Morfología polínica de las especies de cítricos cultivadas en Andalucía occidental (España)

. Morfología polínica de las especies de cítricos cultivadas en Andalucía occidental (España). Se estudia la morfología polínica de seis especies de cítricos de los géneros Citrus (C. aurantium, C. deliciosa, C. grandis, C. limon y C. sinensis) y Fortunella (F. margarita), con los microscopios óptico y electrónico de barrido. Por los caracteres estudiados (polaridad, simetría, contorno (en visión ecuatorial y corte óptico meridiano y visión polar y corte ecuatorial), tamaño, número, tipo y dimensiones de las aberturas, grosor de la exina y ornamentación) se describe la morfología del polen y se discuten los resultados obtenidos.No es posible la separación de los dos géneros, pero se pueden diferenciar parte de las especies del género Citrus

The formation of a nanohybrid shish-kebab (NHSK) structure in melt-processed composites of poly (ethylene terephthalate) (PET) and multi-walled carbon nanotubes (MWCNTs)

The combination of synchrotron Small- and Wide-Angle X-ray scattering (SAXS/WAXS), and thermal analysis was used to follow the evolution of crystalline morphology and crystallization kinetics in a series of melt-processed composites of poly(ethylene terephthalate) (PET) and multiwall carbon nanotubes (MWCNT). The as-extruded PET-MWCNT composites underwent both hot and cold isothermal crystallizations where a final oriented nanohybrid shish-kebab (NHSK) crystalline structure was observed. An oriented NHSK structure was seen to persist even after melting and recrystallization of the composites. From the scattering data, we propose a model whereby the oriented MWCNTs act as heterogeneous nucleation surfaces (shish) and the polymer chains wrap around them and the crystallites (kebabs) grow epitaxially outwards during crystallization. However, depending on crystallization temperature, unoriented crystallites also grow in the polymer matrix, resulting in a combination of a NHSK and lamellar morphology. In contrast, the neat PET homopolymer showed the sporadic nucleation of a classic unoriented lamellar structure under the same isothermal crystallization conditions. These results provide a valuable insight into the distinctive modification of the crystalline morphology of melt-processed polymer-MWCNT composites prior to any secondary processing, having a significant impact on the use of MWCNTs as fillers in the processing and modification of the physical and mechanical properties of engineering polymers

Beyond gold: rediscovering tetrakis-(hydroxymethyl)-phosphonium chloride (THPC) as an effective agent for the synthesis of ultra-small noble metal nanoparticles and Pt-containing nanoalloys

The use of tetrakis-(hydroxymethyl)-phosphonium chloride (THPC) as simultaneous reducing agent and stabilizing ligand has been extended to the single-step synthesis at room temperature of a wide variety of monometallic nanoparticles and bi-/tri- metallic nanoalloys containing noble metals with potential application in catalysis. The colloidal suspensions exhibit mean diameters below 4 nm with narrow size distributions and high stability in aqueous solution for long periods of time

Risk factors for major adverse cardiovascular events after osteoporotic hip fracture repair surgery

Osteoporotic hip fracture (OHF) is an increasingly frequent age-related pathology, which results in high rates of functional loss and mortality within the first year after surgery. This study assessed whether preoperative levels of brain natriuretic peptide (NT-proBNP) and troponin I were related to early occurrence (30d) of major adverse cardio-vascular events (MACE) after OHF repair surgery. During a 6-month period, perioperative clinical and analytical data from consecutive patients, without known history of cardiovascular disease and undergoing surgery for OHF repair at a single centre, were prospectively collected. MACE was defined as acute myocardial ischaemia or infarction, acute heart failure or cardiovascular death. amongst the 140 patients included, 23 (16.4%) developed postoperative MACE (MACE group) and 117 did not (Control group). Compared to those from control group, patients from MACE group were older, had poorer physical status (ASA III–IV), received preoperative red blood cell transfusion (RBCT) more frequently, presented with lower haemoglobin concentrations and higher NT-proBNP, creatinine and troponin I concentrations. Overall, RBCT requirements and 30d mortality rate were also higher in MACE group. However, in multivariate analysis, only preoperative RBCT, creatinine >1 mg/dL and NT-proBNP >450 pg/mL remained as independent preoperative risks factors for postoperative MACE, while 95% confidence intervals of odds ratios were wide. Though our findings require confirmation in a larger multicentre cohort, identifying risk factors for early postoperative MACE after OHF repair surgery, might facilitate assessing patients’ risk prior to and following surgery, and targeting them the appropriate preventive and/or therapeutic interventions

Numerical Study of the Seismic Response of an Urban Overpass Support System

A strategic urban overpass is to be built in the so-called transition and hill zones in Mexico City. The subsoil conditions at these zones typically consist on soft to stiff clay and medium to dense sand deposits, randomly interbedded by loose sand lenses, and underlain by rock formations that may outcrop in some areas. Several critical supports of this overpass are going to be instrumented with accelerometers, inclinometers and extensometers to assess their seismic performance during future earthquakes and to generate a database to calibrate soil-structure-interaction numerical models. This paper presents the seismic performance evaluation of one of these supports. The support foundation is a 3.6 by 4.6 m mat, structurally connected to four cast-in-place 0.80 m diameter piles. A finite elements model of the soil-foundation-structure system was developed. Initially, the model was calibrated analyzing the seismic response that an instrumented bridge support exhibited during the June 15th, 1999 Tehuacan (Mw=7) Earthquake. This bridge is located also within the surroundings of Mexico City, but at the lake zone, where highly compressible clays are found. The computed response was compared with the measured response in the free field, box foundation, and structure. Once the model prediction capabilities were established, the seismic response of the critical support of the urban overpass was evaluated for the design earthquake in terms of transfer functions and displacement time histories

