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Restoring nervous system structure and function using tissue engineered living scaffolds

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Neural Regeneration Research 2015年第5期10卷 679-685页

作者： Laura A.Struzyna James P.harris Kritika S.Katiyar h.isaac Chen D.Kacy Cullen Center for Brain Injury and Repair Department of NeurosurgeryPerelman School of MedicineUniversity of Pennsylvania Center for Neurotrauma Neurodegenerationand RestorationPhiladelphia Veterans Affairs Medical Center School of Biomedical Engineering Drexel University

Neural tissue engineering is premised on the integration of engineered living tissue with the host nervous system to directly restore lost function or to augment regenerative capacity following ner- vous system injury or neurodegenerative disease. Disconnection of axon pathways - the long-distance fibers connecting specialized regions of the central nervous system or relaying peripheral signals - is a common feature of many neurological disorders and injury. however, functional axonal regenera- tion rarely occurs due to extreme distances to targets, absence of directed guidance, and the presence of inhibitory factors in the central nervous system, resulting in devastating effects on cognitive and sensorimotor function. to address this need, we are pursuing multiple strategies using tissue engi- neered ＂living scaffolds＂, which are preformed three-dimensional constructs consisting of living neural cells in a defined, often anisotropic architecture. Living scaffolds are designed to restore function by serving as a living labeled pathway for targeted axonal regeneration - mimicking key developmental mechanisms- or by restoring lost neural circuitry via direct replacement of neurons and axonal tracts. We are currently utilizing preformed living scaffolds consisting of neuronal dusters spanned by long axonal tracts as regenerative bridges to facilitate long-distance axonal regeneration and for targeted neurosurgical reconstruction of local circuits in the brain. Although there are formidable challenges in predinical and clinical advancement, these living tissue engineered constructs represent a promising strategy to facilitate nervous system repair and functional recovery.

关键词： living scaffolds neural tissue engineering cell transplant biomaterials regeneration neurotrauma neurodegeneration axon pathfinding cell migration

Rate Constants for Reaction Between hydroxyl Radical and Dimethyl Sulfide Under Real Atmospheric Condition

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Chinese Journal of Chemical Physics 2008年第5期21卷 407-414页

作者： hai-tao Wang chang-jiang hu Yu-jing Mu Yu-jie Zhang Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beifing 100085 China

the rate constants of the reaction between hydroxyl radical （Oh-） and dimethyl sulfide （DMS） were investigated by using the relative methods in air, N2, and 02. Strong influences of ground state oxygen O（3p） on DMS consumption were found by the photolysis of hONO and Ch3ONO as Oh. sources, and the rate constants obtained in these systems varied significantly. the rate constants of the reaction between DMS and Oh- （generated by photolysis of h2 O2） at room temperature were 8.56 × 10^-12, 11.31× 10^-12, and 4.50× 10^-12 cm3/（molecule.s）, in air, O2, and N2, respectively. the temperature dependence of the rate constants for Oh- with DMS over the temperature range of 287-338 K was also investigated in nitrogen and air, and the Arrhenius expression was obtained as follows： kaire=（7.24±0.28）× 10^-13exp[（770.7±E97.2）/t], kN2 =（3.40±0.15） × 10^-11 exp[-- （590.3±165.9）/t].

关键词： Dimethyl sulfide hydroxyl radical Ground state oxygen Kinetics

In Vitro Anti-hepatitis B Virus Activity of 2',3'-Dideoxyguanosine

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Virologica Sinica 2018年第6期33卷 538-544页

作者： Pinghu Zhang Shuo Zhai Jinhong chang Ju-tao Guo Institute of translational Medicine and Jiangsu Key Laboratory of Integrated traditional Chinese and Western Medicine for Prevention and treatment of Senile Diseases Yangzhou UniversityYangzhou 225001China Baruch S.Blumberg Institute Hepatitis B FoundationDoylestownPA 18902USA Qinghai himalayan Experimental Animal Center Xining 810006China

