bluuebunny/crossref_metadata_2025 huggingface dataset:
Low‐Spin and High‐Spin Perferryl Intermediates in Non‐Heme Iron Catalyzed Oxidations of Aliphatic C−H Groups
Authors: Zima Alexandra M. , Lyakin Oleg Y. , Bryliakov Konstantin P. , Talsi Evgenii P.
Published: March 2021

The selectivity patterns of iron catalysts of the Fe(PDP) family in aliphatic C−H oxidation with H2O2 have been studied (PDP=N,N′‐bis(pyridine‐2‐ylmethyl)‐2,2′‐bipyrrolidine). Cyclohexane, adamantane, 1‐bromo‐3,7‐dimethyloctane, 3,7‐dimethyloctyl acetate, (−)‐acetoxy‐p‐menthane, and cis‐1,2‐dimethylcyclohexane were used as substrates. The studied catalyst systems generate low‐spin (S=1/2) oxoiron(V) intermediates or high‐spin (S=3/2) oxoiron(V) intermediates, depending on the electron‐donating ability of remote substituents at the pyridine rings. The low‐spin perferryl intermediates demonstrate lower stability and higher reactivity toward aliphatic C−H groups of cyclohexane than their high‐spin congeners, according to the measured self‐decay and second‐order rate constants k1 and k2. Unexpectedly, there appears to be no uniform correlation between the spin state of the oxoiron(V) intermediates, and the chemo‐ and regioselectivity of the corresponding catalyst systems in the oxidation of the considered substrates. This contrasts with the asymmetric epoxidations by the same catalyst systems, in which case the epoxidation enantioselectivity increases when passing from the systems featuring the more reactive low‐spin perferryl intermediates to those with their less reactive high‐spin congeners.
[10]CPP‐Based Inclusion Complexes of Charged Fulleropyrrolidines. Effect of the Charge Location on the Photoinduced Electron Transfer
Authors: Stasyuk Olga A. , Stasyuk Anton J. , Solà Miquel , Voityuk Alexander A.
Published: March 2021

A number of non‐covalently bound donor‐acceptor dyads, consisting of C60 as the electron acceptor and cycloparaphenylene (CPP) as the electron donor, have been reported. A hypsochromic shift of the charge transfer (CT) band in polar medium has been found in [10]CPP⊃Li+@C60. To explore this anomalous effect, we study inclusion complexes [10]CPP⊃Li+@C60‐MP, [10]CPP⊃C60‐MPH+, and [10]CPP⊃C60‐PPyMe+ formed by fulleropyrrolidine derivatives and [10]CPP using the DFT/TDDFT approach. We show that the introduction of a positively charged fragment into fullerene stabilizes CT states that become the lowest‐lying excited states. These charge‐separated states can be generated by the decay of locally excited states on a nanosecond to picosecond time scale. The distance of the charged fragment to the center of the fullerenic cage and its accessibility to the solvent determine the strength of the hypsochromic shift.
Cyclopentadienone Derivative Dimers as Tunable Photoswitches
Authors: Lu Ru‐Qiang , Zhuo You‐Zhen , Bao Yue‐Hua , Yang Lin‐Lin , Qu Hang , Tang Xiao , Wang Xin‐Chang , Li Zhi‐Hao , Cao Xiao‐Yu
Published: March 2021

A series of photoswitchable cyclopentadienone derivative dimers bearing bromo, thienyl, 4‐(dimethylamino)phenyl, 3‐pyridinyl, 4‐nitrophenyl and cyano groups was designed and facilely synthesized. Photoswitching properties such as the photoconversions in the photostationary state (PSS), the thermal kinetics and thermal half‐lives of photoisomers were systematically investigated. These photoswitches show high fatigue resistance and large photoconversions in the PSS. This work proves that the photoswitching properties of photoswitches based on cyclopentadienone dimers can be tuned by substitution groups and also pave the way to functionalize the cyclopentadienone derivative dimer‐based photoswitch, which is important for its future applications.
Photo‐/Electroinduced Irreversible Isomerization of 2,2’‐Azobispyridine Ligands in Arene Ruthenium(II) Complexes
Authors: Long Jonathan , Kumar Divyaratan , Deo Claire , Retailleau Pascal , Dubacheva Galina V. , Royal Guy , Xie Juan , Bogliotti Nicolas
Published: March 2021

Novel arene RuII complexes containing 2,2’‐azobispyridine ligands were synthesized and characterized by using 1H and 13C NMR spectroscopy, UV/vis spectroscopy, electrochemistry, DFT calculations and single‐crystal X‐ray diffraction. Z‐configured complexes featuring unprecedented seven‐membered chelate rings involving the nitrogen atom of both pyridines were isolated and were shown to undergo irreversible isomerization to the corresponding E‐configured five‐membered chelate complexes in response to light or electrochemical stimulus.
DNA‐Scaffolded Disulfide Redox Network for Programming Drug‐Delivery Kinetics
Authors: Ji Wei , Li Xiaodan , Xiao Mingshu , Sun Yueyang , Lai Wei , Zhang Hongbo , Pei Hao , Li Li
Published: March 2021

