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Simple Summary: Ticks, key vectors for multiple pathogens in veterinary medicine, lack the ability to fly. To feed on blood, they must climb onto a host's hair coat from their natural habitat. Their life cycle is closely linked to wildlife, with the Cervidae family serving as primary hosts for adult ticks. In South Korea, the Korean water deer and roe deer are prominent members of the Cervidae family. Notably, the Korean water deer exhibit a lower rate of tick infestation compared to the roe deer. This study aims to understand the reasons behind this difference by conducting an in-depth comparative analysis of the skin and hair characteristics of both species. We found significant variations in certain factors that may hinder ticks from reaching their feeding sites on Korean water deer, potentially acting as a natural defense mechanism against ticks. To our knowledge, this research is the first to focus on comparing the skin and hair attributes of Korean water deer and roe deer in the context of tick bite prevention. The Korean water deer (WD), a predominant wildlife species in South Korea, is listed as vulnerable by the IUCN Red List. Despite belonging to the same family, Cervidae, WD show significantly fewer adult ixodid tick infestations compared to roe deer (RD). Ticks, which cannot fly, engage in questing behavior in natural environments to latch onto hosts. They detect signals like body temperature and host skin chemicals to navigate through the hair coat to the preferred epidermis. In light of this, we performed an extensive comparative study of the skin tissue and hair characteristics of both deer species, focusing on elements contributing to the reduced tick bite incidence in WD. Remarkably, WD exhibited more prominent blood vessels, sebaceous glands, and sweat glands, which are crucial for skin barrier functions (p < 0.005). Moreover, WD had irregular scale patterns on their hair cuticles and possessed hair that was significantly stiffer and 2.83 times thicker than that of RD (p < 0.001). These characteristics potentially impede ticks from reaching the epidermis hair in WD and RD in the context of tick bite prevention. Further investigations in this area could enhance our understanding of tick–host dynamics and contribute to developing preventive measures against tick-borne diseases in other deer species. [ABSTRACT FROM AUTHOR]

Simple Summary: A 6-month-old male Korean native calf, known for its highly marbled meat, was purchased but found dead three days later, without any notable medical history. The calf had a significantly higher body weight than average for its age. Postmortem examination revealed fat necrosis, along with gastric dilatation, volvulus and intestinal obstruction, as the cause of death. Serum chemistry analysis indicated disrupted lipid metabolism and pancreatic damage—obstructive acute pancreatitis. To investigate the cause of fat necrosis, microRNA patterns were analyzed. Interestingly, the results resembled those found in human patients with diabetes mellitus. To explore the potential correlation between fat necrosis and human diabetic-like miRNA patterns, a comprehensive analysis of miRNAs and the miRNA-mediated Kyoto Encyclopedia of Gene and Genome (KEGG) pathway were conducted. The bovine target gene prediction and KEGG analysis indicated a significant association between multiple genes and diabetic-like clinical conditions. These findings suggest fat necrosis can occur in high-spec cattle such as Korean native calves, and in such cases clinical indicators such as diabetes are observed, providing the factors contributing to the breed's high meat quality and marbling. The in-depth analysis of miRNA and the KEGG pathway offers valuable insights into the potential mechanisms underlying this correlation. Korean native cattle are highly valued for their rich marbling and flavor. Nonetheless, endeavors to enhance marbling levels can result in obesity, a prevalent contributor to fat necrosis. Fat necrosis is characterized by the formation of necrotic fat masses in the abdominal cavity, which physically puts pressure on affected organs, causing physical torsion or obstruction, resulting in death and consequent economic loss. Pancreatic injuries or diabetes mellitus were reported as factors of fat necrosis in humans; however, the pathogenesis in animals has not been established. In this study, we identified fat necrosis in a 6-month-old Korean native cow and investigated its potential underlying causes. Serum samples were utilized for a microarray analysis of bovine miRNA. Comparative examination of miRNA expression levels between cattle afflicted with fat necrosis and healthy cattle unveiled notable variances in 24 miRNAs, such as bta-miR-26a, bta-miR-29a, bta-miR-30a-5p and bta-miR-181a. Upon conducting miRNA-mediated KEGG pathway analysis, several pathways including the prolactin signal pathway, insulin resistance, autophagy, the insulin-signaling pathway and the FoxO-signaling pathway were found to be significantly enriched in the calf affected by fat necrosis. As a result, this study potentially indicates a potential connection between fat necrosis and diabetes in Korean native cattle. [ABSTRACT FROM AUTHOR]

The recent Coronavirus Disease 2019 pandemic has highlighted the importance of indoor ventilation. In particular, ventilation is crucial in residential spaces and workspaces, where people spent most of their day. Natural ventilation is a cost-effective method for improving indoor ventilation. It can provide safe and comfortable residential and working environments without additional energy consumption. In this study, the ventilation performance was experimentally studied by measuring the concentration of ultrafine particulate matter according to the opening conditions of the windows and door of an office model in a wind tunnel. Furthermore, the internal flow structure in the office model was quantitatively analyzed through particle image velocimetry to determine the factors that affected the ventilation performance. The mean velocity inside the model and the ventilation performance increased with the opening angle of the windows. In particular, the opening condition of the door strongly affected the ventilation performance. This study is expected to provide a guideline for effectively improving the ventilation performance in indoor spaces. [ABSTRACT FROM AUTHOR]

Summary: Despite a high theoretical capacity, relatively low potential, and natural abundance, the practical application of Si anode is limited by a drastic volume change and low electrical conductivity. To resolve these issues, herein, we demonstrated a hierarchically structured composite, consisting of Si microparticle/reduced graphene oxide (rGO) wrapped by interconnected carbon nanotube (CNT) branches (CNT@NiNP@Si/rGO), for lithium‐ion battery (LIB) anodes. Chemical vapor deposition is used to in situ grow CNT branches integrated onto the rGO and to encapsulate Ni nanoparticles (NiNP) at the tip of CNTs for the construction of three‐dimensional (3D) hierarchical complex structures. Moreover, ultrasonication is required for achieving uniform dispersion of NiNP catalyst for the growth of well‐defined CNT branches. The resulting CNT@NiNP@Si/rGO composites deliver the high rate capacity of 806 mAh g−1 at 8,400 mA g−1 and high capacity of 973 mAh g−1 after 250 cycles. Consequently, these improved performances of CNT@NiNP@Si/rGO composites are attributed to the effect of stress delocalization and facilitated charge transfer of Si arising from the hierarchical structure and covalent SiC bonds. [ABSTRACT FROM AUTHOR]

We evaluated the effectiveness of intravitreal anti-vascular endothelial growth factor (anti-VEGF) antibody injection (IVAI) for the prevention of recurrent vitreous hemorrhage (VH) due to neovascularization on disc (NVD) in patients with proliferative diabetic retinopathy (PDR) after panretinal photocoagulation (PRP). This retrospective case series reviewed the medical records of 12 PDR patients with recurrent VH after PRP from NVD. The interval between IVAIs was decided on the basis of the interval between VH recurrences after the initial IVAI, and NVD regression/recurrence during follow-up. We recorded the success rate of VH prevention, and the interval between IVAIs. Fundus examination revealed NVD regression at 1 month after the injection. However, NVD progressed gradually and VH recurred after 3–4 months. Thereafter, IVAIs were administered every 3–4 months; VH did not recur and visual acuity remained stable during the treatment period. In one case, NVD did not recur after 4 years of periodic injections. No systemic or ocular complications of IVAI were observed. In conclusion, proactive and periodic IVAIs (at 3–4-month intervals) may prevent recurrent VH in association with NVD in PDR patients after PRP. [ABSTRACT FROM AUTHOR]

