bluuebunny/crossref_metadata_2025 huggingface dataset:
Classification of tumor subtypes leveraging constriction‐channel based impedance flow cytometry and optical imaging
Authors: Jiang Mei , Wang Xiaojie , Zhao Xiaoting , Teng Yu , Chen Jian , Wang Junbo , Yue Wentao
Published: April 2021

As label‐free biomarkers, electrical properties of single cells have been widely used for cell‐type classification and cell‐status evaluation. However, as intrinsic bioelectrical markers, previously reported membrane capacitance and cytoplasmic resistance (e.g., specific membrane capacitance Cspecific membrane and cytoplasmic conductivity σcytoplasm) of tumor subtypes were derived from tens of single cells, lacking statistical significance due to low cell numbers. In this study, tumor subtypes were constructed based on phenotype (treatment with 4‐methylumbelliferone) or genotype (knockdown of ROCK1) modifications and then aspirated through a constriction‐channel based impedance flow cytometry to characterize single‐cell Cspecific membrane and σcytoplasm. Thousands of single tumor cells with phenotype modifications were measured, resulting in significant differences in 1.64 ± 0.43 μF/cm2 vs. 1.55 ± 0.47 μF/cm2 of Cspecific membrane and 0.96 ± 0.37 S/m vs. 1.24 ± 0.47 S/m of σcytoplasm for 95C cells (792 cells of 95C‐control vs. 1529 cells of 95C‐pheno‐mod); 2.56 ± 0.88 μF/cm2 vs. 2.33 ± 0.56 μF/cm2 of Cspecific membrane and 0.83 ± 0.18 S/m vs. 0.93 ± 0.25 S/m of σcytoplasm for H1299 cells (962 cells of H1299‐control vs. 637 cells of H1299‐pheno‐mod). Furthermore, thousands of single tumor cells with genotype modifications were measured, resulting in significant differences in 3.82 ± 0.92 vs. 3.18 ± 0.47 μF/cm2 of Cspecific membrane and 0.47 ± 0.05 vs. 0.52 ± 0.05 S/m of σcytoplasm (1100 cells of A549‐control vs. 1100 cells of A549‐geno‐mod). These results indicate that as intrinsic bioelectrical markers, specific membrane capacitance and cytoplasmic conductivity can be used to classify tumor subtypes.
Emergency upper gastrointestinal endoscopy performed safely in a patient with COVID‐19 with suspected hemorrhagic shock
Authors: Misumi Yoshitsugu , Nitta Yuki , Nonaka Kouichi , Kawana Masatoshi , Arimura Ken , Tokushige Katsutoshi , Tanabe Kazunari
Published: April 2021

Coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 has spread explosively throughout the world and has since been declared a pandemic by the World Health Organization. Although it is recommended that upper gastrointestinal endoscopies either be postponed or canceled during the pandemic because of their high risk of aerosol generation, this does not apply in emergency cases, which may include patients with coronavirus disease. In this case report, we describe the safe undertaking of an emergency upper gastrointestinal endoscopy in a patient with suspected hemorrhagic shock who tested positive for the severe acute respiratory syndrome coronavirus 2 using the polymerase chain reaction. We performed the procedure in the contamination zone of a specialized coronavirus disease ward with prespecified zones. Full personal protective equipment was worn during the procedure, as recommended by various academic societies, and careful attention was paid to the sterilization of all equipment after the procedure. Thus, emergency endoscopies can be performed safely in patients with coronavirus disease in a suitable environment by using appropriate personal protective equipment and by handling the equipment appropriately.
Development and validation of a fast ultra‐high‐performance liquid chromatography tandem mass spectrometry method for determining carbonic anhydrase inhibitors and their metabolites in urine and hair
Authors: Lo Faro Alfredo Fabrizio , Tini Anastasio , Gottardi Massimo , Pirani Filippo , Sirignano Ascanio , Giorgetti Raffaele , Busardò Francesco Paolo
Published: April 2021

A new, rapid, sensitive, and comprehensive ultra‐high‐performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) method for quantifying diuretics (acetazolamide, brinzolamide, dorzolamide, and their metabolites) in human urine and hair was developed and fully validated. Twenty‐five milligrams of hair were incubated with 500‐μl M3® buffer reagent at 100°C for 1 h for complete digestion. After cooling, 1‐μl supernatant was injected onto chromatography system. Urine samples were simply diluted before injection. The chromatographic run time was short (8 min) through a column with a mobile phase gradient. The method was linear (determination coefficients always higher than 0.99) from limit of quantification (LOQ) to 500 ng/ml in urine and from LOQ to 10 ng/mg in hair. LOQs ranged from 0.07 to 1.16 ng/ml in urine and from 0.02 to 0.15 ng/mg in hair. No significant ion suppression due to matrix effect was observed, and process efficiency was always higher than 80%. Intra‐ and inter‐assay precision was lower than 15%. The suitability of the methods was tested with six urine and hair specimens from patients treated with acetazolamide, dorzolamide, or brinzolamide for ocular diseases or systemic hypertension. Average urine concentrations were 266.32 ng/ml for dorzolamide and 47.61 ng/ml for N‐deethyl‐dorzolamide (n = 3), 109.27 ng/ml for brinzolamide and 1.02 ng/ml for O‐desmethyl‐brinzolamide (n = 2), and finally, 12.63 ng/ml for acetazolamide. Average hair concentrations were 5.94 ng/mg for dorzolamide and 0.048 ng/mg for N‐deethyl‐dorzolamide (n = 3), 3.26 ng/mg for brinzolamide (n = 2), and 2.3 ng/mg for acetazolamide (n = 1). The developed method was simple and fast both in the extraction procedures making it eligible in high‐throughput analysis for clinical forensic and doping purposes.
Synergism between oral paracetamol and nefopam in a murine model of postoperative pain
Authors: Cabañero David , Maldonado Rafael
Published: April 2021

Background

The use of paracetamol or nefopam for postoperative pain control is limited by the need of high doses associated with unwanted effects. Previous works suggest positive interactions between both compounds that may be exploited to obtain potentiation of antinociception.

