A Redox-active Cyclometalated Platinum Ring Enables Synthetic Post-processing of a [2]Rotaxane.

Post-synthetic modification of mechanically interlocked molecules (MIMs) is an attractive avenue to add complexity to already intricate systems. This remains an important, challenging topic that is under-developed. In this paper, we report the synthesis and characterization of a [2]rotaxane molecule featuring a ring appended to an emissive cyclometalated Pt unit.

Enhancing late postmortem interval prediction: a pilot study integrating proteomics and machine learning to distinguish human bone remains over 15 years.

Background: Determining the postmortem interval (PMI) accurately remains a significant challenge in forensic sciences, especially for intervals greater than 5 years (late PMI). Traditional methods often fail due to the extensive degradation of soft tissues, necessitating reliance on bone material examinations. The precision in estimating PMIs diminishes with time, particularly for intervals between 1 and 5 years, dropping to about 50% accuracy.

π-Extended ligands with dual-binding behavior: hindered rotation unlocks unexpected reactivity in cyclometalated Pt complexes.

Cyclometalated platinum complexes play a crucial role in catalysis, bioimaging, and optoelectronics. Phenylpyridines are widespread cyclometalating ligands that generate stable and highly emissive Pt complexes. While it is common practice to modify these ligands to fine-tune their photophysical properties, the incorporation of polycyclic aromatic hydrocarbons into the ligand's structure has been largely overlooked.

Responsive macrocyclic and supramolecular structures powered by platinum.

Humankind's manipulation of platinum dates back more than two millennia to burial objects. Since then, its use has evolved from purely decorative purposes in jewelry to more functional applications such as in catalysts, pharmaceuticals, and bioimaging agents. Platinum offers a range of properties arguably unmatched by any other metal, including electroactivity, photoluminescence, chromic behaviour, catalysis, redox reactivity, photoreactivity, and stimuli-controlled intermetallic interactions.

Cellulose nanocrystal/halloysite nanotube composite aerogels for water purification.

The quest for advanced water purification technologies has been vigorous over recent decades, motivated by the promise of ever more efficient, greener, and affordable tools. Halloysite nanotubes (HNTs) are naturally-occurring materials that have shown potential as dye sorbents. Unfortunately, these nanoclays suffer from low permeation during water treatment, which limits their widespread application.

Molecular Flytraps Held Together by Platinum-Platinum Intermetallic Bonds.

Metal-metal bonds have rarely been explored as active elements in supramolecular assemblies despite their unique potential to introduce responsive behavior. In this report, a dynamic molecular container composed of two cyclometalated Pt units is constructed using Pt-Pt bonds. This molecule-the flytrap-has a flexible jaw composed of two [18]crown-6 ethers that can adapt their shape to bind large inorganic cations with sub-micromolar affinity.

Halloysite nanotubes enhance the mechanical properties and thermal stability of iridescent cellulose nanocrystal films.

Films of cellulose nanocrystals (CNCs) with chiral nematic organization can show vivid iridescence that arises from their hierarchical structure. Unfortunately, the brittleness of the films limits their potential applications. In this paper, we investigate the incorporation of halloysite nanotubes (HNTs) into CNC films to prepare organic-inorganic composite films with enhanced mechanical properties, while preserving the chiral nematic structure and brilliant iridescence.

Mechanically Responsive Circularly Polarized Luminescence from Cellulose-Nanocrystal-Based Shape-Memory Polymers.

Stimulus-responsive materials that display circularly polarized luminescence (CPL) have attracted great attention for application in chiral sensors and smart displays. However, due to difficulties in the regulation of chiral structures, fine control of CPL remains a challenge. Here, it is demonstrated that cellulose nanocrystal shape-memory polymers (CNC-SMPs) with luminescent components enable mechanically responsive CPL.

Cellulose Nanocrystal Gels with Tunable Mechanical Properties from Hybrid Thermal Strategies.

Gels are useful materials for drug delivery, wound dressings, tissue engineering, and 3D printing. These various applications require gels with different mechanical properties that can be easily tuned, also preferably excluding the use of chemical additives, which can be toxic or harmful to the body or environment. Here, we report a novel strategy to synthesize cellulose nanocrystal (CNC) gels with tunable mechanical properties.

Preprogrammed assembly of supramolecular polymer networks via the controlled disassembly of a metastable rotaxane.

In our daily life, some of the most valuable commodities are preprogrammed or preassembled by a manufacturer; the end-user puts together the final product and gathers properties or function as desired. Here, we present a chemical approach to preassembled materials, namely supramolecular polymer networks (SPNs), which wait for an operator's command to organize autonomously. In this prototypical system, the controlled disassembly of a metastable interlocked molecule (rotaxane) liberates an active species to the medium.

Cycling a Tether into Multiple Rings: Pt-Bridged Macrocycles for Differentiated Guest Recognition, Pseudorotaxane Transformations, and Guest Capture and Release.

Macrocycle engineering is a key topic in supramolecular chemistry. When synthesizing a ring, one can obtain either complex mixtures of macrocycles of different sizes or a single ring if a template is utilized. Here, we unite these approaches along with post-synthetic modifications to transform a single tether into multiple rings-up to five per tether.

A Supramolecular Strategy for the Synthesis of Cyclic Oligomers and Polymers by Ring Expansion.

Ring-opening metathesis polymerization (ROMP) of strained macrocycles is a key method to prepare diverse polymers. However, lack of ring strain in most macrocycles is an impediment to polymerization. In this paper, the polymerization/oligomerization of unstrained macrocycles was achieved using a supramolecular approach, leading selectively to cyclic products.

Reproducibility of MRI in the diagnosis of meniscal ramp lesions: an inter-observer study.

