bluuebunny/crossref_metadata_2025 huggingface dataset:
Effectiveness of Non-Presential Individualized Exercise Training PrOgram(NIETO) in Lower Limb Physical Performance in Advanced COPD
Authors: Sánchez-Nieto Juan Miguel , Fernández-Muñoz Irene , Carrillo-Alcaraz Andrés , Bernabeu-Mora Roberto
Published: March 2021

Muscle training, a component of pulmonary rehabilitation (PR), improves the physical performance of patients with chronic obstructive pulmonary disease (COPD). Despite the existing evidence, the traditional center-based PR model is applied to a small percentage of patients and presents numerous problems of accessibility, adherence, and costs. This study presents a home model of simple muscle training, non-presential, monitored by telephone and individualized, according to the severity of the COPD. In addition, to evaluate the results, simple tests associated with the physical performance of the lower limbs, previously validated in COPD, have been used, such as the four-meter walk, speed test (4MGS) and the five-repetition test sitting and standing (5STS). The objective was to evaluate whether the Individualized Non-Presential Exercise Training PrOgram (NIETO) induces improvements in the 4MGS, 5STS and quadriceps muscle strength (QMS) tests in outpatients with advanced COPD (FEV1 ≤ 50%). After one year, the QMS was significantly higher in the intervention group (IG) than in the control group (CG) (2.44 ± 4.07 vs. 0.05 ± 4.26 kg; p = 0.009). The 4MGS and 5STS tests were significantly shorter in IG than in CG (−0.39 ± 0.86 vs. 0.37 ± 0.96 s; p = 0.001) and (−1.55 ± 2.83 vs. 0.60 ± 2.06 s; p = 0.001), respectively. A home model of simple muscle training monitored by telephone such as NIETO, can improve 4MGS, 5STS, and quadriceps strength tests in outpatients with advanced COPD.
Fertility-Sparing Methods in Adolescents Affected by Endometrial Cancer: A Comprehensive Review
Authors: Gałczyński Krzysztof , Olcha Piotr , Romanek-Piva Katarzyna , Jóźwik Maciej , Semczuk Andrzej
Published: March 2021

Although in developed countries endometrial cancer (EC) is the most common gynecological malignancy, its occurrence in adolescents is exceedingly rare. The increasing rate of obesity in children and adolescents is held responsible for the increasing prevalence of EC in younger cohorts of patients. The diagnosis of this malignancy can have devastating consequences for future fertility because standard treatment protocols for EC include hysterectomy. Here, we present the first detailed review of the world literature on EC in subjects aged 21 years or younger (n = 19). The mean age at diagnosis was 16.7 ± 0.6 years. One patient (5.3%) had a Type II (high-risk) disease. No communication retrieved from the search reported on patient death; however, two (10.5%) patients were lost to follow-up. There was also a high proportion (five subjects, or 26.3%) of cases with genetic background (Cowden syndrome and Turner syndrome), therefore genetic screening or a direct genetic study should be considered in very young patients with EC. The current fertility-sparing options, limited to Type I (low-risk) disease, are presented and discussed. Such information, obtained from studies on older women, translates well to adolescent girls and very young women. Careful anatomopathological monitoring at follow-up is essential for the safety of a conservative approach. Improved survival in very young EC patients makes the preservation of fertility a central survivorship issue, therefore both patients and caregivers should undergo counseling regarding available options. Moreover, our study suggests that genetic syndromes other than Lynch syndrome may be associated with EC more frequently than previously thought.
Role of Provocable Brugada ECG Pattern in The Correct Risk Stratification for Major Arrhythmic Events
Authors: Martini Nicolò , Testolina Martina , Toffanin Gian Luca , Arancio Rocco , De Mattia Luca , Cannas Sergio , Morani Giovanni , Martini Bortolo
Published: March 2021

The so-called Brugada syndrome (BS), first called precordial early repolarization syndrome (PERS), is characterized by the association of a fascinating electrocardiographic pattern, namely an aspect resembling right bundle branch block with a coved and sometime upsloping ST segment elevation in the precordial leads, and major ventricular arrhythmic events that could rarely lead to sudden death. Its electrogenesis has been related to a conduction delay mostly, but not only, located on the right ventricular outflow tract (RVOT), probably due to a progressive fibrosis of the conduction system. Many tests have been proposed to identify people at risk of sudden death and, among all, ajmaline challenge, thanks to its ability to enhance latent conduction defects, became so popular, even if its role is still controversial as it is neither specific nor sensitive enough to guide further invasive investigations and managements. Interestingly, a type 1 pattern has also been induced in many other cardiac diseases or systemic diseases with a cardiac involvement, such as long QT syndrome (LQTS), arrhythmogenic right ventricular cardiomyopathy (ARVC), hypertrophic cardiomyopathy (HCM) and myotonic dystrophy, without any clear arrhythmic risk profile. Evidence-based studies clearly showed that a positive ajmaline test does not provide any additional information on the risk stratification for major ventricular arrhythmic events on asymptomatic individuals with a non-diagnostic Brugada ECG pattern.
Assessment of Numerical Methods for Plunging Breaking Wave Predictions
Authors: Bhushan Shanti , El Fajri Oumnia , Hubbard Graham , Chambers Bradley , Kees Christopher
Published: March 2021

