336 research outputs found
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Liquid biopsy genotyping in lung cancer: ready for clinical utility?
Liquid biopsy is a blood test that detects evidence of cancer cells or tumor DNA in the circulation. Despite complicated collection methods and the requirement for technique-dependent platforms, it has generated substantial interest due, in part, to its potential to detect driver oncogenes such as epidermal growth factor receptor (EGFR) mutants in lung cancer. This technology is advancing rapidly and is being incorporated into numerous EGFR tyrosine kinase inhibitor (EGFR-TKI) development programs. It appears ready for integration into clinical care. Recent studies have demonstrated that biological fluids such as saliva and urine can also be used for detecting EGFR mutant DNA through application other user-friendly techniques. This review focuses on the clinical application of liquid biopsies to lung cancer genotyping, including EGFR and other targets of genotype-directed therapy and compares multiple platforms used for liquid biopsy
Using Type-2 Fuzzy Models to Detect Fall Incidents and Abnormal Gaits Among Elderly
— June 2012, 11% of the overall population in Taiwan
was over the age of 65. This ratio is higher than the average
figure for the United Nations (8%)
. Critical issues concerning
elderly in healthcare include fall detection, loneliness prevention
and retard of obliviousness. In this study we design type-2 fuzzy
models that utilize smart phone tri-axial accelerometer signals to
detect fall incidents and identify abnormal gaits among elderly.
Once a fall incident is detected an alarm is sent to notify the
medical staff for taking any necessary treatment. When the
proposed system is used as a pedometer, all the tri-axial
accelerometer signals are used to identify the gaits during
walking. Based on the proposed type-2 fuzzy models, the walking
gaits can be identified as normal, left-tilted, and right-tilted.
Experimental results from type-2 fuzzy models reveal that the
accuracy rates in identifying normal walking and fall over are
92.3% and 100%, respectively, exceeding what are obtained
using type-1 fuzzy models
A Comparison of Thermal Deformation of Scroll Profiles inside Oil-free Scroll Vacuum Pump and Compressor via CAE/CFD Analysis
Scroll machine is simply constructed by fixed and orbit scrolls, rotary shaft, and some mechanical components. It can impressively operate at low noise level with high reliability and high efficiency. Scroll machine achieves oil-free application through reasonable clearance control, cooling solution, and the tip seal application, and has been designed and applied as vacuum pump or compressor. In order to compactly design structure and optimize the gaps or clearances of a scroll machine, the issue of heat deformation must be considered. Deformation inside a scroll machine is not easy to be discovered, but is the necessary information for scroll profile design. In this study, the internal flow fields of oil-free scroll vacuum pump and compressor are obtained by CFD analysis. Based on the results of flow fields, this study shows the basic performance of a scroll machine, including loading on structures, gas torque, volume flow rate, and the pulsation of outlet pressure. The fluid phenomena under sub-atmospheric and positive pressure are quite different. The difference would cause different heat transfer and heat deformation. Therefore, the fluid-thermal-solid coupling analysis is also carried out. The temperature distribution of scroll structures, the thermal deformation, and gap changes are also discussed in this study
Outcome of lung cancer patients with acute respiratory failure requiring mechanical ventilation
AbstractTo assess the weaning outcome of lung cancer patients with acute respiratory failure (ARF) requiring mechanical ventilation, we retrospectively analyzed the database of the respiratory intensive care unit at a university-affiliated tertiary care hospital.Charts were reviewed for cancer status, biochemistries before respiratory failure, causes of respiratory failure, acute physiology and chronic health evaluation (APACHE) III score, ventilatory settings, data recorded during spontaneous breathing, duration of ventilator days, and weaning outcome. Ninety-five consecutive respiratory failure events in 81 patients were recorded from January 1, 1995 through June 30, 1999.Twenty-six episodes ended with successful weaning (27.4%). Age, gender, and cancer status did not affect the weaning outcome. Serum albumin level, APACHE III score, highest fractional inspired O2 (FiO2) and highest positive end-expiratory pressure, organ failure, ability to shift to partial ventilatory support, and duration of mechanical ventilation could significantly influence the weaning outcome statistically. The overall hospital mortality rate was 85.2%.Our results suggested that lung cancer patients with ARF will have a better chance to wean if the initial APACHE III score was less than 70, use of FiO2 never exceeded 0.6, or less than 2 additional organ systems failed during the treatment course
Tooth Position Determination by Automatic Cutting and Marking of Dental Panoramic X-ray Film in Medical Image Processing
