Upper Gastrointestinal Bleeding Secondary to Sodium Polystyrene Sulfonate Use: A Rare Adverse Effect of Commonly Prescribed Treatment.

We report a case of a 62-year-old man who was brought in by emergency medical services after a fall and change in mental status. He was found to have severe hyperkalemia, acute kidney injury, and rhabdomyolysis. The hyperkalemia was treated with sodium polystyrene sulfonate (SPS). During hospitalization, he witnessed having black tarry stools along with a significant drop in hemoglobin. Endoscopic evaluation demonstrated nonbleeding large diffuse gastric ulcers with stigmata of recent bleeding, and ulcer biopsy revealed findings consistent with SPS-induced gastric ulceration. No other source of bleeding was localized, suggesting acute upper gastrointestinal bleeding due to SPS mucosal injury.

Dynamic Microparticle Assembly at the Interface of Chemoresponsive Liquid Crystal Droplets.

The confinement of liquid crystals (LCs) in spherical microdroplets results in exotic internal configurations and topological defects in response to physical and chemical stimuli. Recent exploration into the placement of colloids on the surface of LC microdroplets has led to the design of a new class of functional materials with patterned surface properties. It is established that the placement of a colloid on a LC droplet surface can pin the topological defect at the interface, thereby restricting changes in the LC configuration. Herein, we build upon the handful of reports published to provide a fundamental understanding of the colloid positioning in response to external stimuli. Using polystyrene (PS) colloids, we explored the dynamics of particle self-assembly in response to an interfacial enzymatic breakdown of poly-l-lysine by trypsin. We found that for a significant population of droplets, the positioning of the colloid is unaffected by the changes in the internal ordering of LC. Inspired by the new observations, we delved deeper to understand the role of interfacial stabilizers in modulating the preferential alignment of LC and the placement of colloidal microparticles. We also demonstrated that for a certain population of droplets, the positioning of the colloids remains unperturbed in response to multistep reversible adsorption of interfacial amphiphiles. Our findings reveal interesting possibilities of correlating the stimuli-responsive switching of internal configurations of LC with colloid placement on the particle-decorated LC droplets.

Distinct interfacial ordering of liquid crystals observed by protein-lipid interactions that enabled the label-free sensing of cytoplasmic protein at the liquid crystal-aqueous interface.

Interfaces formed between a lipid decorated liquid crystal (LC) film and an aqueous phase can mimic the bimolecular membrane where interfacially occurring biological phenomena (e.g., lipid-protein interactions, protein adsorption) can be visually monitored by observing the surface-sensitive orientations of LCs. The ordering behavior of LCs at different phospholipid-based LC interfaces (1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) and lysophosphatidic acid (LPA)) were investigated to determine the sensing of an important cytoplasmic protein (juxtamembrane of epidermal growth factor receptor (JM-EGFR)). At both DLPC and LPA decorated interfaces, the LC adopts homeotropic ordering, causing a dark optical appearance under crossed polarizers. Interestingly, upon the introduction of JM-EGFR to these LC-aqueous interfaces, the homeotropic orientation of the LC changed to planar (bright optical appearance), suggesting the potential of the designed system for JM-EGFR sensing. The use of different lipid decorated LC-aqueous interfaces results in the emergence of distinct optical patterns. For example, at a DLPC laden interface, elongated bright domains are observed, whereas a uniform bright texture is observed on an LPA laden interface. The DLPC decorated LC-aqueous interface is found to be highly selective for the sensing of JM-EGFR with a detection limit in the nanomolar concentration region (∼ 50 nM). When compared to spectroscopic and other conventional techniques, the LC-based design is simpler, and it allows the simple and label-free optical sensing of JM-EGFR at fluidic interfaces.

Luminescent Conductive Columnar π-Gelators for Fe(II) Sensing and Bio-Imaging Applications.

The high demand and scarcity of luminescent, photoconductive, and transparent gels necessitate its finding as they are potential components in photonic devices such as solar cell concentrators where optical losses via scattering and reabsorption require to be minimized. In this direction, we have reported highly transparent, blue luminescent as well as photoconductive gels exhibiting the hole mobility of 10-3 cm2/V s at ambient temperature as investigated by the time-of-flight technique. The π-driven self-standing supergels were formed using triazole-modified phenylene-vinylene derivatives as gelators in a nonpolar solvent. Different microscopic studies revealed its entangled network of interwoven fibrilar self-assembly and anisotropic order in the gel state. Supramolecular assembly of xerogels, studied by small- and wide-angle X-ray scattering (SAXS/WAXS) suggesting their local columnar hexagonal (Colh) superstructure, is beneficial for conducting gels. Rheological measurements direct the stiffness and robustness of the organogels. In addition, the gelators were developed as a sensing platform for the ultrasensitive detection of Fe(II) ions at ppb level. 1H nuclear magnetic resonance (NMR) titrimetric studies revealed that the interaction of the H-atom of triazole units with Fe(II) is responsible for quenching of blue fluorescence. Also, one of the gelators was successfully applied in bio-imaging using the pollen grains of the Hibiscus rosa-sinensis plant.