This study evaluates the capability of Navier–Stokes solvers in predicting forward and backward plunging breaking, including assessment of the effect of grid resolution, turbulence model, and VoF, CLSVoF interface models on predictions. For this purpose, 2D simulations are performed for four test cases: dam break, solitary wave run up on a slope, flow over a submerged bump, and solitary wave over a submerged rectangular obstacle. Plunging wave breaking involves high wave crest, plunger formation, and splash up, followed by second plunger, and chaotic water motions. Coarser grids reasonably predict the wave breaking features, but finer grids are required for accurate prediction of the splash up events. However, instabilities are triggered at the air–water interface (primarily for the air flow) on very fine grids, which induces surface peel-off or kinks and roll-up of the plunger tips. Reynolds averaged Navier–Stokes (RANS) turbulence models result in high eddy-viscosity in the air–water region which decays the fluid momentum and adversely affects the predictions. Both VoF and CLSVoF methods predict the large-scale plunging breaking characteristics well; however, they vary in the prediction of the finer details. The CLSVoF solver predicts the splash-up event and secondary plunger better than the VoF solver; however, the latter predicts the plunger shape better than the former for the solitary wave run-up on a slope case.
Distributed Architecture to Enhance Systems Protection against Unauthorized Activity via USB Devices
Authors: Oliveira José , Pinto Pedro , Santos Henrique
Published: March 2021

Cyberattacks exploiting Universal Serial Bus (USB) interfaces may have a high impact on individual and corporate systems. The BadUSB is an attack where a USB device’s firmware is spoofed and, once mounted, allows attackers to execute a set of malicious actions in a target system. The countermeasures against this type of attack can be grouped into two strategies: phyiscal blocking of USB ports and software blocking. This paper proposes a distributed architecture that uses software blocking to enhance system protection against BadUSB attacks. This architecture is composed of multiple agents and external databases, and it is designed for personal or corporate computers using Microsoft Windows Operating System. When a USB device is connected, the agent inspects the device, provides filtered information about its functionality and presents a threat assessment to the user, based on all previous user choices stored in external databases. By providing valuable information to the user, and also threat assessments from multiple users, the proposed distributed architecture improves system protection.
Influence of Active Cooling at the Trailing Edge on the Thermal Behavior of a Tilting-Pad Journal Bearing
Authors: Buchhorn Nico , Stottrop Michael , Bender Beate
Published: March 2021

In tilting-pad journal bearings (TPJB) with a non-flooded lubrication concept, higher maximum pad temperatures occur than with a flooded bearing design due to the lower convective heat transfer at the pad edges. In this paper, we present an approach to influence the thermal behavior of a five-pad TPJB by active cooling. The aim of this research is to investigate the influence of additional oil supply grooves at the trailing edge of the two loaded pads on the maximum pad temperature of a large TPJB in non-flooded design. We carry out experimental and numerical investigations for a redesigned test bearing. Within the experimental analysis, the reduction in pad temperature is quantified. A simulation model of the bearing is synthesized with respect to the additional oil supply grooves. The simulation results are compared with the experimental data to derive heat transfer coefficients for the pad surfaces. The experimental results indicate a considerable reduction of the maximum pad temperatures. An overall lower temperature level is observed for the rear pad in circumferential direction (pad 4). The authors attribute this effect by a cooling oil carry-over from the previous pad (3). Within the model limits, a good agreement of the simulation and experimental results can be found.
An Extended Finite Element Method (XFEM) Study on the Elastic T-Stress Evaluations for a Notch in a Pipe Steel Exposed to Internal Pressure
Authors: Yakoubi Khadija , Montassir Soufiane , Moustabchir Hassane , Elkhalfi Ahmed , Pruncu Catalin Iulian , Arbaoui Jamal , Farooq Muhammad Umar
Published: March 2021

The work investigates the importance of the K-T approach in the modelling of pressure cracked structures. T-stress is the constant in the second term of the Williams expression; it is often negligible, but recent literature has shown that there are cases where T-stress plays the role of opening the crack, also T-stress improves elastic modeling at the point of crack. In this research study, the most important effects of the T-stress are collected and analyzed. A numerical analysis was carried out by the extended finite element method (X-FEM) to analyze T-stress in an arc with external notch under internal pressure. The different stress method (SDM) is employed to calculate T-stress. Moreover, the influence of the geometry of the notch on the biaxiality is also examined. The biaxiality gave us a view on the initiation of the crack. The results are extended with a comparison to previous literature to validate the promising investigations.
A Poisson Process-Based Random Access Channel for 5G and Beyond Networks
Authors: Almagrabi Alaa Omran , Ali Rashid , Alghazzawi Daniyal , AlBarakati Abdullah , Khurshaid Tahir
Published: March 2021

