A RESONANCE-BASED THROUGH-TUBING CEMENT EVALUATION TECHNOLOGY

2021 ◽  
Author(s):  
Jie Li ◽  
◽  
Qinshan Yang ◽  
Jinsong Zhao ◽  
Jeff Olson ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Acoustic Energy ◽  
Hydraulic Pressure ◽  
Novel Technology ◽  
Multiple Interfaces ◽  
Main Challenge ◽  
String Structure ◽  
Cost Efficient ◽  
Low Sensitivity ◽  
And Storage

Through tubing cement evaluation in a multi-string well has been considered as a cost-efficient way for well integrity evaluation without removing the production tubing. Conventional acoustic cement bond logging methods are not able to operate accurately with the multi-string structure due to an extremely low sensitivity and Signal-to-Noise (SNR) ratio. Therefore, it is important to develop novel technology and apparatus that can accurately and efficiently monitor the cement condition in the multi-pipe cased well. Applications would include use in production, injection, and storage well configurations as well as for plug and abandonment planning. To this end, a novel through-tubing cement evaluation technology based on a Selective Non-Harmonic Resonance (SNHR) is proposed. Unlike the traditional acoustic wave propagation method (WPM), the new tool emits continuous energy to excites the SNHR of the multi-string structure, considered to be a multi-degree of freedom Duffing system. This includes coupling of the hydraulic pressure in fluid and elastic stress-strain of solid materials. The continuous sinusoidal excitation from the SNHR tool drives the structure in a long burst mode and measures the resonance power loss due to the energy leaking through the cement layer, to represent the casing-cement bond, as well as cement-formation bond condition. The SNHR tool, therefore, has overcome the main challenge, which is the acoustic energy reflections and dissipation through multiple interfaces for existing WPMs. The SNHR tool was validated theoretically and experimentally. Results showed that the SNHR tool can reach high sensitivity (> 10%) and SNR (>10 dB) for variable combinations of pipe sizes up to 14”. This implies that the SNHR is a promising technique for evaluating cement bond integrity in the annulus of an outer-most pipe string when multiple inner pipes and their associated annuli are liquid-filled. In addition, the SNHR tool does not require direct coupling to the first pipe string through pads or extensions, which reduces the engineering complexity of a field-worthy instrument.

scholarly journals High-Performance Liquid Chromatography-Tandem Mass Spectrometry for Buprenorphine Evaluation in Plasma—Application to Pharmacokinetic Studies in Rabbits

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 437
Author(s):  
Marta Tikhomirov ◽  
Błażej Poźniak ◽  
Tomasz Śniegocki
Keyword(s):  
High Performance ◽  
Pharmacokinetic Profile ◽  
Pharmacokinetic Studies ◽  
Limit Of Quantification ◽  
Reliable Determination ◽  
Main Challenge ◽  
Analytical Protocol ◽  
Liquid Chromatography Tandem Mass ◽  
Cost Efficient

The precise and reliable determination of buprenorphine concentration is fundamental in certain medical or research applications, particularly in pharmacokinetic studies of this opioid. The main challenge is, however, the development of an analytical method that is sensitive enough, as the detected in vivo concentrations often fall in very low ranges. Thus, in this study we aimed at developing a sensitive, repeatable, cost-efficient, and easy HPLC analytical protocol for buprenorphine in rabbit plasma. In order to obtain this, the HPLC-MS2 system was used to elaborate and validate the method for samples purified with liquid-liquid extraction. Fragment ions 468.6→396.2 and 468.6→414.2 were monitored, and the method resulted in a high repeatability and reproducibility and a limit of quantification of 0.25 µg/L with a recovery of 98.7–109.0%. The method was linear in a range of 0.25–2000 µg/L. The suitability of the analytical procedure was tested in rabbits in a pilot pharmacokinetic study, and it was revealed that the method was suitable for comprehensively describing the pharmacokinetic profile after buprenorphine intravenous administration at a dose of 300 µg/kg. Thus, the method suitability for pharmacokinetic application was confirmed by both the good validation results of the method and successful in vivo tests in rabbits.

scholarly journals Second harmonic generation correlation spectroscopy for characterizing translationally diffusing protein nanocrystals

2016 ◽  
Vol 72 (7) ◽  
pp. 849-859
Author(s):  
Ximeng Y. Dow ◽  
Christopher M. Dettmar ◽  
Emma L. DeWalt ◽  
Justin A. Newman ◽  
Alexander R. Dow ◽  
...  
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Unit Volume ◽  
Second Harmonic ◽  
Incident Beam ◽  
High Sensitivity ◽  
Correlation Spectroscopy ◽  
Optical Process ◽  
Active Nanoparticles ◽  
Low Sensitivity

