Effect of surfactant type and concentration on the gas-liquid mass transfer in biotrickling filters used for air pollution control.

Volatile organic compounds (VOCs) emitted into the atmosphere negatively affect the environment and human health. Biotrickling filtration, an effective technology for treating VOC-laden waste gases, faces challenges in removing hydrophobic VOCs due to their low water solubility and therefore limited bioavailability to microorganisms. Consequently, the addition of (bio)surfactants has proven to be a promising strategy to enhance the removal of hydrophobic VOCs in biotrickling filters (BTFs). Yet, up to now, no single study has ever performed a mass transfer characterization of a BTF under (bio)surfactants addition. In this study, the effect of (bio)surfactant addition on the gas-liquid mass transfer characteristics of two BTFs was measured by using oxygen (O2) as a model gas. Through an empirical correlation, the mass transfer coefficients (kLa) of two hydrophobic VOCs, toluene and hexane, which are of industrial and environmental significance, were estimated. One BTF was filled with expanded perlite, while the other with a mixture of compost and wood chips (C + WC). Both BTFs were operated under different liquid velocities (UL: 0.95 and 1.53 m h-1). Saponin, a biological surfactant, and Tween 80, a synthetic surfactant, were added to the recirculating liquid at different critical micelle concentrations (CMCs: 0-3 CMC). The higher interfacial and surface area of the perlite BTF compared to the C + WC BTF led to higher kLaO2 values regardless of the operational condition: 308 ± 18-612 ± 19 h-1 versus 42 ± 4-177 ± 24 h-1, respectively. Saponin addition at 0.5 and 1 CMC had positive effects on the perlite BTF, with kLaO2 values two times higher compared to those at 0 CMC. Tween 80 exhibited a neutral or slightly positive effect on the mass transfer of both BTFs under all conditions. Overall, the CMC, along with the physical characteristics of the packing materials and the operational conditions evaluated explained the results obtained. This study provides fundamental data essential to improve the performance and design of BTFs for hydrophobic VOCs abatement.

Morphological Study before and after Thermal Treatment of Polymer-Polymer Mixed-Matrix Membranes for Gas Separations.

A good integration of the polymer materials that form a mixed-matrix membrane (MMM) for gas separation is essential to reaching interesting permselective properties. In this work, a porous polymer network (PPN), obtained by combining triptycene and trifluoroacetophenone, has been used as a filler, which was blended with two o-hydroxypolyamides (HPAs) that act as polymer matrices. These polymer matrices have been thermally treated to induce a thermal rearrangement (TR) of the HPAs to polybenzoxazoles (ß-TR-PBOs) through a solid-state reaction. For its structural study, various techniques have been proposed that allow us to undertake a morphological investigation into the integration of these materials. To access the internal structure of the MMMs, three different methods were used: a polishing process for the material surface, the partial dissolution of the polymer matrix, or argon plasma etching. The argon plasma technique has not only revealed its potential to visualize the internal structure of these materials; it has also been proven to allow for the transformation of their permselective properties. Force modulation and phase contrast in lift-mode techniques, along with the topographic images obtained via the tapping mode using a scanning probe microscope (SPM), have allowed us to study the distribution of the filler particles and the interaction of the polymer and the filler. The morphological information obtained via SPM, along with that of other more commonly used techniques (SEM, TGA, DSC, FTIR, WASX, gas adsorption, and permeability measurements), has allowed us to postulate the most probable structural configuration in this type of system.

Saline Retention and Permeability of Nanofiltration Membranes Versus Resistance and Capacitance as Obtained from Impedance Spectroscopy under a Concentration Gradient.

Impedance spectroscopy has been widely used for the study of the electrical properties of membranes for their characterization. The most common use of this technique is the measure of the conductivity of different electrolyte solutions to study the behavior and movement of electrically charged particles inside the pores of membranes. The objective of this investigation was to observe if there is a relation present between the retention that a nanofiltration membrane possesses to certain electrolytic solutions (NaCl, KCl, MgCl2, CaCl2, and Na2SO4) and the parameters that are obtained through IS measurements of the active layer of the membrane. To achieve our objective, different characterization techniques were performed to obtain the permeability, retention, and zeta potential values of a Desal-HL nanofiltration membrane. Impedance spectroscopy measurements were performed when a gradient concentration was present between both sides of the membrane to study the variation that the electrical parameters had with the time evolution.

Intrasession Repeatability of the Contact Angle Measured Using the Captive Bubble Method and Agreement Assessed Between Different Analysis Software Programs.

