Результаты поиска

Personal review: alarmism or legitimate concerns about long-term suppression of gastric acid secretion?

This article responds to controversial issues about the long-term use of acid suppression raised in a recent article in this journal by Waldum & Brenna. Although rebound acid secretion occurs following proton pump inhibitor therapy, the clinical significance of this is unclear, but the proposal that this is a major driver of acid-related diseases is considered implausible. The polypoid deformity of the gastric corpus that can occur with long-term proton pump inhibitor therapy is not neoplastic, and therefore has no bearing on other issues raised about proton pump inhibitor therapy and gastric

Effects of Paclitaxel-conjugated N-Succinyl-Hydroxyethyl Chitosan Film for Proliferative Cholangitis in Rabbit Biliary Stricture Model.

BACKGROUND: Paclitaxel (PTX) could inhibit the growth of fibroblasts, which occurs in proliferative cholangitis and leads to biliary strictu … the appearance of signals at 7.41-7.99 ppm, 1.50 ppm, and 1.03 ppm, due to the presence of aromatic protons, methylene protons, and methyl protons of PTX, respectively. No bile leak was observed. The PTX-conjugated film could slowly release PTX for 4 weeks (8.89 ± 0.03 μg at day 30). The in vitro cell viability test revealed significantly different levels …

A highly pH-sensitive Zn(II) chemosensor.

Proton and Cu(II), Zn(II), Cd(II) and Pb(II) binding by ligand H(2)L, containing two bis(aminoethyl)amine (dien) units connected by a 2',7'-dichlorofluorescein (DCF) unit has been analyzed by means of potentiometric, UV-vis and fluorescence emission measurements. Considering proton binding, the ligand in its fully deprotonated form, L(2-), binds up to four acidic protons in the alkaline pH region. These protonation steps occur on the amine groups, whereas protonation of DCF takes place only below pH 4. In metal complexation, the ligand displays a marked selectivity for Zn(II) over Cd(II) and P…

Treatment of patients with persistent heartburn symptoms: a double-blind, randomized trial.

BACKGROUND & AIMS: Common treatment practices in patients who continue to be symptomatic on proton pump inhibitor once-daily treatment include either increasing the dosage or the use of supplemental medication. This trial's purpose was to compare 2 therapeutic strategies, increasing the proton pump inhibitor dosage to twice daily versus switching to another proton pump inhibitor, in patients with persistent heartburn while receiving standard-dose proton pump inhibitor therapy. METHODS: This multicenter, randomized, double-blind, double-dummy trial included patients with persistent heartburn s

Omeprazole-induced blood dyscrasia in a clozapine-treated patient.

Proton pump inhibitors are among the world's most widely used therapeutic classes. Much of their use is attributed to their documented efficacy and apparent safety. For the most part, proton pump inhibitors are well tolerated with very few serious adverse events reported in the literature. Only a few previously identified case reports of severe neutropenia or agranulocytosis attributed to proton pump inhibitors use have been identified in the literature. However, agranulocytosis, neutropenia, and/or leukopenia are labeled as possible adverse events from post-marketing surveillance in the summa

Study of accelerator-based epithermal neutron flux depending on Li and Be targets.

The Li(p,n) and Be(p,n) reactions are widely used as accelerator-based neutron sources for boron neutron capture therapy (BNCT). Because the energy of the neutrons produced by these reactions is high for BNCT, a moderator is required to reduce the energy to the epithermal energy region. The neutron yields and energy spectra derived from the Li(p,n) and Be(p,n) reactions vary with the incident proton energy; a high proton energy results in a high neutron yield. However, a high proton energy can also increase the neutron energy, and in this case, a high neutron energy requires a thick moderator,

Conical Intersection-Mediated Nonradiative Decay in an ESIPT-Active Imidazole Derivative.

