Fate and behavior of dissolved organic matter in a submerged anoxic-aerobic membrane bioreactor (MBR)

Abstract

In this study, the production, composition, and characteristics of dissolved organic matter (DOM) in an anoxic-aerobic submerged membrane bioreactor (MBR) were investigated. The average concentrations of proteins and carbohydrates in the MBR aerobic stage were 3.96 ± 0.28 and 8.36 ± 0.89 mg/L, respectively. After membrane filtration, these values decreased to 2.9 ± 0.2 and 2.8 ± 0.2 mg/L, respectively. High performance size exclusion chromatograph (HP-SEC) analysis indicated a bimodal molecular weight (MW) distribution of DOMs, and that the intensities of all the peaks were reduced in the MBR effluent compared to the influent. Three-dimensional fluorescence excitation emission matrix (FEEM) indicated that fulvic and humic acid-like substances were the predominant DOMs in biological treatment processes. Precise identification and characterization of low-MW DOMs was carried out using gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis indicated that the highest peak numbers (170) were found in the anoxic stage, and 54 (32%) compounds were identified with a similarity greater than 80%. Alkanes (28), esters (11), and aromatics (7) were the main compounds detected. DOMs exhibited both biodegradable and recalcitrant characteristics. There were noticeable differences in the low-MW DOMs present down the treatment process train in terms of numbers, concentrations, molecular weight, biodegradability, and recalcitrance.

What makes a good head positioner for preventing occipital pressure ulcers

Patients who are stationary endure prolonged soft tissue distortions and deformations at contact areas between their body and the support surface, which may lead to the onset of pressure ulcers (PUs) over time. A novel technology for patient positioning employs innovation in materials science, specifically viscoelastic materials with shape memory properties that compose the Z-Flo™ head positioner (Mölnlycke Health Care, Gothenburg, Sweden). Head positioners are generally known to reduce the occurrence of PUs in scalp tissues and the ears, but quantitative assessments of their biomechanical efficacy are missing in the literature. To determine potential differences in mechanical loads formed in the soft tissues of the back of the head while in contact with 2 head positioner types, Z-Flo vs flat medical foam, we developed 2 comparable finite element model configurations, both including the same 3-dimensional adult head. For both model variants, stresses in skin and fat peaked at the occiput. The skin at the back of the resting head is subjected to greater stress values with respect to fat; however, the Z-Flo positioner reduced the exposure of both skin and fat tissues to elevated stresses considerably (by a factor of 3) compared to the medical foam support. We found the Z-Flo device effective in reducing tissue loads at the surface of the head as well as internally in scalp tissues, with a particular strength in reducing internal tissue shear. The Z-Flo device achieves this protective quality through highly effective immersion and envelopment of the back of the head, generated in the process of manual moulding of the device in preparation for use. Additional protection is achieved through the viscoelastic response of the filling material of this positioner, which relaxes promptly and considerably under the weight of the head (by more than 2-fold within approximately 1 s) as opposed to the elastic recoil of the foam that pushes back on scalp tissues.

Measuring the quality of pressure ulcer prevention: A systematic mapping review of quality indicators

The aim of this study was to provide a systematic overview of available pressure ulcer prevention quality indicators and to evaluate the underlying empirical evidence. A systematic mapping review was conducted with combined searches in Embase and Medline, and websites of relevant institutions and organisations. The eligibility criteria were clear use of the term "quality indicator" regarding pressure ulcer prevention; English or German language; and all settings, populations, and types of resources, including articles, brochures, and online material. In total, n = 146 quality indicators were identified. Most indicators were published in the United States (n = 50). The majority of indicators was developed for the hospital setting (n = 102). Process indicators were the most common (n = 71), followed by outcome indicators (n = 49). Less than half of identified indicators appeared to be practically used. Evidence supporting the validity and reliability were reported for n = 25 and n = 30 indicators respectively. The high number of indicators demonstrate the importance of measuring pressure ulcer prevention quality. This is not an indicator of our ability to accurately measure and evaluate this construct. There is an urgent need to develop evidence-based and internationally comparable indicators to help improve patient care and safety worldwide.

