bluuebunny/crossref_metadata_2025_split huggingface dataset:
An experimentally validated heat and mass transfer model for wax deposition from flowing oil onto a cold surface
Authors: Mahir Luqman Hakim Ahmad , Lee Jieun , Fogler H. Scott , Larson Ronald G. 
Published: September 2020

AbstractA transport model is proposed for wax deposition onto a cold finger from flowing wax‐containing oils. The model solves transient energy and mass balances simultaneously for a reversible first‐order kinetic rate for precipitation of pseudo‐single‐component wax, and the effects of yield stress using a critical solid wax concentration to withstand flow‐induced stress at the deposit‐fluid interface. The model can predict the time evolution of the deposit thickness, and the spatial and temporal evolution of temperature and wax concentration as validated using cold finger experiments. It was found that for high wax content oils, deposit thickness growth is dominated by heat transfer. For low wax content oils that are unable to gel, the thickness growth is slow and accompanied by occasional sloughing. Regardless of the mechanism controlling the growth, mass transfer cannot be neglected as wax diffusion into the deposit continues to take place after the deposit has stopped growing.
Potential exoskeleton uses for reducing low back muscular activity during farm tasks
Authors: Thamsuwan Ornwipa , Milosavljevic Stephan , Srinivasan Divya , Trask Catherine 
Published: September 2020

AbstractBackgroundAs the sustainability of the agricultural workforce has been threatened by the high prevalence of back pain, developing effective interventions to reduce its burden within farming will contribute to the long‐term health and productivity of workers. Passive back‐support exoskeletons are being explored as an intervention to reduce the physical demands on the back muscles, and consequently mitigate the risk of back pain, in many industrial sectors.MethodsThis study investigated whether exoskeleton use could reduce farmers' low back muscle load. Electromyography was used to evaluate exoskeleton use in field and laboratory settings. A total of 14 farmers (13 males and 1 female) with a mean age of 49 (SD = 12) years and 6 female nonfarmers (mean age 28, SD = 5 years) performed a standardized set of tasks that included symmetric and asymmetric lifting and sustained trunk flexion. Following the standardized tasks, 14 farmers also performed regular, real‐world, farm tasks with and without use of the exoskeleton at their farms.ResultsExoskeleton use decreased back muscular load during farming activities up to 65%, 56%, and 48% in static, median, and peak muscle activity, respectively. This indicates potential benefits of exoskeleton use to help farmers work under less muscular load. Paradoxically, exoskeleton use during standardized tasks increased muscle activity for some participants.ConclusionsThis study demonstrates the potential effects of using passive exoskeletons in agriculture through observational and experimental research, and is among the first that explores the potential for using exoskeletons during actual work tasks in farm settings.
Assembly‐Induced Strong Circularly Polarized Luminescence of Spirocyclic Chiral Silver(I) Clusters
Authors: Wu Han , He Xin , Yang Biao , Li Cui‐Cui , Zhao Liang 
Published: September 2020

AbstractSpirocyclic Ag9 clusters, as a new form of intrinsically chiral metal clusters, were constructed through vertex‐sharing of two in‐situ‐generated heteroaryl diide‐centered metal rings. Such core‐peripheral type clusters exhibit versatile photoluminescent and chiroptical behavior under different aggregation conditions. In contrast to a ligand‐based fluorescence emission in a diluted solution of the clusters, a solvent polarity‐caused assembly gives rise to new cluster‐based phosphorous luminescence owing to radiative mode switching and aggregation‐induced emission. Assembly of cluster enantiomers leads to micrometer‐long helical nanofibers, whose handedness is determined by absolute configuration of individual spirocyclic clusters. Benefiting from exciton couplings of helical arrangements of chelating ligands at molecular and microscopic levels, the assembled film of cluster enantiomers exhibits circularly polarized luminescence with a high anisotropy factor (0.16).
Pentacyclic Nano‐Trefoil
Authors: Ju Huiyeong , Tsuruoka Yumiko , Hayano Miho , Lee Eunji , Park Ki‐Min , Ikeda Mari , Ishi‐i Jun‐ichi , Kuwahara Shunsuke , Habata Yoichi 
Published: September 2020

