bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of light trapping mechanism of Silicon solar cell performance utilizing Silvaco TCAD
Authors: Abd Rahim A F , Shamlan M , Mohd Razali N S , Radzali R , Mahmood A , Hamzah I H , Abu Bakar A
Published: June 2020

In this project, an investigation on the effect of difference shapes of the top surface silicon (Si) solar cell as an antireflective (AR) layer was carried out. Texturing the top surface of silicon solar cell helps to reduce light reflection from the solar cell. The different surface texturing which is planar structure, columnar structure and pyramid structure was created and simulated using Athena process simulator by SILVACO TCAD tools. The structures were then loaded into ATLAS device simulator to extract the electrical performance parameters of the solar cell. The results showed that the planar, pyramid and columnar structures of the Si solar cells exhibited efficiency of 2.04%, 2.18% and 2.39% respectively. The short circuit current, Isc, open circuit voltage, Voc and the maximum power, Pmax for the columnar structures are 2.35444 nA, 0.366605 V and 0.630363 nW respectively. The columnar structures exhibited better performances compared to the other structures indicating the columnar structure is good in trapping the light and efficiently collecting the current carrier at the electrode.
Phase and Morphological Studies of LiCo0.3Ni0.3Mn0.3Ti0.1-xSnxO2Cathode Materials
Authors: Elong K , Kamarulzaman N , Chayed N F , Badar N , Abdillih N S S M
Published: June 2020

The substitution of LiCo0.3Ni0.3Mn0.3Ti0.1O2materials with Sn is done to investigate the effect on the phase and morphology. The materials were synthesized via a combustion method. The annealing temperature and time of the precursors was obtained at 700 °C for 24 hours. The crystalline phase and purity of the materials are studied using X-Ray Powder Diffraction (XRPD). All the materials were observed to be pure phase and good cation ordering. Field Emission Scanning Electron Microscope (FESEM) is used to assess the morphology and the crystallites size of the materials. The images showed that the materials consist of polyhedral shaped crystals and well-crystallized particles with smooth surfaces. The % calculated synthesized materials shows close stoichiometry to the % element content from the EDX measurements of the synthesized materials within experimental error.
Dependence of V2O5 Nanorods Properties on Substrate Type Prepared by Simple Hydrothermal Method
Authors: Abd-Alghafour N.M. , Naeem Ghassan Adnan , Mohammad Sabah M.
Published: June 2020

V
2O5 (Vanadium pentoxide) nanorods were prepared onto various substrates by using simple hydrothermal method. The structural characteristics of the V
2O5 nanorods (NRs) have been examined via using XRD diffraction analysis. The effects of the various substrates on the morphological characteristics of V
2O5 NRs were investigated by using field emission scanning electron microscopy (FESEM) technique. The XRD results show that the preferred orientation along (001) plane. Raman spectra indicate that glass substrate has optimum results due to the size and number of the nanorods with lower defects. It can be found from the absorbance of the glass substrate increases compared with the other substrates.
Fabrication and Physical Characterization of Electrospun PVA-ZnO Fibers with Different Deposition Distance
Authors: Hadi Zulkefle Muhammad Al , Mohamad Puad Mohd Izham , Rahman Rohanieza Abdul , Zulkifli Zurita , Herman Sukreen Hana
Published: June 2020

PVA-ZnO composite nanofibers were successfully fabricated by electrospinning method. The effect of the deposition distance (the distance between the needle tip to the substrate) on the fiber diameter was investigated. The distance was varied from 4 cm to 20 cm and it was found out that the fiber diameter decreased as the distance increased. The fiber diameter was in the range of 156 to 251 nm with the finest fiber film was obtained for the distance of 20 cm. The presence of ZnO particles were confirmed with XRD characterization performed in which all PVA-ZnO composite samples displayed typical ZnO XRD peaks 32°, 34° and 36° that corresponded to Miller indices of (100), (002) and (101) of ZnO yet the peaks are more apparent at sample fabricated at the closer distance of 4 cm and 8 cm.
Comparison between standing transparent mirrorless packaging and planar-mounted packaging for GaN-on-GaN LEDs
Authors: Alias E A , Samsudin M E A , Zainal N , Iza M , Alhassan A I , DenBaars S P , Speck J S , Nakamura S
Published: June 2020

This work demonstrates that standing transparent mirrorless LED packaging as an attractive alternative configuration to increase the light extraction of LED on GaN substrate rather than standard planar-mounted packaging. From comparison study, it was found that the external quantum efficiency and the wall-plug efficiency of the standing transparent mirrorless LED is improved by 7% with respect to the planar-packed LED at a standard operating current of 20 A/cm2. The extraction of light of the LED with the standing transparent mirrorless packaging is contributed from all sides of the LED. In contrast, the light extraction for the LED with the planar-mounted packaging is only coming from the top and the sidewalls of the LED as well as having a longer path length for the photon to escape from LED and might increasing the possibility of light absorption in the GaN substrate.
In situ micro gas tungsten constricted arc welding of ultra-thin walled 2.275 mm outer diameter grade 2 commercially pure titanium tubing
Authors: Cooper L. , Crouvizier M. , Edwards S. , French R. , Gannaway F. , Kemp-Russell P. , Marin-Reyes H. , Mercer I. , Rendell-Read A. , Viehhauser G. , Yeadon W.
Published: June 2020

