bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paraffin Wax-Based Thermal Composites
Authors: Raza Gulfam , Iqbal Saqib , Samad Farooq Abdul 
Published: June 2021

Paraffin waxes are organic phase change materials possessing a great potential to store and release thermal energy. The reversible solid–liquid phase change phenomenon is the under-lying mechanism enabling the paraffin waxes as robust thermal reservoirs based on inherently high latent heat (i.e., ~200–250 J/g). However, the main drawback of paraffin waxes is their inability to expedite the phase change process owing to low thermal conductivity (i.e., ~0.19–0.35 Wm−1 K−1). This drawback has long been documented as a technological challenge of paraffin waxes especially for temperature-control applications where faster thermal storage/release is necessitated, encompassing thermal management of batteries, thermoelectric modules and photovoltaic panels. Besides, sustaining the solid-like form of paraffin waxes (shape-stability) is also recommended to avoid the liquid drainage threats for crucial applications, like thermal management of buildings and fabrics. These objectives can be met by developing the paraffin wax-based thermal composites (PWTCs) with help of various thermal reinforcements. However, PWTCs also encounter severe challenges, probably due to lack of design standards. This chapter attempts presenting the recent advances and major bottlenecks of PWTCs, as well as proposing the design standards for optimal PWTCs. Also, the fundamental classification of phase change phenomenon, paraffin waxes and potential thermal reinforcements is thoroughly included.
Chemical Pollution of Drinking Water in Haiti: An Important Threat to Public Health
Authors: Emmanuel Alexandra , Emmanuel Evens 
Published: June 2021

The geophysical environment of the Republic of Haiti is characterized by hydrological and biogeographical climatic phenomena, and a relief marked by its rugged appearance. Most of the territory is occupied by mountains formed of limestone. The differences in level are very marked. Fragmentation is another feature of the relief. These environmental imperfections juxtaposed with difficult socioeconomic conditions and anthropogenic actions raise questions about possible chemical metal pollution of the country’s water resources. Indeed, the predominance of limestone in the Haitian geology generate water hardness, and in the case where the magnesium concentration is less than 7 mg/l, this water may be the source of cardiovascular diseases. Studies carried out on several water points show a total hardness greater than 200 mg/l. In Port-au-Prince, concentrations of lead ranging from 40 μg/L to 90 μg/L and high Cr (III) risks were measured and estimated in groundwater and drinking water. Concentration of fluorine ranging from 0 to 2 mg/l were obtained from water resources. Concentration above 1.5 mg/l have been found from alluvial aquifers. Chronic public health risks, such as cardiovascular diseases, deterioration of the psychological development of children, irreversible functional and morphological renal changes, and dental fluorosis, strain Haiti’s water resources. Chemicals’ exposures seem to pose a threat to public health in Haiti, which need to be studied. The aim of this study is: (i) to analyze the contribution of geology and anthropogenic actions in the alteration of water quality, (ii) to review the toxicology of chemicals detected in water distributed in Port-au-Prince.
Enhancement of the traveling front speeds in reaction-diffusion equations with advection
Authors: Kiselev Alexander , Ryzhik Leonid 
Published: July 2002

We establish rigorous lower bounds on the speed of traveling fronts and on the bulk burning rate in reaction-diffusion equation with passive advection. The non-linearity is assumed to be of either KPP or ignition type. We consider two main classes of flows. Percolating flows, which are characterized by the presence of long tubes of streamlines mixing hot and cold material, lead to strong speed-up of burning which is linear in the amplitude of the flow,

U

. On the other hand the cellular flows, which have closed streamlines, are shown to produce weaker increase in reaction. For such flows we get a lower bound which grows as

U^{1/5}

for a large amplitude of the flow.

Résumé

Nous établissons rigoureusement une estimation inférieure de la vitesse de propagation de fronts et du taux global de combustion pour des équations de réaction-diffusion avec convection donnée. La non-linéarité est de type KPP ou de type “ignition”. Nous considérons deux principales classes d’écoulements. Les écoulements de percolation, caractérisés par la présence de longs tubes de lignes de courant mélangeant des régions chaudes et froides, entraı̂nent une accélération importante du taux de combustion, linéaire en fonction de l’intensité

U

de l’écoulement. D’autre part, les écoulements circulaires, avec lignes de champs fermées, conduisent à une augmentation plus faible du taux de réaction. Pour de tels écoulements, nous obtenons une estimation inférieure qui croı̂t comme

U^{1/5}

pour des écoulements de grande amplitude.
Stationary solutions for the Cahn–Hilliard equation
Authors: Wei Juncheng , Winter Matthias 
Published: July 2002

We study the Cahn–Hilliard equation in a bounded domain without any symmetry assumptions. We assume that the mean curvature of the boundary has a nondegenerate critical point. Then we show that there exists a spike-like stationary solution whose global maximum lies on the boundary. Our method is based on Lyapunov–Schmidt reduction and the Brouwer fixed-point theorem.