Pseudomonas aeruginosa biofilm hampers murine central wound healing by suppression of vascular epithelial growth factor

Abstract

Biofilm-infected wounds are clinically challenging. Vascular endothelial growth factor and host defence S100A8/A9 are crucial for wound healing but may be suppressed by biofilms. The natural course of Pseudomonas aeruginosa biofilm infection was compared in central and peripheral zones of burn-wounded, infection-susceptible BALB/c mice, which display delayed wound closure compared to C3H/HeN mice. Wounds were evaluated histopathologically 4, 7 or 10 days post-infection. Photoplanimetry evaluated necrotic areas. P. aeruginosa biofilm suppressed vascular endothelial growth factor levels centrally in BALB/c wounds but increased peripheral levels 4–7 days post-infection. Central zones of the burn wound displayed lower levels of central vascular endothelial growth factor as observed 4 and 7 days post-infection in BALB/c mice compared to their C3H/HeN counterparts. Biofilm suppressed early, centrally located S100A8/A9 in BALB/c and centrally and peripherally later on in C3H/HeN wounds as compared to uninfected mice. Peripheral polymorphonuclear-dominated inflammation and larger necrosis were observed in BALB/c wounds. In conclusion, P. aeruginosa biofilm modulates wounds by suppressing central, but inducing peripheral, vascular endothelial growth factor levels and reducing host response in wounds of BALB/c mice. This suppression is detrimental to the resolution of biofilm-infected necrosis.

Evidence-based (S3) guideline for the treatment of androgenetic alopecia in women and in men – short version

Abstract

Androgenetic alopecia is the most common hair loss disorder, affecting both men and women. Initial signs of androgenetic alopecia usually develop during teenage years leading to progressive hair loss with a pattern distribution. Moreover, its frequency increases with age and affects up to 80% Caucasian men and 42% of women. Patients afflicted with androgenetic alopecia may undergo significant impairment of quality of life. The European Dermatology Forum (EDF) initiated a project to develop evidence-based guidelines for the treatment of androgenetic alopecia. Based on a systematic literature research the efficacy of the currently available therapeutic options was assessed and therapeutic recommendations were passed in a consensus conference. The purpose of the guideline is to provide dermatologists with an evidence-based tool for choosing an efficacious and safe therapy for patients with androgenetic alopecia.

Enfermedad de Kimura e hiperplasia angiolinfoide con eosinofilia. ¿La misma enfermedad o distintas entidades?

Publication date: Available online 26 November 2017
Source:Piel
Author(s): Minia Campos Domínguez, Ricardo Suárez Fernández

Conceptos novedosos, técnicas pelo a pelo y tira en trasplante de pelo

Publication date: Available online 26 November 2017
Source:Piel
Author(s): Javier Pedraz Muñoz, María José García Fernández de Villalta

Asociación de eritema nudoso y epiescleritis como manifestación inicial de la enfermedad de Crohn

Publication date: Available online 26 November 2017
Source:Piel
Author(s): Jorge Magdaleno-Tapial, Cristian Valenzuela-Oñate, Gemma Pérez-Pastor

Afectación psicosocial en el paciente con hidradenitis supurativa

Publication date: Available online 26 November 2017
Source:Piel
Author(s): Marta C. García Bustínduy

Papilomatosis vestibular: variante anatómica de la vulva

Publication date: Available online 26 November 2017
Source:Piel
Author(s): Carolina Pardo-Zamudio, Nathalia Plaza-Arteaga

Disección ganglionar en el paciente de edad avanzada con melanoma

Publication date: Available online 26 November 2017
Source:Piel
Author(s): David Moreno-Ramírez, Almudena Fernández-Orland, Lara Ferrándiz

Novedades en la patogenia de las úlceras por presión

Publication date: Available online 26 November 2017
Source:Piel
Author(s): Julio E. Valdivia-Silva, Luis Peña, Carolina Rosado, Rafaela Salazar, Cynthia Tellez, Juan Carlos Chávez

Verruga viral subungueal recalcitrante: más que una infección por el virus del papiloma humano

Publication date: Available online 26 November 2017
Source:Piel
Author(s): Laura Aguilar, Fernando Bulla, Adriana Motta, Luis Fernando González

Nevus sebáceo asociado a carcinoma basocelular multifocal con diferenciación escamosa

