Detection of Periodontal Disease Marker with Geometrical Transformation of Ag Nanoplates.

Alkaline phosphatase (ALP) and interleukin-1beta (IL-1ß) are crucial salivary biomarkers for the diagnosis of periodontal disease that harms the periodontal tissue along with tooth loss. However, there has been no way of sensitive and portable detection of both biomarkers in saliva with multivariate signal readout. In this work, we design the multicolorimetric ALP and IL-1ß sensing platform based on geometrical transformation of silver nanoplate transducer. By utilizing enzymatic activity of ALP that dephosphorylates p-aminophenol phosphate (p-APP) to p-aminophenol (p-AP), localized surface plasmon resonance properties of silver nanoplate vary with ALP and show a distinct color change from blue to yellow based on a controlled seed transformation from triangular to hexagonal, rounded pentagonal, and spherical shape. The multicolor sensor shows an ALP detection range of 0-25 U/L with a limit of detection (LOD) of 0.0011 U/L, which is the lowest range of LOD demonstrated to date for state-of-the-art ALP sensor. Furthermore, we integrate the sensor with the conventional ELISA to detect IL-1ß for multicolor signaling and it exhibits a linear detection range of 0-250 pg/mL and an LOD of 0.066 pg/mL, which is 2 orders of magnitude lower than the monochromic conventional ELISA (LOD of 3.8 pg/mL). The ALP multicolor sensor shows high selectivity with a recovery of 100.9% in real human saliva proving its reliability and suitability for the readily accessible periodontal diagnosis with multivariate signal readout.

Divalent Metal Cation Optical Sensing Using Single-Walled Carbon Nanotube Corona Phase Molecular Recognition.

Colloidal single-walled carbon nanotubes (SWCNTs) offer a promising platform for the nanoscale engineering of molecular recognition. Optical sensors have been recently designed through the modification of noncovalent corona phases (CPs) of SWCNTs through a phenomenon known as corona phase molecular recognition (CoPhMoRe). In CoPhMoRe constructs, DNA CPs are of great interest due to the breadth of the design space and our ability to control these molecules with sequence specificity at scale. Utilizing these constructs for metal ion sensing is a natural extension of this technology due to DNA's well-known coordination chemistry. Additionally, understanding metal ion interactions of these constructs allows for improved sensor design for use in complex aqueous environments. In this work, we study the interactions between a panel of 9 dilute divalent metal cations and 35 DNA CPs under the most controlled experimental conditions for SWCNT optical sensing to date. We found that best practices for the study of colloidal SWCNT analyte responses involve mitigating the effects of ionic strength, dilution kinetics, laser power, and analyte response kinetics. We also discover that SWCNT with DNA CPs generally offers two unique sensing states at pH 6 and 8. The combined set of sensors in this work allowed for the differentiation of Hg2+, Pb2+, Cr2+, and Mn2+. Finally, we implemented Hg2+ sensing in the context of portable detection within fish tissue extract, demonstrating nanomolar level detection.

Antibody-Free Rapid Detection of SARS-CoV-2 Proteins Using Corona Phase Molecular Recognition to Accelerate Development Time.

To develop better analytical approaches for future global pandemics, it is widely recognized that sensing materials are necessary that enable molecular recognition and sensor assay development on a much faster scale than currently possible. Previously developed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) point-of-care devices are based on the specific molecular recognition using subunit protein antibodies and protein receptors that selectively capture the viral proteins. However, these necessarily involve complex and lengthy development and processing times and are notoriously prone to a loss of biological activity upon sensor immobilization and device interfacing, potentially limiting their use in applications at scale. Here, we report a synthetic strategy for nanoparticle corona interfaces that enables the molecular recognition of SARS-CoV-2 proteins without any antibody and receptor design. Our nanosensor constructs consist of poly(ethylene glycol) (PEG)─phospholipid heteropolymers adsorbed onto near-infrared (nIR) fluorescent single-walled carbon nanotubes (SWCNTs) that recognize the nucleocapsid (N) and spike (S) protein of SARS-CoV-2 using unique three-dimensional (3D) nanosensor interfaces. This results in rapid and label-free nIR fluorescence detection. This antibody-free nanosensor shows up to 50% sensor responses within 5 min of viral protein injections with limit of detection (LOD) values of 48 fM and 350 pM for N and S proteins, respectively. Finally, we demonstrate instrumentation based on a fiber-optic platform that interfaces the advantages of antibody-free molecular recognition and biofluid compatibility in human saliva conditions.

