bluuebunny/crossref_metadata_2025 huggingface dataset:
Parameters for Calcium Metabolism in Women with Polycystic Ovary Syndrome Who Undergo Stimulation with Letrozole: A Prospective Cohort Study
Authors: Holzer Iris , Parry John Preston , Beitl Klara , Pozderovic Boban , Marculescu Rodrig , Ott Johannes
Published: May 2022

For women with polycystic ovarian syndrome (PCOS) and infertility, stimulation with the aromatase-inhibitor letrozole has been recommended as a first-line for ovulation induction. Calcium-associated signaling has also been a component for other ovulation induction and superovulation medications. This study’s aim was to evaluate parameters of calcium metabolism in PCOS women. In a prospective cohort study, 61 anovulatory, infertile PCOS patients who underwent letrozole stimulation were included. Outcome measures were: follicular maturation after letrozole stimulation; parathyroid hormone (PTH); 25-hydroxyvitamin D3 (25OHD3); serum levels of calcium, phosphorus, magnesium, albumin, and total protein. Successful recruitment of a dominant follicle was achieved in 35 patients (57.4%). Women with and without successful follicular development did not differ in serum levels of PTH (38.4 ± 19.7 vs. 39.6 ± 16.2 pg/mL), 25OHD3 (62.5 ± 32.1 vs. 65.4 ± 30.9 nmol/L), calcium (2.36 ± 0.08 vs. 2.37 ± 0.12 mmol/L), or protein (70.2 ± 13.3 vs. 74.0 ± 3.7 g/L), respectively (p > 0.05). However, women who were not responsive to letrozole for ovulation induction demonstrated higher anti-Müllerian hormone (AMH) levels (9.7 ± 4.7 vs. 5.0 ± 3.2 ng/mL, p = 0.005). In conclusion, the success of letrozole stimulation in women with PCOS is independent from calcium metabolism parameters. However, AMH levels seem predictive of medication resistance.
Potential Therapeutic Effects of Long-Term Stem Cell Administration: Impact on the Gene Profile and Kidney Function of PKD/Mhm (Cy/+) Rats
Authors: Nardozi Daniela , Palumbo Stefania , Khan Arif ul Maula , Sticht Carsten , Bieback Karen , Sadeghi Samar , Kluth Mark Andreas , Keese Michael , Gretz Norbert
Published: May 2022

Cystic kidney disease (CKD) is a heterogeneous group of genetic disorders and one of the most common causes of end-stage renal disease. Here, we investigate the potential effects of long-term human stem cell treatment on kidney function and the gene expression profile of PKD/Mhm (Cy/+) rats. Human adipose-derived stromal cells (ASC) and human skin-derived ABCB5+ stromal cells (2 × 106) were infused intravenously or intraperitoneally monthly, over 6 months. Additionally, ASC and ABCB5+-derived conditioned media were administrated intraperitoneally. The gene expression profile results showed a significant reprogramming of metabolism-related pathways along with downregulation of the cAMP, NF-kB and apoptosis pathways. During the experimental period, we measured the principal renal parameters as well as renal function using an innovative non-invasive transcutaneous device. All together, these analyses show a moderate amelioration of renal function in the ABCB5+ and ASC-treated groups. Additionally, ABCB5+ and ASC-derived conditioned media treatments lead to milder but still promising improvements. Even though further analyses have to be performed, the preliminary results obtained in this study can lay the foundations for a novel therapeutic approach with the application of cell-based therapy in CKD.
Preoperative MRI and Intraoperative Monitoring Differentially Prevent Neurological Sequelae in Idiopathic Scoliosis Surgical Correction, While Curves >70 Degrees Increase the Risk of Neurophysiological Incidences
Authors: Pazarlis Konstantinos , Jonsson Håkan , Karlsson Thomas , Schizas Nikos
Published: May 2022

The aim was to investigate the role of preoperative magnetic resonance imaging (MRI) and intraoperative monitoring (IOM) in the prevention of correction-related complications in idiopathic scoliosis (IS). We conducted a retrospective case study of 129 patients with juvenile and adolescent IS. The operations took place between 2005 and 2018 in Uppsala University Hospital. Data from MRI scans and IOM were collected. The patients were divided into groups depending on Lenke’s classification, sex, major curve (MC) size, and onset age. Neurophysiological incidences were reported in ten patients (7.8%), while nine of them had no signs of intraspinal pathology. Six patients (4.7%) had transient incidences; however, in four patients (3.1%), an intervention was required for the normalization of action potentials. Three of them had an MC >70 degrees, which was significantly higher than the expected value. Eight patients (6.1%) had intraspinal pathologies, and two of them (1.5%) underwent decompression. We suggest the continuation of MRI screening preoperatively and, most importantly, the use of IOM. In three cases with no signs of pathology in the MRI, IOM prevented possible neurological injuries. MCs >70 degrees should be considered a risk factor for the occurrence of neurophysiological deficiencies that require action to be normalized.
The Acute Effects of Attaching Chains to the Barbell on Kinematics and Muscle Activation in Bench Press in Resistance-Trained Men
Authors: van den Tillaar Roland , Saeterbakken Atle Hole , Andersen Vidar
Published: May 2022

