bluuebunny/crossref_metadata_2025 huggingface dataset:
Особенности протонирования 2,6-ди-трет-бутилпиридина. Подвижность протонированных молекул
Authors: Лебедев А.В.
Published: December 2024

2,6-Ди-трет-бутилпиридин (DTBP) широко используется в спектрометрии ионной подвижности и ее сочетании с масс-спектрометрией как стандартное соединение для калибровки шкалы подвижности ионов. В настоящей работе с помощью квантово-химических методов рассчитано строение и определен конформационный состав DTBP и продуктов его протонирования. Найдено три конформера DTBP, близких по стабильности. Показано, что их протонирование приводит к трем близким по стабильности продуктам. Вычислена энергия сродства к протону и газофазная основность DTBP. Рассчитаны термодинамические параметры реакций DTBP с ионами гидратированного гидроксония H3O(H2O)n (n 03). Результаты расчета хорошо согласуются с экспериментальными данными и подтверждают, что реакции приводят к образованию протонированных молекул DTBP, которые не гидратируются и не образуют протон-связанных димеров. Показано, что особенности протонирования DTBP в значительной степени обусловлены стерическим эффектом трет-бутильных групп. Траекторным методом вычислена приведенная подвижность ионов протонированного DTBP. Достигнута погрешность расчета, близкая к экспериментальной. В соответствии с экспериментальными данными температура не оказывает существенного влияния на расчетную приведенную подвижность.

2,6-Di-tert-butylpyridine (DTBP) is widely used in ion mobility spectrometry and its combination with mass spectrometry as a standard compound for calibration of the ion mobility scale. In this work, using quantum chemical methods we computed the structure and determined the conformational composition of DTBP and products of its protonation. Three conformers with similar stability are found. It is shown that their protonation leads to three products with similar stability. Proton affinity and gas-phase basicity of DTBP are calculated. The thermodynamic parameters of DTBP reactions with hydrated hydroxonium ions H3O(H2O)n (n 03) are computed. The calculations confirmed that, in agreement with experimental data, the reactions lead to the formation of protonated DTBP molecules that are not hydrated and do not form proton-bound dimers. It is shown that peculiarities of DTBP protonation are largely due to the steric effect of the tert-butyl groups. The reduced mobility of protonated DTBP molecules is calculated by the trajectory method. The calculation error close to the experimental one is reached. According to experimental data, the calculated reduced mobility does not change significantly with temperature.
ХРОМАТО-МАСС-СПЕКТРОМЕТРИЧЕСКАЯ ИДЕНТИФИКАЦИЯ УГЛЕВОДОРОДОВ, АССОЦИИРОВАННЫХ С МУМИЁ В ТЫВЕ
Authors: Д.А. Бушнев , С.А. Ондар
Published: December 2024

Методом хромато-масс-спектрометрии изучен состав углеводородов, выделенных из породы, содержащей мумиё. Анализ масс-спектров электронной ионизации и характеристик удерживания позволил установить структуру ряда обнаруженных компонентов. Идентифицированы н‑алканы С23–С29, а также моно- и диметилзамещённые алканы С28–С32. Углеводороды, выделенные из мумиё-содержащей породы, не являются родственными углеводородам горючих ископаемых, таких как нефть, битум, ископаемый уголь или горючие сланцы, а, по-видимому, связаны с мумиё, образованным при аквапереносе компонентов экскрементов мелких грызунов.

Composition of hydrocarbons from the sample of the rock containing mumijo was studied by gas chromatography/mass spectrometry. Analysis of electron ionization mass spectra and retention characteristics allowed determining the structure of the found components. Long-chain n-alkanes C23–C29 and mono- and dimethylalkanes C28–C32were identified in the extract. Hydrocarbons extracted from the rock containing mumijo do not relate to hydrocarbons of oil, bitumen, coal or oil shales. These hydrocarbons are in close association with mumijo formed during the aquatic transfer of biochemical components of small rodents excrements.
Определение параметоксифенацилбромидных производных алкилметилфосфоновых кислот в моче методом газовой хроматографии с масс-спектрометрическим детектированием высокого разрешения
Authors: Д.В. Орешкин , Т.М. Байгильдиев , М.Ф. Вокуев , А.В. Браун , И.А. Годовиков , И.В. Рыбальченко , И.А. Родин
Published: December 2024

Разработан метод определения этилметилфосфоновой, изопропилметилфосфоновой, изобутилметилфосфоновой и пинаколилметилфосфоновой кислот в моче человека с использованием газовой хроматографии с масс-спектрометрией высокого разрешения и дериватизации п-метоксифенацилбромидом. Эти четыре алкилметилфосфоновые кислоты являются специфическими продуктами гидролиза и биомаркерами воздействия отравляющих веществ нервно-паралитического действия. В ходе исследования оптимизированы условия реакции дериватизации алкилметилфосфоновых кислот п-метоксифенацилбромидом, выявлены особенности и общие закономерности формирования МС1 и МС2спектров дериватов в условиях электронной и химической ионизации. Достигнутые пределы обнаружения методом газовой хроматографии с тандемным масс-спектрометрическим детектированием высокого разрешения находятся в диапазоне от 20 до 70 нг мл–1.

