156 research outputs found
Slag Prediction in Submerged Rocket Nozzle Through Two-Phase CFD Simulations
A computational procedure has been established to predict the slag in a practical solid rocket motor with submerged nozzle. Both single-phase and two-phase flow analyses have been performed in the rocket motor port. Three-dimensional Navier-Stokes equations along with SST turbulence model have been solved for gas-phase calculations. The effect of ejected alumina particles from the propellant geometry on the flow field has been simulated through Lagrangian tracking method. The computational methodology is firstly validated by comparing against other numerical results of rocket motors available in the literature before applying the same to predict the slag accumulation of a submerged rocket motor for strategic applications. Burn-back geometries at different instants have been simulated and parametric studies were performed to find out the effect of Al2O3 particle size. It was observed that the slag capture rate increases uniformly with A12O3 particle size. The predicted slag accumulation data match closely with the ground test data for the range of conditions simulated in the present work.Defence Science Journal, Vol. 65, No. 2, March 2015, pp.99-106, DOI:http://dx.doi.org/10.14429/dsj.65.714
Statistically significant association of the single nucleotide polymorphism (SNP) rs13181 (ERCC2) with predisposition to Squamous Cell Carcinomas of the Head and Neck (SCCHN) and Breast cancer in the north Indian population
<p>Abstract</p> <p>Background</p> <p>Non-synonymous single nucleotide polymorphisms (SNPs) within vital DNA repair genes may cause reduction of activity leaving the genome unrepaired resulting in genomic instability and cancer.</p> <p>Materials and methods</p> <p>The present endeavour involved study on the association of the SNP rs13181 (Lys751Gln/A18911C) in the Nucleotide Excision Repair (NER) pathway gene ERCC2 (excision repair cross-complementing rodent repair deficiency, complementation group 2) with the risks of Squamous Cell Carcinomas of the Head and Neck (SCCHN) and Breast cancer using a case-control based association study among 685 (400 controls and 285 SCCHN-affected cases) and 395 (227 normal healthy female controls and 168 breast cancer cases) ethnically-matched samples, respectively from north India using Polymerase Chain Reaction followed by Restriction Fragment Length Polymorphism (PCR-RFLP) analysis.</p> <p>Results</p> <p>Results showed significant association of rs13181 homozygous mutant (CC) [Odds Ratio (OR) 4.412, 95% Confidence Interval (CI) 2.413 to 8.068], heterozygous (AC) (OR 2.086, 95% CI 1.246 to 3.492) and combined mutant (AC + CC) (OR 2.672, 95% CI 1.647 to 4.334) genotypes with predisposition to Breast cancer. Statistically significant increase in SCCHN risk was also associated with the mutant genotypes of rs13181 (ERCC2), viz. homozygous mutant (CC) (OR 1.680, 95% CI 1.014 to 2.784), heterozygous (AC) (OR 1.531, 95% CI 1.092 to 2.149) and combined mutant (AC + CC) (OR 1.560, 95% CI 1.128 to 2.158) genotypes.</p> <p>Conclusion</p> <p>The results of this case-control study indicate that the polymorphism rs13181 might be a risk factor for predisposition towards SCCHN and breast cancer among north Indian subpopulations.</p
Load Flow Analysis with UPFC under Unsymmetrical Fault Condition
This paper addresses the comparative load flow analysis with and without Unified Power Flow Controller (UPFC) for six buses, three phase transmission line under unsymmetrical faults (L-G, L-L and L-L-G) in simulation model. Unified Power Flow Controller (UPFC) is a typical Flexible AC Transmission System (FACTS) device playing a vital role as a stability aid for large transient disturbances in an interconnected power system. The main objective of this paper is to improve transient stability of the six bus system. Here active and reactive power on load bus of the system considered has been determined under different fault conditions. UPFC has been connected to the system and its effects on power flow and voltage profile of test system has been determined with various line data and bus data for six buses, three lines power system and simulation model by using simulation toolbox has been developed. In this work a versatile model is presented for UPFC inherent order to improve the transient stability and damp oscillation. Index Terms β Unified Power Flow Controller (UPFC), Control, simulation, transients, line to ground fault (L-G), double line to ground fault (L-L-G), double line fault (L-L
Treatment of Pseudo Class III Malocclusion with Multiple Loop Protraction Utility Arch