Ultra-thin walled cooling tubes for heat exchangers and condenser units have applications in multiple high-value manufacturing industries. Grade 2 commercially pure titanium (CP-2 Ti) requires far less mass to achieve the same mass flow handling abilities as stainless steel tubing yet it is more challenging to join, particularly at wall thicknesses less than 500 μm (termed ultra-thin walled tube). This paper presents a single-pass joinery method that produces reliable welds on 2.275 mm outer diameter (OD), 160 ± 10 μm wall thickness tubing with a service life of 20 of more years. This is achieved through an automated orbital gas tungsten constricted arc welding (GTCAW) process incorporating enveloping low-mass sleeves used in tandem with a buttressing internal gas pressure to support the molten metal and maintain consistent internal diameter inside the tube. The industrial applicability is demonstrated through the production of a 1:1 scale mock-up of a fixed geometry CO2 cooling circuit for a next-generation particle detector. The tensile strengths of the joints, 403.8 ± 4.2 MPa, exceed the tensile strength of the parent CP-2 Ti.
Study of Biomass Management Systems for Agricultural Lands without Fuel and Friendly Environment in West Kalimantan
Authors: Hatta M , Sulakhudin
Published: June 2020

Almost every year in the dry season in West Kalimantan and other regions in Indonesia there are forest and land fires. The prolonged impact of El Nino has resulted in hundreds of thousands of hectares of land being burnt Human health, destruction of plant and animal genetic resources, and huge economic losses. Therefore, it is necessary to open and manage land without burning and environmentally friendly. These methods include the biomanagement system, namely the management of land resources by utilizing biodecomposers and human resource management by engineering institutions. Management of land resources by making a pile of grooves and decomposing biomass. This method in clearing and processing without burning the land but by arranging the trunks, branches and leaves of the remaining felling trees (biomass) into the trenches and then the biomass is decay using decomposers. The land can then be processed and ready to be planted with agricultural commodities such as rice, corn, soybeans, vegetables, and others. Human resource management by engineering institutions such as farmer groups or farmer group combinations, fire care communities and fire prepared communities play an active role in land clearing and land management without burning biomass. The results of the study showed that clearing paddy fields without burning biomass produced 5.7 tons of dry milled unhulled rice ha−1 and 5.8 t ha−1 of dry shelled corn.
High Adsorption Capacity of Activated Carbon from Rubber Seed Shells on Tofu (Soybean Whey) Wastewater
Authors: Irawan C , Yuniar S , Khotimah H , Nata IF , Putra MD
Published: June 2020

Rubber seed shells are the wastes of rubber plants containing active compounds in the form of lignin, so that this part is quite potential to be processed into activated carbon products. Activated carbon is a material that contains amorphous carbon which has an internal surface that has a high adsorption capacity and is often used as an adsorbent. This study aims to determine the effect of the size of the adsorbent, the adsorbent dose and the modified adsorbent from rubber shells on the adsorption process of BOD, COD and TSS in tofu (soybean whey) wastewater. Batch experimental adsorption using magnetic stirrer with a speed of 100 rpm during 6 hours, pHe of 7,5 ± p 0.2 and room temperature showed the optimum dosage adsorbent were 10 g/L, 355 microns particle size, resulting in decrease in the concentration and levels of COD parameters from 8,287 mg/L to 504 mg/L and 93.92% percentage removal; BOD parameters from 1,300 mg/L to 109 mg/L and 91.61% percentage removal; and TSS from 382 mg/L to 95 mg/L and 75.13% percentage removal, respectively. Therefore, the adsorbent from rubber seed shells has a potential to be used as an adsorbent for water and wastewater treatment.
In Vitro and In Silico Characterization of Antimalarial Myristicyl Propanoate
Authors: Mustikasari Kamilia , Eka Harap Joshua , Cahaya Noor
Published: June 2020

Myristicyl propanoate is an ester derived from myristicin, the most aromatic compound of Nutmeg (Myristica fragrans) which has been successfully synthesized. The myristicyl propanoate compound in this study was characterized in terms of its antimalarial activity in vitro and in silico using P. falciparum and molecular docking studies of the Dihydrofolate Reductases-Thymidylate Synthase(DHFR-TS) enzyme, respectively. IC50 value of myristicylpropanoate as 751.96 μg mL−1, while the binding energy value of ΔG myristicyl propanoate ligand with receptors was -5.44 kcal mole−1 and the value of inhibition constant (Ki) was 103509 nM. Hydrogen bonding between the test ligand with the DHFTR-TS enzyme occured in one amino acid residue TRP48, and the π bond was observed in the amino acid residue PHE58. In addition, hydrophobic bonds occured in several amino acid residues such as THR185, TRY57, CYS15, ILE, ILE14, TYR170, ASP54, MET55, ALA16, LEU46. The results of characterization in vitro and in silico of the myristicyl propanoate compounds showed that the compounds are inactive as an antimalarial.
Assessment of land evaluation on erosion reduction with Agroforestry approach around Lake Ngade area
Authors: Shadikin Nurdin Aqshan , Kurniawan Andy , Hadun Ramli
Published: June 2020

