bluuebunny/crossref_metadata_2025 huggingface dataset:
Imaging Dielectric Breakdown in Valence Change Memory
Authors: Hubbard William A. , Lodico Jared J. , Chan Ho Leung , Mecklenburg Matthew , Regan Brian C.
Published: September 2021

Dielectric breakdown (DB) controls the failure, and increasingly the function, of microelectronic devices. Standard imaging techniques, which generate contrast based on physical structure, struggle to visualize this electronic process. Here in situ scanning transmission electron microscopy (STEM) electron beam‐induced current (EBIC) imaging of DB in Pt/HfO2/Ti valence change memory devices is reported. STEM EBIC imaging directly visualizes the electronic signatures of DB, namely local changes in the conductivity and in the electric field, with high spatial resolution and good contrast. DB is observed to proceed through two distinct structures arranged in series: a volatile, “soft” filament created by electron injection; and a non‐volatile, “hard” filament created by oxygen‐vacancy aggregation. This picture makes a physical distinction between “soft” and “hard” DB, while at the same time accommodating “progressive” DB, where the relative lengths of the hard and soft filaments can change on a continuum.
Architected Multimaterial Lattices with Thermally Programmable Mechanical Response
Authors: Mueller Jochen , Lewis Jennifer A. , Bertoldi Katia
Published: September 2021

Architected materials typically maintain their properties throughout their lifetime. However, there is growing interest in the design and fabrication of responsive materials with properties that adapt to their environment. Toward this goal, a versatile framework to realize thermally programmable lattice architectures capable of exhibiting a broader range of mechanical responses is reported. The lattices are composed of two polymeric materials with disparate glass transition temperatures, which are deterministically arranged via 3D printing. By tailoring the local composition and structure, architected lattices with tunable stiffness, Poisson's ratio, and deformation modes controlled through changes in the thermal environment are generated. The platform yields lightweight polymer lattices with programmable composition, architecture, and mechanical response.
Endowing imidazole derivatives with thermally activated delayed fluorescence and aggregation‐induced emission properties for highly efficient non‐doped organic light‐emitting diodes
Authors: Yang Ge , Ran You , Wu Yimin , Chen Minqi , Bin Zhengyang , You Jingsong
Published: September 2021

The development and enrichment of high‐performance organic fluorophores that simultaneously possess thermally activated delayed fluorescence (TADF) and aggregation‐induced emission (AIE) properties is going pursued but remains a great challenge due to severe exciton quenching. Herein, a systematical investigation on imidazole moiety has successfully given rise to a series of highly efficient imidazole‐based TADF‐AIE luminogens for the first time. The attachment of two cyano functionalities on imidazole moiety can significantly increase the electron‐withdrawing ability, so as to realize TADF emissions with small singlet‐triplet energy gaps (ΔEST) values. Meanwhile, the installation of a steric hindrance group at N1 position of imidazole moiety can twist the geometry between imidazole and phenyl bridge, thus transforming imidazole derivative from an aggregation‐caused quenching emitter into an AIE luminogen. Consequently, the non‐doped organic light‐emitting diodes (OLEDs) utilizing these TADF‐AIE luminogens as emitters exhibit outstanding sky‐blue and green emissions, with external quantum efficiency (EQE) as high as 20.0% and low efficiency roll‐off (EQE at 1000 cd m−2, 16.1%). These values represent the state‐of‐the‐art performance for all imidazole‐based OLED devices, which illustrates the significant potential of imidazole derivatives in assembling high‐performance OLEDs.
Photocatalytic Three‐Component Tandem Annulation Access to Multiply Substituted 1,2,4‐Triazole‐3,5‐diamines
Authors: Zheng Lvyin , Tao Kailiang , Zhuo Xiaoya , Xie Zhen , Liu Gongping , Deng Ling , Mei Weijie , Zou Xiaoying , Zhong Yumei , Wu Yongquan , Guo Wei
Published: September 2021

A visible light catalyzed three‐component tandem annulation strategy for the synthesis of multiply substituted 1,2,4‐triazole‐3,5‐diamines from phenylhydrazines, isothiocyanatobenzenes and 1,1,3,3‐tetramethylguanidine is reported herein. The transformations proceed under simple and mild reaction conditions without the requirement of any external metals, ligands, and reductants. This one‐step procedure provides facile access to highly substituted 1,2,4‐triazole‐3,5‐diamines, which could be used in the field of medicinal chemistry.
Predesign of Catalytically Active Sites via Stable Coordination Cluster Model System for Electroreduction of CO2 to Ethylene
Authors: Lu Yun‐Feng , Dong Long‐Zhang , Liu Jiang , Yang Ru‐Xin , Liu Jing‐Jing , Zhang Yu , Zhang Lei , Wang Yi‐Rong , Li Shun‐Li , Lan Ya‐Qian
Published: September 2021

Purposefully designing the well‐defined catalysts for the selective electroreduction of CO2 to C2H4 is an extremely important but challenging work. In this work, three crystalline trinuclear copper clusters (Cu3‐X, X=Cl−, Br−, NO3−) have been designed, containing three active Cu sites with the identical coordination environment and appropriate spatial distance, delivering high selectivity for the electrocatalytic reduction of CO2 to C2H4. The highest faradaic efficiency of Cu3‐X for CO2‐to‐C2H4 conversion can be adjusted from 31.90 % to 55.01 % by simply replacing the counter anions (NO3−, Cl−, Br−). The DFT calculation results verify that Cu3‐X can facilitate the C−C coupling of identical *CHO intermediates, subsequently forming molecular symmetrical C2H4 product. This work provides an important molecular model system and a new design perspective for electroreduction of CO2 to C2 products with symmetrical molecular structure.
Missing‐Linker‐Assisted Artesunate Delivery by Metal–Organic Frameworks for Synergistic Cancer Treatment
Authors: Wang Dongdong , He Isabel Wenjia , Liu Jiawei , Jana Deblin , Wu Yinglong , Zhang Xiaodong , Qian Cheng , Guo Yi , Chen Xiaokai , Bindra Anivind Kaur , Zhao Yanli
Published: September 2021

