Effect of FeCl3 concentration in chemically enhanced primary treatment on the performance of a conventional wastewater treatment plant. A case study.

The effect of coagulant dosage in a chemically enhanced primary treatment (CEPT) on the performance of a conventional wastewater treatment plant (WWTP) has been investigated. Lab-scale experiments simulations were carried out in order to evaluate the effect of coagulant addition on the primary settling performance. In these experiments, FeCl3 was used as coagulant. Later, the WWTP was theoretically simulated using a commercial software (WEST®) to evaluate the effect of coagulation/flocculation on the global system, based on the results obtained at lab-scale. According to these results, the CEPT modifies the organic matter balance in the WWTP, decreasing the contribution of readily (SS) and slowly (XS) biodegradable fractions of COD to the aerobic biological process up to 27.3% and 80.8%, respectively, for a dosage of FeCl3 of 24 mg L-1. Consequently, total suspended solids in the aerobic reactor and the secondary purged sludge decreased up to 33% and 13%, respectively. However, the influence on effluent quality was negligible. On the contrary, suspended solids concentration in the sludge to be treated by anaerobic digestion increased, mainly regarding the Ss and Xs fractions, which caused an 8.1% increase in biogas production potential, with approximately 60% of CH4 concentration.

Population pharmacokinetics of levetiracetam in neonates with seizures.

WHAT IS KNOWN AND OBJECTIVE: This study developed a population pharmacokinetic (PK) model of levetiracetam (LEV) for treating neonatal seizures (NS) and determined the influence of clinically relevant covariates to explain the interindividual variability and residual error. METHODS: Twenty newborns admitted to the Neonatal Intensive Care Unit at the Hospital Central "Dr. Ignacio Morones Prieto" were included. LEV doses were administered by intermittent infusion. Blood samples were drawn 3 times post-infusion. Levetiracetam was quantified by a chromatographic technique. NONMEM software was used to determine the population PK model of LEV in neonates and the influence of clinical covariates on drug disposition. RESULTS AND DISCUSSION: The LEV PK in neonates is described by a one-compartment open model with first-order elimination. The influence of creatinine clearance (CRCL) and body weight (BW) on clearance (CL[L/h] = 0.47*CRCL), as well as the volume of the distribution (Vd[L] = 0.65*BW) of LEV, were confirmed, considering interindividual variabilities of 36% and 22%, respectively, and a residual error of 13%. WHAT IS NEW AND CONCLUSION: Based on the PK of LEV in neonates and the influence of the final PK model, a priori dosing guidelines are proposed considering CRCL, BW and LEV plasma concentrations between 6 and 20 mg/L for NS treatment.

Ultrasonic irradiation for ultrafiltration membrane cleaning in MBR systems: operational conditions and consequences.

Ultrasonic irradiation is one of the most promising membrane cleaning techniques for membrane bioreactors (MBRs) because of several advantages such as high flux-recovery capacity and in situ application without interrupting the filtration process. However, significant contradictions may be found and, consequently, this method has not yet been widely developed. In this paper, four MBRs equipped with hollow-fibre polyvinylidene fluoride ultrafiltration membranes were operated continuously. The cleaning method applied consisted of sonication at low power (15 W) with different frequencies (20, 25, 30, and 40 kHz) for each module and aerated backwashing. The different MBRs were analysed comparatively between them and with a conventional MBR in order to check the effects of the irradiated waves on membrane integrity, effluent quality and process performance. Effluent turbidity and chemical oxygen demand, total and volatile suspended solid concentration and activated sludge viscosity were affected by biomass fragmentation or membrane cake removal, mainly at lower frequencies. The best transmembrane pressure control was achieved at the frequency of 20 kHz without a significant effect on membrane integrity. The results showed that under these operational conditions, no negative effects on effluent quality or membrane integrity were found, suggesting that this method was suitable for this type of membrane.

Cardiovascular Risk Factors and Carotid Intima-Media Thickness in a Colombian Population With Psoriasis. / Factores de riesgo cardiovascular y grosor de la íntima media carotídea en una población colombiana con psoriasis.

