bluuebunny/crossref_metadata_2025 huggingface dataset:
Extremity free fillet flap for reconstruction of massive oncologic resection—Surgical technique and outcomes
Authors: Kreutz‐Rodrigues Lucas , Mohan Anita T. , Moran Steven L. , Carlsen Brian T. , Mardini Samir , Houdek Matthew T. , Rose Peter S. , Bakri Karim
Published: December 2019

Background and Objectives

The purpose of this study is to present our experience using free fillet flaps to reconstruct massive oncologic defects of the upper and lower extremity.

Methods

A retrospective chart review was performed to include patients who underwent oncologic resection followed by reconstruction using free fillet flaps from July 2001 to October 2018. Patient demographics, clinical and surgical characteristics, and postoperative complications were reviewed.

Results

In total, 12 patients were identified and included in this study. Mean age was 48.9 years old. Five patients had extended forequarter amputations and seven patients had external hemipelvectomies, all for locally advanced tumors. Mean tumor size was 15 ± SD 6.4 cm, and negative tumor margins were achieved in all the patients. Mean flap size was 1028 ± SD 869 cm2. The mean follow‐up was 13 months. There were no partial or total flap losses in the postoperative period. Two patients had flap‐related postoperative complications, including flap bleeding and wound dehiscence. Median survival was 18 months.

Conclusion

The free fillet flap is a safe, reliable, and valuable approach for reconstructing oncological defects. It offers the advantage of avoiding donor site morbidity, while providing extensive soft‐tissue coverage as a one‐step solution for massive oncologic defects.
Impact of initial imaging with gallium‐68 dotatate PET/CT on diagnosis and management of patients with neuroendocrine tumors
Authors: Crown Angelena , Rocha Flavio G. , Raghu Preethi , Lin Bruce , Funk Gayle , Alseidi Adnan , Hubka Misho , Rosales Joseph , Lee Marie , Kennecke Hagen
Published: December 2019

Background

Somatostatin analog functional imaging with gallium‐68 (Ga‐68) dotatate positron emission tomography/computed tomography (PET/CT) has demonstrated superiority in lesion detection in patients with neuroendocrine tumors (NETs). The clinical impact of this imaging modality on US surgical and medical oncology practices has not been established.

Methods

Consecutive patients with NET at our institution who received an initial Ga‐68 dotatate PET/CT between July 2017 and September 2018 were included. Ga‐68 dotatate PET/CT was compared with prior imaging.

Results

Among 101 eligible patients, 51 of 50 were female/male, site of origin was gastroenteropancreatic (75%), unknown primary (13%), lung (8%), thymus (2%), and other (2%). All NETs were histologically well/moderately differentiated. Ga‐68 dotatate imaging findings altered management in 36 (35.6%) patients: documentation of progression led to the initiation of systemic therapy in 14 patients, obviated the need for biopsy in four patients, and altered surgical plans in 7 of 14 (50%) patients referred for surgery. In 11 patients, decisions regarding peptide receptor radionucleotide therapy and somatostatin analogs were altered.

Conclusions

In this series, Ga‐68 dotatate PET/CT altered diagnosis and management in one‐third of patients and changed operative plans in half of the patients who were referred for surgical evaluation. These results support the routine use of this imaging in the care of patients with early‐stage and advanced NETs.
Spatial distribution of type II collagen gene expression in the mouse intervertebral disc
Authors: Wei Yulong , Tower Robert J. , Tian Zuozhen , Mohanraj Bhavana , Mauck Robert L. , Qin Ling , Zhang Yejia
Published: December 2019

Genetic tools such as the Cre‐Lox reporter system are powerful aids for tissue‐specific cell tracking. For example, it would be useful in examining intervertebral disc (IVD) cell populations in normal and diseased states. A Cre recombinase and its recognition site, loxP have been adapted from the bacteriophage for use in genetic manipulation. The reporter mice used here express the red fluorescent protein, tdTomato with flanking LoxP sites (Rosa26 TdTomato mice). We compared two different Collagen type II (Col2) promoter constructs that drive Cre‐recombinase expression in mice: (a) Col2‐Cre, which allows constitutive Cre‐recombinase expression under the control of the Col2 promoter/enhancer and (b) Col2‐CreER, which contains a shorter promoter/enhancer region than Col2‐Cre, but has human estrogen binding elements that bind tamoxifen, resulting in Cre‐recombinase expression. The goal of the study is to characterize Cre‐recombinase distribution pattern in Col2‐Cre and Col2‐CreER mice using tdTomato as reporter in the spine. The expression patterns of these two mice were further compared with Col2 gene expression in the native mouse NP and AF tissues by real‐time PCR. We crossed Col2‐Cre mice or Col2‐CreER mice with the tdTomato reporter mice, and compared the tdTomato expression patterns. Col2‐CreER/tdTomato mice were injected with tamoxifen at postnatal day 7 to activate the Cre‐recombinase. TdTomato in the constitutively active Col2‐Cre mice was detected in the nucleus pulposus (NP), the entire annulus fibrosus (AF), and in cartilaginous endplate and growth plate cells in the lower lumbar and coccygeal spine. In contrast, when Col2‐CreER activity was induced by tamoxifen at P7, tdTomato was limited to the inner AF, and was absent from the NP. We have described the differences in Col2 reporter gene expression, in Col2‐Cre/tdTomato and Col2‐Cre‐ER/tdTomato mouse IVD. The information provided here will help to guide future investigations of IVD biology.
Value of Grayscale and Power Doppler High‐Resolution Ultrasound in Assessment of Patients with Clinically Suspected Carpal Tunnel Syndrome
Authors: Gamil Amr Mohamed , Shalaby Mennatallah Hatem , Shehata Khaled Ali , El Deeb Ahmed Mohamed
Published: December 2019

Objectives

To determine the value of grayscale and power Doppler ultrasound (PDUS) in the evaluation of carpal tunnel syndrome (CTS) in clinically suspected patients.

