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Implications of Elevated Serum Cortisol in the Onset of Postoperative Delirium Following Off-Pump Coronary Artery Bypass Grafting: Insights from a Bangladesh-Based Single Center Experience

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World Journal of Cardiovascular Diseases 2024年第4期14卷 252-267页

作者： Vivek kumar jha Md Abir Tazim Chowdhury Munama Magdum Manoj Tiwari Md Abul Bashar Maruf Md Saiful Islam Khan Priyanka Sinha Rajesh Naryan Kapar Md. Rezwanul Hoque Department of Cardiothoracic and Vascular Surgery BP Koirala Institute of Health Sciences Dharan Nepal Department of Cardiothoracic and Vascular Surgery Evercare Hospital Dhaka Dhaka Bangladesh Department of Preventive and Social Medicine National Institute of Preventive and Social Medicine Dhaka Bangladesh Department of Thoracic Surgery BP Koirala Memorial Cancer Hospital Bharatpur Nepal Department of Cardiac Surgery United Hospital Limited Dhaka Bangladesh Department of Cardiothoracic Anesthesia Evercare Hospital Dhaka Dhaka Bangladesh Department of Microbiology Kathmandu Medical College Kathmandu Nepal Department of Nephrology Bangabandhu Sheikh Mujib Medical University Dhaka Bangladesh Department of Cardiac Surgery Bangabandhu Sheikh Mujib Medical University Dhaka Bangladesh

Background: Following coronary artery bypass grafting (CABG), delirium emerges as a prevalent complication. This study aimed to assess the correlation between elevated serum cortisol levels and the occurrence of postoperative delirium subsequent to off-pump CABG. Methods: Conducted in the Department of Cardiac Surgery at BSMMU from October 2020 to September 2022, this comparative cross-sectional study included a total of 44 participants. Subjects, meeting specific criteria, were purposefully assigned to two groups based on off-pump CABG. Group A (n = 22) consisted of patients with normal serum cortisol levels, while Group B (n = 22) comprised individuals with high serum cortisol levels on the first postoperative day. Delirium onset was assessed at the bedside in the ICU on the 1st, 2nd, 3rd, 4th, and 5th postoperative days using standard tools, namely the Richmond Agitation Sedation score (RASS) and The Confusion Assessment Method (CAM-ICU). Data were collected based on the presence or absence of delirium. Statistical analysis utilized SPSS version 26.0, employing an independent Student’s t-test for continuous data and chi-square and Fischer’s exact test for categorical data. A p-value ≤ 0.05 was considered statistically significant. Results: Group-A had a mean age of 54.50 ± 17.97, and Group-B had a mean age of 55.22 ± 15.45, both with a male predominance (81.81% and 86.36% respectively). The mean serum cortisol level was significantly higher in Group B (829.71 ± vs. 389.98 ± 68.77). Postoperative delirium occurred in 27.3% of Group B patients, statistically significant compared to the 4.5% in Group A. However, patients in Group B who developed delirium experienced significantly longer postoperative ICU and hospital stays (79.29 ± 12.27 vs. 11.44 ± 2.85, p ≤ 0.05). There was one mortality in Group B, which was statistically not significant. Conclusion: This study observed a significant association between elevated serum cortisol levels in the postoperative period a

关键词： Coronary Artery Bypass Grafting (CABG) Serum Cortisol Postoperative Delirium Bangladesh

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Adaptive Linear Quadratic Regulator for Continuous-Time Systems With Uncertain Dynamics

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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 833-841页

作者： Sumit kumar jha Shubhendu Bhasin IEEE Department of Electronics and Communication Engineering Motilal Nehru National Institute of Technology AllahabadPrayagraj-211004India Department of Electrical Engineering Indian Institute of Technology DelhiNew Delhi-110016India

In this paper, adaptive linear quadratic regulator(LQR) is proposed for continuous-time systems with uncertain dynamics. The dynamic state-feedback controller uses inputoutput data along the system trajectory to continuously adapt and converge to the optimal controller. The result differs from previous results in that the adaptive optimal controller is designed without the knowledge of the system dynamics and an initial stabilizing policy. Further, the controller is updated continuously using input-output data, as opposed to the commonly used switched/intermittent updates which can potentially lead to stability issues. An online state derivative estimator facilitates the design of a model-free controller. Gradient-based update laws are developed for online estimation of the optimal gain. Uniform exponential stability of the closed-loop system is established using the Lyapunov-based analysis, and a simulation example is provided to validate the theoretical contribution.

