Prediction of Tool Eccentricity Effects on the Mechanical Properties of Friction Stir Welded AA5754-H24 Aluminum Alloy Using ANN Model.

The current study uses three different pin eccentricities (e) and six different welding speeds to investigate the impact of pin eccentricity on friction stir welding (FSW) of AA5754-H24. To simulate and forecast the impact of (e) and welding speed on the mechanical properties of friction stir welded joints for (FSWed) AA5754-H24, an artificial neural network (ANN) model was developed. The input parameters for the model in this work are welding speed (WS) and tool pin eccentricity (e). The outputs of the developed ANN model include the mechanical properties of FSW AA5754-H24 (ultimate tensile strength, elongation, hardness of the thermomechanically affected zone (TMAZ), and hardness of the weld nugget zone (NG)). The ANN model yielded a satisfactory performance. The model has been used to predict the mechanical properties of the FSW AA5754 aluminum alloy as a function of TPE and WS with excellent reliability. Experimentally, the tensile strength is increased by increasing both the (e) and the speed, which was already captured from the ANN predictions. The R2 values are higher than 0.97 for all the predictions, reflecting the output quality.

Pulmonary artery banding: still a role for staged bi-ventricular repair of intracardiac shunts?

OBJECTIVES: Although pulmonary artery banding remains a useful palliation in bi-ventricular shunting lesions, single-stage repair holds several advantages. We investigate outcomes of the former approach in high-risk patients. METHODS: Retrospective cohort study including all pulmonary artery banding procedures over 9 years, excluding single ventricle physiology and left ventricular training. RESULTS: Banding was performed in 125 patients at a median age of 41 days (2-294) and weight of 3.4 kg (1.8-7.32). Staged repair was undertaken for significant co-morbidity in 81 (64.8%) and anatomical complexity in 44 (35.2%). The median hospital stay was 14 days (interquartile range 8-33.5) and 14 patients (11.2%) required anatomical repair before discharge. Nine patients died during the initial admission (hospital mortality 7.2 %) and five following discharge (inter-stage mortality 4.8%). Of 105 banded patients who survived, 19 (18.1%) needed inter-stage re-admission and 18 (14.4%) required unplanned re-intervention. Full repair was performed in 93 (74.4%) at a median age of 13 months (3.1-49.9) and weight of 8.5 kg (3.08-16.8). Prior banding, 54% were below the 0.4th weight centile, but only 28% remained so at repair. Post-repair, 5/93 (5.4%) developed heart block requiring permanent pacemaker, and 11/93 (11.8%) required unplanned re-intervention. The post-repair mortality (including repairs during the initial admission) was 6/93 (6.5%), with overall mortality of the staged approach 13.6% (17/125). CONCLUSIONS: In a cohort with a high incidence of co-morbidity, pulmonary artery banding is associated with a significant risk of re-intervention and mortality. Weight gain improves after banding, but heart block, re-intervention, and mortality remain frequent following repair.

Salivary progesterone as a biochemical marker to predict early preterm birth in asymptomatic high-risk women.

OBJECTIVE: To evaluate salivary progesterone as a predictor of early preterm birth (PTB) and compare it with transvaginal sonographic (TVS) cervical length in asymptomatic high-risk women. DESIGN: Prospective study. SETTING: Departments of Obstetrics and Gynaecology and Biochemistry at UCMS & GTBH, Delhi, India. SAMPLE: Ninety pregnant women. METHODS: The progesterone concentration in saliva of asymptomatic pregnant women at high risk for preterm delivery was estimated by immunoassay, and cervical length was measured by TVS, at the first antenatal visit at 24-28 weeks of gestation, and then repeated 3-4 weeks later. MAIN OUTCOME MEASURES: Early PTB, mean and critical cut-off values of salivary progesterone, and a diagnostic value comparison of salivary progesterone with TVS cervical length. RESULTS: The mean value of salivary progesterone was significantly lower in all women who delivered at <37 weeks of gestation (n = 38), compared with the term group (n = 52; P < 0.001). Salivary progesterone decreased significantly from the first to the second visit, with the maximum decrease observed in women who delivered at <34 weeks of gestation (29.6%, 95% CI 17.8-41.4%, P < 0.002). The single predictive critical cut-off value for salivary progesterone was 2575 pg/ml, below which more than 80% of women delivered prematurely before 34 weeks of gestation, with sensitivity, specificity, and positive and negative predictive values of 83% (95% CI 58.6-96.4%), 86% (95% CI 75.9-93.1%), 60% (95% CI 38.6-78.8%) and 95% (95% CI 87.1-99.0%), respectively. The TVS cervical length decreased significantly (P < 0.001) in the women who delivered prematurely. CONCLUSIONS: Low salivary progesterone concentration can be used for predicting early PTB in asymptomatic high-risk women.