Methods

Eighty‐seven wrists of 61 patients with clinically suspected CTS and 57 wrists of 30 healthy control participants were included in our study. Median nerve (MN) cross‐sectional area (CSA) measurements were performed at the tunnel inlet level (wCSA) and proximal pronator quadratus muscle level (fCSA). Two parameters were calculated: CSA absolute difference (ΔCSA), which was the difference between the two measurements; and CSA ratio (RCSA), calculated by dividing wCSA over fCSA. The MN at the wrist level was evaluated for hypervascularity with PDUS.

Results

The mean wCSA, R‐CSA, and ΔCSA values were significantly higher in patients (17 mm2, 2.45, and 9.9 mm2, respectively) than in control participants (8 mm2, 1.29, and 1.65 mm2; (P < .0001). At their corresponding cutoff values, the wCSA yielded higher sensitivity (95%) and lower specificity (88%) compared to the RCSA and ΔCSA (89% and 93% sensitivity and 93% and 89% specificity). Power Doppler US was the most specific US parameter (100%) but the least sensitive (76%). A multivariate logistic regression model including the wCSA, RCSA, and PDUS yielded 97% diagnostic accuracy at their optimal cutoffs, which increased to 99% after eliminating age and body mass index confounding effects.

Conclusions

The combination of MN swelling measurements and PDUS increases the diagnostic accuracy of US in patients with clinically suspected CTS.
Enhancement of Tg of Poly(l‐lactide) by Incorporation of Biobased Mandelic‐Acid‐Derived Phenyl Groups by Polymerization and Polymer Blending
Authors: Otsugu Satoshi , Kimura Yoshiharu , Nakajima Hajime , Loos Katja
Published: December 2019

A high‐molecular‐weight polyester of poly(mandelate‐co‐lactate) (PML) is prepared by ring‐opening polymerization of stereo‐configuration controlled cyclic diester monomers of methyl‐6‐phenyl‐1,4‐dioxane‐2,5‐dione (MPDD) and lactide. The attained PML shows excellent glassy properties, although the original stereo‐configuration of MPDD is not preserved. The intrinsic high glass transition temperature (Tg) of PML is promising, and it is able to be further enhanced by thermal treatment to as high as 90 °C. Interestingly, the enhanced high Tg is attained by only 15 mol% of mandelate content in the polymer chain which is far lower than the ones suggested by theoretical calculation. The enhancement in Tg is also attained by polymer blending of PML and poly(l‐lactide) (PLLA). The Tg of the polymer blend also reaches 90 °C which is almost 20 °C higher than the ones suggested by theoretical calculations. These results indicate that the rigid mandelate unit consisting of phenyl groups in PML chain effectively interact with PLLA chains in amorphous domain to restrict their chain mobility. The thermal and glassy properties are sufficient to explore new applications in engineering fields.
A construction strategy for a baculovirus‐silkworm multigene expression system and its application for coexpression of type I and type II interferons
Authors: Liu Xingjian , Yang Xin , Mehboob Arslan , Hu Xiaoyuan , Yi Yongzhu , Li Yinü , Zhang Zhifang
Published: December 2019

The Bombyx mori nucleopolyhedrovirus (BmNPV) baculovirus expression system (BES) is a eukaryotic expression system. It possesses great capability for post‐translation modification in expression of foreign proteins. With the counterselection cassette rpsL‐neo and phage λ‐Red recombinase, the defective‐rescue BmNPV BES reBmBac can be employed for efficient heterologous multigene coexpression at different gene sites in one baculovirus genome. In the present study, a recombinant baculovirus, reBm‐Cαγ, carrying two types of chicken interferon (IFN) genes (chIFN‐α and chIFN‐γ) was constructed using the reBmBac system. The chIFN‐α and chIFN‐γ genes were inserted into the same baculovirus genome at the polyhedron and p10 gene sites, respectively. The recombinant baculovirus was capable of coexpressing both chIFN‐α and chIFN‐γ. The expression levels of the two types of IFN in the coexpression product were exponentially high, at approximately 1.7 and 2.5 times higher, respectively, than those in the corresponding single‐expression products. The increase in expression level corresponds to replacement of the nonessential p10 gene in the reBm‐Cαγ recombinant baculovirus. This coexpression of recombinant chicken IFNs showed superior antiviral activity.
Feasibility of imaging 90Y microspheres at diagnostic activity levels for hepatic radioembolization treatment planning
Authors: Kunnen Britt , Dietze Martijn M. A. , Braat Arthur J. A. T. , Lam Marnix G. E. H. , Viergever Max A. , de Jong Hugo W. A. M.
Published: December 2019

Purpose

Prior to 90Y hepatic radioembolization, a dosage of 99mTc‐macroaggregated albumin (99mTc‐MAA) is administered to simulate the distribution of the 90Y‐loaded microspheres. This pretreatment procedure enables lung shunt estimation, detection of potential extrahepatic depositions, and estimation of the intrahepatic dose distribution. However, the predictive accuracy of the MAA particle distribution is often limited. Ideally, 90Y microspheres would also be used for the pretreatment procedure. Based on previous research, the pretreatment activity should be limited to the estimated safety threshold of 100 MBq, making imaging challenging. The purpose of this study was to evaluate the quality of intra‐ and extrahepatic imaging of 90Y‐based pretreatment positron emission tomography/computed tomography (PET/CT) and quantitative single photon emission computed tomography (SPECT)/CT scans, by means of phantom experiments and a patient study.