Ngade Lake is surrounded by steep cliffs with a very high level of erosion insecurity with a very steep slope > 45% without sloping edges and no outlets. In the upstream region the water catchment area of Ngade Lake is dominated by land use in the form of coconut and nutmeg plantations. This study aims to examine the form of land evaluation strategy to maintain forest function from erosion threat in the area of Ngade Lake water catchment with agroforestry management pattern. The method used in this research was a quantitative descriptive method using field surveys to collect data on the characteristics of the land that is assisted by secondary data from various literature. The collection of land characteristics data was done at each observation point. To collect the primary data used sampling techniques carried out with stratified random sampling method considering accessibility of roads. The results of the study showed that there were several classes of land capacity. Among them were Class II with high potential of land so it can be cultivated for agriculture and settlements. Land capacity Class VI and VII with low-potential land or difficult to be cultivated for agriculture, this land capacity class intended for forestry plants and grazing fields.
The effect of thermostatic test environment on the flexural fatigue performance of hydraulic hose assemblies
Authors: Patil Sandip , Bagade Rutuja , Tamboli Javedkhan
Published: June 2020

The present study investigates the effect of thermostatic subzero (−65°F) and high ambient temperature (+275°F) on the hose performance when tested at a flexing frequency of 70 CPM with an amplitude of ±3.5 inches. The investigation was carried out through hose tear down analysis which includes surface and subsurface deformations at crimp zone, wire braid analysis, over the crimp silicon crack propagation, and microhardness measurements. It was observed that the flexing mechanism of hose when combined with thermostatic subzero and high ambient temperature, it contributes to different deformation mechanisms for the hose and the fitting juncture.
Modification of 4-Stroke S.I. Engine to a Compressed Air Engine for a Light Utility Vehicle
Authors: Yadav Vishal , Pujari Prashant Chandra , Kumar Naveen
Published: June 2020

The paper presents experimental investigation of a 100-cc four-stroke air-cooled SI engine modified to be driven by compressed air. The engine was modified from a conventional four-stroke to a two-stroke engine by designing a new cam system driven by the crankshaft. Variations in pressure were noted and the engine was tested at different engine speeds and inlet pressure for analyzing several performance parameters such as torque, efficiency and power output. This technology has a long way to go, but for light utility vehicles it can be the game changer. It can trim down our current demand for fossil fuels to some extent and alleviate the problem of global fuel crisis. The major intent of this study is to explore the compressed air engine technology and its viability as a transportation option by enhancing various performance parameters.
Thermal Cracking of Karanja de-oiled seed cake on Pyrolysis Reactor for producing Bio-oil with focus on its application in diesel Engine
Authors: Singh Chandra Shekhar , Kumar Naveen , Gautam Raghvendra
Published: June 2020

A thermal cracking experiment was conducted on Karanja seed (de-oiled) cake at to determine its potential to be an automotive fuel. Experiment was conducted on a fluidised bed type Pyrolysis reactor. The production parameter such as particle size of de-oiled seed and temperature on the oil yield were studied. Fluidization was achieved with the help of Nitrogen gas that is why Nitrogen gas flow rate was also considered as production parameter. For the study purpose a particular particle size range were used. Similarly the Temperature and Flow rate of Nitrogen range were selected from the initial run data of experiment. After investigating the test data the optimized parameter were found for 65.56 wt % of bio oil. The temperature was 500°C and the particle size was in the range of 0.50-0.99 mm at sweep gas flow rate about 8 LPM for the optimized condition. The pyrolysis oil obtained after condensation can be used as fuel. And by some up-gradation technique like trans-esterification process, bio oil can be made suitable for the today’s engine technology. Non condensable gases were consisting of Hydrogen, Methane, Carbon Dioxide, Carbon Monoxide, Oxygen and Nitrogen as major fractions.
Effect of Process Parameters on Hardness of AA-6063 In-Situ Microwave Casting by Using Taguchi Method
Authors: Gangwar Vaibhav , Kumar Sudhir , Singh Vikram , Singh Hari
Published: June 2020

In-situ microwave casting is one of the recently developed advanced metal casting techniques in which the bulk metal and mould assembly are exposed to microwave radiations at 2.45 GHz. In in-situ microwave casting, the exposure and self-pouring is done inside the microwave. The cast quality that has been casted through the microwave casting process is directly dependent on the process parameters that are selected during the process. This paper explores the effect of process parameters on hardness of AA-6063 by using microwave hybrid heating technique. Apply Taguchi L9 orthogonal array to conduct the experimentations. Here consider three process parameters: solidification environment, susceptor material and microwave power.
A review on cold flow properties of biodiesel and their improvement
Authors: Yadav Khushbu , Kumar Naveen , Chaudhary Rajiv
Published: June 2020

The depletion of petroleum derivatives and expanded contamination caused by the consuming of fossil fuel is a driving component to consider the renewable source. Biodiesel is considered as most promising fuel to use in diesel engines. Biodiesel obtains from animal fats, Straight vegetable oils and waste by transesterification and esterification process. The properties of biodiesel oil meet the requirement of fuels and it can build a huge positive impact on pollution and make the fuel eco-friendly. Biodiesel with its points of interest undergoes a notable downside in the low-temperature properties. Due to inferior low-temperature properties of biodiesel, fuel crystallization and gum formation occur at low-temperature which leads to stopping of channels and tubes. It indicated higher pour point and cloud point, higher nitrogen oxide (NOx) which cuts down engine speed and power, injector coking. The present study review is done on low-temperature properties and Impact of different actions taken to improve these properties.
A comprehensive review on performance, combustion and emission characteristics of diesel/biodiesel/alcohols and their blends
Authors: Mishra Dushyant , Kumar Naveen , Chaudhary Rajiv
Published: June 2020

