bluuebunny/crossref_metadata_2025 huggingface dataset:
A note on numerical solution of classical Darboux problem
Authors: Harish Kumar Kotapally , Jiwari Ram
Published: June 2021

Recently, many authors studied the numerical solution of the classical Darboux problem in its integral form via two‐dimensional nonlinear Volterra–Fredholm integral equation. In the present article, a numerical technique based on the Chebyshev wavelet is proposed to solve the Darboux problem directly without converting into a nonlinear Volterra–Fredholm integral equation. The proposed technique is different from the techniques discussed in the literature. The proposed approach produces higher accuracy than its counterpart techniques. The proposed scheme is illustrated with suitable examples to show the advantages in terms of its accuracy with a lesser grid size.
Multi‐band bandpass filter based on direct‐connected T‐shaped stub‐loaded resonator
Authors: Wu Jia‐Kang , Liang Jun‐Ge , Wang Xiao , Kim Nam‐Young , Gu Xiaofeng
Published: June 2021

In this paper, we proposed an optimized structure, named direct‐connected T‐shaped stub‐loaded resonator (DC‐TSSLR), which generates nine high‐performance resonant modes (RMs) while the conventional works only produces two RMs (odd‐ and even‐mode) with the similar structure. Based on this method, a triple‐band nine‐RM bandpass filter (BPF) is realized with fractional bandwidths (FBW) of 65%, 42%, and 31%, the insertion losses (IL) of 0.11 dB, 0.21 dB, and 0.37 dB and the return losses (RL) of 42.9 dB, 44.5 dB, and 42.9 dB, respectively. In addition, this scheme was further developed into a modularized design for multi‐mode filter design. As example, by cascading another DC‐TSSLR, a dual‐wideband BPF with eight RMs is realized with the FBW of 55% and 38%, the IL of 0.15 dB and 0.4 dB and the RLs of 16.2 dB and 21.7 dB, respectively. The proposed method offers a modularized‐design scheme for multiband BPF design as well as the reference for RMs modulation.
Modeling viscous damping in actuated breast tissue to provide diagnostic insight for breast cancer: A proof‐of‐concept analysis
Authors: Fitzjohn Jessica L. , Zhou Cong , Chase J. Geoffrey , Ormsby Zane , Haggers Marcus
Published: June 2021

Purpose

This study develops a viscous damping model (VDM) based on Rayleigh Damping (RD) with potential use in low cost, non‐invasive breast cancer diagnostics using Digital Image Elasto Tomography (DIET).

Methods

A clinical trial involving 13 subjects, each with a tumor in one breast, resulted in 13 cancerous and 13 healthy breasts. Displacement data following actuator induced steady state vibration in the breast tissue were captured using the DIET system. Over 14 000 reference points on the breast surface were split into four segments and viscous damping constant calculated for each reference point. The VDM was fit to median‐filtered data for each breast segment and VDM coefficients compared within each breast. One model coefficient, relating to stiffness, was hypothesized to differ in breast segments containing a tumor. Comparison of “” coefficients in different breast segments using percentage tolerances provided an unbiased, generalizable diagnostic method. Bootstrapping with replacement was used to upsample the data and create smooth receiver operator characteristic (ROC) curves. A total of 12 breast segmentation configurations were used to demonstrate the robustness of the method.

Results

Fitting the VDM to median‐filtered data gave consistent results for one VDM coefficient (“”) across all breasts. The second VDM coefficient (“”) showed diagnostic potential with breast segments having consistent coefficients in healthy breasts. In cancerous breasts “” coefficients were found to be statistically different in segments containing and adjacent to the tumor compared with the segment furthest from the tumor with p < 0.02 using the Student t‐Test. Large discrepancies in “” coefficients were found to be indicative of a tumor with a 14.5% tolerance resulting in sensitivity and specificity of 76.9%. The optimal breast configuration resulted in an area under the ROC curve (AUC) of 0.81 with sensitivity and specificity at 77% and 72%, respectively.

Conclusion

This VDM method enables a computationally simple diagnostic technique using DIET for comfortable breast screening for women of all ages. Regular screening potential allows for tolerance alteration based on age, prior subject‐specific results, and other risk factors to manage false positives, reducing psychological harm while optimizing early detection for successful treatment and decreased mortality.
Technical Note: End‐to‐end verification of an MR‐Linac using a dynamic motion phantom
Authors: Liu Xuechun , Li Chengqiang , Zhu Jian , Gong Guanzhong , Sun Hongqiang , Li Xu , Sun Mengdi , Zhang Zicheng , Li Baosheng , Yin Yong , Li Zhenjiang
Published: June 2021

Purpose

MR‐Linac integrates an MRI scanner and a linear accelerator to provide adaptive radiation treatment. Superior tissue contrast and real‐time imaging can give the clinicians confidence to reduce the margins of the planning target volume (PTV). The purpose of this study was to verify the dosimetric accuracy of an MR‐Linac system in treating a moving target and assess the error with different motion patterns and adaptation methods.

Methods

We performed an end‐to‐end test for Elekta Unity (Elekta) using the 4D Dynamic Thorax Phantom (CIRS MRgRT 008Z), comparing the measured and planned dose. The moving phantom had four measurement locations in the tumor, liver, kidney, and spinal cord regions with a PTW30013 ion chamber. For seven different motion patterns, we first acquired simulation CT using a slow‐scanning protocol, based on which we generated reference plans. The treatment technique was the standard intensity‐modulated radiation therapy (IMRT). We tested both adaptation workflows: the Adapt‐to‐Position (ATP) and the Adapt‐to‐Shape (ATS). The three‐dimensional (3D) distribution was measured using a diode array phantom (Sun Nuclear Inc.) to check the dose distribution accuracy as part of the routine QA process. We also performed end‐to‐end tests on a conventional Linac. Finally, we used SPSS Statistics 22.0 (Inc., Chicago, IL, USA) for data analysis.