Excited-state intramolecular proton transfer (ESIPT) is a photoinduced process that involves proton migration within an intramolecular hydrogen-bonded framework following electronic excitation and is often associated with large Stokes-shifted emission. However, the excited-state fate after proton transfer is not exclusively governed by radiative decay from a stabilized keto tautomer, and nonradiative relaxation may also play a decisive role. In this work, the excited-state relaxation mechanism of 2-(4,5-diphenyl-1H-imidazol-2-yl)phenol (DIP) was investigated using multireference electronic str

Comprehensive measurement of pp-chain solar neutrinos.

About 99 per cent of solar energy is produced through sequences of nuclear reactions that convert hydrogen into helium, starting from the fusion of two protons (the pp chain). The neutrinos emitted by five of these reactions represent a unique probe of the Sun's internal working and, at the same time, offer an intense natural neutrino beam for fundamental physics. Here we report a complete study of the pp chain. We measure the neutrino-electron elastic-scattering rates for neutrinos produced by four reactions of the chain: the initial proton-proton fusion, the electron-capture decay of berylli…

Elucidation of hydrolysis mechanisms for fatty acid amide hydrolase and its Lys142Ala variant via QM/MM simulations.

Fatty acid amide hydrolase (FAAH) is a serine hydrolase that degrades anandamide, an endocannabinoid, and oleamide, a sleep-inducing lipid, and has potential applications as a therapeutic target for neurological disorders. Remarkably, FAAH hydrolyzes amides and esters with similar rates; however, the normal preference for esters reemerges when Lys142 is mutated to alanine. To elucidate the hydrolysis mechanisms and the causes behind this variation of selectivity, mixed quantum and molecular mechanics (QM/MM) calculations were carried out to obtain free-energy profiles for alternative mechanism

Organic photoredox-catalyzed unimolecular PCET of benzylic alcohols.

Proton-coupled electron transfer (PCET) is a crucial chemical process involving the simultaneous or sequential transfer of protons and electrons, playing a vital role in biological processes and energy conversion technologies. This study investigates the use of an organic photoredox catalyst to facilitate a unimolecular PCET process for the generation of alkyl radicals from benzylic alcohols, with a particular focus on alcohols containing electron-rich arene units. By employing a benzophenone derivative as the catalyst, the reaction proceeds efficiently under photoirradiation, achieving signif…

Oxidant-Free Amidation of Aldehydes Enabled by Electrophotocatalysis.

Electrophotocatalysis (EPC) is emerging as a powerful tool in organic synthesis, offering unique redox transformations without the need for sacrificial oxidants or reductants. Building on this activation mode, we have developed an electrophotocatalytic method for the direct amidation of aldehydes, utilizing electricity and protons as oxidants and light to generate chlorine radicals for hydrogen atom transfer (HAT). This sustainable approach is compatible with a wide range of aldehydes and nitrogen-based nucleophiles, performing efficiently under batch conditions and demonstrating scalability w…

Датчик I-мотив для фторметрической обнаружения обезьяноксина.

В этом исследовании мы разработали изотермальный фторометрический диагностический метод для таких вирусных расстройств ДНК, как Mpox. Наши результаты показали, что высвобождение большого количества протонов во время мультиплекс-LAMP заметно снизило уровень pH, который преобразовал линейную сновидение retinoblastoma (Rb) в i-мотивы. Следовательно, тиазол апельсин (TO; фторометрический зонд, чувствительный к i-мотиву) усилил флюоресцентную способность сигнала в силу его способности избирательно связываться с i-мотивами. Эта система мультиплекс-LAMP/i-motif-TO позволила одновременно выявлять мног

Совпадение в аннотации оригинала
In this study, we developed an isothermal fluorometric diagnostic method for DNA virus-generating disorders such as Mpox. Our results showed that the release of a large number of protons during multiplex-LAMP markedly lowered the pH level, which transformed the retinoblastoma (Rb) linear ssDNA into i-motifs. Consequently, thiazole orange (TO; a fluorometric …

The Retrotrapezoid Nucleus: Central Chemoreceptor and Regulator of Breathing Automaticity.

