Auto-segmentation of head and neck organs at risk in radiotherapy and its dependence on anatomic similari

Anantharaman Ayyalusamy,Subramani Vellaiyan,Shanmuga Subramanian,Arivarasan Ilamurugu,Shyama Satpathy,Mohammed Nauman,Gowtham Katta,Aneesha Madine 대한방사선종양학회 2019 Radiation Oncology Journal Vol.37 No.2

Purpose: The aim is to study the dependence of deformable based auto-segmentation of head and neck organs-at-risks (OAR) on anatomy matching for a single atlas based system and generate an acceptable set of contours. Methods: A sample of ten patients in neutral neck position and three atlas sets consisting of ten patients each in different head and neck positions were utilized to generate three scenarios representing poor, average and perfect anatomy matching respectively and auto-segmentation was carried out for each scenario. Brainstem, larynx, mandible, cervical oesophagus, oral cavity, pharyngeal muscles, parotids, spinal cord, and trachea were the structures selected for the study. Automatic and oncologist reference contours were compared using the dice similarity index (DSI), Hausdroff distance and variation in the centre of mass (COM). Results: The mean DSI scores for brainstem was good irrespective of the anatomy matching scenarios. The scores for mandible, oral cavity, larynx, parotids, spinal cord, and trachea were unacceptable with poor matching but improved with enhanced bony matching whereas cervical oesophagus and pharyngeal muscles had less than acceptable scores for even perfect matching scenario. HD value and variation in COM decreased with better matching for all the structures. Conclusion: Improved anatomy matching resulted in better segmentation. At least a similar setup can help generate an acceptable set of automatic contours in systems employing single atlas method. Automatic contours from average matching scenario were acceptable for most structures. Importance should be given to head and neck position during atlas generation for a single atlas based system.

Auto-segmentation of head and neck organs at risk in radiotherapy and its dependence on anatomic similarity

Ayyalusamy, Anantharaman,Vellaiyan, Subramani,Subramanian, Shanmuga,Ilamurugu, Arivarasan,Satpathy, Shyama,Nauman, Mohammed,Katta, Gowtham,Madineni, Aneesha The Korean Society for Radiation Oncology 2019 Radiation Oncology Journal Vol.37 No.2

Purpose: The aim is to study the dependence of deformable based auto-segmentation of head and neck organs-at-risks (OAR) on anatomy matching for a single atlas based system and generate an acceptable set of contours. Methods: A sample of ten patients in neutral neck position and three atlas sets consisting of ten patients each in different head and neck positions were utilized to generate three scenarios representing poor, average and perfect anatomy matching respectively and auto-segmentation was carried out for each scenario. Brainstem, larynx, mandible, cervical oesophagus, oral cavity, pharyngeal muscles, parotids, spinal cord, and trachea were the structures selected for the study. Automatic and oncologist reference contours were compared using the dice similarity index (DSI), Hausdroff distance and variation in the centre of mass (COM). Results: The mean DSI scores for brainstem was good irrespective of the anatomy matching scenarios. The scores for mandible, oral cavity, larynx, parotids, spinal cord, and trachea were unacceptable with poor matching but improved with enhanced bony matching whereas cervical oesophagus and pharyngeal muscles had less than acceptable scores for even perfect matching scenario. HD value and variation in COM decreased with better matching for all the structures. Conclusion: Improved anatomy matching resulted in better segmentation. At least a similar setup can help generate an acceptable set of automatic contours in systems employing single atlas method. Automatic contours from average matching scenario were acceptable for most structures. Importance should be given to head and neck position during atlas generation for a single atlas based system.

Assessing Abiotic Reductive Dechlorination of cis-DCE by Reduced Fe Species Forming under Various Redox Conditions

정훈영,Karthik Anantharaman,Sung Pil Hyun,Kim F. Hayes 대한지질학회 2010 대한지질학회 학술대회 Vol.2010 No.

