bluuebunny/crossref_metadata_2025 huggingface dataset:
Two-Phase Dynamics and Hysteresis in the PEM Fuel Cell Catalyst Layer with the Lattice-Boltzmann Method
Authors: Grunewald Jonathan B. , Goswami Navneet , Mukherjee Partha P. , Fuller Thomas F.
Published: February 2021

In this work, a Lattice-Boltzmann-Method (LBM) model for simulating hysteresis in a proton exchange membrane fuel cell (PEMFC) electrode is presented. One of the main challenges hindering study of the cathode catalyst layer (CCL) in PEMFCs is the lack of understanding of two-phase transport and how it affects electrochemical performance. Previously, the microstructure details needed to build an accurate mesoscale model to examine such phenomena have eluded researchers; however, with advances in tomography and focused-ion-beam scanning-electron-microscopy (FIB-SEM), reconstruction of the complex porous media has become possible. Using LBM with these representations, the difficult problem of catalyst layer capillary hysteresis can be examined. In two-phase capillary hysteresis, both the equilibrium saturation position as well as its absolute value depends on the wetting history. Based on the models, it is ascertained that at lower capillary numbers, the liquid begins to undergo capillary fingering—only above a capillary pressure of 5 MPa, a regime change into stable displacement is observed. As capillary fingering does not lead to uniform removal of liquid, the prediction is that because high capillary pressures are needed to change to the regime of stable displacement, wicking is not as effective as the primary means of water removal.
High-Current Density Durability of Pt/C and PtCo/C Catalysts at Similar Particle Sizes in PEMFCs
Authors: Ramaswamy Nagappan , Kumaraguru Swami , Gu Wenbin , Kukreja Ratandeep Singh , Yu Kang , Groom Daniel , Ferreira Paulo
Published: February 2021

The durability of carbon supported PtCo-alloy based nanoparticle catalysts play a key role in the longevity of proton-exchange membrane fuel cells (PEMFC) in electric vehicle applications. To improve its durability, it is important to understand and mitigate the various factors that cause PtCo-based cathode catalyst layers (CCL) to lose performance over time. These factors include i) electrochemical surface area (ECSA) loss, ii) specific activity loss, iii) H+/O2-transport changes and iv) Co2+contamination effects. We use a catalyst-specific accelerated stress test (AST) voltage cycling protocol to compare the durability of Pt and PtCo catalysts at similar average nanoparticle size and distribution. Our studies indicate that while Pt and PtCo nanoparticle catalysts suffer from similar magnitudes of electrochemical surface area (ECSA) losses, PtCo catalyst shows a significantly larger cell voltage loss at high current densities upon durability testing. The distinctive factor causing the large cell voltage loss of PtCo catalyst appears to be the secondary effects of the leached Co2+cations that contaminate the electrode ionomer. A 1D performance model has been used to quantify the cell voltage losses arising from various factors causing degradation of the membrane electrode assembly (MEA).
Editors’ Choice—Ionomer Side Chain Length and Equivalent Weight Impact on High Current Density Transport Resistances in PEMFC Cathodes
Authors: Ramaswamy Nagappan , Kumaraguru Swami , Koestner Roland , Fuller Timothy , Gu Wenbin , Kariuki Nancy , Myers Deborah , Dudenas Peter J. , Kusoglu Ahmet
Published: February 2021

Cell voltage at high current densities (HCD) of an operating proton-exchange membrane fuel cell (PEMFC) suffers from losses due to the local-O2 and bulk-H+ transport resistances in the cathode catalyst layer (CCL). Particularly, the interaction of perfluorosulfonic acid (PFSA) ionomer with the carbon supported platinum catalyst plays a critical role in controlling reactant transport to the active site. In this study, we perform a systematic analysis of the side chain length and equivalent weight (EW) of PFSA ionomers on the CCL transport resistances. Ex situ measurements were carried out to quantify the ionomer characteristics such as the molecular weight, proton conductivity and water uptake. Nanomorphology of ionomers cast as 60–120 nm thin-films is characterized using grazing-incidence X-ray scattering. In situ fuel cell electrochemical diagnostic measurements were carried out to quantify the reactant (H+/O2) transport properties of the CCL. Ionomer EW was found to play a major role with decreasing EW yielding higher proton conductivity and water uptake that led to lower bulk-H+ and local-O2 transport resistances in the CCL. Finally, a 1D-semi-empirical performance model has been developed to quantify the impact of ionomer EW on cell voltage loss factors.
Direct Observation and Quantitative Analysis of Lithium Dendrite Growth by In Situ Transmission Electron Microscopy
Authors: Diaz Megan , Kushima Akihiro
Published: February 2021

In this work, a unique in situ transmission electron microscopy technique (TEM) was developed to evaluate the mechanical stress imposed at the lithium metal and the electrolyte interface during lithium dendrite growth. The method enables a direct observation of the lithium deposition process and the quantification of the mechanical stress associated with the dendritic growth of lithium metal. We successfully observed a nano-sized lithium dendrite nucleation/growth and quantified its pushing force during the process. The transition of the growth mode from a vertical direction to a parallel direction (relative to the solid electrolyte surface) after the compressive stress reached a threshold value was observed. The transition stress was much lower than the yield stress of nano-sized lithium and the stiffness of the solid electrolyte. The fundamental information obtained by this work gives useful insight towards designing a robust solid electrolyte necessary for all-solid-state lithium batteries.
Enhanced endothelial barrier function by monoclonal antibody activation of vascular endothelial cadherin
Authors: Park Ki-Sook , Schecterson Leslayann , Gumbiner Barry M.
Published: February 2021