In the current scenario as governments are facing the issue of environmental depletion. The main cause of this depletion is emission by the transport sector. The heavy-duty vehicles mainly depend on diesel (a hydrocarbon fuel). This review paper shares information regarding the alternative sources of diesel for a compression ignition engine. For reduction in emission content researchers made great efforts but proportionally the number of vehicles continuously increases. In this field the binary and ternary fuel are gratefully used in such engine. The alcohols family help to make such blends where considerably results being achieved. The binary fuels have its own impacts on environment during the combustion inside the engine. It found that the less number of works done in field of quaternary blends. Some special features being required to accept such blends. These factors include viscosity, lubricity, and stability and material compatibility. Further work is required in acceptable blended fuel characteristics to ensure the long term effects on engine workability.
A Review on the selection of the variant Water in Concreting
Authors: Gupta Nakul , Shukla Ashish , Gupta Ankur , Goel Rajesh , Singh Vikram
Published: June 2020

According to the global agencies of world health organization, world metrological organization and UNICEF, the utilization of fresh water goes on enlarging from twenty century due to overpopulation and frequent implementation of safe accessible water in relative fields, diminishing the quantity and quality available which ultimately causes gap between ecology and environment for livable water. In our construction industry, this safe water can be saved to a large extent by just interchanging this water by various water available viz. seawater, waste water, sewage water and waste wash water based on literature data and studies which show normal and insignificant changes in the strength of cement hardened concrete. This literature based study will provide the base for adoption of waste water a as source in the construction field for preparing the formwork and a small donation towards national water saving programs launched by government of India.
Shear resistance of hybrid steel and basalt fiber reinforced concrete
Authors: Pal Shilpa , Singh Kartik
Published: June 2020

The study aimed at investigating the mechanical properties and shear resistance of hybrid steel and basalt fiber reinforced M-25 grade of concrete. Crimped steel fibers with chopped basalt fiber have been used with varying (0.25%, 0.5%, 0.75%, and 1%) percentage volumetric ratio of concrete. The results indicated that crimped steel fiber performs better under compressive loading and chopped basalt fiber performs better under tensile loading. The beams are observed to fail in shear with majority of cracks developed near the support and some cracks were developed in middle third portion of beam with varying fiber dosage. Beam with 0.75S0.25B hybrid fiber performs and found 29% cheaper than the conventional beam with stirrups.
TVCCCS: Television Viewer’s Channel Cost Calculation System On Per Second Usage
Authors: Dixit Ashutosh , Garg Puneet , Sethi Preeti , Singh Yashpal
Published: June 2020

This invention is very useful the our country as well as society ‘Television viewers channel cost calculation system (TVCCCS)’ monitors users channel watching time in seconds and charged according to channel usage. TVCCCS is specifically defined to give benefit of various broadcasting channels. User will be charged as per their usage on viewing every channel every day per second basis. This has been done with the help of a programming card mounted inside the set top box of the viewers. Which calculates amount of time in seconds of every channel which user views every day and converted to the total amount at last of the month or a day timer is fixed to count amount of time in seconds. This amount is deducted from the main balance which is initial recharge of the user. This will continue till end of main balance. Also this calculated amount will be sent to the Channel Transmission Company and end user through internet or IOT kit or mobile chip placed inside the set top box. Because of which two way communications has been done. Also this whole remaining amount or charged amount summary displayed on the television screen to view in the message folder. So that user will come to know when to recharge for next time. Proposed technology provides one more facility which defines; user can be able to select channels as per user demand or use rather than company channel packages. User can select the channel through their registration id and will be informed to the Channel broadcasting Company, this user data stored in the company’s database. This information next forwarded to broadcasting satellite which will broadcast only selected channels. Proposed system also focuses on activation and de-activation of selected channel. When User views any channel that time that channel will be activated and other channels are de-activated. This is also done with the help of broadcasting Channel Company and satellite. Satellite will broadcast only selected channel at that time to that particular user according to transmission company guide. TVCCCS will be used for the common people to get rid of from unnecessary and extra amount of charges from various channel broadcasting companies.
Production Process Smoothening and Elimination of Bottleneck
Authors: Kumar Lalit , Pooja  , Kumar Pradeep
Published: June 2020

Efficiency of production line plays an important role in growth of manufacturing industry. We have to utilize our available resources. Manpower utilization and machine efficiency are the main contributing factor in line efficiency. Manpower utilization and machine efficacy measurement method should be accurate. There should be transparency with the higher management for looking for the production data so that they can easily find out fault and take immediate action on that fault for improvement of efficiency. A feedback method also used for checking the accurate solution implementation and ensuring that problem resolved.
Synthesis and Characterization of Hydrophilic Mixed Matrix Polymeric Membrane
Authors: Dey Subhadeepa , Adhikary Utpal , Mandal Tamal , Halder Gopinath , Sikder Jaya
Published: June 2020

