bluuebunny/crossref_metadata_2025 huggingface dataset:
Screening of Neonatal UK Dried Blood Spots Using a Duplex SMN1 Screening Assay
Authors: Adams Stuart P. , Gravett Emma , Kent Natalie , Kricke Susanne , Ifederu Adeboye , Scoto Mariacristina , Samsuddin Salma , Muntoni Francesco
Published: October 2021

Spinal muscular atrophy (SMA) is an autosomal inherited neuromuscular genetic disease caused, in 95% of cases, by homozygous deletions involving the SMN1 gene exon 7. It remains the leading cause of death in children under 2 years of age. New treatments have been developed and adopted for use in many countries, including the UK. Success of these treatments depends on early diagnosis and intervention in newborn babies, and many countries have implemented a newborn screening (NBS) or pilot NBS program to detect SMN1 exon 7 deletions on dried blood spots. In the UK, there is no current NBS program for SMA, and no pilot studies have commenced. For consideration of adoption of NBS for a new condition, numerous criteria must be satisfied, including critical assessment of a working methodology. This study uses a commercially available real-time PCR assay to simultaneously detect two different DNA segments (SMN1 exon 7 and control gene RPP30) using DNA extracted from a dried blood spot. This study was carried out in a routine clinical laboratory to determine the specificity, sensitivity, and feasibility of SMA screening in a UK NBS lab setting. Just under 5000 normal DBSs were used alongside 43 known SMA positive DBSs. Study results demonstrate that NBS for SMA using real-time PCR is feasible within the current UK NBS Laboratory infrastructure using the proposed algorithm.
Albuminuria Pre-Emptively Identifies Cardiac Patients at Risk of Contrast-Induced Nephropathy
Authors: Vicente-Vicente Laura , Casanova Alfredo G. , Hernández-Sánchez M. Teresa , Prieto Marta , Martínez-Salgado Carlos , López-Hernández Francisco J. , Cruz-González Ignacio , Morales Ana I.
Published: October 2021

Contrast-induced nephropathy (CIN) is a complication associated with the administration of contrast media (CM). The CIN diagnosis is based on creatinine, a biomarker late and insensitive. The objective proposed was to evaluate the ability of novel biomarkers to detect patients susceptible to suffering CIN before CM administration. The study was carried out with patients undergoing cardiac catheterization involving CM. Patients were divided into two groups: (1) CIN, patients who developed this pathology; (2) control, patients who did not suffer CIN. Prior to the administration of CM, urine samples were collected to measure proteinuria, N-acetyl-β-d-glucosaminidase, neutrophil gelatinase-associated lipocalin and kidney injury molecule-1, albumin, transferrin, t-gelsolin and GM2 ganglioside activator protein (GM2AP). The risk factors advanced age, low body mass index and low estimated glomerular filtration rate; and the urinary biomarkers albumin, transferrin and GM2AP showed significant predictive capacity. Of all of them, albuminuria demonstrated the highest diagnostic power. When a cutoff point was established for albuminuria at values still considered subclinical (10–30 µg/mg Cru), it was found that there was a high incidence of CIN (40–75%). Therefore, albuminuria could be applied as a new diagnostic tool to prevent and predict CIN with P4 medicine criteria, independently of risk factors and comorbidities.
The Role of Magnetic Resonance Imaging to Inform Clinical Decision-Making in Acute Spinal Cord Injury: A Systematic Review and Meta-Analysis
Authors: Ghaffari-Rafi Arash , Peterson Catherine , Leon-Rojas Jose E. , Tadokoro Nobuaki , Lange Stefan F. , Kaushal Mayank , Tetreault Lindsay , Fehlings Michael G. , Martin Allan R.
Published: October 2021

The clinical indications and added value of obtaining MRI in the acute phase of spinal cord injury (SCI) remain controversial. This review aims to critically evaluate evidence regarding the role of MRI to influence decision-making and outcomes in acute SCI. A systematic review and meta-analysis were performed according to PRISMA methodology to identify studies that address six key questions (KQs) regarding diagnostic accuracy, frequency of abnormal findings, frequency of altered decision-making, optimal timing, and differences in outcomes related to obtaining an MRI in acute SCI. A total of 32 studies were identified that addressed one or more KQs. MRI showed no adverse events in 156 patients (five studies) and frequently identified cord compression (70%, 12 studies), disc herniation (43%, 16 studies), ligamentous injury (39%, 13 studies), and epidural hematoma (10%, two studies), with good diagnostic accuracy (seven comparative studies) except for fracture detection. MRI findings often altered management, including timing of surgery (78%, three studies), decision to operate (36%, 15 studies), and surgical approach (29%, nine studies). MRI may also be useful to determine the need for instrumentation (100%, one study), which levels to decompress (100%, one study), and if reoperation is needed (34%, two studies). The available literature consistently concluded that MRI was useful prior to surgical treatment (13 studies) and after surgery to assess decompression (two studies), but utility before/after closed reduction of cervical dislocations was unclear (three studies). One study showed improved outcomes with an MRI-based protocol but had a high risk of bias. Heterogeneity was high for most findings (I2 > 0.75). MRI is safe and frequently identifies findings alter clinical management in acute SCI, although direct evidence of its impact on outcomes is lacking. MRI should be performed before and after surgery, when feasible, to facilitate improved clinical decision-making. However, further research is needed to determine its optimal timing, effect on outcomes, cost-effectiveness, and utility before and after closed reduction.
Sex Differences in Clinical Course and Intensive Care Unit Admission in a National Cohort of Hospitalized Patients with COVID-19
Authors: Nachtigall Irit , Bonsignore Marzia , Thürmann Petra , Hohenstein Sven , Jóźwiak Katarzyna , Hauptmann Michael , Eifert Sandra , Dengler Julius , Bollmann Andreas , Groesdonk Heinrich V. , Kuhlen Ralf , Meier-Hellmann Andreas
Published: October 2021