Purpose: Considering the scarcity of normal and strabismic images, this study proposed a method that combines a meta-learning approach with image processing methods to improve the classification accuracy when meta-learning alone is used for screening strabismus. Methods: The meta-learning approach was first pre-trained on a public dataset to obtain a well-generalized embedding network to extract distinctive features of images. On the other hand, the image processing methods were used to extract the position features of eye regions (e.g., iris position, corneal light reflex) as supplementary features to the distinctive features. Afterward, principal component analysis was applied to reduce the dimensionality of distinctive features for integration with low-dimensional supplementary features. The integrated features were then used to train a support vector machine classifier for performing strabismus screening. Sixty images (30 normal and 30 strabismus) were used to verify the effectiveness of the proposed method, and its classification performance was assessed by computing the accuracy, specificity, and sensitivity through 5,000 experiments. Results: The proposed method achieved a classification accuracy of 0.805 with a sensitivity (correct classification of strabismus) of 0.768 and a specificity (correct classification of normal) of 0.842, whereas the classification accuracy of using meta-learning alone was 0.709 with a sensitivity of 0.740 and a specificity of 0.678. Conclusion: The proposed strabismus screening method achieved promising classification accuracy and gained significant accuracy improvement over using meta-learning alone under data scarcity. [ABSTRACT FROM AUTHOR]

Lubricant-infused surfaces (LISs), whose initial development was inspired by the slippery surface of Nepenthes pitcher plants, have been eliciting considerable attraction. LISs have been extensively investigated during the last decade due to their potential for various applications, including antifouling, self-cleaning, and drag reduction. However, they can lose slipperiness when the outermost lubricant layer is severely depleted by external forces, such as flow-induced shear force. In the current study, we examined the shear-induced depletion of a lubricant impregnated into a spherical cavity exposed to a laminar channel flow. When the depth of interfacial meniscus exceeds a critical value due to depletion of the infused lubricant, the rotational direction of the lubricant flow inside the cavity is changed. This conversion in the lubricant's rotational direction is attributed to the flow separation above the meniscus between the lubricant and the working fluid. The flow separation induces the formation of a vortex and largely increases the drag force, which is an undesirable situation for LISs to achieve a sustainable drag reduction. To identify the unfavorable drag increasing conditions, we examined the critical depth of meniscus, defined as the depth of meniscus at the onset of switch in the rotational direction of the lubricant flow, with varying cavity geometry, flow velocity, and dynamic viscosity of the working fluid. In addition, a simple scaling analysis was conducted by balancing the viscous pressure and capillary pressure to deduce a theoretical prediction of the critical meniscus depth. The experimentally measured results are matched well with the theoretical predictions. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to provide an automatic strabismus screening method for people who live in remote areas with poor medical accessibility. Materials and methods: The proposed method first utilizes a pretrained convolutional neural network-based face-detection model and a detector for 68 facial landmarks to extract the eye region for a frontal facial image. Second, Otsu's binarization and the HSV color model are applied to the image to eliminate the influence of eyelashes and canthi. Then, the method samples all of the pixel points on the limbus and applies the least square method to obtain the coordinate of the pupil center. Lastly, we calculated the distances from the pupil center to the medial and lateral canthus to measure the deviation of the positional similarity of two eyes for strabismus screening. Result: We used a total of 60 frontal facial images (30 strabismus images, 30 normal images) to validate the proposed method. The average value of the iris positional similarity of normal images was smaller than one of the strabismus images via the method (p-value<0.001). The sample mean and sample standard deviation of the positional similarity of the normal and strabismus images were 1.073 ± 0.014 and 0.039, as well as 1.924 ± 0.169 and 0.472, respectively. Conclusion: The experimental results of 60 images show that the proposed method is a promising automatic strabismus screening method for people living in remote areas with poor medical accessibility. [ABSTRACT FROM AUTHOR]

In response to the COVID-19 pandemic, K-12 schools in the United States closed and teachers transitioned to distance learning. The purpose of this survey research study is to determine technology resources and strategies K-12 teachers have used in this transition. Additionally, this study examines the difficulties teachers experienced, along with support they wish they had during the transition. Findings indicate that a wide variety of websites and applications were used to provide academic continuity, the majority of which were familiar to teachers. In the transition process, teachers were faced with various challenges, including difficulty engaging students and parents, a lack of school/district guidelines, and student Internet and computer access issues. Recommendations to prepare for future emergencies include making clear plans for emergencies and incorporating online components and training within current face-to-face classes and professional development. [ABSTRACT FROM AUTHOR]

One of the major concerns about online learning has been the low level of student satisfaction and retention rates. Using the community of inquiry (CoI) framework, this study examined course delivery modes and students' perceived ratings of course difficulty in online and face-to-face sections of a technology-intensive course and how the delivery modes and perceived difficulty were related to the essential elements of the CoI framework and course satisfaction. The findings revealed that more students in the online section found it difficult to learn in a technology-intensive course. Also, while different delivery modes were closely related to social presence, students' perceived course difficulty was significantly related to teaching and cognitive presences of the CoI framework. Additionally, there was a correlation between students' perceived difficulty ratings and student satisfaction in online learning. [ABSTRACT FROM AUTHOR]

The wettability of surfaces plays a crucial role in determining their applications, and slippery surfaces have been utilized in various fields. Especially, lubricant-infused surface (LIS) has been undergone extensive research over the past decade. However, LIS tends to lose its infused lubricant and consequently lose its slippery properties when exposed to harsh conditions. Therefore, there is a strong need to enhance the durability of the infused lubricant. Herein, two strategies are adopted to improve the durability of slippery properties against centrifugal forces and high-speed shear flows. One strategy is using re-entrant shaped nanocavities, and the other is grafting PDMS brush onto the surface. Anodic aluminum oxide (AAO) is employed to fabricate the re-entrant shaped nanocavities, and the durability of the infused lubricant is improved when the cavities have a smaller diameter. Furthermore, the re-entrant shape of nanocavity significantly improves the durability compared to nanocavity with a constant diameter. The grafting of PDMS brush is essential for enhancing the durability, and an increase in the length of the PDMS brush also improves the durability. The fabricated AAO-based LIS (AAO-LIS) maintains the slippery properties for 50 min under a high-speed water flow of 12 m/s. In addition, it maintains its superior slipperiness for more than a few days when exposed to actual seawater. Furthermore, the frictional drag reduction performance of the fabricated AAO-LIS is assessed. The proposed AAO-LIS maintains a certain drag reduction performance durably even after losing its superior slipperiness, demonstrating its strong potential for practical applications across various industrial fields. [Display omitted] • A durable slippery AAO-LIS with re-entrant shaped nanocavity and grafting of a PDMS brush onto it is proposed. • The re-entrant shaped nanocavity and grafting PDMS brush significantly enhance the durability of the slippery properties. • The proposed AAO-LIS exhibits excellent chemical resistance. • The proposed AAO-LIS maintains its frictional drag reduction effect even after losing slippery properties. [ABSTRACT FROM AUTHOR]

