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Dieckol is a brown algae-derived polyphenol that has broad bioactivity and low toxicity. Therefore, it is a promising lead compound for the development of therapeutic agents to treat various pathological conditions, including viral infections, allergies, diabetes, skin ageing, cancers, and neurodegenerative conditions. To exploit the pharmacological potential of dieckol, its stability, solubility, pharmacokinetics, and drug delivery must be improved. This can be achieved by the controlled modification of the hydroxyl groups, but the presence of eleven nearly equivalent hydroxyl groups makes the task highly challenging. In this study, the regioselectivities in five substitution reactions of the hydroxyl groups of dieckol under various SN2 reaction conditions were investigated. After reaction optimization, five substituents (methyl, benzyl, methoxymethyl, 3-hydroxypropyl, and 3-(ethoxycarbonyl)propyl) could be introduced at the 6-Oposition of dieckol with surprisingly high regioselectivity, as confirmed by 2D-NMR spectroscopic analyses. The prepared dieckol derivatives showed antioxidant and anticancer activities analogous to those of unmodified dieckol, indicating that the mono-O-substitutions did not affect the biochemical and biological characteristics of dieckol. Therefore, the proposed methodology for the mono-O-substitution of a specific oxygen of dieckol is a powerful tool to add various pharmaceutical attributes to dieckol, thus contributing to the development of various dieckol-based drug candidates.

In recent years, the challenge of efficient oil-water separation has become the subject of immense fundamental research, with significant impact in the development of industrial applications. This article reviews the recent progress in the fabrication of porous polydimethylsiloxane (PDMS) materials, which are the most widely investigated materials for oil-water separation. Various strategies for the fabrication of porous PDMS have produced a diversity of bulk and surface structures, where these structures in turn determine the performance of the materials for oil-water separation. Understanding the interrelationship governing the fabrication strategy, structure, and performance is essential for the development of future selective oil absorbents with improved commercial potential. The separation of organic contaminants from industrially produced wastewater is a serious environmental challenge, and the preparation of superior oil absorbents is critical for overcoming this challenge. To address the issues in the development of promising candidates as oil absorbents, the current strategies for the design of low-surface energy coatings of three-dimensionally (3-D) interconnected porous materials are also discussed. The reusability, surface roughness, and superhydrophobic properties are discussed as vital parameters.

Purpose: To investigate risk factors of coronary arterial calcification in chronic kidney disease (CKD) patients who did not undergo hemodialysis or peritoneal dialysis. Materials and Methods: We enrolled 83 patients of normal renal function (Group I) and 112 patients of CKD [Group II (CKD stage 1–2) and Group III (CKD stage 3–5)], who were assessed coronary artery calcium score (CACS) with cardiac CT. CACS between the groups were compared. Risk factors for coronary artery calcification in patients with CKD including diabetes, hypertension, and smoking were identified as relevant to CACS using logistic regression analysis. Serologic data of electrolytes were analyzed to evaluate effect for coronary calcification in patients with CKD. Results: Group III showed significant increment of CACS compared to Group I at the CACS level over 400 [odds ratio (OR) = 7.581, p = 0.01]. The OR were decreased in non-diabetic patients group, increased in non-hypertensive patients group, no significant differences in non-current smoker group. Serum phosphorous level was the only factor which showed significant effect for increased CACS (OR of 2.649, p = 0.02). Conclusion: In CKD patients, higher stage of CKD was associated with increased CACS. Diabetes mellitus and increased serum phosphorous level would be considered as factors influencing coronary arterial calcification in CKD patients.

This paper uses pragmatic findings and lessons learned from three case studies to deduce that community-based rainwater harvesting (CB-RWH) is an innovative solution to develop sustainable drinking water supply systems in developing countries, especially in Africa and Asia. Taking advantage of traditional community-based activities in African and Asian villages, the water supply system can be significantly improved with the introduction and implementation of CB-RWH systems. Furthermore, sustainable, safe water sources in Africa and Asia can be brought to fruition when transparent self-regulatory management systems are supported through comprehensive design and maintenance guidelines and funded from private and public sources. To this end, the potential for CB-RWH to lead toward greater resilience and sustainability was investigated. Based on case studies of three successful demonstration projects in Africa and Asia, this paper identifies 14 innovative solutions resolving technical, economic, and social problems which have been barriers preventing the wide implementation of CB-RWH in developing countries, especially in Africa and Asia. It also recommends strategies to promote CB-RWH in African and Asian villages, which include the following: implementation of more pilot projects at local levels; promotion of and education in rainwater preservation and harvesting at all levels of the education system; and innovation in micro-funding systems in cooperation with corporate social responsibility activities. These strategies will promote the implementation of CB-RWH as a mainstream and high-priority technique for national, regional, and global water strategies.

