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A gist of gastrointestinal stromal tumors: A review 被引量:28
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作者 Ashwin Rammohan Jeswanth Sathyanesan +6 位作者 Kamalakannan Rajendran Anbalagan Pitchaimuthu Senthil-Kumar Perumal UP Srinivasan Ravi Ramasamy ravichandran Palaniappan Manoharan Govindan 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2013年第6期102-112,共11页
Gastrointestinal stromal tumors (GISTs) have been recognized as a biologically distinctive tumor type, different from smooth muscle and neural tumors of the gastrointestinal tract (GIT). They constitute the majority o... Gastrointestinal stromal tumors (GISTs) have been recognized as a biologically distinctive tumor type, different from smooth muscle and neural tumors of the gastrointestinal tract (GIT). They constitute the majority of gastrointestinal mesenchymal tumors of the GIT and are known to be refractory to conventional chemotherapy or radiation. They are defined and diagnosed by the expression of a proto-oncogene protein detected by immunohistochemistry which serves as a crucial diagnostic and therapeutic target. The identification of these mutations has resulted in a better understanding of their oncogenic mechanisms. The remarkable antitumor effects of the molecular inhibitor imatinib have necessitated accurate diagnosis of GIST and their distinction from other gastrointestinal mes-enchymal tumors. Both traditional and minimally invasive surgery are used to remove these tumors with minimal morbidity and excellent perioperative outcomes. The revolutionary use of specific, molecularlytargeted therapies, such as imatinib mesylate, reduces the frequency of disease recurrence when used as an adjuvant following complete resection. Neoadjuvant treatment with these agents appears to stabilize disease in the majority of patients and may reduce the extent of surgical resection required for subsequent complete tumor removal. The important interplay between the molecular genetics of GIST and responses to targeted therapeutics serves as a model for the study of targeted therapies in other solid tumors. This review summarizes our current knowledge and recent advances regarding the histogenesis, pathology, molecular biology, the basis for the novel targeted cancer therapy and current evidence based management of these unique tumors. 展开更多
关键词 Gastrointestinal STROMAL tumors C-KIT IMATINIB MESYLATE Surgery REVIEW
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Embolization of liver tumors:Past,present and future 被引量:12
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作者 Ashwin Rammohan Jeswanth Sathyanesan +5 位作者 Sukumar Ramaswami Anand Lakshmanan Perumal Senthil-Kumar Ulagendra Perumal Srinivasan Ravi Ramasamy Palaniappan ravichandran 《World Journal of Radiology》 CAS 2012年第9期405-412,共8页
Curative therapies for hepatocellular carcinoma(HCC),such as resection and liver transplantation,can only be applied in selected patients with early tumors.More advanced stages require local or systemic therapies.Rese... Curative therapies for hepatocellular carcinoma(HCC),such as resection and liver transplantation,can only be applied in selected patients with early tumors.More advanced stages require local or systemic therapies.Resection of HCC offers the only hope for cure.Even in patients undergoing resection,recurrences are common.Chemoembolization,a technique combining intraarterial chemotherapy with selective tumor ischemia,has been shown by randomized controlled trials to be efficacious in the palliative setting.There is now renewed interest in transarterial embolization/transarterial chemoembolization(TACE) with regards to its use as a palliative tool in a combined modality approach,as a neoadjuvant therapy,in bridging therapy before transplantation,for symptomatic indications,and even as an alternative to resection.There have also been rapid advances in the agents being embolized trans-arterially(genes,biological response modifiers,etc.).The current review provides an evidence-based overview of the past,present and future trends of TACE in patients with HCC. 展开更多
关键词 LIVER TUMORS EMBOLIZATION CHEMOEMBOLIZATION Review
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Epidemiology of Helicobacter pylori among multiracial community in Northern Peninsular,Malaysia:effect of age across race and gender 被引量:11
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作者 Sreenivasan Sasidharan Subramanion Jo Thy Lachumy +2 位作者 Manickam ravichandran Lachimanan Yoga Latha Surasa Rao Surya Gegu 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2011年第1期72-75,共4页
