bluuebunny/crossref_metadata_2025 huggingface dataset:
Local meteoric water lines describe extratropical precipitation
Authors: Smith Devin F. , Saelens Elsa , Leslie Deborah L. , Carey Anne E.
Published: January 2021

Stable water isotopes δ18O and δ2H are used to investigate precipitation trends and storm dynamics to advance knowledge of precipitation patterns in a warming world. Herein, δ18O and δ2H were used to determine the relationship between extratropical cyclonic precipitation and local meteoric water lines (LMWLs) in the eastern Ohio Valley and the eastern United States. Precipitation volume weighted and unweighted central Ohio LMWLs, created with samples collected during 2012–2018, showed that temperature had the greatest effect on precipitation isotopic composition. HYSPLIT back trajectory modelling showed that precipitation was primarily derived from a mid‐continental moisture source. Remnants of major hurricanes were collected as extratropical precipitation during the 2012–2018 sampling period in central Ohio. Extratropical precipitation samples were not significantly different from the samples that created the central Ohio LMWL. Six additional LMWLs were derived from United States Geological Survey (USGS) Atmospheric Integrated Research Monitoring Network (AIRMoN) samples collected in Pennsylvania, Delaware, Tennessee, Vermont, New Hampshire, and Oxford, Ohio. Meteoric water lines describing published samples from Superstorm Sandy, plotted with these AIRMoN LMWLs, showed isotopic composition of Superstorm Sandy precipitation was commonly more depleted than the average isotopic composition at the mid‐latitude locations. Meteoric water lines describing the Superstorm Sandy precipitation were not significantly different in slope from LMWLs generated within 300 km of the USGS AIRMoN site. This finding, which was observed across the eastern Ohio Valley and eastern United States, demonstrated a consistent precipitation δ2H–δ18O relationship for extratropical cyclonic and non‐cyclonic events. This work also facilitates the analysis of storm development based on the relationship between extratropical event signature and the LMWL. Analysis of extratropical precipitation in relation to LMWLs along storm tracks allows for stronger development of precipitation models and understanding of which climatic and atmospheric factors determine the isotopic composition of precipitation.
Skin melanoma deaths within 1 or 3 years from diagnosis in Europe
Authors: Sacchetto Lidia , Rosso Stefano , Comber Harry , Bouchardy Christine , Broganelli Paolo , Galceran Jaume , Hackl Monika , Katalinic Alexander , Louwman Marieke , Robsahm Trude E. , Tryggvadottir Laufey , Tumino Rosario , Van Eycken Elizabeth , Walsh Paul M. , Zadnik Vesna , Zanetti Roberto
Published: January 2021

The steep increase in incidence of cutaneous malignant melanoma in white populations mainly applies to thin lesions with good survival suggesting overdiagnosis. Based on population‐based cancer registries (CRs), we have investigated changes in aggressive melanoma, selecting only cases who died within 1 or 3 years after diagnosis in 11 European countries between 1995 and 2012. Trends in fatal cases were analysed by period of diagnosis, sex, tumour thickness, histologic subtype of the lesion, tumour site and CR with a multivariate generalised linear mixed effects model, where geographical area was considered as a random effect. We collected data on 123 360 invasive melanomas, with 5133 fatal cases at 1 year (4%) and 12 330 (10%) at 3 years. The number of fatal cases showed a 16% decrease at 1 year and 8% at 3 years between the first (1995‐2000) and the last (2007‐2012) period. The highest proportion of fatal cases was seen for men, older age (≥65 years), thick lesions (>1 mm), nodular melanoma, melanoma on the trunk and for poorly documented cases, lacking information about thickness and histologic subtype. The mixed‐effects model showed a remarkable variability among European countries. The majority of registries showed a decreasing trend in fatal cases, but a few registries showed an opposite pattern. Trends in fatal melanoma cases, highlighting real changes in risk not related to overdiagnosis, showed a decrease in most European countries, with a few exceptions. Stronger efforts for early detection could lead to a more efficient treatment of melanoma in general.
Pregnant Hispanic women's views and knowledge of prenatal genetic testing
Authors: Page Robin L. , Murphey Christina , Aras Yahyahan , Chen Lei‐Shih , Loftin Ryan
Published: January 2021

Pregnant Hispanic women are underserved with their needs for genetic counseling, despite birth defects remaining the leading cause of infant death in the United States. We present the qualitative findings of a study to understand knowledge and perceptions of prenatal testing in a sample of hard‐to‐reach underrepresented Hispanic pregnant women in South Texas. The sample for this study was 10 Hispanic pregnant women who were recruited from a high‐risk prenatal clinic in South Texas in 2019. The semi‐structured interview questions were created based on the researchers' clinical experiences with this population and were designed to examine knowledge and perceptions of participants toward prenatal testing. Analysis of the qualitative data yielded several themes related to prenatal testing: (a) knowledge, (b) confusion, (c) partner's and support persons' opinions, (d) information sharing from providers, (e) psychological benefits, (f) preparation for baby, (g) obstacles, (h) religious influence, and (i) educational tools to assist with understanding. Women's understanding and knowledge of prenatal testing was limited, specifically regarding its purpose, how it works, the benefits, and why it was recommended by their provider. Lack of clarity about why they should take the test and its risks for them and their babies was perceived as something that could impede their acceptance of prenatal testing. All participants agreed that healthcare providers should share more information about prenatal testing in a way that uses ‘everyday language' so that they can understand it better. All respondents mentioned that prenatal testing provides information about their baby's health conditions, alleviates their stress and concerns, and psychologically prepares them and their family for what is to come. Identifying ways to increase culturally appropriate education delivered by genetic counselors such as through the adoption of telemedicine and mobile technology can help fill the gap for this underserved population.
Recent achievements on the agricultural applications of thioether derivatives: A 2010–2020 decade in review
Authors: Li Pei , Yang Ying , Wang Xiang , Wu Xianzhi
Published: January 2021