BACKGROUND AND OBJECTIVES: Psoriasis is now known to have a clear association with metabolic syndrome and its components. The aim of our study was to determine the prevalence of cardiovascular risk factors (CVRFs) and increased carotid intima-media thickness in psoriasis patients seen in the dermatology department of a quaternary hospital. MATERIAL AND METHODS: This was a descriptive cross-sectional study of psoriasis patients aged over 18 years seen in the dermatology department of Hospital de San José in Bogota, Colombia, between March and August, 2015. Directed medical history and physical examination were performed to detect CVRFs, laboratory studies to exclude metabolic syndrome, and ultrasound examination to measure carotid intima-media thickness. RESULTS: Forty patients with psoriasis were included in the study. The prevalence of the distinct CVRFs was 35% for systemic hypertension, 17.5% for dyslipidemia, 17.5% for smoking, and 10% for type 2 diabetes mellitus. A history of acute myocardial infarction was detected in 12.5% of patients. Metabolic syndrome was found in 20 patients (50%), and blood biochemistry revealed dyslipidemia in 32 patients (80%). Based on the Framingham score, the cardiovascular risk was low in 11 patients (31.4%), intermediate in 22 (62.8%), and high in 2 (5.7%). Mean (SD) carotid intima-media thickness was 0.7 (0.12) mm, with thickening observed in 6 patients (15%). CONCLUSIONS: This study provides evidence of the high prevalence of CVRFs in psoriasis patients and indicates the need for strict clinical control to monitor cardiovascular risk in this population.

Sensitivity analyses and simulations of a full-scale experimental membrane bioreactor system using the activated sludge model No. 3 (ASM3).

An ASM3-based model was implemented in the numerical software MATHEMATICA where sensitivity analyses and simulations of a membrane bioreactor (MBR) system were carried out. These results were compared with those obtained using the commercial simulator WEST. Predicted values did not show significant variations between both software and simulations showed that the most influential operational conditions were influent flow rate and concentrations and bioreactor volumes. On the other hand, sensitivity analyses were carried out with both software programs for the same five outputs: COD, ammonium and nitrate concentrations in the effluent, total suspended solids concentration and oxygen uptake rate in the aerobic bioreactor. Similar results were in general obtained in both cases and according to these analyses, the most significant inputs over the model predictions were growth and storage heterotrophic biomass yields and decay coefficient. Other parameters related to the hydrolysis process or to the autotrophic biomass also significantly influenced model outputs.

The extremophile Acidithiobacillus ferrooxidans possesses a c-di-GMP signalling pathway that could play a significant role during bioleaching of minerals.

AIMS: The primary goal of this study was to characterize the existence of a functional c-di-GMP pathway in the bioleaching bacterium Acidithiobacillus ferrooxidans. METHODS AND RESULTS: A bioinformatic search revealed that the genome sequence of At. ferrooxidans ATCC 23270 codes for several proteins involved in the c-di-GMP pathway, including diguanylate cyclases (DGC), phosphodiesterases and PilZ effector proteins. Overexpression in Escherichia coli demonstrated that four At. ferrooxidans genes code for proteins containing GGDEF/EAL domains with functional DGC activity. MS/MS analysis allowed the identification of c-di-GMP in nucleotide preparations obtained from At. ferrooxidans cells. In addition, c-di-GMP levels in cells grown on the surface of solid energetic substrates such as sulfur prills or pyrite were higher than those measured in ferrous iron planktonic cells. CONCLUSIONS: At. ferrooxidans possesses a functional c-di-GMP pathway that could play a key role in At. ferrooxidans biofilm formation during bioleaching processes. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first global study about the c-di-GMP pathway in an acidophilic bacterium of great interest for the biomining industry. It opens a new way to explore the regulation of biofilm formation by biomining micro-organisms during the bioleaching process.

Respirometric assays of two different MBR (microfiltration and ultrafiltration) to obtain kinetic and stoichiometric parameters.

