bluuebunny/crossref_metadata_2025_split huggingface dataset:
A review on bi/multifunctional catalytic oxydehydration of bioglycerol to acrylic acid: Catalyst type, kinetics, and reaction mechanism
Authors: Abdullah Anas , Abdullah Ahmad Zuhairi , Ahmed Mukhtar , Okoye Patrick U. , Shahadat Mohammad 
Published: August 2021

AbstractAcrylic acid, conventionally produced via propylene (non‐renewable fossil fuel route), is an industrially important chemical. The bio‐based feedstock process employing glycerol (a by‐product of biodiesel production) has attracted the attention of researchers due to its non‐polluting and renewable characteristics. Bi/multifunctional catalysts using a combination of zeolites, metal oxides, heteropoly acids, and phosphates have been mainly studied for the glycerol oxydehydration process. Brønsted acid sites favour acrolein generation over Lewis acid sites, whereas the redox sites convert the generated acrolein to acrylic acid. So far, the maximum acrylic acid yields of 60% and 59% have been reported on heteropoly acid and mixed metal oxide catalysts, respectively. Some DFT studies also revealed the deprotonation energy of acid sites and further helped in designing efficient catalysts. Despite these accomplishments, catalyst deactivation because of coking and stability remains a major problem. In this paper, various bi/multifunctional catalysts employed in glycerol oxydehydration to acrylic acid are critically reviewed. Different catalyst forms, preparation techniques, reaction kinetics, reaction mechanisms, deactivation, reactivation, process operating parameters, and sustainability are considered. In addition, the challenges associated with each catalyst type and strategies to overcome low yield, deactivation, and future directions are discussed.
Impact of radiation therapy facility volume on survival in patients with cancer
Authors: Tchelebi Leila T. , Shen Biyi , Wang Ming , Gusani Niraj J. , Walter Vonn , Abrams Ross , Verma Vivek , Zaorsky Nicholas G. 
Published: August 2021

BackgroundThis study examined whether radiation therapy facility volumes correlate with survival after curative intent treatment of solid tumors.MethodsThe National Cancer Database was queried for patients with solid tumors treated with curative‐intent radiation therapy from 2004‐2013. Facilities were stratified into 4 volume categories: low, intermediate, high, and very high. Primary cancer sites were divided into neoadjuvant, adjuvant, or definitive radiation subgroups. Kaplan‐Meier curves of 5‐year postradiation survival probability, stratified by facility volume, were generated with log‐rank tests for group comparisons. Cox proportional hazard models were used to evaluate the effect of facility volume on survival, adjusted for multiple covariates.ResultsThere were 253,422 patients treated at 1289 facilities: 6231 received neoadjuvant radiation, 147,980 received adjuvant radiation, and 99,211 received definitive radiation without surgery. Among patients receiving neoadjuvant radiation, survival correlated with facility volume for patients with rectal cancer (hazard ratio [HR], 0.75; 95% CI, 0.6‐0.94; P = .01). For cancers of the breast and uterus, patients receiving adjuvant radiation at very high‐volume facilities (vs low volume) had improved survival (HR, 0.83; 95% CI, 0.77‐0.90; P < .001 and HR, 0.77, 95% CI, 0.62‐0.97; P = .03, respectively). For patients receiving definitive radiation for prostate, non–small cell lung, pancreas, and head and neck cancer, there was an improvement in survival for patients treated at very high‐volume centers (P < .05).ConclusionsFor select cancer patients, treatment with curative radiation at higher volume facilities is associated with improved survival. In particular, patients receiving radiation therapy in the definitive setting without surgery may benefit most from treatment at high‐volume centers.
Gaussian Regularization of the Pseudospectrum and Davies’ Conjecture
Authors: Banks Jess , Kulkarni Archit , Mukherjee Satyaki , Srivastava Nikhil 
Published: August 2021

AbstractA matrix is diagonalizable if it has a basis of linearly independent eigenvectors. Since the set of nondiagonalizable matrices has measure zero, every is the limit of diagonalizable matrices. We prove a quantitative version of this fact conjectured by E. B. Davies: for each , every matrix is at least ‐close to one whose eigenvectors have condition number at worst , for some depending only on n. We further show that the dependence on δ cannot be improved to for any constant .Our proof uses tools from random matrix theory to show that the pseudospectrum of A can be regularized with the addition of a complex Gaussian perturbation. Along the way, we explain how a variant of a theorem of Śniady implies a conjecture of Sankar, Spielman, and Teng on the optimal constant for smoothed analysis of condition numbers. © 2021 Wiley Periodicals, Inc.
Parental separation or divorce and adulthood attachment: The mediating role of the Abandonment schema
Authors: D'Rozario Annelyse B. , Pilkington Pamela D. 
Published: August 2021