AbstractTetra‐armed cyclen (1) bearing two 4‐(4′‐pyridyl)benzyl and two 3,5‐difluorobenzyl groups and its Ag+ complexes were prepared and structurally characterized. The complexes formed between 1 and Ag+ undergoes a reversible structural transformation between a 2:2 dimeric complex and a 3:5 pentacyclic trefoil complex with changes in the Ag+/1 molar ratio. It was also revealed that the 3:5 trefoil complex could encapsulate benzene and [D6]benzene selectively in solid‐state. The benzene‐included structures are stabilized by C−H⋅⋅⋅F−C interactions between the benzene molecule and the ligand molecule.
A Simple Homoleptic Gallium(I) Olefin Complex: Mimicking Transition‐Metal Chemistry at a Main‐Group Metal?
Authors: Glootz Kim , Barthélemy Antoine , Krossing Ingo 
Published: September 2020

AbstractThe earth‐metal olefin complex [GaI(COD)2]+[Al(ORF)4]− (COD=1,5‐cyclooctadiene; RF=C(CF3)3) constitutes the first homoleptic olefin complex of any main‐group metal accessible as a bulk compound. It is straight forward to prepare in good yield and constitutes an olefin complex of a main‐group metal that—similar to many transition‐metals—may adopt the +1 and +3 oxidation states opening potential applications. Crystallographic‐, vibrational‐ and computational investigations give an insight to the atypical bonding between an olefin and a main‐group metal. They are compared to classical transition‐metal relatives.
Simultaner enantiospezifischer Nachweis mehrerer Verbindungen in Mischungen mittels NMR‐Spektroskopie
Authors: Kuhn Lars T. , Motiram‐Corral Kumar , Athersuch Toby J. , Parella Teodor , Pérez‐Trujillo Míriam 
Published: September 2020

AbstractDas Konzept der Chiralität spielt in der Natur eine fundamentale Rolle, obwohl sowohl ihr analytischer Nachweis als auch ihre Quantifizierung nach wie vor oftmals an experimentelle Grenzen stoßen. Bis heute erfordert zum Beispiel die enantiospezifische Analyse chiraler Komponenten eines Stoffgemisches notwendigerweise die vorherige Trennung der einzelnen Komponenten. Der simultane bzw. gleichzeitige enantiospezifische Nachweis mehrerer chiraler Moleküle in einem Gemisch stellt eine veritable Herausforderung dar, deren erfolgreiche Realisierung zu einem besseren Verständnis der zugrundeliegenden biologischen Prozesse führen würde, z. B. durch die enantiospezifische Analyse mehrerer Metabolite in ihrer natürlichen Umgebung. Wir berichten in dieser Zuschrift über den ersten “in situ” durchgeführten enantiospezifischen Nachweis eines aus neununddreißig Komponenten bestehenden Stoffgemisches. Als Beweis für die Durchführbarkeit des Konzeptes wurden achtzehn essentielle Aminosäuren in physiologischen Konzentrationen gleichzeitig enantiospezifisch mittels NMR‐Spektroskopie in Anwesenheit eines chiralen Solvatisierungsmittels (CSA; chiral solvating agent) nachgewiesen. Diese Arbeit beschreibt damit einen ersten Schritt zur simultanen enantiospezifischen Mehrkomponenten‐Analyse komplexer Mischungen; eine Fähigkeit, die erhebliche Auswirkungen auf Forschungsfelder wie z. B. Stoffwechselstudien, metabolische Phänotypisierungen, chemisches Reaktionsmonitoring und viele andere Bereiche haben wird, in denen komplexe Gemische chiraler Moleküle eine effiziente Charakterisierung erfordern.
Unusual Magnetic Field Responsive Circularly Polarized Luminescence Probes with Highly Emissive Chiral Europium(III) Complexes
Authors: Zhang Junhui , Dai Lixiong , Webster Alexandra M. , Chan Wesley Ting Kwok , Mackenzie Lewis E. , Pal Robert , Cobb Steven L. , Law Ga‐Lai 
Published: September 2020

AbstractChirality is ubiquitous within biological systems where many of the roles and functions are still undetermined. Given this, there is a clear need to design and develop sensitive chiral optical probes that can function within a biological setting. Here we report the design and synthesis of magnetically responsive Circularly Polarized Luminescence (CPL) complexes displaying exceptional photophysical properties (quantum yield up to 31 % and |glum| up to 0.240) by introducing chiral substituents onto the macrocyclic scaffolds. Magnetic CPL responses are observed in these chiral EuIII complexes, promoting an exciting development to the field of magneto‐optics. The |glum| of the 5D0 → 7F1 transition increases by 20 % from 0.222 (0 T) to 0.266 (1.4 T) displaying a linear relationship between the Δglum and the magnetic field strength. These EuIII complexes with magnetic CPL responses, provides potential development to be used in CPL imaging applications due to improved sensitivity and resolution.
A General and Highly Selective Palladium‐Catalyzed Hydroamidation of 1,3‐Diynes
Authors: Liu Jiawang , Schneider Carolin , Yang Ji , Wei Zhihong , Jiao Haijun , Franke Robert , Jackstell Ralf , Beller Matthias 
Published: September 2020