Objective:To study the epidemiology of Helicobacter pylori(H.pylori) infection according to age group.Methods:H.pylori infection data among 1 965 consecutive patients referred to the Endoscopy Unit collected at Sungai... Objective:To study the epidemiology of Helicobacter pylori(H.pylori) infection according to age group.Methods:H.pylori infection data among 1 965 consecutive patients referred to the Endoscopy Unit collected at Sungai Petani Hospital for oesophagogastro-duodenoscopy(OGD). The patients were divided into 9 age groups(10-19,20-29,30-39,40-49,50-59,60-69,70-79, 80-89 and 90-99 years).In addition these groups were further divided into three minor group namely young adults(10-39),older adults(40-69) and geriatric groups(70-99).Results:Overall prevalence of infection of H.pylori was analyzed and found that the prevalence increase with age (P【0.05).When the patients divided by ethnic and gender group with age,prevalence rate among young adults and older adults significantly higher(P【0.05) compared to geriatric groups across all races and gender(P【0.05).Furthermore,significantly higher number of males were infected compared to female(P【0.05) but such trend was only observed among older adult groups.In addition,there is a significant differences in H.pylori infection prevalence rates among ethnic groups(highest in Indians adults,followed Chinese and low in Malays,P【0.05).Conclusions: The overall prevalence of H.pylori did increase with age group across ethnicity and gender,in Northern Peninsular Malaysia. 展开更多
关键词 EPIDEMIOLOGY HELICOBACTER PYLORI Age MALAYSIA
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Exploring the Synergy: Experimental and Theoretical Investigation of Steel and Glass Fiber Reinforced Polymer (GFRP) Reinforced Slab Incorporating Alccofine and M-Sand
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作者 Vijayalakshmi ravichandran ravichandran Ramanujam Srinivasan +1 位作者 Saravanan Jagadeesan Prithiviraj Chidambaram 《Open Journal of Civil Engineering》 2024年第3期334-347,共14页
Introduction: This study investigates the Experimental and Theoretical Investigation of Steel and Glass Fiber Reinforced Polymer (GFRP) Reinforced Slab Incorporating Alccofine and M-sand. Objective: Specific objective... Introduction: This study investigates the Experimental and Theoretical Investigation of Steel and Glass Fiber Reinforced Polymer (GFRP) Reinforced Slab Incorporating Alccofine and M-sand. Objective: Specific objectives include evaluating the mechanical properties and structural behaviour of steel and GFRP-reinforced one-way slabs and comparing experimental and theoretical predictions. Methods: Four different mix proportions were arrived at, comprising both conventional concrete and Alccofine-based concrete. In each formulation, a combination of normal river sand and M-sand was utilized. Results: Concrete with Alccofine exhibits superior mechanical properties, while M-sand incorporation minimally affects strength but reduces reliance on natural sand. GFRP-reinforced slabs display distinct brittle behaviour with significant deflections post-cracking, contrasting steel-reinforced slabs’ gradual, ductile failure. Discrepancies between experimental data and design recommendations underscore the need for guideline refinement. Conclusion: Alccofine and M-sand enhance concrete properties, but reinforcement type significantly influences slab behaviour. GFRP-reinforced slabs, though exhibiting lower values than steel, offer advantages in harsh environments, warranting further optimization. 展开更多
关键词 Fiber Reinforced Polymer Alccofine Concrete Structural Behaviour Mechanical Properties One-Way Slab Sustainable Construction Materials Alternative Aggregates
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镰孢菌属镰刀菌致与接触镜有关的真菌性角膜炎1例(英文) 被引量:7
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作者 Shawarinin Jusoh Effat Omar +1 位作者 Manickam ravichandran Mohtar Ibrahim 《国际眼科杂志》 CAS 2008年第4期666-669,共4页
目的:报道1例罕见的被确诊为由镰孢菌属镰刀菌引起的与接触镜有关的严重的真菌性角膜炎,该病例最后通过治疗性穿透性角膜移植术成功治疗。方法:病例报告。结果:一位39岁的马来西亚女士,私企职员,配戴长戴性软性接触镜18a。感右眼剧痛、... 目的:报道1例罕见的被确诊为由镰孢菌属镰刀菌引起的与接触镜有关的严重的真菌性角膜炎,该病例最后通过治疗性穿透性角膜移植术成功治疗。方法:病例报告。结果:一位39岁的马来西亚女士,私企职员,配戴长戴性软性接触镜18a。感右眼剧痛、眼红10d。眼部检查见多个长有伪足的圆形旁中心角膜溃疡,前房少许积脓,临床诊断为真菌性角膜炎。经重复角膜刮片检查真菌和细菌结果均阴性后给予局部广谱抗生素和抗真菌治疗,但患者右眼角膜炎病情进一步加重,又给予其他的局部和全身抗真菌药物治疗,患者右眼角膜溃疡进一步加深。最后,为保留眼球,限制感染,在发病1.5mo后,给予患者治疗性的穿透性角膜移植术。术后,角膜组织病理学检查和PCR检查证实为镰孢菌属镰刀菌感染所致。结论:这是1例罕见的由镰孢菌属镰刀菌感染引起的严重的与接触镜有关的真菌性角膜炎。这也说明了在真菌性角膜炎的治疗上存在挑战性。为控制真菌性角膜炎进一步发展,并保护眼球,治疗性的穿透性角膜移植术应该是最后的选择。 展开更多
关键词 接触镜 真菌性角膜炎 镰孢菌属镰刀菌
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Anticancer and multidrug-resistance reversing potential of traditional medicinal plants and their bioactive compounds in leukemia cell lines 被引量:7
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作者 ravichandran Senthilkumar CHEN Bao-An +1 位作者 CAI Xiao-Hui FU Rong 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2014年第12期881-894,共14页