A method for determination of ethyl methylphosphonic, isopropyl methylphosphonic, isobutyl methylphosphonic and pinacolylmethylphosphonic acids in human urine was developed using gas chromatography with high-resolution mass spectrometry and preliminary derivatization with p-methoxyphenacyl bromide. All of the acids are specific hydrolysis products and biomarkers of nerve agents. Conditions of the derivatization reaction was optimized. Features and general patterns of MC1and MC2 spectra of derivatives recorded using electron and chemical ionization modes are revealed. Achieved limits of detection by the developed method are in the range from 20 to 70 ng ml–1.
Характеристики масс-спектра высокого разрешения аддукта 2-(диэтиламино)этилтиола c дипептидом (Cys-Pro)
Authors: А.В. Браун , М.Ф. Вокуев , Я.В. Ставитская , Т.М Байгильдиев , В.А. Якшир , И.В. Рыбальченко , И.А. Родин
Published: December 2024

Фосфорорганические вещества нервно-паралитического действия (ФВНПД) представляют значительную угрозу для здоровья человека. К наиболее токсичным соединениям класса ФВНПД относятся боевые отравляющие вещества (ОВ), а том числе ОВ V-типа (V-газы), а именно VX, CVX и VR (рис. 1) [1]. Обнаружение ОВ в нативном виде в биопробах сильно осложнено из-за быстрого выведения их из организма, а также структурных изменений в ходе процессов биотрансформации [2–5]. В связи с этим, в настоящее время основные усилия направлены на идентификацию аддуктов ОВ с эндогенными молекулами (например, белками), поскольку эти биомаркеры присутствуют в организме спустя несколько дней или даже недель после интоксикации. [2, 6].
Эффекты изомерии в масс-спектрах стимулированной диссоциации сульфониевых катионов, десорбируемых из S-алкилированных тиацикланов в условиях МАЛДИ. Удобный способ дериватизации сульфидов под воздействием алкилформиатов
Authors: Н.Ю. Половков , Ж.Е. Старкова , А.Ю. Канатьева , Р.С. Борисов , В.Г. Заикин
Published: December 2024

Для исследования и анализа неполярных органических сульфидов методом матрично-активированной лазерной десорбции/ионизации (МАЛДИ) предложено их предварительное превращение в сульфониевые соли с использованием электрофильной реакции с алкилформиатами в присутствии трифторметансульфокислоты. В качестве объектов исследования взяты тиабицикланы с различным расположением атома серы и метильных заместителей (2- и 3-тиабицикло[4.4.0]деканы, 7- и 8-тиабицикло[4.3.0]нонаны). Показано, что использованная реакция обеспечивает количественное S-алкилирование в достаточно мягких условиях. В масс-спектрах МАЛДИ регистрируются только пики соответствующих сульфониевых катионов, масса которых отвечает сумме молекулярной массы сульфида и инкремента вводимой алкильной группы. Обнаружены и интерпретированы резкие качественные и количественные различия в масс-спектрах, зарегистрированных в режиме диссоциации, индуцированной соударениями, для региоизомерных сульфониевых катионов.
ИОН-РЕАГЕНТ NH4+(H2O)n. РАСЧЕТ СТРОЕНИЯ, ТЕРМОДИНАМИЧЕСКИХ ПАРАМЕТРОВ ГИДРАТАЦИИ, РАВНОВЕСНОГО СОСТАВА И ПОДВИЖНОСТИ
Authors: А.В. Лебедев , С.С. Колбинев
Published: December 2024

Значительный интерес к исследованию иона-реагента NH4+(H2O)n обусловлен его успешным применением в спектрометрии ионной подвижности и масс-спектрометрии с химической ионизацией. В настоящей работе получены расчетные данные по строению и свойствам ионов NH4+(H2O)n (n = 0–4), которые необходимы для изучения закономерностей химической ионизации, прогнозирования и интерпретации спектров ионной подвижности и масс-спектров. С помощью квантово-химических методов рассчитано строение и уточнен изомерный состав ионов NH4+(H2O)n. Выявлен наиболее полный набор изомеров с n = 3 и 4 (7 и 23 изомера соответственно). Установлено, что более стабильные изомеры NH4+(H2O)n отличаются разветвленной нециклической структурой с ядром NH4+ и максимальным числом ионных водородных связей NH…O. Вычислены термодинамические параметры реакций гидратации наиболее стабильных изомеров NH4+(H2O)n (n = 0–3). Достигнута точность расчета, сопоставимая с погрешностью экспериментального определения термодинамических параметров. Вычислен состав иона-реагента для типичных экспериментальных условий. Расчет показал, что ион-реагент представлен ионами NH4+(H2O)n (n = 0–2). С использованием найденных структурных данных и данных о составе иона-реагента рассчитана его приведенная подвижность траекторным методом с двумя различными алгоритмами. Вычисленные приведенные подвижности согласуются с экспериментальными величинами.
Разрешающая способность масс-анализатора – ключевой фактор в анализе объектов окружающей среды методом ГХ-МС?
Authors: Д.М. Мазур
Published: December 2024

Масс-спектрометрия высокого разрешения (МСВР) в сочетании с хроматографическими методами разделения является одним из самых востребованных и распространенных методов в изучении объектов окружающей среды. Газовая хроматография/масс-спектрометрия высокого разрешения (ГХ/МСВР) представляет большой интерес в области целевого и нецелевого анализа различных ксенобиотиков. В связи с очевидными ограничениями метода ГХ/МСВР по диапазону анализируемых органических веществ среди исследователей и пользователей современного ГХ/МСВР оборудования давно идет спор о целесообразности и оправданности использования высокого и сверхвысокого разрешения. В данной работе рассмотрен ряд примеров использования ГХ/МСВР как для сложных смесей полигалогенированных соединений, так и в рутинном анализе в попытке ответа на вопрос об оптимальной разрешающей способности масс-анализатора для ГХ/МСВР.
Моделирование квадрупольного фильтра масс с октупольным полем
Authors: П.В. Бугров , А.А. Сысоев , Н.В. Коненков
Published: December 2024