Results

All pretreatment reference plans and delivered plans had excellent QA results with a better than 95% passing rate of relative gamma analysis (2%/2 mm criteria). The adaptive planning for MR‐Linac produced quality plans. The measured dose in the target agreed with the calculated dose.

Conclusions

The adaptive treatment on the MR‐Linac system investigated met the expected performance with tumor motions. The outline of the target could be visualized and accurately contoured on the 3D MR for online planning. Under different motion patterns, the difference between the measured and calculated dose was acceptable clinically.
Dynamic cardiac PET motion correction using 3D normalized gradient fields in patients and phantom simulations
Authors: Nye Jonathon A. , Piccinelli Marina , Hwang Doyeon , David Cooke Charles , Paeng Jin Chul , Lee Joo Myung , Cho Sang‐Geon , Folks Russell , Bom Hee‐Seung , Koo Bon‐Kwon , Garcia Ernest V.
Published: June 2021

This work expands on the implementation of three‐dimensional (3D) normalized gradient fields to correct for whole‐body motion and cardiac creep in [N‐13]‐ammonia patient studies and evaluates its accuracy using a dynamic phantom simulation model.

Methods

A full rigid‐body algorithm was developed using 3D normalized gradient fields including a multi‐resolution step and sampling off the voxel grid to reduce interpolation artifacts. Optimization was performed using a weighted similarity metric that accounts for opposing gradients between images of blood pool and perfused tissue without the need for segmentation. Forty‐three retrospective dynamic [N‐13]‐ammonia PET/CT rest/adenosine‐stress patient studies were motion corrected and the mean motion parameters plotted at each frame time point. Motion correction accuracy was assessed using a comprehensive dynamic XCAT simulation incorporating published physiologic parameters of the heart's trajectory following adenosine infusion as well as corrupted attenuation correction commonly observed in clinical studies. Accuracy of the algorithm was assessed objectively by comparing the errors between isosurfaces and centers of mass of the motion corrected XCAT simulations.

Results

In the patient studies, the overall mean cranial‐to‐caudal translation was 7 mm at stress over the duration of the adenosine infusion. Noninvasive clinical measures of relative flow reserve and myocardial flow reserve were highly correlated with their invasive analogues. Motion correction accuracy assessed with the XCAT simulations showed an error of <1 mm in late perfusion frames that broadened gradually to <3 mm in earlier frames containing blood pool.

Conclusion

This work demonstrates that patients undergoing [N‐13]‐ammonia dynamic PET/CT exhibit a large cranial‐to‐caudal translation related to cardiac creep primarily at stress and to a lesser extent at rest, which can be accurately corrected by optimizing their 3D normalized gradient fields. Our approach provides a solution to the challenging condition where the image intensity and its gradients are opposed without the need for segmentation and remains robust in the presence of PET‐CT mismatch.
Denoising of hyperpolarized 13C MR images of the human brain using patch‐based higher‐order singular value decomposition
Authors: Kim Yaewon , Chen Hsin‐Yu , Autry Adam W. , Villanueva‐Meyer Javier , Chang Susan M. , Li Yan , Larson Peder E. Z. , Brender Jeffrey R. , Krishna Murali C. , Xu Duan , Vigneron Daniel B. , Gordon Jeremy W.
Published: June 2021

Purpose

To improve hyperpolarized 13C (HP‐13C) MRI by image denoising with a new approach, patch‐based higher‐order singular value decomposition (HOSVD).

Methods

The benefit of using a patch‐based HOSVD method to denoise dynamic HP‐13C MR imaging data was investigated. Image quality and the accuracy of quantitative analyses following denoising were evaluated first using simulated data of [1‐13C]pyruvate and its metabolic product, [1‐13C]lactate, and compared the results to a global HOSVD method. The patch‐based HOSVD method was then applied to healthy volunteer HP [1‐13C]pyruvate EPI studies. Voxel‐wise kinetic modeling was performed on both non‐denoised and denoised data to compare the number of voxels quantifiable based on SNR criteria and fitting error.

Results

Simulation results demonstrated an 8‐fold increase in the calculated SNR of [1‐13C]pyruvate and [1‐13C]lactate with the patch‐based HOSVD denoising. The voxel‐wise quantification of kPL (pyruvate‐to‐lactate conversion rate) showed a 9‐fold decrease in standard errors for the fitted kPL after denoising. The patch‐based denoising performed superior to the global denoising in recovering kPL information. In volunteer data sets, [1‐13C]lactate and [13C]bicarbonate signals became distinguishable from noise across captured time points with over a 5‐fold apparent SNR gain. This resulted in >3‐fold increase in the number of voxels quantifiable for mapping kPB (pyruvate‐to‐bicarbonate conversion rate) and whole brain coverage for mapping kPL.

