994 resultados para Laser range finder


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Laser desorption ionisation mass spectrometry (LDI-MS) has demonstrated to be an excellent analytical method for the forensic analysis of inks on a questioned document. The ink can be analysed directly on its substrate (paper) and hence offers a fast method of analysis as sample preparation is kept to a minimum and more importantly, damage to the document is minimised. LDI-MS has also previously been reported to provide a high power of discrimination in the statistical comparison of ink samples and has the potential to be introduced as part of routine ink analysis. This paper looks into the methodology further and evaluates statistically the reproducibility and the influence of paper on black gel pen ink LDI-MS spectra; by comparing spectra of three different black gel pen inks on three different paper substrates. Although generally minimal, the influences of sample homogeneity and paper type were found to be sample dependent. This should be taken into account to avoid the risk of false differentiation of black gel pen ink samples. Other statistical approaches such as principal component analysis (PCA) proved to be a good alternative to correlation coefficients for the comparison of whole mass spectra.

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Objective: To discuss the convenience of laser surgery as optimal treatment for melanoma of the oral mucosa.Patients and methods: A retrospective evaluation of four patients with primary oral melanomas treated at a single Cancer Institution in Mexico City.Results: Two patients were treated with resection of the melanoma with CO2 laser together with extraction of the involved dental organs and curettage of the alveolar walls. These two cases had melanoma in situ with multiple isolated foci. The third patient had a lesion with vertical growth, who was submitted to partial maxillectomy along with selective dissection of bilateral neck levels I-V with a negative report and the fourth patient had a history of oral nodular melanoma and presented with lymph node metastasis. According to follow-up status, there was no distant metastasis in any of the patients reported here.Conclusion: In our experience, conservative management with CO2 laser is adequate for melanomas of the oral mucosa with extraction of the dental organs and curettage of the alveoli to achieve complete surgical resection microscopically without sacrifice of the quality of life. Management of the neck is controversial. We recommend selective therapeutic resection of the neck only if it is found to be clinically positive. Elective dissection has not shown to have an impact in overall survival.

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Terrestrial laser scanning (TLS) provides high-resolution point clouds of the topography and new TLS instruments with ranges exceeding 300 m or even 1000 m are powerful tools for characterizing and monitoring slope movements. This study focuses on the 35 million m3 Åknes rockslide in Western Norway, which is one of the most investigated and monitored rockslides in the world. The TLS point clouds are used for the structural analysis of the steep, inaccessible main scarp of the rockslide, including an assessment of the discontinuity sets and fold axes. TLS acquisitions in 2006, 2007 and 2008 provide information on 3-D displacements for the entire scanned area and are not restricted like conventional survey instruments to single measurement points. The affine transformation matrix between two TLS acquisitions precisely describes the rockslide displacements and enables their separation into translational components, such as the displacement velocity and direction, and rotational components, like toppling. This study shows the ability of TLS to obtain reliable 3-D displacement information over a large, unstable area. Finally, a possible instability model for the upper part of Åknes rockslide explains the measured translational and rotational displacements by a combination of southward planar sliding along the gneiss foliation, gravitational vertical settlement along the complex, stepped basal sliding surface and northward toppling toward the opened graben structure.

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The apicomplexan parasite Toxoplasma gondii is unusual in being able to infect almost any cell from almost any warm-blooded animal it encounters. This extraordinary host-range contrasts with its far more particular cousins such as the various species of the malaria parasite Plasmodium where each species of parasite has a single genus or even species of host that it can infect. Genetic and genomic studies have revealed a key role for a number of gene families in how Toxoplasma invades a host cell, modulates gene expression of that cell and successfully evades the resulting immune response. In this review, I will explore the hypothesis that a combination of sexual recombination and expansion of host range may be the major driving forces in the evolution of some of these gene families and the specific genes they encompass. These ideas stem from results and thoughts published by several labs in the last few years but especially recent papers on the role of different forms of rhoptry proteins in the relative virulence of F1 Toxoplasma progeny in a particular host species (mice).

