Effect of Delay Released Welan Gum on the Performance of Cement Mortar

Welan gum is widely applied in environmental admixtures due to its good thickening and rheological properties. With its powerful charge density in the molecular structure, the competitive adsorption between welan gum and other admixtures happened remarkably during the addition process. So controlling the releasing rate of welan gum will be able to improve the competitive adsorption, while having no disadvantages to its thickening and workability at the same time. The investigation of influences of the delay released welan gum（DRWG） on the fluidity and strength of cement mortar, bleeding rate and rheological properties of cement paste, adsorption amount and zeta potential of clinker single mineralogical phases, shows that there will be a better mortar workability and certain improvement in mortar strength with DRWG. For mortar with DRWG, the standing bleeding rate is 0, and there is less thixotropic, less adsorption, and a lower zeta potential value on the surface of clinker mineralogical phases.

Synthesis of (R)(E)-3,7-Dimethyl-2-octene-1,8-dioic Acid, a Copulation Released Pheromone Component of Azuki Bean Weevil

Started from 5-hydroxy-2-pentanone, (R)(E)-3,7-dimethyl-2-octene-1,8-dioic acid, callosobruchusic acid, was synthesized via five steps with D-(-)-camphor sultam as the chiral auxiliary. It was of good optical purity and yield.

Luminescent properties of thermally activated delayed fluorescence molecule with intramolecular π-π interaction between donor and acceptor

Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence（TADF） molecule（3, 5-bis（3,6-di-tert-butyl-9 H-carbazol-9-yl）-phenyl）（pyridin-4-yl） methanone（DTCBPY） is theoretically studied by using the density functional theory（DFT） and time-dependent density functional theory（TD-DFT）.Four conformations（named as A, B, C, and D） of the DTCBPY can be found by relax scanning, and the configuration C corresponds to the luminescent molecule detected experimentally. Besides, we calculate the proportion of each conformation by Boltzmann distribution, high configuration ratios（44% and 52%） can be found for C and D. Moreover, C and D are found to exist with an intramolecular π-π interaction between one donor and the acceptor; the intramolecular interaction brings a smaller Huang-Rhys factor and reduced reorganization energy. Our work presents a rational explanation for the experimental results and demonstrates the importance of the intramolecular π-π interaction to the photophysical properties of TADF molecules.

Stability and oscillations in a slow-fast flexible joint system with transformation delay

Flexible joints are usually used to transfer velocities in robot systems and may lead to delays in motion transformation due to joint flexibility. In this paper, a linkrotor structure connected by a flexible joint or shaft is firstly modeled to be a slow-fast delayed system when moment of inertia of the lightweight link is far less than that of the heavy rotor. To analyze the stability and oscillations of the slowfast system, the geometric singular perturbation method is extended, with both slow and fast manifolds expressed analytically. The stability of the slow manifold is investigated and critical boundaries are obtained to divide the stable and the unstable regions. To study effects of the transformation delay on the stability and oscillations of the link, two quantitatively different driving forces derived from the negative feedback of the link are considered. The results show that one of these two typical driving forces may drive the link to exhibit a stable state and the other kind of driving force may induce a relaxation oscillation for a very small delay. However, the link loses stability and undergoes regular periodic and bursting oscillation when the transformation delay is large. Basically, a very small delay does not affect the stability of the slow manifold but a large delay affects substantially.

