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Investigation of a cyanine dye assay for the evaluation of the biocompatibility of magnesium alloys by direct and indirect methods

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Bioactive Materials 2020年第1期5卷 26-33页

作者： Afrah Al Hegy Ryan Smith eric R.Gauthier Joy e.gray-Munro Dept.of Chemistry and Biochemistry Laurentian UniversitySudburyOntarioP3E 2C6Canada

Magnesium and its alloys are promising candidates for a new generation of biodegradable metals in orthopaedic applications due to their excellent biocompatibility,biodegradability,and mechanical properties that are similar to natural bone.However,direct in vitro assessment of these materials in the presence of cells is complicated by degradation products from the alloy that lead to a false positive for the most commonly used cell adhesion and cell proliferation assays.In this paper,a cyanine dye was used to quantitatively evaluate the in vitro biocompatibility of a Mg AZ31 alloy by both direct and indirect methods.The cytotoxicity of the corrosion products was evaluated via an indirect method;a 25%decrease in cell viability compared to control samples was observed.Moreover,direct assessment of cell adhesion and proliferation showed a statistically significant increase in cell number at the surface after 72 h.In addition,the degradation rate and surface characteristics of the Mg AZ31 alloy were evaluated for both direct and indirect tests.The degradation rate was unaffected by the presence of cells while evidence of an increase in calcium phosphate deposition on the magnesium alloy surface in the presence of cells was observed.This study demonstrates that a cyanine dye based assay provides a more accurate assessment of the overall in vitro biocompatibility of biodegradable metals than the more commonly used assays reported in the literature to date.

关键词： Magnesium alloys Biocompatibility Direct method Indirect method Cyanine dye Cell adhesion Cell proliferation Cytotoxicity

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21世纪摩天大楼的模式转变

21世纪摩天大楼的模式转变

Neural lineage differentiation of human pluripotent stem cells:Advances in disease modeling

崛起中的亚洲：可持续性摩天大楼城市的时代：多学科背景下...

作者： emily Merrill Lee e.gray 夏洛特北卡罗莱纳大学建筑学院

二十一世纪新一代的摩天大楼应运而生。这些摩天大楼解决了人口增长、城市化以及迅速耗竭的不可再生能源的问题。因此,它们是由能源和生态环境的可持续性发展想法推动的。现在摩天大楼被认为是智能和节能的,与过去的摩天大楼有着根本上... 详细信息

二十一世纪新一代的摩天大楼应运而生。这些摩天大楼解决了人口增长、城市化以及迅速耗竭的不可再生能源的问题。因此,它们是由能源和生态环境的可持续性发展想法推动的。现在摩天大楼被认为是智能和节能的,与过去的摩天大楼有着根本上的不同。虽然很多因素促成二十一世纪摩天大楼的这种模式转变,本文试图通过三个特定的设计状况来探讨这种转变。这些状况为:建筑基底设计和垂直组织,形式,外墙。本文的目的是分析和探讨新一代的现代摩天大楼的状况,最终提供有关这一重要类型学的当前状态以及可能的发展方向的新见解,以继续摩天大楼的成功。

关键词：摩天大楼可持续性设计建筑基底设计垂直组织形式外墙

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World Journal of Stem Cells 2023年第6期15卷 530-545页

作者： Yuan-Wei Yan eddie S Qian Lauren e Woodard julie Bejoy Waisman Center University of Wisconsin-MadisonMadisonWI 53705United States Nephrology and Hypertension Vanderbilt University Medical CenterNashvilleTN 37232United States Department of Medicine Vanderbilt University Medical CenterNashvilleTN 37232United States Department of Veterans Affairs Tennessee Valley Healthcare SystemNashvilleTN 37232United States Biomedical engineering Vanderbilt UniversityNashvilleTN 37232United States

Brain diseases affect 1 in 6 people worldwide.These diseases range from acute neurological conditions such as stroke to chronic neurodegenerative disorders such as Alzheimer’s disease.Recent advancements in tissue-engineered brain disease models have overcome many of the different shortcomings associated with the various animal models,tissue culture models,and epidemiologic patient data that are commonly used to study brain disease.One innovative method by which to model human neurological disease is via the directed differentiation of human pluripotent stem cells(hPSCs)to neural lineages including neurons,astrocytes,and oligodendrocytes.Three-dimensional models such as brain organoids have also been derived from hPSCs,offering more physiological relevance due to their incorporation of various cell types.As such,brain organoids can better model the pathophysiology of neural diseases observed in patients.In this review,we will emphasize recent developments in hPSC-based tissue culture models of neurological disorders and how they are being used to create neural disease models.