OBJECTIVES: The material biocompatibility of hydrogel and silicone hydrogel (SiHy) contact lens (CL) is of paramount importance in CL wear because a decrease in CL wettability reduces wearer comfort and increases wearer dropout. The aim of this study is to report on the repeatability and agreement between two different software programs that measure the contact angle with the captive bubble method in marketed CLs, which will help to translate this information into clinical practice. METHODS: The contact angle of 23 different CLs was measured with the captive bubble method using 2 software programs: FTÅ200 and ImageJ. Three consecutive measurements were conducted for each CL. Reproducibility, repeatability, and agreement values were calculated according to the British Standards Institute and the International Organization for Standardization. RESULTS: All methods showed good repeatability values in both CL materials (coefficient of variation <1.51%, Sw <2.26°, intraclass correlation coefficient >0.89, and the range of limits of agreement was between 7.22° and 7.57°). Higher concordance was achieved between the spherical and nonspherical options when using FTÅ200 software than when using ImageJ software. Statistically significant differences (P<0.05) between the 2 software programs were found, and they ranged between 5° and 10°. CONCLUSIONS: The captive bubble method showed great repeatability in measuring the contact angle in marketed CLs with both software programs (FTÅ200 and ImageJ) assessed in this study. However, differences in the measured contact angles suggest that these techniques are not interchangeable. Therefore, standardization is recommended for contact angle measurement in hydrogel CL materials to facilitate comparisons, to improve clinical use of this information, and to analyze their impact in CL user comfort.

Island nail flap in the treatment of foot macrodactyly of the first ray in children: report of two cases.

PURPOSE: We evaluated the result of a combined single-stage surgery in the treatment of first ray macrodactyly in children. INTRODUCTION: Macrodactyly is a rare congenital abnormality that involves thickening of both the soft tissue and bone of the affected digits. It is more frequent in fingers than toes, where there is less neural involvement. Increased growth is also seen in neurofibromatosis, hemangiomatosis, arteriovenous malformations, congenital lymphedema, and syndromes such as Klippel-Trenaunay-Weber syndrome and Proteus syndrome. The goal of treatment is to obtain a pain-free, functional foot that can accommodate normal shoes. Treatment of macrodactyly of the first ray generates numerous difficulties since ray resection, which has been recommended for other toes as a means to of shortening and narrowing the foot, cannot be performed. In addition to this, cosmetic results are better if the nail is preserved. METHODS: We retrospectively reviewed our cases of first ray macrodactyly treated by a single-stage multiple-technique procedure. RESULTS: We obtained satisfactory results, in that same-sized shoes could be worn on by our patients and patients and family were happy with the outcome. However, one of our cases patients lost the nail 10 months postoperatively. CONCLUSIONS: We believe that island-nail transfer in children obtains excellent results.

Nota clínica. Complicaciones del método Ponseti: Edema de miembro por efecto ventana / Complication of Ponseti’s method: Edema member for windows effect

El pie equinovaro es la deformidad congénita más frecuente, afectando a 1 de cada 1000 recién nacidos vivos. El método más aceptado para su tratamiento es el método Ponseti, que consiste en la utilización de yesos seriados, encaminados a corregir las deformidades asociadas a dicha deformidad. Varias son las complicaciones que pueden aparecer durante el enyesado seriado, aunque la mayoría son banales. En nuestro centro hemos diagnosticado 5 casos de edema de miembro por efecto ventana asociado a este tratamiento. En todos los casos, esta complicación ha aparecido tras retirar el yeso post-tenotomía, previo a la colocación de la férula de abducción. Asociamos esta complicación con la rigidez de las vendas de algodón utilizadas, lo que nos ha llevado a cambiarlas por otras sin trenzado, mucho más distensibles. Actualmente no ha aparecido ningún nuevo caso

The clubfoot is the most common birth defect, affecting 1 in 1000 live births. The most accepted method for treatment is the Ponseti method which consists of serial casting, which corrects all the deformities associated with this deformity. There are several complications that can arise during serial casting, although most are banal. In our center we have diagnosed 5 cases of edema member for windows effect with this treatment. In all cases, this complication has appeared after removal of the post-tenotomy cast, prior to using the abduction brace. We associate this complication with the rigidity of the cotton bandages used, which has led us to change them for other without mesh, much more distensible. Currently, no new caseshave appeared