The ventral surface of the rostral medulla oblongata has been suspected since the 1960s to harbor central respiratory chemoreceptors [i.e., … chanisms that contribute to the activation of RTN neurons by CO2in vivo: cell-autonomous effects of protons; paracrine effects of pH mediated by surrounding astrocytes and blood vessels; and excitatory inputs from other CO2-responsive CNS neurons.

Shuttling mechanism of ion transfer at the interface between two immiscible liquids.

The transfers of hydrophilic ions between aqueous and organic phases are ubiquitous in biological and technological systems. These energetic … explain important features of transfer processes for a wide class of ions including metal cations, protons, and hydrophilic anions. The proposed new mechanism of ion transfer involves transient interfacial ion paring and shuttling of a hydrophilic ion across the mixed-solvent layer.

Synthesis and reactivity of dipole-stabilized but unchelated alpha-aminoorganolithiums.

Two N-methyl-5-lithio-2-pyrrolidinones have been prepared by tin-lithium exchange. These two alpha-aminoorganolithium compounds that are stabilized by an amide dipole, but not by chelation to the amide carbonyl. Both constitute test cases for comparing the stability and reactivity of "dipole-stabilized" and "unstabilized" alpha-aminoorganolithiums. We find that active methylene protons interfere with the reaction, so geminal disubstitution alpha to the amide carbonyl was necessary to suppress side reactions. These species do not react as efficiently as unstabilized alpha-aminoorganolithiums, o…

Relaxivity enhancement of low molecular weight nitroxide stable free radicals: importance of structure and medium.

The longitudinal relaxivities of seven water-soluble nitroxide derivatives of low-molecular weight have been measured at 5 degrees C and 37 … ystem involving nitroxides adsorbed at the surface of albumin and magnetically interacting with the protons of hydrogen bonded water molecules.

V-ATPase functions in normal and disease processes.

Eukaryotic cells have evolved a family of ATP-dependent proton pumps known as the vacuolar (H(+))-ATPases (or V-ATPases) to regulate the pH of intracellular compartments, the extracellular space, and the cytoplasm. V-ATPases present within intracellular compartments are important for such normal cellular processes as receptor-mediated endocytosis and intracellular membrane traffic, protein processing and degradation and coupled transport of small molecules and ions. They also facilitate the entry of a number of envelope viruses and bacterial toxins, including influenza virus and anthrax toxin.

Organic Photoredox Catalysts for CO2 Reduction: Understanding the Mechanisms of Catalyst Deactivation.

Organic photoredox catalysts, such as terphenyls, offer sustainable alternatives to precious-metal-based catalysts for carbon dioxide utilization. However, their practical application is hindered by low turnover numbers, believed to be caused by rapid catalyst deactivation via reactions, such as Birch reduction. This computational study examines two possible deactivation mechanisms of the three terphenyl isomers: (1) hydrogen atom transfer from an exciplex ([OPP-3δ--TEAδ+]*) formed as a result of incomplete excited-state quenching of the catalyst and (2) protonation of the radical anion terphe

In search of the grail: A race for acid suppression.

Proton pump inhibitors are the reference standards for the treatment of acid-related diseases. Acid suppression in gastroesophageal reflux disease is associated with a high rate of mucosal cicatrization, but symptom response differs among endoscopic phenotypes. Extraesophageal manifestations have a good clinical response in patients that present with abnormal acid exposure (diagnostic test) in the esophagus. Proton pump inhibitors have shown their effectiveness for reducing symptom intensity in nighttime reflux and sleep disorders, improving quality of life and work productivity. That can some

[Basic Knowledge of Neutron: Generation of Neutrons Accompanied with Particle Therapy].

Particle therapy uses high-energy charged particles, which cause nuclear reactions with a beam limiting device and a patient, resulting in the generation of high-energy secondary neutrons. These secondary neutrons cause low-dose exposure to organs far from the treatment target, and have a high biological effect due to their energy characteristics, which may cause of secondary cancers after radiotherapy. This article describes the neutron generation mechanism (cross section, and energy spectrum), interaction with the secondary neutron source (beam limiting device, and the patient), measurement