Methods

Mechanical and heat antinociception induced by oral doses of paracetamol, nefopam or their combination was studied by isobolographic analysis in a murine model of postsurgical pain. The effective doses that produced 50% antinociception (ED50) were calculated from the log dose–response curves for each compound. Subsequently, the effects of ED8.7s, ED12.5s, ED17.5s and ED35s of nefopam and paracetamol combined were assessed.

Results

Oral paracetamol induced dose‐dependent relief of postoperative sensitivity and showed higher efficacy reducing mechanical hypersensitivity (ED50 177.3 ± 15.4 mg/kg) than heat hyperalgesia (ED50 278.6 ± 43 mg/kg). Oral nefopam induced dose‐dependent antinociception with similar efficacy for mechanical and heat hypersensitivity (ED50s 5.42 ± 0.81 vs. 5.83 ± 0.72). Combinations of increasing isoeffective doses revealed that combined ED17.5s (85.76 mg/kg paracetamol and 1.9 mg/kg nefopam) and ED35s (132.67 mg/kg and 3.73 mg/kg) showed synergistic effects leading to 75% and 90% mechanical antinociception, respectively. These mixtures were defined by interaction indexes of 0.43 and 0.41 and ratios 45:1 and 35:1 paracetamol:nefopam, respectively. The same combinations showed additive effects for the inhibition of incisional thermal hyperalgesia.

Conclusions and limitations

This work describes a synergistic antinociceptive interaction between low doses of nefopam and paracetamol for the treatment of postoperative hypersensitivity to peripheral stimuli. The promising results obtained on reflexive nociceptive responses of young male mice subjected to plantar surgery highlight the interest of further research evaluating the effects of this mixture on the affective‐motivational component of pain and in females and additional age groups. Confirmation of pain‐relieving efficacy and safety of this oral combination clinically available in European and Asian countries could provide a useful tool for postsurgical pain management.

Significance

Early postoperative pain is currently undertreated and has been recognized as a relevant source of chronic postsurgical pain. Oral efficient treatments could facilitate fast‐track surgeries and patient recovery at home. Here, we identify in a mouse model of postoperative pain a potent synergistic oral combination consisting of low paracetamol and nefopam doses that provides relief of postsurgical hypersensitivity to mechanical and thermal stimuli. Oral multimodal paracetamol–nefopam mixtures represent a potential clinically available pharmacological strategy for the relief of incisional sensitivity and the promotion of patient recovery.
Energy analysis and simulation of PCM‐enhanced building envelopes in commercial buildings: A case study
Authors: Beiranvand Mostafa , Mohaghegh Mohammad Reza
Published: April 2021

Integrating phase change materials (PCMs) into the building envelopes is considered a promising solution to reduce the energy consumption in buildings. These materials, acting as thermal energy storage systems, delay the heat transfer from the building to out or in for several hours. The present research investigates the effect of PCM employed in the building envelopes on the building's energy‐saving. For this purpose, the central office building of the University of Torbat Heydarieh is simulated as the case study using DesignBuilder software in climatic conditions of East of Iran (dry climate with hot summer and cold winter). All materials are defined in the software, and a dynamic thermal model is developed to simulate the thermal loads of the building. The energy consumption of the building for cold seasons (from October to March) is simulated for the two scenarios of with and without PCM. The effect of the melting point is also investigated by considering three types of PCMs with different melting temperatures. After choosing the proper PCM according to weather conditions for this building, the effect of different combinations of PCMs applied to the south wall of the building on the reduction of the total energy consumption is investigated.
Front capturing by level set method for the reactive Euler equations
Authors: Xiao Min , Ni Guoxi , Wang Cheng , Yang Tonghui
Published: April 2021

In this article, we present a front capturing method for compressible reactive flows, where a shock tracking technique is applied with level set method. In stiff reaction problems, the difficulty arises when the time scale of the source term is significantly shorter than the time scale of the homogeneous conservation law. The spurious numerical phenomenon may occur due to the smeared out shock profiles. In order to overcome the difficulty, the detonation front is captured sharply by level set technique, and a modified finite volume scheme is developed at the computational cells cut by detonation front. The mass, momentum, and energy transitions are occurred on shock front for chemical reactive flows. In our method, the interface exchanges are calculated by considering a Riemann problem. Unlike the standard level set/ghost fluid method, our method can maintain the conservation on the shock discontinuity. One‐ and two‐dimensional numerical examples including stable and unstable detonation problems are illustrated to verify the good reliability and robustness of our method.
Social network size, loneliness, physical functioning and depressive symptoms among older adults: Examining reciprocal associations in four waves of the Longitudinal Aging Study Amsterdam (LASA)
Authors: Domènech‐Abella Joan , Mundó Jordi , Switsers Lise , van Tilburg Theo , Fernández Daniel , Aznar‐Lou Ignacio
Published: April 2021

Introduction

Previous research indicates that social isolation, loneliness, physical dysfunction and depressive symptoms are interrelated factors, little is known about the potential pathways among them. The aim of the study is to analyse simultaneously reciprocal relationships that could exist between the four factors to clarify potential mediation effects.

