Assessing effects of mechanical stimulation of fluid shear stress on inducing matrix Metalloproteinase-9 in cultured corneal epithelial cells.

Blinking is regarded as mechanical stimulation of fluid shear stress on the corneal epithelial cells. Therefore, we evaluated whether fluid shear stress affects matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in cultured human corneal epithelial cells (HCECs). No other study has shown the influence of fluid shear stress on HCECs regarding mRNA expression and the protein levels of MMPs. Cultured HCECs were exposed to shear stress (0, 1.2, 12 dyne/cm2) for 12 and 24 h with the parallel-plate type of flow chamber. Gene expression of MMPs and TIMPs was measured by real-time polymerase reaction. Concentrations of MMP-1 and MMP-9 in cell lysates were determined using bead-based amplified luminescent proximity homogenous assay-linked immunosorbent assay. The expression of MMP-9 and MMP-1 in HCECs exposed to low and high flow for 12 and 24 h, respectively, increased significantly compared with those under static conditions. The expression of MMP-9 in the cells exposed to high flow for 24 h increased significantly compared with those under static and low flow conditions. Levels of MMP-9 in cell lysates exposed to fluid flow for 24 h were elevated significantly with increasing shear stress. Fluid shear stress exerted on HCECs affected MMPs, which was associated with inflammation and pathogenesis. Mechanical stress induced by blinking might influence expression of MMPs on the ocular surface. Further studies are warranted to establish the molecular mechanism of shear stress-induced alternations of MMPs.

Relationship between nonperfusion area from widefield optical coherence tomography angiography and macular vascular parameters in diabetic retinopathy.

PURPOSE: To evaluate the relationship between the nonperfusion area (NPA) from widefield optical coherence tomography angiography (OCTA) and macular vascular parameters in diabetic retinopathy (DR). METHODS: In total, 51 eyes from 51 patients with proliferative DR (PDR) or moderate/severe non-PDR were included. Widefield OCTA using the Zeiss Plex Elite 9000 was performed. A semi-automatic algorithm calculated the percentages of the NPA within the total image. Macular OCTA (3 × 3 mm and 6 × 6 mm area) was scanned using the RTVue-XR Avanti. Vessel density (VD) was automatically separated into the superficial (SCP) and deep capillary plexus (DCP), and foveal avascular zone (FAZ) measurements were computed according to the parafoveal (1-3 mm) and perifoveal (3-6 mm) regions. RESULTS: A negative correlation was found between the average VD of the SCP and DCP obtained 3 × 3 mm and 6 × 6 mm area and the NPA. Multiple regression analysis revealed that the temporal-perifoveal region most negatively correlated with the NPA (r = - 0.55, p < 0.0001). No correlation was found between FAZ measurements and DR severity (area, p = 0.07; perimeter, p = 0.13). CONCLUSION: Diabetic macular nonperfusion was significantly associated with the NPA from widefield OCTA. In particular, the temporal-perifoveal DCP disorder may be a sensitive indicator of wide NPA.

Niclosamide suppresses the expansion of follicular helper T cells and alleviates disease severity in two murine models of lupus via STAT3.