The aim of the study was to investigate the acute effects of attaching chains on barbell kinematics and muscle activation in the bench press. Twelve resistance-trained men (height: 1.79 ± 0.05 m, weight: 84.3 ± 13.5 kg, one repetition maximum (1-RM) bench press of 105 ± 17.1 kg) lifted three repetitions of bench press in three conditions: (1) conventional bench press at 85% of 1-RM and bench press with chains that were (2) top-matched and (3) bottom-matched with the resistance from the conventional resistance lift. Barbell kinematics and the muscle activity of eight muscles were measured at different heights during lowering and lifting in the three conditions of the bench press. The main findings were that barbell kinematics were altered using the chains, especially the 85% bottom-matched condition that resulted in lower peak velocities and longer lifting times compared with the conventional 85% condition (p ≤ 0.043). However, muscle activity was mainly only affected during the lowering phase. Based upon the findings, it was concluded that using chains during the bench press alters barbell kinematics, especially when the resistance is matched in the bottom position. Furthermore, muscle activation was only altered during the lowering phase when adding chains to the barbell.
A Standard-Cell-Based CMFB for Fully Synthesizable OTAs
Authors: Centurelli Francesco , Della Sala Riccardo , Scotti Giuseppe
Published: May 2022

In this paper, we propose a fully standard-cell-based common-mode feedback (CMFB) loop with an explicit voltage reference to improve the CMRR of pseudo-differential standard-cell-based amplifiers and to stabilize the dc output voltage. This latter feature allows robust biasing of operational transconductance amplifiers (OTAs) based on a cascade of such stages. A detailed analysis of the CMFB is reported to both provide insight into circuit behavior and to derive useful design guidelines. The proposed CMFB is then exploited to build a fully standard-cell OTA suitable for automatic place and route. Simulation results referring to the standard-cell library of a commercial 130 nm CMOS process illustrated a differential gain of 28.3 dB with a gain-bandwidth product of 15.4 MHz when driving a 1.5 pF load capacitance. The OTA exhibits good robustness under PVT and mismatch variations and achieves state-of-the-art FOMs also thanks to the limited area footprint.
Additive Surface Graining in Prototype Tooling for Injection Molding
Authors: Burggräf Peter , Bergweiler Georg , Abrams Josef Andrew , Dunst Anna
Published: May 2022

Surface properties of injection molded parts have a strong effect on the visual and haptic perception of the parts by customers. Especially for injection molded automotive interior parts, grained surfaces can often be found. In conventional tooling, graining requires separate process steps. This makes the realization of grained injection molded prototype parts very complex. By additive manufacturing of injection molds in prototype tooling, it is possible to print micro structures into the mold surface in one printing operation. An injection mold with four different graining structures varying in depth and distance was designed and additively manufactured. The specification regarding the surface graining was analyzed by means of roughness measurements of the CAD model, injection mold and injection molded parts. Results show the feasibility of highly controllable additive surface graining.
Distribution and Environmental Impact Factors of Picophytoplankton in the Eastern Indian Ocean
Authors: Wang Xingzhou , Wang Feng , Sun Jun
Published: May 2022

Picophytoplankton (pico) in the eastern Indian Ocean (EIO) were investigated during the inter-monsoon periods. They were found to typically comprise Prochlorococcus (Pro), Synechococcus (Syn), and Picoeukaryotes (PEuks). In the survey area, the pico showed two different vertical distribution patterns in different regions, whereby the Syn abundance decreased with depth, whereas those of Pro and PEuks increased and then decreased with depth, with the maximum depths ranging from 50 to 100 m. The cell abundance and community structure of the pico were similar at the equator (EQ) and the eastern boundary of the Indian Ocean near Sumatra (EB), but the pico cell abundance was significantly lower in the Bay of Bengal (BOB). Pro dominated most regions of the entire EIO and were approximately one-to-two orders of magnitude more abundant than Syn and PEuks. The distributions of Syn and PEuks showed little difference across various regions. Influenced by the physicochemistry of circulation and water masses, there were many different environmental factors in the different regions. The abundance of pico domination by Pro showed a strong positive correlation with the nutrients and salinity in the survey area, indicating increasing nutrient availability, particularly in the oligotrophic EIO. Generalized additive models (GAMs) analysis showed the differences in their responses to environmental variability. Pro and PEuks both increased strongly with warming up to below 26 °C, and Pro and PEuks were more responsive to chemical (nutrient) variability. Syn showed a broader tolerance of low-salinity conditions. In a certain range, an increase in nitrite and nitric acid can improve the cell abundance of Pro. As a significant contributor to primary productivity in oligotrophic waters, this study provides essential information for studying pico communities in the EIO and its adjacent marine ecosystems.
Following the Sand Grains
Authors: FitzGerald Duncan M. , Hughes Zoe J. , Staro Alice , Hein Christopher J. , Sakib Md Mohiuddin , Georgiou Ioannis Y. , Novak Alyssa
Published: May 2022