Conclusions

Sensitivity enhancement provided by this denoising significantly improved quantification of metabolite dynamics and could benefit future studies by improving image quality, enabling higher spatial resolution, and facilitating the extraction of metabolic information for clinical research.
3D printed step‐gradient composite hydrogels for directed migration and osteogenic differentiation of human bone marrow‐derived mesenchymal stem cells
Authors: Motealleh Andisheh , Schulten Alicia , Kehr Nermin S.
Published: June 2021

With the aid of a 3D printing technique, we create a 3D printed step‐gradient (nano)composite scaffold (GradS). GradS is generated by spatially connecting different (nano)composite hydrogel precursors varying in their concentrations of GelMA, alginate, and functional nanomaterials [DexPMO‐PDL = dexamethasone (Dex)‐ and poly‐d‐lysine (PDL)‐functionalized periodic mesoporous organosilicas (PMO)]. GradS not only allows for improving the viability of human bone marrow‐derived mesenchymal stem cells (hBM MSC), but GradS is also applied to direct the migration of hBM MSC toward the higher concentration of GelMA and nanomaterials (NMs) within the 3D gradient porous hydrogel network. Furthermore, we demonstrate that the osteogenic differentiation capacity of hBM MSC is promoted by an increase in the content of GelMA andDexPMO‐PDL; increasing concentrations of GelMA andDexPMO‐PDL within the GradS regulates the migration and subsequent osteogenic differentiation of hBM MSC within the 3D gradient hydrogel network.
Association between female urinary urgency and aponeurotic ptosis: Results from a community‐based cross‐sectional study in Japan
Authors: Ozaki Yusuke , Okamoto Teppei , Miura Yuuki , Iida Keiichiro , Uemura Nozomi , Sugimura Yoshikuni , Hatakeyama Shingo , Urushidate Satoshi , Ohyama Chikara
Published: June 2021

Aims

To investigate the relationship between urinary urgency (UU) and aponeurotic ptosis (AP) in a health promotion project.

Methods

This cross‐sectional study analyzed 658 women in Aomori, Japan. The presence of UU was evaluated using the Overactive Bladder Symptom Score. The distance from the light reflex on the cornea to the upper eyelid (margin reflex distance‐1 [MRD‐1]) was measured. AP was defined as MRD‐1 of less than 2.0 mm. The daily salt intake amount was estimated using the dietary questionnaire. Daily salt intake was defined as excessive if it was 10 g/day or higher. Independent factors of UU and AP were analyzed via multivariable logistic regression model.

Results

The number of women with UU and AP was 193 and 65, respectively. Similar background differences were observed in age, cardiovascular disease history, renal function, hypertension, diabetes mellitus, dyslipidemia, and daily salt intake between participants with UU and those with AP. Participants with UU had a higher prevalence of AP (19% vs. 6.2%) than those without. Moreover, more than 50% of the women with AP experienced UU. Multivariable logistic analysis on UU showed that age (≥65 years), diabetes mellitus, daily salt intake (≥10 g/day), and AP (odds ratio, 2.07, p = .014) were independent factors. Multivariable analysis on AP revealed that age (≥65 years), hypertension, daily salt intake (≥10 g/day), and UU were independent factors.

Conclusions

AP was an independent indicator of UU, in addition to excessive daily salt intake. Women with AP may tend to intake excessive salt and experience UU.
Cutaneous melanoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations
Authors: Ferrari Andrea , Lopez Almaraz Ricardo , Reguerre Yves , Cesen Maja , Bergamaschi Luca , Indini Alice , Schneider Dominik T. , Godzinski Jan , Bien Ewa , Stachowicz‐Stencel Teresa , Eigentler Thomas K. , Chiaravalli Stefano , Krawczyk Malgorzata A. , Pappo Alberto , Orbach Daniel , Bisogno Gianni , Brecht Ines B.
Published: June 2021

Cutaneous melanoma is rare in children and, like other very rare pediatric tumors, it suffers from a shortage of knowledge and clinical expertise. The clinical management of pediatric melanoma is often challenging. Its clinical and pathological diagnosis may be difficult, and there is no standard treatment. In the absence of specific treatment guidelines, young patients are generally treated following the same principle as for adults, but concern remains about their access to clinical trials and new drugs, which have been shown to dramatically change the natural history of advanced melanoma. This paper presents the internationally recognized recommendations for the diagnosis and treatment of children and adolescents with cutaneous melanoma, established by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the EU‐funded project called PARTNER (Paediatric Rare Tumours Network ‐ European Registry). Main recommendations for melanoma are to discuss pediatric patients in multidisciplinary teams that include both pediatric oncologists and specialists in adult melanoma; to enroll patients in prospective trials, if available; to collect data in national–international databases; and to develop an effective international collaboration between pediatric and adult melanoma groups in order to facilitate the transfer of potentially effective new agents from the adult to the pediatric setting.
Facing the challenges of very rare tumors of pediatric age: The European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) background, goals, and achievements
Authors: Ferrari Andrea , Schneider Dominik T. , Bisogno Gianni , Reguerre Yves , Godzinski Jan , Bien Ewa , Stachowicz‐Stencel Teresa , Cecchetto Giovanni , Brennan Bernadette , Roganovic Jelena , Ben‐Ami Tal , Virgone Calogero , Farinha Nuno Reis , Mancini Serena , Orbach Daniel , Brecht Ines B.
Published: June 2021