Males have a higher risk for an adverse outcome of COVID-19. The aim of the study was to analyze sex differences in the clinical course with focus on patients who received intensive care. Research was conducted as an observational retrospective cohort study. A group of 23,235 patients from 83 hospitals with PCR-confirmed infection with SARS-CoV-2 between 4 February 2020 and 22 March 2021 were included. Data on symptoms were retrieved from a separate registry, which served as a routine infection control system. Males accounted for 51.4% of all included patients. Males received more intensive care (ratio OR = 1.61, 95% CI = 1.51–1.71) and mechanical ventilation (invasive or noninvasive, OR = 1.87, 95% CI = 1.73–2.01). A model for the prediction of mortality showed that until the age 60 y, mortality increased with age with no substantial difference between sexes. After 60 y, the risk of death increased more in males than in females. At 90 y, females had a predicted mortality risk of 31%, corresponding to males of 84 y. In the intensive care unit (ICU) cohort, females of 90 y had a mortality risk of 46%, equivalent to males of 72 y. Seventy-five percent of males over 90 died, but only 46% of females of the same age. In conclusion, the sex gap was most evident among the oldest in the ICU. Understanding sex-determined differences in COVID-19 can be useful to facilitate individualized treatments.
Longitudinal Morphological Changes in the Adenoids and Tonsils in Japanese School Children
Authors: Yamada Hiroshi , Sawada Masaki , Higashino Masaaki , Abe Susumu , El-Bialy Tarek , Tanaka Eiji
Published: October 2021

The adenoid (Ad) and tonsil (Ts), located in the upper airway, play an important role in immunological protection. These lymphoid tissues grow rapidly, reach a peak of growth at the age of 6–8 years, and decrease in their size thereafter. However, little information is available on the longitudinal growth patterns of Ad and Ts in the general population. This study aimed to evaluate the individual growth of Ad and Ts during childhood using lateral cephalograms taken longitudinally from the same individuals at the ages of 8–12 years. Our results showed that the cross-sectional areas of the Ad, nasopharynx (Np), and oropharynx (Op) significantly increased with age while small changes in the size of Ts were present throughout the study period. In addition, the values of Ad/Np and Ts/Op decreased significantly with age in the elementary school. Furthermore, there was a strong and significant correlation between the Ad/Np ratio and upper airway resistance, indicating the narrowest distance in the upper airway. In conclusion, the airway occupation in Np and Op increased with age due to the increase in the sizes of Np and Op but not the decrease in the sizes of Ad and Ts.
Correlates of Sexual Function in a Sample of Spanish Women with Endometriosis
Authors: González-Mesa Ernesto , Moya-Bejarano Davinia , Butrón-Hinojo Carmen Aisha , Marín-Sánchez Pilar , Blasco-Alonso Marta , Jimenez-López Jesús Salvador , Villegas-Muñoz Emilia , Lubián-López Daniel María
Published: October 2021

Background: In the present study, we aim to report on the sexual function of women experiencing symptoms of endometriosis, analysing the clinical and psychosocial factors that may be associated. Methods: A multicentre cross-sectional study was performed to analyse the sexual function in a sample of 196 Spanish women with endometriosis, using the Female Sexual Function Inventory. Results: The Female Sexual Function Inventory (FSFI) was validated in our endometriosis study group. The mean FSFI score for the sample was 22.5 (SD 6.6), with 20.9 and 26.9 being in the 25th and 75th percentiles, respectively. Although physical sexual pain and dyspareunia were factors that influenced the sexual function of women with endometriosis, our results show that the impairment was multifactorial. Conclusions: We found impaired sexual function in women diagnosed with endometriosis. The final model included deep endometriosis, depression, age, and unemployment as strongest predictive factors for poor (deteriorated) sexual function.
Functionally Heterogenous Macrophage Subsets in the Pathogenesis of Giant Cell Arteritis: Novel Targets for Disease Monitoring and Treatment
Authors: Esen Idil , Jiemy William F. , van Sleen Yannick , van der Geest Kornelis S.M. , Sandovici Maria , Heeringa Peter , Boots Annemieke M. H. , Brouwer Elisabeth
Published: October 2021

Giant cell arteritis (GCA) is a granulomatous large-vessel vasculitis that affects adults above 50 years of age. In GCA, circulating monocytes are recruited to the inflamed arteries. With cues from the vascular microenvironment, they differentiate into macrophages and play important roles in the pathogenesis of GCA via pro-inflammatory cytokine production and vascular remodeling. However, a deeper understanding of macrophage heterogeneity in GCA pathogenesis is needed to assist the development of novel diagnostic tools and targeted therapies. Here, we review the current knowledge on macrophage heterogeneity and diverse functions of macrophage subsets in the pathogenesis of GCA. We next discuss the possibility to exploit their heterogeneity as a source of novel biomarkers and as targets for nuclear imaging. Finally, we discuss novel macrophage-targeted therapies and future directions for targeting these cells in GCA.
Immediate Implants in the Aesthetic Zone: Is Socket Shield Technique a Predictable Treatment Option? A Narrative Review
Authors: De Angelis Nicola , Signore Antonio , Alsayed Arwa , Hai Hock Wong , Solimei Luca , Barberis Fabrizio , Amaroli Andrea
Published: October 2021

