bluuebunny/crossref_metadata_2025 huggingface dataset:
Strength and durability properties (effect of salts) of internal curing concrete
Authors: Kastro Kiran V , Sathyan Dhanya , Anand K B , Devi P Rubitha
Published: June 2020

Concrete is the second most largely consumed material on Earth. The strength and durability parameters of concrete largely depends on the curing process. The quality of concrete to a great extent relies upon the process of curing. It is estimated that 1m3 of concrete requires about 3m3 of water, approximately and a period of 28 days continuous water curing is required to develop the desired properties. In order to restrict the usage of excess amount of water, Internal Curing of Concrete is perhaps the best other option. In this study, internal curing agent – Poly Ethylene Glycol is used at various dosages, 0%, 0.5%, 1.0%, 1.5%, 2%, 2.5%, and 3.0% by cement weight and the mechanical properties are evaluated. The effect of salts on Internal Cured Concrete are evaluated by using two salt solutions viz., NaCl and CaCl2. It was perceived that 2% PEG solution was effective for compressive strength and 1.5% for split tensile and flexural strengths. NaCl and CaCl2 solutions had shown an adverse effect on Internal Cured Concrete.
Solar reduced graphene oxide coated sponge for oil and organic solvent adsorption studies
Authors: Anand K B , Mohanapriya K , Datar S D , Jha N
Published: June 2020

In this work, we have synthesized solar reduced graphene oxide (SRGO)by facile, fast and cost effective technique. The as-prepared SRGO was coated on polyurethane sponge and used for oil adsorption from the oil-water interface. The material was characterized by x-ray diffraction spectroscopy and scanning electron microscopy for structural, surface and morphological analysis. Further the hydrophobicity of the graphene coated sponge was investigated by measuring the contact angle of water droplet with the graphene coated sponge. The graphene coated sponge demonstrates strong hydrophobicity along with oleophilic property. SRGO coated sponge shows high adsorption and achieves equilibrium in few seconds. Highest adsorption capacity has been obtained for tetrahydrofuran, which is 65.67 g/g. SRGO coated sponge prepared could be a desirable material for cleanup of oil spills in sea.
A review on durability properties of alkali activated composites
Authors: Nagaraj V K , Venkatesh Babu D L , Ramzane Shaik Nawaz Shreef , Manjunath R , Manjunath S , Rakesh T M
Published: June 2020

Global warming predominantly caused due to greenhouse gas emission from the cement manufacturing industry is associating climate changes. Thus, these has allured researchers towards alkali activated composite customarily known has geopolymer concrete. At this moment in time the researchers are in an unremitting process to ameliorate the durability properties of concrete. As durability of concrete chiefly sway the services viability of structural element, hence this property has a vital role. In these review paper the various durability properties of geopolymer concrete has been explored. The review of literature divulged that the production of geopolymer concrete necessitate substantial case unerring composition. The various parameters like activator to binder ratio, activator ratio, molarity, water to solid ratio, type of source materials and their proportions govern the durability property of geopolymer concrete. The various researchers in the field of GPC had concluded that geopolymer concrete had astounding property compare to cement based traditional concrete.
Irradiation studies on nano-scale single crystal copper by molecular dynamics simulation
Authors: Katakam Krishna Chaitanya , Yedla Natraj
Published: June 2020

We report molecular dynamics (MD) simulation studies on the structure and tensile properties (temperature = 300 K and strain rate = 1010 s−1) of irradiated copper single crystals (101.8 Å× 50.54Å × 50.54Å) oriented along the [100] and [110] crystallographic orientations. Primary knock-on atom (PKA) method is used for radiation (0.5 keV to 5 keV). Structural studies indicate liquid like regions near the PKA region and are more in [110] orientation. The self-diffusivity (D) of copper in the PKA regions is found to increase from 4.05 × 10−5 m2/s at 1 keV irradiation energy to 27.36 × 10−5 at 5 keV irradiation energy in [110] orientation. However, no such relationship is observed in the [100] orientation. Vacancies, self-interstitials, and dislocations are more prominent in [100] orientation (dislocation density = 1 × 1016 m−2). Young’s modulus and yield strength decrease due to the formation of defects as anticipated.
Experimental study on strength characteristics of geopolymer based voided specimens
Authors: Suchitra B , Bhuvaneshwari P
Published: June 2020

Self-weight is the load imposed by its own weight upon astructure. The material density of the system directly influences the self-weight. By creating voids inside the structure, we can reduce the self-weight and material density. In this study, voids are created by using void formers made of recycled plastic materials that do not react with concrete and steel chemically. Tests are conducted on the plastic void former and voided specimen of 150mm × 150mm × 150mm size. Geopolymer concrete is a type of concrete produced by using waste materials generated from power plants along with an activator solution. For solid specimens, cubes of 100mm × 100mm × 100mm size are cast and tested by considering different curing methods. It can be concluded that the strength characteristics of geopolymer concrete was found to be significantly greater than that of conventional concrete. Voided specimens show reduced density apart from achieving comparable strength to that of solid specimens
Material performance of agro based hybrid natural fibre reinforced high strength concrete
Authors: Poongodi K , Mahesh V , Murthi P , Sivaraja M
Published: June 2020

