Zinculose: A New Fibrous Material with Embedded Zinc Particles

In this paper, we report a simple and inexpensive procedure to make a composite material of cellulose fibers with embedded zinc micoparticles. This fibrous material is produced by sedimentation and is referred to as “Zinculose”. Zinculose increases the surface contact area between a sample fluid and zinc microparticles. The effect of different parameters including fiber content, zinc content, water volume, applied weight and its duration on the thickness of produced Zinculose were investigated. Results show that thickness depends on the amount of initial fiber and zinc while other parameters investigated had little to no effect. Measured porosity values for Zinculose ranged between 0.699 and 0.843. Characterization of flow in Zinculose exhibits a linear relationship between distance and the square root of time which is a distinctive feature of capillary driven flow in porous media. This is an important quality that allows Zinculose to be easily incorporated into any paper-based microfluidic device that requires a sample to flow and interact with zinc microparticles without disrupting the flow path between different sections of the device. An application is presented in which a strip of Zinculose is used to convert nitrate to nitrite. With the use of Zinculose in a paper-based microfluidic device, a conversion efficiency of 27% nitrate to nitrite was achieved. This represents a 36% enhancement over what has been previously published when zinc microparticles were not embedded within the fibers of the paper channel

Infrared Lightbox and iPhone App for Improving Detection Limit of Phosphate Detecting Dip Strips

In this paper, we report the development of a portable and inexpensive infrared lightbox for improving the detection limits of paper-based phosphate devices. Commercial paper-based devices utilize the molybdenum blue protocol to detect phosphate in the environment. Although these devices are easy to use and have a long shelf life, their main deficiency is their low sensitivity based on the qualitative results obtained via a color chart. To improve the results, we constructed a compact infrared lightbox that communicates wirelessly with a smartphone. The system measures the absorbance of radiation for the molybdenum blue reaction in the infrared region of the spectrum. It consists of a lightbox illuminated by four infrared light-emitting diodes, an infrared digital camera, a Raspberry Pi microcontroller, a mini-router, and an iPhone to control the microcontroller. An iPhone application was also developed to analyze images captured by the infrared camera in order to quantify phosphate concentrations. Additionally, the app connects to an online data center to present a highly scalable worldwide system for tracking and analyzing field measurements. In this study, the detection limits for two popular commercial devices were improved by a factor of 4 for the Quantofix devices (from 1.3 ppm using visible light to 300 ppb using infrared illumination) and a factor of 6 for the Indigo units (from 9.2 ppm to 1.4 ppm) with repeatability of less than or equal to 1.2% relative standard deviation (RSD). The system also provides more granular concentration information compared to the discrete color chart used by commercial devices and it can be easily adapted for use in other applications

Idiopathic Macular Hole: Algorithm for Nonsurgical Closure Based on Literature Review

Our purpose is to review the closure time and optical coherence tomography (OCT) biomarkers that result in the non-surgical repair of idiopathic full-thickness macular holes (IFTMH). Our methodology consisted of a comprehensive literature review of the nonsurgical resolution of IFTMH followed by the calculation of the estimated closure time using the structural equation model. Forty-nine studies were found eligible yielding 181 eyes with IFTMH: 81.1% being small holes (<250 μm) with a median diameter of 166 μm. Final vision (mean 20/41) was related to initial vision (mean 20/65) and mean age (67 years). The hole diameter was correlated with initial vision and closure time (mean 3.9 months). Closure time was related to hole diameter and initial vision in the following algorithm: Closure time (month)= −0.057 + 0.008 diameter (μm) + 0.021 age (year) + 2.153 initial vision (logMAR). Biomarkers by OCT for self-closure included in decreasing frequency: pointed edge, de-turgescence of cystic macular edema (CME) with reversal of bascule bridge, and vitreomacular traction (VMT) release. The crucial function of Muller cell bridging in sealing the hole attests to its exceptional capacity for regeneration. After the hole has begun to close; however in less than 5%, a delayed restoration of the ellipsoid layer or a persistent outer foveal defect may prevent visual recovery and reopening of the hole is possible. In conclusion, eyes with small-size IFTMH and good baseline vision can have the additional option of close OCT monitoring for biomarkers of self-sealing biomarkers. When rehabilitative activity seems to be lacking, surgery is therefore mandatory

Protein corona formation and its influence on biomimetic magnetite nanoparticles

Biomimetic magnetite nanoparticles (BMNPs) synthesized in the presence of MamC, a magnetosome-associated protein from Magnetoccus marinus MC-1, have gained interest for biomedical applications because of their unique magnetic properties. However, their behavior in biological systems, like their interaction with proteins, still has to be evaluated prior to their use in clinics. In this study, doxorubicin (DOXO) as a model drug was adsorbed onto BMNPs to form nanoassemblies. These were incubated with human plasma to trigger protein corona (PC) formation. Proteins from the human plasma stably attached to either BMNPs or DOXO-BMNP nanoassemblies. In particular, fibrinogen was detected as the main component in the PC of DOXO-BMNPs that potentially provides advantages, e.g. protecting the particles from phagocytosis, thus prolonging their circulation time. Adsorption of PC to the BMNPs did not alter their magnetic properties but improved their colloidal stability, thus reducing their toxicity in human macrophages. In addition, PC formation enhanced cellular internalization and did not interfere with DOXO activity. Overall, our data indicate that the adsorption of PC onto DOXO-BMNPs in biological environment even increases their efficiency as drug carrier systems

INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR INJECTIONS for EXUDATIVE RETINAL ARTERIAL MACROANEURYSMS

Purpose:There is no established therapy for exudative-hemorrhagic complications in primary retinal arteriolar macroaneurysm (RAM).Methods:Retrospective multicenter interventional study of anti-vascular endothelial growth factor in symptomatic RAMs. Central macular thickness in m and best-corrected visual acuity in logMar were correlated with the RAM size and distance to the macula. Statistical analyses were performed using paired comparisons and Pearson correlation.Results:Thirty-two eyes (32 patients) were treated with a mean of 2.7 injections over a mean follow-up of 16.6 months. Initial best-corrected visual acuity correlated with the RAM size and distance to the macula (P = 0.02). Central macular thickness decreased by 131,180, and 211 m at 1, 2, and 3 months after the first injection (P < 0.001). Best-corrected visual acuity improved by 0.47 and 0.38 Early Treatment Diabetic Retinopathy Study lines at 2 and 3 months (P = 0.005). Anti-vascular endothelial growth factor response correlated with the RAM size (P = 0.04) and the distance to the macula (P = 0.009).Conclusion:Symptomatic RAMs can be treated successfully with anti-vascular endothelial growth factor injections, leading to a decrease in macular edema. © 2019 Ophthalmic Communications Society, Inc

INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR INJECTIONS FOR EXUDATIVE RETINAL ARTERIAL MACROANEURYSMS

Purpose: There is no established therapy for exudative-hemorrhagic complications in primary retinal arteriolar macroaneurysm (RAM)