Methods

An anthropomorphic phantom with three extrahepatic depositions was filled with 90Y chloride to simulate a lung shunt fraction (LSF) of 5.3% and a tumor to nontumor ratio (T/N) of 7.9. PET /CT (Siemens Biograph mCT) and Bremsstrahlung SPECT/CT (Siemens Symbia T16) images were acquired at activities ranging from 1999 MBq down to 24 MBq, representing post‐ and pretreatment activities. PET/CT images were reconstructed with the clinical protocol and SPECT/CT images were reconstructed with a quantitative Monte Carlo‐based reconstruction protocol. Estimated LSF, T/N, contrast to noise ratio of all extrahepatic depositions, and liver parenchymal and tumor dose were compared with the phantom ground truth. A clinically reconstructed SPECT/CT of 150 MBq 99mTc represented the current clinical standard. In addition, a 90Y pretreatment scan was simulated for a patient by acquiring posttreatment PET/CT and SPECT/CT data with shortened acquisition times.

Results

At an activity of 100 MBq 90Y, PET/CT overestimated LSF [+10 percentage point (pp)], underestimated liver parenchymal dose (−3 Gy/GBq), and could not detect the extrahepatic depositions. SPECT/CT more accurately estimated LSF (−0.7 pp), parenchymal dose (−0.3 Gy/GBq) and could detect all three extrahepatic depositions. 99mTc SPECT/CT showed similar accuracy as 90Y SPECT/CT (LSF: +0.2 pp, parenchymal dose: +0.4 Gy/GBq, all extrahepatic depositions visible), although the noise level in the liver compartment was considerably lower for 99mTc SPECT/CT compared to 90Y SPECT/CT. The patient’s SPECT/CT simulating a pretreatment 90Y procedure accurately represented the posttreatment 90Y microsphere distribution.

Conclusions

Quantitative SPECT/CT of 100 MBq 90Y could accurately estimate LSF, T/N, parenchymal and tumor dose, and visualize extrahepatic depositions.
Submillimeter MR fingerprinting using deep learning–based tissue quantification
Authors: Fang Zhenghan , Chen Yong , Hung Sheng‐Che , Zhang Xiaoxia , Lin Weili , Shen Dinggang
Published: December 2019

Purpose

To develop a rapid 2D MR fingerprinting technique with a submillimeter in‐plane resolution using a deep learning–based tissue quantification approach.

Methods

A rapid and high‐resolution MR fingerprinting technique was developed for brain T1 and T2 quantification. The 2D acquisition was performed using a FISP‐based MR fingerprinting sequence and a spiral trajectory with 0.8‐mm in‐plane resolution. A deep learning–based method was used to replace the standard template matching method for improved tissue characterization. A novel network architecture (i.e., residual channel attention U‐Net) was proposed to improve high‐resolution details in the estimated tissue maps. Quantitative brain imaging was performed with 5 adults and 2 pediatric subjects, and the performance of the proposed approach was compared with several existing methods in the literature.

Results

In vivo measurements with both adult and pediatric subjects show that high‐quality T1 and T2 mapping with 0.8‐mm in‐plane resolution can be achieved in 7.5 seconds per slice. The proposed deep learning method outperformed existing algorithms in tissue quantification with improved accuracy. Compared with the standard U‐Net, high‐resolution details in brain tissues were better preserved by the proposed residual channel attention U‐Net. Experiments on pediatric subjects further demonstrated the potential of the proposed technique for fast pediatric neuroimaging. Alongside reduced data acquisition time, a 5‐fold acceleration in tissue property mapping was also achieved with the proposed method.

Conclusion

A rapid and high‐resolution MR fingerprinting technique was developed, which enables high‐quality T1 and T2 quantification with 0.8‐mm in‐plane resolution in 7.5 seconds per slice.
Across‐vendor standardization of semi‐LASER for single‐voxel MRS at 3T
Authors: Deelchand Dinesh K. , Berrington Adam , Noeske Ralph , Joers James M. , Arani Arvin , Gillen Joseph , Schär Michael , Nielsen Jon‐Fredrik , Peltier Scott , Seraji‐Bozorgzad Navid , Landheer Karl , Juchem Christoph , Soher Brian J. , Noll Douglas C. , Kantarci Kejal , Ratai Eva M. , Mareci Thomas H. , Barker Peter B. , Öz Gülin
Published: December 2019