This paper presents a novel method for automatic segmentation of dental X-ray images into single tooth sections and for placing every segmented tooth onto a precise corresponding position table. Moreover, the proposed method automatically determines the tooth’s position in a panoramic X-ray film. The image-processing step incorporates a variety of image-enhancement techniques, including sharpening, histogram equalization, and flat-field correction. Moreover, image processing was implemented iteratively to achieve higher pixel value contrast between the teeth and cavity. The next image-enhancement step is aimed at detecting the teeth cavity and involves determining the segment and points separating the upper and lower jaw, using the difference in pixel values to cut the image into several equal sections and then connecting each cavity feature point to extend a curve that completes the description of the separated jaw. The curve is shifted up and down to look for the gap between the teeth, to identify and address missing teeth and overlapping. Under FDI World Dental Federation notation, the left and right sides receive eight-code sequences to mark each tooth, which provides improved convenience in clinical use. According to the literature, X-ray film cannot be marked correctly when a tooth is missing. This paper utilizes artificial center positioning and sets the teeth gap feature points to have the same count. Then, the gap feature points are connected as a curve with the curve of the jaw to illustrate the dental segmentation. In addition, we incorporate different image-processing methods to sequentially strengthen the X-ray film. The proposed procedure had an 89.95% accuracy rate for tooth positioning. As for the tooth cutting, where the edge of the cutting box is used to determine the position of each tooth number, the accuracy of the tooth positioning method in this proposed study is 92.78%
Cytochrome P450 Metabolism of Betel Quid-Derived Compounds: Implications for the Development of Prevention Strategies for Oral and Pharyngeal Cancers
Betel quid (BQ) products, with or without tobacco, have been classified by the International Agency for Research on Cancer (IARC) as group I human carcinogens that are associated with an elevated risk of oral potentially malignant disorders (OPMDs) and cancers of the oral cavity and pharynx. There are estimated 600 million BQ users worldwide. In Taiwan alone there are 2 million habitual users (approximately 10% of the population). Oral and pharyngeal cancers result from interactions between genes and environmental factors (BQ exposure). Cytochrome p450 (CYP) families are implicated in the metabolic activation of BQ- and areca nut-specific nitrosamines. In this review, we summarize the current knowledge base regarding CYP genetic variants and related oral disorders. In clinical applications, we focus on cancers of the oral cavity and pharynx and OPMDs associated with CYP gene polymorphisms, including CYP1A1, CYP2A6, CYP2E1, and CYP26B1. Our discussion of CYP polymorphisms provides insight into the importance of screening tests in OPMDs patients for the prevention of oral and pharyngeal cancers. Future studies will establish a strong foundation for the development of chemoprevention strategies, polymorphism-based clinical diagnostic tools (e.g., specific single-nucleotide polymorphism (SNP) “barcodes”), and effective treatments for BQ-related oral disorders
Arsenic exposure and lung fibrotic changes-evidence from a longitudinal cohort study and experimental models
IntroductionArsenic (As) exposure is associated with lung toxicity and we aim to investigate the effects of arsenic exposure on lung fibrotic changes.MethodsParticipants (n= 976) enrolled via a general health survey underwent chest low-dose computed tomography (LDCT), spirometry forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and urinary arsenic examination during 2016 and 2018. Lung fibrotic changes from LDCT were defined. AsLtoL, low arsenic levels in both 2016 and 2018; AsLtoH, low arsenic in 2016 but high levels in 2018; AsHtoL, high arsenic in 2016 but low levels in 2018; AsHtoH, high arsenic levels in both 2016 and 2018. Mice exposed to 0. 0.2mg/L, 2 mg/L, 50 mg/L of sodium arsenite (NaAsO2) through drinking water for 12 weeks and 24 weeks were applied for histological analysis. Cultured lung epithelial cells were exposed to NaAsO2 and the mesenchymal changes were examined.ResultsAsHtoH increased the risk (OR= 1.65, 95% CI 1.10, 2.49) of Lung fibrotic positive to positive (reference: Lung fibrotic negative to negative) compared with AsLtoL. Moreover, the predicted mean of FVC and FEV1 in AsHtoH (−0.09 units, 95% CI: −0.27, −0.09; −0.09 units, 95% CI: −0.17, −0.01) and AsLtoH (−0.13 units, 95% CI: −0.30, −0.10; −0.13 units, 95% CI: −0.22, −0.04) was significantly lower than ASLtoL. Significant lung fibrotic changes including the increase of the alveolar septum thickness and collagen fiber deposition were observed upon 2 mg/L NaAsO2 treatment for 12 weeks, and the damage was dose- and time-dependent. In vitro, sodium arsenite treatment promotes the epithelial-mesenchymal transition (EMT)-like changes of the normal human bronchial epithelial cells, including upregulation of several fibrotic and mesenchymal markers (fibronectin, MMP-2, and Snail) and cell migration. Inhibition of reactive oxygen species (ROS) and MMP-2 impaired the arsenic-induced EMT changes. Administration of a flavonoid, apigenin, inhibited EMT in vitro and pulmonary damages in vivo with the reduction of mesenchymal markers.Discussionwe demonstrated that continued exposure to arsenic causes lung fibrosis in humans and mice. Targeting lung epithelial cells EMT is effective on the development of therapeutic strategy. Apigenin is effective in the inhibition of arsenic-induced pulmonary fibrosis and EMT
Caries and Restoration Detection Using Bitewing Film Based on Transfer Learning with CNNs