It has become increasingly clear in recent years that we need to develop ad hoc strategies to combat very rare tumors (VRT) of pediatric age. In 2008, several schemes being run in different countries were pooled together to create the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) project: a cooperative study group that aimed to promote research in the relatively uncharted territory of rare tumors of pediatric age. EXPeRT members were able to activate different levels of cooperation to achieve their goals, and to obtain dedicated funding by participating in EU‐financed projects. Their experiences emphasize the merits of networking, seeking new partnerships, joining forces, and pooling resources to extend the reach of research efforts, and ultimately improve the quality of patient care. Between 2018 and 2021, the EXPeRT has been active in establishing the Pediatric Rare Tumors Network ‐ European Registry (PARTNER). This project had the main purposes of building a European common registry of pediatric VRT, but also the major task of developing diagnostic and treatment guidelines for VRT (or at least part of them). These clinical recommendations are the subject of a series of papers on Pediatric Blood and Cancer.
Pancreatoblastoma in children: EXPeRT/PARTNER diagnostic and therapeutic recommendations
Authors: Bien Ewa , Roganovic Jelena , Krawczyk Malgorzata A. , Godzinski Jan , Orbach Daniel , Cecchetto Giovanni , Barthlen Winfred , Defachelles Anne‐Sophie , Ferrari Andrea , Weldon Christopher B. , Brecht Ines B. , Schneider Dominik T. , Bisogno Gianni , Kolenova Alexandra , Ben‐Ami Tal , Martinova Kata , Virgone Calogero , Stachowicz‐Stencel Teresa , Kachanov Denis , Reguerre Yves
Published: June 2021

Pancreatoblastoma (PBL) is a rare malignant epithelial neoplasm that affects typically young children. Signs related to advanced upper‐abdominal tumor accompanied by elevated serum α‐fetoprotein levels in a young child suggest PBL, however histopathological confirmation is mandatory. The mainstay of the treatment is a complete surgical resection. Unresectable and/or metastatic PBL may become amenable to complete delayed surgery after neoadjuvant chemotherapy. This manuscript presents the international consensus recommendations for the diagnosis and treatment of children with PBL, established by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the EU‐funded PARTNER (Paediatric Rare Tumors Network – European Registry) project.
Efficient reinforcement of epoxy resin with amine‐rich rigid short‐chain grafted graphene oxide
Authors: Shen Lu , Zhang Xueqin , Lei Yanzhou , Liang Mei , Chen Yang , Chen Wenbin , Zou Huawei
Published: June 2021

For improving the mechanical properties of epoxy resin (EP), it is an effective strategy to utilize surface‐modified graphene oxide (GO) as a reinforcement. However, there is nearly no report on surface modification using rigid short‐chain grafted GO, especially with multiple reactive sites. In this work, a novel surface functionalization of GO with an amine‐rich rigid short‐chain was successfully prepared and applied as a filler for EP with simultaneously high toughness and mechanical strength. Superior toughness and mechanical strength of the resultant epoxy nanocomposite can be obtained by grafting amine‐rich rigid short‐chain onto GO (DHN‐GO) owing to the enhanced interface binding ability with the EP and the optimized dispersibility in the matrix. Compared with the pure EP, the epoxy nanocomposites at an extremely low loading (0.75 wt‰) of DHN‐GO showed excellent mechanical properties. The tensile strength, elongation at break, and bending strength are increased by 28%, 37%, and 29%, respectively. This work is expected to provide more inspiration for the preparation of GO/EP composites with high toughness and mechanical strength.
Carbon nanotubes interaction with amorphous and semi‐crystalline domains of polypropylene in melt‐mixed composites: Influence of multiwall carbon nanotubes agglomerate and their modifications
Authors: Banerjee Joyita , Samajdar Rajarshi , Kummara Sreenivas , Panwar Ajay S. , Mukhopadhyay Kingsuk , Saxena Arvind K. , Bhattacharyya Arup R.
Published: June 2021

Polypropylene (PP) and multi‐walled carbon nanotubes (MWCNTs) composites were prepared by melt‐mixing with two types of MWCNTs of varying agglomerate size. Agglomerate dominated dispersion was observed in the PP matrix, wherein N‐MWCNTs exhibit a finer dispersion as compared to D‐MWCNTs. Further, MWCNTs were encapsulated by Li‐salt of 6‐amino caproic acid in various proportions along with PP‐g‐maleic anhydride in order to achieve finer MWCNTs dispersion. Thermogravimetric analysis exhibited an increase in onset of degradation temperature and higher residual weight (%) at 500 °C of PP with increased MWCNTs concentration, which suggests the formation of a thicker “interphase.” Glass transition temperature of the PP phase was increased monotonically as a function of unmodified MWCNTs concentration, which suggests a strong interfacial interaction between PP and MWCNTs. An extensive analysis was carried out with modified MWCNTs based PP composites. Moreover, MWCNTs act as a strong hetero‐nucleating agent manifesting in smaller spherulite size of PP, wherein bulk crystallization temperature is increased to ~130 °C of the PP phase at 5 wt% MWCNTs content. The influence of unmodified and modified MWCNTs on the interaction between the PP chains and MWCNTs in the amorphous phase as well as in the crystalline domains are analyzed in PP/MWCNTs composites.
GISAXS: A versatile tool to assess structure and self‐assembly kinetics in block copolymer thin films
Authors: Smilgies Detlef‐M.
Published: June 2021

Over the past two decades grazing incidence small‐angle scattering (GISAXS) has morphed into a powerful tool for the determination of the structure and self‐assembly kinetics of block copolymer thin films. An overview of the scattering process and the interpretation of GISAXS data is given and experimental requirements are discussed. The application of the technique for the characterization of block copolymer thin films is illustrated with selected examples.
Recent Progress in Anisotropic 2D Semiconductors: From Material Properties to Photoelectric Detection
Authors: Wei Liubo , Li Yanran , Tian Changfa , Jiang Jie
Published: June 2021