Clinical translation of artesunate (ATS) as a potent antitumor drug has been obstructed by its rapid degradation and low bioavailability. Herein, we report the development of an ATS nanomedicine through the self‐assembly with Mn[Co(CN)6]2/3□1/3 metal–organic frameworks (MOFs) that have hidden missing linkers. The defects in MOFs originating from the missing linkers play a key role in increasing the biological stability and tumor accumulation of ATS. Chlorin e6 (Ce6) and ATS can be co‐loaded into MOFs for a synergistic antitumor efficacy. In the presence of intracellular HCO3−, Mn2+ acts as an efficient catalyst to promote the bicarbonate‐activated H2O2 system which oxidizes ATS to generate reactive oxygen species and induce oxidative death to cancer cells. The released [CoIII(CN)6] linker undergoes a redox reaction with intracellular glutathione to prevent the scavenging ability of reactive oxygen species, contributing to synergistic chemodynamic therapy of ATS and photodynamic therapy of Ce6. Thus, defect‐engineered MOFs with hidden missing linkers hold great promise in advancing the practical use of ATS as an antitumor medicine.
A General Strategy for Instantaneous and Continuous Synthesis of Ultrasmall Metal–Organic Framework Nanoparticles
Authors: Chang Miao , Wei Yan , Liu Dahuan , Wang Jie‐Xin , Chen Jian‐Feng
Published: September 2021

Ultrasmall metal–organic frameworks (MOFs) may generate unique properties to expand the scope of applications. However, the synthesis is still a great challenge. Herein, we propose a strategy to synthesize ultrasmall MOFs by high gravity technology. With the aid of tremendous intensification of molecular mixing and mass transfer in high‐gravity field, six typical MOFs were obtained instantaneously in a continuous way. These samples are monodispersed with sub‐5 nm in size, smaller than the previously reported values and even close to the length of one crystal unit cell. As a proof‐of‐concept, catalytic activity for Knoevenagel reaction can be significantly enhanced using ultrasmall ZIF‐8. Conversion time of benzaldehyde was decreased by 94 % or 75 % compared to those using conventional or hierarchically porous ZIF‐8. More importantly, this approach is readily scalable with the highest space‐time yield for nano‐MOFs, which may promote the convenient synthesis and practical applications of ultrasmall MOFs in large‐scale.
Redox‐Neutral Vicinal Difunctionalization of Five‐Membered Heteroarenes with Dual Electrophiles
Authors: Li Renhe , Dong Guangbin
Published: September 2021

A new reaction mode of palladium/norbornene (Pd/NBE) cooperative catalysis is reported involving the selective coupling of two different carbon‐based electrophiles for vicinal double C‐H functionalization of five‐membered heteroarenes in a site‐selective and redox‐neutral manner. The key is to use alkynyl bromides as the second electrophile, which allows vicinal difunctionalization of a wide range of heteroarenes including pyrroles, thiophenes and furans at their C4 and C5 positions. One‐ or two‐step tetrafunctionalizations of simple pyrrole and thiophene have also been realized. The C2‐substituted NBEs prove most effective in these reactions, and the mechanistic exploration discloses the origin of the high selectivity of this transformation. Synthetic utility of this method has been exemplified in the concise preparations of thiophene‐containing organic materials and a protein kinase inhibitor analogue. Preliminary success has also been achieved in a direct annulation event, using a tethered ketone as the second electrophile.
Osteological characteristics of the Setouchi salamander Hynobius setouchi (Urodela, Hynobiidae)
Authors: Hara Sotaro , Nishikawa Kanto
Published: September 2021

This study described the detailed osteological features of the Setouchi salamander Hynobius setouchi. H. setouchi, which is endemic to central Japan, was recently delineated from the wide range of H. nebulosus species based on molecular and external morphological characteristics. However, the osteological features of the species belonging to the genus Hynobius have not been examined, which has hindered the detailed understanding of morphological diversity in the genus. To address this problem, this study elucidated the osteological features of the salamander using micro‐computed tomography scanning and whole‐mount double staining methods. The articular, a part of the hypobranchial I, a part of coracoid, pubis, carpus, and tarsus were cartilaginous in small‐sized individuals and were partially or completely ossified in large‐sized individuals. The degree of ossification varied in the operculum, basibranchial II, and ascending process of the palatoquadrate. However, ossification was not associated with body size. The lacrimal, ossified manus, and ossified pes exhibited varying degrees of articulation or fusion irrespective of body size. Moreover, the cranium and tarsus of H. setouchi exhibited several unique characteristics. These osteological characteristics will aid in revising the taxonomy and phylogeny of the Hynobius species.
Nonheme Iron Imido Complexes Bearing a Non‐Innocent Ligand: A Synthetic Chameleon Species in Oxidation Reactions
Authors: Li Xiao‐Xi , Lu Xiaoyan , Park Jae Woo , Cho Kyung‐Bin , Nam Wonwoo
Published: September 2021