AbstractThis study investigated whether the Abandonment schema mediates the relationship between a history of parental separation or divorce and attachment styles in adulthood. Participants (N = 426; Mage = 30.78 years) completed online measures, using Qualtrics. Results demonstrated that a history of parental separation or divorce was positively associated with anxious and avoidant attachment styles in adulthood. Mediation analyses revealed that the Abandonment schema mediated these relationships (p < 0.001). This suggests that adults with a history of parental divorce or separation are more likely to report anxious and avoidant attachment styles, and this is partially accounted for by an expectation that they will be abandoned by others. These findings have implications for case formulation and can be used to inform treatment. Schema therapy focused on healing the Abandonment schema could promote attachment security in individuals with a history of parental separation or divorce. For example, limited reparenting (i.e., the therapist seeking to meet the client's unmet emotional needs, within the professional boundaries of the relationship), could be tailored to address the individual's underlying unmet need for security and stability. Further research is needed to advance our understanding of the implications of these findings for treatment.
Photoacoustic imaging of fresh human surgically and endoscopically resected gastrointestinal specimens
Authors: Ikematsu Hiroaki , Ishihara Miya , Okawa Shinpei , Minamide Tatsunori , Mitsui Tomohiro , Kuwata Takeshi , Ito Masaaki , Kinoshita Takahiro , Fujita Takeo , Yano Tomonori , Omori Toshihiko , Ozawa Satoshi , Murakoshi Dai , Irisawa Kaku , Ochiai Atsushi 
Published: August 2021

AbstractObjectivePhotoacoustic (PA) imaging is a novel noninvasive technique that offers high‐contrast tomographic imaging with ultrasound‐like resolution at depths of centimeters, enabling visualization of deep small vessels. The aim of this pilot study was to survey the characteristics of deep vessel networks in the mucosa of neoplastic gastrointestinal (GI) lesions using PA imaging.MethodsSpecimens of patients who had undergone surgical and endoscopic resection for GI lesions were included in this study. The PA/ultrasound imaging system for clinical research is characterized by a technology that can superimpose a PA image over an ultrasound image. Three‐dimensional PA images were acquired for the resected specimen before fixation. The stomach and colon of live pigs were incised, and the walls were scanned from the mucosa.ResultsA total of 32 specimens (nine esophageal, 12 gastric, 11 colorectal) were scanned. The pathological diagnoses were adenomas (n = 2), intramucosal cancers (n = 14), and invasive cancers (n = 16). The deep vessel networks of all lesions could be visualized. In the intramucosal lesions, the deep vessel network was similar to that of a normal tissue. In invasive cancers, the thick and prominent vessel network was visible in the surface layer of esophageal cancers, infiltrated area of gastric cancers, and surface layer and infiltrated area of colorectal cancers. In the images of living pigs, visualizing the vascular network deeper than the submucosa in both the stomach and large intestine was possible.ConclusionOur study confirmed that the deep vessel networks of neoplastic GI lesions were visible by PA imaging.
Understanding extinction risk and resilience in an extremely small population facing climate and ecosystem change
Authors: Bakker Victoria J. , Doak Daniel F. , Ferrara Francesca J. 
Published: August 2021