Pulmonary dysfunctions, oxidative stress and DNA damage in brick kiln workers.

Brick kilns in the suburban areas in developing countries pose a big threat to the environment and hence the health of their workers and people residing around them. The present study was planned to assess the lung functions, oxidative stress parameters and DNA damage in brick kiln workers. A total of 31 male subjects working in brick kiln, and 32 age, sex and socioeconomic status matched controls were included in the study. The lung volumes, capacities and flow rates, namely, forced expiratory volume in first second (FEV(1)), forced vital capacity (FVC), FEV(1)/FVC, expiratory reserve volume, inspiratory capacity (IC), maximal expiratory flow when 50% of FVC is remaining to be expired, maximum voluntary ventilation, peak expiratory flow rate and vital capacity were significantly decreased in the brick kiln workers. Increased oxidative stress as evidenced by increased malonedialdehyde levels and reduced glutathione content, glutathione S-transferase activity and ferric reducing ability of plasma were observed in the study group when compared with controls. Our results indicate a significant correlation between oxidative stress parameters and pulmonary dysfunction, which may be due to silica-induced oxidative stress and resulting lung damage.

Attenuation of phosphamidon-induced oxidative stress and immune dysfunction in rats treated with N-acetylcysteine.

The effect of N-acetylcysteine, a thiolic antioxidant, on attenuation of phosphamidon-induced oxidative stress and immune dysfunction was evaluated in adult male Wistar rats weighing 200-250 g. Rats were divided into four groups, 8 animals/group, and treated with phosphamidon, N-acetylcysteine or the combination of both for 28 days. Oral administration of phosphamidon (1.74 mg/kg), an organophosphate insecticide, increased serum malondialdehyde (3.83 +/- 0.18 vs 2.91 +/- 0.24 nmol/mL; P < 0.05) and decreased erythrocyte superoxide dismutase (567.8 +/- 24.36 vs 749.16 +/- 102.61 U/gHb; P < 0.05), catalase activity (1.86 +/- 0.18 vs 2.43 +/- 0.08 U/gHb; P < 0.05) and whole blood glutathione levels (1.25 +/- 0.21 vs 2.28 +/- 0.08 mg/gHb; P < 0.05) showing phosphamidon-induced oxidative stress. Phosphamidon exposure markedly suppressed humoral immune response as assessed by antibody titer to ovalbumin (4.71 +/- 0.51 vs 8.00 +/- 0.12 -log(2); P < 0.05), and cell-mediated immune response as assessed by leukocyte migration inhibition (25.24 +/- 1.04 vs 70.8 +/- 1.09%; P < 0.05) and macrophage migration inhibition (20.38 +/- 0.99 vs 67.16 +/- 5.30%; P < 0.05) response. Phosphamidon exposure decreased IFN-small u, Cyrillic levels (40.7 +/- 3.21 vs 55.84 +/- 3.02 pg/mL; P < 0.05) suggesting a profound effect of phosphamidon on cell-mediated immune response. A phosphamidon-induced increase in TNF-alpha level (64.19 +/- 6.0 vs 23.16 +/- 4.0 pg/mL; P < 0.05) suggests a contributory role of immunocytes in oxidative stress. Co-administration of N-acetylcysteine (3.5 mmol/kg, orally) with phosphamidon attenuated the adverse effects of phosphamidon. These findings suggest that oral N-acetylcysteine treatment exerts protective effect and attenuates free radical injury and immune dysfunction caused by subchronic phosphamidon exposure.

Attenuation of phosphamidon-induced oxidative stress and immune dysfunction in rats treated with N-acetylcysteine

