110 research outputs found
Radiation damping for rigid foundations. Approximate expressions
The dynamic response of machine foundations was one of the first problems studied in soil dynamics with results going back to the 1930s. A number of approximations and graphical results were proposed in the 60s. In this paper we present a series of approximate expressions for the natural frequencies and effective damping of rigid masses on the surface of an elastic half space subjected to both vertical and coupled horizontal-rocking harmonic excitations. The formulas are obtained using the approximate expressions for the dynamic stiffness of circular foundations suggested by Veletsos et al [1, 2] for two different values of Poisson’s ratio of the soil. For the vertical case the expressions are only a function of the mass ratio (ratio of the mass of the foundation to an effective mass of soil) and of Poisson’s ratio. For the horizontal-rocking case they depend also on the ratio of the height of the foundation to its equivalent radius (a slenderness ratio)
Acute Colchicine-induced Neuromyopathy in a Patient Treated With Atorvastatin and Clarithromycin
Neuromyopathy is a rare side effect of chronic colchicine therapy, especially without renal impairment. Drugs interacting with colchicine metabolism through CYP3A4 can accelerate accumulation and toxicity. We describe a case of an interaction between atorvastatin, clarithromycin and colchicine resulting in acute neuromyopathy.
Learning points: Colchicine has a narrow therapeutic window, and therefore, often produces side effects.Special caution should be adopted if patients with renal disease and concomitant medications are given colchicine.Before prescribing colchicine, the clinical history, including previous medications and conditions, should be carefully considered
Osteochemonecrosis of the jaws due to bisphosphonate treatments : update
Bisphosphonates (BP),were initially used in industry and later as a drug due to their great affinity to osseous tissue, because of their powerful antiresorptive effect as a treatment in various osteopathies, such as osteoporosis, Paget disease or hypercalcemia associated with some malignant tumors, as myeloma or breast cancer. They are administered orally or intravenously, and although well tolerated, the most frequent side effects are gastrointestinal, in addition to osteonecrosis when they are administered via endovenous. The aim of this work has been to evaluate the existing publications in accredited scientific literature on biphosphonates and their action mechanism and the relationship with the appearance of osteonecrosis of the jaws. Although the mechanism by which osteonecrosis of the jaws develops is not known exactly, there seems to be influence by osteoclast inhibiton, antiangiogenic action, an inhibitory effect on the cellular cycle by the keratinocytes, as well as, reinforcement of the chemiotoxic action in oncological patients treated with other drugs. Clinically, it ranges from a non-specificity of symptoms to lesions such as osteomyelitis with necrosis and osseous sequesters that may be accompanied by fetor ex oris, with the appearance of many Actinomyces contaminated lesions. As for published antecedents on osteonecrosis due to bisphosphonate treatment found until 2006: 46.5% had a previous diagnosis of multiple myeloma; 38.8% were patients with metastatic breast cancer; 6.2% patients of metastatic prostate cancer; 4.1% suffered from osteoporosis; 3.5% from other metastatic diseases and 0.8% had Paget disease. The drugs that seem to have the highest incidence of osteochemionecrosis are: zoledronate, pamidronate, alendronate, risendronate and ibandronate, from the greatest to the least. Additionally, the risk of osteonecrosis being produced is accumulative and may reach 21% in the third year of intravenous bisphosphonate use
Electrosynthesis of inorganic compounds: Chloro-Alcali industry
La electrosÃntesis se define como la obtención de sustancias quÃmicas con la ayuda de una celda electroquÃmica mediante reacciones redox. MuchÃsimos procesos electrosintéticos acaban aplicándose para usos industriales. Distinguimos dos tipos de procesos electrosintéticos: inorgánicos y orgánicos. En los inorgánicos se obtiene directamente la sustancia deseada en el electrodo de trabajo, además de otros posibles subproductos. Los principales productos obtenidos por la electrosÃntesis inorgánica son: flúor, aluminio, cloro y sosa.Electrosynthesis is the obtaining of chemical compounds. We use a electrochemistry cell with electrochemistry reactions. Electrochemistry processes have industrial uses. We have two types of electrochemistry processes: inorganic and organic. At inorganic process we obtain directy the product in the work electrode and other possible derivates. The main products obtained by inorganic methods are: fluorine, aluminunm, chlorine and caustic soda. These methods can be very useful for get these substance
Revisión de la evidencia cientÃfica sobre uso clÃnico del Trabecular Bone Score (TBS). Posiciones oficiales de la SEIOMM (2018)
La incorporación de nuevas aplicaciones tecnológicas en el campo médico conlleva un prolongado periodo de valoración de la evidencia cientÃfica que se va generando en el proceso de validación clÃnica.