High‐valent iron‐imido complexes can perform C−H activation and sulfimidation reactions, but are far less studied than the more ubiquitous iron‐oxo species. As case studies, we have looked at a recently published iron(V)‐imido ligand π‐cation radical complex, which is formally an iron(VI)‐imido complex [FeV(NTs)(TAML+.)] (1; NTs=tosylimido), and an iron(V)‐imido complex [FeV(NTs)(TAML)]− (2). Using a theoretical approach, we found that they have multiple energetically close‐lying electromers, sometimes even without changing spin states, reminiscent of the so‐called Compound I in Cytochrome P450. When studying their reactivity theoretically, it is indeed found that their electronic structures may change to perform efficient oxidations, emulating the multi‐spin state reactivity in FeIVO systems. This is actually in contrast to the known [FeV(O)(TAML)]− species (3), where the reactions occur only on the ground spin state. We also looked into the whole reaction pathway for the C−H bond activation of 1,4‐cyclohexadiene by these intermediates to reproduce the experimentally observed products, including steps that usually attract no interest (neither theoretically nor experimentally) due to their non‐rate‐limiting status and fast reactivity. A new “clustering non‐rebound mechanism” is presented for this C−H activation reaction.
Outcomes of men with HIV and germ cell cancer: Results from an international collaborative study
Authors: Hentrich Marcus Ulrich , Bower Mark , Daugaard Gedske , Dieing Annette , Bickel Markus , Berretta Massimiliano , Lesmeister Florian , Jurinovic Vindi , Stoehr Albrecht , Heinzelbecker Julia , Krznaric Ivanka , Dieckmann Klaus‐Peter , Necchi Andrea , Maroto Rey Pablo , Rockstroh Jürgen Kurt , Brito Margarida , Pfister David , Hoffmann Christian
Published: September 2021

Background

Previous studies have shown that men with HIV and germ cell cancer (HIV‐GCC) have inferior overall survival (OS) in comparison with their HIV‐negative counterparts. However, little information is available on treatments and outcomes of HIV‐GCC in the era of combination antiretroviral therapy (cART).

Methods

This study examined men living with HIV who were 18 years old or older and had a diagnosis of histologically proven germ cell cancer (GCC). The primary outcomes were OS and progression‐free survival (PFS).

Results

Data for 89 men with a total of 92 HIV‐GCCs (2 synchronous GCCs and 1 metachronous bilateral GCC) were analyzed; among them were 64 seminomas (70%) and 28 nonseminomas (30%). The median age was 36 years, the median CD4 T‐cell count at GCC diagnosis was 420 cells/µL, and 77% of the patients on cART had an HIV RNA load < 500 copies/mL. Stage I disease was found in 44 of 79 gonadal GCCs (56%). Among 45 cases with primary disseminated GCC, 78%, 18%, and 4% were assigned to the good‐, intermediate‐, and poor‐prognosis groups, respectively, of the International Germ Cell Cancer Collaborative Group. Relapses occurred in 14 patients. Overall, 12 of 89 patients (13%) died. The causes of death were refractory GCC (n = 5), an AIDS‐defining illness (n = 3), and other causes (n = 4). After a median follow‐up of 6.5 years, the 5‐ and 10‐year PFS rates were 81% and 73%, respectively, and the 5‐ and 10‐year OS rates were 91% and 85%, respectively.

Conclusions

The 5‐ and 10‐year PFS and OS rates of men with HIV‐GCC were similar to those reported for men with HIV‐negative GCC. Patients with HIV‐GCC should be managed identically to HIV‐negative patients.

Lay Summary

Men living with HIV are at increased risk for germ cell cancer (GCC).

Previous studies have shown that the survival of men with HIV‐associated germ cell cancer (HIV‐GCC) is poorer than the survival of their HIV‐negative counterparts.

This study examined the characteristics, treatments, and outcomes of 89 men with HIV‐GCC in the era of effective combination antiretroviral therapies.

The long‐term outcomes of men with HIV‐GCC were similar to those reported for men with HIV‐negative GCC.

Patients with HIV‐GCC should be managed identically to HIV‐negative patients.
Maize diversity for fall armyworm resistance in a warming world
Authors: Singh G. Mahendra , Xu Jianchu , Schaefer Douglas , Day Roger , Wang Zhenying , Zhang Feng
Published: September 2021

Currently, maize (Zea maysL.) production is under threat from climate change, drought, and pests such as fall armyworm (FAW) [Spodoptera frugiperda(J.E. Smith) (Lepidoptera: Noctuidae)]. Since its first detection outside of its native range in 2016, FAW has spread into 76 nations across Africa and Asia adversely affecting maize production and, in turn, the livelihoods of millions of smallholder farmers. Thus, there is a strong need for the development of cost‐effective and biologically based integrated pest management (IPM) practices including host‐plant resistance (HPR). However, most of the commercial maize cultivars have lost some defensive traits through selective breeding for yield during domestication. The majority of the commercially cultivated hybrids and cultivars in Asia and Africa are highly susceptible to FAW. Therefore, this review summarizes information about various maize landraces, native germplasm, and crop wild relatives (CWRs) possessing FAW resistance traits and about their potential resistance mechanisms, namely antibiosis, antixenosis, and tolerance. There is clear evidence of FAW resistance acting through diverse mechanisms in several maize landraces, germplasm lines, native populations, and CWRs such as Antigua race, FAW Tuxpeno, Zapalote Chico 2451F, Doce Flor da Serra, FAWCC (C5), CMS 14C, PopG (C2), MpSWCB‐4, Mp708, Mp 704, CML 67, and FAW 7050, as well as a few species of teosinte andTripsacumL. Further, a scheme that outlines strategies and approaches for prebreeding and their introgression into elite cultivars for developing FAW‐resistant maize is proposed as a possible way forward.
Lithiation and Sodiation of Hydrogenated Silicene: A Density Functional Theory Investigation
Authors: Rehman Javed , Fan Xiaofeng , Samad Abdus , Zheng Weitao
Published: September 2021

