ravi chandran | The Tamilnadu Dr MGR Medical University (original) (raw)

Papers by ravi chandran

Crop improvement, 2007

Genetic divergence was studied for different yield and quality traits in 70 rice genotypes. These... more Genetic divergence was studied for different yield and quality traits in 70 rice genotypes. These genotypes were collected from different rice eco-geographical regions of India. The analysis of variance revealed significant differences among the genotypes for each character studied. Based on genetic distance 70 genotypes were grouped into nine different clusters. The mode of distribution of genotypes from different eco-regions into various clusters was at random indicating that geographical diversity and genetic diversity were not related. The characters like water uptake, gel consistency and head rice recovery percentage contributed maximum towards genetic diversity. The maximum inter-cluster distance was recorded between cluster VII and cluster VIII. The genotypes in these clusters may serve as potential donors for future hybridization programmes to develop potential recombinants with high yield coupled with desirable grain quality.

Singapore Academy of Law Journal, 2015

The recently enacted Protection from Harassment Act offers greater protection against harassment ... more The recently enacted Protection from Harassment Act offers greater protection against harassment as compared to the position before. While the said Act covers both criminal and civil liability, this article focuses on the latter and seeks to examine the persons who may incur civil liability and the principles that may apply to damages awarded. While the main focus of this article is on harassment that takes place in a workplace, the principles discussed may also apply to other contexts.

South Asian Journal of Cancer, 2020

Introduction Ewing sarcoma (ES) is more common in children and relatively rare in adults. Adult E... more Introduction Ewing sarcoma (ES) is more common in children and relatively rare in adults. Adult ES has poor prognosis than children. Treatment approaches for adults have been extrapolated from pediatric experience. Data on adult ES are very few because of its rarity in adults. The present study was done to analyze the clinical profile and outcome of adult ES. Aims The aim was to study the clinical and pathological treatment and outcomes in adult ES. Subjects and Methods Between 2010 and 2017, a total of 73 ES patients with age more than 18 years were retrospectively analyzed. Survival analysis was done by plotting Kaplan–Meier curves. Results A total of 73 patients were diagnosed with ES during 2010 to 2017. Among them, 43 (58.9%) had localized disease with a median age of 24.5 years. Males were 44 (60.3%) and females were 29 (39.7). Pain (75.3%) was the most common symptom at presentation. Nine patients had incomplete details and were excluded from the analysis. Among 21 (28.8%) pa...

$Research paper thumbnail of Final Technical Report: Application of in situ Neutron Diffraction to Understand the Mechanism of Phase Transitions$

Journal of Oral and Maxillofacial Radiology, 2019

Background: Intraoperative three-dimensional (3D) imaging can be utilized to detect bone malposit... more Background: Intraoperative three-dimensional (3D) imaging can be utilized to detect bone malpositioning during facial fracture repair. Aim: This article exhibits a case of left Zygomatic maxillary complex fracture that was repaired with the aid of intraoperative 3D imaging technology. Methods: A critical size orbital floor defect was apparent on the imaging, necessitating an immediate repair avoiding a second-revision surgery. Results and Conclusion: The use of 3D imaging has historically been underutilized due to financial and time constraints. However, when comparing to costs and time utilized to undergo a second surgery, usage of 3D imaging intraoperatively is beneficial to the patient, team, and the institution.

Journal of Oral and Maxillofacial Surgery, 2019

Current techniques for orthognathic surgery after Le Fort I osteotomy and bilateral sagittal spli... more Current techniques for orthognathic surgery after Le Fort I osteotomy and bilateral sagittal split osteotomy (BSSO) rely on intermediate and final occlusal splints for proper positioning of the dental arches without any control in positioning the condyle and ramus segments. Setting the 2 condyles in centric relation in the glenoid fossae at fixation is paramount for condylar function and the accuracy and stability of postoperative occlusion. Usually the 2 ramus segments are manually positioned and fixated in the final position according to the surgeon's experience. This report describes a novel technique to position the condyle and ramus segments in centric relation using skeletal guides designed by computer-assisted designed and computer-assisted manufactured (CAD-CAM) technology. The skeletal guides have a double-U shape designed to be tooth borne on the distal segment and bone borne on the proximal segment. The guides fit on the last molar crown and the anterior border of the ramus; using these reference points will position the mandibular arch and 2 ramus segments in ideal centric occlusion and centric relation. The condyle position in the sagittal, horizontal, and transverse planes was analyzed by computed tomography and differences in measurements were calculated. This technique confirms precise control of the condylar segment in centric relation with stable centric occlusion using CAD-CAM guides during BSSO.