Excessive vascular permeability is a serious complication of many inflammatory disease conditions. We have developed monoclonal antibodies that inhibit increases in endothelial monolayer permeability induced by several signaling factors by activating VE-cadherin mediated adhesion and stabilizing cell junctions. These antibodies and/or the mechanisms they reveal may lead to important therapeutics to treat vascular leakiness and inflammation.
The Fractional View Analysis of Polytropic Gas, Unsteady Flow System
Authors: Khan Hassan , Islam Saeed , Arif Muhammad
Published: February 2021

Generally, the differential equations of integer order do not properly model various phenomena in different areas of science and engineering as compared to differential equations of fractional order. The fractional-order differential equations provide the useful dynamics of the physical system and thus provide the innovative and effective information about the given physical system. Keeping in view the above properties of fractional calculus, the present article is related to the analytical solution of the time-fractional system of equations which describe the unsteady flow of polytropic gas dynamics. The present method provides the series form solution with easily computable components and a higher rate of convergence towards the targeted problem’s exact solution. The present techniques are straightforward and effective for dealing with the solutions of fractional-order problems. The fractional derivatives are expressed in terms of the Caputo operator. The targeted problems’ solutions are calculated using the Adomian decomposition method and variational iteration methods along with Shehu transformation. In the current procedures, we first applied the Shehu transform to reduce the problems into a more straightforward form and then implemented the decomposition and variational iteration methods to achieve the problems’ comprehensive results. The solution of the nonlinear equations of unsteady flow of a polytropic gas at various fractional orders of the derivative is the core point of the present study. The solution of the proposed fractional model is plotted via two- and three-dimensional graphs. It is investigated that each problem’s solution-graphs are best fitted with each other and with the exact solution. The convergence of fractional-order problems can be observed towards the solution of integer-order problems. Less computational time is the major attraction of the suggested methods. The present work will be considered a useful tool to handle the solution of fractional partial differential equations.
Synthesis of MIL‐53(Fe) Metal‐Organic Framework Material and Its Application as a Catalyst for Fenton‐Type Oxidation of Organic Pollutants
Authors: Dinh Du Pham , Ngoc Hoai Pham
Published: February 2021

The iron (III) benzene dicarboxylate metal‐organic framework material (MIL‐53(Fe)) was synthesized with either the solvent‐thermal or hydrothermal method under different conditions. The influence of the type of solvents, molar ratio of precursors and solvent, temperature, and reaction time on the structure of MIL‐53(Fe) was investigated. The material was characterized by using X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), high‐resolution transmission electron microscopy (HR‐TEM), X‐ray photoelectron spectroscopy (XPS), and N2 adsorption/desorption isotherm. The MIL‐53(Fe) structure formed in N′, N‐dimethylformamide (DMF) and methanol (MeOH) but not in water. In DMF, the molar ratio of precursors and solvent, temperature, and reaction time had a significant effect on the crystal structure of MIL‐53(Fe). Under optimal conditions, MIL‐53(Fe) has high crystallinity and a large specific surface area (SBET = 88.2 m2/g). The obtained MIL‐53(Fe) could serve as a potential heterogeneous catalyst to oxidize phenol (PhN), rhodamine B (RhB), and methylene blue (MtB) in the Fenton‐like reaction system at the different solution pHs.
An Intelligent Fault Diagnosis Method for Transformer Based on IPSO-gcForest
Authors: Liu Kezhen , Wu Shizhe , Luo Zhao , Gongze Zeweiyi , Ma Xianlong , Cao Zhanguo , Li Hejian
Published: February 2021

Transformers are the main equipment for power system operation. Undiagnosed faults in the internal components of the transformer will increase the downtime during operation and cause significant economic losses. Efficient and accurate transformer fault diagnosis is an important part of power grid research, which plays a key role in the safe and stable operation of the power system. Existing traditional transformer fault diagnosis methods have the problems of low accuracy, difficulty in effectively processing fault characteristic information, and superparameters that adversely affect transformer fault diagnosis. In this paper, we propose a transformer fault diagnosis method based on improved particle swarm optimization (IPSO) and multigrained cascade forest (gcForest). Considering the correlation between the characteristic gas dissolved in oil and the type of fault, firstly, the noncode ratios of the characteristic gas dissolved in the oil are determined as the characteristic parameter of the model. Then, the IPSO algorithm is used to iteratively optimize the parameters of the gcForest model and obtain the optimal parameters with the highest diagnostic accuracy. Finally, the diagnosis effect of IPSO-gcForest model under different characteristic parameters and size samples is analyzed by identification experiments and compared with that of various methods. The results show that the diagnostic effect of the model with noncode ratios as the characteristic parameter is better than DGA data, IEC ratios, and Rogers ratios. And the IPSO-gcForest model can effectively improve the accuracy of transformer fault diagnosis, thus verifying the feasibility and effectiveness of the method.
Diversity and Regularity of Periodic Impact Motions of a Mechanical Vibration System with Multiple Rigid Stops
Authors: Yin Fengwei , Luo Guanwei , Wang Xueming
Published: February 2021