The next‐generation renewable energy machineries necessitate the electrodes with appropriate electrochemical performance. Here, the anodic properties of silicane for Li‐ and Na‐ion batteries were scrutinized employing first‐principle calculations. The projected single‐layer hydrogen‐functionalized Si (Si2H2) structure was energetically, mechanically, dynamically, and thermally stable based on theoretical simulations, confirming its experimental feasibility. The electronic properties revealed the semiconducting nature of silicane on the basis of PBE and HSE06 schemes with an indirect bandgap. As anode material for Li‐ and Na‐ion batteries, hydrogenated silicene showed promising electrochemical performance because of the proper adsorption strength between Si2H2 and the adsorbed Li and Na. The average open circuit voltages for Li2xSi2H2 and Na2xSi2H2 were as low as 0.42 and 0. 64 V, while its specific capacity was as high as 921 and 1842 mAh g−1 for Li and Na, respectively. It also showed ultra‐fast diffusion channels for Li and Na ions. The diffusion barriers for Li and Na migrations were as low as 0.18 and 0.14 eV, respectively, which revealed rapid charge/discharge processes using hydrogenated silicene as anode. These important features facilitate silicane as favorable anode material for Li/Na‐ion batteries.
Interface‐Induced Self‐Assembly Strategy Toward 2D Ordered Mesoporous Carbon/MXene Heterostructures for High‐Performance Supercapacitors
Authors: Liu Zhilin , Xiong Hailong , Luo Yaxiao , Zhang Liangliang , Hu Kuo , Zhang Ling , Gao Yu , Qiao Zhen‐An
Published: September 2021

Invited for this month′s cover is the group of Zhen‐An Qiao at the Jilin University. The image shows the application of 2D ordered mesoporous carbon/MXene heterostructures in supercapacitors. The Full Paper itself is available at 10.1002/cssc.202101374.
Multi‐input multi‐phase transformerless large voltage conversion ratio DC/DC converter
Authors: Saadatizadeh Zahra , Chavoshipour Heris Pedram , Sabahi Mehran , Liang Xiaodong
Published: September 2021

This paper proposes a two‐input transformerless DC‐DC converter. The proposed converter has large voltage conversion ratio with low‐voltage and current stress on semiconductors and low input current ripple. It can transfer energy as two‐phase converter with three and four input voltage sources to increase the availability of the input voltage of the converter. Despite the capability of extending the number of the input sources up to four, the range of operating duty cycle for the switches and the voltage conversion ratio are remained the same as the values for two‐input topology of the proposed converter. By increasing diode‐capacitor (D‐C) cells in upper and lower modules, not only the amount of transferred energy will be increased, but also the voltage stress on semiconductors would be decreased. In this paper, theoretical analysis for continuous current mode (CCM), analysis under discontinuous current mode (DCM), voltage gain and voltages and currents of all of the elements are calculated. Finally, the performance of the proposed converter is confirmed by implemented prototype which converts two 40‐V input voltages to output voltage of 600 V with the power of 400 W.
Performance, environment, and cost‐benefit analysis of a split air conditioning unit usingHC‐290 andHCFC‐22
Authors: Saravanan A. Lalitha , Prabakaran Rajendran , Sidney Shaji , Kim Sung Chul , Lal Dhasan Mohan
Published: September 2021

A widely used hydrochlorofluorocarbon (HCFC) refrigerant HCFC‐22 in the split air conditioner (AC) is being phased out in all countries under the Montreal Protocol. Propane (HC‐290) is a favorable substitute for HCFC‐22. The performance, environment impact and cost‐benefit analysis of a split AC unit operated with HCFC‐22 and HC‐290 has been carried out experimentally under different test conditions prescribed by IS 1391. The results showed that the variation in system performance was more significant for HCFC‐22 than for that of HC‐290 while varying the refrigerant charge. The experienced optimum charges that represent the maximum coefficient of performance (COP) was varied with the working environment and it was realized that, generally the optimum charge for HC‐290 was 50% lesser than that of HCFC‐22. The COP of the AC unit with HC‐290 was observed to be 5% more than that of HCFC‐22. However, the system capacity diminished by 7.8%. The operation of a split AC unit with HC‐290 produced up to 15.9% lesser CO2emission than that of HCFC‐22 under all the test conditions. The use of HC‐290 in an existing HCFC‐22 split AC system can save up to 12.22% of the life time total cost. Finally, it was inferred that the replacement of HCFC‐22 with HC‐290 in the split AC unit showed dominance in all aspects such as performance, emission, and life time total cost.
On the accuracy, robustness, and performance of high order interpolation schemes for the overset method on unstructured grids
Authors: Lemaire Sébastien , Vaz Guilherme , Deij‐van Rijswijk Menno , Turnock Stephen R.
Published: September 2021

A comprehensive study on interpolation schemes used in overset grid techniques is here presented. Based on a literature review, numerous schemes are implemented, and their robustness, accuracy, and performance are assessed. Two code verification exercises are performed for this purpose: a 2D analytical solution of a laminar Poiseuille steady flow; and an intricate manufactured solution of a turbulent flow case, characteristic of a boundary layer flow combined with an unsteady separation bubble. For both cases, the influence of grid layouts, grid refinement, and time‐step is investigated. Local and global errors, convergence orders, and mass imbalance are quantified. In terms of computational performance, strong scalability, cpu timings, load imbalancing, and domain connectivity information (DCI) overhead are reported. The effect of the overset‐grid interpolation schemes on the numerical performance of the solver, that is, number of nonlinear iterations, is also scrutinized. The results show that, for a second order finite volume code, once diffusion is dominant (low Reynolds number), interpolation schemes higher than second order, for example, least squares of degree 2, are needed not to increase the total discretization errors. For convection dominated flows (high Reynolds numbers), the results suggest that second order schemes, for example, nearest cell gradient, are sufficient to prevent overset grid schemes to taint the underlying discretization errors. In terms of performance, by single‐process and parallel communication optimization, the total overset‐grid overhead (with DCI done externally to the CFD code) may be less than 4% of the total run time for second‐order schemes and 8% for third‐order ones, therefore empowering higher‐order schemes and more accurate solutions.
Characterization of cortical hemodynamic changes following sensory, visual, and speech activation by intraoperative optical imaging utilizing phase‐based evaluation methods
Authors: Oelschlägel Martin , Polanski Witold H. , Morgenstern Ute , Steiner Gerald , Kirsch Matthias , Koch Edmund , Schackert Gabriele , Sobottka Stephan B.
Published: September 2021