Proton-Triggered Fluorescence Switching in Self-Exfoliated Ionic Covalent Organic Nanosheets for Applications in Selective Detection of Anions.

The exfoliation of covalent organic frameworks into covalent organic nanosheets (CONs) not only helps to reduce fluorescence turn-off phenomena but also provides well-exposed active sites for fast response and recovery for various applications. The present work is an example of rational designing of a structure constructed by condensing triaminoguanidinium chloride (TGCl), an intrinsic ionic linker, with a fluorophore, 2, 5-dimethoxyterephthalaldehyde (DA), to produce highly fluorescent self-exfoliable ionic CONs (DATGCl-iCONs). These fluorescent iCONs are able to sense fluoride ions selectively down to the ppb level via the fluorescence turn-off mechanism. A closer look at the quenching mechanism via NMR, zeta potential measurement, lifetime measurement, and density functional theory calculations reveals unique proton-triggered fluorescence switching behavior of newly synthesized DATGCl-iCONs.

Liquid Crystal based Detection of Pb(II) Ions Using Spinach RNA as Recognition Probe.

We report a new method for label-free, sensitive, and facile detection of lead(II) ions (Pb2+) based on an aptamer-target binding event, which is recognized by orientations of liquid crystals (LCs) at aqueous interfaces. The LC film suspended in the aqueous phase demonstrated a homeotropic orientation in contact with a cationic surfactant cetyltrimethylammonium bromide (CTAB) due to self-assembly of CTAB molecules at the aqueous-LC interface. The ordering of LC subsequently changed to planar in the presence of the spinach RNA aptamer (SRNA) due to interactions between CTAB and SRNA. In the presence of the Pb2+ ion, the ordering of LC changed to homeotropic caused by reorganization of CTAB at the LC-aqueous interface. This is due to formation of more stable quadruplex structures of SRNA with Pb2+ ions in comparison to the CTAB-SRNA complex. The sensor exhibited a detection limit of 3 nM, which is well below the permissible limit of Pb2+ in drinking water. Our experiments establish that addition of Pb2+ leads to (i) the formation of Pb2+-SRNA complexes and (ii) a decrease in density of SRNA on the LC interface, but additional studies are required to determine which of these processes underlie the response of the LCs to the Pb2+. We have also demonstrated the potential application of the LC sensor for detection of Pb2+ in tap water. Unlike current laboratory-based heavy-metal-ion assays, this method is comparatively simple in terms of instrumentation, operation, and optical readout.

Management of myofascial pain dysfunction syndrome with meditation and yoga: Healing through natural therapy.

AIMS AND OBJECTIVES: Aims and objectives of the study were to study the effectiveness of Raj-yoga meditation and pranayama in patients with myofascial pain dysfunction syndrome (MPDS) and compared the effects with ongoing conventional noninvasive treatment modalities. MATERIALS AND METHODS: The study comprised 30 patients divided equally (10 each) into 3 group, i.e., control group (conventional, noninvasive treatment), Experimental A group (conventional, noninvasive treatment with raj-yoga meditation therapy and pranayama), and Experimental B group (Raj-yoga meditation therapy and pranayama only). Parameters such as pain, mouth opening, mandibular deviation, inflammation, swelling, clicking, occlusion, and psychologic evaluation such as anxiety, stress, and depression were assessed before the start of the study and at weekly intervals for 3 months. RESULTS: Posttreatment pain and inflammation improved both in the control group and Experimental A group, but statistically it is highly significant in the Experimental A group. Furthermore, it is effective immediately as well as for a long period in Experimental A group. Improvement in mouth opening was statistically highly significant in control group but not in the experimental groups. Posttreatment anxiety and stress status was improved with statistically highly significant result in the Experimental A and B. The posttreatment depression status along with mandibular deviation, swelling, clicking, and occlusion has not improved significantly in any of the groups. INTERPRETATION AND CONCLUSION: Raj-yoga meditation and pranayama in combination with conventional, noninvasive, treatment modalities showed promising results in MPDS patients as compared to either modalities alone.

Facile Synthesis of an Organic Solid State Near-Infrared-Emitter with Large Stokes Shift via Excited-State Intramolecular Proton Transfer.

An organic solid-state near-infrared (NIR)-emitter (λem = 738 nm) exhibiting large Stokes shift (Δλ = 293 nm) through the excited-state intramolecular proton transfer phenomenon has been synthesized and characterized. The present discovery points to the possibility of achieving a new family of solid-state NIR emitters starting from simple aldehyde and amine precursors.

Engineering Multifunctionality in Hybrid Polyoxometalates: Aromatic Sulfonium Octamolybdates as Excellent Photochromic Materials and Self-Separating Catalysts for Epoxidation.