AbstractSan Nicolas Island (SNI) foxes historically had the highest densities of the six subspecies of Channel Island fox, four of which were listed as endangered in the 1990s. As an island species, SNI foxes are inherently vulnerable because they evolved in isolation from many potential threats, and their small range features relatively simple and degraded habitats, limiting their population size and heightening susceptibility to climate‐driven habitat changes. In the past decade, the SNI fox population has decreased by nearly half, spurring concern. Our analyses of 18 yr of trapping data suggest that both drought and density dependence contributed to this decline. Density dependence in survival acted on older individuals and its strength doubled after recent drought‐induced habitat changes. Annual precipitation was a strong driver of pup production, but density dependence moderated precipitation benefits. Using a stochastic model with island‐specific drivers of demography, we developed a risk isocline tool to predict 50‐yr quasi‐extinction risk based on population size and mortality. Predicted extinction risk for SNI foxes is currently <5% and expected to decrease. Compared to the previously listed subspecies, risk isoclines indicate the SNI subspecies is more resistant to quasi‐extinction at moderate population sizes and mortality rates, but quasi‐extinction risk does not decline as rapidly at higher population sizes or lower mortality rates. Thus, limiting human‐caused mortality and monitoring for novel threats such as exotic disease remain important. The ability of SNI foxes to increase pup production following high‐rainfall low‐density years is a key feature stabilizing their dynamics. Habitat‐ and location‐specific dynamics produce substantial portfolio effects, whereby asynchrony in growth rates stabilizes overall population numbers, and restoration efforts that increase food resources and habitat diversity will further enhance the resilience of this population. Although the SNI fox appears to be rebounding, its recent decline may foreshadow future dynamics and serves as a cautionary tale for stewards of island species facing unprecedented climatic conditions, especially those inhabiting small and less diverse systems. Finally, our analyses highlight limitations in applying risk analyses from one population to related species, or even the same species in different habitat settings.
Heterogeneous Olefin Aziridination Reactions Catalyzed by Polymer‐Bound Tris(triazolyl)methane Copper Complexes
Authors: Rodríguez Manuel R. , Molina Francisco , Etayo Pablo , Pericàs Miquel A. , Pérez Pedro J. , Díaz‐Requejo M. Mar 
Published: August 2021

AbstractEfficient olefin aziridination has been achieved with a tris(triazolyl)methane copper catalyst supported onto polystyrene. Aryl, alkyl and methoxycarbonyl‐substituted olefins are converted into N‐tosylaziridines in good to high yields. The solid catalyst is readily separated by filtration and recycled, allowing its reuse with no significant loss of the catalytic activity.
1,3‐Thiazolium‐4‐aminides: Syntheses and Characterization of Fluorescent Mesoionic Compounds
Authors: Storm Alena Therese , Gjikaj Mimoza , Namyslo Jan C. , Adams Jörg , Schmidt Andreas 
Published: August 2021

AbstractA series of mesoionic 1,3‐thiazolium‐4‐aminides was synthesized starting from thioamides and chloroacetonitrile via cyanomethylbenzimidothioates which were cyclized by benzoylchloride. Depending on the reaction conditions 4‐amino‐1,3‐thiazolium salts and 4‐N‐benzamido‐1,3‐thiazolium salts were obtained (X‐ray structure analysis). Substitution of the amino groups with benzoyl chloride gave a series of the title mesoionic compounds (X‐ray structure analysis) which were examined spectroscopically. Negative solvatochromism was found and temperature‐dependent as well as time‐resolved fluorescence measurements were made. Long lifetimes of the excited states (30–50 ns) were detected. Calculated frontier orbital profiles gain insight into the characteristics of 1,3‐thiazolium‐4‐aminides as conjugated mesomeric betaines.
A critical review on the variations in anodization parameters toward microstructural formation of TiO2 nanotubes
Authors: David T. Manovah , Dev Priya Ranjan , Wilson P. , Sagayaraj P. , Mathews Tom 
Published: August 2021

AbstractOver the past couple of decades (2001–2020), titania (TiO2) nanotubes (NTs) have been prepared by anodization techniques. The architecture of TiO2 NTs is predominantly dependent on the potential, current density, electrolyte and time, in addition to other few minor factors. This review is about the state‐of‐the‐art formation of TiO2 NTs involving anodization technique. In fact, the principal motive is to briefly discuss the slight variations involved within the anodization technique in terms of applied potential and/or applied current density and the resultant outcome. An initial overview of the technique is given so as to understand the beauty of the reactions when variations are incorporated. A minute alteration in the conventional anodization technique results in the formation of highly different morphological features. There are about 30 different miniscule modifications in the anodization processes that have been reported, thus, far. The review primarily introduces and outlines the various anodization techniques involved in growing TiO2 NTs and the consequent variations arising from these introduced variations. This review is a tribute to the bountiful and fruitful researches based on modifying anodization that was conducted in the recently passed bi‐decades.
RozinBDouble Helix of Phyllotaxis: Analysis of the geometric model of plant morphogenesisBrownWalker PressIrvine (2020)
Authors: Mayo Simon Joseph 
Published: August 2021

AbstractA new theoretical model of phyllotactic patterns is presented in this book, based on the geometry of two oppositely twisted spirals or helices. Many of the models previously proposed to explain observations of phyllotactic patterns are thus explained mathematically. The book is abundantly illustrated with computer graphics and supplemented by hyperlinks to many more images and video animations avaiable online, showing the way phyllotactic patterns vary with growth and change in the geometry of the plant axis.
Chemistry and quantum mechanics
Authors: Ogilvie J. F. 
Published: August 2021