The widespread implementation and rapid growing development of emerging sensor systems has posed stringent performance requirements on high‐performance photoelectric detection. Therefore, researchers are committed to finding a new kind of semiconductors with faster response time, higher sensitivity, and better stability. Nowadays, anisotropic 2D materials have drawn great attentions in photoelectric detection due to their unique crystal structures and optical absorption properties. These properties make them possible to detect a wide spectrum from ultraviolet to infrared, which provides a good choice for photoelectric detection under complex conditions. Herein, the various anisotropic 2D materials with intriguing physical properties and their device applications for optoelectronic detection are reviewed.
Passivating Polysilicon Recombination Junctions for Crystalline Silicon Solar Cells
Authors: Haug Franz-Josef , Morisset Audrey , Wyss Philippe , Lehmann Mario , Hessler-Wyser Aicha , Jeangros Quentin , Ingenito Andrea , Ballif Christophe , Kumar C. N. Shyam , Eswara Santhana , Valle Nathalie
Published: June 2021

Polysilicon recombination junctions whose n‐type bottom layers double as a passivating contact to the silicon surface are investigated. Such recombination junctions are a key element in the interconnection of tandem devices with a silicon bottom cell, and they could be used to simplify the processing sequence of single‐junction cells with interdigitated back contacts (IBCs). Polysilicon tunneling junctions require high processing temperatures to crystallize the layers; however, this also facilitates interdiffusion of dopants, whereas tunnelling relies on degenerate doping concentrations in the constituent layers and sharp interfaces between them. Using secondary‐ion mass spectrometry (SIMS) in dynamic mode, it is found that dopants diffuse readily across the interface, thus compromising the junction. The undesired diffusion is suppressed by modifying the interface with C, O, or a combination of these. Moreover, it is found that the modification does not interfere with diffusion of H, an essential element to passivate defects at the surface of the silicon wafer. Thus, implied open‐circuit voltages (iV
oc) of up to 740 mV are demonstrated for contact resistivities less than 40 mΩ cm2.
Therapeutic effect of curcumin in gastrointestinal cancers: A comprehensive review
Authors: Morshedi Korosh , Borran Sarina , Ebrahimi Mohammad Saeid , Masoud khooy Mohammad Jaber , Seyedi Zeynab Sadat , Amiri Atefeh , Abbasi‐Kolli Mohammad , Fallah Maryam , Khan Haroon , Sahebkar Amirhossein , Mirzaei Hamed
Published: June 2021

Gastrointestinal (GI) cancers with a high global prevalence are a leading cause of morbidity and mortality. Accordingly, there is a great need to develop efficient therapeutic approaches. Curcumin, a naturally occurring agent, is a promising compound with documented safety and anticancer activities. Recent studies have demonstrated the activity of curcumin in the prevention and treatment of different cancers. According to systematic studies on curcumin use in various diseases, it can be particularly effective in GI cancers because of its high bioavailability in the gastrointestinal tract. Nevertheless, the clinical applications of curcumin are largely limited because of its low solubility and low chemical stability in water. These limitations may be addressed by the use of relevant analogues or novel delivery systems. Herein, we summarize the pharmacological effects of curcumin against GI cancers. Moreover, we highlight the application of curcumin's analogues and novel delivery systems in the treatment of GI cancers.
Nanotube‐Boramidic Acid Derivative for Dopamine Sensing
Authors: Yigit Aybek , Pınar Pınar Talay , Akinay Yüksel , Alma Mehmet Hakkı , Menges Nurettin
Published: June 2021

A new sensor, based on boramidic acid‐bounded MWCNTs (Multi‐walled carbon nanotubes), was synthesized in three simple steps. Modification of the sensor surface was accomplished using boric acid in which the boron atom is adjacent to the NH group. Characterization, electrochemical behaviors, and stability of newly modified nanosensor were completed using SEM (scanning electron microscope), TEM (Transmission electron microscope), CV (cyclic voltammetry), EIS (electron impedance), DTA (Differential thermal analysis), and XPS (X‐ray photoelectron spectroscopy). SEM and TEM analysis were confirmed the modified surface of the nanosensor. The stability of the newly synthesized sensor was also designated that the initial weight loss occurred between 50–145 °C was corresponded to the degradation of both ethylene diamine and boric acid. According to the EIS study, the Nyquist plot of the MWCNTs‐NH‐B (OH)2/GC electrode displayed a 0.435 kΩ Rct with a smaller semicircle than the bare GC (6.57 kΩ). The electrochemical behavior of dopamine was investigated using cyclic and square wave voltammetry (0.1 M phosphate buffer solution‐pH 7.4). The diffusion‐controlled process was determined when the oxidation of dopamine was studied. The detection limit of dopamine was found to be 5.1 nM. An actual sample study was done using the developed analytical method, and the detection of dopamine in urine was successfully performed. This study is the first example of boramidic acid‐modified multi‐walled carbon nanotubes
The Influence of Anomeric Configuration and Aglycone Structure on the Outcome of Acid‐Promoted Ring Contraction in 2,3‐Di‐O‐Silylated S‐Galactopyranosides
Authors: Abronina Polina I. , Zinin Alexander I. , Malysheva Nelly N. , Karpenko Maxim Y. , Kolotyrkina Natalya G. , Kononov Leonid O.
Published: June 2021