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The registration of full 3-D models is an important task in computer vision. Range finders only reconstruct a partial view of the object. Many authors have proposed several techniques to register 3D surfaces from multiple views in which there are basically two aspects to consider. First, poor registration in which some sort of correspondences are established. Second, accurate registration in order to obtain a better solution. A survey of the most common techniques is presented and includes experimental results of some of them

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Photons participate in many atomic and molecular interactions and processes. Recent biophysical research has discovered an ultraweak radiation in biological tissues. It is now recognized that plants, animal and human cells emit this very weak biophotonic emission which can be readily measured with a sensitive photomultiplier system. UVA laser induced biophotonic emission of cultured cells was used in this report with the intention to detect biophysical changes between young and adult fibroblasts as well as between fibroblasts and keratinocytes. With suspension densities ranging from 1-8 x 106 cells/ml, it was evident that an increase of the UVA-laser-light induced photon emission intensity could be observed in young as well as adult fibroblastic cells. By the use of this method to determine ultraweak light emission, photons in cell suspensions in low volumes (100 microl) could be detected, in contrast to previous procedures using quantities up to 10 ml. Moreover, the analysis has been further refined by turning off the photomultiplier system electronically during irradiation leading to the first measurements of induced light emission in the cells after less than 10 micros instead of more than 100 milliseconds. These significant changes lead to an improvement factor up to 106 in comparison to classical detection procedures. In addition, different skin cells as fibroblasts and keratinocytes stemming from the same donor were measured using this new highly sensitive method in order to find new biophysical insight of light pathways. This is important in view to develop new strategies in biophotonics especially for use in alternative therapies.

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By this study we seek the expectable range of waist circumference (WC) for every degree of body mass index (BMI), which will serve to studies targeting ascertaining the health risk. We studied 2,932 patients (39.6% men and 60.4% women, between 18 and 96 years ) of the same ethnic group who consecutively attended outpatient departments of our clinics between 2000 and 2004. BMI correlated linearly with the WC (cc: 0.85; p < 0.001). The men, the obese, and diabetics were older (p < 0.001). BMI was greater in women and WC in men. The women had a greater WC if they had diabetes (p < 0.01), being equal to diabetic males. The men had greater WC when they had diabetes (p < 0.001). Waist at risk was detected (men > or = 102 cm and women > or = 88 cm) in 94.3% of the obese, in 32.3% of overweight patients, in 3.8% of patients with BMI < 25, in 84.3% of diabetics, and in 72.6% of patients without diabetes. We made graphic standardisation of WC with regard to BMI, and we calculated the percentiles 10, 25, 50, 75 and 90, grouping in ranges of 2 kg/m(2) of BMI. The diabetic patients are grouped in ranges of 4 kg/m(2). As conclusion we present a standardisation of the WC measurement of patients attended to in our Endocrinology and Nutrition practices distributed in percentiles as a clinically usable tool to define the ranges of WC for every BMI value.

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2320 composés chimiques ont été screenés à l'aide d'une lignée transgénique de zébrafish. Cette lignée comportait un gène humain fortement exprimé très tôt dans le développement et la croissance de différentes tumeurs, dont celle du rétinoblastome. L'activation de ce gène induisait la mort des embryons de lâ lignée transgénique. Nous avons donc pu identifier des composés agissant sur l'effet létal de ce gène. Cette étude a permis d'isoler plusieurs composés dont 1 très intéressant, l'Amitriptyline. Ce composé induit une inhibition de la prolifération et une induction d'apoptose dans les cellules humaines de rétinoblastome mais également dans d'autres cellules cancéreuses dont les ostéosarcomes connus. L'ostéosarçome est connu pour faire partie des cancers secondaires dû au rétinoblastome dans la forme héréditaire notamment. Ce composé induit la survie des embryons et réduit également le niveau d'expression de la protéine humaine intégrée dans la lignée de poisson zèbre transgénique de 50%. Le niveau d'expression de ce gène est également réduit de 50 à 60% dans des cultures cellulaire de rétinoblastome humain. L'inhibition de la prolifération a été démontrée par la réduction d'ATP dans plusieurs lignées cellulaires lorsque celles-ci sont traitées avec ce composé. L'induction d'apoptose a été démontrée par induction 10 fois plus élevée des éléments pro-apoptotiques caspase-3 et caspase-7 ainsi que par l'augmentation 10 fois plus élevée d'un élément anti-apoptotique bcl-2. Ces résultats permettent de croire que ce composé pourrait être utilisé pour traiter le rétinoblastome humain. -- Background: Retinoblastoma is a rare malignant tumor. This disease is the most prevalent intraocular cancer in childhood with an incidence of 1 in 15,000 live births. Many therapies are available to treat retinoblastoma, but best treatments are individually selected according to cases. Cryotherapy, thermotherapy, laser therapy including brachytherapy, radiation therapy and chemotherapy are some examples. New drug and new treatments discovery is essential for cancer therapy including retinoblastoma. Purpose: A vertebrate model as zebrafish for retinoblastoma would provide many advantages especially to perform drug screening. The high number of fertilized eggs per mating, the rapidity of extra¬utero development, the available genetic manipulation, the easy manipulations under a microscope, the ability to dispense embryos in 96-well plates and the direct incubation of chemical compounds in fish water are some examples of the advantages. Therefore, we design a transgenic zebrafish carrying a human gene implicated in retinoblastoma development and maintenance. Results: With the small compounds screening, several compounds were isolated. One of these compounds, Amitriptyline demonstrated proliferation inhibition and apoptosis in human retinoblastoma cells, U20S osteosarcoma cells and MBA-231 breast cancer cells. Osteosarcoma is known as secondary cancer due to retinoblastoma. Amitriptyline induced survival in our zebrafish transgenic line and 50% reduction of the integrated gene expression. In retinoblastoma cultured cells, the expression of this gene was also reduced in a range of 50-60 %. Proliferation inhibition was demonstrated by ATP luminescence assay. Apoptosis was demonstrated by a 10-fold induction of caspase-3 and caspase-7, two pro-apoptotic elements and by a 10-fold reduction of bcl-2 anti-apoptotic element. Conclusion: The results suggest that Amitriptyline could be used to treat human retinoblastoma in the near future.