The mechanical model of a two‐degree‐of‐freedom vibration system with multiple rigid stops was established, and the effects of the multiple rigid stops to dynamic characteristics of two mass blocks of the system were studied. The judgment conditions and differential equations of motion of the system masses impacting rigid stops were analyzed. Based on the multiparameter and multiobjective collaborative simulation analysis, the correlation between the dynamic characteristics of the vibration system and the model parameters is studied. The basic periodic and subharmonic impact motions are analyzed with emphasis on the influences of dynamical parameters on the mode diversity and the distribution characteristics, and the law of emergence and competition of various periodic impact motions on the parametric plane is revealed. The singular points, the hysteresis transition domains, and the accompanying codimension‐two bifurcations, caused by the irreversibility of the transition between adjacent basic periodic impact motions in the low‐frequency domain, are analyzed. The reasonable parameter matching range, associated with dynamic characteristic optimization of the system, is determined.
Process Monitoring for Gamma Distributed Product under Neutrosophic Statistics Using Resampling Scheme
Authors: Almarashi Abdullah M. , Aslam Muhammad
Published: February 2021

In this article, a repetitive sampling control chart for the gamma distribution under the indeterminate environment has been presented. The control chart coefficients, probability of in-control, probability of out-of-control, and average run lengths have been determined under the assumption of the symmetrical property of the normal distribution using the neutrosophic interval method. The performance of the designed chart has been evaluated using the average run length measurements under different process settings for an indeterminate environment. In-control and out-of-control nature of the proposed chart under different levels of shifts have been described. The comparison of the proposed chart has been made with the existing chart. A real-world example from the healthcare department has been included for the practical application of the proposed chart. It has been observed from the simulation study and real example that the proposed control chart is efficient in quick monitoring of the out-of-control process. It can be concluded that the proposed control chart can be applied effectively in uncertainty.
CDK12 Promotes Cervical Cancer Progression through Enhancing Macrophage Infiltration
Authors: Yang Bikang , Chen Jing , Teng Yincheng
Published: February 2021

Cervical cancer (CC) is a commonly diagnosed and primary consideration of cancer patient death in female reproductive system malignancy. Cyclin-dependent kinase 12 (CDK12), as a transcription-associated CDK, plays important roles in tumor-promoting behaviors, whereas the underlying mechanisms of CDK12 in CC progression are still obscure. In this report, we investigated the role of CDK12 in cervical cancer. The current study identified CDK12 mRNA and protein expression remarkably upregulated in CC patients. Upregulated CDK12 was closely associated with CC progression and poor prognosis. In vitro and in vivo functional experiments showed that knockdown of CDK12 inhibited cancer cell proliferation and colony formation and promoted apoptosis. Further investigations demonstrated that CDK12 regulated the immune microenvironment to facilitate the progression of CC cells by promoting macrophage infiltration. Meanwhile, we first demonstrated that nuclear import of CDK12 is mediated by TNPO1 and might be a new therapeutic target in oncology. Collectively, this study pointed out the potential of CDK12 to serve as a novel therapeutic target in restricting CC proliferation and cell cycle process through promoting macrophage infiltration.
Impact of Prone Position on 12-Lead Electrocardiogram in Healthy Adults: A Comparison Study with Standard Electrocardiogram
Authors: Daralammouri Yunis , Azamtta Murad , Hamayel Hamza , Adas Amro , Sawalmeh Osama , Ismail Yahia , Zyoud Saed H.
Published: February 2021

Background. The standard electrocardiogram (ECG) is commonly performed in the supine posture. It may be difficult to report ECG in a supine posture for those who are unable to adopt the supine posture because of certain circumstances such as acute respiratory distress syndrome—patients who are placed in a prone position for long periods to improve oxygenation. Few data are available on the impact of the prone position on the ECG recording with electrodes on the posterior chest. Examining and analyzing the type and extent of changes observed in the prone ECG in healthy adults have become vitally valuable. Methods. A cross-sectional observational study enrolled forty healthy adults (24 males and 16 females) aged between 18 and 40 years. The ECG was performed in two different body positions, supine and prone. Influence of prone position on the heart rate, mean QRS axis, amplitude, morphology, duration, mean T wave axis and polarity, mean P wave axis, PR, and mean QTc duration was evaluated. Results. The mean heart rate was higher in the prone position (73.2 ± 12.4 bpm) compared with the supine position (69.5 ± 11.5 bpm, p = 0.03). The QRS duration decreased considerably from supine (92.8 ± 12.6 ms) to prone (84.9 ± 11.9 ms,

p
<
0.001

). The mean QRS axis moved to the left in the prone posture (40.5° ± 32°) relative to the supine (49° ± 28°,

p
=
0.015

). The QRS amplitude in the precordial leads was significantly decreased from supine (7.42 ± 3.1 mV) to prone (3.68 ± 1.7 mV,

p
<
0.001

). In addition, changes in the QRS morphology in leads V1–V3 with the appearance of new Q waves were noted. A notable variation in the mean corrected QT (QTc) period with decrease in duration in prone posture ECG (385 ± 64.8) relative to supine (406 ± 18.8,

p
=
0.05

). Conclusions. Prone position ECG resulted in significant changes in healthy adults that should be aware of this as this can affect diagnosis and management strategies. Further studies are needed to investigate the impact of prone position on ECG recording in patients with cardiovascular diseases.
Mechanism of Roadway Floor Heave Controlled by Floor Corner Pile in Deep Roadway under High Horizontal Stress
Authors: Kang Xinchao , Guo Dongming , Lu Zhiying
Published: February 2021