(1) Background. Dental implant placement in the anterior region requires extreme precision due to relatively high aesthetic demand. This narrative review aimed to analyse some of the available clinical studies of the socket-shield technique and determine its viability for dental implant survival/success and complication rates. (2) Methods. An electronic search for publications was performed using the Cochrane, PubMed-MEDLINE, Web of Science, and Google Scholar databases. All electronic searches included human clinical and animal studies and were performed by three independent examiners. (3) Results. A total of 1383 records were identified with the initial search strategies, but only 25 full texts + five abstracts clinical studies were kept after the recruitment criteria screening. The technical details, advantages, and limitations of the techniques were illustrated. (4) Conclusion. Within the limitations of the present review, it would be merely justified that immediate dental implant placement in conjunction with the socket-shield technique can be a promising strategy for dental implant therapy.
How Do Polish Students Manage Emotional Distress during the COVID-19 Lockdown? A Web-Based Cross-Sectional Study
Authors: Sitarz Ryszard , Forma Alicja , Karakuła Kaja , Juchnowicz Dariusz , Baj Jacek , Bogucki Jacek , Karakuła-Juchnowicz Hanna
Published: October 2021

Choices regarding coping strategies during the COVID-19 pandemic outbreak may imply the development as well as the severity of emotional disorders. The aim of this web-based cross-sectional study was to: (1) assess the coping strategies for stress in a population of Polish students and (2) evaluate the impact of those strategies on the severity of depression, stress, and anxiety symptoms during the COVID-19 lockdown. To evaluate emotional distress, we used the DASS-21 scale and coping strategies Brief-COPE Inventory. The study included 2172 respondents (73% female, 27% male) with a mean age of 22.1 ± 2.2. Students more frequently chose stress coping strategies belonging to the ‘approach’ coping strategies (M = 29.60 ± 6.89) compared to ‘avoidant’ coping strategies (M = 22.82 ± 5.78). The intensification of distress in women caused a turn to religion (p = 0.001), while men used substances (p < 0.001) and a sense of humor (p < 0.001). Medical students coped best with emotional distress, which is very encouraging for their future profession. The highest level of DASS total score was associated with the usage of avoidant coping strategies, prior use of psychiatric or psychological support, and loneliness. Planning interventions to prevent emotional disorders in students requires the identification of factors contributing to increased emotional distress.
Sphinkeeper Procedure for Treating Severe Faecal Incontinence—A Prospective Cohort Study
Authors: Dawoud Christopher , Bender Leonhard , Widmann Kerstin Melanie , Harpain Felix , Riss Stefan
Published: October 2021

(1) Background: The Sphinkeeper implantation for faecal incontinence (FI) is a novel surgical procedure with limited data on its clinical efficacy. Therefore, we aimed to assess the functional outcome following Sphinkeeper surgery in patients with refractory FI. (2) Methods: Between 2018 and 2020, eleven consecutive patients (9 female) with FI met the inclusion criteria and were enrolled for surgery. Functional outcome and quality of life were evaluated by standard questionnaires pre- and post-surgery. Migration of protheses was demonstrated by 3D endoanal ultrasound. The median follow-up time was eight months (range 3–18 months). (3) Results: The median age was 75 years (range 46–89 years) with a median BMI of 27.4 (range 21.2–30.1). The median number of implanted prostheses per intervention was nine (range 9–10). We found no intraoperative or early postoperative complications. After two months, two prostheses in one patient had to be removed due to pain at the perianal skin site. The median St. Mark’s incontinence score decreased significantly from 22 to 13 points (p = 0.008). The SF-12 showed a significant improvement (35.9 versus 46.3) after surgery (p = 0.028). A migration of at least one prosthesis was observed in ten patients (91%). Six (60%) prostheses were found at the same level in another ten patients. (4) Conclusion: Sphinkeeper implantation is a promising surgical technique for patients with severe FI. The complication rate is low, and short-term functional improvement can be achieved even in severe forms of FI. Migration of implants commonly occurs.
Analysis of the Spatial and Temporal Variation of Sea Ice and Connectivity in the NEP of the Arctic in Summer in Hot Years
Authors: Liu Guochong , Ji Min , Jin Fengxiang , Li Ying , He Yawen , Li Ting
Published: October 2021

