bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymmetric Catalytic Reactions of Donor–Acceptor Cyclopropanes
Authors: Xia Yong , Liu Xiaohua , Feng Xiaoming
Published: July 2020

Due to the synergistic “push–pull” effect of vicinal electron‐donating and electron‐withdrawing groups, donor–acceptor (D‐A) cyclopropanes have been recognized as one of the most powerful building blocks to generate polyfunctional reactive intermediates after a strain‐driven ring cleavage. Enantioselective reactions of D‐A cyclopropanes provide an efficient approach to enantioenriched acyclic and cyclic compounds. A number of chiral Lewis/Brønsted acids, transition metals, and organocatalysts have been designed for such transformations, including ring‐openings, annulations, and rearrangements. This minireview highlights the developments and new advances in this field and describes new synthetic opportunities offered by these interesting methodologies.
Solar Reforming of Biomass with Homogeneous Carbon Dots
Authors: Achilleos Demetra S. , Yang Wenxing , Kasap Hatice , Savateev Aleksandr , Markushyna Yevheniia , Durrant James R. , Reisner Erwin
Published: July 2020

A sunlight‐powered process is reported that employs carbon dots (CDs) as light absorbers for the conversion of lignocellulose into sustainable H2 fuel and organics. This photocatalytic system operates in pure and untreated sea water at benign pH (2–8) and ambient temperature and pressure. The CDs can be produced in a scalable synthesis directly from biomass itself and their solubility allows for good interactions with the insoluble biomass substrates. They also display excellent photophysical properties with a high fraction of long‐lived charge carriers and the availability of a reductive and an oxidative quenching pathway. The presented CD‐based biomass photoconversion system opens new avenues for sustainable, practical, and renewable fuel production through biomass valorization.
Rational Manipulation of Stacking Arrangements in Three‐Dimensional Zeolites Built from Two‐Dimensional Zeolitic Nanosheets
Authors: Xu Le , Ma Tianqiong , Shen Yihan , Wang Yong , Han Lu , Chaikittisilp Watcharop , Yokoi Toshiyuki , Sun Junliang , Wakihara Toru , Okubo Tatsuya
Published: July 2020

Unit‐cell‐thin zeolitic nanosheets have emerged as fascinating materials for catalysis and separation. The controllability of nanosheet stacking is extremely challenging in the chemistry of two‐dimensional zeolitic materials. To date, the organization of zeolitic nanosheets in hydrothermal synthesis has been limited by the lack of tunable control over the guest–host interactions between organic structure‐directing agents (OSDAs) and zeolitic nanosheets. A direct synthetic methodology is reported that enables systematic manipulation of the aluminosilicate MWW‐type nanosheet stacking. Variable control of guest–host interactions is rationally achieved by synergistically altering the charge density of OSDAs and synthetic silica‐to‐alumina composition. These finely controlled interactions allow successful preparation of a series of three‐dimensional (3D) zeolites, with MWW‐layer stacking in wide ranges from variably disorder to fully ordered, leading to tunable catalytic activity in the cracking reaction. These results highlight unprecedented opportunities to modulate zeolitic nanosheets arrangement in 3D zeolites whose structure can be tailored for catalysis and separation.
Integrating Biomass into the Organonitrogen Chemical Supply Chain: Production of Pyrrole and d‐Proline from Furfural
Authors: Song Song , Fung Kin Yuen Vincent , Di Lu , Sun Qiming , Zhou Kang , Yan Ning
Published: July 2020

Production of renewable, high‐value N‐containing chemicals from lignocellulose will expand product diversity and increase the economic competitiveness of the biorefinery. Herein, we report a single‐step conversion of furfural to pyrrole in 75 % yield as a key N‐containing building block, achieved via tandem decarbonylation–amination reactions over tailor‐designed Pd@S‐1 and H‐beta zeolite catalytic system. Pyrrole was further transformed into dl‐proline in two steps following carboxylation with CO2 and hydrogenation over Rh/C catalyst. After treating with Escherichia coli, valuable d‐proline was obtained in theoretically maximum yield (50 %) bearing 99 % ee. The report here establishes a route bridging commercial commodity feedstock from biomass with high‐value organonitrogen chemicals through pyrrole as a hub molecule.
Light‐Controlled Regioselective Synthesis of Fullerene Bis‐Adducts
Authors: Ðorđević Luka , Casimiro Lorenzo , Demitri Nicola , Baroncini Massimo , Silvi Serena , Arcudi Francesca , Credi Alberto , Prato Maurizio
Published: July 2020

Multi‐functionalization and isomer‐purity of fullerenes are crucial tasks for the development of their chemistry in various fields. In both current main approaches—tether‐directed covalent functionalization and supramolecular masks—the control of regioselectivity requires multi‐step synthetic procedures to prepare the desired tether or mask. Herein, we describe light‐responsive tethers, containing an azobenzene photoswitch and two malonate groups, in the double cyclopropanation of [60]fullerene. The formation of the bis‐adducts and their spectroscopic and photochemical properties, as well as the effect of azobenzene photoswitching on the regiochemistry of the bis‐addition, have been studied. The behavior of the tethers depends on the geometry of the connection between the photoactive core and the malonate moieties. One tether lead to a strikingly different adduct distribution for the E and Z isomers, indicating that the covalent bis‐functionalization of C60 can be controlled by light.
X‐ray photoelectron spectroscopy study on the photodegradation of copolyester model compounds
Authors: Arangdad Kiarash , Yildirim Erol , Detwiler Andrew , Cleven Curtis D. , Burk Christopher , Shamey Renzo , Pasquinelli Melissa A. , Freeman Harold , El‐Shafei Ahmed
Published: July 2020