BACKGROUND: Autoantibody production against endogenous cellular components is pathogenic feature of systemic lupus erythematosus (SLE). Follicular helper T (TFH) cells aid in B cell differentiation into autoantibody-producing plasma cells (PCs). The IL-6 and IL-21 cytokine-mediated STAT3 signaling are crucial for the differentiation to TFH cells. Niclosamide is an anti-helminthic drug used to treat parasitic infections but also exhibits a therapeutic effect on autoimmune diseases due to its potential immune regulatory effects. In this study, we examined whether niclosamide treatment could relieve lupus-like autoimmunity by modulating the differentiation of TFH cells in two murine models of lupus. METHODS: 10-week-old MRL/lpr mice were orally administered with 100 mg/kg of niclosamide or with 0.5% methylcellulose (MC, vehicle) daily for 7 weeks. TLR7 agonist, resiquimod was topically applied to an ear of 8-week-old C57BL/6 mice 3 times a week for 5 weeks. And they were orally administered with 100 mg/kg of niclosamide or with 0.5% MC daily for 5 weeks. Every mouse was analyzed for lupus nephritis, proteinuria, autoantibodies, immune complex, immune cell subsets at the time of the euthanization. RESULTS: Niclosamide treatment greatly improved proteinuria, anti-dsDNA antibody levels, immunoglobulin subclass titers, histology of lupus nephritis, and C3 deposition in MRL/lpr and R848-induced mice. In addition, niclosamide inhibited the proportion of TFH cells and PCs in the spleens of these animals, and effectively suppressed differentiation of TFH-like cells and expression of associated genes in vitro. CONCLUSIONS: Niclosamide exerted therapeutic effects on murine lupus models by suppressing TFH cells and plasma cells through STAT3 inhibition.

Optorheological Characteristics of Photosynthetic Bacterium Suspension.

Understanding the rheological behavior of materials is of great importance in science. Here, we report a microscopic foundation for optorheology by manipulating the rheological feature through light. A new phenomenon is observed in the photosynthetic bacterial suspension, that the fluid viscosity changes by light-induced electrons. Type IV pili of photosynthetic bacteria is found, and it allows the electron to transport through the exterior of cells and changes the surface potential of cells, which causes an adjustment in the spatial arrangement of cells in the suspension. When an external electric field is applied, the electric dipole of the cells is induced and their dispersion is changed. The rheological properties are measured to evaluate the internal structure of the suspension depending on the light. The photoelectrons enhance the dispersion of the photosynthetic bacteria in the solution, thus leading to a significant increment in the viscosity. We envision that this discovery will provide new applications to the interface of optics, bioengineering, and rheology.

A Broadband Multiplex Living Solar Cell.

Developing renewable and sustainable energy sources is a compelling goal in materials science and engineering. In particular, natural photosynthesis with its infinite energy reservoir provides profound inspiration for energy conversion and storage systems. Here, we report a multiplex living solar cell that offers a drastic power enhancement by harnessing the broadband spectra of the visible wavelength range for photosynthesis. Cyanobacteria are embedded into a nanostructural complex composed of Au nanoparticles (NPs) and ZnO nanorods (NRs). This nanocomposite system is capable of not only generating excitons but also amplifying the photosynthetic performance of the cell via a far-field scattering effect in the broadband region of the light, resulting in multiplex energy harvesting with a peak power density of 6.15 mW/m2. We envision that this study will provide a strategic way to enhance the performance of biophotovoltaics, enabling efficient and durable energy generation.

Fabrication and Analysis of Sepiolite/Glass Microcapsules/Liquid Crystal Polymer Composites.

Liquid crystal polymer (LCP) composites filled with sepiolite and glass microcapsules were prepared by melt compounding. The composites were extruded using a twin-screw extruder and injection-molded. The objective of this study is to check a possibility of producing a polymeric composite with a low dielectric constant. Physical characteristics of the composites, such as morphological, rheological, mechanical, and electrical properties were analyzed. In particular, the glass microcapsule-reinforced LCP composites showed a significant improvement in lowering the dielectric constant due to its high air content. Additionally, sepiolite could act as an effective filler to improve the mechanical properties of the composites.

Carrier transport of all carbonized ß-glucosic eco-materials.