AbstractOf quantum physics, quantum chemistry, and quantum mechanics, the latter is least directly useful for both chemical education and the practice of chemistry as a science concerned with the reactions and properties of chemical substances. We show that quantum mechanics must be viewed as a collection of methods, numbering at least 13, that one might apply to make calculations on a system of an atomic scale. Instead of quantum mechanics, we advocate the quantum laws or laws of discreteness, which have simple roots in laws of conservation and which have practical applications in various areas of observations of chemical phenomena. We conclude that quantum mechanics is largely irrelevant for the general practice of chemistry.
Different Attenuation Models of Diffusion‐Weighted MR Imaging for the Differentiation of Benign and Malignant Musculoskeletal Tumors
Authors: Arslan Sevtap , Ergen Fatma Bilge , Aydın Güzide Burça , Ayvaz Mehmet , Karakaya Jale , Kösemehmetoğlu Kemal , Yıldız Adalet Elçin , Aydıngöz Üstün 
Published: August 2021

BackgroundSeveral functional imaging techniques, including monoexponential diffusion‐weighted imaging (m‐DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis (DK) imaging, have been used in differentiating benign and malignant musculoskeletal tumors. Combining all three techniques in the same study population may improve differentiation.PurposeTo compare the diagnostic performance of m‐DWI, IVIM, and DK models and their combinations in differentiating benign and malignant musculoskeletal tumors.Study TypeProspective.PopulationFifty patients with benign and malignant musculoskeletal tumors divided into nonmyxoid and nonchondroid and myxoid and/or chondroid subgroups.Field strength/SequenceA 1.5 T/m‐DWI, IVIM, and DK single‐shot spin‐echo echo‐planar sequences.AssessmentMinimum and volumetric values of apparent diffusion coefficient (ADC), pure molecular diffusion (Divim), pseudodiffusion (D*), perfusion fraction (f), diffusion coefficient for kurtosis model (DK), and Kurtosis (K) were compared between all benign and malignant tumors. Subgroup analysis was also performed for nonmyxoid and nonchondroid and myxoid and/or chondroid tumors.Statistical testsIndependent samples t‐test, Mann–Whitney U test, intraclass correlation coefficient, ROC analysis, and logistic regression analysis. A P value < 0.05 was considered statistically significant.ResultsADCmin, Divim‐min, D*vol, DK‐min, Kvol, and Kmin values showed statistically significant differences between all benign and malignant tumors and nonmyxoid and nonchondroid tumor subgroup. Kmin showed the highest diagnostic performance in differentiating benign and malignant tumors with AUCs of 0.760 for “all tumors” and 0.825 for the nonmyxoid and nonchondroid tumor subgroup. No significant differences were detected in m‐DWI‐, IVIM‐, and DK‐derived parameters for differentiating benign and malignant myxoid and/or chondroid tumors. Only three of 63 combinations of prediction models demonstrated a higher diagnostic performance than Kmin; however, improvements were not significantly different.Data conclusionADCmin, Divim‐min, D*vol, DK‐min, Kvol, and Kmin values can be used to differentiate benign and malignant musculoskeletal tumors. Our findings suggest that the added value of multiparametric approach in such differentiation is not significant.Evidence Level1Technical EfficacyStage 2
Bias and Precision in Magnetic Resonance Imaging‐Based Estimates of Renal Blood Flow: Assessment by Triangulation
Authors: Alhummiany Bashair A. , Shelley David , Saysell Margaret , Olaru Maria‐Alexandra , Kühn Bernd , Buckley David L. , Bailey Julie , Wroe Kelly , Coupland Cherry , Mansfield Michael W. , Sourbron Steven P. , Sharma Kanishka 
Published: August 2021