2',3'-dideoxyguanosine(DoG) has been demonstrated to inhibit duck hepatitis B virus(DhBV) replication in vivo in a duck model of hBV infection. In the current study, the in vitro antiviral effects of DoG on human and animal hepadnaviruses were investigated. Our results showed that DoG effectively inhibited hBV, DhBV, and woodchuck hepatitis virus(WhV)replication in hepatocyte-derived cells in a dose-dependent manner, with 50% effective concentrations(EC50) of 0.3 ± 0.05, 6.82 ± 0.25, and 23.0 ± 1.5 lmol/L, respectively. Similar to other hepadnaviral DNA polymerase inhibitors,DoG did not alter the levels of intracellular viral RNA but induced the accumulation of a less-than-full-length viral RNA species, which was recently demonstrated to be generated by RNase h cleavage of pgRNA. Furthermore, using a transient transfection assay, DoG showed similar antiviral activity against hBV wild-type, 3tC-resistant rtA181 V, and adefovirresistant rtN236t mutants. Our results suggest that DoG has potential as a nucleoside analogue drug with anti-hBV activity.

关键词： hBV Woodchuck hepatitis virus(WhV) hepatitis B Antiviral Nucleoside analogues

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肺容积和肺泡表面张力对肺血管阻力的影响

中国医学科学院学报 1987年第6期9卷 439-444页

作者：孙仁宇 G.F.Nieman t.S.hakim h.K.chang McGill UniversityMontrealCanada 中国医学科学院基础医学研究所北京北京中国医学科学院基础医学研究所 McGill UniversityMontrealCanada

灌流狗在体左下肺叶,在肺内压力-容积环上分别选择等压和等容两点,比较吸气和呼气支上相等肺泡压或相等肺容积时的肺血管阻力。呼吸周期中肺动脉压的改变主要取决于肺泡血管阻力的变化。呼气期由肺泡表面液体层产生的向肺泡中心的表面... 详细信息

灌流狗在体左下肺叶,在肺内压力-容积环上分别选择等压和等容两点,比较吸气和呼气支上相等肺泡压或相等肺容积时的肺血管阻力。呼吸周期中肺动脉压的改变主要取决于肺泡血管阻力的变化。呼气期由肺泡表面液体层产生的向肺泡中心的表面张力较吸气期低,使肺泡压能更有效地传递至肺泡血管.估计在中等肺容积时,呼气期较吸气期毛细血管周围压高465～505Pa(3.5～3.8mmhg).

关键词：肺灌流表面活性剂间质间隙压阻断法压力容积环

Dendritic Boundary Corrosion of AA2198 Weld Using Fiber Laser Welding with Al–Cu Filler Wire

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Acta Metallurgica Sinica(English Letters) 2018年第7期31卷 735-741页

作者： Jun-Xia Lu Ling chang Shi-Kai Wu Shi-Kun Yin Institute of Laser Engineering Beijing University of Technology

the microstructures and corrosion behaviors of AA2198-t851 alloy and weld were analyzed under corrosive conditions. Weld was formed using an innovative fiber laser welding process with AA2319 Al-Cu filler wire. the metallurgic morphology and distribution of the chemical compositions were determined using imaging techniques such as optical micrograph, scanning electron micrograph, high-resolution transmission electron microscopy, energy-dispersive X-ray spectrometry and X-ray diffraction. Corrosion was evaluated using an immersion test and electrochemical impedance spectroscopy in 3.5% NaC1 solution at room temperature. Results indicate that the parent alloy suffered from pitting corrosion during the initial 4-h immersion which was caused by the inhomogeneous distribution of its chemical compo- nents and the different intermetallics formed during the rolling process. the weld experienced dendritic boundary corrosion under the same conditions due to the addition of the Al-Cu filler and rapid solidification during laser welding, which led to the precipitates Cu enrichment along the grain boundary. When a welding joint was immersed in the solution for 5 days, a big crack was observed across the center of the weld. In comparison, there was good corrosion resistance in the heat- affected zone with a compact protective film.