На основе численного моделирования траекторий ионов в квадрупольном поле с малыми пространственными гармониками исследуется контур пропускания (форма массового пика). Для октупольной компоненты поля в 2 % подтверждена возможность достижения разрешающей способности R_0.5=5000 при отрицательной постоянной составляющей на паре электродов меньшего радиуса. Представлена диаграмма стабильности вблизи рабочей вершины, которая существенно модифицирована октупольным полем. Результаты моделирования качественно подтверждаются данными ранее выполненного эксперимента.
Проект времяпролетного много-отражательного масс-спектрометра для лаборатории ядерных реакций ОИЯИ
Authors: М.И. Явор , Н.Р. Галль , М.З. Мурадымов , Т.В. Помозов , И.В. Курнин , А.Г. Монаков , А.Н. Арсеньев , Ю.Ц. Оганесян , А.В. Карпов , А.М. Родин , К. Любош
Published: December 2024

В работе представлен проект специализированного масс-спектрометра для прецизионного измерения масс сверхтяжелых элементов на Фабрике сверхтяжелых элементов в Объединенном институте ядерных исследований (ОИЯИ) в г. Дубна. Масс-спектрометр рассчитан на достижение массовой точности 10-7 при малой статистике измерений (порядка 5 событий). Ядром масс-спектрометра является много-отражательный времяпролетный масс-анализатор нового поколения. Для подготовки и сепарации ионов пробы и калибранта в спектрометре предусмотрен ряд новых ионно-оптических элементов, таких, как радиочастотный селектор зарядовых состояний, квадрупольные масс-фильтры, работающие в режиме совпадения узлов биения пучка на выходе, ячейка столкновительной диссоциации с фокусировкой пучка в промежутке вакуумного затвора, и ионный источник калибранта с электронной ионизацией фуллереновой сажи.
Письмо в редакцию. Газовая хроматография/масс-спектрометрия с фотоионизацией при атмосферном давлении. Обнаружение компонентов сложных смесей низкомолекулярных органических соединений неизвестного состава на уровне следов
Authors: И.А. Ревельский , Ю.С. Яшин , А.С. Самохин , А.И. Ревельский
Published: December 2024

Предел детектирования метода газовой хроматографии/масс-спектрометрии (ГХ/МС) с ионизацией электронами (ИЭ) при сканировании в режиме полного ионного тока составляет 10-11–10-10 г, в зависимости от типа вещества. Полный масс-спектр ИЭ вещества можно зарегистрировать для 10-10–10-9 г; при этом пик молекулярного иона в этих масс-спектрах часто либо отсутствует, либо малоинтенсивен. Минимальное количество вещества, которое можно обнаружить методом ГХ/МС с фотоионизацией при атмосферном давлении (ФИАД) составляет 10-12–10-10 г, а методом ГХ/МС с фотохимической ионизацией при атмосферном давлении – 10-14–10-12 г, в зависимости от природы аналита и вещества реагента. При этом для количества вещества в диапазоне от 10-9–10-10 г и вплоть до предела детектирования регистрируется масс-спектр, состоящий из пика иона М+• либо МН+, либо обоих, что обеспечивает селективную информацию о молекулярной массе аналита во всём исследуемом диапазоне. Для идентификации следовых количеств неизвестных компонентов сложных смесей представляет интерес совместное использование данных масс-спектров ИЭ и ФИАД.
Дериватизация с генерацией фиксированного заряда для детектирования 3-хлорпропандиола-1,2 «мягкими» масс-спектрометрическими методами
Authors: М.Е. Зименс , А.Р. Борисова , Е.О. Рысцова , С.В. Горяинов , А.П. Топольян , Р.С. Борисов , В.Г. Заикин
Published: December 2024

Предложен новый подход к детектированию 3-хлорпропандиола-1,2 (3-МХПД) «мягкими» масс-спектрометрическими методами. В основе предложенного способа лежит химическая модификация целевого соединения дериватизирующими агентами, такими как 4-бромбутил- и 4-(бромметил)фенилбороновые кислоты, с последующей кватернизацией пиридина полученными производными. Продуктами взаимодействия являются органические соли, катионы которых легко детектируются методами масс-спектрометрии с матрично-активированной лазерной десорбцией/ионизацией (МАЛДИ) и ионизацией электрораспылением (ИЭР). Масс-спектры стимулированной фрагментации таких катионов содержат в основном пики ионов, соответствующие протонированным молекулам пиридина, что дает возможность использования мониторинга выбранных реакций для селективного детектирования 3-МХПД и других диолов.
Evaluation des pratiques professionnelles dans la prise en charge de l’anémie et la nutrition chez le patient en dialyse péritonéale
Authors: Geeraert Manon , SCHRICKE Justine , Azar Raymond
Published: December 2024

Dans une démarche constante d’amélioration des pratiques médicales, depuis la loi du 4 Mars 2004, en France, les professionnels de santé, qu’ils soient du domaine médical ou paramédical, participent au développement des évaluations des pratiques professionnelles (EPP). L’EPP est un outil incontournable pour améliorer la qualité des soins et garantir la sécurité du patient. Cette évaluation peut être individuelle ou collective. Elle vise à cibler un ou différents thèmes afin de corriger les écarts entre les soins prodigués aux patients par rapport à un référentiel de soins et de prise en charge.Nous effectuons les EPP, de manière constante depuis 2012, essentiellement portée sur l’anémie et la nutrition des patients en dialyse péritonéale. Au travers de ce travail, nous souhaitons montrer l’intérêt de la réalisation des EPP dans le suivi des patients en dialyse péritonéale.
Douleurs abdominales en dialyse péritonéale : péritonite ou pancréatite, à propos de trois cas
Authors: Boumaiz Firdaous , EL Maakoul Sara , Hmaidouch Nabil , Ouzeddoun Naima , Benamar Loubna
Published: December 2024