The photodegradation of irradiated PETG and PCCT model compounds namely Tm‐CHDM‐Tm and Tm‐TMCD‐Tm, where Tm refers to the methyl ester of terephthalic acid, CHDM refers to 1, 4‐cyclohexanedimethanol, and TMCD refers to tetramethyl‐1, 3‐cyclobutanediol, was analyzed using X‐ray photoelectron spectroscopy. Photodegradation products were characterized based on high resolution O1s x‐ray photoelectron spectroscopy (XPS) spectra and the spectra of irradiated model compounds showed a decrease in the relative intensity of CO compared to the CO peak. The percentage of CO formation in irradiated model compounds changed in proportion to irradiation time and showed that the model compound containing CHDM was slightly more UV stable than the TMCD based model compound. Photodegradation mechanisms for model compounds were proposed based on XPS spectra. In parallel studies, density functional theory calculations were performed as an approach to predict degradation products, to help interpreting the XPS spectra of model compounds and characterize the reactivity of model compounds.
Role of aqueous extract of saffron in ameliorating effect of sofosbuvir on the cerebellar cortex in rat
Authors: Ibrahim Marwa A. A. , Sharaf Eldin Heba E. M. , Elswaidy Noha R. M.
Published: July 2020

Sofosbuvir is a promising antiviral drug against chronic hepatitis C virus. Although it is characterized by its high efficacy, its adverse effects on nervous tissue are still unclear. Saffron is known for its neuroprotective property. This is a biochemical, histological and immunohistochemical study of the effect of sofosbuvir on the cerebellar cortex of rat and the possible ameliorating role of saffron's aqueous extract. Twenty‐four adult male Wistar albino rats were equally divided into four groups; control, saffron extract‐treated, sofosbuvir‐treated (41.1 mg/kg/day for 6 weeks) and group concomitantly treated with saffron extract and sofosbuvir. Sofosbuvir‐treated group recorded a significant increase in cerebellar malondialdehyde level coupling with a significant decrease in tissue glutathione and superoxide dismutase. Light microscopy revealed reduced number of Purkinje cells. The granular layer depicted many granular cells and Bergmann astrocytes with nuclear and cytoplasmic alterations. Electron microscopy revealed disorganized molecular layer with disarranged myelinated axons and disrupted mitochondria. Few shrunken Purkinje cells showed electron‐dense cytoplasm and rarefied nuclei, indistinct nuclear envelope and dilated perinuclear space, areas of vacuolated cytoplasm, fragmented rough endoplasmic reticulum and few dark mitochondria. Some axons with tiny mitochondria were detected. A significant upregulation in immunohistochemical expression of GFAP‐positive astrocytes was recorded. Concomitant administration of saffron extract significantly improved all studied parameters. Saffron extract is beneficial in ameliorating sofosbuvir‐induced cerebellar morphological changes mainly through its antioxidant and neuroprotective properties.
Chemical components of plastics as endocrine disruptors: Overview and commentary
Authors: Darbre Philippa D.
Published: July 2020

Bisphenol A and phthalate esters are used as additives in the manufacture of plastic materials, but their ability to leach out with age and heat has resulted in their becoming ubiquitous contaminants of the ecosystem including within human body tissues. Over recent years, these compounds have been shown to possess endocrine disrupting properties with an ability to interfere in the actions of many hormones and to contribute to human health problems. Much of the reported disruptive activity has been in relation to the action of estrogens, androgens, and thyroid hormones, and concerns have been raised for adverse consequences on female and male reproductive health, thyroid function, metabolic alterations, brain development/function, immune responses, and development of cancers in hormone‐sensitive tissues. A recurring theme throughout seems to be that there are windows of susceptibility to exposure in utero and in early postnatal life, which may then result in disease in later life without any need for further exposure. This commentary highlights key issues in a historical context and raises questions regarding the many data gaps.
Driving Protein Conformational Cycles in Physiology and Disease: “Frustrated” Amino Acid Interaction Networks Define Dynamic Energy Landscapes
Authors: D'Amico Rebecca N. , Murray Alec M. , Boehr David D.
Published: July 2020

A general framework by which dynamic interactions within a protein will promote the necessary series of structural changes, or “conformational cycle,” required for function is proposed. It is suggested that the free‐energy landscape of a protein is biased toward this conformational cycle. Fluctuations into higher energy, although thermally accessible, conformations drive the conformational cycle forward. The amino acid interaction network is defined as those intraprotein interactions that contribute most to the free‐energy landscape. Some network connections are consistent in every structural state, while others periodically change their interaction strength according to the conformational cycle. It is reviewed here that structural transitions change these periodic network connections, which then predisposes the protein toward the next set of network changes, and hence the next structural change. These concepts are illustrated by recent work on tryptophan synthase. Disruption of these dynamic connections may lead to aberrant protein function and disease states.
Analysis of severity and preventability in patients of—Toxic epidermal necrolysis—A case series
Authors: Ciddhavaduta Deepa Latha , Kalaiselvan Vivekanandan , Midde Madhavi Latha , Baloju Deepika
Published: July 2020

SJS‐TEN is life‐threatening autoimmune disorder triggered due to drugs such as analgesics, antibiotics, anticonvulsants, and antipsychotics. This report provides awareness to the Clinicians regarding prescription of drugs which cause SJS‐TEN. Among young females of 20‐40 years, screening for previous history, issuing drug alert cards, and preventing OTC prescriptions decreases mortality.
Structural Deterioration of Well‐Faceted MOFs upon H2S Exposure and Its Effect in the Adsorption Performance
Authors: Reljic Snezana , Broto‐Ribas Anna , Cuadrado‐Collados Carlos , Jardim Erika O. , Maspoch Daniel , Imaz Inhar , Silvestre‐Albero Joaquin
Published: July 2020