Climate warming has enabled the Arctic region to achieve seasonal navigation, and sea ice concentration is an important factor affecting the navigation of the Arctic waterways. This article uses the Arctic sea ice concentration data of the three highest temperatures in 2016, 2019, and 2020, combined with the Arctic summer sea level pressure, wind field, temperature, temperature anomaly, ice age, and sea ice movement data to analyze the spatial and temporal variation of sea ice and connectivity in the Northeast Passage (NEP) of the Arctic in Summer in three hot years, and summarizes the causes of sea ice anomalies. The results show that: (1) the summer Arctic sea ice extent in 2016, 2019 and 2020 were all lower than the multi-year average sea ice extent, and the summer sea ice extent in 2020 had the largest change trend; (2) in October of these three years, the sea ice was all negative anomalies, extending the opening time of the NEP; (3) when the sea ice concentration was 30% as the threshold, the navigation period of the NEP in 2016 was from mid-August to late October, 2019 was from the beginning of August to mid-October, 2020 was from the end of July to the end of October, and 2020 was the longest year since the opening of the NEP; (4) when the sea ice concentration was 10% as the threshold, the navigation period of the NEP in 2016 was from the end of August to the end of October, 2019 was from early August to mid-October, and 2020 was from the beginning of August to the end of October; (5) the key navigable areas of the NEP in the past three years were the central waters of the East Siberian Sea, the New Siberian Islands and the Vilkitsky Strait; (6) the navigation period of the NEP in 2016, 2019 and 2020 was longer. The main reasons were that the temperature of the NEP in the past 3 years was relatively high, the wind was weak, the sea ice movement had little effect, and the sea ice age in the key navigable areas was first year ice, which was easy to melt, which greatly promoted the opening of the NEP.
Characterization of the Fungitoxic Activity on Botrytis cinerea of N-phenyl-driman-9-carboxamides
Authors: Melo Ricardo , Armstrong Verónica , Navarro Freddy , Castro Paulo , Mendoza Leonora , Cotoras Milena
Published: October 2021

A total of 12 compounds were synthesized from the natural sesquiterpene (-) drimenol (compounds 4 to 15). The synthesized compounds corresponded to N-phenyl-driman-9-carboxamide derivatives, similar to some fungicides that inhibit the electron-transport chain. Their structures were characterized and confirmed by 1H NMR, 13C NMR spectroscopy, and mass spectrometry. Compounds 5 to 15 corresponded to novel compounds. The effect of the compounds on the mycelial growth of Botrytis cinerea was evaluated. Methoxylated and chlorinated compounds in the aromatic ring (compounds 6, 7, 12, and 13) exhibited the highest antifungal activity with IC50 values between 0.20 and 0.26 mM. On the other hand, the effect on conidial germination of B. cinerea of one methoxylated compound (6) and one chlorinated compound (7) was analyzed, and no inhibition was observed. Additionally, compound 7 decreased 36% the rate of oxygen consumption by germinating conidia.
Australians’ Financial Wellbeing and Household Debt: A Panel Analysis
Authors: Tahir Muhammad S. , Ahmed Abdullahi D.
Published: October 2021

“An excess of everything is bad”. This famous old proverb fits well with the current condition of Australian household debt that is continuously rising. Research in Australia’s household indebtedness is scarce and strategies to control the rising household debt remain contentious. The government of Australia has introduced financial literacy and financial capability measures to help control the rising household debt. Given that the literature highlights the importance of improving financial wellbeing, we analyse if financial wellbeing is a factor, which could be relevant to the reduced household debt. We use the Household, Income and Labour Dynamics in Australia panel survey in our analysis and find that improved financial wellbeing is associated with the reduced debt-taking behaviour of Australians. Our robust analysis confirms our findings. Finally, our empirical results suggest that improving households’ perception of their personal financial situation can bring improvement in their financial decisions, including the decision to take on debt.
Analysis on the Evolution of Rural Settlement Pattern and Its Influencing Factors in China from 1995 to 2015
Authors: Wang Jieyong , Zhang Yu
Published: October 2021

Since the early 1990s, China has experienced rapid industrialization and urbanization. As cities have expanded rapidly, the spatial patterns of rural settlements also changed significantly. This study uses land use data from satellite imagery interpretation, socioeconomic statistics, and field survey data, together with techniques including landscape pattern analysis, kernel density estimation, and spatial measurement models, to analyze the evolving spatial patterns of rural settlements influencing factors in China from 1995 to 2015. The results indicate the following: First, China’s rural settlements experienced significant changes in the period 1995–2015, as 88.92% of Prefectural-level administrative district units saw an increase in rural settlement area, with total settlement size increasing by 1.35 million hectares, and settlement area sprawl index values can be summarized as “high in the west and low in the east”. Second, in the two-decade study period, the population agglomeration capacity of rural settlements in China continuously weakened, and the shape and structure of rural settlement became more complex and irregular. The scale and scope of the disappearance of rural settlement areas in the northeast and southeast regions was relatively drastic, and the kernel density value of settlements dropped significantly. Third, the increase in rural settlement land area is concentrated in low-altitude and low-slope areas, with a significant tendency to be near water and roads. Fourth, social and economic factors, such as per capita net income of rural residents, the proportion of the population employed in agriculture, the size and structure of the permanent rural population, local fiscal revenue, and urbanization level, are the main factors that cause changes of rural settlement patterns. The results of this study can serve as a reference for promoting regional rural sustainable development policies and advancing rural spatial governance and comprehensive revitalization.
Understanding Friction in Cam–Tappet Contacts—An Application-Oriented Time-Dependent Simulation Approach Considering Surface Asperities and Edge Effects
Authors: Orgeldinger Christian , Tremmel Stephan
Published: October 2021