ECS Proceedings Volumes, 2005

The high operating temperature of ceramic membrane electrolyzers (800-. 1000°C) can lead to compl... more The high operating temperature of ceramic membrane electrolyzers (800-. 1000°C) can lead to complex materials problems. In order to reduce the high temperature, the resistive loss in the electrolyte should be minimized. One of the solutions would be to decrease the thickness of the solid electrolyte. Thin dense yttria-stabilized zirconia (YSZ) membranes (about 20 pm) were prepared, characterized and tested in a multilayer device with lanthanum strontium manganite (LSM) electrodes, built on a porous alumina tube. By using a sol-gel process, a molecular bond was produced between the electrode layers and the solid electrolyte. The YSZ can withstand a pressure differential of 3 psi. At lower operating temperature of 700°C, the calculated voltage drop across our thin YSZ film is about 1/3 of the voltage drop using conventional thicker membranes. Experimental data show that our sol-gel processed multilayer thin film device (as oxygen generator) performs better at lower operating temperature.

International Journal of Modern Education Forum, 2017

Indian Journal of Surgical Oncology, 2016

The axillary reverse mapping (ARM) technique has been described as an attempt to map and preserve... more The axillary reverse mapping (ARM) technique has been described as an attempt to map and preserve the upper extremity lymphatic drainage during axillary lymph node dissection (ALND) and/or SLNB. This technique is based on the hypothesis that the lymphatic pathway from the upper extremity is not involved by metastasis from primary breast cancer. The ARM node/s however, has been found, in various studies, to be involved with metastatic foci in patients with extensive axillary lymph node metastases. Therefore, the oncological safety of this procedure has not yet been determined. In this pilot study, we assessed the ARM node intraoperatively for various parameters and compared it to final HPR, to try and determine the oncologic safety of preserving the ARM node. Seventy-two breast cancer patients were screened for this prospective pilot study which was planned to recruit 20 patients. The study was initiated on May 2014, 20 patients were recruited till July 2015. Eligibility criterion was as follows: patients requiring primary axillary lymph node dissection based on a clinically positive axilla. Forty-five patients were ineligible because they had either received neoadjuvant chemotherapy or underwent previous axillary surgery or axillary radiation (exclusion criteria). Seven patients refused to give consent. ARM node identification rate was 75%. The most common location of the ARM node was lateral to the latissimus dorsi pedicle (42.10%), none of them being malignant. None of the oval or firm nodes were malignant. Tumor deposits were identified in 13%. Fine-needle aspiration cytology (FNAC) had 100% specificity, 94.4% negative predictive value, 100% positive predictive value, and 50% sensitivity. ARM is feasible using blue dye alone, with an acceptable identification rate. Location, consistency, and intraoperative FNAC of the ARM node, put together, may be reliable parameters to predict involvement of the ARM node with metastasis.

This article traces the development and applicability of the implied term of trust and confidence... more This article traces the development and applicability of the implied term of trust and confidence in a contract of employment, with specific reference to Singapore. Assuming such a term is recognised in Singapore, it also examines the issue of whether the term applies to the termination of an employment contract, with the effect being that a termination cannot be made in bad faith. It also examines the remedies should such a term exist and be applicable to the termination of an employment contract. The article also examines some of the policy reasons and implications pertaining to these issues.

CHEST Journal, 2015

Isolated malignant pleural effusion of lung origin (IMPE) without obvious radiological evidence o... more Isolated malignant pleural effusion of lung origin (IMPE) without obvious radiological evidence of lung lesion is a rare presentation of lung cancer. At the present time, IMPE is designated as stage IV lung cancer under the TNM classification. Clinical experience by the author shows the prognosis of IMPE is better than the stage IV lung cancer. The purpose of the study is to assess the pathology of IMPE. METHODS: We retrospectively reviewed the cytopathology results of pleural effusion sent to the lab from 2010 to 2014 in our hospital pathology department. Patients with malignant pleural effusion were separated from patients with non-malignant pleural effusion. We reviewed the CT scan and X-ray chest report of the patients with malignant pleural effusion post thoracentesis and their medical records. Malignant pleural effusion of pulmonary origin were separated from malignant pleural effusion of nonpulmonary origin. Subsequently, IMPE was isolated from malignant pleural effusion with lung and/or mediastinal mass. RESULTS: A total of 139 patients were found to have pleural effusion sent for cytopathology analysis. Of those 139 pleural effusion, 23 were diagnosed as malignant pleural effusion. 6 of those were nonpulmonary malignant pleural effusion (3 breast cancer, 1 peritoneal cancer, 1 renal cancer, and 1 colon cancer). 5 of the malignant pleural effusion were associated with a pulmonary mass on presentation (3 adenocarcinoma, 1 squamous cell carcinoma, and 1 non-small cell carcinoma). 12 of the malignant pleural effusion were IMPE (without any lung lesions on presentation). All 12 were found to be adenocarcinoma of lung origin. CONCLUSIONS: The most common cause of IMPE is adenocarcinoma of lung origin. CLINICAL IMPLICATIONS: Adenocarcinoma has the advantage of molecular testing based targeted chemotherapy. IMPE should be considered as a distinct clinical entity because of the availability of molecular testing based chemotherapy. Further studies are required to assess the prognosis of IMPE compared to stage IV lung carcinoma.