Alterations within cerebral hemodynamics are the intrinsic signal source for a wide variety of neuroimaging techniques. Stimulation of specific functions leads due to neurovascular coupling, to changes in regional cerebral blood flow, oxygenation and volume. In this study, we investigated the temporal characteristics of cortical hemodynamic responses following electrical, tactile, visual, and speech activation for different stimulation paradigms using Intraoperative Optical Imaging (IOI). Image datasets from a total of 22 patients that underwent surgical resection of brain tumors were evaluated. The measured reflectance changes at different light wavelength bands, representing alterations in regional cortical blood volume (CBV), and deoxyhemoglobin (HbR) concentration, were assessed by using Fourier‐based evaluation methods. We found a decrease of CBV connected to an increase of HbR within the contralateral primary sensory cortex (SI) in patients that were prolonged (30 s/15 s) electrically stimulated. Additionally, we found differences in amplitude as well as localization of activated areas for different stimulation patterns. Contrary to electrical stimulation, prolonged tactile as well as prolonged visual stimulation are provoking increases in CBV within the corresponding activated areas (SI, visual cortex). The processing of the acquired data from awake patients performing speech tasks reveals areas with increased, as well as areas with decreased CBV. The results lead us to the conclusion, that the CBV decreases in connection with HbR increases in SI are associated to processing of nociceptive stimuli and that stimulation type, as well as paradigm have a nonnegligible impact on the temporal characteristics of the following hemodynamic response.
CP‐25 exerts therapeutic effects in mice with dextran sodium sulfate‐induced colitis by inhibiting GRK2 translocation to downregulate the TLR4‐NF‐κB‐NLRP3 inflammasome signaling pathway in macrophages
Authors: Li Ying , Jiang Meng‐Ya , Chen Jing‐Yu , Xu Zhou‐Wei , Zhang Jia‐Wei , Li Tao , Zhang Ling‐Ling , Wei Wei
Published: September 2021

Deficiency of G protein‐coupled receptor kinase 2 (GRK2) was found to protect mice from dextran sulfate sodium (DSS)‐induced colitis. Paeoniflorin‐6′‐O‐benzene sulfonate (CP‐25) has been shown to exert anti‐inflammatory immune regulatory effects in animal models of inflammatory autoimmune disease. This study aimed to investigate the of GRK2 in the pathogenesis of ulcerative colitis (UC) and its effects on macrophage polarization, macrophage subtype regulation of intestinal barrier function, and therapeutic effects of CP‐25 in mice with DSS‐induced colitis. We found imbalanced macrophage polarization, intestinal barrier dysfunction, and abnormal activation of GRK2 and TLR4‐NF‐κB‐NLRP3 inflammasome signaling pathway in the colonic mucosa of patients with UC. CP‐25, restored the damaged intestinal barrier function by inhibiting the transmembrane region of GRK2 in macrophages stimulated by lipopolysaccharides. CP‐25 exerted therapeutic effects by ameliorating clinical manifestation, regulating macrophage polarization, and restoring abnormally activated TLR4‐NF‐κB‐NLRP3 inflammasome signaling pathway by inhibiting GRK2. These data suggest the pathogenesis of UC may be related to the imbalance of macrophage polarization, which leads to abnormal activation of TLR4‐NF‐κB‐NLRP3 inflammasome signaling pathway mediated by GRK2 and destruction of the intestinal mucosal barrier. CP‐25 confers therapeutic effects on colitis by inhibiting GRK2 translocation to induce the downregulation of TLR4‐NF‐κB‐NLRP3 inflammasome signaling in macrophages.
Measurement of glomerular filtration rate reveals that subcapsular injection of shear‐thinning hyaluronic acid hydrogels does not impair kidney function in mice
Authors: Soranno Danielle E. , Kirkbride‐Romeo Lara , Han Daniel , Altmann Christopher , Rodell Christopher B.
Published: September 2021

The continued development of minimally invasive therapeutic implants, such as injectable hydrogels, necessitates the concurrent advancement of methods to best assess their biocompatibility via functional outcomes in vivo. Biomaterial implants have been studied to treat kidney disease; however, assessment of biocompatibility has been limited to biomarker and histological assessments. Techniques now exist to measure kidney function serially in vivo in murine studies via transcutaneous measurements of glomerular filtration rate (tGFR). In this study, adult male and female wild‐type BalbC mice underwent right unilateral nephrectomy. The remaining solitary left kidney was allowed 4 weeks to recover via compensatory hypertrophy, after which subcapsular injection of either saline or shear‐thinning hyaluronic acid hydrogel was performed. Serial tGFR measurements before and after treatment were used to assess the effect of hydrogel injection on kidney filtration. Urine and serum biomarkers of kidney function, and kidney histology were also quantified. Hydrogel injection did not affect kidney function, as assessed by tGFR. Results were in agreement with standard metrics of serum and urine biomarkers of injury as well as histological assessment of inflammation. The model developed provides a direct functional assessment of implant compatibility for the treatment of kidney disease and impact on kidney function.
Characterization of the primo vascular system in rabbit vagina
Authors: Mustafa Fatma El‐Zahraa A. , Abdelhafez Enas A. , Abd‐Elhafeez Hanan H.
Published: September 2021