Multidrug resistance remains a serious clinical problem in the successful therapy of malignant diseases. It occurs in cultured tumor cell lines, as well as in human cancers. Therefore, it is critical to develop novel ... Multidrug resistance remains a serious clinical problem in the successful therapy of malignant diseases. It occurs in cultured tumor cell lines, as well as in human cancers. Therefore, it is critical to develop novel anticancer drugs with multidrug-resistance modulating potential to increase the survival rate of leukemia patients. Plant-derived natural products have been used for the treatment of various diseases for thousands of years. This review summarizes the anticancer and multidrug-resistance reversing properties of the extracts and bioactive compounds from traditional medicinal plants in different leukemia cell lines. Further mechanistic studies will pave the road to establish the anticancer potential of plant-derived natural compounds. 展开更多
关键词 Traditional medicinal plants LEUKEMIA Multidrug resistance(MDR) Reversal multidrug resistance Apoptosis
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Neuroendocrine carcinoma of the ampulla of Vater:a clinicopathologic evaluation 被引量:7
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作者 Eswaran Selvakumar Shanmugasundaram Rajendran +4 位作者 Tirupporur Govindaswamy Balachandar Devy Gounder Kannan Satyanesan Jeswanth Palaniappan ravichandran Rajagopal Surendran 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2008年第4期422-425,共4页
BACKGROUND:Only 105 cases of neuroendocrine tumor(NET)of the ampulla of Vater have been described, mostly as single case reports.The incidence of NET is rising.The changes in incidence may result from changes in detec... BACKGROUND:Only 105 cases of neuroendocrine tumor(NET)of the ampulla of Vater have been described, mostly as single case reports.The incidence of NET is rising.The changes in incidence may result from changes in detection.This study was to determine the relative incidence and clinicopathological characteristics of high- grade neuroendocrine carcinoma(small cell carcinoma and large cell carcinoma)of the ampulla of Vater at a single institution. METHODS:Sections from paraffin blocks of tumors of the ampulla of Vater taken from 45 patients who underwent Whipple’s procedure and 6 patients who underwent palliative bypass between September 2003 and January 2007 were subjected to immunohistochemical analysis.The clinical and pathological data from 5 patients diagnosed with NET of the ampulla of Vater were analyzed. RESULTS:The patients were 3 men and 2 women,ranging in age from 39 to 47 years(mean 44 years).Operative procedures included Whipple’s procedure in 4 patients and palliative bypass in 1 patient.Histopathological examination revealed large-cell neuroendocrine carcinoma in 2 patients,small cell carcinoma in 2,and carcinoid in 1.Three patients with high-grade neuroendocrine carcinoma who had undergone Whipple’s procedure died at postoperatively 7,11,and 13 months.The patient who had undergone palliative triple bypass died 3 months after surgery.CONCLUSIONS:The relative incidence of high-grade neuroendocrine carcinomas of the ampulla of Vater is higher than that generally expected.The tumors behave aggressively and have a dismal prognosis despite aggressive treatment. 展开更多
关键词 neuroendocrine tumor carcinoid tumor ampulla of Vater Whipple's procedure
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Long-term outcome of gastric access loop in hepaticojejunostomy 被引量:6
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作者 Eswaran Selvakumar Shanmugasundaram Rajendran +4 位作者 Tirupporur G. Balachandar Devy Gounder Kannan Satyanesan Jeswanth Palaniappan ravichandran Rajagopal Surendran 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2008年第2期152-155,共4页
BACKGROUND:?The incidence of hepaticojejunostomy stricture is 4%-10% in experienced centres. Many access loops have been designed and used to facilitate endoscopic intervention for this complication of hepaticojejunos... BACKGROUND:?The incidence of hepaticojejunostomy stricture is 4%-10% in experienced centres. Many access loops have been designed and used to facilitate endoscopic intervention for this complication of hepaticojejunostomy. In this study, we investigated the effectiveness and safety of gastric access loop. METHODS:A retrospective analysis was conducted on 13 patients who had undergone hepaticojejunostomy with gastric access loop between June 1999 and September 2003. Eleven patients were followed up for a mean period of 51 months (range 20-81 months). Two patients were lost to follow up. RESULTS:?On follow-up, 8 patients had patent jejuno- gastrostomy (end to side anastomosis between Roux loop of jejunum and stomach) and hepaticojejunostomy. Three patients developed stricture of jejunogastrostomy at 41 months, 63 months and 81 months of follow-up. Among these 3 patients, one also had hepaticojejunostomy stricture. In the patient with hepaticojejunostomy stricture, dilatation of jejunogastrostomy stricture was attempted but failed. None of the patients had any evidence of bile gastritis/cholangitis. There was no procedure related morbidity/mortality. CONCLUSIONS:Further studies involving large numbers of patients are required before wide application of gastric access loop in hepaticojejunostomy though it is a safer option than percutaneous transhepatic manipulations or revision surgery. 展开更多
