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A highly sensitive diagnostic system for determining low-density infections that are missed by conventional methods is necessary to detect the carriers of Plasmodium falciparum. A fluorescent blue-ray optical system with a polycarbonate scan disc was developed to detect P. falciparum-infected red blood cells (Pf-iRBCs), and nine samples could be analyzed simultaneously. The cultured P. falciparum strain 3D7 was used to examine the potential of the system for diagnosing malaria. After an RBC suspension had been applied to the disc, the cells were dispersed on the disc by rotation. During the 10 min standing period to allow the RBCs to settle on the disc surface, the cells were simultaneously stained with nuclear fluorescence staining dye Hoechst 34580, which was previously adsorbed on the disc surface. RBCs were arranged on the disc surface as a monolayer by removing excess cells through momentary rotation. Over 1.1 million RBCs remained on the disc for fluorescence analysis. A portable, battery-driven fluorescence image reader was employed to detect fluorescence-positive RBCs for approximately 40 min. A good correlation between examination of Giemsa-stained RBCs by light microscopy and the developed system was demonstrated in the parasitemia range of 0.0001–1.0% by linear regression analysis (R2 = 0.99993). The limit of detection of 0.00020% and good reproducibility for parasitemia determination were observed. The ability of the developed system to detect sub-microscopic low-density Pf-iRBCs and provide accurate quantitative evaluation with easy operation was demonstrated.

This paper presents a numerical procedure using shell element to evaluate the buckling behavior of the cylindrical structure subjected to pressure load. In numerical simulation for pressure vessels using conventional shell elements, the pressure loads imposed to both top and bottom surfaces are expressed as the difference between the internal and external pressures. In this work, the special shell element, in which the surface traction is exactly expressed at the surface, is applied to the buckling analysis. In this approach, the distribution of the transverse normal stress through the thickness can be evaluated. Therefore, the influence of the difference between the internal and the external pressures to the behavior of the buckling of the cylindrical shell structures can be assessed. In the situation that a perturbative load is applied under a certain stress state, bifurcation points are searched by solving a standard eigenvalue problem. Several numerical examples are presented to examine the effectiveness of the proposed approach. The buckling behavior that cannot be considered with the conventional shell elements can be observed by this approach.

This paper presents a numerical procedure to couple shell to solid elements by using the Nitsche’s method. The continuity of displacements can be satisfied approximately with the penalty method, which is effective in setting the penalty parameter to a sufficiently large value. When the continuity of only displacements on the interface is applied between shell and solid elements, an unreasonable deformation may be observed near the interface. In this work, the continuity of the stress vector on the interface is considered by employing the Nitsche’s method, and hence a reasonable deformation can be obtained on the interface. The authors propose two types of shell elements coupled with solid elements in this paper. One of them is the conventional MITC4 shell element, which is one of the most popular elements in engineering applications. This approach shows the capability of discretizing the domain of the structure with the different types of elements. The other is the shell element with additional degrees of freedom to represent thickness–stretch developed by the authors. In this approach, the continuity of displacements including the deformation in the thickness direction on the interface can be considered. Several numerical examples are presented to examine the fundamental performance of the proposed procedure. The behavior of the proposed simulation model is compared with that of the whole domain discretized with only solid elements., This is a post-peer-review, pre-copyedit version of an article published in "Computational Mechanics". The final authenticated version is available online at: https://doi.org/10.1007/s00466-018-1585-6

There is an urgent need to develop an automated malaria diagnostic system that can easily and rapidly detect malaria parasites and determine the proportion of malaria-infected erythrocytes in the clinical blood samples. In this study, we developed a quantitative, mobile, and fully automated malaria diagnostic system equipped with an on-disc SiO2 nanofiber filter and blue-ray devices. The filter removes the leukocytes and platelets from the blood samples, which interfere with the accurate detection of malaria by the blue-ray devices. We confirmed that the filter, which can be operated automatically by centrifugal force due to the rotation of the disc, achieved a high removal rate of leukocytes (99.7%) and platelets (90.2%) in just 30 s. The automated system exhibited a higher sensitivity (100%) and specificity (92.8%) for detecting Plasmodium falciparum from the blood of 274 asymptomatic individuals in Kenya when compared to the common rapid diagnosis test (sensitivity = 98.1% and specificity = 54.8%). This indicated that this system can be a potential alternative to conventional methods used at local health facilities, which lack basic infrastructure.