The semi‐adiabatic localization by adiabatic selective refocusing (sLASER) sequence provides single‐shot full intensity signal with clean localization and minimal chemical shift displacement error and was recommended by the international MRS Consensus Group as the preferred localization sequence at high‐ and ultra‐high fields. Across‐vendor standardization of the sLASER sequence at 3 tesla has been challenging due to the B1 requirements of the adiabatic inversion pulses and maximum B1 limitations on some platforms. The aims of this study were to design a short‐echo sLASER sequence that can be executed within a B1 limit of 15 μT by taking advantage of gradient‐modulated RF pulses, to implement it on three major platforms and to evaluate the between‐vendor reproducibility of its perfomance with phantoms and in vivo. In addition, voxel‐based first and second order B0 shimming and voxel‐based B1 adjustments of RF pulses were implemented on all platforms. Amongst the gradient‐modulated pulses considered (GOIA, FOCI and BASSI), GOIA‐WURST was identified as the optimal refocusing pulse that provides good voxel selection within a maximum B1 of 15 μT based on localization efficiency, contamination error and ripple artifacts of the inversion profile. An sLASER sequence (30 ms echo time) that incorporates VAPOR water suppression and 3D outer volume suppression was implemented with identical parameters (RF pulse type and duration, spoiler gradients and inter‐pulse delays) on GE, Philips and Siemens and generated identical spectra on the GE ‘Braino’ phantom between vendors. High‐quality spectra were consistently obtained in multiple regions (cerebellar white matter, hippocampus, pons, posterior cingulate cortex and putamen) in the human brain across vendors (5 subjects scanned per vendor per region; mean signal‐to‐noise ratio > 33; mean water linewidth between 6.5 Hz to 11.4 Hz). The harmonized sLASER protocol is expected to produce high reproducibility of MRS across sites thereby allowing large multi‐site studies with clinical cohorts.
A feature‐based convolutional neural network for reconstruction of interventional MRI
Authors: Zufiria Blanca , Qiu Suhao , Yan Kang , Zhao Ruiyang , Wang Runke , She Huajun , Zhang Chengcheng , Sun Bomin , Herman Pawel , Du Yiping , Feng Yuan
Published: December 2019

Real‐time interventional MRI (I‐MRI) could help to visualize the position of the interventional feature, thus improving patient outcomes in MR‐guided neurosurgery. In particular, in deep brain stimulation, real‐time visualization of the intervention procedure using I‐MRI could improve the accuracy of the electrode placement. However, the requirements of a high undersampling rate and fast reconstruction speed for real‐time imaging pose a great challenge for reconstruction of the interventional images. Based on recent advances in deep learning (DL), we proposed a feature‐based convolutional neural network (FbCNN) for reconstructing interventional images from golden‐angle radially sampled data. The method was composed of two stages: (a) reconstruction of the interventional feature and (b) feature refinement and postprocessing. With only five radially sampled spokes, the interventional feature was reconstructed with a cascade CNN. The final interventional image was constructed with a refined feature and a fully sampled reference image. With a comparison of traditional reconstruction techniques and recent DL‐based methods, it was shown that only FbCNN could reconstruct the interventional feature and the final interventional image. With a reconstruction time of ~ 500 ms per frame and an acceleration factor of ~ 80, it was demonstrated that FbCNN had the potential for application in real‐time I‐MRI.
Hybrid‐Trefftz stress elements for plate bending
Authors: Teixeira de Freitas João António , Tiago Carlos
Published: December 2019

The hybrid‐Trefftz stress element is used to emulate conventional finite elements for analysis of Kirchhoff and Mindlin‐Reissner plate bending problems. The element is hybrid because it is based on the independent approximation of the stress‐resultant and boundary displacement fields. The Trefftz variant is consequent on the use of the formal solutions of the governing Lagrange equation to approximate the stress‐resultant field. In order to emulate conventional elements, nodal functions are used to approximate the displacements on the boundary of the element. Duality is used to set up the element solving system. The associated variational statements and conditions for existence and uniqueness of solutions are recovered. Triangular and quadrilateral elements are tested and characterized in terms of convergence, sensitivity to shear‐locking, and shape distortion. Their relative performance is assessed using assumed strain Mixed Interpolation of Tensorial Components (MITC) elements and recently proposed Trefftz‐based elements. This relative assessment is extended to a hypersingular problem to illustrate the effect of enriching the domain and boundary approximation bases.
A quadrilateral shell element incorporating thickness‐stretch for nearly incompressible hyperelasticity
Authors: Yamamoto Takeki , Yamada Takahiro
Published: December 2019

The authors proposed a quadrilateral shell element enriched with degrees of freedom to represent thickness‐stretch. The quadrilateral shell element can be utilized to consider large deformations for nearly incompressible materials, and its performance is demonstrated in small and large deformation analyses of hyperelastic materials in this study. Formulation of the proposed shell element is based on extension of the MITC4 shell element. A displacement variation in the thickness direction is introduced to evaluate the change in thickness. In the proposed approach, the thickness direction is defined using the director vectors at each midsurface node. The thickness‐stretch is approximated by the movements of additional nodes, which are placed along the thickness direction from the bottom to the top surface. The transverse normal strain is calculated using these additional nodes without assuming the plane stress condition; hence, a three‐dimensional constitutive equation can be employed without any modification. In this work, the authors apply an assumed strain technique to the special shell element to alleviate volumetric locking for nearly incompressible materials. Several numerical examples are presented to examine the effectiveness of the proposed element.
Teacher Skill Development: Evidence from Performance Ratings by Principals
Authors: Kraft Matthew A. , Papay John P. , Chi Olivia L.
Published: December 2019