Abiotic Reductive Dechlorination of <i>cis</i>-Dichloroethylene by Fe Species Formed during Iron- or Sulfate-Reduction

Jeong, Hoon Y.,Anantharaman, Karthik,Han, Young-Soo,Hayes, Kim F. American Chemical Society 2011 Environmental science & technology Vol.45 No.12

<P>This study investigated reductive dechlorination of <I>cis</I>-dichloroethylene (<I>cis</I>-DCE) by the reduced Fe phases obtained from in situ precipitation, which involved mixing of Fe(II), Fe(III), and S(-II) solutions. A range of redox conditions were simulated by varying the ratio of initial Fe(II) concentration ([Fe(II)]<SUB>o</SUB>) to initial Fe(III) concentration ([Fe(III)]<SUB>o</SUB>) for iron-reducing conditions (IRC) and the ratio of [Fe(II)]<SUB>o</SUB> to initial sulfide concentration ([S(-II)]<SUB>o</SUB>) for sulfate-reducing conditions (SRC). Significant dechlorination of <I>cis</I>-DCE occurred under highly reducing IRC and iron-rich SRC, suggesting that Fe (oxyhydr)oxides including green rusts are highly reactive with <I>cis</I>-DCE but that Fe sulfide as mackinawite (FeS) is nonreactive. Relative concentrations of sulfate to chloride were also varied to examine the anion impact on <I>cis</I>-DCE dechlorination. Generally, slower dechlorination occurred in the batches with higher sulfate concentrations. As indicated by higher dissolved Fe concentration, the slower dechlorination in the presence of sulfate was probably due to the decreased surface-complexed Fe(II). This study demonstrates that the chemical form of reduced Fe(II) is critical in determining the fate of <I>cis</I>-DCE under anoxic conditions.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2010/esthag.2010.45.issue-12/es104387w/production/images/medium/es-2010-04387w_0002.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es104387w'>ACS Electronic Supporting Info</A></P>

Effect of Ag loading on praseodymium doped ceria catalyst for soot oxidation activity

Pandurangappa Govardhan,Anjana Payyalore Anantharaman,Sunaina Shivasharanappa Patil,Hari Prasad Dasari,Harshini Dasari,Atmuri Shourya 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.2

Silver-loaded praseodymium doped ceria (XAg/PDC) was synthesized by microwave-assisted co-precipitation and wetness impregnation. XRD confirms the fluorite structure of ceria without secondary phase, and Raman spectroscopy represents the increased generation of oxygen vacancies with Ag loading. The TEM analysis shows lattice fringes corresponding to both CeO2 and Ag on the surface. The BET and BJH analysis of catalyst confirms the high porosity accompanied by high surface area and pore diameter of 5Ag/PDC and 15Ag/PDC, making it more active for the oxidation reaction. From the XPS analysis the amount of surface Ce3+ concentration and the surface chemisorbed oxygen species (O2 2) is high for 5Ag/PDC and 15Ag/PDC, in line with XRD and Raman results. The soot oxidation T50 temperature follows the trend: 5Ag/PDC~15Ag/PDC>10Ag/PDC>20Ag/PDC>0Ag/PDC. The Ag loading increased the surface reducibility of cerium ions and thus 5 wt% was optimized.

Healthy aging and chronic kidney disease

( Reshma Aziz Merchant ),( Anantharaman Vathsala ) 대한신장학회 2022 Kidney Research and Clinical Practice Vol.41 No.6

The world population is aging and the prevalence of noncommunicable diseases such as chronic kidney disease (CKD) will increase significantly. With advances in medical treatment and public health, the human lifespan continues to outpace the health span and the last decade of life is generally spent in poor health. In 2015, the World Health Organization defined healthy aging as ‘the process of developing and maintaining the functional ability that enables wellbeing in older age.’ CKD is increasingly being recognized as a model of accelerated aging and is associated with physical performance decline, cognitive decline, falls and fractures, poor quality of life, loss of appetite, and inflammation. Frailty and dementia are the final pathways and key determinants of disability and mortality independent of underlying disease. CKD, dementia, and frailty share a triangular relationship with synergistic actions and have common risk factors wherein CKD accelerates frailty and dementia through mechanisms such as uremic toxicity, metabolic acidosis and derangements, anorexia and malnutrition, dialysis-related hemodynamic instability, and sleep disturbance. Frailty accelerates glomerular filtration decline as well as dialysis induction in CKD and more than doubles the mortality risk. Anorexia is one of the major causes of protein-energy malnutrition, which is also prevalent in the aging population and warrants screening. Healthcare systems across the world need to have a system in place for the prevention of CKD amongst high-risk older adults, focusing on screening for poor prognostic factors amongst patients with CKD such as frailty, poor appetite, and cognitive impairment and providing necessary person-centered interventions to reverse underlying factors that may contribute to poor outcomes.