Flexible materials with high electromechanical coupling performance are highly demanded for wide applications for electromechanical sensors and transducers, including mechanical energy harvesters. ...Here, outstanding electromechanical performance is obtained in electrospun‐aligned polyvinylidene fluoride (PVDF) fiber film. A theoretical model is developed from systematic theoretical analyses to clarify the underlying constructive piezoelectric‐triboelectric mechanism in the polarized PVDF fiber films that explains the experimental observations well. The electrospinning process induces polarization alignment and thus tunes the electron affinity for PVDF fibers with different polarization terminals, which results in the constructive piezoelectric and triboelectric responses in the obtained PVDF fiber films. Extremely large effective piezoelectric performance properties are achieved in the direct piezoelectric measurements, reaching the maximum effective piezoelectric strain and voltage coefficients of −1065 pm V−1 and −9178 V mm N−1, respectively, at 100 Hz. In the converse piezoelectric measurements without a significant contribution from reversible triboelectric effect, the maximum effective piezoelectric strain and voltage coefficients are −166 pm V−1 and −1499 V mm N−1, respectively. The theoretical analyses and experimental results show the great potential of the electrospun aligned polar PVDF fiber material for various electromechanical device applications, particularly for mechanical energy harvesting.
Outstanding electromechanical conversion performance is achieved through constructive piezoelectric and triboelectric effects in aligned electrospun polyvinylidene fluoride (PVDF) fibers. A theoretical model is developed from systematic theoretical analyses to clarify the constructive piezoelectric‐triboelectric mechanism and explain the giant electric output in response to vibration in the polarized PVDF fiber material. Showing great potential for mechanical energy harvesting applications.
•Liraglutide modulated the canonical Hh signaling in DXR-induced gonadotoxicity.•Liraglutide potentiated the PI3K/AKT/p-GSK3β cascade.•Liraglutide relieved the oxidative burden-induced by the DXR.
...Chemotherapy-accompanied reproductive dysfunction has lately begun to draw the attention of the scientific community owing to the irreversible impact on the patient’s quality of life. Here we tended to investigate the potential role of liraglutide (LRG) in modulating the canonical Hedgehog (Hh) signaling in doxorubicin (DXR)-induced gonadotoxicity in rats. Female virgin Wistar rats were divided into 4 groups; control, DXR-treated (25 mg/kg, single i.p. injection), LRG-treated (150 μg/Kg/day, s.c) and itraconazole (ITC; 150 mg/kg/day, p.o)-pretreated group, as the Hh pathway inhibitor. Treatment with LRG potentiated the PI3K/AKT/p-GSK3β cascade and relieved the oxidative burden-induced by the DXR-driven immunogenic cell death (ICD). LRG also upregulated the expression of the Desert hedgehog ligand (DHh) and the patched-1 (PTCH1) receptor and augmented the protein level of Indian hedgehog (IHh) ligand, Gli1 and cyclin-D1 (CD1). Besides, hypertranscription of IHh, DHh, Ptch1, Smo, Gli1/2 and CD1 genes along with a transcriptional recession of Gli3 gene were reported in LRG-treated group. ITC pre-administration partially abrogated this positive effect of LRG, proving the implication of the examined pathway. Microscopically, LRG ameliorated the follicular atresia noticed in the DXR group; effect that was, at least partially, declined by ITC pre-treatment. These findings end to a conclusion that LRG treatment might hinder the DXR-associated reproductive toxicity, resultant from ROS generated by the cells undergoing ICD, and trigger follicular growth and repair by the PI3K/AKT- dependent switching-on of the canonical Hh pathway.
Non-steroidal anti-inflammatory drugs (NSAIDs)-induced gastric ulcers represent a significant clinical concern and adversely affect the quality of life. Inducible nitric oxide synthase/endothelial ...nitric oxide synthase (iNOS/eNOS) and asymmetric dimethylarginine/ dimethylarginine dimethylaminohydrolase-1 (ADMA/DDAH-1) signaling are key players in gastric ulcer pathogenesis. This work was planned to explore the role of iNOS/eNOS and ADMA/DDAH-1 signaling in rats with indomethacin-induced gastric ulcer, as potential pathways for the gastro-protective effect of tadalafil. Split into 5 separate groups, rats were assigned to control, tadalafil (10 mg/kg, p.o), indomethacin (single oral dose of 60 mg/kg), indomethacin + pantoprazole (40 mg/kg, p.o), and indomethacin + tadalafil (10 mg/kg, p.o). The results indicated that pretreatment with tadalafil significantly reduced ulcer index (UI), increased preventive index (PI), and counteracted indomethacin-induced histopathological aberrations. Tadalafil significantly reduced the gastric content of NO while it significantly elevated that of GSH and enhanced SOD activity. It significantly reduced the gastric expression of TNF-α and ADMA while it significantly elevated that of COX-2, PGE-2, and DDAH-1. Western blot analysis revealed that pretreatment with tadalafil significantly reduced iNOS protein expression while it significantly elevated that of eNOS. Collectively, these data suggest that tadalafil exerts potential protective effect against indomethacin-induced ulcer through suppression of inflammation, attenuation of oxidative stress, and boosting of antioxidants. Moreover, tadalafil protective effects are mediated via upregulation of PGE-2 with modulating the signaling pathways of ADMA/DDAH-1, and iNOS/eNOS. As a result, the current evidence corroborates the use of tadalafil in controlling gastric ulcers and preventing NSAID gastric side effects.