Catastrophes can occur without warning and inevitably cause short-term and long-term problems. In disaster zones, having an action plan to alleviate difficulties can reduce or prevent many long-lasting complications. One of the most critical and urgent issues is sanitation. Water, energy, personnel, transportation, and the allocation of resources in disaster areas tend to become very limited during emergencies. Sanitation systems suffer in the process, potentially leading to crises due to unsafe and unhygienic surroundings. This article explores the problems of current sanitation practices in disaster areas and identifies the essential characteristics of sustainable sanitation systems. This study also presents a plan for an innovative and sustainable sanitation system using a waterless, portable, private toilet, in addition to a procedure for collecting and disposing waste. The system is agronomic, is socially acceptable, prevents contact with human waste, and can be used for individuals or families. Environmental pollution and social problems (such as sexual harassment) can be reduced both during and after restoration. (Disaster Med Public Health Preparedness. 2016;10:281–285)

The glucose level is a critical issue for individuals with diabetes, and thus selective and efficient detection of glucose is very important. A variety of optical techniques for the detection of glucose in solution have been reported. However, an effective, reversible, and reusable probe for glucose monitoring still remains a challenge. A new hydrogel sensor based on a copolymer was developed. The copolymer consisted of acrylamide and fluorescent monomers of fluorescein and rhodamine B, in which glucose oxidase (GOx) was immobilized on the resultant hydrogel and showed effective fluorescence-sensing performance toward glucose. GOx was immobilized on the hydrogel either by simple mixing or by covalent bonding to improve enzyme stability. The fluorophores of both fluorescein and rhodamine B moieties were pH-responsive and could change their fluorescence colors with pH changes. The change in the pH of the glucose solution was attributed to the hydrolytic decomposition of glucose, induced by the action of GOx. Upon exposure to glucose, the sensing hydrogel induced visual changes in fluorescence colors that could be identified by the naked-eye. The hydrogel sensor showed a highly reproducible response toward glucose and could be reused even after rinsing with buffer solution because of the robust covalent bond between the hydrogel and GOx. This work provides a facile and promising strategy for constructing a stable, naked-eye-detectable optical protocol that offers sensor reusability for glucose detection.

We present a new composite material composed of pH sensitive fluorescent dyes in a poly(N-isopropylacrylamide)-based hydrogel and incorporating glucose oxidase (GOx), which provides a platform for fluorescence sensing of glucose in the clinically relevant range of 100 μM to 100 mM in aqueous solution. Fluorescein and rhodamine B dyes are well known for their dramatic pH-responsive changes in fluorescence emission color, in which they were introduced to the hydrogel as comonomers. As D-glucose was oxidized to D-glucono-δ-lactone producing hydrogen peroxide and a proton through the enzymatic action of GOx, the generated proton affects the fluorescence of the composite hydrogel. The composite hydrogel exhibited high selectivity to glucose over other sugars and metal ions. The combined role of a soft hydrogel and oxidase highlights the potential of the new composite material design for selective detection of glucose in aqueous solution.

Large DNA molecules have been utilized as a model system to investigate polymer physics. However, DNA visualization via intercalating dyes has generated equivocal results due to dye-induced structural deformation, particularly unwanted unwinding of the double helix. Thus, the contour length increases and the persistence length changes so unpredictably that there has been a controversy. In this paper, we used TAMRA-polypyrrole to stain single DNA molecules. Since this staining did not change the contour length of B-form DNA, we utilized TAMRA-polypyrrole stained DNA as a tool to measure the persistence length by changing the ionic strength. Then, we investigated DNA stretching in nanochannels by varying the ionic strength from 0.06 mM to 47 mM to evaluate several polymer physics theories proposed by Odijk, de Gennes and recent papers to deal with these regimes.