Polyvinylidene fluoride (PVDF) was modified by functionalized polymethyl methacrylate (PMMA) andpolyvinyl alcohol (PVA) for synthesizing a tailor-made hydrophilic and antifouling membrane via phase inversion technique. The polymer blends were made by doping different compositions of PVDF and PVA in an organic solvent, NMP. The functionalization of PMMA by Hexamethylene diamine (HMDA) was characterized by Fourier Transformed Infrared Spectroscopy (FTIR). Porosity and water content test validated the increase in wettability of the mixed matrix membrane. Further study is being done to analyze morphological characteristics of the membrane.
Study of the Attenuation Force Generated by a Magnetorheological Fluid in Industrial Robot Grippers Shock Absorbers
Authors: Carlos Valencia Salinas Juan , Alejandro Jumbo Auquilla Diego , Singana Marco , Donoso Caterine
Published: June 2020

The attenuation force generated by the use of magnetorheological fluid (FMR) during the expansion and compression of the shock absorber in robot grippers has been studied. The shock absorber has a stroke of 25 mm and a volume of 4 071.50 mm3in which the FMR made up of ferric micro-particles and nanoparticles is housed; this fluid modifies its rheological properties when exposed to a magnetic field of variable intensity generated by an electromagnet. The intensity of the magnetic field is gradually varied in order to obtain an attenuated and controlled dynamic force in the dissipation of energy. The research includes an analysis of magnetic field generation with the purpose that the particles of the fluid are aligned according to the polarity of the flow lines, thus forming a fibrillary structure chained in a few milliseconds. This magnetic field modifies the viscosity of the fluid, taking it from a low viscosity to a higher density state without altering its chemical composition and shape. The results are reflected in the direct correlation and in the obtaining of data where the saturation of the fluid is given to a maximum intensity of magnetic flux (B) of 0.01 Tesla; and a damping force of 6, 12 Newtons. This concludes that the theoretical and experimental analysis of attenuation in FMR based buffers serve to mitigate impact excitations, in order to provide a buffered velocity of motion.
Identification of Unbalance in Rotating Machinery Using Vibration Analyse Solution
Authors: Vinh Dang Phuoc , Toan Do Le Hung , Thanh Vo Nhu , Nghi Ngo Thanh , Nam Le Hoai
Published: June 2020

Vibrations in rotating machinery are normally the consequence of mechanical faults such as mass unbalance, manufacturing, mechanical looseness, assembly, installed machines, coupling misalignment, and many other causes. However, unbalance is the most popular reason of machine vibration. An unbalanced rotor always causes more vibration and generates excessive force in the bearing area and reduces the life of the machine. In this paper, experimental studies were performed on a rotor with two mounted disks to identify the unbalance in rotor using order tracking technique based on one key phasor. After calculation of the coefficients of influence α of each experimental test, the matrix of influence coefficient [C] and the global matrix of coefficients [H] can be obtained. Finally, the two suitable masses are identified in order to reduce the unbalance of the rotor systems.
Zeros of a one-parameter family of harmonic trinomials
Authors: Brilleslyper Michael , Brooks Jennifer , Dorff Michael , Howell Russell , Schaubroeck Lisbeth
Published: June 2020

It is well known that complex harmonic polynomials of degreennmay have more thannnzeros. In this paper, we examine a one-parameter family of harmonic trinomials and determine how the number of zeros depends on the parameter. Our proof heavily utilizes the Argument Principle for Harmonic Functions and involves finding the winding numbers about the origin for a family of hypocycloids.
An optimal plank theorem
Authors: Ortega-Moreno Oscar
Published: June 2020

We give a new proof of Fejes Tóth’s zone conjecture: for any sequence

v
1

,

v
2

,
…
,

v
n

v_1,v_2,\dots ,v_n

of unit vectors in a real Hilbert space

H

\mathcal {H}

, there exists a unit vector

v
v

in

H

\mathcal {H}

such that

|

⟨

v
k

,
v
⟩

|

≥
sin
⁡
(
π

/

2
n
)

\begin{equation*} |\langle v_k,v \rangle | \geq \sin (\pi /2n) \end{equation*}

for all

k
k

. This can be seen as a sharp version of the plank theorem for real Hilbert spaces. Our approach is inspired by Ball’s solution to the complex plank problem and thus unifies both the complex and the real solution under the same method.
Phosphatidylinositol 4-kinase III beta regulates cell shape, migration, and focal adhesion number
Authors: Bilodeau Patricia , Jacobsen Daniel , Law-Vinh Denise , Lee Jonathan M.
Published: June 2020

This work describes a role for the lipid phosphatidylinositol 4-phosphate (PI4P) and lipid kinase phosphatidylinositol 4-kinase III beta (PI4KIIIβ) in cell motility, cell shape, and focal adhesion (FA) formation. During fibroblast migration, PI4P vesicles move to the leading edge and fuse with FA there. Deletion of PI4KIIIB impairs fibroblast migration, increases the number of FA, and alters cell shape.
Neuropsychological Test Performance Among Native and Non-Native Swedes: Second Language Effects
Authors: Stålhammar Jacob , Hellström Per , Eckerström Carl , Wallin Anders
Published: June 2020

Objective

We aimed to study second language effects on neuropsychological (NP) test performance.

Method

We administered an NP test battery in Swedish to 322 healthy community dwelling participants, recruited through the Gothenburg Pilot phase of the Swedish CArdioPulmonary BioImage Study (SCAPIS Pilot). All participants were conversationally fluent Swedish speakers (237 native, 85 non-native, mean age 61.1 years). We compared the NP scores of native and non-native participants. We also investigated the influence of (a) age of arrival to Sweden, (b) majority language family of the birth country, and (c) proficiency in Swedish as assessed with a 30 item Boston naming test (BNT).