Attempts have been made to bring eco-friendly biomaterials into high-end electronic devices that require both high performance and durability. Polysaccharides, glycosidically linked monosaccharide units, are of particular interest because they serve as a promising material, owing to their environmentally friendly and adaptable features. We used a carbonized polysaccharide eco-material encompassing nanoparticles and chitosan to study the carrier-transport behavior of ß-glucosic materials. Chitosan composites incorporating nanoparticles were prepared and then carbonized to control the crystal structure of the material. Three kinds of metal-insulator-metal devices were fabricated using carbonized materials, and their carrier-transport properties were analyzed. The results showed that the addition of cellulose nano-whiskers (CNWs) into chitosan leads to a more ordered carbon structure, increasing the charge transport in the carbonized material. We anticipate that carbonizing nanoparticle dispersed green composites provides a new pathway for the development of sustainable and environmentally benign material systems.

Improved performance of carbon nanotubes embedded photomicrobial solar cell.

Enhancing the energy efficiency of power out is a key issue of microorganisms based energy harvesting. Here, we introduced carbon nanotubes (CNTs) into a photomicrobial solar cell (PMSC) system in order to increase the harvesting energy power. Microcystis aeruginosa was used as a solar energy converter, microorganism. It revealed that when a small amount of CNTs (e.g. 0.001 wt%) were added in the cyanobacterium suspension, the photocurrents were enhanced dramatically. The optical and electrical properties of the CNT suspension were analyzed. The biochemical features of the PMSC were evaluated under dark and light conditions. This study is expected to offer a strategic way for harvesting living cell-based solar energy in a more efficient manner.

miR-106b-5p and miR-17-5p could predict recurrence and progression in breast ductal carcinoma in situ based on the transforming growth factor-beta pathway.

PURPOSE: Ductal carcinoma in situ (DCIS) is well-known precursor of invasive ductal carcinoma (IDC). Parts of patients show recurrence as DCIS or IDC after local treatment, but there are no established markers predicting relapse. We analyzed changes in miRNA and oncogene expression during DCIS progression/evolution to identify potential markers predicting recurrence. METHODS: Forty archival tissues diagnosed as primary or recurrent DCIS and DCIS adjacent to IDC were analyzed. MiRNA hierarchical clustering showed up-regulation of miR-17-5p and miR-106b-5p in recurrent DCIS and DCIS adjacent to IDC. Target genes were predicted based on pre-formed miRNA databases and PanCancer Pathway panel. MiRNAs were transfected into MCF-10A and MCF-7 cells; western blot analysis was performed with MCF-7 cell line to evaluate the effects on TGF-ß downstream pathway. RESULTS: miRNA hierarchical clustering showed 17 dysregulated miRNAs, including miR-17-5p and miR-106b-5p. Based on miRNA database and nCounter Pancancer pathway analysis, TGFßRII was selected as target of miR-106b-5p and miR-17-5p. MiR-106b-5p- and miR-17-5p-transfected MCF-7 cells showed decreased expression of TGFßRII, especially in cells transfected with both miRNAs. CONCLUSION: miR-106b-5p and miR-17-5p might have a role in breast cancer recurrence and progression by suppressing TGF-ß activity, leading to early breast cancer carcinogenesis.

Hydrodynamic Metamaterial Cloak for Drag-Free Flow.

Metamaterials engineered based on transformation optics have facilitated inaccessible manipulation of various physical phenomena. However, such metamaterials have not been introduced for flowing viscous matter. Here we propose a hydrodynamic metamaterial cloak that can conceal an object in two-dimensional creeping flow by guiding viscous forces. Coordinate transformation of fluidic space is implemented to calculate a tensoric viscosity based on a form invariance of Navier-Stokes equations. The hydrodynamic cloak with the viscosity tensor is numerically simulated to verify a fictitious fluidic empty space created in it. The corresponding metamaterial microstructure is systemically designed and fabricated in a microfluidic device. The experimental results reveal that a solid object amid the flow can be hydrodynamically hidden without entailing a disturbance in flow fields and experiencing a drag.

Eco-friendly flame retardant nanocrystalline cellulose prepared via silylation.

