bluuebunny/crossref_metadata_2025 huggingface dataset:
ВОЗМОЖНОСТИ СВЕРХШИРОКОПОЛОСНЫХ СИСТЕМ НАБЛЮДЕНИЯ НА ПРИМЕРЕ ИССЛЕДОВАНИЯ ПРИРОДНОГО СОНАРА ЗУБАТЫХ КИТОВ, "Фундаментальная и прикладная гидрофизика"
Authors: Иванов М.П. , Родионов А.А. , Стефанов В.Е.
Published: February 2021

Сверхширокополосные системы наблюдения еще не созданы. Однако теоретические преимущества гидроакустических систем адаптироваться к изменяющимся гидрофизическим условиям хорошо заметны при исследовании сонара морских млекопитающих. Для исследования подвижного широкополосного сонара необходимы точные биофизические эксперименты. Это делает возможным изучение подвижного широкополосного сонара, используя соответствующее техническое оснащение и методики, ограничивающие подвижность животного вовремя эхолокации. В работе приводится ряд методических решений проведения эксперимента на дельфинах, с помощью которых можно исследовать защищённость от помех и скрытность природного сонара, и впоследствии провести сравнительные испытания с техническими аналогами. На основе представленных методик будут получены сравнительные оценки сигналов эхолокации, принадлежащих различным видам морских млекопитающих. Будет сформирована база данных биологических сигналов поиска, сопровождения и распознавания подводных объектов в сложных условиях естественных и искусственных акустических помех.
ФАКТОРЫ РИСКА ЛЕТАЛЬНОГО ИСХОДА БОЛЬНЫХ ТУБЕРКУЛЕЗОМ С МНОЖЕСТВЕННОЙ ЛЕКАРСТВЕННОЙ УСТОЙЧИВОСТЬЮ ВОЗБУДИТЕЛЯ, "Вестник Центрального научно-исследовательского института туберкулеза"
Authors: Саенко С.С. , Стерликов С.А. , Русакова Л.И.
Published: February 2021

Цель исследования: на репрезентативной выборке изучить предикторы летального исхода у пациентов с туберкулезом (ТБ), получающих лечение по IV, V режимам противотуберкулезной химиотерапии (ПХТ). Материалы и методы. Мультицентровое ретроспективное когортное исследование 1909 случаев лечения больных ТБ с подтвержденной устойчивостью как минимум к рифампицину по IV, V режимам ПХТ, зарегистрированных в 2016 г., учитывали препараты: рифампицин, изониазид, аминогликозид или полипептид, фторхинолоны, прерывание лечения в анамнезе, пол, возраст, место проживания, ВИЧ-статус, результат бактериоскопии и наличие деструкции легочной ткани на момент регистрации курса ПХТ. Проводили однофакторный, а затем многофакторный анализ с расчетом скорректированного отношения шансов (aOR). Результаты. Наиболее значимыми предикторами летального исхода были: наличие ВИЧ-инфекции (aOR = 5,6), прерывание лечения в анамнезе (aOR = 3,9), положительный результат бактериоскопии мокроты при регистрации (aOR = 2,0), ЛУ МБТ (aOR = 1,3 при повышении градации ЛУ в ряду: устойчивость только к рифампицину; устойчивость только к изониазиду и рифампицину; устойчивость к изониазиду, рифампицину, аминогликозидам/полипептиду; устойчивость к изониазиду, рифампицину, фторхинолонам; широкая ЛУ – ШЛУ). Также определенную роль играло проживание в сельской местности (aOR = 1,6), наличие деструктивных изменений в легочной ткани (aOR = 1,6), мужской пол (aOR = 1,3), возраст (aOR = 1,03 на год жизни). Заключение. Результаты исследования могут быть использованы для отбора лиц в группы риска для проведения мероприятий по предотвращению у них летального исхода.
ФОРМЫ-ФАЗЫ ПАТОЛОГИЧЕСКИХ ИЗМЕНЕНИЙ В ЛЕГКИХ ПРИ НОВОЙ КОРОНАВИРУСНОЙ ИНФЕКЦИИ, ВЫЗВАННОЙ SARS-CoV-2, "Вестник Центрального научно-исследовательского института туберкулеза"
Authors: Коган Е.А. , Демура С.А. , Березовский Ю.С. , Эргешов А.Э. , Голухова Е. З. , Рыбка М.М. , Шигеев С.В.
Published: February 2021

Материалом для исследования послужили легкие от 232 аутопсий пациентов, страдавших инфекцией COVID-19, подтвержденной ПЦР при жизни и/или при исследовании парафиновых блоков ткани легкого. При помощи макрои микроскопического и иммуногистохимического исследований (CD3, CD20, TLR4, TLR9, Ki67, p63, OCT4, ALDH1) продемонстрированы особенности патологических процессов в легких. Полученные данные позволяют выдвинуть предположение, что такие патологические процессы в легких как диффузное альвеолярное повреждение (ДАП), лимфоцитарный альвеолит, сопровождающийся васкулитами веточек легочной артерии мелкого и среднего калибра, вирусно-бактериальная пневмония, распространенная коагулопатия с тромбозами и тромбоэмболией легочной артерии, интерстициальный фиброз и дисрегенераторные изменения легочного эпителия взаимосвязаны и могут быть формами-фазами патологии легких при COVID-19. Процесс в легких может развиваться по трем морфогенетическим путям, начиная с развития диффузного альвеолярного повреждения или лимфоцитарного альвеолита или коагулопатии. Последний вариант начала инфекции вероятнее всего связан с первичным поражением кишечника. При этом легкие вовлекаются вторично, после развития виремии, ДВС-синдрома и цитокинового шторма. Плоскоклеточная метаплазия с формированием сфероидных структур в легких носит дисрегенераторный характер, и в дальнейшем эпителий таких очагов может подвергаться злокачественной трансформации.
КЛИНИЧЕСКИЕ И МИКРОБИОЛОГИЧЕСКИЕ АСПЕКТЫ ДИАГНОСТИКИ НЕТУБЕРКУЛЕЗНЫХ МИКОБАКТЕРИОЗОВ ПРИ ПОЛОСТНЫХ ОБРАЗОВАНИЯХ В ЛЕГКИХ, "Вестник Центрального научно-исследовательского института туберкулеза"
Authors: Карпина Н.Л. , Асанов Р.Б. , Шишкина Е.Р. , Ларионова Е.Е. , Шабалина И.Ю. , Эргешов А.Э.
Published: February 2021