Résumé
Nous étudions l’équation de Cahn et Hilliard dans un domaine ouvert en ne supposant de symétrie pour le domaine. Nous supposons que la courbure moyenne sur la frontière a un point critique non dégénéré. Nous montrons qu’il existe une solution stationnaire avec un pic qui atteint son maximum sur la frontière du domaine. Notre méthode utilise la réduction de Lyapunov et Schmidt et le théorème du point fixe de Brouwer.
Levels of transforming growth factor alpha (TGF‐a)in human cerebrospinal fluid
Authors: Setten G.‐B.Van , Edström Lars , Stibler Helena , Rasmussen Susan , Schultz Gregory 
Published: July 2002

AbstractIn this study, we investigated cerebrospinal fluid of patients with various neurologicalsymptoms for the presence of transforming growth factor alpha (TGF‐a). 41 samples ofcerebrospinal fluid were collected by lumbar puncture performed routinely due to the clinicalsuspicion of neurological disease from 22 females (age 15–80 years, median 42 years) and from19 males (age 18–82 years, median 48 years). A highly sensitive and specific radioimmunoassaywas used to determine the concentration of TGF‐a in the samples. The detection limit of the assaywas about 200 pg TGF‐a. There was no cross‐reactivity to human EGF. We showed CSF indeeddoes contain TGFa. As TGF‐a was detected in all 41 samples investigated, this growth factorappears to be a constant component of CSF. The mean concentration was 5.5 ng TGF‐a (S.D.±2.7 pg/ml, range 1.1 to 13.9 pg/ml). There was no significant correlation between TGF‐aconcentration in CSF and age (r=−0.006) and there was no significant differencebetween females (mean 5.8±3.10 pg/ml) and males (mean 5.2±1.96 pg/ml). No diagnosis wasover represented in patients with TGF‐a concentrations above or below 1 S. D. off the mean.However, highest concentrations of TGF‐a were found in the group of patients with peripheralneurological sensory dysfunctions and polyneuropathy. We conclude that TGF‐a is not only aconstant component of human cerebrospinal fluid in adults but could also be significantly involvedin the pathophysiology of various neurological diseases. The earlier hypothesis that TGF‐a couldmainly have a role in brain development needs hence to be re‐evaluated.
Refractory schizophrenia: Historical and currently prevailing criteria and definitions
Authors: Vanelle JM 
Published: July 2002

SummaryVarious historical aspects of resistant schizophrenia are described: limitations of treatment efficacy, attempts at proposing therapeutic strategies in non-responding patients, first attempts to define resistance in schizophrenia, and first attempts to distinguish resistance factors. Interest in treatment-refractory schizophrenia was stimulated by several studies in the period 1985–1990, including a pivotal study of clozapine. The need to include biological and psychosocial factors when defining resistance was emphasised by a group who defined a systematic approach to treatment resistance in schizophrenia, including degrees of resistance. The concept of a continuum from full remission to complete refractoriness was proposed by an international study group in 1990. Difficulties in identifying patients with refractory schizophrenia include: variability of schizophrenia diagnostic criteria, lack of consensus concerning good treatment practice with neuroleptic agents, and confusion between resistance, chronicity and severity. A better definition of refractoriness is needed, not only for pharmacological studies but also for a more precise characterisation of a possible subgroup of schizophrenia termed ‘Kraepelinian’.
Synaptic density in carriers of C9orf72 mutations: a [11C]UCB‐J PET study
Authors: Malpetti Maura , Holland Negin , Jones P. Simon , Ye Rong , Cope Thomas E. , Fryer Tim D. , Hong Young T. , Savulich George , Rittman Timothy , Passamonti Luca , Mak Elijah , Aigbirhio Franklin I. , O’Brien John T. , Rowe James B. 
Published: June 2021