Results

Native speakers obtained better results on all NP tasks with a verbal component, whereas no significant differences were seen on completely nonverbal tasks (Rey complex figure). For non-native speakers, lower age at arrival to Sweden, arrival from a country where Swedish was also spoken, or arrival from a country with a majority language closer to Swedish, were all linked to better NP scores. Dichotomizing by BNT showed that normally-to-highly proficient non-native speakers obtained better scores.

Conclusions

Second language effects may contribute to misclassification of non-native speakers. Assumptions of fluency based on short conversations may be misleading. A proficiency assessment with BNT may improve NP score interpretation among non-native speakers.
Tranexamic Acid in Aesthetic Facial Plastic Surgery: A Systematic Review of Evidence, Applications, and Outcomes
Authors: Locketz Garrett D , Lozada Kirkland N , Bloom Jason D
Published: June 2020

Background

Tranexamic acid (TXA) is an antifibrinolytic that has become widely used in aesthetic facial plastic surgery, although its efficacy has not been well investigated.

Objectives

To evaluate the existing evidence for use of TXA in aesthetic facial plastic surgery, highlighting routes of administration, dosing, surgical applications, and clinical outcomes.

Methods

Systematic review of primary literature evaluating TXA in aesthetic facial plastic surgery.

Results

Eleven studies met inclusion criteria: 8 prospective randomized controlled trials, 2 retrospective case series/cohort studies, and 1 clinical opinion. Six studies evaluated TXA in rhinoplasty, 4 in rhytidectomy, and 1 in blepharoplasty. Significant reductions in intraoperative blood loss were found in 5 rhinoplasty studies. Three rhinoplasty and 2 rhytidectomy studies found significantly reduced postoperative edema and ecchymosis. One rhinoplasty and 1 rhytidectomy study reported reduced operative time and time to achieve hemostasis. One rhytidectomy study reported reduced postoperative drain output and faster time to drain removal. No studies reported an adverse outcome directly related to TXA.

Conclusions

Existing literature investigating TXA in aesthetic facial plastic surgery is sparse with varying levels of evidence and heterogeneous data. Literature suggests systemic TXA reduces intraoperative blood loss during rhinoplasty, although the clinical significance of this blood loss reduction is unclear. TXA may also reduce postoperative edema and/or ecchymosis in rhytidectomy and rhinoplasty, although the lack of validated grading scales yields insufficient evidence to support this claim. Topical and subcutaneously injected TXA are emerging administration routes in rhytidectomy, with evidence suggesting TXA mixed with tumescent may reduce postoperative drain output, thereby expediting drain removal.

Level of Evidence: 2
How Well Does TSTin3D Predict Risk of Active Tuberculosis in the Canadian Immigrant Population? An External Validation Study
Authors: Puyat Joseph H , Shulha Hennady P , Balshaw Robert , Campbell Jonathon R , Law Stephanie , Menzies Richard , Johnston James C
Published: June 2020

Background

The online Tuberculin Skin Test/Interferon Gamma Release Assay (TST/IGRA) Interpreter V3.0 (TSTin3D), a tool for estimating the risk of active tuberculosis (TB) in individuals with latent TB infection (LTBI), has been in use for more than a decade, but its predictive performance has never been evaluated.

Methods

People with a positive TST or IGRA result from 1985 to 2015 were identified using a health data linkage that involved migrants to British Columbia, Canada. Comorbid conditions at the time of LTBI testing were identified from physician claims, hospitalizations, vital statistics, outpatient prescriptions, and kidney and HIV databases. The risk of developing active TB within 2 and 5 years was estimated using TSTin3D. The discrimination and calibration of these estimates were evaluated.

Results

A total of 37 163 individuals met study inclusion criteria; 10.4% were tested by IGRA. Generally, the TSTin3D algorithm assigned higher risks to demographic and clinical groups known to have higher active TB risks. Concordance estimates ranged from 0.66 to 0.68 in 2- and 5-year time frames. Comparing predicted to observed counts suggests that TSTin3D overestimates active TB risks and that overestimation increases over time (with relative bias of 3% and 12% in 2- and 5-year periods, respectively). Calibration plots also suggest that overestimation increases toward the upper end of the risk spectrum.

Conclusions

TSTin3D can discriminate adequately between people who developed and did not develop active TB in this linked database of migrants with predominately positive skin tests. Further work is needed to improve TSTin3D’s calibration.
Tony Lawson and the history of economic thought
Authors: Lourenço Diogo , Graça Moura Mário
Published: June 2020

Tony Lawson’s writings, including those in the history of economics, have an ontological orientation. Several scholars influenced by him likewise practice an ontologically oriented history of economic thought. However, the programme for this sort of history has not been explicitly articulated. In the present paper, we argue that Lawson’s The nature of heterodox economics contains implicitly an ontologically oriented programme in the history of economic thought. We also illustrate the achievements of this programme by reviewing the writings on the later Austrians by Lawson and his associates. Finally, we assess the programme and its achievements in the light of Lawson’s comments on the importance of doing social-scientific ontology and doing history of economic thought.
Epigenetic biomarkers and preterm birth
Authors: Park Bongsoo , Khanam Rasheda , Vinayachandran Vinesh , Baqui Abdullah H , London Stephanie J , Biswal Shyam
Published: June 2020