Résumé
La pancréatite chez les patients en dialyse péritonéale (DP) représente un défi clinique complexe, souvent masqué par des symptômes qui se chevauchent avec ceux d’autres affections, comme la péritonite. Cet article présente trois cas cliniques illustrant la difficulté du diagnostic et de la prise en charge de la pancréatite dans ce contexte.Le premier cas concerne un patient de 40 ans, présentant une pancréatite aiguë sévère après deux ans de DP. Le diagnostic, initialement confondu avec une péritonite en raison de la présence de liquide de dialysat hématique, a été rectifié grâce à une élévation marquée des enzymes pancréatiques et une tomodensitométrie confirmant une nécrose pancréatique. Malgré une prise en charge rapide, incluant un drainage scanno-guidé, le patient est décédé des suites d’un choc septique.Le deuxième cas met en lumière une patiente de 64 ans, atteinte de pancréatite chronique, favorisée par une hypertriglycéridémie familiale. Bien que cette patiente ait survécu à plusieurs épisodes de pancréatite, la gestion de sa condition a nécessité une surveillance constante et une adaptation continue de son traitement sous DP.Le troisième cas décrit un patient de 58 ans, dont la pancréatite aiguë lithiasique a rapidement évolué vers une nécrose pancréatique, entraînant un état de choc septique fatal, malgré un drainage scanno-guidé.Ces cas soulignent l’importance d’une vigilance accrue dans la surveillance des patients en DP, où la pancréatite peut se manifester de manière insidieuse. Le diagnostic doit reposer sur une évaluation clinique rigoureuse, des marqueurs biologiques pertinents comme la lipase, et des imageries adaptées pour éviter des retards de traitement qui peuvent être fatals. La prise en charge précoce et multidisciplinaire est essentielle pour améliorer le pronostic de cette complication sévère, souvent sous-estimée dans la population sous dialyse péritonéale.
A rare case of refractory ascites due to aortic regurgitation delaying peritoneal dialysis catheter removal after renal transplantation
Authors: Antoun Joseph , Jacobs Lucas , Brayer Isabelle , Taghavi Maxime , Nortier Joëlle
Published: December 2024

Introduction
Removing the peritoneal dialysis (PD) catheter after transplantation is necessary in order to improve quality of life after transplantation. However, there is no consensus on the best timeframe of PD-catheter removal in transplanted patients. Early removal can lead to the absence of dialysis access in case of graft failure. However, late removal is associated with significant infectious risk given the immunosuppression. Herein, we describe an exceptional case of refractory ascites secondary to aortic regurgitation in a cirrhotic patient, delaying the removal of his PD catheter. Case reportWe describe the case of a 49-year old patient, with Child B cirrhosis and end-stage kidney disease on chronic peritoneal dialysis who benefited from kidney transplantation. The scheduled PD catheter flushes were marked by the drainage of ascitic fluid, leading to the postponement of the PD catheter removal. The ascites, thought to be secondary to his long-known cirrhosis, was refractory to optimal drug treatment and the PD catheter was used to remove ascites periodically. As a transjugular intrahepatic portosystemic shunt was planned, a severe aortic regurgitation was diagnosed. After aortic valve replacement, the ascites completely disappeared, and the PD catheter could be removed.DiscussionHeart failure represents only 3% of all refractory ascites. Furthermore, left-side heart failure causing ascites but without signs of right-side heart failure has only been described once in the medical literature. Patients with ascites and kidney failure on PD can safely be managed through the PD catheter instead of recurrent paracentesis. However, in transplanted patients especially, keeping the catheter in place brings significant infectious risk. ConclusionWe described an unusual case of refractory ascites after renal transplantation, due to aortic valve regurgitation. This case highlights the importance of weighing the pros and cons of early PD catheter removal, as PD catheter might be useful as a means of removing ascites.
Predictive factors for Peritoneal Dialysis Catheter Survival: a ten-year single center study
Authors: Beirão Rodrigues Bárbara , Freitas Mariana , S. Borges João , Pereira Beatriz , Prata Catarina , Castro Rui , Morgado Teresa
Published: December 2024

Introduction and Objectives: Timely insertion and adequate management of peritoneal dialysis catheter (PDC) related complications are crucial for the success of Peritoneal Dialysis. The aim of this study was to review the peritoneal dialysis catheter outcomes at our center, identifying factors that influence catheter survival.
Materials and Methods: A retrospective study was conducted on 146 PD patients who received their first PDC between August/ 2012 and July/2022. The mean follow-up was 26.5 ± 22.7 months.
Results: Mean age was 55.1 ± 16.6 years, and 58.2% were male. Peritonitis occurred in 75 patients (51.4%), with 26 (34.7%) requiring catheter removal. Mechanical complications were observed in 66 patients (45.2%), with 16 requiring catheter removal. Catheter survival at 12, 24, and 36 months was 80.2%, 72.4%, and 61.6%, respectively. Non-infectious complications (p=0.006) and peritonitis episodes (p=0.017) were associated with higher rate of PDC-associated removal. In the multivariate analysis, non-infectious complications were the only independent variable significantly associated with catheter survival (Hazard ratio 2.53; 95% CI 1.383–4.624). No association was found between PDC survival and age, diabetic status, obesity, prior kidney transplant, previous abdominal surgery, or method of catheter insertion.
Conclusions: Despite the significant number of infectious complications, including peritonitis, these did not result in a substantial decrease in catheter survival in the multivariate analysis. These findings emphasize the importance of effectively managing non-infectious complications to ensure successful and long-term use of PDCs. Preventive measures, such as omentectomy simultaneously with PDC implantation, may be considered on a case-by-case basis.
Oxazoline (ImOx): A C1-Symmetric N,N-Bidentate Ligand for Asymmetric Catalysis
Authors: Silk Elliot , Shtukenberg Alexander , Diao Tianning
Published: December 2024