Thioether derivatives, an important synthetic strategy in drug discovery, are acquiring more importance in plant protection field in recent years because of their broad spectrum of agricultural activities, such as antifungal, antibacterial, insecticidal, acaricidal, nematocidal, antiviral, herbicidal, and plant growth‐regulating activity. Thioethers and their analogues have been an area of great interest in recent years. This review summarizes the structure and agricultural activities of the thioether derivatives as reported in the literature that mainly covers the past 10 years from 2010 to 2020 as well as may contribute to a better understanding of thioether derivatives as efficient agricultural agents and provide some ideas on the development of novel pesticides.
Synthesis of [4S‐2H]NADH, [4R‐2H]NADH, [4‐2H2]NADH and [4‐2H]NAD+ cofactors through heterogeneous biocatalysis in heavy water
Authors: Rowbotham Jack S. , Hardy Adam P. , Reeve Holly A. , Vincent Kylie A.
Published: January 2021

This practitioner protocol describes the synthesis of a family of deuterated nicotinamide cofactors: [4S‐2H]NADH, [4R‐2H]NADH, [4‐2H2]NADH and [4‐2H]NAD+. The application of a recently developed H2‐driven heterogeneous biocatalyst enables the cofactors to be prepared with high (>90%) 2H‐incorporation with 2H2O as the only isotope source.
NO solubility in water and brine up to 60 MPa and 373 K by combining Raman spectroscopy and molecular simulation
Authors: Sterpenich Jérôme , Caumon Marie‐Camille , Lachet Véronique , Creton Benoit , El Jarmouni Mohamed , Randi Aurélien , Robert Pascal
Published: January 2021

In the processes of carbon capture and storage, sulfur and nitrogen oxides (SOx and NOx) would be possibly injected with CO2 depending on the origin of CO2. The thermodynamic properties of these gases in saline aquifer are poorly known. Solubility is one of the key parameter to be implemented in geochemical codes modelling long‐term evolution of the aquifer after injection. The solubility of NO is known only at atmospheric pressure. In this study, the solubility of NO in water and NaCl solutions was measured by Raman spectroscopy in the ranges 295–373 K and 2–60 MPa using a high pressure optical cell and after calibration on a few data from molecular simulations. The results show a decrease of solubility when temperature increases and when salinity increases. No modification of NO speciation was observed.
Establishment and validation of a prediction model for the probability of malignancy in solid solitary pulmonary nodules in northwest China
Authors: Duan Xue‐Qin , Wang Xiao‐Li , Zhang Li‐Fen , Liu Xi‐Zhi , Zhang Wen‐Wen , Liu Yi‐Hui , Dong Chun‐Hui , Zhao Xin‐Han , Chen Ling
Published: January 2021

Background and Objectives

To construct a prediction model of solitary pulmonary nodules (SPNs), to predict the possibility of malignant SPNs in patients aged 15–85 years in northwest China for clinical diagnostic and therapeutic decision‐making.

Methods

The features of SPNs were assessed by multivariate logistic regression, followed by visualization using a nomogram. Hosmer lemeshow was applied to evaluate the fitting degree of the model. The area under the receiver operating characteristic (ROC) curve was identified to determine the discriminative ability of the model.

Results

Lobulation, spiculation, pleural‐tag, carcinoembryonic antigen, neuron‐specific enolase, and total serum protein were independent predictors of malignant pulmonary nodules (p < .05). Lobulation (100 points) scored the highest in the nomogram, and the Hosmer‐Lemeshow goodness‐of‐fit statistic was 0.805 (p > .05). The area under curve (AUC) of the modeling and validation groups using logistic regression were 0.859 (95% CI, 0.805–0.903) and 0.823 (95% CI, 0.738–0.890), respectively. Moreover, the AUC of our model was higher than that of the Mayo model, VA model, and Peking University (AUC 0.823 vs. 0.655 vs. 0.603 vs. 0.521).

Conclusion

Our prediction model is more suitable for predicting the possibility of malignant SPNs in northwest China, and can be calculated using a nomogram to determine further treatments.
Clinical significance of RBM3 expression in surgically treated colorectal lung metastases and paired primary tumors
Authors: Vidarsdottir Halla , Siesing Christina , Nodin Björn , Jönsson Per , Eberhard Jakob , Jirström Karin , Brunnström Hans
Published: January 2021

Background

The lungs are the second most common site of metastases in colorectal cancer (CRC). The aim of this study was to investigate prognostic factors, including RNA‐binding motif protein 3 (RBM3) expression, in patients with CRC treated with pulmonary metastasectomy (PM).

Methods

The cohort included all patients treated with PM at Skåne University Hospital, Lund, Sweden, from 2000 to 2014. Clinicopathological, treatment, and survival data were collected. Immunohistochemical staining of RBM3 was evaluated on tissue microarrays with samples from all lung metastases and a subset of paired primary tumors. Kaplan–Meier analysis and Cox proportional hazards modeling were applied to examine the associations of investigative factors with overall survival (OS) and recurrence‐free survival.

Results

In total, 216 patients with a primary tumor in the rectum (57%), left colon (34%), or right colon (9%) underwent PM. The 5‐year OS rate was 56%. Age > 60 years, more than one metastasis, size of metastasis > 3 cm, disease‐free interval < 24 months, low RBM3 score in the lung metastasis, and no adjuvant chemotherapy following PM were prognostic factors for shorter OS.