We examine the dynamic nature of teacher skill development using panel data on principals’ subjective performance ratings of teachers. Past research on teacher productivity improvement has focused primarily on one important but narrow measure of performance: teachers’ value‐added to student achievement on standardized tests. Unlike value‐added, subjective performance ratings provide detailed information about specific skill dimensions and are available for teachers in non‐tested grades and subjects. Using a within‐teacher returns‐to‐experience framework, we find, on average, large and rapid improvements in teachers’ instructional practices throughout their first 10 years on the job as well as substantial differences in improvement rates across individual teachers. We also document that subjective performance ratings contain important information about teacher effectiveness. In the district we study, principals appear to differentiate teacher performance throughout the full distribution instead of just in the tails. Furthermore, prior performance ratings and gains in these ratings provide additional information about teachers’ ability to improve test scores that is not captured by prior value‐added scores. Taken together, our study provides new insights on teacher performance improvement and variation in teacher development across instructional skills and individual teachers.
Poly (diallyldimethylammonium) and polyphosphate polyelectrolyte complexes as an all‐in‐one flame retardant for polypropylene
Authors: Zhang Lichen , Yi Deqi , Hao Jianwei
Published: December 2019

Poly (diallyldimethylammonium chloride) (PDDA) and ammonium polyphosphate (APP) deionized chloride ions and ammonium ions by ionizing in aqueous solution respectively, then combined to form poly (diallyldimethylammonium) and polyphosphate (PAPP) polyelectrolyte complexes as an all‐in‐one flame retardant for polypropylene and its composites were characterized by Fourier transform infrared (FTIR) spectroscopy and X‐ray photoelectron spectroscopy. One flame retardant system composed of PAPP and PP, the other flame retardant system composed of PAPP, Polyamide‐6 (PA6) and PP were tested by limiting oxygen index (LOI), UL‐94, cone calorimeter tests and thermogravimetric analysis (TGA) and compared with pure PP. The results showed that the LOI value of PP/PAPP composite can reach 27.5%, and UL‐94 V‐2 rating can be reached at 25 wt% PAPP loading. Meanwhile the cone calorimetry results displayed that the peak heat release rate (PHRR) and total heat release (THR) were reduced up to 69.3% and 22.5%, respectively, compared with those of pure PP. After adding 5 wt% PA6, the carbon source missing due to the early PAPP decomposition can be made up, and PHRR and THR can be further reduced slightly. The flame retardant mechanism of PAPP was studied by FTIR spectroscopy and X‐ray photoelectron spectroscopy. Six‐membered ring of C─N containing conjugate double bonds, cross‐linked phosphate structure formed stable, intumescent, compact char layer which greatly improved the flame retardancy of PP.
Childhood homelessness, resilience, and adolescent mental health: A prospective, person‐centered approach
Authors: Herbers Janette E. , Cutuli J. J. , Keane Joanna N. , Leonard Jake A.
Published: December 2019

School districts and other service providers are increasingly aware of the substantial mental health needs of students experiencing family homelessness. Past findings are mixed regarding whether homelessness conveys unique risk beyond the risks associated with extreme poverty. With prospective longitudinal data on homelessness experiences across childhood, we utilized latent profile analysis as a person‐centered approach to conceptualizing mental health outcomes in adolescence for 3,778 youth. We considered literal family homelessness as well as families living doubled‐up, and we employed propensity score matching to identify a comparison group of nonhomeless students balanced across a range of covariates to address systematic bias. Results indicated that students who experienced literal homelessness during childhood were significantly less likely to demonstrate profiles of resilience in mental health functioning. We considered our approach and findings in light of challenges and opportunities particularly relevant to the school context.
Inhibition of noncanonical Wnt pathway overcomes enzalutamide resistance in castration‐resistant prostate cancer
Authors: Chen Xiaoliang , Liu Jinghui , Cheng Lijun , Li Chaohao , Zhang Zhuangzhuang , Bai Yunfeng , Wang Ruixin , Han Tao , Huang Changkun , Kong Yifan , Feng Feng , Liu Xiaoqi
Published: December 2019

Background

Because androgen receptor (AR) signaling is essential for prostate cancer (PCa) initiation and progression, castration is the main approach for treatment. Unfortunately, patients tend to enter a stage called castration‐resistant prostate cancer (CRPC) despite the initial response to castration. For various reasons, AR signaling is reactivated in CRPC. As such, AR signaling inhibitors, such as enzalutamide, has been approved by the Food and Drug Administration to treat CRPC in the clinic. However, the limited success of these new drugs suggests an immediate unmet need to understand the underlying mechanisms for resistance so novel targets can be identified to enhance their efficacy.

Methods

An unbiased bioinformatics analysis was performed with the existing human patient dataset and RNA‐seq results of in‐house PCa cell lines to identify new targets to overcome enzalutamide resistance. Cell viability and growth were detected by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide and colony formation assay. Cell invasion and migration were detected by transwell assay. Protein levels were detected by Western blot or immunofluorescence.