Publication date: Available online 26 November 2017
Source:Piel
Author(s): Karla Gálvez, Raúl Charlín, María A. Alfaro, Laura Segovia, Bobadilla Francisco

Presentaciones clínicas inusuales del poroma: el nuevo gran imitador

Publication date: Available online 26 November 2017
Source:Piel
Author(s): Javier Arellano, Nadia Vega, Vivian Águila, Yamile Corredoira

Osteoma cutis primario solitario

Publication date: Available online 26 November 2017
Source:Piel
Author(s): Francesc Messeguer, Anna Agusti-Mejias, Pau Agusti

Empoderamiento del paciente dermatológico

Publication date: Available online 26 November 2017
Source:Piel
Author(s): José Juan Pereyra-Rodriguez, Javier J. Domínguez-Cruz, Ricardo Ruiz-Villaverde

Acute intraventricular conduction disorder due to combination therapy with dabrafenib and trametinib for metastatic melanoma: Case report

Case of pigmented lipofibromatosis in a 27-year-old woman

Generalized verrucosis caused by various human papillomaviruses in a patient with GATA2 deficiency

Dermoscopic features of endocrine mucin-producing sweat gland carcinoma

Abstract

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is very rare, with only 61 cases reported to date. EMPSGC is considered to be a low-grade carcinoma of sweat gland origin. Dermoscopic findings of EMPSGC have not been previously reported. We report the first case of a man with EMPSGC, featuring dermoscopic findings. Dermoscopic examinations of the present EMPSGC lesion revealed tumor cell proliferation that appeared as pink ovoid nests and elongated epidermis that resembled a whitish-pink network. Another characteristic finding of the present lesion was the large red/blue globules in pink ovoid nests in the tumor. Those reflected lacunae containing secretory fluid with red blood cells. We think that the large red/blue globules in pink ovoid nests in our case could be a characteristic dermoscopic finding specific to EMPSGC. We dermatologists encounter many "pink nodules" at out-patient clinics. The present dermoscopic findings may be useful for the differential diagnosis of EMPSGC.

Histiocytic necrotizing lymphadenitis (Kikuchi's disease) with vasculitis

Diagnóstico genético de la epidermólisis bullosa: recomendaciones de un grupo español de expertos

Publication date: Available online 26 November 2017
Source:Actas Dermo-Sifiliográficas
Author(s): C. Sánchez-Jimeno, M.J. Escámez, C. Ayuso, M.J. Trujillo-Tiebas, M. del Río
La epidermólisis bullosa (EB), enfermedad genética de fragilidad mucocutánea rara y devastadora, es clínica y genéticamente heterogénea. Se caracteriza por la aparición de ampollas inducidas por contacto/fricción o de forma espontánea. La EB se clasifica en 4 tipos: simple, juntural, distrófica y síndrome de Kindler 19 y en 30 subtipos. Esta genodermatosis está causada por defectos en proteínas implicadas en la adhesión dermoepidérmica, con al menos 19 genes caracterizados hasta el momento y más de 1.000 mutaciones identificadas, que explican la complejidad de su diagnóstico. El diagnóstico molecular de la EB es el último paso de un proceso laborioso que se inicia con la recogida de una historia clínica detallada y la toma de una biopsia cutánea, que incluya una zona de despegamiento entre la dermis y la epidermis inducida, en el momento de la recolección. Dicho despegamiento permite establecer el plano de rotura por mapeo antigénico y, en el mejor de los casos, un único gen candidato en el que realizar la búsqueda de las mutaciones patogénicas. Finalizado el diagnóstico molecular, se está en condiciones de ofrecer al paciente un asesoramiento genético adecuado (patrón de herencia, riesgo de recurrencia y opciones de diagnóstico prenatal y preimplantacional) y los consecuentes programas preventivos, así como un pronóstico clínico razonable que facilite su acceso a opciones terapéuticas y de rehabilitación específicas. Por último, el diagnóstico molecular es imprescindible para la participación de los pacientes en ensayos clínicos, de gran importancia en una enfermedad como la EB, que no tiene cura. El objetivo de la presente guía es difundir el procedimiento de diagnóstico de la EB tal y como se está llevando a cabo en nuestro laboratorio y, así, evitar diagnósticos clínicos subóptimos o incompletos. Las recomendaciones recogidas son fruto de nuestra experiencia de más de 10 años de diagnóstico molecular de EB en España.Epidermolysis bullosa (EB) is a rare genetic disease that causes mucocutaneous fragility. It comprises a clinically and genetically heterogeneous group of disorder characterized by spontaneous or contact/friction–induced blistering. EB is classified into 4 types–simplex, junctional, dystrophic, and Kindler syndrome—and 30 subtypes. The disease is caused by defects in proteins implicated in dermal-epidermal adhesion. At least 19 genes have been characterized and more than 1000 mutations identified, thus rendering diagnosis complex. Molecular diagnosis of EB is the last stage of a laborious process that starts with a detailed clinical history compilation and careful procurement of a skin fresh biopsy that includes an area where the epidermis detaches from the dermis. The detachment area makes it possible to establish the cleavage plane by antigen mapping and, in the best scenario, to identify a single candidate gene to search for pathogenic mutations. The results of the molecular diagnosis enable the physician to provide appropriate genetic counseling (inheritance pattern, risk of recurrence, and options for prenatal and preimplantation diagnosis) and implement subsequent preventive programs, as well as to establish a reasonable clinical prognosis facilitating access to specific therapy and rehabilitation. Lastly, molecular diagnosis is essential for the participation of patients in clinical trials, a critical issue given the current incurable status of EB. The present guidelines aim to disseminate the procedure for diagnosing EB in our laboratory and thus avoid suboptimal or incomplete clinical diagnoses. The recommendations we provide are the result of more than 10 years' experience in the molecular diagnosis of EB in Spain.