Conclusions

Several prognostic factors, including RBM3 expression, may be of aid in selecting CRC patients with lung metastases for PM as well as adjuvant therapy.
Tumor dimension‐dependent microscopic extensions of hypopharyngeal cancer: Therapeutic implications for larynx‐preserving hypopharyngectomy
Authors: Shin Joongbo , Lee Jiyeon , Hwang Nayoung , Choi Sung Yong , Park Woori , Choi Nayeon , Son Young‐Ik , Cho Junhun , Jeong Han‐Sin
Published: January 2021

Introduction

Hypopharyngeal cancer (HPC) is well characterized by the early submucosal spread of cancer cells into adjacent subsites of the hypopharynx and deep tissues, advocating a wide extent of treatment. However, the microscopic extensions (ME) from gross tumors, according to the primary tumor dimensions, has not been reported in detail.

Methods

We included patients who underwent upfront curative surgery, and retrospectively reviewed pathology specimens from 45 HPC cases. The distance of the MEs, defined as tumor infiltration beyond the gross tumor border on the submucosal and deep sides, was measured. We analyzed potential correlations between MEs and various physical tumor factors.

Results

A rough linear correlation between the submucosal ME and the maximal diameter of tumors was found (p < .001, r2 = 0.225). Deep MEs did not correlate with tumor physical factors. However, the MEs differed significantly by the T status (p = .033 and .015 in submucosal and deep sides). In T1‐2 tumors, the submucosal MEs were less than 0.5 cm, whereas those of T3‐4 tumors were 1.5–2.0 cm.

Conclusion

In HPC, local MEs beyond the gross tumor border correlated with primary tumor T status. Our findings support that the surgical safety margin for HPC can be adjusted according to tumor dimension.
Fertility after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: A call to action
Authors: Violette Caroline , Kim Tesia , Shandley Lisa , Lee Rachel , Staley Charles , Winer Joshua , Maithel Shishir , Hipp Heather , Kawwass Jennifer , Russell Maria
Published: January 2021

Introduction

Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is increasingly accepted as the best therapeutic option in primary and some secondary peritoneal malignancies. The ramifications of this procedure on fertility are unknown. The aim of this study was to assess the current association of CRS/HIPEC with fertility following surgery.

Methods

A review of patients who underwent CRS/HIPEC between 2009 and 2018 was performed. Female patients were included if they were between ages 18–50 at the time of surgery. Gynecologic and obstetric history before and following CRS/HIPEC was collected by phone interview.

Results

Of 48 eligible participants, 21 completed the survey. Sixty‐five percent of women underwent a total abdominal hysterectomy before or during CRS. Twenty‐nine percent of these women recall fertility counseling before CRS/HIPEC, while 14.3% saw a fertility specialist for consultation, and only one patient proceeded with oocyte cryopreservation before treatment. There were no pregnancies reported following treatment with CRS/HIPEC.

Conclusion

Few patients after CRS/HIPEC retain child‐bearing potential, partly due to the high rate of hysterectomy and oophorectomy at time of surgery. Efforts towards improved preoperative counseling, increased oocyte cryopreservation, and evaluating the safety of preserving reproductive organs at the time of surgery are needed.
Identification of patients who may benefit the most from adjuvant chemotherapy following resection of incidental gallbladder carcinoma
Authors: Xiang Jun‐Xi , Zhang Xu‐Feng , Weber Sharon M. , Poultsides George , Fields Ryan C. , Hatzaras Ioannis , Weiss Matthew , Scoggins Charles , Idrees Kamron , Shen Perry , Maithel Shishir K. , Pawlik Timothy M.
Published: January 2021

Background

To develop a scoring system to identify the subset of patients who may benefit the most from adjuvant chemotherapy following curative‐intent resection for incidental gallbladder cancer (IGBC).

Methods

A novel scoring system was utilized to stratify patients relative to overall survival (OS), as well as potential benefit from adjuvant chemotherapy following curative resection for IGBC.

Results

Among 266 patients with IGBC, a total of 99 (37.2%) patients received adjuvant chemotherapy. Five risk factors were used to develop an integer‐based score to predict OS. Risk of death at 5‐years incrementally increased among patients in the low (n = 42, 69.0%), medium (n = 64, 56.3%) and high‐risk groups (n = 40, 30.0%) (median OS, 99.4 vs. 33.5 vs. 15.6 months, all p < .001). Use of adjuvant chemotherapy did not provide a survival benefit among patients in the low‐risk group (median survival, 99.4 vs. 60.7 months, p = .56). In contrast, utilization of adjuvant chemotherapy was associated with an improvement in survival among medium‐ (median survival, 21.7 vs. 59.5 months, p = .04) and high‐risk patients (median survival, 11.6 vs. 20.1 months, p = .01).

Conclusions

While low‐risk patients did not benefit from adjuvant chemotherapy, individuals with medium or high‐risk scores had an improved survival with the utilization of adjuvant chemotherapy.
Cost drivers of locally advanced rectal cancer treatment—An analysis of a leading healthcare insurer
Authors: Grass Fabian , Merchea Amit , Mathis Kellie L. , Mishra Nitin , Heien Herbert , Sangaralingham Lindsey R. , Larson David W.
Published: January 2021

Background

To evaluate the economic burden of locally advanced rectal cancer (LARC) treatment from a society perspective through analysis of health insurance‐derived data of commercially insured and Medicare Advantage (MA) patients.

Methods

Retrospective cost analysis of patients undergoing rectal resection within a multimodal (neoadjuvant chemoradiation + adjuvant chemotherapy) treatment strategy between January 1, 2010 and October 31, 2018, using the claims OptumLabs Data Warehouse database.