When longshore transport systems encounter tidal inlets, complex mechanisms are involved in bypassing sand to downdrift barriers. Here, this process is examined at Plum Island Sound and Essex Inlets, Massachusetts, USA. One major finding from this study is that sand is transferred along the coast—especially at tidal inlets—by parcels, in discrete steps, and over decadal-scale periods. The southerly orientation of the main-ebb channel at Plum Island Sound, coupled with the landward migration of bars from the ebb delta to the central portion of the downdrift Castle Neck barrier island, have formed a beach protuberance. During the constructional phase, sand is sequestered at the protuberance and the spit-end of the barrier becomes sediment starved, leading to shoreline retreat and a broadening of the spit platform at the mouth to Essex Bay (downdrift side of Castle Neck). Storm-induced sand transport from erosion of the spit and across the spit platform is washed into Essex Bay, filling channels and enlarging flood deltas. This study illustrates the pathways and processes of sand transfer along the shoreline of a barrier-island/tidal-inlet system and provides an important example of the processes that future hydrodynamic and sediment-transport modeling should strive to replicate.
Targeting HIF-1α Function in Cancer through the Chaperone Action of NQO1: Implications of Genetic Diversity of NQO1
Authors: Salido Eduardo , Timson David J. , Betancor-Fernández Isabel , Palomino-Morales Rogelio , Anoz-Carbonell Ernesto , Pacheco-García Juan Luis , Medina Milagros , Pey Angel L.
Published: May 2022

HIF-1α is a master regulator of oxygen homeostasis involved in different stages of cancer development. Thus, HIF-1α inhibition represents an interesting target for anti-cancer therapy. It was recently shown that the HIF-1α interaction with NQO1 inhibits proteasomal degradation of the former, thus suggesting that targeting the stability and/or function of NQO1 could lead to the destabilization of HIF-1α as a therapeutic approach. Since the molecular interactions of NQO1 with HIF-1α are beginning to be unraveled, in this review we discuss: (1) Structure–function relationships of HIF-1α; (2) our current knowledge on the intracellular functions and stability of NQO1; (3) the pharmacological modulation of NQO1 by small ligands regarding function and stability; (4) the potential effects of genetic variability of NQO1 in HIF-1α levels and function; (5) the molecular determinants of NQO1 as a chaperone of many different proteins including cancer-associated factors such as HIF-1α, p53 and p73α. This knowledge is then further discussed in the context of potentially targeting the intracellular stability of HIF-1α by acting on its chaperone, NQO1. This could result in novel anti-cancer therapies, always considering that the substantial genetic variability in NQO1 would likely result in different phenotypic responses among individuals.
FFPE-Based NGS Approaches into Clinical Practice: The Limits of Glory from a Pathologist Viewpoint
Authors: Cappello Filippo , Angerilli Valentina , Munari Giada , Ceccon Carlotta , Sabbadin Marianna , Pagni Fabio , Fusco Nicola , Malapelle Umberto , Fassan Matteo
Published: May 2022

The introduction of next-generation sequencing (NGS) in the molecular diagnostic armamentarium is deeply changing pathology practice and laboratory frameworks. NGS allows for the comprehensive molecular characterization of neoplasms, in order to provide the best treatment to oncologic patients. On the other hand, NGS raises technical issues and poses several challenges in terms of education, infrastructures and costs. The aim of this review is to give an overview of the main NGS sequencing platforms that can be used in current molecular diagnostics and gain insights into the clinical applications of NGS in precision oncology. Hence, we also focus on the preanalytical, analytical and interpretative issues raised by the incorporation of NGS in routine pathology diagnostics.
Introduction to the Special Issue ‘Transnational and Transdisciplinary Lessons of COVID-19 from the Perspective of Risk and Management’
Authors: Cole Alistair , Baker Julien S. , Tran Emilie , Gao Yang
Published: May 2022

Rarely has scientific research been as solicited as in the past two years, as societies struggle to cope with the coronavirus [...]
Climate Insurance for Agriculture in Europe: On the Merits of Smart Contracts and Distributed Ledger Technologies
Authors: Schwarze Reimund , Sushchenko Oleksandr
Published: May 2022

Climate insurance has become a crucial issue due to the increasing number of climate-related catastrophic events and the associated losses for the economy in general and insurance companies in particular. The extremely hot and dry summers of 2018 and 2019 in some European countries highlighted existing weaknesses in European agricultural insurance mechanisms, with farmers having to wait for months before compensation payments could be made. Our paper compares features of yield-based insurance and index-based insurance (IBI) in agriculture in the light of new developments and trends in information technology (IT). The results show that applying Distributed Ledger Technologies (DLT) in combination with IBI could not only resolve existing problems but also facilitate the development of innovative risk management tools under the EU’s Common Agricultural Policy (CAP) post-2020 reform.
Efficacy of Different Cold-Water Immersion Temperatures on Neuromotor Performance in Young Athletes
Authors: Gaspar-Junior Jair J. , Dellagrana Rodolfo A. , Barbosa Fernando S. S. , Anghinoni Ana P. , Taciro Charles , Carregaro Rodrigo L. , Martinez Paula F. , Oliveira-Junior Silvio A.
Published: May 2022

