Self-Trephination in Cranial Excoriation Disorder.

Background And Importance: Trephination is a procedure in which a small hole is made in the skull. Rare cases of self-trephination by individuals seeking medical benefit have been reported. Excoriation disorder is a compulsive skin-picking condition in which an individual self-inflicts cutaneous lesions.

Size Control and Antioxidant Properties of Sulfur-Rich Polymer Colloids from Interfacial Polymerization.

High sulfur content polymeric materials, known for their intriguing properties such as high refractive indices and high electrochemical capacities, have garnered significant interest in recent years for their applications in optics, antifouling surfaces, triboelectrics, and electrochemistry. Despite the high interest, most high sulfur-content polymers reported to date are either bulk materials or thin films, and there is a general lack of research into sulfur-rich polymer colloids. Water-dispersed, sulfur-rich particles are anticipated to broaden the range of applications for sulfur-containing materials.

Diffusely invasive supratentorial rosette-forming glioneuronal tumor: illustrative case.

Background: Rosette-forming glioneuronal tumors (RGNTs) are rare tumors composed of mixed glial and neurocytic components. Most lesions are confined to the posterior fossa, especially in the region of the fourth ventricle, in young adults. In few instances, diffuse involvement of the supratentorial region is identified, thereby creating significant challenges in diagnosis, surgical intervention, and prognostication.

Mechanochemical ring-opening metathesis polymerization: development, scope, and mechano-exclusive polymer synthesis.

Ruthenium-alkylidene initiated ring-opening metathesis polymerization has been realized under solid-state conditions by employing a mechanochemical ball milling method. This method promotes greenness and broadens the scope to include mechano-exclusive products. The carbene- and pyridine-based Grubbs 3-generation complex outperformed other catalysts and maintained similar mechanistic features of solution-phase reactions.

High strength, epoxy cross-linked high sulfur content polymers from one-step reactive compatibilization inverse vulcanization.

Inverse vulcanization provides a simple, solvent-free method for the preparation of high sulfur content polymers using elemental sulfur, a byproduct of refining processes, as feedstock. Despite the successful demonstration of sulfur polymers from inverse vulcanization in optical, electrochemical, and self-healing applications, the mechanical properties of these materials have remained limited. We herein report a one-step inverse vulcanization using allyl glycidyl ether, a heterobifunctional comonomer.

Transparent, Ultrahigh-Refractive Index Polymer Film ( ∼1.97) with Minimal Birefringence (Δ <0.0010).

High refractive index (RI) thin films are of critical importance for advanced optical devices, and the high refractive index polymers (HRIPs) constitute an interesting class of materials for high RI thin films due to low cost, good processability, light weight, and high flexibility. However, HRIPs have yet to realize their full potential in high RI thin film applications due to their relatively low RI, strong absorption in the blue light region, and limited film formation methods such as rapid vitrification. Herein, we report a development of a new HRIP thin film generated through a one-step vapor-phase process, termed sulfur chemical vapor deposition (sCVD), using elemental sulfur and divinyl benzene.

Cardiovascular Risk Factors Affect Specific Segments of the Intracranial Vasculature in High-Resolution (HR) Vessel Wall Imaging (VWI).

Objectives: Luminal-based imaging have identified different risk factors for extracranial and intracranial atherosclerosis (ICAS), but these techniques are known to underestimate the true extent of the disease. High-resolution (HR) vessel wall imaging (VWI) has recently gained recognition as a valuable tool in the assessment of ICAS. The aim of this study is to determine the association between cardiovascular risk factors and specific intracranial vessel segment involvement using HR-VWI.

Structural Analysis of Bottlebrush Block Copolymer Micelles Using Small-Angle X-ray Scattering.

We present structural analysis of spherical diblock copolymer micelles where core blocks have bottlebrush architecture. The dependence of the core radius () and the corona thickness () on the core block length () is investigated using small-angle X-ray scattering (SAXS) and discussed in terms of the stiffness of a core-forming polymer posed by its long fluoroalkyl side chains. The conformation of the core block is strongly stretched, and the measured exponents α and β from power-law correlations, ∼ and ∼ , respectively, are greater than those from any scaling predictions for block copolymer micelles with a flexible, linear core-block.

One-step vapor-phase synthesis of transparent high refractive index sulfur-containing polymers.

High refractive index polymers (HRIPs) have recently emerged as an important class of materials for use in a variety of optoelectronic devices including image sensors, lithography, and light-emitting diodes. However, achieving polymers having refractive index exceeding 1.8 while maintaining full transparency in the visible range still remains formidably challenging.

Inverse Vulcanization Polymers with Enhanced Thermal Properties via Divinylbenzene Homopolymerization-Assisted Cross-Linking.

