Morphological Evolution of Metal-Organic Frameworks into Hedrite, Sheaf and Spherulite Superstructures with Localized Different Coloration.

The branched metal-organic frameworks (MOFs) are the first superstructures of this kind, and the growth mechanism may explain crystal shapes of other materials. The mechanism of the formation of fascinating structures having a hedrite, sheaf or spherulite appearance are detailed. The branching can be controlled, resulting in crystals that either exhibit multiple generations of branching or a single generation.

Altering the structures of 3D supramolecular assemblies from melamine and cyanuric acid derivatives in water.

Herein, we obtained two supramolecular assemblies with layered structures from melamine, -methylmelamine, and hexynyl-cyanuric acid in water. By combination of X-ray diffraction, electron microscopy, and molecular dynamics studies, we found that introducing one methyl group in melamine alters the arrangement of the layers in these structures.

Encapsulation of Uranium Oxide in Multiwall WS Nanotubes.

Uranium is a high-value energy element, yet also poses an appreciable environmental burden. The demand for a straightforward, low energy, and environmentally friendly method for encapsulating uranium species can be beneficial for long-term storage of spent uranium fuel and a host of other applications. Leveraging on the low melting point (60 °C) of uranyl nitrate hexahydrate and nanocapillary effect, a uranium compound is entrapped in the hollow core of WS nanotubes.

Equilibrium Fractionation of Oxygen Isotopes in the UO-Atmospheric Oxygen System.

As a major component in the nuclear fuel cycle, octoxide uranium is subjected to intensive nuclear forensics research. Scientific efforts have been mainly dedicated to determine signatures, allowing for clear and distinct attribution. The oxygen isotopic composition of octoxide uranium, acquired during the fabrication process of the nuclear fuel, might serve as a signature.

Real-Time Study of Surface-Guided Nanowire Growth by Scanning Electron Microscopy.

Surface-guided growth has proven to be an efficient approach for the production of nanowire arrays with controlled orientations and their large-scale integration into electronic and optoelectronic devices. Much has been learned about the different mechanisms of guided nanowire growth by epitaxy, graphoepitaxy, and artificial epitaxy. A model describing the kinetics of surface-guided nanowire growth has been recently reported.

-Axis Textured, 2-3 μm Thick AlScN Films Grown on Chemically Formed TiN/Ti Seeding Layers for MEMS Applications.

A protocol for successfully depositing [001] textured, 2−3 µm thick films of Al0.75Sc0.25N, is proposed.

Chiral Motifs in Highly Interpenetrated Metal-Organic Frameworks Formed from Achiral Tetrahedral Ligands.

Formation of highly interpenetrated frameworks is demonstrated. An interesting observation is the presence of very large adamantane-shaped cages in a single network, making these crystals new entries in the collection of diamondoid-type metal-organic frameworks (MOFs). The frameworks were constructed by assembling tetrahedral pyridine ligands and copper dichloride.

Strain relaxation and order-disorder phase transition in irradiated MgAl2O4.

MgAl2O4 spinel is widely studied in many fields of material science because of its variety of interesting properties and potential applications. The influence of cation disorder on the physical properties of MgAl2O4 makes understanding of the effects related to this disorder particularly important. It is known that, upon ion irradiation at low temperature, MgAl2O4 undergoes an order-disorder phase transition followed by amorphization.

Comparing resonant photon tunneling via cavity modes and Tamm plasmon polariton modes in metal-coated Bragg mirrors.

Resonant photon tunneling was investigated experimentally in multilayer structures containing a high-contrast (TiO(2)/SiO(2)) Bragg mirror capped with a semitransparent gold film. Transmission via a fundamental cavity resonance was compared with transmission via the Tamm plasmon polariton resonance that appears at the interface between a metal film and a one-dimensional photonic bandgap structure. The Tamm-plasmon-mediated transmission exhibits a smaller dependence on the angle and polarization of the incident light for similar values of peak transmission, resonance wavelength, and finesse.

Giant electrostriction in Gd-doped ceria.

Gd-doped CeO(2) exhibits an anomalously large electrostriction effect generating stress that can reach 500 MPa. In situ XANES measurements indicate that the stress develops in response to the rearrangement of cerium-oxygen vacancy pairs. This mechanism is fundamentally different from that of materials currently in use and suggests that Gd-doped ceria is a representative of a new family of high-performance electromechanical materials.