关键词 access loop HEPATICOJEJUNOSTOMY anastomotic stricture biliary stricture
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Transforming Education with Photogrammetry:Creating Realistic 3D Objects for Augmented Reality Applications
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作者 Kaviyaraj ravichandran Uma Mohan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期185-208,共24页
Augmented reality(AR)is an emerging dynamic technology that effectively supports education across different levels.The increased use of mobile devices has an even greater impact.As the demand for AR applications in ed... Augmented reality(AR)is an emerging dynamic technology that effectively supports education across different levels.The increased use of mobile devices has an even greater impact.As the demand for AR applications in education continues to increase,educators actively seek innovative and immersive methods to engage students in learning.However,exploring these possibilities also entails identifying and overcoming existing barriers to optimal educational integration.Concurrently,this surge in demand has prompted the identification of specific barriers,one of which is three-dimensional(3D)modeling.Creating 3D objects for augmented reality education applications can be challenging and time-consuming for the educators.To address this,we have developed a pipeline that creates realistic 3D objects from the two-dimensional(2D)photograph.Applications for augmented and virtual reality can then utilize these created 3D objects.We evaluated the proposed pipeline based on the usability of the 3D object and performance metrics.Quantitatively,with 117 respondents,the co-creation team was surveyed with openended questions to evaluate the precision of the 3D object created by the proposed photogrammetry pipeline.We analyzed the survey data using descriptive-analytical methods and found that the proposed pipeline produces 3D models that are positively accurate when compared to real-world objects,with an average mean score above 8.This study adds new knowledge in creating 3D objects for augmented reality applications by using the photogrammetry technique;finally,it discusses potential problems and future research directions for 3D objects in the education sector. 展开更多
关键词 Augmented reality education immersive learning 3D object creation PHOTOGRAMMETRY and StructureFromMotion
Free radical scavenging property and antiproliferative activity of Rhodiola imbricata Edgew extracts in HT-29 human colon cancer cells 被引量:5
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作者 ravichandran Senthilkumar Thangaraj Parimelazhagan +1 位作者 Om Prakash Chaurasia R.B.Srivastava 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2013年第1期11-19,共9页
Objective:To investigate the in vitro antioxidant and antiproliferative activity of rhizome extracts of Rhodiola imbricata(R.imbricata) in HT-29 human colon cancer cell line.Methods:The successively extracted rhizome ... Objective:To investigate the in vitro antioxidant and antiproliferative activity of rhizome extracts of Rhodiola imbricata(R.imbricata) in HT-29 human colon cancer cell line.Methods:The successively extracted rhizome of R.imbricata using various solvents was analyzed for their total phenolics,tannins and flavonoid contents.In vitro antioxidant activity was evaluated by employing different assays,including DPPH,ABTS radical scavenging assays,FRAP, phosphomolybdenum reduction assay,superoxide anion,hydroxyl radical scavenging activities and metal chelating ability.Results:Acetone and methanol extracts recorded higher phenolic content and showed comparable antioxidant activity with standard reference.Additionally,they also inhibited the proliferation of HT-29 cells upon treatment at higher concentration(200μg/mL) (acetone and methanol,84%and 84%.respectively).On examination acetone extract exhibited antiproliferative activity in a concentration dependent manner whereas,methanol extract showed both dose dependent and lime dependent inhibitory activity.Conclusions:The results obtained justify the traditional usage of R.imbricata from their promising antioxidant activity. 展开更多
关键词 RHODIOLA imbricata ANTIOXIDANT activity Phenolics FLAVONOIDS ADENOCARCINOMA cell lines
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Incidental gall bladder cancers:Are they truly incidental? 被引量:5
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作者 Ashwin Rammohan Sathya D Cherukuri +2 位作者 Jeswanth Sathyanesan ravichandran Palaniappan Manoharan Govindan 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2014年第12期441-443,共3页