Development of a novel multifocal lens using a polarization directed flat lens: possible candidate for a multifocal intraocular lens.

BACKGROUND: A polarization-directed flat (PDF) lens acts as a converging lens with a focal length (f) > 0 and a diverging lens with f < 0, depending on the polarization state of the incidental light. To produce a multifocal lens with two focal lengths, a PDF and a converging lens having shorter focal length were combined. In this study, we tested a bifocal PDF to determine its potential as a new multifocal intraocular lens (IOL). METHODS: Constructed a multifocal lens with a PDF lens (f = +/- 100 mm) and a converging lens (f = + 25 mm). In an optical bench test, we measured the defocus curve to test the multifocal function. The multifocal function and optical quality of the lens in various situations were tested. An Early Treatment Diabetic Retinopathy Study (ETDRS) chart as a near target and a building as a distant target were photographed using a digital single-lens reflex (DSLR) camera. Both lenses (multifocal and monofocal) were tested under the same conditions. RESULTS: For the 0 D and - 20 D focal points, the multifocal lens showed sharp images in the optical bench test. In the DSLR test using the multifocal lens, the building appeared slightly blurry compared with the results using the monofocal lens. With the multifocal lens, the ETDRS chart's images became blurry as the ETDRS chart's distance decreased, but became very clear again at a certain position. CONCLUSIONS: We confirmed the multifocal function of the multifocal lens using a PDF lens. This lens can be used as a multifocal IOL in the future.

Finding Hidden Signals in Chemical Sensors Using Deep Learning.

Achieving high signal-to-noise ratio in chemical and biological sensors enables accurate detection of target analytes. Unfortunately, below the limit of detection (LOD), it becomes difficult to detect the presence of small amounts of analytes and extract useful information via any of the conventional methods. In this work, we examine the possibility of extracting "hidden signals" using deep neural network to enhance gas sensing below the LOD region. As a test case system, we conduct experiments for H2 sensing in six different metallic channels (Au, Cu, Mo, Ni, Pt, Pd) and demonstrate that deep neural network can enhance the sensing capabilities for H2 concentration below the LOD. We demonstrate that this technique could be universally used for different types of sensors and target analytes. Our approach can extract new information from the hidden signals, which can be crucial for next-generation chemical sensing applications and analytical chemistry.

Ten Nanometer Scale WO3/CuO Heterojunction Nanochannel for an Ultrasensitive Chemical Sensor.

The fabrication of p-n heterostructures of a metal oxide semiconductor (MOS) showed that a large amount of heterojunction interfaces is one of the key issues in MOS gas sensor research, since it could significantly enhance the sensing performance. Despite considerable progress in this area, fabrication of an ideal p-n heterojunction sensing channel has been challenging because of morphological limitations of synthetic methods in the conventional bottom-up fabrication based on precursor reductions. In this study, a 10 nm scale p-n heterojunction nanochannel was fabricated with ultrasmall grained WO3/CuO nanopatterns in a large area (centimeter scale) through unique one-step top-down lithographic approaches. The fabricated p-n heterostructure nanochannel showed ultrathinness (20 nm thickness) and high aspect ratio (>10) and consisted of highly dispersed p-type dopants and n-type channel materials. This facile heterojunction nanostructure could induce a high degree of extended depletion layer and efficient catalytic properties within its single-nanochannel surfaces. Accordingly, the WO3/CuO nanochannel exhibited ultrasensitive detection performance toward ethanol (C2H5OH) ( Ra/ Rg = 224 at100 ppb), 12 times higher than that of a pristine WO3 nanochannel. The limit of detection of the sensors was calculated to be below parts per billion levels (0.094 ppb) with significant response amplitudes ( Ra/ Rg = 75), which is the best ethanol-sensing performance among previously reported MOS-based sensors. Our unique lithographic approach for the p-n heterojunction nanochannel is expected to be universally applicable to various heteronanostructures such as the n-n junction, p-p junction, and metal-semiconductor junction without combinatorial limitations.