In 2017, Food and Drug Administration (FDA) circulated a draft guidance on analytical similarity assessment to assist the sponsors for providing totality-of-the-evidence in support of the demonstration of biosimilarity between a proposed biosimilar product and an innovative biological product. The guidance was subsequently withdrawn by the FDA due to some major criticisms received from general public. These major criticisms include, but are not limited to, (i) the use of 90% confidence interval (CI) versus 95% CI, (ii) tiered approach for analytical similarity evaluation, and (iii) current practical issues related to analytical similarity assessment. In this article, these major criticisms and issues are discussed. In addition, some recommendations regarding alternative thinking or methods for analytical similarity evaluation are provided. [ABSTRACT FROM AUTHOR]

To elucidate the differences in muscle bundle and satellite cells in medial rectus muscle through histological and Immunofluorescence studies of intermittent exotropia patients and normal controls. Materials and Methods: From January 2015 to December 2017, 15 patients who underwent medial rectus resection surgery at Kosin University Gospel Hospital were enrolled. Four medial recti muscles collected from two brain-dead men without strabismus were used as controls and compared with the intermittent exotropia group. Hematoxylin and eosin (HE) staining were performed, and all muscle bundle diameters were measured with the Image J program and compared to the mean value. Immunological staining for MyoHC (Myosin Heavy Chain), PAX7 (Transcription Factor), and PCNA (Proliferating Cell Nuclear Antigen) were performed to analyze the distribution of myocytes and PAX7-positive and PCNA-positive cells. Results: The mean ages of the strabismus and control groups were 17.33 ± 13.05 and 22.0 ± 5.85 years, respectively, and the male to female ratio was 7:2 and 2:0. The average angle of deviation in the exotropia patients was 36.0 ± 16.83 prism diopters. The mean muscle bundle diameter under light microscopy was 60.21 ± 1.48 in the exotropia group and 52.27 ± 0.74 in the control group. The exotropia group showed significantly greater mean muscle bundle diameter (p <.001) and diameter regularity than the control group. The PAX7(+)/muscle bundle number ratio was 0.016 ± 0.014 and 0.056 ± 0.015 in the exotropia group and control group, respectively (p <.001), and the PCNA(+)/muscular bundle number ratio was 0.015 ± 0.017 and 0.182 ± 0.102 (p <.001). Both were significantly higher in the control group compared to that in the exotropia patients. Conclusion: In the exotropia group, mean diameter of medial rectus muscle bundle was significantly larger than that of control group. The ratios of PAX7 and PCNA to muscle bundle number were significantly higher in the control group than intermittent extropia group. We found the negative relationship between activation of satellite cells and muscle bundle diameter, and it might take one step forward to elucidate the pathogenesis of intermittent extropia. [ABSTRACT FROM AUTHOR]

Liquid-infused surfaces are a promising passive technique for frictional drag reduction. However, their practical application is limited by the easy depletion of the lubricant infused in the surface by external forces. Miyeok contains mucus on its surface, which induces a sustainable slippery surface under flow conditions. In this study, the effect of the surface morphological structures of miyeok on slippery characteristics was examined. The surface of miyeok has bump-like microstructures and tiny pores of mucilage gland cells with a re-entrant inlet configuration. A replica model of the miyeok surface was fabricated by adopting a molding process using polydimethylsiloxane. The miyeok replica model was dipped into a silicone oil solution to obtain a slippery surface property. The surface structures of fresh miyeok and the replica were checked by comparing their scanning electron microscopy images. A replica of a kelp surface was also fabricated by employing the same method. The heights of the surface microstructures of the miyeok replica were more uniform than those of the kelp replica. The sustainable drag reduction effect of the replica models' surfaces was assessed by a sessile drop method. The liquid-infused miyeok replica surface (LIMRS) showed better sustainability than other surfaces. The slippery properties of the LIMRS were examined by measuring slip length and pressure drop. The drag reduction rates measured by the two methods were approximately 24% and 19%. The present results would be helpful for understanding the effects of the surface structure of natural miyeok on sustainable drag reduction and developing a biomimetic sustainable drag-reducing surface. [ABSTRACT FROM AUTHOR]

Studies of medical flow imaging have technical limitations for accurate analysis of blood flow dynamics and vessel wall interaction at arteries. We propose a new deep learning-based boundary detection and compensation (DL-BDC) technique in ultrasound (US) imaging. It can segment vessel boundaries by harnessing the convolutional neural network and wall motion compensation in the analysis of near-wall flow dynamics. The network enables training from real and synthetic US images together. The performance of the technique is validated through synthetic US images and tissue-mimicking phantom experiments. The neural network performs well with high Dice coefficients of over 0.94 and 0.9 for lumens and walls, outperforming previous segmentation techniques. Then, the performance of the wall motion compensation is examined for compliant phantoms. When DL-BDC is applied to flow influenced by wall motion, root-mean-square errors are less than 0.07%. The technique is utilized to analyze flow dynamics and wall interaction with varying elastic moduli of the phantoms. The results show that the flow dynamics and wall shear stress values are consistent with the expected values of the compliant phantoms, and their wall motion behavior is observed with pulse wave propagation. This strategy makes US imaging capable of simultaneous measurement of blood flow and vessel dynamics in human arteries for their accurate interaction analysis. DL-BDC can segment vessel walls fast, accurately, and robustly. It enables to measure the near-wall flow precisely by determining the vessel boundary dynamics. This approach can be beneficial in flow dynamics and wall interaction analyses in various biomedical applications. [ABSTRACT FROM AUTHOR]

Background: At EU marketing authorisation, safety data for CT-P13 (biosimilar infliximab) were limited, particularly in some indications, and uncommon adverse events (AEs) could not be evaluated among relatively small analysis populations. Objectives: Our objective was to investigate the overall safety profile and incidence rate of AEs of special interest (AESIs), including serious infections and tuberculosis, in CT-P13-treated patients. Methods: Data were pooled from six observational studies representing authorised indications of CT-P13 (ankylosing spondylitis, rheumatoid arthritis, psoriatic arthritis, plaque psoriasis, adult and paediatric Crohn's disease and ulcerative colitis). Patients were analysed by indication and treatment (patients who received CT-P13 or those who switched from reference infliximab to CT-P13 ≤ 6 months prior to enrolment or during the study). Results: Overall, 4393 patients were included (n = 3677 CT-P13 group; n = 716 switched group); 64.03% of patients had inflammatory bowel disease and 6.31% of patients were antidrug antibody positive. Overall, 32.94% and 9.58% of patients experienced treatment-emergent AEs (TEAEs) and treatment-emergent serious AEs, respectively. Across indications, TEAEs were more frequent with CT-P13 than with the switched group. Infections including tuberculosis were the most frequent serious AESI overall (2.48%) and by treatment group or indication. In total, 14 patients (0.32%) reported active tuberculosis. Overall incidence rates per 100 patient-years (95% confidence interval) were 3.40 (2.788–4.096) for serious infections including tuberculosis and 0.44 (0.238–0.732) for active tuberculosis. Infusion-related reactions were the second most frequent AESI following infection including tuberculosis. Conclusion: The CT-P13 safety profile appears consistent with previous studies for CT-P13 and reference infliximab, supporting the favourable risk/benefit balance for CT-P13 treatment. [ABSTRACT FROM AUTHOR]