Acid‐promoted rearrangement of a series of 1‐thio‐α/β‐d‐galactopyranosides with bulky triisopropylsilyl (TIPS) or tert‐butyldiphenylsilyl (TBDPS) groups at both O‐2 and O‐3 and bearing various substituents at the S atom in anomeric position leading to ring contraction has been studied. The reaction rates of pyranose ring contraction in S‐galactopyranosides were found to be strongly influenced by anomeric configuration and aglycone structure. Ethyl 1‐thio‐β‐d‐galactopyranosides underwent ring contraction faster than ethyl 1‐thio‐α‐d‐thiogalactopyranosides. 1‐Thio‐β‐d‐galactopyranosides with TIPS groups bearing electron‐donating 5‐tert‐butyl‐2‐methylphenyl group in aglycone could be involved into rearrangement to furanosides under milder acidic conditions (aq TFA in CH2Cl2) than the corresponding 1‐thio‐β‐d‐galactopyranosides with phenyl or 4‐chlorophenyl groups in aglycone (anhydrous TFA in CH2Cl2). On the contrary, 1‐thio‐β‐d‐thiogalactopyranoside bearing electron‐withdrawing 4‐nitrophenyl group in aglycone did not undergo ring contraction under identical conditions.
Tunable and Nacre‐Mimetic Multifunctional Electronic Skins for Highly Stretchable Contact‐Noncontact Sensing
Authors: Zhou Kangkang , Xu Wangjiehao , Yu Yunfei , Zhai Wei , Yuan Zuqing , Dai Kun , Zheng Guoqiang , Mi Liwei , Pan Caofeng , Liu Chuntai , Shen Changyu
Published: June 2021

Electronic skins (e‐skins) have attracted great attention for their applications in disease diagnostics, soft robots, and human–machine interaction. The integration of high sensitivity, low detection limit, large stretchability, and multiple stimulus response capacity into a single e‐skin remains an enormous challenge. Herein, inspired by the structure of nacre, an ultra‐stretchable and multifunctional e‐skin with tunable strain detection range based on nacre‐mimetic multi‐layered silver nanowires /reduced graphene oxide /thermoplastic polyurethane mats is fabricated. The e‐skin possesses extraordinary strain response performance with a tunable detection range (50 to 200% strain), an ultralow response limit (0.1% strain), a high sensitivity (gauge factor up to 1902.5), a fast response time (20 ms), and an excellent stability (stretching/releasing test of 11 000 cycles). These excellent response behaviors enable the e‐skin to accurately monitor full‐range human body motions. Additionally, the e‐skin can detect relative humidity quickly and sensitively through a reversible physical adsorption/desorption of water vapor, and the assembled e‐skin array exhibits excellent performance in noncontact sensing. The tunable and multifunctional e‐skins show promising applications in motion monitoring and contact‐noncontact human machine interaction.
Flexible Phase Change Materials for Electrically‐Tuned Active Absorbers
Authors: Wang Jia‐Nan , Xiong Bo , Peng Ru‐Wen , Li Cheng‐Yao , Hou Ben‐Qi , Chen Chao‐Wei , Liu Yu , Wang Mu
Published: June 2021

Phase change materials (PCMs), such as GeSbTe (GST) alloys and vanadium dioxide (VO2), play an important role in dynamically tunable optical metadevices. However, the PCMs usually require high thermal annealing temperatures above 700 K, but most flexible metadevices can only work below 500 K owing to the thermal instability of polymer substrates. This contradiction limits the integration of PCMs into flexible metadevices. Here, a mica sheet is chosen as the chemosynthetic support for VO2 and a smooth and uniformly flexible phase change material (FPCM) is realized. Such FPCMs can withstand high temperatures while remaining mechanically flexible. As an example, a metal‐FPCM‐metal infrared meta‐absorber with mechanical flexibility and electrical tunability is demonstrated. Based on the electrically‐tuned phase transition of FPCMs, the infrared absorption of the metadevice is continuously tuned from 20% to 90% as the applied current changes, and it remains quite stable at bending states. The metadevice is bent up to 1500 times, while no visible deterioration is detected. For the first time, the FPCM metastructures are significantly added to the flexible material family, and the FPCM‐based metadevices show various application prospects in electrically‐tunable conformal metadevices, dynamic flexible photodetectors, and active wearable devices.
A Green and Scalable Synthesis of Na3Fe2(PO4)P2O7/rGO Cathode for High‐Rate and Long‐Life Sodium‐Ion Batteries
Authors: Wang Huiming , Pan Zibing , Zhang Haotian , Dong Chongrui , Ding Yan , Cao Yuliang , Chen Zhongxue
Published: June 2021

Sodium‐ion battery has been considered as one of the most promising power sources for large‐scale energy storage systems due to its similar electrochemistry to the lithium‐ion battery and the crust abundance of Na resources. Essentially, developing low‐cost electrode materials along with a facile and economical synthesis procedure is critically important to promote the commercialization of sodium‐ion batteries. However, applicable cathode materials capable of being massively produced are still scarcely reported to date. Herein, a green and scalable synthesis approach is developed to obtain Na3Fe2(PO4)P2O7 (NFPP)/rGO composite by using FePO4 and Na3PO4 as the resources, during which all the atoms present in the starting materials end up in the product. The prepared Na3Fe2(PO4)P2O7/rGO cathode exhibits an ultralong cycle life (capacity retention of 72.4% after 8000 cycles at 20 C) and outstanding rate capability (42.4 mAh g−1 at 100 C). In particular, the NFPP/rGO‐HC full battery assembled by the Na3Fe2(PO4)P2O7/rGO cathode and hard carbon anode demonstrates an energy density of 192 Wh kg−1 and superior cycling performance (capacity retention of 85.2% after 500 cycles). These results will contribute to the development of sodium‐ion batteries from applicable Na3Fe2(PO4)P2O7/rGO cathode material.
Role of Gd in Enhancing the Charge Carrier Mobility of Spray–Deposited BiVO4 Photoanodes
Authors: Sriwichai Surassa , Irani Rowshanak , Xi Fanxing , Friedrich Dennis , Höhn Christian , Ahmet Ibbi Y. , Wetchakun Natda , Abdi Fatwa F.
Published: June 2021

