Two previous literature review-based studies have provided important insights into mobile learning, but the issue still needs to be examined from other directions such as the distribution of research ...purposes. This study takes a meta-analysis approach to systematically reviewing the literature, thus providing a more comprehensive analysis and synthesis of 164 studies from 2003 to 2010. Major findings include that most studies of mobile learning focus on effectiveness, followed by mobile learning system design, and surveys and experiments were used as the primary research methods. Also, mobile phones and PDAs are currently the most widely used devices for mobile learning but these may be displaced by emerging technologies. In addition, the most highly-cited articles are found to focus on mobile learning system design, followed by system effectiveness. These findings may provide insights for researchers and educators into research trends in mobile learning.
► Most studies of M-learning focus on effectiveness and mobile learning system design. ► Most M-learning studies adopted surveys and experiments as the main research methods. ► Mobile phones and PDAs currently are the most used devices for mobile learning. ► Use of M-devices for learning is common in higher education and elementary schools. ► Most highly cited articles categorize to M-learning system design and effectiveness.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
An on-field colorimetric sensing strategy employing gold nanoparticles (AuNPs) and a paper-based analytical platform was investigated for mercury ion (Hg2+) detection at water sources. By utilizing ...thymine–Hg2+–thymine (T–Hg2+–T) coordination chemistry, label-free detection oligonucleotide sequences were attached to unmodified gold nanoparticles to provide rapid mercury ion sensing without complicated and time-consuming thiolated or other costly labeled probe preparation processes. Not only is this strategy’s sensing mechanism specific toward Hg2+, rather than other metal ions, but also the conformational change in the detection oligonucleotide sequences introduces different degrees of AuNP aggregation that causes the color of AuNPs to exhibit a mixture variance. To eliminate the use of sophisticated equipment and minimize the power requirement for data analysis and transmission, the color variance of multiple detection results were transferred and concentrated on cellulose-based paper analytical devices, and the data were subsequently transmitted for the readout and storage of results using cloud computing via a smartphone. As a result, a detection limit of 50 nM for Hg2+ spiked pond and river water could be achieved. Furthermore, multiple tests could be performed simultaneously with a 40 min turnaround time. These results suggest that the proposed platform possesses the capability for sensitive and high-throughput on-site mercury pollution monitoring in resource-constrained settings.
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IJS, KILJ, NUK, PNG, UL, UM
Next-generation-sequencing (NGS) has revolutionized the field of genome assembly because of its much higher data throughput and much lower cost compared with traditional Sanger sequencing. However, ...NGS poses new computational challenges to de novo genome assembly. Among the challenges, GC bias in NGS data is known to aggravate genome assembly. However, it is not clear to what extent GC bias affects genome assembly in general. In this work, we conduct a systematic analysis on the effects of GC bias on genome assembly. Our analyses reveal that GC bias only lowers assembly completeness when the degree of GC bias is above a threshold. At a strong GC bias, the assembly fragmentation due to GC bias can be explained by the low coverage of reads in the GC-poor or GC-rich regions of a genome. This effect is observed for all the assemblers under study. Increasing the total amount of NGS data thus rescues the assembly fragmentation because of GC bias. However, the amount of data needed for a full rescue depends on the distribution of GC contents. Both low and high coverage depths due to GC bias lower the accuracy of assembly. These pieces of information provide guidance toward a better de novo genome assembly in the presence of GC bias.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Objectives
To investigate the influence of resistance training (RT), aerobic training (AT), or combination training (CT) interventions on the body composition, muscle strength performance, and ...insulin‐like growth factor 1 (IGF‐1) of patients with sarcopenic obesity.
Design
Randomized controlled trial.
Setting
Community center and research center.
Participants
Sixty men and women aged 65–75 with sarcopenic obesity.
Intervention
Participants were randomly assigned to RT, AT, CT, and control (CON) groups. After training twice a week for 8 weeks, the participants in each group ceased training for 4 weeks before being examined for the retention effects of the training interventions.
Measurements
The body composition, grip strength, maximum back extensor strength, maximum knee extensor muscle strength, and blood IGF‐1 concentration were measured.