Engineering multifunctionality in hybrid polyoxometalates (hybrid POMs) is an interesting but scarcely explored topic. Herein, we set about engineering two important materials properties, viz., photochromism and self-separating catalysis, in a hybrid POM by modulating the counterion motif. A series of six aromatic sulfonium counterions have been developed on the basis of an aromatic sulfonium counterion motif that allows structural and electronic fine-tuning by changing substituents at multiple locations. Using the aromatic sulfonium counterions and sodium molybdate, six new aromatic sulfonium octamolybdate hybrids (1-6) having formulas (HPDS)4[Mo8O26] (1), (HMPDS)4[Mo8O26] (2), (MPDS)4[Mo8O26] (3), (APDS)4[Mo8O26] (4), (AMPDS)4[Mo8O26] (5), and (MAPDS)4[Mo8O26] (6) (where HPDS = (4-hydroxyphenyl)dimethylsulfonium, HMPDS = (4-hydroxy-2-methylphenyl)dimethylsulfonium, MPDS = (4-methoxyphenyl)dimethylsulfonium, APDS = (4-(allyloxy)phenyl)dimethylsulfonium, AMPDS = (4-(allyloxy)-2-methylphenyl)dimethylsulfonium and MAPDS = (4(methacryloyloxy)phenyl)dimethylsulfonium) have been synthesized, and their structures were confirmed by single crystal X-ray diffraction and ESI-MS analyses. Hybrids 1-6 acted as good solid-state photochromic materials exhibiting color change from white to purple under UV illumination (350 nm), and we show here that the photochromic properties of hybrids 1-6 could be modulated by changing the substitutions on the counterion motif. A coloration kinetic half-life (t1/2) of 0.33 min was achieved with this class of hybrid POMs. Hybrids 1-6 exhibited excellent self-separating catalytic properties toward the epoxidation of olefins, yielding up to 99% epoxide product with good selectivity in short time. The substituents on the aromatic sulfonium counterions helps to fine-tune the electronic, lipophilic, and solubility properties of the hybrids and thereby their catalytic properties. Moreover, we used ESI-MS analyses to understand the mechanism of catalysis exhibited by octamolybdates 1-6 in the presence of H2O2, and we succeeded in identifying a hitherto undetected intermediate, tetraperoxo-octamolybdates, shedding more light on the epoxidation mechanism.

Aromatic Sulfonium Polyoxomolybdates: Solid-State Photochromic Materials with Tunable Properties.

A new aromatic sulfonium counter-ion motif for polyoxometalate (POM) clusters with potential for structural and electronic fine-tuning has been designed. Its two derivatives 4-hydroxyphenyl dimethylsulfonium triflate (HPDST) and 4-(allyloxy)phenyl dimethylsulfonium triflate (APDST) exhibit ionic liquid behaviors under ambient conditions. HPDST and APDST are used to develop a series of aromatic sulfonium POM hybrids (HPDS/APDS)n[XMo12 O40] (HPDS and APDS are the cations of HPDST and APDST, respectively; X=P or Si; n=3 or 4), which are tested for photochromic behavior. On exposure to UV light, these POM hybrids undergo color change from yellow to green/blue. The coloration kinetics half lives (t1/2) are less for APDS-based hybrids than for HPDS-based hybrids, suggesting that alkyl substitution on the phenolic group helps to fine-tune the electron availability on the sulfonium moiety and hence to control the photochromic behavior of the POM hybrids. The t1/2 values of these hybrids are considerably lower than those of the reported aliphatic sulfonium POM hybrids. We have also demonstrated the application of photoreduced POM hybrids as catalysts for the reduction of 4-nitrophenol to 4-aminophenol.

Imatinib intermediate as a two in one dual channel sensor for the recognition of Cu²âº and I⁻ ions in aqueous media and its practical applications.

An imatinib intermediate, 6-methyl-N-[4-(pyridin-3-yl)pyrimidin-2-yl]benzene-1,3-diaminepyridopyrimidotoluidine (PPT-1), was developed for the colorimetric sensing of Cu(2+) ions in aqueous solution. With Cu(2+), the receptor PPT-1 showed a highly selective naked-eye detectable color change from colorless to red over the seventy other tested cations. The colorimetric sensing ability of PPT-1 was successfully utilized in the preparation of test strips and supported silica for the real samples analysis to detect Cu(2+) ions from 100% aqueous environment. Moreover, the iodide-sensing ability of receptor PPT-1 was explored among the ten examined anions.

Au microparticles mediated construction of a logic based dual channel molecular keypad lock.

New melamine based ligand with pyrene as a fluorophore is synthesized and characterized. The sequential addition of Au(3+) ions and ascorbic acid to the solution of in EtOH-H2O (9.5 : 0.5 v/v) generates gold microparticles (AuMPs). However, the particle size distribution and fluorescence behaviour on sequential additions are different and contribute to the construction of a new logic based molecular dual channel keypad lock system.