Results

In total, 1738 (935 commercial and 803 MA) patients were included. Overall treatment costs totaled $230,881,746 (on average $183 653 ± 82 384 per commercially insured and $73 681 ± 32 917 per MA patient). Cost distribution according to category (commercially insured patients) was: 29.92% related to outpatient care (follow‐up visits/diagnostics), radiotherapy: 21.83%, index resection: 20.62%, chemotherapy: 17.44%, surgical inpatient: 6.32%, medical inpatient: 3.28%, emergency room: 0.58%. Relative cost distribution of the index resection itself differed marginally between the three approaches and was 21.49% for open, 19.30% for laparoscopic, and 20.93% for robotic surgery. Relative cost distributions of neoadjuvant, adjuvant, and outpatient treatments remained unchanged, independently of the surgical approach. This representation was similar in MA patients.

Conclusion

Index‐surgery related costs were outweighed by costs related to oncological and outpatient workup/follow‐up treatments independently of both surgical approach and insurance type.
Prognostic value of pathological tumor regression grade in locally advanced gastric cancer: New perspectives from a single‐center experience
Authors: Lombardi Pietro Maria , Mazzola Michele , Achilli Pietro , Aquilano Maria Costanza , De Martini Paolo , Curaba Annabella , Gualtierotti Monica , Bertoglio Camillo L. , Magistro Carmelo , Ferrari Giovanni
Published: January 2021

Background and Objective

Perioperative chemotherapy (PC) with radical surgery represents the gold standard of treatment for resectable advanced gastric cancer (GC). The prognostic value of pathological tumor regression grade (TRG) induced by neoadjuvant chemotherapy (NACT) is not clearly established. This study aimed to investigate the correlation between TRG and survival in GC.

Methods

Patients affected by advanced GC undergoing PC and radical surgery were considered. TRG was assessed for each patient according to Becker's grading system. The correlation between TRG and survival was investigated.

Results

One‐hundred patients were selected; 25 showed a good response (GR) (TRG 1a/1b), while 75 had a poor response (PR) (TRG 2/3) to NACT. GR patients showed better disease‐free survival (DFS) (52 vs. 19 months, p < .001) and disease‐specific survival (DSS) (57 vs. 25 months, p < .0001) when compared to PR patients. On univariate analysis, TRG, lymph node ratio (LNR), tumor size, grading, and post‐neoadjuvant therapy TNM stage were significantly correlated with survival. On multivariate analysis, TRG, LNR and tumor size were independent prognostic factors for DFS and DSS.

Conclusions

TRG, LNR, and tumor size are independent prognostic factors for DFS and DSS in patients with advanced GC undergoing NACT.
Forecasting performance of cruise passengers: the Spanish ports case
Authors: Grifoll Manel , Sanchez‐Espigares Josep , Feng Hongxiang
Published: January 2021

This contribution examines the passenger forecasting performance of the SARIMA method applied to cruise activities in the main Spanish ports. In this port system, the cruise activity market is characterized by different seasonal patterns (i.e., once‐ or twice‐yearly peaks, which means unimodal or bimodal behavior) due to repositioning strategy. The outcome of standard indicators for accuracy testing reveals inconsistent prediction performances among ports. These inconsistencies are analyzed using an index of bimodality and seasonal variability. The forecasted values for a high‐level of bimodality and seasonal variability show worse prediction performances than unimodal patterns and low seasonal variability. Ports with less passenger activity entail larger predictions errors. Exponential and linear models were adjusted between the error metrics and the mentioned indexes.
A soil quality index for seven productive landscapes in the Andean‐Amazonian foothills of Ecuador
Authors: Bravo‐Medina C. , Goyes‐Vera F. , Arteaga‐Crespo Y. , García‐Quintana Y. , Changoluisa D.
Published: January 2021

Few studies have comprehensively evaluated the effect of changing land use on the soil quality in the Ecuadorian Amazon region that is subject to continued deforestation processes. This study evaluated the influence of different types of land use on soil quality using an integrated soil quality index (SQI) with a minimum set of indicators, based on 140 soil samples from 7 land use types, in seven productive distinct landscapes in Pastaza Province, Ecuador. The land use type evaluated was Chakra_A, Chakra_B, Chakra_C, Cattle_A, Cattle_B, Cattle_C, and Forest. Land use type had significant effects on soil properties and thus on soil quality. SQI was developed by using, AP, Zn, TOC, BD, and LL; AP and Zn had highest weighting values (0.38), which indicated that these indicators contributed the most to final SQI. In general, the SQI varied significantly depending on the type of land use and two groups were established: the first categorized as of moderate quality with mean SQI values of 0.45, 0.44, and 0.41 for Chakra_A, Forest and Chakra_B, respectively; while the second group registered average SQI values of 0.33, 0.33, 0.32, and 0.30 for Chakra_C, Cattle_C, Cattle_A and Cattle_B, respectively, considered of low quality. The methods used are applicable to the study of changes in soil properties as functions of agroforestry systems, which are generated by changes in land use in similar landscape of the Ecuadorian Amazon.
2,5‐Dimethylfuran/Acrylonitrile as Latent Monomer for Sequence‐Controlled Copolymer and Sequence‐Dependent Thermo‐Responsivity
Authors: Gao Yang , Zhang Liuqiao , Jia Rui , Huang Zhihao , Xie Yujie , Xuan Sunting , Zhou Nianchen , Zhang Zhengbiao , Zhu Xiulin
Published: January 2021