Guía terapéutica en úlceras venosas / Therapeutic guide in venous ulcers

El tratamiento de las úlceras venosas y de las heridas crónicas en general constituye un complejo e importante problema de salud pública, con repercusiones personales, familiares y sociales, sin olvidar el impacto económico que supone la asistencia y cuidado de los pacientes con lesiones ulcerosas. El aumento de la esperanza de vida, propiciado por las mejores condiciones sociosanitarias, condiciona que este envejecimiento de la población facilite la aparición de las enfermedades crónicas, que pueden complicarse con la presencia de úlceras cutáneas. No cabe duda de que la mejor forma de tratar una úlcera cutánea es evitando que se produzca, de ahí la importancia de establecer un diagnóstico precoz de los factores de riesgo y actuar sobre los mismos. En relación con las úlceras venosas es esencial, además del tratamiento local, actuar sobre la causa, ya que, en caso contrario, la recidiva será la norma habitual en este tipo de lesiones. Actualmente, la cura en ambiente húmedo supone un avance importante en la resolución más precoz de estas heridas crónicas. Este hecho ha propiciado que la industria farmacéutica se haya implicado en investigar y crear diferentes tipos de apósitos, que tengan actividad específica en las diferentes fases del proceso de curación de la úlcera venosa, es decir: fase inflamatoria, proliferativa y de remodelación. La proliferación de estos productos se ha ido incrementando con el paso de los años. No en vano, hay descritas más de 12 familias terapéuticas que se emplean en el manejo y cuidado de estas lesiones. El hecho de que existan tantas opciones terapéuticas pone de manifiesto la ineficacia individualizada de estos productos. Por ello, el profesional de enfermería no olvidará que el tratamiento óptimo de las úlceras venosas pasa necesariamente por la elección del producto más adecuado para cada tipo y estadio de lesión. En este proceso de decisión, muy condicionado por las características específicas de cada paciente y lesión, la enfermera tendrá en cuenta una gran cantidad de factores a la hora de elegir el producto, sin olvidar que una úlcera no se cura con un solo elemento terapéutico, pues son varios los productos que deberá utilizar a lo largo del proceso evolutivo de la úlcera venosa, hasta su completa resolución (AU)

The treatment of venous ulcers and wounds in general, is a complex and important public health problem, with personal effects, family and health, without addressing the economic impact includes assistance, care of patients with ulcerative lesions. The increase in life expectancy, driven by improved socio-sanitary conditions that this aging population, facilitates the emergence of chronic diseases may be complicated by the presence of skin ulcers. There is no doubt that the best way to treat a skin ulcer is avoiding to occur, hence the importance of early diagnosis and risk factors act alone them. In relation to venous ulcers is crucial, provide local treatment, act on the cause, because if not, relapse is the norm in this type of injury. Currently, the moist wound healing, is an important step in solving earlier of these chronic wounds. This has meant that the pharmaceutical industry has been involved in researching and creating different types of dressings, having specific activity at different stages of venous ulcer healing, ie inflammatory phase, proliferative and remodeling. The proliferation of these products has been increasing over the years, not surprisingly, are described therapeutic 12 families that are applied in the management, care of these injuries. The fact of existing therapeutic options highlights the ineffectiveness of these products individually. Therefore, the nurse will not forget that the optimal treatment of venous ulcers, necessarily involves choosing the right product for every type and stage of the lesion. In this decision process, strongly influenced by the specific characteristics of each patient and injury, the nurse will take into account a lot of factors when choosing the product, not forgetting that an ulcer is not cured with a single therapeutic element, several products being used throughout the process to evolutionary venous ulcer until complete resolution (AU)

Lower Extremity Fibro-Adipose Vascular Anomaly (FAVA): A New Case of a Newly Delineated Disorder.

The acronym FAVA (Fibro-Adipose Vascular Anomaly) has been recently given to a distinct vascular entity that is characterized by fibrofatty infiltration of muscle, unusual phlebectasia with pain, and contracture of the affected extremity. We report a new case of FAVA in a 10-year-old girl with pain in her right lower leg and equinus contracture. As in our case, FAVA typically presents in young females with calf involvement and limited ankle dorsiflexion with local pain. FAVA should be considered as a differential diagnosis when evaluating vascular anomalies in the lower extremities.

[THERAPEUTIC GUIDE IN VENOUS ULCERS]. / Guía terapéutica en úlceras venosas.

The treatment of venous ulcers and wounds in general, is a complex and important public health problem, with personal effects, family and health, without addressing the economic impact includes assistance, care of patients with ulcerative lesions. The increase in life expectancy, driven by improved socio-sanitary conditions that this aging population, facilitates the emergence of chronic diseases may be complicated by the presence of skin ulcers. There is no doubt that the best way to treat a skin ulcer is avoiding to occur, hence the importance of early diagnosis and risk factors act alone them. In relation to venous ulcers is crucial, provide local treatment, act on the cause, because if not, relapse is the norm in this type of injury. Currently, the moist wound healing, is an important step in solving earlier of these chronic wounds. This has meant that the pharmaceutical industry has been involved in researching and creating different types of dressings, having specific activity at different stages of venous ulcer healing, ie inflammatory phase, proliferative and remodeling. The proliferation of these products has been increasing over the years, not surprisingly, are described therapeutic 12 families that are applied in the management, care of these injuries. The fact of existing therapeutic options highlights the ineffectiveness of these products individually. Therefore, the nurse will not forget that the optimal treatment of venous ulcers, necessarily involves choosing the right product for every type and stage of the lesion. In this decision process, strongly influenced by the specific characteristics of each patient and injury, the nurse will take into account a lot of factors when choosing the product, not forgetting that an ulcer is not cured with a single therapeutic element, several products being used throughout the process to evolutionary venous ulcer until complete resolution.