The primo vascular system (PVS) is observed in different parts of the body under different physiological and disease conditions. Previously, the PVS was not observed in the vagina. The vaginal samples of this study were collected from the female genitalia of healthy New Zealand white rabbits from the animal house, Faculty of Medicine, Assiut University. The vaginal samples were fixed in Bouin's solution. The sections were stained with hematoxylin and eosin and Crossmon's trichrome. Additionally, the sections were immunohistochemically stained with neuron‐specific enolase (NSE) and vascular endothelial growth factor (VEGF). A primo node was observed on the lymph vessel of the vagina and has several characteristics that resemble those of the previously discovered primo nodes. The primo node in this study was surrounded by mesothelial cells that provide positive immunoreactivity to NSE and VEGF. Sinuses of different sizes, floating cells, telocyte‐like cell, and primo microcells were observed as the main constituents of the primo node. Additionally, migratory cells were detected, which passed from the primo node to the enclosing lymph vessel.
Identification of Atlantic water inflow on the north Svalbard shelf during the Holocene
Authors: Peral Marion , Austin William E. N. , Noormets Riko
Published: September 2021

Nordaustlandet is located in the northeastern part of the Svalbard archipelago, within the northernmost reach of the West Spitsbergen Current. This current transports Atlantic water to the Arctic Ocean along the western and northern Svalbard margins. This region is well‐suited for reconstructing the history of changing Atlantic water inflow to the Arctic Ocean. We studied the marine sediment core HH12‐04‐GC from Rijpfjorden. Benthic foraminiferal assemblages and sedimentological data are combined to reconstruct the palaeoenvironment of the fjord from the end of the last local deglaciation to the late Holocene. The local deglaciation, between 11.3 and 10.6 cal ka bp, was dominated by active glacier calving processes, associated with a strong inflow of Atlantic water. This led to the establishment of glaciomarine conditions. The Holocene was initially characterised by a relatively stable and warm environment associated with a strong contribution of Atlantic water. Glaciomarine influence progressively decreases after 9.7 cal ka bp and the Atlantic water contribution increases. The late Holocene displayed a similar environment to today, with the influence of glaciomarine conditions and limited Atlantic water inflow. These results confirm that Atlantic water inflows made a continuous contribution to northern Nordaustlandet throughout the postglacial period.
Identifying crystallographic faces of the fluorites urania and thoria with rotational polarized Raman spectroscopy
Authors: Morgan Phyllis K. , Prusnick Timothy A. , Velez Michael A. , Rickert Karl , Turner David B. , Mann James Matthew
Published: September 2021

Crystallite orientation identification is invaluable, but is often limited to small area identification or requires a large area sample. Nondestructive optical methods such as polarized Raman spectroscopy, in contrast, can be used to completely map a variety of sample sizes, but their potential is not yet fully realized. Here, we report a systematic study of polarized Raman scattering of high‐quality, hydrothermally grown, single crystals of urania and thoria. The peak intensity variations for as‐grown major crystal planes, post‐growth polished crystal planes, and a post‐growth polished non‐crystallographic plane are directly linked to crystallographic orientation and crystal rotation, and agree with computed models. In particular, the parallel polarized peak intensity results are directly correlated with metal–oxygen–metal chains in the fluorite structure and can be used to determine both orientation and rotational alignment of a given crystal face if sufficiently small rotational steps are applied. These results are structure based, being applicable to the larger fluorite phase space, which is useful for optical, semiconductor, nuclear, and solid oxide fuel cell industries. Further, these results suggest that Raman spectroscopy can identify non‐crystallographic orientations that are not discernable by traditional means.
Melt Electrowriting of Amphiphilic Physically Crosslinked Segmented Copolymers
Authors: Bakirci Ezgi , Frank Andreas , Gumbel Simon , Otto Paul F. , Fürsattel Eva , Tessmer Ingrid , Schmidt Hans‐Werner , Dalton Paul D.
Published: September 2021

Various (AB)n and (ABAC)n segmented copolymers with hydrophilic and hydrophobic segments are processed via melt electrowriting (MEW). Two different (AB)n segmented copolymers composed of bisurea segments and hydrophobic poly(dimethyl siloxane) (PDMS) or hydrophilic poly(propylene oxide)‐poly(ethylene oxide)‐poly(propylene oxide) (PPO‐PEG‐PPO) segments, while the amphiphilic (ABAC)n segmented copolymers consist of bisurea segments in the combination of hydrophobic PDMS segments and hydrophilic PPO‐PEG‐PPO segments with different ratios, are explored. All copolymer compositions are processed using the same conditions, including nozzle temperature, applied voltage, and collector distance, while changes in applied pressure and collector speed altered the fiber diameter in the range of 7 and 60 µm. All copolymers showed excellent processability with MEW, well‐controlled fiber stacking, and inter‐layer bonding. Notably, the surfaces of all four copolymer fibers are very smooth when visualized using scanning electron microscopy. However, the fibers show different roughness demonstrated with atomic force microscopy. The non‐cytotoxic copolymers increased L929 fibroblast attachment with increasing PDMS content while the different copolymer compositions result in a spectrum of physical properties.
Consistent depiction of the acidic ischemic lesion with APT MRI—Dual RF power evaluation of pH‐sensitive image in acute stroke
Authors: Sun Phillip Zhe
Published: September 2021

Purpose

Amide proton transfer‐weighted (APTw) MRI provides a non‐invasive pH‐sensitive image, complementing perfusion and diffusion imaging for refined stratification of ischemic tissue. Although the commonly used magnetization transfer (MT) asymmetry (MTRasym) calculation reasonably corrects the direct RF saturation effect, it is susceptible to the concomitant semisolid macromolecular MT contribution. Therefore, this study aimed to compare the performance of MTRasym and magnetization transfer and relaxation‐normalized APT (MRAPT) analyses under 2 representative experimental conditions.