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•Tadalafil attenuated gastric histopathological damage.•It increased GSH content and SOD activity while decreased NO content.•It modulated gastric ADMA and DDAH-1 activity.•It reduced TNF-α, while increased COX-2 and PGE-2 expression.•It upregulated eNOS expression and downregulated iNOS expression.
Introduction
Vaccine coverage remains inequitable globally. Many systematic reviews have looked at the effectiveness of strategies to improve vaccine uptake; however, these reviews frequently lack ...data from low and middle-income countries (LMICs), where evidence of cost-effective strategies is most valuable. This is partly because reviews often exclude non-randomised, observational or unpublished evaluations that are common in LMICs. Many reviews also exclude multicomponent interventions due to challenges isolating the effect of each component. A comprehensive mapping of multicomponent interventions implemented in LMICs would increase the visibility of studies excluded from systematic reviews and improve comparability of future evaluations by providing guidance for researchers on evaluation frameworks. This scoping review aims to identify, compare and summarise the properties and evaluation methods of multicomponent interventions to improve uptake of routine childhood vaccines in LMICs, and to assess the strengths and limitations of evaluation frameworks applied.
Methods and analysis
This review will be conducted using the Joanna Briggs Institute methodology for scoping reviews and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for Scoping Reviews guidelines. We will search the following databases: MEDLINE, Embase, PubMed, Cochrane, Eldis and Global Health (CAB Direct), Global Index Medicus, 3ie Portal, Google Scholar, COnnecting REpositories, and reference lists. One author will screen titles and abstracts and extract data from included articles using a pretested data extraction template. Uncertainties will be resolved through discussion with another author. Only studies published in English will be included for full review. We will assess the practicability, applicability, sensitivity and specificity of the evaluation frameworks used and present results using descriptive statistics, summary tables and charts.
Ethics and dissemination
Ethics approval is not required. The review will be submitted as part of a doctoral thesis, presented at conferences and published in peer-reviewed journals.
Study registration
https://osf.io/7r84g
.
Shear mode guided waves are highly demanded for underwater structural health monitoring (SHM) applications due to their simplified non‐dispersive feature and minimal acoustic energy loss in the ...presence of liquid. Excitation and detection of pure shear wave are challenging using conventional piezoelectric materials used in the current ultrasonic transducers because they have complex piezoelectric responses mixed with multiple longitudinal, transverse, and shear modes. They also suffer from aging issue due to depoling. Here, conformable shear mode ultrasonic transducers are designed and made of flexible piezoelectric poly (L‐lactic acid) (PLLA) fibers on both flat and tubular structures. The electromechanical responses over a macroscopic area of the transducers are evaluated in a wide frequency range up to 500 kHz. The PLLA fiber‐based shear mode ultrasonic transducers exhibit a consistent sensitivity of detecting defects in liquid and air. In addition, the only shear mode in PLLA fibers originates from crystal structure without requiring electrical poling to render piezoelectricity, thus does not depole due to aging. The theoretical analyses including ab initio calculations and experimental results on both flat and tubular structures show the great potential of PLLA material and significant advantage of PLLA fiber‐based shear mode ultrasonic transducers for underwater SHM applications.
Pure shear mode and conformable ultrasonic transducers are designed and produced from flexible piezoelectric poly (L‐lactic acid) (PLLA) fibers with molecular chain orientation. The PLLA‐fiber transducers exhibit unique directivity for non‐dispersive shear wave, and no substantial change in the ultrasonic signals for operation in water. The theoretical analysis and experimental demonstration show great value for underwater ultrasonic structural health monitoring applications.
The power system is one of the most susceptible systems to failures, which are most frequently caused by transmission line faults. Transmission line failures account for 85% of all power system ...malfunctions. However, over the last decade, numerous fault detection methods have been developed to ensure the reliability and stability of power systems. A hybrid detection method based on the idea of redundancy property is presented in this paper. Because the continuous wavelet transform itself does not extract fault features for small defects effectively, the stationary wavelet transform approach is employed to assist in their detection. As a result of its ability to decompose the signal into high- and low-frequency components, undecimated reconstruction by using the algebraic summation operation (ASO) is used. This approach creates redundancy, which is useful for the feature extraction of small defects and makes faulty parts more evident. The numerical value of the redundancy ratio’s contribution to the original signal is approximately equal to 36%. Following this method for redundant signal reconstruction, a continuous wavelet transform is used to extract the fault characteristic significantly easier in the time-scale (frequency) domain. Finally, the suggested technique has been demonstrated to be an efficient fault detection and identification tool for use in power systems. In fact, using this advanced signal processing technique will help with early fault detection, which is mainly about predictive maintenance. This application provides more reliable operation conditions.