AIM: To seek and analyze features suggestive of gallbladder cancer(GBC) on preoperative imaging and intraoperative findings in patients diagnosed as having incidental GBC(IGBC). METHODS: The study was conducted on 79 ... AIM: To seek and analyze features suggestive of gallbladder cancer(GBC) on preoperative imaging and intraoperative findings in patients diagnosed as having incidental GBC(IGBC). METHODS: The study was conducted on 79 patients of IGBC managed in our department over a 10-year period(2003-2012). Review of preoperative imaging and operative notes was done to ascertain any suspicion of malignancy-in-retrospect.RESULTS: Of the 79 patients, Ultrasound abdomen showed diffuse thickening, not suspicious of malignancy in 5 patients, and diffuse suspicious thickening was seen in 4 patients. Focal thickening suspicious of malignancy was present in 24 patients. Preoperative computed tomography/magnetic resonance imaging was done in 9 patients for suspicion of malignancy. In 5 patients, dif-ficult Cholecystectomy was encountered due to dense/inflammatory adhesions. Intraoperative findings showed focal thickening of the gallbladder and a gallbladder mass in 9 and 17 patients respectively. On overall analysis, 37 patients had preoperative imaging or intraoperative findings suggestive of malignancy, which was either a missed GBC or an unsuspected/unexpected GBC. In 42(53.2%) patients, there was no evidence suggestive of malignancy and was an unanticipated diagnosis.CONCLUSION: Our study highlights a potential and not-so-rare pitfall of Laparoscopic Cholecystectomy. A greater awareness of this clinical entity along with a high index of suspicion and a low threshold for conversion to open procedure, especially in endemic areas may avert avoidable patient morbidity and mortality. 展开更多
关键词 INCIDENTAL GALLBLADDER cancer PREOPERATIVE detection Imaging
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Performance analysis of a floating photovoltaic covering system in an Indian reservoir 被引量:2
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作者 Nagananthini ravichandran Nagavinothini ravichandran Balamurugan Panneerselvam 《Clean Energy》 EI 2021年第2期208-228,共21页
Floating photovoltaic(FPV)systems are one of the globally emerging technologies of renewable energy production that tend to balance the water-energy demand by effectively saving the evaporated water from reservoirs wh... Floating photovoltaic(FPV)systems are one of the globally emerging technologies of renewable energy production that tend to balance the water-energy demand by effectively saving the evaporated water from reservoirs while generating electrical power.This study presents the performance analysis of a model FPV plant in an Indian reservoir.The Mettur dam reservoir located in Tamil Nadu,India with a hydroelectric power plant of 150-MW capacity is considered as a test case.The preliminary design of the FPV plant is proposed based on a detailed study of the key design elements and their suitability for Indian reservoirs.The proposed plant is numerically analysed for various tilt angles,mounting systems and tracking mechanisms in order to assess its potential power generation.A flat-mount system in landscape orientation was found to exhibit a high performance ratio.Further,a fixed-tilt FPV system with a panel slope of 10°and an FPV system with single-axis tracking were found to be suitable for the Mettur reservoir.Further,cost analysis of the FPV system is also presented along with the carbon-footprint estimation to establish the economic and environmental benefits of the system.The results show that the total potential CO_(2) saving by a FPV system with tracking is 135918.87 t CO_(2) and it is 12.5%higher than that of a fixed-mount FPV system. 展开更多
关键词 solar energy floating photovoltaic system evaporation loss hydroelectric power plants
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Unravelling the physicochemical and antimicrobial mechanisms of human serum albumin/tannic acid coatings for medical-grade polycaprolactone scaffolds
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作者 Silvia Cometta Bogdan C.Donose +6 位作者 Alfredo Juarez-Saldivar Akhilandeshwari ravichandran Yanan Xu Nathalie Bock Tim R.Dargaville Aleksandar D.Rakic Dietmar W.Hutmacher 《Bioactive Materials》 SCIE CSCD 2024年第12期68-84,共17页
Biofilm-related biomaterial infections are notoriously challenging to treat and can lead to chronic infection and persisting inflammation.To date,a large body of research can be reviewed for coatings which potentially... Biofilm-related biomaterial infections are notoriously challenging to treat and can lead to chronic infection and persisting inflammation.To date,a large body of research can be reviewed for coatings which potentially prevent bacterial infection while promoting implant integration.Yet only a very small number has been translated from bench to bedside.This study provides an in-depth analysis of the stability,antibacterial mechanism,and biocompatibility of medical grade polycaprolactone(mPCL),coated with human serum albumin(HSA),the most abundant protein in blood plasma,and tannic acid(TA),a natural polyphenol with