A comparison of two different medium scale MBRs (ultrafiltration and microfiltration) using respirometric methods has been achieved. The ultrafiltration membrane plant (0.034 microm pore size) maintained recirculation sludge flow at seven times the influent flow, and membranes were backwashed every 5 min and chemically cleaned weekly. The microfiltration membrane plant (0.4 microm pore size) maintained recirculation sludge flow at four times the influent flow, membrane-relax was applied after the production phase and membranes were chemically cleaned in the event of high trans-membrane pressure. Both technologies showed a similar performance with regard to heterotrophic kinetic and stoichiometric parameters and organic matter effluent concentrations. The influent was characterized by means of its COD fractions and the average removal percentages for COD concentrations were around 97% for both plants in spite of influent COD fluctuation, temperature variations and sludge retention time (SRT) evolution. Both SRT evolution and temperature affect the heterotrophic yield (Y(H)) and the decay coefficient (bH) in the same range for both plants. Y(H) values of over 0.8 mg COD/mg COD were obtained during the unsteady periods, while under steady state conditions these values fell to less than 0.4 mg COD/mg COD. bH by contrast reached values of less than 0.05 d(-1).

A diversity of U1 small nuclear RNAs in the silk moth Bombyx mori.

Variants of U1 small nuclear RNAs (snRNAs) have been previously detected in a permanent cell line (BmN) of the silk moth Bombyx mori. In this study, the existence of U1 snRNA isoforms in the silk gland (SG) of the organism is investigated. The polyploidy (approximately 200,000X the 2N somatic value) state of the B. mori silk gland cells represents a unique system to explore the potential presence and differential expression of multiple U1 variants in a normal tissue. B. mori U1-specific RT-PCR libraries from the silk gland were generated and five U1 isoforms were isolated and characterized. Nucleotide differences, structural alterations, as well as protein and RNA interaction sites were examined in these variants and compared to the previously reported isoforms from the transformed BmN cell line. In all these SG U1 variants, variant sites and inter-species differences are located in moderately conserved regions. Substitutional or compensatory changes were found in the double stranded areas and clustered in moderately conserved regions. Some of the changes generate stronger base pairing. Calculated free energy (DeltaG) values for the entire U1 snRNA secondary structures and for the individual stem/loops (I, II, III and IV) domains of the isoforms were generated and compared to determine their structural stability. Using phylogenetic analysis, an evolutionary parallelism is observed between the polymorphic sites in B. mori and variant locations found among animal and plant species.

Studies on the interaction between antitrypanosome cis-DDP analogs with DNA.

The nature of the conformational changes produced in DNA by cis-DDP analogs has been studied by physiochemical techniques. The UV spectra showed that the DNA undergoes bathochromic shifts accompanied by hyperchromic effects in reaction with specific analogs (cis-Pt(DDH) (mucobromic)2, cis-Pt(tranilcypromine)2Cl2 and cis-Pt(DDH) Cl2), while a different series of analogs (cis-Pt(DDH) (metafluorobenzoic)2 and cis-Pt(pentamidine)Cl2) induce a significative decrease in the absorbance at 258 nm. Moreover one of these analogs (cis-Pt(pentamidine)Cl2) causes strong stabilization of the double helix to heat denaturation. The CD spectra indicate moreover that cis-Pt(pentamidine)Cl2 modifies the secondary structure of the DNA in a significant way with an increase of the positive band and a decrease of the ellipticity of the negative band. The antitrypanosome activity of cis-Pt(pentamidine)Cl2 is probably due to inhibition of the intracellular parasites division in parasitized cells.

Evaluation of complications due to percutaneous renal biopsy in allografts and native kidneys with color-coded Doppler sonography.