Patterns in materials are not just decoration but also important for function. In view of this, the dynamics of patterning procedures in materials has been investigated as an important developmental procedure. In this study, nanoscale components in a continuum are traced in terms of natural patterning procedures. Externally applied compressive or extensive forces to an elastic thin sheet commonly induce an orientated lateral line pattern. From a nanoscale element point of view, the dynamics of natural arrangements, forming anisotropic patterns in preference to isotropy, still remains unclear. In this study, new developmental procedures for line patterns are suggested by stimuli‐responsive viscoelastic nanocomposite network model systems. Forces originating from an internal source without directional orientation generate lines in preference to isotropic patterns. With repeated, non‐oriented (or isotropic) and self‐modulated strain variations, stress is accumulated to drive anisotropic orientations and further lines. The anisotropic elemental arrangement is justified by the equilibrium between the short‐range attraction and long‐range repulsion from a bottom‐up viewpoint. This study suggests a new material design methodology that is useful for electrical devices, biomedical devices and other patterned soft condensed matter in conjunction with line patterns typically generated in a broad range of viscoelastic materials. [ABSTRACT FROM AUTHOR]

Optimal strength and stability of blood clots are keys to hemostasis and in prevention of hemorrhagic or thrombotic complications. Clots are biocomposite materials composed of fibrin network enmeshing platelets and other blood cells. We have previously shown that the storage temperature of platelets significantly impacts clot structure and stiffness. The objective of this work is to delineate the relationship between morphological characteristics and mechanical response of clot networks. We examined scanning electron microscope images of clots prepared from fresh apheresis platelets, and from apheresis platelets stored for 5 days at room temperature or at 4 °C, suspended in pooled plasma. Principal component analysis of nine different morphometric parameters revealed that a single principal component (PC1) can distinguish the effect of platelet storage on clot ultrastructure. Finite element analysis of clot response to uniaxial strain was used to map the spatially heterogeneous distribution of strain energy density for each clot. At modest deformations (25% strain), a single principal component (PC2) was able to predict these heterogeneities as quantified by variability in strain energy density distribution and in linear elastic stiffness, respectively. We have identified structural parameters that are primary regulators of stress distribution, and the observations provide insights into the importance of spatial heterogeneity on hemostasis and thrombosis. [ABSTRACT FROM AUTHOR]

Angiography and Doppler methods used for diagnosing vascular diseases give information on the shape of blood vessels and pointwise blood speed but do not provide detailed information on the flow fields inside the blood vessels. In this study, we developed a method for visualizing blood flow by using coherent synchrotron x rays. This method, which does not require the addition of any contrast agent or tracer particles, visualizes the flow pattern of blood by enhancing the diffraction and interference characteristics of the blood cells. This was achieved by optimizing the sample- (blood) to-detector (charge-coupled device camera) distance and the sample thickness. The proposed method was used to extract quantitative velocity field information from blood flowing inside an opaque microchannel by applying a two-frame particle image velocimetry algorithm to enhanced x-ray images of the blood flow. The measured velocity field data showed a flow structure typical of flow in a macrochannel. [ABSTRACT FROM AUTHOR]

An x-ray particle image velocimetry (PIV) technique was developed to measure quantitative information on flows inside opaque objects. To acquire x-ray images suitable for PIV velocity field measurements, refraction-based edge enhancement was employed using detectable tracer particles with the object and detector separated by an experimentally determined optimal distance. The x-ray PIV method was applied to a flow in an opaque Teflon tube. The resulting amassed velocity field data were in reasonable agreement with theoretical predictions. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Under the US Biologics Price Competition and Innovation Act of 2009 (BPCI), the development of biosimilar (test) products provides affordable alternatives to innovative biological (reference) products for the general patient population. However, in practice, as the number of biosimilar products available on the market increases, whether these biosimilars can be used interchangeably is a concern. Thus, using switching studies to evaluate the risk of reduced efficacy and increased safety concerns with and without switch(es) in the development of biosimilar products is of interest. For this purpose, the US FDA, in its recent draft guidance on interchangeability, suggested using a 2 × 2 crossover design (RT, RR) to evaluate a single switch and (RTR, RRR) and (RTRT, RRRR) to evaluate multiple switches. In this article, we examine the statistical properties, analyses, and sample size requirements of these switching study designs. We also investigate the relative efficiencies of these switching designs compared with the complete n-of-1 trial design. [ABSTRACT FROM AUTHOR]

Spontaneous filtration without a power supply was investigated using highly charged precursor mixtures instead of recognized microfluidic desalination techniques. The proposed filtration method consisted of a main channel (depth: 1 mm) and shallow channels (depth: 400 μm) in which the precursor mixture was injected. The filtration performance of the proposed device was evaluated by injecting a fluorescent dye that moved toward the centerline of the main channel. The respective rejection rates of CaCl 2 , NaCl, CaSO 4 , and Na 2 SO 4 were 3.16%, 30.13%, 43.74%, and 36.32%, respectively. This trend can be explained by the mechanism of Donnan exclusion theory. The focusing of charged species toward the centerline of the main channel was caused by highly charged surfaces. The proposed filtration method exhibited a migration of charged microparticles toward a certain direction. This particle migration behavior was consistent with the simulation data. These results suggested that the proposed filtration method had strong potential for desalinating brackish water or salty surface water without an external power supply. • A spontaneous filtration of ions and charged particles without an external electrical power supply. • Crossly charged channel surfaces had the same surface charge between diagonal-directional shallow channels. • The proposed method exhibited a noticeable filtration performance by focusing charged materials toward a certain direction. • This work can be considered a promising paradigm of nature-inspired desalination technology. [ABSTRACT FROM AUTHOR]

Molecular interactions in Cu2+-alginate beads blended at high and low mannuronate-to-guluronate residue ratios, hereafter denoted as H-Alg and L-Alg, respectively, during the intercalation of Li+ and Mg2+ were analyzed using X-ray absorption spectroscopy. Cu2+ ions are slightly deoxidized from Cu(II) to Cu(I) after the intercalation, but their oxidation state remains as Cu(II). The lengths of Cu O bonds are elongated and coordination numbers are more decreased in flexible conformation of H-Alg, compared with structured conformation of L-Alg after intercalation of Li+ and Mg2+. These results suggest that the flexible conformation can facilitate metal intercalation by rearranging the alginate G junctions as forming a coordinate structure in alginate G junctions. Moreover, the higher adsorption capacity for Mg2+ in H-Alg corroborates its advanced molecular interaction in flexible conformation. Overall, this study helps elucidate the localized molecular interactions in alginate beads that are cross-linked noncovalently with divalent cations. • The metal intercalation in Cu2+-alginate beads was structurally examined by XAS. • Cross-linked Cu ions were slightly deoxidized from Cu(II) to Cu(I). • Coordination environment was more changed in alginate beads with high M/G ratio. • Flexible conformation could facilitate molecular interaction. • Adsorption capacity for Mg2+ was higher in alginate beads with high M/G ratio. [ABSTRACT FROM AUTHOR]