Malformaciones capilares tratadas con aplicación secuencial de láser de colorante pulsado y Nd:YAG: estudio retrospectivo

Publication date: Available online 26 November 2017
Source:Actas Dermo-Sifiliográficas
Author(s): J. Alcántara-González, P. Boixeda, M.T. Truchuelo-Díez, N. Jiménez-Gómez, B. Pérez-García, L. Pérez-Carmona, P. Jaén Olasolo
Introducción y objetivoLas malformaciones capilares son las malformaciones vasculares más frecuentes en la infancia. El tratamiento de elección sigue siendo el láser de colorante pulsado (LCP), sin embargo, la resolución completa con este habitualmente no se consigue, motivo por el que se siguen buscando otras alternativas terapéuticas. En este estudio comunicamos nuestra experiencia con el láser dual secuencial de LCP y Nd:YAG.Material y métodosSe efectuó un estudio retrospectivo y descriptivo de los pacientes con malformaciones capilares tratados con el láser dual de LCP y Nd:YAG desde 2006 hasta 2011. Cuatro dermatólogos valoraron el grado de eficacia en una escala del 10 al 0. Se analizó la posibilidad de factores predictores de mejor respuesta al tratamiento: sexo, color de la lesión, existencia de hipertrofia asociada y tamaño de la malformación. Se recogieron igualmente los efectos secundarios.ResultadosSe incluyeron 71 pacientes, presentando el conjunto de ellos una mejoría estadísticamente significativa tras el tratamiento. Las malformaciones de coloración violácea que tenían hipertrofia asociada y las de menor tamaño se asociaron con una mejor respuesta. Se produjeron efectos adversos en un 26,76% de los pacientes, siendo la presencia de zonas atróficas puntuales el más frecuente.ConclusionesConsideramos que el láser dual de LCP y Nd:YAG es una alternativa eficaz para el tratamiento de malformaciones capilares en paciente seleccionados.Introduction and objectiveCapillary malformations are the most common vascular malformations in childhood. The current treatment of choice is pulsed dye laser (PDL) therapy, but this frequently does not result in complete resolution. The search for alternative treatment strategies thus continues. In this study we describe our experience with the use of sequential dual-wavelength PDL and Nd:YAG laser therapy in patients with capillary malformations.Material and methodsWe conducted a retrospective, descriptive study of patients with capillary malformations treated with dual-wavelength PDL and Nd:YAG laser therapy between 2006 and 2011. Four dermatologists rated the effectiveness of treatment on a scale of 10 to 0. We also investigated the potential value of the following factors as predictors of better treatment response: sex, malformation size and color, and presence of associated hypertrophy. Adverse effects were also analyzed.ResultsWe studied 71 patients and most of them experienced a statistically significant improvement after treatment. More favorable responses were observed for violaceous malformations, lesions with associated hypertrophy, and smaller lesions. Adverse effects were reported for 26.76% of patients, and the most common effect was the appearance of isolated areas of skin atrophy.ConclusionsWe consider that sequential dual-wavelength PDL and ND:YAG laser therapy is an effective alternative for treating capillary malformations in selected patients.