The High Strength Concrete (HSC) is relatively higher brittle nature than normal concrete. Addition of fibre in concrete enhances the ductility properties. In the present research, agricultural products such as coir fibre (CF) and banana fibre (BF) were used to investigate the performance of HSC. The Fibre Reinforced High Strength Concrete (FRHSC) was developed with ternary blended combination using Metakaolin and Micro Silica. The concrete grades of M60 and M70 were designed for the study purpose. The fibre were added with 1.5% of volume of concrete and established three hybrid fibre combination such as 25% CF + 75% BF, 50% CF + 50% BF and 75% CF + 25% BF of total fibre content. The workability of FRHSC was maintained in the range of 100-120 mm with the assistance of superplastizer. The performance of FRHSC was determined using mechanical properties including the strength ratio and compared with the control HSC. The material performance of hybrid FRHSC was significantly improved and the ductility nature was increased up to 25% than the control HSC
A review on strength characteristics of GGBS based fiber-reinforced lightweight aggregate concrete
Authors: Sindhuja S , Raman K Saketh , Bhuvaneshwari P
Published: June 2020

This study is a review on the strength characteristics of Lightweight concrete (LWC)using lightweight expanded clay aggregate (LECA), supplementary cementing material (GGBS) and micro-steel fibers at its optimum percentages. Based on the review of literatures, preliminary experiment is conducted to determine the effect of partial replacement of conventional coarse aggregate with light weight expanded clay aggregate (LECA) on its strength characteristics, Comparison is made with conventional concrete to check the suitability of structural lightweight concrete for various construction purposes. A total of 14 cubes of size 100 mm × 100 mm × 100 mm are cast by varying the percentages of LECA as 30%, 50% and 100%. On comparison, it is noted that the density of concrete decreased in the range of (6.2%-38%) with increase of LECA content, meanwhile strength characteristics were reduced. So in order to achieve enhanced strength characteristics by retaining the benefits of LECA, cement was partially replaced with Ground granulated blast furnace slag (GGBS) at its optimum percentage (40%) and Micro steel fibers are also added to improve tensile characteristics and to prevent micro cracks in the Light weight concrete specimens.
Synthesis, growth, structure, spectroscopic, and physicochemical properties of 18-Crown-6-ether barium (II) bisthiocyanate monohydrate single crystal: BCBT
Authors: Showrilu K , Ramesh V , Rajarajan K , Dhas S A Martin Britto
Published: June 2020

We reported the bulk size with a dimension of 18×5×5 mm3 single-crystals of 18C6(Ba)(SCN)2.H2O [18-crown-6-ether barium(II) bisthiocyanate monohydrate]; abbreviated as BCBT, have been grown from an aqueous solution via slow evaporation solvent technique(SEST). The grown pristine single-crystals have characterized by single crystal X-ray diffraction (XRD), FT-IR, micro-Raman, and UV-Vis-NIR spectral studies. BCBT crystallizes in a monoclinic with a non-centrosymeetric space group of P21 crystal system. Additionally, the chemical etching studies showed that the reverse crystal growth rates of BCBT. The FT-IR studies confirmed the present of functional groups in the grown single-crystal of BCBT. Interestingly, the CN stretching observed at 2012 cm−1 is clearly shown the N-bonded nature of SCN with Ba2+. Moreover, the micro-Raman spectrum is used to further additional confirmation of BCBT single-crystal. In the entire visible region, the BCBT crystal has found to be wide (UV-Vis-IR) optically absorption from 231 to 800 nm, which is suitable for optoelectronic applications. The laser damage threshold measurements on the BCBT crystal with Q-switched Nd: YAG laser of fundamental wavelength 1064 nm (QUANTA RAY Model LAB – 170 - 10, pulse width 10 ns and repetition rate 6 Hz used as the source of light for laser damage threshold experiment. Moreover, the thermal stability of grown BCBT is stable up to 289 °C. From the results reveal that the sample possess admirable thermal stability compared to other IOPS series such as CLTC (171°C), and ACCTC (241°C).
Organic base catalysed synthesis of benzimidazole
Authors: John Sarah , Kavya G , Aparna M M , Krishnan R Anuja , Parvathy R , Sreenath T S , Sivan Akhil
Published: June 2020

A mild and effective protocol for benzimidazolesynthesis from o-phenylenediamine and aromatic aldehydes catalysed by DBU is described. The synthesized compounds find application in the pharmaceutical, dye and material science fields. Mild reaction conditions, low amount of chemicals and use of metal-free catalysts are the highlights of the reaction.
Hemicyanines-potential heavy metal ion sensors
Authors: Gopika G S , Raj M P Pranav , Eapen Merin , Rani P , Lekshmipriya S , Dev Anandu P , Pillai Zeena S
Published: June 2020

The synthesis of four hemicyanine dyes are reported. Varying the donor-acceptor properties of hemicyanine dyes has a drastic influence on the aggregation properties and photophysical properties. 4-(N, N-dimethyl)amino benzaldehyde, 4-nitro benzaldehyde and 4-hydroxy benzaldehyde are used as donors. Quarternary salts of 2-methyl benzothiazole with bromoacetic acid and methyl iodide are used as acceptors. Synthesis and characterization of the dyes were carried out. Preliminary studies shows that these compounds possess pH sensing as well as heavy metal ion sensing properties.
Study on mechanical properties of alkali activated binary blended binder containing steatite powder and fly ash / GGBS
Authors: Premkumar R , Chokkalingam Ramesh Babu , Shanmugasundaram M , Ragasree A
Published: June 2020

