Belousov-Zhabotinsky type reactions: the non-linear behavior of chemical systems

AbstractChemical oscillators are open systems characterized by periodic variations of some reaction species concentration due to complex physico-chemical phenomena that may cause bistability, rise of limit cycle attractors, birth of spiral waves and Turing patterns and finally deterministic chaos. Specifically, the Belousov-Zhabotinsky reaction is a noteworthy example of non-linear behavior of chemical systems occurring in homogenous media. This reaction can take place in several variants and may offer an overview on chemical oscillators, owing to its simplicity of mathematical handling and several more complex deriving phenomena. This work provides an overview of Belousov-Zhabotinsky-type reactions, focusing on modeling under different operating conditions, from the most simple to the most widely applicable models presented during the years. In particular, the stability of simplified models as a function of bifurcation parameters is studied as causes of several complex behaviors. Rise of waves and fronts is mathematically explained as well as birth and evolution issues of the chaotic ODEs system describing the Györgyi-Field model of the Belousov-Zhabotinsky reaction. This review provides not only the general information about oscillatory reactions, but also provides the mathematical solutions in order to be used in future biochemical reactions and reactor designs

Cardiac filariosis in migratory Mute swans (Cygnus olor) in Sicily

Sarconema eurycerca is a common parasitic disease of North America swans and geese. The infection has been correlated with severe heart lesions, often resulting in cardiac failure and death of the animals. Heartworms infections have been previously reported in European swans, and specifically in the United Kingdom and Nederland. Both the countries are characterized by a cold temperate weather, similar to the one that can be found in swan wintering areas of U.S.A. and Canada. The first record of cardiac filariasis associated with Sarconema eurycerca infection in four swans in Italy. Twelve mute swans were examined during avian influenza surveillance activities on migratory birds. Birds were collected in the year 2006, in wintering areas of Eastern Sicily (Italy). Four of the twelve swans showed necrotic-haemorrhagic myocarditis with intra-lesional nematodes. Morphological characteristics identified the parasite as a filarial nematode. Birds lungs samples were used for parasites DNA extraction. The latter was used as template for polymerase chain reaction (PCR) amplification and sequencing of part of the 12S rDNA gene. Comparison of genomic DNA extracted from a reference S. eurycerca isolate confirmed parasite identity and provided the first sequence resources for this species of value to future diagnostic and epidemiological studies

Planeamiento estratégico de la Provincia Datem del Marañón 2017- 2030

Haciendo uso de la metodología del modelo secuencial, creada por D’Alessio (2015), se ha desarrollado este plan estratégico para la provincia Datem del Marañón, la cual se encuentra ubicada en el noroeste del departamento de Loreto, sobre una extensa llanura de selva tropical, con una población de 64,060 habitantes a junio del año 2015 (INEI, 2017c). Se propone que, para el año 2030, sea una provincial sostenible, pero con desarrollo económico y social, lo cual se logrará mediante el aprovechamiento de recursos naturales, con miras a crear ventajas competitivas. Se hará énfasis en dos industrias, la del aguaje, que actualmente se trabaja, y la de la acuicultura, que no se ha desarrollado hasta la fecha. Las estrategias a implementar son las siguientes: (a) desarrollar productos del aguaje con valor agregado, (b) desarrollar el cultivo de peces propios de la selva, en piscinas; (c) desarrollar productos de pescado fresco, como eviscerado y filetes; (d) desarrollar el mercado de Lima y la costa para los productos de pescado, (e) desarrollar el mercado de la costa del Perú para los productos frescos y derivados del aguaje, (f) penetrar en el mercado de Iquitos con diversos productos agrícolas, de la pesca y caza; y (g) penetrar en la prestación de servicios de electricidad y agua potable. Con esto, se alcanzará el interés supremo de elevar la calidad de vida de los habitantes de la provinciaUsing the methodology of the Sequential Model, created by D'Alessio (2015), this strategic plan has been developed for the province of Datem del Marañón, which is located in the northwest of the department of Loreto, on an extensive tropical forest plain, with a population of 64,060 inhabitants by June 2015 (INEI, 2017c). It is proposed that by 2030, it be a sustainable provincial, but with economic and social development, which will be achieved through the use of natural resources, with a view to creating competitive advantages. Emphasis will be placed on two industries, the water industry currently being worked on, and aquaculture which has not been developed to date. The strategies to be implemented are: (a) to develop value added aguaje fruit products, (b) developing the fish culture of the jungle in swimming pools, (c) developing fresh fish products, such as gutter and fillets; (d) developing the Lima and coastal market for fish products, (e) develop the market of the coast of Peru for fresh products and derivatives of water, (f) penetrate the market of Iquitos with various agricultural, fishery and hunting products; and (g) penetrate the provision of electricity and drinking water services. This will achieve the supreme interest of raising the quality of life of the inhabitants of the provinceTesi