AbstractSynaptic loss is an early and clinically relevant feature of many neurodegenerative diseases. Here we assess three adults at risk of frontotemporal dementia from C9orf72 mutation, using [11C]UCB‐J PET to quantify synaptic density in comparison with 19 healthy controls and one symptomatic patient with behavioural variant frontotemporal dementia. The three pre‐symptomatic C9orf72 carriers showed reduced synaptic density in the thalamus compared to controls, and there was an additional extensive synaptic loss in frontotemporal regions of the symptomatic patient. [11C]UCB‐J PET may facilitate early, pre‐symptomatic assessment, monitoring of disease progression and evaluation of new preventive treatment strategies for frontotemporal dementia.
Piezoelectric Nanogenerators Derived Self‐Powered Sensors for Multifunctional Applications and Artificial Intelligence
Authors: Cao Xiaole , Xiong Yao , Sun Jia , Zhu Xiaoxiao , Sun Qijun , Wang Zhong Lin 
Published: June 2021

AbstractWith the arrival of the Internet of Things (IoTs) era, there is a growing requirement for systems with many sensor nodes in a variety of fields of applications. The demands for wireless, sustainable and independent operation are becoming more and more important for large‐scale sensor networks and systems. For these purposes, a self‐powered sensory system that can utilize the self‐harvested energy from its surroundings to drive the sensors and directly sense external stimuli has attracted great attention. The invention and rapid development of piezoelectric generators (PENGs), which take Maxwell's displacement current as the driving force, has been pushing forward research on self‐powered active mechanical sensors, electronic skins, and human‐robotic interaction. Here, this review starts with a brief introduction of piezoelectric materials, fabrication, and performance improvement. Then, the energy harvesters used for self‐power systems based on recent progress are reviewed. After that, PENGs applications toward recent self‐powered active sensors are divided into four aspects and highlighted, respectively. Moreover, some challenges and future directions for the self‐powered multifunctional sensors are put forward. It is believed that through the continuous investigations into PENG‐based self‐powered active sensors, they will soon be used in touch screens, electronic skins, health care, environmental monitoring, and intelligence systems.
Environmentally Friendly Graphene Inks for Touch Screen Sensors
Authors: Tkachev Sergey , Monteiro Miguel , Santos João , Placidi Ernesto , Hassine Mohamed Ben , Marques Pedro , Ferreira Paulo , Alpuim Pedro , Capasso Andrea 
Published: June 2021

AbstractGraphene‐based materials have attracted significant attention in many technological fields, but scaling up graphene‐based technologies still faces substantial challenges. High‐throughput top‐down methods generally require hazardous, toxic, and high‐boiling‐point solvents. Here, an efficient and inexpensive strategy is proposed to produce graphene dispersions by liquid‐phase exfoliation (LPE) through a combination of shear‐mixing (SM) and tip sonication (TS) techniques, yielding highly concentrated graphene inks compatible with spray coating. The quality of graphene flakes (e.g., lateral size and thickness) and their concentration in the dispersions are compared using different spectroscopic and microscopy techniques. Several approaches (individual SM and TS, and their combination) are tested in three solvents (N‐methyl‐2‐pyrrolidone, dimethylformamide, and cyrene). Interestingly, the combination of SM and TS in cyrene yields high‐quality graphene dispersions, overcoming the environmental issues linked to the other two solvents. Starting from the cyrene dispersion, a graphene‐based ink is prepared to spray‐coat flexible electrodes and assemble a touch screen prototype. The electrodes feature a low sheet resistance (290 Ω □−1) and high optical transmittance (78%), which provide the prototype with a high signal‐to‐noise ratio (14 dB) and multi‐touch functionality (up to four simultaneous touches). These results illustrate a potential pathway toward the integration of LPE‐graphene in commercial flexible electronics.
Third‐Order Nonlinear Optical Response‐Driven Upconversion Phosphors
Authors: Viswanath Noolu Srinivasa Manikanta , Cho Jeong Bin , Byun Hye Ryung , Han Joo Hyeong , Unithrattil Sanjith , Jang Joon Ik , Ok Kang Min , Im Won Bin 
Published: June 2021