Pseudo Class III malocclusion has been characterized by an anterior crossbite in the presence of a forward mandibular displacement. There are various methods to correct pseudo Class III malocclusion, e.g., Inclined planes, reverse stainless steel crown, bonded composite resin slopes, tongue blade, the removable appliance with auxiliary springs, and maxillary lingual arch with finger springs. In this article, we are presenting a case of pseudo Class III malocclusion treated with multiple loop protraction utility arch. Patient had functional mandibular anterior deviation resulting into traumatic anterior cross bite and concave profile. We fabricated multiple loop arch wire (0.016βΓ0.022β blue elgiloy) which was activated at four 90Β° bends without disturbing other segments of the arch
Resveratrol and Black Tea Polyphenol Combination Synergistically Suppress Mouse Skin Tumors Growth by Inhibition of Activated MAPKs and p53
Cancer chemoprevention by natural dietary agents has received considerable importance because of their cost-effectiveness and wide safety margin. However, single agent intervention has failed to bring the expected outcome in clinical trials; therefore, combinations of chemopreventive agents are gaining increasing popularity. The present study aims to evaluate the combinatorial chemopreventive effects of resveratrol and black tea polyphenol (BTP) in suppressing two-stage mouse skin carcinogenesis induced by DMBA and TPA. Resveratrol/BTP alone treatment decreased tumor incidence by βΌ67% and βΌ75%, while combination of both at low doses synergistically decreased tumor incidence even more significantly by βΌ89% (p<0.01). This combination also significantly regressed tumor volume and number (p<0.01). Mechanistic studies revealed that this combinatorial inhibition was associated with decreased expression of phosphorylated mitogen-activated protein kinase family proteins: extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase 1/2, p38 and increased in total p53 and phospho p53 (Ser 15) in skin tissue/tumor. Treatment with combinations of resveratrol and BTP also decreased expression of proliferating cell nuclear antigen in mouse skin tissues/tumors than their solitary treatments as determined by immunohistochemistry. In addition, histological and cell death analysis also confirmed that resveratrol and BTP treatment together inhibits cellular proliferation and markedly induces apoptosis. Taken together, our results for the first time lucidly illustrate that resveratrol and BTP in combination impart better suppressive activity than either of these agents alone and accentuate that development of novel combination therapies/chemoprevention using dietary agents will be more beneficial against cancer. This promising combination should be examined in therapeutic trials of skin and possibly other cancers
Energy Minimization for Multi-core Platforms through DVFS and VR Phase Scaling With Comprehensive Convex Model
Energy management is a critical challenge in multi-core processors due to continuous technology scaling. Previous methods have mostly focused on the energy minimization of the processor cores. However, energy overhead of the off-chip voltage regulator (VR) has recently shown to be a non-trivial part of the total energy consumption and has been previously overlooked. In this paper, we propose an overall energy optimization method for the system that minimizes both per-core energy consumption and VR energy consumption using dynamic voltage frequency scaling (DVFS) and VR phase scaling by solving a comprehensive convex model. In order to improve the accuracy of the task latency model, a new task model considering both computation and memory access of the task is also developed. Furthermore, for better scalability and lower on-line overhead, we decompose our proposed convex method into two stages: an off-line stage and an on-line stage. During the off-line stage, we explore the convex model by assuming different numbers of active phases of the VR, various workload pressures and workload characteristics to collect the optimal frequency assignments under different scenarios. During the online stage, the specific frequency assignment for cores and optimal active phase number of the VR are selected and applied based on the actual workload pressure and its characteristics running on the cores. Experiments on real benchmarks show that when compared with state-of-the-art approaches, which are oblivious to VR overheads and exploit slack time to achieve energy minimization, our method can achieve a significant energy saving of up to 22.4% with negligible on-line overhead
