesis of enriched iridium nanodots/carbon architecture for robust electrocatalytic nitrogen fixation

Electrocatalytic nitrogen reduction reaction(NRR)is considered as a promising candidate to achieve ammonia synthesis because of clean electric energy,moderate reaction condition,safe operating process and harmless by-products.However,the chemical inertness of nitrogen and poor activated capacity on catalyst surface usually produce low ammonia yield and faradic efficiency.Herein,the microfluidic technology is proposed to efficiently fabricate enriched iridium nanodots/carbon architecture.Owing to in-situ co-precipitation reaction and microfluidic manipulation,the iridium nanodots/carbon nanomaterials possess small average size,uniform dispersion,high conductivity and abundant active sites,producing good proton activation and rapid electrons transmission and moderate adsorption/desorption capacity.As a result,the as-prepared iridium nanodots/carbon nanomaterials realize large ammonia yield of 28.73 μg h^(-1) cm^(-2) and faradic efficiency of 9.14%in KOH solution.Moreover,the high ammonia yield of 11.21 μg h^(-1) cm^(-2) and faradic efficiency of 24.30%are also achieved in H_(2)SO_(4) solution.The microfluidic method provides a reference for large-scale fabrication of nano-sized catalyst materials,which may accelerate the progress of electrocatalytic NRR in industrialization field.

Microfluidic thermotaxic selection of highlymotile sperm and in vitro fertilization

The selection of the most motile and functionally competent sperm is an essential basis for in vitro fertilization(IVF)and normal embryonic development.Widely adopted clinical approaches for sperm sample processing intensely rely on centrifugation and wash steps that may induce mechanical damage and oxidative stress to sperm.Although a few microfluidic sperm sorting devices may avoid these adverse effects by exploiting intrinsic guidance mechanisms of sperm swimming,none of these approaches have been fully validated by clinical-grade assessment criteria.In this study,a microfluidic sperm sorting device that enables the selection of highly motile and functional sperm via their intrinsic thermotaxis is presented.Bioinspired by the temperature microenvironment in the fallopian tube during natural sperm selection,a microfluidic device with controllable temperature gradients along the sperm separation channel was designed and fabricated.This study investigated the optimal temperature conditions for human sperm selection and fully characterized thermotaxis-selected sperm with 45 human sperm samples.Results indicated that a temperature range of 35–36.5℃along the separation channel significantly improves human sperm motility rate((85.25±6.28)%vs.(60.72±1.37)%;P=0.0484),increases normal sperm morphology rate((16.42±1.43)%vs.(12.55±0.88)%;P<0.0001),and reduces DNA fragmentation((7.44±0.79)%vs.(10.36±0.72)%;P=0.0485)compared to the nonthermotaxis group.Sperm thermotaxis is species-specific,and selected mouse sperm displayed the highest motility in response to a temperature range of 36–37.5℃ along the separation channel.Furthermore,IVF experiments indicated that the selected sperm permitted an increased fertilization rate and improved embryonic development from zygote to blastocyst.This microfluidic thermotaxic selection approach will be translated into clinical practice to improve the IVF success rate for patients with oligozoospermia and asthenozoospermia.

探索年产15万t甲胺DMF装置能量系统优化综合改造

针对年产15万t甲胺DMF装置的能量系统进行了深入分析与优化改造。研究发现,原有系统存在蒸汽利用不充分、余热回收不足等问题,导致能源消耗较高。通过实施热量梯级利用、余热回收增强、循环水系统优化及严寒条件下的汽化供暖等措施,实现了能量系统的综合升级。改造后,中低压蒸汽回收量显著提升,精馏余热利用率大幅增加,循环水使用量占比提高,能源系统指标得到全面优化。改造效果表明,甲胺DMF装置的总体能耗降低了20%以上,为化工行业提供了节能减排的有效途径。

Microfluidic preparation of surfactant-free ultrafine DAAF with tunable particle size for insensitive initiator explosives

High purity and ultrafine DAAF(u-DAAF)is an emerging insensitive charge in initiators.Although there are many ways to obtain u-DAAF,developing a preparation method with stable operation,accurate control,good quality consistency,equipment miniaturization,and minimum manpower is an inevitable requirement to adapt to the current social technology development trend.Here reported is the microfluidic preparation of u-DAAF with tunable particle size by a passive swirling microreactor.Under the guidance of recrystallization growth kinetics and mixing behavior of fluids in the swirling microreactor,the key parameters(liquid flow rate,explosive concentration and crystallization temperature)were screened and optimized through screening experiments.Under the condition that no surfactant is added and only experimental parameters are controlled,the particle size of recrystallized DAAF can be adjusted from 98 nm to 785 nm,and the corresponding specific surface area is 8.45 m^(2)·g^(-1)to 1.33 m^(2)·g^(-1).In addition,the preparation method has good batch stability,high yield(90.8%-92.6%)and high purity(99.0%-99.4%),indicating a high practical application potential.Electric explosion derived flyer initiation tests demonstrate that the u-DAAF shows an initiation sensitivity much lower than that of the raw DAAF,and comparable to that of the refined DAAF by conventional spraying crystallization method.This study provides an efficient method to fabricate u-DAAF with narrow particle size distribution and high reproducibility as well as a theoretical reference for fabrication of other ultrafine explosives.