关键词： Adaptive optimal control continuous policy update linear quadratic regulator uncertain system dynamics

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Temporal patterns of storage and flux of N and P in young Teak plantations of tropical moist deciduous forest,India

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Journal of Forestry Research 2014年第1期25卷 75-86页

作者： Kaushalendra kumar jha Technical Forestry Indian Institute of Forest Management

Teak （Tectona grandis Linn. f.） ranks among the top five tropical hardwood species and is being promoted for use in plantations in its non-native range due to its high economic value. However, there is a general lack of data on ecosystem functioning of teak plantations. We aimed at understanding storage and flux of nutrients related to young plantations of teak. Cycling of nitrogen （N） and phosphorus （P） in a chronosequence of plantations （1, 5, 11, 18, 24 and 30 years） was studied in the Moist Deciduous Forest Region of North India with the objective of investigating the nutrient cycling pattern at younger age since the current trend of harvesting age of the species in several tropical countries is being drastically reduced for quick return from this high value crop. Standing state, nutrient uptake, nutrient return and nutrient retransloca-tion in these plantations were estimated by tree harvesting and chemical analysis methods. The range of total standing nutrient across all these plantations was 20.3 to 586.6 kg？ha-1 for N and 5.3 to 208.8 kg？ha-1 for P. Net uptake of N ranged from 19.4 to 88.9 kg？ha-1？a-1 and P from 3.8 to 18.1 kg？ha-1？a-1. Retranslocation of N and P among all the stands ranged from 8.7 to 48.0 kg？ha-1？a-1 and 0.01 to 3.5 kg？ha-1？a-1, respectively. Range of total nutrient return was 25.8 to 91.3 kg？ha-1？a-1 for N and 2.7 to 10.1 kg？ha-1？a-1 for P. N and P use efficiency was between 107.4 and 192.5 g dry organic matter （OM） g-1N, and 551.9 and 841.1 g OM g-1P, respec-tively. The turnover time ranged from 2.04-13.17 years for N and be-tween 2.40-22.66 years for P. Quantity of N and P in the soil nutrient pool ranged from 2566.8 to 4426.8 kg？ha-1 and 372 to 520 kg？ha-1, re-spectively. Storage and flux of components in different plant parts of different aged plantations were assessed and depicted in compartment models. Percentage storage in soil, litter and vegetation ranged from 82% to 99%, 0.6% to 2.4% and 0.5% to 15% for N, respectively, and from

关键词： nutrient uptake standing state return turnover time nutrient use efficiency compartment model harvest loss Tectona grandis

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Biomass production and carbon balance in two hybrid poplar(Populus euramericana)plantations raised with and without agriculture in southern France

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Journal of Forestry Research 2018年第6期29卷 1689-1701页

作者： Kaushalendra kumar jha UMR Systems Institute Nationale de la Recherche Agronomique2 place Pierre Viala34060 MontpellierFrance Technical Forestry Indian Institute of Forest ManagementBhopalIndia

Poplar is useful in different climates for bioenergy production and carbon sequestration when planted as a single species or in agroforestry. Europe has large areas potentially suitable for poplar forestry and a bioenergy policy that would encourage poplar forestry. In this study I estimated biomass production and carbon sequestration in poplar monoculture plantation and poplar-wheat agroforestry, in the Mediterranean region of France. A single-tree harvesting method was used to estimate biomass and an empirical conversion factor was adopted to calculate sequestered carbon. Total biomass was higher in agroforestry trees(1223 kg tree) than in monoculture plantation trees(1102 kg tree).Aboveground and belowground biomass distributions were similar in both cases(89 and 88% aboveground, and 11 and12% belowground, respectively in agroforestry and monoculture). The partitioning of total biomass in an agroforestry tree in leaves, branch, and trunk(aboveground), and fine roots, medium roots, coarse roots and underground stem(belowground) was 1,22,and 77,and 6,9, 44 and 40%,respectively. Except for branch and trunk, all other compartments were similarly distributed in a monoculture *** of C was higher in agroforestry trees(612 kg tree)than in monoculture trees(512 kg tree). In contrast, C storage on a per hectare basis was lower in agroforestry(85 Mg ha) than in monoculture(105 Mg ha) due to the lower density of trees per hectare in agroforestry(139 trees in agroforestry vs 204 trees in monoculture). On a per hectare basis, soil C stocks pattern were similar to per tree stocking:They were higher in agroforestry at 330 Mg hathan in monoculture 304 Mg ha. Higher C accumulation by agroforestry has a direct management implication in the sense that expanding agroforestry into agriculture production areas with short rotation and fast growing trees like poplar would encourage quicker and greater C sequestration. This could simultaneously fulfil the requirement of bioenergy

关键词： Populus euramericana Wood volume and density Root:shoot ratio Vegetation and soil carbon System efficiency

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Carbon storage and sequestration rate assessment and allometric model development in young teak plantations of tropical moist deciduous forest, India

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Journal of Forestry Research 2015年第3期26卷 589-604页