The structural deterioration of archetypical, well‐faceted metal–organic frameworks (MOFs) has been evaluated upon exposure to an acidic environment (H2S). Experimental results show that the structural damage highly depends on the nature of the hybrid network (e.g., softness of the metal ions, hydrophilic properties, among others) and the crystallographic orientation of the exposed facets. Microscopy images show that HKUST‐1 with well‐defined octahedral (111) facets is completely deteriorated, ZIF‐8 with preferentially exposed (110) facets exhibits a large external deterioration with the development of holes or cavities in the mesoporous range, whereas UiO‐66‐NH2 with (111) exposed facets, and PCN‐250 with (100) facets does not reflect any sign of surface damage. Despite the selectivity in the external deterioration, X‐ray diffraction and gas adsorption measurements confirm that indeed all MOFs suffer an important internal deterioration, these effects being more severe for MOFs based on softer cations (e.g., Cu‐based HKUST‐1 and Fe‐based PCN‐250). These structural changes have inevitable important effects in the final adsorption performance for CO2 and CH4 at low and high pressures.
Impact of Molecular Size and Shape on the Supramolecular Co‐Assembly of Chiral Tricarboxamides: A Comparative Study
Authors: Dorca Yeray , Sánchez‐Naya Roberto , Cerdá Jesús , Calbo Joaquín , Aragó Juan , Gómez Rafael , Ortí Enrique , Sánchez Luis
Published: July 2020

A comparative investigation of the chiral amplification features of a series of three families of C3‐symmetric tricarboxamides, 1,3,5‐triphenylbenzenetricarboxamides (TPBAs), benzenetricarboxamides (BTAs) and oligo(phenylene ethynylene) tricarboxamides (OPE‐TAs), is here reported. As previously observed for BTAs and OPE‐TAs, a similar dichroic response is obtained for TPBAs decorated with one, two or three chiral side chains bearing stereogenic centers, thus confirming the efficient transfer of point chirality to the supramolecular helical aggregates. Unlike BTAs and OPE‐TAs, the chiral amplification ability of TPBAs in majority rules experiments shows a negligible dependence on the number of chiral centers per monomeric unit, and stands the largest among the series of tricarboxamides. Detailed experimental and theoretical studies demonstrate that the rotation angle between the TPBA units in the helical stack is intermediate to that observed for BTAs and OPE‐TAs. This feature strongly conditions the steric interactions between vicinal molecules in the stack and the final chiral amplification outcome. Furthermore, theoretical calculations show that achiral side chains favor the interdigitation of the helical aggregates and thereby the formation of bundle superstructures.
N‐Heterocyclic Carbene Analogues of Nucleophilic Phosphinidene Transition Metal Complexes
Authors: Doddi Adinarayana , Bockfeld Dirk , Bannenberg Thomas , Tamm Matthias
Published: July 2020

Chloride abstraction from the complexes [(η6‐p‐cymene){(IDipp)P}MCl] (2 a, M=Ru; 2 b, M=Os) and [(η5‐C5Me5){(IDipp)P}IrCl] (3 b, IDipp=1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene) with sodium tetrakis[3,5‐bis(trifluoromethyl)phenyl]borate (NaBArF) in the presence of trimethylphosphine (PMe3), 1,3,4,5‐tetramethylimidazolin‐2‐ylidene (MeIMe) or carbon monoxide (CO) afforded the complexes [(η6‐p‐cymene){(IDipp)P}M(PMe3)]BArF] (4 a, M=Ru; 4 b, M=Os), [(η6‐p‐cymene){(IDipp)P}Os(MeIMe)]BArF] (5) and [(η5‐C5Me5){(IDipp)P}IrL][BArF] (6, L=PMe3; 7, L=MeIMe; 8, L=CO). These cationic N‐heterocyclic carbene‐phosphinidene complexes feature very similar structural and spectroscopic properties as prototypic nucleophilic arylphosphinidene complexes such as low‐field 31P NMR resonances and short metal‐phosphorus double bonds. Density functional theory (DFT) calculations reveal that the metal‐phosphorus bond can be described in terms of an interaction between a triplet [(IDipp)P]+ cation and a triplet metal complex fragment ligand with highly covalent σ‐ and π‐contributions. Crystals of the C−H activated complex 9 were isolated from solutions containing the PMe3 complex, and its formation can be rationalized by PMe3 dissociation and formation of a putative 16‐electron intermediate [(η5‐C5Me5)Ir{P(IDipp)}I][BArF], which undergoes C−H activation at one of the Dipp isopropyl groups and addition along the iridium‐phosphorus bond to afford an unusual η3‐benzyl coordination mode.
Bis‐Anthracene Fused Porphyrin as an Efficient Photocatalyst: Facile Synthesis and Visible‐Light‐Driven Oxidative Coupling of Amines
Authors: Zhang Pengfei , Yu Chunyang , Yin Yucheng , Droste Jörn , Klabunde Sina , Hansen Michael Ryan , Mai Yiyong
Published: July 2020

Development of high‐performance photocatalysts for the conversion of amines is of great importance, but has remained a challenging task. Here, a bis‐anthracene fused porphyrin (AFP) was synthesized in a high yield by a facile synthetic protocol, which involves a Suzuki coupling for the conjugation of two anthracene groups with a porphyrin ring, followed by oxidative cyclodehydrogenation. When serving as a photocatalyst, AFP exhibits an outstanding photocatalytic performance for the visible‐light‐induced aerobic oxidation of amines to imines at ambient conditions. Density functional theory calculations revealed that the low energy band gap, caused by the large planar and π‐extended porphyrin structure of AFP, contributed to its high photocatalytic performance.
Clinical relevance of serum uric acid and abdominal aortic‐calcification in a national survey
Authors: Li Yen‐Wei , Chen Wei‐Liang
Published: July 2020

Background

Hyperuricemia was often found in subjects with an elevated risk of cardiovascular disease (CVD). Abdominal aortic‐calcification (AAC) is significantly associated with subclinical atherosclerotic disease.

