Magnetic resonance imaging-derived radiomic signature predicts locoregional failure after organ preservation therapy in patients with hypopharyngeal squamous cell carcinoma.

BACKGROUND AND PURPOSE: To develop and validate a magnetic resonance imaging (MRI)-derived radiomic signature (RS) for the prediction of 1-year locoregional failure (LRF) in patients with hypopharyngeal squamous cell carcinoma (HPSCC) who received organ preservation therapy (OPT). MATERIAL AND METHODS: A total of 800 MRI-based features of pretreatment tumors were obtained from 116 patients with HPSCC who received OPT from two independent cohorts. The least absolute shrinkage and selection operator regression model were used to select the features used to develop the RS. Harrell's C-index and corrected C-index were used to evaluate the discriminative ability of RS. The Youden index was used to select the optimal cut-point for risk category. RESULTS: The RS yielded 1000 times bootstrapping corrected C-index of 0.8036 and 0.78235 in the experimental (n = 82) and validation cohorts (n = 34), respectively. With respect to the subgroup of patients with stage III/IV and cT4 disease, the RS also showed good predictive performance with corrected C-indices of 0.760 and 0.754, respectively. The dichotomized risk category using an RS of 0.0326 as the cut-off value yielded a 1-year LRF predictive accuracy of 79.27%, 79.41%, 76.74%, and 71.15% in the experimental, validation, stage III/IV, and cT4a cohorts, respectively. The low-risk group was associated with a significantly better progression-free laryngectomy-free and overall survival outcome in two independent institutions, stage III/IV, and cT4a cohorts. CONCLUSION: The RS-based model provides a novel and convenient approach for the prediction of the 1-year LRF and survival outcome in patients with HPSCC who received OPT.

A Rapid and Low-Cost Pathogen Detection Platform by Using a Molecular Agglutination Assay.

Rapid and low-cost pathogen diagnostic approaches are critical for clinical decision-making procedures. Cultivating bacteria often takes days to identify pathogens and provide antimicrobial susceptibilities. The delay in diagnosis may result in compromised treatment and inappropriate antibiotic use. Over the past decades, molecular-based techniques have significantly shortened pathogen identification turnaround time with high accuracy. However, these assays often use complex fluorescent labeling and nucleic acid amplification processes, which limit their use in resource-limited settings. In this work, we demonstrate a wash-free molecular agglutination assay with a straightforward mixing and incubation step that significantly simplifies procedures of molecular testing. By targeting the 16S rRNA gene of pathogens, we perform a rapid pathogen identification within 30 min on a dark-field imaging microfluidic cytometry platform. The dark-field images with low background noise can be obtained using a narrow beam scanning technique with off-the-shelf complementary metal oxide semiconductor (CMOS) imagers such as smartphone cameras. We utilize a machine learning algorithm to deconvolute topological features of agglutinated clusters and thus quantify the abundance of bacteria. Consequently, we unambiguously distinguish Escherichia coli positive from other E. coli negative among 50 clinical urinary tract infection samples with 96% sensitivity and 100% specificity. Furthermore, we also apply this quantitative detection approach to achieve rapid antimicrobial susceptibility testing within 3 h. This work exhibits easy-to-use protocols, high sensitivity, and short turnaround time for point-of-care testing uses.

Mitigation of performance degradation due to dynamic display contents in visible light communication using TV backlight and CMOS image sensor.

Here, we propose and demonstrate a performance degradation mitigation scheme in TV backlight and smart-phone-based visible light communication (VLC) system when the display content in the light-panel is dynamically changing. In order to evaluate the influence of the dynamic display contents to the VLC performance, we use a noise-ratio (NR) and noise-ratio standard deviation (NRSD) as the figure-of-merits for the bright-and-dark contrast of the display content; and the dispersal of the changing display content regarding the bright-and-dark contrast respectively. Performances of 4 dynamic display contents with different combinations of NR and NRSD are analyzed. They are: low NR and low NRSD (NR = 36.69%; NRSD = 0.0226); low NR and high NRSD (NR = 30.09%; NRSD = 0.2698); high NR and low NRSD (NR = 81.66%; NRSD = 0.0052); high NR and high NRSD (NR = 73.91%; and NRSD = 0.2717). The proposed scheme can work well; that is, even the transmission distance is up to 200 cm in both smart-phones. If the proposed scheme is not used, then high success rate can be observed only at the low NR and low NRSD display content when the transmission distance is < 100 cm.