Delayed seed dispersal species and related traits in the desert of the United Arab Emirates

The ability of plants to safely retain seeds in the mother plant is an adaptive mechanism described in many desert plants.However,research about delayed seed dispersal species in the desert of the United Arab Emirates(UAE)is lacking.This study aims to identify these delayed seed dispersal species and assess the relationships of the presence of delayed seed dispersal with plant growth form,habit,spatial dispersal,antitelechoric mechanism,and seed release time.The relationships between the presence of delayed seed dispersal and the above studied traits were assessed by using the Pearson Chi-square test and Nonlinear Principal Components Analysis(NLPCA).Results showed that a total of 46 delayed seed dispersal species were recorded(15.0%of 307 studied species)and the highest incidence occurred in the Fabaceae family(17.4%).Delayed seed dispersal species were predominantly perennial plants(73.9%)with spatial restricted dispersal(67.4%),which released seed in the dry season(45.7%).The dominant groups of delayed seed dispersal species were persistent fruits species and synaptospermy(28.3%).All graminoids showed persistent lignified fruits,while prostrate annuals were basicarpic species with myxospermy.Sandy habitats had the highest number of delayed seed dispersal species(54.3%),whereas salt flats had the lowest(23.9%).In the desert of the UAE,delayed seed dispersal species spread seeds until the end of the dry and windy season,thus breaking seed dormancy at this time and ensuring seed germination in the next arrival of the rainy season.This morphological and ecological adaptation of delayed dispersal species is essential to the survival and sustainable development of vegetation in desert environments.

Effects of information transmission delay and channel blocking on synchronization in scale-free Hodgkin-Huxley neuronal networks

In this paper,we investigate the evolution of spatiotemporal patterns and synchronization transitions in dependence on the information transmission delay and ion channel blocking in scale-free neuronal networks.As the underlying model of neuronal dynamics,we use the Hodgkin-Huxley equations incorporating channel blocking and intrinsic noise.It is shown that delays play a significant yet subtle role in shaping the dynamics of neuronal networks.In particular,regions of irregular and regular propagating excitatory fronts related to the synchronization transitions appear intermittently as the delay increases.Moreover,the fraction of working sodium and potassium ion channels can also have a significant impact on the spatiotemporal dynamics of neuronal networks.As the fraction of blocked sodium channels increases,the frequency of excitatory events decreases,which in turn manifests as an increase in the neuronal synchrony that,however,is dysfunctional due to the virtual absence of large-amplitude excitations.Expectedly,we also show that larger coupling strengths improve synchronization irrespective of the information transmission delay and channel blocking.The presented results are also robust against the variation of the network size,thus providing insights that could facilitate understanding of the joint impact of ion channel blocking and information transmission delay on the spatiotemporal dynamics of neuronal networks.

Suppressive Influence of Time- Space White Noise on the Explosion of Solutions of Stochastic Fokker- Planck Delay Differential Equations

It is generally known that the solutions of deterministic and stochastic differential equations （SDEs） usually grow linearly at such a rate that they may become unbounded after a small lapse of time and may eventually blow up or explode in finite time. If the drift and diffusion functions are globally Lipschitz, linear growth may still be experienced, as well as a possible blow-up of solutions in finite time. In this paper, a nonlinear scalar delay differential equation with a constant time lag is perturbed by a multiplicative Ito-type time - space white noise to form a stochastic Fokker-Planck delay differential equation. It is established that no explosion is possible in the presence of any intrinsically slow time - space white noise of Ito - type as manifested in the resulting stochastic Fokker- Planck delay differential equation. Time - space white noise has a role to play since the solution of the classical nonlinear equation without it still exhibits explosion.

时延QoS保证的D2D-based V2V车载通信功率分配方案

OFDMA蜂窝网络中采用Underlay模式的基于终端直通技术的车-车(D2D-based V2V)通信能够提高频谱利用率、增大系统吞吐量,但随之产生的同频干扰问题严重影响通信质量。为了解决该问题,同时满足车辆通信的低时延服务质量(QoS)需求,提出一种基于时延QoS保证的D2D-based V2V车载通信功率分配方案。该方案同时考虑了蜂窝用户和D2D-based V2V用户所受到的干扰,并采用有效容量提供QoS保障,通过拉格朗日对偶分解法求解优化问题。数值仿真表明,相比于其他方案,该方案能够很好地提高系统有效容量。