Genome-wide identification and characterization of Puccinia striiformis-responsive lncRNAs in Triticum aestivum
Wheat stripe rust (yellow rust) caused by Puccinia striiformis f. sp. tritici (Pst) is a serious biotic stress factor limiting wheat production worldwide. Emerging evidence demonstrates that long non-coding RNAs (lncRNAs) participate in various developmental processes in plants via post-transcription regulation. In this study, RNA sequencing (RNA-seq) was performed on a pair of near-isogenic linesβrust resistance line FLW29 and rust susceptible line PBW343βwhich differed only in the rust susceptibility trait. A total of 6,807 lncRNA transcripts were identified using bioinformatics analyses, among which 10 lncRNAs were found to be differentially expressed between resistance and susceptible lines. In order to find the target genes of the identified lncRNAs, their interactions with wheat microRNA (miRNAs) were predicted. A total of 199 lncRNAs showed interactions with 65 miRNAs, which further target 757 distinct mRNA transcripts. Moreover, detailed functional annotations of the target genes were used to identify the candidate genes, pathways, domains, families, and transcription factors that may be related to stripe rust resistance response in wheat plants. The NAC domain protein, disease resistance proteins RPP13 and RPM1, At1g58400, monodehydroascorbate reductase, NBS-LRR-like protein, rust resistance kinase Lr10-like, LRR receptor, serine/threonine-protein kinase, and cysteine proteinase are among the identified targets that are crucial for wheat stripe rust resistance. Semiquantitative PCR analysis of some of the differentially expressed lncRNAs revealed variations in expression profiles of two lncRNAs between the Pst-resistant and Pst-susceptible genotypes at least under one condition. Additionally, simple sequence repeats (SSRs) were also identified from wheat lncRNA sequences, which may be very useful for conducting targeted gene mapping studies of stripe rust resistance in wheat. These findings improved our understanding of the molecular mechanism responsible for the stripe rust disease that can be further utilized to develop wheat varieties with durable resistance to this disease
Nimotuzumab-cisplatin-radiation versus cisplatin-radiation in HPV negative oropharyngeal cancer
BACKGROUND: Addition of nimotuzumab to weekly cisplatin and radiation improves outcomes in head and neck cancer. HPV negative oropharyngeal cancer has unsatisfactory treatment outcomes and is a candidate for escalation of treatment. We wanted to determine whether the addition of nimotuzumab to cisplatin-radiation could improve outcomes in these poor-risk tumors.METHODS: This was a subgroup analysis of a phase 3 randomized study. In this study, locally advanced head and neck cancer patients undergoing definitive chemoradiation were randomly allocated to weekly cisplatin (30 mg/m2 IV)- radiation (66β70 Gy) {CRT arm} or nimotuzumab (200 mg weekly) -weekly cisplatin (30 mg/m2)-radiation (66β70 Gy) {NCRT arm}. The data of HPV negative oropharyngeal cancer was extracted from the database of this study for the analysis. HPV testing was done with p16 immunohistochemistry (IHC) staining and reported according to the CAP criteria. The outcomes assessed were progression-free survival (PFS), disease-free survival (DFS), locoregional control, and overall survival (OS). Interaction test was performed between the study arms and HPV status prior to doing any HPV specific analysis for each of the studied outcomes. Kaplan Meier estimates for 2 year OS with 95% CI was calculated. The hazard ratio was obtained using COX regression analysis.RESULTS: We had 187 HPV negative oropharyngeal cancers, 91 in the CRT arm and 96 in NCRT arm. The interaction test was significant for PFS (p = 0.000), locoregional control (p = 0.007) and overall survival (p = 0.002) but not for DFS (p = 0.072). The 2- year PFS was 31.5% (95%CI 21.5β42) in CRT arm versus 57.2% (95%CI 45.8β67.1) in NCRT arm (HR -0.54; 95%CI 0.36β0.79, p = 0.002). The 2-year LRC was 41.4% (95%CI 29.8β52.6) in the CRT arm versus in 60.4% (95%CI 48.7β70.2) in the NCRT arm (HR -0.61; 95%CI 0.4β0.94, p = 0.024). The addition of nimotuzumab also lead to an improvement in 2-year OS from 39.0% (95%CI 28.4β49.6) to 57.6% (95%CI 46.3β67.4) (HR-0.63, 95%CI 0.43β0.92, p = 0.018).CONCLUSIONS:Β The addition of nimotuzumab to weekly cisplatin-radiation improves outcomes inclusive of OS in HPV negative oropharyngeal cancers.<br/
Nimotuzumab-cisplatin-radiation versus cisplatin-radiation in HPV negative oropharyngeal cancer
