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Polyhydroxyalkanoates (PHAs) are biobased and biodegradable polymers that may be considered to replace fossil-based materials. However, their widespread deployment is slowed down because of the high production cost and their low quality. Using methane during the generation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-co-HV) could reduce the production costs, which are usually owed to the carbon source used, and enhance the performance of the material. In fact, the properties of PHB-co-HV make it more suitable than the most common homopolymer, named poly(3-hydroxybutyrate) (PHB), for many applications since it is more flexible, has a wider thermal processing range, a lower crystallinity and permeability to water. In this work, the production of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) was simulated using an innovative process scheme consisting of two bioreactors working in series equipped with a gas recycling unit, which was designed to increase the methane mass transfer from the gas to the liquid. During the first step, a Methylocystis dominated culture was grown on ammonia and methane to reach a high cell concentration; then, the cells were moved to the second bioreactor and subjected to nutrients starvation to favour the metabolic pathway addressed to the accumulation of PHB-co-HV. The effect of the variation of valeric acid concentration (100-400 ppm), which was used as co-substrate, on the fraction of PHB-co-HV stored in the cells and the percentage of 3-hydroxyvalerate (3-HV) was investigated: results showed that the highest the valeric acid concentration, the lower the total polymer content and the higher the HV fraction accumulated.

Thanks to their properties, fossil fuel-based plastics are widely used daily (for industrial, domestic and environmental applications). However, they are not biodegradable, and their end of life is the cause of one of the most dangerous pollution in the world. Plastic, if recovered, can be recycled or used to recover energy, but it is not possible to recover all the tons of waste produced, so some end up in landfills. Therefore all non-recycled and non-collected plastic can take up to a thousand years to degrade. So the scientific idea is to produce biodegradable plastic capable of replacing conventional plastics. One possible solution is the poly(3Hydroxybutyrate) (PHB) of the polyhydroxyalkanoates (PHA) family. PHB is a biopolymer accumulated in intracellular granules, under unfavourable growth conditions, by many prokaryotes and can be extracted with eco-friendly solvents. In particular, the extraction phase consists of the disruption of the cells and the subsequent separation of the biopolymer from the non-biopolymeric material (non-PHB). Currently, solvent extraction is the most used method for PHB recovery because it guarantees a high recovery yield and keeps the characteristics of the extracted biopolymer almost unaltered. In this study, the extraction of PHB with eco-friendly solvents was investigated. Simulations were carried out using 1,2-propylene carbonate as the solvent and acetone as the anti-solvent. Two process schemes were analyzed, without and with the recirculation of solvents (by distillation) and with two different types of biomass (wet and dry). The present work aims to study the final recovery yield in different operating conditions and the influence of PHB solubility on the process. The simulation results confirm the importance of solubility for optimizing the extraction process and underline the problem related to the lack of data in the literature.

effetti benefici nel ridurre timing cicatrizzazione post operatoria dopo uso di spray nasale a base di Vit A e E con liposomi

Myoepithelioma represents less than 1% of all salivary glands tumors. Generally are benign tumors localized in parotid gland. Only FNAC, often, is insufficient for the correct diagnosis of the lesion, which can be confused with a pleomorfic adenoma or a malignant myoepithelial carcinoma. Because of its rarity, we describe a case report of parotid gland myoepithelioma treated, successfully, with total parotidectomy and preservation of the facial nerve.

descriviamo caso di un paziente con tumore di Warthin che presenta ascesso e paralisi del facciale in seguito ad un FNAC della parotide paziente

The marine pollution in Latin America and the Caribbean is due to domestic sewage discharges into the sea, which do not receive previous treatment, thus generating health problems for the population. This is due to the presence of thermotolerant coliforms and solid waste on the beaches in the Peruvian coast. The beach Los Pavos, as well as other beaches in Lima, is a very popular recreation area especially in summer. This beach complies with the parameters of beaches cleaning quality and presence of hygienic services, thus qualifying as a healthy beach. However, the analysis carried out in this research have found the presence of thermotolerant coliforms of 1400 NMP / 100mL at pH 7.13 and 44.5 ºC (or 112.1 ºF), exceeding the environmental standard values.In order to reduce this considerable amount of thermotolerant coliforms, sea water microbubbles (MNBs) of air-ozone were tested. These micro-bubbles were generated by a device for the generation of Micro Nanobubbles invented by Dr. Jhonny Valverde Flores. The air / ozone volume ratio was 3/1, the size of the MNB was 7 µm, with a water flow of 4.67 L / min and a pressure of the air-ozone mixture of 90 PSI. The volume ratio of sea water / water with MNBs for sample A was 3/1, for sample B of 1/1 and for Sample C of 1/3. As a result of research, the presence of thermotolerant coliforms of sample A decreased to 56 NMP / 100mL, of sample B decreased to 79 NMP / 100mL and of sample C decreased to 130 NMP / 100mL, achieving an efficiency of 96%, 94.36% and 90.71%, respectively. Lima Norte Escuela Profesional de Ingeniería Ambiental Transacciones Ingeniería Química

We discuss the methodological aspects related to the evaluation of turn-over and up-down sizing as indicators of work-related stress, in complex organizations like a university hospital. To estimate the active workers population we developed an algorithm which integrated several administrative databases. The indicators were standardized to take into account some potential confounders (age, sex, work seniority) when considering different hospital structures and job mansions. Main advantages of our method include flexibility in the choice of the analysis detail (hospital units, job mansions, a combination of both) and the possibility to describe over-time trends to measure the success of preventive strategies.