With the increasing challenges of climate change and scarce resources, the development of sustainable and energy-efficient technical systems is becoming increasingly important. In many applications, the friction losses occurring in contacts have a decisive influence on the overall efficiency. At this point, tribological contact optimization can make an important contribution to increasing the efficiency of technical systems. However, improvements are often associated with a considerable experimental effort. To reduce the development time, additional simulation models can be applied to predict the tribological behavior. This requires the closest possible approximation of the real contact within a numerical model. This paper presents a simulation approach for the time-dependent simulation of a cam–tappet contact. The simulation uses realistic operating conditions as they arise in the valve train of internal combustion engines. The influence of edge effects on the friction behavior is considered by a scaled calculation area and the influence of the surface roughness is investigated using stochastic asperity models. It is shown that the tribological behavior within the contact strongly depends on the surface properties and the load spectrum used. In addition, edge effects on the sides of the contact area have a clear influence on the pressure and film thickness distribution.
Enhancement of Catalytic Activity and Stability of La0.6Ca0.4Fe0.7Ni0.3O2.9 Perovskite with ppm Concentration of Fe in the Electrolyte for the Oxygen Evolution Reaction
Authors: Porokhin Sergei V. , Nikitina Victoria A. , Abakumov Artem M.
Published: October 2021

The catalytic activity and stability of an iron-nickel based oxygen-deficient perovskite for the oxygen evolution reaction (OER) are drastically improved with the ppm additive of Fe ions to the alkaline electrolyte. The enhancement is attributed to a 1–2 nm restructured Ni0.5Fe0.5Ox(OH)2-x (oxy)hydroxide layer, as demonstrated with scanning transmission electron microscopy. La0.6Ca0.4Fe0.7Ni0.3O2.9 shows almost a four-fold increase in OER activity after Fe addition relative to the as-prepared pristine electrolyte, which demonstrates the low Tafel slope of 44 ± 2.4 mV dec−1 and the superior intrinsic activity of 706 ± 71 A g−1oxide at 1.61 V vs. RHE.
A Flow Stress Model of the AA3104-H19 Alloy for the FEM Simulation of the Beverage Can Manufacturing Process under Large Plastic Deformations
Authors: Wędrychowicz Przemysław , Kustra Piotr , Paćko Marek , Milenin Andrij
Published: October 2021

This paper discusses the development of a flow stress model to simulate the AA3104-H19 alloy under the conditions of large plastic deformations characteristic of the beverage can manufacturing process. This study focuses on the first five steps of this process: cupping, redrawing, ironing #1, ironing #2, ironing #3. These are the stages that reduce the thickness of the base material to the maximum, resulting in an effective strain of more than 2.0, unattainable in conventional plastometric tests. To solve this problem, the specific calculation-experimental method for the development of the flow stress model was proposed. Based on the FEM modeling of the technological process, data on the history of deformation and the trajectory of movement of the selected points of the material at all stages of the production were obtained. Microspecimens for the tensile tests were taken from the points of the beverage can wall that were determined in this way. The initial strain of each sample was taken from the FEM simulation. In this way, the tensile curves were obtained for the material points at different stages of the production. The processing of these curves allowed the creation of a flow stress model for large strains, corresponding to production conditions. The tensile tests were performed on a Zwick Z250 machine at room temperature and strain rate of 0.005 s−1. The FEM-based algorithm for the determination of empirical coefficients of the analytical flow stress model is presented. The final flow stress model covers the range of effective strain from 0–2. Validation of the developed model based on the measured beverage can thicknesses showed that a flow stress model was developed that correctly and accurately describes the forming process.
Surface Effect of Nano-Roughened Yttria-Doped Zirconia on Salivary Protein Adhesion
Authors: Iqbal Muhammad Naeem , Shen Zhijian James , Bengtsson Tore , Eriksson Mirva
Published: October 2021

Biocompatibility of yttria (3 mol%) stabilized zirconia ceramics, 3Y-TZP, was affected to a large degree as a result of protein adsorption from human saliva that in turn depends on materials surface properties. Variable nano-roughness levels in 3Y-TZP discs were characterized and tested for specificity and selectivity with respect to size and uptake for human salivary protein.
Optimization and Modeling of Material Removal Rate in Wire-EDM of Silicon Particle Reinforced Al6061 Composite
Authors: Doreswamy Deepak , Bongale Anupkumar M. , Piekarski Marcin , Bongale Arunkumar , Kumar Satish , Pimenov Danil Yurievich , Giasin Khaled , Nadolny Krzysztof
Published: October 2021

