新型乳化体系及其在化妆品中的应用(Ⅴ)——Janus乳液

Janus乳液是内相由两种互不相溶、彼此独立、界面分明的液相组成的单液滴形式的多分散体系,其内相两腔室的物质组成不同,两腔室的性质和形状具有不对称性,是一类特殊类型的各向异性乳液。Janus乳液不但保持了传统乳液的基本性质,其两腔室、多样的界面和灵活的结构、较大的界面面积和独立的空间等独特的结构优势使其对诸多功能性物质的选择性增溶、隔离、保护以及缓释等作用优于传统乳液。Janus乳液具有结构多样、定量可调的特点,可通过改变乳化剂种类、含量及各相的比例等实现对体系内界面的种类、数量和相对面积的调整,进而调控体系性质,以满足不同的使用需求。Janus乳液在化妆品、食品、生物医药以及微反应器等领域具有潜在的应用前景。本文介绍了Janus乳液及其制备方法,总结了影响Janus乳液性质的关键因素,概况了Janus乳液的性能优势。并基于目前对Janus乳液的研究及应用现状,展望了Janus乳液在化妆品领域的应用前景,并简单介绍了另外一种新型各向异性乳液——Cerberus乳液。同时,指出了Janus乳液在化妆品中应用面临的问题,并对有必要开展的研究工作提出了个人观点,旨在为性能优异的Janus乳液的开发及其在化妆品领域的实际应用提供参考信息。

Resting-state brain network remodeling after different nerve reconstruction surgeries:a functional magnetic resonance imaging study in brachial plexus injury rats

Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network level have not been elucidated.This study aimed to explore intranetwork changes related to altered peripheral neural pathways after different nerve reconstruction surgeries,including nerve repair,endto-end nerve transfer,and end-to-side nerve transfer.Sprague–Dawley rats underwent complete left brachial plexus transection and were divided into four equal groups of eight:no nerve repair,grafted nerve repair,phrenic nerve end-to-end transfer,and end-to-side transfer with a graft sutured to the anterior upper trunk.Resting-state brain functional magnetic resonance imaging was obtained 7 months after surgery.The independent component analysis algorithm was utilized to identify group-level network components of interest and extract resting-state functional connectivity values of each voxel within the component.Alterations in intra-network resting-state functional connectivity were compared among the groups.Target muscle reinnervation was assessed by behavioral observation(elbow flexion)and electromyography.The results showed that alterations in the sensorimotor and interoception networks were mostly related to changes in the peripheral neural pathway.Nerve repair was related to enhanced connectivity within the sensorimotor network,while end-to-side nerve transfer might be more beneficial for restoring control over the affected limb by the original motor representation.The thalamic-cortical pathway was enhanced within the interoception network after nerve repair and end-to-end nerve transfer.Brain areas related to cognition and emotion were enhanced after end-to-side nerve transfer.Our study revealed important brain networks related to different nerve reconstructions.These networks may be potential targets for enhancing motor recovery.

Adsorption characteristics of Cd(Ⅱ) and Ni(Ⅱ) from aqueous solution using succinylated hay

An environmentally friendly organic biosorbent was fabricated using hay by succinylation. Metallic cation adsorption tests were performed using synthetic nickel(Ⅱ) and cadmium(Ⅱ) solutions to simulate heavy-metal recovery from aqueous solution. The adsorption efficiency was greater than 98% for both cadmium and nickel ions when the biosorbent concentration was 5.0 g/L and the initial metal concentrations were 50 mg/L. The surface of the biosorbent was characterized using Fourier transform infrared spectroscopy to investigate the changes in the surface functional groups. The functional groups changed according to the surface treatment, resulting in an effective biosorbent. The kinetics of the metals adsorption revealed that the reactions are pseudo-second order, and the adsorption isotherm well followed the Langmuir model. The maximum adsorption capacities predicted by the Langmuir model were 75.19 mg/g and 57.77 mg/g for cadmium and nickel, respectively. The fabricated biosorbent was regenerated using Na Cl multiple times, with 2.1% for Cd and 4.0% for Ni in adsorption capacity after three regeneration cycles. The proposed biosorbent can be a good alternative to resin or other chemical adsorbents for heavy-metal recovery in metallurgical processing or municipal water treatment.