DIFFERENCE IN TREATMENT OUTCOMES ACCORDING TO OPTICAL COHERENCE TOMOGRAPHY-BASED STAGES IN TYPE 3 NEOVASCULARIZATION (RETINAL ANGIOMATOUS PROLIFERATION).

PURPOSE: To compare 12-month treatment outcomes of Type 3 neovascularization among its different stages as classified using an optical coherence tomography-based method. METHODS: This retrospective observational study included 40 patients (40 eyes) who were newly diagnosed with Type 3 neovascularization. The patients were initially administered 3 monthly anti-vascular endothelial growth factor injections. Repeat treatment was performed when recurrence of fluid was noted. Disease staging was classified using the optical coherence tomography-based method. The best-corrected visual acuity at diagnosis and at 12 months and degree of change in best-corrected visual acuity were compared among the different stages of the disease. In addition, incidence of progression in the disease stages was estimated. RESULTS: Among the 40 patients, 14 (35.0%) were classified as Stage 2 and 26 (65.0%) were classified as Stage 3. The best-corrected visual acuity values at diagnosis and at 12 months were 0.61 ± 0.31 (20/81 Snellen equivalents) and 0.46 ± 0.30 (20/57) in the Stage 2 group and 0.67 ± 0.42 (20/93) and 0.70 ± 0.49 (20/100) in the Stage 3 group, respectively. There was a significant difference in best-corrected visual acuity change between the two groups (P = 0.036). During the follow-up period, 3 retinal pigment epithelium tears and 2 submacular hemorrhages had developed in the Stage 3 group. Progression of the disease from Stage 2 to Stage 3 was noted in 2 patients (14.3%). CONCLUSION: The visual outcome was worse in Stage 3 than in Stage 2, and adverse events that may lead to abrupt visual deterioration developed only in Stage 3. Further studies are needed to reveal whether anti-vascular endothelial growth factor therapy can suppress the progression of the disease stages.

Selective Functionalization of High-Resolution Cu2O Nanopatterns via Galvanic Replacement for Highly Enhanced Gas Sensing Performance.

Recently, high-resolution patterned metal oxide semiconductors (MOS) have gained considerable attention for enhanced gas sensing performance due to their polycrystalline nature, ultrasmall grain size (~5 nm), patternable properties, and high surface-to-volume ratio. Herein, we significantly enhanced the sensing performance of that patterned MOS by galvanic replacement, which allows for selective functionalization on ultrathin Cu2O nanopatterns. Based on the reduction potential energy difference between the base channel material (Cu2O) and the decorated metal ion (Pt2+), Pt could be selectively and precisely decorated onto the desired area of the Cu2O nanochannel array. Overall, the Pt-decorated Cu2O exhibited 11-fold higher NO2 (100 ppm) sensing sensitivity as compared to the non-decorated sensing channel, the while the channel device with excessive Pt doping showed complete loss of sensing properties.

High-Resolution p-Type Metal Oxide Semiconductor Nanowire Array as an Ultrasensitive Sensor for Volatile Organic Compounds.

The development of high-performance volatile organic compound (VOC) sensor based on a p-type metal oxide semiconductor (MOS) is one of the important topics in gas sensor research because of its unique sensing characteristics, namely, rapid recovery kinetics, low temperature dependence, high humidity or thermal stability, and high potential for p-n junction applications. Despite intensive efforts made in this area, the applications of such sensors are hindered because of drawbacks related to the low sensitivity and slow response or long recovery time of p-type MOSs. In this study, the VOC sensing performance of a p-type MOS was significantly enhanced by forming a patterned p-type polycrystalline MOS with an ultrathin, high-aspect-ratio (∼25) structure (∼14 nm thickness) composed of ultrasmall grains (∼5 nm size). A high-resolution polycrystalline p-type MOS nanowire array with a grain size of ∼5 nm was fabricated by secondary sputtering via Ar(+) bombardment. Various p-type nanowire arrays of CuO, NiO, and Cr2O3 were easily fabricated by simply changing the sputtering material. The VOC sensor thus fabricated exhibited higher sensitivity (ΔR/Ra = 30 at 1 ppm hexane using NiO channels), as well as faster response or shorter recovery time (∼30 s) than that of previously reported p-type MOS sensors. This result is attributed to the high resolution and small grain size of p-type MOSs, which lead to overlap of fully charged zones; as a result, electrical properties are predominantly determined by surface states. Our new approach may be used as a route for producing high-resolution MOSs with particle sizes of ∼5 nm within a highly ordered, tall nanowire array structure.

