129 research outputs found

    Management of autoimmune hemolytic anemia in children and adolescents: A single center experience

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    Objective: To present and discuss the treatment of autoimmune hemolytic anemia (AIHA). Materials and Methods: The medical records of all patients (n=19) diagnosed in a tertiary hematology center between 1999 and 2010 were retrospectively reviewed.Results: Median age at diagnosis of AIHA was 5 years (range: 4 months-17 years). In all, 13 patients had primary (idiopathic) AIHA, whereas 2 had primary Evans Syndrome (ES), 2 had autoimmune lymphoproliferative syndrome (ALPS)+ES, and 1 had Wiskott-Aldrich syndrome (WAS)+AIHA. Among the 13 primary idiopathic AIHA patients, 9 recovered following a 4-8-week course of prednisolone treatment without relapses, whereas 3 patients required a longer course of prednisolone. One AIHA patient that was very resistant to prednisolone recovered after cyclosporine A was added to the treatment. All patients with primary idiopathic AIHA were in remission for a median of 3 years (range: 4 months-10 years) at the time this manuscript was written. Among the patients with primary ES, 2 had relapses similar to the ALPS patients. Splenectomy was performed in 1 primary ES patient, who at the time this report was written was also in remission. One ALPS patient required the addition of mycophenolate mofetil due to prednisolone resistance. The WAS patient was treatment resistant and died due to septicemia.Conclusions: Primary AIHA in pediatric patients generally has an acute onset and good response to corticosteroids. Primary or secondary ES has a chronic or relapsing course, and treatment may require other immunosuppressive agents in addition to corticosteroids. Complications of splenectomy must not be underestimated in patients with underlying immunodeficiency. AIHA often causes considerable morbidity and mortality in WAS