Cold-Water-Immersion (CWI) has been frequently used to accelerate muscle recovery and to improve performance after fatigue onset. In the present study, the aim was to investigate the effects of different CWI temperatures on neuromuscular activity on quadriceps after acute fatigue protocol. Thirty-six young athletes (16.9 ± 1.4 years-old; 72.1 ± 13.8 kg; 178.4 ± 7.2 cm) were divided into three groups: passive recovery group (PRG); CWI at 5 °C group (5G); and CWI at 10 °C group (10G). All participants performed a fatigue exercise protocol; afterwards, PRG performed a passive recovery (rest), while 5G and 10G were submitted to CWI by means of 5 °C and 10 °C temperatures during 10 min, respectively. Fatigue protocol was performed by knee extension at 40% of isometric peak force from maximal isometric voluntary contraction. Electromyography was used to evaluate neuromuscular performance. The passive recovery and CWI at 5 °C were associated with normalized isometric force and quadriceps activation amplitude from 15 until 120 min after exercise-induced fatigue (F = 7.169, p < 0.001). CWI at 5 °C and 10 °C showed higher muscle activation (F = 6.850, p < 0.001) and lower median frequency (MF) than passive recovery after 15 and 30 min of fatigue (F = 5.386, p < 0.001). For neuromuscular efficiency (NME) recovery, while PRG normalized NME values after 15 min, 5G and 10G exhibited these responses after 60 and 30 min (F = 4.330, p < 0.01), respectively. Passive recovery and CWI at 5 °C and 10 °C revealed similar effects in terms of recovery of muscle strength and NME, but ice interventions resulted in higher quadriceps activation recovery.
Quantification of Lung Perfusion Blood Volume in Dual-Energy Computed Tomography in Patients with Pulmonary Hypertension
Authors: Ugawa Satoko , Akagi Satoshi , Ejiri Kentaro , Nakamura Kazufumi , Ito Hiroshi
Published: May 2022

Dual-energy computed tomography (DECT) is a promising technique for the assessment of the lung perfused blood volume (LPBV) in the lung parenchyma. This study was performed to compare the LPBV by DECT of patients with pulmonary hypertension (PH) and controls and to evaluate the association between the LPBV and the perfusion ratio derived by lung perfusion scintigraphy. This study involved 45 patients who underwent DECT (25 patients with PH and 20 controls). We measured the total LPBV and distribution of the LPBV in each lung. The total LPBV was significantly lower in the PH group than the control group (38 ± 9 vs. 45 ± 8 HU, p = 0.024). Significant differences were observed between the LPBV of the upper lung of the PH and control groups (34 ± 10 vs. 47 ± 10, p = 0.021 and 37 ± 10 vs. 47 ± 8, p < 0.001). A significant correlation was observed between the LPBV and the lung perfusion scintigraphy. A lower total LPBV and lower LPBV of the upper lung as detected by DECT might be specific findings of PH.
Metal Ion-Directed Specific DNA Structures and Their Functions
Authors: Ihara Toshihiro , Kitamura Yusuke , Katsuda Yousuke
Published: May 2022

Various DNA structures, including specific metal ion complexes, have been designed based on the knowledge of canonical base pairing as well as general coordination chemistry. The role of metal ions in these studies is quite broad and diverse. Metal ions can be targets themselves in analytical applications, essential building blocks of certain DNA structures that one wishes to construct, or they can be responsible for signal generation, such as luminescence or redox. Using DNA conjugates with metal chelators, one can more freely design DNA complexes with diverse structures and functions by following the simple HSAB rule. In this short review, the authors summarize a part of their DNA chemistries involving specific metal ion coordination. It consists of three topics: (1) significant stabilization of DNA triple helix by silver ion; (2) metal ion-directed dynamic sequence edition through global conformational change by intramolecular complexation; and (3) reconstruction of luminescent lanthanide complexes on DNA and their analytical applications.
The Antileukemic and Anti-Prostatic Effect of Aeroplysinin-1 Is Mediated through ROS-Induced Apoptosis via NOX Activation and Inhibition of HIF-1a Activity
Authors: Shih Shou-Ping , Lu Mei-Chin , El-Shazly Mohamed , Lin Yu-Hsuan , Chen Chun-Lin , Yu Steve Sheng-Fa , Liu Yi-Chang
Published: May 2022

Aeroplysinin-1 is a brominated isoxazoline alkaloid that has exhibited a potent antitumor cell effect in previous reports. We evaluated the cytotoxicity of aeroplysinin-1 against leukemia and prostate cancer cells in vitro. This marine alkaloid inhibited the cell proliferation of leukemia Molt-4, K562 cells, and prostate cancer cells Du145 and PC-3 with IC50 values of 0.12 ± 0.002, 0.54 ± 0.085, 0.58 ± 0.109 and 0.33 ± 0.042 µM, respectively, as shown by the MTT assay. Furthermore, in the non-malignant cells, CCD966SK and NR8383, its IC50 values were 1.54 ± 0.138 and 6.77 ± 0.190 μM, respectively. In a cell-free system, the thermal shift assay and Western blot assay verified the binding affinity of aeroplysinin-1 to Hsp90 and Topo IIα, which inhibited their activity. Flow cytometry analysis showed that the cytotoxic effect of aeroplysinin-1 is mediated through mitochondria-dependent apoptosis induced by reactive oxygen species (ROS). ROS interrupted the cellular oxidative balance by activating NOX and inhibiting HIF-1α and HO-1 expression. Pretreatment with N-acetylcysteine (NAC) reduced Apl-1-induced mitochondria-dependent apoptosis and preserved the expression of NOX, HO-1, and HIF-1a. Our findings indicated that aeroplysinin-1 targeted leukemia and prostate cancer cells through multiple pathways, suggesting its potential application as an anti-leukemia and prostate cancer drug lead.
Electrical Field Strength in Rough Infinite Line Contact Elastohydrodynamic Conjunctions
Authors: Morris Samuel A. , Leighton Michael , Morris Nicholas J.
Published: May 2022