En los últimos 5 años se han generado múltiples publicaciones, comunicaciones en congresos
y reuniones de sociedades cientÃficas. La aplicación del Trabecular Bone Score (TBS) ha recibido también la atención de la Sociedad Internacional de DensitometrÃa ClÃnica (The International Society for Clinical Densitometry -ISCD-) que la ha incorporado a sus posiciones oficiales
Edificación: ejercicios resueltos y prácticas de informática
El objetivo del presente libro es poner a disposición de los alumnos de la asignatura de Edificación, impartida en 4º curso del Grado de IngenierÃa Civil de la UPCT, una serie de ejercicios resueltos y de prácticas de informática guiadas que les sirvan para introducirse en campo de los proyectos de estructuras de hormigón para edificios.
Los ejercicios que aquà se aportan están resueltos utilizando métodos que podemos calificar ya como clásicos en el diseño de elementos estructurales. Estos métodos, que se encuentran desarrollados en las referencias bibliográficas de este libro, se pueden describir como métodos simplificados y reglas prácticas, que establecen unas hipótesis aceptables para poder aplicar casi exclusivamente las ecuaciones de equilibrio a los elementos estructurales con el fin de obtener esfuerzos en dichos elementos. A partir de la obtención de dichos esfuerzos, en el presente documento se comprueban varios de los Estados LÃmites Últimos y de Servicio siguiendo la Instrucción EHE.
La resolución de ejercicios de diseño de elementos con métodos clásicos o simplificados - estos son por ejemplo el método del equilibrio lÃmite, el método de bielas y tirantes, método de los pórticos virtuales – adquiere la función de predimensionamiento en el flujo de trabajo para el diseño de la estructura.
El libro contiene seis ejercicios tipo resueltos de elementos estructurales de un edificio y tres prácticas de informática guiadas, con el programa Cype, con el objetivo de introducir al alumno en su uso dentro del proyecto de cimentaciones, de muros pantalla y de la estructura completa de un edificio de oficinas. Finalmente, el libro también incluye el enunciado del trabajo de curso de la asignatura propuesto para el presente año académico 2020-2021
Sarcopenic osteoporosis, sarcopenic obesity, and sarcopenic osteoporotic obesity in the Camargo cohort (Cantabria, Spain)
Summary
The associations of sarcopenia with osteoporosis or obesity have a very low prevalence. No trend towards an association between osteoporosis and sarcopenia is observed. Sarcopenia and obesity tend not to coincide, as if they were antagonistic disorders.
Purpose
To know (a) the prevalence in our region of sarcopenic osteoporosis (association of sarcopenia and osteoporosis (T-score<2.5)), sarcopenic obesity, and the association of osteoporosis, sarcopenia, and obesity; (b) the tendency of osteoporosis, sarcopenia, and obesity to associate with each other; and (c) the bone mineral density (BMD), the components of sarcopenia, and the prevalence of fragility fractures in these associations.
Methods
The study was performed in the Camargo cohort. Osteoporosis was diagnosed by DXA, sarcopenia by the EWGSOP-1 criteria, and obesity by body mass index (BMI) and fat percentage. Fractures were verified radiographically or by consulting the medical records.
Results
The prevalence of sarcopenic osteoporosis was 2.8% and the OR for this association 1.03 (p=0.89). The prevalence of sarcopenic obesity by BMI was 1.4% and by fat percentage 5.9% (corresponding ORs: 0.18 (p<0.0001) and 0.58 (p<0.003) respectively). The prevalence of the association of osteoporosis, sarcopenia, and obesity was 0.0% when assessed by BMI and 0.8% when assessed by fat percentage. Patients with sarcopenic osteoporosis have less muscle mass and more fragility fractures than sarcopenic patients overall. In patients with sarcopenic obesity by fat percentage, muscle mass and strength, as well as physical performance, were similar to those of sarcopenic patients overall. Neither BMD nor fracture prevalence showed differences between patients with sarcopenic obesity and patients with sarcopenia or obesity in general.