Materials Science and Engineering: A, 2015

Multiple mechanisms of fatigue crack initiations from pores leading to short-term and long-term f... more Multiple mechanisms of fatigue crack initiations from pores leading to short-term and long-term fatigue life have been observed in a powder metallurgy (PM) Ti-6Al-4V alloy made by the hydrogen sintering and phase transformations (HSPT) process. The pores in the sintered alloy could be classified into two groups; type-I being caused by particle interstices that did not fully close during sintering (sinter-pores) and the type-II originating from larger voids that did not close during powder packing (cave-pores). The fatigue life trends can be classified by the type and the location of pore from which the crack initiated. Interestingly, the two types of pores, and the two different locations (surface vs. interior) from which the cracks initiated lead to four distinct S-N trends in the fatigue data. When the stress amplitude level and the pore size were accounted for through initial stress intensity factors, the fatigue data reduced to dual S-N fatigue curves. The results offer new insights into how pores, especially their type and size, and location control the fatigue behavior of PM Ti-6Al-4V alloy. Large improvements in fatigue life can be obtained if the large cave-pores are eliminated or their volume density reduced to very low levels.

Acta Materialia, 2015

Hydrogen has been investigated for decades as a temporary alloying element to refine the microstr... more Hydrogen has been investigated for decades as a temporary alloying element to refine the microstructure of Ti-6Al-4V, and is now being used in a novel powder metallurgy method, Hydrogen Sintering and Phase Transformations (HSPT). In earlier work from the literature, pseudo-binary phase diagrams of (Ti-6Al-4V)-xH have been studied and developed, but they are not well established due to limitations of their methodologies. In this paper, in situ studies of phase transformations during hydrogenation and dehydrogenation of (Ti-6Al-4V)-xH alloys were conducted using high energy synchrotron X-ray diffraction (XRD), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The eutectoid phase transformation of β↔α+δ was observed in the (Ti-6Al-4V)-xH alloy via in situ synchrotron XRD at 211 ºC with a hydrogen concentration of 37.5 at.% (measured using TGA-DSC). The relationships of hydrogen composition to partial pressure and temperature were investigated in the temperature range of 450 to 900 ºC. Based on these results, a partial pseudo-binary phase diagram of (Ti-6Al-4V)-xH is proposed for hydrogen compositions up to 60 at.% in the temperature range of 100

28th Joint Propulsion Conference and Exhibit, 1992

Concepts, Methodologies, Tools and Applications

Rapid e-learning (REL) is a phrase in common use since 2003. This article defines REL, describes ... more Rapid e-learning (REL) is a phrase in common use since 2003. This article defines REL, describes types of REL authoring tools, discusses management and instructional issues surrounding REL in corporate and academic settings, and summarizes the experience of the National University of Singapore (NUS), an early adopter of the concept of REL since 2004. Almost all current literature on the topic focuses on REL applications in corporate e-learning. There is very little academic research into issues surrounding REL because this is a recent development. At this stage of implementation of REL, the literature on the topic is limited. The following three definitions are commonly used: 1. Josh Bersin defined REL as a category of online training content, which can be developed in weeks, can be authored by subject matter experts (SMEs), and maintains instructional focus and quality (Bersin & De Vries, 2004). REL tools leverage on common software such as PowerPoint and then convert that to Flash...

This report was prepared as an account of work sponsored by an agency of the United States Govern... more This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufactam, or otherwise does not necessarily constitute or imply its endmement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not ne&sdy state or reflect those of the United States Government or any agency thereof. This report has been reproduced directly from tfie best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information, 175 Oak Ridge Turnpike, Oak Ridge, TN 37831; prices available at (615) 576-8401.

SAcLJ, 1999

... also been calls to apply greater flexibility and business sense when dealing with issues of c... more ... also been calls to apply greater flexibility and business sense when dealing with issues of consideration under the Malaysian Contracts Act; see South East Asia Insurance Bhd v NasirIbrahim, [1992] 2 ... 20 Emmanuel Ayodeji Ajayi v RT Briscoe (Nigeria) Ltd, [1964] 3 ALL ER 556 ...

The Journal of the Acoustical Society of America, 1995

The purpose of these acoustical patent reviews is to provide enough information for a Journal rea... more The purpose of these acoustical patent reviews is to provide enough information for a Journal reader to decide whether to seek more information from the patent itself. Any opinions expressed here are those of reviewers as individuals and are not legal opinions.

Journal of Financial Crime, 2000

Though there are no reported cases on the matter, Singapore, with its well‐developed financial ce... more Though there are no reported cases on the matter, Singapore, with its well‐developed financial centre, is the target of money launderers just like any other major city in the world. To deal with the problem, the Singapore government passed the Drug Trafficking (Confiscation of Benefits) Act in 1993. This Act was recently amended by the Drug Trafficking (Confiscation of Benefits) Amendment Bill which came into effect on 6th July, 1999.