AbstractA chemo‐, regio‐, and stereoselective mono‐hydroamidation of (un)symmetrical 1,3‐diynes is described. Key for the success of this novel transformation is the utilization of an advanced palladium catalyst system with the specific ligand Neolephos. The synthetic value of this general approach to synthetically useful α‐alkynyl‐α, β‐unsaturated amides is showcased by diversification of several structurally complex molecules and marketed drugs. Control experiments and density‐functional theory (M06L‐SMD) computations also suggest the crucial role of the substrate in controlling the regioselectivity of unsymmetrical 1,3‐diynes.
Directional Bonding in Decaniobate Inorganic Frameworks
Authors: Martin Nicolas P. , Nyman May 
Published: September 2020

AbstractMetal–oxo clusters offer an opportunity to assemble inorganic and metal–organic frameworks (MOFs) by a controlled building‐block approach, which led to the revolutionary discoveries of zeolites and MOFs. Polyoxometalate clusters are soluble in water, but more challenging to link into frameworks; the inert oxo‐caps that provide solubility are resistant to replacement or further connectivity. We demonstrate how the unique directional bonding and varying basicity of the decaniobate ([Nb10]) oxo‐caps can be exploited to build 1D, 2D, and 3D inorganic frameworks. In nine structures, A+(A=Li, Na, K, Rb and Cs), AE2+(AE=Ca, Sr, Ba) and Mn2+demonstrate that the dimensionality of the obtained material is controlled by cation charge and size. Increased cation charge decreases selectivity for oxo‐site bonding, leading to higher dimensional linking. Larger cation radii also decreases bonding selectivity, yielding higher dimensional materials. Ion‐exchange studies of the A+‐Nb10family shows exclusive selectivity for Cs+over other alkalis, which is important for radioactive Cs removal and sequestration.
Simultaneous Enantiospecific Detection of Multiple Compounds in Mixtures using NMR Spectroscopy
Authors: Kuhn Lars T. , Motiram‐Corral Kumar , Athersuch Toby J. , Parella Teodor , Pérez‐Trujillo Míriam 
Published: September 2020

AbstractChirality plays a fundamental role in nature, but its detection and quantification still face many limitations. To date, the enantiospecific analysis of mixtures necessarily requires prior separation of the individual components. The simultaneous enantiospecific detection of multiple chiral molecules in a mixture represents a major challenge, which would lead to a significantly better understanding of the underlying biological processes; for example, via enantiospecifically analysing metabolites in their native environment. Here, we report on the first in situ enantiospecific detection of a thirty‐nine‐component mixture. As a proof of concept, eighteen essential amino acids at physiological concentrations were simultaneously enantiospecifically detected using NMR spectroscopy and a chiral solvating agent. This work represents a first step towards the simultaneous multicomponent enantiospecific analysis of complex mixtures, a capability that will have substantial impact on metabolism studies, metabolic phenotyping, chemical reaction monitoring, and many other fields where complex mixtures containing chiral molecules require efficient characterisation.
Morphology, physical, and mechanical properties of potentially applicable coelectrospun polysulfone/chitosan‐polyvinylalcohol fibrous membranes in water purification
Authors: Rezaei Soulegani Sanaz , Sherafat Zahra , Rasouli Maryam 
Published: September 2020