Hypothesis

The aim of this study is to evaluate the relationship between serum uric acid (SUA) level and AAC from a national database.

Methods

A total of 2765 eligible participants older than 40 years who received dual‐energy X‐ray absorptiometry (DXA) scans with SUA data were enrolled from the National Health and Nutrition Examination Survey (2013‐2014). The association between SUA level and AAC was analyzed using multivariate regression models for covariate adjustment.

Results

After categorizing SUA level into four quartiles, the odds ratios for the presence of subclinical atherosclerosis via contrasting the highest SUA quartile with the lowest SUA quartile were 1.876 (95% CI = 1.298‐2.711), 2.038 (95% CI = 1.303‐3.187), 1.935 (95% CI = 1.221‐3.065), and 1.956 (95% CI = 1.225‐3.124) (all, P value less than .05) in Model 1, Model 2, Model 3, and Model 4, respectively. The above relationship remained still in the fully adjusted model for the male but not female subjects. The optimal SUA cutoff value was 6.35 mg/dL for male and 5.25 mg/dL for female to predict the presence of subclinical atherosclerosis.

Conclusions

Our results explore the promising evidences that SUA level showed a positive correlation with AAC score in a dose‐response manner. These findings decisively indicated that SUA may act as a promising tool to forecast the incidence of subclinical atherosclerosis in males.
Applicability of the REDUCE‐IT trial to the FAST‐MI registry. Are the results of randomized trials relevant in routine clinical practice?
Authors: Ferrières Jean , Bataille Vincent , Puymirat Etienne , Schiele François , Simon Tabassome , Danchin Nicolas ,   for the FAST‐MI investigators
Published: July 2020

Background

The reduction of cardiovascular events with icosapent ethyl‐intervention trial (REDUCE‐IT) trial revealed robust atherosclerotic cardiovascular risk reduction with a strategy comprising high‐dose omega‐3 icosapent ethyl vs placebo in statin‐treated patients with elevated triglycerides and controlled low‐density lipoprotein cholesterol (LDL‐C).

Hypothesis

Are the results of the REDUCE‐IT trial applicable to the French registry on acute ST‐elevation and non‐ST‐elevation myocardial infarction (FAST‐MI) population?

Methods

Data were extracted from the FAST‐MI 2010 and 2015 registries. We applied the REDUCE‐IT enrolment criteria (triglycerides 150‐500 mg/dL and LDL‐C 40‐100 mg/dL on statins) to the FAST‐MI population in patients aged ≥45 years who had detailed lipid values postacute hospitalization, focusing on their clinical profile and cardiovascular prognosis.

Results

Of the 3789 FAST‐MI patients with a full lipid profile (median 11.1 [IQR 7.6‐17.4] months after hospitalization for myocardial infarction), 472 (12.5%; 95% CI 11.4‐13.5) met the eligibility criteria for REDUCE‐IT (REDUCE‐IT‐like group). The cardiovascular event rate (all‐cause death, nonfatal myocardial infarction, nonfatal stroke) was 36.7 (95% CI 27.8‐48.6) per 1000 person‐years for the REDUCE‐IT‐like group, which compares with the 36.9 (95% CI 26.1‐51.5) per 1000 person‐years (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke) reported in the REDUCE‐IT trial. The residual cardiovascular risk related to elevated triglycerides in the REDUCE‐IT‐like group was similar to the risk in the REDUCE‐IT trial.

Conclusions

If the results of REDUCE‐IT are applied to patients hospitalized for a myocardial infarction in France, 12.5% of these patients could benefit from a strategy of high‐dose omega‐3 icosapent ethyl on top of contemporary therapy including statins to improve their clinical outcomes.
HIV‐1 Envelope Spike MPER: From a Vaccine Target to a New Druggable Pocket for Novel and Effective Fusion Inhibitors
Authors: Luque Francisco Javier , Camarasa María‐José
Published: July 2020

Here we highlight a sound and unique work reported by Chen and co‐workers entitled “HIV‐1 fusion inhibitors targeting the membrane‐proximal external region of Env spikes” (Xiao et al., Nat. Chem. Biol. 2020, 16, 529). In this article, the authors identify, by means of a clever antibody‐guided strategy, several small molecules as fusion inhibitors of HIV‐1 replication acting at the membrane proximal external region (MPER) of the HIV‐1 envelope (Env) spike. MPER, which was previously recognized as a vaccine target, emerges as a novel druggable target for the discovery of HIV‐1 fusion inhibitors. The compounds (exemplified by dequalinium and dequalinium‐inspired analogues) prevent the conformational changes of Env from the prefusion species to the intermediate states required for membrane fusion. This work not only paves the way to novel, specific and useful anti‐HIV‐1 inhibitors, but also discloses new therapeutic strategies against other infectious diseases.
A noninterventional, multinational study to assess PD‐L1 expression in cytological and histological lung cancer specimens
Authors: Bubendorf Lukas , Conde Esther , Cappuzzo Federico , Langfort Renata , Schildhaus Hans‐Ulrich , Votruba Jiří , Concha‐López Ángel , Esteban‐Rodriguez Isabel , Feng Janine , Devenport Jenny , Boyiddle Christine , Morris Stefanie , Trunzer Kerstin , Kerr Keith M.
Published: July 2020

Background

The diagnosis of advanced lung cancer is made with minimally invasive procedures. This often results in the availability of cytological material only for subtype determination and companion diagnostic testing, with the latter being technically and clinically validated on histological material only. Thus, the primary objective of the MO29978 clinical study was to assess programmed death ligand 1 (PD‐L1) protein expression on cytology samples as surrogates for histology samples in patients with lung cancer.