A normalization method for combination of laboratory test results from different electronic healthcare databases in a distributed research network.

PURPOSE: Distributed research networks (DRNs) afford statistical power by integrating observational data from multiple partners for retrospective studies. However, laboratory test results across care sites are derived using different assays from varying patient populations, making it difficult to simply combine data for analysis. Additionally, existing normalization methods are not suitable for retrospective studies. We normalized laboratory results from different data sources by adjusting for heterogeneous clinico-epidemiologic characteristics of the data and called this the subgroup-adjusted normalization (SAN) method. METHODS: Subgroup-adjusted normalization renders the means and standard deviations of distributions identical under population structure-adjusted conditions. To evaluate its performance, we compared SAN with existing methods for simulated and real datasets consisting of blood urea nitrogen, serum creatinine, hematocrit, hemoglobin, serum potassium, and total bilirubin. Various clinico-epidemiologic characteristics can be applied together in SAN. For simplicity of comparison, age and gender were used to adjust population heterogeneity in this study. RESULTS: In simulations, SAN had the lowest standardized difference in means (SDM) and Kolmogorov-Smirnov values for all tests (p < 0.05). In a real dataset, SAN had the lowest SDM and Kolmogorov-Smirnov values for blood urea nitrogen, hematocrit, hemoglobin, and serum potassium, and the lowest SDM for serum creatinine (p < 0.05). CONCLUSION: Subgroup-adjusted normalization performed better than normalization using other methods. The SAN method is applicable in a DRN environment and should facilitate analysis of data integrated across DRN partners for retrospective observational studies.

Highly Enhanced Fluorescence Signals of Quantum Dot-Polymer Composite Arrays Formed by Hybridization of Ultrathin Plasmonic Au Nanowalls.

Enhancement of the fluorescence intensity of quantum dot (QD)-polymer nanocomposite arrays is an important issue in QD studies because of the significant reduction of fluorescence signals of such arrays due to nonradiative processes in densely packed polymer chains in solid films. In this study, we enhance the fluorescence intensity of such arrays without significantly reducing their optical transparency. Enhanced fluorescence is achieved by hybridizing ultrathin plasmonic Au nanowalls onto the sidewalls of the arrays via single-step patterning and hybridization. The plasmonic Au nanowall induces metal-enhanced fluorescence, resulting in a maximum 7-fold enhancement of the fluorescence signals. We also prepare QD nanostructures of various shapes and sizes by controlling the dry etching time. In the near future, this facile approach can be used for fluorescence enhancement of colloidal QDs with plasmonic hybrid structures. Such structures can be used as optical substrates for imaging applications and for fabrication of QD-LED devices.

Direct Observation of Highly Ordered Dendrimer Soft Building Blocks over a Large Area.

Developing large-area, single domain of organic soft-building blocks such as block copolymers, colloids, and supramolecular materials is one of the most important issues in the materials science and nanotechnology. Owing to their small sizes, complex molecular architectures, and high mobility, supramolecular materials are not well-suited for building large area, single domain structures. In the described study, a single domain of supramolecular columnar dendrimers was created over large area. The columnar structures in these domains have smaller (4.5 nm) diameters, higher area densities (ca. 36 Tera-dots/in(2)) and larger domains (>0.1 × 0.1 mm(2)) than those of all existing BCP and colloidal assemblies. By simply annealing dendrimer thin films between two flat solid surfaces, single domains of hexagonal columnar structures are created over large macroscopic areas. Observations made in this effort should serve as the foundation for the design of new routes for bottom-up lithography based on supramolecular building blocks.

