43 research outputs found
A Novel Video Logging Method based on the Self-Focus Lens Array
At present, down-hole video logging method is used to observe the bottom and lateral well wall image, which places video camera on the bottom of logging instrument. This method can acquire the bottom image clearly. It’s difficult to obtain lateral image because optic axis of lenses is placed along with the well axis, and it’s impossible to place an existing camera along the radial direction because of restriction of borehole diameter or pipe diameter and object distance of camera, etc. A method and instrument for acquiring lateral image is presented on this paper, multiple self-focus lenses are placed along radial direction, used special relay lens transmitting the multiple imaging to an image sensor, and formed one image, then transmitted the image to ground. In order to use optic spectral properties, light cone circling the self-focus lenses is used to transfer the image, the minimum overlap radius for measurement boreholethe is analyzed,the seal problem for the optical system is designed.The lateral well wall image is acquired through researching the method of lateral multiple lens, then the phase correction method is used to fuse the image from different angles of lateral well wall. The video well logging instrument is developed using the above method, which can real-timely display the crack opening , filling substance, porosity and rock component of down-hole casing and borehole.So this method can provide an interpretation tools for the pipe internal or downhole phenomena.Key words: Lateral video logging; Image acquisition; Self-focus lens array; Circular light source; Phase correction method; Image fusio
Anticonvulsant and sedative effect of Fufang Changniu pills and probable mechanism of action in mice
Purpose: To investigate the anticonvulsant and sedative effects of Fufang Changniu Pills (FCP) and its probable mechanism of action in mice.Methods: The water decoction of FCP was prepared and the main constituents were determined by high performance liquid chromatography (HPLC). The anticonvulsant activities of FCP were evaluated by maximal electroshock (MES) and pentylenetetrazole (PTZ)-induced seizures in mice. Pentobarbital sodium-induced sleeping time and locomotor activity measurements were performed to evaluate the sedative effects of FCP in mice. Finally, PTZ-induced chronic seizures were established, and expressions of gamma-aminobutyric acid A receptor (GABA-A) and glutamic acid decarboxylase 65 (GAD65) in the brains of the mice were assayed by western blot in order to explore the probable mechanisms of action of the drug.Results: Gallic acid, liquiritin, cinnamyl alcohol, cinnamic acid and glycyrrhizic acid were detected in FCP decoction. FCP (50, 100 and 200 mg/kg) showed significant anticonvulsant and sedative effects on epileptic mice induced by MES (p < 0.05) and PTZ (p < 0.05). Moreover, pentobarbital sodium-induced sleeping time and locomotor activity tests showed that FCP possesses sedative effect (p < 0.05). Western blot data indicate that FCP significantly up-regulated GABA-A and GAD 65 in the brains of chronic epileptic rats (p < 0.05).Conclusion: FCP has significant anticonvulsant and sedative effects, and the mechanism of its action may be related to the up-regulation of GABA-A and GAD 65 in mice brain.Keywords: Epilepsy, Fufang Changniu pills, Anticonvulsant, Sedative effect, Gamma-aminobutyric acid, Glutamate dehydrogenas
Single photon detection performance of highly disordered NbTiN thin films
We experimentally investigated the detection performance of highly disordered
NbxTi1-xN based superconducting nanowire single photon detectors (SNSPDs). The
dependence on the composition of the transition temperature Tc for NbxTi1-xN
films show a dome-like behavior on the Nb content, with a maximal Tc at
xNb~0.65 , and the Nb0.65Ti0.35N films also combine relatively large sheet
resistance and intermediate residual resistivity ratio. Moreover, 60-nm-wide
and 7-nm-thick Nb0.65Ti0.35N nanowires show a switching current as high as 14.5
uA, and saturated intrinsic detection efficiency with a plateau of more than 2
uA at 2.4 K. Finally, the corresponding SNSPDs on an alternative SiO2/Ta2O5
dielectric mirror showed a system detection efficiency of approximately 92% for
1550 nm photons, and the timing jitter is around 26 ps. Our results demonstrate
that the highly disordered NbxTi1-xN films are promising for fabricating SNSPDs
for near- and middle-infrared single photons with high detection efficiency and
low timing jitter.Comment: 9 pages,5 figure
A Radiomics Model Based on Synthetic MRI Acquisition for Predicting Neoadjuvant Systemic Treatment Response in Triple-Negative Breast Cancer
Purpose
To determine if a radiomics model based on quantitative maps acquired with synthetic MRI (SyMRI) is useful for predicting neoadjuvant systemic therapy (NAST) response in triple-negative breast cancer (TNBC). Materials and Methods
In this prospective study, 181 women diagnosed with stage I–III TNBC were scanned with a SyMRI sequence at baseline and at midtreatment (after four cycles of NAST), producing T1, T2, and proton density (PD) maps. Histopathologic analysis at surgery was used to determine pathologic complete response (pCR) or non-pCR status. From three-dimensional tumor contours drawn on the three maps, 310 histogram and textural features were extracted, resulting in 930 features per scan. Radiomic features were compared between pCR and non-pCR groups by using Wilcoxon rank sum test. To build a multivariable predictive model, logistic regression with elastic net regularization and cross-validation was performed for texture feature selection using 119 participants (median age, 52 years [range, 26–77 years]). An independent testing cohort of 62 participants (median age, 48 years [range, 23–74 years]) was used to evaluate and compare the models by area under the receiver operating characteristic curve (AUC). Results
Univariable analysis identified 15 T1, 10 T2, and 12 PD radiomic features at midtreatment that predicted pCR with an AUC greater than 0.70 in both the training and testing cohorts. Multivariable radiomics models of maps acquired at midtreatment demonstrated superior performance over those acquired at baseline, achieving AUCs as high as 0.78 and 0.72 in the training and testing cohorts, respectively. Conclusion