Methods

Formalin‐fixed, paraffin‐embedded histological samples and cytological cell blocks from 190 patients were analyzed with immunohistochemical assays using the rabbit monoclonal anti–PD‐L1 antibody clones SP142 and SP263. PD‐L1 expression was quantified on both tumor cells (TC) and tumor‐infiltrating immune cells (IC). Overall concordance, sensitivity, specificity, and accuracy, with a 1% cutoff used for both assays, were assessed for PD‐L1 expression on TC and IC.

Results

In non–small cell lung cancer histology and cytology samples measured with the PD‐L1 (SP142) antibody (n = 173), the intraclass correlation coefficients were 0.40 and 0.06 on TC and IC, respectively. With SP142 and SP263, accuracies of 74.1% for TC and 51.9% for IC and accuracies of 75.2% for TC and 61.2% for IC, respectively, were reported.

Conclusions

Overall, this study has demonstrated that PD‐L1 analysis on TC is feasible in cytological material, but quantification is challenging. Tumor tissue should be preferred over cell block cytology for PD‐L1 immunohistochemical analysis unless laboratories have validated their cytology preanalytical approaches and demonstrated the comparability of histology and cytology for TC PD‐L1 results.
Cannabinoid receptor Type 1 densities reflect social organization in Microtus
Authors: Simmons Trenton C. , Freeman Sara M. , Lackey Nicholas S. , Dreyer Brooke K. , Manoli Devanand S. , Bales Karen L.
Published: July 2020

Across many species, endocannabinoids play an important role in regulating social play, reward, and anxiety. These processes are mediated through at least two distinct cannabinoid receptors (CB), CB1 and CB2. CB1 expression is found in appreciable densities across regions of the brain that integrate memory with socio‐spatial information; many of these regions have been directly linked to the neurobiology of pair bonding in monogamous species. Using receptor autoradiography, we provide the first distributional map of CB1 within the brains of closely related monogamous prairie voles and promiscuous meadow voles, and compare receptor densities across sexes and species in limbic regions. We observe CB1‐specific signal using [3H] CP‐55,940 and [3H] SR141716A, though the latter exhibited a lower signal to noise ratio. We confirmed the presence of CB2 in prairie vole spleen tissue using [3H] CP‐55,940. However, we found no evidence of CB2 in the brain using either [3H] CP‐55,940 or [3H] A‐836,339. The overall distribution of putative CB1 in the brain was similar across vole species and followed the pattern of CB1 expression observed in other species—high intensity binding within the telencephalon, moderate binding within the diencephalon, and mild binding within the mesencephalon and metencephalon (aside from the cerebellar cortex). However, we found profound differences in CB1 densities across species, with prairie voles having higher CB1 binding in regions implicated in social attachment and spatial memory (e.g., periaqueductal gray, hippocampus). These findings suggest that CB1 densities, but not distribution, correlate with the social systems of vole species.
Brain of the African wild dog. I. Anatomy, architecture, and volumetrics
Authors: Chengetanai Samson , Tenley Jonathan D. , Bertelsen Mads F. , Hård Therese , Bhagwandin Adhil , Haagensen Mark , Tang Cheuk Y. , Wang Victoria X. , Wicinski Bridget , Hof Patrick R. , Manger Paul R. , Spocter Muhammad A.
Published: July 2020

The African wild dog is endemic to sub‐Saharan Africa and belongs to the family Canidae which includes domestic dogs and their closest relatives (i.e., wolves, coyotes, jackals, dingoes, and foxes). The African wild dog is known for its highly social behavior, co‐ordinated pack predation, and striking vocal repertoire, but little is known about its brain and whether it differs in any significant way from that of other canids. We employed gross anatomical observation, magnetic resonance imaging, and classical neuroanatomical staining to provide a broad overview of the structure of the African wild dog brain. Our results reveal a mean brain mass of 154.08 g, with an encephalization quotient of 1.73, indicating that the African wild dog has a relatively large brain size. Analysis of the various structures that comprise their brains and their topological inter‐relationships, as well as the areas and volumes of the corpus callosum, ventricular system, hippocampus, amygdala, cerebellum and the gyrification index, all reveal that the African wild dog brain is, in general, similar to that of other mammals, and very similar to that of other carnivorans. While at this level of analysis we do not find any striking specializations within the brain of the African wild dog, apart from a relatively large brain size, the observations made indicate that more detailed analyses of specific neural systems, particularly those involved in sensorimotor processing, sociality or cognition, may reveal features that are either unique to this species or shared among the Canidae to the exclusion of other Carnivora.
Assessing spatial confounding in cancer disease mapping using R
Authors: Azevedo Douglas R. M. , Bandyopadhyay Dipankar , Prates Marcos O. , Abdel‐Salam Abdel‐Salam G. , Garcia Dina
Published: July 2020

Background

Exploring spatial patterns in the context of cancer disease mapping (DM) is a decisive approach to bring evidence of geographical tendencies in assessing disease status and progression. However, this framework is not insulated from spatial confounding, a topic of significant interest in cancer epidemiology, where the latent correlation between the spatial random effects and fixed effects (such as covariates), often lead to misleading interpretation.

Aims

To introduce three popular approaches (RHZ, HH and SPOCK; details in paper) often employed to tackle spatial confounding, and illustrate their implementation in cancer research via the popular statistical software R.

Methods

As a solution to alleviate spatial confounding, restricted spatial regressions are constructed by either projecting the latent effect onto the orthogonal space of covariates, or by displacing the spatial locations. Popular parametric count data models, such as the Poisson, generalized Poisson and negative binomial, were considered for the areal count responses, while the spatial association is quantified via the conditional autoregressive (CAR) model. Our method of inference in Bayesian, sometimes aided by the integrated nested Laplace approximation (INLA) to accelerate computing. The methods are implemented in the R package RASCO available from the first author's GitHub page.