The 5th generation (5G) wireless networks propose to address a variety of usage scenarios, such as enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). Due to the exponential increase in the user equipment (UE) devices of wireless communication technologies, 5G and beyond networks (B5G) expect to support far higher user density and far lower latency than currently deployed cellular technologies, like long-term evolution-Advanced (LTE-A). However, one of the critical challenges for B5G is finding a clever way for various channel access mechanisms to maintain dense UE deployments. Random access channel (RACH) is a mandatory procedure for the UEs to connect with the evolved node B (eNB). The performance of the RACH directly affects the performance of the entire network. Currently, RACH uses a uniform distribution-based (UD) random access to prevent a possible network collision among multiple UEs attempting to access channel resources. However, in a UD-based channel access, every UE has an equal chance to choose a similar contention preamble close to the expected value, which causes an increase in the collision among the UEs. Therefore, in this paper, we propose a Poisson process-based RACH (2PRACH) alternative to a UD-based RACH. A Poisson process-based distribution, such as exponential distribution, disperses the random preambles between two bounds in a Poisson point method, where random variables occur continuously and independently with a constant parametric rate. In this way, our proposed 2PRACH approach distributes the UEs in a probability distribution of a parametric collection. Simulation results show that the shift of RACH from UD-based channel access to a Poisson process-based distribution enhances the reliability and lowers the network’s latency.
Rapid Exponential Stabilization of Nonlinear Wave Equation Derived from Brain Activity via Event-Triggered Impulsive Control
Authors: Dlala Mohsen , Saud Almutairi Adarey
Published: March 2021

This paper investigates the problem of rapid exponential stabilization for damped wave equations. Based on a new event-triggered impulsive control (ETIC) method, impulsive control was designed to solve the rapid exponential stabilization of a class of damped wave equations derived from brain activity. The effectiveness of our control was verified through a numerical example.
Superior Capsular Reconstruction of the Shoulder Using the Long Head of the Biceps Tendon: A Systematic Review of Surgical Techniques and Clinical Outcomes
Authors: Kitridis Dimitrios , Yiannakopoulos Christos , Sinopidis Chris , Givissis Panagiotis , Galanis Nikiforos
Published: March 2021

Background and Objectives: Superior capsular reconstruction (SCR) with the use of a fascia lata autograft or a dermal allograft is an established treatment in treating irreparable rotator cuff (RC) tears. The long head of the biceps tendon (LHBT) has been recently proposed as an alternative graft for SCR. The purpose of this study was to present the surgical techniques and clinical studies utilizing the LHBT for SCR. Material and Methods: Medline, Scopus, and the Cochrane library were searched for relevant studies up to December 2020. The primary outcomes were pain intensity improvement and the incidence of RC and LHBT graft retears. Secondary outcomes were functional scores and acromiohumeral distance (AHD) improvements. Results: Nine studies described surgical techniques of SCR using the LHBT, and four clinical studies reported the outcomes of the technique. The mean pain intensity improved from 4.9 ± 2.3 to 1.6 ± 1.5 in terms of the visual analog scale, exceeding the minimum clinically important difference for adequate pain relief. Significant improvements were also noted in functional scores and AHD. When compared with other repair techniques for massive RC tears, i.e., the double-row repair, the transosseous-equivalent technique with absorbable patch reinforcement, and the traditional SCR with a fascia lata autograft, there were no significant differences in pain and function improvements. Conclusion: SCR using the LHBT is a useful treatment option for massive RC tears; it is equally effective with the traditional SCR and other established techniques. It presents numerous advantages being a safe, easy, time-saving, and cost-effective method. The only precondition for the technique is the presence of an intact LHBT. Additional clinical trials are necessary to determine which treatment is superior for treating massive RC tears, as well as to evaluate the long-term results of the technique.
Safety of Laparoscopic Cholecystectomy for Acute Cholecystitis in the Elderly: A Multivariate Analysis of Risk Factors for Intra and Postoperative Complications
Authors: Serban Dragos , Socea Bogdan , Balasescu Simona Andreea , Badiu Cristinel Dumitru , Tudor Corneliu , Dascalu Ana Maria , Vancea Geta , Spataru Radu Iulian , Sabau Alexandru Dan , Sabau Dan , Tanasescu Ciprian
Published: March 2021

Background and Objectives: This study investigates the impact of age upon the safety and outcomes of laparoscopic cholecystectomy performed for acute cholecystitis, by a multivariate approach. Materials and Methods: A 2-year retrospective study was performed on 333 patients admitted for acute cholecystitis who underwent emergency cholecystectomy. The patients included in the study group were divided into four age subgroups: A ≤49 years; B: 50–64 years; C: 65–79 years; D ≥80 years. Results: Surgery after 72 h from onset (p = 0.007), severe forms, and higher American Society of Anesthesiologists Physical Status Classification and Charlson comorbidity index scores (p < 0.001) are well correlated with older age. Both cardiovascular and surgical related complications were significantly higher in patients over 50 years (p = 0.045), which also proved to be a turning point for increasing the rate of conversion and open surgery. However, the comparative incidence did not differ significantly between patients aged from 50–64 years, 65–79 years and over 80 years (6.03%, 9.09% and 5.8%, respectively). Laparoscopic cholecystectomy (LC) was the most frequently used surgical approach in the treatment of acute cholecystitis in all age groups, with better outcomes than open cholecystectomy in terms of decreased overall and postoperative hospital stay, reduced surgery related complications, and the incidence of acute cardiovascular events in the early postoperative period (p < 0.001). Conclusions: The degree of systemic inflammation was the main factor that influenced the adverse outcome of LC in the elderly. Among comorbidities, diabetes was associated with increased surgical and systemic postoperative morbidity, while stroke and chronic renal insufficiency were correlated with a high risk of cardiovascular complications. With adequate perioperative care, the elderly has much to gain from the benefits of a minimally invasive approach, which allows a decreased rate of postoperative complications and a reduced hospital stay.
Effect of Lead and Zinc Impurities in Ironmaking and the Corresponding Removal Methods: A Review
Authors: Mustafa Sayaf , Luo Liqun , Zheng Bo-Tao , Wei Chen-Xi , Christophe Niyonzima
Published: March 2021