AbstractA series of silicate materials with noncentrosymmetric structures, namely, Na3ScSi3O9 (NSSO), NSSO:Ce3+, NSSO:Eu2+, and NSSO:Tb3+, have been successfully synthesized by a microwave‐assisted solid‐state reaction. The materials reveal interesting second‐ and third‐harmonic generation and two‐photon absorption (2PA) properties attributable to the unusual connectivity and unique coordination environments around the cations, as evidenced by detailed structural analysis and maximum entropy method calculations. Upon irradiation with 980 nm laser light, the activator‐doped NSSO materials show an unusual upconversion emission property without using Yb3+ sensitizer ions, because of nonlinear absorption processes, as evidenced from 2PA spectroscopy results. The materials also show good chemical stability compared to NaYF4:Er3+, Yb3+. The findings of this work can stimulate the creation of a new scientific field devoted to upconversion luminescence in solid‐state materials.
Expanding the genetic landscape of oral‐facial‐digital syndrome with two novel genes
Authors: Strong Alanna , Simone Laurie , Krentz Anthony , Vaccaro Courtney , Watson Deborah , Ron Hayley , Kalish Jennifer M. , Pedro Helio F. , Zackai Elaine H. , Hakonarson Hakon 
Published: June 2021

AbstractOral‐facial‐digital syndromes (OFDS) are a heterogeneous and rare group of Mendelian disorders characterized by developmental abnormalities of the oral cavity, face, and digits caused by dysfunction of the primary cilium, a mechanosensory organelle that exists atop most cell types that facilitates organ patterning and growth. OFDS is inherited both in an X‐linked dominant, X‐linked recessive, and autosomal recessive manner. Importantly, though many of the causal genes for OFDS have been identified, up to 40% of OFD syndromes are of unknown genetic basis. Here we describe three children with classical presentations of OFDS including lingual hamartomas, polydactyly, and characteristic facial features found by exome sequencing to harbor variants in causal genes not previously associated with OFDS. We describe a female with hypothalamic hamartoma, urogenital sinus, polysyndactyly, and multiple lingual hamartomas consistent with OFDVI with biallelic pathogenic variants inCEP164, a gene associated with ciliopathy‐spectrum disease, but never before with OFDS. We additionally describe two unrelated probands with postaxial polydactyly, multiple lingual hamartomas, and dysmorphic features both found to be homozygous for an identicalTOPORSmissense variant, c.29 C>A; (p.Pro10Gln). HeterozygousTOPORSpathogenic gene variants are associated with autosomal dominant retinitis pigmentosa, but never before with syndromic ciliopathy. Of note, both probands are of Dominican ancestry, suggesting a possible founder allele.
Near‐Infrared‐Emitting Boron‐Difluoride‐Curcuminoid‐Based Polymers Exhibiting Thermally Activated Delayed Fluorescence as Biological Imaging Probes
Authors: Paisley Nathan R. , Halldorson Sarah V. , Tran Michael V. , Gupta Rupsa , Kamal Saeid , Algar W. Russ , Hudson Zachary M. 
Published: June 2021

AbstractNear‐infrared‐emitting polymers were prepared using four boron‐difluoride‐curcuminoid‐based monomers using ring‐opening metathesis polymerization (ROMP). Well‐defined polymers with molecular weights of ≈20 kDa and dispersities <1.07 were produced and exhibited near‐infrared (NIR) emission in solution and in the solid state with photoluminescence quantum yields (ΦPL) as high as 0.72 and 0.18, respectively. Time‐resolved emission spectroscopy revealed thermally activated delayed fluorescence (TADF) in polymers containing highly planar dopants, whereas room‐temperature phosphorescence dominated with twisted species. Density functional theory demonstrated that rotation about the donor–acceptor linker can give rise to TADF, even where none would be expected based on calculations using ground‐state geometries. Incorporation of TADF‐active materials into water‐soluble polymer dots (Pdots) gave NIR‐emissive nanoparticles, and conjugation of these Pdots with antibodies enabled immunofluorescent labeling of SK‐BR3 human breast‐cancer cells.
Alkene Isomerization Revitalizes the Coates–Claisen Rearrangement
Authors: Massad Itai , Marek Ilan 
Published: June 2021

