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Investigating neurogenic bowel in experimental spinal cord injury: where to begin?

Neural Regeneration Research 2019年第2期14卷 222-226页

作者： Amanda R.White gregory m.holmes Department of Neural & Behavioral Sciences Penn State University College of Medicine

The devastating losses following traumatic spinal cord injury(SCI) encompass the motor, sensory and autonomic nervous systems. Neurogenic bowel is a slow transit colonic dysfunction marked by constipation, rectal evacuation difficulties, decreased anorectal sensation, fecal incontinence or some combination thereof. Furthermore, neurogenic bowel is one of the most prevalent comorbidities of SCI and is recognized by afflicted individuals and caregivers as a lifelong physical and psychological challenge that profoundly affects quality of life. The restoration of post-injury control of movement has received considerable scientific scrutiny yet the daily necessity of voiding the bowel and bladder remains critically under-investigated. Subsequently, physicians and caregivers are rarely presented with consistent, evidence-based strategies to successfully address the consequences of dysregulated voiding reflexes. Neurogenic bowel is commonly believed to result from the interruption of the supraspinal control of the spinal autonomic circuits regulating the colon. In this mini-review, we discuss the clinical challenges presented by neurogenic bowel and emerging pre-clinical evidence that is revealing that SCI also initiates functional remodeling of the colonic wall concurrent with a decrease in local enteric neurons. Since the enteric input to the colonic smooth muscle is the final common pathway for functional contractions of the colon, changes to the neuromuscular interface must first be understood in order to maximize the efficacy of therapeutic interventions targeting colonic dysfunction following SCI.

关键词： colon enteric nervous system parasympathetic sympathetic autonomic nervous system defecationreflexes gastrointestinal inflammation constipation incontinence

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Altered physiology of gastrointestinal vagal afferents following neurotrauma

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Neural Regeneration Research 2021年第2期16卷 254-263页

作者： Emily N.Blanke gregory m.holmes Emily m.Besecker Department of Health Sciences Gettysburg CollegeGettysburgPAUSA Department of Neural and Behavioral Sciences Penn State University College of MedicineHersheyPAUSA

The adaptability of the central nervous system has been revealed in several model *** particular interest to central nervous system-injured individuals is the ability for neural components to be modified for regain of *** both types of neurotrauma,traumatic brain injury and spinal cord injury,the primary parasympathetic control to the gastrointestinal tract,the vagus nerve,remains anatomically ***,individuals with traumatic brain injury or spinal cord injury are highly susceptible to gastrointestinal *** gastrointestinal dysfunctions attribute to higher morbidity and mortality following traumatic brain injury and spinal cord *** the vagal efferent output remains capable of eliciting motor responses following injury,evidence suggests impairment of the vagal *** sensory input drives motor output,this review will discuss the normal and altered anatomy and physiology of the gastrointestinal vagal afferents to better understand the contributions of vagal afferent plasticity following neurotrauma.

关键词： gastrointestinal functions microbiome neurotrauma nodose ganglia sensory neuropathy spinal cord injury traumatic brain injury vagal afferents visceral reflexes

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Nonuniform Dependence on the Initial Data for Solutions of Conservation Laws

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Communications on Applied mathematics and Computation 2024年第1期6卷 489-500页

作者： John m.holmes Barbara Lee Keyfitz Department of mathematics The Ohio State UniversityColumbusOH43210USA

In this paper,we study systems of conservation laws in one space *** prove that for classical solutions in Sobolev spaces H^(s),with s>3/2,the data-to-solution map is not uniformly *** results apply to all nonlinear s... 详细信息

关键词： Conservation laws Data-to-solution map Nonuniform dependence

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Geriatric assessment for oncologists

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Cancer Biology & medicine 2015年第4期12卷 261-274页

作者： Beatriz Korc-Grodzicki Holly m.holmes Armin Shahrokni memorial Sloan Kettering Cancer Center Weill Cornell Medical CollegeNew York Division of Geriatric and Palliative medicine The University of Texas Health Science Center at Houston

