Colonoscopy and Upper Endoscopy Surveillance in Lynch Syndrome: A Longitudinal Study From a Large Tertiary Healthcare System.

Background And Aims: Lynch syndrome (LS) is caused by pathogenic mutations in mismatch repair (MMR) genes. There are limited data on differences in colorectal cancer (CRC) surveillance by MMR genes, and an international consensus on surveillance based on genes is not established. We aimed to evaluate colonoscopy and esophagogastroduodenoscopy (EGD) surveillance outcomes and compare CRC surveillance findings by the mutated gene.

Siloxide tripodal ligands as a scaffold for stabilizing lanthanides in the +4 oxidation state.

Synthetic strategies to isolate molecular complexes of lanthanides, other than cerium, in the +4 oxidation state remain elusive, with only four complexes of Tb(iv) isolated so far. Herein, we present a new approach for the stabilization of Tb(iv) using a siloxide tripodal trianionic ligand, which allows the control of unwanted ligand rearrangements, while tuning the Ln(iii)/Ln(iv) redox-couple. The Ln(iii) complexes, [Ln((OSiPhAr)-arene)(THF)] (1-Ln) and [K(toluene){Ln((OSiPhAr)-arene)(OSiPh)}] (2-Ln) (Ln = Ce, Tb, Pr), of the (HOSiPhAr)-arene ligand were prepared.

Dinitrogen cleavage by a dinuclear uranium(iii) complex.

Understanding the role of multimetallic cooperativity and of alkali ion-binding in the second coordination sphere is important for the design of complexes that can promote dinitrogen (N) cleavage and functionalization. Herein, we compare the reaction products and mechanism of N reduction of the previously reported K-bound dinuclear uranium(iii) complex, [K{[U(OSi(OBu))](μ-O)}], B, with those of the analogous dinuclear uranium(iii) complexes, [K(2.2.

Multielectron Redox Chemistry of Uranium by Accessing the +II Oxidation State and Enabling Reduction to a U(I) Synthon.

The synthesis of molecular uranium complexes in oxidation states lower than +3 remains a challenge despite the interest for their multielectron transfer reactivity and electronic structures. Herein, we report the one- and two-electron reduction of a U(III) complex supported by an arene-tethered tris(siloxide) tripodal ligand leading to the mono-reduced complexes, [K(THF)U((OSi(OBu)Ar)-arene)(THF)] () and [K(2.2.

Progress in the chemistry of molecular actinide-nitride compounds.

The chemistry of actinide-nitrides has witnessed significant advances in the last ten years with a large focus on uranium and a few breakthroughs with thorium. Following the early discovery of the first terminal and bridging nitride complexes, various synthetic routes to uranium nitrides have since been identified, although the range of ligands capable of stabilizing uranium nitrides still remains scarce. In particular, both terminal- and bridging-nitrides possess attractive advantages for potential reactivity, especially in light of the recent development of uranium complexes for dinitrogen reduction and functionalization.

A Route to Stabilize Uranium(II) and Uranium(I) Synthons in Multimetallic Complexes.

Herein, we report the redox reactivity of a multimetallic uranium complex supported by triphenylsiloxide (-OSiPh ) ligands, where we show that low valent synthons can be stabilized via an unprecedented mechanism involving intramolecular ligand migration. The two- and three-electron reduction of the oxo-bridged diuranium(IV) complex [{(Ph SiO) (DME)U} (μ-O)], 4, yields the formal "U /U ", 5, and "U /U ", 6, complexes via ligand migration and formation of uranium-arene δ-bond interactions. Remarkably, complex 5 effects the two-electron reductive coupling of pyridine affording complex 7, which demonstrates that the electron-transfer is accompanied by ligand migration, restoring the original ligand arrangement found in 4.

Nitrogen activation and cleavage by a multimetallic uranium complex.

Multimetallic-multielectron cooperativity plays a key role in the metal-mediated cleavage of N to nitrides (N). In particular, low-valent uranium complexes coupled with strong alkali metal reducing agents can lead to N cleavage, but often, it is ambiguous how many electrons are transferred from the uranium centers to cleave N. Herein, we designed new dinuclear uranium nitride complexes presenting a combination of electronically diverse ancillary ligands to promote the multielectron transformation of N.

Design Principles for the Development of Gd(III) Polarizing Agents for Magic Angle Spinning Dynamic Nuclear Polarization.

Nuclear magnetic resonance suffers from an intrinsically low sensitivity, which can be overcome by dynamic nuclear polarization (DNP). Gd(III) complexes are attractive exogenous polarizing agents for magic angle spinning (MAS) DNP due to their high chemical stability in contrast to nitroxide-based radicals. However, even the state-of-the-art Gd(III) complexes have so far provided relatively low DNP signal enhancements of ca.

Selective electrochemical capture and release of uranyl from aqueous alkali, lanthanide, and actinide mixtures using redox-switchable carboranes.

We report the selective electrochemical biphasic capture of the uranyl cation (UO ) from mixed-metal alkali (Cs), lanthanide (Nd, Sm), and actinide (Th, UO ) aqueous solutions to an organic, 1,2-dichloroethane (DCE), phase using the -substituted -carborane anion, [1,2-(PhPO)-1,2-CBH] (Cb). The reduced Cb is generated by electrochemical reduction of the -carborane, Cb, prior to mixing with the aqueous mixed-metal solution. Subsequent UO release from the captured product, [UO(Cb)], was performed by galvanostatic bulk electrolysis of the DCE phase and back-extraction of UO to a fresh aqueous phase.