We studied 142 consecutive percutaneous renal biopsies (puncturing on 73 allografts and 69 native kidneys) which were performed under continuous ultrasonic guidance, on 133 adult patients. The patients were monitored, at least, during the next 24 hours. We compared the complication rate for biopsies recording clinical and biochemical data and, the day after the biopsy, the kidney was examined with a color-coded Doppler sonography (CCDS): in real-time survey of the kidney and with spectral wave form analysis. The diagnosis of arteriovenous (AV) fistula was achieved detecting increased color saturation toward white, high peak systolic flow velocity and low resistive index in the supplying artery. Three procedures were excluded of the analyses because of incomplete data recorded, although none of them showed any remarkable complication. There was a 94.3% rate of successful biopsies. The mean +/- SEM number of glomeruli under light microscopic examination was 8.5 +/- 0.6. Complications occurred 64 times in relation to 55 patients with a higher incidence in allografts (61%) than in native kidneys (31%). Renal transplant patients showed higher serum creatinine values (5.8 +/- 0.8 vs. 3.2 +/- 0.4; p > 0.0001) and lower hematocrit (31.3 +/- 1.1 vs. 34.4 +/- 0.9; p = 0.025) than the native-kidney patients at the time of biopsy. De novo hematuria occurred in 30% of the procedures. In transplant patients, the gross hematuria incidence (9.9%) more than doubled that showed by native-kidney patients. The incidence of serious complications (hematoma, hemoperitoneum and AV fistula) was 16.5% and these were more frequent in transplant than in native kidneys.(ABSTRACT TRUNCATED AT 250 WORDS)

Malignant neoplasms of the nasal cavity and paranasal sinuses: a series of 256 patients in Mexico City and Monterrey. Is air pollution the missing link?

Air pollution is a serious health problem in major cities in Mexico. The concentrations of monitored criteria pollutants have been above the US National Ambient Air Quality Standards for the last decade. To determine whether the number of primary malignant nasal and paranasal neoplasms has increased, we surveyed 256 such cases admitted to a major adult oncology hospital located in metropolitan Mexico City (MMC) for the period from 1976-1997 and to a tertiary hospital in Monterrey, an industrial city, for the period from 1993-1998. The clinical histories and histopathologic material were reviewed, and a brief clinical summary was written for each case. In the MMC hospital the number of newly diagnosed nasal and paranasal neoplasms per year for the period from 1976-1986 averaged 5.1, whereas for the next 11 years it increased to 12.5. The maximal increase was observed in 1995-1997, with an average of 20.3 new cases per year (P = 0.0006). The predominant neoplasms in these series were non-Hodgkin's lymphoma, squamous cell carcinoma, melanoma, adenocarcinoma, Schneiderian carcinoma, and nasopharyngeal carcinoma. In the Monterrey hospital a 2-fold increase in the numbers of newly diagnosed nasal and paranasal neoplasms was recorded between 1993 and 1998. The predominant MMC neoplasm in this series, namely nasal T-cell/natural killer cell non-Hodgkin's lymphoma, is potentially Epstein-Barr virus related. Nasal and paranasal malignant neoplasms are generally rare. Environmental causative factors include exposure in industries such as nickel refining, leather, and wood furniture manufacturing. Although epidemiologic studies have not addressed the relationship between outdoor air pollution and sinonasal malignant neoplasms, there is strong evidence for the nasal and paranasal carcinogenic effect of occupational aerosol complex chemical mixtures. General practitioners and ear, nose, and throat physicians working in highly polluted cities should be aware of the clinical presentations of these patients. Identification of this apparent increase in sinonasal malignant neoplasms in two urban Mexican polluted cities warrants further mechanistic and epidemiologic studies.

Tegumentary leishmaniasis in Northern Argentina: distribution of infection and disease, in three municipalities of Salta, 1990-1992.