The world is experiencing aging of its population. Age-specific incidence rates of cancer are higher and cancer is now recognized as a part of aging. Treating older patients can be challenging. The clinical behavior of some tumors changes with age and the aging process itself brings physiological changes leading to decline in the function of organs. It is essential to identify those patients with longer life expectancy, potentially more likely to benefit from aggressive treatment vs. those that are more vulnerable to adverse outcomes. A primary determination when considering therapy for an older cancer patient is a patient's physiologic, rather than chronologic age. In order to differentiate amongst patients of the same age, it is useful to determine if a patient is fit or frail. Frail older adults have multiple chronic conditions and difficulties maintaining independence. They may be more vulnerable to therapy toxicities, and may not have substantial lasting benefits from therapy. Geriatric assessment(GA) may be used as a tool to determine reversible deficits and devise treatment strategies to mitigate such deficits. GA is also used in treatment decision making by clinicians, helping to risk stratify patients prior to potentially high-risk therapy. An important practical aspect of GA is the feasibility of incorporating it into a busy oncology practice. Key considerations in performing the GA include: available resources, patient population, GA tools to use, and who will be responsible for using the GA results and develop care plans. Challenges in implementing GA in clinical practice will be discussed.

关键词： Geriatric oncology geriatric assessment(GA) frailty

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Recent advances in phosphoric acid-based membranes for high-temperature proton exchange membrane fuel cells

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Journal of Energy Chemistry 2021年第12期30卷 393-429,I0010页

作者： Zunmin Guo maria Perez-Page Jianuo Chen Zhaoqi Ji Stuart m.holmes Department of Chemical Engineering and Analytical Science The University of Manchester.Ml39PLUnited Kingdom

High-temperature proton exchange membrane fuel cells(HT-PEmFCs)are pursued worldwide as efficient energy conversion *** efforts have been made in the area of designing and developing phosphoric acid(PA)-based proton exchange membrane(PEm)of *** review focuses on recent advances in the limitations of acid-based PEm(acid leaching,oxidative degradation,and mechanical degradation)and the approaches mitigating the membrane *** multilayer or polymers with continuous network,adding hygroscopic inorganic materials,and introducing PA doping sites or covalent interactions with PA can effectively reduce acid *** oxidative degradation can be alleviated by synthesizing crosslinked or branched polymers,and introducing antioxidative groups or highly oxidative stable *** to get a compact structure,blending with stable polymers and inorganic materials,preparing polymer with high molecular weight,and fabricating the polymer with PA doping sites away from backbones,are recommended to improve the membrane mechanical ***,by comparing the running hours and decay rate,three current approaches,*** via thermally curing or polymeric crosslinker,*** hygroscopic inorganic materials,*** membrane layers or introducing strong basic groups and electron-withdrawing groups,have been concluded to be promising approaches to improve the durability of *** overall aim of this review is to explore the existing degradation challenges and opportunities to serve as a solid basis for the deployment in the fuel cell market.

关键词： High-temperature proton exchange membrane fuel cells Acid leaching Oxidative degradation mechanical degradation Durability

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High Temperature Iron Ethylene Polymerization Catalysts Bearing N,N,N'-2-(1-(2,4-Dibenzhydryl-6-fluorophenylimino)ethyl)-6-(1-(arylphenylimino)ethyl)pyridines

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Chinese Journal of Polymer Science 2024年第2期42卷 188-201,I0007页

作者： Chantsalnyam Bariashir Qiu-Yue Zhang Bayasgalan Ulambayar gregory A.Solan Tong-Ling Liang Wen-Hua Sun Institute of Chemistry and Chemical Technology Mongolian Academy of SciencesUlaanbaatar13330Mongolia Key Laboratory of Engineering Plastics and Beijing National Laboratory for molecular Science Institute of ChemistryChinese Academy of SciencesBeijing100190China Department of Chemistry University of LeicesterUniversity RoadLeicesterLE17RHUK State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China

