Browsing by Author "N. Gopalakrishnan"

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Microseismic monitoring application for primary stability evaluation of the powerhouse of the Tapovan Vishnugad Hydropower Project
(Springer, 2019) Vikalp Kumar; N. Gopalakrishnan; N.P. Singh; Sivakumar Cherukuri
The study of micro-cracks, shear zone and redistribution of stress after excavation in the rockmass is required for a stability analysis of the underground structure. The powerhouse of the Tapovan Vishnugad Hydropower Project (TVHPP) of NTPC Ltd. is located in the seismic zone V of India and is positioned at the junction of the middle and higher Himalayan region under challenging geological conditions. The powerhouse cavern constructed by drill and blast method encountered a number of rockbursts of various intensities during and after construction. So, a real-time remote microseismic monitoring network was used to evaluate the stability of the powerhouse cavern rockmass. Strata condition, rockburst occurrence during construction and drilling feasibility for sensor installation were studied for an array of designs of the microseismic monitoring network. The primary monitoring period demarcated the micro-crack locations and probable failure zones in the powerhouse rockmass by processing and analysis of various temporal and spatial variations of microseismic parameters to evaluate the underground powerhouse structural stability. Although a large number of microseismic events occurred in the powerhouse which resulted in high displacement in a few areas, due to the low amount of energy released from the events occurring inside the powerhouse, the structure appears to be stable. © 2019, Indian Academy of Sciences.
Outcomes of symptomatic coronavirus disease 19 in maintenance hemodialysis patient in India
(John Wiley and Sons Inc, 2021) Narayan Prasad; Manas Ranjan Behera; Mansi Bhatt; Sanjay Kumar Agarwal; N. Gopalakrishnan; Edwin Fernando; Arpita Roy Chaudhary; Manisha Sahay; Shivendra Singh; Apoorva Jain; Shruti Tapiawala; Aniket Kamble; Umesh Khanna; Rubina Bohra; Anurag Gupta; Urmila Anandh; Vivekanand Jha
Background: Maintenance hemodialysis (MHD) patients face disadvantages with higher risk of acquiring SARS-CoV-2 infection, atypical manifestations, and associated multiple comorbidities. We describe patients' outcomes with symptomatic COVID-19 on MHD in a large cohort of patients from India. Methods: Data were collected prospectively from hemodialysis units in 11 public and private hospitals between March 15, 2020, and July 31, 2020. The survival determinants were analyzed using stepwise backward elimination cox-regression analysis. Results: Of the 263 total patients (mean age 51.76 ± 13.63 years and males 173) on MHD with symptomatic COVID-19, 35 (13.3%) died. Those who died were older (p = 0.01), had higher frequency of diabetic kidney disease (p = 0.001), comorbidities (p = 0.04), and severe COVID-19 (p = 0.001). Mortality was higher among patients on twice-weekly MHD than thrice-weekly (p = 0.001) and dialysis through central venous catheter (CVC) as compared to arteriovenous fistula (p = 0.001). On multivariate analysis, CVC use (HR 2.53, 95% CI 1.26–5.07, p = 0.009), disease severity (HR = 3.54, 95% CI 1.52–8.26, p = 0.003), and noninvasive ventilatory support (HR 0.59, 95% CI 0.25–0.99, p = 0.049) had significant effect on mortality. Conclusion: The adjusted mortality risk of COVID-19 in MHD patients is high in patients associated with severe COVID-19 and patients having CVC as vascular access. © 2021 Wiley Periodicals LLC.
The Adverse Effect of COVID Pandemic on the Care of Patients With Kidney Diseases in India
(Elsevier Inc, 2020) Narayan Prasad; Mansi Bhatt; Sanjay K. Agarwal; H.S. Kohli; N. Gopalakrishnan; Edwin Fernando; Manisha Sahay; Mohan Rajapurkar; Arpita Roy Chowdhary; Manish Rathi; Tarun Jeloka; Valentine Lobo; Shivendra Singh; A.K. Bhalla; Umesh Khanna; S.B. Bansal; P.K. Rai; Amol Bhawane; Urmila Anandh; Ajit Kumar Singh; Bharat Shah; Amit Gupta; Vivekanand Jha
Introduction: The coronavirus disease 2019 (COVID-19) pandemic has affected the care of patients with noncommunicable diseases, including those suffering from kidney-related ailments. Many parts of the world, including India, adopted lockdown to curb community transmission of disease. The lockdown affected transportation, access to health care facilities, and availability of medicines and consumables as well as outpatient and inpatient services. We aimed to analyze the effect of lockdown imposed due to the COVID-19 pandemic on the care of patients with kidney diseases in India. Methods: We surveyed 19 major hospitals (8 in the public and 11 in the private sector) to determine the effect of lockdown on the care of patients with kidney disease, including those on dialysis after the first 3 weeks of lockdown. Results: The total number of dialysis patients in these centers came down from 2517 to 2404. Approximately 710 (28.2%) patients missed 1 or more dialysis sessions, 69 (2.74%) required emergency dialysis sessions, 104 (4.13%) stopped reporting for dialysis, and 9 (0.36%) were confirmed to have died. Outpatient attendance in the surveyed hospital came down by 92.3%, and inpatient service reduced by 61%. Tele-consultation was started but was accessed by only a small number of patients. Conclusion: Lack of preparedness before lockdown resulted in an interruption in health care services and posed an immediate adverse effect on the outcome of dialysis patients and patients with kidney disease in India. The long-term impact on the health of patients with less severe forms of kidney disease remains unknown. © 2020 International Society of Nephrology