Electronic structure of the α-(BEDT-TTF)2I3 surface by photoelectron spectroscopy

We report anomalies observed in photoelectron spectroscopy measurements performed on α-(BEDT-TTF)2I3 crystals. In particular, above its metal-insulator transition temperature (T ' 135 K), we observe the lack of a sharp Fermi edge in contradiction with the metallic transport properties exhib- ited by this quasi-bidimensional organic material. We interpret these unusual results as a signature of a one-dimensional electronic behavior confirmed by DFT band structure calculations. Using photoelectron spectroscopy we probe a Luttinger liquid with a large correlation parameter (α ą 1) that we interpret to be caused by the chain-like electronic structure of α-(BEDT-TTF)2I3 surface doped by iodine defects. These new surface effects are inaccessible by bulk sensitive measurements of electronic transport techniques

La chirurgia resettiva e ricostruttiva nelle neoplasie primitive o secondarie della parete toracica: la nostra esperienza

ajor chest wall resections often represent a difficult challenge for surgeons because of surgical and aesthetic reconstruction. In case of large defects a synthetic mesh with armoured ribs or titanium bar skeletron covered or uncovered with pedicled muscle transposition or omental flaps could be used. We report our experience on 57 patients, 43 males and 14 females mean age 66.2y (range 34-86). 35 (61.4%) cases were lung cancers with thoracic wall involvement, 16 were sternal, scapular or chest wall sarcomas, 6 were sternal and rib metastastatic involvement from extrathoracic neoplasms. We performed 51 thoracectomies and 6 sternetomies, 5 subtotal and one total. We resected an average of 3 ribs (range 1-6) and performed in 35 cases a reconstruction with synthetic mesh, in 7 associated with cyanomethacrilate armoured ribs, in 2 with thytanium bars. In total sternectomy we reconstruct the anterior ribs with 2 silicon tubes, in one of subtotals with 2 titanium bars. 25 cases needed pedicled muscle transposition, in 20 cases with latissimus dorsi in 5 with pectoralis major. We had no mortality or major complications. 13 patients presented minor complications as atrial fibrillation in 4, respiratory failure in 6, 2 wall hematoma and one syeroma. Mean hospital stay was 9.8 days (range 7-20). Major chest wall resections are possible for the multiple reconstructive choices actually proposed. An adequate preoperative study of the patient, a correct surgical strategy and the use of all reconstructive techniques are the keys for a successful outcome

Early and long-term Results of pulmonary resection for non-small-cell lung cancer in patients over 75 years of age: A multi-institutional study

none8noOBJECTIVES: Older lung cancer patients with multiple morbidities are increasingly referred to thoracic surgery departments. The aim of this multicenter study was to analyse the prognostic factors for in-hospital morbidity and mortality and to elucidate the predictors of long-term survival and oncological outcomes. METHODS: We identified 319 patients aged ≥ 75 years who underwent intended curative lung resection for lung cancer in three different thoracic surgery departments between January 2000 and December 2010. RESULTS: Seventy-one patients underwent limited resection, 202 had lobectomy, 16 had bilobectomy and 30 had pneumonectomy. The in-hospital mortality was 6.6%. Chronic renal failure, low respiratory reserve and pneumonectomy were predictors of in-hospital mortality. The mean follow-up time was 3.9 years, ranging from 1 month to 10.4 years. The disease-free survivals at 1, 3 and 5 years were 82, 60 and 47%, respectively. The overall survivals at 1, 3 and 5 years were 86, 59 and 38%, respectively. The long-term overall survival was negatively influenced by pneumonectomy, extended resection, N(1-2) subgroups and pathological TNM stage. CONCLUSIONS: Nowadays, we can consider surgery a safe and justifiable option for elderly patients. Careful preoperative work-up and selection are mandatory to gain satisfactory results. Good long-term results were achieved in elderly patients with early stage who underwent lobar or sublobar lung resection. The role of surgery or other alternative therapies, in patients with advanced stages, extensive nodal involvement and/or requiring extensive surgical resection for curative intent, is still unclear and further studies are certainly needed.openDell'Amore, Andrea; Monteverde, Marco; Martucci, Nicola; Sanna, Stefano; Caroli, Guido; Stella, Franco; Dell'Amore, Davide; Rocco, GaetanoDell'Amore, Andrea; Monteverde, Marco; Martucci, Nicola; Sanna, Stefano; Caroli, Guido; Stella, Franco; Dell'Amore, Davide; Rocco, Gaetan