Results
The skeletal muscle mass (SMM), body fat mass, appendicular SMM/weight %, and visceral fat area (VFA) of the RT, AT, and CT groups were significantly superior to those of the CON group at both week 8 and week 12. Regarding muscle strength performance, the RT group exhibited greater grip strength at weeks 8 and 12 as well as higher knee extensor performance at week 8 than that of the other groups. At week 8, the serum IGF‐1 concentration of the RT group was higher than the CON group, whereas the CT group was superior to the AT and CON groups.
Conclusion
Older adults with sarcopenic obesity who engaged in the RT, AT, and CT interventions demonstrated increased muscle mass and reduced total fat mass and VFA compared with those without training. The muscle strength performance and serum IGF‐1 level in trained groups, especially in the RT group, were superior to the control group.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Objective
To develop and evaluate the performance of U-Net for fully automated localization and segmentation of cervical tumors in magnetic resonance (MR) images and the robustness of extracting ...apparent diffusion coefficient (ADC) radiomics features.
Methods
This retrospective study involved analysis of MR images from 169 patients with cervical cancer stage IB–IVA captured; among them, diffusion-weighted (DW) images from 144 patients were used for training, and another 25 patients were recruited for testing. A U-Net convolutional network was developed to perform automated tumor segmentation. The manually delineated tumor region was used as the ground truth for comparison. Segmentation performance was assessed for various combinations of input sources for training. ADC radiomics were extracted and assessed using Pearson correlation. The reproducibility of the training was also assessed.
Results
Combining b0, b1000, and ADC images as a triple-channel input exhibited the highest learning efficacy in the training phase and had the highest accuracy in the testing dataset, with a dice coefficient of 0.82, sensitivity 0.89, and a positive predicted value 0.92. The first-order ADC radiomics parameters were significantly correlated between the manually contoured and fully automated segmentation methods (
p
< 0.05). Reproducibility between the first and second training iterations was high for the first-order radiomics parameters (intraclass correlation coefficient = 0.70–0.99).
Conclusion
U-Net-based deep learning can perform accurate localization and segmentation of cervical cancer in DW MR images. First-order radiomics features extracted from whole tumor volume demonstrate the potential robustness for longitudinal monitoring of tumor responses in broad clinical settings.
Summary
U-Net-based deep learning can perform accurate localization and segmentation of cervical cancer in DW MR images.
Key Points
•
U-Net-based deep learning can perform accurate fully automated localization and segmentation of cervical cancer in diffusion-weighted MR images.
•
Combining b0, b1000, and apparent diffusion coefficient (ADC) images exhibited the highest accuracy in fully automated localization.
• First-order radiomics feature extraction from whole tumor volume was robust and could thus potentially be used for longitudinal monitoring of treatment responses.
Stenotrophomonas maltophilia is a Gram-negative, biofilm-forming bacterium. Although generally regarded as an organism of low virulence, S. maltophilia is an emerging multi-drug resistant ...opportunistic pathogen in hospital and community settings, especially among immunocompromised hosts. Risk factors associated with S. maltophilia infection include underlying malignancy, cystic fibrosis, corticosteroid or immunosuppressant therapy, the presence of an indwelling central venous catheter and exposure to broad spectrum antibiotics. In this review, we provide a synthesis of information on current global trends in S. maltophilia pathogenicity as well as updated information on the molecular mechanisms contributing to its resistance to an array of antimicrobial agents. The prevalence of S. maltophilia infection in the general population increased from 0.8-1.4% during 1997-2003 to 1.3-1.68% during 2007-2012. The most important molecular mechanisms contributing to its resistance to antibiotics include β-lactamase production, the expression of Qnr genes, and the presence of class 1 integrons and efflux pumps. Trimethoprim/sulfamethoxazole (TMP/SMX) is the antimicrobial drug of choice. Although a few studies have reported increased resistance to TMP/SMX, the majority of studies worldwide show that S. maltophilia continues to be highly susceptible. Drugs with historically good susceptibility results include ceftazidime, ticarcillin-clavulanate, and fluoroquinolones; however, a number of studies show an alarming trend in resistance to those agents. Tetracyclines such as tigecycline, minocycline, and doxycycline are also effective agents and consistently display good activity against S. maltophilia in various geographic regions and across different time periods. Combination therapies, novel agents, and aerosolized forms of antimicrobial drugs are currently being tested for their ability to treat infections caused by this multi-drug resistant organism.