Highlights • The boiling bubbles with varying nanofluid formation methods, were investigated. • The changes in the wettability and bubble generating rate were analyzed. • Once particle sedimentation occurred, the wettability and bubble behaviors changed. • Formulation method is not related to bubble behaviors when particles are deposited. Abstract Understanding the boiling heat transfer characteristics of nanofluid suspensions containing nanoparticles is one of the challenging issues in the heat transfer research field. The addition of nanoparticles modifies both the surface characteristics and the thermo-physical properties of the suspension, including thermal conductivity, viscosity, and surface tensions. One of the critical features is the stability of nanoparticle suspension, which is strongly related to the formulation method of nanofluids. In this study, to investigate the effect of several formation methods, the pool-boiling bubble behaviors of Al 2 O 3 nanofluid, with varying nanofluid formation methods, were systematically analyzed using an X-ray imaging system. The changes in the wettability of Al 2 O 3 nanofluid suspensions and the variations of boiling bubble characteristics were analyzed to determine the relationship between boiling-bubble behaviors and examine the effects of heating the substrate. Before the heating substrate, the bubble generating ratio was increased by 1.4 times, when the concentration of Nanofluid 3 increased from 0.05 wt% to 1 wt% with adopting the electrostatic stabilization method and high-speed rotating procedure. On the other hand, at the end of heating process, the bubble generating ratio was decreased by 0.78 times for the same concentration change. Once the nanoparticle sedimentation occurred, the trend of wettability and bubble behaviors of nanofluids changed based on the surface modification, regardless of the nanofluid formation method. An increase in the Al 2 O 3 nanofluid concentration results in a deterioration of the heat transfer characteristics, and the formulation method is not related to the boiling heat transfer performance when nanoparticles are deposited. [ABSTRACT FROM AUTHOR]

Abstract Mobile personal cloud storage services (PCSSs) have become increasingly common among mobile users in recent years. Prior studies largely focused on understanding users' early adoption of mobile PCSSs, but attention to post-adoption switching behavior is still rare. Based on the push-pull-mooring framework of migration theory, to explore the factors that influence the voluntary switching intentions of mobile PCSS users in the Chinese market, we developed a model around three effects: pushing, pulling, and mooring. The results show that two push factors (privacy risk and security risk), six pull factors (referent network size, complementarity, usefulness, technical compatibility, lifestyle compatibility, and enjoyment), and two mooring factors (habit and switching cost) have significant effects on switching intention. Moreover, referent network size, total network size, complementarity, technical compatibility, lifestyle compatibility and enjoyment are significant to usefulness, and usefulness mediates between them and switching intention. The findings will help practitioners devise proper strategies for retaining current users and attracting new users. Highlights • Explore users' voluntary switching for mobile personal cloud storage services. • Push-Pull-Mooring framework is adopted to build our model. • Divide privacy and security risk into two clear dimensions. • Explore multi-dimensions of network externality and highlight their differences. • Compatibility is divided into technical compatibility and lifestyle compatibility. [ABSTRACT FROM AUTHOR]

Highlights • The behavior of boiling bubbles were investigated using a synchrotron X-ray imaging. • The bubble generating rate was newly defined to examine the nanofluid heat transfer. • The bubble generating rate decreases with increase of nanofluid concentration. • Wettability increase reduces the bubble generating rate and heat transfer. Abstract Nanofluid, a liquid suspension containing nanoparticles, has been widely used to enhance heat transfer. However, the heat transfer enhancement mechanism of nanofluids has not been clearly revealed yet. Therefore, understanding the boiling heat transfer of nanofluids is a challenging research issue in the field of heat transfer. When nanoparticles are added into a base fluid, the thermo-physical properties of the fluid and surface characteristics are modified. Those modifications induce changes in the behavior of boiling bubbles. In addition to the size and number of bubbles, the generating rate of boiling bubbles was newly defined to estimate the heat transfer coefficient directly from bubble behaviors according to nanofluid concentration. As the nanofluid concentration increases, both the generating rate of boiling bubbles and the heat transfer coefficient decrease. Wettability and hydrodynamic size were also employed to reason those degradations. Wettability increase leads to the reduction of activated nucleation sites, which reduces the bubble generating rate and heat transfer coefficient with an increase in nanofluid concentration. In this study, the feasibility and usefulness of synchrotron X-ray imaging and a newly defined boiling generating rate for examining boiling heat transfer were verified by observing boiling-bubble behaviors. Moreover, it was also shown that wettability plays an important role in changes of the bubble behaviors and the heat transfer coefficient as surface roughness modification. [ABSTRACT FROM AUTHOR]

Student-centred learning requires students to be an active participant in knowledge construction. Due to the unique self-directed aspects that characterise student-centred instruction, students may feel uncomfortable and find themselves unprepared for the demands associated with student-centred learning environments (SCLEs). This qualitative case study explored 11 students’ beliefs about teaching and learning and how their beliefs influenced their perceptions of a SCLE in a graduate programme. The results showed that students’ prior knowledge as well as their beliefs about teaching and learning influenced their perceptions of the SCLE. This study suggests that teachers and educational practitioners acknowledge students’ individual differences in their beliefs and prior knowledge, and provide personal support and guidance. [ABSTRACT FROM AUTHOR]

In this study, the spontaneous ion concentration polarization phenomenon induced by pressure via a cation-selective membrane was theoretically and experimentally investigated. Unlike conventional electrokinetic ion concentration polarization, which uses electric current as a driving flux of cations through the membrane, advection caused by pressure is used as a transmembrane driving flux of cations to spontaneously and stably form an ion depletion zone in the present ion concentration polarization technique. The ion depletion zone produced in a simple experimental setup was used to filter electrolyte and preconcentrate ions and microparticles. Different from the general assumption of the negligible thickness of the electric double layer in microchannels, the low concentration in the ion depletion zone considerably increased the length of the electric double layer. This enhanced the formation of the ion depletion zone. The present results can improve the understanding on ion transport in the ion concentration polarization system and can be utilized to develop a portable water desalination device for rural/remote areas and for preconcentrating biomolecules. [ABSTRACT FROM AUTHOR]

Haemorheologically impaired microcirculation, such as blood clotting or abnormal blood flow, causes interrupted blood flows in vascular networks. The biophysical properties of blood, including blood viscosity, blood viscoelasticity, haematocrit, red blood bell (RBC) aggregation, erythrocyte sedimentation rate and RBC deformability, have been used to monitor haematological diseases. In this review, we summarise several techniques for measuring haemorheological properties, such as blood viscosity, RBC deformability and RBC aggregation, using in vitro microfluidic platforms. Several methodologies for the measurement of haemorheological properties with the assistance of an extracorporeal rat bypass loop are also presented. We briefly discuss several emerging technologies for continuous, long-term, multiple measurements of haemorheological properties under in vitro or ex vivo conditions. [ABSTRACT FROM AUTHOR]

Venous valve dysfunction and induced secondary abnormal flows are closely associated with venous diseases. Thus, detailed analysis of venous valvular flow is invaluable from biological and medical perspectives. However, most of the previous studies on venous perivalvular flows were based on qualitative analysis. On the contrary, quantitative analysis of perivalvular flows has not been fully understood. In this study, we used the ultrasound speckle image velocimetry (SIV) technique, which utilizes the speckle patterns of red blood cells (RBCs) created by ultrasound waves to measure 3-D valvular flows quantitatively. The flow structures obtained with the proposed SIV technique for an in vitro model were compared with those obtained by numerical simulation and the color Doppler method to validate the measurement accuracy of the ultrasound SIV technique. Blood flow in the human great saphenous vein was then measured at various distances from the valve with and without exercise. 3-D valvular flow was analyzed in accordance with the dimensionless index, helical intensity. The results obtained by the proposed method matched well with those obtained by numerical simulation and the color Doppler method. The hemodynamic characteristics of 3-D valvular helical flow which were analyzed experimentally using the SIV method would be used for quantitative diagnosis of venous valvular diseases. [ABSTRACT FROM AUTHOR]