Background
The recently developed Caries Impacts and Experiences Questionnaire for Children (CARIES‐QC) is originally an English questionnaire targeting the assessment of caries‐related quality of ...life from a child's point of view.
Aim
This study aimed to translate and adapt the CARIES‐QC into the Arabic language and to test its reliability and validity on Arabic‐speaking children.
Design
A total of 234 children aged 5–16 years answered the translated questionnaire. Internal consistency was measured using Cronbach's alpha; 62 children answered the questionnaire again to evaluate the test‐retest reliability by calculating the intraclass correlation coefficient (ICC). Convergent validity was evaluated by correlating question scores with global question scores. Confirmatory factor analysis (CFA) was conducted to evaluate cross‐cultural validity.
Results
Cronbach's alpha of the CARIES‐QC/A was 0.905. The inter‐item correlation coefficients of the CARIES‐QC/A ranged from 0.240 to 0.850. The total ICC score was 0.960. CFA demonstrated acceptable fit to the data in the one‐factor model. Convergent validity indicated moderate correlation with the global question (rs = .740).
Conclusion
The CARIES‐QC/A is a valid and reliable tool that could be used to evaluate oral health–related quality of life in Arabic‐speaking children.
The present work aimed to investigate the effect of salinity in natural habitats in Egypt on the main secondary metabolites of Rosmarinus officinalis L. and Artemisia monosperma L. plants compared to ...plants grown at normal conditions. Plants grown under salinity were collected from Egyptian Western Coastal region habitats irrigated with underground water. Results showed that salinity increased the essential oil percentage of R. officinalis L. by 52.7% and A. monosperma L by 0.29% in addition to the total phenolics and flavonoids content in dry leaves compared to control plants. GC/MS analysis of rosemary essential oils revealed that salinity decreased the amount of some major oil monoterpenes component as verbenone, with a slight effect on 1,8 cineole and increased Camphor, endo- Boreneol, and linalool in addition to the appearance of new specific components such as Chrysanthenone monoterpene ketone and Caryophyllene sesquiterpene, while, in the case of Artemisia, the GC/MS showed that Artemisia ketone, Camphor, β -phellandrene monoterpenes andα-Bisabolol sesquiterpenewere the major oil components; salinity decreased Camphor and β -phellandrene content and increased artemisia ketone and α-Bisabolol oil content. About 11 new oil constituents were detected such as ( +)-2-Bornanone and Sesquisabinene hydrate. Mineral ions (N, K
, Ca
, P, and Mg
) uptake by R. officinalis and A. monosperma decreased in plants grown under salinity, while Na content increased compared to corresponding controls. Results demonstrated that both plants could tolerate the high salinity level in natural Western Coastal region soil which promoted more production of valuable secondary metabolites. The antimicrobial effect of R. officinalis L. and A. monosperma L. leaf methanolic extracts, results showed that R. officinalis extracts had an inhibitory response against all tested gram-positive and negative bacteria, in addition to the yeast (Candida albicans), whereas there was no any inhibitory effect concerning A. monosperma L extract on the tested species.
During the novel COVID-19 pandemic, many universities adopted distance and hybrid learning as a modification to their teaching methods to ensure continuity of education, abiding by the worldwide ...recommendations of social distancing.
To compare learning environments created through hybrid learning versus distance learning, to deliver paediatric dentistry course, and to assess the correlation between the created learning environment and students' satisfaction.
In this cross-sectional study, students enrolled in a hybrid paediatric dentistry course were asked to participate in an electronic survey. The learning environment was assessed using Distance Educational Learning Environment Survey (DELES), students' satisfaction was assessed using Satisfaction Scale (SS). Retrospective data for distance learning course was used for comparison. Ordinal data were compared using Mann-Whitney U test. Spearman's rank order correlation coefficient was used to correlate students' satisfaction with DELES. Multiple regression analysis was used to predict satisfaction.
A total of 376 students' data were considered in the study. Hybrid learning had significantly higher scores than distance learning in 3 DELES scales. There was a statistically significant weak positive correlation between satisfaction and DELES. Multiple regression analysis model was statistically significant and accounted for (22.8%) of the variance in students' satisfaction. Only "Instructor support" (p = 0.001) and "Student autonomy" (p < 0.001) had a significant effect on satisfaction.
This study supports the superiority of a hybrid learning environment over a complete distance learning environment, it also shows that satisfaction is correlated and can be predicted by the created learning environment.
This study has been registered on clinicaltrials.gov on 21 May 2020 with an identifier: NCT04401371 .