Sequence control has attracted increasing attention for its ability of regulating polymer property and performance. Herein, the sequence‐controlled polymer containing acrylonitrile (AN) is achieved by using 2,5‐dimethylfuran/acrylonitrile adduct as a latent monomer. The temperature‐dependent retro Diels–Alder reaction is engaged in controlling the release of AN during RAFT polymerization, that is, regulating the instant AN concentration via a non‐invasive and in situ manner. Such control over the instant AN concentration and particularly the molar ratio of comonomer pair leads to the simultaneous change of monomer units in “living” polymeric chain, thus resulting in the sequence–controlled polymeric structures. By delicately manipulating the polymerization temperature, diverse sequence‐on‐demand structures of AN‐containing copolymers, such as poly(AN/methyl methacrylate), poly(AN/styrene), poly(AN/butyl acrylate), poly(AN/N,N‐dimethylacrylamide), and poly(AN/N‐isopropylacrylamide) are created. Meanwhile, this study presents an initial attempt in tuning the thermal responsivity of poly(AN/N‐isopropylacrylamide), which is closely correlated to the sequence of polymer structure. More importantly, the polymer with averagely distributed AN units results in the higher thermal sensitivity. Therefore, the synthetic strategy proposed in this work offers a promising platform for accessing the sequence‐controlled copolymers containing AN structures, thus expanding the investigation on the relationship between the polymer structures and correlated properties.
Preference modelling in sorting problems: Multiple criteria decision aid and statistical learning perspectives
Authors: Erişkin Levent
Published: January 2021

Many decision problems in a variety of fields such as marketing, quality prediction, and economics correspond to the sorting decision problematic where an ordinal scale is used to express a preference of objects. Both Multiple Criteria Decision Aid and Statistical Learning fields offer methodologies to represent the preference of the decision maker facing the sorting problem, however, there are differences in terminology, objectives, key assumptions, and solution philosophies. In this context, this paper aims to explain these differences as well as similarities and connections between these two fields by reviewing exemplary methodologies in sorting problems. As we discuss, there are significant research opportunities for developing new methodologies by exploiting the strong aspects of these two fields.
Effect of intelligent logistics transformation announcements on shareholder value: Evidence from Chinese listed firms
Authors: Liu Weihua , Zhang Jiahui , Hou Jiahe , Wang Siyu
Published: January 2021

This study empirically examines the impact of the intelligent logistics transformation (ILT) announcement on companies' shareholder value. The market model is used to estimate abnormal return. ILT inspires a significantly positive average (median) market response on the announcement day. There is a strong relationship between the announcing firm features like industry features and abnormal returns. The announcement features like investment direction of ILT also affect the market response. In addition, an interesting finding is that firms with worse prior financial performance than the industry level will receive a more positive market response when they conduct ILT by establishing an information platform.
Accurate spectral algorithm for two‐dimensional variable‐order fractional percolation equations
Authors: Abdelkawy Mohamed A. , Mahmoud Emad E. , Abualnaja Kholod M. , Abdel‐Aty Abdel‐Haleem , Kumar Sunil
Published: January 2021

A highly accurate spectral algorithm for (2 + 1) fractional percolation equations with variable order (VO‐FPEs) is considered. We propose a shifted Legendre–Gauss–Lobatto collocation (SL‐GL‐C) method in conjunction with shifted Chebyshev–Gauss–Radau collocation (SC‐GR‐C) method to solve the two‐dimensional VO‐FPEs. A complete theoretical formulation is presented, and numerical results are given to illustrate the performance and efficiency of the algorithm. The superiority of the scheme to tackle VO‐FPEs is revealed, even when dealing with non‐smooth time solutions.
Parallel transmit optimized 3D composite adiabatic spectral‐spatial pulse for spectroscopy
Authors: He Xiaoxuan , Auerbach Edward J. , Garwood Michael , Kobayashi Naoharu , Wu Xiaoping , Metzger Gregory J.
Published: January 2021

Purpose

To develop a 3D composite adiabatic spectral‐spatial pulse for refocusing in spin‐echo spectroscopy acquisitions and to compare its performance against standard acquisition methods.

Methods

A 3D composite adiabatic pulse was designed by modulating a train of parallel transmit–optimized 2D subpulses with an adiabatic envelope. The spatial and spectral profiles were simulated and validated by experiments to demonstrate the feasibility of the design in both single and double spin‐echo spectroscopy acquisitions. Phantom and in vivo studies were performed to evaluate the pulse performance and compared with semi‐LASER with respect to localization performance, sequence timing, signal suppression, and specific absorption rate.

Results

Simultaneous 2D spatial localization with water and lipid suppression was achieved with the designed refocusing pulse, allowing high‐quality spectra to be acquired with shorter minimum TE/TR, reduced SAR, as well as adaptation to spatially varying B0 and field inhomogeneities in both prostate and brain studies.

Conclusion

The proposed composite pulse can serve as a more SAR efficient alternative to conventional localization methods such as semi‐LASER at ultrahigh field for spin echo–based spectroscopy studies. Subpulse parallel‐transmit optimization provides the flexibility to manage the tradeoff among multiple design criteria to accommodate different field strengths and applications.
A fully‐mixed finite element method for the coupling of the Navier–Stokes and Darcy–Forchheimer equations
Authors: Caucao Sergio , Gatica Gabriel N. , Sandoval Felipe
Published: January 2021

