长循环脂质体的研究进展

脂质体的稳定性包括脂质体的物理、化学和生物学稳定性三个方面。其中生物学稳定性是脂质体在生物体内保持长循环的关键，制备长循环脂质体是实现脂质体许多性质的前提和基础。本文从脂质体的物理、化学特性，膜材组成及构造等几个方面综述了制备长循环脂质体的基本原理、制备手段和方法。

Multifunctional devices based on planar microsupercapacitors:Progress and challenges

With the boom of portable,wearable,and implantable smart electronics in the last decade,the demand for multifunctional microscale electrochemical energy storage devices has increased.Owing to their excellent rate performance,high power density,long cycling lifetime,easy fabrication,and integration,multifunctional planar microsupercapacitors(PMSCs)are deemed as one of the ideal micropower sources for next-generation flexible on-chip electronics.Therefore,we offer a comprehensive overview of the recent progress regarding multifunctional devices based on PMSCs,including stretchable,self-healing,stimulus-responsive,thermosensitive,biodegradable,and temperaturetolerant microdevices.We also emphasize the unique applications of multifunctionally integrated PMSCs in the construction of self-powered and sensor-integrated systems in terms of multifunctional operation modes.Finally,the key challenges and future prospects related to these multifunctional devices are discussed to stimulate further research in this flourishing field.

Ultralong-life and high-rate web-like Li4Ti5O12 anode for high-performance flexible lithium-ion batteries

Flexible lithium ion batteries （LIBs） have recently attracted increasing attention as they show unique promising advantages, such as flexibility, shape diversity, and light weight. Similar to conventional LIBs, flexible LIBs with long cycle life and high-rate performance are very important for applications of high performance flexible electronics. Herein, we report a three-dimensional （3D） web-like binderfree Li4Ti5O12 （LTO） anode assembled from numerous 1D nanowires exhibiting excellent cycling performance with high capacities of 153 and 115 mA·h·g^-1 after 5,000 cycles at 2 C and 20 C, respectively, and excellent rate property with a capacity of 103 mA·h·g^-1 even at a very high current rate of 80 C. Surprisingly, a flexible full battery assembled from the web-like LTO nanostructure and LiMn2O4 （LMO） nanorods exhibited a high capacity of 125 mA·h·g^-1 at high current rate of 20 C, and showed excellent flexibility with little performance degradation even in seriously bent states.

A Class of Constacyclic Codes over Ring R+vR

By constructing a Gray map, a class of constacyclic codes over ring R = R＋ vR is studied. Using cyclic codes and negacyclic codes of length p^s over ring R, the structure of （1 - 2v）-constacyclic codes and dual codes of length p^s over ring R are given, the Gray images of （1 - 2v）-constacyclic codes in a particular case are also studied. It is shown that linear codes of length pS over ring R are （1 -2v）-constacyclic codes if and only if their Gray images are distance-invariant cyclic codes of length 2p^s over ring R.

Self-catalyzed growth of Zn/Co-N-C carbon nanotubes derived from metal-organic frameworks as efficient oxygen reduction catalysts for Zn-air battery

Designing cost-effective and high-performance carbon-based oxygen reduction reaction(ORR)electrocatalysts is crucial in the development of Zn-air batteries(ZABs).In this study,a facile one-pot synthesis approach is engineered to construct Zn/Co-N-C carbonaceous polyhedrons interconnected with self-catalyzed-grown carbon nanotubes(CNTs)from zeolitic imidazolium frameworks linked with graphene oxide nanosheets.The special N-doped threedimensional(3 D)carbon matrix allows manipulating the exposure of active sites and the synergistic interaction between metal nanoparticles and CNTs.The as-synthesized catalyst features impressive ORR activity in 0.1 mol L^(-1)KOH(E_(1/2)=0.83 V)and 0.5 mol L^(-1)H_(2)SO_(4)(E_(1/2)=0.73 V),satisfactory cycling stability and methanol resistance comparable to those of the benchmark Pt/C catalyst(E_(1/2)=0.80 V in 0.1 mol L^(-1)KOH,E_(1/2)=0.75 V in 0.5 mol L^(-1)H_(2)SO_(4)).Furthermore,the asestablished ZAB demonstrates a competitive peak power density(90 mW cm^(-2))and prominent long-term stability,which are better than those of devices based on the commercial Pt/C catalyst(82 mW cm^(-2)).This work provides promising guidance for fabricating highly effective ORR catalysts with in situ formed CNTs,which can be applied in portable ZABrelated devices.