In order to overcome the support difficulty of serious floor heave caused by rock burst, with the floor heave of ventilation roadway in Hegang Xing An Coal Mine as the engineering background, the treatment scheme of the concrete‐filled steel tube corner pile and floor grouting is put forward. Based on the solution of the slip line field under plane strain condition, the mechanical model of the slip‐type floor heave is established, and the formula for calculating the critical failure depth of the roadway floor and the minimum support depth of the corner pile is derived. Through numerical analysis and similar model tests, the deformation and stress distribution of surrounding rock under the support of the corner piles are studied, and the force law of the pile under high horizontal stress is analyzed. The results show that, compared with the floor corner anchor, the floor corner pile + floor grouting support scheme can significantly improve the mechanical properties of the floor rock mass, and the plastic slip line of the floor plate part can be cut by corner piles, which effectively controls the deformation of the floor plate under high horizontal stress; the length and inclination angle of the corner pile have a great influence on the support effect. In the on‐site treatment scheme, 1.1 times the calculated length of pile should be selected. The results of a similar model and field test show that the corner pile is effective in controlling the deformation of roadway floor and two sides.
Casein Kinase 2-Interacting Protein-1 Alleviates High Glucose-Reduced Autophagy, Oxidative Stress, and Apoptosis in Retinal Pigment Epithelial Cells via Activating the p62/KEAP1/NRF2 Signaling Pathway
Authors: Zhao Xia , Wang Jing , Li Pei , Tang Liying , Bai Yuzhi
Published: February 2021

Background. Casein kinase 2-interacting protein-1 (CKIP-1) has been proved to be associated with complications of diabetes. Diabetic retinopathy is a main diabetic complication which usually leads to blindness. The current study aims to investigate the role of CKIP-1 in high glucose-treated retinal pigment epithelial (RPE) cells which is a component of blood-retinal barriers. Methods. The RPE cells, ARPE-19, are treated with high glucose to mimic the diabetic stimulation. CKIP-1 was overexpressed in ARPE-19 cells to evaluate its effects on autophagy, oxidative stress, and apoptosis induced by high glucose treatment, using Western blot, immunofluorescence, and flow cytometry assays, respectively. Results. CKIP-1 was expressed at a lower level in high glucose-treated cells than in normal glucose cells. Overexpression of CKIP-1 enhanced the Nrf2 translocation to the nucleus. Furthermore, high glucose-induced autophagy, oxidative stress, and apoptosis were inhibited after overexpression of CKIP-1. Also, CKIP-1 regulates the p62/Keap1/Nrf2 signaling, which might be the potential mechanism in this model. Conclusion. In conclusion, CKIP-1 may be a potential therapeutic target that protects RPE cells from injury and subsequent diabetic retinopathy induced by high glucose.
Humanoid Lower Limb: Design, Analysis, Observer-Based Fuzzy Adaptive Control and Experiment
Authors: Jiang Feilong , Liu Hao , Chai Daxia
Published: February 2021

With flexibility similar to human muscles, pneumatic artificial muscles (PAMs) are widely used in bionic robots. They have a high power-mass ratio and are only affected by single-acting pneumatic pressure. Some robots are actuated by a pair of PAMs in the form of antagonistic muscles or joints through a parallel mechanism. The pneumatic pressure and length of PAMs should be measured simultaneously for feedback using a pressure transducer and draw-wire displacement sensor. The PAM designed by the FESTO (10 mm diameter) is too small to install a draw-wire displacement sensor coaxially and cannot measure muscle length change directly. To solve this problem, an angular transducer is adopted to measure joint angles as a whole. Then, the inertia of the lower limb is identified, and observer-based fuzzy adaptive control is introduced to combine with integrated control of the angular transducer. The parameters of the fuzzy control are optimized by the Gaussian basis neural network function, and an observer is developed to estimate the unmeasured angular accelerations. Finally, two experiments are conducted to confirm the effectiveness of the method. It is demonstrated that piriformis and musculi obturator internus act as agonistic muscle and antagonistic muscles alternatively, and iliopsoas is mainly responsible for strengthening because of the constant output force. Piriformis has a greater influence on yaw and roll angles, while musculi obturator internus is the one that influences the pitch angle the most. Due to joint friction, the dead zone of the high-speed on-off valve, lag of compressed air in the trachea, and coupling among angles are very difficult to realize precise trajectory tracking of the pitch, yaw, and roll angles simultaneously.
A New Zoning Method of Blasting Vibration Based on Energy Proportion and Its SVM Classification Models
Authors: Wei Haixia , Chen Jinfeng , Zhu Jie , Yang Xiaolin , Chu Huaibao , Liu Xisen
Published: February 2021

The blasting vibration signals show obvious zoning propagation characteristics. Because of not considering the specific influences of geological and topographical conditions, the existing zoning methods of blasting vibration cannot fully describe the internal details of blasting vibration signals. Therefore, a new zoning method of blasting vibration based on energy proportion was proposed in this paper, in which the energy proportion in low, medium, and high frequency bands after multiresolution wavelet analysis is used as the zoning index to distinguish the different characteristics of blasting vibration signals in different zones. Based on the proposed zoning method, 343 sets of measured blasting vibration signals were used to train and test the SVM classification models with four different types of kernel functions. The testing results demonstrate that the zoning method of blasting vibration based on energy proportion has high feasibility, flexibility, and reliability, and the SVM classification models with RBF have higher accuracy than models with other kernel functions in blasting vibration zoning prediction.
Optimization Analysis Method of New Orthotropic Steel Deck Based on Backpropagation Neural Network‐Simulated Annealing Algorithm
Authors: Xu Xiuli , Shi Kewei , Li Xuehong , Li Zhijun , Wang Rengui , Chen Yuwen
Published: February 2021