Reactivity of Multimetallic Thorium Nitrides Generated by Reduction of Thorium Azides.

Thorium nitrides are likely intermediates in the reported cleavage and functionalization of dinitrogen by molecular thorium complexes and are attractive compounds for the study of multiple bond formation in f-element chemistry, but only one example of thorium nitride isolable from solution was reported. Here, we show that stable multimetallic azide/nitride thorium complexes can be generated by reduction of thorium azide precursors─a route that has failed so far to produce Th nitrides. Once isolated, the thorium azide/nitride clusters, MTh═N═Th (M = K or Cs), are stable in solutions probably due to the presence of alkali ions capping the nitride, but their synthesis requires a careful control of the reaction conditions (solvent, temperature, nature of precursor, and alkali ion).

Cancer Risk in Patients With and Relatives of Serrated Polyposis Syndrome and Sporadic Sessile Serrated Lesions.

Introduction: Patients with serrated polyposis syndrome (SPS) and their first-degree relatives (FDRs) have increased colorectal cancer (CRC) risk. Patients with sporadic sessile serrated lesion (SSL) have risk for progression to CRC. Yet familial risks of common extracolonic cancers and even CRC in these cohorts are poorly understood.

Nitride protonation and NH binding N-H bond cleavage in uranium nitrides.

The conversion of metal nitrides to NH is an essential step in dinitrogen fixation, but there is limited knowledge of the reactivity of nitrides with protons (H). Herein, we report comparative studies for the reactions of H and NH with uranium nitrides, containing different types of ancillary ligands. We show that the differences in ancillary ligands, leads to dramatically different reactivity.

Redox-switchable carboranes for uranium capture and release.

The uranyl ion (UO; U(VI) oxidation state) is the most common form of uranium found in terrestrial and aquatic environments and is a central component in nuclear fuel processing and waste remediation efforts. Uranyl capture from either seawater or nuclear waste has been well studied and typically relies on extremely strong chelating/binding affinities to UO using chelating polymers, porous inorganic or carbon-based materials, as well as homogeneous compounds. By contrast, the controlled release of uranyl after capture is less established and can be difficult, expensive or destructive to the initial material.

Surgical Interventions, Malignancies, and Causes of Death in a FAP Patient Registry.

Background: Familial adenomatous polyposis (FAP) patients are at risk for numerous malignancies. Multiple surgeries exist to mitigate the risk of colorectal cancer. Surgeons must weigh future quality of life versus the risk of dysplasia.

Patterns of family communication and preferred resources for sharing information among families with a Lynch syndrome diagnosis.

Objectives: To explore patterns of communication among families with a Lynch syndrome diagnosis and understand what resources could facilitate family communication.

Methods: 127 probands (i.e.

Outcomes and complications of radiation therapy in patients with familial adenomatous polyposis.

Background: The outcomes, complications, and rates of secondary malignancies from radiation therapy (RT) are not known for patients with familial adenomatous polyposis (FAP).

Methods: We queried the Hereditary Gastrointestinal Cancer Registry (HGCR) for patients with FAP who received RT. Outcomes assessed included acute and late treatment toxicity and secondary malignancies.

Towards Catalytic Ammonia Oxidation to Dinitrogen: A Synthetic Cycle by Using a Simple Manganese Complex.

Oxidation of the nucleophilic nitride, (salen)Mn≡N (1) with stoichiometric [Ar N][X] initiated a nitride coupling reaction to N , a major step toward catalytic ammonia oxidation (salen=N,N'-bis(salicylidene)-ethylenediamine dianion; Ar=p-bromophenyl; X=[SbCl ] or [B(C F ) ] ). N production was confirmed by mass spectral analysis of the isotopomer, 1- N, and the gas quantified. The metal products of oxidation were the reduced Mn dimers, [(salen)MnCl] (2) or [(salen)Mn(OEt )] [B(C F ) ] (3) for X=[SbCl ] or [B(C F ) ] , respectively.

Photodegradation of clothianidin under simulated California rice field conditions.

Background: Photodegradation can be a major route of dissipation for pesticides applied to shallow rice field water, leading to diminished persistence and reducing the risk of offsite transport. The objective of this study was to characterize the aqueous-phase photodegradation of clothianidin under simulated California rice field conditions.

Results: Photodegradation of clothianidin was characterized in deionized, Sacramento River and rice field water samples.

Amide and Peptide Bond Formation in Water at Room Temperature.

A general and environmentally responsible method for the formation of amide/peptide bonds in an aqueous micellar medium is described. Use of uronium salt (1-cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethylaminomorpholinocarbenium hexafluorophosphate (COMU) as a coupling reagent, 2,6-lutidine, and TPGS-750-M represents mild conditions associated with these valuable types of couplings. The aqueous reaction medium is recyclable leading to low E Factors.

Photochemical degradation of imazosulfuron under simulated California rice field conditions.

Background: The photodegradation of imazosulfuron (IMZ), a potent broad-spectrum herbicide, was investigated under simulated rice field conditions. Previous reports have indicated that it is photolabile, but have failed to report radiation intensity or determine a quantum yield, precluding extrapolation to environmental rates. Therefore, the objective of this investigation was to determine the photolytic rate of IMZ under simulated rice field conditions and how it is influenced by environmental factors such as turbidity, salinity and temperature.