Employing proper flame retardant materials is one of the most important fire safety guidelines when constructing buildings. Most flame retardants, however, contain halogen atoms that might become harmful gases to human body during combustion. We designed and fabricated an environmentally friendly flame retardant material with a superior performance for thermal insulation. Nanocrystalline cellulose (NCC) was prepared using acid hydrolysis method, and its surface was chemically modified through silylation treatment. Various characteristics of the flame retardant material, such as morphology, chemical structure, thermal stability, and thermal conductivity were investigated. When a mass ratio of NCC to methyltrimethoxysilane was 1:5, the limiting oxygen index of the silylated NCC increased to 34% and a char yield of 80% was obtained. The silylation led to enhancement in the thermal stability of NCC and generation of the char residue. Chemical structure of the residual materials after combustion was investigated by using Fourier transform infrared spectroscopy and x-ray differential photo spectroscopy.

Multiple-Line Particle Focusing under Viscoelastic Flow in a Microfluidic Device.

Particles in a viscoelastic fluid are typically focused at the center and four corners of a rectangular channel because of the combination of fluid elasticity and inertia forces. In this study, we observe the transition between single-line and multiple-line particle focusing in a microfluidic device induced by the synergetic effect of inertia and viscoelasticity. The elastic and inertial forces acting on suspended particles are manipulated by controlling the concentration of dilute polymer solution and the flow rate of a fluid. The finding shows that the confinement effects determined by the channel aspect ratio and the inlet geometry lead to the multiple-line focusing of particles in the microfluidic channel due to the fluid elasticity and hydrodynamic behavior of the fluid. A microfluidic channel with high channel aspect ratio possesses broad minimal region of the elastic force across the channel, which generates a wide particle focusing band rather than a single particle focusing at the center. The multiple-line particle focusing occurs as the inertial force outweighs the elastic force, resulting in the particle migration toward the channel sidewalls.

Do surveillance intervals in patients with more than five adenomas at index colonoscopy be shorter than those in patients with three to four adenomas? A Korean Association for the Study of Intestinal Disease study.

BACKGROUND AND AIM: There is controversy about the surveillance interval after colonoscopy when 5-10 adenomas have been found on index colonoscopy. This study aimed to investigate the risk of colorectal neoplasm (CRN) according to the number of adenomas at index colonoscopy. METHODS: A retrospective, multicenter study was conducted at 10 university hospitals in Korea. We included 1394 patients with ≥ 3 adenomas at index colonoscopy. The risk of advanced CRN was compared according to the number of adenomas (intermediate risk group, 3-4 small adenomas or at least one ≥ 10 mm, and high risk group, ≥ 5 small adenomas or ≥ 3 at least one ≥ 10 mm). RESULTS: Overall, 164 (11.8%) developed an advanced CRN after a mean of 4.0 years from baseline colonoscopy. The 3-year and 5-year risk of advanced CRN was 2.1% (95% CI 2.09-2.11) and 14.4% (95% CI 14.36-14.44) in intermediate risk group and 3.2% (95% CI 3.19-3.21) and 23.3% (95% CI 19.15-19.25) in high risk group (P = 0.01). Having ≥ 5 adenomas (OR = 1.57, 95% CI 1.11-2.23, P = 0.01) detected at index colonoscopy was a significant risk factor for developing advanced CRN. CONCLUSIONS: Although risk of advanced CRN in patients with 5-10 adenomas was significantly higher than that in patients with 3-4 adenomas, the cumulative risk at 3 years was low at 3.2%. Thus, we suggest that a 3-year surveillance interval might be appropriate for the patients with 5-10 adenomas, and further prospective studies are needed to investigate whether more intensive surveillance is needed in this group.

Novel microbial photobioelectrochemical cell using an invasive ultramicroelectrode array and a microfluidic chamber.

