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| 1 | Consideration of corneal biomechanics in the diagnosis and management of keratoconus: is it important?显示文摘Keratoconus is a bilateral,non-inflammatory,degenerative corneal disease.The occurrence and development of keratoconus is associated with corneal thinning and conical protrusion,which causes irregular astigmatism.With the disruption of the collagen organization,the cornea loses its shape and function resulting in progressive visual degradation.Currently,corneal topography is the most important tool for the diagnosis of keratoconus,which may lead to false negatives among the patient population in the subclinical phase.However,it is now hypothesised that biomechanical destabilisation of the cornea may take place ahead of the topographic evidence of keratoconus,hence possibly assisting with disease diagnosis and management.This article provides a review of the definition,diagnosis,and management strategies for keratoconus based on corneal biomechanics. | FangJun Bao Brendan Geraghty QinMei Wang Ahmed Elsheikh | 2016 | Eye and Vision2016，3，1： | 8 |
| 2 | Associations of chronic hepatitis C with metabolic and cardiac outcomes显示文摘 | Z. M. Younossi M. Stepanova F. Nader Z. Younossi E. Elsheikh | 2013 | Aliment Pharmacol Ther2013，，6： | 4 |
| 3 | Human adipose derived stem cells are superior to human osteoblasts (HOB) in bone tissue engineering on a collagen-fibroin-ELR blend显示文摘The ultrastructure of the bone provides a unique mechanical strength against compressive, torsional andtensional stresses. An elastin-like recombinamer (ELR) with a nucleation sequence for hydroxyapatitewas incorporated into films prepared from a collagen-silk fibroin blend carrying microchannel patternsto stimulate anisotropic osteogenesis. SEM and fluorescence microscopy showed the alignment ofadipose-derived stem cells (ADSCs) and the human osteoblasts (HOBs) on the ridges and in the groovesof microchannel patterned collagen-fibroin-ELR blend films. The Young's modulus and the ultimatetensile strength (UTS) of untreated films were 0.58 ± 0.13 MPa and 0.18 ± 0.05 MPa, respectively. After 28days of cell culture, ADSC seeded film had a Young's modulus of 1.21 ± 0.42 MPa and UTS of0.32 ± 0.15 MPa which were about 3 fold higher than HOB seeded films. The difference in Young'smodulus was statistically significant (p: 0.02). ADSCs attached, proliferated and mineralized better thanthe HOBs. In the light of these results, ADSCs served as a better cell source than HOBs for bone tissueengineering of collagen-fibroin-ELR based constructs used in this study. We have thus shown theenhancement in the tensile mechanical properties of the bone tissue engineered scaffolds by usingADSCs. | Esen Sayin Rosti Hama Rashid JoséCarlos Rodríguez-Cabello Ahmed Elsheikh Erkan Türker Baran Vasif Hasirci | 2017 | Bioactive Materials2017，2，2： | 2 |
| 4 | Ex vivo testing of intact eye globes under inflation conditions to determine regional variation of mechanical stiffness显示文摘Background:The eye globe exhibits significant regional variation of mechanical behaviour.The aim of this present study is to develop a new experimental technique for testing intact eye globes in a form that is representative of in vivo conditions,and therefore suitable for determining the material properties of the complete outer ocular tunic.Methods:A test rig has been developed to provide closed-loop control of either applied intra-ocular pressure or resulting apical displacement;measurement of displacements across the external surface of the eye globe using high-resolution digital cameras and digital image correlation software;prevention of rigid-body motion and protection of the ocular surface from environmental drying.The method has been demonstrated on one human and one porcine eye globe,which were cyclically loaded.Finite element models based on specimen specific tomography,free from rotational symmetry,were used along with experimental pressure-displacement data in