Results

The results reveal that all three methods perform well in alleviating the bias and variance inflation present in the spatial models. The effects of spatial confounding were also explored, which, if ignored in practice, may lead to wrong conclusions.

Conclusion

Spatial confounding continues to remain a critical bottleneck in deriving precise inference from spatial DM models. Hence, its effects must be investigated, and mitigated. Several approaches are available in the literature, and they produce trustworthy results. The central contribution of this paper is providing the practitioners the R package RASCO, capable of fitting a large number of spatial models, as well as their restricted versions.
Minimize the delays in software defined network switch controller communication
Authors: Iqbal Saleem , Qureshi Kashif Naseer , Shoaib Faisal , Ahmad Awais , Jeon Gwanggil
Published: July 2020

Summar

Software Defined Networks (SDN) is now the leading framework for the existing network infrastructure. Increasing Internet traffic leads to attract SDN infrastructure in large networks like enterprise or data centers by using logical centralize control concept. This abstraction, flexibility, and agility enable the network managers to view the global picture of the network and flow the traffic in an efficient way to avoid congestion and traffic delay issues. However, besides the benefits, the internal mechanism of SDN has some serious challenges, which leads flow table overflow, congestions, controller and switch overloading, link failure and latency issues. This research focus on the delays produced during communication between control plane and data plane due to the parameters like rule formation, mismatches, buffer/queue constraints, flow entries, controller resource utilization or duplicate flow packets, and unordered packets. These delays become more critical in large networks especially in‐case of reactive modes. Furthermore, the frequent rule composition and installation causes extra burden at the controller, this control communication needs prompt reply to forward the traffic in a stipulated time. This article presents the Efficient Resource Management Scheme (ERMS), which efficiently handle the inter‐communication delay and minimize the network overheads. The experiment results depict the better performance of ERMS during the communication between controller and switch by efficient packet handling and flow rules management while minimizes the overheads on controller. The proposed solution enhances the performance of SDN networks by improving the quality of services parameters.
Investigation of Morphology‐Controlled Ultrafast Relaxation Processes of Aggregated Porphyrin
Authors: Mondal Bodhisatwa , Bera Rajesh , Ghosh Srijon , Nayak Sandip K. , Patra Amitava
Published: July 2020

Here, we have synthesized rod and flake shaped morphology of porphyrin aggregates from 5, 10, 15, 20‐tetra (4‐n‐octyloxyphenyl) porphyrin (4‐opTPP) molecule which are evident from scanning electron microscopy (SEM). The formation of J‐type aggregation is evident from steady state and time‐resolved fluorescence spectroscopic studies. Ultrafast transient absorption spectroscopic studies reveal that the excited state lifetime is controlled by the morphology and the time constant for S1→S0 relaxation changes from 3.05 ps to 744 ps with changing the shape from rod to flake, respectively. In spite of similar exciton coupling energy in both the aggregates, the flake shaped aggregates undergo a faster exciton relaxation process and the non‐radiative relaxation channels are found to depend on the shape of aggregates. The fundamental understanding of morphology controlled ultrafast relaxation processes of aggregated porphyrin is important for designing efficient light harvesting devices.
Dirhodium Coordination Polymers for Asymmetric Cyclopropanation of Diazooxindoles with Olefins: Synthesis and Spectroscopic Analysis
Authors: Li Zhenzhong , Rösler Lorenz , Herr Kevin , Brodrecht Martin , Breitzke Hergen , Hofmann Kathrin , Limbach Hans‐Heinrich , Gutmann Torsten , Buntkowsky Gerd
Published: July 2020

A facile approach is reported for the preparation of dirhodium coordination polymers [Rh2(L1)2]n (Rh2‐L1) and [Rh2(L2)2]n (Rh2‐L2; L1=N,N’‐(pyromellitoyl)‐bis‐L‐phenylalanine diacid anion, L2=bis‐N,N’‐(L‐phenylalanyl) naphthalene‐1,4,5,8‐tetracarboxylate diimide) from chiral dicarboxylic acids by ligand exchange. Multiple techniques including FTIR, XPS, and 1H→13C CP MAS NMR spectroscopy reveal the formation of the coordination polymers. 19F MAS NMR was utilized to investigate the remaining TFA groups in the obtained coordination polymers, and demonstrated near‐quantitative ligand exchange. DR‐UV‐vis and XPS confirm the oxidation state of the Rh center and that the Rh‐single bond in the dirhodium node is maintained in the synthesis of Rh2‐L1 and Rh2‐L2. Both coordination polymers exhibit excellent catalytic performance in the asymmetric cyclopropanation reaction between styrene and diazooxindole. The catalysts can be easily recycled and reused without significant reduction in their catalytic efficiency.
Conjunctive Photoluminescence Enhancement Through Plasmonic and Photonic Band‐Gap Pathways in a Chiral Self‐Assembled System
Authors: Baral Marlin , Krishna Prasad S. , Bhat Sachin A. , Nayak Rashmi A. , Yelamaggad C. V.
Published: July 2020

The front cover artwork is provided by the Prasad group at the Centre for Nano and Soft Matter Sciences at Bengaluru (India). The image shows the enhancement of photoluminescence by deploying metal nanoparticles and creating an appropriate chiral environment. Besides exhibiting an electric‐field modulation of photoluminescence, the system quite effectively performs chiral discrimination of the emitted light. Read the full text of the Article at 10.1002/cptc.2020000077.
Relating angiotensin‐converting enzyme inhibitors or angiotensin receptor blockers with incidence or mortality of COVID‐19
Authors: Wong Martin C.S. , Wong Sunny , Huang Junjie , Yan Bryan
Published: July 2020