This study proposes a numerical simulation for the deformation of laminates incorporating a combination of the novel shell element, whose thickness is allowed to change in a macro-scale model, with a decoupled two-scale viscoelastic analysis of FRP. The dependence of resin properties on the degree of cure (DOC) is considered in the simulation. Because the shell element of interest is enriched with degrees of freedom (DOFs) to represent the transverse deformations, it is capable of evaluating and controlling the thickness change during curing process of laminates. Since the additional DOFs are introduced to each element independently, they are condensed out at the element level in assembling the global finite element (FE) equation. Besides the force, the displacement can also be imposed on the outermost DOFs to control the change in thickness. Thus, numerical simulations where the plate thickness is controlled according to the requirements for molded products can be realized without introducing solid-shell-type formulations. The macroscopic mechanical behavior of FRP can be represented by the orthotropic version of the model employed for resin whose DOC-dependent macroscopic viscoelastic properties (the macroscopic coefficient of thermal expansions (CTEs) and coefficient of cure shrinkages (CCSs)) are identified from the relaxation curves obtained by results of numerical material tests (NMTs) conducted on the periodic microstructure (unit cell). The usefulness of the proposed approach was clarified by the results of the numerical verifications.

We improved a previously developed quantitative malaria diagnostic system based on fluorescent Blue-ray optical device. Here, we first improved the diagnostic system to enable fully automated operation and the field application was evaluated in Kenya. We detected Plasmodium falciparum in blood samples collected from 288 individuals aged 1-16 years using nested polymerase chain reaction (nPCR), rapid diagnostic test (RDT), and automated system. Compared to RDT, the automated system exhibited a higher sensitivity (100%; 95% confidence interval [CI], 93.3–100%) and specificity (92.8%; 95%CI, 88.5–95.8%). The limit of detection was 0.0061%. Linear regression analysis revealed a correlation between the automated system and microscopic examination for detecting parasitemia (adjusted R2 value=0.63, P=1.13×10−12). The automated system exhibited a stable quantification of parasitemia and a higher diagnostic accuracy for parasitemia than RDT. This indicates the potential of this system as a valid alternative to conventional methods used at local health facilities, which lack basic infrastructure.

This study performed an analysis for the fluid-structural design of aircraft wings composed of carbon fiber reinforced plastics (CFRPs). Specifically, the effects of carbon fibers on structural weight were evaluated. A multiscale computational framework was developed for designing CFRP wings so that even those CFRPs can be considered whose mechanical properties are not available as experimentally-measured data, thereby bridging two different scales by the following processes: 1) a microscale analysis for evaluating the mechanical properties (stiffness and strength) of unidirectional CFRP laminates and 2) a macroscale fluid-structural analysis that involves structural sizing of wingbox structures based on the mechanical properties given by the microscale analysis. To this end, five fibers were examined in this study, namely: T300, T700S, T800H, T800S, and T1100G. It was discovered that T1100G exhibited the lightest wingbox structures, followed by T800S, T800H, T700S, T300. This was mainly due to the difference in a thickness of the lower panels, where the thickness was minimized with T1100G among the five fibers, resulting from the tensile failure mode. Meanwhile, the upper panels under compressive load showed two different failure modes, namely: fiber microbuckling and skin buckling. In the region where the fiber microbuckling was dominant, the panel thickness was in order of the stiffness of the fiber, i.e., the panel made with T1100G having the highest stiffness was thicker than that made with T800S, T800H, T700S and T300, and vice versa in the region where the skin buckling was dominant. Based on the microscale analysis, the aforementioned failure mechanisms are consistent with the fact that a quasiisotropic laminate with the fibers of higher stiffness is more resistant to tensile load and skin buckling but less resistant to compressive load.

This paper presents a quadrilateral shell element incorporating thickness---stretch, and demonstrates its performance in small and large deformation analyses for hyperelastic material and elastoplastic models. In terms of geometry, the proposed shell element is based on the formulation of the MITC4 shell element, with additional degrees of freedom to represent thickness---stretch. To consider the change in thickness, we introduce a displacement variation to the MITC4 shell element, in the thickness direction. After the thickness direction is expressed in terms of the director vectors that are defined at each midsurface node, additional nodes are placed along the thickness direction from the bottom surface to the top surface. The thickness---stretch is described by the movement of these additional nodes. The additional degrees of freedom are used to compute the transverse normal strain without assuming the plane stress condition. Hence, the three dimensional constitutive equation can be employed in the proposed formulation without any modification. By virtue of not imposing the plane stress condition, the surface traction is evaluated at the surface where the traction is applied, whereas it is assessed at the midsurface for conventional shell elements. Several numerical examples are presented to examine the fundamental performance of the proposed shell element. In particular, the proposed approach is capable of evaluating the change in thickness and the stress distribution when the effect of the surface traction is included. The behavior of the proposed shell element is compared with that of solid elements.