Results

We found that the noncanonical Wnt signaling was activated in enzalutamide‐resistant PCa cells and that the activation of noncanonical Wnt signaling was correlated with AR expression and disease progression. This was validated by the elevated expression of noncanonical Wnt pathway members such as Wnt5a, RhoA, and ROCK in enzalutamide‐resistant PCa cells in comparison to their enzalutamide‐sensitive counterparts. And, both Y27632, an inhibitor of ROCK, and depletion of ROCK enhanced the efficacy of enzalutamide in enzalutamide‐resistant PCa cells. Of significance, a combination of Y27632 and enzalutamide inhibited 22RV1‐derived xenograft tumor growth synergistically. Finally, ROCK depletion plus enzalutamide treatment inhibited invasion and migration of enzalutamide‐resistant PCa cells via inhibition of epithelial‐mesenchymal transition.

Conclusions

The noncanonical Wnt pathway is activated in enzalutamide‐resistant PCa and inhibition of noncanonical Wnt pathway overcomes enzalutamide resistance and enhances its efficacy in CRPC.
Probability analysis of damages to subsea pipeline
Authors: Sulaiman Nurul S. , Tan Henry
Published: December 2019

Pipeline failure due to various threats may contribute to significant adverse impact on human safety, environment, and economy. In order to mitigate the severity of pipeline failure consequences, maintaining the integrity of the vast and aging pipeline structure is crucial. The main concern in offshore risk analysis is the unpredictable and uncertain pipeline conditions. In probability theory, Bayesian network is known as a powerful tool for knowledge presentation and condition inference under uncertainty. Probability analysis of pipeline damages is necessary to prevent unwanted incidents that may cause catastrophic accidents. In this paper, a Bayesian network model was developed to identify and analyze the probability of subsea pipeline condition subjected to corrosion, third party, operational, and material damages. Statistical data and experts' knowledge were integrated in addressing data limitation. Attaining the proposed network model, diagnostic analysis, mutual analysis, and sensitivity analysis were performed to validate and provide a substantial amount of confidence on the outcomes of the proposed model. The analyses have demonstrated that estimation of the developed model is reliable. The outcome obtained can be used to assist the decision maker to prepare preventive safety measures and allocate proper resources to significantly minimize the occurrence probability of the risk factors.
Migration trajectories and their relationship to mental health among internal migrants in urban China: A sequence alignment approach
Authors: Yang Min , Dijst Martin , Helbich Marco
Published: December 2019

Although migration trajectories over people's life courses seem to be associated with mental health outcomes, previous studies have considered migration at only one point in time when correlating migration with mental health. However, people can migrate multiple times during their life courses. The decision to migrate can be triggered by several life course development events, such as education, entry to the labour market, marriage, or retirement. The present study addressed this research gap by focusing on the trajectories of migration and their relationship to mental health among internal migrants in China. Data were collected from a cross‐sectional survey (N = 534) in Shenzhen, China, in 2017. People's migration trajectories were aligned into migration groups using sequence alignment method. Binary logistic regression models were estimated to assess the associations between each migration trajectory group and the prevalence of mental health problems, controlling for sociodemographics and self‐reported physical health. The results show that migration trajectories—namely, the sequence of multiple migrations between migrants' places of origin and their final destinations—are significantly related to mental health outcomes. Our findings suggest that treating migration as a one‐time transition could be problematic because many migrants undertake multiple migration trips.
Tracking and parameter identification for model reference adaptive control
Authors: Malisoff Michael
Published: December 2019

We provide barrier Lyapunov functions for model reference adaptive control algorithms, allowing us to prove robustness in the input‐to‐state stability framework and to compute rates of exponential convergence of the tracking and parameter identification errors to zero. Our results ensure identification of all entries of the unknown weight and control effectiveness matrices. We provide easily checked sufficient conditions for our relaxed persistency of excitation conditions to hold. Our illustrative numerical example demonstrates the performance of the control methods.
Multigradient recursive reinforcement learning NN control for affine nonlinear systems with unmodeled dynamics
Authors: Bai Weiwei , Zhang Bin , Zhou Qi , Lu Renquan
Published: December 2019

In this paper, an adaptive reinforcement learning approach is developed for a class of discrete‐time affine nonlinear systems with unmodeled dynamics. The multigradient recursive (MGR) algorithm is employed to solve the local optimal problem, which is inherent in gradient descent method. The MGR radial basis function neural network approximates the utility functions and unmodeled dynamics, which has a faster rate of convergence than that of the gradient descent method. A novel strategic utility function and cost function are defined for the affine systems. Finally, it concludes that all the signals in the closed‐loop system are semiglobal uniformly ultimately bounded through differential Lyapunov function method, and two simulation examples are presented to demonstrate the effectiveness of the proposed scheme.
Adult Vocabulary Modulates Speed of Word Integration Into Preceding Text Across Sentence Boundaries: Evidence From Self‐Paced Reading
Authors: Guerra Ernesto , Kronmüller Edmundo
Published: December 2019

An important component of reading comprehension is the reader's capacity to make inferences that can maintain the coherence between propositions within the text. However, the cognitive and linguistic skills that underlie online inference making remain elusive. The authors aimed to clarify the effects of vocabulary and text comprehension on word‐to‐text integration during reading. In a self‐paced reading study, the authors measured participants’ integration of words across sentence boundaries by comparing reading times at a critical word and the subsequent region, when preceded by the same critical word (repetition condition), by a lexically associated word (association condition), or by a word with no direct lexical link (inference condition). Furthermore, the authors assessed vocabulary knowledge, text comprehension, working memory, decoding, and fluid intelligence in the sample. Results showed that richer vocabulary was associated with immediate integration, as evidenced by reading time differences between the critical word and the subsequent word in the inference condition. Other individual differences did not predict self‐paced reading times. Findings suggest that lexical knowledge plays a stronger role relative to other individual skills in online inference making and contributes to refining understanding of the mechanisms that underlie efficient reading.
The Effect of Orthographic Neighbors on Second‐Grade Students’ Spelling Acquisition
Authors: Chen Yi‐Jui Iva , Cunningham Anne E. , Rabe‐Hesketh Sophia , Hinshaw Stephen P. , Irey Robin C.
Published: December 2019