In this work we present and analyze a fully‐mixed formulation for the nonlinear model given by the coupling of the Navier–Stokes and Darcy–Forchheimer equations with the Beavers–Joseph–Saffman condition on the interface. Our approach yields non‐Hilbertian normed spaces and a twofold saddle point structure for the corresponding operator equation. Furthermore, since the convective term in the Navier–Stokes equation forces the velocity to live in a smaller space than usual, we augment the variational formulation with suitable Galerkin type terms. The resulting augmented scheme is then written equivalently as a fixed point equation, so that the well‐known Schauder and Banach theorems, combined with classical results on nonlinear monotone operators, are applied to prove the unique solvability of the continuous and discrete systems. In particular, given an integer k ≥ 0, Raviart–Thomas spaces of order k, continuous piecewise polynomials of degree ≤k + 1 and piecewise polynomials of degree ≤k are employed in the fluid for approximating the pseudostress tensor, velocity and vorticity, respectively, whereas Raviart–Thomas spaces of order k and piecewise polynomials of degree ≤k for the velocity and pressure, constitute a feasible choice in the porous medium. A priori error estimates and associated rates of convergence are derived, and several numerical examples illustrating the good performance of the method are reported.
Treatment Outcomes of Well-Differentiated High-Grade Neuroendocrine Tumors
Authors: Liu Alex J. , Ueberroth Benjamin E. , McGarrah Patrick W. , Buckner Petty Skye A. , Kendi Ayse Tuba , Starr Jason , Hobday Timothy J. , Halfdanarson Thorvardur R. , Sonbol Mohamad Bassam
Published: January 2021

Introduction

Recent classification of neuroendocrine neoplasms has defined well-differentiated high-grade neuroendocrine tumors (NET G3) as a distinct entity from poorly differentiated neuroendocrine carcinoma. The optimal treatment for NET G3 has not been well-described. This study aimed to evaluate metastatic NET G3 response to different treatment regimens.

Materials and Methods

This was a retrospective study of patients with NET G3 within the Mayo Clinic database. Patients’ demographics along with treatment characteristics, responses, and survival were assessed. Primary endpoints were progression-free survival (PFS) and overall survival. Secondary endpoints were objective response rate (ORR) and disease control rate (DCR).

Results

Treatment data was available in 30 patients with median age of 59.5 years at diagnosis. The primary tumor was mostly pancreatic (73.3%). Ki-67 index was ≥55% in 26.7% of cases. Treatments included capecitabine + temozolomide (CAPTEM) (n = 20), lutetium 177 DOTATATE (PRRT; n = 10), Platinum-etoposide (EP; n = 8), FOLFOX (n = 7), and everolimus (n = 2). CAPTEM exhibited ORR 35%, DCR 65%, and median PFS 9.4 months (95% confidence interval, 2.96–16.07). Both EP and FOLFOX showed similar radiographic response rates with ORR 25.0% and 28.6%; however, median PFS durations were quite distinct at 2.94 and 13.04 months, respectively. PRRT had ORR of 20%, DCR of 70%, and median PFS of 9.13 months.

Conclusion

Among patients with NET G3, CAPTEM was the most commonly used treatment with clinically meaningful efficacy and disease control. FOLFOX or PRRT are other potentially active treatment options. EP has some activity in NET G3, but responses appear to be short-lived. Prospective studies evaluating different treatments effects in patients with NET G3 are needed to determine an optimal treatment strategy.

Implications for Practice

High-grade well-differentiated neuroendocrine tumors (NET G3) are considered a different entity from low-grade NET and neuroendocrine carcinoma in terms of prognosis and management. The oral combination of capecitabine and temozolomide is considered a good option in the management of metastatic NET G3 and may be preferred. FOLFOX is another systemic option with reasonable efficacy. Similar to other well-differentiated neuroendocrine tumors, peptide receptor radionuclide therapy seems to have some efficacy in these tumors.
Thermoresponsive zwitterionic poly(phosphobetaine) microgels: Effect of macro‐RAFT chain length and cross‐linker molecular weight on their antifouling properties
Authors: Saha Pabitra , Palanisamy Anand Raj , Santi Marta , Ganguly Ritabrata , Mondal Somashree , Singha Nikhil K. , Pich Andrij
Published: January 2021

Adsorption of proteins on biological surfaces is a detrimental phenomenon that reduces the work‐life of the implants in various biomedical applications. Here, we synthesized a new class of thermoresponsive zwitterionic poly(phosphobetaine) (PMPC) microgel with excellent surface antifouling property by macro‐RAFT mediated thiol‐epoxy click reaction. End‐group modified zwitterionic PMPC homopolymers with well‐defined molecular weight and narrow dispersity were grafted onto poly(N‐vinylcaprolactam‐co‐glycidyl methacrylate) (PVG) copolymer backbone followed by addition of a cross‐linker, leading to microgel formation. While no upper critical solution temperature (UCST) was found in poly(N‐vinylcaprolactam‐co‐glycidyl methacrylate‐g‐2‐methacryloyloxyethyl phosphorylcholine) (PVGP) graft copolymers, the corresponding microgels exhibited both UCST and lower critical solution temperature (LCST) transitions, related to the swelling and collapse of PMPC and poly (N‐vinylcaprolactam) (PVCL) components respectively. An increase in the molecular chain length of the PMPC increased the shifting of UCST and LCST of the microgels to higher temperatures, due to the ability of zwitterionic groups to coordinate a large number of water molecules. The effect of the variation in the molecular weights of amphiphilic poly(ethylene glycol) diamine (PEG‐NH2) cross‐linker was also reflected in both temperature and salt responsiveness of the microgels. The efficacy of the microgels as potential antifouling materials was further studied by fluorescence microscopy and XPS analysis on microgel coatings treated with FITC‐BSA solution and pure BSA solution respectively. Lower protein adsorption was observed for microgels grafted with higher molecular chain length of PMPC, whereas, the microgels synthesized using higher molecular weight PEG‐NH2 diamine cross‐linker displayed greater protein adsorption on their surfaces.
Structure regulation of boron‐doped calcium hydroxystannate and its enhancement on flame retardancy and mechanical properties of PVC
Authors: Dong Luming , Su Yanyue , Qiao Yafei , Li Ruotong , Xu Jianzhong , Chen Yajun , Ma Haiyun
Published: January 2021