AbstractPolysulfone (PSU) is a widely used polymer in water purification membranes. However, its hydrophobicity hinders its practical application. Herein, the wettability of PSU has been improved by producing a coelectrospun fibrous composite membrane using a hydrophilic component, chitosan‐polyvinyl alcohol (CS‐PVA). First, different proportions of PVA and CS solutions were mixed and electrospun to prepare CS‐PVA blend fibers. Scanning electron microscope (SEM) observations revealed that CS‐PVA blend fibers with maximum CS content can be obtained in 30:70 CS:PVA weight ratio. The optimum CS‐PVA solution was subsequently used alongside PSU solution and were fed into two distinct syringes, which were then electrospun simultaneously at a constant voltage and distance of 15 kV and 15 cm, respectively. Different composite compositions of PSU/CS‐PVA were achieved using different feeding rates for each solution. Based on SEM images, the prepared composite fibers were beadless. The ultimate strength of the composite mats decreased by increasing the amount of CS‐PVA due to the significant difference in the fiber diameter of each component and the resulting stress concentration. However, the thermal stability of composite membranes remained almost the same as pure PSU fibers. Moreover, samples with higher CS‐PVA content showed better wettability and higher water flux.
Polyamide‐based membranes consisting of nanocomposite interlayers for high performance nanofiltration
Authors: Zhu Cheng‐Ye , Zhang Xi , Xu Zhi‐Kang 
Published: September 2020

AbstractIt is still a task to synthesize polyamide‐based membranes with selective layers down to 10–20 nm for high performance desalination. Herein, cellulose nanocrystals (CNC) were used as one‐dimensional (1D) nanorods and graphene oxides (GO) as two‐dimensional (2D) nanosheets, respectively, to construct nanocomposite interlayers for synthesizing polyamide layers thinner than 15 nm. The 2D nanosheets are homogeneously mixed with the 1D nanorods and effectively reduce the surface roughness of the nanocomposite interlayers with decreasing the mass ratio of CNC/GO. Polyamide layers with a thickness of 10–15 nm have been synthesized at an ultralow monomer concentration of 0.025 wt% on these CNC/GO nanocomposite interlayers. The polyamide‐based membranes exhibit extremely high water permeation (45.9 L/m2·h·bar) without losing their salt rejection ability. The nanofiltration performances of these polyamide‐based membranes are higher than most of the reported nanofiltration membranes in recent years.
Sodium Quasi‐Intercalation in Black P for Superior Sodium‐Ion Battery Anodes
Authors: Kim Tae‐Hyun , Park Cheol‐Min 
Published: September 2020

AbstractHerein, a Na quasi‐intercalation concept in black P is developed in order to achieve superior P‐based Na‐ion battery (NIB) anodes. Firstly, black P with a puckered layer structure is synthesized via a simple solid‐state reaction using commercially available red P. Additionally, an amorphous carbon modified black P nanocomposite (black P@C) is prepared to optimize its electrochemical Na reversibility. Furthermore, the Na reaction pathways of black P are demonstrated using various ex situ analytical tools. During sodiation/desodiation, black P undergoes the two‐step reactions of sequential quasi‐intercalation of NaP formation (at 0.25 V) and conversion of Na3P formation (at 0 V). Interestingly, black P@C shows poor cycling performance when using the conversion reaction, but it shows superior performance when using the quasi‐intercalation reaction between black P and NaP. Therefore, we anticipate that the Na quasi‐intercalation in black P@C will lead to high‐performance NIB anodes.
Model of the slow pyrolysis of lignin to predict the product yield and composition of the liquid phase
Authors: Farag Sherif , Attia Mai , Mohaddespour Ahmad 
Published: September 2020

AbstractThe organic phase obtained from the slow pyrolysis of lignin contains several highly functional chemical families. These make lignin‐based oil, which is suitable for producing several end products. The composition and quality of the liquid phase are crucial for identifying the downstream processes. They are affected by several factors, including the feedstock precipitation process, pyrolysis conditions, and the presence of an in situ or ex situ catalytic agent. In this regard, this work aims to predict the yield of the slow pyrolysis products from kraft lignin and the composition of the liquid phase under different conditions. A kinetic model based on a lumped approach is employed. A temperature range from ambient to 1100 K and a heating rate from 2 to 200 °C min−1 are applied. The results predicted from the study are compared under selected conditions against lab‐scale experimental data, which show the strong capabilities of the model employed. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd
Accuracy of faecal immunochemical testing in patients with symptomatic colorectal cancer
Authors: Khan A A , Klimovskij M , Harshen R 
Published: September 2020

Abstract

Background
The aim of this study was to determine the diagnostic accuracy of the faecal immunochemical test (FIT) for detecting colorectal cancer in symptomatic patients.

Methods
This was a prospective study of patients with bowel symptoms. Stool samples were collected during rectal examination. The HM-JACKarc assay (Kyowa Medex, Tokyo, Japan) was used to quantify faecal haemoglobin (Hb); positive results were those with at least 10 μg Hb/g faeces. Two-by-two tables and receiver operating characteristic (ROC) curve analysis were used to determine diagnostic accuracy; χ2 and Mann–Whitney U tests were used to compare other parameters.