This paper reviews the effects of Pb and Zn impurities and their removal in the ironmaking process. The phase changes during ironmaking were investigated, along with the removal techniques of such impurities and their environmental impact. Results show that distribution of Pb–Zn–Fe in Fe ore is complicated, the particles are fine, and the removal of mineral phase at high temperature is difficult. Therefore, the production and occurrence of Pb and Zn impurities in the ironmaking process were analyzed; such impurities reduced the overall productivity of the process. In addition, the important treatments for the removal of these impurities were investigated. Most of these processes eliminated the Pb and Zn impurities from the dust or sludge, but the main impact of the reduced productivity of the ironmaking process in the furnaces was still observed.
Impact of Solidification on Inclusion Morphology in ESR and PESR Remelted Martensitic Stainless Steel Ingots
Authors: Persson Ewa Sjöqvist , Brorson Sofia , Mitchell Alec , Jönsson Pär G.
Published: March 2021

This study focuses on the impact of solidification on the inclusion morphologies in different sizes of production-scale electro-slag remelting (ESR) and electro-slag remelting under a protected pressure-controlled atmosphere, (PESR), ingots, in a common martensitic stainless steel grade. The investigation has been carried out to increase the knowledge of the solidification and change in inclusion morphologies during ESR and PESR remelting. In order to optimize process routes for different steel grades, it is important to define the advantages of different processes. A comparison is made between an electrode, ESR, and PESR ingots with different production-scale ingot sizes, from 400 mm square to 1050 mm in diameter. The electrode and two of the smallest ingots are from the same electrode charge. The samples are taken from both the electrode, ingots, and rolled/forged material. The solidification structure, dendrite arm spacing, chemical analyzes, and inclusion number on ingots and/or forged/rolled material are studied. The results show that the larger the ingot and the further towards the center of the ingot, the larger inclusions are found. As long as an ingot solidifies with a columnar dendritic structure (DS), the increase in inclusion number and size with ingot diameter is approximately linear. However, at the ingot size (1050 mm in diameter in this study) when the center of the ingot converts to solidification in the equiaxial mode (EQ), the increase in number and size of the inclusions is much higher. The transition between a dendritic and an equiaxial solidification in the center of the ingots in this steel grade takes place in the region between the ingot diameters of 800 and 1050 mm.
Ni Doping: A Viable Route to Make Body-Centered-Cubic Fe Stable at Earth’s Inner Core
Authors: Chatterjee Swastika , Ghosh Sujoy , Saha-Dasgupta Tanusri
Published: March 2021

With the goal of answering the highly debated question of whether the presence of Ni at the Earth’s inner core can make body-centered cubic (bcc) Fe stable, we performed a computational study based on first-principles calculations on bcc, hexagonal closed packed (hcp), and face-centered cubic (fcc) structures of the Fe1−xNix alloys (x = 0, 0.0312, 0.042, 0.0625, 0.084, 0.125, 0.14, 0.175) at 200–364 GPa and investigated their relative stability. Our thorough study reveals that the stability of Ni-doped bcc Fe is crucially dependent on the nature of the distribution of Ni in the Fe matrix. We confirm this observation by considering several possible configurations for a given concentration of Ni doping. Our theoretical evidence suggests that Ni-doped bcc Fe could be a stable phase at the Earth’s inner core condition as compared to its hcp and fcc counterparts.
Nanomagnetic Actuation of Hybrid Stents for Hyperthermia Treatment of Hollow Organ Tumors
Authors: Mues Benedikt , Bauer Benedict , Roeth Anjali A. , Ortega Jeanette , Buhl Eva Miriam , Radon Patricia , Wiekhorst Frank , Gries Thomas , Schmitz-Rode Thomas , Slabu Ioana
Published: March 2021

This paper describes a magnetic nanotechnology that locally enables hyperthermia treatment of hollow organ tumors by using polymer hybrid stents with incorporated magnetic nanoparticles (MNP). The hybrid stents are implanted and activated in an alternating magnetic field to generate therapeutically effective heat, thereby destroying the tumor. Here, we demonstrate the feasibility of nanomagnetic actuation of three prototype hybrid stents for hyperthermia treatment of hollow organ tumors. The results show that the heating efficiency of stent filaments increases with frequency from approximately 60 W/gFe (95 kHz) to approximately 250 W/gFe (270 kHz). The same trend is observed for the variation of magnetic field amplitude; however, heating efficiency saturates at approximately 30 kA/m. MNP immobilization strongly influences heating efficiency showing a relative difference in heating output of up to 60% compared to that of freely dispersed MNP. The stents showed uniformly distributed heat on their surface reaching therapeutically effective temperatures of 43 °C and were tested in an explanted pig bile duct for their biological safety. Nanomagnetic actuation of hybrid stents opens new possibilities in cancer treatment of hollow organ tumors.
Septins in Infections: Focus on Viruses
Authors: Henzi Thomas , Lannes Nils , Filgueira Luis
Published: March 2021