BACKGROUND: Addition of nimotuzumab to weekly cisplatin and radiation improves outcomes in head and neck cancer. HPV negative oropharyngeal cancer has unsatisfactory treatment outcomes and is a candidate for escalation of treatment. We wanted to determine whether the addition of nimotuzumab to cisplatin-radiation could improve outcomes in these poor-risk tumors.METHODS: This was a subgroup analysis of a phase 3 randomized study. In this study, locally advanced head and neck cancer patients undergoing definitive chemoradiation were randomly allocated to weekly cisplatin (30 mg/m2 IV)- radiation (66β70 Gy) {CRT arm} or nimotuzumab (200 mg weekly) -weekly cisplatin (30 mg/m2)-radiation (66β70 Gy) {NCRT arm}. The data of HPV negative oropharyngeal cancer was extracted from the database of this study for the analysis. HPV testing was done with p16 immunohistochemistry (IHC) staining and reported according to the CAP criteria. The outcomes assessed were progression-free survival (PFS), disease-free survival (DFS), locoregional control, and overall survival (OS). Interaction test was performed between the study arms and HPV status prior to doing any HPV specific analysis for each of the studied outcomes. Kaplan Meier estimates for 2 year OS with 95% CI was calculated. The hazard ratio was obtained using COX regression analysis.RESULTS: We had 187 HPV negative oropharyngeal cancers, 91 in the CRT arm and 96 in NCRT arm. The interaction test was significant for PFS (p = 0.000), locoregional control (p = 0.007) and overall survival (p = 0.002) but not for DFS (p = 0.072). The 2- year PFS was 31.5% (95%CI 21.5β42) in CRT arm versus 57.2% (95%CI 45.8β67.1) in NCRT arm (HR -0.54; 95%CI 0.36β0.79, p = 0.002). The 2-year LRC was 41.4% (95%CI 29.8β52.6) in the CRT arm versus in 60.4% (95%CI 48.7β70.2) in the NCRT arm (HR -0.61; 95%CI 0.4β0.94, p = 0.024). The addition of nimotuzumab also lead to an improvement in 2-year OS from 39.0% (95%CI 28.4β49.6) to 57.6% (95%CI 46.3β67.4) (HR-0.63, 95%CI 0.43β0.92, p = 0.018).CONCLUSIONS:Β The addition of nimotuzumab to weekly cisplatin-radiation improves outcomes inclusive of OS in HPV negative oropharyngeal cancers.<br/
RMAC study:A randomized study for evaluation of metronomic adjuvant chemotherapy in recurrent head and neck cancers post salvage surgical resection in those who are ineligible for re-irradiation
Background: Adjuvant re-chemoradiation after salvage surgery improves disease-free survival in recurrent head and neck cancer. However, most patients are ineligible for re-irradiation and are kept on observation. We investigated the efficacy of metronomic adjuvant chemotherapy (MAC) in this group of patients compared to observation. Methods: This was a randomized integrated phase II/III clinical trial. Adults with recurrent head and neck cancer, who had undergone salvage surgery, but were ineligible for adjuvant re-irradiation were randomized in a 1:1 ratio to either MAC arm or observation. MAC consisted of weekly oral methotrexate (at a dose of 15 mg per square meter of body surface area) and celecoxib (at a dose of 200 mg orally twice daily) for 6 months. The primary endpoint of phase 2 was disease-free survival (DFS) while that of phase 3 was overall survival (OS). For phase 2, to detect an improvement in the hazard ratio (HR) 0.67 with MAC, with a type 1 error of 10% (1-sided), type 2 error of 30%, 105 patients were required. While for phase 3, with a target HR of 0.77, with a type 1 error of 5%, type 2 error of 20%, 318 patients were required. Here we report the results of phase 2 part of the study. Results: At a median follow up of 30.2 months (95% confidence interval (CI), 25.3 to 35.1) the 1 year and 2-year DFS were 57.4% (95% CI, 42.8β69.5) and 37.6% (95% CI, 24.1β51) in MAC arm whereas the corresponding numbers were 62.3% (95% CI, 47.8 to 73.8) and 54.2%(95% CI, 39.8 to 66.5) in observation arm, respectively (hazard ratio for progression, 1.45; 95% CI, 0.87 to 2.47; P = 0.15). In the MAC arm, the 1 and 2 year OS was 78.7% (95% CI, 64.9 to 87.6) and 48% (95% CI, 34.1 to 62).The corresponding figures in the observation arm were 79.2% (95% CI, 65.7 to 87.9) and 65.5% (95% CI, 50.9 to 76.7) (hazard ratio for death, 1.7, 95% CI, 0.94 to 3.08; P = 0.08). Conclusion: The adjuvant 6-month metronomic schedule was ineffective in improving outcomes in recurrent head and neck cancers post salvage surgery who are ineligible for re-radiation. Trial registration. Clinical trial registry of India (CTRI)- CTRI/2016/04/006872 [Registered on 26/4/2016] Β© 2022 Elsevier Lt
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