4,374 research outputs found

    Thermomechanical treatment of austempered ductile iron

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    The production of lightweight ferrous castings with increased strength properties became unavoidable facing the serious challenge of lighter aluminum and magnesium castings. The relatively new ferrous casting alloy ADI offers promising strength prospects, and the thermo-mechanical treatment of ductile iron may suggest a new route for production of thin-wall products. This work aims at studying the influence of thermomechanical treatment, either by ausforming just after quenching and before the onset of austempering reaction or by cold rolling after austempering. In the first part of this work, ausforming of ADI up to 25% reduction in height during a rolling operation was found to add a mechanical processing component compared to the conventional ADI heat treatment, thus increasing the rate of ausferrite formation and leading to a much finer and more homogeneous ausferrite product. The kinetics of ausferrite formation was studied using both metallographic as well as XRD-techniques. The effect of ausforming on the strength was quite dramatic (up to 70% and 50% increase in the yield and ultimate strength respectively). A mechanism involving both a refined microstructural scale and an elevated dislocation density was suggested. Nickel is added to ADI to increase hardenability of thick section castings, while ausforming to higher degrees of deformation is necessary to alleviate the deleterious effect of alloy segregation on ductility. In the second part of this work, the influence of cold rolling (CR) on the mechanical properties and structural characteristics of ADI was investigated. The variation in properties was related to the amount of retained austenite (Ī³r) and its mechanically induced ransformation. In the course of tensile deformation of ADI, transformation induced plasticity (TRIP) takes place, indicated by the increase of the instantaneous value of strain-hardening exponent with tensile strain. The amount of retained austenite was found to decrease due to partial transformation of Ī³r to martensite under the CR strain. Such strain-induced transformation resulted in higher amounts of mechanically generated martensite. The strength and hardness properties were therefore increased, while ductility and impact toughness decreased with increasing CR reduction

    MICROWAVE-ASSISTED EXTRACTION OF BIO-ACTIVE COMPOUNDS (PHENOLICS AND ALKAMIDES) FROM ECHINACEA PURPUREA

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    Objective: Echinacea purpurea is used widely for its unspecific enhancement of the immune system. It contains multiple bioactive substances, including, phenolics (caffeic acid derivatives), flavonoids, anthocyanins and alkamides. In this currently investigation, efforts are focused on the evaluation of extraction techniques viz., conventional extraction (CE) and microwave-assisted extraction (MAE) for the regeneration of the active constituents of Echinacea purpurea. Methods: The aerial parts have been separately extracted with 80% methanol by two methods; CE and MAE. Identification of the isolated compounds was carried out by spectroscopic analysis viz., UV, TLC, 1H- NMR and MS. TLC scanner system and RP-HPLC with UV detection have been employed for the quantitative determination of caffeic acid derivatives and that of alkamides content in both extracts. Results: Chicoric and caftaric acids have been isolated and identified. The results of the TLC scanner system have revealed that the concentration is about 1.19 Ā± 0.02 and 1.35 Ā± 0.03 % (w/w) for caftaric and chicoric acid, respectively of the dry plant material extracted with CE, while the concentration is 1.81 Ā± 0.04 and 6.19 Ā± 0.26 % (w/w) for the two acids, respectively of the dry plant material extracted by MAE. The results of the HPLC have revealed that the concentration of alkamides is 0.25 and 0.33 % (w/w) of the dry plant material obtained with CE and MAE, respectively. Conclusion: Our study proved that MAE is a more effective technique compared to the CE. Extraction time was reduced, with the use of less solvent and the yield amount of the extracted active compounds was increased

    Effect of Calcium Soap of Fatty Acids Supplementation on Serum Biochemical Parameters and Ovarian Activity during Out-of-the-Breeding Season in Crossbred Ewes

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    This experiment aimed to evaluate the effect of calcium soap of fatty acid (CSFA) supplementation on serum biochemical and hormones and ovarian activity during out-of-the-breeding season in ewes. Twelve crossbred ewes, 2-3 years of age and weighting 45ā€“55ā€‰kg, were allocated into two equal groups. The first group was control and the other was treated with 50ā€‰g/head of CSFA. All ewes were fed basal diet and treated with 60ā€‰mg of medroxy progesterone acetate intravaginal sponge for 12 day. At the third day of sponge removal, the CSFA-treated group was given 50ā€‰g/head of CSFA daily for two estrous cycles. During the estrus phase, ovarian activity was detected using ultrasonography in both groups. All ewes were then subjected to natural breeding and conception rate. Blood samples were collected from all ewes during treatment period. Results revealed significant (P < 0.05) increases in serum cholesterol, triglycerides, low-density lipoprotein cholesterol, glucose, and progesterone levels with decrease in calcium and phosphorous levels in treated group. In treated group, normal-size ovaries and more than one follicle on the ovaries were detected and pregnancy rate increased. In conclusion, CSFA supplementation was effective to maintain the reproductive performance when ewes were out of the breeding season