The primary advantage of geo polymeric concrete is the decrease in ecological effect in agreement with the concept of sustainable development. The present investigation thinks about the quality, and transport properties of GGBS–and fly debris based geopolymer mortars with different level of steatite powder. The main variables investigated were the hybrid binder of geopolymer mortar. In this present study fly ash and GGBS is partial replacement with different amounts of steatite powder (soap stone) 0%,10%, 20%, 30%, 40% & 50% to obtained the mechanical properties such as compressive strength and split tensile strength. For comparison, one mixture of ordinary portland cement mortar (OPC) is also studied. The alkali activators are prepared by combining NaOH and Na2SiO3 solution in the ratio of 2.5 and NaOH concentration 10M. The flyash based Geopolymer mortar specimens are heat curing (oven dry) at 70°C for 48 hours and ambient curing was done in GGBS based Geopolymer mortar. Test results were obtained that, when increasing percentages of fly ash partial replaced with the steatite powder is gradually increased the strength and the proportion of steatite powder 30% are the optimum range value.
Structural performance of hybrid fiber geopolymer concrete beams
Authors: Chithambar Ganesh A , Muthukannan M , Dhivya M , Sangeetha C B , Daffodile S P
Published: June 2020

This research work aims at investigating the structural properties of hybrid fiber reinforced geopolymer concrete specimens such as load-deflection behaviour, stiffness, ductility, toughness index. In this research work, effort has been made towards reducing the brittleness of geopolymer concrete by the addition of glass (high modulus) and polypropylene (low modulus) fibers inside GGBS based geopolymer concrete made of M-sand. The glass and polypropylene fibers were added in various proportions such as 1/0, 0.75/0.25, 0.5/0.5, 0.25/0.75,0/1. The research work recorded enhancement of structural properties of geopolymer concrete under ambient curing. This work paved way for the utilization of fibers inside geopolymer concrete and replace cement concrete in all facets.
Novel fabrication of fixed suspended silicon nitride structure for MEMS devices with dry etching
Authors: Subhani Khawaja Nizammuddin , Khandare Shubham , Biradar R C , Bhat K N
Published: June 2020

A method of fabricating suspended LPCVD and PECVD silicon nitride structure is demonstrated for a wide range of MEMS (Micro-Electro-Mechanical Systems) applications. Low stress LPCVD and PECVD silicon nitride film of 1 μm thickness were selected for the structure separately. Optical Lithographic parameters, viz, photoresist (PR) thickness, PR variety and baking parameters were optimized to obtain the PR suitable for selective etching of silicon and silicon nitride. Parameters of the dry etching process were also optimized to achieve anisotropic etching of silicon nitride and isotropic etching of Si to release the silicon nitride beam. The silicon nitride structures, thus released, were characterized using Scanning Electron Microscope (SEM) and Laser Doppler Vibrometer (LDV). Finite Element Method (FEM) analysis was carried out using COMSOL, to compare with the experimental modes of vibration investigated using the Laser Doppler Vibrometer (LDV). Thus we demonstrate that the first mode at 30 kHz was indeed the optimum match.
Optimisation of bio medical waste ash in GGBS based of geopolymer concrete
Authors: Suresh Kumar A , Muthukannan M , Sri Krishna I
Published: June 2020

Bio-Medical Waste Ash (BMWA) in Geopolymer Concrete (GPC) has been studied for its potential use as a substitute for Ground Granulated Blast Furnace Slag (GGBS). The raw materials were determined to have physical and chemical characteristics. Bio-medical waste ash was used for GGBS at 0%, 1%, 2%, 3%, 4%, 5% 6%, 7%, 8%, 9% and 10% by weight replacement. The mixing proportion of the GGBS, M-Sand, and Alkaline solution is 1:2.21:3.48, respectively. A compressive strength test was performed for all of the specimens. Results showed that up to 10 % of BMWA replacement for GGBS had higher compressive strength than a standard mix (0 % BMWA). Use 7 % BMWA after 28 days of curing, the maximum compressive strength of 39.8 N / mm2 was achieved. After 28 days of curing, specimens prepared using 13 M NaOH yielded a better compressive strength than the normal mix. At 28 days of curing time, the average compressive strength of 40.12 N / mm2 was reached.
Crystal growth, surface morphology, mechanical and thermal properties of UV-nonlinear optical crystal: Mercury cadmium chloride thiocyanate (MCCTC) single crystal
Authors: Ramesh V , Gunasekaran B , Suresh P , Sundaravadivel E , Showrilu K , Rajarajan K
Published: June 2020

Single crystal of mercury cadmium chloride thiocyanate (MCCTC) was grown by slow evaporation solvent method at ambient temperature (SEST) with a dimension of 10×5×5 mm3. The grown single-crystal’s structure and lattice constant, density and volume were estimated by using single-crystal X-ray diffraction studies. Additionally, the chemical etching and atomic force microscopy (AFM) analysis were used to investigate reverse growth and surface morphology. Moreover, the mechanical properties such as, hardness number, yield strength, Mayer index number, and stiffness constant were calculated by Vickers’s micro-hardness measurement. The thermal stability of grown single is stable up to 171 °C observed from TG-DSC, which reveals that the sample posses low thermal stability compared to other organometallic thiocyanate families of single crystals like MMTC(381°C), MFCTC (241°C) and ACCTC (247 °C). The non-linear optical study of second harmonic generation efficiency for MCCTC single crystal is 17 times superior to Urea.
Synthesis & characterization of doped nickel ferrite filled natural rubber nano composites
Authors: Hema S , Sambhudevan Sreedha , Mahitha P M , Rashid Sultan K , Raj Malavika , Anjana A , Parvathy S U , Mahalekshmi M S , Shankar Balakrishnan
Published: June 2020