Во всех развитых странах отмечается значительный рост заболеваемости микобактериозами, проблема диагностики микобактериоза стоит достаточно остро. Проведенный анализ результатов обследования 122 пациентов с полостными образованиями в легких показал, что в 82,8% случаев выявляется микобактериальная инфекция. Соотношение туберкулеза (ТБ) и микобактериоза составило 41,8% и 41,2% соответственно. Опровергнуто мнение, что при наличии полости в легком наиболее часто диагностируется ТБ. Показано, что основным этиологическим фактором микобактериоза при полостных образованиях в легких в 92% (46/50 чел.) являются медленнорастущие нетуберкулезные микобактерии (НТМБ) с преобладанием M. avium complex. Для исключения диагностических ошибок при дифференциальной диагностике ТБ и микобактериоза легких несомненно требуется внедрение методологического подхода, обеспечивающего микробиологическую и молекулярно-генетическую верификацию микобактерий до вида. Отсутствие иммунокомпроментированных лиц среди пациентов с верифицированным микобактериозом легких демонстрирует, что микобактериоз может развиваться и у лиц без нарушения иммунитета.
Can Plant Lectins be Alternatives to Treat Anxiety and Depressive Disorders?
Authors: Lima Bárbara Raíssa Ferreira de , Patriota Leydianne Leite de Siqueira , Albuquerque Lidiane Pereira de , Ramos Dalila de Brito Marques , Paiva Patrícia Maria Guedes , Pontual Emmanuel Viana , Rosa Michelle Melgarejo da , Napoleão Thiago Henrique
Published: February 2021

Depression and anxiety disorder are the most common mental disorders worldwide and their treatments are combinations of pharmacological and psychotherapeutic approaches. Depression treatment depends largely on a pharmacotherapy that improves the transmission of monoamines in the brain. However, the drugs available have adverse reactions and do not contemplate positively all patients, which stimulates scientific research that seeks new molecules, including from natural sources. Lectins are proteins capable of binding reversibly and non-covalently to specific sugars. For example, it has been reported the antimicrobial, antitumor, antiparasitic, anti-inflammatory and antinociceptive activities of lectins. The ability of some lectins in modulating nociception and inflammation stimulated studies on the possible effects on processes that share some pathways and molecular agents, like depression and anxiety. Lectins isolated from plants showed antidepressant effects, which were demonstrated to be linked to activation of serotonergic, adrenergic, and dopaminergic systems as well as to inhibition of the glutamatergic system and L-arginine–NO–cGMP pathway. In view of their immunomodulatory properties, it is also suggested that lectins can ameliorate the inflammatory framework associated with depression. Anxiolytic effects were also reported and associated with modulation of GABAergic mechanisms, serotonergic system, and NO pathway. It should be taken in account that some lectins induced depressive-like behavior, associated with an neuroinflammatory action, as well anxiogenic action. Thus, it is important to use combinations of batteries for testing anxiety, depression, despair, and anhedonia behaviors in the studies with lectins. The mechanisms by which lectins exactly modulate depression or anxiety frameworks are still unclear but important windows had already been open by researchers and preclinical studies with lectins have indicated these proteins as candidates for alternative or complementary agents in therapies of depression and anxiety disorder.
Generalized Weighted Rama Distribution: Properties and Application to Model Lifetime Data
Authors: Enogwe Samuel U. , John Chisimkwuo , Obiora-Ilouno Happiness O. , Onyekwere Chrisogonus K.
Published: February 2021

In this paper, we propose a new lifetime distribution called the generalized weighted Rama (GWR) distribution, which extends the two-parameter Rama distribution and has the Rama distribution as a special case. The GWR distribution has the ability to model data sets that have positive skewness and upside-down bathtub shape hazard rate. Expressions for mathematical and reliability properties of the GWR distribution have been derived. Estimation of parameters was achieved using the method of maximum likelihood estimation and a simulation was performed to verify the stability of the maximum likelihood estimates of the model parameters. The asymptotic confidence intervals of the parameters of the proposed distribution are obtained. The applicability of the GWR distribution was illustrated with a real data set and the results obtained show that the GWR distribution is a better candidate for the data than the other competing distributions being investigated.
THE IMPROVEMENT OF GENERATION Z FINANCIAL WELL-BEING IN PEKANBARU
Authors: Renaldo Nicholas , Sudarno Sudarno , Marice Hutahuruk Br.
Published: February 2021

The current economic condition of generation Z was pretty unexpected. It might trigger problems personally or even their families. This study aimed to reveal the factors influencing the financial well-being and altering perso­nality problems of generation Z. There were more than 800,000 peoples in po­pulation and the number of the sample was 239 peoples using a combination of pur­posive and convenience sampling methods. The data was then analyzed using multiple linear regression. The researchers used primary data by distri­buting questionnaires based on a Likert Scale. All classic assumptions met the criteria and testing produced financial self-efficacy, financial attitude, financial knowledge, financial behavior, and had a significant positive effect on finan­cial well-being. However, locus of control had no significant effect on financial well-being. Generation Z must increase their independence and con­fidence to achieve what they want. It would be good to have financial atitude and in­vestment behavior along with financial knowledge. They must also believe that only theirself can provide personal well-being. Generation Z needed character education, more mature, and independent thinking models to deal with eco­no­mic problems
Polyelectrolyte Complex Tubular Membranes via a Salt Dilution Induced Phase Inversion Process
Authors: Emonds Stephan , Kamp Johannes , Borowec Julian , Roth Hannah , Wessling Matthias
Published: February 2021