BackgroundRenal blood flow (RBF) can be measured with dynamic contrast enhanced‐MRI (DCE‐MRI) and arterial spin labeling (ASL). Unfortunately, individual estimates from both methods vary and reference‐standard methods are not available. A potential solution is to include a third, arbitrating MRI method in the comparison.PurposeTo compare RBF estimates between ASL, DCE, and phase contrast (PC)‐MRI.Study TypeProspective.PopulationTwenty‐five patients with type‐2 diabetes (36% female) and five healthy volunteers (HV, 80% female).Field Strength/SequencesA 3 T; gradient‐echo 2D‐DCE, pseudo‐continuous ASL (pCASL) and cine 2D‐PC.AssessmentASL, DCE, and PC were acquired once in all patients. ASL and PC were acquired four times in each HV. RBF was estimated and split‐RBF was derived as (right kidney RBF)/total RBF. Repeatability error (RE) was calculated for each HV, RE = 1.96 × SD, where SD is the standard deviation of repeat scans.Statistical TestsPaired t‐tests and one‐way analysis of variance (ANOVA) were used for statistical analysis. The 95% confidence interval (CI) for difference between ASL/PC and DCE/PC was assessed using two‐sample F‐test for variances. Statistical significance level was P < 0.05. Influential outliers were assessed with Cook's distance (Di > 1) and results with outliers removed were presented.ResultsIn patients, the mean RBF (mL/min/1.73m2) was 618 ± 62 (PC), 526 ± 91 (ASL), and 569 ± 110 (DCE). Differences between measurements were not significant (P = 0.28). Intrasubject agreement was poor for RBF with limits‐of‐agreement (mL/min/1.73m2) [−687, 772] DCE‐ASL, [−482, 580] PC‐DCE, and [−277, 460] PC‐ASL. The difference PC‐ASL was significantly smaller than PC‐DCE, but this was driven by a single‐DCE outlier (P = 0.31, after removing outlier). The difference in split‐RBF was comparatively small. In HVs, mean RE (±95% CI; mL/min/1.73 m2) was significantly smaller for PC (79 ± 41) than for ASL (241 ± 85).ConclusionsASL, DCE, and PC RBF show poor agreement in individual subjects but agree well on average. Triangulation with PC suggests that the accuracy of ASL and DCE is comparable.Evidence Level2Technical EfficacyStage 2
A multiple‐method comparative study using GC–MS, AMDIS and in‐house‐built software for the detection and identification of “unknown” volatile organic compounds in breath
Authors: Marder Dana , Tzanani Nitzan , Baratz Adva , Drug Eyal , Prihed Hagit , Weiss Shay , Ben‐Chetrit Eli , Eichel Roni , Dagan Shai , Yishai Aviram Lilach 
Published: August 2021

AbstractThe human respiratory system is a highly complex matrix that exhales many volatile organic compounds (VOCs). Breath‐exhaled VOCs are often “unknowns” and possess low concentrations, which make their analysis, peak digging and data processing challenging. We report a new methodology, applied in a proof‐of‐concept experiment, for the detection of VOCs in breath. For this purpose, we developed and compared four complementary analysis methods based on solid‐phase microextraction and thermal desorption (TD) tubes with two GC–mass spectrometer (MS) methods. Using eight model compounds, we obtained an LOD range of 0.02–20 ng/ml. We found that in breath analysis, sampling the exhausted air from Tedlar bags is better when TD tubes are used, not only because of the preconcentration but also due to the stability of analytes in the TD tubes. Data processing (peak picking) was based on two data retrieval approaches with an in‐house script written for comparison and differentiation between two populations: sick and healthy. We found it best to use “raw” AMDIS deconvolution data (.ELU) rather than its NIST (.FIN) identification data for comparison between samples. A successful demonstration of this method was conducted in a pilot study (n = 21) that took place in a closed hospital ward (Covid‐19 ward) with the discovery of four potential markers. These preliminary findings, at the molecular level, demonstrate the capabilities of our method and can be applied in larger and more comprehensive experiments in the omics world.
The effect of perceived organizational politics on responses to job dissatisfaction: The moderating roles of self‐efficacy and political skill
Authors: Atshan Nadia A. , Al‐Abrrow Hadi , Abdullah Hasan Oudah , Khaw Khai Wah , Alnoor Alhamzah , Abbas Sammar 
Published: August 2021

AbstractA high level of perceived organizational politics can lead to adverse consequences for the organization. This article examines the impact of perceived organizational politics on responses to job dissatisfaction by considering the moderating role of self‐efficacy and political skill using data from a sample of 202 health sector staff in Iraq. The results show that self‐efficacy and political skill are moderators in the relationship between perceived organizational politics and staff responses to job dissatisfaction. Using measures based on four responses to job dissatisfaction–voice, loyalty, neglect, and exit–the study found that there was a moderative role for self‐efficacy related to the dimensions of silence and loyalty, and a moderative role for political skill related to the dimensions of silence, voice, and loyalty. There was no moderating role for the exit dimension. The article concludes with several suggestions for how to deal with the adverse consequences of high levels of perceived organizational politics.