Methods

Within a large representative sample of older people in the Longitudinal Aging Study Amsterdam (LASA), participants aged 75 and over were followed up over a period of 11 years (four waves). We tested cross‐lagged and autoregressive longitudinal associations of social network size, loneliness, physical functioning and depressive symptoms using structural equation modelling (SEM).

Results

Several statistically significant cross‐lagged associations were found: decreasing physical functioning (Coef. = −0.03; p < 0.05), as well as social network size (Coef. = −0.02; p < 0.05), predicted higher levels of loneliness, which predicted an increase in depressive symptoms (Coef. = 0.17; p < 0.05) and further reduction of social network (Coef. = −0.20; p < 0.05). Decreasing physical functioning also predicted an increase in depressive symptoms (Coef. = −0.08; p < 0.05). All autoregressive associations were statistically significant.

Conclusion

Interventions focused on promoting social activities among older adults after negative life events, such as loss of social contacts or declining physical function, may alleviate feelings of loneliness and act as mental health protector.
Survival outcomes in patients with parotid gland carcinoma treated with postoperative therapies using risk stratification
Authors: Wei Zhi‐Gong , Peng Xing‐Chen , He Yan , Guan Hui , Wang Jing‐Jing , He Ling , Mu Xiao‐Li , Liu Zhe‐Ran , Li Rui‐Dan , Zhang Zhuang
Published: April 2021

Background

To evaluate the role of postoperative treatment in parotid gland carcinoma (PGC) based on risk stratification.

Material and Methods

A total of 301 PGC patients were retrospectively analyzed using risk stratification. The Kaplan–Meier method and Cox analysis were performed to conduct survival analysis.

Results

In the high‐risk group, those treated with postoperative radiotherapy (RT) had a better 5‐year disease‐free survival (DFS) than those treated with surgery alone. In the low‐risk group, both surgery + RT and surgery +  chemotherapy (CT) significantly improved DFS when compared with surgery alone. Cox analysis showed that patients who underwent surgery + RT or surgery + CT had a lower risk of disease progression than those who underwent surgery alone in the low‐risk group. In the high‐risk group, patients who underwent surgery + RT had a lower risk of disease progression.

Conclusions

Postoperative RT showed considerable benefit in improving disease control in patients with PGC, even in those without high‐risk factors.
Monitoring and modelling of hydrological processes in the semiarid region of Brazil: The Cariri experimental basins
Authors: S. Srinivasan Vajapeyam , M. de Alcântara Hugo , de O. Galvão Carlos , A. Bezerra Ulisses , E. de Brito Leite Cunha John
Published: April 2021

Catchments have highly variable yields of runoff and soil erosion. The size, land use and the surface cover play a significant role and influence the catchment response and parameter values of simulation models. Two experimental basins—the Cariri basins—were equipped in a semi‐arid region of Brazil, for obtaining runoff and sediment yield at different catchment scales, as well as, to evaluate the influence of the land use and surface cover. In the first basin, located in the municipality of Sumé, the field studies were carried out at two different scales: four micro‐catchments with an area of around 0.5 ha and nine standard Wischmeier‐type erosion plots of 100 m2. The experimental units had varied vegetation and management. They were subjected only to natural rainfall events, and were monitored from 1982 to 1991. The total runoff and total sediment yield were determined for each of the events. The installations in the second basin, in the municipality of São João do Cariri, from 1999, include two erosion plots, three micro‐catchments, and two sub‐catchments of a small basin. These basins are still being monitored for runoff and sediment production. Among the micro‐catchments two are nested to detect any scale effect at the micro‐catchment level. Nearly 600 events of precipitation, that produced runoff in at least one of the experimental units, have been registered. These data have been used to evaluate the influence of various factors, including cultivation practices and to calibrate hydrological models for plots and micro‐catchments. Parameters have been tested by means of cross validations among micro‐catchments and sub‐catchments. The data sets are made available to all the catchment hydrology researchers and others at https://doi.org/10.5281/zenodo.4690886.
Snags in mobile money in developing economies
Authors: Kanobe Fredrick , Bwalya Kelvin Joseph
Published: April 2021

Lessening snags in the management of mobile money systems is a fundamental prerequisite. The study was motivated by the continuous mobile money management snags. Previous studies in developing economies focused mainly on technological algorithm for mobile money systems with untraceable attention given to management matters. The study aimed at lessening snags in the management of mobile money system. Underpinned by activity theory and guided by an interpretive paradigm, a qualitative inquiry was conducted. Semi‐structured interviews and internal document review formed the key data instruments. Expert purposive sampling was adopted, data thematically analyzed and themes mapped on activity theory nodes. The study revealed inadequate monitoring of the mobile money agents, insufficient confidentiality and privacy in financial transactions; use of general accounts for financial transactions, use of generic guidelines and polices, third party involvement in sensitive mobile money activities and weak staff recruitment policies as the key findings. Managerial implications for the study include online registration of customers, introduction of online transaction monitoring, online categorization of mobile money accounts, digital financial crime checks, digital validation of customer identities and continuous review and updates of mobile money guidelines.
In situ deposition of CdS on MoS2/rGO‐based nanocomposites for highly efficient photocatalytic H2 evolution reaction with visible light
Authors: Tan Bi‐yu , Song Xiao‐jie , Xian‐yang Shi
Published: April 2021

BACKGROUND

The development of advanced and inexpensive photocatalytic systems exhibiting high efficiency is highly desired for hydrogen (H2) production. In this work, a hydrothermal and in situ growth method was employed for the construction of CdS/MoS2/rGO nanocomposites by coupling MoS2/rGO with CdS to produce H2. The stability and photocatalytic properties of the nanocomposites for H2 evolution at different CdS content were investigated.