Osteoartropatía hipertrófica pulmonar asociada a megaesófago en un perro

La osteoartropatía hipertrófica pulmonar (OHP) es una enfermedad de escasa presentación en la clínica rutinaria canina, secundaria a patologías intratorácicas crónicas, con lesiones que ocupan un cierto volumen intratorácico (neoplasias, abscesos, etc.), y que se caracteriza por la presencia de neoformaciones óseas en el periostio de los huesos de las extremidades. En el presente artículo se describe un caso clínico de osteoartropatía hipertrófica pulmonar (clínica, radiología, analítica sanguínea y urinaria, necropsia y estudios histopatológicos), asociada a un megaesófago, condición no descrita en la bibliografía consultada sobre la OHP canina.Hypertrophic pulmonary osteoarthropathy (HPO) is a rare clinical disease in the dog, secondary to spaceoccuping masses inside the thoracic cavity (neoplasms, abcesses, etc.) and it's characterized by neoformation of periosteal bone affecting mainly the distallimbs. The authors review the physiopathology of the disease and describe one clinical case of hypertrophic pulmonary osteoarthropathy (clinical state, radiology, blood and urine analysis, necropsy results and histologic conclusions) associated with megaesofagus, condition not yet described associated to HPO

Attenuation of Peak Ground Acceleration with Distance of the June 15, 1999, Tehuacán, México, Earthquake

A seismic event of moment magnitude 7.0 struck the central region of Mexico on June 15, 1999 at 15:41 hrs (local time) between the states of Puebla and Oaxaca. The epicenter of the earthquake was located approximately 20 km to the south-southeast of the town of Tehuacán, Puebla and 55 km to the northeast of Huajuapan de León, Oaxaca. A reconnaissance team consisting of a group of researchers from the University of California at Berkeley (UCB) and the Autonomous University of Mexico (UNAM) visited the area and gathered some preliminary information on the geotechnical aspects of this earthquake. This paper briefly presents some key geotechnical observations and then focuses on the attenuation of peak ground acceleration with distance. A total of 29 strong-motion recordings over a variety of geologic site conditions were compiled and used to develop the observed attenuation of the peak ground acceleration (PGA) with distance for the main event. The results obtained were compared with estimations of PGA using North American attenuation relationships

Spontaneous formation of Au-Pt alloyed nanoparticles using pure nano-counterparts as starters: a ligand and size dependent process

In this work we investigate the formation of PtAu monodisperse alloyed nanoparticles by ageing pure metallic Au and Pt small nanoparticles (sNPs), nanoparticle size <5 nm, under certain conditions. We demonstrate that those bimetallic entities can be obtained by controlling the size of the initial metallic sNPs separately prepared and by selecting their appropriate capping agents. The formation of this spontaneous phenomenon was studied using HR-STEM, EDS, ionic conductivity, UV-Vis spectroscopy and cyclic voltammetry. Depending on the type of capping agent used and the size of the initial Au sNPs, three different materials were obtained: (i) AuPt bimetallic sNPs showing a surface rich in Au atoms, (ii) segregated Au and Pt sNPs and (iii) a mixture of bimetallic nanoparticles as well as Pt sNPs and Au NPs. Surface segregation energies and the nature of the reaction environment are the driving forces to direct the distribution of atoms in the bimetallic sNPs. PtAu alloyed nanoparticles were obtained after 150 h of reaction at room temperature if a weak capping agent was used for the stabilization of the nanoparticles. It was also found that Au atoms diffuse towards Pt sNPs, producing a surface enriched in Au atoms. This study shows that even pure nanoparticles are prone to be modified by the surrounding nanoparticles to give rise to new nanomaterials if atomic diffusion is feasible

A refraction/wide-angle reflection seismic profile through the Iberian Chain: preliminary report

As a result of the Eurasian and African plates convergence, Tertiary intraplate deformation of the Iberian plate gave rise to the basement-involved thrust-system of the Iberian Chain. Subsequently, a crustal thickening beneath the Iberian Chain was produced, as deduced from Bouguer anomaly maps. A very preliminary interpretation of a new seismic profile through the Iberian Chain is presented, which leads us to infer a crustal thickening beneath the central part of the profile, where Moho depths of at least 40 km should be reached

Exploring the Consistency of Data Collected in Archaeological Geophysics: A Case Study from the Iron Age Hillfort of Villasviejas del Tamuja (Extremadura, Spain)

Different geophysical methods applied at the settlement of Villasviejas del Tamuja (Botija, Spain) have identified robust anomalies located at the same position, but some anomalies are reflected by only one method. Furthermore, analysing the spatial correlation of these anomalies is of fundamental importance for obtaining a correct archaeological interpretation. In this work, we analysed the main results of electrical resistivity tomography (ERT), ground-penetrating radar (GPR) and magnetic gradiometry methods in a particular area of the archaeological site. In this analysis, we performed graphical and numerical spatial correlation analyses of the anomalies and observed strong agreement among the results provided by each method. Certain anomalies were reflected only in the magnetic and ERT studies. The results highlight the importance of applying several geophysical methods and performing spatial correlational analyses. Furthermore, the methodology that we have applied to evaluate the spatial correlation offers interesting results