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This study investigated the sandfly fauna of two quartzite caves in the Espinhaço Mountain Range, located in the municipality of Diamantina, state Minas Gerais. From August 2010-July 2011, entomological sampling was performed in the caves of Salitre and Monte Cristo with two HP light traps exposed in the photic and aphotic zones of each cave. The sandfly fauna consisted of 17 species, among which Lutzomyia cipoensis was predominant (54.76%). The male/female ratio in the total captures was 1:2.5. The aphotic zone showed the highest frequency of specimens captured (65%). A greater density of sandflies occurred during the summer (January-February), coinciding with the period of higher temperatures, humidity and rainfall. The presence of Lutzomyia longipalpis, Lutzomyia whitmani and Lutzomyia pessoai, proven or suspected vectors of leishmaniasis, is of concern because the area is visited by many tourists.

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The geographical distribution of Aedes albopictus in Brazil was updated according to the data recorded across the country over the last eight years. Countrywide house indexes (HI) for Ae. albopictus in urban and suburban areas were described for the first time using a sample of Brazilian municipalities. This mosquito is currently present in at least 59% of the Brazilian municipalities and in 24 of the 27 federal units (i.e., 26 states and the Federal District). In 34 Brazilian municipalities, the HI values for Ae. albopictus were higher than those recorded for Ae. aegypti, reaching figures as high as HI = 7.72 in the Southeast Region. Remarks regarding the current range of this mosquito species in the Americas are also presented. Nineteen American countries are currently infested and few mainland American countries have not confirmed the occurrence of Ae. albopictus. The large distribution and high frequency of Ae. albopictus in the Americas may become a critical factor in the spread of arboviruses like chikungunya in the new world.

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The publication of a draft of the human genome and of large collections of transcribed sequences has made it possible to study the complex relationship between the transcriptome and the genome. In the work presented here, we have focused on mapping mRNA 3' ends onto the genome by use of the raw data generated by the expressed sequence tag (EST) sequencing projects. We find that at least half of the human genes encode multiple transcripts whose polyadenylation is driven by multiple signals. The corresponding transcript 3' ends are spread over distances in the kilobase range. This finding has profound implications for our understanding of gene expression regulation and of the diversity of human transcripts, for the design of cDNA microarray probes, and for the interpretation of gene expression profiling experiments.

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Morphological and functional effects of transmyocardial laser revascularization (TMLR) are analyzed in an acute setting on a porcine model. Ten channels were drilled in the left lateral wall of the heart of 15 pigs (mean weight, 73 +/- 4 kg) with a Holmium-YAG laser (wavelength: 2.1 mu, probe diameter: 1.75 mm). Echocardiographic control was performed before the TMLR procedure as well as 5 min and 30 min thereafter. Echocardiographic parameters were recorded in short-axis at the level of the laser channels, and included left ventricular ejection fraction, fractional shortening and segmental wall motility of the channels' area (scale 0-3: 0 = normal, 1 = hypokinesia, 2 = akinesia, 3 = dyskinesia). After sacrifice the lased region was sliced perpendicularly to the channels for histological and morphometrical analysis. Five minutes after the drilling of the channels, all the echocardiographic index worsened significantly in comparison with baseline values (p < 0.01). All recovered after 30 min and showed no difference with baseline values. Cross-section of the channel lesions measured 8.8 +/- 2.4 mm2 which is more than three times that of the probe (p < 0.01). In acute conditions, the lesions due to the TMLR probe are significantly larger than the probe itself and cause a transient drop of the segmental wall motility on a healthy myocardium. These results suggest that TMLR should be used cautiously in the clinical setting for patients with an impaired ventricular function.