Second harmonic generation correlation spectroscopy (SHG-CS) is demonstrated as a new approach to protein nanocrystal characterization. A novel line-scanning approach was performed to enable autocorrelation analysis without sample damage from the intense incident beam. An analytical model for autocorrelation was developed, which includes a correction for the optical scattering forces arising when focusing intense, infrared beams. SHG-CS was applied to the analysis of BaTiO3nanoparticles ranging from 200 to ∼500 nm and of photosystem I nanocrystals. A size distribution was recovered for each sample and compared with the size histogram measured by scanning electron microscopy (SEM). Good agreement was observed between the two independent measurements. The intrinsic selectivity of the second-order nonlinear optical process provides SHG-CS with the ability to distinguish well ordered nanocrystals from conglomerates and amorphous aggregates. Combining the recovered distribution of particle diameters with the histogram of measured SHG intensities provides the inherent hyperpolarizability per unit volume of the SHG-active nanoparticles. Simulations suggest that the SHG activity per unit volume is likely to exhibit relatively low sensitivity to the subtle distortions within the lattice that contribute to resolution loss in X-ray diffraction, but high sensitivity to the presence of multi-domain crystals.

scholarly journals k-Nearest Neighbor Learning with Graph Neural Networks

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 830
Author(s):  
Seokho Kang
Keyword(s):  
Neural Network ◽  
Nearest Neighbor ◽  
Learning Algorithm ◽  
Weighting Function ◽  
High Sensitivity ◽  
Training Data ◽  
K Nearest Neighbor ◽  
Main Challenge ◽  
Benchmark Datasets ◽  
Graph Neural Networks

k-nearest neighbor (kNN) is a widely used learning algorithm for supervised learning tasks. In practice, the main challenge when using kNN is its high sensitivity to its hyperparameter setting, including the number of nearest neighbors k, the distance function, and the weighting function. To improve the robustness to hyperparameters, this study presents a novel kNN learning method based on a graph neural network, named kNNGNN. Given training data, the method learns a task-specific kNN rule in an end-to-end fashion by means of a graph neural network that takes the kNN graph of an instance to predict the label of the instance. The distance and weighting functions are implicitly embedded within the graph neural network. For a query instance, the prediction is obtained by performing a kNN search from the training data to create a kNN graph and passing it through the graph neural network. The effectiveness of the proposed method is demonstrated using various benchmark datasets for classification and regression tasks.

Influence of Irrational Beliefs and Sensitivity to a Person on Future Psychology Students’ Propensity to Coercion or Nonviolence

2021 ◽  
pp. 143-165
Author(s):  
V.G. Maralov ◽  
◽  
V.A. Sitarov ◽  
Keyword(s):  
Irrational Beliefs ◽  
High Sensitivity ◽  
Daily Practice ◽  
Psychology Students ◽  
State Universities ◽  
Low Level ◽  
Level Of Understanding ◽  
Low Sensitivity ◽  
High Level ◽  
Dependent Type

The relevance of the problem is due to the importance of identifying factors that determine the propensity of students to coercion or nonviolence, creating psychological and pedagogical conditions for the formation of the socionomic sphere of nonviolent competencies for future specialists at universities. The theoretical basis of the study was the position of nonviolence as a daily practice of interaction, by which we understand the ability of a person to choose from a number of possible alternatives that carry the least charge of coercion. The aim of the work was to study the influence of irrational beliefs and sensitivity to a person (interest, empathy, understanding and assistance) on the students’ tendency to coercion, manipulation, non-violence and non-interference in the processes of interaction with people. The hypothesis was tested that the tendency of students to coercion, manipulation, and noninterference will be due to expressed irrational beliefs and low level of sensitivity to a person and the tendency to non-violence will be explained by the absence of irrational beliefs and a high level of sensitivity to a person. The study involved 125 students of pedagogical and psychological faculties of the Moscow Humanitarian and Cherepovets State universities. The authors used questionnaires to identify the positions of interaction among students and sensitivity to a person, as well as a list of irrational beliefs proposed by A. Beck and A. Freeman. It is established that the tendency to both coercion and manipulation are determined by the beliefs of anti-social type and low sensitivity to the person. The tendency to manipulate the narcissistic beliefs, high interest in people and understanding them, at the same time the tendency to non-violence and non-interference are determined by beliefs of avoidant and dependent types with a low level of understanding people. And a tendency to non-interference is determined by beliefs of dependent type with unexpressed orientation on helping. The tendency to nonviolence is determined by the high sensitivity to a person and the absence of irrational beliefs of antisocial, passive-aggressive and narcissistic types. As a result, the conclusion is made about the need to form purposefully the ability to nonviolent interaction among students, which should include the work on awareness and overcoming irrational beliefs and the development of sensitivity to a person. The obtained results can be used in practical work with students on the formation of their nonviolent competencies.