RESULTS

It was found that CdS/MoS2/rGO nanocomposites with 0.35 wt% CdS displayed the highest H2 evolution rate of 11 331.65 μmol h−1 g−1. This corresponded to the apparent quantum efficiency of 10.4% at 420 nm, which was approximately 46 times higher than that of pure CdS. The CdS/MoS2/rGO nanocomposites showed excellent stability in 6‐run recycling experiments. Additionally, a plausible H2 production mechanism was proposed.

CONCLUSION

The remarkable photocatalytic activity was attributed to the high electron–hole pair separation efficiency upon the introduction of MoS2/rGO. This work provides new insights for enhancing the photocatalytic H2 evolution activity. © 2021 Society of Chemical Industry (SCI).
Evaluation of automated segmentation algorithms for neurons in macaque cerebral microscopic images
Authors: You Zhenzhen , Jiang Ming , Shi Zhenghao , Ning Xiaojuan , Shi Cheng , Du Shuangli , Hérard Anne‐Sophie , Jan Caroline , Souedet Nicolas , Delzescaux Thierry
Published: April 2021

Accurate cerebral neuron segmentation is required before neuron counting and neuron morphological analysis. Numerous algorithms for neuron segmentation have been published, but they are mainly evaluated using limited subsets from a specific anatomical region, targeting neurons of clear contrast and/or neurons with similar staining intensity. It is thus unclear how these algorithms perform on cerebral neurons in diverse anatomical regions. In this article, we introduce and reliably evaluate existing machine learning algorithms using a data set of microscopy images of macaque brain. This data set highlights various anatomical regions (e.g., cortex, caudate, thalamus, claustrum, putamen, hippocampus, subiculum, lateral geniculate, globus pallidus, etc.), poor contrast, and staining intensity differences of neurons. The evaluation was performed using 10 architectures of six classic machine learning algorithms in terms of typical Recall, Precision, F‐score, aggregated Jaccard index (AJI), as well as a performance ranking of algorithms. F‐score of most of the algorithms is superior to 0.7. Deep learning algorithms facilitate generally higher F‐scores. U‐net with suitable layer depth has been evaluated to be excellent classifiers with F‐score of 0.846 and 0.837 when performing cross validation. The evaluation and analysis indicate the performance gap among algorithms in various anatomical regions and the strengths and limitations of each algorithm. The comparative result highlights at the same time the importance and difficulty of neuron segmentation and provides clues for future improvement. To the best of our knowledge, this work is the first comprehensive study for neuron segmentation in such large‐scale anatomical regions.

Neuron segmentation plays a critical role in extracting cerebral information, such as neuron counting and neuron morphological analysis.

Accurate automated cerebral neuron segmentation is a challenging task due to different kinds, poor contrast, staining intensity differences, and fuzzy boundaries of neurons.

The comprehensive evaluation and analysis of performance among existing machine learning algorithms in diverse anatomical regions allows to make clear of the strengths and limitations of state‐of‐the‐art algorithm.

The comprehensive study provides clues for future improvement and creation of automated methods.
Synthesis of julolidines via one‐pot cascade three component Povarov reaction in the presence of silica sulfuric acid
Authors: Kaboudin Babak , Sohrabi Masoumeh , Kazemi Foad
Published: April 2021

In this report, synthesis of julolidines via one‐pot cascade reaction of aniline derivatives with a mixture of styrene and formaldehyde in the presence of silica sulfuric acid as an efficient catalyst has been studied under aerobic condition. By presented method, various julolidines are obtained under mild and transition metal‐free conditions. The reaction is proceeded with imine formation and followed by an Aza‐Diels‐Alder cycloaddition with styrene gave julolidine derivatives. The catalyst can be recycled and reused multiple times to catalyze the reaction.
Identifying the primary meteorological factors affecting the growth and development of Tartary buckwheat and a comprehensive landrace evaluation using a multi‐environment phenotypic investigation
Authors: Li Jing , Feng Shan , Qu Yang , Gong Xiangwei , Luo Yan , Yang Qinghua , Zhang Yuchuan , Dang Ke , Gao Xiaoli , Feng Baili
Published: April 2021

BACKGROUND

Tartary buckwheat (Fagopyrum tataricum) is a traditional edible and medicinal crop and has been praised as one of the green foods for humans in the 21st century. However, its production and promotion are restricted by the low yields of current varieties. The interaction of genotype and environment could lead to inconsistent phenotypic performance of genotypes across different environments. Climate change has intensified these effects and poses a substantial threat to crop production.

RESULTS

In the present study, the effects of meteorological factors on the phenotypic traits of 200 Tartary buckwheat landraces across four macro‐environments were investigated. Overall, the phenotypic performance of these Tartary buckwheat landraces was markedly varied across the different environments. Also, the average daily temperature and precipitation had relatively higher impacts on phenotypic performance. The results also revealed the negative impacts of relative humidity on the yield‐related traits. Twenty‐five Tartary buckwheat landraces were ultimately identified as having good overall phenotypic performance and high yield stability.