Graphical abstract

Empoderamiento y Dermatología

Publication date: Available online 26 November 2017
Source:Actas Dermo-Sifiliográficas
Author(s): J.J. Domínguez-Cruz, J.J. Pereyra-Rodríguez, R. Ruiz-Villaverde
El término empoderamiento (empowerment) se refiere a un proceso que facilita el cambio conductual, favorece la responsabilidad y la toma de decisiones informadas de los pacientes principalmente en patologías crónicas para alcanzar objetivos terapéuticos. El empoderamiento se orienta a fomentar el autocuidado en salud y la autoeficacia. El término proviene del inglés empower que significa «dar poder» o «hacer poderoso o fuerte a un individuo o grupo». Es tarea de los profesionales de la salud facilitar los mejores conocimientos y habilidades para que el paciente sea capaz de escoger entre las opciones que tiene al alcance y actuar en consecuencia. En este artículo se revisarán las diferentes definiciones de empoderamiento, sus herramientas de medición, las implicaciones que debe tener en el manejo de pacientes con patologías crónicas y su uso en las afecciones dermatológicas.The term empowerment refers to any process that facilitates behavioral changes and encourages responsibility and making informed choices. The concept has been applied mainly to help patients with chronic conditions achieve therapeutic goals. The aim of the approach in health care is to enhance self-caring and self-efficacy. The term derives from the English verb to empower meaning "to give (someone) the authority or power to do something" or "to make an individual or a group stronger or more powerful". One of the responsibilities of health professionals is to improve patients' knowledge and their ability to choose between the different alternatives available to them so that they can act accordingly. In this article, we review the various definitions of the term empowerment, the tools used to measure patient empowerment, the implications of the concept for the management of chronic disease, and its use in dermatological conditions.

Las reacciones alérgicas frente a las tintas de los tatuajes, un nuevo reto diagnóstico

Publication date: Available online 26 November 2017
Source:Actas Dermo-Sifiliográficas
Author(s): D. Muñoz Borrás

Líneas de demarcación pigmentarias tipo B en gestante

Publication date: Available online 26 November 2017
Source:Actas Dermo-Sifiliográficas
Author(s): J.F. Mir-Bonafé, S. Planas-Ciudad, E. Rozas-Muñoz, L. Puig

The Idea of Beauty and Its Biases: Critical Notes on the Aesthetics of Plastic Surgery

Summary: Two biases affect the idea of beauty often embodied in aesthetic surgery. The first one is that the living body is the sum of different parts; the second one claims that beauty results from the sum of beautiful elements. Taken together, these 2 biases explain most of the aesthetic surgery procedures, in which a localized improvement is supposed to impact on the whole body image. In this article, I put into question these 2 problematic assumptions, showing that Western and Eastern aesthetics, on one side, and philosophical reflections, on the other side, support a different conception of beauty. In particular, an alternative idea that opens to authenticity and imperfection and focuses on the living body rather than on the mere anatomical surface is proposed here as a more adequate concept of beauty for aesthetic surgery.

Large, Long-standing Tumor on the Scalp and Ipsilateral Lymphadenopathy

Publication date: Available online 26 November 2017
Source:Actas Dermo-Sifiliográficas (English Edition)
Author(s): A. Hermosa-Gelbard, C. Moreno García del Real, S. Vañó-Galván

Bibliometric Indicators of the Status of Clinical Research in Dermatology in Spain: Implications for the Future

Publication date: Available online 26 November 2017
Source:Actas Dermo-Sifiliográficas (English Edition)
Author(s): I. Belinchón Romero

