Kinetic modelling and optimization of flotation process of electrum

The investigation of flotation as an alternative method to cyanide leaching of gold ores is significant in terms of economic and environmental aspects. In this study, a gold ore sample containing 4.79 ppm Au and 7.72 ppm Ag was used. Gold and silver were observed to be present as liberated electrum or associated with or within quartz, galena, and sphalerite. Initially, five-stage rougher flotation tests were conducted, and then three-stage scavenger circuits and four-stage cleaning flotation circuits were performed in order to obtain high-content gold concentrate and decrease losses of Au and Ag in tailings. As a result of tests, the flotation concentrate assayed as 437 ppm Au and 511 ppm Ag was obtained with recoveries of 76.3% and 58.5%, respectively. This study reveals that the concentrates ready for direct smelting without any additional process can be obtained with flotation. In order to determine kinetic characteristic of electrum in the sample, the tests were conducted using firstorder model, first-order model with rectangular distribution of rate constants, second-order model and second-order model with rectangular distribution of rate constant. The second-order model was considered as most reasonable for fitting the recoveries of gold as a function of flotation time during the flotation process

The photodegradation of a zinc phthalocyanine

A water-soluble zinc phthalocyanine (Pc), ZnPc (3), bearing 12 dimethylamino groups, which enhance the solubility of the macrocycle was synthesized and characterized. Photobleaching of the compound was examined both invivo and invitro. Laser irradiation causes photo-oxidation of the newly synthesized ZnPc. A photobleachable phthalocyanine can be an alternative in imaging; phthalocyanine dyes are used in imaging the cardiovascular system. Besides, it can be used in fluorescein angiography in some cases. When compared to stable ones, a photobleaching ZnPc (3) might be an attractive compound for imaging in medicine

Natural killer cells dominate a Th-1 polarised response in Behcet's disease patients with uveitis

Objective. Behcet's disease (BD) is a systemic inflammatory disorder of unknown aetiology, characterised by recurring relapses and remissions. BD manifetations have been thought to be associated with the immunological abnormalities triggered by environmental factors in genetically susceptible individuals. Natural killer (NK) cells are important members of innate immunity with their cytotoxic activity and also cytokine secretions. They have the capacity to induce or dampen immune responses. Different study groups have reported conflicting results about NK cell activity in the BD pathogenesis, however, contribution of NK cells to BD is still unclear

Autoimmune haemolytic anaemia and thrombocytopaenia in a single-centre cohort of patients with systemic lupus erythematosus from Turkey: clinical associations and effect on disease damage and survival.

Introduction Thrombocytopaenia and autoimmune haemolytic anaemia (AIHA) have considerable impact on prognosis in systemic lupus erythematosus (SLE). We investigated the frequencies of these haemocytopaenias, along with their associations and effect on outcome in a single-centre cohort of patients with SLE. Methods Demographic characteristics, clinical features, autoantibody profiles, damage and mortality data were compared between patients with and without each haematological abnormality. Variables displaying significant differences between the groups were entered into logistic regression. Results Ninety-three patients had AIHA and 215 had thrombocytopaenia. Both were associated with neuropsychiatric (NP) involvement, with each other, leucopaenia, antiphospholipid syndrome (APS) and antiphospholipid antibodies. More patients in both groups had organ damage, and their damage scores were higher. Association to NP damage was discernible. In addition, cardiovascular and renal damage and diabetes were more pronounced in patients with thrombocytopaenia. At logistic regression analysis, younger age, anticardiolipin antibody IgM positivity, leucopaenia and thrombocytopaenia were associated with AIHA whilst lupus anticoagulant activity, AIHA, leucopaenia, APS and NP involvement were associated with thrombocytopaenia. Among damage items, peripheral vascular damage, diabetes, NP damage, renal and ocular damage displayed significant associations with thrombocytopaenia, whereas none of the items did with AIHA. Patients with AIHA had significantly reduced survival rates at 10 and 20 years. Conclusions We observed that AIHA and thrombocytopaenia were associated with severe lupus, affecting major organs and causing end organ damage. Thus, they may be considered as prognostic markers. Furthermore, AIHA and especially thrombocytopaenia may also be a marker for a subgroup of lupus patients who have or may develop APS

Favourable pregnancy outcome in Takayasu arteritis: a single-centre experience.

Introduction. Takayasu arteritis is a chronic large-vessel vasculitis in young women of reproductive age. We aimed to obtain information on pregnancy in TA retrospectively

Adult-onset still's disease

Background: Adult-onset Still's disease (AOSD) is a febrile disorder of unknown aetiology characterised by typical spiking fever, evanescent rash, arthralgia and leucocytosis. Methods: According to the diagnostic criteria of AOSD, we identified 84 patients between 1990 and 2003. The aim of this study was to analyse the characteristics of AOSD in Turkish patients who were followed-up in a tertiary referral centre. Results: Of 84 patients of AOSD, 59 (70.2%) were female, 25 (29.8%) were male. Arthralgia (96.4%), fever (95.2%), arthritis (69%), sore throat (65.5%) and typical rheumatoid rash (59.5%) were the most common findings. The mean value of laboratory findings were as follows; C-reactive protein level of 11.59 +/- 6.81 mg/dl, erythrocyte sedimentation rate (ESR) of 89.05 +/- 31 mm/h, leukocyte count of 16,234.51 +/- 7785.2/mu l. Leucocytosis was present in 69 patients (84.15%). Forty-eight patients had a WBC count >= 15,000/mu l. Hypoalbuminaemia was present in 35 patients. Abnormal levels of aspartate aminotransferase and alanine aminotransferase were observed in 30 patients, whereas abnormal levels of alkaline phosphatase in 16 patients. Thirty-seven patients had an ESR value of more than 100 mm/h. Thirty-two patients had a ferritin value of more than 1000 ng/dl. Conclusion: High fever, sore throat, rheumatoid rash, polyarthritis, hyperferritinaemia (>= 1000 ng/ml), leucocytosis with a neutrophilic predominance, anaemia and hypoalbuminaemia were remarkable observations in the initial examination

Serum and urine TNF-like weak inducer of apoptosis, monocyte chemoattractant protein-1 and neutrophil gelatinase-associated lipocalin as biomarkers of disease activity in patients with systemic lupus erythematosus.

Objective

Metabolic syndrome is not only a risk factor for cardiovascular diseases in systemic lupus erythematosus but is also associated with cumulative organ damage: a cross-sectional analysis of 311 patients.

Background/Purpose Patients with systemic lupus erythematosus (SLE) have increased rates of cardiovascular disease (CVD) that are one of the major causes of mortality. The aim of this study was to determine the frequencies of metabolic syndrome (MetS) and CVD in SLE patients and investigate the link between these and clinical features of SLE