The mechanical, physical and interfacial properties of aluminum alloys are improved by reinforcing the silicon carbide particles (SiCp). Machinability of such alloys by traditional methods is challenging due to higher tool wear and surface roughness. The objective of research is to investigate the machinability of SiCp reinforced Al6061 composite by Wire-Electrical Discharge Machining (wire-EDM). The effect of wire-EDM parameters namely current (I), pulse-on time (Ton), wire-speed (Ws), voltage (Iv) and pulse-off time (Toff) on material removal rate (MRR) is investigated and their settings are optimized for achieving the high MRR. The experiments are designed by using Taguchi L16 orthogonal arrays. The MRR obtained at different experiments are analyzed using statistical tools. It is observed that all the chosen process parameters showed significant influence of on the MRR with contribution of 27.39%, 22.08%, 21.32%, 15.76% and 12.94% by I, Iv, Toff, Ton and Ws, respectively. At optimum settings, the Wire-EDM resulted in MRR of 65.21 mg/min and 62.41 mg/min for samples with 4% and 8% SiCp. The results also indicated reinforcing SiCp upto 8% showed marginally low influence on MRR. Microstructural investigation of the cut surface revealed the presence of craters with wave pattern on its surface. The top surface of the crater is featured by the recast layers connecting adjacent craters. Further, the statistical model is developed using linear regression to predict the MRR (?2—73.65%) and its predicting accuracy is verified by the confirmation trials. The statistical model is useful for predicting the MRR for different settings of the process parameters. The optimized settings can be used to improve the machining productivity by increasing the MRR while machining of Al6061-SiCp (upto 8 wt. %) alloy by wire-EDM industries.
Fluorescent Chitosan Modified with Heterocyclic Aromatic Dyes
Authors: Kaczmarek Halina , Tafelska-Kaczmarek Agnieszka , Roszek Katarzyna , Czarnecka Joanna , Jędrzejewska Beata , Zblewska Katarzyna
Published: October 2021

Chitosan is a valuable, functional, and biodegradable polysaccharide that can be modified to expand its applications. This work aimed to obtain chitosan derivatives with fluorescent properties. Three heterocyclic aromatic dyes (based on benzimidazole, benzoxazole, and benzothiazole) were synthesized and used for the chemical modification of chitosan. Emission spectroscopy revealed the strong fluorescent properties of the obtained chitosan derivatives even at a low N-substitution degree of the dye. The effect of high-energy ultraviolet radiation (UV–C) on modified chitosan samples was studied in solution with UV–Vis spectroscopy and in the solid state with FTIR spectroscopy. Moreover, cytotoxicity towards three different cell types was evaluated to estimate the possibilities of biomedical applications of such fluorescent chitosan-based materials. It was found that the three new derivatives of chitosan were characterized by good resistance to UV–C, which suggests the possibility of using these materials in medicine and various industrial sectors.
A Novel Algorithm to Detect Broken Bars in Induction Motors
Authors: Souza Mateus Ventura , Lima José Claudeni Oliveira , Roque Alexandre Magno Pinto , Riffel Douglas Bressan
Published: October 2021

A new algorithm is proposed in order to detect and quantify partially broken bars in induction motors during start-up without load. In the qualification process, no threshold is used. It uses the principle of the harmonic generated by the broken bar in the stator current, it should vary with the slip to confirm the failure and provide more security in the diagnosis. A severity index is also proposed, based on the maximum peaks of the Teager energy operator of the Gaussian filter applied in the stator current signal. Experimental data were used to validate the algorithm, comparing rotors manufactured with one partially bar, one failed bar, and two completely failed bars, arranged in a variety of ways. The results show that the algorithm qualifies correctly the faulty bar, even for a partially broken bar. In the quantification phase, the severity index of the fault shows the higher sensibility in comparison to the state-of-the-art. Its value for a 3 HP motor is: 8.837 × 10−10 for a healthy rotor, 2.553 × 10−8 for a partially broken bar, and 4.058 × 10−7 for one broken bar.
Functional Electrical Stimulation System for Drop Foot Correction Using a Dynamic NARX Neural Network
Authors: Carvalho Simão , Correia Ana , Figueiredo Joana , Martins Jorge M. , Santos Cristina P.
Published: October 2021

Neurological diseases may reduce Tibialis Anterior (TA) muscle recruitment capacity causing gait disorders, such as drop foot (DF). The majority of DF patients still retain excitable nerves and muscles which makes Functional Electrical Stimulation (FES) an adequate technique to restore lost mobility. Recent studies suggest the need for developing personalized and assist-as-needed control strategies for wearable FES in order to promote natural and functional movements while reducing the early onset of fatigue. This study contributes to a real-time implementation of a trajectory tracking FES control strategy for personalized DF correction. This strategy combines a feedforward Non-Linear Autoregressive Neural Network with Exogenous inputs (NARXNN) with a feedback PD controller. This control strategy advances with a user-specific TA muscle model achieved by the NARXNN’s ability to model dynamic systems relying on the foot angle and angular velocity as inputs. A closed-loop, fully wearable stimulation system was achieved using an ISTim stimulator and wearable inertial sensor for electrical stimulation and user’s kinematic gait sensing, respectively. Results showed that the NARXNN architecture with 2 hidden layers and 10 neurons provided the highest performance for modelling the kinematic behaviour of the TA muscle. The proposed trajectory tracking control revealed a low discrepancy between real and reference foot trajectories (goodness of fit = 77.87%) and time-effectiveness for correctly stimulating the TA muscle towards a natural gait and DF correction.
Design, Development and Control of a Therapeutic Robot Incorporating Aquatic Therapy for Ankle Rehabilitation
Authors: Guzmán-Valdivia César H. , Madrigal-López Oscar , Désiga-Orenday Omar , Talavera-Otero Jorge , Brizuela-Mendoza Jorge A. , Chávez-Olivares César A. , Cruz-Domínguez Oscar , Blanco-Ortega Andrés , Berumen-Torres Javier Alejandro , Gómez-Becerra Fabio Abel
Published: October 2021