    Influence of pH on soluble substrate generation with primary sludge fermentation

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    Çalışma kapsamında pH’nın ön çökeltme çamuru fermentasyonu sonucu çözünmüş besi maddesi oluşumuna etkisi incelenmiştir. Bu kapsamda pH kontrollü ve konrolsüz koşullarda paralel deney setleri yürütülmüştür. 20°C sabit sıcaklıkta gerçekleştirilen ön çökeltme çamuru fermentasyonu sonucunda çözünmüş Kimyasal Oksijen İhtiyacı (KOİ) salımı ortalama 14 mg/L olarak hesaplanmıştır. Bu değere karşı gelen Uçucu Yağ Asiti (UYA) oluşumu ise 11.7 mg/L KOİ olarak hesaplanmıştır. Elde edilen bu değer, toplam biyolojik ayrışabilir KOİ içeriğinde %5 artışa karşı gelmektedir. Bu değere karşı gelen UYA üretimi ise ortalama 9.2 mg KOİ/L olarak belirlenmiştir. Fermentasyon sonrasında azot (0.4 mg/L) ve fosfor (0.1 mg/L) şeklinde besi maddesi salımlarının ihmal edilebilecek düzeyde olduğu gözlemlenmiştir. Yapılan bütün deneylerin sonucunda asetik asit üretimi toplam UYA’nın %45’inden fazlasını oluşturmuştur. Yüksek pH değerlerinde ve başlangıç UAKM değerlerinin arttığı durumlarda UYA’nın asetik asit içeriğinde düşüş, propiyonik asit ve C4-C5 asitlerinin oranlarında artış gözlenmiştir. Ön çökeltme çamurunda pH ayarının ve kontrolünün 5.5 ve 6 değerlerinde fermentasyon reaksiyonunu olumsuz yönde etkileyerek daha düşük konsantrasyonda UYA oluşumuna neden olduğu belirlenmiştir. Aynı zamanda pH ayarının ve kontrolünün 5.5 ve 6 değerlerinde asidojenik fazda gecikmeye ve reaksiyon süresinin uzamasına neden olduğu görülmüştür. Yüksek pH değerlerinde ise (pH 7.5) hidroliz fazında iyileşme saptanmış, ancak düşük pH değerlerinde olduğu gibi yüksek pH değerlerinin de asidojenik fazı olumsuz etkilediği gözlemlenmiştir. Çamurun başlangıç pH değerine yakın olan pH 6.5 ve 7 kontrollü setleri ise kontrolsüz setlerle aynı sonuçları verdiği için pH kontrolünün ekonomik anlamda uygulanabilir olmadığı belirlenmiştir. Anahtar Kelimeler: Besi maddesi giderimi, çözünmüş fermentasyon ürünleri, KOİ bileşenleri, kütle dengesi, uçucu yağ asitleri.A significant function of primary sludge fermentation is now regarded as the generation of soluble organic compounds, in particular Volatile Fatty Acids (VFAs), that are necessary for Biological Nutrient Removal (BNR) processes. VFAs are by nature readily biodegradable and therefore most suitable carbon source for denitrification. Their presence in sufficient quantity is also required for biological phosphorus removal systems. The merit of primary sludge fermentation is partial conversion of the settled Chemical Oxygen Demand (COD) into soluble and mostly readily biodegradable components and especially VFAs. In fact, pre-fermentation essentially sustains the first phase of anaerobic biodegradation. It is basically characterized by the generation of soluble COD. The study was undertaken to evaluate the effect of pH control on the generation of soluble fermentation products from primary sludge. The effect was tested by running parallel experiments under pH controlled and uncontrolled conditions. Primary sludge samples were taken from the Atakoy treatment plant, a small domestic wastewater treatment facility located in Istanbul, Turkey. The effect of pH on primary sludge fermentation was assessed using a series of experiments where the pH of the anaerobic reactor was sequentially adjusted and maintained at the following pH values: 5.5, 6, 6.5, 7, and 7.5 throughout the tests (controlled series). In fermentation experiments conducted at 20 ºC without pH control, the average soluble COD release was 14 mg per liter of wastewater treated, representing a potential increase of 5% in the biodegradable COD content of the primary sedimentation effluent. 27% lower VFA production was observed at pH 5.5, 18% at pH 6.0 and 12% at pH 7.5. The corresponding average VFA generation was 9.2 mg COD/L. Similarly, soluble COD generation was 10% lower at pH 5.5 and remained practically the same at pH 6.0. Increasing the pH to 7.5 resulted in 26% higher soluble COD generation indicating that higher pH favored hydrolysis but not acidification. Experimental assessment of VFAs composition indicated the predominance of acetic acid in fermentation products. In the majority of runs, the acetic acid fraction of the total VFA was over 45%. The average COD equivalent of VFAs was computed as 1.36 mg COD mg/L VFA for uncontrolled pH conditions. Increasing the pH level of primary sludge fermentation, the acetic acid percentage of the generated VFAs significantly decreased leading to the production of more propionic acid and C4?C5 (butyric, izobutyric, valeric ve izovaleric) acids. The highest percentage of the acetic acid production was around 70%, observed at pH 5.5. In experiments where pH was not controlled, the soluble TKN concentration released changed in the range of 75?175 mg/L with an average value of 97 mg/L, presumably depending on wastewater quality and resulting primary sludge characteristics. The soluble TKN represented on the average 2% of the VSS reduced, 4.6% of the soluble COD released and 5.7% of the VFA COD generated (0.057 mg N/mg CODVFA). Soluble P release was practically the same for experiments with pH controlled and uncontrolled runs with an average value of around 20 mg/L. This level corresponded to 1.3?1.4% of the VFA COD produced (0.013 mg P/mg CODVFA). Sludge fermentation experiments without pH control induced an average soluble COD release of 14 mg/L, which varied in the range of 8.4?19.6 mg COD/L. In terms of mass balance, this represents 5% of the biodegradable COD in the primary sedimentation effluent, which would be increased to 279 mg COD/L if the fermenter supernatant were to be added back to the effluent stream. The corresponding average VFA generation was calculated as 11.7 mg COD/L. Also, 0.6 mg/L of the nitrogen and 0.1 mg/L of phosphorus removed by settling were released with primary sludge fermentation. pH adjustment and control outside the initial pH of the primary sludge had a negative effect on VFA generation. Two general comments may be associated with the pH control (i) delay in acidification/ longer fermentation times (ii) lower VFA production. pH adjustment and control in the range of 5.5?6.0 had a negative effect on fermentation efficiency, mainly observed as lower VFA generation and delay in acidification and longer fermentation times. A similar negative effect was also observed when the pH was increased to 7.5. pH control in the 6.5?7.0 range, close to the initial pH of the primary sludge essentially yielded the same results and did not prove meaningful. Keywords: Nutrient removal, soluble fermentation products, COD fractions, mass balance, volatile fatty acids