Results
A total of 928 patients were included (M : F ratio 1 : 1·5; median age 72 (i.q.r. 64–80) years). The overall prevalence of colorectal cancer was 5·1 per cent. The FIT had sensitivity of 85·1 per cent, specificity of 83·5 per cent, positive predictive value of 22·6 per cent and negative predictive value of 99·0 per cent. ROC analysis of FIT for diagnosing colorectal cancer gave an area under the curve value of 0·89 (95 per cent c.i. 0·84 to 0·94). Significant bowel pathology was detected more frequently in FIT-positive patients (35·1 per cent versus 7·1 per cent in FIT-negative patients; P &lt; 0·001). There were sex differences in FIT positivity (23·7 per cent in men versus 17·4 per cent in women; P = 0·019); the sensitivity of FIT for colorectal cancer in women was also low. False-negative FIT results were found mainly in women referred with iron-deficiency anaemia, who were found to have caecal cancer.

Conclusion
FIT effectively excluded colorectal cancer in symptomatic patients. Integration of FIT into the diagnostic pathway for colorectal cancer would direct resources appropriately to patients with a greater likelihood of having the disease.
Brain reactions to the use of sensorized hand prosthesis in amputees
Authors: Granata Giuseppe , Di Iorio Riccardo , Miraglia Francesca , Caulo Massimo , Iodice Francesco , Vecchio Fabrizio , Valle Giacomo , Strauss Ivo , D'anna Edoardo , Iberite Francesco , Lauretti Liverana , Fernandez Eduardo , Romanello Roberto , Petrini Francesco M. , Raspopovic Stanisa , Micera Silvestro , Rossini Paolo M. 
Published: September 2020

AbstractObjectiveWe investigated for the first time the presence of chronic changes in the functional organization of sensorimotor brain areas induced by prolonged training with a bidirectional hand prosthesis.MethodsA multimodal neurophysiological and neuroimaging evaluation of brain functional changes occurring during training in five consecutive amputees participating to experimental trials with robotic hands over a period of 10 years was carried out. In particular, modifications to the functional anatomy of sensorimotor brain areas under resting conditions were explored in order to check for eventual changes with respect to baseline.ResultsFull evidence is provided to demonstrate brain functional changes, and some of them in both the hemispheres and others restricted to the hemisphere contralateral to the amputation/prosthetic hand.ConclusionsThe study describes a unique experimental experience showing that brain reactions to the prolonged use of an artificial hand can be tracked for a tailored approach to a fully embedded artificial upper limb for future chronic uses in daily activities.
Sudden death in epilepsy: There is room for intracranial pressure
Authors: Dibué Maxine , Spoor Jochem K. H. , Dremmen Marjolein , von Saß Christiane Freiin , Hänggi Daniel , Steiger Hans‐Jakob , Ryvlin Philippe , Kamp Marcel A. 
Published: September 2020

AbstractIntroductionSudden unexpected death in patients with epilepsy (SUDEP) remains a poorly understood entity, and it is unclear whether the same pathomechanisms underlie all sudden deaths occurring in patients with epilepsy. One aspect not included in current models of SUDEP is the role of increased intracranial pressure (ICP) which can be observed immediately upon seizure activity in neurosurgical practice.MethodsWe conducted a systematic review of the occurrence of edema in patients with epilepsy reported to have died of sudden death who underwent brain autopsy or postmortem brain imaging and discuss how increased ICP may contribute to clinical features of SUDEP.Results19 eligible studies comprising a total of 623 patients were identified. Edema—mostly mild or moderate—was reported in 17% of cases and 74% of studies. 1% (n = 6) of the overall cases were clearly identified as having Dravet syndrome or an SCN1A mutation. In these patients, edema was found in 4 (67%) of cases.ConclusionEdema is regularly found in patients with epilepsy classified to have died from SUDEP. We argue that seizures preceding SUDEP may in certain cases elicit acute edema which may represent an additional contributing factor in the cascade of events leading to sudden death of patients with epilepsy. Furthermore, we hypothesize that mild edema may especially progress to severe edema in patients with sodium channel mutations which may represent an important mechanism to investigate in the context of understanding the significantly elevated risk of SUDEP in patients with SCN1A mutations.