关键词： 2198 Aluminum alloy. Fiber laser welding Dendritic boundary corrosion Al-Cu filler wire

Simple instruments facilitating achievement of transanal total mesorectal excision in male patients

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World Journal of Gastroenterology 2017年第31期23卷 5798-5808页

作者： chang Xu hua-Yu Song Shao-Liang han Shi-chang Ni hu-Xiang Zhang Chun-Gen Xing Department of General Surgery the Second Affiliated Hospital of Soochow University Department of Colorectal Surgery the First Affiliated Hospital of Wenzhou Medical University Department of Pathology the First Affiliated Hospital of Wenzhou Medical University

AIM to assess the efficacy of a modified approach with transanal total mesorectal excision(ta tME) using simple customized instruments in male patients with low rectal *** A total of 115 male patients with low rectal cancer from December 2006 to August 2015 were retrospectively studied. All patients had a bulky tumor(tumor diameter ≥ 40 mm). Forty-one patients(group A) underwent a classical approach of transabdominal total mesorectal excision(tME) and transanal intersphincteric resection(ISR), and the other 74 patients(group B) underwent a modified approach with transabdominal tME,transanal ISR, and ta tME. Some simple instruments including modified retractors and an anal dilator with a papilionaceous fixture were used to perform ta tME. the operative time, quality of mesorectal excision, circumferential resection margin, local recurrence, and postoperative survival were *** All 115 patients had successful sphincter preservation. the operative time in group B(240 min, range: 160-330 min) was significantly shorter than that in group A(280 min, range: 200-360 min; P = 0.000). Co m pa r e d w it h g r o up A, m o r e c o m p le t e d is t a l mesorectum and total mesorectum were achieved in group B(100% vs 75.6%, P = 0.000; 90.5% vs 70.7%, P = 0.008, respectively). After 46.1 ± 25.6 mo followup, group B had a lower local recurrence rate and higher disease-free survival rate compared with group A, but these differences were not statistically significant(5.4% vs 14.6%, P = 0.093; 79.5% vs 65.1%, P = 0.130). CONCLUSION Retrograde ta tME with simple customized instruments can achieve high-quality tME, and it might be an effective and economical alternative for male patients with bulky tumors.

关键词： Rectal neoplasm total mesorectal excision transanal approach Intersphincteric resection Longterm outcome Local recurrence

A potentiometric determination of the dissociation constants of glycine in {14.926 mass% urea+water} mixed solvent at 278.15 to 318.15K

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Chinese Journal of Chemistry 1991年第6期9卷 481-487页

作者： YUAN chang-Bo YANG Jia-Zhen Department of Chemistry Liaoning UniversityShenyang 110036

First and second thermodynamic dissociation constants of glycine at five temperatures from 278.15K to 318,15K in {14.926 mass％ urea + water} mixed solvent have been determined from precise emfmeasurements of hydrogen-silver chloride electrodes in two cells, (A) and (B), without liquid junc- tion, by the new method of polynomial approximation proposed on the basis of Pitzer's electro- lytic solution theory in our previous papers, as compared with traditional extrapolation on the basis of the extended Debye-(?) equation. the results obtained from both methods are in agreement within experimental error. the thermodynamic quantities △G^0, △h^0, △S^0 and △C_p^0 were derived from the dependence of pK^0 values on temperature, and pK_1 = 367.60 (K / t) - 0.3973 + 3.108× 10^(-3) (t/K), whereas pK_2=2028.77 (K/ t)+ 2.8791-2.110×10^(-3) (t/K). the results have been discussed in terms of the solute-solvent interaction and have been compared with those results in water and in other mixed solvents.