    Effect of primary sludge fermentation products on mass balance for biological nutrient removal system

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    Ön çökeltme çamuru fermentasyonunun kolay ayrışabilir organik madde oluşturma potansiyeli ve karbon, azot ve fosfor olmak üzere oluşan ön çökeltme ürünlerinin kütle dengesine olan etkisi, laboratuvar ortamında, 20°C sabit sıcaklıkta gerçekleştirilen kesikli deneyler ile incelenmiştir. Fermentasyon sonucunda, ön çökeltme çamurundaki uçucu askıda katı madde’nin %18’den %30’a varan oranlarda çözünmüş biyolojik ayrışabilir KOİ’ye dönüştürüldüğü gözlenmiştir. Fermentasyon sonrasında, çözünmüş KOİ’nin %85’inin uçucu yağ asitlerinden oluştuğu belirlenmiştir. Uçucu Yağ Asitlerinin (UYA) dağılımı, %47 asetik asit, %35 propiyonik asit, %9 bütirik asit ve %9 valerik asit olarak bulunmuştur. Toplamda oluşan UYA’ların KOİ karşılığı 1.38 mg KOİ/ mg UYA olarak hesaplanmıştır. Biyolojik fermentasyon sonrasında elde edilen ve toplam uçucu yağ asitlerinin yaklaşık yarısını oluşturan asetat, denitirikasyon ve biyolojik besi maddesi gideren sistemlerde çok önemli bir karbon kaynağıdır. Ön çökeltme çamurunun fermentasyonu sonucunda, çözünmüş azot üretiminde 0.7 - 3.6 mg NH4-N/g KOİ ve çözünmüş fosfor üretiminde 0.3 - 0.8 mg PO4-P/g KOİ dönüşüm oranları belirlenmiştir. Fermentasyon ürünlerinin, 0.4’ten 0.1’e doğru düşen anoksik hacmin proses hacmine oranı (VDN/V) çalıştırma koşullarına bağlı olarak ön çökeltme çıkış akımında denitrifikasyon potansiyelini (NDP) %10 - 20 arasında arttırdığı görülmüştür. Fermente olmuş ön çökeltme çamurunun üst fazının geri kazanılabilen kısmı, çıkış akımının kolay ayrışabilir KOİ içeriğini %5 ve aynı zamanda çözünmüş azot ve fosfor içeriğini de %2 arttırabilmektedir. Anahtar Kelimeler: Aktif çamur, besi maddesi giderimi, çökelebilen KOİ, fermentasyon ürünleri, KOİ bileşenleri, kolay ayrışabilir KOİ, ön çökeltme.Nutrient removal from wastewater is the main concern, especially in areas sensitive to eutrophication. Coastal zones open to touristic activities require wastewater treatment involving maximum nutrient control in order to maintain the delicate balance between excessive land use and desired water quality. Effective biological nitrogen and phosphorus removal requires full utilization of the internal pool coming from the process influent. In most cases, primary settling is the commonly prescribed step before biological wastewater treatment. It removes a significant portion of the influent COD, around 30 to 40% in domestic sewage. Primary settling step is sometimes omitted to increase the internal carbon potential in cases where the magnitude of the COD available in the influent is critically limiting for the desired level of nutrient removal. It is a fact that, the nature and the biodegradation rate of the available carbon are important factors for an efficient system operation. The COD fractionation identifying fractions with different biodegradation rates has been a milestone in understanding and modeling the substrate utilization, especially in nutrient removal. This study evaluates mass balance applicable to internal organic carbon pool of domestic sewage in terms of different COD fractions, with the specific objective of investigating the potential of simple (uncontrolled) primary sludge fermentation for the generation of readily biodegradable substrate. Fermentation products were also evaluated by means of respirometric analyses. Batch experiments were conducted, at 20°C constant temperature, to investigate the potential of primary sludge fermentation for the generation of readily biodegradable substrate and to evaluate the effect of primary sludge fermentation products on mass balance including nitrogen and phosphorus. Limited fermentation without pH control converted 17% of the particulate COD removed from sewage by means of primary settling to simpler soluble compounds, mainly to VFAs through acidification of the sludge in the fermenter. Experimental evaluation shows that fermentation converted between 18 to 30% of the initial volatile suspended solids (VSS) in the sludge into soluble biodegradable COD. Approximately 85% of the soluble COD is volatile fatty acids after the fermentation process. The net yield giving the fraction of the total COD in the primary sludge converted into volatile fatty acids (VFA's) varied in the range of 0.095 to 0.19 g VFA COD/g COD. The average fraction of the VFA's in fermentation is 47% acetic acid, 35% propionic acid, 9% butyric acid and 9% valeric acid. Based on these observations, the COD equivalent of VFA was calculated as 1.38 mg COD/mg VFA. The recoverable fraction of the fermented sludge supernatant was calculated to have the potential of increasing the biodegradable COD content of the primary effluent by 5% and the readily biodegradable COD in the effluent by 30%. The results clearly showed that the predominant fermentation products are always acetic and propionic acid, independent of the values of the operational parameters. The most important volatile fatty acids obtained during the biological fermentation process is acetate with approximately half of total VFA concentration, which is one of the most important carbon source for denitrification and biological nutrient removal processes. Ammonium and phosphate release during biological fermentation process were less than 1% and 2%, respectively. Therefore, the fermentation may be used directly in the BNR process without any separation of ammonia and phosphate. Primary settling reduced NDP of the raw sewage by 17 to 29%, approaching the level of the COD fraction removed as VDN/V ratio increases. Fermentation products provided an additional denitrification potential of around 2 mg N/L, increasing NDP of the primary effluent in the range of 10 to 20% depending on the gradual decrease of the operating VDN/V ratio from 0.4 to 0.1. Model simulation indicated that fermentation products could improve the biological P removal potential of the primary effluent reducing the effluent P concentration from 2.7 mg P/L to 0.6 mg P/L. The recoverable fraction of the fermented sludge supernatant may potentially increase the readily biodegradable COD content of the primary effluent by 5% and soluble nitrogen and phosphorus content by 2%. Keywords: Activated sludge, nutrient removal, settleable COD, fermentation products, COD fractionation, readily biodegradable COD, primary settling