To study the effects of the fatigue performance due to the major design parameter of the orthotropic steel deck and to obtain a better design parameter, a construction parameter optimization method based on a backpropagation neural network (BPNN) and simulated annealing (SA) algorithm was proposed. First, the finite element (FE) model was established, and the numerical results were validated against available full‐scale fatigue experimental data. Then, by calculating the influence surface of each fatigue detail, the most unfavorable loading position of each fatigue detail was obtained. After that, combined with the data from actual engineering applications, the weight coefficient of each fatigue detail was calculated by an analytic hierarchy process (AHP). Finally, to minimize the comprehensive stress amplitude, a BPNN and SA algorithm were used to optimize the construction parameters, and the optimization results for the conventional weight coefficients were compared with the construction parameters. It can be concluded that compared with the FE method through single‐parameter optimization, the BPNN and SA method can synthetically optimize multiple parameters. In addition, compared with the common weighting coefficients, the weighting coefficients proposed in this paper can be better optimized for vulnerable parts. The optimized fatigue detail stress amplitude is minimized, and the optimization results are reliable. For these reasons, the parameter optimization method presented in this paper can be used for other similar applications.
Finite Element Analysis of Stress on Cross‐Wavy Primary Surface Recuperator Based on Thermal‐Structural Coupling Model
Authors: Gui Xiaohong , Song Xiange , Gong Haiwen , Yao Dianbao , Chen Ruogu , Xu Guang
Published: February 2021

In order to study the stress, strain and deformation of the recuperator, the thermal‐structural coupling finite element analysis model of cross‐wavy primary surface recuperator of gas microturbine was established. The stress of cross‐wavy primary surface recuperator after operation under design conditions was analyzed by finite element method. The reliability of the material selected for the recuperator was verified, and the effects of pressure ratio and gas inlet temperature on stress and displacement of the recuperator were analyzed. The research results show that the maximum stress and strain on the gas outlet side of the recuperator are higher than the maximum stress and strain on the gas inlet side when only pressure is considered, and the result is the opposite when pressure and thermal stress are considered. The air passage of the recuperator deforms to the side of the gas passage, the air passage becomes larger, and the gas passage shrinks. With the increase of pressure ratio between air side and gas side, the maximum stress of recuperator passage also increases. When the pressure ratio increases to 8.4, the strength limit of the heat exchange fin material is reached. When the gas and air outlet temperatures remain unchanged and the thermal ratio decreases, as the gas inlet temperature increases, the maximum stress increases. For every 50 K increase in the gas inlet temperature, the maximum stress of the recuperator increases by about 2.3 MPa. The research results can be used to guide the designing and optimization of recuperator.
Decolonization and Coloniality in Human Development: Neoliberalism, Globalization and Narratives of Indian Youth
Authors: Bhatia Sunil
Published: February 2021

In this article, I argue that globalization is interwoven with colonialism and coloniality and both psychology and human development are shaped by the enduring legacy of Eurocentric colonial knowledge. In particular, I draw on my ethnographic research in Pune, India, to show how the transnational elite, middle- and working-class urban Indian youth are engaging with new practices of globalization. I examine how particular class practices shape youth narratives about globalization and “Indianness” generally, as well as specific stories about their self, identity, and family. This article is organized around three questions: (a) How has Euro-American psychology as a dominant force supported colonization and racialized models of human development? (b) What kind of stories do urban Indian youth from varied classes tell about their identity formation in contexts of neoliberal globalization? (c) How can we create and promote models of human development and psychology that are inclusive of the lives of people who live in the Global South?
ТЕНДЕНЦІЇ ФАРМАКОЕПІДЕМІОЛОГІЇ РЕВМАТОЇДНОГО АРТРИТУ
Authors: Khanyk N. L. , Levytska О. R. , Bilushchak H. I. , Horodetska I. Ya. , Khanyk Т. Ya.
Published: February 2021

Мета роботи. Порівняльний аналіз призначень лікарських засобів (ЛЗ) для фармакотерапії (ФТ) хворих з ревматоїдним артритом (РА) в умовах закладу охорони здоров’я стаціонарного типу (ЗОЗст) у 2009 та 2019 рр. і встановлення впливу чинних медико-технологічних документів на структуру таких призначень.

Матеріали і методи. Об’єктами дослідження були медичні карти і листки лікарських призначень (ЛЛП) 89 та 108 стаціонарних хворих з РА, котрі знаходилися на лікуванні у ревматологічному відділенні комунального некомерційного підприємства «4-а міська клінічна лікарня міста Львова» (КНП «4 МКЛ м. Львова») у 2009 та 2019 рр. відповідно. У роботі використовували методи: інформаційного пошуку, частотного, порівняльного, контент-аналізів, узагальнення даних та кластерного аналізу.

