OALib Journal期刊

ISSN: 2333-9721



匹配條件: “ DB Gurung” ,找到相關結果約282條。
Two dimensional temperature distribution model in human dermal region exposed at low ambient temperatures with air flow
DB Gurung
Kathmandu University Journal of Science, Engineering and Technology , 2012, DOI: 10.3126/kuset.v8i2.7320
Abstract: This paper deals with thermo-regulation in human dermal part in a cold atmosphere with significant air flow. The mathematical model involving bio-heat equation has been solved using finite element method and Crank-Nicolson technique to numerically investigate two dimensional temperature distributions. The natural three layers of dermal part – epidermis, dermis, and subcutaneous tissue are considered for the study. The important parameters like blood mass flow rate, metabolic heat generation rate and thermal conductivity are taken distinct in each layer according to their distinct sub-regional activities. The human subject is assumed in static condition. The wind speed is considered in the range from the start of forced convection (? 0.2 m/s) and up to 5 m/s. The loss of heat from the skin surface to the environment is taken due to convection, radiation, and insensible perspiration. Kathmandu University Journal of Science, Engineering and Technology Vol. 8, No. II, December, 2012, 11-24 DOI: http://dx.doi.org/10.3126/kuset.v8i2.7320
Thermoregulation through Skin at Low Atmospheric Temperatures
DB Gurung
Kathmandu University Journal of Science, Engineering and Technology , 2009, DOI: 10.3126/kuset.v5i1.2843
Abstract: The metabolic heat generation decreases exponentially if the persistence of cooling in human body is sustained. This phenomena is under consideration in dermis and subcutaneous tissue to study the exact solution of temperature distribution in dermal layers at low atmospheric temperatures. Other suitable variable physiological conditions are taken and the solution has been obtained using laplace tranform in one dimensional case. Key words: Thermoregulation; Human dermal part; Laplace transform. 2000 Mathematics Subject Classification : 92 C 35. ? DOI: 10.3126/kuset.v5i1.2843 Kathmandu University Journal of Science, Engineering and Technology Vol.5, No.1, January 2009, pp 14-22
Time dependent temperature distribution model in layered human dermal part
Saraswati Acharya,DB Gurung,VP Saxena
Kathmandu University Journal of Science, Engineering and Technology , 2012, DOI: 10.3126/kuset.v8i2.7327
Abstract: The paper developed application of finite element method with linear function in the study of temperature distribution in the layers of dermal part-stratum corneum, stratum germinativum, papillary region, reticular region and subcutaneous tissues as elements. The method is applied to obtain the numerical solution of governing differential equation for one dimensional unsteady state bio-heat transfer using suitable values of parameters that effect the heat transfer in human body. The numerical results obtained are exhibited graphically for various atmospheric temperatures for comparative study of temperature distribution profiles. The loss of heat from the outer surface of the body to the environment is taken due to convection, radiation and sweat evaporation. Kathmandu University Journal of Science, Engineering and Technology Vol. 8, No. II, December, 2012, 66-76 DOI: http://dx.doi.org/10.3126/kuset.v8i2.7327
Visual outcome of conventional extracapsular cataract extraction with posterior chamber intraocular lens implantation versus manual small-incision cataract surgery
A Gurung,DB Karki,S Shrestha,AP Rijal
Nepalese Journal of Ophthalmology , 2009, DOI: 10.3126/nepjoph.v1i1.3668
Abstract: Background: An effective method for cataract surgery should be identified to combat cataract blindness. Aim: To study the surgical outcome of conventional extracapsular cataract extraction versus manual small-incision cataract surgery. Materials and methods: A randomized clinical trial was carried out including one hundred eyes (88 patients) which were divided into two groups using systematic randomization: groups of conventional extracapsular cataract extraction with posterior chamber intraocular lens (ECCE with PCIOL) implantation and manual small-incision cataract surgery (MSICS). The postoperative parameters/variables studied were the unaided and best-corrected visual acuity and astigmatism. Statistics: Epi info 2000 version statistical software was used for data analysis and calculation of relative risk, 95% CI and p value. The p value of less than 0.05 was considered as significant. Results: In the immediate postoperative period, unaided visual acuity of =/> 6/18 was achieved in 24 subjects in MSICS group versus 7 in ECCE with PCIOL group (RR=2.05, 95% CI=1.44 - 2.94, p = 0.0002), whereas the same at 6 - 8 weeks postoperatively was found in 28 and 22 subjects in those groups respectively (RR=1.27, 95% CI=0.86-1.89, p=0.23). The astigmatism of =/> 2 at 6 - 8 weeks was found in 35 and 17 subjects from the conventional and MSICS groups respectively ( R=2.28, 95% CI = 1.39-3.73, p=0.0002). Conclusion: Both MSICS and conventional ECCE with PCIOL are safe and effective techniques for treatment of cataract patients. A more rapid recovery of good vision can be achieved with MSICS than with conventional ECCE with PCIOL in the immediate postoperative period. Key words: ECCE; MSICS; visual acuity; astigmatism DOI: 10.3126/nepjoph.v1i1.3668 Nep J Oph 2009;1(1):13-19
Short communication: Heterosis and combining ability of Nepalese yellow maize (Zea mays L.)