Human septins comprise a family of 13 genes that encode conserved GTP-binding proteins. They form nonpolar complexes, which assemble into higher-order structures, such as bundles, scaffolding structures, or rings. Septins are counted among the cytoskeletal elements. They interact with the actin and microtubule networks and can bind to membranes. Many cellular functions with septin participation have been described in the literature, including cytokinesis, motility, forming of scaffolding platforms or lateral diffusion barriers, vesicle transport, exocytosis, and recognition of micron-scale curvature. Septin dysfunction has been implicated in diverse human pathologies, including neurodegeneration and tumorigenesis. Moreover, septins are thought to affect the outcome of host–microbe interactions. Implication of septins has been demonstrated in fungal, bacterial, and viral infections. Knowledge on the precise function of a particular septin in the different steps of the virus infection and replication cycle is still limited. Published data for vaccinia virus (VACV), hepatitis C virus (HCV), influenza A virus (H1N1 and H5N1), human herpesvirus 8 (HHV-8), and Zika virus (ZIKV), all of major concern for public health, will be discussed here.
PvMSP8 as a Novel Plasmodium vivax Malaria Sero-Marker for the Peruvian Amazon
Authors: Villasis Elizabeth , Garro Katherine , Rosas-Aguirre Angel , Rodriguez Pamela , Rosado Jason , Gave Anthony , Guzman-Guzman Mitchel , Manrique Paulo , White Michael , Speybroeck Niko , Vinetz Joseph Michael , Torres Katherine , Gamboa Dionicia
Published: March 2021

The measurement of recent malaria exposure can support malaria control efforts. This study evaluated serological responses to an in-house Plasmodium vivax Merozoite Surface Protein 8 (PvMSP8) expressed in a Baculovirus system as sero-marker of recent exposure to P. vivax (Pv) in the Peruvian Amazon. In a first evaluation, IgGs against PvMSP8 and PvMSP10 proteins were measured by Luminex in a cohort of 422 Amazonian individuals with known history of Pv exposure (monthly data of infection status by qPCR and/or microscopy over five months). Both serological responses were able to discriminate between exposed and non-exposed individuals in a good manner, with slightly higher performance of anti-PvMSP10 IgGs (area under the curve AUC = 0.78 [95% CI = 0.72–0.83]) than anti-PvMSP8 IgGs (AUC = 0.72 [95% CI = 0.67–0.78]) (p = 0.01). In a second evaluation, the analysis by ELISA of 1251 plasma samples, collected during a population-based cross-sectional survey, confirmed the good performance of anti-PvMSP8 IgGs for discriminating between individuals with Pv infection at the time of survey and/or with antecedent of Pv in the past month (AUC = 0.79 [95% CI = 0.74–0.83]). Anti-PvMSP8 IgG antibodies can be considered as a good biomarker of recent Pv exposure in low-moderate transmission settings of the Peruvian Amazon.
Anthelmintic Activity of Antioxidants: In Vitro Effects on the Liver Fluke Opisthorchis felineus
Authors: Mordvinov Viatcheslav A. , Ponomarev Denis V. , Pakharukov Yuri V. , Pakharukova Maria Y.
Published: March 2021

Currently, molecular parasitologists are searching for new agents against trematodiases. Redox metabolism is important for parasites as far as long-lived adult parasites inside a mammalian host are exposed to redox challenges. Antioxidants have been poorly studied as anthelmintic agents, in particular against the foodborne trematodes. Study of in vitro anthelmintic activity of nonenzymatic natural and synthetic antioxidants of various chemical structures was performed using standard motility and mortality assays against juvenile and adult Opisthorchis felineus worms. Promising agents have been found among both natural and synthetic compounds. The mitochondria-targeted antioxidant SkQ1 [10-(6′-plastoquinonyl)decyltriphenylphosphonium] in motility assays was as effective (half-maximal inhibitory concentration [IC50] 0.6–1.4 μM) as praziquantel (IC50 0.47–1.4 μM), and SkQ1 was significantly more effective than praziquantel in mortality assays. Moreover, extensive tegument damage of the adult fluke was revealed after SkQ1 treatment. Flavonoids manifested potency too, with IC50 values in a micromolar range (5.1–17.4 μM). Other natural and synthetic compounds tested against helminths were significantly less effective than praziquantel. Results of our study indicate that SkQ1 and flavonoids have high anthelmintic activities against the liver flukes. We propose that structure–activity relationship research might be worthwhile based on the structures of the most effective substances.
Development of Micron Sized Photonic Devices Based on Deep GaN Etching
Authors: Dogheche Karim , Alshehri Bandar , Patriache Galles , Dogheche Elhadj
Published: March 2021

