Adsorption of Phthalic Acid Esters by Humic Acid and Its Research Progress

Humic acid is rich in highly electronegative oxygen-containing organic functional groups,so it has high reactivity and can adsorb phthalic acid ester(PAEs)in the environment to reduce the risk of environmental pollution from PAEs.In this paper,the extraction,characterization and adsorption models of humic acid were reviewed,and the research status of adsorption of PAEs by humic acid was further summarized.Based on these,the feasibility and observable application prospect of humic acid as a cheap adsorbent were analyzed.

Mechanisms regulating cerebral hypoperfusion in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy

Cerebral small vessel disease (CSVD) is a leading cause of stroke and dementia. As the most common type of inherited CSVD, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is characterized by the NOTCH3 gene mutation which leads to Notch3 ectodomain deposition and extracellular matrix aggregation around the small vessels. It further causes smooth muscle cell degeneration and small vessel arteriopathy in the central nervous system. Compromised cerebral blood flow occurs in the early stage of CADASIL and is associated with white matter hyperintensity, the typical neuroimaging pathology of CADASIL. This suggests that cerebral hypoperfusion may play an important role in the pathogenesis of CADASIL. However, the mechanistic linkage between NOTCH3 mutation and cerebral hypoperfusion remains unknown. Therefore, in this mini-review, it examines the cellular and molecular mechanisms contributing to cerebral hypoperfusion in CADASIL.

Effects of different regional cerebral blood flow on white matter hyperintensity in CADASIL patients

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy(CADASIL)is an early-onset inherited small vessel disease.Decreased cerebral blood flow(CBF)may contribute to white matter hyperintensity(WMH)severity in CADASIL,but more evidence is needed to support this hypothesis.This study comprised six patients with CADASIL who harbored mutations in the coding sequence of NOTCH3 and twelve age-matched neurologically healthy controls.We collected clinical and imaging data from patients with CADASIL and divided the brain into four regions:WMH,normal-appearing white matter(NAWM),gray matter(GM),and global brain.We analyzed the relationship between CBF of each region and the WMH volume.Compared with the control group,CBF was significantly decreased in all four regions in the CADASIL group.Lower CBF in these regions was correlated with higher WMH volume in CADASIL.CBF in the NAWM,GM and global regions was positively correlated with that in WMH region.However,after correction tests,only CBF in the WMH region but not in NAWM,GM and global regions was associated with WMH volume.Our findings suggest that CBF in the WMH region is an influencing factor of the WMH severity in CADASIL.

Respiratory protein-driven selectivity during the Permian-Triassic mass extinction

Extinction selectivity determines the direction of macroevolution,especially during mass extinction;however,its driving mechanisms remain poorly understood.By investigating the physiological selectivity of marine animals during the Permian-Triassic mass extinction,we found that marine clades with lower O2-carrying capacity hemerythrin proteins and those relying on O2 diffusion experienced significantly greater extinction intensity and body-size reduction than those with higher O2-carrying capacity hemoglobin or hemocyanin proteins.Our findings suggest that animals with high O2-carrying capacity obtained the necessary O2 even under hypoxia and compensated for the increased energy requirements caused by ocean acidification,which enabled their survival during the Permian-Triassic mass extinction.Thus,high O2-carrying capacity may have been crucial for the transition from the Paleozoic to the Modern Evolutionary Fauna.

Thiol-ene conjugation of a VEGF peptide to electrospun scaffolds for potential applications in angiogenesis

Vascular endothelial growth factor(VEGF)plays a vital role in promoting attachment and proliferation of endothelial cells,and induces angiogenesis.In recent years,much research has been conducted on the functionalization of tissue engineering scaffolds with VEGF or a VEGF-mimetic peptide to promote angiogenesis.However,most chemical reactions are nonspecific and require organic solvents,which can compromise control over functionalization and alter peptide/protein activity.An attractive alternative is the fabrication of functionalizable electrospun fibers,which can overcome these hurdles.In this study,we used thiol-ene chemistry for the conjugation of a VEGF-mimetic peptide to the surface of poly(ε-caprolactone)(PCL)fibrous scaffolds with varying amounts of a functional PCL-diacrylate(PCL-DA)polymer.30%PCL-DA was selected due to homogeneous fiber morphology.A VEGF-mimetic peptide was then immobilized on PCL-DA fibrous scaffolds by a light-initiated thiol-ene reaction.7-Mercapto-4-methylcoumarin,RGD-FITC peptide and VEGF-TAMRA mimetic peptide were used to validate the thiol-ene reaction on the fibrous scaffolds.Tensile strength and elastic modulus of the 30%PCL-DA fibrous scaffolds were significantly increased after the reaction.Conjugation of the 30%PCL-DA fibrous scaffolds with the VEGF peptide increased the surface water wettability of the scaffolds.Patterned structures could be obtained after using a photomask on the fibrous film.Moreover,in vitro studies indicated that scaffolds functionalized with the VEGF-mimetic peptide were able to induce phosphorylation of the VEGF receptor and enhanced HUVECs survival,proliferation and adhesion.A chick chorioallantoic membrane(CAM)assay further indicated that the VEGF peptide functionalized scaffolds were able to promote angiogenesis in vivo.These results show that scaffold functionalization can be controlled via a simple polymer mixing approach,and that the functionalized VEGF peptide-scaffolds have potential for vascular tissue regeneration.