Tubular membrane geometries are key elements of many industrial filtration applications and artificial organs. Established processes to fabricate polymeric membranes require the use of organic solvents, which are prone to be phased out due to stricter regulations. In the quest of developing solvent‐free alternative fabrication processes, polyelectrolyte complex (PEC) membranes are recently discovered, offering a promising alternative. While flat sheet PEC membranes are successfully fabricated, tubular or hollow fiber geometries remain a material engineering challenge. For the first time, the organic solvent‐free fabrication of PEC tubular membranes in a dry‐jet wet spinning process is demonstrated. The aqueous polymer solution comprising the polyanion—poly(sodium‐4‐styrenesulfonate) (PSS), the polycation—poly(diallyldimethylammonium‐chloride) (PDADMAC), and KBr is extruded with the water‐based bore fluid through a single‐orifice spinneret, passing an air‐gap before immersed into an aqueous coagulation bath. The phase inversion kinetics are influenced to form a defect‐free lumen separation layer through the addition of glycerol to the bore fluid. The resulting tubular membranes show reproducible nanofiltration membrane properties. They have a molecular cut‐off of 320 Da, are positively charged and retain salts with a characteristic salt retention hierarchy. This promising material engineering strategy motivates to continue the quest for smaller tubular dimensions toward hollow fibers.
De Novo Construction of Substituted Terephthalates via Phosphine Catalyzed Domino Benzannulation Reactions
Authors: Wang Dan , Lin Junhui , Zhu Yannan , Huang You
Published: February 2021

The robustness of phosphine catalysis enabling the domino benzannulation reactions of allenoates with enamines is described. A broad array of substituted terephthalates were delivered under simple and practical reaction conditions. Furthermore, the reaction could be carried out on a gram scale with higher yield, and various conversions of the terephthalate products demonstrate the versatility of this transformation.

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Die Sandarazole sind kryptische und strukturell einzigartige, Plasmid‐codierte Toxine aus einem seltenen Myxobakterium**
Authors: Panter Fabian , Bader Chantal D. , Müller Rolf
Published: February 2021

Wir beschreiben ein neues, 209,7 kbp umfassendes Plasmid aus Sandaracinus sp. MSr10575 (pSa001), das ein kryptisches Sekundärmetabolit‐Biosynthese‐Gencluster (BGC) trägt. Die Aktivierung dieses BGC durch Austausch der nativen Promotorsequenz mittels homologer Rekombination gegen ein Vanillat‐induzierbares System führte zu Produktion, Isolierung und Strukturaufklärung einer neuartigen Sekundärmetabolitenfamilie – der Sandarazole A–G. Sie besitzen faszinierende Strukturmerkmale und reaktive funktionelle Gruppen, wie etwa ein α‐chloriertes Keton, ein Epoxyketon und einen (2R)‐2‐Amino‐3‐(N,N‐dimethylamino)propionsäure‐Baustein. Die Untersuchung ihrer Biosynthese erlaubte den Vorschlag eines schlüssigen Biosynthesemodells, das mehrere ungewöhnliche Schritte umfasst. Das chlorierte Sandarazol C zeigte einen IC50‐Wert von 0,5 μm gegen HCT‐116‐Zellen und eine MHK von 14 μm gegen Mycobacterium smegmatis, was auf eine Funktion der Sandarazole als defensive Sekundärmetabolite oder Toxine hinweist.
Mass Spectrometry Imaging of Bio‐oligomer Polydispersity in Plant Tissues by Laser Desorption Ionization from Silicon Nanopost Arrays
Authors: Samarah Laith Z. , Tran Tina H. , Stacey Gary , Vertes Akos
Published: February 2021

Mass spectrometry imaging (MSI) enables simultaneous spatial mapping for diverse molecules in biological tissues. Matrix‐assisted laser desorption ionization (MALDI) mass spectrometry (MS) has been a mainstream MSI method for a wide range of biomolecules. However, MALDI‐MSI of biological homopolymers used for energy storage and molecular feedstock is limited by, e.g., preferential ionization for certain molecular classes. Matrix‐free nanophotonic ionization from silicon nanopost arrays (NAPAs) is an emerging laser desorption ionization (LDI) platform with ultra‐trace sensitivity and molecular imaging capabilities. Here, we show complementary analysis and MSI of polyhydroxybutyric acid (PHB), polyglutamic acid (PGA), and polysaccharide oligomers in soybean root nodule sections by NAPA‐LDI and MALDI. For PHB, number and weight average molar mass, polydispersity, and oligomer size distributions across the tissue section and in regions of interest were characterized by NAPA‐LDI‐MSI.
Polyhedral Oligosilsesquioxanes in Functional Chiral Nanoassemblies
Authors: An Shuguo , Hao Aiyou , Xing Pengyao
Published: February 2021