Synthesis of rubber nanocomposite containing differently doped ferrites were fabricated using Co-precipitation method. The nano particles characterization was carried out by SEM, FTIR and XRD to confirm that the ferrites were synthesized in nanometer dimensions. The rubber mixes were incorporated with metallic nano fillers and the obtained nanocomposites were analysed for mechanical studies such as hardness, specific gravity, tear and tensile strength. The copper doped samples shows excellent mechanical properties over other dopants and hence paving the way for decisive technical applications.
Preparation of graphene oxide by dry planetary ball milling technique under oxygen atmosphere
Authors: Dash Soumen , Dash Tapan , Rout Tapan Kumar
Published: June 2020

The work explores the preparation of graphene oxide (GO) from natural graphite by dry planetary ball milling technique under oxygen atmosphere. The ball milling was carried out between 4 and 8 hrs. The structure and composition were studied by various advanced characterization techniques. X-ray diffraction (XRD) confirms the successful formation of graphene oxide showing C(001) peak. X-ray photoelectron spectroscopy (XPS) agrees with XRD result exhibiting various oxygenated functional groups along with matrix of carbon. The increasing oxidation behaviour was confirmed from Raman study with increasing trend of I2D/IGratio. The sample prepared by 8 hr ball milling exhibits BET surface area of 454 m2/g. The sheet type and folded morphology confirm the high quality formation of graphene oxide. The GO-8 hr shows a high O/C ratio (58.87). Purity of typical GO sample was confirmed from EDS analysis exhibiting only presence of carbon and oxygen.
Comparative Oxygen Evolution Reaction performance of cobalt oxide electrocatalyst in combination with various metal ions MCo2O4 (M= Mn2+, Cu2+, Co2+, Zn2+, Fe2+, Mg2+)
Authors: Rai Varun , Reddy MV Venkatashamy , Adams Stefan , Blackwood Daniel John
Published: June 2020

Oxygen evolution reaction (OER) supported by electrocatalyst is very important reaction in electrochemical system e.g. air-battery based energy storage devices, water splitting, and photo electrochemical cells. Therefore developing inexpensive, non-hazardous, noble metal free, transition metal oxide based electrocatalyst is necessary for energy application and environmental sustainability. MCo2(III)O4 based oxides in combination of various metal ions (Mn2+, Cu2+, Co2+, Zn2+, Fe2+, Mg2+) are studied as OER electrocatalyst in both acidic and basic medium. When deposited on a glassy carbon current collector the comparative LSV polarization plots revealed that in acidic medium FeCo2O4 is the best OER performing electrocatalyst, showing onset potential +1.62 V vs RHE with current 1.66 mA/cm2, while in basic medium it is MnCo2O4 that preforms the best, showing an onset potential +1.53 V vs RHE with OER current density 2.06 mA/cm2. When nickel foam was used as the current collector, Co3O4 shows the best OER performance, with an onset potential 1.508 V vs RHE and OER current 159 mA/cm2 in acidic medium. However in the basic medium the substrate nickel foam outperforms all the oxides combinations with different metal ions due to partially oxidized NiO at nickel foam, showing onset OER potential +1.58 V vs RHE and OER current density 13mA/cm2. No correlation was found between the rates of OER and the bond dissociation energies of the respective metal-oxygen bonds nor the metal-hydroxide bond strength.
Effect of spatial distribution of nanopores on mechanical properties of mono layer graphene
Authors: Saumya K , Gupta K K , Roy A , Dey S
Published: June 2020

Since the discovery of graphene, it has immense popularity among scientists and researchers due to its superior mechanical and electrical properties. In the present study, the effects of the spatial distribution of nanopore defects on the mechanical properties of the single-layer graphene sheet (SLGS) are investigated. Based on Tersoff potential functions, molecular dynamics (MD) simulations are conducted to perform the uniaxial deformation of defected graphene. The nanopore defects are induced intentionally at various spatial locations on a pristine graphene sheet for studying the variation in its mechanical properties such as fracture strength, Young’s modulus and failure strain. The results illustrate that the mechanical properties are predominantly dependent on the spatial locations of the defects. It is also observed that the mechanical properties are slightly higher in case of zigzag direction than armchair direction but it decreases with the presence of defects in both the cases. In the consequence, it is suggested to consider spatial locations of defects while fabricating nanodevices with graphene.
Effect of silicon dopant on mechanical properties of monolayer graphene
Authors: Majeti V K , Roy A , Gupta K K , Dey S
Published: June 2020

The exceptional qualities of graphene have drawn the attention of many researchers and scientists. It has exhaustive real-life applications, ranging from mechanical and medical domain to electronic fields. The significant properties of graphene can be tailored by chemical functionalization methods. By incorporating foreign atoms, the properties of pristine graphene can be modified. Molecular dynamics (MD) simulations are carried out to conduct tensile tests on square-shaped graphene doped by silicon. The fracture strength, failure strain and Young’s modulus are measured on grapheme doped by silicon. The carbon atoms in the graphene sheet are replaced randomly with silicon atoms for this simulation and the variation of mechanical properties are observed by comparing with the pristine form of graphene. The properties such as Young’s modulus, fracture strength and failure strain are found to reduce with the increase of doping intensity. During chemical vapour deposition (CVD) method as silicon atoms are likely to replace the carbon atoms, it may promote the electronic properties but in the present study, it is found to decline its mechanical properties due to increase in silicon doping concentration. As a result, it is therefore suggested to consider the effect of silicon dopants in the applications of graphene.
Quick-start guide for first-principles modelling of point defects in crystalline materials
Authors: Kim Sunghyun , Hood Samantha N , Park Ji-Sang , Whalley Lucy D , Walsh Aron
Published: June 2020