The present Perspective examined the latest evidence on the association between the use of angiotensin‐converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) and the incidence/mortality of coronavirus disease 2019 (COVID‐19). Our critical appraisal from existing literature does not support discontinuation of ACEIs/ARBs in clinical practice as there is absence of solid evidence. However, we do recommend future research perspective in formulation and implementation of practice‐changing guidelines.
Ligand‐Free Suzuki–Miyaura Cross‐Coupling Reactions in Deep Eutectic Solvents: Synthesis of Benzodithiophene Derivatives and Study of their Optical and Electrochemical Performance
Authors: Pelliccioli Valentina , Dilauro Giuseppe , Grecchi Sara , Arnaboldi Serena , Graiff Claudia , Perna Filippo M. , Vitale Paola , Licandro Emanuela , Aliprandi Alessandro , Cauteruccio Silvia , Capriati Vito
Published: July 2020

We report that dihalogeno‐substituted benzodithiophenes (BDTs) undergo a smooth ligand‐free Suzuki–Miyaura cross‐coupling reaction, under air and moderate heating (60 °C), with aryl‐, alkenyl‐ and alkynyltrifluoroborate salts in a biodegradable choline chloride‐based eutectic mixture, thereby granting access to valuable π‐conjugated BDT compounds (up to 79 % yield), which are gaining great interest in the field of material sciences. The optical and electrochemical properties of these systems have been thoroughly investigated by means of absorption and cyclic voltammetry measurements. The first electrooligomerization study of a representative BDT derivative has also been undertaken.
Electrocatalytic Production of Hydrogen‐peroxide from Molecular Oxygen by Rare Earth (Pr, Nd, Sm or Gd) Oxide Nanorods
Authors: Hota Ipsha , Debnath A. K , Muthe K. P , Varadwaj K. S. K , Parhi Purnendu
Published: July 2020

Highly selective two electron oxygen reduction pathway to generate hydrogen peroxide using four different rare earth (Pr, Nd, Sm, Gd) oxides has been studied. From the rotating‐ring‐disc electrochemical experimental observations, it can be concluded that among the four rare earth oxides, Gd2O3 shows higher ring current and can efficiently produce H2O2 (yield of HO2−=80 %) following 2 electron (number of electrons involved in the process was calculated as 2.2) pathway in 0.1 M KOH. The selectivity for H2O2 was improved by the synergistic coexistence of volcano carbon (VC) with rare‐earth oxides, while Nd2O3 mixed with VC ink showed maximum (91.91 %) selectivity for the H2O2 production. The electrochemical active surface area calculated by measuring the charging current of the electric double layer is compared. The ORR kinetics of the synthesized catalysts were studied by comparing the rate constants and tafel slopes at selected potential ranges.
Microelectrode Combinations of Gold and Polypyrrole Enable Highly Stable Two‐electrode Electrochemical Impedance Spectroscopy Measurements under Turbulent Flow Conditions
Authors: Kremers Tom , Tintelott Marcel , Pachauri Vivek , Vu Xuan Thang , Ingebrandt Sven , Schnakenberg Uwe
Published: July 2020

An electrochemical impedance spectroscopy (EIS) sensor design is proposed based on a standard interdigitated electrode layout in which the smaller working electrode consists of gold (Au) whereas the larger combined counter and reference electrode is coated with a porous layer of polypyrrole (PPy) doped with polystyrene sulfonate (PSS) (PPy : PSS). Each electrode material was first characterized by EIS in a standard 3‐electrode setup with subsequent spectra fitting by a modified Randles equivalent circuit. The differences in the spectra obtained by the PPy : PSS coated electrodes can be explained by an increased electroactive surface area due to the porous polymer film. The changes in morphology of the film are discussed with respect to the evolution of the elements of the electric equivalent circuit. When applying the Au/PPy : PSS electrode combination to a standard 2‐electrode arrangement, the enlarged highly electroactive surface area of the PPy : PSS coating lowers the interfacial impedance in a way that mainly the gold working electrode contributes to the overall system impedance. Therefore, obtaining reproducible EIS signals depends only on the electrode's open‐circuit potential (OCP) and on additional adsorption events at the gold electrode/electrolyte interface. We present a protocol for microelectrode coating with PPy : PSS, which enables highly stable 2‐electrode EIS experiments without the need of a reference electrode. This combination is believed to be very useful if an integration of sensing electrodes inside Micro Total Analysis Systems is aspired.
Enzymeless Electrochemical Glucose Sensor Based on Carboxylated Multiwalled Carbon Nanotubes Decorated with Nickel (II) Electrocatalyst and Self‐assembled Molecularly Imprinted Polyethylenimine
Authors: Okhokhonin A. , Stepanova V. , Malysheva N. , Matern A. , Kozitsina A.
Published: July 2020

In this paper a new enzymeless electrochemical glucose sensor based on carboxylated multiwalled carbon nanotubes (cMWCNT) with immobilized nickel (II) acetylacetonate (NiL) as electrocatalyst and molecularly imprinted polymer fabricated through electrostatic self‐assembling of polyethyleneimine (PEI) crosslinked with glutaric dialdehyde (GDA). The electrocatalytic properties of NiL and PEI‐cMWCNT, PEI‐GDA and PEI‐glucose interactions is studied for the first time. Developed sensor demonstrates excellent electrocatalytic activity towards glucose oxidation and possessing high stability, sensitivity of 5897.42±161.00 μA ⋅ mM−1 cm−2, LOD of 0.138 mM and high selectivity in the presence of creatinine, L‐alanine, glycine, D‐glutamine, uric acid, L‐ascorbic acid, urea and BSA.
Performance Evaluation of Graphene Oxide Based Co3O4@GO, MnO2@GO and Co3O4/MnO2@GO Electrodes for Supercapacitors
Authors: Obodo Raphael M. , Onah Emmanuel O. , Nsude Hope E. , Agbogu Ada , Nwanya Assumpta C. , Ahmad Ishaq , Zhao Tingkai , Ejikeme Paul M. , Maaza M. , Ezema Fabian I.
Published: July 2020