Methods

Multiparametric MRI scans were performed in a rodent model of acute stroke, including relaxation, diffusion, and Z spectral images under 2 representative RF levels of 0.75 and 1.5 µT. Both MTRasym and MRAPT values in the ischemic diffusion lesion and the contralateral normal areas were compared using correlation and Bland‐Altman tests. In addition, the acidic lesion volumes were compared.

Results

MRAPT measurements from the diffusion lesion under the 2 conditions were highly correlated (R2 = 0.97) versus MTRasym measures (R2 = 0.58). The pH lesion sizes determined from MRAPT analysis were in good agreement (178 ± 43 mm3 vs. 186 ± 55 mm3 for B1 of 0.75 and 1.5 µT, respectively).

Conclusions

The study demonstrated that MRAPT analysis could be generalized to moderately different RF amplitudes, providing a more consistent depiction of acidic lesions than the MTRasym analysis.
Clinical translational neuroimaging of the antioxidant effect of N‐acetylcysteine on neural microstructure
Authors: Yi Sue Y. , Barnett Brian R. , Poetzel McKenzie J. , Stowe Nicholas A. , Yu John‐Paul J.
Published: September 2021

Purpose

Oxidative stress and downstream effectors have emerged as important pathological processes that drive psychiatric illness, suggesting that antioxidants may have a therapeutic role in psychiatric disease. However, no imaging biomarkers are currently available to track therapeutic response. The purpose of this study was to examine whether advanced DWI techniques are able to sensitively detect the potential therapeutic effects of the antioxidant N‐acetylcysteine (NAC) in a Disc1 svΔ2 preclinical rat model of psychiatric illness.

Methods

Male and female Disc1 svΔ2 rats and age‐matched, sex‐matched Sprague‐Dawley wild‐type controls were treated with a saline vehicle or NAC before ex vivo MRI acquisition at P50. Imaging data were fit to DTI and neurite orientation dispersion and density imaging models and analyzed for region‐specific changes in quantitative diffusion metrics. Brains were further processed for cellular quantification of microglial density and morphology. All experiments were repeated for Disc1 svΔ2 rats exposed to chronic early‐life stress to test how gene‐environment interactions might alter effectiveness of NAC therapy.

Results

The DTI and neurite orientation dispersion and density imaging analyses demonstrated amelioration of early‐life, sex‐specific neural microstructural deficits with concomitant differences in microglial morphology across multiple brain regions relevant to neuropsychiatric illness with NAC treatment, but only in male Disc1 svΔ2 rats. Addition of chronic early‐life stress reduced the ability of NAC to restore microstructural deficits.

Conclusion

These findings provide evidence for a treatment pathway targeting endogenous antioxidant capacity, and the clinical translational utility of neurite orientation dispersion and density imaging microstructural imaging to sensitively detect microstructural alterations resulting from antioxidant treatment.
Leben im Untergrund
Authors: Groß Michael
Published: September 2021

Die Gesteinsschichten unterhalb des Bodens, den Pflanzen und Tiere nutzen, galten lange als unbelebt. Erst in den letzten zehn Jahren fand die Wissenschaft heraus, dass die Biosphäre der Erde sich unerwartet weit in die Tiefe ausdehnt. Manche Arten leben sogar von Kernenergie.
Stühle auf Hanfbasis
Authors: Bulmahn Maren
Published: September 2021

Ein Stuhl aus Hanffasern und Bioharz, Flaschen aus enzymatisch recycelten Textilien und ein CO2‐basierter Haushaltsreiniger sind ausgezeichnet worden.
Labor 4.0: Automatenteilchen
Authors: Waag Friedrich
Published: September 2021

Das Start‐up Autopronano aus Essen will kolloidale Nanopartikel besser verfügbar für die Forschung machen. Automatisierung ist dabei der Schlüssel zum Erfolg.
Transaktionen: Raus aus der Pandemiesenke
Authors: Schneider Bernd , Kellermeyer Florian
Published: September 2021

Günstige Finanzierungen, hohe Unternehmensbewertungen und die zunehmende Stabilisierung der Wirtschaft treiben Käufe und Verkäufe an. Investoren gründen sogar Erwerbsgesellschaften, die nur dazu da sind, junge Firmen schnell an die Börse zu bringen.
Chemiedidaktik: Wie reduktive Spaltung einen Wirkstoff freisetzt
Authors: Ducci Matthias
Published: September 2021

Der menschliche Organismus spaltet Azofarbstoffe und bildet dabei aromatische Amine. Die Pharmakologie macht sich dies zunutze: mit dem Prodrug‐Konzept. Was dabei chemisch passiert, können Schüler:innen in Experimenten am Beispiel eines Medikaments gegen eine chronisch‐ entzündliche Darmerkrankung herausfinden.
Quantifying the Spatial Structure of Invasive Lake Trout in Yellowstone Lake to Improve Suppression Efficacy
Authors: Williams Jacob R. , Guy Christopher S. , Bigelow Patricia E. , Koel Todd M.
Published: September 2021