Physeal fracture of the distal femur in a newborn: role of arthrography.

Making the diagnosis of a physeal separation of the distal end of the femur in a newborn is a true challenge. The radiological diagnosis is not always simple and a high index of suspicion is needed. Also, knowing the age of appearance of the ossific nuclei helps in reaching a diagnosis. However, it is imperative to perform a differential diagnosis with other causes that may compromise the life of the newborn. An early diagnosis and adequate treatment are fundamental in avoiding permanent deformity of the affected limb. We present a case report, along with a review of the literature, to describe the clinical and radiological findings that aid in reaching a diagnosis and giving the proper treatment. We also point out the importance of the role of the arthrography and closed reduction as an alternative to simple open reduction.

A proposed subungual exostosis clinical classification and treatment plan.

Subungual exostosis is a slow-growing, benign outgrowth of normal bone under the nail that affects the nail unit. The most common location in the foot is the dorsal surface of the distal phalanx of the big toe. Clinically, it can appear in combination with a variety of nail disorders, masking the underlying bone condition, which is frequently unrecognized or misdiagnosed. A new classification system for these lesions is proposed on the basis of the clinical signs and symptoms present during examination and the associated disorders of the nail plate. Also, a therapeutic algorithm that describes surgical approaches to the different presentations of this disorder is presented.

Effect of 7-degree rearfoot varus and valgus wedging on rearfoot kinematics and kinetics during the stance phase of walking.

BACKGROUND: The scientific evidence behind the mechanical function of foot orthoses is still controversial. Research studies that have investigated the kinematic effect of foot orthoses on the lower extremity have shown variable results, with orthoses causing either no significant change or a small significant change in foot kinematics. METHODS: The right limbs of 12 healthy asymptomatic individuals were studied in three walking conditions: barefoot, with a 7 degrees rearfoot varus wedge, and with a 7 degrees rearfoot valgus wedge. Kinematic and kinetic variables measured were the foot progression angle, the peak internal tibial rotation angle, and net ankle inversion moments during the stance phase in the three conditions. RESULTS: There were statistically significant differences in the foot progression angle between the barefoot and varus wedge conditions and between the varus and valgus wedge conditions. There were no significant changes in peak internal tibial rotation among the three conditions tested. However, rearfoot varus wedges significantly reduced net ankle inversion moments compared with barefoot and rearfoot valgus wedges. CONCLUSIONS: These results support the idea that foot orthoses work by methods other than by changing kinematic parameters. The present study supports the concept that foot orthoses work primarily by altering kinetics, with their effects on kinematics being secondary.

Analysis of gastrocnemius recession and medial column procedures as adjuncts in arthroereisis for the correction of pediatric pes planovalgus: a radiographic retrospective study.

UNLABELLED: The radiographic outcomes of 28 feet in 20 pediatric patients with pes planovalgus treated with subtalar arthroereisis, arthroereisis combined with gastrocnemius recession, or arthroereisis combined with gastrocnemius recession and medial column reconstruction were retrospectively analyzed. Preoperative and postoperative radiographic angles for talar declination, calcaneal inclination, and first metatarsal declination in the lateral view, and the angle formed between the longitudinal axis of the talus and the longitudinal axis of the lesser tarsus in the anteroposterior view were compared. Overall, analyses revealed statistically significant differences in the preoperative and postoperative radiographic angles for the 4 measured angles. Analysis by treatment group revealed statistically significant differences in correction of the angle measured in the anteroposterior view. Arthroereisis with gastrocnemius recession showed the greatest correction of this angle (median 19 degrees, range 11 degrees to 34 degrees) compared with the other treatment groups. There were no statistically significant differences in the degree of correction of the calcaneal inclination or talar declination angles, whereas a statistically significant difference in the correction of first metatarsal declination was observed. The greatest degree of angular change was achieved with medial column reconstruction (median 7 degrees, range 0 degrees to 9 degrees). Gastrocnemius recession displayed a notable effect on the correction of transverse plane deformity when used as an adjunct to arthroereisis. However, medial column reconstruction has a negative impact on the degree of correction in the transverse plane when it is used as an adjunct to arthroereisis and gastrocnemius recession. LEVEL OF CLINICAL EVIDENCE: 4.