Hydrothermally synthesized electrodes of Co3O4@GO, MnO2@GO and Co3O4/MnO2@GO were produced for usages in supercapacitors. Graphene oxide (GO) was incorporated in the nanocomposites used for electrodes synthesis due to its great surface area and electrical conductivity. The synergistic alliance among these composites and GO enhance electrodes performance, life span and stability. The structural properties as obtained from the X‐ray diffraction (XRD) results suggest that nanocomposites are crystalline in nature. The morphological studies indicated that the nanocomposites have platelet nanoparticles with some agglomerations. The energy bandgaps estimated for the Co3O4@GO, MnO2@GO and Co3O4/MnO2@GO are 2.38 eV, 2.05 eV and 2.33 eV respectively The electrochemical studies provided highest specific capacitance from CV using 10 mV/s scan rates and GCD using 1.0 A/g current density were 765, 1215, 1518 and 975, 1358, 1718 F/g for Co3O4@GO, MnO2@GO and Co3O4/MnO2@GO respectively. These results obviously indicate that composites perform better than single transition metal oxide and the addition of graphene oxide enhanced electrodes performance.
A critical analysis of the bat algorithm
Authors: Gagnon Iannick , April Alain , Abran Alain
Published: July 2020

This article presents an analysis of the bat algorithm (BA) based on elementary mathematical analysis and statistical comparisons of the first hitting time performance metric distributions obtained on a test set comprising five carefully selected objective functions. The findings show that the BA is not an original contribution to the metaheuristics literature and that it is not generally superior to the Particle Swarm Optimization algorithm when fair comparisons are made. It is also shown that some components of the BA can be either replaced by simpler alternatives or be removed entirely to increase performance. Finally, the results suggest that the best version of the BA is in fact a simple hybrid between Particle Swarm Optimization and Simulated Annealing. To encourage more transparency in metaheuristics research, the entirety of the MATLAB code used in this article is available in a GitHub repository for suggestions and/or corrections.
Structural health building response induced by earthquakes: Material softening and recovery
Authors: Astorga Ariana , Guéguen Philippe
Published: July 2020

Under proper loading conditions, micro‐to‐nanoscale heterogeneities (ie, the bond system) that are commonly found within the materials of a system can coalesce until causing macroscopic alterations of the system properties. The bond system is responsible for atypical and invariant‐scale nonlinear elastic processes in granular media, from laboratory‐tested materials (mm) to the Earth's crust (km). The unusual observed behavior involves slow recovery, or relaxation, of the elastic properties after dynamic loading. Several models have been designed to explain non‐linear elasticity, although their physics is still partially unknown. Here, we show that recovery processes are also observed at intermediary scales (m) in civil engineering structures, and that they might be related to structural health due to the healing of cracks. For Japanese buildings subjected to earthquakes, we observe rapid co‐seismic reductions of their resonance frequency, followed by fascinating recoveries over different time scales. For the first time, slow recovery is presented in buildings over short times (ie, seconds) for a single earthquake; over intermediate times (ie, months) for a sequence of aftershocks; and over long times (ie, years) for a series of earthquakes. This study focuses on the analysis of long‐term recovery and recovery during aftershocks, in order to detect permanent damage. By comparing two buildings with different damage levels after the 2011 Tohoku earthquake, we show how relaxation models can characterize the level of cracking caused by damaging events. Our results demonstrate that nonlinear elasticity, combined with existing monitoring techniques, can be a powerful approach for damage detection and damage characterization.
Usefulness of lymphocyte transformation test and in vitro cytokine release in differentiating between independent and cross‐reacting nickel/palladium allergy
Authors: Kapp Florian , Summer Burkhard , Thomas Peter
Published: July 2020

Background

Often concomitant patch test (PT) reactivity to palladium (Pd) and nickel (Ni) is found.

Objectives

To determine whether lymphocyte transformation test (LTT) could be useful in discrimination between cross‐reacting or distinct PT results, and to compare the results with in vitro cytokine production upon Pd or Ni stimulation.

Materials and Methods

The study population consisted of two groups: 13 individuals with Pd PT reactions (10 with concomitant Ni PT reaction, 3 individuals with only Pd PT reactivity) and 10 Ni/Pd PT negative individuals. LTT and assessment of cytokine release (interferon‐gamma, interleukin‐5 [IL‐5], IL‐8, IL‐17A, tumor necrosis factor alpha) by cytometric bead assay were performed.

Results

All 10 patients with positive PT to Ni and Pd showed positive LTT to Ni (P < .05) as compared with the 10 Pd/Ni PT negative patients—but had no significant LTT reaction to Pd. In all, 9 out of 10 Pd/Ni PT negative patients were also LTT negative to Ni and 10 out of 10 to Pd. In the 3 only Pd PT reactors 2 out of 3 remained LTT negative to Ni and 0 out of 3 to Pd. As a major finding, cytokine production gave clearly enhanced IL‐5 response to Ni in Ni PT positive individuals (P < .05), whereas Pd PT reactivity was not linked with such enhanced IL‐5 production in vitro to Pd.

Conclusions

Pd and Ni sensitization are mostly found concomitantly, and cross‐reactivity is questioned. By different LTT reactions and particularly IL‐5 production in vitro, predominant Ni sensitization becomes more evident.