Defects influence the properties and functionality of all crystalline materials. For instance, point defects participate in electronic (e.g. carrier generation and recombination) and optical (e.g. absorption and emission) processes critical to solar energy conversion. Solid-state diffusion, mediated by the transport of charged defects, is used for electrochemical energy storage. First-principles calculations of defects based on density functional theory have been widely used to complement, and even validate, experimental observations. In this ‘quick-start guide’, we discuss the best practice in how to calculate the formation energy of point defects in crystalline materials and analysis techniques appropriate to probe changes in structure and properties relevant across energy technologies.
Effective uncooled infrared bolometer based on SOI gate all around electrostatically formed nanowire transistors
Authors: Shimanovich Klimentiy , Mutsafi Zoe , Rosenwaks Yossi
Published: June 2020

This paper presents a novel micro-bolometer structure based on SOI gate all around Electrostatically Formed Nanowire (GAA EFN) transistors. The new design enables formation of the EFN conductive channels in the volume of the SOI devices layers, far from the top and bottom silicon/oxide interfaces, thus reducing the noise level and increasing the temperature sensitivity to 13.3%/K. Detailed electrical and thermal simulations show that the micro-bolometer structure has an effective responsivity of 1.95 × 103 A/W, noise equivalent power of 561 fW, noise equivalent temperature difference of 8 mK, and a thermal time constant of 35 msec, when operated in depletion all around mode (DAA) at the sub-threshold regime.
A Flow Cytometric Study of Reagent Cells to Resolve ABO Typing Discrepancy
Authors: Maracaja Danielle L V , Qiao Jesse , Salazar Tomas , Barry James , LaForce Karen , Holder Kenneth , Olson John D
Published: June 2020

Objectives

RBC alloantibodies can lead to ABO grouping discrepancies unrelated to A or B antigens or antibodies posing challenges in the blood bank testing. Routine blood bank testing and flow cytometry were used to immunophenotype reagent cells and elucidate the cause of ABO discrepancies in two patients.

Methods

ABO discrepancy was identified in two patients after transfusion with several units of RBCs. For both patients, the pretransfusion type and screen demonstrated blood group A. Eight and 16 days later, both patients showed an apparent antibody to reagent group A cells, which prompted additional study with patients’ samples and flow cytometric testing of commercial reagent cells.

Results

In both patients’ specimens, posttransfusion evaluation demonstrated an emerging antibody to the Kell antigen (K). The RBCs of both patients typed negative for K, and both were transfused with K-positive RBCs. Flow cytometric analysis of reagent RBCs demonstrated that five of seven lot numbers were positive for K.

Conclusions

Emerging anti-K antibody led to agglutination of the K-positive reagent A1 cells, highlighting the importance of considering RBC alloantibodies and the composition of reagent cells when interpreting cases with an apparent ABO grouping discrepancy.
The Course of the Angular Artery in the Midface: Implications for Surgical and Minimally Invasive Procedures
Authors: Gombolevskiy Victor , Gelezhe Pavel , Morozov Sergey , Melnikov Dmitry V , Vorontsov Alexander , Kulberg Nikolay , Frank Konstantin , Gotkin Robert H , Lachman Nirusha , Cotofana Sebastian
Published: June 2020

Background

Previous anatomic studies have provided valuable information on the 2-dimensional course of the angular segment of the facial artery in the midface and its arterial connections. The third dimension (ie, the depth of the artery) is less well characterized.

Objectives

The objective of the present study was to describe the 3-dimensional pathway of the angular segment of the facial artery and its relationship to the muscles of facial expression.

Methods

The bilateral location and the depth of the midfacial segment of the facial artery was measured utilizing multi-planar computed tomographic image analyses obtained from contrast agent-enhanced cranial computed tomographic scans of 156 Caucasians aged a of 45.19 ± 18.7 years and with a mean body mass index of 25.05 ± 4.9 kg/m2.

Results

At the nasal ala, the mean depth of the main arterial trunk was 13.7 ± 3.7 mm (range, 2.7-25.0 mm), whereas at the medial canthus it was 1.02 ± 0.62 mm (range, 1.0-3.0 mm). This was reflected by the arteries’ relationship to the midfacial muscles: at the nasal ala superficial to levator anguli oris in 62.0% but deep to the levator labii superioris alaeque nasi in 53.6%; at the medial canthus superficial to the levator labii superioris alaeque nasi in 83.1% and superficial to the orbicularis oculi in 82.7%.

Conclusions

The results presented herein confirm the high variability in the course of the angular segment of the facial artery. Various arterial pathways have been identified providing evidence that, in the midface, there is no guaranteed safe location for minimally invasive procedures.
Nonsurgical Redefinition of the Chin and Jawline of Younger Adults With a Hyaluronic Acid Filler: Results Evaluated With a Grid System Approach
Authors: Bertossi Dario , Robiony Massimo , Lazzarotto Andrea , Giampaoli Giorgio , Nocini Riccardo , Nocini Pier Francesco
Published: June 2020

Background

Aesthetic treatment of the lower face is increasingly in demand, particularly owing to age-related changes in appearance. VYC-25L is a novel hyaluronic acid filler with high G′ and high cohesivity, specifically designed for sculpting and contouring of the chin and jaw.

Objectives

The aim of this study was to assess the use of a grid traced onto the chin and jaw for guiding treatment with VYC-25L.