The N,N,N'-ferrous chloride complexes,[2-{CmeN(2,4-(CHPh)_(2)-6-FC_(6)H_(2))}-6-(CmeNAr)C_(5)H_(3)N]FeCl_(2)(Ar=2,6-me_(2)C_(6)H_(3) Fe1,2,6-Et_(2)C_(6)H_(3)Fe2,2,6-^(i)Pr_(2)C_(6)H_(3) Fe3,2,4,6-me_(3)C_(6)H_(2) Fe4 and 2,6-Et_(2)-4-meC_(6)H_(2) Fe5),each possessing one N-2,4-dibenzhydryl-6-fluorophenyl group,were readily synthesized from their respective unsymmetrical bis(imino)pyridines,*** identification of Fe2 highlighted the variation in the steric properties provided by the dissimilar N-aryl *** pre-treatment with either mAO or mmAO,complexes Fe1-Fe5 all displayed,at an operating temperature of 80℃,high activities for ethylene polymerization with levels falling in the order:Fe4> Fe1> Fe5> Fe2> ***,Fe4/mAO displayed the highest activity of 1.94×10^(7) g_(PE)·mol_(Fe)^(-1)·h^(-1) of the study with only a modest loss in performance at 90℃.Generally,the resulting polyethylenes were highly linear(T_(m) range:122-132℃),narrowly disperse and of low molecular weight(m_(w) range:6.73-46.04kg·mol^(-1)),with the most sterically hindered Fe3 forming the highest molecular weight polymer of the ***-group analysis by ^(1)H-and ^(13)CNmR spectroscopy revealed saturated alkyl(n-propyl and i-propyl) and unsaturated vinyl chain ends indicative of the role of both β-H elimination and chain transfer to aluminum as termination *** comparison with previou sly reported iron precatalysts with similar tridentate ligand skeletons,it is evident that the introduction of a large benzhydryl group in combination with a fluorine as the ortho-substituents of one N-aryl group has the effect of enhancing thermal stability of the iron polymerization catalyst whilst maintaining appreciable polymer molecular weight.

关键词： Iron catalyst Ethylene polymerization Linear polyethylene Fluoride effect Thermal stability

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Synthesis of phosphonated graphene oxide by electrochemical exfoliation to enhance the performance and durability of high-temperature proton exchange membrane fuel cells

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Journal of Energy Chemistry 2023年第1期76卷 448-458,I0011页

作者： Jianuo Chen Zunmin Guo maria Perez-Page Yifeng Jia Ziyu Zhao Stuart m.holmes Department of Chemical Engineering and Analytical Science University of ManchesterOxford RoadManchester M139PLUnited Kingdom Chemistry Research Laboratory Department of ChemistryUniversity of Oxford12 Mansfield RoadOxford OX13TAUnited Kingdom

The doping of functionalized graphene oxide(GO)in the membranes becomes a promising method for improving the performance of high-temperature proton exchange membrane fuel cells(HT-PEmFC).Phosphonated graphene oxide(PGO)with a P/O ratio of 8.5%was quickly synthesised by one-step electrochemical exfoliation based on a three-dimensiaonal(3D)printed reactor and natural graphite *** with the GO prepared by the two-step electrochemical exfoliation method,the PGO synthesized by the one-step electrochemical exfoliation can better improve the performance of the membrane-electrode-assembly(mEA)based on the polybenzimidazole(PBI)membrane in the *** doping of 1.5 wt%GO synthesised by electrochemical exfoliation with the 2-step method or reactor method in PBI increased the peak power density by 17.4%or 35.4%compared to mEA based on pure PBI membrane at 150℃,*** addition,the doping of PGO in PBI improves its durability under accelerated stress test(AST).

关键词： Electrochemical exfoliation Phosphonated graphene oxide High-temperature fuel cells

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Integrins and their potential roles in mammalian pregnancy

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Journal of Animal Science and Biotechnology 2024年第1期15卷 1-19页

作者： gregory A.Johnson Robert C.Burghardt Fuller W.Bazer Heewon Seo Joe W.Cain Department of Veterinary Integrative Biosciences School of Veterinary Medicine and Biomedical SciencesTexas A&M UniversityCollege StationTX 77843‑4459USA Department of Animal Science College of Agriculture and Life SciencesTexas A&M UniversityCollege StationTX 77843‑2471USA

Integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix(ECm) interactions leading to assembly of integrin adhesion complexes(IACs) that initiate many signaling functions both at the membrane and deeper within the cytoplasm to coordinate processes including cell adhesion, migration, proliferation, survival, differentiation, and metabolism. All metazoan organisms possess integrins, and it is generally agreed that integrins were associated with the evolution of multicellularity, being essential for the association of cells with their neighbors and surroundings, during embryonic development and many aspects of cellular and molecular biology. Integrins have important roles in many aspects of embryonic development, normal physiology, and disease processes with a multitude of functions discovered and elucidated for integrins that directly influence many areas of biology and medicine, including mammalian pregnancy, in particular implantation of the blastocyst to the uterine wall, subsequent placentation and conceptus(embryo/fetus and associated placental membranes) development. This review provides a succinct overview of integrin structure, ligand binding, and signaling followed with a concise overview of embryonic development, implantation, and early placentation in pigs, sheep, humans, and mice as an example for rodents. A brief timeline of the initial localization of integrin subunits to the uterine luminal epithelium(LE) and conceptus trophoblast is then presented, followed by sequential summaries of integrin expression and function during gestation in pigs, sheep, humans, and rodents. As appropriate for this journal, summaries of integrin expression and function during gestation in pigs and sheep are in depth, whereas summaries for humans and rodents are brief. Because similar models to those illustrated in Fig. 1, 2, 3, 4, 5 and 6 are present throughout the sc

