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BACKGROUND: Paraoxonase enzyme was first identified as a protective barrier against organophosphorus poisoning. After painstaking research spanning the last three decades, the knowledge about this enzyme has increased immensely. T...
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BACKGROUND: Paraoxonase enzyme was first identified as a protective barrier against organophosphorus poisoning. After painstaking research spanning the last three decades, the knowledge about this enzyme has increased immensely. The present review attempts to elaborate the role of paraoxonase enzyme in normal physiology as well as provide an overview of the various disorders in which the enzyme may have a role in etiopathogenesis. METHODS: The literature was searched from the websites of the National Library of Medicine (http://www.ncbi.nlm.nih.gov/) and Pub Med Central, the U.S. National Library of Medicine's digital archive of life sciences journal literature. RESULTS: Paraoxonase acts as an important antioxidant enzyme against oxidative stress. The enzyme has been implicated in the pathogenesis of a number of disorders including cardiovascular disorders, cancers etc. CONCLUSIONS: A better understanding of the molecular mechanism of the enzyme along with the regulatory circuits will help us to utilize agonists to potentiate the anti oxidant actions of the enzyme.
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BACKGROUND: Anti-tumour necrosis factor (TNF) therapy effectively treats Crohn's perineal fistulas (CPF); the effect on health-related quality of life (HRQoL) remains unknown. AIMS: To evaluate the effect of anti-TNF therapy on th...
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BACKGROUND: Anti-tumour necrosis factor (TNF) therapy effectively treats Crohn's perineal fistulas (CPF); the effect on health-related quality of life (HRQoL) remains unknown. AIMS: To evaluate the effect of anti-TNF therapy on the HRQoL of patients with CPF in daily clinical practice. METHODS: Prospective evaluation of clinical and magnetic resonance imaging (MRI) responses, disease activity (Perianal Disease Activity Index - PDAI), and HRQoL assessment [Inflammatory Bowel Disease Questionnaire (IBDQ)] in patients receiving anti-TNF therapy for CPF treated up to 12 months. RESULTS: In all, 26 patients with CPF were treated (mean age 39 years; 19 infliximab, 7 adalimumab). At baseline, 85% patients had impaired IBDQ scores (mean 137; 'normal' >170). At 12 months, mean increases in IBDQ score for infliximab and adalimumab treated patients were 40 and 41 points respectively (P < 0.05). There were significant improvements in all IBDQ subscores (bowel, emotional, systemic, social) at 12 months (all P < or = 0.003). Fourteen patients (74%) on infliximab and six on adalimumab (86%) achieved IBDQ score > or =170. Mean increase in IBDQ score was 50, 34 and 16 points in patients with clinical fistula closure (P < 0.001), clinical response (P = 0.002) and no response (n = 1) respectively. IBDQ score increased for patients with MRI healing (P < 0.001) and MRI improvement (P = 0.016), but not for those with no MRI change (n = 2). IBDQ correlated significantly with PDAI at baseline and at 12 months. CONCLUSION: Anti-TNF therapy improves HRQoL in patients with CPF at 12 months and this improvement is most pronounced in patients with clinical and MRI healing.
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To gain insight into the instability and trajectory change in projectiles penetrating dry sand at high velocities, two dimensional plane strain mesoscale simulations were carried out using representative models of a particulate sy...
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To gain insight into the instability and trajectory change in projectiles penetrating dry sand at high velocities, two dimensional plane strain mesoscale simulations were carried out using representative models of a particulate system and of a small projectile. A program, ISP-SAND, was developed and used to generate the representative particulate system with mean grain sizes of 60 and 120 μm as well as ±30% uniform size distribution from the mean. Target porosities ranged from 30% to 40%. The penetration of ogive nose steel projectiles with caliber radius head of 3.5 and length-to-diameter (l/d) ratio of 3.85 was simulated using the updated Lagrangian explicit parallel finite element code ISP-TROTP. Deformation of the projectile and individual sand grains was analyzed using a nonlinear elastic-inelastic model for these materials. Grain-grain and grain-projectile interactions were analyzed using a contact algorithm with and without friction. Projectile instability was quantified and compared using the lateral displacement of the center of mass, lateral force acting on the projectile, and its rotational momentum about the center of mass. The main source of projectile instability and the ensuing trajectory change in the penetration simulations was found to be the inhomogeneous loading of the projectile due to the heterogeneities and randomness inherent in a particulate media like sand. The granularity of the media has not been considered explicitly in previous work. Projectile instability increased with impact velocity, as expected. However, it also increased for the case of elastic impactor that preserved the nose shape, with an increase in grain size, and for uniform grain sizes. Moreover, friction, inherently present in geologic materials, was found to be a major contributor to instability. Conclusions derived from one projectile depth simulations were confirmed by two deeper penetration simulations considering up to three full lengths of penetration (requiring a larger sand target). The deep penetration simulation predicted considerable instability with a trajectory change of approximately 45° when friction was considered in the dry sand medium. An overall conclusion of this work is that projectile penetration studies in geologic materials need to explicitly consider the heterogeneous or particulate nature of these materials.