Infl uence of nitrate concentrations on EH40 steel corrosion aff ected by coexistence of Desulfovibrio desulfuricans and Pseudomonas aeruginosa bacteria

Nitrate addition is a common bio-competitive exclusion(BCE)method to mitigate corrosion in produced water reinjection systems,which can aff ect microbial community compositions,especially nitrate and sulfate reducing bacteria,but its eff ectiveness is in controversy.We investigated the infl uence of nitrate concentrations on EH40 steel corrosion aff ected by coexistence of Desulfovibrio vulgaris and Pseudomonas aeruginosa bacteria.Results demonstrate that only mixed bacteria or nitrate had little eff ect on EH40 steel corrosion,and nitrate could accelerate the corrosion of EH40 steel through the action of microorganisms.The corrosion promotion of nitrate was dependent on its concentrations,which increased from 0 to 5 g/L and decreased from 5 to 50 g/L.These diff erences were believed to be related to the regulation of nitrate in the growth of bacteria and biofi lms.Therefore,care must be taken to BCE method with nitrate when nitrate reducing bacteria with high corrosive activity are present in the environments.

Channel modeling and influenced factor analysis of the broadband dual-orthogonal polarized MIMO land mobile satellite channel

An accurate, complete and realistic channel model is re- quired to accurately analyze the system performance of a multiple input multiple output （MIMO） broadband satellite mobile commu- nication system with dual-orthogonal polarized antennas （DPAs）. In most current studies, the channel characteristic matrix （CCM） is always formed by an independent identical distribution （i.i.d） model of Rayleigh or Rice distribution and nevertheless incomplete and inaccurate to describe a broadband dual-orthogonal polarized MIMO land mobile satellite （BDM-LMS） channel. This paper fo- cuses on establishing the BDM-LMS channel statistical model, which combines the 4-state broadband LMS channel model, the time selective fading features, the channel covariance information （CCI） channel model and polarization correlations between an- tennas. The modeling steps of the channel model are introduced. The main emphasis is placed on the effects of the factors, such as antenna numbers, temporal correlations, terminal environments, elevation angles and polarization correlations between the DPAs, on the channel capacity in the BDM-LMS system. Many simulation results are provided to illustrate the effects of these factors through comparisons of the transmit rate, ergodic capacity and outage capacity with different factor values. Besides, the MIMO outage capacity advantages, which indicate the benefits of MIMO com- pared with a single input single output （SISO） system under the same channel condition, are also studied under i.i.d or BDM-LMS channel.

Comedy Movies and Stock Returns of Locally Headquartered Companies:Evidence from China

We utilize data on comedy moviegoers from 18 cities in China to investigate the impact of the positive mood triggered by these movies on the stock returns of locally headquartered listed companies.We find that although these movies have no relation to investment itself,the sentiment triggered by these movies could affect the risk decision making of investors.Moreover,the stock returns of locally headquartered companies become significantly negative after comedy movies are screened in their respective cities.These results support the mood maintenance hypothesis.This research also provides new evidence for the presence of home bias in capital markets.

Controlled Synthesis and Multifunctional Properties of FePt-Au Heterostructures

In this work FePt-Au heterostructured nanocrystals （HNCs） such as tadpole-, dumbbell-, bead-, and necklace-like nanostructures were synthesized by a facile heteroepitaxial growth of Au NCs onto FePt nanorods （NRs）. A study of the growth mechanism revealed that the morphology control of the final products can be correlated with the adsorption sites of hydrogen onto the FePt NRs, which can be manipulated by the amount of the forming gas （At/7% H2） added. Not only the optical characteristic and magnetic properties of the intrinsic materials were retained in the products, but also the FePt-Au HNCs showed the tunable multifunctional properties resulted from the interactions between Au and FePt. Moreover, for methanol oxidation, the FePt-Au HNCs exhibited enhanced catalytic activity and CO tolerance on the catalyst surface compared to commercial Pt catalysts. It is worth noting that as multifunctional units, the FePt-Au HNCs also possess a heterogeneous surface, which could potentially enable their site-specific functionalization for targeting or imaging purposes in biomedical applications. More interestingly, the catalytic properties of the FePt-Au HNCs also endow this material with application potentials in nanocatalysis.