Результати й обговорення. Контент-аналіз ЛЛП дозволив установити, що для ФТ РА використовувались ЛЗ трьох груп: хворобомодифікуючі протиревматичні препарати (ХМПРП), глюкокортикостероїди (ГКС) та нестероїдні протизапальні лікарські засоби (НПЗЛЗ). За досліджуваний період значно зросла частка призначень ХМПРП і знизилася – НПЗЛЗ. Порівняльний аналіз схем призначень ФТ РА засвідчив збільшення частки призначень тих схем лікування, де використовують ХМПРП, що відповідає вимогам чинного клінічного протоколу медичної допомоги хворим з РА. На підставі кластерного аналізу 24 міжнародних непатентованих назв (МНН) ЛЗ за частотою їх призначень виділено три групи ЛЗ. Перша – препарати, які не призначались у 2019 р.; друга – препарати-лідери за призначуваністю; третя – ЛЗ із середнім та низьким рівнем призначуваності.

Висновки. Проведений аналіз призначень ХМПРП, НПЗЛЗ та ГКС для фармакотерапії РА показав вагомий вплив клінічних протоколів на вибір тактики лікування РА. Кластерний аналіз дозволив розбити ЛЗ на групи та визначити найперспективніші ЛЗ для лікування РА.
ОЦІНКА ЕФЕКТИВНОСТІ БОРОТЬБИ З ФАЛЬСИФІКАЦІЄЮ ЛІКАРСЬКИХ ЗАСОБІВ В УКРАЇНІ: ПОГЛЯД ФАХІВЦІВ АПТЕЧНИХ ЗАКЛАДІВ
Authors: Lebed S. O. , Nemchenko A. S. , Pasichnyk M. F.
Published: February 2021

Метою роботи було проведення оцінки ефективності боротьби з фальсифікацією ліків із використанням анкетного опитування фахівців аптечних закладів різних регіонів України.

Матеріали  та  методи  дослідження. Наукові публікації за проблемою фальсифікації ліків, а також аналіз даних анкетування фахівців аптечних закладів різних регіонів України щодо проблем боротьби з фальсифікацією лікарських засобів (ЛЗ). Дослідження проводили з використанням методів анкетного опитування, систематизації та узагальнення.

Результати і обговорення. За результатами анкетного опитування, проведеного на національному рівні (13 областей, що представляють схід, захід, північ, південь та центр України), понад 33% опитуваних відповіли, що частка фальсифікованих лікарських засобів (ФЛЗ) складає від 1% до 5%, що відповідає даним, які наводилися ВООЗ щодо об’єму субстандартних та фальсифікованих лікарських засобів для країн з низьким і середнім рівнем доходу (до 10,5%) [1]. До ознак фальсифікації ЛЗ респонденти найбільше віднесли «Маркування на іноземній мові» (44,85%). Щодо основних каналів збуту ФЛЗ, то понад 75% респондентів назвали інтернет-торгівлю. Стосовно методів та заходів, які слід застосовувати виробникам  та аптечним закладам в боротьбі з фальсифікацією ліків, то такими назвали дотримання стандарту GMP близько 75% опитуваних, в той же час понад 64% очікують від виробників запровадження додаткового захисту упаковок ЛЗ від підробок, зокрема 44% - обов'язковий перехід на маркування 2-d штрих-кодами, а також понад 78% респондентів назвали  закупівлю ЛЗ лише у постачальників, сертифікованих на відповідність GDP.

Висновок. З метою створення ефективної системи боротьби з розповсюдженням фальсифікованих ліків пропонується створення Національної програми боротьби з фальсифікацією ЛЗ, а також розробка практичних рекомендацій для фармацевтичних фахівців щодо виявлення фальсифікованих препаратів і запобігання їх незаконному обігу.
The Emamzadeh Yahya at Varamin: A Present History of a Living Shrine, 2018–20
Authors: Overton Keelan , Maleki Kimia
Published: February 2021

The Emamzadeh Yahya at Varamin, a tomb-shrine located south of Tehran, is well known for supplying global museums with iconic examples of Ilkhanid-period luster tilework. After providing a historiography of the site, including its plunder in the late nineteenth century, we explore its current (2018–20) “life” in order to illuminate the many ways that it can be accessed, used, perceived, and packaged by a wide range of local, national, and global stakeholders. Merging past and present history, art history and amateur anthropology, and the academic, personal, and popular voice, this article explores the Emamzadeh Yahya’s delicate and active existence between historical monument, museum object, sacred space, and cultural heritage.
The Topography of Corporal Relics in Twelver Shiʿism
Authors: Parsapajouh Sepideh
Published: February 2021

Because of the plurality of the venerated figures, the holy places of Twelver Shiʿism are numerous. This paper focuses on places of devotion that are supposed to contain bodily relics and presents them in a schematic framework to discuss the importance of some of these places, and some aspects of their transformations over time. I first identify the sacred figures of Shiʿism and the place or the places (multi-locality of tombs) attributed to each of them. I then move on to a discussion of two things that can seem paradoxical, i.e. the immateriality of the sacred figure, and his/her omnipresence beyond places. My findings are based on field observations and interviews, and on documentary and published sources.
Material Images and Mental Ziyāra: Depicting the Prophet’s Grave in North African Devotional Books (Dalāʾil al-Khayrāt)
Authors: Abid Hiba
Published: February 2021