Asymmetric catalysis relies on the design of chiral ligands, but the variety of nitrogen-based ligands remains limited To address this gap, we have developed a class of C1-symmetric N,N-bidentate ligand, imine-oxazoline (ImOx), derived from amino acids through a four-step synthesis. ImOx features an imine moiety conjugated with a chiral oxazoline ring, as a hybrid of α-diimine (ADI) and pyridine oxazoline (PyOx) ligands. Its low symmetry allows for independent optimization at both coordination sites. ImOx improves the enantioselectivity of palladium-catalyzed conjugate addition reactions, demonstrating a strong correlation between ee and the steric effects on both the imine and oxazoline sites. Studies on well-defined organopalladium intermediates reveal that the steric bulk of ImOx necessitates a cationic pathway to promote alkene insertion. Structural characterization if ImOx suggests a stronger trans-influence compared to PyOx. Moreover, ImOx demonstrates excellent redox activity, promoting the reduction of nickel complexes and stabilizing nickel radical complexes. We anticipate that ImOx will expand the toolkit of chiral N-ligands for asymmetric catalysis.
The Binuclear Copper State of Peptidylglycine Monooxygenase Visualized through a Selenium-Substituted Peptidyl-Homocysteine Complex
Authors: Blackburn Ninian , Welch Evan , Rush Katherine , Eastman Karsten , Bandarian Vahe
Published: December 2024

Bioactive peptides generally require post-translational processing to convert them to their fully active forms. Peptidylglycine monooxygenase (PHM) is a copper-dependent enzyme that catalyzes C-alpha hydroxylation of a glycine-extended pro-peptide, a critical post-translational step in peptide amidation. A canonical mechanism based on experimental and theoretical considerations proposes that molecular oxygen reacts at the mononuclear CuM-center to form a reactive Cu(II)-superoxo intermediate capable of H-atom abstraction from the peptidyl substrate, followed by long range ET from the CuH center positioned 11 Å away across a solvent-filled cleft. However, recent data has challenged this mechanism, suggesting instead that an “open-to-closed” conformational transition brings the copper centers closer to facilitate reaction at a binuclear copper site. Here we present direct observations of an enzyme-bound binuclear copper species, which was enabled by the use of an Ala-Ala-Phe-homoselenocysteine (hSeCys) species. EXAFS, UV/vis, and EPR studies are used to show that this reagent reacts with the oxidized enzyme to form a novel mixed valence entity which is subtly different from that observed previously for the S-peptidyl complex (J. Am. Chem. Soc. (2024)146, 5074-5080). In the ascorbate-reduced Cu(I) state of PHM, EXAFS measurements at both the Se and Cu absorption edges provide a unique signature of a bridging mode of binding, with Se-Cu site occupancy (1.8) measured from the Se-EXAFS simulating to twice that of the Cu-Se site occupancy (0.85) measured at the Cu edge. The ability of the hSeCys entity to induce a binuclear state is further emphasized by the XAS of the selenomethionyl peptide complex, where no such bridging chemistry is observed. The properties of the binuclear PHM derivative are of interest due to their unique chemical signatures, as well as providing the basis for a completely new mechanistic paradigm for PHM and its monooxygenase congeners.
PAH101: A GW +BSE Dataset of 101 Polycyclic1 Aromatic Hydrocarbon (PAH) Molecular Crystals
Authors: Gao Siyu , Liu Xingyu , Luo Yiqun , Wang Xiaopeng , Zhao Kaiji , Chang Vincent , Schatschneider Bohdan , Marom Noa
Published: December 2024

The excited-state properties of molecular crystals are important for applications in organic electronic devices. The GW approximation and Bethe-Salpeter equation (GW +BSE) is the state-of-the-art method for calculating the excited-state properties of crystalline solids with periodic boundary conditions. We present the PAH101 dataset of GW +BSE calculations for 101 molecular crystals of polycyclic aromatic hydrocarbons (PAHs) with up to ∼500 atoms in the unit cell. The data records include the GW quasiparticle band structure, the fundamental band gap, the static dielectric constant, the first singlet exciton energy (optical gap), the first triplet exciton energy, the dielectric function, and optical absorption spectra for light polarized along the three lattice vectors. In addition, the dataset includes the density functional theory (DFT) single-molecule and crystal features used in Liu et al. [npj Computational Materials, 8, 70 (2022)]. We envision the dataset being used to (i) identify correlations between DFT and GW +BSE quantities, (ii) discover materials with desired electronic/ optical properties in the dataset itself, and (iii) train machine-learned models to help in materials discovery efforts. We provide examples to illustrate these three use cases.
Nitrate Radical Cannot Initiate Oxidation of Hg(0) to Hg(II) in the Laboratory or at Ground Level in the Atmosphere
Authors: Tharika Edirappulige Darshi Hewa , Cheng Lan , Castro Pedro , Dibble Theodore
Published: December 2024

