Water as a Reactant: DABCO-Catalyzed Hydration of Activated Alkynes for the Synthesis of Divinyl Ethers.

A practical and efficient addition of water to readily available activated alkynes delivering divinyl ethers is reported. The reaction proceeds with full atom economy in a very straightforward experimental procedure. Additionally, of all the tertiary amines studied to catalyze the reaction, the best and most efficient is clearly DABCO (1,4-diazabicyclo[2.

Tetrazine-based dynamic covalent polymers as degradable extraction materials in sample preparation.

Background: Current trends in Analytical Chemistry are highly focused on the introduction of new extraction materials with a high selectivity towards the target analytes, high extraction capacity as well as sustainable characteristics. In this context, the introduction of smart materials able to respond to an external stimulus constitutes a promising approach in the field. However, investigations regarding the development of such stimuli-responsive polymers have been basically centered on their synthesis and the control of their properties, and hardly on exploiting such properties to generate polymers that, once their extraction function is fulfilled, they can be degraded into fragments with little or negligible toxicity, or even into their constituent monomers for an efficient recycling.

Partial sensory rhizotomy in recurrent trigeminal neuralgia. Our experience and literature review.

Background And Objective: Trigeminal Neuralgia (NT) is a common pathology in Neurosurgery. It can be classified as idiopathic or secondary to other pathologies, such as Multiple Sclerosis (MS). Several surgical treatments have been described, some of them being replaced by more modern techniques.

Kinetic Control of Complexity in Multiple Dynamic Libraries.

Multiple dynamic libraries of compounds are generated when more than one reversible reaction comes into play. Commonly, two or more orthogonal reversible reactions are used, leading to non-communicating dynamic libraries which share no building blocks. Only a few examples of communicating libraries have been reported, and in all those cases, building blocks are reversibly exchanged from one library to the other, constituting an antiparallel dynamic covalent system.

Dynamic Hydroxyl-Yne Reaction with Phenols.

Dynamic Covalent Chemistry (DCvC) has gained increasing importance in supramolecular chemistry and materials science. Herein we prove the dynamic nature of the exchange between phenols and vinyl ethers. Exchange is fast at room temperature and under mild conditions.

Dynamic Nucleophilic Aromatic Substitution of Tetrazines.

A dynamic nucleophilic aromatic substitution of tetrazines (S Tz) is presented herein. It combines all the advantages of dynamic covalent chemistry with the versatility of the tetrazine moiety. Indeed, libraries of compounds or sophisticated molecular structures can be easily obtained, which are susceptible to post-functionalization by inverse electron demand Diels-Alder (IEDDA) reaction, which also locks the exchange.

[Forty years after alma-ata: currency of its fundamental concepts].

As we commemorate 40 years of the International Conference of Primary Health Care celebrated in Alma-Ata (Kazakhstan, ex-USSR) in 1978, the currency of its fundamental principles holds strong, and it is important to remember them as a referent for the near future, and to project them to every individual's health, to be built by all.

Spontaneous subdural hematoma of the thoracolumbar region with massive recurrent bleed.

Spinal subdural hematoma is a rare disorder and can be caused by abnormalities of coagulation, blood dyscrasias, lumbar puncture, trauma, underlying neoplasm, and arteriovenous malformation. We discuss an unusual case of an elderly woman who presented with spontaneous spinal subdural hematoma and developed massive rebleeding on the third day following initial evacuation of hematoma. This case illustrates that a patient with routine normal coagulation profile and adequate hemostasis can still harbor platelet dysfunction (in present case due to polycythemia) and later on can manifest as rebleeding and neurological deterioration.