Incorporation of giant molecular nanoparticles with atomic precision into chiral nanoassemblies facilitates the fabrication of functional ordered phases with supramolecular chirality, which remains mysterious. Reported here is the first example of polyhedral oligosilsesquioxane (POSS) derivatives that self‐assemble into well‐defined chiral nanoassemblies. POSSs were covalently conjugated to N‐terminal aromatic amino acids, which self‐assembled into nanohelices and twists with explicit handedness tuned by solvent polarity. Chiral nanoassemblies showed active chiroptical responses including Cotton effects and circularly polarized luminescence. The chiral systems can bind guest molecules by charge‐transfer interactions, whereby self‐assembled structures, chiroptical activities, and luminescent colors were further modulated. The unique coassembly systems were applied for instant information encryption and storage with multiple luminescent displays. This work offers a new protocol for the design of functional chiral materials of POSS by molecular self‐assembly.
Nanospace Engineering of Metal–Organic Frameworks through Dynamic Spacer Installation of Multifunctionalities for Efficient Separation of Ethane from Ethane/Ethylene Mixtures
Authors: Chen Cheng‐Xia , Wei Zhang‐Wen , Pham Tony , Lan Pui Ching , Zhang Lei , Forrest Katherine A. , Chen Sha , Al‐Enizi Abdullah M. , Nafady Ayman , Su Cheng‐Yong , Ma Shengqian
Published: February 2021

Herein, a dynamic spacer installation (DSI) strategy has been implemented to construct a series of multifunctional metal—organic frameworks (MOFs), LIFM‐61/31/62/63, with optimized pore space and pore environment for ethane/ethylene separation. In this respect, a series of linear dicarboxylic acids were deliberately installed in the prototype MOF, LIFM‐28, leading to a dramatically increased pore volume (from 0.41 to 0.82 cm3 g−1) and reduced pore size (from 11.1×11.1 Å2 to 5.6×5.6 Å2). The increased pore volume endows the multifunctional MOFs with much higher ethane adsorption capacity, especially for LIFM‐63 (4.8 mmol g−1), representing nearly three times as much ethane as the prototypical counterpart (1.7 mmol g−1) at 273 K and 1 bar. Meanwhile, the reduced pore size imparts enhanced ethane/ethylene selectivity of the multifunctional MOFs. Theoretical calculations and dynamic breakthrough experiments confirm that the DSI is a promising approach for the rational design of multifunctional MOFs for this challenging task.
Chromoselective Photocatalysis Enables Stereocomplementary Biocatalytic Pathways**
Authors: Schmermund Luca , Reischauer Susanne , Bierbaumer Sarah , Winkler Christoph K. , Diaz‐Rodriguez Alba , Edwards Lee J. , Kara Selin , Mielke Tamara , Cartwright Jared , Grogan Gideon , Pieber Bartholomäus , Kroutil Wolfgang
Published: February 2021

Controlling the selectivity of a chemical reaction with external stimuli is common in thermal processes, but rare in visible‐light photocatalysis. Here we show that the redox potential of a carbon nitride photocatalyst (CN‐OA‐m) can be tuned by changing the irradiation wavelength to generate electron holes with different oxidation potentials. This tuning was the key to realizing photo‐chemo‐enzymatic cascades that give either the (S)‐ or the (R)‐enantiomer of phenylethanol. In combination with an unspecific peroxygenase from Agrocybe aegerita, green light irradiation of CN‐OA‐m led to the enantioselective hydroxylation of ethylbenzene to (R)‐1‐phenylethanol (99 % ee). In contrast, blue light irradiation triggered the photocatalytic oxidation of ethylbenzene to acetophenone, which in turn was enantioselectively reduced with an alcohol dehydrogenase from Rhodococcus ruber to form (S)‐1‐phenylethanol (93 % ee).
A Reconstructed Common Ancestor of the Fatty Acid Photo‐decarboxylase Clade Shows Photo‐decarboxylation Activity and Increased Thermostability
Authors: Sun Yue , Calderini Elia , Kourist Robert
Published: February 2021

Light‐dependent enzymes are a rare type of biocatalyst with high potential for research and biotechnology. A recently discovered fatty acid photo‐decarboxylase fromChlorella variabilisNC64A (CvFAP) converts fatty acids to the corresponding hydrocarbons only when irradiated with blue light (400 to 520 nm). To expand the available catalytic diversity for fatty acid decarboxylation, we reconstructed possible ancestral decarboxylases from a set of 12 extant sequences that were classified under the fatty acid decarboxylases clade within the glucose‐methanol choline (GMC) oxidoreductase family. One of the resurrected enzymes (ANC1) showed activity in the decarboxylation of fatty acids, showing that the clade indeed contains several photo‐decarboxylases. ANC1 has a 15 °C higher melting temperature (Tm) than the extant CvFAP. Its production yielded 12‐fold more protein than this wild type decarboxylase, which offers practical advantages for the biochemical investigation of this photoenzyme. Homology modelling revealed amino acid substitutions to more hydrophilic residues at the surface and shorter flexible loops compared to the wild type. Using ancestral sequence reconstruction, we have expanded the existing pool of confirmed fatty acid photo‐decarboxylases, providing access to a more robust catalyst for further development via directed evolution.
Probes for Photoaffinity Labelling of Kinases
Authors: Korovesis Dimitris , Beard Hester A. , Mérillat Christel , Verhelst Steven H. L.
Published: February 2021

Protein kinases, one of the largest enzyme superfamilies, regulate many physiological and pathological processes. They are drug targets for multiple human diseases, including various cancer types. Probes for the photoaffinity labelling of kinases are important research tools for the study of members of this enzyme superfamily. In this review, we discuss the design principles of these probes, which are mainly derived from inhibitors targeting the ATP pocket. Overall, insights from crystal structures guide the placement of photoreactive groups and detection tags. This has resulted in a wide variety of probes, of which we provide a comprehensive overview. We also discuss several areas of application of these probes, including the identification of targets and off‐targets of kinase inhibitors, mapping of their binding sites, the development of inhibitor screening assays, the imaging of kinases, and identification of protein binding partners.
Synthesis of Glycodendrimers with Antiviral and Antibacterial Activity
Authors: Hoyos Pilar , Perona Almudena , Juanes Olga , Rumbero Ángel , Hernáiz María J.
Published: February 2021