Multiple field studies have led to suggestions that nitrate radical (NO3) participates in oxidizing gaseous Hg(0) in the atmosphere. These suppositions are hard to reconcile with the two-step mechanism of Hg(0) conversion to Hg(II) via Hg(I), due to the instability of the NO3-Hg(I). We use a high level of computational chemistry to determine its bond energy as 6.5 kcal mol-1. We use statistical mechanics to compute the equilibrium constant, Kc(T) for NO3 + Hg(0) = NO3Hg(I), and a box model to investigate a field study and laboratory kinetic investigation of this chemistry. Under the conditions of the one field study showing a correlation between [NO3] and [Hg(II) (g)] , NO3 could not have contributed significantly to the formation of Hg(II). In addition, we find that the one experimental kinetic study of this reaction does not constrain the rate constant.
Accessing Azetidines through Magnesium-Mediated Nitrogen Atom Transfer from Iminoiodinane to Donor-Acceptor Cyclopropanes
Authors: Bansode Ajay , Yin Lifeng , Deng Ning , Afrasi Mahmoud , Zhu Yiyi , Parasram Marvin
Published: December 2024

Herein, we report a Lewis acid-mediated ring expansion of donor-acceptor cyclopropanes (DACs) to substituted azetidines via nucleophilic nitrogen atom transfer from readily accessible iminoiodinane. This protocol operates under mild, transition-metal-free conditions, and showcases excellent chemoselectivity, along with broad functional group tolerance. We report for the first time that challenging alkyl donor-acceptor cyclopropanes can undergo ring expansion leading to aliphatic azetidines without relying on external oxidants or precious transition-metal catalysts. Mechanistically, the coordination of a magnesium (Mg)-Lewis acid to the DAC promotes nucleophilic ring opening with a putative Mg-amide species generated from the iminoiodinane under the reaction conditions to furnish the azetidine products.
Mapping the Distribution and Affinities of Ligand Interaction Sites on Human Serum Albumin
Authors: Orr Asuka , Uwakweh Agbo-oma , Li Xun , Karanji Ahmad , Hoag Stephen , Deredge Daniel , MacKerell Alexander
Published: December 2024

Ligands in many instances interact with a protein at multiple sites with a range of affinities. In the present study, ligand-protein interaction sites on Human Serum Albumin (HSA) are mapped using the site-identification by ligand competitive saturation (SILCS)-Biologics approach in conjunction with Hydrogen-Deuterium Exchange (HDX)-Mass Spectrometry (MS) experiments. Ligands studied include known HSA binders, Ibuprofen and Ketoprofen, and compounds Arginine, Alanine, Sucrose and Trehalose, excipients used in therapeutic formulations of protein-based drugs. In addition, the impact of excipient binding to HSA on its stability is investigated through temperature-ramp stability studies monitoring solution viscosity. For the studied ligands, interactions that correspond to known drug-binding sites (DS) are identified. These include previously identified Ibuprofen and Ketoprofen interaction sites as well as additional sites and, in the case of the excipients, the ligands are shown to also bind at previously unidentified lower affinity interaction sites, termed excipients sites (ES) with 20 or more sites identified for the studied compounds. HDX-MS titrations were used to determined dissociation constants for a subset of the interaction sites for Ibuprofen, Ketoprofen, Arginine, and Sucrose, which exhibited Kd values in the low micromolar to millimolar range in satisfactory agreement with SILCS-Biologics predicted affinities, validating the computational approach to identify both high and low affinity interaction sites. The stability studies indicate the excipients to offer protection at low excipient-protein ratios up to 66 with destabilization occurring at ratios above 132 with the exception of Sucrose at the t0 timepoint, indicating that the more favorable affinities of Sucrose seen in the SILCS-Biologics and HDX-MS analyses contribute to protein stabilization. These results indicate that ligands can bind to large numbers of interaction sites on proteins, with those interactions having implications for the development of formulations for therapeutic proteins.
The Chilean Constitutional Process Narrated Through a Spiral
Authors: Suárez Delucchi Adriana , Rivera Ugarte Victoria
Published: December 2024

Building on an intertwined spatiotemporal weaving of reckoning-repairing-reworlding, this article analyses the constitutional process experienced in Chile between 2019-2023. Inspired by the sociology of image as a methodological tool and following a narrative that takes the shape of a spiral, we examine a series of photographs representing different layers in this ongoing process. In October 2019, the largest demonstrations in Chile’s history sparked long-brewing demands for social and ecological transformation. The unsustainable pressure pushed political parties to call for a constitutional referendum where the population overwhelmingly voted to overturn the charter inherited from Augusto Pinochet’s regime, and so the process of drafting a new text began. Following the rejection of two drafts, the constitutional process is, for now, closed. Yet, we claim that embracing a failure narrative is not only futile, but misleading, and we propose to see these events in terms of their potential for conceptualising and enacting transformative futures. Drawing on decolonial, anti-colonial, and Indigenous scholarship, this essay focuses mainly on 2019’s uprising and the first constitutional process (2021-2022) examining demands for Indigenous transformation – and the possibilities this case offers resistance movements elsewhere and “elsewhen.”
A Radical Reworlding: Discourses of Abolition and Neoliberal Resilience in the Covid-19 Pandemic
Authors: Clarke Tayah
Published: December 2024