Practical Management of Immunosuppressants in Dermatology

Publication date: Available online 26 November 2017
Source:Actas Dermo-Sifiliográficas (English Edition)
Author(s): V.M. Leis-Dosil, I. Prats-Caelles
The treatment of inflammatory and autoimmune diseases is challenging because of their frequency and complexity. Treatment of these diseases is based on the suppression of the patient's immune system using corticosteroids, corticosteroid-sparing immunosuppressive agents, and biologic drugs, making an understanding of the management of immunosuppressive therapy essential. Before an immunosuppressive agent is prescribed, a study must be carried out to identify contraindications, detect latent infections, and determine the most appropriate dose. During treatment, regular monitoring is required to detect adverse effects. The clinician must be familiar with the time lag between start of treatment and onset of the immunosuppressive effect as well as the maximum recommended duration of treatment and cumulative dose for each drug. As dermatologists we are accustomed to using these immunosuppressive agents, but we should have a good knowledge of the guidelines for their use and the monitoring required in each case if we are to reduce variability and avoid potentially serious adverse effects.

Prospective Single-Center Observational Study of the Allergenic Potential of Mercromina Film and Other Common Antiseptics in Patients With Contact Dermatitis

Publication date: Available online 26 November 2017
Source:Actas Dermo-Sifiliográficas (English Edition)
Author(s): S. Baltà Cruz, N. Moreno Ribera, M.T. Estrach Panella
IntroductionAlthough Mercromina Film and other topical antiseptics are widely used, they are not included in the standard series recommended by the Spanish Contact Dermatitis and Skin Allergy Research Group for testing suspected allergic contact dermatitis (ACD). Furthermore, no recent studies have investigated the allergenic potential of merbromin.ObjectiveTo determine the allergenic potential of merbromin and compare it with that of other topical antiseptics widely used in clinical practice, including povidone-iodine, chlorhexidine, and eosin.Material and methodsProspective single-center observational safety study of 105 patients with suspected ACD seen at the dermatology department of our hospital.ResultsOf the 105 patients studied, 1.9% had a positive patch test to merbromin and 12.4% were sensitized to povidone-iodine. The differences in the proportion of patients with ACD to Betadine Solución Dérmica (povidone-iodine) compared with the rest of the antiseptics was statistically significant (McNemar test, P<.05). No adverse reactions were observed in any of the patients.ConclusionsBased on the patch tests conducted, Mercromina Film has very low allergenic potential. The highest allergenic potential was observed for povidone-iodine.

Intralymphatic Histiocytosis: A Report of 2 Cases

Publication date: Available online 26 November 2017
Source:Actas Dermo-Sifiliográficas (English Edition)
Author(s): M.E. Gómez-Sánchez, J.M. Azaña-Defez, M.L. Martínez-Martínez, M.T. López-Villaescusa
Intralymphatic histiocytosis is a benign condition characterized by poorly defined erythematous plaques (sometimes forming a reticular pattern) as well as the presence of nodules and vesicles. Its etiology and pathogenesis appear to be related to chronic inflammation in the affected area, prior surgery, or systemic disease, particularly rheumatoid arthritis. We report on 2 new cases, both associated with joint surgery in the affected area and osteoarticular disease (primary synovial osteochondromatosis and rheumatoid arthritis). This is a chronic disease and there is no specific treatment. Different treatment options were chosen in the 2 cases described. A spectacular response to treatment with oral pentoxifylline and topical tacrolimus was observed in 1 of the patients.

Cu(II)-catalyzed degradation of ampicillin: effect of pH and dissolved oxygen

Abstract

Cu(II)-catalyzed hydrolysis of β-lactam antibiotics has been well-identified and recognized as the key mechanism of antibiotic degradation. However, the overlooked Cu(II) oxidation susceptibly also plays an important role comparably with hydrolysis. This study evaluated the roles of hydrolysis and oxidation in Cu(II)-catalyzed degraded ampicillin (AMP), as a typical β-lactam antibiotic, under relevant environmental conditions (pH 5.0, 7.0, and 9.0; oxygen 0.2 and 6.2 mg/L). Under AMP and Cu(II) molar ratio of 1:1, AMP degradation was the fastest at pH 9.0, followed by pH 5.0 and pH 7.0. The facilitation of oxygen on AMP degradation was notable at pH 5.0 and 7.0 rather than pH 9.0. AMP degradation rate increased from 21.8% in 0.2 mg/L O₂ solution to 85.9% in 6.2 mg/L O₂ solution at pH 7.0 after 4-h reaction. AMP oxidation was attributed to both oxygen-derived Cu(I)/Cu(II) cycle and intermediate reactive oxygen species (HO^. and O₂^.−). Several intermediate and final products in AMP degradation were firstly identified by LC-quadrupole time-of-flight-MS analysis. Phenylglycine primary amine on the AMP structure was the essential complexation site to proceed with the oxidation reaction. The oxidation of AMP preferentially occurred on the β-lactam structure. The inherent mechanisms related to pH and oxygen conditions were firstly investigated, which could enhance the understanding of both oxidation and hydrolysis mechanisms in AMP degradation. This study not only has an important implication in predicting β-lactam antibiotic transformation and fate in natural environment but also benefits the developing of strategies of antibiotic control to reduce the environmental risk.