In order to design and development efficient III-nitride based optoelectronic devices, technological processes require a major effort. We propose here a detailed review focussing on the etching procedure as a key step for enabling high date rate performances. In our reported research activity, dry etching of an InGaN/GaN heterogeneous structure was investigated by using an inductively coupled plasma reactive ion etching (ICP-RIE). We considered different combinations of etch mask (Ni, SiO2, resist), focussing on the optimization of the deep etching process. A GaN mesa process with an etching depth up to 6 µm was performed in Cl2/Ar-based plasmas using ICP reactors for LEDs dimen sions ranging from 5 to 150 µm². Our strategy was directed toward the mesa formation for vertical-type diode applications, where etch depths are relatively large. Etch characteristics were studied as a function of ICP parameters (RF power, chamber pressure, fixed total flow rate). Surface morphology, etch rates and sidewall profiles observed into InGaN/GaN structures were compared under different types of etching masks. For deep etching up to few microns into the GaN template, we state that a Ni or SiO2 mask is more suitable to obtain a good selectivity and vertical etch profiles. The optimized etch rate was about 200nm/min under moderate ICP conditions. We applied these conditions for the fabrication of micro/nano LEDs dedicated to LiFi applications.
Suitability of Habitats in Nepal for Dactylorhiza hatagirea Now and under Predicted Future Changes in Climate
Authors: Shrestha Bikram , Tsiftsis Spyros , Chapagain Deep Jyoti , Khadka Chhatra , Bhattarai Prakash , Kayastha Shrestha Neelima , Alicja Kolanowska Marta , Kindlmann Pavel
Published: March 2021

Dactylorhiza hatagirea is a terrestrial orchid listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and classified as threatened by International Union for Conservation of Nature (IUCN). It is endemic to the Hindu-Kush Himalayan region, distributed from Pakistan to China. The main threat to its existence is climate change and the associated change in the distribution of its suitable habitats to higher altitudes due to increasing temperature. It is therefore necessary to determine the habitats that are suitable for its survival and their expected distribution after the predicted changes in climate. To do this, we use Maxent modelling of the data for its 208 locations. We predict its distribution in 2050 and 2070 using four climate change models and two greenhouse gas concentration trajectories. This revealed severe losses of suitable habitat in Nepal, in which, under the worst scenario, there will be a 71–81% reduction the number of suitable locations for D. hatagirea by 2050 and 95–98% by 2070. Under the most favorable scenario, this reduction will be 65–85% by 2070. The intermediate greenhouse gas concentration trajectory surprisingly would result in a greater reduction by 2070 than the worst-case scenario. Our results provide important guidelines that local authorities interested in conserving this species could use to select areas that need to be protected now and in the future.
Impact of Legumes as a Pre-Crop on Nitrogen Nutrition and Yield in Organic Greenhouse Tomato
Authors: Gatsios Anastasios , Ntatsi Georgia , Celi Luisella , Said-Pullicino Daniel , Tampakaki Anastasia , Savvas Dimitrios
Published: March 2021

An organic greenhouse crop of tomato was established in February following cultivation of cowpea (CP) or common bean (CB) for green pod production, or faba bean (FB) for green manuring. The vegetative residues of CP and CB were incorporated to the soil together with farmyard manure (FYM), prior to establishing the tomato crop. The FB plants were incorporated to the soil at anthesis together with either FYM or composted olive-mill waste (CO). Green manuring with FB resulted in higher soil mineral N levels during the subsequent tomato crop and higher tomato fruit yield when combined with FYM, compared to compost. The level of soil mineral N was the main restrictive factor for yield in organic greenhouse tomato. FB for green manuring as preceding crop to tomato increased significantly the level of soil mineral N and tomato yield compared to CB or CP aiming to produce green pods. The lowest tomato yield was obtained when the preceding crop was CB cultivated for green pod production. The soil mineral N was significantly higher when FYM was applied as base dressing compared with CO, despite the higher total N concentration in CO, pointing to slower mineralization rates of CO during tomato cultivation.
Low-Cost Fluorescence Sensor for Ammonia Measurement in Livestock Houses
Authors: Kamp Jesper Nørlem , Sørensen Lise Lotte , Hansen Michael Jørgen , Nyord Tavs , Feilberg Anders
Published: March 2021

Measurements of ammonia with inexpensive and reliable sensors are necessary to obtain information about e.g., ammonia emissions. The concentration information is needed for mitigation technologies and documentation of existing technologies in agriculture. A flow-based fluorescence sensor to measure ammonia gas was developed. The automated sensor is robust, flexible and made from inexpensive components. Ammonia is transferred to water in a miniaturized scrubber with high transfer efficiency (>99%) and reacts with o-phthalaldehyde and sulfite (pH 11) to form a fluorescent adduct, which is detected with a photodiode. Laboratory calibrations with standard gas show good linearity over a dynamic range from 0.03 to 14 ppm, and the detection limit of the analyzer based on three-times the standard deviation of blank noise was approximately 10 ppb. The sampling frequency is 0.1 to 10 s, which can easily be changed through serial commands along with UV LED current and filter length. Parallel measurements with a cavity ring-down spectroscopy analyzer in a pig house show good agreement (R2 = 0.99). The fluorescence sensor has the potential to provide ammonia gas measurements in an agricultural environment with high time resolution and linearity over a broad range of concentrations.
Matheuristics for Multi-UAV Routing and Recharge Station Location for Complete Area Coverage
Authors: Santin Rafael , Assis Luciana , Vivas Alessandro , Pimenta Luciano C. A.
Published: March 2021