Rolling element bearings are required to operate in a variety of use cases that determine voltage potentials will form between the rolling elements and races. When the electrical field strength causes the dielectric breakdown of the intermediary lubricant film electrical discharge can damage the bearing surfaces. To reduce the prevalence and severity of electrical discharge machining an improved understanding of the coupled electrical and mechanical behavior is necessary. This paper aims to improve understanding of the problem through a combined elastohydrodynamic and electrostatic numerical study of charged elastohydrodynamic conjunctions. The results show the effect of amplitude reduction means that for typical surface topographies found in EHL conjunctions the maximum field strength is adequately predicted by the elastohydrodynamic minimum film thickness and potential difference. The paper also indicates the width of the elevated electrical field strength region is dependent on EHL parameters which could have important implications on the magnitude of current density during dielectric breakdown.
Heat Treatment of NiTi Alloys Fabricated Using Laser Powder Bed Fusion (LPBF) from Elementally Blended Powders
Authors: Chmielewska Agnieszka , Wysocki Bartłomiej , Kwaśniak Piotr , Kruszewski Mirosław Jakub , Michalski Bartosz , Zielińska Aleksandra , Adamczyk-Cieślak Bogusława , Krawczyńska Agnieszka , Buhagiar Joseph , Święszkowski Wojciech
Published: May 2022

The use of elemental metallic powders and in situ alloying in additive manufacturing (AM) is of industrial relevance as it offers the required flexibility to tailor the batch powder composition. This solution has been applied to the AM manufacturing of nickel-titanium (NiTi) shape memory alloy components. In this work, we show that laser powder bed fusion (LPBF) can be used to create a Ni55.7Ti44.3 alloyed component, but that the chemical composition of the build has a large heterogeneity. To solve this problem three different annealing heat treatments were designed, and the resulting porosity, microstructural homogeneity, and phase formation was investigated. The heat treatments were found to improve the alloy’s chemical and phase homogeneity, but the brittle NiTi2 phase was found to be stabilized by the 0.54 wt.% of oxygen present in all fabricated samples. As a consequence, a Ni2Ti4O phase was formed and was confirmed by transmission electron microscopy (TEM) observation. This study showed that pore formation in in situ alloyed NiTi can be controlled via heat treatment. Moreover, we have shown that the two-step heat treatment is a promising method to homogenise the chemical and phase composition of in situ alloyed NiTi powder fabricated by LPBF.
Influence of Type of Filler and Bitumen on the Mechanical Performance of Asphalt Mortars
Authors: Tauste-Martínez Raul , Hidalgo Ana Elena , García-Travé Gema , Moreno-Navarro Fernando , Rubio-Gámez María del Carmen
Published: May 2022

This article presents a new methodology of analysis based on a fast-running experimental procedure to characterise the mechanical response of asphalt mortars in terms of stiffness, ductility, and fatigue resistance. This was achieved using the DMA (Dynamic Mechanical Analyser) three-point bending configuration. The study was carried out by considering the employment of different types of fillers such cement and CaCO3 and different types of binders such as conventional asphalt binder (B35/50) or modifided polymer-modified bitumen (PMB 25/55–65). From the results of this study, the filler was found to have a greater influence on the stiffness and ductility of the asphalt material, while bitumen had a higher effect on the fatigue life of the asphalt mortar. Fatigue life was observed to increase with the use of a polymer-modified binder, while a lower degree of permanent deformation and higher bearing capacity achieved by the use of cement instead of calcium carbonate as active fillers.
Design and Validation of Additively Manufactured Metallic Cellular Scaffold Structures for Bone Tissue Engineering
Authors: Al-Barqawi Mohammad O. , Church Benjamin , Thevamaran Mythili , Thoma Dan J. , Rahman Adeeb
Published: May 2022

Bone-related defects that cannot heal without significant surgical intervention represent a significant challenge in the orthopedic field. The use of implants for these critical-sized bone defects is being explored to address the limitations of autograft and allograft options. Three-dimensional cellular structures, or bone scaffolds, provide mechanical support and promote bone tissue formation by acting as a template for bone growth. Stress shielding in bones is the reduction in bone density caused by the difference in stiffness between the scaffold and the surrounding bone tissue. This study aimed to reduce the stress shielding and introduce a cellular metal structure to replace defected bone by designing and producing a numerically optimized bone scaffold with an elastic modulus of 15 GPa, which matches the human’s cortical bone modulus. Cubic cell and diagonal cell designs were explored. Strut and cell dimensions were numerically optimized to achieve the desired structural modulus. The resulting scaffold designs were produced from stainless steel using laser powder bed fusion (LPBF). Finite element analysis (FEA) models were validated through compression testing of the printed scaffold designs. The structural configuration of the scaffolds was characterized with scanning electron microscopy (SEM). Cellular struts were found to have minimal internal porosity and rough surfaces. Strut dimensions of the printed scaffolds were found to have variations with the optimized computer-aided design (CAD) models. The experimental results, as expected, were slightly less than FEA results due to structural relative density variations in the scaffolds. Failure of the structures was stretch-dominated for the cubic scaffold and bending-dominated for the diagonal scaffold. The torsional and bending stiffnesses were numerically evaluated and showed higher bending and torsional moduli for the diagonal scaffold. The study successfully contributed to minimizing stress shielding in bone tissue engineering. The study also produced an innovative metal cellular structure that can replace large bone segments anywhere in the human body.
Assessment of Bioceramic Sealer Retreatability and Its Influence on Force and Torque Generation
Authors: Jamleh Ahmed , Nassar Mohannad , Alfadley Abdulmohsen , Alanazi Azhar , Alotiabi Hadeel , Alghilan Maryam , Alfouzan Khalid
Published: May 2022