antibacterial properties.Molecular docking studies demonstrated that HSA and TA interact mainly through hydrogen-bonding,ionic and hydrophobic interactions,leading to smooth and regular assemblies.In vitro bacteria adhesion testing showed that coated scaffolds maintained their antimicrobial properties over 3 days by significantly reducing S.aureus colonization and biofilm formation.Notably,amplitude modulation-frequency modulation(AMFM)based viscoelasticity mapping and transmission electron microscopy(TEM)data suggested that HSA/TA-coatings cause morphological and mechanical changes on the outer cell membrane of s.aureus leading to membrane disruption and cell death while proving non-toxic to human primary cells.These results support this antibiotic-free approach as an effective and biocompatible strategy to prevent biofilm-related biomaterial infections. 展开更多
关键词 Bacterial infection BIOFILM Human serum albumin Tannic acid POLYCAPROLACTONE 3D printing SCAFFOLD
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Effect of Thickness of SnO_2:F over Layer on Certain Physical Properties of ZnO:Al Thin Films for Opto-electronic Applications 被引量:4
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作者 P. Ravikumar K. ravichandran B. Sakthivel 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2012年第11期999-1003,共5页
Bilayered FTO/AZO (fluorine doped tin oxide/aluminium doped zinc oxide) films were fabricated using a simple, cost effective spray pyrolysis technique. X-ray diffraction (XRD) profiles of bilayered films showed th... Bilayered FTO/AZO (fluorine doped tin oxide/aluminium doped zinc oxide) films were fabricated using a simple, cost effective spray pyrolysis technique. X-ray diffraction (XRD) profiles of bilayered films showed that in the case of lower thickness FTO over layers, (002) plane of ZnO phase had the highest intensity, whereas the predominance was changed in favour of (200) plane of SnO2 phase for higher thickness FTO over layer. UV studies showed that bilayered FTO/AZO films exhibited a sharp absorption edge as that of AZO film. The decrease in the photoluminescence (PL) peak at 420 nm with increasing FTO over layer thickness indicated a reduction in the zinc vacancies which caused a reduction in the sheet resistance (Rsh). Electrical studies revealed that, eventhough the Rsh value (916Ω/□) of bilayered FTO (313 nm)/AZO (314 nm) film was found to be higher than that of FTO single layer film (72Ω/□), it was much lower than that of AZO single layer film (5661Ω/□)). The atomic force microscopy (AFM) images reflect the characteristic features of both zinc oxide and tin oxide films. 展开更多
关键词 ZnO thin films Sn02 Semiconductor materials Optical properties ELECTRICALPROPERTIES Atomic force microscopy (AFM)
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Effect of aqueous extract of leaves of Morinda tinctoria on corrosion inhibition of aluminium surface in HCl medium 被引量:4
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作者 K. KRISHNAVENI J. ravichandran 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第8期2704-2712,共9页
The effect of Morinda tinctoria(MT) leaves extract on the corrosion inhibition of Al in acid medium was studied. The inhibition studies were carried out on Al in 0.5 mol/L HCl with the extract of leaves of MT using ma... The effect of Morinda tinctoria(MT) leaves extract on the corrosion inhibition of Al in acid medium was studied. The inhibition studies were carried out on Al in 0.5 mol/L HCl with the extract of leaves of MT using mass loss and electrochemical techniques. Parameters, such as concentration of the inhibitor, concentration of the acid, temperature and concentration of halide ions, were varied and optimized. Increase of the temperature and concentration of acid can decrease the performance of the inhibitor. Thermodynamic parameters show that the physisorption of the inhibitor molecules on Al surface obeys Langmuir isotherm. 展开更多
关键词 aluminium mass loss acid corrosion INHIBITION Morinda tinctoria
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Managerial perspectives of scaling up robotic-assisted surgery in healthcare systems:A systematic literature review
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作者 ravichandran Anitha Komattu Chacko John Gnanadhas Jabarethina 《Laparoscopic, Endoscopic and Robotic Surgery》 2024年第3期113-122,共10页