CONCLUSION

Understanding the impacts of meteorological factors on the phenotypic performance of crops can guide appropriate measures and facilitate germplasm selection for yield enhancement in the context of climate change. The landraces selected comprehensively in this study could be used as parents or intermediate materials for breeding high‐quality Tartary buckwheat varieties in the future. The methods used could also be extended to other crops for breeding and germplasm innovation. © 2021 Society of Chemical Industry.
Prediction of soft tissue sarcoma response to radiotherapy using longitudinal diffusion MRI and a deep neural network with generative adversarial network‐based data augmentation
Authors: Gao Yu , Ghodrati Vahid , Kalbasi Anusha , Fu Jie , Ruan Dan , Cao Minsong , Wang Chenyang , Eilber Fritz C. , Bernthal Nicholas , Bukata Susan , Dry Sarah M. , Nelson Scott D. , Kamrava Mitchell , Lewis John , Low Daniel A. , Steinberg Michael , Hu Peng , Yang Yingli
Published: April 2021

Purpose

The goal of this study was to predict soft tissue sarcoma response to radiotherapy (RT) using longitudinal diffusion‐weighted MRI (DWI). A novel deep‐learning prediction framework along with generative adversarial network (GAN)‐based data augmentation was investigated for the response prediction.

Methods

Thirty soft tissue sarcoma patients who were treated with five‐fraction hypofractionated radiation therapy (RT, 6Gy×5) underwent diffusion‐weighted MRI three times throughout the RT course using an MR‐guided radiotherapy system. Pathologic treatment effect (TE) scores, ranging from 0‐100%, were obtained from the post‐RT surgical specimen as a surrogate of patient treatment response. Patients were divided into three classes based on the TE score (TE ≤ 20%, 20% < TE < 90%, TE ≥ 90%). Apparent diffusion coefficient (ADC) maps of the tumor from the three time points were combined as 3‐channel images. An auxiliary classifier generative adversarial network (ACGAN) was trained on 20 patients to augment the data size. A total of 15,000 synthetic images were generated for each class. A prediction model based on a previously described VGG‐19 network was trained using the synthesized data, validated on five unseen validation patients, and tested on the remaining five test patients. The entire process was repeated seven times, each time shuffling the training, validation, and testing datasets such that each patient was tested at least once during the independent test stage. Prediction performance for slice‐based prediction and patient‐based prediction was evaluated.

Results

The average training and validation accuracies were 86.5% ± 1.6% and 84.8% ± 1.8%, respectively, indicating that the generated samples were good representations of the original patient data. Among the seven rounds of testing, slice by slice prediction accuracy ranged from 81.6% to 86.8%. The overall accuracy of the independent test sets was 83.3%. For patient‐based prediction, 80% was achieved in one round and 100% was achieved in the remaining six rounds. The mean accuracy was 97.1%.

Conclusion

This study demonstrated the potential to use deep learning to predict the pathologic treatment effect from longitudinal DWI. Accuracies of 83.3% and 97.1% were achieved on independent test sets for slice‐based and patient‐based prediction respectively.
Memory‐efficient frequency‐domain Gauss–Newton method for wave‐equation first‐arrival traveltime inversion
Authors: Wang Jianhua , Dong Liangguo
Published: April 2021

Wave‐equation traveltime inversion (WTI) can be used to automatically obtain a background near‐surface velocity model (NSM), which overcomes the high‐frequency approximation in ray theory. It is generally implemented in the time domain. However, the commonly used gradient‐based optimisation methods (such as the steepest‐descent method) in WTI have a low convergence rate and may yield less accurate results within limited iterations in geologically complex regions. To increase the convergence rate and improve the inversion accuracy, we propose a frequency‐domain truncated Gauss–Newton first‐arrival wave‐equation traveltime inversion (GN‐WTI) method to retrieve the background NSM. As only a few frequencies are used for inversion, the proposed frequency‐domain WTI method significantly reduces the computational memory requirements by more than two orders of magnitude in comparison with the conventional time‐domain WTI method. Therefore, the proposed method is especially advantageous for the building of large three‐dimensional models. In this GN‐WTI method, according to the derived explicit traveltime residual kernel, the gradient and Hessian vector products can be computed efficiently using an elegant and improved scattering integral approach as long as the source‐side wavefields and non‐redundant receiver‐side Green's functions are computed and stored in advance. The conjugate gradient approach is used to solve the Gauss–Newton normal equation to obtain the Gauss–Newton direction in inner loops. Here, the Gauss–Newton Hessians of the ray‐based traveltime inversion and WTI are compared to demonstrate the advantages of WTI. The trial runs with a simple periodic velocity model example showed that the proposed GN‐WTI method outperforms the WTI method when using the steepest‐descent and limited‐memory Broyden–Fletcher–Goldfarb–Shanno approaches in terms of the convergence rate and inversion accuracy. A complex Marmousi model was further used to illustrate the effectiveness of GN‐WTI. The proposed method should be beneficial in near‐surface velocity model building.
Nonassociative Geometry of Nonholonomic Phase Spaces with Star R‐flux String Deformations and (non) Symmetric Metrics
Authors: Vacaru Sergiu I. , Veliev Elşen Veli , Bubuianu Laurenţiu
Published: April 2021

