Vascular endothelial growth factor:a double-edged sword in the development of white matter lesions

As the population ages,the burden of age-related diseases becomes greater.Currently,over 55 million people suffer from dementia worldwide,with Alzheimer’s disease being the most common form.However,it is becoming clearer that underlying vascular pathology such as cerebral small vessel disease(cSVD)may be a more detrimental cause for dementia(Cuadrado-Godia et al.,2018).It is estimated that 10%-30%of the elderly population and 35%-90%of all dementia patients exhibit signs of cSVD.The term cSVD refers to pathology affecting the small vessels of the brain,which can lead to lacunar cerebral infarcts,enlarged perivascular spaces,and cortical hemorrhages(Cuadrado-Godia et al.,2018).CSVD is often associated with cognitive decline,gait problems,and dementia(Cuadrado-Godia et al.,2018).

M-矩阵代数Riccati方程的一类改进的交替线性化隐式迭代法（英文）

本文研究了M-矩阵代数Riccati方程的求解问题.基于交替线性化隐式迭代法,提出了一类改进的交替线性化隐式迭代法用于计算M-矩阵代数Riccati方程的最小非负解.在一定条件下证明了新方法的收敛性并给出最优参数表达式.数值实验表明,改进的方法在一定条件下是可行的.

与M-矩阵相关的一类二次矩阵方程的新迭代法

本文研究与M-矩阵相关的一类二次矩阵方程的数值解法.这类方程源于马尔可夫链的带噪Wiener-Hopf问题,其解中具有实际意义的是M-矩阵解.通过简单的变换,将该二次矩阵方程转化为M-矩阵代数Riccati方程.提出一种新的迭代方法,并对其进行收敛性分析.数值实验表明,新的迭代方法是可行的,且在一定条件下比现有的一些方法更为有效.

Comparative Study of Structural, Optical and Electrical Properties of SnO₂Thin Film Growth via CBD, Drop-Cast and Dip-Coating Methods

Tin oxide (SnO2) thin films were deposited on glass substrate by Chemical Bath Deposition (CBD), Drop-Cast and Dip-Coating method. The thin films were post-annealed at 500°C for 2 hours. The structural, optical, and electrical properties of the SnO2 thin films were investigated by using XRD, FTIR, SEM, EDX, UV-Vis spectroscopy, and Electrometer experiment. The XRD patterns of SnO2 thin films deposited on glass substrate by CBD method, Drop-Cast method and Dip-Coating method showed cubic, tetragonal and amorphous structures respectively. The FTIR spectrum exhibited the strong presence of SnO2 with the characteristic vibrational mode of Sn-O-Sn. The SEM analysis was observed that the surface morphology of the thin films toughly depends on the deposition methods of the SnO2 thin films. EDX measurement confirmed that the thin films are the composition of Tin (Sn) and Oxygen (O2). The optical band gap of SnO2 thin films deposited by CBD method, Drop-Cast method and Dip-Coating method is found to be 3.12 eV, 3.14 eV and 3.16 eV respectively. Thin films deposited by Dip-Coating method showed the highest band gap. The electrical results confirmed that the SnO2 thin films are good conductors and pursued Ohm’s Law. These properties of the SnO2 thin films brand are appropriate for application in solar cell assembly, gas sensor devices and transparent electrodes of panel displays.

求解M-矩阵代数Riccati方程的两种不动点迭代法（英文）

M-矩阵代数Riccati方程由于广泛的应用,已成为近年来的热点问题之一,有关其理论和数值方法的研究层出不穷.本文研究M-矩阵代数Riccati方程的数值解法,给出求解其最小非负解的两种新的不动点迭代法.理论分析表明新的不动点迭代法相比现有的不动点迭代法收敛速度快,数值实验也验证了新方法的有效性.

M-矩阵平方根的一类迭代法

矩阵平方根在数学的许多应用中起着重要的作用.本文研究M-矩阵平方根的计算问题,提出一种计算正则M-矩阵平方根的迭代方法.首先将这个问题转化为M-矩阵代数Riccati方程,进而提出一种有效的方法来求解这个特殊的MARE.理论分析表明,该方法在一定条件下是收敛的.数值实验表明该方法是可行的,且优于二项式迭代法.

Decorin treatment of spinal cord injury

The scarring response after a penetrant central nervous system injury results from the interaction between invading leptominingeal/pericyte-derived fibroblasts and endogenous reactive astrocytes about the wound margin. Extracellular matrix and scar-derived axon growth inhibitory mole- cules fill the lesion site providing both a physical and chemical barrier to regenerating axons. Dec orin, a small leucine-rich chondroitin-dermatan sulphate proteoglycan expressed by neurons and astrocytes in the central nervous system, is both anti-fibrotic and anti-inflammatory and attenu- ates the formation and partial dissolution of established and chronic scars. Here, we discuss the potential of using Decorin to antagonise scarring in the central nervous system.