SyMRI-based radiomic features acquired at midtreatment are potentially useful for identifying early NAST responders in TNBC
Longitudinal Dynamic Contrast-Enhanced MRI Radiomic Models for Early Prediction of Response to Neoadjuvant Systemic Therapy in Triple-Negative Breast Cancer
Early prediction of neoadjuvant systemic therapy (NAST) response for triple-negative breast cancer (TNBC) patients could help oncologists select individualized treatment and avoid toxic effects associated with ineffective therapy in patients unlikely to achieve pathologic complete response (pCR). The objective of this study is to evaluate the performance of radiomic features of the peritumoral and tumoral regions from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) acquired at different time points of NAST for early treatment response prediction in TNBC. This study included 163 Stage I-III patients with TNBC undergoing NAST as part of a prospective clinical trial (NCT02276443). Peritumoral and tumoral regions of interest were segmented on DCE images at baseline (BL) and after two (C2) and four (C4) cycles of NAST. Ten first-order (FO) radiomic features and 300 gray-level-co-occurrence matrix (GLCM) features were calculated. Area under the receiver operating characteristic curve (AUC) and Wilcoxon rank sum test were used to determine the most predictive features. Multivariate logistic regression models were used for performance assessment. Pearson correlation was used to assess intrareader and interreader variability. Seventy-eight patients (48%) had pCR (52 training, 26 testing), and 85 (52%) had non-pCR (57 training, 28 testing). Forty-six radiomic features had AUC at least 0.70, and 13 multivariate models had AUC at least 0.75 for training and testing sets. The Pearson correlation showed significant correlation between readers. In conclusion, Radiomic features from DCE-MRI are useful for differentiating pCR and non-pCR. Similarly, predictive radiomic models based on these features can improve early noninvasive treatment response prediction in TNBC patients undergoing NAST
Deep Learning for Fully Automatic Tumor Segmentation on Serially Acquired Dynamic Contrast-Enhanced MRI Images of Triple-Negative Breast Cancer
Accurate tumor segmentation is required for quantitative image analyses, which are increasingly used for evaluation of tumors. We developed a fully automated and high-performance segmentation model of triple-negative breast cancer using a self-configurable deep learning framework and a large set of dynamic contrast-enhanced MRI images acquired serially over the patients\u27 treatment course. Among all models, the top-performing one that was trained with the images across different time points of a treatment course yielded a Dice similarity coefficient of 93% and a sensitivity of 96% on baseline images. The top-performing model also produced accurate tumor size measurements, which is valuable for practical clinical applications
Design and simulation of small-sized antenna in microwave transmission method for water content measurement instrument
Herein, the microwave transmission method is proposed that demonstrates such advantages as non-invasiveness, excellent penetration performance, and fast detection. As a key component of the microwave method water content measurement instrument, the antenna is required to have a smaller radiation size than the inner diameter of the oil pipe. To address this technical challenge, a small-sized microwave projection method based on water content measurement antenna is designed in this study for the water content measurement of oil-water mixtures in downhole pipelines. Also, the half-cut antenna with a size of 17 × 45 m m 2 is proposed to operate in the frequency band of 2–6 GHz (The measured gain of the antenna varies from 2.48 dBi to 4.98 dBi). Then, the designed half-cut antenna is applied to the established water-content test environment for analysis as to the relationship between water content and the variation in transmission coefficient of the half-cut antenna. According to the test results, the relative water content error is about 0.31% between the simulation and measured results for the transmission coefficient S 21 in the range of 0%–30%, while that is about 0.16% for the transmission coefficient S 21 in the range of 40%–100%. The experimental results can be extended to the measurement of the part with high water content of the oil-water mixture in the pipeline, which provides a practical reference for field tests and basic research
An AST-ELM Method for Eliminating the Influence of Charging Phenomenon on ECT
Electrical capacitance tomography (ECT) is a promising imaging technology of permittivity distributions in multiphase flow. To reduce the effect of charging phenomenon on ECT measurement, an improved extreme learning machine method combined with adaptive soft-thresholding (AST-ELM) is presented and studied for image reconstruction. This method can provide a nonlinear mapping model between the capacitance values and medium distributions by using machine learning but not an electromagnetic-sensitive mechanism. Both simulation and experimental tests are carried out to validate the performance of the presented method, and reconstructed images are evaluated by relative error and correlation coefficient. The results have illustrated that the image reconstruction accuracy by the proposed AST-ELM method has greatly improved than that by the conventional methods under the condition with charging object
The Cartesian Product and Join Graphs on Edge-Version Atom-Bond Connectivity and Geometric Arithmetic Indices
The Cartesian product and join are two classical operations in graphs. Let dL(G)(e) be the degree of a vertex e in line graph L(G) of a graph G. The edge versions of atom-bond connectivity (ABCe) and geometric arithmetic (GAe) indices of G are defined as ∑ef∈E(L(G))dL(G)(e)+dL(G)(f)−2dL(G)(e)×dL(G)(f) and ∑ef∈E(L(G))2dL(G)(e)×dL(G)(f)dL(G)(e)+dL(G)(f), respectively. In this paper, ABCe and GAe indices for certain Cartesian product graphs (such as Pnâ–¡Pm, Pnâ–¡Cm and Pnâ–¡Sm) are obtained. In addition, ABCe and GAe indices of certain join graphs (such as Cm+Pn+Sr, Pm+Pn+Pr, Cm+Cn+Cr and Sm+Sn+Sr) are deduced. Our results enrich and revise some known results