This work describes the epidemiological pattern of tegumentary leishmaniasis in an area north of Salta, Argentina. The prevalence and incidence were estimated by means of a cross-sectional study and two follow-up studies during two consecutive years. The Montenegro Skin Test (MST) was administered to 7336 subjects at baseline. The prevalence and incidence between 1990 and 1992 of infection (MST reactive) was 38 per mil persons and 4.5 per mil persons/year respectively. The prevalence and incidence of tegumentary leishmaniasis (presence of clinical signs) was 1.8 per mil and 0.8 per mil persons/year, respectively. A physical examination performed on 264 patients with MST reactive during three years revealed that 130 cases (49.2%) had some evident sign of infection (scar and/or lesion), with a clinical presentation compatible with leishmaniasis. Our study demonstrated that after the epidemic outbreak of 1985 the transmission in the study area returned to endemic levels in 1992, and also demonstrated the presence of the asymptomatic infection in the area.

[Cutaneous leishmaniasis in Northern Argentina: identification of risk factors in a case-cohort study of three municipalities in Salta]. / Leishmaniose cutânea no Norte da Argentina: fatores de risco identificados num estudo caso-coorte em três municípios de Salta.

The objective of this work was evaluate risk factors for acquiring cutaneous leishmaniasis in Salta, the region with the greatest indices of transmission in Argentina. A Case-cohort study was realized from June 1989 to December 1992. The procedures performed on cases and controls included: a) socio-demographic questionnaire; b) domestic and peridomestic environment description; c) physical exam of skin and nasal and oral mucosal; d) Montenegro Skin Test. Multivariate analysis showed a significant risk for factors outside the home (cattle management, hunting, sleeping at the work place) and while at home (sleeping outside of the bedroom, presence of three or more pigs in the yard and windows that cannot be locked in the closed position). This association allowed the identification of risk factors linked to the transmission of leishmaniasis in the home for the first time in Salta (Argentina).

Multiple forms of U2 snRNA coexist in the silk moth Bombyx mori.

Eight U2 snRNA variants were isolated from several Bombyx mori U2-specific RT-PCR libraries. U2 sequences and secondary structures were generated and examined in terms of potential RNA and protein interactions. Analysis indicated that nucleotide changes occurred in both stem/loop and single-stranded areas. Changes in the double stranded areas were either compensatory, single substitutions (e.g. C <--> U) or prevented the double-stranded formation of one or two base pairs. The polymorphisms were clustered in moderately conserved regions. Some of the changes observed generated stronger base pairing. Inter-species conserved protein or RNA-binding sites were relatively unaffected. No polymorphic sites were found in known functional sequences. Bombyx mori and Drosophila melanogaster U2 sequences are 95% and 70% similar at the 5'- and the 3'-ends of the molecule, respectively. Phylogenetic analysis of the U2 sequences demonstrates remarkable conservation across species.

[Domestic violence as a factor associated to women's health problems]. / La violencia contra la mujer en la pareja como factor asociado a una mala salud física y psíquica.

OBJECTIVE: To study the impact of intimate partner violence (IPV) on women's physical and psychological health. DESIGN: Cross-sectional study. SETTING: Primary care centers in 3 Andalusian provinces. PATIENTS: A total of 425 women, aged 18 to 65 years, were recruited following the same randomisation process in 6 primary care centers. MEASUREMENTS: A self-administered structured questionnaire for this study was used to gather the information. As well as sociodemographic variables, the instrument included questions about IPV, physical health indicators (chronic disease and type, lifetime surgeries, days in bed), psychological health (psychological morbidity, use of tranquilizers, antidepressants, pain killers, alcohol and recreational drugs), self-perceived health and social support. RESULTS: Of 425 women, 31.5% ever experienced any type of partner violence. Women experiencing IPV were more likely to suffer a chronic disease. IPV was significantly associated with a number of adverse health outcomes, including spending more than 7 days in bed in the last three months (ORa=2.96; CI 95%, 1.00-8.76), psychological morbidity (ORa=2.68; CI 95%, 1.60-4.49) and worse self-perceived health (ORa=1.89; CI 95%, 1.04-3.43), after controlling for potential confounding variables. CONCLUSION: This study shows that ever experiencing IPV is associated with a worse psychological and self-perceived health. Physical injuries are not the only "evidence" of the presence of IPV. Primary health care professionals are in a privileged position to help women who are abused by their partners.