The emergence of BiVO4 as one of the most promising photoanodes for solar water splitting is largely driven by the success in dopant introduction and optimization to improve its photoelectrochemical performance. To this end, although less commonly used, several trivalent ions (e.g., In3+, Gd3+) that substitute Bi3+ have also been demonstrated to be effective dopants, which can increase the photocurrent of BiVO4 photoanodes. However, the main factor behind such improvement is still unclear as various explanations were proposed in the literature. Herein, Gd3+ is introduced to substitute Bi3+ in spray‐deposited BiVO4 films, which enables up to a ∼2‐fold photocurrent increase. Further analysis suggests that Gd‐doping enhances the carrier separation in BiVO4 and does not affect the catalytic and optical properties. Indeed, time‐resolved microwave conductivity measurements reveal that the carrier mobility of BiVO4 is increased by 50% with the introduction of Gd, while the carrier lifetime is unaffected. This mobility increase is rationalized to be a result of a higher degree of monoclinic lattice distortion in Gd‐doped BiVO4, as evident from the X‐ray diffraction and Raman spectroscopy data. Overall, these findings provide important insights into the nature and the underlying role of Gd in improving the performance of BiVO4.
Investigation on the Effects of Ladle Change Operation and Tundish Cover Powder on Steel Cleanliness in a Continuous Casting Tundish
Authors: Xu Rui , Ling Haitao , Wang Haijun , Chang Lizhong , Qiu Shengtao
Published: June 2021

The multiphase flows involving steel—slag—air phases in a two‐strand tundish during ladle change are investigated using mathematical modeling. Experimental results from water modeling are used to validate the simulated results. Tundish cover powder (TCP) and steel samples are taken from eight heats in one sequence to evaluate the effect of the multiphase flows during ladle change on the composition of the TCPs and steel cleanliness. Furthermore, the effect of the refilling time on the air entrainment and slag aperture during ladle change is analyzed and discussed. It is found that the strong turbulent flows in the tundish impact zone during ladle change promote the mix of the two‐layer cover powder, which consists of a basic TCP layer at the bottom and a top layer of rice hull balls. It results in a significant change in the composition of the TCPs and gradually deteriorates the steel cleanliness by the slag—steel reaction. Increasing the refilling time can effectively decrease the amount of entrained air and area of slag layer aperture in the tundish bath during ladle change. To reduce the steel reoxidation during ladle change, the refilling time should be larger than 184 s. Moreover, a new TCP is developed instead of the top layer of rice hull balls in industrial production. The use of the new TCP significantly improves the steel cleanliness in the tundish.
Building clinically relevant outcomes across the Alzheimer's disease spectrum
Authors: Rentz Dorene M. , Wessels Alette M. , Annapragada Ananth V. , Berger Anna‐Karin , Edgar Chris J. , Gold Michael , Miller David S. , Randolph Christopher , Ryan J. Michael , Wunderlich Glen , Zoschg Megan Canniere , Trépel Dominic , Knopman David S. , Staffaroni Adam M. , Bain Lisa J. , Carrillo Maria C. , Weber Christopher J.
Published: June 2021

Demonstrating that treatments are clinically meaningful across the Alzheimer's disease (AD) continuum is critical for meeting our goals of accelerating a cure by 2025. While this topic has been a focus of several Alzheimer's Association Research Roundtable (AARR) meetings, there remains no consensus as to what constitutes a “clinically meaningful outcome” in the eyes of patients, clinicians, care partners, policymakers, payers, and regulatory bodies. Furthermore, the field has not come to agreement as to what constitutes a clinically meaningful treatment effect at each stage of disease severity. The AARR meeting on November 19–20, 2019, reviewed current approaches to defining clinical meaningfulness from various perspectives including those of patients and care partners, clinicians, regulators, health economists, and public policymakers. Participants discussed approaches that may confer clinical relevance at each stage of the disease continuum and fostered discussion about what should guide us in the future.
Innovative and mission‐oriented financing of renewable energy in Sub‐Saharan Africa: A review and conceptual framework
Authors: Soumonni Ogundiran , Ojah Kalu
Published: June 2021

Notwithstanding the high levels of renewable energy resources across Sub‐Saharan Africa (SSA), modern energy use based on these abundant natural resources remains negligible. Furthermore, the current electrification rates and reliability of available power supply in the region have consistently remained significantly lower than the global average over the last three decades. And of the reasons advanced for this state of affairs, the lack of appropriate financing is said to be a crucial one. Therefore, focusing on a comparative overview of the dominant approaches to financing electrification, we characterize the persistence of this regional gap as a reflection of relative “policy stasis.” We then problematize this condition of stasis by employing the theoretical perspectives of mission‐oriented finance in conjunction with those of innovative finance and renewable energy innovation. In addition, we review relevant peer‐reviewed articles over the same period, and find evidence that indicates an underappreciation of financing models that stimulate endogenous technological innovation in renewable energy in SSA. Our analysis suggests that the types of innovation, associated configurations of financial actors, levels of capital intensity, and perceived risks in relation to beneficiaries, diverge from those accounted for in the dominant financing models. Consequently, we propose a novel, historically path‐dependent conceptual framework that emerges from the intersection among the concepts of mission‐oriented finance, endogenous innovation, and innovative financing, which we term “endogenous innovative financing.” This framework ultimately guides our recommendations for more promising financing mechanisms for resolving the interwoven challenges of sustainable universal electrification and renewable energy innovation in SSA.