Rapid fabrication of modular 3D paper-basedmicrofluidic chips using projection-based 3D printing

Paper-based microchips have different advantages,such as better biocompatibility,simple production,and easy handling,making them promising candidates for clinical diagnosis and other fields.This study describes amethod developed to fabricate modular three-dimensional(3D)paper-based microfluidic chips based on projection-based 3D printing(PBP)technology.A series of two-dimensional(2D)paper-based microfluidic modules was designed and fabricated.After evaluating the effect of exposure time on the accuracy of the flow channel,the resolution of this channel was experimentally analyzed.Furthermore,several 3D paper-based microfluidic chips were assembled based on the 2D ones using different methods,with good channel connectivity.Scaffold-based 2D and hydrogel-based 3D cell culture systems based on 3D paper-based microfluidic chips were verified to be feasible.Furthermore,by combining extrusion 3D bioprinting technology and the proposed 3D paper-based microfluidic chips,multiorgan microfluidic chips were established by directly printing 3D hydrogel structures on 3D paperbased microfluidic chips,confirming that the prepared modular 3D paper-based microfluidic chip is potentially applicable in various biomedical applications.

PYX在DMF中的溶析结晶动力学

为了优化及放大2,6-二苦氨基-3,5-二硝基吡啶(PYX)的溶析结晶工艺,在以DMF为溶剂、H_(2) O为反溶剂的结晶体系下开展了PYX的溶析结晶动力学研究。首先采用激光动态法测定了PYX在DMF纯溶剂和DMF-H_(2) O二元溶剂中的溶解度曲线,建立了相应的溶解度模型;确定了PYX的晶体生长类型,测定了PYX在结晶过程中的晶体生长及成核速率,建立了相应的结晶动力学模型,在此基础上分析了PYX结晶动力学的影响因素及规律。结果表明,PYX在DMF纯溶剂和不同体积比的DMF-H_(2) O二元溶剂中的溶解度随温度的升高而增大,随H_(2) O含量的增加而减小,不同溶剂中Apelblat模型对溶解度拟合结果的相关系数均大于0.99。PYX的晶体生长类型为粒度无关生长,晶体生长及成核活化能分别为8.33×10^(3) J/mol和1.01×10^(4) J/mol,过饱和比对于晶体生长速率的指数为6.73,搅拌强度、过饱和比、悬浮密度对于晶体成核速率的指数分别为0.27、7.16、0.14。PYX晶体生长及成核速率均随温度的升高而增大,随过饱和比的增大而增大,且升高温度或增大过饱和比更有利于PYX晶体成核。相比于过饱和比,搅拌强度、悬浮密度对PYX晶体成核速率的影响较小,增大搅拌强度或悬浮密度不利于PYX晶体生长。

Neurotoxicity mechanism of aconitine in HT22 cells studied by microfluidic chip-mass spectrometry

Aconitine,a common and main toxic component of Aconitum,is toxic to the central nervous system.However,the mechanism of aconitine neurotoxicity is not yet clear.In this work,we had the hypothesis that excitatory amino acids can trigger excitotoxicity as a pointcut to explore the mechanism of neurotoxicity induced by aconitine.HT22 cells were simulated by aconitine and the changes of target cell metabolites were real-time online investigated based on a microfluidic chip-mass spectrometry system.Meanwhile,to confirm the metabolic mechanism of aconitine toxicity on HT22 cells,the levels of lactate dehydrogenase,intracellular Ca^(2+),reactive oxygen species,glutathione and superoxide dismutase,and ratio of Bax/Bcl-2 protein were detected by molecular biotechnology.Integration of the detected results revealed that neurotoxicity induced by aconitine was associated with the process of excitotoxicity caused by glutamic acid and aspartic acid,which was followed by the accumulation of lactic acid and reduction of glucose.The surge of extracellular glutamic acid could further lead to a series of cascade reactions including intracellular Ca^(2+)overload and oxidative stress,and eventually result in cell apoptosis.In general,we illustrated a new mechanism of aconitine neurotoxicity and presented a novel analysis strategy that real-time online monitoring of cell metabolites can provide a new approach to mechanism analysis.

Microfluidic assisted 90%loading CL-20 spherical particles:Enhancing self-sustaining combustion performance

The performance of the chemical fuel determines the altitude,range and longevity of spacecraft in air and space exploration.Promising alternatives(e.g.,hypergolic ionic liquids or high-energy composites)with high-energy density,heat of formation and fast initial rate are considered as potential chemical fuels.As the high-energy density material,hexanitrohexaazaisowurtzitane(CL-20)often serves as secondary explosive with poor self-propagating combustion behaviors.Herein,90%loading CL-20 microspheres with uniform particle sizes are precisely prepared by microfluid method,which exhibit unique hierarchical structure.The morphology,thermal behaviors,as well as combustion performance were further investigated.The results demonstrated that as-prepared spherical particles exhibit prominent thermal compatibility,and the enhanced self-sustaining combustion performance.This work provides an efficient method achieving the uniform high-energy density particles with excellent self-sustaining combustion performance.

五塔多效精馏回收有机溶剂中DMF的工艺研究

针对二甲基甲酰胺(DMF)浓度较高的有机废水,采用五塔多效精馏回收工艺,废有机溶剂通过三效脱水、脱胺以及脱酸精制过程,生产高纯度的DMF产品,并利用化工流程模拟软件Aspen Plus分析精馏塔不同的回流比、进料层数等参数对原料脱水率及产品纯度的影响。结果表明:第一脱水塔回流比为0.7、脱酸塔回流比为1.3、脱胺塔进料层数为13时,回收的DMF产品质量分数>99.5%,DMF回收率>99.5%。脱除的废水中DMF浓度<0.05%(质量分数),废水经脱轻组分后,其中的二甲胺(DMA)和甲醇(CH3OH)的质量浓度可降至0.014mg/L和391.27mg/L,满足可生化的要求。原料废水回收DMF后的高沸点残渣,可通过焚烧过程进行无害化处置。废水中脱除的低沸点混合物中,DMA和CH3OH含量较高,可进一步精制分离,生产高纯度的甲醇和二甲胺产品。