91 research outputs found
PCDD/F Emissions from Light-Duty Diesel Vehicles Operated under Highway Conditions and a Diesel-Engine Based Power Generator
PCDD/F emissions from three light-duty diesel vehicles–two vans and a passenger car–have been measured in on-road conditions. We propose a new methodology for small vehicles: a sample of exhaust gas is collected by means of equipment based on United States Environmental Protection Agency (U.S. EPA) method 23A for stationary stack emissions. The concentrations of O2, CO, CO2, NO, NO2 and SO2 have also been measured. Six tests were carried out at 90-100 km/h on a route 100 km long. Two additional tests were done during the first 10 minutes and the following 60 minutes of the run to assess the effect of the engine temperature on PCDD/F emissions. The emission factors obtained for the vans varied from 1800 to 8400 pg I-TEQ/Nm3 for a 2004 model year van and 490-580 pg I-TEQ/Nm3 for a 2006 model year van. Regarding the passenger car, one run was done in the presence of a catalyst and another without, obtaining emission factors (330-880 pg I-TEQ/Nm3) comparable to those of the modern van. Two other tests were carried out on a power generator leading to emission factors ranging from 31 to 78 pg I-TEQ/Nm3. All the results are discussed and compared with literature.The authors thank the Spanish Ministry of Education which supported the research project CTQ2008-05520 and the Valencian Community Government (Spain) for the support provided under PROMETEO/2009/043/FEDER
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
Kinetics of the combustion of olive oil. A semi-global model
Support for this work was provided by PROMETEO/2009/043/FEDER of Generalitat Valenciana (Spain) and CTQ2008-05520 (Spanish MCI/research)
Immunomodulatory drugs: oral and systemic adverse effects
Objectives: The main objectives are to present the different adverses effects of the immunomodulatory drugs that
can impair the quality of life of the immunosupressed patients and study the impact of immunomodualtion on
oral diseases. Immunomodulatory drugs have changed the treatment protocols of many diseases where immune
functions play a central role, such as rheumatic diseases. Their effect on oral health has not been systematically
investigated, however.
Study Design: We review current data on the new immunomodulatory drugs from the oral health perspective
based on open literature search of the topic.
Results: These target specific drugs appear to have less drug interactions than earlier immunomodulating medicines
but have nevertheless potential side effects such as activating latent infections. There are some data showing
that the new immunomodulatory drugs may also have a role in the treatment of certain oral diseases such as lichen
planus or ameliorating symptoms in Sjögren´s syndrome, but the results have not been overly promising.
Conclusions: In general, data are sparse of the effect of these new drugs vs. oral diseases and there are no properly
powered randomized controlled trials published on this topic
Kinetic study of the pyrolysis and combustion of tomato plant
A kinetic study of the thermal decomposition of tomato plant has been carried out under different conditions by TG and TG–MS. A total of 24 experiments were performed in a nitrogen atmosphere (pyrolysis runs) and also in an oxidative atmosphere with two different oxygen concentrations (10% and 20% oxygen in nitrogen). Dynamic runs and dynamic + isothermal runs have been carried out to obtain many data of decomposition under different operating conditions. A scheme of five independent reactions for pseudocomponents has been proposed for the pyrolysis process, although only three fractions have probed to be significant, comparing the weight fractions of volatiles evolved with the hemicellulose, cellulose and lignin content of the plant. For the combustion runs, four new reactions have been added: two competitive oxidation reactions for the cellulose and lignin, and two combustion reactions of the carbonaceous residue obtained from pyrolysis. The kinetic parametres have been calculated by integration of the differential equations and minimizing the differences between the experimental and calculated values. It is important to emphasize that the same set of parameters has been proposed for the pyrolysis and combustion runs, and which do not depend on either the heating rate in dynamic runs or whether the run is carried out in a dynamic or isothermal mode. The influence of the oxygen pressure has been also discussed.Support for this work was provided by Spanish MEC, research project CTQ2005-05262
Osteoartrosis de la articulación temporomandibular: estudio clínico y radiológico de 16 pacientes
Objetivo: El objetivo del presente estudio fue describir las características
clínicas y radiológicas de 16 pacientes con
osteoartrosis (OA) de la articulación temporomandibular
(ATM).
Material y métodos: En el estudio participaron aquellos pacientes
que reunieran los criterios diagnósticos para la OA propuestos
por Stegenga y cols en 1989. Los pacientes fueron sometidos
a un protocolo de diagnóstico tanto clínico como por técnicas
de imagen (obteniéndose los datos de una resonancia nuclear
magnética).
Resultados: Los signos clínicos más destacados fueron la presencia
de crepitación a la auscultación en un 93,8% de los casos,
y una disminución en el rango de los movimientos
mandibulares. Los hallazgos radiológicos mostraron una alteración
en la morfología de las superficies articulares en un 62%
de los casos en el lado derecho y en un 68,8% de los pacientes
en el lado izquierdo. En el estudio de la posición dinámica del
disco articular se observó un desplazamiento anterior sin reducción
en el 50% de los casos en la ATM derecha y en un
43,8% en la izquierda.
Conclusiones: Los pacientes con OA de la ATM presentan crepitación
y disminución en el rango de los movimientos
mandibulares, siendo la alteración de la morfología articular el
rasgo radiológico más destacable.A study is made of the clinical and radiological characteristics
of 16 patients with osteoarthrosis (OA) of the temporomandibular
joint (TMJ). The study comprised those patients
satisfying the diagnostic criteria for OA proposed by Stegenga et al. in 1989. The patients were subjected to a clinical and
radiological diagnostic protocol (including the obtainment of
magnetic resonance imaging data).