Parallelized microfluidic droplet generators with improved ladder-tree distributors for production of monodisperseγ-Al_(2)O_(3)microspheres

In this paper,we present a parallelized microfluidic device with improved ladder-tree distributors for the scaled-up production of monodisperse microspheres.Owing to the improved distribution form comprising a ladder distributor in the center and tree distributors around the circumference,the uniformity of the generated droplets for our device was improved by 32.9%and 86.1%compared to those achieved in devices with conventional tree and ladder distributors,respectively,in the final production stage with 32 droplet generators,indicating the potential of our device for further scale-up while maintaining the monodispersity of the generated droplets.The effect of the 2D scale-up of our device was investigated by varying the continuous-phase flow rate and viscosity.Using our device,γ-Al_(2)O_(3)microspheres with a diameter of 598.1μm and a CV of 2.58%,as catalyst support for microreactors,were continuously synthesized at high production rate.The nickel-based catalyst prepared fromγ-Al_(2)O_(3)microspheres with large specific surface area and pore volume had an average NiO size of 14 nm,which was 60.9%of that supported on industrial support.The CO methanation conversion of the Ni@Al_(2)O_(3)microspheres was 1.7 times larger than Ni@Al_(2)O_(3)industrial support at 140℃.

Deformable Textile‑Structured Triboelectric Nanogenerator Knitted with Multifunctional Sensing Fibers for Biomechanical Energy Harvesting

Fibers and textiles that harvest mechanical energy via the triboelectric effect are promising candidates as power supplies for wearable electronics.However,triboelectric fibers and textiles are often hindered by problems such as complex fabrication processes,limited length,performances below the state-of-the-art of 2D planar configurations,etc.Here,we demonstrated a scalable fabrication of core-sheath-structured elastomer triboelectric fibers that combine silicone hollow tubes with gelelectrodes.Gel-electrodes were fabricated via a facile freeze–thawing process of blending polyvinyl alcohol(PVA),gelatin,glycerin,poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate)(PEDOT:PSS),and sodium chloride(NaCl).Such fibers can also be knitted into deformable triboelectric nanogenerator textiles with high electrical outputs up to 106 V and 0.8μA,which could work as reliable power supplies for small electronics.Moreover,we demonstrated fabric materials recognition,Morse code communication,and human-motion-recognition capabilities,making such triboelectric fiber platform an exciting avenue for multifunctional wearable systems and human–machine interaction.

Leaf-meridian bio-inspired nanofibrous electronics with uniform distributed microgrid and 3D multi-level structure for wearable applications

The interface between the active electronic and its osculatory target dominates the sensing response of high-sensitivity sensors.However,the interface properties are difficult to be adjusted and preserved owing to the limited strategies for surface engineering.In this work,inspired by nature frond leaf,a spatial multi-level nanofibrous membrane with grid-like microstructure of uniform distribution was fabricated,in which carboxylated carbon nanotubes(CCNTs)/poly(3,4-ethylenedioxythiophene)(PEDOT)was modified onto the surface of grid-like polyurethane(PU)nanofiber via the combination of metal mesh template,in situ polymerization and ultrasonic treatment.Nanofibrous membrane enables a pressure sensor with high sensitivities(5.13 kPa−1),fast response/recovery time(80 ms and 120 ms),and ultralow detection limit of 1 Pa.In addition,as a scalable and integrable platform,we also demonstrate its multifunctional applications for electro-thermal conversion and energy harvesting.All these results indicate the proposed nanofibrous membrane may potentially be applied to next-generation wearable devices.

Improved Stereoselective Syntheses of （-t-）-Valiolamine and （-I-）-Valienamine Starting from （-）-Shikimic Acid

Improved stereoselective syntheses of the targeted compounds （＋）-valiolamine 1 and （＋）-valienamine 2 starting from naturally abundant （–）-shikimic acid are described. A common key intermediate compound 7 was first synthesized from （–）-shikimic acid in 9 steps. The compound 7 was then converted to （＋）-valiolamine 1 in 3 steps, and was also converted to （＋）-valienamine 2 in 4 steps. In summary, （＋）-valiolamine 1 and （＋）-valienamine 2 were synthesized from （–）-shikimic acid in 12 （or 13） steps in 40% and 39% overall yields, respectively.