Glycodendrimers are an important class of synthetic macromolecules that can be used to mimic many structural and functional features of cell‐surface glycoconjugates. Their carbohydrate moieties perform key important functions in bacterial and viral infections, often regulated by carbohydrate–protein interactions. Several studies have shown that the molecular structure, valency and spatial organisation of carbohydrate epitopes in glycoconjugates are key factors in the specificity and avidity of carbohydrate–protein interactions. Choosing the right glycodendrimers almost always helps to interfere with such interactions and blocks bacterial or viral adhesion and entry into host cells as an effective strategy to inhibit bacterial or viral infections. Herein, the state of the art in the design and synthesis of glycodendrimers employed for the development of anti‐adhesion therapy against bacterial and viral infections is described.
The Long and Bright Path of a Lanthanide MOF: From Basics towards the Application
Authors: Otal Eugenio Hernán , Tanaka Hideki , Kim Manuela Leticia , Hinestroza Juan Paulo , Kimura Mutsumi
Published: February 2021

The development of portable, reliable, and low‐cost sensors for assessing the quality of natural water sources is of high relevance in developing countries as they can serve as an intermediate solution prior to the building of permanent potable water distribution infrastructure. These sensors should be simple to operate by non‐trained operators and easy to manufacture locally. Lanthanide‐based metal–organic frameworks (MOFs) offer a trustable platform due to their intense emission in regions of the visible spectra and their high sensitivity to fluorides in water. Cotton was chosen as a substrate due to its high hydrophilicity which, together with the highly porous nature of the MOF, allows for shorter reaction times. The modified cotton was characterized by XRD, SEM as well as XAFS, hence probing the presence of [Tb(BTC)6(H2O)] (Tb‐BTC) attachment to cotton. Changes in the emission when Tb‐BTC modified cotton was exposed to water and aqueous fluoride solutions were monitored as a function of time. Crystalline phase changes were identified that correlated to structural information. Finally, the Tb‐BTC modified cotton was used to build a fluoride demonstrator sensor with a linear response of up to 10 mg L−1 and a limit of detection of 0.8 mg L−1, making it suitable for drinking water analysis under international regulations.
Triggering Electron Transfer in Co(I) Dimers: Computational Evidences for a Reversible Disproportionation Mechanism
Authors: Guillaumont Maya , Fourré Isabelle , Pilmé Julien , Halbert Stéphanie , Gérard Hélène
Published: February 2021

An inner‐sphere disproportionation mechanism of the Co(I) precursor CoCl(PPh3)3 is described through a Density Functional Theory study. The essential role of oleylamine in this process is unravelled. A detailed analysis of the electronic structure of Cobalt dimers of the general formula Co2Cl2Ln (L=NH3 and PH3) demonstrates that electron transfer is triggered by asymetric coordination of amine and phosphine to stabilize a mixed‐valence Co(II)−Co(0) dimer. This is consistent with the HSAB statement that both amine and phosphine ligands are required to stabilize the reaction products, respectively Co(II) and Co(0) centers. We propose a quasi‐athermic multi‐step disproportionation mechanism with low activation barriers where the electron transfer goes through simple ligand exchanges between Co.
A Density Functional Theory Study of Optical Rotation in Some Aziridine and Oxirane Derivatives
Authors: Galeano Carrano Ramiro S. , Provasi Patricio F. , Ferraro Marta B. , Alkorta Ibon , Elguero José , Sauer Stephan P. A.
Published: February 2021

We present time‐dependent density functional theory (TDDFT) calculations of the electronic optical rotation (ORP) for seven oxirane and two aziridine derivatives in the gas phase and in solution and compare the results with the available experimental values. For seven of the studied molecules it is the first time that their optical rotation was studied theoretically and we have therefore investigated the influence of several settings in the TDDFT calculations on the results. This includes the choice of the one‐electron basis set, the exchange‐correlation functional or the particular polarizable continuum model (PCM). We can confirm that polarized quadruple zeta basis sets augmented with diffuse functions are necessary for converged results and find that the aug‐pc‐3 basis set is a viable alternative to the frequently employed aug‐cc‐pVQZ basis set. Based on our study, we cannot recommend the generalized gradient functional KT3 for calculations of the ORP in these compounds, whereas the hybrid functional PBE0 gives results quite similar to the long‐range correct CAM−B3LYP functional. Finally, we observe large differences in the solvent effects predicted by the integral equation formalism of PCM and the SMD variant of PCM. For the majority of solute/solvent combinations in this study, we find that the SMD model in combination with the PBE0 functional and the aug‐pc‐3 basis set gives the best agreement with the experimental values.
The Influence of Water Vapor on the Electrochemical Shift of an Ionic Liquid Measured by Ambient Pressure X‐ray Photoelectron Spectroscopy
Authors: Jia Meng , Broderick Alicia , Newberg John T.
Published: February 2021

Ionic liquids (ILs) are considered to be one of the steppingstones to fabricate next generation electrochemical devices given their unique physical and chemical properties. The addition of water to ILs significantly impact electrochemical related properties including viscosity, density, conductivity, and electrochemical window. Herein we utilize ambient pressure X‐ray photoelectron spectroscopy (APXPS) to examine the impact of water on values of the electrochemical shift (S), which is determined by measuring changes in binding energy shifts as a function of an external bias. APXPS spectra of C 1s, O 1s and N 1s regions are examined for the IL 1‐butyl‐3‐methylimidazolium acetate, [C4mim][OAc], at the IL/gas interface as a function of both water vapor pressure and external bias. Results reveal that in the absence of water vapor there is an IL ohmic drop between the working electrode and quasi reference electrode, giving rise to chemical specific S values of less than one. Upon introducing water vapor, S values approach one as a function of increasing water vapor pressure, indicating a decrease in the IL ohmic drop as the IL/water mixture becomes more conductive and the potential drop is driven by the electric double layer at the electrode/IL interface.
Real‐World Evidence for Assessing Pharmaceutical Treatments in the Context of COVID‐19
Authors: Franklin Jessica M. , Lin Kueiyu Joshua , Gatto Nicolle M. , Rassen Jeremy A. , Glynn Robert J. , Schneeweiss Sebastian
Published: February 2021