The effect of N-acetylcysteine, a thiolic antioxidant, on attenuation of phosphamidon-induced oxidative stress and immune dysfunction was evaluated in adult male Wistar rats weighing 200-250 g. Rats were divided into four groups, 8 animals/group, and treated with phosphamidon, N-acetylcysteine or the combination of both for 28 days. Oral administration of phosphamidon (1.74 mg/kg), an organophosphate insecticide, increased serum malondialdehyde (3.83 ± 0.18 vs 2.91 ± 0.24 nmol/mL; P < 0.05) and decreased erythrocyte superoxide dismutase (567.8 ± 24.36 vs 749.16 ± 102.61 U/gHb; P < 0.05), catalase activity (1.86 ± 0.18 vs 2.43 ± 0.08 U/gHb; P < 0.05) and whole blood glutathione levels (1.25 ± 0.21 vs 2.28 ± 0.08 mg/gHb; P < 0.05) showing phosphamidon-induced oxidative stress. Phosphamidon exposure markedly suppressed humoral immune response as assessed by antibody titer to ovalbumin (4.71 ± 0.51 vs 8.00 ± 0.12 -log2; P < 0.05), and cell-mediated immune response as assessed by leukocyte migration inhibition (25.24 ± 1.04 vs 70.8 ± 1.09%; P < 0.05) and macrophage migration inhibition (20.38 ± 0.99 vs 67.16 ± 5.30%; P < 0.05) response. Phosphamidon exposure decreased IFN-у levels (40.7 ± 3.21 vs 55.84 ± 3.02 pg/mL; P < 0.05) suggesting a profound effect of phosphamidon on cell-mediated immune response. A phosphamidon-induced increase in TNF-α level (64.19 ± 6.0 vs 23.16 ± 4.0 pg/mL; P < 0.05) suggests a contributory role of immunocytes in oxidative stress. Co-administration of N-acetylcysteine (3.5 mmol/kg, orally) with phosphamidon attenuated the adverse effects of phosphamidon. These findings suggest that oral N-acetylcysteine treatment exerts protective effect and attenuates free radical injury and immune dysfunction caused by subchronic phosphamidon exposure.

Influence of dietary ginger (Zingiber officinales Rosc) on antioxidant defense system in rat: comparison with ascorbic acid.

Ginger (Z. officinale; 1% w/w) significantly lowered lipid peroxidation by maintaining the activities of the antioxidant enzymes--superoxide dismutase, catalase and glutathione peroxidase in rats. The blood glutathione content was significantly increased in ginger fed rats. Similar effects were also observed after natural antioxidant ascorbic acid (100 mg/kg, body wt) treatment. The results indicate that ginger is comparatively as effective as ascorbic acid as an antioxidant.

Influence of dietary ginger (Zingiber officinales Rosc) on oxidative stress induced by malathion in rats.

Pesticide chemicals may induce oxidative stress leading to generation of free radicals and alterations in antioxidants or oxygen free radical (OFR) scavenging enzymes. Hence, the effect of subchronic malathion (O,O-dimethyl-S-1,2, bis ethoxy carbonyl ethyl phosphorodithioate) exposure was evaluated on lipid peroxidation, glutathione and related enzymes and OFR scavenging enzymes in albino rats. Administration of malathion (20 ppm) for 4 weeks increased the malondialdehyde (MDA) levels in serum, activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in erythrocytes and glutathione reductase (GR) and glutathione S-transferase (GST) in serum. However, it decreased the glutathione (GSH) level in whole blood. Concomitant dietary feeding of Zingiber officinales Rosc (ginger 1%, w/w) significantly attenuated malathion induced lipid peroxidation and oxidative stress in these rats. These results indicate the possible involvement of free radicals in organophosphate-induced toxicity and highlight the protective action of ginger, an indigenous medicinal plant product.

Evaluation of oxidative stress in some cases of argimone oil poisoning during a recent outbreak of epidemic dropsy in India.

The study was designed to evaluate the oxidative stress and modulation of anti-oxidant enzymes in 10 accidental argimone oil poisoning cases admitted in a hospital in Delhi, India during a recent outbreak of epidemic dropsy in 1998. Serum malondialdehyde (MDA) level, oxygen free-radical scavenging enzymes such as superoxide dismutase (SOD) and catalase (CAT), and glutathione (GSH) and related enzymes, e.g. glutathione reductase (GR), glutathione peroxidase (GPx), gamma glutamyl transpeptidase (GGT) and glutathione-S-transferase (GST) in erythrocytes were assayed. The sanguinarine level in serum was measured by high-performance liquid chromatography. The serum MDA level was higher and the GSH level in erythrocytes was lower in argimone oil poisoning cases than those in controls. There was a significant decrease in SOD and GPx activities in erythrocytes of epidemic dropsy cases but no changes were observed in CAT, GR and GST assay. The depletion of GSH in erythrocytes, serum MDA level and clinical severity were dependent on serum sanguinarine level. The results indicate that sanguinarine (argimone oil) poisoning creates an oxidative stress in humans. The oxidative stress and differential modulation of anti-oxidant enzymes by sanguinarine might play a pathogenic role in epidemic dropsy, which suggests the incorporation of anti-oxidant drugs in the treatment protocol of the disease.