Well-defined and high resolution Pt nanowire arrays for a high performance hydrogen sensor by a surface scattering phenomenon.

Developing hydrogen (H2) sensors with a high sensitivity, rapid response, long-term stability, and high throughput is one of the critical issues in energy and environmental technology [Hübert et al. Sens. Actuators, B 2011, 157, 329]. To date, H2 sensors have been mainly developed using palladium (Pd) as the channel material because of its high selectivity and strong affinity to the H2 molecule [(Xu et al. Appl. Phys. Lett. 2005, 86, 203104), (Offermans et al. Appl. Phys. Lett. 2009, 94, 223110), (Yang et al. Nano Lett. 2009, 9, 2177), (Yang et al. ACS Nano 2010, 4, 5233), and (Zou et al. Chem. Commun. 2012, 48, 1033)]. Despite significant progress in this area, Pd based H2 sensors suffer from fractures on their structure due to hydrogen adsorption induced volumetric swelling during the α → ß phase transition, leading to poor long-term stability and reliability [(Favier et al. Science 2001, 293, 2227), (Walter et al. Microelectron. Eng. 2002, 61­62, 555), and (Walter et al. Anal. Chem. 2002, 74, 1546)]. In this study, we developed a platinum (Pt) nanostructure based H2 sensor that avoids the stability limitations of Pd based sensors. This sensor exhibited an excellent sensing performance, low limit of detection (LOD, 1 ppm), reproducibility, and good recovery behavior at room temperature. This Pt based H2 sensor relies on a highly periodic, small cross sectional dimension (10­40 nm) and a well-defined configuration of Pt nanowire arrays over a large area. The resistance of the Pt nanowire arrays significantly decreased upon exposure to H2 due to reduced electron scattering in the cross section of the hydrogen adsorbed Pt nanowires, as compared to the oxygen terminated original state. Therefore, these well-defined Pt nanowire arrays prepared using advanced lithographic techniques can facilitate the production of high performance H2 sensors.

Non-Mitochondrial Aconitase-2 Mediates the Transcription of Nuclear-Encoded Electron Transport Chain Genes in Fission Yeast.

Aconitase-2 (Aco2) is present in the mitochondria, cytosol, and nucleus of fission yeast. To explore its function beyond the well-known role in the mitochondrial tricarboxylic acid (TCA) cycle, we conducted genome-wide profiling using the aco2ΔNLS mutant, which lacks a nuclear localization signal (NLS). The RNA sequencing (RNA-seq) data showed a general downregulation of electron transport chain (ETC) genes in the aco2ΔNLS mutant, except for those in the complex II, leading to a growth defect in respiratory-prone media. Complementation analysis with non-catalytic Aco2 [aco2ΔNLS + aco2(3CS)], where three cysteines were substituted with serine, restored normal growth and typical ETC gene expression. This suggests that Aco2's catalytic activity is not essential for its role in ETC gene regulation. Our mRNA decay assay indicated that the decrease in ETC gene expression was due to transcriptional regulation rather than changes in mRNA stability. Additionally, we investigated the Php complex's role in ETC gene regulation and found that ETC genes, except those within complex II, were downregulated in php3Δ and php5Δ strains, similar to the aco2ΔNLS mutant. These findings highlight a novel role for nuclear aconitase in ETC gene regulation and suggest a potential connection between the Php complex and Aco2.

Establishment of a Dual-Vector System for Gene Delivery Utilizing Prototype Foamy Virus.