关键词： urea+water mass A potentiometric determination of the dissociation constants of glycine in

StING regulates BCR signaling in normal and malignant B cells

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Cellular & Molecular Immunology 2021年第4期18卷 1016-1031页

作者： Chih-hang Anthony tang Avery C.Lee Shiun chang Qin Xu Andong Shao Yun Lo Walker t.Spalek Javier A.Pinilla-lbarz Juan R.Del Valle Chih-Chi Andrew hu the Wistar Institute 3601 Spruce StreetPhiladelphiaPA 19104USA Department of Malignant hematology H.Lee Moffitt Cancer Center&Research InstituteTampaFL 33612USA Department of Chemistry&Biochemistry University of Notre DameNotre DameIN 46556USA

StING is an endoplasmic reticulum(ER)-resident protein critical for sensing cytoplasmic DNA and promoting the production of type Ⅰ interferons;however,the role of StING in B cell receptor(BCR)signaling remains *** generated StING V154M knock-in mice and showed that B cells carrying constitutively activated StING specifically degraded membrane-bound IgM,Ig a and Igβ via SEL1L/hRD1-mediated ER-associated degradation(ERAD).B cells with activated StING were thus less capable of responding to BCR activation by phosphorylating Igα and Syk than those without activated *** immunized with t-independent antigens,StING V154M mice produced significantly fewer antigen-specific plasma cells and antibodies than immunized wild-type(Wt)*** further generated B cell-specific StING^(KO) mice and showed that StING^(KO) B cells indeed responded to activation by transducing stronger BCR signals than their StING-proficient *** B cell-specific StING^(KO) mice were t-independently immunized,they produced significantly more antigen-specific plasma cells and antibodies than immunized StIN^(Wt)*** both human and m ouse IGhV-unmutated malignant chronic lymphocytic leukemia(CLL)cells downregulated the expression of StING,we explored whether StING downregulation could contribute to the well-established robust BCR signaling phenotype in malignant CLL *** generated a StING-deficient CLL mouse model and showed that StING-deficient CLL cells were indeed more responsive to BCR activation than their StING-proficient *** results revealed a novel B cell-intrinsic role of StING in negatively regulating BCR signaling in both normal and malignant B cells.

关键词： StING BCR ER-associated degradation CLL Plasma cells

Effect of Ball Scribing on Magnetic Shielding Efficiency of Grain-oriented Silicon Steel

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Journal of Iron and Steel Research International 2014年第7期21卷 679-684页

作者： hao WANG chang-sheng LI Rui-bin MEI Gang hUO State Key Laboratory of Rolling and Automation Northeastern University Northeastern University at Qinhuangdao Branch Northeastern University Benxi Steel Posco Cold Strip Rolling Co. Ltd.

Magnetic shielding of grain-oriented silicon steel was investigated. Ball scribing with spacing of 2 to 16 mm was performed at peak flux densities of 8.0 mt to 1.3 t. Magnetic shielding efficiency was calculated, including absorption, reflection and inner multi-reflection shielding efficiencies. Magnetic shielding efficiency （MSE） increase ratios after different scribing spacing were compared, and thickness requirement to achieve absorption shielding of 50 dB was also calculated. the results show that magnetic shielding efficiencies of C711 and h668 silicon steels increase by 4.79 and 3.15 dB respectively after scribing of 16 mm. Before scribing, shielding efficiency of h668 steel was higher than that of C711 steel, while after scribing, both absorption and shielding efficiency gaps were largely abridged between C711 and h668 steels. Plate thickness of C711 steel could be reduced from 3.18 mm without scribing to 2. 20 mm after scribing of 16 mm. there is no apparent thickness reduction at lower flux densities; while the peak flux density is above 0.3 t, the shielding effect becomes apparent, and the thickness could be reduced from 2.28 mm without scribing to 1.70 mm with scribing spacing of 16 ram. Magnetizing process and its effect on variation of magnetic shielding were also analyzed.

关键词： magnetic shielding efficiency grain-oriented silicon steel absorption shielding reflection shielding inner multi-reflection shielding thickness reduction