Many words in English resemble one another in multiple ways. Words with similar spellings are referred to as orthographic neighbors. The purpose of this within‐subject experimental study was to examine the effect of orthographic neighbors on the spelling acquisition of second‐grade students. In each of five sessions of a computer‐based experiment, 71 participants were presented with two prime words and prompted to learn the spelling of seven novel words. The latter seven words were control words (no meaningful connection with the corresponding prime word) and neighbor words (words representing various types of connections with the corresponding prime word). Spelling tasks were administered twice: immediately after the experiment and two days later. The findings suggest that spelling acquisition depends on two critical factors: orthographic neighbor type and orthographic processing ability. Students’ spelling acquisition was supported by analogizing rime neighbors (e.g., rain/vain). However, facilitative effects were not found for substitution neighbors (e.g., rain/ruin) and transposition neighbors (e.g., clam/calm). Additionally, a student’s level of orthographic processing was an important determinant of spelling acquisition; students with well‐developed orthographic processing ability correctly learned the novel words regardless of the presence of rime neighbors. In contrast, acquiring spelling was far more difficult for students with less developed orthographic processing ability, but their spelling acquisition was strongly facilitated by the presence of rime neighbors. Implications of this research are (a) learners’ orthographic processing skills should be considered when designing spelling instruction and (b) early elementary students need instructional support when making orthographic analogies for substitution and transposition neighbors.
Modeling the overdetection of screen‐identified cancers in population‐based cancer screening with the Coxian phase‐type Markov process
Authors: Yen Amy Ming‐Fang , Chen Hsiu‐Hsi
Published: December 2019

Modeling overdetection resulting from screening often uses the conventional competing risk model. This model assigns screen‐detected cases dying from other causes as overdetection modeled by a one‐jump process, which may not be true for the censored overdetected cases. To relax this restrictive assumption, accommodate a finite Markov process for overdetection, and dispense with long‐term follow‐up until death, we propose a generalized Coxian phase‐type Markov process to distinguish the progressive latent multistate pathway from the nonprogressive (overdetected) latent multistate pathway. Various new likelihood functions were developed to estimate the transition parameters with the available data accrued at the time of diagnosis. The proportion of overdetected cancers by the cured model was further estimated by using parameters with and without distinguishing between the two latent pathways. While perturbation analyses were conducted by changing their parameters to assess their effects on overdetection, the results, including of asymptotic analyses, were very robust for an overdetection rate higher than 20% but not for low overdetection rates. These two scenarios were demonstrated by applying the Coxian phase‐type model to prostate cancer and breast cancer screening, yielding a substantial proportion of overdetected prostate cancer (60%) attributed to the prostate specific antigen test and a small fraction of overdetected breast cancer (3%) detected by mammography. This kind of variation in overdetection elucidated by the Coxian phase‐type Markov process provides new insights into the quantitative mechanisms producing overdetection, which is informative for evaluating the benefits and risks of various types of population‐based cancer screening programs.
A Study on the Microstructure and Fatigue Properties of Welding Joints in Vibration‐Assisted Laser Welding Process
Authors: Jin Jiewen , Lu Qinghua , Zhang Peilei , Li Chonggui , Yan Hua
Published: December 2019

A vibration‐assisted laser welding experiment of 4.5 mm industrial pure iron is conducted to focus on the influences of vibration parameters on microstructure, fatigue fracture, and fatigue life. The studies show that the microstructure of the joint is optimized under the condition of 1186 HZ vibration frequency and 36.1 m s−2 vibration acceleration; it is also found that a suitable microvibration process can enhance the penetration depth of the joints, reduce the number of columnar crystals, and homogenize the microhardness. In high‐cycle fatigue experiments, the base material (BM) produces fatigue fracture only under the fatigue load of 52% Rm, the fatigue source area under vibration is at the corner of the fracture or at the inside of the weld seam; a functional consequence is that the vibration can increase the fatigue load strength by 1–3 percentage points, and the fatigue life can be increased by 0.8–1.5 multiples. The microvibration can effectively improve the fatigue performance and increase the fatigue life.
Surveying the reach and maturity of machine learning and artificial intelligence in astronomy
Authors: Fluke Christopher J. , Jacobs Colin
Published: December 2019

Machine learning (automated processes that learn by example in order to classify, predict, discover, or generate new data) and artificial intelligence (methods by which a computer makes decisions or discoveries that would usually require human intelligence) are now firmly established in astronomy. Every week, new applications of machine learning and artificial intelligence are added to a growing corpus of work. Random forests, support vector machines, and neural networks are now having a genuine impact for applications as diverse as discovering extrasolar planets, transient objects, quasars, and gravitationally lensed systems, forecasting solar activity, and distinguishing between signals and instrumental effects in gravitational wave astronomy. This review surveys contemporary, published literature on machine learning and artificial intelligence in astronomy and astrophysics. Applications span seven main categories of activity: classification, regression, clustering, forecasting, generation, discovery, and the development of new scientific insights. These categories form the basis of a hierarchy of maturity, as the use of machine learning and artificial intelligence emerges, progresses, or becomes established.