Long and linear DNA molecules are the mainstream single-molecule analytes for a variety of biochemical analysis within microfluidic devices, including functionalized surfaces and nanostructures. However, for biochemical analysis, large DNA molecules have to be unraveled, elongated, and visualized to obtain biochemical and genomic information. To date, elongated DNA molecules have been exploited in the development of a number of genome analysis systems as well as for the study of polymer physics due to the advantage of direct visualization of single DNA molecule. Moreover, each single DNA molecule provides individual information, which makes it useful for stochastic event analysis. Therefore, numerous studies of enzymatic random motions have been performed on a large elongated DNA molecule. In this review, we introduce mechanisms to elongate DNA molecules using microfluidics and nanostructures in the beginning. Secondly, we discuss how elongated DNA molecules have been utilized to obtain biochemical and genomic information by direct visualization of DNA molecules. Finally, we reviewed the approaches used to study the interaction of proteins and large DNA molecules. Although DNA-protein interactions have been investigated for many decades, it is noticeable that there have been significant achievements for the last five years. Therefore, we focus mainly on recent developments for monitoring enzymatic activity on large elongated DNA molecules.

We have synthesized a highly pH and temperature-sensitive, fluorescent, crosslinked poly(N-isopropylacrylamide) (PNIPAM)-based probe via simple free radical emulsion copolymerization, which formed a reversible microgel containing both fluorophores of fluorescein and rhodamine derivatives. We confirmed that the opening of the lactone ring of fluorescein and the lactam ring of rhodamine in the polymer was responsible for the fluorescence changes in basic and acidic conditions, which showed fluorescence emissions at 514 nm (green) and 586 nm (red), respectively. The polymeric microgel exhibited a linear relationship between the ratio of emission intensity and pH windows of pH 2–6 and 7–12. Moreover, the microgel exhibited changes in fluorescence intensity with an alteration of turbidity of the microgel induced by temperature. Moreover, these fluorescence changes could be easily observed by the naked eye, serving as a potential probe for ratiometric microgel detection of pH or temperature.

Fluorescent conjugated polymers with various monomer compositions were synthesized via Suzuki coupling polymerization and spherically-shaped conjugated polymer dots (CPdot) with uniform size were prepared via conventional reprecipitation technique. Chemically modified graphene oxide (GO) was prepared to use as a component of sensor platform for protein detection. GO showed an excellent interaction with CPdot on its surface via hydrophobic interaction, which, in turn, induced the quenching of the fluorescence of CPdot. Upon exposure to bovine serum albumin (BSA), the quenched fluorescence was recovered, resulting from the release of CPdot from the complex with GO, as BSA adsorbed preferentially on the GO surface.

Fluorescent 3′,6′-bis(octyloxy)-p-terphenyl-4,4′-dialdehyde 3 has been successfully synthesized via a Suzuki cross-coupling reaction of the corresponding dibromo compound with a boronic acid compound in the presence of palladium catalyst. The fluorescent probe molecule has aldehyde groups at both ends, which can be used as reactive sites for amines. Alteration of emission is expected by an interaction of 3 with amines, specifically ethylenediamine, which can be a measure of amine concentration. Moreover, uniform-sized poly(methyl methacrylate) (PMMA) particles were prepared to use as a probe matrix and 3 was incorporated in the PMMA particles during dispersion polymerization, which can be a sensitive and selective sensor platform for ethylenediamine.

A turn-on fluorescent probe, based on a water-soluble terphenyl derivative, for the detection of cysteine and homocysteine is reported. The aldehyde groups in the probe play crucial roles in providing reaction with thiol groups in the amino acids, leading to a formation of thiazolidine (from cysteine) or thiazinane ring (from homocysteine). As a result, the new formation of such rings alters the electronic property of the conjugated system in the probe and results in emission enhancement. The probe in aqueous solution exhibits a remarkable increase in its quantum yield upon exposure to cysteine (up to 20-fold) and to homocysteine (up to 700-fold), while slight quenching is observed in the presence of glutathione. Moreover, an investigation on time-resolved fluorescence spectra of the probe in the presence of cysteine and homocysteine reveals potential discriminatory detection of cysteine and homocysteine. Bioimaging of the thiols in live HeLa cells was successfully applied.