The most relevant clinical findings were the detection of
crepitants in 93.8% of cases, with a reduction in mandibular
movement range. Radiology in turn identified joint surface
alterations in 62% of cases on the right side, and in 68.8% of the
patients on the left side. The joint disc dynamic position study
showed anterior displacement without reduction in 50% of cases
in the right joint and in 43.8% of patients in the left joint.
In conclusion, patients with OA of the TMJ present joint sounds
and a reduced mandibular movement range ' the salient
radiological characteristic being altered joint morphology
Influence of smoking upon the postoperative course of lower third molar surgery
Objectives: To determine whether smoking influences the postoperative course (pain and trismus) of lower third molar surgery, with a clinical evaluation of surgical wound condition and analysis of the possible differences between smokers and nonsmokers. Design: The study subjects were randomly distributed into two groups (smokers and nonsmokers) and subjected to lower third molar extraction in the Unit of Oral and Maxillofacial Surgery (Madrid Complutense University, Spain). The study variables were trismus after 7 days, the intensity of pain and the need for rescue medication during a period of one week. The surgical wound was also assessed (color, presence of plaque, etc.). Results: Two cases of postoperative infection were documented among the smokers, and postoperative trismus was found to be greater among the latter (p=0.05). Conclusions: There were no statistically significant differences between the two groups in terms of pain, though trismus was greater among the smokers. Smoking did not influence wound condition (color, marginal inflammation, appositioning of the margins, ulceration, etc.)
Influencia del hábito tabáquico en el postoperatorio de la cirugía del tercer molar inferior
Objetivos: Determinar si tras la cirugía del tercer molar inferior el tabaco influye en el postoperatorio (dolor y trismo) y valorar clínicamente el estado de la herida, analizando las posibles diferencias entre fumadores y no fumadores.
Diseño del estudio: Los pacientes que participaron en el estudio fueron distribuidos de forma aleatoria en dos grupos: Fumadores y no fumadores. Se les realizó la extracción quirúrgica de los terceros molares inferiores en la Unidad de Cirugía Bucal y Maxilofacial de la Universidad Complutense de Madrid. Las variables registradas fueron el trismo a los 7 días, la intensidad del dolor y la necesidad de medicación de rescate durante un periodo de una semana. Se analizó también el estado de la herida (coloración, presencia de placa, etc.)
Resultados: Hubo dos casos de infección postoperatoria en el grupo de pacientes fumadores. El trismo postoperatorio fue mayor en los fumadores (p=0.05)
Conclusiones: No hubo diferencias estadísticamente significativas en cuanto a dolor, pero sí se observó un mayor trismo en el grupo de fumadores. El tabaco no influyó en el estado de la herida ( color, inflamación de los bordes, confrontación de los mismos, ulceración, etc.).Objectives: To determine whether smoking influences the postoperative course (pain and trismus) of lower third molar surgery, with a clinical evaluation of surgical wound condition and analysis of the possible differences between smokers and nonsmokers.
Design: The study subjects were randomly distributed into two groups (smokers and nonsmokers) and subjected to lower third molar extraction in the Unit of Oral and Maxillofacial Surgery (Madrid Complutense University, Spain). The study variables were trismus after 7 days, the intensity of pain and the need for rescue medication during a period of one week. The surgical wound was also assessed (color, presence of plaque, etc.).
Results: Two cases of postoperative infection were documented among the smokers, and postoperative trismus was found to be greater among the latter (p=0.05).
Conclusions: There were no statistically significant differences between the two groups in terms of pain, though trismus was greater among the smokers. Smoking did not influence wound condition (color, marginal inflammation, appositioning of the margins, ulceration, etc.)
Current status of the torus palatinus and torus mandibularis
While there is a hereditary component to tori, this does not explain all cases. Tori tend to appear more frequently during middle age of life; the torus palatinus is more commonly observed in females, but this is not the case with the torus mandibularis. Certain ethnic groups are more prone to one torus or the other. The torus is mainly removed due to prostodontic reasons, as it may also be used as biomaterial, not only in periodontology, but also in implantology. The aim of this study was a review of the literature from the past twenty years
Evaluation of p53, Caspase-3, Bcl-2, and Ki-67 markers in oral squamous cell carcinoma and premalignant epithelium in a sample from Alava Province (Spain)
Objectives: The objective of this study was to determine whether alterations in the expression of p53, caspase-3
Bcl-2, and ki-67 appear early in premalignant oral epithelium and show clonal behavior.
Study Design: Samples from 41 tumors with their adjacent non-tumor epithelia were immunohistochemically
analyzed using monoclonal antibodies that recognize p53, caspase-3, Bcl-2, and Ki-67
Results: A statistically significant association was found between the expression in tumor and adjacent epithelium
of p53, caspase-3, and Bcl-2 but not of k-67. A significant association was observed between the expression
of ki-67 and p53 in both localizations. In non-tumor (premalignant) epithelium samples, there was a significant
inverse relationship between the expressions of p53 and caspase-3 and a significant direct relationship between
the expressions of p53 and Bcl-2.
Conclusions: Alterations in these proteins appear to operate in combination with premalignant epithelia to create
hyperproliferative cell states that favor the acquisition of summative oncogenic errors that confer invasive capacity
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