Service-learning is an experiential learning experience where students learn and develop through active participation in community service to meet the needs of a community. This study explored student learning experiences in a service-learning group project and their perceptions of service-learning in an undergraduate web design course. The data showed that the service-learning project helped students learn the course material, feel more connected to the surrounding community, and improve their communication and problem-solving skills for their careers. The participants appreciated the opportunity to work with the service-learning partner and will be likely to look for more opportunities to get involved in the community. Time constraints, group work, working with real clients, and technical limitations were reported as major challenges in the group project. [ABSTRACT FROM AUTHOR]

• Calcium alginate hydrogel-coated wires mimic the water film-trapping of Tillandsia. • Our hydrogel-coated wires decrease the droplet pinning and wire tangling problems. • A hydrogel-coated wire maintains the effective diameter and quick water drainage. • Hydrogel-coated dual-wires retain the constant inter-distance as well. • Hydrogel-coated wires are potential to resolve the wire tangling issue. Fog collection has been widely studied to collect fresh water in arid regions. With the demand of optimizing the design of fog collectors, removing the pinned droplets and accelerating the water drainage have become a challenge. To address this challenge, we propose a fog collection method utilizing calcium alginate hydrogel-coated wires inspired by the water film-trapping characteristics of Tillandsia. Maintaining the effective wire diameter by water film trapped on the hydrogel, the fog collection performance of our hydrogel-coated wire precedes that of a bare wire in collection efficiency (up to 136 % higher) under different flow speed conditions. Significantly, retaining the inter-distance between dual-wires, the collection efficiency of hydrogel-coated dual-wires is 1.2 ∼ 1.7 times higher than that of two bare dual-wires. Moreover, the hydrogel-coated wires prevent the formation of water bridges between wires by removing the deposited droplets promptly, which opens different perspectives on designing the hydrogel-coated wires for the purpose of water harvesting, sustainable engineering, and ecofriendly technology. [ABSTRACT FROM AUTHOR]

Due to the realistic, complex natures of authentic cases involved in case-based learning, the use of group work has been encouraged and expected to enhance the quality of interaction among participants and to improve students’ learning experiences. The purpose of this study was to investigate whether the case-based online group work increased students’ satisfaction with interaction among students in an online course. Findings of this study revealed that the group assignment did not have an effect on students’ satisfaction with online interactions. Instead, students’ perceptions of the importance of group work were associated with their satisfaction with interaction in the online course. [ABSTRACT FROM AUTHOR]

Many samaras or winged seeds such as maple seeds make an autorotational flight during their falling. Slow descent speed of autorotating maple seeds has been known to be caused by the high lift generated by Leading-edge vortex (LEV) on the seed blade. The autorotation flight of maple seeds is observed to be very stable after detaching from their parent plants, regardless of their initial attitude. In this study, the effects of initial attitude on the flight characteristics of autorotating maple seeds, such as descending velocity, rotational speed and coning angle were investigated experimentally. Depending on the initial attitude, the transitional flight from the initial detachment to the steady-state autorotation is clearly discernible. It starts with downward facing of the seed base, and then approaches equilibrium by changing the pitch and coning angles of the seed. The lower surface faces downward and tumbles to the downward facing state of the leading edge. Among the six initial attitudes tested, the downward facing of the seed's lower surface exhibits the fastest stabilization. Most maple seeds belong to the case of downward facing of lower surface. The present results demonstrate that the maple seeds make a stable autorotation within a distance of 660 mm after detaching from their parent plants, regardless of their initial attitude. [ABSTRACT FROM AUTHOR]

Although atherosclerosis is a multifactorial disease, the role of hemodynamic information has become more important. Low and oscillating wall shear stress (WSS) that changes its direction is associated with the early stage of atherosclerosis. Several in vitro and in vivo models were proposed to reveal the relation between the WSS and the early atherosclerosis. However, these models possess technical limitations in mimicking real physiological conditions and monitoring the developmental course of the early atherosclerosis. In this study, a hypercholesterolaemic zebrafish model is proposed as a novel experimental model to resolve these limitations. Zebrafish larvae are optically transparent, which enables temporal observation of pathological variations under in vivo condition. WSS in blood vessels of 15 days post-fertilisation zebrafish was measured using a micro particle image velocimetry (PIV) technique, and spatial distribution of lipid deposition inside the model was quantitatively investigated after feeding high cholesterol diet for 10 days. Lipids were mainly deposited in blood vessel of low WSS. The oscillating WSS was not induced by the blood flows in zebrafish models. The present hypercholesterolaemic zebrafish would be used as a potentially useful model for in vivo study about the effects of low WSS in the early atherosclerosis. [ABSTRACT FROM AUTHOR]

The programmed movements of responsive functional hydrogels have received much attention because of their abundant functions and wide range of engineering applications. In this study, an innovative stomata-inspired membrane (SIM) is fabricated by using a temperature-responsive hydrogel through a simple, cost-effective, and high-throughput patterned photopolymerization. Polymerization-induced diffusion on the macroscale surface results in formation of a double-parted polymer membrane with fine pores after single illumination. After heating the SIM, the less deformable thick frame supports the whole structure and the highly deformable thin base regulates pore shape. Among various SIM types, the slit pores of monocot SIM, which are lined up in parallel, exhibit the largest radius deformation. The morphological configuration of the SIM can be easily controlled by changing the photomask for a given application. As the developed SIM features the sensing-to-activation functions of stimuli-responsive hydrogels and can be easily fabricated, this membrane can be potentially used for numerous practical applications, such as filter membranes with adjustable pores, membrane-based sensors, membrane-based actuators, and multifunctional membranes. [ABSTRACT FROM AUTHOR]

Today, nanotechnology plays a vital role in biomedical applications, especially for the diagnosis and treatment of various diseases. Among the many different types of fabricated nanoparticles, magnetic metal oxide nanoparticles stand out as unique and useful tools for biomedical applications, because of their imaging characteristics and therapeutic properties such as drug and gene carriers. Polymer-coated magnetic particles are currently of particular interest to investigators in the fields of nanobiomedicine and fundamental biomaterials. Theranostic magnetic nanoparticles that are encapsulated or coated with polymers not only exhibit imaging properties in response to stimuli, but also can efficiently deliver various drugs and therapeutic genes. Even though a large number of polymer-coated magnetic nanoparticles have been fabricated over the last decade, most of these have only been used for imaging purposes. The focus of this review is on polysaccharide-coated magnetic nanoparticles used for imaging and gene delivery. [ABSTRACT FROM AUTHOR]

Pulsatile blood flows are easily found in the vessels of living organisms. Under pulsatile flow conditions, red blood cells (RBCs) are aggregated and dispersed repetitively. The phenomenon of RBC aggregation is an influential factor in hemorheological and hemodynamic properties. This study aims to investigate the relationship between velocity profile and RBC aggregation in pulsatile blood flows. A rat extracorporeal bypass model was adopted to generate a real pulsatile flow without changing the rheological properties. To check the stability of the experimental model, variations of the hemodynamic parameters were measured consecutively for 2 h. Ultrasound speckle images of the blood flow in the extracorporeal bypass loop were acquired using a 35-MHz ultrasound scanner. The velocity fields were measured by the speckle image velocimetry (SIV) method, in which the cross-correlation algorithm is applied to the speckle images. In addition, the RBC aggregation was estimated by analyzing the echogenicity distribution of the speckle images. The shape of the velocity profile was cyclically varied according to the cardiac cycle. This variation may be closely related to the variation of the echogenicity distribution in pulsatile flows. The simultaneous measurement of velocity and RBC aggregation would be useful for understanding the effects of the hemorheological features on the hemodynamic characteristics of pulsatile blood flows. [ABSTRACT FROM AUTHOR]