an inverse analysis process to derive the mechanical properties of tissue in different regions of the eye’s outer tunic.Results:The test method enabled monitoring of mechanical response to intraocular pressure variation across the surface of the eye globe.For the two eyes tested,the method showed a gradual change in the sclera’s stiffness from a maximum at the limbus to a minimum at the posterior pole,while in the cornea the stiffness was highest at the centre and lowest in the peripheral zone.Further,for both the sclera and cornea,the load–displacement behaviour did not vary significantly between loading cycles.Conclusions:The first methodology capable of mechanically testing intact eye globes,with applied loads and boundary conditions that closely represent in vivo conditions is introduced.The method enables determination of the regional variation in mechanical behaviour across the ocular surface. | Charles Whitford Akram Joda Steve Jones Fangjun Bao Paolo Rama Ahmed Elsheikh | 2016 | Eye and Vision2016，3，1： | 2 |
| 5 | Fast segmentation of anterior segment optical coherence tomography images using graph cut显示文摘Background:Optical coherence tomography(OCT)is a non-invasive imaging system that can be used to obtain images of the anterior segment.Automatic segmentation of these images will enable them to be used to construct patient specific biomechanical models of the human eye.These models could be used to help with treatment planning and diagnosis of patients.Methods:A novel graph cut technique using regional and shape terms was developed.It was evaluated by segmenting 39 OCT images of the anterior segment.The results of this were compared with manual segmentation and a previously reported level set segmentation technique.Three different comparison techniques were used:Dice’s similarity coefficient(DSC),mean unsigned surface positioning error(MSPE),and 95%Hausdorff distance(HD).A paired t-test was used to compare the results of different segmentation techniques.Results:When comparison with manual segmentation was performed,a mean DSC value of 0.943±0.020 was achieved,outperforming other previously published techniques.A substantial reduction in processing time was also achieved using this method.Conclusions:We have developed a new segmentation technique that is both fast and accurate.This has the potential to be used to aid diagnostics and treatment planning. | Dominic Williams Yalin Zheng Fangjun Bao Ahmed Elsheikh | 2015 | Eye and Vision2015，2，1： | 2 |
| 6 | 角膜生物力学检测方法介绍显示文摘力学问题贯穿于生物体的整个生命过程,对生物体中的力学问题进行定量分析,产生了生物学和物理学的交叉学科——生物力学;其研究重点是生理学、医学有关的力学问题.随着医疗检查诊断技术的发展,人们逐渐认识到眼生物力学性能的重要性.角膜生物力学性能测量在角膜疾病诊断、角膜屈光手术效果预测及眼内压测量等方面都具有非常重要的意义.角膜组织主要由致密交错的胶原纤维束和细胞外基质组成,其生物力学特征颇为复杂,表现为非线弹性、各向异性、黏弹性、区域差异性和年龄相关性等特征.生物力学性能测量的关键是找寻描述生物组织力学特性的本构方程,方程内包含的参量为本构参量,包括应力、应变和弹性模量等.根据测量时生物材料初始状态的差异,角膜生物力学性能参数的测量方法可分为离体和在体测量2种.虽然在体测量具有更为广阔的临床应用前景,然而当前在体测量技术并不成熟.临床常用仪器ORA和Corvis无法提供本构参量,尚不能作为眼生物学性能测量的标准实验手段.笔者就目前国际上常见几种离体测量技术的原理及发展做了详细介绍,以方便相关研究者更好地进行选择,这其中包括:轴向拉伸试验、基于薄壳理论的简单离体角膜膨胀试验、基于逆向建模技术的离体角膜膨胀试验和同样基于逆向建模技术的离体全眼球膨胀试验.将切成条状的角膜试件固定于材料试验机进行单向或双向拉伸,获取本构参量,是为轴向拉伸试验.最早用于角膜生物力学性能的测量,此方法设备简单,容易操作,但对角膜的生理结构破坏较大,测量值存在不小的误差.基于薄壳理论的简单离体角膜膨胀试验:将完整分离的角膜试件固定于填充有液体的前房模拟装置,模拟眼内压对角膜后表面施压并实时记录角膜形变;根据薄壳理论推导公式计算得到角膜组织的本构关系方程.离体角膜膨胀试验保持了角膜组织结构的完整性和提供更接近于角膜生理状态的施力方式,但仍存在破坏角巩膜连续解剖结构、机械固定方式导致应力集中等缺点.因薄壳理论的球形角膜结构和均质性生物力学性能假设限制了膨胀试验结果的精确性,通过构建具有个性化几何特征的角膜有限元生物力学模型,模拟角膜在眼内压力作用下的形变过程,将膨胀试验测量所得眼内压和角膜形变关系曲线作为目标曲线,不断调整本构方程系数使得模拟的角膜形变曲线和目标曲线逐渐逼近,反复迭代运算得到角膜组织本构参量的最优化结果,称为基于逆向建模技术的离体角膜嘭胀试验,具有较好的试验测量精度和可重复性.离体全眼球膨胀试验延续了角巩膜完整的曲面形状和采取接近眼球生理的施力方式,是相对最接近角膜生理状态的测量方法,但该试验也存在设备制作复杂、操作繁琐等缺点.如能在试验过程中提供接近生理状态的眼球支撑方式,解决角巩膜随眼内压力变化过程形变数据的准确提取等技术难题,有望实现对角巩膜组织区域差异性、各向异性及黏弹性等生物力学特征的一体化定量测量分析,具有非常广阔的应用前景. | Charles Whitford Ahmed Elsheikh 包芳军(整理翻译) | 2014 | 中华眼视光学与视觉科学杂志2014，16，5： | 2 |