SR Gautam, BR Ojha, SK Ghimire, DB Gurung
Agronomy Journal of Nepal , 2013, DOI: 10.3126/ajn.v3i0.9020
Abstract: Nepalese yellow maize inbred lines were characterized for general combining ability (GCA) and specific combining ability (SCA) of their crosses and parents were identified having high combining ability for determining the heterotic effects on yield and other quantitative traits of hybrids. A line x tester mating design was used for making the crosses in the winter season of 2008 and the hybrids along with their parents and four checks were evaluated in Randomized Complete Block Design (RCBD) with three replications in the spring season of 2009 at the experimental farm of the National Maize Research Program, Chitwan. Significant variations were found among the treatments for grain yield and other traits which indicated presence of high magnitude of genetic variations among tested inbred lines. The cross between RML-32 and RML-17 produced the highest grain yield (15870 kg/ha) among the crosses. Hybrids such as RL-194 x RL-84 (10770 kg/ha), RML-21 x RML-17 (9270 kg/ha), RL-180 x RML-17 (9270 kg/ha) and L-1 x RL-84 (8785 kg/ha) were found superior grain yielder. Thirty-nine hybrids showed positive mid-parent heterosis for grain yield among 40 crosses. The highest positive mid-parent heterosis for grain yield was found 880% in cross between RML-32 and RML-17, followed by RL-98X RML-17 (507%), RL-103 x RML-17 (403%), PUTU-18 x RML- 17 (351%) and RL-180 x RL 84 (316%).
Heterosis and yield potentialities of promising maize hybrids suitable for Terai and inner Terai environments of Nepal
DB Gurung, BR Pandey, SR Upadhyay, B Pokhrel, JB Kshetri
Agronomy Journal of Nepal , 2010, DOI: 10.3126/ajn.v1i0.7544
Abstract: Heterosis has made a dramatic impact on the developing of breeding methods and high yields in many field crops during the 20th century. In general, heterosis is greatest in cross pollinated compared to self pollinated crops and thus widely exploited for hybrid cultivar development. Standard heterosis is one of the most important parameters in commercialization of maize hybrids. A new hybrid must be superior to the standard hybrids in terms of grain yield and other economic traits. We have analyzed four coordinated varietal trials of hybrids, 3 of which were conducted at NMRP, Rampur and another was tested at NMRP, Rampur and at ARS, Belachapi, Janakpur from 2006 to 2008 in order to determine the standard heterosis of the promising hybrids. The objective of this study was to evaluate hybrids under different production domains and to select superior hybrids for commercialization. Standard heterosis was calculated based on the best check hybrids and Indian commercial hybrids. The hybrids showed significant differences for grain yields and days to silking in all the trials. Standard heterosis of the tested hybrids ranged from - 39.4 to 47.8%. Most of the hybrids showed positive standard heterosis for grain yield. Hybrids namely; RML- 4/NML-2, RML-6/RML-8, NML-1/RML-8 in 2006 and RML-57/RL-174, NML-1/RML-6 and RL-197/NML-2 in 2008 had more than15% standard heterosis for grain yield evaluated at NMRP, Rampur. Hybrid between RML- 4/NML-2 had only shown positive standard heterosis in 2007 at NMRP, Rampur. RML-4/NML-2, NML-1/RL-17 and RL-111/RL-189 were superior hybrids, which had >15% standard heterosis across NMRP, Rampur and at ARS, Belachapi, Janakpur in 2008. Seed production aspect of these selected hybrids should be studied to develop a complete package of practices for F1 hybrid seed production. DOI: http://dx.doi.org/10.3126/ajn.v1i0.7544 Agronomy Journal of Nepal (Agron JN) Vol. 1: 2010 pp.67-73
Importance of antiresorptive therapies for patients with bone metastases from solid tumors
Talreja DB
Cancer Management and Research , 2012, DOI: http://dx.doi.org/10.2147/CMAR.S33983
Abstract: rtance of antiresorptive therapies for patients with bone metastases from solid tumors Review (1476) Total Article Views Authors: Talreja DB Published Date September 2012 Volume 2012:4 Pages 287 - 297 DOI: http://dx.doi.org/10.2147/CMAR.S33983 Received: 18 May 2012 Accepted: 07 July 2012 Published: 11 September 2012 Draupadi B Talreja Department of Medicine, David Geffen School of Medicine at UCLA and Northridge Hospital Medical Center, Northridge, CA, USA Abstract: Patients with bone metastases are at risk of skeletal-related events such as pathologic fractures, spinal cord compression, the need for orthopedic surgery to bone, and palliative radiotherapy for severe bone pain. Antiresorptive therapies have demonstrated efficacy for reducing the risk of skeletal-related events and ameliorating bone pain. Despite the well documented clinical benefits of antiresorptive therapies, patient benefits can be limited or compromised by nonadherence with scheduled therapy. Potential reasons for poor compliance include lack of understanding of how antiresorptive therapies work, neglecting the importance of bone health in maintaining quality of life, and being unaware of the potentially debilitating effects of skeletal-related events caused by bone metastases. Indeed, patients may stop therapy after bone pain subsides or discontinue due to generally mild and usually manageable adverse events, leaving them at an increased risk of developing skeletal-related events. In addition, the cost of antiresorptive therapy can be a concern for many patients with cancer. Medical care for patients with cancer requires a coordinated effort between primary care physicians and oncologists. Patients' medical care teams can be leveraged to help educate them about the importance of adherence to antiresorptive therapy when cancer has metastasized to bone. Because primary care physicians generally have more contact with their patients than oncologists, they are in a unique position to understand patient perceptions and habits that may lead to noncompliance and to help educate patients about the benefits and risks of various antiresorptive therapies in the advanced cancer setting. Therefore, primary care physicians need to be aware of various mechanistic and clinical considerations regarding antiresorptive treatment options.