Adsorption of cesium ion by marine actinobacterium Nocardiopsis sp. 13H and their extracellular polymeric substances (EPS) role in bioremediation

Abstract

This paper evaluates the cesium adsorption of marine actinobacterium Nocardiposis sp. 13H strain isolated from nuclear power plant sites in India. It could remove 88.6 ± 0.72% of Cs⁺ from test solution containing 10 mM CsCl₂. The biosorption of Cs⁺ with different environmental factors such as pH, temperature, and time interval is also determined. Scanning electron microscopy coupled with energy dispersive spectroscopy (EDS) confirmed the Cs⁺ adsorption by Nocardiopsis sp. 13H. Most of the bound cesium was found to be associated extracellular polymeric substances (EPS) suggesting its interaction with the surface active groups. The main component of the EPS was carbohydrate followed by protein and nucleic acid. Further, Fourier transform infrared (FTIR) spectroscopy suggested the carboxyl, hydroxyl, and amide groups on the strain cell surface were likely to be involved in Cs⁺ adsorption. Results from this study show Nocardiopsis sp. 13H microorganism could be useful in exploring the biosorption of radioisotope pollution and developing efficient and eco-friendly biosorbent for environmental cleanup.

Study on the influential biochemical indices of Cd(II) on Eisenia fetida in oxidative stress by principal component analysis in the natural soil

Abstract

With the aggravation of heavy metal pollution in soil, the individual heavy metal content monitoring cannot predict the true effects of harmful substances on the ecosystems. Thus, the effective biological evaluation system should be established to assess the pollution risk caused by heavy metal. Earthworms are widely distributed in the soil, and at the bottom of the food chain, the changes of biochemical indices play an important role in the early warning for heavy metal pollution. Principal component analysis (PCA) is a statistical method that derives several independent principal components from the original variable based on retaining the information as much as possible. This paper is aimed at finding out and analyzing the key monitoring factors related to Cd²⁺ on the earthworm Eisenia fetida in oxidative stress. The Cd²⁺ stress concentrations were set at 0, 1, 10, 20, 100, 200, 400, and 800 mg kg⁻¹, and the post-clitellum segment of earthworm was chosen to determine TP, POD, SOD, GST, GPX, CAT, MDA, VE, and AChE. The results showed that the main bioindicators associated with oxidative stress reaction were GST, POD, and MDA at the exposure time of 10 days; at 20 days GPX, MDA, and AChE; at 30 days CAT, TP, and GPX; CAT, MDA, and SOD at 40th day. These results indicated that PCA can quickly, effectively, directly, and scientifically select biomarkers of oxidative stress induced by Cd and improve the accuracy and scientificity of earthworm as a biomarker in monitoring and early warning for heavy metal-contaminated soil.

Spatiotemporal variation and exposure risk to human health of potential toxic elements in suburban vegetable soils of a megacity, SW China, 2012–2016