关键词： Induced pluripotent stem cells Astrocytes Oligodendrocytes Microglia Brain organoids Assembloids

effects of obesity on breast size,thoracic spine structure and function,upper torso musculoskeletal pain and physical activity in women

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Journal of Sport and Health Science 2020年第2期9卷 140-148页

作者： julie R.Steele Celeste e.Coltman Deirdre e.McGhee Biomechanics Research Laboratory School of MedicineUniversity of WollongongWollongongNSW 2522Australia Research Institute for Sport and exercise Faculty of HealthUniversity of CanberraCanberraACT 2601Australia

Purpose:This study investigated the effects of obesity on breast size,thoracic spine structure and function,upper torso musculoskeletal pain and physical activity participation in women living independently in the community.Methods:A total of 378 women were divided into 3 groups(Not Overweight:body mass index(BMI)=22.5±0.2 kg/m^2(mean±Se);Overweight:BMI=27.4±0.3 kg/m^2;Obese:BMI=35.4±0.3 kg/m^2).Outcome variables of breast volume(mL),thoracic flexion torque(N·m),thoracic kyphosis(degrees),upper torso musculoskeletal pain(score) and time spent in physical activity(min) were calculated and compared among the 3 groups,adjusting for between-group differences in age.Results:There was a significant main effect of BMI on all outcome variables.Participants classified as Obese displayed significantly larger breasts,had greater thoracic flexion torques and reported less time participating in physical activity relative to the participants who were classified as Not Overweight and Overweight.Participants in the Obese group also displayed significantly more thoracic kyphosis and reported significantly more upper torso musculoskeletal pain compared to their counterparts who were classified as Not Overweight.Conclusion:This study is the first to demonstrate that increased obesity levels were associated with compromised kyphosis and loading of the thoracic spine,as well as increased symptoms of upper torso musculoskeletal pain and reduced time spent in physical activity in women living in the community.We recommend further research to determine whether evidence-based interventions designed to reduce the flexion torque generated on the thoracic spine can improve these symptoms of upper torso musculoskeletal pain and the ability of women with obesity to participate in physical activity.

关键词： Breast volume Obesity Thoracic kyphosis Upper torso loading

Mudcake effects on wellbore stress and fracture initiation pressure and implications for wellbore strengthening

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Petroleum Science 2018年第2期15卷 319-334页

作者： Yongcun Feng Xiaorong Li K.e.gray The University of Texas at Austin AustinTXUSA

Although a large volume of mudcake filtration test data is available in the literature, effects of mudcake on wellbore strengthening cannot be quantified without incorporating the data into a stress-analysis model. Traditional models for determining fracture initiation pressure （FIP） either consider a wellbore with an impermeable mudcake or with no mudcake at all. An analytical model considering permeable mudcake is proposed in this paper. The model can predict pore pressure and stress profiles around the wellbore, and consequently the FIP, for different mudcake thickness, permeability, and strength. Numerical examples are provided to illustrate the effects of these mudcake parameters. The results show that a low-permeability mudcake enhances FIP, mainly through restricting fluid seepage and pore pressure increase in the near- wellbore region, rather than by mudcake strength. Fluid loss pressure （FLP） should be distinguished from FIP when a mudcake is present on the wellbore wall. Fracture may occur behind the mudcake at FIP without mudcake rupture. The small effect of mudcake strength on FIP does not mean its effect on FLP is small too. Mudcake strength may play an important role in maintaining integrity of the wellbore once a fracture has initiated behind the mudcake.

关键词： Mudcake Hoop stress Fracture initiation pressure Fluid loss pressure Wellbore strengthening

Hypoxia-ischemia in the immature rodent brain impairs serotonergic neuronal function in certain dorsal raphé nuclei

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Neural Regeneration Research 2020年第3期15卷 457-463页

作者： Hanna e.Reinebrant julie A.Wixey Kathryn M.Buller UQ Centre for Clinical Research Faculty of Medicine The University of Queensland

Neonatal hypoxia-ischemia(HI)results in losses of serotonergic neurons in specific dorsal raphe nuclei.However,not all serotonergic raphe neurons are lost and it is therefore important to assess the function of remaining neurons in order to understand their potential to contribute to neurological disorders in the HI-affected neonate.The main objective of this study was to determine how serotonergic neurons,remaining in the dorsal raphe nuclei after neonatal HI,respond to an external stimulus(restraint stress).On postnatal day 3(P3),male rat pups were randomly allocated to one of the following groups:(i)control+no restraint(n=5),(ii)control+restraint(n=6),(iii)P3 HI+no restraint(n=5)or(iv)P3 HI+restraint(n=7).In the two HI groups,rat pups underwent surgery to ligate the common carotid artery and were then exposed to 6%O2 for 30 minutes.Six weeks after P3 HI,on P45,rats were subjected to restraint stress for 30 minutes.Using dual immunolabeling for Fos protein,a marker for neuronal activity,and serotonin(5-hydroxytrypamine;5-HT),numbers of Fos-positive 5-HT neurons were determined in five dorsal raphe nuclei.We found that restraint stress alone increased numbers of Fos-positive 5-HT neurons in all five dorsal raphe nuclei compared to control animals.However,following P3 HI,the number of stress-induced Fos-positive 5-HT neurons was decreased significantly in the dorsal raphe ventrolateral,interfascicular and ventral nuclei compared with control animals exposed to restraint stress.In contrast,numbers of stress-induced Fos-positive 5-HT neurons in the dorsal raphe dorsal and caudal nuclei were not affected by P3 HI.These data indicate that not only are dorsal raphe serotonergic neurons lost after neonatal HI,but also remaining dorsal raphe serotonergic neurons have reduced differential functional viability in response to an external stimulus.Procedures were approved by the University of Queensland Animal ethics Committee(UQCCR958/08/NHMRC)on February 27,2009.