Preterm birth (PTB) is a major public health challenge, and novel, sensitive approaches to predict PTB are still evolving. Epigenomic markers are being explored as biomarkers of PTB because of their molecular stability compared to gene expression. This approach is also relatively new compared to gene-based diagnostics, which relies on mutations or single nucleotide polymorphisms. The fundamental principle of epigenome diagnostics is that epigenetic reprogramming in the target tissue (e.g. placental tissue) might be captured by more accessible surrogate tissue (e.g. blood) using biochemical epigenome assays on circulating DNA that incorporate methylation, histone modifications, nucleosome positioning, and/or chromatin accessibility. Epigenomic-based biomarkers may hold great potential for early identification of the majority of PTBs that are not associated with genetic variants or mutations. In this review, we discuss recent advances made in the development of epigenome assays focusing on its potential exploration for association and prediction of PTB. We also summarize population-level cohort studies conducted in the USA and globally that provide opportunities for genetic and epigenetic marker development for PTB. In addition, we summarize publicly available epigenome resources and published PTB studies. We particularly focus on ongoing genome-wide DNA methylation and epigenome-wide association studies. Finally, we review the limitations of current research, the importance of establishing a comprehensive biobank, and possible directions for future studies in identifying effective epigenome biomarkers to enhance health outcomes for pregnant women at risk of PTB and their infants.
Prognostic value of dipyridamole stress perfusion cardiovascular magnetic resonance in elderly patients >75 years with suspected coronary artery disease
Authors: Pezel Théo , Sanguineti Francesca , Kinnel Marine , Hovasse Thomas , Garot Philippe , Unterseeh Thierry , Champagne Stéphane , Louvard Yves , Morice Marie Claude , Garot Jérôme
Published: June 2020

Aims 

There are only very few data on the prognostic value of stress cardiovascular magnetic resonance (CMR) in elderly people, while life expectancy of the general population is steadily increasing. Therefore, this study aims to assess the prognostic value of vasodilator stress perfusion CMR in elderly >75 years.

Methods and results 

Between 2008 and 2017, we included consecutive elderly >75 years without known coronary artery disease (CAD) referred for dipyridamole stress CMR. They were followed for the occurrence of major adverse cardiovascular events (MACE) including cardiac death or non-fatal myocardial infarction. Univariate and multivariate analyses were performed to determine the prognostic value of ischaemia or late gadolinium enhancement. Of 754 elderly individuals (82.0 ± 3.9 years, 48.4% men), 659 (87.4%) completed the follow-up with median follow-up of 4.7 years. Using Kaplan–Meier analysis, the presence of myocardial ischaemia was associated with the occurrence of MACE [hazard ratio (HR) 5.38, 95% confidence interval (CI): 3.56–9.56; P < 0.001]. In a multivariable Cox regression including clinical characteristics and CMR indexes, inducible ischaemia was an independent predictor of a higher incidence of MACE (HR 4.44, 95% CI: 2.51–7.86; P < 0.001). In patients without ischaemia, the occurrence of MACE was lower in women when compared with men (P < 0.01).

Conclusion 

Stress CMR is safe and has discriminative prognostic value in elderly, with a significantly lower event rate of future cardiovascular event or death in subjects without ischaemia or infarction.
Cardiac sequelae of novel coronavirus disease 2019 (COVID-19): a clinical case series
Authors: Demertzis Zachary D , Dagher Carina , Malette Kelly M , Fadel Raef A , Bradley Patrick B , Brar Indira , Rabbani Bobak T , Suleyman Geehan
Published: June 2020

Background

COVID-19 caused by severe acute respiratory syndrome coronavirus 2 most commonly manifests with fever and respiratory illness. The cardiovascular manifestations have become more prevalent but can potentially go unrecognized. We look to describe cardiac manifestations in three patients with COVID-19 using cardiac enzymes, electrocardiograms, and echocardiography.

Case summaries

The first patient, a 67-year-old Caucasian female with non-ischaemic dilated cardiomyopathy, presented with dyspnoea on exertion and orthopnoea 1 week after testing positive for COVID-19. Echocardiogram revealed large pericardial effusion with findings consistent with tamponade. A pericardial drain was placed, and fluid studies were consistent with viral pericarditis, treated with colchicine, hydroxychloroquine, and methylprednisolone. Follow-up echocardiograms showed apical hypokinesis, that later resolved, consistent with Takotsubo syndrome. The second patient, a 46-year-old African American male with obesity and type 2 diabetes mellitus presented with fevers, cough, and dyspnoea due to COVID-19. Clinical course was complicated with pulseless electrical activity arrest; he was found to have D-dimer and troponin elevation, and inferior wall ST elevation on ECG concerning for STEMI due to microemboli. The patient succumbed to the illness. The third patient, a 76-year-old African American female with hypertension, presented with diarrhoea, fever, and myalgia, and was found to be COVID-19 positive. Clinical course was complicated, with acute troponin elevation, decreased cardiac index, and severe hypokinesis of the basilar wall suggestive of reverse Takotsubo syndrome. The cardiac index improved after pronation and non-STEMI therapy; however, the patient expired due to worsening respiratory status.