A novel missense mutation of the GTP cyclohydrolase 1 gene in a Taiwanese family with dopa-responsive dystonia: A case report.

BACKGROUND: Dopa-responsive dystonia (DRD) is a clinical syndrome characterized by early onset dystonia and a dramatic response to relatively low doses of levodopa. The autosomal dominant DRD is caused by mutations in the gene coding GTP cyclohydrolase 1 (GCH1), the enzyme that catalyzes the first step in the biosynthesis of tetrahydrobiopterin. We herein report a novel gene mutation causally links to DRD. SUBJECT AND METHODS: A 23-year-old woman, presented with a history of gait abnormality and leg dystonia at age 15. Her symptoms were worsened especially in recent 2 years prior to visiting neurological clinic. In view of typical diurnal variation of dystonia, a therapeutic trial with levodopa was given and there was a dramatic response. Hence, a diagnosis of DRD was tentatively made. In addition, her father has leg dystonia since his 14 years old with leg tremor. Her 2 uncles and probably her 2 grandaunts also have limbs tremor. Genetic analysis by using PCR-direct sequencing revealed a novel point mutation (c.263G>T: p. Arg88Leu) in GCH1, including her father and asymptomatic eldest sister. CONCLUSION: We here report a Taiwanese family afflicted with DRD due to a novel missense mutation of the GCH1. The clinical features are considerably variable within the family. The findings extend the genotypic and clinical spectrum of DRD.

Rapid Waterborne Pathogen Detection with Mobile Electronics.

Pathogen detection in water samples, without complex and time consuming procedures such as fluorescent-labeling or culture-based incubation, is essential to public safety. We propose an immunoagglutination-based protocol together with the microfluidic device to quantify pathogen levels directly from water samples. Utilizing ubiquitous complementary metal-oxide-semiconductor (CMOS) imagers from mobile electronics, a low-cost and one-step reaction detection protocol is developed to enable field detection for waterborne pathogens. 10 mL of pathogen-containing water samples was processed using the developed protocol including filtration enrichment, immune-reaction detection and imaging processing. The limit of detection of 10 E. coli O157:H7 cells/10 mL has been demonstrated within 10 min of turnaround time. The protocol can readily be integrated into a mobile electronics such as smartphones for rapid and reproducible field detection of waterborne pathogens.

Long distance non-line-of-sight (NLOS) visible light signal detection based on rolling-shutter-patterning of mobile-phone camera.

We propose and demonstrate a long distance non-line-of-sight (NLOS) visible light signal detection based on the rolling shutter patterning using commercial mobile phone camera. By using our improved rolling shutter pattern demodulation algorithm, such as the background compensation (BC) blooming mitigation, extinction-ratio (ER) enhancement and Bradley adaptive thresholding, a 1.5 m NLOS visible signal (at low illumination of 145 lux) can be retrieved.

The interaction of fatigue cracks with a residual stress field using thermoelastic stress analysis and synchrotron X-ray diffraction experiments.