This study assesses the retreatability of TotalFill bioceramic (TFBC) and AH Plus (AHP) sealers and their impact on retreatment force and torque. Twenty-six premolar teeth with single oval canals were instrumented, obturated using the matched gutta-percha cone technique with one of the tested sealers, and then temporized. After a 6-month incubation at 37 °C and 100% humidity, the canals were retreated with the XP Shaper system. During retreatment, the generated force and torque were measured. Micro-CT scanning was run before and after the retreatment procedure to analyze the remaining obturating materials in the canals. The apically directed maximum force in AHP was higher than that in TFBC. The coronally directed maximum force and the maximum torque were comparable between the groups. A higher amount of remaining obturating materials was found in the AHP compared to that in the TFBC. Based on these findings, endodontic sealer had an influence on retreatability, and the TFBC showed less remaining obturating materials and lower retreatment forces in the apical direction compared to the AHP in extracted teeth with oval canals.
Reliability Assessment Method Based on Condition Information by Using Improved Proportional Covariate Model
Authors: Chen Baojia , Chen Zhengkun , Chen Fafa , Xiao Wenrong , Xiao Nengqi , Fu Wenlong , Li Gongfa
Published: May 2022

If sufficient historical failure life data exist, the failure distribution of the system can be estimated to identify the system initial hazard function. The conventional proportional covariate model (PCM) can reveal the dynamic relationship between the response covariates and the system hazard rate. The system hazard rate function can be constantly updated by the response covariates through the basic covariate function (BCF). Under the circumstances of sparse or zero failure data, the key point of the PCM reliability assessment method is to determine the proportional factor between covariates and the hazard rate for getting BCF. Being devoid of experiments or abundant experience of the experts, it is very hard to determine the proportional factor accurately. In this paper, an improved PCM (IPCM) is put forward based on the logistic regression model (LRM). The salient features reflecting the equipment degradation process are extracted from the existing monitoring signals, which are considered as the input of the LRM. The equipment state data defined by the failure threshold are considered as the output of the LRM. The initial reliability can be first estimated by LRM. Combined with the responding covariates, the initial hazard function can be calculated. Then, it can be incorporated into conventional PCM to implement the reliability estimation process on other equipment. The conventional PCM and the IPCM methods are respectively applied to aero-engine rotor bearing reliability assessment. The comparative results show that the assessing accuracy of IPCM is superior to the conventional PCM for small failure sample. It provides a new method for reliability estimation under sparse or zero failure data conditions.
A Decision-Making Tool for Algorithm Selection Based on a Fuzzy TOPSIS Approach to Solve Replenishment, Production and Distribution Planning Problems
Authors: Guzman Eduardo , Andres Beatriz , Poler Raul
Published: May 2022

A wide variety of methods and techniques with multiple characteristics are used in solving replenishment, production and distribution planning problems. Selecting a solution method (either a solver or an algorithm) when attempting to solve an optimization problem involves considerable difficulty. Identifying the best solution method among the many available ones is a complex activity that depends partly on human experts or a random trial-and-error procedure. This paper addresses the challenge of recommending a solution method for replenishment, production and distribution planning problems by proposing a decision-making tool for algorithm selection based on the fuzzy TOPSIS approach. This approach considers a collection of the different most commonly used solution methods in the literature, including distinct types of algorithms and solvers. To evaluate a solution method, 13 criteria were defined that all address several important dimensions when solving a planning problem, such as the computational difficulty, scheduling knowledge, mathematical knowledge, algorithm knowledge, mathematical modeling software knowledge and expected computational performance of the solution methods. An illustrative example is provided to demonstrate how planners apply the approach to select a solution method. A sensitivity analysis is also performed to examine the effect of decision maker biases on criteria ratings and how it may affect the final selection. The outcome of the approach provides planners with an effective and systematic decision support tool to follow the process of selecting a solution method.
Robust Scheduling of Two-Agent Customer Orders with Scenario-Dependent Component Processing Times and Release Dates
Authors: Wu Chin-Chia , Gupta Jatinder N. D. , Lin Win-Chin , Cheng Shuenn-Ren , Chiu Yen-Lin , Chen Juin-Han , Lee Long-Yuan
Published: May 2022