Discussion

These case reports demonstrate cardiovascular manifestations of COVID-19 that required monitoring and urgent intervention.
Non-parental care in childhood and health up to 30 years later: ONS Longitudinal Study 1971–2011
Authors: Murray Emily T , Lacey Rebecca , Maughan Barbara , Sacker Amanda
Published: June 2020

Background

Children who spend time in non-parental care report worse health later in life on average, but less is known about differences by type of care. We examined whether self-rated health of adults who had been in non-parental care up to 30 years later varied by type of care.

Methods

We used longitudinal data from the office for National Statistics Longitudinal Study. Participants were aged <18 and never-married at baseline of each census year from 1971 to 2001. Separately for each follow-up period (10, 20 and 30 years later), multi-level logistic regression was used to compare self-rated health outcomes by different care types.

Results

For combined census years, sample sizes were 157 896 dependent children with 10 years of follow-up, 166 844 with 20 years of follow-up and 173 801 with 30 years of follow-up. For all follow-up cohorts, longitudinal study members who had been in care in childhood, had higher odds of rating their health as ‘not good’ vs. ‘good’; with highest odds for residential care. For example, 10-year follow-up odds ratios were 3.5 (95% confidence interval: 2.2–5.6) for residential care, 2.1 (1.7–2.5) for relative households and 2.6 (2.1–3.3) for non-relative households, compared with parental households after adjustment for childhood demographics. Associations were weakest for 10-year, and strongest for 20-year, follow-up. Additional adjustment for childhood social circumstances reduced, but did not eliminate, associations.

Conclusion

Decades after children and young people are placed in care, they are still more likely to report worse health than children who grew up in a parental household.
Optimal-rate finite-element solution of Dirichlet problems in curved domains with straight-edged tetrahedra
Authors: Ruas Vitoriano
Published: June 2020

In a series of papers published since 2017 the author introduced a simple alternative of the $n$-simplex type, to enhance the accuracy of approximations of second-order boundary value problems subject to Dirichlet boundary conditions, posed on smooth curved domains. This technique is based upon trial functions consisting of piecewise polynomials defined on straight-edged triangular or tetrahedral meshes, interpolating the Dirichlet boundary conditions at points of the true boundary. In contrast, the test functions are defined by the standard degrees of freedom associated with the underlying method for polytopic domains. While the mathematical analysis of the method for Lagrange and Hermite methods for two-dimensional second- and fourth-order problems was carried out in earlier paper by the author this paper is devoted to the study of the three-dimensional case. Well-posedness, uniform stability and optimal a priori error estimates in the energy norm are proved for a tetrahedron-based Lagrange family of finite elements. Novel error estimates in the $L^2$-norm, for the class of problems considered in this work, are also proved. A series of numerical examples illustrates the potential of the new technique. In particular, its superior accuracy at equivalent cost, as compared to the isoparametric technique, is highlighted.
Elevated Expression of Serum Endothelial Cell Adhesion Molecules in COVID-19 Patients
Authors: Tong Ming , Jiang Yu , Xia Da , Xiong Ying , Zheng Qing , Chen Fang , Zou Lianhong , Xiao Wen , Zhu Yimin
Published: June 2020

In a retrospective study of 39 COVID-19 patients and 32 control participants in China, we collected clinical data and examined the expression of endothelial cell adhesion molecules by enzyme-linked immunosorbent assays. Serum levels of fractalkine, vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and vascular adhesion protein-1 (VAP-1) were elevated in patients with mild disease, dramatically elevated in severe cases, and decreased in the convalescence phase. We conclude the increased expression of endothelial cell adhesion molecules is related to COVID-19 disease severity and may contribute to coagulation dysfunction.
Determination of Selected Cathinones in Blood by Solid-Phase Extraction and GC–MS
Authors: Antunes Mónica , Sequeira Margarida , de Caires Pereira Mariana , Caldeira Maria João , Santos Susana , Franco João , Barroso Mário , Gaspar Helena
Published: June 2020

The emergence of potentially dangerous new psychoactive substances (NPS) is challenging for forensic laboratories, as well as the ability to develop and validate methods for a rapid and unambiguous monitoring of these compounds. Thereupon, the aim of this work was to establish a methodology for the identification and quantification of four synthetic cathinones already seized in Portugal [4-chloroethcathinone (4-CEC), α-pyrrolidinovalerophenone (α-PVP), 4-chloro-pyrrolidinovalerophenone (4-Cl-PVP) and methylenedioxypyrovalerone (MDPV)] in whole blood samples, using gas chromatography coupled to mass spectrometry (GC–MS). The analytes were extracted from blood by solid-phase extraction (SPE) and derivatized with N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) with 5% trimethylchlorosilane (TMCS). For all analytes, linearity was observed from 25 (lower limit of quantification, LLOQ) to 800 ng/mL, with coefficients of determination higher than 0.99. The limits of detection (LOD) were 5 ng/mL for α-PVP, 4-Cl-PVP and MDPV and 25 ng/mL for 4-CEC. The method was selective, precise and accurate, and the extraction efficiency was higher than 85% for all analytes. The target cathinones were stable under different stock conditions, being MDPV the most stable and 4-CEC the least stable compound. The validated analytical method was then applied to real samples that previously tested positive for amphetamines, but no positive samples were found for the cathinones under study. The present method describes for the first time the quantification of 4-CEC and 4-Cl-PVP in whole blood samples by GC–MS, allowing their accurate determination in forensic situations where the compounds are involved.