This article presents an experimental study on the fatigue behaviour of cracks emanating from cold-expanded holes utilizing thermoelastic stress analysis (TSA) and synchrotron X-ray diffraction (SXRD) techniques with the aim of resolving the long-standing ambiguity in the literature regarding potential relaxation, or modification, of beneficial compressive residual stresses as a result of fatigue crack propagation. The crack growth rates are found to be substantially lower as the crack tip moved through the residual stress zone induced by cold expansion. The TSA results demonstrated that the crack tip plastic zones were reduced in size by the presence of the residual compressive stresses induced by cold expansion. The crack tip plastic zones were found to be insignificant in size in comparison to the residual stress zone resulting from cold expansion, which implied that they were unlikely to have had a notable impact on the surrounding residual stresses induced by cold expansion. The residual stress distributions measured along the direction of crack growth, using SXRD, showed no signs of any significant stress relaxation or redistribution, which validates the conclusions drawn from the TSA data. Fractographic analysis qualitatively confirmed the influence on crack initiation of the residual stresses induced by the cold expansion. It was found that the application of single compressive overload caused a relaxation, or reduction in the residual stresses, which has wider implications for improving the fatigue life.

In vitro physiochemical properties of a biomimetic gelatin/chitosan oligosaccharide/calcium silicate cement.

Calcium silicate cement (CSC) has favorable biocompatible properties that may support its clinical use as bone defect repair. A hybrid cement was developed consisting of a chitosan oligosaccharide (COS) solution in a liquid phase and gelatin (GLT)-containing calcium silicate powder in a solid phase. The combination of GLT and COS was chosen due to the benefits achieved from several synergistic effects and for their clinical applications. In this study, the in vitro physicochemical properties of CSC-GLT-COS hybrid cement were investigated. The results indicated that all cement specimens formed apatite spherulites in simulated body fluid (SBF) for as little as 1 h. After immersion in a Tris-HCl solution, a pore structure appeared on all specimen surfaces without any precipitation. The presence of GLT did not adversely affect the physiochemical properties of CSC, even after 30 days of immersion. In contrast, COS could promote the degradation of CSC, as evidenced in the results of mechanical strength, weight loss, and ion concentration. The in vitro physiochemical properties of the hybrid cement makes it an attractive choice for dental and orthopedic applications.

Properties of anti-washout-type calcium silicate bone cements containing gelatin.

Novel washout-resistant bone substitute materials consisting of gelatin-containing calcium silicate cements (CSCs) were developed. The washout resistance, setting time, diametral tensile strength (DTS), morphology, and phase composition of the hybrid cements were evaluated. The results indicated that the dominant phase of beta-Ca(2)SiO(4) for the SiO(2)-CaO powders increased with an increase in the CaO content of the sols. After mixing with water, the setting times of the CSCs ranged from 10 to 29 min, increasing with a decrease in the amount of CaO in the sols. Addition of gelatin into the CSC significantly prolonged (P < 0.05) the setting time by about 2 and 8 times, respectively, for 5% and 10% gelatin. However, the presence of gelatin appreciably improved the anti-washout and brittle properties of the cements without adversely affecting mechanical strength. It was concluded that 5% gelatin-containing CSC may be useful as bioactive bone repair materials.

In vitro bioactivity and biocompatibility of dicalcium silicate cements for endodontic use.

INTRODUCTION: The purpose of this study was to examine the in vitro bioactivity and biocompatibility of sol-gel-derived dicalcium silicate cements. METHODS: The morphology, phase composition, and compressive strength of the novel cement were investigated after immersion in a simulated body fluid for different periods of time. Cement biocompatibility was evaluated by incubating the cement specimens with MG63 human osteoblast-like cells. RESULTS: After immersion in a simulated body fluid as little as 1 hour, the cements were covered with clusters of bone-like apatite spherulites. The characteristic peaks of apatite at 2theta = 25.9 degrees and 31.8 - 32.9 degrees appeared. The compressive strength of the cement was increased from the initial strength value of 12.3 MPa to 1-day strength value of 20.2 MPa; these values were significantly different (P < .05). The MG63 cell viability increased 15% and 23% on the cement surfaces when compared with the control on hour 6 and day 7 of incubation, respectively. The cells appeared flat and exhibited intact, well-defined morphology on the cement surface. CONCLUSIONS: Both bioactivity and biocompatibility of the dicalcium silicate cement consistently make it a potential candidate for endodontic use.