    IgA-dominant post-infectious glomerulonephritis presenting as a fatal pulmonary-renal syndrome

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    Over the last decades, post-infectious glomerulonephritis underwent major changes in its epidemiology, pathophysiology, and outcomes. We are reporting a case of IgA-dominant post-infectious glomerulonephritis (IgA-PIGN) presenting as a fatal pulmonary-renal syndrome. An 86-year-old Filipino man presented with worsening dyspnea, hemoptysis, and decreased urine output over 2 weeks. Past medical history is significant for hypertension, chronic kidney disease stage III, and pneumonia 3 weeks prior treated with intravenous cefazolin for methicillin-sensitive Staphylococcus aureus bacteremia. Physical examination was remarkable for heart rate of 109/min and respiratory rate of 25/min saturating 99% on 3 liters via nasal cannula. There were bibasilar rales in the lungs and bilateral ankle edema. A chest radiograph showed bibasilar opacifications. Blood work was significant for hemoglobin of 8.3 g/dL and creatinine of 9.2 mg/dL (baseline of 1.67). TTE showed EF 55%. Urinalysis revealed large blood and red blood cell casts. Kidney ultrasound showed bilateral echogenicity compatible with renal disease. Pulse methylprednisolone therapy and hemodialysis were initiated with patient\u27s condition precluding kidney biopsy. Serology workup for rapidly progressive glomerulonephritis was negative. On day 7, the patient required mechanical ventilation; bronchoscopy showed alveolar hemorrhage and plasmapheresis was initiated. Renal biopsy revealed IgA-PIGN with endocapillary and focal extracapillary proliferative and exudative features. IgA-PIGN occurs in diabetic elderly (mean age of 60 years), 0-16 weeks after an infection mainly by Staphylococcus. However, this nondiabetic patient had normal complement IgA-PIGN with fatal pulmonary-renal syndrome. Understanding the pathogenesis and identifying the nephrotoxic bacteria species and the aberrant IgA molecule will open new insights toward prevention and treatment

    Major depression and disease activity among systemic lupus erythematosus Egyptian females

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    AbstractAim of the workThe aim of this study was to identify the relationship between disease activity in SLE Egyptian females and the presence, severity and pattern of major depression in these patients.Patients and methodsThe study sample included 100 female patients; fifty SLE patients and fifty healthy adults with matching age serving as control. Patients were assessed using Beck Inventory Score for the presence of major depression, SLEDAI to determine disease activity, SLICC/ACR damage index and HAQ score for functional disability.ResultsThe majority of patients had symptoms of major depression 32/50 (64%) based on Beck Inventory Score while in controls only 16/50 (36%) had major depression. The most common depressive symptoms in SLE patients were: Guilty feeling (92%), Self-dislike (91.6%), Self-criticalness (90.4%), Crying spells (87.5%), Loss of pleasure (83.3%), Change in appetite (83.3%), Agitation (82.8%) and Pessimism (82%). Patients with major depression presented a trend toward having greater severity of SLE disease activity compared with those without major depression (p=0.04). The presence of major depression was significantly associated with functional disability measured by HAQ score (p=0.01). The patients with major depression did not differ significantly from patients without major depression regarding their steroid dosage (p=0.55), SLICC/ACR damage score (p=0.16) and disease duration (p=0.69) but differed significantly as regards Beck Hopelessness Scale (p<0.0001) and suicidal ideation score (p=0.009).ConclusionMajor depression was highly presented in Egyptian SLE patients (64%); its severity was associated with disease activity, but not with steroid administration, cumulative damage or disease duration

    Heat and freezing pre-thermal treatments as a means of freeing potatoes from mosaic virus and its effects on potato plants quality characters

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    The aim of the study was to control of potato mosaic virus by using hot-air, hot-water and freezing as a physical pre-thermal treatments. Infected tubers of Lady Rosetta and Mondial potato (Solanum tuberosum L.) cultivars were treated by hot-air and hot-water treatments at 55Ā± 2 ĢŠ C and freezing treatment at -18Ā±2 ĢŠ C for 1, 2, 3 and 4 hours.Ā  Hot-air and freezing treatments showed complete elimination of mosaic virus from treated tubers. Hot-water treatment caused tuber damage at different exposure times. In this respect, hot-air treatment at 55Ā± 2 ĢŠ C and freezing treatment at -18Ā±2 ĢŠ C for two hours gave the best results of eliminating the virus from tubers and did not affect on economic characters of potato cultivars.