Analysis of a stochastic model for algal bloom with nutrient recycling

In this paper, the dynamics of a stochastic model for algal bloom with nutrient recy- cling is investigated. The model incorporates a white noise term in the growth equation of algae population to describe the effects of random fluctuations in the environment, and a nutrient recycling term in the nutrient equation to account for the conversion of detritus into nutrient. The existence and uniqueness of the global positive solution of the model is first proved. Then we study the long-time behavior of the model. Conditions for the extinction and persistence in the mean of the algae population are established. By using the theory of integral Markov semigroups, we show that the model has an invari- ant and asymptotically stable density. Numerical simulations illustrate our theoretical results.

Effects of electroacupuncture on angiogenesis and cortical VEGF and BDNF expression in rats with focal cerebral ischemia

Objective To observe the effect of electroacupuncture(EA)of“concurrent treatment of the brain and heart”on angiogenesis and cortical vascular endothelial growth factor(VEGF)and brain-derived neurotrophic factor(BDNF)in rats with focal cerebral ischemia,and to explore the mechanism of EA in cerebral ischemia treatment.Methods A total of 108 Sprague-Dawley rats,27 rats were randomly selected as the sham-operation group,and the rest rats received the right middle cerebral artery occlusion operation for model preparation firstly,and then were divided into a model group,a traditional acupoint group,and a concurrent treatment of the brain and heart group,with 27 rats in each group.In the sham-operation group,only the carotid artery was isolated.EA at Shuigou(CV26),Quchi(LI11),Hegu(LI4),and Zusanli(ST36)in the traditional acupoint group,and EA at Fengfu(GV16),Baihui(GV20),Xinshu(BL15),and Neiguan(PC6)in the concurrent treatment of the brain and heart group were performed 4 h after the operation,once a day,for 14 consecutive days.Rats in the sham-operation group and the model group were identically fixed without any treatment.Before and after treatment,the modified neurological severity score(mNSS),regional cerebral blood flow(rCBF),and CD34 positive expression by immunohistochemistry were measured.The positive protein expression levels of VEGF and BDNF were detected by immunofluorescence,and the mRNA expression levels of VEGF and BDNF were detected by quantitative reverse transcription-polymerase chain reaction(qRT-PCR).Results Compared with the sham-operation group,the mNSS,rCBF,and ischemic side cortical micro-vessel density(MVD)decreased,and the protein and mRNA expression levels of VEGF and BDNF increased in the model group(P<0.01).Compared with the model group,the mNSS of the two EA groups decreased,and the mNSS of the concurrent treatment of the brain and heart group was lower than that of the traditional acupoint group on the 14th day(P<0.05).Compared with the model group,the rCBF in the two EA groups increased,and the rCBF reached the highest on the 14th day(P<0.05 or P<0.01),and the rCBF in the concurrent treatment of the brain and heart group was higher than that in the traditional acupoint group(P<0.05);the MVD of the two EA groups was higher than that of the model group,and the MVD of the concurrent treatment of the brain and heart group was higher than that of the traditional acupoint group on the 7th and 14th days(P<0.05 or P<0.01).Compared with the model group,the protein and mRNA expression levels of VEGF and BDNF in the two EA groups increased(P<0.01).The VEGF expression level was the highest on the 7th day in the concurrent treatment of the brain and heart group(P<0.05),and the BDNF expression level was higher on the 7th and 14th days than on the 3rd day(P<0.05).The mRNA expression levels of VEGF and BDNF in both EA groups reached the highest on the 7th day(P<0.05 or P<0.01).Conclusion EA therapy can up-regulate the VEGF and BDNF expression levels and increase the rCBF in the cortex of rats with focal cerebral ischemia,which may be one mechanism of EA in the cerebral ischemia treatment.The therapeutic effect is accumulated with the effective time,and the concurrent treatment of the brain and heart group is superior to the traditional acupoint group in promoting angiogenesis.