Invasive Lake Trout Salvelinus namaycush have altered the once-pristine Yellowstone Lake ecosystem through top-down effects by consuming Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri. To conserve Yellowstone Cutthroat Trout and restore the ecosystem, a Lake Trout gillnetting program was implemented to suppress the invasive population. We evaluated the spatial structure of Lake Trout in Yellowstone Lake with the intent of increasing suppression efficiency. Specifically, we addressed questions related to adult Lake Trout aggregation and movement during summer and autumn (spawning) periods and how Lake Trout used locations in the context of suppression efforts. We tracked 373 Lake Trout (>500 mm TL) during the summer and autumn of 2016 and 2017. Based on kernel density estimates, Lake Trout were highly aggregated at 9 locations during summer and 22 locations during the spawning period. Using a novel metric, individual days (product of mean individuals per survey and mean length of stay), five summer locations and five spawning locations had at least 30 individual days. These locations are suggested as priority areas for targeting Lake Trout suppression. Lake Trout were less aggregated and moved less during the summer, making them less vulnerable to a passive gear in the summer than during the autumn spawning period. Lake Trout exhibited low spawning site fidelity compared to populations elsewhere, possibly due to decades of intensive gill netting at spawning locations. Given the aggregation and movement patterns observed in Yellowstone Lake, continuing to target adult Lake Trout during the spawning period is the most cost-effective approach to Lake Trout suppression.
Perinatal burials at pre‐Hispanic noncemetery sites in Gran Canaria: Tophet, infanticide, or natural mortality?
Authors: Alberto‐Barroso Verónica , Delgado‐Darias Teresa , Ordóñez Alejandra C. , Serrano Javier G. , Fregel Rosa , Velasco‐Vázquez Javier
Published: September 2021

In this paper, we perform the first multidisciplinary study of perinatal burials at a pre‐Hispanic domestic site in Gran Canaria. For that, we carried out bioanthropological analyses, the genetic determination of the molecular sex of the individuals, and the contextualization of their chronological and cultural affiliations. To date, these remains had been associated to a local re‐interpretation of a Phoenician‐Punic tophet or as evidence of female infanticide within the mechanisms of demographic control of the ancient Canarians. However, these proposals did not take into account the recurrence of this type of human remains outside the normative cemeteries of the indigenous population or considered the demographic profile of coetaneous necropolises. In the light of the age of death and the molecular sex of the individuals, and the results obtained from the taphonomic and chronological analyses, we propose an alternative historical scenario, directly linked to high perinatal mortality rates and the development of specific burial practices for those individuals that died around the time of birth.
Multiplex fluorescence imaging‐guided programmed delivery of doxorubicin and curcumin from a nanoparticles/hydrogel system for synergistic chemotherapy
Authors: Sheng Shupei , Wei Chang , Ma Teng , Zhang Yan , Zhu Dunwan , Dong Xia , Lv Feng
Published: September 2021

Synergistic chemotherapy of doxorubicin and curcumin (CUR) is an important strategy for cancer therapy to compensate for the single drug chemotherapy. Programmed and precise delivery of drugs plays a crucial role for optimizing the mode of administration and revealing the mechanism of synergistic chemotherapy. Herein, multiplex fluorescence imaging‐guided programmed delivery of doxorubicin and CUR was achieved by a nanoparticles/hydrogel system for synergistic chemotherapy. CUR‐loaded nanoparticles and doxorubicin were co‐loaded into hydrogel to construct a synergistic chemotherapy drug delivery system. The hydrogel‐nanoparticles combined system can effectively achieve the programmed delivery of hydrophilic drug and hydrophobic drug for the synergistic chemotherapy. They exerted the on‐demand spatiotemporal delivery of doxorubicin and CUR. The combined chemotherapy system significantly inhibited the tumor growth compared to single therapy. Moreover, the programmed delivery of doxorubicin and CUR was visualized precisely based on their self‐fluorescence instead of extra fluorescent tags at the cellular level and in vivo lever using multiplex fluorescence imaging technology. It afforded an imaging guidance for the controllable synergistic chemotherapy based on programmed delivery.
Structure‐based design of a photoswitchable affibody scaffold
Authors: Woloschuk Ryan M. , Reed P. Maximilian M. , Jaikaran Anna S. I. , Demmans Karl Z. , Youn Jeffrey , Kanelis Voula , Uppalapati Maruti , Woolley G. Andrew
Published: September 2021

Photo‐control of affinity reagents offers a general approach for high‐resolution spatiotemporal control of diverse molecular processes. In an effort to develop general design principles for a photo‐controlled affinity reagent, we took a structure‐based approach to the design of a photoswitchable Z‐domain, among the simplest of affinity reagent scaffolds. A chimera, designated Z‐PYP, of photoactive yellow protein (PYP) and the Z‐domain, was designed based on the concept of mutually exclusive folding. NMR analysis indicated that, in the dark, the PYP domain of the chimera was folded, and the Z‐domain was unfolded. Blue light caused loss of structure in PYP and a two‐ to sixfold change in the apparent affinity of Z‐PYP for its target as determined using size exclusion chromatography, UV‐Vis based assays, and enyzme‐linked immunosorbent assay (ELISA). A thermodynamic model indicated that mutations to decrease Z‐domain folding energy would alter target affinity without loss of switching. This prediction was confirmed experimentally with a double alanine mutant in helix 3 of the Z‐domain of the chimera (Z‐PYP‐AA) showing >30‐fold lower dark‐state binding and no loss in switching. The effect of decreased dark‐state binding affinity was tested in a two‐hybrid transcriptional control format and enabled pronounced light/dark differences in yeast growth in vivo. Finally, the design was transferable to the αZ‐Taq affibody enabling tunable light‐dependent binding both in vitro and in vivo to the Z‐Taq target. This system thus provides a framework for the focused development of light switchable affibodies for a range of targets.