Foamy viruses (FVs) are generally recognized as non-pathogenic, often causing asymptomatic or mild symptoms in infections. Leveraging these unique characteristics, FV vectors hold significant promise for applications in gene therapy. This study introduces a novel platform technology using a pseudo-virus with single-round infectivity. In contrast to previous vector approaches, we developed a technique employing only two vectors, pcHFV lacking Env and pCMV-Env, to introduce the desired genes into target cells. Our investigation demonstrated the efficacy of the prototype foamy virus (PFV) dual-vector system in producing viruses and delivering transgenes into host cells. To optimize viral production, we incorporated the codon-optimized Env (optEnv) gene in pCMV-Env and the Woodchuck Hepatitis Virus Posttranscriptional Regulatory Element (WPRE) at the 3' end of the transgene in the transfer vector. Consequently, the use of optEnv led to a significant enhancement in transgene expression in host cells. Additionally, the WPRE exhibited an enhancing effect. Furthermore, the introduced EGFP transgene was present in host cells for a month. In an effort to expand transgene capacity, we further streamlined the viral vector, anticipating the delivery of approximately 4.3 kbp of genes through our PFV dual-vector system. This study underscores the potential of PFVs as an alternative to lentiviruses or other retroviruses in the realm of gene therapy.

Rational Design of 3D Polymer Corona Interfaces of Single-Walled Carbon Nanotubes for Receptor-Free Virus Recognition.

Facing the escalating threat of viruses worldwide, the development of efficient sensor elements for rapid virus detection has never been more critical. Traditional point-of-care (POC) sensors struggle due to their reliance on fragile biological receptors and limited adaptability to viral strains. In this study, we introduce a nanosensor design for receptor-free virus recognitions using near-infrared (NIR) fluorescent single-walled carbon nanotubes (SWCNTs) functionalized with a poly(ethylene glycol) (PEG)-phospholipid (PEG-lipid) array. Three-dimensional (3D) corona interfaces of the nanosensor array enable selective and sensitive detection of diverse viruses, including Ebola, Lassa, H3N2, H1N1, Middle East respiratory syndrome (MERS), severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1), and SARS-CoV-2, even without any biological receptors. The PEG-lipid components, designed considering chain length, fatty acid saturation, molecular weight, and end-group moieties, allow for precise quantification of viral recognition abilities. High-throughput automated screening of the array demonstrates how the physicochemical properties of the PEG-lipid/SWCNT 3D corona interfaces correlate with viral detection efficiency. Utilizing molecular dynamics and AutoDock simulations, we investigated the impact of PEG-lipid components on 3D corona interface formation, such as surface coverage and hydrodynamic radius and specific molecular interactions based on chemical potentials. Our findings not only enhance detection specificity across various antigens but also accelerate the development of sensor materials for promptly identifying and responding to emerging antigen threats.

Retrospective Analysis of a New Intrastromal Dissection Technique Using the Retinal Reflex for Deep Anterior Lamellar Keratoplasty.

PURPOSE: The purpose of this study was to describe a new surgical technique for deep anterior lamellar keratoplasty. METHODS: All pupils in the recipient eyes were dilated preoperatively. Vertical grooving was performed using a crescent blade with a width of 5 mm and a depth of one-third to half corneal thickness on the temporal side of the limbus. Stromal dissection was performed as close as possible to Descemet membrane by observing the gap between the gold line by retinal reflex and the front edge of the crescent blade. Lamellar dissection was performed along the lamellar plane using corneal dissectors. The ophthalmic viscoelastic device was injected into the intrastromal pocket to separate the anterior and posterior stroma and an anterior corneal lamella was excised. A donor cornea was sutured into the recipient bed. RESULTS: In 18 eyes, none of the patients had Descemet membrane rupture during surgery. The mean postoperative residual stromal thickness was 80 ± 31 µm. The mean central corneal thickness after surgery was 660 ± 69 µm. At the last follow-up, the cornea was cleared in all 18 eyes on slit-lamp examination. CONCLUSIONS: We estimated the residual stromal thickness based on the gap between the gold line by the retinal reflex and crescent blade, and intrastromal lamellar dissection was performed using a smooth corneal dissector. Consequently, the surface of stromal dissection was smooth, and the residual stromal thickness was even.

Physicochemical Profiling of Macrophage Heterogeneity Using Deep Learning Integrated Nanosensor Cytometry.