This paper explores the limitations of neoliberal concepts of resilience and the possibilities of abolition in the discourses surrounding the Covid-19 pandemic in Canada. I locate Canada’s state discussions at the outset of the pandemic in 2020 in the neoliberal model of resilience that is rooted in ideologies of individualism and carcerality, rather than the deconstruction of the interdependent systems that create them – despite the temporary questioning of the status quo in political discourse. To contrast the mobilization of neoliberal resilience, I introduce the Doctors for Defunding the Police collective and analyze how they mobilize a more radical praxis by approaching pandemic discourse through a framework of abolition and healing justice. Finally, I draw on Ndlovu-Gatsheni’s (2023) analysis of the components of reworlding from the Global South, locating the praxis of Doctors for Defunding the Police in this tradition due to its rejection of neoliberal individualism, its embrace of alternative subjectivities, and its turn towards a politics of collective care. Ultimately, I argue that while the 2020 resilience discourse afforded an approach to the pandemic that did not fully abandon the population, it remained fundamentally tied to neoliberalism and racial capitalism, whereas the abolitionist response offered a more transformative praxis of reworlding through its commitment to deconstructing harmful systems and reviving a decolonial praxis of collectivity. To conclude, I examine how the contemporary politics of Covid-19 continue to embrace colonial and carceral realities, necessitating a continued abolitionist praxis of reworlding.
“We Need to Live the World that is Possible”: Prefigurative Justice, Creative Collaboration, and the Activism of Rita Wong
Authors: Smyth Heather
Published: December 2024

Although many writers and scholars struggle to cross the threshold between literary expressive culture and activism, poet Rita Wong has fostered and bridged both collaborative artistic and direct-action social justice work. Wong’s collaborations with Dorothy Christian, Larissa Lai, Cindy Mochizuki, and Fred Wah illuminate the promise of creative practice in confronting racial capitalism and climate destruction. This essay draws from the social movement theory of prefigurative politics, routed through abolition feminism and Indigenous place-based epistemology, to account for ethical consistencies between Wong’s poetics, collaborative artistic practice, and direct-action interventions. Prefigurative politics conveys “the embodiment, within the ongoing political practice of a movement, of those forms of social relations, decision-making, culture, and human experience that are the ultimate goal” (Boggs, 1977, p. 100). Wong’s work focuses on “Reckoning” at the pivot point of climate destruction: she writes, “our common survival depends on our collective ability to address the environmental devastation that has accelerated in this century, a devastation that will not end unless we learn to live by values that manifest and respect Indigenous relationships to the land and waters” (Wong, 2012, p. 535). Her scholarship and collaborative poetic engagements have attended to “Repairing” with words, performance, bodily engagement, and crafting a paradigm shift in alliance with human and nonhuman others, thinking with and through water. And Wong “Reworlds” through experimental and imaginative building of new relations, telling new stories. In keeping with prefigurative social movement practice, she and her collaborators act as if that new world has already arrived.
Some Results in Fixed Point Theorem using Weakly Compatible Mappings in Neutrosophic Metric Spaces
Authors: Shakila VB  , Jeyaraman M
Published: December 2024

Neutrosophic metric space was introduced by Kirisci and Simsek in 2020. In this paper, the author introduced the concept of coupled fixed point, coupled coincidence point, common coupled fixed point. To define the above concept two mappings are used also, we prove some common fixed point using compatible and weakly compatible mappings in Neutrosophic metric space.
"The sort of design sophistication we were all in need of," Ernst Plischke’s design for Paul’s Book Arcade (1949), Hamilton
Authors: Grant Matt
Published: December 2024

In 1949 a remarkable interior design for a Hamilton bookshop by Ernst Plischke was, according to the client, "the sort of design sophistication we were all in need of." Paul's Book Arcade played a pivotal role in Hamilton social circles in the 1940s, with the owner David Blackwood Paul (aka Blackwood) and his wife Janet Wilkinson, forming their own "centre of human enlightenment." The Blackwood group of friends included painter Margot Phillips, who like Plischke, was a European refugee, painter, critic, and a writer for The Listener, Geoff Fairburn and his wife Jean (also an artist), as well as writer Alexander Gaskell Pickard.
Paul's Book Arcade was established in Hamilton in 1901 by Blackwood's father William Henry Paul. In 1933, Blackwood took over the management of the bookshop, reportedly as the result of a disagreement with his father, who by then was a powerful community leader. Paul's local services were a more pressing concern, and so Blackwood inherited what was a "modest emporium" with the atmosphere of a general store. Blackwood would later transform Paul's Book Arcade to such an extent that in 1949 the visiting English publisher Sir Stanley Unwin numbered the bookshop among the fourteen best in the world, and one of the two best in New Zealand. So successful was the bookshop that in 1955 a further two stores were opened, each in Auckland. The first was located on Shortland Street, and the second on High Street, also designed by Plischke.
The Blackwood social circle would have a lasting and far‐reaching influence on the mid‐century architecture of Hamilton. Connections with local artists and groups such as the Waikato Society of Arts, allowed a seamless flow of European‐inspired modernist ideals to inform Hamilton's new architecture, interior design, and cultural landscape. The first built manifestation of this movement was the 1949 interior design for Paul's Book Arcade by Austrian architect Ernst Plischke. This presentation will look at the relation between Blackwood and Plischke, the architect's design for the Book Arcade, and how the Blackwood's informed design sensibilities would influence Hamilton's modernist landscape for years afterwards.
E.163 1945 "Emergency Standard Specification for Dwellinghouse Construction" – a forgotten ancestor
Authors: Isaacs Nigel
Published: December 2024