Harnack不等式在Markov过程长时间行为研究中的应用

本文使用Markov半群的无穷维Harnack不等式刻画Markov过程的长时间行为,建立可加泛函的极限定理,简化和放松了原有的条件.所获得的一般结果被应用于随机Hamilton系统和半线性随机偏微分方程,对于一类退化的扩散过程和无穷维扩散过程建立了所需的Harnack不等式,得到了相应的极限定理.

非对称随机微分方程的泛函不等式

通常非对称Markov半群比相应的对称半群有更好的分析性质.例如, Wang (2017)给出一类超压缩(因此,在L2和相对熵下指数遍历)的非对称Markov半群,其对称半群甚至不遍历.本文讨论反方向的问题:在什么条件下,非对称Markov半群和相应的对称半群享有同等的性质.分别对于由Brown运动和Lévy跳过程驱动的随机微分方程,本文得到了非对称半群和对称半群在一些重要性质方面地位对等的充分必要条件,这些性质包括指数收敛性、一致可积性、H-超压缩性和S-超有界性.

Screening and Assessing 11 Mycobacterium tuberculosis Proteins as Potential Serodiagnostical Markers for Discriminating TB Patients from BCG Vaccinees

Purified protein derivative （PPD） skin tests often yield poor specificity, so that to develop new serological antigens for distinguishing between Mycobacterium tuberculosis infection and Bacille Calmette-Guerin （BCG） vaccination is a priority, especially for developing countries like China. We predicted the antigenicity for selected open reading frames （ORFs） based on the genome sequences of M. tuberculosis H37Rv and M. boris BCG, as well as their functions and differences of expression under different stimulus. The candidate ORFs were cloned from H37Rv sequences and expressed as recombinant proteins in Escherichia coli. We studied the serodiagnostic potential of 11 purified recombinants by using enzyme-linked immunosorbent assay （ELISA） and involving a cohort composed of 58 TB patients （34 males and 24 females）, 8 healthy volunteers and 50 PPD-negative individuals before and after BCG vaccination. For all the 11 antigens, the median OD values for the sera from TB patients were statistically significantly higher than those for PPD-negative individuals before or after BCG vaccination （P〈0.01）. They had at least 92% specificity in healthy controls and six seroantigens （Rv0251c, Rv1973, Rv2376c, Rv2537c, Rv2785c and Rv3873A） were never reported with seroantigenicities previously. Thus the approach combining comparative genomics, bioinformatics and ELISA techniques can be employed to identify new seroantigens distinguishing M. tuberculosis infection from BCG vaccination.

关于测度值过程的随机分析

本文介绍使用随机分析方法研究测度值过程的若干最新进展,并提出一些有待研究的问题,期望为读者进入该领域从事研究工作提供帮助.首先回顾关于测度函数的外在导数(extrinsic derivative)、内蕴导数(intrinsic derivative)和L导数,刻画它们之间的关系,使用这些导数和参考测度构造Dirichlet型,并研究这些Dirichlet型的泛函不等式以刻画相应测度值扩散过程的分布性质;然后通过解像(image)依赖的随机微分方程,构造Wasserstein空间上的扩散过程,并研究其遍历性以及在偏微分方程中的应用;最后介绍分布依赖(McKean-Vlasov)随机微分方程的L导数公式.

Pointwise characterizations of curvature and second fundamental form on Riemannian manifolds

Let M be a complete Riemannian manifold possibly with a boundary?M.For any C^1-vector field Z,by using gradient/functional inequalities of the(reflecting)diffusion process generated by L:=?+Z,pointwise characterizations are presented for the Bakry-Emery curvature of L and the second fundamental form of?M if it exists.These characterizations extend and strengthen the recent results derived by Naber for the uniform norm‖RicZ‖∞on manifolds without boundaries.A key point of the present study is to apply the asymptotic formulas for these two tensors found by the first author,such that the proofs are significantly simplified.

关于随机微分方程Girsanov变换的路径独立性

本文介绍了近十年来关于随机微分方程Girsanov变换的路径独立性的主要研究成果.该性质因反映了金融数学中市场的有效性而具有明确的应用背景,也因等价于一些非线性偏微分方程而具有数学研究价值.本文分别就经典的随机微分方程、带跳的随机微分方程、随机偏微分方程和分布依赖随机微分方程,介绍Girsanov变换的路径独立性所联系的非线性偏微分方程,并对其他相关研究加以评注.最后,作为一个新结果,本文使用非线性偏微分方程刻画了随机微分方程解的路径无关性.

Preface

Stochastic analysis occupies a central place in modern probability theory.Besides its intrinsic value as an area of mathematical research,its importance also derives from the interplay with many other areas of mathematics as well as disciplines of sciences and engineering,including harmonic analysis,partial differential equations,functional analysis,differentiable geometry,mathematical physics,economics,finance and biology,to name just a few.Chinese mathematicians have made many fundamental contributions in the diverse areas of stochastic analysis such as Dirichlet form theory,stochastic analysis on Riemannian manifolds and stochastic(partial)differential equations.

Cheeger's inequalities for general symmetric forms and existence criteria for spectral gap

The Cheeger’s inequalities and some existence criteria for spectral gap and for general symmetric forms are established. The criteria are also extended to general reversible Markov processes but not reported here. Even though in the past several decades, the topics have been widely studied, as far as we know the first problem in the unbounded case and the second one in the general case remain open.