作者： Kaushalendra kumar jha Technical Forestry Indian Institute of Forest ManagementPO Box No. 357 Nehru Nagar Bhopal 462 003 MP India

Carbon （C） sequestration through plantations is one of the important mitigation measures for rising levels of carbon dioxide and other greenhouse gases in the atmosphere. This study aimed to assess C stocks and their sequestration rate, and to develop allometric models for estimation of C stocking in age-series young teak （Tectona grandis） planta- tions （1, 5, 11, 18, 24 and 30 years） by using biomass and productivity estimation and regression, respectively. These plantations were raised in tropical moist deciduous forests of Kumaun Himalayan tarai. Total C stocks estimated for these plantations were 1.6, 15.8, 35.4, 39.0, 61.5 and 73.2 Mg ha-1, respectively. Aboveground and belowground C storage in- creased with increasing plantation age; however, the range of their percentage contribution showed little variation （87.8-88.2 and 11.7-12.7 %, respectively）, The rate of C sequestration for these respective plantations was 1.06, 6.95, 5.46, 5.42, 3.39 and 5.37 Mg ha-1 a-1. Forty percent of the aboveground annual storage was retained in the tree while 60 % was released in the form of foliage, twigs, and fruit litter. In the case of total （tree） annual production, 43 % was retained while 57 % was released as litter including root. C stock, C sequestration rate, accumulation ratio （1.4-18.1）, root：shoot C ratio （0.61--0.13） and production efficiency （0.01-0.18） were comparable to some previous reports for other species and forests. These data could be useful in deciding the harvesting age for young teak with respect to C storage and sequestrationrate. Four allometric models using linear regression equations were developed between biomass （twice the C stock） and diameter, girth, and height of the tree at different ages. The diameter model was found more suitable for C stock predic- tion in similar areas.

关键词： Age series Biomass Carbon budget DBH Productivity Production ratios Regression equations -Tectona grandis

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Thermodynamic behaviour of Rashba quantum dot in the presence of magnetic field

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Chinese Physics B 2016年第5期25卷 262-267页

作者： Sukirti Gumber Manoj kumar Pradip kumar jha Man Mohan Department of Physics & Astrophysics University of Delhi Department of Physics DDU College University of Delhi

The thermodynamic properties of an In Sb quantum dot have been investigated in the presence of Rashba spin–orbit interaction and a static magnetic field. The energy spectrum and wave-functions for the system are obtained by solving the Schrodinger wave-equation analytically. These energy levels are employed to calculate the specific heat, entropy,magnetization and susceptibility of the quantum dot system using canonical formalism. It is observed that the system is susceptible to maximum heat absorption at a particular value of magnetic field which depends on the Rashba coupling parameter as well as the temperature. The variation of specific heat shows a Schottky-like anomaly in the low temperature limit and rapidly converges to the value of 2kB with the further increase in temperature. The entropy of the quantum dot is found to be inversely proportional to the magnetic field but has a direct variation with temperature. The substantial effect of Rashba spin–orbit interaction on the magnetic properties of quantum dot is observed at low values of magnetic field and temperature.

关键词： quantum dot Rashba spin–orbit interaction thermal and magnetic properties

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Numerical investigation of the effect of transitory strand opening on mixing in a multistrand tundish

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International Journal of Minerals,Metallurgy and Materials 2011年第5期18卷 535-542页

作者： Sabin kumar Mishra Pradeep kumar jha Satish Chandra Sharma Satish kumar Ajmani Department of Mechanical and Industrial Engineering Indian Institute of Technology RoorkeeRoorkee 247667UttarakhandIndia Steelmaking and Casting Research Group Tata SteelR&DBurma MinesJamshedpur 831007JharkhandIndia

In a multistrand,the outlet near the inlet produces short circuiting *** leads to the formation of dead zones inside the tundish,and consequently,the mean residence time *** the present study,numerical investigation of mixing inside a delta shaped tundish with sloping boundaries was carried out by solving the Navier-Stokes equation and employing the standard turbulence *** decrease the dead zone volume inside the tundish,the effect of closing the outlet near the inlet for a small amount of time and further opening it on the mixing behavior of the tundish was *** outlets near the inlet were closed for varying amount of time,and the transient analysis of fluid flow and the tracer dispersion study were carried out to find the mixing parameters of the tundish,namely,mean residence time and the ratio of mixed to dead volume of the *** optimum closure time of the near outlet has been found,which yields best mixing inside the *** numerical code was validated against the experimental observation by performing the tracer dispersion study inside a multistrand tundish and the reasonably good match between the experimental and numerical results in terms of residence time distribution （RTD） *** results obtained from the present study confirm the strong role of choosing the right time for opening and closing the outlets to get improved characteristics for the fluid flow and mixing behavior of the *** educational version of computational fluid dynamics （CFD） software PHOENICS was used to solve the governing equations and interpret the results in different forms.