OBJECTIVE: To fabricate a novel microbial photobioelectrochemical cell using silicon microfabrication techniques. RESULTS: High-density photosynthetic cells were immobilized in a microfluidic chamber, and ultra-microelectrodes in a microtip array were inserted into the cytosolic space of the cells to directly harvest photosynthetic electrons. In this way, the microbial photobioelectrochemical cell operated without the aid of electron mediators. Both short circuit current and open circuit voltage of the microbial photobioelectrochemical cell responded to light stimuli, and recorded as high as 250 pA and 45 mV, respectively. CONCLUSION: A microbial photobioelectrochemical cell was fabricated with potential use in next-generation photosynthesis-based solar cells and sensors.

Hydrodynamic fabrication of structurally gradient ZnO nanorods.

We studied a new approach where structurally gradient nanostructures were fabricated by means of hydrodynamics. Zinc oxide (ZnO) nanorods were synthesized in a drag-driven rotational flow in a controlled manner. The structural characteristics of nanorods such as orientation and diameter were determined by momentum and mass transfer at the substrate surface. The nucleation of ZnO was induced by shear stress which plays a key role in determining the orientation of ZnO nanorods. The nucleation and growth of such nanostructures were modeled theoretically and analyzed numerically to understand the underlying physics of the fabrication of nanostructures controlled by hydrodynamics. The findings demonstrated that the precise control of momentum and mass transfer enabled the formation of ZnO nanorods with a structural gradient in diameter and orientation.

Methylation status of long interspersed element-1 in advanced gastric cancer and its prognostic implication.

BACKGROUNDS: Reportedly, the pyrosequencing methylation assay can produce inconsistent results between paired snap-frozen and formalin-fixed paraffin-embedded archival tissue samples. In this study, we assayed the methylation levels at four individual CpG sites of L1 using pyrosequencing and found that the methylation levels at individual CpG sites were different but were closely correlated between paired snap-frozen and formalin-fixed paraffin-embedded tissue samples. We aimed to determine whether low methylation status of L1 is associated with gastric cancer patient prognosis. METHODS: We analyzed 434 formalin-fixed paraffin-embedded tissue samples of advanced gastric cancer for their methylation status at four CpG sites of L1 [nucleotide positions 328, 321, 318, and 306 of X58075 (Genbank)] using pyrosequencing, and correlated the L1 methylation level with clinicopathological features. RESULTS: Older age at onset, males, tumor location at antrum or lower body, intestinal type, and lymphatic or venous invasion were associated with a low average methylation level of L1 at the two CpG sites 1 and 4 combined. The average methylation level of L1 at CpG sites 1 and 4 combined was significantly lower in microsatellite-stable and EBV-negative gastric cancers than in EBV-positive or microsatellite-unstable gastric cancers. Low methylation status of L1 was independently correlated with shorter overall survival and disease-free survival time. CONCLUSION: Our findings indicate that the discrepancy in the methylation level of L1 between fresh tissue and formalin-fixed paraffin-embedded tissue samples depends on the CpG sites considered, and that the methylation status of L1 at CpG sites 1 and 4 combined could be utilized as a prognostic parameter for advanced gastric cancers.

Molecular pathogenesis of plasminogen Hakodate: the second Japanese family case of severe type I plasminogen deficiency manifested late-onset multi-organic chronic pseudomembranous mucositis.