In practice, canals located on ridges seldom have symmetric drainages on either side. In this paper, exact solution of the problem of seepage from a canal in a homogeneous medium to asymmetric drains located at finite distance from the canal is presented. The problem is solved by the use of conformal mapping. Equations for seepage discharge and the shape of the free surface are given. The values of seepage discharge are given in the form of easy to use curves. The analysis indicates that the seepage losses increase with increase in bed width and decrease in distance and the lowering of the level of the drainages. If the level of the higher drainage is raised beyond a critical value, this drainage becomes ineffective and seepage to this drainage will be zero. Fee surface rises if drainage on the other side is located at a farther and/or at a higher level.

Dos ejemplares de Panstrongylus rufotuberculatus fueron capturados en una vivienda de El Hatillo, estado Miranda. En ambos se confirma la presencia de Trypanosoma cruzi. Se estudian algunos parámetros biológicos para estimar el comportamiento de uno de los aislados (Pr), encontrándose que tanto el cultivo en medios acelulares como la inoculación en ratones fueron exitosos. Así mismo, 73,3% de los Rhodnius de laboratorio se infectaron y 30,6% de los parásitos presentaron metaciclogénesis, mientras que in vitro se obtuvo 25,5%. La identificación molecular correspondió a T. cruzi. Este hallazgo es importante debido a la posible emergencia de esta especie silvestre que por alteración antrópica de sus hábitats naturales puede estar en proceso de dispersión, penetración y domiciliación de las viviendas, implicando la posibilidad de transmisión del parásito al ser humano y animales domésticos. Two specimens of Panstrongylus rufotuberculatus were captured in a house in El Hatillo, Estado Miranda. In both specimens the presence of Trypanosoma cruzi was confirmed. We studied some biological parameters for estimating the behavior of the isolates, finding in both that cell-free culture media as inoculation in mice were successful. Also, 73.3% of Rhodnius prolixus fed on infected mice became infected and 30.6% of the parasites developed to metacyclic forms whereas in vitro only 25.5% was obtained. Furthermore, the molecular identification corresponded to T. cruzi. This finding is important due to the possible emergence of wild species by anthropogenic alteration of their natural habitats, and this may become a process of dispersion, penetration and clearance of houses, implying the possibility of transmitting the parasite to humans and pets.

Squamous cell carcinoma of the larynx (LSCC) represents approximately 2% of all tumors. The involvement of metastatic cervical lymph nodes has the major negative prognostic impact. Researching new factors with prognostic significance is indispensable. Patterns for predicting metastasis improves TNM classification, helping medical equipe and releasing information with tumor behavior and surgical indication.

We have studied the cell differentiation of Trypanosoma cruzi in an vitro system that allows the transformation of epimastigotes into metacyclic trypomastigotes. Intracellular cAMP levels of epimastigotes increased 3 fold prior to their differentiation into metacyclics where cAMP remained elevated 3.7 fold with respect to epimastigotes. We also observed a 3 fold increase in the specific activity of cAMP-binding of metacyclics crude homogenates. This activity resided in a cAMP-binding receptor protein (CARPT) which was different from the typical cAMP-binding subunits (RI and RII) of cAMP-dependent protein kinases, as shown by the use of polyclonal antibodies prepared against these two types of proteins. Anti-RI antibodies did not react with CARPT, and anti-RII antibodies gave a cross reaction with CARPT which was at least 1,000 fold less sensitive than the one shown by the homologous antigen. On Western blots CARPT displayed a major band with Mr = 87,000 instead of Mr = 56,000 for RII. These studies implicate that cAMP may act as a mediator of the cell differentiation of T. cruzi by a mechanism involving a novel type of cAMP-binding receptor.

The addition to epimastigotes cultures of T. cruzi, of either cAMP, monobutyryl-cAMP, dibutyryl-cAMP, 8-Br-cAMP (at 2 mM each), or the cAMP-phosphodiesterase inhibitor, papaverine (0.2 mM), promoted the in vitro differentiation of these parasite forms into metacyclics. This effect of cAMP may also be exerted in vivo in the insect vector, since cAMP was detected in the urine and in the Malpighi secretion fluids of Rodnius prolixus.