Comparative analysis of the methods for SADT determination.

The self-accelerating decomposition temperature (SADT) is an important parameter that characterizes thermal safety at transport of self-reactive substances. A great many articles were published focusing on various methodological aspects of SADT determination. Nevertheless there remain several serious problems that require further analysis and solution.

On the origin of the lattice constant anomaly in nanocrystalline ceria.

The lattice parameter of nanocrystalline ceria films prepared by sputtering was monitored as a function of annealing temperature. Within the temperature range of 150-420 degrees C, an equilibrium with atmospheric oxygen is established within a few hours, whereas grain growth does not occur. On the basis of the experimental results and analysis of literature data, we present a model that posits the formation of a non-uniform grain structure with stoichiometric interiors and oxygen deficient boundaries.

An advanced approach to reactivity rating.

Reactive hazards remain a significant safety challenge in the chemical industry despite continual attention devoted to this problem. The application of various criteria, which are recommended by the guidelines for assessment of reactive hazards, often causes unsafe results to be obtained. The main origins of such failures are as follows: (a) reactivity of a compound is considered as an inherent property of a compound; (b) some appropriate criteria are determined by using too simple methods that cannot reveal potential hazards properly.

Reaction to epilepsy in the workplace.

Purpose: The purpose of this study was to determine the characteristics of epilepsy that produce avoidant behavior in the workplace and therefore contribute to the actual stigma that persons with epilepsy are subjected to on the job.

Methods: We developed a survey consisting three vignettes briefly describing a coworker with either depression, multiple sclerosis, or epilepsy. Each vignette was followed by eight identical questions addressing the level of comfort during interactions with the vignette subject.

Sexual dysfunction secondary to depressive disorders.

Human sexuality has received less systematic study and is less well understood than other aspects of mental and physical health. Although depression itself, apart from medication, is generally believed to be associated with sexual dysfunction, the few existing studies report wide discrepancies with regard to frequency, gender, and quality of sexual dysfunction. Loss of libido is frequently and consistently associated with major depression.

The Therapeutic Alliance in Randomized Controlled Clinical Trials.

The therapeutic alliance, familiar to those who treat patients and conduct clinical trials, is considered by many to be a non-specific effect in research studies. The concept of the therapeutic alliance has its roots in the doctor-patient relationship and has been discussed extensively in the context of psychodynamic psychotherapy. Research has demonstrated that the strength of the alliance is a strong predictor of outcome in psychotherapy and has emphasized its importance in ensuring compliance in pharmacotherapy.

Are theophylline "levels" a reliable indicator of compliance?

Clinicians frequently rely on serum theophylline concentrations (STCs) as an indicator of compliance for asthma medications. Most patients with good compliance do not have excessive fluctuations during routine STC monitoring. However, our experience is that in certain patients, persistently low or erratic STCs may be a sign of abnormal theophylline disposition.

Renal tubular acidosis in infancy: a clinical approach to diagnosis and treatment.

Renal tubular acidosis is defined as the failure of the kidneys to respond appropriately to systemic acidosis. The usual criterion for diagnosis involves titration curves to establish renal bicarbonate threshold. This evaluation is time consuming, expensive, and probably avoidable in selected patients.

Therapeutic indications in carbamazepine overdose.

After ingesting carbamazepine, our four patients had elevated serum drug levels but minimal symptoms and were treated conservatively with excellent results. While serum levels may provide the diagnosis, they do not indicate therapy, which depends upon clinical manifestations.

Potentially toxic theophylline ingestions: are heroic measures indicated?

We have treated six patients with theophylline overdoses, all of whom had high blood theophylline levels but lacked symptoms of serious toxicity. All improved with conservative therapy. While other reports of theophylline overdose describe aggressive therapy in patients with high blood levels and serious toxic signs, we believe blood levels cannot be used to predict serious toxic reactions.

Microbiological transformations of nabilone, a synthetic cannabinoid.

A screening program was conducted to find microorganisms that modify the synthetic cannabinoid nabilone. After purification, the products from three cultures were analyzed by spectral methods to determine their chemical structures. An optically active 9S-hydroxy-6aR,10aR-trans cannabinoid was isolated from a culture of an unidentified soil bacterium designated A24007.