This paper presents matheuristics for routing a heterogeneous group of capacitated unmanned air vehicles (UAVs) for complete coverage of ground areas, considering simultaneous minimization of the coverage time and locating the minimal number of refueling stations. Whereas coverage path planning (CPP) is widely studied in the literature, previous works did not combine heterogeneous vehicle performance and complete area coverage constraints to optimize UAV tours by considering both objectives. As this problem cannot be easily solved, we designed high-level path planning that combines the multiobjective variable neighborhood search (MOVNS) metaheuristic and the exact mathematical formulation to explore the set of nondominated solutions. Since the exact method can interact in different ways with MOVNS, we evaluated four different strategies using four metrics: execution time, coverage, cardinality, and hypervolume. The experimental results show that applying the exact method as an intraroute operator into the variable neighborhood descent (VND) can return solutions as good as those obtained by the closest to optimal strategy but with higher efficiency.
ZARATAMAP: Noise Characterization in the Scope of a Smart City through a Low Cost and Mobile Electronic Embedded System
Authors: Hernandez-Jayo Unai , Goñi Amaia
Published: March 2021

Like other sources of pollution, noise is considered to be one of the main concerns of citizens, due to its invisibility and the potential harm it can cause. Noise pollution could be considered as one of the biggest quality-of-life concerns for urban residents in big cities, mainly due to the high levels of noise to which they may be exposed. Such levels have proven effects on health, such as: sleep disruption, hypertension, heart disease, and hearing loss. In a scenario where the number of people concentrated in cities is increasing, tools are needed to quantify, monitor, characterize, and quantify noise levels. This paper presents the ZARATAMAP project, which combines machine learning techniques with a geo-sensing application so that the authorities can have as much information as possible, using a low-cost embedded and mobile node, that is easy to deploy, develop, and use.
6G Enabled Smart Infrastructure for Sustainable Society: Opportunities, Challenges, and Research Roadmap
Authors: Imoize Agbotiname Lucky , Adedeji Oluwadara , Tandiya Nistha , Shetty Sachin
Published: March 2021

The 5G wireless communication network is currently faced with the challenge of limited data speed exacerbated by the proliferation of billions of data-intensive applications. To address this problem, researchers are developing cutting-edge technologies for the envisioned 6G wireless communication standards to satisfy the escalating wireless services demands. Though some of the candidate technologies in the 5G standards will apply to 6G wireless networks, key disruptive technologies that will guarantee the desired quality of physical experience to achieve ubiquitous wireless connectivity are expected in 6G. This article first provides a foundational background on the evolution of different wireless communication standards to have a proper insight into the vision and requirements of 6G. Second, we provide a panoramic view of the enabling technologies proposed to facilitate 6G and introduce emerging 6G applications such as multi-sensory–extended reality, digital replica, and more. Next, the technology-driven challenges, social, psychological, health and commercialization issues posed to actualizing 6G, and the probable solutions to tackle these challenges are discussed extensively. Additionally, we present new use cases of the 6G technology in agriculture, education, media and entertainment, logistics and transportation, and tourism. Furthermore, we discuss the multi-faceted communication capabilities of 6G that will contribute significantly to global sustainability and how 6G will bring about a dramatic change in the business arena. Finally, we highlight the research trends, open research issues, and key take-away lessons for future research exploration in 6G wireless communication.
Profiles of Accelerometry-Derived Physical Activity Are Related to Perceived Physical Fatigability in Older Adults
Authors: Graves Jessica L. , Qiao Yujia (Susanna) , Moored Kyle D. , Boudreau Robert M. , Venditti Elizabeth M. , Krafty Robert T. , Shiroma Eric J. , Harezlak Jaroslaw , Glynn Nancy W.
Published: March 2021

Physical activity (PA) is associated with greater fatigability in older adults; little is known about magnitude, shape, timing and variability of the entire 24-h rest–activity rhythm (RAR) associated with fatigability. We identified which features of the 24-h RAR pattern were independently and jointly associated with greater perceived physical fatigability (Pittsburgh Fatigability Scale, PFS, 0–50) in older adults (n = 181, 71.3 ± 6.7 years). RARs were characterized using anti-logistic extended cosine models and 4-h intervals of PA means and standard deviations across days. A K-means clustering algorithm approach identified four profiles of RAR features: “Less Active/Robust”, “Earlier Risers”, “More Active/Robust” and “Later RAR”. Quantile regression tested associations of each RAR feature/profile on median PFS adjusted for age, sex, race, body mass index and depression symptomatology. Later rise times (up mesor; β = 1.38, p = 0.01) and timing of midpoint of activity (acrophase; β = 1.29, p = 0.01) were associated with higher PFS scores. Lower PA between 4 a.m. and 8 a.m. was associated with higher PFS scores (β = −4.50, p = 0.03). “Less Active/Robust” (β = 6.14, p = 0.01) and “Later RAR” (β = 3.53, p = 0.01) patterns were associated with higher PFS scores compared to “Earlier Risers”. Greater physical fatigability in older adults was associated with dampened, more variable, and later RARs. This work can guide development of interventions aimed at modifying RARs to reduce fatigability in older adults.
A Portable Tunable Diode Laser Absorption Spectroscopy System for Dissolved CO2 Detection Using a High-Efficiency Headspace Equilibrator
Authors: Zhang Zhihao , Li Meng , Guo Jinjia , Du Baolu , Zheng Ronger
Published: March 2021