In this study, a perovskite type calcium hydroxystannate (CaSn[OH]6, CSH) was prepared by a facial coprecipitation method. Then boron was further doped into CaSn(OH)6 to obtain B@CSH as a new inorganic flame retardant to polyvinyl chloride (PVC). The characterization of chemical composition, morphology, and bonding structure for CSH and B@CSH reveals that the doping of boron can effectively regulate the morphology and particle size of CSH. When applying into PVC, flame retardancy, smoke suppression, and mechanical performance are significantly enhanced by the addition of CSH and B@CSH. Under 5% addition of CSH and B@CSH, the limited oxygen index (LOI) value of PVC composites was increased from 26.6% to 32.9% and 34.0%, respectively. The cone calorimetry tests show that the peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) of PVC composites are all greatly reduced. The PHRR and TSP are reduced by 49.2% and 42.3% with the 5% loading of B@CSH, respectively. Furthermore, the mechanical strength and toughness of PVC are both improved by CSH and B@CSH. The synthesized CSH and B@CSH act as a multi‐functional additive for PVC with high efficiency.
Hybrid carbonaceous materials for radar absorbing poly(vinylidene fluoride) composites with multilayered structures
Authors: Indrusiak Tamara , Pereira Iaci M. , Pontes Ketly , Pereira Elaine C. L. , Peixoto Guilherme G. , Migliano Antônio C. C. , Soares Bluma G.
Published: January 2021

Poly(vinylidene fluoride) (PVDF) based composites loaded with 3 wt% of carbon black (CB), graphite (GF), and the hybrid CB/GF (1.5/1.5 wt%) were prepared by melt mixing and tested as microwave absorbing material at X‐band frequencies (8–12 GHz). The materials were processed and pressed at 220°C into plates of 20 × 20 × 0.1 cm3. Dielectric and magnetic properties were evaluated using the wave‐guide accessory to simulate the reflectivity of single‐layered PVDF composites through impedance matching behavior. The best absorbing properties were achieved with the composite loaded with the CB/GF hybrid material, whose maximum of radiation attenuation of −33 dB at 9.3 GHz was predicted with 4 mm thickness. Afterwards, the reflectivity of sandwiched structures (20 × 20 cm2 in size) with one‐layer honeycomb core sandwiched by two plates of PVDF composites was measured. The PVDF/HB‐honeycomb‐PVDF/HB structure reached reflection loss = −12 dB (Ea = 94%) on a broadband frequency. CB/GF hybrid material in PVDF composites has a promising future as a lightweight and cost‐effective microwave absorbing materials for both telecommunication and stealth technology.
Rate sensitivity and deformation mechanism of semi‐crystalline polymers during instrumented indentation
Authors: Liu Erqiang , Wu Jianguo , Li Huaying , Liu Haitao , Zhao Guanghui , Kong Lingyu , Lin Jinbao , Xiao Gesheng , Jia You
Published: January 2021

Instrumented indentation tests using both constant loading rate (CLR) and continuous stiffness measurement (CSM) operation modes were performed to investigate the deformation mechanism and their sensitivity to the deformation rate in semi‐crystalline polymers through the quantitative analysis of load‐depth loading and unloading curves. The strain rate was constant during the CSM tests, while the strain rate decreased with the increasing of loading time in CLR tests. The mechanical response mechanism of the semi‐crystalline polymers to these tests was very complicated because of the combined effects of strain‐hardening in the crystal phase and strain‐softening in the amorphous phase. Results show that the loading index m reflects the strain‐hardening or strain‐softening response during indentation. When m > 2, the mechanical response was due to the strain‐hardening, and when m < 2, the response was due to strain‐softening. A method based on the measured contact hardness was proposed to obtain the unloading stiffness, and the other mechanical parameters could then be determined according to the unloading stiffness.
Preserved pressure delivery during high‐frequency oscillation of bubble CPAP in a premature infant lung model with both normal and abnormal lung mechanics
Authors: Sivieri Emidio M. , Rub David M. , Abbasi Soraya , Eichenwald Eric C.
Published: January 2021

Background

Bubble continuous positive airway pressure (BCPAP) generates pressure oscillations which are suggested to improve gas exchange through mechanisms similar to high frequency (HF) ventilation. In a previous in‐vitro lung model with normal lung mechanics, significantly improved CO2 washout was demonstrated using an HF interrupter in the supply flow of a BCPAP system. The effect of HF with BCPAP on delivered airway pressure (Paw) has not been fully investigated in a lung model having abnormal pulmonary mechanics.

Objective

To measure Paw in an infant lung model simulating normal and abnormal pulmonary compliance and resistance while connected to a BCPAP system with superimposed HF oscillations created using an in‐line flow interrupter.

Design/Methods

A premature infant lung model with either: normal lung mechanics, compliance 1.0 ml/cm H2O, airway resistance 56 cm H2O/(L/s); or abnormal mechanics, compliance 0.5 ml/cm H2O, airway resistance 136 cm H2O/(L/s), was connected to BCPAP with HF at either 4, 6, 8, 10, or 12 Hz. Paw was measured at BCPAPs of 4, 6, and 8 cm H2O and respiratory rates (RR) of 40, 60, and 80 breaths/min and 6.0 ml tidal volume.

Results

Mean Paw averaged over all five frequencies showed no significant change from non‐oscillated levels at all BCPAPs and RRs for both lung models. Paw amplitudes (peak‐to‐trough) during oscillation were significantly greater than the non‐oscillated levels by an average of 1.7 ± 0.5 SD and 2.6 ± 0.5 SD cm H2O (p < .001) for the normal and abnormal models, respectively.