    Late haemorrhagic disease of the newborn

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    Abstract Background: Late haemorrhagic disease of the newborn (HDN) can occur owing to a lack of vitamin K prophylaxis, as a manifestation of an underlying disorder or idiopatically from the 8th day to 12 weeks after birth. Methods: Eight infants admitted to Kocaeli University Hospital with nine episodes of late HDN between January 2002 and April 2005 were evaluated retrospectively from hospital records. Results: The median age at presentation was 46 (26-111) days. All the infants were born at full-term to healthy mothers and were exclusively breast-fed. All had an uneventful perinatal history, except one who had meconium aspiration. Four patients had received no vitamin K prophylaxis and another three had uncertain histories. At presentation, six had intracranial bleeding and the remainder had bleeding either from the venepuncture site or the gastro-intestinal tract. The presenting signs and symptoms were irritability, vomiting, bulging or full fontanelle, convulsions and diminished or absent neonatal reflexes. Galactosaemia was detected in a 2-month-old infant with prolonged jaundice. There was no surgery-related mortality or complications but one survived for only 2 days on ventilatory support following surgery. Only one of the six survivors had severe neurological sequelae. Conclusions: Late HDN frequently presents with intracranial haemorrhage, leading to high morbidity and mortality. HDN can be the manifestation of an underlying metabolic disorder. Vitamin K prophylaxis of the newborn should be routine in developing countries