Caries is a dental disease caused by bacterial infection. If the cause of the caries is detected early; the treatment will be relatively easy; which in turn prevents caries from spreading. The current common procedure of dentists is to first perform radiographic examination on the patient and mark the lesions manually. However; the work of judging lesions and markings requires professional experience and is very time-consuming and repetitive. Taking advantage of the rapid development of artificial intelligence imaging research and technical methods will help dentists make accurate markings and improve medical treatments. It can also shorten the judgment time of professionals. In addition to the use of Gaussian high-pass filter and Otsu’s threshold image enhancement technology; this research solves the problem that the original cutting technology cannot extract certain single teeth; and it proposes a caries and lesions area analysis model based on convolutional neural networks (CNN); which can identify caries and restorations from the bitewing images. Moreover; it provides dentists with more accurate objective judgment data to achieve the purpose of automatic diagnosis and treatment planning as a technology for assisting precision medicine. A standardized database established following a defined set of steps is also proposed in this study. There are three main steps to generate the image of a single tooth from a bitewing image; which can increase the accuracy of the analysis model. The steps include (1) preprocessing of the dental image to obtain a high-quality binarization; (2) a dental image cropping procedure to obtain individually separated tooth samples; and (3) a dental image masking step which masks the fine broken teeth from the sample and enhances the quality of the training. Among the current four common neural networks; namely; AlexNet; GoogleNet; Vgg19; and ResNet50; experimental results show that the proposed AlexNet model in this study for restoration and caries judgments has an accuracy as high as 95.56% and 90.30%; respectively. These are promising results that lead to the possibility of developing an automatic judgment method of bitewing film
Detection of Dental Apical Lesions Using CNNs on Periapical Radiograph
Apical lesions, the general term for chronic infectious diseases, are very common dental diseases in modern life, and are caused by various factors. The current prevailing endodontic treatment makes use of X-ray photography taken from patients where the lesion area is marked manually, which is therefore time consuming. Additionally, for some images the significant details might not be recognizable due to the different shooting angles or doses. To make the diagnosis process shorter and efficient, repetitive tasks should be performed automatically to allow the dentists to focus more on the technical and medical diagnosis, such as treatment, tooth cleaning, or medical communication. To realize the automatic diagnosis, this article proposes and establishes a lesion area analysis model based on convolutional neural networks (CNN). For establishing a standardized database for clinical application, the Institutional Review Board (IRB) with application number 202002030B0 has been approved with the database established by dentists who provided the practical clinical data. In this study, the image data is preprocessed by a Gaussian high-pass filter. Then, an iterative thresholding is applied to slice the X-ray image into several individual tooth sample images. The collection of individual tooth images that comprises the image database are used as input into the CNN migration learning model for training. Seventy percent (70%) of the image database is used for training and validating the model while the remaining 30% is used for testing and estimating the accuracy of the model. The practical diagnosis accuracy of the proposed CNN model is 92.5%. The proposed model successfully facilitated the automatic diagnosis of the apical lesion
Platform Deformation Phase Correction for the AMiBA-13 Coplanar Interferometer
[[abstract]]We present a new way to solve the platform deformation problem of coplanar interferometers. The platform of a coplanar interferometer can be deformed due to driving forces and gravity. A deformed platform will induce extra components into the geometric delay of each baseline and change the phases of observed visibilities. The reconstructed images will also be diluted due to the errors of the phases. The platform deformations of The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) were modeled based on photogrammetry data with about 20 mount pointing positions. We then used the differential optical pointing error between two optical telescopes to fit the model parameters in the entire horizontal coordinate space. With the platform deformation model, we can predict the errors of the geometric phase delays due to platform deformation with a given azimuth and elevation of the targets and calibrators. After correcting the phases of the radio point sources in the AMiBA interferometric data, we recover 50%-70% flux loss due to phase errors. This allows us to restore more than 90% of a source flux. The method outlined in this work is not only applicable to the correction of deformation for other coplanar telescopes but also to single-dish telescopes with deformation problems. This work also forms the basis of the upcoming science results of AMiBA-13.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]電子版[[booktype]]紙本[[countrycodes]]US
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