Conclusions

HF oscillation of BCPAP using a flow interrupter did not alter mean delivered Paw compared to non‐oscillated BCPAP for both normal and abnormal lung mechanics models. This simple modification to BCPAP may be a useful enhancement to this mode of non‐invasive respiratory support.
Kinetics and Mechanism of Thermal and Catalytic Decomposition of Hydroxylammonium Nitrate (HAN) Monopropellant
Authors: Agnihotri Ruchika , Oommen Charlie
Published: January 2021

Hydroxylammonium nitrate (HAN) monopropellant with its low sensitivity, volatility and toxicity, not only promises a safer substitute to hydrazine but also offers a higher specific impulse and a positive oxygen balance. This study primarily explores the decomposition mechanism and underlying kinetics for a newly developed cerium oxide‐based catalyst. The chemical kinetics involved in the thermal and catalytic decomposition was examined through an isoconversional method using thermogravimetric analysis (TG) data. The activation energy (Ea) was evaluated using differential isoconversional method (Friedman's method) and advanced integral isoconversional method (Popescu‐Ortega's method). To find frequency factor, compensation effect method (ACE) and intercept method (A0) were used. Advanced integral method could not provide realistic kinetic parameters while differential method predicted values similar to reported values for thermal decomposition. The values obtained for thermal decomposition were found matching with reported values obtained by other techniques which validated the methodology adopted. The reaction mechanism for both thermal and catalytic decomposition were proposed based on evolved gas analysis. The mechanism proposed was able to describe the variable kinetic parameters extracted from isoconversional method. Overall Ea of thermal decomposition of HAN was ∼95 kJ/mol. The decomposition over ceria‐based catalyst was distributed over three stages namely inception, peak and decay with Ea of ∼33 kJ/mol, ∼170 kJ/mol and ∼130 kJ/mol, respectively. Under identical conditions, iridium‐based catalyst show two decomposition stages with Ea of ∼65 kJ/mol and ∼120 kJ/mol while final stage being evaporation of HNO3. The ceria catalyst favoured N2 formation, increased decomposition of HNO3 and enhanced decomposition enthalpy.
Effect of carrier volume and spray quality on glyphosate‐resistant soybean response to sublethal dicamba exposure
Authors: Sperry Benjamin P , Calhoun Justin S , Ferguson Jason C , Kruger Greg R , Bond Jason A , Johnson Ashli B , Reynolds Daniel B
Published: January 2021

BACKGROUND

Field experiments were conducted across three sites in Mississippi in 2018 to evaluate carrier volume and spray quality effects on glyphosate‐resistant soybean response to dicamba. Treatments consisted of dicamba (5.6 g a.e. ha−1) plus glyphosate (8.7 g a.e. ha−1) applied to soybean at R1 using 140, 105, 70, 35, 14, or 7 L ha−1. Each carrier volume was applied with TT11002 and XR110015 nozzles which resulted in Fine and Coarse spray qualities, respectively. A colorimetric dye was included in spray solutions to quantify spray coverage of each treatment.

RESULTS

Spray coverage decreased with carrier volume and ranged from 21% to 3%. Conversely, soybean injury increased as carrier volume decreased. Soybean height 14 days after treatment (DAT) was reduced 34% to 37% from carrier volumes of 70 to 140 L ha−1; however, carrier volumes of 14 and 7 L ha−1 resulted in 45% height reductions. By 28 DAT soybean height was similar among volumes of 35 to 140 L ha−1 (39% to 42% reduction); however, volumes of 14 and 7 L ha−1 resulted in 46% and 51% reductions, respectively. Grain yield was reduced 14% from treatment at 140 L ha−1 and reductions increased with decreased carrier volume to 41% loss at 7 L ha−1. Averaged across carrier volumes, Fine and Coarse sprays caused 30% and 26% yield loss, respectively.

CONCLUSION

These data suggest that carrier volume profoundly affects soybean response to dicamba. Therefore, soybean response to sublethal dicamba doses applied at a constant carrier volume may not reflect physical drift exposure.

© 2021 Society of Chemical Industry
Single GaN Nanowires for Extremely High Current Commutation
Authors: Shugurov Konstantin , Mozharov Alexey , Sapunov Georgiy , Fedorov Vladimir , Tchernycheva Maria , Mukhin Ivan
Published: January 2021

An array of GaN nanowires (NWs) on Si substrate is synthesized by molecular beam epitaxy. Measurements of electrical properties at room temperature of single NWs transferred to an auxiliary substrate demonstrate that the current density reaches an extremely high level of 2 MA cm−2 without NW damage. Taking into account the limited conductivity of the NW periphery due to electron surface states, that is, the conduction channel narrowing, the effective current density can reach 3 MA cm−2.
Robust MPC for linear systems with bounded disturbances based on admissible equilibria sets
Authors: Santos Tito L. M. , Cunha Victor M.
Published: January 2021

This article presents a robust model predictive control (MPC) for piecewise constant reference tracking based on a constrained linear model and a terminal constraint defined from the admissible equilibria set. The new robust MPC algorithm based on nominal predictions ensures recursive feasibility and convergence to an optimal target, but the terminal constraint is derived from an admissible equilibria set with a suitable disturbance translation. The computation of the proposed terminal constraint is simple because no subset verification is required and the number of half‐spaces of the proposed terminal constraint is fixed a priori. A zonotope disturbance bound description is used to simplify the computation of the admissible equilibria. Furthermore, it is shown that the proposed strategy can be directly extended to other MPC algorithms based on artificial targets, as a stochastic MPC based on the individual chance constraints, for instance. Two case studies are used to illustrate the usefulness of the proposed robust MPC for piecewise constant set‐point tracking based on nominal predictions.