AbstractThe [3,3]‐sigmatropic rearrangement of allylic vinyl acetals, first investigated by Coates nearly four decades ago, is set apart from other variants of the Claisen rearrangement owing to the versatile monoprotected 1,5‐dicarbonyl motif featured in the products. Unfortunately, the synthetically elusive nature of the substrates has thus far precluded the widespread application of this attractive transformation. Herein, we show that the key allylic vinyl acetals can be efficiently generated through alkene isomerization of their readily available regioisomeric counterparts (derived from allylic alcohols and α,β‐unsaturated aldehydes), thus enabling the first systematic study of the substrate scope of this rearrangement, as well as the discovery of exceptionally mild conditions for its mediation by Lewis and Brønsted acids.
A Universal Strategy for Organic Fluid Phosphorescence Materials**
Authors: Sun Siyu , Wang Jie , Ma Liangwei , Ma Xiang , Tian He 
Published: June 2021

AbstractIt is an accepted approach to construct room‐temperature phosphorescence (RTP) materials by suppressing the non‐radiative decay process. However, there is limited success in developing fluid phosphorescence materials owing to the ultrafast non‐radiation relaxation of vibration and collision of molecules in fluid matrixes. Here, a universal deep‐eutectic‐solvent strategy is proposed for developing pure organic phosphorescent fluid materials that are able to generate effective phosphorescent emissions at both room temperature (ΦRTP,293 K≈30 %) and even higher temperature (ΦRTP,358 K≈4.53 %). Based on these findings, a qualitative analytical method was developed for leak detection and a quantitative analytical technique was further validated to help visually identify the heat distribution of irregular surfaces. This advancement empowers the current organic phosphorescent system offering an alternative to determine moisture and heat from non‐invasive photoluminescence emission colors.
Hemocompatibility of polymers for use in vascular endoluminal implants
Authors: Ammann Kaitlyn R. , Hossainy Syed F. A. , Hossainy Sahir , Slepian Marvin J. 
Published: June 2021

AbstractImplanted polymers for cardiovascular applications may function as structural supports, barriers, or provide a means for local drug delivery. Several thermoplastic biodegradable drug delivery polymers are potential candidates for blood‐contacting implant applications. For intravascular applications specifically, a criterion for material selection is the intrinsic hemocompatibility of the baseline polymer. As an initial screening approach for selection of polymers for in vivo use, thin films of polyesters: poly(ɛ‐caprolactone) (PCL), poly(lactic acid) (PLA), poly(lactic‐co‐glycolic acid) (PLGA); polyanhydrides: poly(fatty acid dimer‐co‐sebacic acid) (PFAD:SA) and poly(biscarboxyphenoxypropane‐co‐sebacic acid) (PCPP:SA); and poly(ethylene glycol) (PEG)‐ylated polyesters: PLA:PEG, PCL:PEG and PCL:PLA:PEG polymers were spin‐cast on glass cover slips and placed in an in vitro flow system exposing them at a controlled shear to overflowing human whole blood. Platelet adherence, aggregate formation, and thrombus formation, as well as leukocyte adherence were assessed following 5 min of flow. At 5 min of flow the rank order of materials, in terms of least to most thrombogenic was: PCL < PFAD:SA < PCPP:SA < PLGA < PLA. All PEGylated materials, in general, had less thrombus formation than baseline unmodified materials.
Dual‐crosslinked hydrogels with metal coordination from novel co‐polyaspartamide containing 1,2‐dihydroxy and imidazole pendant groups
Authors: Dang Dat Quoc , Park Nuri , Kim Jaeyun , Kim Ji‐Heung 
Published: June 2021

AbstractHerein, a series of new polyaspartamide derivatives, PolyAspAm(API/APD)s, is prepared from polysuccinimide, which is the thermal polycondensation product of aspartic acid, via successive ring‐opening using 1‐(3‐aminopropyl)imidazole (API) and 3‐amino‐1,2‐propanediol (APD). Metal‐coordinated hydrogels are generated by adding divalent metal ions (Cu2+, Zn2+) to the aqueous polymer solution. The resulting gels can adhere strongly to various substrates. Further, novel dual‐crosslinked hydrogels are prepared, where the first network is generated via acetal formation between the massive 1,2‐hydroxyl groups of the polymer and glutaldehyde as the crosslinker. Subsequent immersion of the product gel in various metal ion‐containing solutions forms a second network via metal coordination, thereby affording mechanically robust hydrogels. Multiple metal‐coordination interactions are expected to occur between the imidazole functional groups and metal cations. The mechanical properties of resulting gel vary depending on the metallic species. These novel kinds of hydrogels are expected to find biomedical applications as adhesives and antibacterial soft matter.