关键词： dorsal raphe nuclei Fos hypoxia-ischemia neonate newborn brain injury preterm restraint stress serotonin

作为接种后不良事件的婴儿及儿童急性肠套叠:病例定义和数据收集、分析及报告指南

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中国疫苗和免疫 2017年第5期23卷 597-600页

作者： julie e.Bines 刘娜左树岩世界卫生组织驻华办事处

1前言为提高疫苗安全性数据的可比性,Brighton协作中心肠套叠工作组制定了肠套叠的病例定义和操作指南,指导资源情况不尽相同的研究机构、医疗服务能力及可及性不同的卫生服务机构以及不同的地理区域进行研究。以世界卫生组织（WHO）总... 详细信息

1前言为提高疫苗安全性数据的可比性,Brighton协作中心肠套叠工作组制定了肠套叠的病例定义和操作指南,指导资源情况不尽相同的研究机构、医疗服务能力及可及性不同的卫生服务机构以及不同的地理区域进行研究。以世界卫生组织（WHO）总部疫苗发展部的腹泻病疫苗指导委员会撰写的报告为基础,

关键词：病例定义疫苗安全性医疗服务能力卫生服务可及性数据收集疫苗接种协作中心轮状病毒疫苗接种者

Accuracy and safety of partial thickness femtosecond laser radial and arcuate keratotomy incisions in porcine eyes

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eye and Vision 2021年第1期8卷 412-421页

作者： e.Valas Teuma Frank A.Bucci Jr Raman Bedi Gary gray Mark Packer LeNSAR Inc.OrlandoFLUSA Bucci Laser Vision Institute Wilkes-BarreWilkes‑BarrePAUSA IrisARC ChandigarhIndia Packer Research Associates Inc.1400 Bluebell Ave.BoulderCO 80302USA

Background:To evaluate the accuracy and safety of micro radial and arcuate keratotomy incisions constructed by a femtosecond laser system with a curved contact patient interface in porcine eyes.Methods:Partial thickness micro radial and arcuate keratotomy incisions were constructed in porcine eyes with a femtosecond laser system and evaluated for precision of depth,quality,and consistency.Optical coherence tomography was used to determine the accuracy and precision of incision depth.Corneal endothelial safety was assessed by a fluorescent live/dead cell viability assay to demonstrate laser-induced endothelial cell loss.Quality was evaluated by ease of opening and examination of interfaces.Results:In two micro radial incision groups,intended incision depths of 50%and 80%resulted in mean achieved depths of 50.01%and 77.69%,respectively.In three arcuate incision groups,intended incision depths of 80%,600μm or 100μm residual uncut bed thickness resulted in mean achieved depths of 80.16%,603.03μm and residual bed of 115μm,respectively.No loss of endothelial cell density occurred when the residual corneal bed was maintained at a minimum of 85-116μm.The incisions were easy to open,and interfaces were smooth.Conclusions:A femtosecond laser system with curved contact interface created precise and reproducible micro radial and arcuate keratotomy incisions.Accuracy and precision of the incision depth and preservation of endothelial cell density demonstrated the effectiveness and safety of the system.

关键词： Partial thickness micro radial and arcuate keratotomy incisions Curved contact patient interface Micro radial keratotomy Arcuate keratotomy Femtosecond laser system with curved contact interface LeNSAR femtosecond laser system

Local buckling of thin plate on tensionless elastic foundations under interactive uniaxial compression and shear

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Theoretical & Applied Mechanics Letters 2018年第2期8卷 75-82页

作者： Iianghui Dong Xing Ma Yan Zhuge julie e.Mills School of Natural and Built environments University of South AustraliaAdelaideSA 5095Australia

This paper uses a mathematical method to develop an analytical solution to the local buckling behaviour of long rectangular plates resting on tensionless elastic Winkler foundations and under combined uniform longitudinal uniaxial compressive and uniform in-plane shear loads. Fitted formulas are derived for plates with clamped edges and simplified supported edges. Two examples are given to demonstrate the application of the current method： one is a plate on tensionless spring foundations and the other is the contact between the steel sheet and elastic solid foundation. Finite element （Fe） analysis is also conducted to validate the analytical results. Good agreement is obtained between the current method and Fe analysis.

关键词： Buckling coefficient Contact buckling Winkler foundation Interaction curve Finite element analysis