Objectives Robotic-assisted surgery(RAS)is a minimally invasive technique practiced in multiple specialties.Standard training is essential for the acquisition of RAS skills.The cost of RAS is considered to be high,whi... Objectives Robotic-assisted surgery(RAS)is a minimally invasive technique practiced in multiple specialties.Standard training is essential for the acquisition of RAS skills.The cost of RAS is considered to be high,which makes it a burden for institutes and unaffordable for patients.This systematic literature review(SLR)focused on the various RAS training methods applied in different surgical specialties,as well as the cost elements of RAS,and was to summarize the opportunities and challenges associated with scaling up RAS.Methods An SLR was carried out based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses reporting guidelines.The PubMed,EBSCO,and Scopus databases were searched for reports from January 2018 through January 2024.Full-text reviews and research articles in the English language from Asia-Pacific countries were included.Articles that outlined training and costs associated with RAS were chosen.Results The most common training system is the da Vinci system.The simulation technique,which includes dry-lab,wet-lab,and virtual reality training,was found to be a common and important practice.The cost of RAS encompasses the installation and maintenance costs of the robotic system,the operation theatre rent,personnel cost,surgical instrument and material cost,and other miscellaneous charges.The synthesis of SLR revealed the challenges and opportunities regarding RAS training and cost.Conclusions The results of this SLR will help stakeholders such as decision-makers,influencers,and end users of RAS to understand the significance of training and cost in scaling up RAS from a managerial perspective.For any healthcare innovation to reach a vast population,cost-effectiveness and standard training are crucial. 展开更多
关键词 da Vinci system Healthcare Robotic-assisted surgery Robotic surgery Robotic training Robotic surgery cost
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Estimating cooling loads of Indian residences using building geometry data and multiple linear regression
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作者 Chittella ravichandran Padmanaban Gopalakrishnan 《Energy and Built Environment》 EI 2024年第5期741-771,共31页
International Energy Agency(IEA)predicts India’s AC stock will reach 1144 million units by 2050,making it the second largest ACs holder globally.Studies on the effect of building geometry on cooling load reduction ar... International Energy Agency(IEA)predicts India’s AC stock will reach 1144 million units by 2050,making it the second largest ACs holder globally.Studies on the effect of building geometry on cooling load reduction are primarily focused on material and envelope specifications.However,studies on building morphological parame-ters in the Indian context are scarce.Therefore,this research quantifies the effect of four morphology predictors,namely,FL(floor number),ESA(exposed surface area),CZB(conditioned zones per building),and CZF(con-ditioned zones per floor)on cooling load in 75 dominant residential built forms of Navi Mumbai.The selected buildings are simulated using the Rhinoceros 6 tool with the energy plus plugin.Despite having the same sim-ulation inputs,envelope parameters,and conditioned volume,the results indicated a 90%variation between the compact and loosely designed forms.Multiple Linear Regression shows that the four predictors explain 78%(R2=0.78)of variation in the cooling load.It is observed that tall buildings show greater efficiency in cooling load reduction due to lesser CZF values.Also,an increase in CZB and a decrease in ESA significantly reduce the mean cooling load due to compactness and wall sharing,respectively. 展开更多
关键词 Building Geometry Navi Mumbai Cooling loads Simulation Multiple Linear Regression
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Predictors of malignancy in chronic calcific pancreatitis with head mass 被引量:4
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作者 Senthilkumar Perumal ravichandran Palaniappan +2 位作者 Sastha Ahanatha Pillai Vimalraj Velayutham Jeswanth Sathyanesan 《World Journal of Gastrointestinal Surgery》 SCIE CAS 2013年第4期97-103,共7页
AIM: To prospectively analyse the clinical, biochemical and radiological characteristics of the mass lesions arising in a background of chronic calcific pancreatitis (CCP). METHODS: Eighty three patients, who presente... AIM: To prospectively analyse the clinical, biochemical and radiological characteristics of the mass lesions arising in a background of chronic calcific pancreatitis (CCP). METHODS: Eighty three patients, who presented with chronic pancreatitis (CP) and a mass lesion in the head of pancreas between February 2005 and December 2011, were included in the study. Patients who were identified to have malignancy underwent Whipple' s procedure and patients whose investigations were suggestive of a benign lesion underwent Frey's procedure. Student t-test was used to compare the mean values of imaging findings [common bile duct (CBD), main pancreatic duct (MPD) size] and laboratory data [Serum bilirubin, carbohydrate antigen 19-9 (CA 19-9)] between the groups. Receiver operating characteristic curve (ROC curve) analysis was done to calculate the cutoff valves of serum bilirubin, CA 19-9, MPD and CBD size. The sensitivity, specificity, positive predictive valve (PPV) and negative predictive value (NPV) were calculated