关键词： Humans Implantation Integrins Pigs Pregnancy Rodents Sheep

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High-performance polymer electrolyte membranes incorporated with 2D silica nanosheets in high-temperature proton exchange membrane fuel cells

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Journal of Energy Chemistry 2022年第1期31卷 323-334,I0009页

作者： Zunmin Guo Jianuo Chen Jae Jong Byun Rongsheng Cai maria Perez-Page madhumita Sahoo Zhaoqi Ji Sarah J.Haigh Stuart m.holmes Department of Chemical Engineering and Analytical Science The University of ManchesterM139PLUnited Kingdom Department of materials The University of ManchesterM139PLUnited Kingdom

Silica nanosheets(SN)derived from natural vermiculite(Verm)were successfully incorporated into polyethersulfone-polyvinylpyrrolidone(PES-PVP)polymer to fabricate high-temperature proton exchange membranes(HT-PEms).The content of SN filler was varied(0.1-0.75 wt%)to study its influence on proton conductivity,power density and *** from the hydroxyl groups of SN that enable the formation of additional proton-transferring pathways,the inorganic-organic membrane displayed enhanced proton conductivity of 48.2 mS/cm and power density of 495 mW/cm^(2) at 150℃ without humidification when the content of SN is 0.25 wt%.Furthermore,exfoliated SN(E-SN)and sulfonated SN(S-SN),which were fabricated by a liquid-phase exfoliation method and silane condensation,respectively,were embedded in PES-PVP polymer matrix by a simple blending *** to the significant contribution from sulfonic groups in S-SN,the membrane with 0.25 wt%S-SN reached the highest proton conductivity of51.5 mS/cm and peak power density of 546 mW/cm^(2) at150℃,48%higher than the pristine PES-PVP *** to unaltered PES-PVP membrane,SN added hybrid composite membrane demonstrated excellent durability for the fuel cell at 150℃.Using a facile method to prepare 2D SN from natural clay minerals,the strategy of exfoliation and functionalization of SN can be potentially used in the production of HT-PEms.

关键词： Silica nanosheets Vermiculite High-temperature proton exchange membrane Proton conductivity

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Doped graphene/carbon black hybrid catalyst giving enhanced oxygen reduction reaction activity with high resistance to corrosion in proton exchange membrane fuel cells

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Journal of Energy Chemistry 2022年第5期31卷 143-153页

作者： Zhaoqi Ji Jianuo Chen maría Pérez-Page Zunmin Guo Ziyu Zhao Rongsheng Cai maxwell T.P.Rigby Sarah J.Haigh Stuart m.holmes School of Automotive Engineering Harbin Institute of TechnologyWeihai264209ShandongChina Department of Chemical Engineering and Analytical Science The University of ManchesterManchester M139PLUK Department of materials The University of ManchesterManchester M139PLUK

Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows that p-phenyl groups and graphitic N acting bridges linking platinum and the graphene/carbon black(the ratio graphene/carbon black = 2/3) hybrid support materials achieved the average size of platinum nanoparticles with(4.88 ± 1.79) nm. It improved the performance of the lower-temperature hydrogen fuel cell up to 0.934 W cm^(-2) at 0.60 V, which is 1.55 times greater than that of commercial Pt/C. Doping also enhanced the interaction between Pt and the support materials, and the resistance to corrosion, thus improving the durability of the low-temperature hydrogen fuel cell with a much lower decay of 10 mV at 0.80 A cm^(-2) after 30 k cycles of an in-situ accelerated stress test of catalyst degradation than that of 92 mV in Pt/C, which achieves the target of Department of Energy(mV). meanwhile,Pt/Nr EGO_(2)-CB_(3) remains 78% of initial power density at 1.5 A cm^(-2) after 5 k cycles of in-situ accelerated stress test of carbon corrosion, which is more stable than the power density of commercial Pt/C, keeping only 54% after accelerated stress test.

关键词： Nitrogen doped graphene Low-temperature hydrogen fuel cell Catalyst degradation Carbon corrosion

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