Use of natural isotopes and groundwater quality for improved recharge and flow estimates in dolomitic aquifers
DB Bredenkamp
Water SA , 2007,
Abstract: The application of a model to several dolomitic aquifers in the RSA is presented and has successfully simulated the reappearance of 14C injected from nuclear tests in the discharge from springs. This is based on a new conceptual model, which accounts for the large variations of 14C in the groundwater still representing recently recharged water. The input of 14C is related to the recharge mechanism to yield low concentrations if the infiltration is direct; and higher concentrations if the recharge water interacts with biogenic CO2 generated in the soil zone. The model has produced estimates of the recharge parameters and their controls but requires an independent estimate of the average recharge e.g. the chloride mass balance method. A close match has been obtained with 14C measurements over the past three decades. A shallow component of the recharge mixes with a larger and older deep-water component. The model has provided the turn-over times of water in the system, which represent the storage capacity as multiples of the mean annual recharge. Quantitative estimates of the recharge of dolomitic aquifers could be derived from the bicarbonate concentrations of the spring waters. The model has also been used to simulate the response of the limited temporal tritium measurements and single determinations of CFC for some springs. This has revealed significant differences that are related to additional dilution of the tritium tracer in the unsaturated zone, in comparison to 14C and CFC.
Computer-animated model of accommodation and theory of reciprocal zonular action
Goldberg DB
Clinical Ophthalmology , 2011, DOI: http://dx.doi.org/10.2147/OPTH.S25983
Abstract: mputer-animated model of accommodation and theory of reciprocal zonular action Original Research (2812) Total Article Views Authors: Goldberg DB Published Date October 2011 Volume 2011:5 Pages 1559 - 1566 DOI: http://dx.doi.org/10.2147/OPTH.S25983 Daniel B Goldberg1,2 1Ophthalmology Department, Drexel College of Medicine, Philadelphia, PA, 2Eye Physicians, Little Silver, NJ, USA Abstract: This report presents a computer-animated model of the structures of accommodation based on new understanding of the anatomy of the zonular apparatus integrated with current understanding of the mechanism of accommodation. Analysis of this model suggests a new, consolidated theory of the mechanism of accommodation including a new theory of reciprocal zonular action. A three-dimensional animated model of the eye in accommodation and disaccommodation was produced in collaboration with an experienced medical animator. Current understanding of the anatomy of the zonule and the attachments of the vitreous zonule to the anterior hyaloid membrane is incomplete. Recent studies have demonstrated three components of the vitreous zonule: (1) anterior vitreous zonule (previously “hyalocapsular” zonule), which attaches the ciliary plexus in the valleys of the ciliary processes to the anterior hyaloid membrane in the region medial to the ciliary body and Weiger’s ligament; (2) intermediate vitreous zonule, which attaches the ciliary plexus to the anterior hyaloid peripherally; and (3) posterior vitreous zonule, which creates a sponge-like ring at the attachment zone that anchors the pars plana zonules. The pars plana zonules attach posteriorly to the elastic choroid above the ora serrata. Analysis of the computer-animated model demonstrates the synchronized movements of the accommodative structures in accommodation and disaccommodation. Utilizing model-based reasoning, it is shown that the posterior zonules attach to and provide traction to the anterior vitreous membrane and Weiger’s ligament. This model supports the concept that the ciliary body/zonule/anterior hyaloid complex contributes to the changes in the posterior lens capsule during accommodation, supporting an extralenticular component to accommodation and demonstrating an alternative to the “vitreous support” theories. There is a reciprocal action of the anterior zonules and the posterior zonules. During ciliary body contraction, the anterior zonules lose tension while the posterior zonules stretch and exert force on the posterior lens capsule playing a role in shaping the posterior lens thickness and curvature. During ciliary body relaxation, the posterior zonules lose tension as the lens flattens and is pulled back by the increasing tension of the anterior zonules.