Incorporation of Sphingosine 1-Phosphate Loaded Mesoporous Silica Nanoparticles into Poly ( L-lactic acid ) Nanofibrous Scaffolds for Bone Tissue Engineering

Controlled release of the functional factors is the key to improve clinical therapeutic efficacy during the tissue repair and regeneration. The thrce-dimensional （3D） scaffold can provide not only physical properties such as high strength and porosity hut also an optimal environment to enhance tissue regeneration. Sphingosine 1-phosphate （SIP）, an angiogenlc factor, was loaded into mesoporous silica nanoparticles （MSNs） and then incorporated into poly （ L-lactic add ） （ PLLA ） nanofibrons scaffold, which was fabricated by thermally induced phase separation （TIPS） method. The prepared scaffolds were examined by attenuated total reflection Fourier transform infrared spectroscopy （ATR-FTIR）, scanning electron microscopy （ SEM）, and transmission electron microscopy （TEM） and compressive mechanical test. The ATR-FTIR result demonstrated the existence of MSNs in the PLLA nanofibrous scaffold. The SEM images showed that PLLA scaffold had regular pore channel, interconnected pores and nanofibrous structure. The addition of MSNs at appropriate content had no visible effect on the structure of scaffold. The compressive modulus of scaffold containing MSNs was higher than that of the scaffold without MSNs. Furthermore, fluorescein isothiocyanate （FTTC） was used as model molecule to investigate the release behavior of SIP from MSNs- incorporated PLLA （MSNs/PLLA） nanofibrons scaffold. The result showed that the composite scaffold largely reduced the initial burst release and exhibited prolonged release of FITC than MSNs. Thus, these results indicated that SIP-loaded composite uanofibrons scaffold has potential applications for bone tissue engneering.

Penny-shaped interfacial crack between dissimilar magnetoelectroelastic layers

A penny-shaped interfacial crack between dissimilar magnetoelectroelastic layers subjected to magnetoelectromechanical loads is investigated,where the magnetoelectrically impermeable crack surface condition is adopted. By using Hankel transform technique,the mixed boundary value problem is firstly reduced to a system of singular integral equations,which are further reduced to a system of algebraic equations. The field intensity factors and energy release rate are finally derived. Numerical results elucidate the eects of crack configuration,electric and/or magnetic loads,and material parameters of the magnetoelectroelastic layers on crack propagation and growth. This work should be useful for the design of magnetoelectroelastic composite structures.

A classification of genes involved in normal and delayed male puberty

Puberty is a pivotal biological process that completes sexual maturation to achieve full reproductive capability.It is a major transformational period of life,whose timing is strongly affected by genetic makeup of the individual,along with various internal and external factors.Although the exact mechanism for initiation of the cascade of molecular events that culminate in puberty is not yet known,the process of pubertal onset involves interaction of numerous complex signaling pathways of hypothalamopituitary-testicular(HPT)axis.We developed a classification of the mechanisms involved in male puberty that allowed placing many genes into physiological context.These include(i)hypothalamic development during embryogenesis,(ii)synaptogenesis where gonadotropin releasing hormone(GnRH)neurons form neuronal connections with suprahypothalamic neurons,(iii)maintenance of neuron homeostasis,(iv)regulation of synthesis and secretion of GnRH,(v)appropriate receptors/proteins on neurons governing GnRH production and release,(vi)signaling molecules activated by the receptors,(vii)the synthesis and release of GnRH,(viii)the production and release of gonadotropins,(ix)testicular development,(x)synthesis and release of steroid hormones from testes,and(xi)the action of steroid hormones in downstream effector tissues.Defects in components of this system during embryonic development,childhood/adolescence,or adulthood may disrupt/nullify puberty,leading to long-term male infertility and/or hypogonadism.This review provides a list of 598 genes involved in the development of HPT axis and classified according to this schema.Furthermore,this review identifies a subset of 75 genes for which genetic mutations are reported to delay or disrupt male puberty.