A 64-year-old man first developed ligneous conjunctivitis at the age of 58 years after right pulmonary resection because of suspected cancer; otherwise, he had been healthy. Since then, he began to suffer from various forms of chronic pseudomembranous mucositis. Laboratory tests demonstrated that he had 7.8 % of plasminogen activity and 5.9 % of the normal antigen level. Thus, he was diagnosed as having severe type I plasminogen deficiency, making him the third case in Japan. DNA sequencing and PCR-restriction fragment length polymorphism analyses revealed that this patient was a compound heterozygote of a G-to-A missense mutation (G266E) in exon VIII and a g-to-a mutation at the obligatory splicing acceptor site in intron 12 (IVS12-1g>a). These two mutations were confirmed to be novel. Molecular modeling and splice site strength calculation predicted conformational disorder(s) for the Glu266 mutant and a drastic decrease in splicing efficiency for intron 12, respectively. Western blot analysis demonstrated that the patient contained a small amount of the normal-sized plasminogen protein. Mass spectrometric analysis of the patient's plasminogen revealed a peptide containing the wild-type Gly266 residue and no peptides with mutations at Glu266. However, he had never suffered from thrombosis. Low levels of fibrinogen/fibrin degradation products (FDP), D-dimer, and plasmin-α2-plasmin inhibitor complex clearly indicated a hypo-fibrinolytic condition. However, his plasma concentration of elastase-digested crosslinked FDPs was 4.8 U/mL, suggesting the presence of an on-going plasmin(ogen)-independent "alternative" fibrinolytic system, which may protect the patient from thrombosis. The patient has been free from recurrence of ligneous conjunctivitis for approximately 2.5 years.

SYSTEMIC RISK FACTORS IN BILATERAL PROLIFERATIVE DIABETIC RETINOPATHY REQUIRING VITRECTOMY.

PURPOSE: The visual outcome after vitrectomy for proliferative diabetic retinopathy (PDR) is often poor. Bilateral vitrectomy has been especially associated with a poor visual prognosis in patients with PDR. The authors investigated the systemic risk factors for PDR requiring bilateral vitrectomy compared with unilateral vitrectomy. METHODS: The authors retrospectively reviewed 86 consecutive patients with Type 2 diabetes mellitus with PDR who underwent vitrectomy. These patients were divided into 2 groups: bilateral vitrectomy within 1 year (n = 25) and unilateral vitrectomy (n = 61). The authors compared the systemic risk factors: age, sex, duration of diabetes, hemoglobin A1c, body mass index, estimated glomerular filtration rate, uric albumin, hypertension, dyslipidemia, history of ischemic heart disease, arteriosclerosis obliterans, and smoking. RESULTS: There were significantly more cases with severe renal dysfunction in the bilateral vitrectomy group compared with the unilateral one (estimated glomerular filtration rate <30 mL/minute/1.73 m; bilateral cases = 5/25; unilateral cases = 2/61; P = 0.02). CONCLUSION: The authors found that severe renal dysfunction may be a risk factor in PDR requiring bilateral vitrectomy, indicating that careful attention needs to be paid to prevent the progression of diabetic retinopathy to severe PDR in the other eye if patients have severe unilateral PDR and severe renal dysfunction.

Characterization of a single cell of Chlorella in a microfluidic channel using amperometric electrode arrays.

Electrochemical characteristics of O2 and/or mediators secreted by a single cell of Chlorella fusea were analyzed by using amperometric measurements on microelectrodes embedded in a microfluidic device. A single cell was trapped in a microfluidic channel, which simplifies the mass transfer phenomenon, i.e., one-dimensional distribution of solutes in the channel. Such amperometric measurements allowed us to obtain more refined data in a localized space and to understand photosynthetic behavior of algae at the single cell level. In addition, the concentration of a photosynthetic mediator, p-benzoquinone, was numerically calculated by using the finite element method.

Enhanced Dichroism of Polarizing Composite Films by Embedding Sepiolite.

The present study investigated the use of fibrous nanoparticle-filled polarizing films. Sepiolites were selected as nanoparticles and incorporated into a PVA-iodine complex. The resulting nanocomposite film was elongated and dyed with iodine. Various properties of the nanocomposite polarizing films, including thermal, morphological, optical, and rheological features, were experimentally analyzed. The study demonstrated that an increase in sepiolite loading was accompanied by an enhancement in both the mechanical and viscoelastic properties. In particular, the incorporation of nanoparticles led to an increase in birefringence and the degree of polarization. This was attributed to the alteration of the internal structure of the PVA film caused by the embedded sepiolites. The thermal analysis showed that the composite film with a higher content of sepiolites exhibited higher crystallinity and a higher melting temperature.