High-refractive-index sulfur-rich polymers with significantly improved thermal properties are prepared using divinylbenzene (DVB) as a comonomer in a modified, low-temperature inverse vulcanization with elemental sulfur. Differential scanning calorimetry and Fourier transform infrared studies reveal that under the modified inverse vulcanization conditions, homopolymerized DVB segments form, leading to high glass-transition temperatures ( > 100 °C) and thermal stability previously unattainable from the inverse vulcanization of bifunctional olefin comonomers. On the basis of the modified procedures, a three-step molding process of the inverse vulcanization product of DVB, poly(S--DVB), involving (1) prepolymer formation, (2) hot-press compression molding of the soft prepolymer, and (3) thermal annealing of the molded product is demonstrated.

Type-B response regulators of rice play key roles in growth, development and cytokinin signaling.

Cytokinins are plant hormones with crucial roles in growth and development. Although cytokinin signaling is well characterized in the model dicot , we are only beginning to understand its role in monocots, such as rice () and other cereals of agronomic importance. Here, we used primarily a CRISPR/Cas9 gene-editing approach to characterize the roles of a key family of transcription factors, the type-B response regulators (RRs), in cytokinin signaling in rice.

Controlled Phase Separation in Poly( p-phenyleneethynylene) Thin Films and Its Relationship to Vapor-Sensing Properties.

In this paper, we report the synthesis and mesoporous film formation of hydrophobic rodlike poly( p-phenyleneethynylene)s (PPEs) and present porosity-dependent quenching studies using 1,3,5-trinitrotoluene (TNT) vapors. Nonsolvent vapor-induced phase separation was used to induce pore formation during film casting, and the concentration of PPEs in the casting solution was controlled carefully to prevent excimer formation. We found that the structures of the sidechains of the PPEs strongly influence the range of relative humidity at which controlled pore generation occurs, which could be rationalized from interfacial energies calculated from contact angle measurements.

Living Light-Induced Crystallization-Driven Self-Assembly for Rapid Preparation of Semiconducting Nanofibers.

Well-defined nanostructures composed of conjugated polymers have attracted significant attention due to their intriguing electronic and optical properties. However, precise control of the size and uniformity of these semiconducting nanostructures is still rare and challenging, despite recent advances in strategies to obtain self-assembled nanostructures with narrow dispersions. Herein, we demonstrate the preparation of fluorescent conjugated block copolymers by one-shot polymerization and rapid formation of nanofibers in a few minutes via light-induced crystallization-driven self-assembly, driven by facile cis-to- trans photoisomerization of its poly( p-phenylenevinylene) blocks.

A one-pot synthesis of polysulfane-bearing block copolymer nanoparticles with tunable size and refractive index.

A one-pot synthesis of sulfur-rich polymer nanoparticles through a ring-opening metathesis polymerization is reported. The nanoparticles are formed in situ from diblock copolymers containing a polynorbornene derivative bearing cyclic polysulfanes. The refractive indices of the resulting nanoparticles are readily controlled in the range from 1.

High sulfur content polymer nanoparticles obtained from interfacial polymerization of sodium polysulfide and 1,2,3-trichloropropane in water.

Sulfur-rich materials have recently attracted keen interest for their potentials in optical, electrochemical, and pesticidal applications as well as their utility in dynamic covalent bond chemistry. Many sulfur-rich polymers, however, are insoluble and processing methods are therefore very limited. The synthesis and characterization of water-dispersible polymer nanoparticles (NPs) with the sulfur content exceeding 75% by weight, obtained from the interfacial polymerization between 1,2,3-trichloropropane and sodium polysulfide in water is reported here.

Facile synthesis of fluorescent polymer nanoparticles by covalent modification-nanoprecipitation of amine-reactive ester polymers.

Emission wavelength control in fluorescent nanoparticles (NPs) is crucial for their applications. In the case of inorganic quantum dots or dye-impregnated silica NPs, such a control is readily achieved by changing the size of the particles or choosing appropriate fluorescent dyes, respectively. A similar modular approach for controlling the emission wavelength of fluo-rescent polymer NPs, however, is difficult.

Regiospecific synthesis of Au-nanorod/SWCNT/Au-nanorod heterojunctions.

The synthesis of precisely defined nanoscale hybrid materials remains a challenge at the frontier of chemistry and material science. In particular, the assembly of diverse high-aspect ratio one-dimensional materials such as gold nanorods and carbon nanotubes into functional systems is of ever increasing interest due to their electronic and sensing applications. To meet these challenges, methods for interfacing gold nanorods with carbon materials such as single-walled carbon nanotubes (SWCNTs) in a regio-controlled manner are needed.