We present a single molecule visualization approach for the quantitative analysis of reactive oxygen species (ROS) induced DNA damage, such as base oxidation and single stranded breaks in large DNA molecules. We utilized the Fenton reaction to generate DNA damage with subsequent enzymatic treatment using a mixture of three types of glycosylases to remove oxidized bases, and then fluorescent labeling on damaged lesions via nick translation. This single molecule analytical platform provided the capability to count one or two damaged sites per λ DNA molecule (48.5 kb), which were reliably dependent on the concentrations of hydrogen peroxide and ferrous ion at the micromolar level. More importantly, the labeled damaged sites that were visualized under a microscope provided positional information, which offered the capability of comparing DNA damaged sites with the in silico genomic map to reveal sequence specificity that GTGR is more sensitive to oxidative damage. Consequently, single DNA molecule analysis provides a sensitive analytical platform for ROS-induced DNA damage and suggests an interesting biochemical insight that the genome primarily active during the lysogenic cycle may have less probability for oxidative DNA damage.

Patients with corticospinal tract dysfunction have slow voluntary movements with brisk stretch reflexes and spasticity. Previous studies reported reduced firing rates of motor units during voluntary contraction. To assess whether this firing behavior occurs because motor neurons do not respond normally to excitatory inputs, we studied motor units in patients with primary lateral sclerosis, a degenerative syndrome of progressive spasticity. Firing rates were measured from motor units in the wrist extensor muscles at varying levels of voluntary contraction ≤10% maximal force. At each force level, the firing rate was measured with and without added muscle vibration, a maneuver that repetitively activates muscle spindles. In motor units from age-matched control subjects, the firing rate increased with successively stronger contractions as well as with the addition of vibration at each force level. In patients with primary lateral sclerosis, motor-unit firing rates remained stable, or in some cases declined, with progressively stronger contractions or with muscle vibration. We conclude that excitatory inputs produce a blunted response in motor neurons in patients with primary lateral sclerosis compared with age-matched controls. The potential explanations include abnormal activation of voltage-activated channels that produce stable membrane plateaus at low voltages, abnormal recruitment of the motor pool, or tonic inhibition of motor neurons.

Long and linear DNA molecules are the mainstream single-molecule analytes for a variety of biochemical analysis within microfluidic devices, including functionalized surfaces and nanostructures. However, for biochemical analysis, large DNA molecules have to be unraveled, elongated, and visualized to obtain biochemical and genomic information. To date, elongated DNA molecules have been exploited in the development of a number of genome analysis systems as well as for the study of polymer physics due to the advantage of direct visualization of single DNA molecule. Moreover, each single DNA molecule provides individual information, which makes it useful for stochastic event analysis. Therefore, numerous studies of enzymatic random motions have been performed on a large elongated DNA molecule. In this review, we introduce mechanisms to elongate DNA molecules using microfluidics and nanostructures in the beginning. Secondly, we discuss how elongated DNA molecules have been utilized to obtain biochemical and genomic information by direct visualization of DNA molecules. Finally, we reviewed the approaches used to study the interaction of proteins and large DNA molecules. Although DNA-protein interactions have been investigated for many decades, it is noticeable that there have been significant achievements for the last five years. Therefore, we focus mainly on recent developments for monitoring enzymatic activity on large elongated DNA molecules.

Conjugated polymer of poly(fluorene-co-quinoxaline) was synthesized via Suzuki coupling polymerization. The emission color of the polymer can be tuned depending on the concentration of the polymer in solution. A low-energy bandgap is observed both in the concentrated solution and in the solid state, caused by aggregation of the polymer chains, resulting in long wavelength emission from the quinoxaline moiety, while short wavelength emission can be seen in diluted, well-dissolved solution. The presence of quinoxaline units enables us to demonstrate fluorescence switching and imaging. Paper-based strips containing the polymer are prepared via simple immersion of filter paper in the polymer solution for practical use in the detection of nerve agents. The emission of the paper-based strip is quenched upon exposure to diethyl chlorophosphate (DCP), a nerve agent simulant, and the initial emission intensity can be almost restored by treatment with aqueous sodium hydroxide solution, making a possible reversible paper-based sensor.