| 7 | Robotic surgery and liver transplantation:A single-center experience of 501 robotic donor hepatectomies显示文摘Background:Over the past two decades robotic surgery has been introduced to many areas including liver surgery.Laparoscopic liver surgery is an alternative minimally invasive approach.However,moving on to the complexity of living donor hepatectomies,the advantages of robotic versus laparoscopic approach have convinced us to establish the robotic platform as a standard for living donor hepatectomy.Methods:From November 2018 to January 2022,501 fully robotic donor hepatectomies,including 177 left lateral donor lobes,112 full left lobes and 212 full right lobes were performed.Grafts were donated to 296 adult recipients and 205 pediatric recipients.Donor age,sex,body weight,body mass index(BMI),graft weight,graft to body weight ratio(GBWR),operative time,blood loss,first warm ischemic time,pain score,length of intensive care unit(ICU)stay and hospital stay,and complications were retrospectively analyzed based on a prospectively kept database.Recipients were evaluated for graft and patient survival,age,sex,BMI,body weight,model of end-stage liver disease score,blood loss,transfusions,operative time,cold ischemic time,length of hospital stay and complications.Results:There was no donor mortality.Two cases needed to be converted to open surgery.The median blood loss was 60 mL(range 20-800),median donor operative time was 6.77 h(range 2.93-11.53),median length of hospital stay was 4 days(range 2-22).Complication rate in donors classified following ClavienDindo was 6.4%(n=32)with one grade Ⅲ complication.Three-year actual recipient overall survival was 91.4%;87.5% for adult recipients and 97.1% for pediatric recipients.Three-year actual graft overall survival was 90.6%;87.5% for adult recipients and 95.1% for pediatric recipients.In-hospital mortality was 6%,9.1%(27/296)for adult recipients and 1.4%(3/205)for pediatric recipients.The recipients’morbidity was 19.8%(n=99).Twenty-eight recipients(5.6%)had biliary and 22(4.4%)vascular complications.Six(12.0%)recipients needed to be re-transplanted.Conclusions:With growing experience it is nowadays possible to perform any donor hepatectomy by robotic approach regardless of anatomical variations and graft size.Donor morbidity and quality for life results are encouraging and should motivate other transplant centers with interest in minimally invasive donor surgery to adopt this robotic technique. | Maren Schulze Yasser Elsheikh Markus Ulrich Boehnert Yasir Alnemary Saleh Alabbad Dieter Clemens Broering | 2022 | Hepatobiliary & Pancreatic Diseases International2022，21，4： | 2 |
| 8 | Effect of Gold Nanocomposite on the Cytotoxicity of Human Cancer Cell Lines显示文摘 | A. M. H. Abaza G. A. Mahmoud B. B. Elsheikh | 2018 | Journal of Pharmacy and Pharmacology2018，6，8： | 2 |
| 9 | In vivo study of corneal responses to increased intraocular pressure loading显示文摘Background:The cornea is responsible for two-thirds of the eye's refractive power which is a function of the shape and refractive index.The aim of this present study is to examine human eyes in vivo for corneal shape changes in response to short-term elevation in intraocular pressure.Methods:Videokeratographic and tonometric assessments at baseline were compared with the same assessments when intraocular pressure was elevated to approximately double(199±22%)the baseline levels using ophthalmodynamometer applanation of the sclera.Composite maps of the cornea and limbus were created by combining topographical assessments for central,nasal,temporal,inferior and superior fixation.Numerical finiteelement simulations were custom built for each subject and the stiffness distribution across corneal surface modified to achieve matches between simulated and experimental data.Results:The stiffness distributions required to achieve simulation-experimental matches showed a consistent trend with the 2.5 mm annulus bounded by the limbus showing a mean stiffness reduction of 47.3±10.8%compared with the central cornea(P=0.001).Conclusions:Corneal structure appears to provide the central cornea with a greater stiffness compared with the peripheral cornea and associated greater tolerance to elevation in intraocular pressure,consistent with the need for stable corneal refraction and vision.The method adopted to examine corneal biomechanical performance in vivo may have applications in additional studies. | Ahmed Elsheikh Charles W.McMonnies Charles Whitford Gavin C.Boneham | 2015 | Eye and Vision2015，2，1： | 2 |