The emergence and global spread of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has resulted in an urgent need for evidence on medical interventions and outcomes of the resulting disease, coronavirus disease 2019 (COVID‐19). Although many randomized controlled trials (RCTs) evaluating treatments and vaccines for COVID‐19 are already in progress, the number of clinical questions of interest greatly outpaces the available resources to conduct RCTs. Therefore, there is growing interest in whether nonrandomized real‐world evidence (RWE) can be used to supplement RCT evidence and aid in clinical decision making, but concerns about nonrandomized RWE have been highlighted by a proliferation of RWE studies on medications and COVID‐19 outcomes with widely varying conclusions. The objective of this paper is to review some clinical questions of interest, potential data types, challenges, and merits of RWE in COVID‐19, resulting in recommendations for nonrandomized RWE designs and analyses based on established RWE principles.
A validated method for the quantification of IOX‐2, a potent prolyl hydroxylase inhibitor in equine urine and plasma using liquid chromatography–high‐resolution mass spectrometry
Authors: Mikhail Ezra , Siccardi Erik , Bawazir Ali , Rajesh Ambika , Prathyush Seetharani , Al Wazani Duaa Mohammad Kamal , Sabeek Muhammed , John Thomas
Published: February 2021

IOX‐2 is a potent inhibitor of enzyme prolyl hydroxylases‐2 (PHD) that plays a critical role in regulating hypoxia inducible factor (HIF) abundance and oxygen homeostasis. Federation for Equestrian Sports has listed HIF activators as prohibited substances to prevent their usage in doping. Consequently, it became essential to develop adequate knowledge and testing methods to detect it in equine sports drug testing samples. The validated method utilizes ultra‐high‐performance liquid chromatography coupled to high‐resolution mass spectrometry in order to detect extremely low concentration of the analyte present in both matrices. Confirmation for the presence of the analyte was achieved by comparing ion ratios, retention time, and accurate mass. Method linear range for plasma was between 0.25 to 100 ng/ml, and limit of detection (LOD) was 0.075 ng/ml. The linear range for urine was 0.125 to 100 ng/ml, and LOD was 0.025 ng/ml. Intraday precision at 0.5, 10, and 50 ng/ml was between 4.0% and 9.7% for plasma and 4.2% and 10.4% for urine. Accuracy at 0.5, 10, and 50 ng/ml was between 91% and 94% for plasma and 99% and 103% for urine. Elimination profile of IOX‐2 in equine plasma and urine was carried out using the developed method in which two horses were intravenously administered IOX‐2 and samples were collected. Metabolic profile in plasma and urine was investigated. IOX‐2 was detected for a minimum of 54 and 151 h of post administration in plasma and urine, respectively, thereby providing a valuable tool for evaluating its misuse in equine racing.
Highly Efficient DMSO‐Promoted α‐Hydrolysis of α‐Halohydroxamates under Mild Conditions
Authors: Yoon Lee Chang , Kim Sung‐Gon
Published: February 2021

A novel and efficient method for the nucleophilic α‐hydrolysis of α‐halohydroxamates with water under metal‐free conditions is described. In this reaction, the simple and readily available dimethyl sulfoxide (DMSO) was used as a catalyst, while water served as the nucleophile and oxygen source. This method was successfully employed in the synthesis of secondary α‐hydroxy‐α‐alkyl and α‐hydroxy‐α‐arylhydroxamates as well as tertiary α‐hydroxy‐α‐dialkylhydroxamates. Furthermore, the α‐hydrolysis of α‐halo‐α‐dialkylhydroxamates was achieved in the absence of the DMSO catalyst. This is a novel, mild, less toxic, and facile strategy for α‐hydroxylation of amides.
Is opioid therapy for chronic non‐cancer pain associated with a greater risk of all‐cause mortality compared to non‐opioid analgesics? A systematic review of propensity score matched observational studies
Authors: Tölle Thomas , Fitzcharles Mary‐Ann , Häuser Winfried
Published: February 2021

Background

The many risks associated with opioid therapy for chronic non‐cancer pain (CNCP) have led to questions about use. This is particularly relevant for risk of increased mortality. However, underlying medical conditions of those using opioids may influence mortality findings due to confounding by indication. Similarly, non‐opioid analgesics are also associated with an increased risk of mortality, too.

Methods

We have conducted a systematic review of propensity score matched observational studies comparing mortality associated with opioid use compared to non‐opioid analgesics. Clinicaltrials.gov, Google Scholar, MEDLINE and Scopus were searched from inception to July 2020. Propensity score matched observational studies comparing opioids to non‐opioid analgesics in real‐world settings were analysed. Primary outcome was pooled adjusted hazard ratio (aHR) of all‐cause death. Effects were summarized by a random effects model.

Results

Four studies with seven study arms and 120,186 patients were analysed. Pooled aHR for all‐cause death was 1.69 (95% confidence interval [CI] 1.47, 1.95). When mortality risk was confined to out‐of‐hospital deaths, the pooled aHR was 2.12 (95% CI 1.46, 3.09). The most frequent cause of death was cardiovascular death. Before matching, patients with opioids were older and had more somatic diseases than patients with non‐opioids. Despite extensive propensity score matchings and sensitivity analyses, all studies could not fully exclude confounding by indication.

Conclusions

Possibly, opioids are associated with an increased all‐cause mortality risk compared to non‐opioid analgesics. When considering treatment options for patients with CNCP, the possible risk of increased all‐cause mortality with opioids should be discussed.