using these cut off points. Multivariate analysis was performed using logistic regression model. RESULTS: The study included 56 men (67.5%) and 27 women (32.5%). Sixty (72.3%) patients had tropical calcific pancreatitis and 23 (27.7%) had alcohol related CCP. Histologically, it was confirmed that 55 (66.3%) of the 83 patients had an inflammatory head mass and 28 (33.7%) had a malignant head mass. The mean age of individuals with benign inflammatory mass and those with malignant mass was 38.4 years and 45 years respectively. Significant clinical features that predicted a malignant head mass in CP were presence of a head mass in CCP of tropics, old age, jaundice, sudden worsening abdominal pain, gastric outlet obstruction and significant weight loss (P ≤ 0.05). The ROC curve analysis showed a cut off value of 5.8 mg/dL for serum bilirubin, 127 U/mL for CA 19-9, 11.5 mm for MPD size and 14.5 mm for CBD size. CONCLUSION: Elevated Serum bilirubin and CA 19-9, and dilated MPD and CBD were useful in predicting mali 展开更多
关键词 CHRONIC calcific PANCREATITIS Pancreatic HEAD MASS Carcinoma HEAD of PANCREAS Risk factors of MALIGNANCY
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Calibration of a hysteretic model for glass fiber reinforced gypsum wall panels 被引量:4
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作者 Maganti Janardhana Robin Davis P +2 位作者 S.S.ravichandran A.M.Prasad D.Menon 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2014年第2期347-355,共9页
Glass fi ber reinforced gypsum(GFRG) wall panels are prefabricated panels with hollow cores, originally developed in Australia and subsequently adopted by India and China for use in buildings. This paper discusses ide... Glass fi ber reinforced gypsum(GFRG) wall panels are prefabricated panels with hollow cores, originally developed in Australia and subsequently adopted by India and China for use in buildings. This paper discusses identifi cation and calibration of a suitable hysteretic model for GFRG wall panels fi lled with reinforced concrete. As considerable pinching was observed in the experimental results, a suitable hysteretic model with pinched hysteretic rule is used to conduct a series of quasi-static as inelastic hysteretic response analyses of GFRG panels with two different widths. The calibration of the pinching model parameters was carried out to approximately match the simulated and experimental responses up to 80% of the peak load in the post peak region. Interestingly, the same values of various parameters(energy dissipation and pinching related parameters) were obtained for all fi ve test specimens. 展开更多
关键词 glass fi ber reinforced gypsum walls hysteretic model pinching model
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Implications of the presence of an aberrant right hepatic artery in patients undergoing pancreaticoduodenectomy 被引量:4
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作者 Ashwin Rammohan ravichandran Palaniappan +6 位作者 Anbalagan Pitchaimuthu Kamalakannan Rajendran Senthil Kumar Perumal Kesavan Balaraman Ravi Ramasamy Jeswanth Sathyanesan Manoharan Govindan 《World Journal of Gastrointestinal Surgery》 SCIE CAS 2014年第1期9-13,共5页
AIM:To analyze the differences in outcomes and the clinical impact following pancreatoduodenectomy(PD)in patients with and without aberrant right hepatic artery(aRHA).METHODS:All patients undergoing PD between January... AIM:To analyze the differences in outcomes and the clinical impact following pancreatoduodenectomy(PD)in patients with and without aberrant right hepatic artery(aRHA).METHODS:All patients undergoing PD between January 2008 and December 2012 were divided into two groups,one with aRHA and the other without.These groups were compared to identify differences in the intraoperative variables,the oncological clearance and the postoperative morbidity,mortality and hospital stay.RESULTS:A total of 225 patients underwent PD,of which 43(19.1%)patients were found to have eitheraccessory or replaced right hepatic arteries(aRHA group).The aRHA was preserved in 79%of the patients.There was no significant difference in the intraoperative blood loss but operative time was prolonged,reflecting the complexity of the procedure[420±44(240-540)min vs 480±45(300-600)min,P<0.05)].There were no differences in the incidence of postoperative complications(pancreatic leak,pancreatic fistula,delayed gastric emptying and mortality)and hospital stay.Oncological clearance in the form of positive resection margins[13(7.1%)vs 3(6.9%)]and lymph node yield were also similar in the two groups.CONCLUSION:An aRHA is found in approximately one fifth of patients undergoing PD.Preservation is technically possible in most patients and can increase the operative complexity but does not negatively affect the safety or oncological outcomes of the procedure. 展开更多
关键词 PANCREATODUODENECTOMY ABERRANT RIGHT hepatic artery ARTERIAL ANOMALIES Outcomes
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