关键词： continuous casting billets tundish flow simulation mean residence time dead volume computational fluid dynamics (CFD)

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An exponential expanding meshes sequence and finite difference method adopted for two-dimensional elliptic equations

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International Journal of Modeling, Simulation, and Scientific Computing 2016年第2期7卷 109-125页

作者： Navnit jha Neelesh kumar Faculty of Mathematics and Computer Science Department of Mathematics South Asian University ChanakyapuriNew Delhi 110021India

We demonstrate a new nonuniform mesh finite difference method to obtain accurate solutions for the elliptic partial differential equations in two dimensions with nonlinear first-order partial derivative *** method will be based on a geometric grid network area and included among the most stable differencing scheme in which the nine-point spatial finite differences are implemented,thus arriving at a compact *** general,a third order of accuracy has been achieved and a fourth-order truncation error in the solution values will follow as a particular *** efficiency of using geometric mesh ratio parameter has been shown with the help of *** convergence of the scheme has been established using the matrix analysis,and irreducibility is proved with the help of strongly connected characteristics of the iteration *** difference scheme has been applied to test convection diffusion equation,steady state Burger’s equation,ocean model and a semi-linear elliptic *** computational results confirm the theoretical order and accuracy of the method.

关键词： Geometric mesh finite difference compact method elliptic partial differential equations convection diffusion equation Stommel ocean model

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Habitat Range of two Alpine Medicinal Plants in a Trans-Himalayan Dry Valley,Central Nepal

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Journal of Mountain Science 2009年第1期6卷 66-77页

作者： Bharat Babu SHRESTHA Pramod kumar jha Central Department of Botany Tribhuvan UniversityKathmanduNepal

Understanding of the habitat range of threatened Himalayan medicinal plants which are declining in their abundance due to high anthropogenic disturbances is essential for developing conservation strategies and agrotechnologies for cultivation. In this communication, we have discussed the habitat range of two alpine medicinal plants, Aconitum naviculare （Bruehl） Stapf and Neopicrorhiza scrophulariiflora （Pennel） Hong in a trans-Himalayan dry valley of central Nepal, Manang district. They are the most prioritized medicinal plants of the study area in terms of ethnomedicinal uses. A. naviculare occurs on warm and dry south facing slopes between 4090-4650 m asl along with sclerophyllous and thorny alpine scrubs, while N. scrophulariiflora is exclusively found on cool and moist north facing slope between 4000 and 4400 m asl where adequate water is available from snow melt to create a suitable habitat for this wetland dependent species. The soil in rooting zone of the two plants differs significantly in organic carbon （OC）, organic matter （OM）, total nitrogen （N） and carbon to nitrogen （C/N） ratio. Due to cool and moist condition of N. scrophulariiflora habitat, accumulation of soil OC is higher, but soil N content is lower probably due to slow release from litter, higher leaching loss and greater retention in perennial live biomass of the plant. The C/N ratio of soil is more suitable in A. navuculare habitat than that of N scrophulariiflora for N supply. Warm and sunny site with N rich soil can be suitable for cultivation ofA. naviculare, while moist and cool site with organic soil for N. scrophulariiflora. The populations of both the plants are fragmented and small. Due to collection by human and trampling damage by livestock, the population of A. naviculare was found absent in open areas in five of the six sampling sites and it was confined only within the bushes of alpine scrubs. For N. serophulariiflora, high probability of complete receding of small glaeiers may be

关键词： Aconitum naviculare Neopicrorhizascrophulariiflora habitat degradation nitrogen organic carbon radiation Manang Nepal

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Effects of chemical reactions on MHD micropolar fluid flow past a vertical plate in slip-flow regime

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Applied Mathematics and Mechanics(English Edition) 2008年第9期29卷 1179-1194页

作者： R.C.Chaudhary Abhay kumar jha Department of Mathematics University of Rajasthan

Heat and mass transfer effects on the unsteady flow of a micropolar fluid through a porous medium bounded by a semi-infinite vertical plate in a slip-flow regime are studied taking into account a homogeneous chemical reaction of the first order. A uniform magnetic field acts perpendicular to the porous surface absorb micropolar fluid with a suction velocity varying with time. The free stream velocity follows an exponentially increasing or decreasing small perturbation law. Using the approximate method, the expressions for the velocity microrotation, temperature, and concentration are obtained. Futher, the results of the skin friction coefficient, the couple stress coefficient, and the rate of heat and mass transfer at the wall are presented with various values of fluid properties and flow conditions.

关键词： micropolar fluid microrotation chemical reaction slip-flow magnetohy-drodynamics heat and mass transfer

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