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BACKGROUND: Ablation of the left atrium and pulmonary veins antrum (PVAI) can be an effective treatment of atrial fibrillation (AF). However, there is discrepancy in the literature regarding the effect extensive ablation has on le...
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BACKGROUND: Ablation of the left atrium and pulmonary veins antrum (PVAI) can be an effective treatment of atrial fibrillation (AF). However, there is discrepancy in the literature regarding the effect extensive ablation has on left atrial (LA) function. We sought to evaluate the effect that AF ablation procedures has on global and regional wall motion as assessed by cardiovascular magnetic resonance imaging (MRI). METHODS: Consecutive patients undergoing PVAI had cardiac MRI performed preablation and 3 months post ablation. Patients included paroxysmal (n = 16) and persistent/permanent (n = 13). In addition, 12 volunteers underwent cardiac MRI to provide a control population. LA transport function was assessed by obtaining cyclical change indices, total percent emptying, LA stroke volume indices, and LA active percent emptying. Using chordal segment analysis and radial motion of the left atrium, regional motion was assessed throughout the LA emptying cycle. RESULTS: All four PVs were isolated for all patients. Imaging revealed a significant reduction in LA volumes in AF patients post-PVAI. In the subset of patients with persistent AF, post-PVAI improvements were seen in global (p < 0.01) and regional LA functions (p = 0.01). In the paroxysmal AF patients, post-PVAI measurements revealed decreases in LA transport function (p = 0.02) as well as diminished regional function in the LA lateral wall (p = 0.02). The paroxysmal AF patients had global and regional LA functions comparable to the normal volunteers prior to ablation; however, these were significantly diminished post ablation. CONCLUSION: Extensive ablation during PVAI causes mild deterioration in LA function. However, in patients with a high burden of AF, it appears that the positive remodeling that occurs with rhythm restoration outweighs any negative effects of ablation.
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PrNi_2B_2C as a member of the borocarbide series is characterized by antiferromagnetic order below T_N =4 K and the absence of superconductivity (at least down to 100 mK). There are two effects responsible for the absence of super...
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PrNi_2B_2C as a member of the borocarbide series is characterized by antiferromagnetic order below T_N =4 K and the absence of superconductivity (at least down to 100 mK). There are two effects responsible for the absence of superconductivity in PrNi_2B_2C. These are the strong conduction electron-Pr moment interaction and a comparatively lower density of states. We studied the crystalline electric field (CEF) excitations and excitons in this compound by inelastic neutron scattering. The CEF level scheme obtained from these data comprises a singlet ground state, a doublet at 1 meV, and further higher levels at 5.2, 24.3 (doublet), 25.1, 29.4, and 31.5 meV. Large dispersion was found for the 1 meV excitation and explained theoretically taking into account magnetic exchange interactions. The calculated crystal-field parameters explain satisfactorily the neutron spectra as well as the heat-capacity and magnetic-susceptibility data. This leads to the conclusion that PrNi2B2C can be described by the standard model of rare-earth magnetism. Thus the heavy-fermion concept, suggested by some groups earlier in literature, is not the cause of the suppression of superconductivity. Excitation spectra of the diluted series Pr_(1-x)Y_xNi_2B_2C were also investigated. No drastic changes in the CEF level scheme have been observed in these compounds. Hence the CEF level scheme of the full compound, i.e., PrNi_2B_2C, is reasonably valid for these samples too. The superconducting-transition temperature T_C ～ 15.5 K for YNi_2B_2C decreases linearly with decreasing Y concentration x. Samples with x≤0.65 do not exhibit superconductivity down to 2 K.
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In this study, a distributed hydrological model (MIKE SHE) was employed in an integrated framework to use remote sensing data, and its advantages over using conventional data were analyzed. The command of 6 Main Canal of the Damod...