We elaborate on nonassociative differential geometry of phase spaces endowed with nonholonomic (non‐integrable) distributions and frames, nonlinear and linear connections, symmetric and nonsymmetric metrics, and correspondingly adapted quasi‐Hopf algebra structures. The approach is based on the concept of nonassociative star product introduced for describing closed strings moving in a constant R‐flux background. Generalized Moyal‐Weyl deformations are considered when, for nonassociative and noncommutative terms of star deformations, there are used nonholonomic frames (bases) instead of local partial derivatives. In such modified nonassociative and nonholonomic spacetimes and associated complex/real phase spaces, the coefficients of geometric and physical objects depend both on base spacetime coordinates and conventional (co) fiber velocity/momentum variables like in (non) commutative Finsler‐Lagrange‐Hamilton geometry. For nonassociative and (non) commutative phase spaces modelled as total spaces of (co) tangent bundles on Lorentz manifolds enabled with star products and nonholonomic frames, we consider associated nonlinear connection, N‐connection, structures determining conventional horizontal and (co) vertical (for instance, 4+4) splitting of dimensions and N‐adapted decompositions of fundamental geometric objects. There are defined and computed in abstract geometric and N‐adapted coefficient forms the torsion, curvature and Ricci tensors. We extend certain methods of nonholonomic geometry in order to construct R‐flux deformations of vacuum Einstein equations for the case of N‐adapted linear connections and symmetric and nonsymmetric metric structures.
Sublethal concentration of emamectin benzoate inhibits the growth of gypsy moth by inducing digestive dysfunction and nutrient metabolism disorder
Authors: Xu Zhe , Bai Jianyang , Li Lu , Liang Liwei , Ma Xiaoqian , Ma Ling
Published: April 2021

BACKGROUND

Gypsy moth (Lymantria dispar) is one of the most important pests in the world. Emamectin benzoate (EMB) is widely used in the control of agricultural and forestry pests. Here, we explored the sublethal effects of EMB on gypsy moths in order to better understand the toxicological mechanism of EMB.

RESULTS

The sublethal concentration of EMB exposure significantly decreased the larvae body weight. To further explore the mechanism, indicators related to digestion and nutrient metabolism were detected. The results showed that EMB exposure caused midgut damage, reduced the activities of digestive enzymes and changed the content of sugar and amino acids. Moreover, the expression of insulin/phosphoinositide‐3‐kinase (PI3K)/forkhead box protein O (FoxO) pathway and sugar metabolism‐related genes was abnormal. The expression of insulin receptor (InR), chico, PI3K, and protein kinase B (Akt) significantly reduced, and that of phosphatase and tensin homologue (PTEN) and FoxO increased. The expression of glycogen phosphorylase (GP) was upregulation and that of glycogen synthase (GS), trehalase (TRE) and trehalose‐phosphate synthase (TPS) were downregulation. All results indicated that EMB inhibits the growth of gypsy moth by inducing midgut injury, digestive dysfunction and nutrient metabolism disorder. In addition, EMB caused midgut injury may be related to apoptosis or a collateral effect of the damage in other tissues, and more extensive and deeper research is still needed to investigate the detailed mechanism.

CONCLUSION

Our finding strengthens the understanding of the sublethal effect of EMB, and provides a theoretical basis for the application of EMB in the prevention and control of gypsy moth.
The use of external controls: To what extent can it currently be recommended?
Authors: Burger Hans Ulrich , Gerlinger Christoph , Harbron Chris , Koch Armin , Posch Martin , Rochon Justine , Schiel Anja
Published: April 2021

With more and better clinical data being captured outside of clinical studies and greater data sharing of clinical studies, external controls may become a more attractive alternative to randomized clinical trials (RCTs). Both industry and regulators recognize that in situations where a randomized study cannot be performed, external controls can provide the needed contextualization to allow a better interpretation of studies without a randomized control. It is also agreed that external controls will not fully replace RCTs as the gold standard for formal proof of efficacy in drug development and the yardstick of clinical research. However, it remains unclear in which situations conclusions about efficacy and a positive benefit/risk can reliably be based on the use of an external control. This paper will provide an overview on types of external control, their applications and the different sources of bias their use may incur, and discuss potential mitigation steps. It will also give recommendations on how the use of external controls can be justified.
Using marginal structural models to analyze the impact of subsequent therapy on the treatment effect in survival data: Simulations and clinical trial examples
Authors: Xu Qing , Przepiorka Donna
Published: April 2021

We explore the impact of time‐varying subsequent therapy on the statistical power and treatment effects in survival analysis. The marginal structural model (MSM) with stabilized inverse probability treatment weights (sIPTW) was used to account for the effects due to the subsequent therapy. Simulations were performed to compare the MSM‐sIPTW method with the conventional method without accounting for the time‐varying covariate such as subsequent therapy that is dependent on the initial response of the treatment effect. The results of the simulations indicated that the statistical power, thereby the Type I error, of the trials to detect the frontline treatment effect could be inflated if no appropriate adjustment was made for the impact due to the add‐on effects of the subsequent therapy. Correspondingly, the hazard ratio between the treatment groups may be overestimated by the conventional analysis methods. In contrast, MSM‐sIPTW can maintain the Type I error rate and gave unbiased estimates of the hazard ratio for the treatment. Two real examples were used to discuss the potential clinical implications. The study demonstrated the importance of accounting for time‐varying subsequent therapy for obtaining unbiased interpretation of data.
Giant Microwave Spontaneous Emission Enhancements in Planar Aperture Waveguide Structures
Authors: Shugayev Roman , Devkota Jagannath , Crawford Scott , Lu Ping , Buric Michael
Published: April 2021