The simple act of walking can occasionally cause ankle sprains. Traditionally, the rehabilitation of a sprained ankle involves physical therapy. Physical therapy is one of the health professions that help regain mobility through manual exercises. Aquatic therapy is one of the most potent water-based anti-inflammatory methods currently employed that increases local blood circulation, decreases pain and swelling, and promotes speedy healing. Several studies have demonstrated that ankle rehabilitation robots have immense potential in patients’ rehabilitation and recovery; however, these robots cannot be used underwater. This paper introduces the design, development, and control of a therapeutic robot incorporating aquatic therapy for ankle rehabilitation. Its primary objective is to design and control a one degree of freedom ankle rehabilitation robot that can be used in water and can recirculate hot water to simultaneously perform physical therapy and aquatic therapy. To conduct this study, an ankle rehabilitation robot was designed, modeled, developed, and controlled. The design and control techniques were evaluated by means of simulation and experimental results.
Mortality and Clinical Outcomes among Patients with COVID-19 and Diabetes
Authors: Kantroo Viny , Kanwar Manjit S. , Goyal Piyush , Rosha Deepak , Modi Nikhil , Bansal Avdhesh , Ansari Athar Parvez , Wangnoo Subhash Kumar , Sobti Sanjay , Kansal Sudha , Chawla Rajesh , Jasuja Sanjiv , Gupta Ishan
Published: October 2021

Background Diabetes mellitus (DM) is a decisive risk factor for severe illness in coronavirus disease 2019 (COVID-19). India is home to a large number of people with DM, and many of them were infected with COVID-19. It is critical to understand the impact of DM on mortality and other clinical outcomes of COVID-19 infection from this region. Aims The primary objective of our study was to analyze the mortality rate in people with DM infected with COVID-19. The secondary objectives were to assess the effect of various comorbidities on mortality and study the impact of DM on other clinical outcomes. Methods This is a retrospective study of COVID-19 infected patients admitted to a tertiary care hospital in north India in the early phase of the pandemic. Results Of the 1211 cases admitted, 19 were excluded because of incomplete data, and 1192 cases were finally considered for analysis. DM constituted 26.8% of total patients. The overall mortality rate was 6.1%, and the rate was 10.7% in the presence of diabetes (p < 0.01, OR 2.55). In univariate analysis, increased age, chronic kidney disease (CKD), coronary artery disease (CAD), stroke, and cancer were associated with mortality. On multiple logistic regression, the independent predictors of mortality were CAD, CKD, and cancer. Breathlessness and low SpO2 at presentation, extensive involvement in CXR, and elevated ANC/ALC ratio were also significantly associated with mortality. Conclusions The presence of comorbidities such as DM, hypertension, CAD, CKD, and cancer strongly predict the risk of mortality in COVID-19 infection. Early triaging and aggressive therapy of patients with these comorbidities can optimize clinical outcomes.
Preparation of Al-3Ga-3In-3Sn Alloy Powder by Coupling Alloying and Ball Milling and Its Application on High-Rate Hydrogen Generation at Room Temperature
Authors: Wang Shuo , Zhu Lixiang , Zhang Lichen , Zhang Xiaodong , Wang Xiaoxuan , Ge Mengchen , Li Xiaodong , Zou Meishuai
Published: October 2021

High hydro-active Al-3Ga-3In-3Sn alloys were prepared by coupling alloying and mechanical milling methods. NiCl2 was added to the alloy during ball milling as the catalyst. XRD, SEM, and XAFS were used for the characterization of the hydro-active alloy. The hydrogen generation properties were systematically investigated in tap water at room temperature. The results show that the hydrogen generation rate is 11.02 L∙min−1∙g−1, and the conversion yield is 90.25% for the Al-3Ga-3In-3Sn-2NiCl2 composite with a ball milling time of 2 h at room temperature in tap water. The hydrolysis reaction contains the expansion of the Al-based phase into a nano-sized layer and the further hydrolysis reaction of the layered Al phase with water. The activation mechanism was also investigated, and the activation of Al was attributed to the Al-Ni galvanic with the existing Cl−, which leads to a faster hydrolysis reaction rate for ball-milled powder with NiCl2.
Investigation on the Thermal Effects of WC-Co Turning Inserts Deposited by Additive Manufacturing of Titanium Alloy Powder
Authors: Park Joon-Koo , Lee Choon-Man , Kim Dong-Hyeon
Published: October 2021

Metal additive manufacturing (AM) has been one of the most useful processes in the manufacturing field. It has significant advantages in terms of the benefits of feature freedom and material waste reduction. These processes commonly use a heat source to fabricate a 3D shape through melting of a metal powder and subsequent solidification. The directed energy deposition method can stack the desired amount of material in the required location. This study addresses the thermal effects of a WC-Co cutting tool insert deposited by AM of titanium alloy powder in the turning process. First, the optimal deposition conditions were selected by conducting preliminary experiments. Second, titanium alloy powder was deposited on the turning insert under the selected conditions. Finally, verification evaluation was carried out in the turning process. The thermal effects of the turning insert with the titanium alloy were compared with an ordinary cutting tool insert. The average temperature of the cutting tool was reduced by 15% during operation.
Preparation of Multiscale α Phase by Heat Treatments and Its Effect on Tensile Properties in Metastable β Titanium Alloy Sheet
Authors: Jiang Hanyu , Du Zhaoxin , Wang Da , Gong Tianhao , Cui Xiaoming , Liu Fei , Cheng Jun , Chen Wenzhen
Published: October 2021