    Isotretinoin-induced spondyloarthropathy-related symptoms: A prospective study

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    Objective. Acne vulgaris is a chronic inflammatory disease involving the pilosebaceous unit of the skin. Isotretinoin is a systemic retinoid that is often used as an effective treatment option for severe and treatment-resistant acne. Isotretinoin may also cause rheumatologic symptoms. The aim of this prospective observational study was to present followup results regarding the rheumatologic symptoms of patients who received systemic therapy for the treatment of acne (isotretinoin and tetracycline). Methods. For inclusion in the study, all consecutive patients with acne who were aged > 18 years were evaluated by the same dermatologist. The first 42 consecutive patients were included in the isotretinoin group, and after matching for age and sex, 32 consecutive patients were included in the tetracycline group. Isotretinoin treatment was planned as an average dose of 30 mg daily and a total dose of 120-150 mg/kg for 4-6 months. The patients were administered a dose of 1 g/day of tetracycline as 2 equal doses for 3 months. Results. Forty-two patients diagnosed with acne vulgaris were treated with isotretinoin 20.6 ± 4.4 (male/female: 17/22), and 32 patients were treated with tetracycline 20.6 ± 2.7 (male/female: 8/24). There was no significant difference between the 2 groups with respect to age and sex. Unilateral Achilles enthesopathy developed in 3 patients, whereas both Achilles enthesopathy and unilateral sacroiliitis developed in 1 patient. Inflammatory back pain developed in 6 patients in the isotretinoin group. Conclusion. To our knowledge, this was the first prospective observational study that assessed the rheumatologic symptoms of isotretinoin treatment. The spondyloarthropathy findings were identified in 23.1% of the patients who used isotretinoin

    Model based process optimization of enhanced wastewater treatment plants

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    Avrupa Birliği’ne uyum sürecinde ele alınan atık sorunu kapsamında, alıcı ortamlara yapılacak deşarjlarda konvansiyonal parametrelerin yanısıra azot ve fosfor (besi maddesi) parametrelerinin de belli standart değerlerin altına indirilmesi gerekli hale gelmiştir. Bu nedenle, “Kentsel Atıksu Arıtımı Yönetmeliği, 2006” ile uyum sürecinde olan ülkemizde azot ve fosfor standartları mevzuatımıza dâhil edilmiştir. “Kentsel Atıksu Arıtımı Yönetmeliği, 2006” kapsamında mevcut tesislerin besi maddesi giderimine yönelik olarak geliştirilmesi, yeni kurulacak tesislerin ise besi maddesi giderecek şekilde en uygun arıtma teknolojisi kavramı çerçevesinde boyutlandırılması gereklidir. Besi maddesi giderimine yönelik en uygun arıtma teknolojisi biyolojik prosesler, bunlar arasında en ekonomik çözüm ise aktif çamur sistemleri olarak tanımlanmaktadır. Bu çalışma aktif çamur tesislerinin, Avrupa Birliği normlarında performansını sağlayabilecek optimum tasarım ve işletme süreçlerinin değerlendirilmesini amaçlamaktadır. Bu kapsamda, bir örnek olarak ele alınan İstanbul Su ve Kanalizasyon İdaresi (İSKİ) Paşaköy İleri Biyolojik Atıksu Arıtma Tesisi’nde mevcut durumda atıksu karakterizasyonu ve sistem performansı deneysel olarak belirlenmiş, elde edilen bilgiler kullanılarak sürekli kullanıma uygun olacak model-bazlı tasarım ile işletme simülasyon programları hazırlanmış ve işletme optimizasyonu çerçevesinde çıkış besi maddesi konsantrasyonlarının düşürülmesi amacıyla işletme senaryoları oluşturularak önerilerde bulunulmuştur. Yürütülen senaryo analizleri ile, havalandırma tanklarındaki çözünmüş oksijen seviyelerinin uygun ayarlanması, tesisin geri devir denitrifikasyonu prensibi yerine A2O veya UCT tipi sistem şeklinde işletilmesi ile sistem veriminin arttırılabileceği ve dolayısıyla çıkış besi maddesi konsantrasyonlarının azaltılabileceği belirlenmiştir. Anahtar Kelimeler: İleri biyolojik atıksu arıtma tesisi, atıksu karakterizasyonu, model-bazlı tasarım, işletme optimizasyonu.The Urban Wastewater Treatment Directive published in the Official Gazette No. 26047 of 08.01.2006 was adapted from the “The Council Directive (91/271/EEC)” concerning urban waste-water treatment was accepted in European Union Countries, which imposes enforcements about the collection and treatment of wastewater. This directive requires that also nitrogen and phosphorus (nutrients) to be removed together with the conventional parameters. In this context, it is very important to follow and apply the technological advances while the harmonization of legislations in Turkey with European Union Standards. Mathematical models are frequently used for the design and optimum operation of wastewater treatment systems. In order to use the activated sludge models for the process design and control, it is crucial to understand the behavior of complex biological reactions under steady and dynamic conditions. The initial step for the use of models should be, a model calibration according to the data obtained from the treatment plant and an analysis of the behavior of the treatment plant under dynamic influent and environmental conditions (Vanrolleghem et al., 2003). After the calibration of the prepared model according to the operational conditions of the treatment plant, the model can be used for the optimization of the plant, meeting the effluent quality standards, minimizing operational costs and for developing appropriate process control strategies. On the other hand the effect of changes in the process conditions on the model stability should be taken into consideration (Insel et al., 2007). The aim of this study was to evaluate the optimum design and operational criteria of advanced biological wastewater treatment plants by applying international monitoring and evaluation mechanisms that will increase the performance to norms required in the European Union. Accordingly, İSKİ Paşaköy Advanced Biological Wastewater Treatment Plant (ABWWTP) was chosen as a model plant and in the first stage on influent wastewater characterization, chemical oxygen demand (COD) fractionation and performance of the activated sludge system were experimentally determined. In the second stage, using the dimensions of the İSKİ Paşaköy ABWWTP units and the experimentally determined operational parameters, model calibration studies were conducted. On this context, theoretical parameters of model-based design and operational simulation programs applied for the plant were evaluated. In the last stage of the study, for operational optimization, according to the results obtained from the experimental and simulation studies conducted at İSKİ Paşaköy ABWWTP, operational scenarios were developed and suggestions were made. In the scenario analysis reduction of effluent phosphorus and total nitrogen concentration was aimed and the effect of (i) the aeration system control, (ii) recycle denitrification (iii) influent VFA concentration was analyzed and the effect of (iv) different system configurations was evaluated. The results of statistical data analysis of wastewater characterization studies conducted at İSKİ Paşaköy Advanced Biological Wastewater Treatment Plant aiming nitrogen and phosphorus removal revealed that due to low influent Chemical Oxygen Demand (COD), Total Kjeldahl Nitrogen (TKN), Total Phosphorus (TP) and Volatile Fatty Acids (VFA) concentrations, high efficiencies of biological phosphorus removal was not achievable. According to the scenario analysis performed for the treatment plant it has been concluded that it is possible to increase the removal efficiency of the system and achieve lower effluent total nitrogen and phosphorus concentrations by setting the dissolved oxygen levels to appropriate levels and operating the systems as an A2O or a UCT type system instead of a recycle denitrification system. It has been concluded that if the scenario analyses were applied it is not possible to meet the European Union Effluent Quality Standard of 1.0 mg/l for the phosphorus parameter. Experimental and model based studies have to be conducted for the installation of a fermentation process together with different system configurations that are required to meet the effluent quality standard by biological treatment. Keywords: Paşaköy wastewater treatment plant, wastewater characterization, model based optimization, process control