Significance

An increased all‐cause mortality associated with opioid use compared to non‐opioid analgesics for CNCP was identified by a systematic review of four propensity score matched cohort studies in real‐world settings. The number needed to harm for an additional excess death per 10,000 person‐years was 116. Despite extensive propensity score matchings and sensitivity analyses, all studies could not fully exclude confounding by indication. The potential risk of increased all‐cause mortality with opioids should be discussed with patients when considering opioid treatment.
Effects of multifocal transcranial direct current stimulation targeting the motor network during prolonged experimental pain
Authors: Gregoret Luisina , Zamorano Anna M. , Graven‐Nielsen Thomas
Published: February 2021

Abstract

Background

Antinociceptive effects of transcranial direct current stimulation (tDCS) over the primary motor cortex (M1) have been extensively studied in the past years. However, M1 does not work in isolation, but it rather interacts within a network, the so‐called resting‐state motor network.

Objective

To explore the anti‐nociceptive effects of a new multifocal tDCS approach administered to regions linked to the resting state motor network (network‐tDCS) compared to sham tDCS.

Methods

Healthy individuals were included in this randomized, parallel and double‐blinded study comprising two consecutive interventions with 24‐hr interval of either active (n = 19) or sham (n = 19) network‐tDCS. Prolonged pain was induced by application of topical capsaicin on the dorsum of the hand during a 24‐hr period. Assessments of corticomotor excitability (transcranial magnetic stimulation), pain ratings (numerical rating scale, NRS), skin pain sensitivity on the arm (heat and mechanical), temporal summation of pain (TSP) and conditioned pain modulation (CPM) were performed at baseline (Day1‐baseline), after 25 min of capsaicin application and before the first tDCS session (Day1‐post‐cap), and after the second tDCS session (Day2).

Results

Comparing Day2 to Day1‐baseline measures, there was reduced corticomotor excitability (p < .05) and impaired CPM‐effect (p < .05) after sham but not after active network‐tDCS. Pain NRS ratings increased at Day2 compared to Day1‐post‐cap (p < .01) in both groups whereas no significant changes were found in pain sensitivity and TSP.

Conclusions

Present findings demonstrate that tDCS applied over regions linked to the resting state motor network reverts the inhibition of corticomotor excitability and CPM impairment both provoked by prolonged experimental pain for 24 hr.

Significance

These findings highlight that the stimulation of the resting state motor network with multifocal tDCS may represent a potential cortical target to treat chronic pain, particularly in patients exhibiting maladaptive corticomotor excitability and impaired conditioned pain modulation effects.
A review of postpartum hemorrhage in low‐income countries and implications for strengthening health systems
Authors: Borovac‐Pinheiro Anderson , Priyadarshani Preeti , Burke Thomas F.
Published: February 2021

Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and mortality worldwide. Disparities in PPH‐associated survival between high and low‐/middle‐income countries reflect an imperative for low‐resource countries to improve strategies for rapid diagnosis and treatment. A review of current PPH diagnosis, prevention, treatment, and access to care in low‐income countries has been used to understand, extract, and report the challenges that public health systems face in trying to solve the marked global disparity in PPH outcomes. Improvement in PPH survival begins with holistic strengthening of each step along the continuum of care in health systems and should include performance feedback measures and quality‐of‐care research.
Influence of the human immunodeficiency virus on cervical precancerous lesions
Authors: Nkwabong Elie , Kengne Berenis , Nkene Mawamba Yvette , Sando Zacharie
Published: February 2021

Objective

To study the influence of HIV status on the occurrence of cervical precancerous lesions (CPL).

Methods

This analytical cross‐sectional study was carried out between December 1, 2019 and May 31, 2020. All women with documented HIV status screened for CPL with biopsies performed were recruited. The main variables recorded included maternal age, educational level, number of sexual partners, age at first sexual intercourse, smoking, alcohol consumption, HIV status, CD4 count, and cervical biopsy result. Fisher exact test and Student's t test were used for comparison. A p value <0.05 was considered statistically significant.

Results

Concerning women attending our screening units, CPL was more frequent among those living with HIV/AIDS (20/92; 21.7%) than among those not living with HIV/AIDS (29/290; 10.0%) (p = 0.004). As regards women living with HIV/AIDS, those with a CD4 count below 350/mL were more at risk of having a CPL (odds ratio [OR] 21.39, 95% confidence interval [CI] 5.60–81.56, p ˂ 0.001). High‐grade lesions (cervical intraepithelial neoplasia Stage 2 or 3) were more often found in women living with HIV/AIDS (OR 3.83, 95% CI 1.09–13.45, p = 0.033).

Conclusion

More attention should be paid to women living with HIV/AIDS, especially those with CD4 count less than 350/mL, who should be screened more often with biopsy frequently conducted if indicated.
Clinical characteristics of 4499 COVID‐19 patients in Africa: A meta‐analysis
Authors: Olumade Testimony Jesupamilerin , Uzairue Leonard Ighodalo
Published: February 2021

The novel coronavirus disease‐2019 (COVID‐19) pandemic that started in December 2019 has affected over 95 million people and killed over 2 million people as of January 19, 2021. While more studies are published to help us understand the virus, there is a dearth of studies on the clinical characteristics and associated outcomes of the severe acute respiratory syndrome coronavirus 2 on the African continent. We evaluated evidence from previous studies in Africa available in six databases between January 1 and October 6, 2020. Meta‐analysis was then performed using Open‐Meta Analyst and Jamovi software. A total of seven studies, including 4499 COVID‐19 patients, were included. The result of the meta‐analysis showed that 68.8% of infected patients were male. Common symptoms presented (with their incidences) were fever (42.8%), cough (33.3%), headache (11.3%), and breathing problems (16.8%). Other minor occurring symptoms included diarrhea (7.5%) and rhinorrhea (9.4%). Fatality rate was 5.6%. There was no publication bias in the study. This study presents the first description and analysis of the clinical characteristics of COVID‐19 patients in Africa. The most common symptoms are fever, cough, and breathing problems.
Terminal residue and dietary intake risk assessment of prothioconazole‐desthio and fluoxastrobin in wheat field ecosystem
Authors: Liang Yiran , Chen Xiaoxin , Hu Jiye
Published: February 2021

BACKGROUND

Wheat is one of the most important cereal crops worldwide, and use of fungicides is an essential part of wheat production. Both prothioconazole and fluoxastrobin give excellent control of important seed and soilborne pathogens. The combination of these two fungicides shows a complementary mode of action and has a wide usage around the world. But the residue levels of these fungicides in the wheat matrix are still unknown.