Although some uncertainty factors can occur in many practical environments, customer order scheduling problems involving two agents in such uncertain environments have not received attention in the current literature. Motivated by this observation, we address a two-agent customer order scheduling problem where various customer orders have scenario-dependent component processing times and release dates in order to find an appropriate schedule to minimize the maximum of the total completion time of the customer orders that belong to one agent and are subject to a constraint with the other agent. In order to solve this problem, a lower bound and six dominant properties are derived and used to propose a branch-and-bound algorithm to find an exact optimal solution. Afterward, three local search heuristics and two variants of a simulated annealing hyper-heuristic are proposed and empirically evaluated in order to find approximate solutions. Finally, we conclude the paper with a summary of our findings and some directions for future research.
Remarks on Nonlocal Dirichlet Problems
Authors: Albalawi Kholoud Saad , Bin-Asfour Mona , Vetro Francesca
Published: May 2022

We study a nonlocal Dirichlet problem with the (p(b(u)),q(b(u)))-Laplacian operator and integrable data on a bounded domain with smooth boundary. We establish the existence of at least one weak solution in the case the variable exponents of the leading operator depend on the solution u, without assuming any growth conditions on g. The proof is based on the characterization of the energy functional associated to the problem, using the methods of the calculus of variations.
Propensity Score Matching Underestimates Real Treatment Effect, in a Simulated Theoretical Multivariate Model
Authors: Garcia Iglesias Daniel
Published: May 2022

Propensity Score Matching (PSM) is a useful method to reduce the impact of Treatment-Selection Bias in the estimation of causal effects in observational studies. After matching, the PSM significantly reduces the sample under investigation, which may lead to other possible biases (due to overfitting, excess of covariation or a reduced number of observations). In this sense, we wanted to analyze the behavior of this PSM compared with other widely used methods to deal with non-comparable groups, such as the Multivariate Regression Model (MRM). Monte Carlo Simulations are made to construct groups with different effects in order to compare the behavior of PSM and MRM estimating these effects. In addition, the Treatment Selection Bias reduction for the PSM is calculated. With the PSM a reduction in the Treatment Selection Bias is achieved (0.983 [0.982, 0.984]), with a reduction in the Relative Real Treatment Effect Estimation Error (0.216 [0.2, 0.232]), but despite this bias reduction and estimation error reduction, the MRM reduces this estimation error significantly more than the PSM (0.539 [0.522, 0.556], p < 0.001). In addition, the PSM leads to a 30% reduction in the sample. This loss of information derived from the matching process may lead to another not known bias and thus to the inaccuracy of the effect estimation compared with the MRM.
A Dynamic Analysis for Probabilistic/Possibilistic Problems Model Reduction Analysis Using Special Functions
Authors: Hassis Hedi , Jendoubi Abir , Kolsi Lioua , Omri Mohamed
Published: May 2022

Information and data in mechanics, as in many other scientific disciplines, can be certainly known with an error-safety coefficient (deterministic), random with a known probability distribution (probabilistic), or random known with an uncertainty factor in the information (possibilistic). When the information on the parameters is undermined, probabilistic/possibilistic mechanical techniques attempt to provide an estimate of the solution. For various mechanical problems involving probabilistic/possibility parameters, a constraint that must be met is sometimes added, as in the case of reliability analysis. In this paper, an approach for probabilistic/possibilistic dynamic analysis is introduced and validated. In addition, its extension for finite element structural analysis is presented.
Analytical Treatment of Unsteady Fluid Flow of Nonhomogeneous Nanofluids among Two Infinite Parallel Surfaces: Collocation Method-Based Study
Authors: Gao Fengkai , Yu Dongmin , Sheng Qiang
Published: May 2022

Fluid flow and heat transfer of nanofluids have gained a lot of attention due to their wide application in industry. In this context, the appropriate solution to such phenomena is the study of this exciting and challenging field by the research community. This paper presents an extension of a well-known collocation method (CM) to investigate the accurate solutions to unsteady flow and heat transfer among two parallel plates. First, a mathematical model is developed for the discussed phenomena, then this model is converted into a non-dimensional form using viable similarity variables. In order to inspect the accurate solutions of the accomplished set of nonlinear ordinary differential equations, a collocation method is proposed and applied successfully. Various simulations are performed to analyze the behavior of non-dimensional velocity, temperature, and concentration profiles alongside the deviation of physical parameters present in the model, and then plotted graphically. It is important to mention that the velocity is enhanced due to the higher impact of the parameter Ha. The parameter Nt caused an efficient enhancement in the temperature distribution while the parameters Nt provided a drop in the temperature that actually affected the rate of heat transmission. Dual behavior of concentration is noted for parameter b, while it can be noted that mixed increasing behavior is available for the concentration against Le. The behavior of skin friction, the Nusselt number, and the Sherwood number were also investigated in addition to the physical parameters. It was observed that the Nusselt number increases with the enhancement of the effects of the magnetic field parameter and the Prandtl number. A comparative study shows that the proposed scheme is very effective and reliable in investigating the solutions of the discussed phenomena and can be extended to find the solutions to more nonlinear physical problems with complex geometry.
How to Train Novices in Bayesian Reasoning
Authors: Büchter Theresa , Eichler Andreas , Steib Nicole , Binder Karin , Böcherer-Linder Katharina , Krauss Stefan , Vogel Markus
Published: May 2022