scholarly journals Predicting Response to Total Neoadjuvant Treatment (TNT) in Locally Advanced Rectal Cancer Based on Multiparametric Magnetic Resonance Imaging: A Retrospective Study

2020 ◽  
Author(s):  
Ganlu Ouyang ◽  
Xibiao Yang ◽  
Xiangbing Deng ◽  
Wenjian Meng ◽  
Yongyang Yu ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Rectal Cancer ◽  
Lymph Node ◽  
Locally Advanced ◽  
Neoadjuvant Treatment ◽  
High Sensitivity ◽  
Advanced Rectal Cancer ◽  
Locally Advanced Rectal Cancer ◽  
Resonance Imaging ◽  
Low Sensitivity

Abstract Purpose: To investigate the potential value of magnetic resonance imaging (MRI) in predicting response relevance to total neoadjuvant treatment (TNT) in locally advanced rectal cancer.Methods: We analyzed MRI of 71 patients underwent TNT from 2015 to 2017 retrospectively. We categorized the response of TNT as CR (complete response) and non-CR, and high, moderate and low sensitivity. Logistic regression analysis was used to identify the best predictors of response. Diagnostic performance was assessed using receiver - operating characteristic curve analysis.Results: Post–ICT (induction chemotherapy) ∆TL (tumor length), post-CRT (concurrent chemoradiotherapy) ∆LNN (the numbers of lymph node metastases), post–CCT (consolidation chemotherapy) ∆SDWI (maximum cross-sectional area of tumor on diffusion-weighted imaging), post-CCT ADCT (the mean apparent diffusion coefficient values of tumor) and post-CCT ∆LNV (volume of lymph node) were the best CR predictors. Post-CRT EMVI (extramural vascular invasion) and post-CCT ∆ST2 (S on T2-weight) were the best significant factors for high sensitivity. Conclusions: Post-ICT ∆TL and post-CRT EMVI may an early predictor of CR and high sensitivity to TNT, respectively. The grouping scheme of CR and non–CR was more suitable for predicting response by MRI parameters than high, moderate and low sensitivity.Trial registration: retrospectively registered

scholarly journals A dual electro-optical biosensor based on Chlamydomonas reinhardtii immobilised on paper-based nanomodified screen-printed electrodes for herbicide monitoring

2021 ◽  
Author(s):  
Amina Antonacci ◽  
Raouia Attaallah ◽  
Fabiana Arduini ◽  
Aziz Amine ◽  
Maria Teresa Giardi ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
High Sensitivity ◽  
Optical Biosensor ◽  
Whole Cells ◽  
Screen Printed Electrodes ◽  
And Storage ◽  
High Repeatability ◽  
High Sensitivity Detection ◽  
Screen Printed

Abstract The indiscriminate use of herbicides in agriculture contributes to soil and water pollution, with important endangering consequences on the ecosystems. Among the available analytical systems, algal biosensors have demonstrated to be valid tools thanks to their high sensitivity, cost-effectiveness, and eco-design. Herein, we report the development of a dual electro-optical biosensor for herbicide monitoring, based on Chlamydomonas reinhardtii whole cells immobilised on paper-based screen-printed electrodes modified with carbon black nanomaterials. To this aim, a systematic study was performed for the selection and characterisation of a collection among 28 different genetic variants of the alga with difference response behaviour towards diverse herbicide classes. Thus, CC125 strain was exploited as case study for the study of the analytical parameters. The biosensor was tested in standard solutions and real samples, providing high sensitivity (detection limit in the pico/nanomolar), high repeatability (RSD of 5% with n = 100), long lasting working (10 h) and storage stability (3 weeks), any interference in the presence of heavy metals and insecticides, and low matrix effect in drinking water and moderate effect in surface one.

scholarly journals The Effect of Oral Tactile Sensitivity on Texture Perception and Mastication Behavior in Humans

2018 ◽  
Author(s):  
Grace E. Shupe ◽  
Arran Wilson ◽  
Curtis R. Luckett
Keyword(s):  
High Sensitivity ◽  
Tactile Feedback ◽  
Interindividual Variation ◽  
Texture Perception ◽  
Tactile Acuity ◽  
Force Sensitivity ◽  
Significant Difference ◽  
Low Sensitivity ◽  
Oral Sensitivity ◽  
The Brain