Methods

This was a retrospective, single-center analysis of data from adult patients undergoing treatment of the lower third of the face with VYC-25L. A grid system of horizontal and vertical lines was used to systematize the process of treatment planning and performance.

Results

Thirty subjects were enrolled (53.3% female; mean [standard deviation] age, 34.4 [2.8] years). The mean quantity of VYC-25L used was 4.0 [0.8] mL. Based on the 5-point Global Aesthetic Improvement Scale, 29 patients (96.7%) rated their appearance at 20 days posttreatment as “much improved” or “very much improved.” The only complications recorded were early transient soft-tissue edema (n = 14; 46.7%) and bruising (n = 6; 20.0%). There were no cases of infection, paresthesia, asymmetry, hematoma, necrosis, or skin discoloration.

Conclusions

Treatment of the chin and jawline with VYC-25L, with injection locations determined by a standardized grid-based approach, appears to be effective and safe with high rates of patient satisfaction. Injection of this filler offers a potentially high-impact approach for patients across a variety of biological and economic circumstances.

Level of Evidence: 4
Impact of Severe Acute Respiratory Syndrome Coronavirus 2 Viral Load on Risk of Intubation and Mortality Among Hospitalized Patients With Coronavirus Disease 2019
Authors: Magleby Reed , Westblade Lars F , Trzebucki Alex , Simon Matthew S , Rajan Mangala , Park Joel , Goyal Parag , Safford Monika M , Satlin Michael J
Published: June 2020

Background

Patients hospitalized with coronavirus disease 2019 (COVID-19) frequently require mechanical ventilation and have high mortality rates. However, the impact of viral burden on these outcomes is unknown.

Methods

We conducted a retrospective cohort study of patients hospitalized with COVID-19 from 30 March 2020 to 30 April 2020 at 2 hospitals in New York City. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load was assessed using cycle threshold (Ct) values from a reverse transcription-polymerase chain reaction assay applied to nasopharyngeal swab samples. We compared characteristics and outcomes of patients with high, medium, and low admission viral loads and assessed whether viral load was independently associated with intubation and in-hospital mortality.

Results

We evaluated 678 patients with COVID-19. Higher viral load was associated with increased age, comorbidities, smoking status, and recent chemotherapy. In-hospital mortality was 35.0% (Ct <25; n = 220), 17.6% (Ct 25–30; n = 216), and 6.2% (Ct >30; n = 242) with high, medium, and low viral loads, respectively (P < .001). The risk of intubation was also higher in patients with a high viral load (29.1%) compared with those with a medium (20.8%) or low viral load (14.9%; P < .001). High viral load was independently associated with mortality (adjusted odds ratio [aOR], 6.05; 95% confidence interval [CI], 2.92–12.52) and intubation (aOR, 2.73; 95% CI, 1.68–4.44).

Conclusions

Admission SARS-CoV-2 viral load among hospitalized patients with COVID-19 independently correlates with the risk of intubation and in-hospital mortality. Providing this information to clinicians could potentially be used to guide patient care.
Subgraph Reliability of Alternating Group Graph With Uniform and Nonuniform Vertex Fault-Free Probabilities
Authors: Huang Yanze , Lin Limei , Xu Li
Published: June 2020

As the size of a multiprocessor system grows, the probability that faults occur in this system increases. One measure of the reliability of a multiprocessor system is the probability that a fault-free subsystem of a certain size still exists with the presence of individual faults. In this paper, we use the probabilistic fault model to establish the subgraph reliability for $AG_n$, the $n$-dimensional alternating group graph. More precisely, we first analyze the probability $R_n^{n-1}(p)$ that at least one subgraph with dimension $n-1$ is fault-free in $AG_n$, when given a uniform probability of a single vertex being fault-free. Since subgraphs of $AG_n$ intersect in rather complicated manners, we resort to the principle of inclusion–exclusion by considering intersections of up to five subgraphs and obtain an upper bound of the probability. Then we consider the probabilistic fault model when the probability of a single vertex being fault-free is nonuniform, and we show that the upper bound under these two models is very close to the lower bound obtained in a previous result, and it is better than the upper bound deduced from that of the arrangement graph, which means that the upper bound we obtained is very tight.
Caregiver and Adolescent Patient Perspectives on Comprehensive Care for Inflammatory Bowel Diseases: Building a Family-Centered Care Delivery Model
Authors: Michel Hilary K , Siripong Nalyn , Noll Robert B , Kim Sandra C
Published: June 2020

Background

Children with inflammatory bowel diseases (IBDs) require primary and gastrointestinal (GI) care, but little is known about patient and family preferences for care receipt. We aimed to understand caregiver perceptions of current healthcare quality, describe barriers to receiving healthcare, and elicit caregiver and adolescent preferences for how comprehensive care ideally would be delivered.

Methods

This was an anonymous survey of caregivers of 2- to 17-year olds with IBD and adolescents with IBD aged 13–17 years at a large, free-standing children’s hospital. Surveys assessed patient medical history, family demographics, perceptions of health care quality and delivery, barriers to primary and GI care, and preferences for optimal care delivery.