Microwave interactions are an invaluable tool for probing atomic states of matter and are currently being extensively explored for the development of scalable quantum computing. However, many of the available methods for spectroscopic analysis and photonic quantum manipulations are inaccessible for microwaves due to the weak spontaneous emission of quantum emitters. In this work, a mechanism for giant resonant enhancement of spontaneous emission from magnetic dipole emitters is suggested that employs a new phenomenon of near field impedance cancellation via magnetic flux confinement. Enhancements of at least 1011are theoretically shown for structures with 100 nm features, and much greater potential enhancements are predicted with this method. Subsequently, the realization of integrated systems with enhanced quantum emitters using microwave spoof plasmon waveguides is demonstrated. Taken together, these findings will pave the way for microwave quantum photonics and microwave hybrid quantum computing.
Low‐energy electron interactions with chlorotrimethylsilane (Si(CH3)3Cl), dichlorodimethylsilane (Si(CH3)2Cl2) and chloromethyldimethylsilane (SiH(CH3)2(CH2Cl))
Authors: Michalczuk Bartosz , Barszczewska Wiesława
Published: April 2021

Rationale

Silane derivatives are widely used in industrial plasmas for manufacturing lighting devices, solar cells, displays, etc. Models of technological plasmas require quantitative data. The rate coefficients (k) and the activation energies (Ea) of thermal electron attachment for chlorotrimethylsilane (Si(CH3)3Cl), dichlorodimethylsilane (Si(CH3)2Cl2) and chloromethyldimethylsilane (SiH(CH3)2(CH2Cl)) are reported. This is important for understanding the basic processes occurring in plasmas.

Methods

The pulsed Townsend technique (known as the electron swarm method) has been applied for the measurements. In this technique, electrons generated by a laser, under a uniform electric field, traverse to an anode and induce a charge on it. In the buffer gas charge grows linearly, but in the presence of a scavenger, electrons are captured, and thus the rate of charge increase slows down with time. From the shape of the pulse, the kinetic parameters are determined.

Results

Kinetic parameters from the study of thermal electron attachment by Si(CH3)3Cl, Si(CH3)2Cl2 and SiH(CH3)2(CH2Cl) were determined for the first time. The corresponding rate coefficients at 298 K are equal to (9.56 ± 0.02) × 10−11, (6.62 ± 0.02) × 10−11 and (1.24 ± 0.05) × 10−11 cm3 s−1 and Ea values are equal to 0.29 ± 0.01, 0.24 ± 0.01 and 0.31 ± 0.01 eV for Si(CH3)3Cl, Si(CH3)2Cl2 and SiH(CH3)2(CH2Cl), respectively. The experiment was performed in the 298–378 K temperature range.

Conclusions

The presented results provide important new information about fundamental quantities such as rate coefficients and activation energies for thermal electron capture by chlorinated derivatives of silane. These data can further advance our understanding of thermal electron interactions with chlorosilanes that can be used to control the important species in the plasmas of many modern technologies.
A new technology using a customized 3D printed fixator to assist fracture reduction and fixation: Technical note
Authors: Wu Jianghong , Zhou Panyu , Zhang Yuntong , Xiao Liang , Li Lei , Xu Shuogui
Published: April 2021

Background

Poor reduction can lead to complications such as deformity and delayed fracture healing. We introduce a 3D printed external fixator technology that can assist in fracture reduction and fixation.

Methods

A fractured long bone was first fixed by a temporary external fixator and then scanned with computed tomography. Three‐dimensional reconstruction of the contour and bone fragments of the affected limb was performed using Mimics software, and the fracture reduction was simulated. Subsequently, data were imported into SolidWorks software for customized external fixator design and 3D printing. Through the precise assembly of the 3D printed external fixator and external fixation pins, automatic fracture reduction.

Results

The patient's fractures were well reduced, firmly fixed, and the postoperative fractures healed well with no complications.

Conclusion

The technique we introduce not only assists in fracture reduction for temporary external fixation but can also be used as a definitive treatment for long bone fractures.
2D‐MA3Sb2I9 Back Surface Field for Efficient and Stable Perovskite Solar Cells
Authors: Yuan Haobo , Zhang Jing , Yu Luting , Guo Tonghui , Zhang Zequn , Wang Yanyan , Shang Minghui , Liu Xiaohui , Hu Ziyang , Zhu Yuejin , Han Liyuan
Published: April 2021

In perovskite solar cells (PSCs), a defective perovskite (PVK) surface and cliff‐like energy offset at the interface always slow down the charge extraction; meanwhile, interface ion diffusion causes oxidation of the metal electrode, inducing device instability. Here, the in situ grown 2D‐(CH3NH2)3Sb2I9 (MA3Sb2I9) on the back surface of MAPbI3 results in a more robust interface. MA3Sb2I9 changes the MAPbI3 surface to p‐type and thus acts like a back surface field to drive charge extraction and suppress recombination, resulting in an obviously higher fill factor (FF) = 0.8 and power conversion efficiency (PCE) = 20.4% of SnO2/MAPbI3/MA3Sb2I9/Spiro‐OMeTAD (2,2′,7,7′‐Tetrakis[N,N‐di(4‐methoxyphenyl)amino]‐9,9′‐spirobifluorene) PSC than the pure MAPbI3 device. More importantly, strong chemical bonding of SbI prohibits ion diffusion, largely enhancing the thermal stability and longtime stability. Here, special 2D‐MA3Sb2I9 constructs’ robust band alignment and chemical environment at the interface are highlighted for efficient and stable PSCs.
Silurian (late Llandovery – Wenlock) conodont fauna and biostratigraphy from the Yanbian area of Sichuan Province, south‐west China
Authors: Yan Guanzhou , Wu Rongchang
Published: April 2021

