Effects of black liquor shocks on activated sludge treatment of bleached kraft pulp mill wastewater

Kraft pulp mills use activated sludge systems to remove organic matter from effluents. Process streams may appear as toxic spills in treatment plant effluents, such as black liquor, which is toxic to microorganisms of the activated sludge. The present study evaluates the effects of black liquor shocks in activated sludge systems. Four black liquor shocks from 883 to 3,225 mg chemical oxygen demand-COD L(-1) were applied during 24 hours in a continuously operating lab-scale activated sludge system. Removal efficiencies of COD, color and specific compounds were determined. Moreover, specific oxygen uptake rate (SOUR), sludge volumetric index (SVI) and indicator microorganisms were evaluated. Results show that the addition of black liquor caused an increase in COD removal (76-67%) immediately post shock; followed two days later by a decrease (-19-50%). On the other hand, SOUR ranged between 0.152 and 0.336 mgO2 g(-1) volatile suspended solids-VSS• min(-1) during shocks, but the initial value was reestablished at hour 24. When the COD concentration of the shock was higher than 1,014 mg/L, the abundance of stalked ciliates and rotifers dropped. Finally, no changes in SVI were observed, with values remaining in the range 65.8-40.2 mL g(-1) total suspended solids-TSS during the entire operating process. Based on the results, the principal conclusion is that the activated sludge system with the biomass adapted to the kraft pulp effluent could resist a black liquor shock with 3,225 mgCOD L(-1) of concentration during 24 h, under this study's conditions.

Spermatozoa from mice deficient in Niemann-Pick disease type C2 (NPC2) protein have defective cholesterol content and reduced in vitro fertilising ability

The cholesterol content of the sperm membrane is regulated during both maturation in the epididymis and capacitation in the female tract, two processes required for the spermatozoa to acquire their fertilising ability. Because Niemann-Pick disease, type C2 (NPC2) protein is one of the most abundant components of the epididymal fluid and contains a functional cholesterol-binding site that can transfer cholesterol between membranes, it has been suggested for years that NPC2 could be involved in the regulation of cholesterol levels in spermatozoa during epididymal maturation. In the present study, western blot and immunohistochemistry analyses demonstrated significant levels of NPC2 in the mouse epididymal epithelium. Epididymal spermatozoa obtained from NPC2(-/-) mice were morphologically normal and had normal motility parameters, but had a reduced cholesterol content compared with that of wild-type (WT) spermatozoa, as determined by both biochemical and by flow cytometry analyses. These results suggest that NPC2 could be involved in regulating cholesterol levels in spermatozoa during epididymal maturation. To understand the relevance of epididymal NPC2 for sperm function, the ability of spermatozoa to undergo events influenced by epididymal maturation, such as capacitation and fertilisation, were compared between WT and NPC2(-/-) mice. Capacitated NPC2(-/-) spermatozoa exhibited defective tyrosine phosphorylation patterns and a reduced ability to fertilise cumulus-oocyte complexes compared with WT spermatozoa, supporting the relevance of mouse epididymal NPC2 for male fertility.

How To Achieve Durable Pulmonary Vein Antral Isolation?

The inability to achieve durable pulmonary vein isolation(PVI) remains a major limitation to a catheter ablation for thew treatment of atrial fibrillation(AF), potentially resulting in AF recurrence.In this review,we discuss the research performed investigating methods to improve lesion permanence for the goal of durable PVI.Investigations evaluted procedural techniques,various catheres utilized, adjunctive pharamacologic therapy and novel energy sources designed to improve ablation lesion permanence are discussed.

Cardiac myxoma with prenatal diagnosis

The presentation of myxoma in the neonatal period is quite rare. We report the case of a female patient in whom two cardiac tumors were diagnosed prenatally. Surgery was performed at eight days of age, using cardiopulmonary bypass and circulatory arrest to facilitate excision of two polypoid tumors from within the right atrium. Pathology studies were consistent with myxoma. The postoperative course was satisfactory and the patient was discharged 14 days after surgery, at 22 days old.

Niemann-Pick C2 protein expression regulates lithogenic diet-induced gallstone formation and dietary cholesterol metabolism in mice

Niemann-Pick C2 protein (NPC2) is a lysosomal soluble protein that is highly expressed in the liver; it binds to cholesterol and is involved in intracellular cholesterol trafficking, allowing the exit of lysosomal cholesterol obtained via the lipoprotein endocytic pathway. Thus, this protein may play an important role in controlling hepatic cholesterol transport and metabolism. The aim of this work was to study the relevance of NPC2 protein expression in hepatic cholesterol metabolism, biliary lipid secretion and gallstone formation by comparing NPC2 hypomorph [NPC2 (h/h)] and wild-type mice fed control, 2% cholesterol, and lithogenic diets. NPC2 (h/h) mice exhibited resistance to a diet-induced increase in plasma cholesterol levels. When consuming the chow diet, we observed increased biliary cholesterol and phospholipid secretions in NPC2 (h/h) mice. When fed the 2% cholesterol diet, NPC2 (h/h) mice exhibited low and high gallbladder bile cholesterol and phospholipid concentrations, respectively. NPC2 (h/h) mice fed with the lithogenic diet showed reduced biliary cholesterol secretion, gallbladder bile cholesterol saturation, and cholesterol crystal and gallstone formation. This work indicates that hepatic NPC2 expression is an important factor in the regulation of diet-derived cholesterol metabolism and disposal as well as in diet-induced cholesterol gallstone formation in mice.