Conclusion
Our study supports the idea that the prevalence of the mixed disorders studied is low. No significant association between osteoporosis and sarcopenia was found. Sarcopenia and obesity seem to tend to occur in different people, as if suffering from one of them hinders suffering from the other.Funding: Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was funded by grants from
the Instituto de Salud Carlos III (PI18/00762), Ministerio de EconomÃa y Competitividad, Spain, which included FEDER funds from the EU
Casos prácticos de análisis y diseño de puentes con SOFISTIK: un software BIM
El objetivo del presente libro es facilitar a los alumnos de la asignatura Diseño, Análisis y Modelo BIM de Puentes habituales de Carretera y Ferrocarril del Máster Universitario en MetodologÃa BIM para el Desarrollo de Proyectos de Infraestructuras (MUMBIM), y a los alumnos de futuros cursos de especialización de la UPCT, una serie de casos prácticos de análisis y diseño de puentes, donde se emplea el software SOFiSTiK.
Con los casos prácticos que se presentan aquÃ, que tienen un formato de prácticas de informática guiadas, se pretende que los estudiantes del MUMBIM se inicien en el manejo de uno de los programas de referencia en el diseño de puentes.
El libro incluye: la construcción de un modelo BIM 3D de un puente losa con Revit y su plugin SOFiSTiK Bridge Modeler; el análisis, el diseño estructural y el modelado BIM del tablero de un puente de carretera de vigas más losa, teniendo en cuenta las fases constructivas, el pretensado y sus pérdidas, y comprobando la resistencia de las secciones y las tensiones en servicio según el Eurocódico 2; además de una práctica para conocer la metodologÃa para determinar el factor de impacto de los elementos estructurales de un viaducto de ferrocarril de una lÃnea de alta velocidad, práctica en la que se realiza un análisis dinámico por integración directa en el tiempo con un modelo de cargas móviles correspondiente al tren HSLM-A1 del Eurocódigo 1 (EN 1991) viajando a 360 km/h.
El contenido del libro tiene únicamente un fin educativo. En él se hace referencia a una serie de material en forma de archivos CAD, archivos de modelos intermedios y finales de SOFiSTiK SSD y documentos PDF que se encuentran a disposición de los estudiantes en el Aula Virtual de la asignatura mencionada del MUMBIM, y que estará también disponible en el Aula Virtual de futuros cursos de especialización en diseño de puentes de la UPCT
Bone turnover markers in Spanish adult men The Camargo Cohort Study
BACKGROUND. This cross-sectional study was performed to determine the
reference ranges for two bone turnover markers -aminoterminal propeptide of
type I collagen (P1NP) and C-terminal telopeptide of type I collagen (-CTX)- in
normal adult Spanish men as measured in serum by automated methods.
METHODS. A community-based population of 660 healthy men ≥ 50 years was
evaluated. Fasting serum levels of P1NP, -CTX, 25-hydroxivitamin D, and
intact parathyroid hormone were measured on the Elecsys 2010 automated
analyzer (Roche). BMD at lumbar spine, femoral neck and total hip was
determined by DXA.
RESULTS. Mean age of participants was 65±9 yrs. Logarithmic transformation
of both markers was performed to allow for normal distribution. Mid-95% ranges
for P1NP and -CTX were 15-78 ng/ml and 0.069-0.760 ng/ml, respectively.
Median and interquartile range of serum P1NP and -CTX were 33.5 [25.5;44.4]
ng/ml and 0.27 [0.19;0.38] ng/ml, respectively. Mean values of P1NP
(37.1±16.7 ng/ml) were similar to those previously described. -CTX mean
values (0.300±0.171 ng/ml) were also similar to those quoted by the
manufacturers in men younger than 70 yrs, but slightly lower than those
reported in subjects older than 70 yrs. Both markers were higher among
osteoporotic men. After excluding from the analysis those men who were found
to have BMD below -2.5 T-score, 25OHD serum level below 30 ng/ml or serum
PTH above 65 pg/ml, P1NP and -CTX ranges were 17-71 ng/ml and 0.070-
0.681 ng/ml, again respectively.
CONCLUSIONS. Values obtained from this well-characterized population study
provide reference ranges for serum automated P1NP and -CTX in normal
Spanish adult men
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