The detachment (or removal) of droplets from a solid surface is an indispensable process in numerous practical applications which utilize digital microfluidics, including cell-based assay, chip cooling, and particle sampling. When a droplet that is fully stretched by impacting or electrowetting is released, the conversion of stored surface energy to kinetic energy can lead to the departure of the droplet from a solid surface. Here we firstly detach sessile droplets in immiscible fluids from a hydrophobic surface by electrowetting. The physical conditions for droplet detachment depend on droplet volume, viscosity of ambient fluid, and applied voltage. Their critical conditions are determined by exploring the retracting dynamics for a wide range of driving voltages and physical properties of fluids. The relationships between physical parameters and dynamic characteristics of retracting and jumping droplets, such as contact time and jumping height, are also established. The threshold voltage for droplet detachment in oil with high viscosity is largely reduced (~70%) by electrowetting actuations with a square pulse. To examine the applicability of three-dimensional digital microfluidic (3D-DMF) platforms to biological applications such as cell culture and cell-based assays, we demonstrate the detachment of droplets containing a mixture of human umbilical vein endothelial cells (HUVECs) and collagen (concentration of 4 × 104 cells mL−1) in silicone oil with a viscosity of 0.65 cSt. Furthermore, to complement the technical limitations due to the use of a needle electrode and to demonstrate the applicability of the 3D-DMF platform with patterned electrodes to chemical analysis and synthesis, we examine the transport, merging, mixing, and detachment of droplets with different pH values on the platform. Finally, by using DC and AC electrowetting actuations, we demonstrate the detachment of oil droplets with a very low contact angle (＜~13°) in water on a hydrophobic surface. [ABSTRACT FROM AUTHOR]

Trajectories of aeolian sand particles behind a porous wind fence embedded in a simulated atmospheric boundary layer were visualized experimentally, to investigate the shelter effect of the fence on sand saltation. Two sand samples, one collected from a beach (d = 250 μm) and the other from a desert (d = 100 μm), were tested in comparison with the previous studies of a ‘no-fence’ case. A wind fence ( ε = 38.5%) was installed on a flat sand bed filled with each sand sample. A high-speed photography technique and the particle tracking velocimetry (PTV) method were employed to reconstruct the trajectories of particles saltating behind the fence. The collision processes of these sand particles were analyzed, momentum and kinetic energy transfer between saltating particles and ground surface were also investigated. In the wake region, probability density distributions of the impact velocities agree well with the pattern of no-fence case, and can be explained by a log-normal law. The horizontal component of impact velocity for the beach sand is decreased by about 54%, and about 76% for the desert sand. Vertical restitution coefficients of bouncing particles are smaller than 1.0 due to the presence of the wind fence. The saltating particles lose a large proportion of their energy during the collision process. These results illustrate that the porous wind fence effectively abates the further evolution of saltating sand particles. [ABSTRACT FROM AUTHOR]

• This systematic review examined how CS education was implemented in schools and its efficacy for developing students' computational thinking (CT). • Although educational interventions have not always been successful in CS education, this review provides strong evidence that overall, CS education promotes the development of students' CT in the K-12 setting while improving their creative and critical thinking skills. • When integrated into other subjects, CS education increases students' motivation, commitment, participation, and interest in the subject matter. • We recommend early access to CS education, various innovative instructional approaches to CS education and appropriate support and guidance for student learning. Also, there is a need for professional development opportunities for CS educators. This systematic review examined how computer science (CS) education was implemented in schools and its efficacy for developing students' computational thinking (CT). Sixty-six papers were selected for this systematic review and analyzed for patterns in relation to the implementation of CS education in K-12 schools and its impact on the development of students' CT skills. Although educational interventions have not always been successful in CS education, this review provides strong evidence that overall, CS education promotes the development of students' CT in the K-12 setting while improving their creative and critical thinking skills. We recommend early access to CS education, various innovative instructional approaches to CS education and appropriate support and guidance for student learning. [ABSTRACT FROM AUTHOR]

Methods for obtaining valuable knowledge from the vast amount of mixed-quality information have become a top priority for knowledge demanders. As an online knowledge-sharing channel, the socialized question and answer (Q&A) platform provides important support services for knowledge payment. Based on the personal psychological dimensions of users and social capital theory, this paper aims to study the behavior mechanisms of knowledge payment users and examine the significant factors affecting user payment. Our research was conducted in two steps: a qualitative study to find these factors and a research model based on a quantitative study for testing the hypothesis. The results show that the three dimensions of individual psychology are not all positively correlated with cognitive and structural capital. Our results fill a gap in the literature on the formation of social capital in the knowledge payment environment by showing how individual psychological dimensions affect cognitive and structural capital differently. Thus, this study offers effective countermeasures for knowledge producers on social Q&A platforms to better amass their social capital. This research also makes practical recommendations for social Q&A platforms to strengthen the knowledge payment model. [ABSTRACT FROM AUTHOR]

Flow patterns inside a droplet ofdiluted aqueous NaCl solutionconfined by two flat substrates under natural evaporation were investigatedboth experimentally and numerically. We focused on natural convection-drivenflows inside confined droplets at high Rayleigh numbers (i.e., theratio of buoyancy to diffusion, Ra), where the convection of solutesis strongly dominant, compared to diffusion. The evaporated waterat the free surface of the droplet builds up a concentration gradientinside the solution, which induces the Rayleigh convection flow. Three-dimensionaltrajectories of tracer particles in the droplet were tracked, andaxisymmetric flow motions induced by the Rayleigh convection wereexperimentally measured by using a digital in-line holographic microscopytechnique. In addition, the effects of the confined droplet’saspect ratio and the liquid’s molar concentration on the evaporation-inducedflows were investigated. The convection velocity is found to be increasedas molar concentration increases, because Rayleigh convection becomessignificant at high the molar concentration is high (i.e. high Ra).Our numerical simulation based on the Boussinesq approximation fairlywell predicted the velocity profiles of evaporating confined dropletsat low concentrations. Consequently, evaporation kinetics inside theconfined droplets can be controlled with varying droplet’saspect ratio and the liquid’s molar concentration, which provideshelpful information for the design of biochemical microplating withlimited resources and for tuning self-assembly micro/nanoparticleclusters. [ABSTRACT FROM AUTHOR]

Abstract: Butterflies drink liquid through a slender proboscis using a large pressure gradient induced by the systaltic operation of a muscular pump inside their head. Although the proboscis is a naturally well-designed coiled micro conduit for liquid uptake and deployment, it has been regarded as a simple straw connected to the muscular pump. There are few studies on the transport of liquid food in the proboscis of a liquid-feeding butterfly. To understand the liquid-feeding mechanism in the proboscis of butterflies, the intake flow around the tip of the proboscis was investigated in detail. In this study, the intake flow was quantitatively visualized using a micro-PIV (particle image velocimetry) velocity field measurement technique. As a result, the liquid-feeding process consists of an intake phase, an ejection phase and a rest phase. When butterflies drink pooled liquid, the liquid is not sucked into the apical tip of the proboscis, but into the dorsal linkage aligned longitudinally along the proboscis. To analyze main characteristics of the intake flow around a butterfly proboscis, a theoretical model was established by assuming that liquid is sucked into a line sink whose suction rate linearly decreases proximally. In addition, the intake flow around the tip of a female mosquito׳s proboscis which has a distinct terminal opening was also visualized and modeled for comparison. The present results would be helpful to understand the liquid-feeding mechanism of a butterfly. [Copyright &y& Elsevier]