Continuous observation of aquatic pCO2  at the ocean surface, with a sensitive response time and high spatiotemporal resolution, is essential for research into the carbon biogeochemical cycle. In this work, a portable tunable diode laser absorption spectroscopy (TDLAS) system for dissolved CO2 detection in surface seawater, coupled with a home-made headspace equilibrator, allowing real time underway measurements, is described. Both the optical detection part and sample extraction part were integrated together into a compact chamber. An empirical equation suitable for this system was acquired, which can convert the concentration from the gas-phase to the aqueous-phase. A monitoring precision of 0.5% was obtained with time-series measurement, and the detection limits of 2.3 ppmv and 0.1 ppmv were determined with 1 s and 128 s averaging time, respectively. Sampling device used in this work was ameliorated so that the response time of system reduced by about 50% compared to the traditional ‘shower head’ system. The fast response time reached the order of 41 s when the final concentration span was 3079 ppmv. For1902 ppmv, this figure was as short as 20 s. Finally, a field underway measurement campaign was carried out and the results were briefly analyzed. Our work proved the feasibility of the TDLAS system for dissolved CO2 rapid detection.
Two-Phase Robust Target Localization in Ocean Sensor Networks Using Received Signal Strength Measurements
Authors: Zhang Yuanyuan , Wu Huafeng , Mei Xiaojun , Xian Jiangfeng , Wang Weijun , Zhang Qiannan , Liang Linian
Published: March 2021

Target localization plays a vital role in ocean sensor networks (OSNs), in which accurate position information is not only a critical need of ocean observation but a necessary condition for the implementation of ocean engineering. Compared with other range-based localization technologies in OSNs, the received signal strength (RSS)-based localization technique has attracted widespread attention due to its low cost and synchronization-free nature. However, maintaining relatively good accuracy in an environment as dynamic and complex as the ocean remains challenging. One of the most damaging factors that degrade the localization accuracy is the uncertainty in transmission power. Besides the equipment loss, the uncertain factors in the fickle ocean environment may result in a significant deviation between the standard rated transmission power and the usable transmission power. The difference between the rated and actual transmission power would lead to an extra error when it comes to the localization in OSNs. In this case, a method that can locate the target without needing prior knowledge of the transmission power is proposed. The method relies on a two-phase procedure in which the location information and the transmission power are jointly estimated. First, the original nonconvex localization problem is transformed into an alternating non-negativity-constrained least square framework with the unknown transmission power (UT-ANLS). Under this framework, a two-stage optimization method based on interior point method (IPM) and majorization-minimization tactic (MMT) is proposed to search for the optimal solution. In the first stage, the barrier function method is used to limit the optimization scope to find an approximate solution to the problem. However, it is infeasible to approach the constraint boundary due to its intrinsic error. Then, in the second stage, the original objective is converted into a surrogate function consisting of a convex quadratic and concave term. The solution obtained by IPM is considered the initial guess of MMT to jointly estimate both the location and transmission power in the iteration. In addition, in order to evaluate the performance of IPM-MM, the Cramer Rao lower bound (CRLB) is derived. Numerical simulation results demonstrate that IPM-MM achieves better performance than the others in different scenarios.
Successful Treatment of Embolic Aortic Valve Endocarditis in a Patient Affected by COVID-19 Pneumonia
Authors: Belluschi Igor , Melisurgo Giulio , Campana Carlo , Castiglioni Alessandro
Published: March 2021

The COVID-19 pandemic has required reorganization of the cardiac surgery system in the Italian region of Lombardy during early 2020. As a consequence, the hub-and-spoke (H&S) model was introduced to manage emergent/urgent cardiac surgery cases. In this challenging scenario, in which thousands of people were affected by the novel coronavirus, we present the case of a successful treatment of a middle-aged patient affected by both COVID-19 pneumonia and subacute aortic endocarditis. Learning objective: How to treat endocarditis during the COVID-19 pandemic.
Ecotoxicity and Hemolytic Activity of Fluorinated Ionic Liquids
Authors: Vieira Nicole S. M. , Oliveira Ana L. S. , Araújo João M. M. , Gaspar Maria Manuela , Pereiro Ana B.
Published: March 2021

The task-specific design of ionic liquids (ILs) has emerged in several industrial and pharmaceutical applications. The family of ILs with fluorine tags equal to or longer than four carbon atoms, the fluorinated ionic liquids (FILs), combine the best properties of ILs with the ones of perfluorinated compounds, and are being designed for several specific purposes. In the pharmaceutical field, there is an urgency to search for novel antibacterial agents to overcome problems associated to antimicrobial resistances. Then, the main purpose of this work is to evaluate the environmental impact and the ability of FILs to be used as antibacterial agents against Pseudomonas stutzeri bacteria. Beyond its rare pathogenicity, these bacteria are also used as a bioremediation agent to treat several contamination sites. Then, it is important to determine which FILs have antibacterial properties, and which do not impact the bacterial growth. The biocompatibility of FILs was also evaluated through their hemolytic activity and represent a step forward the application of FILs in pharmaceutical applications. The results proved that high concentrations of FILs can have a reduced ecotoxicity and a high biocompatibility. [C8C1Im][CF3SO3] was identified as the most promising compound to be used as an antibacterial agent since it prevents the growth of bacteria at concentrations compatible with the red blood cells’ viability.