The outbreak of World War II led to a focus on the most efficient use of materials within New Zealand. In 1944 the New Zealand Standards Council was requested to develop an "Emergency Standard Specification for Dwellinghouse Construction." Unlike NZSS 95 "New Zealand Standard Model Building By‐Law" which was limited to structural stability, public health and other council‐controlled issues, this new specification (NZSS E.163) could deal with materials and construction methods. Published in January 1945, only two copies appear extant – a partial copy in Wellington City Archives and a full copy in Auckland City Archives, although the Committee minutes are held in Archives New Zealand.
As well as dealing with house construction (foundations, concrete work, carpentry, etc.) it deals with internal finishing (solid‐ and fibrous‐plaster, terrazzo, painting and paperhanging, etc.) and services (plumbing, drainage and electrical). E.163 was promoted as being of real benefit to occupants (owners or tenants) as they could be assured as to "essential considerations relating to materials, workmanship, and design" – placing quality, not speed at the heart of the then Government's actions. The paper compares the requirements of E.163 with the relevant parts of NZSS95, as well as exploring its relationship to NZS 3604 "Code of Practice for Light Timber Frame Buildings Not Requiring Specific Design" and modern model specifications.
Appendix A: William John Dewitt Prouse (1877-1956): Biography
Authors: McCarthy Christine
Published: December 2024

This appendix provides background material on William Prouse of Prouse and Wilson up to the time the University Senate Building was designed. The factual record suggests Prouse's life was experientially rich and unusual. He was a talented musician married to an even more talented musician, who travelled the world. He held partnerships in a string of significant architectural firms in early‐twentieth‐century New Zealand, and shareholdings in building development companies and in what appears to be pioneering ventures in motor camps in the Wellington region. 1940 was not only significant as the year that saw the design of the University Senate building ‐ but it was also the year that his wife Ava died. Helliwell states that c1941, Prouse was "feeling the advance of age and did little at the office," suggesting that his involvement in architecture lessened from this time.
Making New Zealand: Celebration and Anti-Myth
Authors: Dudding Michael
Published: December 2024

The Making New Zealand publications were a New Zealand government‐produced series of magazines to celebrate the centenary of the 1840 signing of the Treaty of Waitangi. Each issue of the series (covering topics from infrastructure and defence, to fashion and sport) was to present an objective overview of the history of its subject – within the confines of a publication commemorating New Zealand's history. Joe Heenan, Undersecretary of Internal Affairs, was keen for the centenary celebrations and ephemera to "celebrate 100 years of colonisation," bringing "the bright side of our national progress" before the eyes of the world. While some authors were happy to articulate their topics in support of Heenan's vision, others became interested in producing what they believed to be a more realistic narrative grounded in the social realities of this country, including its negative aspects. Rather than making a case for the maintenance of cultural continuity, these writers sought a national identity arising from cultural adaptation to the specific conditions of New Zealand as a new world. This paper looks at a range of Making New Zealand issues to explore the narratives put forward as retrospective accounts of and normative directives for the design of New Zealand's interior and landscape environments.
"Ruffled by the number of windows": The 1948 Halberstam House by Henry Kulka
Authors: Jacobson Cherie
Published: December 2024

In March 1940 architect Henry Kulka arrived in New Zealand as a refugee of the Second World War. He had enjoyed a successful career in Vienna, including collaborations with his former teacher Adolf Loos. Kulkaʹs wife Hilda followed with the coupleʹs children a few weeks later and during her journey she met another refugee family, the Halberstams ‐ Hugo, Martha and their daughter Lucie. Eight years later Henry Kulka designed a house for a section the Halberstams had bought in Karori. In an oral history interview with Lucie, she recalled that once the house was completed, her parents invited people they had met while renting in Kelburn to visit their new home. The feedback received about the number of windows and the wood‐panelled living and dining room gave the distinct impression that their former neighbours felt they had built a house "above [their] social level.ʺ This paper looks at the reaction to the Halberstam House and similar houses built by émigré architects when they were completed. It concludes with the perspective of a current inhabitant ‐ how well does it suit contemporary living?.
Outside the Crazy House, New Zealand Centennial Exhibition, Wellington
Authors: Wood Peter
Published: December 2024

Writing on public buildings for the war time publication series Making New Zealand, Paul Pascoe described the Centennial Exhibition at Rongotai, Wellington, as displaying the degree of modernity that was then generally accepted and approved of by New Zealanders. An accompanying photograph (in all probability selected for inclusion by Pascoe's brother, John) shows Edmund Anscombe's Moderne tower building, and it is noted in the caption that the exhibition drew favourable comment from overseas visitors. At a moment in New Zealandʹs history when the heat of World War was once more accelerating, Anscombeʹs restrained stream‐lined modernism was met with approval. But not excitement. That reaction was reserved for Playland, the collection of amusement park attractions operating on the periphery of the exhibition grounds, and which, for many, offered the most compelling argument for attending. Of the varied offerings in Playland, the most popular attraction was The Crazy House where visitors were promised to encounter ‐ without warning! – innumerable diversions and never‐ending sources of mirth‐making. The Crazy House, like all elements of the Centennial Exhibition, was temporary, but unlike the latter, very little documentary of it remains. The few photographs of it present a modest façade with little hint of mirth, and of the interior of we have no descriptions at all. With reference to historic developments in entertainment attractions, this paper assembles what little information we have of The Crazy House to make a case for its significance as a defining development in New Zealand architecture. Just as the academic assurances of the Exhibition buildings would become a swansong to architectural stylism, The Crazy House would signal the appearance of demands on architecture that it now compete in an emergent field of international architecture called "popular entertainment.ʺ