The Dalāʾil al-Khayrāt (Guidelines to the Blessings) is a very popular book of prayers over the Prophet Muḥammad, originally written around the mid-fifteenth century by Muḥammad b. Sulaymān al-Jazūlī (d. 869/1465). The Dalāʾil is probably the only illustrated religious text in the Maghreb, where the image has been the subject of more profound reluctance than in the rest of the Muslim world. They show the sacred tomb of the Prophet inside the mosque of Medina, as well as his minbar, his miḥrāb and his sandals (naʿl), one of the most venerated relics in Islam. If the images in North African books have been systematically interpreted in a superficial way, this article proposes a reading at the crossroads of art history, codicology and a careful examination of the main text and the precious annotations added by the readers of some unpublished manuscripts. We will then understand that these illustrations have gradually acquired an autonomous place within the book. They act alongside the text, as memorial images of the sacred space hosting the holy body of the Prophet, and as a virtual substitute for the pilgrimage to Medina. It is in fact through this act, be it physical or virtual, that Muslims hope to visualize, in a dream, the figure of their loved one, Muḥammad.
Rediscovery and taxonomic analysis of Romulea melitensis (Iridaceae) from the Maltese islands
Authors: MIFSUD STEPHEN
Published: February 2021

The status of the Maltese endemic Romulea melitensis remained doubtful since its description by Beguinot in 1907, primarily because plants with the morphological characters as referred in the diagnosis have not been substantiated in situ. A sand crocus with the combination of a smallish, dark violet corolla with a yellow throat and perianth segments up to 1.5 mm wide have never been witnessed in the Maltese Islands. A detailed analysis of the protologue and the type of R. melitensis has resulted that when Beguinot examined the 30-year-old exsiccatae, two important characters were misinterpreted, leading to the current ambiguous status of R. melitensis. A detailed account accompanied by specific illustrations and tabulated datasets are given to address this taxonomic misconception. In effect, R. melitensis has wider tepals and the dark colour of the corolla referred in the protologue is exhibited only at the abaxial surface of the tepals in some individuals. Under this adjusted morphological approach, ten populations corresponding to R. melitensis have been found in the Maltese islands, three of which matching completely with the taxon’s lectotype. In addition, morphological, palynological and chorological studies on these populations strongly suggest that R. melitensis is a hybrid between R. columnae and R. variicolor - a Siculo-Maltese endemic species. An identification key to the species of Romulea occurring or reported in the past from the Maltese Islands is supplied in this work.
A new species of Ceroxylon (Arecaceae) from Cordillera Azul National Park – Peru
Authors: VALDIVIA MARÍA ISABEL VILLALBA , GAMARRA LUIS VALENZUELA
Published: February 2021

A new species of Ceroxylon from the Cordillera Azul National Park in Peru is described and illustrated. The main distinguishing feature of the new species, named C. ravenii, is its acaulescent habit. So far, only one population has been recorded at an elevation of 1240 m in the wilderness zone of the protected area.
The new inland Hornschuchia mediterranea (Annonaceae) from Bahia, Brazil
Authors: MELLO-SILVA RENATO , LOPES JENIFER DE CARVALHO , JOHNSON DAVID M.
Published: February 2021

A new species of Hornschuchia (Bocageeae, Annonaceae) is described from seasonal semideciduous forests in the Brazilian state of Bahia. Hornschuchia mediterranea resembles H. lianarum in its solitary, internodal flowers with a deeply cup-shaped calyx. However, H. mediterranea has glabrous and shiny leaves, a sericeous calyx, and free petals that are white in bud, while H. lianarum has coarser and denser pubescence of the leaves and calyx, and connate petals that are orange-cream in bud.
Taxonomic notes on some Cosmarium species (Desmidiaceae, Zygnematophyceae) from Brazil
Authors: RAMOS GERALDO JOSÉ PEIXOTO , SANTOS MARIA APARECIDA DOS , MOURA CARLOS WALLACE DO NASCIMENTO
Published: February 2021

Taxonomic studies on desmids from the Caatinga domain, northeastern Brazil, revealed eight interesting taxa of Cosmarium: C. boeckii var. areolatum, C. clepsydra var. incrassatum, C. heptangulare, C. kanetsunae, C. pygmaeum, C. trinodulum, C. trinodulum var. brasiliense, and C. trinodulum var. pilgeri. Taxonomic notes and information on habitat are provided.
Spiciness Anomalies of Subantarctic Mode Water in the South Indian Ocean
Authors: Nagura Motoki
Published: February 2021

This study investigates spreading and generation of spiciness anomalies of the Subantarctic Mode Water (SAMW) located on 26.6 to 26.8 σθ in the south Indian Ocean, using in situ hydrographic observations, satellite measurements, reanalysis datasets, and numerical model output. The amplitude of spiciness anomalies is about 0.03 psu or 0.13°C and tends to be large along the streamline of the subtropical gyre, whose upstream end is the outcrop region south of Australia. The speed of spreading is comparable to that of the mean current, and it takes about a decade for a spiciness anomaly in the outcrop region to spread into the interior up to Madagascar. In the outcrop region, interannual variability in mixed layer temperature and salinity tends to be density compensating, which indicates that Eulerian temperature or salinity changes account for the generation of isopycnal spiciness anomalies. It is known that wintertime temperature and salinity in the surface mixed layer determine the temperature and salinity relationship of a subducted water mass. Considering this, the mixed layer heat budget in the outcrop region is estimated based on the concept of effective mixed layer depth, the result of which shows the primary contribution from horizontal advection. The contributions from Ekman and geostrophic currents are comparable. Ekman flow advection is caused by zonal wind stress anomalies and the resulting meridional Ekman current anomalies, as is pointed out by a previous study. Geostrophic velocity is decomposed into large-scale and mesoscale variability, both of which significantly contribute to horizontal advection.
Comparison of the ATRIA, CHA2DS2-VASc, and Modified Scores ATRIA-HSV, CHA2DS2-VASc-HS, for the Prediction of Coronary Artery Disease Severity
Authors: Yildirim Arafat , Kucukosmanoglu Mehmet , Yavuz Fethi , Koyunsever Nermin Yildiz , Cekici Yusuf , Dogdus Mustafa , Abacioğlu Özge Özcan , Kilic Salih
Published: February 2021