RESULTS

In the current study, a simple, low‐cost and highly sensitive method using modified QuECHERS procedure combined with high‐performance liquid chromatography–tandem mass spectrometry was developed to simultaneously quantify E‐ and Z‐fluoxastrobin and the main metabolite prothioconazole‐desthio of prothioconazole in the wheat matrix. The recoveries of prothioconazole‐desthio, E‐fluoxastrobin and Z‐fluoxastrobin ranged from 84% to 101%, with relative standard deviation of less than 13.2%. The terminal residues of prothioconazole‐desthio and E‐ and Z‐fluoxastrobin were studied in wheat grain and straw under field conditions. The results showed that the terminal residue of the target compounds ranged from <0.01 to 0.029 mg kg−1 and <0.05 to 7.6 mg kg−1 in wheat grain and straw (expressed as dry weight), respectively. The risk quotients of prothioconazole‐desthio and fluoxastrobin were 0.2% and 3.2%.

CONCLUSIONS

The residue levels of the target analytes in wheat grain were lower than the maximum residue limits recommended by the Chinese Ministry of Agriculture. And the calculated risk quotient values were far below 100%, indicating a low dietary intake health risk to consumers. © 2021 Society of Chemical Industry
Comparative biotransformation of luteolin and apigenin from the flower extract and the stem‐and‐leaf extract of Dendranthema morifolium Ramat. Tzvel. in rats
Authors: Chiang Yi‐He , Wu Yu‐Tse , Lin Lie‐Chwen , Tsai Tung‐Hu
Published: February 2021

BACKGROUND

The flower of Dendranthema morifolium Ramat Tzvel has been widely used as a nutritional health supplement worldwide. However, most of the studies have focused on the flower and the rest of the plant was neglected. Our hypothesis is that similar flavonoids may be present at different parts of D. morifolium, and the flavonoids may undergo a similar biotransformation pathway within the body. To investigate this hypothesis, an in vivo pharmacokinetic experimental model was developed to explore the comparative biotransformation of luteolin and apigenin after administration of D. morifolium extracts (10 g kg−1, p.o.) in freely moving rats. Because luteolin and apigenin mainly underwent phase II metabolism, the metabolic enzymes of β‐glucuronidase/sulfatase or β‐glucuronidase were used to hydrolyze the plasma sample, depending on the biotransformation pathway involved.

RESULTS

The results revealed that luteolin and apigenin mainly went through glucuronide and sulfate conjugations, respectively, in both the extract of flowers and the stem‐and‐leaf group. In addition, the area under the concentration curve (AUClast) of luteolin glucuronides and sulfates in the group administered the stem‐and‐leaf extract was approximately 4.6 times higher than that of the flower extract group. The dominant products of biotransformation for apigenin were sulfates.

CONCLUSION

These findings support our hypothesis that not only the flower parts of D. morifolium, but also the stem‐and‐leaf parts contain rich flavones, including glycosides and aglycone, and they undergo similar biotransformation pathways. © 2021 Society of Chemical Industry
Ultra‐wideband radar cross‐section reduction for ring‐shaped microstrip antenna based on characteristic mode analysis
Authors: Liu Yakun , Du Biao , Jia Dan , Jia Yongtao
Published: February 2021

In this letter, a characteristic mode analysis method is presented for ultra‐wideband radar cross‐section (RCS) reduction of microstrip antenna. By analyzing the magnitude of the modal weighting coefficients (MWCs), the important scattering modes can be found, which contribute a lot to the RCS of the antenna. Then, these scattering modes are suppressed through shape modification. To realize an ultra‐wideband RCS reduction (RCSR) of a ring‐shaped microstrip antenna, three pairs of slots are placed at suitable locations of the reference antenna to disrupt the current path, so as to suppress the important scattering modes while keeping the radiation modes work properly. Compared to the reference antenna, the proposed antenna achieves 6 dB RCSR on average over the frequency band of 0.5 GHz−5 GHz (163.64%) for x‐polarization incident wave. The peak reduction at 3.0 GHz is up to 23 dB. Meanwhile, the radiation performance keeps well. The measured and simulated results are in good agreement, which validates the presented method.
A chiral metamaterial with high reflectance for antenna applications
Authors: Chen Chunling , Liu Zhen‐Guo , Wang Hao
Published: February 2021

In this article, a chiral metamaterial (CMM) with high reflectance is constructed by using both the S‐shaped strip and the grid strip. Numerical simulation results reveal that the reflectance reaches 0.7 and the transmitted wave is converted from y‐polarization to left‐hand circular polarization. Therefore, the proposed CMM has the function of polarized transformation from linear polarization (LP) wave to circular polarization (CP). In addition, a Fabry‐Perot resonator cavity‐like behavior is found in the CMM itself. We design and measure a CP CMM‐based Fabry‐Pérot resonator cavity antenna. A bandwidth of 13.25% (|S11| < −10 dB, AR < 3 dB, and peak gain drop<3 dB) and a peak gain of 14.76 dBic are attained. The proposed antenna has potential applications in advanced nanosatellite communication systems.