Abstract: Blood flow in an artery is closely related to atherosclerosis progression. Hemodynamic environments influence platelet activation, aggregation, and rupture of atherosclerotic plaque. The existence of swirling flow components in an artery is frequently observed under in vivo conditions. However, the fluid-dynamic roles of spiral flow are not fully understood to date. In this study, the spiral blood flow effect in an axisymmetric stenosis model was experimentally investigated using particle image velocimetry velocity field measurement technique and streakline flow visualization. Spiral inserts with two different helical pitches (10D and 10/3D) were installed upstream of the stenosis to induce swirling flows. Results show that the spiral flow significantly reduces the length of recirculation flow and provokes early breakout of turbulent transition, but variation of swirling intensity does not induce significant changes of turbulence intensity. The present results about the spiral flow effects through the stenosis will contribute in achieving better understanding of the hemodynamic characteristics of atherosclerosis and in discovering better diagnosis procedures and clinical treatments. [Copyright &y& Elsevier]

Abstract: Platelet aggregation has been known to be closely influenced by the surrounding hemodynamic environments. Especially, platelet activation, aggregation, and thrombus formation frequently occur at the locally stenosed blood vessel where recirculation and stagnation flow regions are developed. However, the relationship between hemodynamic feature and platelet aggregation is not fully understood yet. The main objective of this study is to investigate the hemodynamic characteristics of blood flow in a stenosis channel and their effects on platelet aggregation. Whole blood was injected into a stenosed microchannel with 85% severity at various flow rates, ranging from 10 to 50mLhr−1. The velocity vector field of the blood flow in the stenosed microchannel was measured using newly developed LED (light emitting diode)-illumination microparticle image velocimetry (micro-PIV). The blood flow is highly disturbed by the micro-stenosis, and a recirculation flow region is formed at the post-stenosis region. The occurring site and the shape of the platelet aggregation are highly influenced by the hemodynamic characteristics of blood flow around the stenosis. Especially, the platelet aggregation is found to occur at the interface where the downward momentum of the central jet at the post-stenosis region and the upward momentum of the recirculation flow are balanced. These experimental results would be helpful to understand the platelet aggregation under disturbed blood flow conditions. [Copyright &y& Elsevier]

Seawater desalination has a strong potential for solving global water shortage problem, and solar-based evaporative desalination technology has received increased attention. For successful solar steam generation (SSG), solar energy should be utilized in a balanced manner through heat localization. In this study, we propose a sucrose‑carbonized sugar-templating polydimethylsiloxane (PDMS) sponge sealed with ethyl vinyl acetate (EVA) foam, called as C-STP sponge. The C-STP sponge consists of a double-layered porous structure with carbonaceous material on the top surface. The C-STP sponge exhibits high SSG performance in long-term operation with anti-salt fouling ability by its self-cleaning feature. Several factors governing the C-STP sponge were optimized by examining two different kinds of sugar with different porosity levels and carbonized layer thicknesses. The porous C-STP sponge has numerous micropores caused by sugar-leaching, thereby decreasing the thermal conductivity to improve the evaporation rate. The heat localization aspects of PDMS were also investigated. The highest solar evaporation was 1.53 kg m−2 h−1 during long-term operation up to water depletion. The C-STP sponge is easy to fabricate as a solar evaporator and has much room for enhancing solar evaporation efficiency in the future. This work on dual-insulation sponge-based SSG system will provide insights for practical applications. [Display omitted] • The structure was fabricated by carbonizing sugar based on the porous PDMS structure. • The effect of carbonization thickness and porosity were investigated. • The sponge could be used for a long time with a constant evaporation rate. • The sponge has a self-cleaning surface when not in use. • The bilayer sponge with insulation foam could minimize the heat loss. [ABSTRACT FROM AUTHOR]

Accurate measurement of blood viscoelasticity including viscosity and elasticity is essential in estimating blood flows in arteries, arterials, and capillaries and in investigating sub-lethal damage of RBCs. Furthermore, the blood viscoelasticity could be clinically used as key indices in monitoring patients with cardiovascular diseases. In this study, we propose a new method to simultaneously measure the viscosity and elasticity of blood by simply controlling the steady and transient blood flows in a microfluidic analogue of Wheastone-bridge channel, without fully integrated sensors and labelling operations. The microfluidic device is designed to have two inlets and outlets, two side channels, and one bridge channel connecting the two side channels. Blood and PBS solution are simultaneously delivered into the microfluidic device as test fluid and reference fluid, respectively. Using a fluidic-circuit model for the microfluidic device, the analytical formula is derived by applying the linear viscoelasticity model for rheological representation of blood. First, in the steady blood flow, the relationship between the viscosity of blood and that of PBS solution (μBlood/μPBS) is obtained by monitoring the reverse flows in the bridge channel at a specific flow-rate rate (QPBSSS/QBloodL). Next, in the transient blood flow, a sudden increase in the blood flow-rate induces the transient behaviors of the blood flow in the bridge channel. Here, the elasticity (or characteristic time) of blood can be quantitatively measured by analyzing the dynamic movement of blood in the bridge channel. The regression formula (ABlood (t) = Aα + Aβ exp [-(t - t0)/λBlood]) is selected based on the pressure difference (ΔP = PA - PB) at each junction (A, B) of both side channels. The characteristic time of blood (λBlood) is measured by analyzing the area (ABlood) filled with blood in the bridge channel by selecting an appropriate detection window in the microscopic images captured by a high-speed camera (frame rate = 200 Hz, total measurement time = 7 s). The elasticity of blood (GBlood) is identified using the relationship between the characteristic time and the viscosity of blood. For practical demonstrations, the proposed method is successfully applied to evaluate the variations in viscosity and elasticity of various blood samples: (a) various hematocrits form 20% to 50%, (b) thermal-induced treatment (50 °C for 30 min), (c) flow-induced shear stress (53 ± 0.5 mL/h for 120 min), and (d) normal rat versus spontaneously hypertensive rat. Based on these experimental demonstrations, the proposed method can be effectively used to monitor variations in viscosity and elasticity of bloods, even with the absence of fully integrated sensors, tedious labeling and calibrations. [ABSTRACT FROM AUTHOR]

Abstract: Water management of polymer electrolyte fuel cell (PEFC) has been extensively studied because of its effect on the performance of a PEFC system. The transport and congelation of water significantly affect the efficiency and durability of a PEFC. Several empirical methods have been employed to visualize the spatial distribution of water in a PEFC. Experimental studies using high-resolution imaging techniques have been conducted to reveal the unknown morphological aspects that reduce the performance of a PEFC system. The X-ray imaging technique is the preferred method over other imaging techniques because of its high spatial and temporal resolution. Recently, X-ray micro computed tomography (X-ray μCT) is introduced to better characterize the anisotropic structure of a gas diffusion layer (GDL) by reconstructing its three-dimensional structure. With the development of advanced software and hardware, the X-ray imaging technique becomes essential in the visualization of water management in PEFCs. This article reviews the X-ray imaging studies on water management in a PEFC system. [Copyright &y& Elsevier]