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In this study, a distributed hydrological model (MIKE SHE) was employed in an integrated framework to use remote sensing data, and its advantages over using conventional data were analyzed. The command of 6 Main Canal of the Damodar Irrigation Project, West Bengal, India was chosen as the study area. IRS LISS III and RADARSAT SAR data were processed for generating soil and land use/cover maps, respectively. Thematic layers for topography, groundwater table, Thiessen polygons for rainfall and evapotranspiration, settlement area, and soil were prepared in GIS (ARC-INFO). An application program was developed to transform GIS processed ASCII data into the model input format (matrix data) and also model output to GIS. The model was subsequently calibrated and validated for monsoon season (June to October) of 1999 and 2000, respectively, considering the goodness of fit criteria between observed and simulated groundwater depths. Simulations were done with different combinations of remote sensing (RS) and conventional data setups to study the impact of using RS data on the model calibration and simulation results. The introduction of remotely sensed data shows improvements in the model calibration and eventually in its performance. Statistical results for the RS data integrated model show high Nash-Sutcliffe coefficient (0.85), lower root mean square error (0.31), and closer agreement between the mean simulated (8.37 m) and observed (8.32 m) groundwater depths as compared to the conventional data. Model results show little increase in the total irrigation demand by 7.7% using RS data in comparison to conventional data. In contrast, spatial distribution of irrigation demands was found to vary considerably among distributaries using RS data. The large impact of remotely sensed versus conventional data is that the RS data integrated distributed model gives more reliable and accurate results and, hence, could play a major role in irrigation studies.
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In Maintenance design for any system can be divided into two components; (i) maintenance policy component (ii) maintenance scheduling component. The current research paper focuses on the maintenance scheduling for production equip...
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In Maintenance design for any system can be divided into two components; (i) maintenance policy component (ii) maintenance scheduling component. The current research paper focuses on the maintenance scheduling for production equipment keeping cost control as the primary goal. The paper highlights the resource prioritization and the usefulness of an importance measure based ranking of subsystems/components for scientific allocation of limited resources. Based on the detailed understanding of maximizing benefits from available resources, a cost-effective importance measure has been evolved and proposed for scheduling various maintenance tasks involved in heavy duty belt conveyors operating in an underground coal mine.
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C57Bl/6 mice were administered a high fat, Western diet (WD, 41% fat) or a very high fat lard diet (HFL, 60% fat), and evaluated for cognitive ability using the Stone T-maze and for biochemical markers of brain inflammation. WD co...
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C57Bl/6 mice were administered a high fat, Western diet (WD, 41% fat) or a very high fat lard diet (HFL, 60% fat), and evaluated for cognitive ability using the Stone T-maze and for biochemical markers of brain inflammation. WD consumption resulted in significantly increased body weight and astrocyte reactivity, but not impaired cognition, microglial reactivity, or heightened cytokine levels. HFL increased body weight, and impaired cognition, increased brain inflammation, and decreased BDNF. Collectively, these data suggest that while different diet formulations can increase body weight, the ability of high fat diets to disrupt cognition is linked to brain inflammation.
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BACKGROUND: Inhaled corticosteroids (ICS) have been shown to decrease the occurrence of COPD exacerbations. However, the relationship of baseline lung function and reduction of exacerbations with the use of ICS remains unknown. He...
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BACKGROUND: Inhaled corticosteroids (ICS) have been shown to decrease the occurrence of COPD exacerbations. However, the relationship of baseline lung function and reduction of exacerbations with the use of ICS remains unknown. Herein, we perform a metaregression to evaluate the efficacy of ICS in preventing COPD exacerbations. METHODS: We searched the PubMed, EmBase, and Cochrane Central Database of Controlled Trials databases (1988-2008) for studies that have reported the efficacy of ICS vs placebo in preventing COPD exacerbations. We pooled the risk ratio (RR) and 95% CIs from individual studies using a random-effects model to assess the exacerbations in the two groups. We also performed a weighted random effects metaregression using baseline FEV(1) values. RESULTS: Our search yielded 11 studies (8,164 patients). The use of ICS was associated with reduction in the occurrence of exacerbations (RR, 0.82; 95% CI, 0.73-0.92). There was the presence of significant statistical heterogeneity but no evidence of publication bias. Sensitivity analysis revealed benefit of ICS only in patients with FEV(1) < 50% (RR, 0.79; 95% CI, 0.69-0.89) with persistence of statistical heterogeneity. Metaregression showed that the percentage risk reduction in exacerbations with the use of ICS is invariant across the severity of COPD (assessed by FEV(1)). CONCLUSION: There is only a modest benefit of ICS in preventing COPD exacerbations, which is not related to the level of baseline lung function on metaregression analysis. The benefits of ICS in preventing COPD exacerbations thus seem to be overstated.
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