Label-free single-cell analytics have been developed for understanding the collective immune response mechanism of immune cells. However, it remains difficult to analyze the physicochemical properties of a single cell in high spatiotemporal resolution for an immune cell having dynamic morphological changes and significant molecular heterogeneities. It is deemed due to the absence of a sensitive molecular sensing construct and single-cell imaging analytic program. In this study, we developed a deep learning integrated nanosensor chemical cytometry (DI-NCC) platform, which combines a fluorescent nanosensor array in microfluidics and a deep learning model for cell feature analysis. The DI-NCC platform possesses the capability to collect rich, multivariate data sets for each individual immune cell (e.g., macrophage) within the population. We obtained LPS+ (n = 25) and LPS- (n = 61) near-infrared images and analyzed 250 cells/mm2 in 1 µm spatial resolution and 0 to 1.0 confidence level even with overlapped or adhered cell configurations. This enables automatic quantification of the activation and nonactivation levels of a single macrophage upon instantaneous immune stimulations. Furthermore, we support the activation level quantified by deep learning with heterogeneities analysis of both biophysical (cell size) and biochemical (nitric oxide efflux) properties. The DI-NCC platform can be promising for activation profiling of dynamic heterogeneity variations of cell populations.

The effect of 6% hydroxyethyl starch 130/0.4 preloading on the blood glucose levels in diabetic patients undergoing orthopedic surgery with spinal anesthesia: a randomized pilot study.

BACKGROUND: Perioperative hyperglycemia can occur in surgical patients and may increase postoperative morbidity and mortality, especially in patients with diabetes. Therefore, we conducted the present study to evaluate whether the administration of 6% hydroxyethyl starch (HES)-130/0.4 increases blood glucose levels in patients with diabetes. METHODS: Forty patients undergoing lower limb surgery under spinal anesthesia were randomly allocated into two groups according to the fluids administered 20 min before spinal anesthesia (Group L, lactated Ringer's solution; Group H, 6% HES-130/0.4). Patient characteristics, intraoperative variables, blood glucose levels, mean blood pressure (MBP), and heart rate (HR) were recorded at five time-points (0, 20, 60, 120, and 240 min). RESULTS: A total of 39 patients were analyzed (Group L, n = 20; Group H, n = 19). The amount of intraoperative fluid was significantly higher in Group L than in Group H (718.2 ml vs. 530.0 ml, P = 0.010). There were no significant differences in the changes in blood glucose levels, HR, or MBP between the two groups (P = 0.737, P = 0.896, and P = 0.141, respectively). Serial changes in mean blood glucose levels from baseline also showed no significant differences between the groups (P = 0.764). CONCLUSIONS: There were no significant changes in blood glucose levels when lactated Ringer's solution or 6% HES-130 was used. When compared to the lactated Ringer's solution, no evidence that 6% HES-130/0.4 produces hyperglycemia in diabetic patients could be found. Further evaluation of larger populations is needed.

Effects of household water-repellent agents and number of coating layers on the physical properties of cotton woven fabrics.

The increased interest in outdoor activities has prompted the demand for water-repellent fabrics that can withstand various environmental factors. In this study, the water repellency and physical properties, namely thickness, weight, tensile strength, elongation, and stiffness, of cotton woven fabrics were analyzed according to various treatments with different types of household water-repellent agents and number of coating layers. Fluorine-, silicone-, and wax-based water-repellent agents were coated on cotton woven fabrics once, thrice, and five times. Thickness, weight, and stiffness increased with the number of coating layers, which may reduce comfort. These properties increased minimally for the fluorine- and silicone-based water-repellent agents, whereas they considerably increased for the wax-based water-repellent agent. The fluorine-based water-repellent agent had a low water repellency rating of 2.2 even after five coating layers, and the silicone-based water-repellent agent had a higher rating of 3.4 with the same five coating layers. Meanwhile, the wax-based water-repellent agent had the highest water repellency rating of 5 even with only one coating layer, which was maintained with repeated coatings. Therefore, fluorine- and silicone-based water-repellent agents minimally altered the fabric properties even with repeated coatings; multiple coating layers, especially five or more layers for the fluorine-based water-repellent agent, are recommended to attain excellent water repellency. Conversely, one coating layer of the wax-based water-repellent agent is recommended to retain the comfort of the wearer.