Background: Meniscal ramp lesions have gained much prominence in recent years due to a significant increase in their diagnosis and their important biomechanical involvement in the knee. A new proposed classification of these lesions has recently been published.

Purpose: To evaluate the reproducibility of the new classification of meniscal ramp lesions recently published using magnetic resonance imaging (MRI).

Revolution in modern teaching in dentistry since the appearance of the COVID-19 pandemic: A review.

Dentistry schools have attempted to overcome the challenges imposed by the coronavirus disease 2019 (COVID-19) pandemic through teaching via the Internet with the use of virtual platforms, designed to simulate face-to-face interaction and counteract the social isolation affecting the integral development of students. This review searched the main health databases, including MEDLINE via PubMed, Scopus and LILACS, and selected 31 articles to proceed with the research. During the pandemic, platforms such as Facebook, Instagram, YouTube, Zoom, Google Meet, and other similar tools allowed teachers to develop dynamic slides and dental models to simulate procedures, which played an important role in the course of mainly theoretical classes.

Use of Live Community Events on Facebook to Share Health and Clinical Research Information With a Minnesota Statewide Community: Exploratory Study.

Background: Community engagement can make a substantial difference in health outcomes and strengthen the capacity to deal with disruptive public health events such as the COVID-19 pandemic. Social media platforms such as Facebook are a promising avenue to reach the broader public and enhance access to clinical and translational science, and require further evaluation from the scientific community.

Objective: This study aims to describe the use of live community events to enhance communication about clinical and health research through a Facebook platform case study (Minnesota [MN] Research Link) with a Minnesota statewide community.

Multiresponsive Cyclometalated Crown Ether Bearing a Platinum(II) Metal Center.

Multiresponsive materials can adapt to numerous changes in their local environment, which makes them highly valuable for various applications. Although nanostructured and polymeric multiresponsive materials are plentiful, small-molecule analogues are scarce. This work presents a compact cyclometalated platinum(II) complex that bears a crown ether cavity (-Pt); the intimate ring/emitter connectivity is key to unlocking multiresponsiveness.

Microsurgical Anatomy of the Anterior Circulation of the Brain Adjusted to the Neurosurgeon's Daily Practice.

The study of cerebrovascular anatomy can be difficult and may take time due to its intrinsic complexity. However, it can also be difficult for the following reasons: the excessive description of neuroanatomy making articles hard to read, the unclear clinical application of what is written, the use of simplified or intricate schematic drawings that are not always appropriate for effective teaching, the poor quality of neuroanatomy dissections and the use of unusual views of figures that are not strictly related to the most frequent neuroimages to be interpreted in daily practice. Because of this, we designed an article that incorporates original and accurate anatomical dissections in an attempt to improve its comprehensibility.

Structural Elucidation of Selective Solvatochromism in a Responsive-at-Metal Cyclometalated Platinum(II) Complex.

We report the synthesis, characterization, and spectroscopic investigations of a new responsive-at-metal cyclometalated platinum(II) complex. With mild chemical oxidants and reductants, it was possible to obtain the same complex in three different oxidation states and each of these complexes was structurally characterized by single-crystal X-ray diffraction. We discovered that the platinum(II) complex displays strong solvatochromism in the solid state, which can be attributed to modulation of Pt⋅⋅⋅Pt interactions that results in switching between optical and photoluminescent states.

Programming permanent and transient molecular protection mechanical stoppering.

Chemical protection is an essential tool in synthetic chemistry, which involves blocking reactive sites on a molecule through covalent bonds. Physical approaches, such as encapsulation and host-mediated protection, have emerged as interesting alternatives that use steric bulk to inhibit reactivity. Here, we report the protection of a redox-active viologen through its incorporation into mechanically interlocked molecules (MIMs), namely hetero[4]rotaxanes.

Host-Guest Chemistry Within Cellulose Nanocrystal Gel Receptors.

Cellulose nanocrystals (CNCs) spontaneously assemble into gels when mixed with a polyionic organic or inorganic salt. Here, we have used this ion-induced gelation strategy to create functional CNC gels with a rigid tetracationic macrocycle, cyclobis(paraquat-p-phenylene) (CBPQT ). Addition of [CBPQT]Cl to CNCs causes gelation and embeds an active host inside the material.

Disabling Molecular Recognition through Reversible Mechanical Stoppering.

Mechanical stoppering of a guest molecule prevents its self-assembly with a macrocycle unit, so that both species coexist in a medium but do not recognize each other. The application of a chemical or physical stimulus reverses mechanical stoppering and subsequently enables molecular recognition. This process, which occurs without cross-reactivity and is perceptible at the macroscopic scale, could facilitate programming on/off states in supramolecular materials and molecular devices.

Spectral shadowing suppression technique in phase-OTDR sensing based on weak fiber Bragg grating array.

A postprocessing procedure is presented to suppress spectral shadowing in phase-OTDR sensing systems based on a weak fiber Bragg grating array. A complete theoretical analysis of the interfering signals has been carried out to identify a compensation method. The proposed approach has been applied to simulated and experimental phase-OTDR in the context of vibration measurements.

Ligand-modulated ring-expansion.

An unstrained palladium-containing macrocycle was expanded by a ring-opening metathesis strategy. This reaction was driven by coordination of a bulky ligand, 2,6-lutidine, to the palladium center, enabling a monometallic macrocycle to transform into a bimetallic dimeric macrocycle.

On Practical Issues for Stochastic STDP Hardware With 1-bit Synaptic Weights.

In computational neuroscience, synaptic plasticity learning rules are typically studied using the full 64-bit floating point precision computers provide. However, for dedicated hardware implementations, the precision used not only penalizes directly the required memory resources, but also the computing, communication, and energy resources. When it comes to hardware engineering, a key question is always to find the minimum number of necessary bits to keep the neurocomputational system working satisfactorily.