Glutamate-releasing BEST1 channel is a new target for neuroprotection against ischemic stroke with wide time window

Many efforts have been made to understand excitotoxicity and develop neuroprotectants for the therapy of ischemic stroke.The narrow treatment time window is still to be solved.Given that the ischemic core expanded over days,treatment with an extended time window is anticipated.Bestrophin1(BEST1)belongs to a bestrophin family of calcium-activated chloride channels.We revealed an increase in neuronal BEST1 expression and function within the peri-infarct from 8 to 48 h after ischemic stroke in mice.Interfering the protein expression or inhibiting the channel function of BEST1 by genetic manipulation displayed neuroprotective effects and improved motor functional deficits.Using electrophysiological recordings,we demonstrated that extrasynaptic glutamate release through BEST1 channel resulted in delayed excitotoxicity.Finally,we confirmed the therapeutic efficacy of pharmacological inhibition of BEST1 during 6—72 h post-ischemia in rodents.This delayed treatment prevented the expansion of infarct volume and the exacerbation of neurological functions.Our study identifies the glutamatereleasing BEST1 channel as a potential therapeutic target against ischemic stroke with a wide time window.

Protein-spatiotemporal partition releasing gradient porous scaffolds and anti-inflammatory and antioxidant regulation remodel tissue engineered anisotropic meniscus

Meniscus is a wedge-shaped fibrocartilaginous tissue,playing important roles in maintaining joint stability and function.Meniscus injuries are difficult to heal and frequently progress into structural breakdown,which then leads to osteoarthritis.Regeneration of heterogeneous tissue engineering meniscus(TEM)continues to be a scientific and translational challenge.The morphology,tissue architecture,mechanical strength,and functional applications of the cultivated TEMs have not been able to meet clinical needs,which may due to the negligent attention on the importance of microenvironment in vitro and in vivo.Herein,we combined the 3D(three-dimensional)-printed gradient porous scaffolds,spatiotemporal partition release of growth factors,and anti-inflammatory and anti-oxidant microenvironment regulation of Ac2-26 peptide to prepare a versatile meniscus composite scaffold with heterogeneous bionic structures,excellent biomechanical properties and anti-inflammatory and anti-oxidant effects.By observing the results of cell activity and differentiation,and biomechanics under anti-inflammatory and anti-oxidant microenvironments in vitro,we explored the effects of anti-inflammatory and anti-oxidant microenvironments on construction of regional and functional heterogeneous TEM via the growth process regulation,with a view to cultivating a high-quality of TEM from bench to bedside.

Thermally Activated Delayed Fluorescence of Aggregates Induced by Strongπ–πInteractions and Reversible Dual-Responsive Luminescence Switching

A reversible dual-responsive luminescent material was introduced by our group to show the simultaneous color and lifetime switching in response to external stimuli.Pristine crystalline powder of(E)-2-(benzo[d]thiazol-2-yl)-3-(pyren-1-yl)acrylonitrile(Py-BZTCN)shows the orderedπ–πstacking with only near-monomer-normal orange-yellow fluorescence,but it exhibits red emission with thermally activated delayed fluorescence(TADF)after grinding,which can be reversibly recovered by heating or fuming treatment.Grinding disturbs the orderedπ–πstacking of pristine powder,leading to the formation of small aggregates with compressed distance and increased overlap ofπ–πstacking between adjacent molecules.The cause of switching was verified by single-crystal X-ray diffraction experiments of two corresponding crystals.This strongπ–πinteraction effectively promotes the excited-state energy splitting and substantially decreases the singlet–triplet energy gap(ΔEST)of aggregates,resulting in the red TADF emission of aggregates through reverse intersystem crossing.This finding proposes a new route to realizing the TADF emission of aggregates through strong intermolecular interactions based on non-TADF monomer,thereby enabling a novel high-contrast dualresponsive luminescence switching.