| 10 | Mapping of three QTLs for seed setting and analysis on the candidate gene for qSS-1 in rice(Oryza sativa L.)显示文摘The lower seed setting is one of the major hindrances which face grain yield in rice.One of the main reasons to cause low spikelet fertility(seed setting)is male sterility or pollen abortion.Notably,pollen abortion has been frequently observed in advanced progenies of rice.In the present study,149 BC_2F_6 individuals with significant segregation in spikelet fertility were generated from the cross between N040212(indica)and Nipponbare(japonica)and used for primary gene mapping.Three QTLs,qSS-1,qSS-7 and qSS-9 at chromosomes 1,7 and 9,respectively,were found to be associated with seed setting.The recombinant analysis and the physical mapping information from publicly available resources exhibited that the qSS-1,qSS-7 and qSS-9 loci were mapped to an interval of 188,701 and 3741 kb,respectively.The seed setting responsible for QTL qSS-1 was further fine mapped to 93.5 kb by using BC_2F_7 population of 1 849 individuals.There are 16possible putative genes in this 93.5 kb region.Pollen vitality tests and artificial pollination indicated that the male gamete has abnormal pollen while the female gamete was normal.These data showed that low seed setting rate relative to qSS-1may be caused by abnormal pollen grains.These results will be useful for cloning,functional analysis of the target gene governing spikelet fertility(seed setting)and understanding the genetic bases of pollen sterility. | Elsheikh Y M Ahmed ZHANG Yan-pei YU Jian-ping Rashid M A Rehman ZHANG Zhan-ying ZHANG Hong-liang LI Jin-jie LI Zi-chao | 2016 | Journal of Integrative Agriculture2016，15，4： | 2 |
| 11 | Comparison of ThinPrep and Cytospin Preparations in the Evaluation of Exfoliative Cytology Specimens显示文摘 | Elsheikh TM Kirkpatrick JL Wu HH | 2006 | Cancer2006，108，3： | 1 |
| 12 | Predicting screening sensitivity fromworkload in gynecologic cytology:a review显示文摘 | Renshaw AA Elsheikh TM | 2011 | Diagn Cytopathol2011，39，11： | 1 |
| 13 | Preparation of citrullus colocynthis biodiesel via dual-step catalyzedprocess using functionalized imidazolium and pyrazolium ionicliquids for esterification step显示文摘 | ELSHEIKH Y A | 2013 | Industrial Crops&Products2013，49，8： | 1 |
| 14 | Simulating cyber- physical energy systems:challenges,tools and methods 显示文摘 | Palensky P Widl E Elsheikh A | 2014 | IEEE Transactions on Systems Man and Cybernetics:Systems2014，44，3： | 1 |
| 15 | Cytotoxic Effect of Chitosan Based Nanocomposite Synthesized by Radiation: In Vitro Liver and Breast Cancer Cell Line显示文摘 | A. Abaza G. A. Mahmoud E. A. Hegazy M. Amin E Shoukry B. Elsheikh | 2018 | Journal of Pharmacy and Pharmacology2018，6，4： | 1 |
| 16 | The rennin - aldosterone system during normal and hypertensive pregnancy显示文摘 | Elsheikh A Creatsa S G Mastorakos G | 2001 | Arch Gynecol Obstet2001，264，4： | 1 |
| 17 | Triple-negative breast cancer:Distinguishing between basal and nonbasal subtypes显示文摘 | Rakha EA Elsheikh SE Aleskandarany MA | 2009 | Clin Cancer Res2009，15，7： | 1 |
| 18 | Triple-neg- ative breast cancer: distinguishing between basal and nonbasal subtypes 显示文摘 | Rakha EA Elsheikh SE Aleskandarany MA | 2009 | Clin Cancer Res2009，15，7： | 1 |
| 19 | Spinal angiography and epidural venography in jtxVenile muscular atrophy of the distal arm ' Hirayama disease' 显示文摘 | Elsheikh B Kissel JT Christoforidis G | 2009 | Muscle Nerve2009，40，2： | 1 |
| 20 | Anti endothelial cell autoantibodies selectively activate SAPK/JNK signalling in Wegener's granulomatosis 显示文摘 | Holmen C Elsheikh E Christensson M | 2007 | J Am Soc Nephrol2007，18，9： | 1 |
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