    Response of primiparous and multiparous buffaloes to yeast culture supplementation during early and mid-lactation

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    Strains of live Saccharomyces cerevisiae yeast have exhibited probiotic effects in ruminants. This study investigated the effects of the dietary yeast supplement, S. cerevisiae (Yea-Sacc1026), on primiparous (PP) and multiparous (MP) Egyptian buffaloes in early to mid-lactation. Lactating buffaloes were fed either a basal total mixed ration (TMR, control; 4Ā PP and 8Ā MP) or the basal TMR plus 10Ā g Yea-Sacc1026 per buffalo cow per day (yeast; 4Ā PP and 8Ā MP). The feeds were given from 15 days prepartum to 180 days postpartum. Feed intake, body weight, and milk yields (MY) were recorded, and milk and blood samples were collected for analyses. Feces were collected from days 45 to 47 during early lactation and from days 90 to 92 during mid-lactation to determine apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and crude fiber (CF). Energy corrected milk yield (ECM), feed conversion, and energy and nitrogen conversion efficiency were calculated. Yeast treated MP buffaloes consumed more DM (PĀ ā‰¤Ā 0.041) and CP than the untreated control group. Apparent digestibility of DM and OM were significantly greater at mid-lactation for treated versus control group (PĀ =Ā 0.001). Crude fiber digestibility was greater in MP than in PP buffaloes (PĀ =Ā 0.049), and yeast supplemented MP cows had a greater CF digestibility than control MP buffaloes at mid-lactation (PĀ =Ā 0.010). Total blood lipids decreased after yeast supplementation (PĀ =Ā 0.029). Milk yields, ECM, fat and protein yields increased for yeast treated MP buffaloes (PĀ ā‰¤Ā 0.039). The study concluded that the response to yeast supplementation in buffalo cows is parity dependent. Multiparous buffaloes respond to yeast supplementation with an increased DM intake and CF digestibility without significant weight gains, allowing a greater ECM yield with less fat mobilization. Supplementing buffaloes with yeast culture may increase milk production in early lactation and results in a more persistent milk production during mid-lactation. Feed conversion and energy and nitrogen conversion efficiency may be increased with the use of yeast supplementation in Egyptian buffaloes

    Major depression and disease activity among systemic lupus erythematosus Egyptian females

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    AbstractAim of the workThe aim of this study was to identify the relationship between disease activity in SLE Egyptian females and the presence, severity and pattern of major depression in these patients.Patients and methodsThe study sample included 100 female patients; fifty SLE patients and fifty healthy adults with matching age serving as control. Patients were assessed using Beck Inventory Score for the presence of major depression, SLEDAI to determine disease activity, SLICC/ACR damage index and HAQ score for functional disability.ResultsThe majority of patients had symptoms of major depression 32/50 (64%) based on Beck Inventory Score while in controls only 16/50 (36%) had major depression. The most common depressive symptoms in SLE patients were: Guilty feeling (92%), Self-dislike (91.6%), Self-criticalness (90.4%), Crying spells (87.5%), Loss of pleasure (83.3%), Change in appetite (83.3%), Agitation (82.8%) and Pessimism (82%). Patients with major depression presented a trend toward having greater severity of SLE disease activity compared with those without major depression (p=0.04). The presence of major depression was significantly associated with functional disability measured by HAQ score (p=0.01). The patients with major depression did not differ significantly from patients without major depression regarding their steroid dosage (p=0.55), SLICC/ACR damage score (p=0.16) and disease duration (p=0.69) but differed significantly as regards Beck Hopelessness Scale (p<0.0001) and suicidal ideation score (p=0.009).ConclusionMajor depression was highly presented in Egyptian SLE patients (64%); its severity was associated with disease activity, but not with steroid administration, cumulative damage or disease duration
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