    Impact of laboratory test use strategies in a Turkish hospital

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    Objectives: Eliminating unnecessary laboratory tests is a good way to reduce costs while maintain patient safety. The aim of this study was to define and process strategies to rationalize laboratory use in Ankara Numune Training and Research Hospital (ANH) and calculate potential savings in costs. Methods: A collaborative plan was defined by hospital managers; joint meetings with ANHTA and laboratory professors were set; the joint committee invited relevant staff for input, and a laboratory efficiency committee was created. Literature was reviewed systematically to identify strategies used to improve laboratory efficiency. Strategies that would be applicable in local settings were identified for implementation, processed, and the impact on clinical use and costs assessed for 12 months. Results: Laboratory use in ANH differed enormously among clinics. Major use was identified in internal medicine. The mean number of tests per patient was 15.8. Unnecessary testing for chloride, folic acid, free prostate specific antigen, hepatitis and HIV testing were observed. Test panel use was pinpointed as the main cause of overuse of the laboratory and the Hospital Information System test ordering page was reorganized. A significant decrease (between 12.6-85.0%) was observed for the tests that were taken to an alternative page on the computer screen. The one year study saving was equivalent to 371,183 US dollars. Conclusion: Hospital-based committees including laboratory professionals and clinicians can define hospital based problems and led to a standardized approach to test use that can help clinicians reduce laboratory costs through appropriate use of laboratory test
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