Stimuli-responsive ion nanochannels have attracted considerable attention in various fields because of their remote controllability of ionic transportation. For photoresponsive ion nanochannels, ...however, achieving precise regulation of ion conductivity is still challenging, primarily due to the difficulty of programmable structural changes in confined environments. Moreover, the relationship between noncontact photo-stimulation in nanoscale and light-induced ion conductivity has not been well understood. In this work, a versatile design for fabricating guard cell-inspired photoswitchable ion channels is presented by infiltrating azobenzene-cross-linked polymer (AAZO-PDAC) into nanoporous anodic aluminum oxide (AAO) membranes. The azobenzene-cross-linked polymer is formed by azobenzene chromophore (AAZO)-cross-linked poly(diallyldimethylammonium chloride) (PDAC) with electrostatic interactions. Under UV irradiation, the trans-AAZO isomerizes to the cis-AAZO, causing the volume compression of the polymer network, whereas, in darkness, the cis-AAZO reverts to the trans-AAZO, leading to the recovery of the structure. Consequently, the resultant nanopore sizes can be manipulated by the photomechanical effect of the AAZO-PDAC polymers. By adding ionic liquids, the ion conductivity of the light-driven ion nanochannels can be controlled with good repeatability and fast responses (within seconds) in multiple cycles. The ion channels have promising potential in the applications of biomimetic materials, sensors, and biomedical sciences.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A mask is one of the most basic protections to prevent the transmission of COVID-19. Surgical mask tension release bands (SMTRBs) are commonly used to ease the pain caused by prolonged mask use. ...However, the structural strength of SMTRBs and the effect that wearing masks with SMTRBs has on the face are unclear. Thus, this study assessed the mechanics of seven different types of 3D-printed SMTRBs. In this study, a tensile testing machine, a sensor array system, and finite element analysis were used to evaluate the mechanisms of seven SMTRBs. The tensile testing machine was applied to measure the breaking strength, elongation, stiffness, and rupture of the band. The sensor array system was used to calculate the pressure on the face when the band was used together with the mask. Finite element analysis was applied to evaluate the level of stress on the SMTRB structure when each of the seven bands was subjected to external force. The results demonstrated that thick SMTRBs put more pressure on the face but had greater structural strength. The thinner bands did not break easily; however, the mask ear loops tended to slip off more often. In addition, the size of the band hook affected the magnitude of the external force. This study provides a biomechanical reference for the future design of SMTRBs.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Microporous activated carbon fibers (ACFs) were developed for CO₂ capture based on potassium hydroxide (KOH) activation and tetraethylenepentamine (TEPA) amination. The material properties of the ...modified ACFs were characterized using several techniques. The adsorption breakthrough curves of CO₂ were measured and the effect of relative humidity in the carrier gas was determined. The KOH activation at high temperature generated additional pore networks and the intercalation of metallic K into the carbon matrix, leading to the production of mesopore and micropore volumes and providing access to the active sites in the micropores. However, this treatment also resulted in the loss of nitrogen functionalities. The TEPA amination has successfully introduced nitrogen functionalities onto the fiber surface, but its long-chain structure blocked parts of the micropores and, thus, made the available surface area and pore volume limited. Introduction of the power of time into the Wheeler equation was required to fit the data well. The relative humidity within the studied range had almost no effects on the breakthrough curves. It was expected that the concentration of CO₂ was high enough so that the impact on CO₂ adsorption capacity lessened due to increased relative humidity.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The tightly regulated biosynthesis and catabolism of the glycosaminoglycan hyaluronan, as well as its role in organizing tissues and cell signaling, is crucial for the homeostasis of tissues. ...Overexpression of hyaluronan plays pivotal roles in inflammation and cancer, and markedly high serum and tissue levels of hyaluronan are noted under such pathological conditions. This review focuses on the complexity of the regulation at transcriptional and posttranslational level of hyaluronan synthetic enzymes, and the outcome of their aberrant expression and accumulation of hyaluronan in clinical conditions, such as systemic B-cell cancers, aggressive breast carcinomas, metabolic diseases and virus infection.
•Mechanisms that regulate hyaluronan biosynthesis at transcriptional and posttranslational levels.•Consequences of hyaluronan deficiency.•Functional implications of overproduction of HAS1, HAS2 and HAS3 in cancer, metabolic diseases and infection.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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