This study presents a strategy for the preparation of multiscale α phase by high/low-temperature two-step aging in metastable β titanium alloy, Ti-15Mo-3Al-2.7Nb-0.2Si. The purpose of high-temperature aging is to obtain a number of micro-scale secondary α phases (αS), besides precipitation-free zones (PFZs). After that, in the second stage of low-temperature aging, the nano-scale tertiary α phase (αT) precipitates in the PFZs. The second-step aging temperature and the time at low temperature will have an important effect on αT. On the one hand, with the extension of aging time, the morphology of αT changes from dot-like to needle-like. Secondly, the increase of the second-step aging temperature will promote precipitation of αT in PFZs. The strength increases gradually with the accelerated precipitation of αT, and good plasticity is still maintained. The effect of multiscale α on fracture behavior was investigated by in situ tensile testing. Results show that cracks form a transgranular fracture along the slip line after solution treatment. After first-step aging, the crack easily passes through αS and forms an intergranular fracture. After second-step aging, the formation of multiscale α phase has a stronger effect in hindering the crack growth, which leads to crack propagation mainly by transgranular fracture. Overall, this study demonstrates that the alloy can be heat-treated to achieve an excellent match between strength and ductility, which is expected to meet the application requirements of structural materials of the new generation of aircraft.
Astrocyte Gliotransmission in the Regulation of Systemic Metabolism
Authors: Murat Cahuê De Bernardis , García-Cáceres Cristina
Published: October 2021

Normal brain function highly relies on the appropriate functioning of astrocytes. These glial cells are strategically situated between blood vessels and neurons, provide significant substrate support to neuronal demand, and are sensitive to neuronal activity and energy-related molecules. Astrocytes respond to many metabolic conditions and regulate a wide array of physiological processes, including cerebral vascular remodeling, glucose sensing, feeding, and circadian rhythms for the control of systemic metabolism and behavior-related responses. This regulation ultimately elicits counterregulatory mechanisms in order to couple whole-body energy availability with brain function. Therefore, understanding the role of astrocyte crosstalk with neighboring cells via the release of molecules, e.g., gliotransmitters, into the parenchyma in response to metabolic and neuronal cues is of fundamental relevance to elucidate the distinct roles of these glial cells in the neuroendocrine control of metabolism. Here, we review the mechanisms underlying astrocyte-released gliotransmitters that have been reported to be crucial for maintaining homeostatic regulation of systemic metabolism.
Evolving from Laboratory Toys towards Life-Savers: Small-Scale Magnetic Robotic Systems with Medical Imaging Modalities
Authors: Zhang Jiachen
Published: October 2021

Small-scale magnetic robots are remotely actuated and controlled by an externally applied magnetic field. These robots have a characteristic size ranging from several millimetres down to a few nanometres. They are often untethered in order to access constrained and hard-to-reach space buried deep in human body. Thus, they promise to bring revolutionary improvement to minimally invasive diagnostics and therapeutics. However, existing research is still mostly limited to scenarios in over-simplified laboratory environment with unrealistic working conditions. Further advancement of this field demands researchers to consider complex unstructured biological workspace. In order to deliver its promised potentials, next-generation small-scale magnetic robotic systems need to address the constraints and meet the demands of real-world clinical tasks. In particular, integrating medical imaging modalities into the robotic systems is a critical step in their evolution from laboratory toys towards potential life-savers. This review discusses the recent efforts made in this direction to push small-scale magnetic robots towards genuine biomedical applications. This review examines the accomplishment achieved so far and sheds light on the open challenges. It is hoped that this review can offer a perspective on how next-generation robotic systems can not only effectively integrate medical imaging methods, but also take full advantage of the imaging equipments to enable additional functionalities.
Suspended Silicon Waveguide with Sub-Wavelength Grating Cladding for Optical MEMS in Mid-Infrared
Authors: Qiao Qifeng , Sun Haoyang , Liu Xinmiao , Dong Bowei , Xia Ji , Lee Chengkuo , Zhou Guangya
Published: October 2021

Mid-infrared (MIR) photonics are generating considerable interest because of the potential applications in spectroscopic sensing, thermal imaging, and remote sensing. Silicon photonics is believed to be a promising solution to realize MIR photonic integrated circuits (PICs). The past decade has seen a huge growth in MIR PIC building blocks. However, there is still a need for the development of MIR reconfigurable photonics to enable powerful on-chip optical systems and new functionalities. In this paper, we present an MIR (3.7~4.1 μm wavelength range) MEMS reconfiguration approach using the suspended silicon waveguide platform on the silicon-on-insulator. With the sub-wavelength grating claddings, the photonic waveguide can be well integrated with the MEMS actuator, thus offering low-loss, energy-efficient, and effective reconfiguration. We present a simulation study on the waveguide design and depict the MEMS-integration approach. Moreover, we experimentally report the suspended waveguide with propagation loss (−2.9 dB/cm) and bending loss (−0.076 dB each). The suspended waveguide coupler is experimentally investigated. In addition, we validate the proposed optical MEMS approach using a reconfigurable ring resonator design. In conclusion, we experimentally demonstrate the proposed waveguide platform’s capability for MIR MEMS-reconfigurable photonics, which empowers the MIR on-chip optical systems for various applications.