Accurate, sensitive, rapid and easy operative diagnosis is necessary to prevent the spread of malaria. A cell microarray chip system including a push column for the recovery of erythrocytes and a fluorescence detector was employed for malaria diagnosis in Uganda. The chip with 20,944 microchambers (105 μm width and 50 μm depth) was made of polystyrene. For the analysis, 6 μl of whole blood was employed and leukocytes were practically removed by filtration through SiO2-nano-fibers in a column. Regular formation of an erythrocyte monolayer in each microchamber was observed following dispersion of an erythrocyte suspension in a nuclear staining dye, SYTO 21, onto the chip surface and washing. About 500,000 erythrocytes were analyzed in a total of 4675 microchambers and malaria parasite-infected erythrocytes could be detected in 5 min by using the fluorescence detector. The percentage of infected erythrocytes in each of 41 patients was determined. Accurate and quantitative detection of the parasites could be performed. A good correlation between examinations via optical microscopy and by our chip system was demonstrated over the parasitemia range of 0.0039–2.3438% by linear regression analysis (R2 = 0.9945). Thus, we showed the potential of this chip system for the diagnosis of malaria.

In marine aquaculture, rotifers and Artemia nauplii employed as larval fish feed are often nutritionally enriched with forage such as yeast and algal cells supplemented with polyunsaturated fatty acids and xanthophylls, which are required for normal growth and a high survival ratio of fish larvae. To reduce the enrichment steps, we propose here the use of a marine thraustochytrid strain, Schizochytrium sp. KH105, producing docosahexaenoic acid, docosapentaenoic acid, canthaxanthin, and astaxanthin. The KH105 cells prepared by cultivation under optimized conditions were successfully incorporated by rotifers and Artemia nauplii. The contents of docosahexaenoic acid surpassed the levels required in feed for fish larvae, and the enriched Artemia showed an increased body length. The results demonstrate that we have developed an improved method of increasing the dietary value of larval fish feed.

Epitaxial LiTaO3 thin films were deposited on epitaxial Pt(111)/Al2O3(001) and Al2O3(001) substrates by metal organic chemical vapor deposition using LiTa(OC2H5)4(OC2H4OCH3)2 and Li(DPM) precursors. The full-width at half-maximum of the rocking curve of LiTaO3 thin films were respectively 0.29° on Al2O3(001) substrates and 0.98° on epitaxial Pt(111)/Al2O3(001). Electrical measurements showed that the remanent polarization and coercive field of the films were 2Pr=76 μC/cm2 and E =130 kV/cm, respectively. The leakage current density was 10-6–10-8 A/cm2 at 120 kV/cm. Refractive indices n measured at 632.8 nm were measured respectively as 2.15 on Al2O3(001) and 2.14 on Pt(111)/Al2O3(001).

A major target protein of antineutrophil cytoplasmic antibody with a perinuclear staining pattern (P-ANCA) has been identified as myeloperoxidase (MPO). Recombinant deletion mutants of MPO, eight fragments of the heavy-chain subunit, and two fragments of the light chain subunit were expressed in E. coli using a pQE expression vector. The recombinant hexamer histidine-tagged fragments were partially purified as the denatured proteins on a Ni2+-charged nitrirotriacetic acid column. The recombinant fragments were reacted with a rabbit polyclonal antibody to human MPO in Western blotting. In addition, the reactivities of the proteins with MPO-ANCA-positive sera of four patients with renal diseases were examined by Western blotting. The profile of the reactivity showed that different sera recognized different sets of fragments of the heavy chain, whereas no serum reacted with the fragments of the light chain. These results indicate that the sera of patients with MPO-ANCA-positive diseases showed varied reactivities with the different fragments. Furthermore, an ELISA system using a set of the fragments completely purified by Sephacryl S-200HR column chromatography was established. The panel set is useful for subclassification of MPO-ANCA-related diseases.