In vitro activity of retapamulin against linezolid and methicillin-resistant Staphylococcus aureus isolates

OBJECTIVES

To determine the in vitro activity of retapamulin and other topical antibiotics (mupirocin, bacitracin, and fusidic acid) usually employed for nasal decolonization, against methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and linezolid and methicillin-resistant S. aureus.

METHODS

The minimum inhibitory concentrations (MICs) were determined on Mueller-Hinton agar according to the guidelines of the Clinical and Laboratory Standards Institute and of the European Committee for Antimicrobial Susceptibility Testing. Presence of the cfr gene in linezolid and methicillin-resistant S. aureus isolates was detected using polymerase chain reaction.

RESULTS

Retapamulin inhibited all the isolates of MSSA and MRSA at 0.125 mg/L, but the 18 linezolid-resistant-MRSA strains proved resistant, with MICs over 32 mg/L. Most MSSA isolates (9/10) were susceptible to mupirocin with MICs under 0.19 mg/L, although this value decreased to half against MRSA, and almost all linezolid-resistant MRSA (17/18) strains were resistant to mupirocin with an MIC range of between 8 mg/L and 28 mg/L. The MIC of fusidic acid increased substantially against linezolid-resistant MRSA, whereas that of bacitracin showed no differences.

CONCLUSIONS

Retapamulin demonstrated excellent in vitro activity against MSSA and MRSA strains, but not against MRSA isolates harbouring the cfr gene. The results of this in vitro study support cut-off values for retapamulin of ≤ 0.5, 1, and ≥ 2 mg/L for susceptible, intermediate, and resistant strains, respectively.

[Causes, characteristics and mid-term course of acute urinary retention in women referred to a urodynamics unit]

OBJECTIVES

Acute urinary retention (AUR) is uncommon in women and can be related to different conditions. Only some patients are referred to the urodynamics units for a more extensive study. We intend to describe the charcteristics and causes of AUR in women referred to our unit and to analyze their middle term evolution.

MATERIAL AND METHODS

We performed a descriptive retrospective study (January 1982-December 2006), including the women referred to our Uro-Neurology and Urodynamics Unit after suffering an AUR. Medical charts were reviewed with special emphasis on medical history, physical examination, and also complete urodynamics study during the AUR event and after its resolution.

RESULTS

A total of 202 women were included, median age of 57 years (12-87 years). Prior to the AUR, 59 women (28.7%) reported voiding symptoms. The urodynamics findings were: 65 (32.2%) detrusor hypocontractility; 64 (31.7%) normal study; 37 (18.3%) detrusor acontractility; 21 (10.4%) bladder outlet obstruction; 15 (7.4%) poor pelvic floor relaxation. The causes of the AUR were: 53 neurological (26.2%); 46 unknown (22.8%); 19 gynecological (9.4%); 22 diabetes mellitus (10.9%); 16 urological (7.9%). Renal insufficiency was observed in 14 patients (6.9%). After the AUR 106 women (52.4%) needed some kind of prolonged treatment.

CONCLUSIONS

In our experience, AUR in the female is mainly related to underlying neurologic/urogynecologic disease, even though the etiology could not be known in a significant percentage of patients. Half of the patients recovered completely and did not require any treatment.

Texture Analysis of Al and Cu Metallization Materials Using Orientation Imaging Microscopy

X-ray diffraction (XRD) is generally used to measure crystallographic texture, but complete analysis is rarely performed. Orientation imaging microscopy (OIM) gives similar data by electron diffraction and has potential for widespread use since it may be added to any scanning electron microscope. Analysis software has been developed to reduce QIM results into a form which may be compared directly to XRD results. OIM texture parameters measured from Al films showed good quantitative agreement with XRD parameters, however the texture in Cu films is more complex and difficult to compare. Although subject to certain limitations, OIM has several advantages over XRD including more efficient data collection, better sensitivity to minor texture components, and more flexible data analysis.

[Basic techniques of electroencephalography: principles and clinical applications]

The electroencephalogram is a technique for the functional exploration of the central nervous system (CNS). It is a relatively old technique but even today it continues to be a tool of great assistance to the clinician in diagnosing and treating certain pathologies, such as epilepsy, encephalopathies, alterations to the state of consciousness, CNS infections, etc. On the other hand, it is a diagnostic tool whose applications are expanding in combination with other neurophysiological techniques, such as in the field of the study and diagnosis of sleep pathology (polysomnography, multiple sleep latency test...) and in intraoperative monitoring together with somasensory evoked potentials. This article describes the basic techniques of electroencephalography, with special emphasis on its main clinical applications and on future perspectives.

[Narcolepsy: update on etiology, clinical features and treatment]

Narcolepsy is a disease that involves an alteration in the generation and organisation of sleep. The main symptoms are excessive daytime sleepiness and cataplexy, followed by hypnagogic hallucinations, sleep paralysis and disrupted nocturnal sleep. The prevalence of typical narcolepsy oscillates between 25-50: 100.000 in general. Recently there has been a peak incidence in patients born in the month of March. According to the new classification, the Multiple Sleep Latency Test (MSLT) is mandatory for diagnosing narcolepsy without cataplexy, and advisable for diagnosing narcolepsy with cataplexy. Until now, the attempt has been made to control each symptom by its own specific treatment. At present, new American and European treatment guidelines propose new drugs that act on all the symptoms. The application of new criteria of diagnosis and treatment has improved the diagnosis, giving better options of treatment.