口服结肠靶向释药系统

口服结肠靶向释药系统(oral colon—specific drug delivery system,OCDDS)是通过适当的方法,使药物避免在胃、十二指肠、空肠和回肠前端释放,运送到人体回盲部后释放而发挥局部或全身治疗作用的一种给药系统.近10年来,OCDDS受到国外研究者的普遍关注,并已有产品上市;国内OCDDS的研究尚处于起步阶段,但据1995年中国药学会全国药剂学交流会报道已有研究成果试用于临床.本文就结肠解剖、生理和病理特点,OCDDS的分类及其体内外评价方法等作一综述.1 结肠解剖、生理和病理特点结肠位于消化道末段,延迟药物释放,可达到结肠靶向释药目的.结肠壁内分布有许多淋巴结和淋巴管,药物吸收后易进入淋巴循环发挥疗效,所以结肠是某些抗癌药物理想的靶向吸收器官.

STABILITY OF THE STOCHASTIC θ-METHOD FOR SUPER-LINEAR STOCHASTIC DIFFERENTIAL EQUATIONS WITH UNBOUNDED DELAY

This paper deals with numerical stability properties of super-linear stochastic differential equations with unbounded delay. Sufficient conditions for mean square and almost sure decay stability of the above system and its stochastic θ-method approximation are investigated in this paper. The author establishes numerical stability under a monotone-type condition in unbounded delay setting. An example is presented to illustrate the result.

Overview of In—Situ Biodegradation and Enhancement

Microbial degradation technologies have been developed to restore ground water quality in aquifers polluted by organic contaminants effectively in recent years. However, in course of the degradation, the formation of biofilms in ground water remediation technology can be detrimental to the effectiveness of a ground water remediation project. Several alternatives are available to a remedial design engineer, such as Permeable Reactive Barriers (PRBs) and in -situ bioremediation, Hydrogen Releasing Compounds (HRCs) barrier, Oxygen Releasing Compounds (ORCs) barrier etc. which are efficient and cost- effective technologies. Excessive biomass formation renders a barrier ineffective in degrading the contaminants, Efforts are made to develop kinetics models which accurately determine bio - fouling and bio - filn formation and to control excessive biomass formation.

W^(1,2)(Ω)-and X^(1,2)(Ω)-stability of reactiondiffusion cellular neural networks with delay

With Poincare＇s inequality and auxiliary function applied in a class of retarded cellular neural networks with reaction-diffusion, the conditions of the systems＇ W^1,2（Ω）-exponential and X^1,2（Ω）-asmptotic stability are obtained. The stability conditions containing diffusion term are different from those obtained in the previous papers in their exponential stability conditions. One example is given to illustrate the feasibility of this method in the end.

CDM GDP技术在我国机场流量优化管理中的应用研究

借鉴美国CDM GDP的成功经验,结合我国的实际,对CDM GDP在我国机场流量优化管理中的应用进行了初步的研究.由于恶劣天气等原因,使机场降落容量大幅度降低,必然导致降落航班延误.通过CDM GDP的关键技术RBS和压缩,得到每架延误航班的起飞时间,从而使被延误的航班在起飞机场等待,避免了改航、备降和空中等待等问题,提高了安全性,降低了费用.在满足公平性的同时,使航班的总延误最小.

干扰素-γ释放试验在结核病诊断中的价值

结核菌素皮肤试验（tuberculin skin test,TST）是用于检测潜伏结核感染（latent tuberculosis infection,LTBI）的传统方法.自从干扰素-γ释放试验（interferon-γrelease assay,IGRA）进入临床应用之后大有取代TST之势.IGRA是在体外检测T细胞经结核特异性抗原刺激之后产生和释放干扰素-γ能力的免疫学技术,藉此判断细胞介导的免疫反应.国际上广泛使用的IGRA有2种,即4澳大利亚产的Quanti FERON-TB Gold In-Tube（QFT-GIT）和英国产的T-SPOT.TB.