This article is categorized under:

Energy Research & Innovation > Economics and Policy

Energy and Development > Economics and Policy

Energy and Climate > Economics and Policy
The two-loop remainder function for eight and nine particles
Authors: Golden John , McLeod Andrew J.
Published: June 2021

Abstract

Two-loop MHV amplitudes in planar $$ \mathcal{N} $$
N
= 4 supersymmetric Yang Mills theory are known to exhibit many intriguing forms of cluster-algebraic structure. We leverage this structure to upgrade the symbols of the eight- and nine-particle amplitudes to complete analytic functions. This is done by systematically projecting onto the components of these amplitudes that take different functional forms, and matching each component to an ansatz of multiple polylogarithms with negative cluster-coordinate arguments. The remaining additive constant can be determined analytically by comparing the collinear limit of each amplitude to known lower-multiplicity results. We also observe that the nonclassical part of each of these amplitudes admits a unique decomposition in terms of a specific A3 cluster polylogarithm, and explore the numerical behavior of the remainder function along lines in the positive region.
Comprehensive studies of ϒ inclusive production in Z boson decay
Authors: Sun Zhan , Zhang Hong Fei
Published: June 2021

Abstract

In this paper, we present a comprehensive study of ϒ inclusive production in Z boson decay, including the first complete next-to-leading-order calculations of the color-octet (CO) contributions. With the inclusion of the newly-calculated remarkable QCD corrections, the CO processes exhibit crucially phenomenological influence on the existing predictions built on the color-singlet mechanism. We also include the exhaustive evaluations of the feed-down contributions, which remained ignored in the literature, and find them to be considerable. Summing up all the contributions, the ℬZ → ϒ(nS) + X still notably undershoot the data released by the L3 Collaboration.
Towards the classification of symplectic linear quotient singularities admitting a symplectic resolution
Authors: Bellamy Gwyn , Schmitt Johannes , Thiel Ulrich
Published: June 2021

Over the past 2 decades, there has been much progress on the classification of symplectic linear quotient singularities V/G admitting a symplectic (equivalently, crepant) resolution of singularities. The classification is almost complete but there is an infinite series of groups in dimension 4—the symplectically primitive but complex imprimitive groups—and 10 exceptional groups up to dimension 10, for which it is still open. In this paper, we treat the remaining infinite series and prove that for all but possibly 39 cases there is no symplectic resolution. We thereby reduce the classification problem to finitely many open cases. We furthermore prove non-existence of a symplectic resolution for one exceptional group, leaving $$39+9=48$$

39
+
9
=
48

open cases in total. We do not expect any of the remaining cases to admit a symplectic resolution.
Adenosine A2A receptor in schizophrenia: an in vivo brain PET imaging study
Authors: Marques Tiago Reis , Natesan Sridhar , Rabiner Eugenii A. , Searle Graham E. , Gunn Roger , Howes Oliver D. , Kapur Shitij
Published: June 2021

Adenosine A2A receptors are highly enriched in the basal ganglia system, a region that is functionally implicated in schizophrenia. Preclinical evidence suggests a cross-regulation between adenosine A2A and dopamine D2 receptors in this region and that it is linked to the sensitization of the dopamine system. However, the relationship between A2A receptor availability and schizophrenia has not been directly examined in vivo in patients with this disorder. To investigate, using positron emission tomography (PET), the availability of A2A receptors in patients diagnosed with schizophrenia in comparison to matched healthy controls. A2A receptor availability was measured using the PET tracer [11C]SCH442416. Twelve male patients with chronic schizophrenia were compared to 13 matched healthy subjects. All patients were medicated with antipsychotics and none presented with any motor or extrapyramidal symptoms. Binding potential (BPND), a ratio measure between specific and non-specific tracer uptake, were compared between the groups for the caudate, putamen, accumbens and globus pallidum. There was no differences between A2A receptor binding potential (BPND) of schizophrenia patients in the caudate (p = 0.16), putamen (p = 0.86), accumbens (p = 0.44) and globus pallidum (p = 0.09) to that of matched healthy subjects. There was also no significant correlation between [11C]SCH442416 binding and severity of psychotic symptoms (p = 0.2 to 0.82) or antipsychotic dosage (p = 0.13 to 0.34). By showing that A2A receptor availability in medicated patients with chronic male schizophrenia is not different than in healthy controls, this study does not support the primary role of this receptor in the pathogenesis of schizophrenia.
Three-dimensional maps and subgroup growth
Authors: Bottinelli Rémi , Ciobanu Laura , Kolpakov Alexander
Published: June 2021

In this paper we derive a generating series for the number of cellular complexes known as pavings or three-dimensional maps, on n darts, thus solving an analogue of Tutte’s problem in dimension three. The generating series we derive also counts free subgroups of index n in $$\Delta ^+ = {\mathbb {Z}}_2*{\mathbb {Z}}_2*{\mathbb {Z}}_2$$

Δ
+

=

Z
2

∗

Z
2

∗

Z
2

via a simple bijection between pavings and finite index subgroups which can be deduced from the action of $$\Delta ^+$$

Δ
+

on the cosets of a given subgroup. We then show that this generating series is non-holonomic. Furthermore, we provide and study the generating series for isomorphism classes of pavings, which correspond to conjugacy classes of free subgroups of finite index in $$\Delta ^+$$

Δ
+

. Computational experiments performed with software designed by the authors provide some statistics about the topology and combinatorics of pavings on $$n\le 16$$

n
≤
16

darts.
Correction to: Portosystemic shunt surgery in the era of TIPS: imaging‑based planning of the surgical approach
Authors: Fehrenbach Uli , Gul‑Klein Safak , de Sousa Mendes Miguel , Steffen Ingo , Stern Julienne , Geisel Dominik , Puhl Gero , Denecke Timm
Published: June 2021

A correction to this paper has been published: https://doi.org/10.1007/s00261-021-03153-1