This article is categorized under:

Application Areas > Science and Technology

Fundamental Concepts of Data and Knowledge > Motivation and Emergence of Data Mining

Technologies > Machine Learning
Dynamical constraints on RG flows and cosmology
Authors: Baumann Daniel , Green Daniel , Hartman Thomas
Published: December 2019

Abstract

Sum rules connecting low-energy observables to high-energy physics are an interesting way to probe the mechanism of inflation and its ultraviolet origin. Unfortunately, such sum rules have proven difficult to study in a cosmological setting. Motivated by this problem, we investigate a precise analogue of inflation in anti-de Sitter spacetime, where it becomes dual to a slow renormalization group flow in the boundary quantum field theory. This dual description provides a firm footing for exploring the constraints of unitarity, analyticity, and causality on the bulk effective field theory. We derive a sum rule that constrains the bulk coupling constants in this theory. In the bulk, the sum rule is related to the speed of radial propagation, while on the boundary, it governs the spreading of nonlocal operators. When the spreading speed approaches the speed of light, the sum rule is saturated, suggesting that the theory becomes free in this limit. We also discuss whether similar results apply to inflation, where an analogous sum rule exists for the propagation speed of inflationary fluctuations.
Real time dynamics from low point correlators in 2d BCFT
Authors: Das Suchetan , Ezhuthachan Bobby , Kundu Arnab
Published: December 2019

Abstract

In this article, we demonstrate how a 3-point correlation function can capture the out-of-time-ordered features of a higher point correlation function, in the context of a conformal field theory (CFT) with a boundary, in two dimensions. Our general analyses of the analytic structures are independent of the details of the CFT and the operators, however, to demonstrate a Lyapunov growth we focus on the Virasoro identity block in large-c CFT’s. Motivated by this, we also show that the phenomenon of pole-skipping is present in a 2-point correlation function in a two-dimensional CFT with a boundary. This pole-skipping is related, by an analytic continuation, to the maximal Lyapunov exponent for maximally chaotic systems. Our results hint that, the dynamical content of higher point correlation functions, in certain cases, may be encrypted within low-point correlation functions, and analytic properties thereof.
A new surrogate model–based method for individualized spot welding sequence optimization with respect to geometrical quality
Authors: Tabar Roham Sadeghi , Wärmefjord Kristina , Söderberg Rikard
Published: December 2019

In an individualized shee metal assembly line, form and dimensional variation of the in-going parts and different disturbances from the assembly process result in the final geometrical deviations. Securing the final geometrical requirements in the sheet metal assemblies is of importance for achieving aesthetic and functional quality. Spot welding sequence is one of the influential contributors to the final geometrical deviation. Evaluating spot welding sequences to retrieve lower geometrical deviations is computationally expensive. In a geometry assurance digital twin, where assembly parameters are set to reach an optimal geometrical outcome, a limited time is available for performing this computation. Building a surrogate model based on the physical experiment data for each assembly is time-consuming. Performing heuristic search algorithms, together with the FEM simulation, requires extensive evaluations times. In this paper, a neural network approach is introduced for building surrogate models of the individual assemblies. The surrogate model builds the relationship between the spot welding sequence and geometrical deviation. The approach results in a drastic reduction in evaluation time, up to 90%, compared to the genetic algorithm, while reaching a geometrical deviation with marginal error from the global optimum after welding in a sequence.
Speech changes in patients with a full rehabilitation for severe tooth wear, a first evaluation study
Authors: Sterenborg Bernadette A.M.M. , Kalaykova Stanimira I. , Knuijt Simone , Loomans Bas A.C. , Huysmans Marie-Charlotte D. N. J. M.
Published: December 2019

Objective

The aim of this study was to evaluate changes in speech characteristics and self-perceived quality of speech in tooth wear patients, after occlusal rehabilitation.

Materials and methods

Patients with tooth wear were included in this study after informed consent. The amount of tooth wear was scored with Tooth Wear Evaluation System (TWES). To assess the perspective of the patient, the Dutch Speech Handicap Index was used (SHI). Acoustic analysis was performed to evaluate changes with the use of voice recordings. These were made before treatment, T0; directly after treatment, T1; 1 month after treatment, T2. With the use of PRAAT software, the spectral characteristic centre of gravity (COG) was evaluated for the sounds /s/, /f/, /v/, /d/, /t/, /m/.

Results

Recordings of 17 patients (14 men, 3 women, mean age 41.2 ± 10.4 years) were included. SHI scores did not change significantly between T0 and T2 (p = 0.054). A multiple regression model showed that for all sounds the intercept was negative, but statistically significant only for /s/ and /f/ between T0 and T1. The effect of the initial change (between T0 and T1) on the change between T1 and T2 was clearly negative for all sounds (p < 0.001), showing a rebound effect ranging between 29 and 68% of the initial change.

Conclusion

Tooth wear patients perceive improvement in speech function after treatment.

Clinical significance

Clinicians may explain to patients that speech is likely to alter for a short period due to treatment but that there will be a good adaption to the new situation.