Bayesian Reasoning is both a fundamental idea of probability and a key model in applied sciences for evaluating situations of uncertainty. Bayesian Reasoning may be defined as the dealing with, and understanding of, Bayesian situations. This includes various aspects such as calculating a conditional probability (performance), assessing the effects of changes to the parameters of a formula on the result (covariation) and adequately interpreting and explaining the results of a formula (communication). Bayesian Reasoning is crucial in several non-mathematical disciplines such as medicine and law. However, even experts from these domains struggle to reason in a Bayesian manner. Therefore, it is desirable to develop a training course for this specific audience regarding the different aspects of Bayesian Reasoning. In this paper, we present an evidence-based development of such training courses by considering relevant prior research on successful strategies for Bayesian Reasoning (e.g., natural frequencies and adequate visualizations) and on the 4C/ID model as a promising instructional approach. The results of a formative evaluation are described, which show that students from the target audience (i.e., medicine or law) increased their Bayesian Reasoning skills and found taking part in the training courses to be relevant and fruitful for their professional expertise.
Constructing Exact and Approximate Diffusion Wave Solutions for a Quasilinear Parabolic Equation with Power Nonlinearities
Authors: Kazakov Alexander , Spevak Lev
Published: May 2022

The paper studies a degenerate nonlinear parabolic equation containing a convective term and a source (reaction) term. It considers the construction of approximate solutions to this equation with a specified law of diffusion wave motion, the existence of these solutions being proved in our previous studies. A stepwise algorithm of the numerical solution with a time-difference scheme is proposed, the second-order difference scheme being used in such problems for the first time. At each step the problem is solved iteratively on the basis of a radial basis function (RBF) collocation method. In order to verify the numerical solution algorithm, two classes of exact generalized traveling wave solutions are proposed, whose construction is reduced to solving a Cauchy problem for second order ordinary differential equations (ODEs) with a singularity at the higher derivative. The theorem of the existence and uniqueness of the analytical solution in the form of a power series is proved for it, and the estimates of the radius of convergence are obtained. The Euler method is used to prove a similar statement concerning the existence of a continuous solution in the non-analytical case. The RBF collocation method is also applied for the approximate solution of the Cauchy problem. The solutions to the Cauchy problem are numerically analyzed, and this has enabled us to reveal and describe some of their properties, including those not previously observed, and to assess the accuracy of the method.
Geodesics in the TPS Space
Authors: Varano Valerio , Gabriele Stefano , Milicchio Franco , Shlager Stefan , Dryden Ian , Piras Paolo
Published: May 2022

In shape analysis, the interpolation of shapes’ trajectories is often performed by means of geodesics in an appropriate Riemannian Shape Space. Over the past several decades, different metrics and shape spaces have been proposed, including Kendall shape space, LDDMM based approaches, and elastic contour, among others. Once a Riemannian space is chosen, geodesics and parallel transports can be used to build splines or piecewise geodesics paths. In a recent paper, we introduced a new Riemannian shape space named TPS Space based on the Thin Plate Spline interpolant and characterized by an appropriate metric and parallel transport rule. In the present paper, we further explore the geometry of the TPS Space by characterizing the properties of its geodesics. Several applications show the capability of the proposed formulation to conserve important physical properties of deformation, such as local strains and global elastic energy.
Management of Hypertension with Female Sexual Dysfunction
Authors: Zhong Qing , Anderson Yuri
Published: May 2022

Female sexual dysfunction (FSD) in hypertension has been less studied than male sexual dysfunction, and antihypertensive agents’ impact on female sexual function is not defined. In this review, randomized double-blind clinical trials and cross-sectional studies related to female sexual function in hypertension were analyzed from 1991 to 2021. FSD appeared to be higher in hypertensive women than in normotensive women. Beta-blockers are the only antihypertensive agents with relatively strong evidence of damaging the female sexual function. Angiotensin receptor blockers (ARB) are relatively beneficial to female sexual function. To treat FSD in the presence of hypertension, controlling blood pressure is key, and the administration of angiotensin receptor blockers is preferred. In addition to controlling blood pressure, for premenopausal women, flibanserin and bremelanotide can be tried, while ospemifene and hormone supplements are preferred for postmenopausal women.
Effect of Cationic/Anionic Diffusion Dominated Passive Film Growth on Tribocorrosion
Authors: Zhang Renpeng , Wang Zhongwei , Ma Yanlong , Yan Yu , Qiao Lijie
Published: May 2022

Tribocorrosion behaviours of nickel (Ni) and niobium (Nb) in sodium sulfate (Na2SO4) solution under potentiodynamic and potentiostatic conditions were studied. Under the potentiodynamic condition, the passivation was early broken, accompanied by a sharp increase in frictional coefficient on Nb. The current was more fluctuant, and larger material loss appeared at the higher potential in the potentiostatic condition. However, these phenomena did not occur for Ni, and it even showed lower material loss at the higher potential in the potentiostatic tribocorrosion test. The differences in tribocorrosion behaviour had a close relationship to the passive film growth mechanism, which decided the passive film/metal interface structure. Nb with anionic diffusion dominated mechanism in passive growth would cause the accumulation of oxygen vacancies at the passive film/metal interface. This may weaken the adhesion between the metal and the passive film. However, with the cationic diffusion dominated passive film growth on Ni, cation vacancies concentrated at the passive film/tribo-film interface, and this did not affect the adhesion between metal and passive film. Ni or other passive elements with the cationic diffusion-dominated mechanism in passive film growth were recommended as the alloying element for improving the tribocorrosion resistance of alloys.