LINGO-1 and AMIGO3, potential therapeutic targets for neurological and dysmyelinating disorders？

Leucine rich repeat proteins have gained considerable interest as therapeutic targets due to their expression and biological activity within the central nervous system. LINGO-1 has received particular attention since it inhibits axonal regeneration after spinal cord injury in a Rho A dependent manner while inhibiting leucine rich repeat and immunoglobulin-like domain-containing protein 1（LINGO-1） disinhibits neuron outgrowth. Furthermore, LINGO-1 suppresses oligodendrocyte precursor cell maturation and myelin production. Inhibiting the action of LINGO-1 encourages remyelination both in vitro and in vivo. Accordingly, LINGO-1 antagonists show promise as therapies for demyelinating diseases. An analogous protein to LINGO-1, amphoterin-induced gene and open reading frame-3（AMIGO3）, exerts the same inhibitory effect on the axonal outgrowth of central nervous system neurons, as well as interacting with the same receptors as LINGO-1. However, AMIGO3 is upregulated more rapidly after spinal cord injury than LINGO-1. We speculate that AMIGO3 has a similar inhibitory effect on oligodendrocyte precursor cell maturation and myelin production as with axogenesis. Therefore, inhibiting AMIGO3 will likely encourage central nervous system axonal regeneration as well as the production of myelin from local oligodendrocyte precursor cell, thus providing a promising therapeutic target and an area for future investigation.

Decorin treatment for reversing trabecular meshwork fibrosis in open-angle glaucoma

In this perspective,we discuss the use of an anti-fibrotic agent Decorin to treat established fibrosis associated with glaucoma originally published by Hill et al.（2015）.Glaucoma describes a group of progressive optic neuropathies that have the potential to cause irreversible blindness.

Reviving the use of inhibitors of matrix metalloproteases in spinal cord injury:a case for specificity

At present,there are no resto rative therapies in the clinic for spinal cord injury,with current treatments offering only palliative treatment options.The role of matrix metalloproteases is well established in spinal cord injury,howeve r,translation into the clinical space was plagued by early designs of matrix metalloprotease inhibitors that lacked specificity and fears of musculos keletal syndrome prevented their further development.Newe r,much more specific matrix metalloprotease inhibitors have revived the possibility of using these inhibitors in the clinic since they are much more specific to their to rget matrix metalloproteases.Here,the evidence for use of matrix metalloproteases after spinal cord injury is reviewed and researche rs are urged to overcome their old fears rega rding matrix metalloprotease inhibition and possible side effects for the field to progress.Recently published work by us shows that inhibition of specific matrix metalloproteases after spinal cord injury holds promise since four key consequences of spinal cord injury could be alleviated by specific,next-gene ration matrix metalloprotease inhibitors.For example,specific inhibition of matrix metalloprotease-9 and matrix metalloprotease-12 within 24 hours after injury and for 3 days,alleviates spinal cord injury-induced edema,blood-s pinal co rd barrier breakdown,neuro pathic pain and resto res sensory and locomotor function.Attempts are now underway to translate this therapy into the clinic.

Facies Analysis, Sequence Stratigraphy and Diagenetic Studies of the Jurassic Carbonates of the Kohat Basin, Northwest Pakistan: Reservoir Implications

The present study deals with the depositional facies, diagenetic processes and sequence stratigraphy of the shallow marine carbonates of the Samana Suk Formation, Kohat Basin, in order to elucidate its reservoir quality. The Samana Suk Formation consists of thin to thick-bedded, oolitic, bioclastic, dolomitic and fractured limestone. Based on the integration of outcrop, petrographic and biofacies analyses, the unit is thought to have been deposited on a gentle homoclinal ramp in peritidal, lagoonal and carbonate shoal settings. Frequent variations in microfacies based sea-level curve have revealed seven Transgressive Systems Tracts(TSTs) and six Regressive Systems Tracts(RSTs). The unit has undergone various stages of diagenetic processes, including mechanical and chemical compaction, cementation,micritization, dissolution and dolomitization. The petrographic analyses show the evolution of porosity in various depositional and diagenetic phases. The fenestral porosity was mainly developed in peritidal carbonates during deposition,while the burial dissolution and diagenetic dolomitization have greatly enhanced the reservoir potential of the rock unit, as is further confirmed by the plug porosity and permeability analyses. The porosities and permeabilities were higher in shoal facies deposited in TSTs, as compared to lagoonal and peritidal facies, except for the dolomite in mudstone, deposited during RSTs. Hence good, moderate and poor reservoir potential is suggested for shoal, lagoonal and peritidal facies,respectively.