Results

Two hundred and seventeen caregivers and 140 adolescents were recruited, 214 caregivers and 133 adolescents consented/assented, and 160 caregivers and 84 adolescents completed the survey (75% and 60% response rate, respectively). Mean patient age was 14 years (SD = 3); 51% male; 79% Crohn’s disease, 16% ulcerative colitis, and 4% indeterminate colitis. Caregivers were primarily female (86%), Caucasian (94%), and living in a 2-caregiver household (79%). Most caregivers reported that their child’s primary care physician (PCP) and GI doctor oversaw their primary care (71%) and their IBD care (94%), respectively. Caregivers were satisfied with communication with their PCP and GI providers (>90%) but did not know how well they communicated with one another (54%). Barriers to primary and GI care varied, and few caregivers (6%) reported unmet healthcare needs. Caregivers and adolescents saw PCPs and GI doctors having important roles in comprehensive care, though specific preferences for care delivery differed.

Conclusion

Caregivers and adolescent perspectives are essential to developing family-centered care models for children with IBD.
Histological intratumoral heterogeneity in pretreatment esophageal cancer biopsies predicts survival benefit from neoadjuvant chemotherapy: results from the UK MRC OE02 trial
Authors: Davarzani Naser , Hewitt Lindsay C , Hale Matthew D , Melotte Veerle , Nankivell Matthew , Hutchins Gordon G A , Cunningham David , Allum William H , Langley Ruth E , Jolani Shahab , Grabsch Heike I
Published: June 2020

Despite the use of multimodal treatment, survival of esophageal cancer (EC) patients remains poor. One proposed explanation for the relatively poor response to cytotoxic chemotherapy is intratumor heterogeneity. The aim was to establish a statistical model to objectively measure intratumor heterogeneity of the proportion of tumor (IHPoT) and to use this newly developed method to measure IHPoT in the pretreatment biopsies from from EC patients recruited to the OE02 trial. A statistical mixed effect model (MEM) was established for estimating IHPoT based on variation in hematoxylin/eosin (HE) stained pretreatment biopsy pieces from the same individual in 218 OE02 trial patients (103 treated by chemotherapy and surgery (chemo+surgery); 115 patients treated by surgery alone). The relationship between IHPoT, prognosis, chemotherapy survival benefit, and clinicopathological variables was assessed. About 97 (44.5%) and 121 (55.5%) ECs showed high and low IHPoT, respectively. There was no significant difference in IHPoT between surgery (median [range], 0.1637 [0–3.17]) and chemo+surgery (median [range], 0.1692 [0–2.69]) patients (P = 0.43). Chemo+surgery patients with low IHPoT had a significantly longer survival than surgery patients (HR = 1.81, 95% CI: 1.20–2.75, P = 0.005). There was no survival difference between chemo+surgery and surgery patients with high IHPoT (HR = 1.15, 95% CI: 0.72–1.81, P = 0.566). This is the first study suggesting that IHPoT measured in the pretreatment biopsy can predict chemotherapy survival benefit in EC patients. IHPoT may represent a clinically useful biomarker for patient treatment stratification. Future studies should determine if pathologists can reliably estimate IHPoT.
An incidental finding of a bicuspid aortic valve and pseudocoarctation of the descending aorta in a patient presenting with an acute coronary syndrome: a case report
Authors: Vivekanantham Hari , Cook Stéphane , Stauffer Jean-Christophe
Published: June 2020

Background

Aortic pseudocoarctation (PsCoA) is an elongation of the supra-isthmic aorta with kinking and low-grade narrowing. Consequently, no collateral circulation is found. It is frequently associated with other congenital heart anomalies, such as bicuspid aortic valve (BAV).

Case summary

We report the case of 60-year-old patient who presented to the ED with acute chest pain. Physical examination was remarkable for an elevated blood pressure (BP) and the presence of a systolic murmur on the left lower sternal border. An acute coronary syndrome was suspected and the patient underwent urgent coronary angiogram which showed an occluded obtuse marginal artery. Additionally, the presence of an aortic anomaly was noted during the aortography, and additional work-up, including a thoracic computed tomography angiography and transoesophageal echocardiography, revealed a BAV and a PsCoA of the descending aorta. The patient was discharged after optimizing BP control with oral medication and periodical follow-up was arranged.

Discussion

Aortic PsCoA may mimic true coarctation (CoA), but the absence of a haemodynamically significant descending aortic narrowing and of the typical clinical findings associated with aortic CoA, distinguishes both entities. Treatment is therefore conservative and based on the control of cardiovascular risk factors and in particular of arterial hypertension. Work-up should include imaging of the entire aorta and the search for associated congenital cardiac anomalies, which, if present, should be managed in consequence.
Differential effects of dual antiplatelet therapy in patients presented with acute coronary syndrome vs. stable ischaemic heart disease after coronary artery bypass grafting
Authors: Choi Ki Hong , Song Young Bin , Jeong Dong Seop , Jang Yong Ho , Hong David , Lee Sang Yoon , Youn Taeho , Bak Minjung , Min Kyung Min , Lee Joo Myung , Park Taek Kyu , Yang Jeong Hoon , Hahn Joo-Yong , Choi Jin-Ho , Choi Seung-Hyuk , Chung Su Ryeun , Cho Yang Hyun , Sung Kiick , Kim Wook Sung , Gwon Hyeon-Cheol , Lee Young Tak
Published: June 2020

Aims

The current study sought to evaluate whether long-term clinical outcomes according to the use of dual antiplatelet therapy (DAPT) or single antiplatelet therapy (SAPT) differed between acute coronary syndrome (ACS) and stable ischaemic heart disease (SIHD) patients who underwent coronary artery bypass grafting surgery (CABG).