Abstract

Trace element contamination in soils of vegetable fields can threat public health. Seven potential toxic elements (As, Cd, Cr, Cu, Ni, Pb, and Zn) in suburban vegetable soils of Chengdu city, Southwest China, in 2012 and 2016, were analyzed to identify their sources with the spatiotemporal variation and assess their contamination and health risk for residents. The results showed that the concentrations of soil elements did not increase significantly in 2016 compared with that in 2012, whereas their spatial distributions altered markedly. The hot spots of soil As, Cd, and Pb as well as Cu and Zn in 2016 revealed the anthropogenic sources including agricultural activities, industrial emissions, road dust with heavy traffic, and open burning of solid waste. The apparent spatial difference of anthropogenic elements was related to the layout of land use surrounding the vegetable field. The contamination of soil elements decreased in the order of Cd > As ≈ Zn > Cu ≈ Pb > Cr ≈ Ni in 2012 and Cd > Zn > As ≈ Cu ≈ Pb > Cr ≈ Ni in 2016, and the vegetable soils were slightly to moderately contaminated by these elements through integrated contamination index. The sites affected by the trace elements did not increase in 2016 than in 2012, whereas the sites with relatively high contamination increased markedly. The non-carcinogenic risk of trace elements was generally acceptable, and children showed higher health risk than adults. The As carcinogenic risk for children varied between 5.48 × 10⁻⁵ and 1.59 × 10⁻⁴ in 2012 and between 4.40 × 10⁻⁵ and 1.82 × 10⁻⁴ in 2016, and the sites above acceptable levels (> 10⁻⁴) reached 60.6% and 48.5% in 2012 and 2016, respectively. The health risk of As in the vegetable soils should be paid more attention due to its high toxicity.

A critical approach to the toxic metal ion removal by hazelnut and almond shells

Abstract

The adsorption capacity of ground hazelnut (HS) and almond (AS) shells towards Pb(II) and Cd(II) has been studied at pH = 5, in NaNO₃ and NaCl ionic media, in the ionic strength range 0.05–0.5 mol L⁻¹. Kinetic and equilibrium experiments were carried out by using the Differential Pulse Anodic Stripping Voltammetry technique to check the amount of the metal ion removed by HS and AS materials. Different kinetic and equilibrium equations were used to fit experimental data and a statistical study was done to establish the suitable model for the data fitting. A speciation study of the metal ions in solution was also done in order to evaluate the influence of the ionic medium on the adsorption process. TGA-DSC, FT-IR, and SEM-EDX techniques were used to characterize the adsorbent materials. The mechanism of metal ions adsorption was explained on the basis of the results obtained by the metal ions speciation study and the characterization of materials.

Longitudinal trends in the prevalence of detectable HIV viremia: Population-based evidence from rural KwaZulu-Natal, South Africa

Abstract

Background

The prevalence of detectable viremia has previously been used to infer the potential for ongoing HIV transmission. To date, no study has evaluated the longitudinal change in the prevalence of detectable viremia within the HIV-positive community (PDV₊) and the entire population (PDV_P) using data from a sub-Saharan African setting.

Methods

In 2011, 2013, and 2014, we obtained 6,752 HIV-positive and 15,415 HIV-negative test results from a population-based surveillance system in the KwaZulu-Natal province of South Africa. We quantified the PDV₊ as the proportion of the 6,752 HIV-positive results with a viral load >1,550 copies/mL and the PDV_P as the proportion of the 6,752 HIV-positive and 15,415 HIV-negative results with a viral load >1,550 copies/mL.

Results

Between 2011 and 2014, the PDV₊ decreased by 16.5 percentage points (pp) for women (from 71.8% to 55.3%) and 10.6 pp for men (from 77.8% to 67.2%). However, a steady rise in the overall HIV prevalence, from 26.7% to 32.4%, offset the declines in the PDV₊ for both sexes. For woman, the PDV_P decreased by only 2.1 pp, from 21.3% to 19.2%; but for men, the PDV_P actually increased by 1.6 pp, from 14.6% to 16.2%, over the survey period.

Discussion

The PDV₊, which is currently being tracked under the UNAID 90-90-90 targets, may not be accurate indicator of the potential for ongoing HIV transmission. There is a critical need for countries to monitor and report the prevalence of detectable viremia among all adults (PDV_P), irrespective of HIV status.

Discharge Criteria for Patient With Lassa Fever Infection

To the Editor—We read with interest the report on 2 epidemiologically linked patients with Lassa fever (LF) secondarily acquired from the same index case in Togo and medically evacuated to Cologne, Germany (patient E) and to Atlanta, Georgia (patient F), respectively [1].

Reply to Nicastri et al

To The Editor— We appreciate the comments of Nicastri, Vairo, and Ippolito regarding the need to identify parameters for safe hospital discharge of Lassa fever patients in nonendemic settings.