Cannabinoids: Do they have the potential to treat the symptoms of multiple sclerosis?

This article reviews the role of cannabinoids in inhibiting neurodegeneration in models of multiple sclerosis(MS). MS is a chronic, debilitating disease of the central nervous system(CNS), induced by autoimmunity-driven inflammation that leads to demyelination and thus disconnection of the normal transmission of nerve impulses. Despite the use of an array of immune modulating drugs that restore blood brain barrier function, disability continues in patients concomitant with the loss of axons in the spinal cord. MS patients therefore suffer neuropathic pain, spasticity and tremor. Anecdotal evidence suggests that MS patients using cannabis, though illegal, achieve symptomatic relief from neuropathic pain and spasticity associated with MS. The discovery of the endogenous cannabinoid(endocannabinoid) system that naturally exists in the body and which responds to cannabinoids to exert their effects has aided research into the therapeutic utility of cannabinoids. The endocannabinoid system consists of two G-protein coupled receptors cannabinoid receptor type-1(CB1) and CB2.CB1 is mainly expressed in the CNS and CB2 is predominantly found in leukocytes, while an increasing number of potential ligands and endocannabinoid degradation molecules are being isolated. Several studies have highlighted the involvement of this system in regulating neurotransmission and its ability to prevent excessive neurotransmitter release, consistent with a capacity to provide symptomatic relief. In summary, antagonism of the CB1 receptor pathway contributes to neuronal damage in chronic relapsing experimental allergic encephalomyelitis(EAE) and suppresses tremor and spasticity. The addition of exogenous CB1 agonists derived from cannabis also afforded significant neuroprotection from the consequences of inflammatory CNS disease in EAE and experimental allergic uveitis models. Although clear neuroprotective benefits of cannabinoids have been demonstrated, the unwanted psychotropic effects need to be addressed. However, manipulating the endogenous cannabinoid system may be one way of eliciting beneficial effects without some or all of the unwanted side effects.

Highly active ZIF-8@CNT composite catalysts as cathode materials for anion exchange membrane fuel cells

Developing non-precious metal-based inexpensive and highly active electrocatalysts for the oxygen reduction reaction(ORR)in alkaline media is important for fuel cell applications.Herein,we report a simple and effective synthesis of transition-metal-doped zeolitic imidazolate framework-8(ZIF-8)and carbon nanotube(CNT)composite catalysts(ZIF-8@CNT)prepared via high-temperature pyrolysis at 900℃.The catalysts were characterized using different physicochemical techniques and employed as cathode materials in anion exchange membrane fuel cells(AEMFC).The prepared metal-free(ZNT-900),single-metal-doped(Fe-ZNT-900,Co-ZNT-900)and binary-metal-doped(Fe_(1)Co_(1)-ZNT-900,Fe_(1)Co_(2)-ZNT-900)catalysts had a sufficient amount of N-doping with the presence of FeCo moieties in the carbon skeleton of the latter two materials.N_(2) adsorption–desorption isotherms showed that all the prepared catalysts possess a sufficient Brunauer–Emmett–Teller surface area with more micropores present in ZNT-900,while a combined micro–mesoporous structure was obtained for transition-metal-doped catalysts.Binary-metal-doped catalysts showed the highest number of ORR-active sites(pyridinic-N,pyrrolic-N,graphitic-N,M–Nx)and exhibited a half-wave potential(E_(1/2))of 0.846 and 0.847 V vs.RHE for Fe_(1)Co_(1)-ZNT-900 and Fe_(1)Co_(2)-ZNT-900,respectively,which surpassed that of the commercial Pt/C catalyst(E_(1/2)=0.834 V).In H_(2)–O_(2) AEMFCs,the Fe_(1)Co_(2)-ZNT-900 catalyst delivered a maximum power density(P_(max))of 0.171 W cm^(-2) and current density at 0.5 V(j_(0.5))of 0.326 A cm^(-2),which is very close to that of the Pt/C catalyst(P_(max)=0.215 W cm^(-2) and j_(0.5)=0.359 A cm^(-2)).The prepared ZIF-8@CNT catalysts showed remarkable electrocatalytic ORR activity in 0.1 M KOH solution and fuel cell performance comparable to that of the benchmark Pt/C catalyst.