AbstractMastication behavior is a notable source of interindividual variation in texture perception and could be linked to oral sensitivity. As oral sensitivity declines so does the amount of tactile feedback relayed to the brain, resulting in less effective manipulation or food and a reduced ability to discriminate differences. To address these hypotheses, we measured masticatory behavior and related this to texture discrimination and oral sensitivity. The study was performed on 41 participants in two groups, with high (n = 20) or low (n=21) sensitivity. Oral sensitivity was measured using a battery of tests that included: oral stereognosis, lingual tactile acuity, and bite force sensitivity. Sensitivity to texture changes was measured using a series of triangle tests with confectionaries of different hardness, with masticatory patterns and behaviors being video recorded and analyzed using jaw tracking software. Overall, there was no significant difference between high and low sensitivity participants and their ability to distinguish texture changes. But, there were significantly different trends found between the groups based on their masticatory behaviors including chewing pattern and overall number of chews. But, it was found that multiple masticatory behaviors were being modulated by oral sensitivity, including overall chewing cycles used (p < 0.0001). More, specifically those in the high sensitivity group used more stochastic chewing movements, while those in the low sensitivity group were found to use crescent-shaped chewing cycles. It was also noted that in the high sensitivity group the jaw moved further distances (p < 0.0001) in all phases and moved at a higher velocity when opening (p < 0.0001) but not when closing, when compared to the low sensitivity group. These results help bolster evidence that mastication and oral sensitivity are related.

1267 Utility of Artificial Intelligence in the Cystoscopic Detection of Bladder Cancer: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 108 (Supplement_6) ◽  
Author(s):  
S Ganesananthan ◽  
S Ganesananthan ◽  
B S Simpson ◽  
J M Norris
Keyword(s):  
Artificial Intelligence ◽  
Bladder Cancer ◽  
Sensitivity And Specificity ◽  
Meta Analysis ◽  
External Validation ◽  
High Sensitivity ◽  
Diagnostic Odds Ratio ◽  
Pooled Analysis ◽  
Likelihood Ratios ◽  
Novel Technology

Abstract Aim Detection of suspected bladder cancer at diagnostic cystoscopy is challenging and is dependent on clinician skill. Artificial Intelligence (AI) algorithms, specifically, machine learning and deep learning, have shown promise in accurate classification of pathological images in various specialties. However, utility of AI for urothelial cancer diagnosis is unknown. Here, we aimed to systematically review the extant literature in this field and quantitively summarise the role of these algorithms in bladder cancer detection. Method The EMBASE, PubMed and CENTRAL databases were searched up to December 22nd 2020 , in accordance with the PRISMA guidelines, for studies that evaluated AI algorithms for cystoscopic diagnosis of bladder cancer. Random-effects meta-analysis was performed to summarise eligible studies. Risk of Bias was assessed using the QUADAS-2 tool. Results Five from 6715 studies met criteria for inclusion. Pooled sensitivity and specificity values were 0.93 (95% CI 0.89–0.95) and 0.93 (95% CI 0.80–0.89) respectively. Pooled positive likelihood and negative likelihood ratios were 14 (95% CI 4.3–44) and 0.08 (95% CI: 0.05–0.11), respectively. Pooled diagnostic odds ratio was 182 (95% CI 61–546). Summary AUC curve value was 0.95 (95% CI 0.93–0.97). No significant publication bias was noted. Conclusions In summary, AI algorithms performed very well in detection of bladder cancer in this pooled analysis, with high sensitivity and specificity values. However, as with other clinical AI usage, further external validation through deployment in real clinical situations is essential to assess true applicability of this novel technology.

scholarly journals Nonlinear Hydraulic Pressure Response of an Improved Fiber Tip Interferometric High-Pressure Sensor

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2548
Author(s):  
Wei Huang ◽  
Zhe Zhang ◽  
Jun He ◽  
Bin Du ◽  
Changrui Liao ◽  
...  
Keyword(s):  
High Pressure ◽  
Nonlinear Response ◽  
Arc Discharge ◽  
High Sensitivity ◽  
Measurement Range ◽  
Hydraulic Pressure ◽  
Discharge Process ◽  
Pressure Sensitivity ◽  
Diaphragm Thickness ◽  
Order Of Magnitude

We demonstrate a silica diaphragm-based fiber tip Fabry–Perot interferometer (FPI) for high-pressure (40 MPa) sensing. By using a fiber tip polishing technique, the thickness of the silica diaphragm could be precisely controlled and the pressure sensitivity of the fabricated FPI sensor was enhanced significantly by reducing the diaphragm thickness; however, the relationship between the pressure sensitivity and diaphragm thickness is not linear. A high sensitivity of −1.436 nm/MPa and a linearity of 0.99124 in hydraulic pressure range of 0 to 40 MPa were demonstrated for a sensor with a diaphragm thickness of 4.63 μm. The achieved sensitivity was about one order of magnitude higher than the previous results reported on similar fiber tip FPI sensors in the same pressure measurement range. Sensors with a thinner silica diaphragm (i.e., 4.01 and 2.09 μm) rendered further increased hydraulic pressure sensitivity, but yield a significant nonlinear response. Two geometric models and a finite element method (FEM) were carried out to explain the nonlinear response. The simulation results indicated the formation of cambered internal silica surface during the arc discharge process in the fiber tip FPI sensor fabrication.

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