Many parameters included in the Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) and CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke, vascular disease, age 65-74 years, sex category) scores also predict coronary artery disease (CAD). We modified the ATRIA score (ATRIA-HSV) by adding hyperlipidemia, smoking, and vascular disease and also male sex instead of female. We evaluated whether the CHA2DS2-VASc, CHA2DS2-VASc-HS, ATRIA, and ATRIA-HSV scores predict severe CAD. Consecutive patients with coronary angiography were prospectively included. A ≥50% stenosis in ≥1epicardial coronary artery (CA) was defined as severe CAD. Patient with normal CA (n = 210) were defined as group 1, with <50% CA stenosis (n = 178) as group 2, and with ≥50% stenosis (n = 297) as group 3. The mean ATRIA, ATRIA-HSV, CHA2DS2-VASc, and CHA2DS2VASc-HS scores increased from group 1 to group 3. A correlation was found between the Synergy between PCI with Taxus and Cardiac Surgery score and ATRIA ( r = 0.570), ATRIA-HSV ( r = 0.614), CHA2DS2-VASc ( r = 0.428), and CHA2DS2-VASc-HS ( r = 0.500) scores ( Ps < .005). Pairwise comparisons of receiver operating characteristics curves showed that ATRIA-HSV (>3 area under curve [AUC]: 0.874) and ATRIA (>3, AUC: 0.854) have a better performance than CHA2DS2-VASc (>1, AUC: 0.746) and CHA2DS2-VASc-HS (>2, AUC: 0.769). In conclusion, the ATRIA and ATRIA-HSV scores are simple and may be useful to predict severe CAD.
Recent Studies on Common Ownership, Firm Behavior, and Market Outcomes
Authors: Schmalz Martin C.
Published: February 2021

The literature on competitive effects of common ownership has grown at a fast rate in the past two years. Anticompetitive effects have been confirmed with alternative reduced-form and structural estimation methods, in different industries, geographies, and jurisdictions. Multiple independent studies have disproven early critiques of the literature. Other papers document the heterogeneity of common ownership effects on competition across markets and industries. Important advances were made on the study of the economic mechanisms and governance channels that implement anti-competitive incentives. New theory refines the interpretation of existing empirical work. Access to high-quality ownership and product-market data remains a bottleneck for meaningful research in the area.
Is Differential Noneffortful Responding Associated With Type I Error in Measurement Invariance Testing?
Authors: Rios Joseph A.
Published: February 2021

Low test-taking effort as a validity threat is common when examinees perceive an assessment context to have minimal personal value. Prior research has shown that in such contexts, subgroups may differ in their effort, which raises two concerns when making subgroup mean comparisons. First, it is unclear how differential effort could influence evaluations of scale property equivalence. Second, if attaining full scalar invariance, the degree to which differential effort can bias subgroup mean comparisons is unknown. To address these issues, a simulation study was conducted to examine the influence of differential noneffortful responding (NER) on evaluations of measurement invariance and latent mean comparisons. Results showed that as differential rates of NER grew, increased Type I errors of measurement invariance were observed only at the metric invariance level, while no negative effects were apparent for configural or scalar invariance. When full scalar invariance was correctly attained, differential NER led to bias of mean score comparisons as large as 0.18 standard deviations with a differential NER rate of 7%. These findings suggest that test users should evaluate and document potential differential NER prior to both conducting measurement quality analyses and reporting disaggregated subgroup mean performance.
A Polytomous Scoring Approach to Handle Not-Reached Items in Low-Stakes Assessments
Authors: Gorgun Guher , Bulut Okan
Published: February 2021

In low-stakes assessments, some students may not reach the end of the test and leave some items unanswered due to various reasons (e.g., lack of test-taking motivation, poor time management, and test speededness). Not-reached items are often treated as incorrect or not-administered in the scoring process. However, when the proportion of not-reached items is high, these traditional approaches may yield biased scores and thereby threatening the validity of test results. In this study, we propose a polytomous scoring approach for handling not-reached items and compare its performance with those of the traditional scoring approaches. Real data from a low-stakes math assessment administered to second and third graders were used. The assessment consisted of 40 short-answer items focusing on addition and subtraction. The students were instructed to answer as many items as possible within 5 minutes. Using the traditional scoring approaches, students’ responses for not-reached items were treated as either not-administered or incorrect in the scoring process. With the proposed scoring approach, students’ nonmissing responses were scored polytomously based on how accurately and rapidly they responded to the items to reduce the impact of not-reached items on ability estimation. The traditional and polytomous scoring approaches were compared based on several evaluation criteria, such as model fit indices, test information function, and bias. The results indicated that the polytomous scoring approaches outperformed the traditional approaches. The complete case simulation corroborated our empirical findings that the scoring approach in which nonmissing items were scored polytomously and not-reached items were considered not-administered performed the best. Implications of the polytomous scoring approach for low-stakes assessments were discussed.