Late Llandovery and Wenlock conodonts are still inadequately documented in China, with data collected chiefly from the Baizitian section in Yanbian County, Sichuan Province, south‐west China. A collection of over 32 000 conodont elements was recovered from 38 samples from the Xiabaizitian and Shangbaizitian formations at this classic locality. The conodont fauna is dominated by cosmopolitan species and can be assigned to 50 species representing 17 genera. Of these, one new species, Apsidognathus yanbianensis sp. nov., is proposed herein. Six conodont zones are recognized in this section, including the Pterospathodus eopennatus Zone, the Pt. amorphognathoides angulatus Taxon‐range Zone of the Pt. a. amorphognathoides Superzone, the Kockelella ranuliformis Zone, the Kockelella walliseri Taxon‐range Zone, and the Kockelella patula Taxon‐range Zone, in ascending order. These zones can be correlated with other conodont zones around the world based on the occurrences of the stratigraphically diagnostic species. Moreover, the stratigraphical ranges of Pterospathodus enable greater understanding of the correlation of the Telychian guide taxa. The conodont biodiversity changes and faunal turnover across the Silurian Ireviken Bioevent are here documented for the first time in the Baizitian section from the South China palaeoplate.
The effect of rebalancing on LDA in imbalanced classification
Authors: Kim Arlene K. H. , Chung Hyunwoo
Published: April 2021

In binary classification, class imbalance is undesirable in that it may worsen the performance of a classifier. One of the remedies to handle this problem is rebalancing with the optimal rate. Theoretical derivation of the rate is not usually considered and often empirically detected, because it is complex and depends on the classifier. To simplify this, we used a linear discriminant classifier, deriving the theoretical optimal rate that maximizes the Matthews Correlation Coefficient (MCC) and F1 score assuming normality. We showed that adjusting the size of each class to be equal is not always the best solution. Instead, we found that there exists the optimal rate depending on the level of class imbalance and the Mahalanobis distance between two classes. Conducting extensive simulation studies and real data analyses, we confirmed that rebalancing with the optimal rate improves the test MCC and F1 score. These findings suggest that with a careful consideration on the level of class imbalance and the separability between two classes, we can achieve better classification results in presence of class imbalance.
Implementation of National Water Policy by eastern states of India—A review and analysis
Authors: Parween Fakeha , Singh Ajai
Published: April 2021

The mainstay of this study is to highlight the implementation of recommendations of the National Water Policy (NWP) of India. All the policy documents advocate the adoption of a volumetric system of water pricing, the Integrated Water Resource Management (IWRM) approach, and the creation of River Basin Organizations (RBOs). IWRM needs to be redefined, reconsidered, and recalibrated and should be explicit. Except for Odisha, no state has constituted the RBOs. The reasons for nonformation of RBO are public resistance, not understanding the basic principle of RBO, and limitation and lack of expertise to handle large river basin organization activities. Revenue collection records are very poor except Odisha. Water pricing was not revised frequently and no water pricing regulatory body had been constituted as per the recommendation of NWP, 2012, by all the eastern states. Odisha has formulated a water policy in line with NWP and has implemented it well. All the north‐eastern states have adopted their own water policy recently but have not implemented effectively. The existing system of assessment based on crop‐wise irrigated areas must be rationalized and simplified. The revenue collection system needs mechanization. The revenue collection needs to be increased in all the eastern states.
Dinuclear Zn Complex: Phenoxyl Radical Formation Driven by Superoxide Coordination
Authors: Squarcina Andrea , Fehn Dominik , Senft Laura , Langer Jens , Ivanović‐Burmazović Ivana
Published: April 2021

The dinuclear zinc complex Zn2L2 (HL=2‐{[[di(2‐pyridyl)methyl](methyl)amino]methyl}phenol) has been synthesized and isolated as colorless crystals. The interaction of the compound with superoxide in anhydrous organic solvents has been evaluated by CV, stopped‐flow Uv‐vis, EPR and ESI‐MS suggesting the binding and the activation of the coordinated superoxide, thanks to the Lewis acidity of the Zn(II) centers. The results obtained in this study highlight the formation of a Zn2L2−O2.− intermediate and a metastable phenoxyl‐radical driven by the coordinated superoxide.
Fast evaluation for magnetohydrodynamic flow and heat transfer of fractional Oldroyd‐B fluids between parallel plates
Authors: Liu Yi , Zhang Hui , Jiang Xiaoyun
Published: April 2021

In this work, we establish a model to describe the unsteady magnetohydrodynamic (MHD) flow of fractional Oldroyd‐B fluid between parallel plates on heat transfer, by introducing the fractional derivative into the constitutive equation. The flow is driven by magnetic, electroosmotic and pressure gradient forcings. In the numerical implementation, the spectral collocation method combined with fast algorithm based on sum‐of‐exponentials (SOE) approximation is performed to solve the model. Effects of several parameters on the velocity profiles, temperature field and Nusselt number are investigated graphically.