Methods and results

Between January 2001 and December 2017, 3199 patients with ACS (55.3%) and 2583 with SIHD (44.7%) who underwent isolated CABG were enrolled. The study population was stratified using DAPT or SAPT in ACS patients and SIHD patients. The primary outcome was a cardiovascular death or myocardial infarction (MI) at 5 years. After CABG, DAPT was more frequently used in patients with ACS than in those with SIHD [n = 1960 (61.3%) vs. n = 1313 (50.8%), P < 0.001]. Among patients with ACS, the DAPT group showed a significantly lower risk of cardiovascular death or MI at 5 years than the SAPT group [DAPT vs. SAPT, 4.0% vs. 7.8%, hazard ratio (HR) 0.521, 95% confidence interval (CI) 0.339–0.799; P = 0.003]. In contrast, among patients with SIHD, there was no significant difference in the rate of cardiovascular death or MI at 5 years between the use of DAPT and SAPT (4.0% vs. 4.0%, HR 0.991, 95% CI 0.604–1.626; P = 0.971). These findings were robust to multiple sensitivity analyses and competing risk analysis. In the subgroup analysis, the use of DAPT was associated with a significantly lower risk of cardiovascular death or MI among SIHD patients with a previous percutaneous coronary intervention (PCI), with a significant interaction between the use of DAPT and PCI history (interaction P = 0.011).

Conclusion

Among ACS patients who underwent CABG, the use of DAPT was associated with lower cardiovascular death or MI than the use of SAPT, but this was not the case in SIHD patients.

Trial registration

ClinicalTrials.gov, NCT03870815.
The Last Will be First, and the First Last: Segregation in Societies with Relative Pay-off Concerns*
Authors: Herings P Jean-Jacques , Saulle Riccardo D , Seel Christian
Published: June 2020

This article studies coalition formation among individuals who differ in productivity. We consider egalitarian societies in which coalitions split their surplus equally and individualistic societies in which coalitions split their surplus according to productivity. Preferences of coalition members depend on their material pay-offs, but are also influenced by relative pay-off concerns. The stable partitions in both egalitarian and individualistic societies are segregated, i.e., individuals with adjacent productivities form coalitions. If some individuals are not part of a productive coalition, then these are the least productive ones for egalitarian societies and the most productive ones for individualistic societies.
Teaching about antibiotic resistance to a broad audience: a multidisciplinary approach
Authors: Kvint Kristian , Palm Martin , Farewell Anne
Published: June 2020

Education for the general public about antibiotic resistance is advocated as a key component of our response to this crisis. Since this is a multidisciplinary problem encompassing natural, medical and social sciences, it is an educational challenge as both students and lecturers will have vastly different backgrounds in the topics. Here we describe an online multidisciplinary course on antibiotic resistance spanning topics as diverse as chemistry and practical philosophy. The target group was any post-secondary school student and the participating students had different occupations and educational experience. Although as many as 38% of the students were currently studying natural sciences at university, the course included a diverse group with medical professionals (16%) and teachers (6%) making up a significant fraction of the class. The outcomes based on examination and the course evaluations were very positive and we have indications that the information students gained from this course has been spread to others. Unlike other online courses addressing antibiotic resistance, this course is both accessible to a wide range of students and covers a broad range of topics. We advocate courses like ours as an effective tool in educating the public about this crisis.
The Mental Landscape of Imagining Life Beyond the Current Life Span: Implications for Construal and Self-Continuity
Authors: Tausen Brittany M , Csordas Attila , Macrae C Neil
Published: June 2020

Background and Objectives

With rapid advancements in medicine, technology, and nutrition, the future holds the possibility of longer and healthier lives. Despite garnering attention from myriad disciplines, psychological perspectives on life extension are scarce. In three studies, we addressed this gap by exploring key mental characteristics and psychological variables associated with simulating an expanded life span and thus an extremely distant future self.

Research Design and Methods

Three studies investigated the construal (i.e., valence, vividness, and visual perspective) of extremely distant future simulations and the extent to which participants felt connected to their future selves (i.e., self-continuity). Studies 1 and 2 investigated the characteristics of imagery associated with different ages ranging from near the current species maximum (e.g., 120, 150) to more highly hypothetical ages (e.g., 201, 501). Study 3 probed the mental construal of extreme aging among different populations (i.e., life-extension supporters, students, and Mechanical Turk workers). Studies also assessed participants’ general feelings about the ethicality and likelihood of techniques that halt or reverse biological aging to help individuals live beyond the current life expectancy.

Results

Participants in all studies reported being able to vividly imagine expanded aging scenarios (increased chronological, without biological, and aging), but these simulations were characterized by a decreased sense of connection to one’s future self (i.e., self-continuity) compared to a control condition. Temporal distance did not, however, impact ratings of self-continuity when comparing experimental conditions (i.e., imagining one’s self 120 vs 150 or 201 vs 501). Curiously, a sense of self-continuity (when simulating oneself well beyond the current life expectancy) remained intact for individuals who belonged to a community of life-extension supporters. The perceived likelihood and ethicality of extended life-span scenarios also varied significantly across different populations.

Discussion and Implications

The current work is the first to quantify the disconnect between one’s current and extremely distant (i.e., beyond the current life expectancy) future self. Given the behavioral implications of feeling disconnected from one’s future self (e.g., failing to save for retirement or care for one’s own physical health), these findings inform a critical barrier of extended life spans and provide insight into potential remedies (e.g., enhancing the perceived likelihood of living longer). Theoretical implications of hypotheticality and temporal distance, two key dimensions of Construal Level Theory, and their impact on the construal and self-continuity associated with future simulations are also discussed.