Comparing performances, costs and energy balance of ex situ remediation processes for PAH-contaminated marine sediments

This study proposes a comparison of different ex situ technologies aimed at the removal of polycyclic aromatic hydrocarbons from marine sediments in terms of performances, costs and energy balance. In accordance with the principles of water-energy nexus, anaerobic bioremediation, soil washing and thermal desorption were investigated under low liquid phase and temperature conditions using phenanthrene (PHE) as model compound. After 42 days of anaerobic bioremediation, the highest PHE biodegradation of 68 and 64% was observed under denitrifying and methanogenic conditions, respectively, accompanied by N2 and CH4 production and volatile fatty acid accumulation. During soil washing, more than 97% of PHE was removed after 60 min using a solid-to-liquid ratio of 1:3. Along the same treatment time, low-temperature thermal desorption (LTTD) allowed a PHE removal of 88% at 200 °C. The economic analysis indicated that LTTD resulted in a higher cost (i.e. 1782 € m−3) than bioremediation and soil washing (228 and 371 € m−3, respectively). The energy balance also suggested that bioremediation and soil washing are more sustainable technologies as a lower required energy (i.e. 16 and 14 kWh m−3, respectively) than LTTD (i.e. 417 kWh m−3) is needed

Influence of different transition metals on the properties of Me-N-C (Me = Fe, Co, Cu, Zn) catalysts synthesized using SBA-15 as tubular nano-silica reactor for oxygen reduction reaction

Different MeeNeC catalysts for oxygen reduction reaction (ORR) are synthesized using Me(II)-phthalocyanines (Me ¼ Fe, Co, Cu, Zn) as a unique precursor molecule, and SBA-15 silica as a sacrificial template. The influence of different transition metals on the pyrolysis process and the consequent physicalechemical properties of the final catalysts were investigated using different characterization techniques such as N2 physisorption, FESEM, EDX, XPS, XRD, and thermogravimetric analysis coupled with mass spectrometry (TGAMS). The ORR activity and selectivity toward a complete 4-electrons reaction were assessed by RDE analysis in alkaline conditions. The ORR activity of the different MeeNeC catalysts decreases in the order Fe > Co > Cu > ZnzH. Microporosity, pyridinic nitrogen content and temperature at which H2 starts to be detected during the pyrolysis are directly related to the ORR activity of the different catalysts

Varying the morphology of Fe-N-C electrocatalysts by templating Iron Phthalocyanine precursor with different porous SiO2 to promote the Oxygen Reduction Reaction

Iron phtalocyanine (FePc) is used as iron/nitrogen/carbon source to synthesized Fe-N-C electrocatalysts for ORR by pyrolysis treatment in inert atmosphere for 2 h. Various temperatures are investigated, and the most favorable temperature, 850 °C, is selected as best temperature to carry on the pyrolysis treatment. To increase the ORR activity, the morphology of the catalysts is on purpose modified with the use of different porous silica during the synthesis (SBA15 in house prepared and commercial mesoporous SiO2) as templating agent during synthesis. The use of the templating agent allows to drastically increase the specific surface area and the microporosity the catalysts, especially with the use of the commercial mesoporous SiO2. The electrocatalytic activity towards ORR of the catalysts in acid conditions is assessed by RDE and RRDE apparatuses to quantify the hydrogen peroxide production. The Fe-N-C/850_mSiO2 catalyst exhibits higher electroactivity. Furthermore, in the GDE configuration this catalyst reached a mass activity of -1.4 mA mg-1, under IR corrected conditions. The chronoamperometry performed at 0.47 V vs RHE up to 4500 min shows relatively good stability values up to 60 hours. The catalysts are characterized by means of BET, FTIR, FESEM, EDX, and XPS analyses. The obtained catalysts present a nitrogen content varying from 0.9 to 2 at.% and an iron Fe content from 0.1 to 0.5 at.