In response to specific stimuli, dynamic covalent materials enable the generation of new structures by reversibly forming/breaking chemical bonds, thus showing great potential for application in controlled drug release. However, using dynamic covalent chemistry to program drug‐delivery kinetics remains challenging. Herein, an in situ polymerization‐generated DNA‐scaffolded disulfide redox network (DdiSRN) is reported in which nucleic acids are used as a scaffold for dynamic disulfide bonds. The constructed DdiSRN allows selective release of loading cargos inside cancer cells in response to redox stimuli. Moreover, the density of disulfide bonds in network can be tuned by precise control over their position and number on DNA scaffolds. As a result, drug‐delivery kinetics can be programmed with a half‐life, t1/2, decreasing from 8.3 to 4.4 h, thus facilitating keeping an adequate drug concentration within the therapeutic window. Both in vitro and in vivo studies confirm that co‐delivery of DOX and siRNA in combination with fast drug release inside cells using this DdiSRN enhances the therapeutic effect on multidrug‐resistant cancer. This nontrivial therapeutic platform enabling kinetic control provides a good paradigm for precision cancer medicine.
Activated Self‐Resolution and Error‐Correction in Catalytic Reaction Networks**
Authors: Schaufelberger Fredrik , Ramström Olof
Published: March 2021

Understanding the emergence of function in complex reaction networks is a primary goal of systems chemistry and origin‐of‐life studies. Especially challenging is to create systems that simultaneously exhibit several emergent functions that can be independently tuned. In this work, a multifunctional complex reaction network of nucleophilic small molecule catalysts for the Morita‐Baylis‐Hillman (MBH) reaction is demonstrated. The dynamic system exhibited triggered self‐resolution, preferentially amplifying a specific catalyst/product set out of a many potential alternatives. By utilizing selective reversibility of the products of the reaction set, systemic thermodynamically driven error‐correction could also be introduced. To achieve this, a dynamic covalent MBH reaction based on adducts with internal H‐transfer capabilities was developed. By careful tuning of the substituents, rate accelerations of retro‐MBH reactions of up to four orders of magnitude could be obtained. This study thus demonstrates how efficient self‐sorting of catalytic systems can be achieved through an interplay of several complex emergent functionalities.
On the Reactivity Enhancement of Graphene by Metallic Substrates towards Aryl Nitrene Cycloadditions
Authors: Yang Xiaojian , Chen Feiran , Kim Min A. , Liu Haitao , Wolf Lawrence M. , Yan Mingdi
Published: March 2021

Pristine graphene is fairly inert chemically, and as such, most application‐driven studies use graphene oxide, or reduced graphene oxide. Using substrates to modulate the reactivity of graphene represents a unique strategy in the covalent functionalization of this otherwise fairly inert material. It was found that the reactivity of pristine graphene towards perfluorophenyl azide (PFPA) can be enhanced by a metal substrate on which graphene is supported. Results on the extent of functionalization, defect density, and reaction kinetics all show that graphene supported on Ni (G/Ni) has the highest reactivity toward PFPA, followed by G/Cu and then G/silicon wafer. DFT calculations suggest that the metal substrate stabilizes the physisorbed nitrene through enhanced electron transfer to the singlet nitrene from the graphene surface assisted by the electron rich metal substrate. The G/Ni substantially stabilizes the singlet nitrene relative to G/Cu and the free‐standing graphene. The product structure is also predicted to be substrate dependent. These findings open up opportunities to enhance the reactivity of pristine graphene simply through the selection of the substrate. This also represents a new and powerful approach to increasing the reactivity of singlet nitrenes through direct electronic communication with graphene.
Binding of a TlCl Entity by a Tetragold Tetramercaptothiacalixarene Metalloligand via Metallophilic Interactions
Authors: Frank N. , Pryjomska‐Ray I. , Grubert L. , Hecht S. , Usvyat D. , Limberg C.
Published: March 2021

The successive auration of p‐tert‐butyltetramercaptotetrathiacalix[4]arene, H4(MTC[4]), with gold(I) phosphine units was investigated. Through deprotonation with NaOMe, followed by salt metathesis reactions with (PR3)AuCl (R=Me, Ph) complexes with two and three [(PR3)Au]+ moieties could be prepared and isolated, namely [(Ph3PAu)2H2(MTC[4])] and [(Me3PAu)3H(MTC[4])]. In [(Me3PAu)3H(MTC[4])] two gold atoms already come close enough to undergo aurophilic interactions. To introduce a fourth [(PR3)Au]+ entity TlOEt had to be used for the deprotonation, which led to the finding that four gold atoms organised by the (MTC[4])4− coordination platform are able to bind and stabilize a TlCl entity, yielding [(Me3PAu)4TlCl(MTC[4])]. As evidenced by structural and theoretical investigations the binding occurs through strong metallophilic interactions, which lead to photoluminescence at low temperatures.
N‐Doped Porous Carbon Derived from Solvent‐Free Synthesis of Cross‐Linked Triazine Polymers for Simultaneously Achieving CO2 Capture and Supercapacitors
Authors: Wang Yuan , Xiao Jianfei , Wang Hanzhi , Zhang Tian C. , Yuan Shaojun
Published: March 2021

It is highly desirable to design advanced heteroatomic doped porous carbon for wide application. Herein, N‐doped porous carbon (NPC) was developed via the fabrication of high nitrogen cross‐linked triazine polymers followed by pyrolysis and activation with controllable porous structure. The as‐synthesized NPC at the pyrolysis temperature of 700 °C possessed rich nitrogen content (up to 11.51 %) and high specific surface area (1353 m2 g−1), which led to a high CO2 adsorption capability at 5.67 mmol g−1 at 298.15 K and 5 bar pressure and excellent stability. When the activation temperature was at 600 °C, such NPC exhibited a superior electrochemical performance as anode for supercapacitors with a specific capacitance of 158.8 and 113 F g−1 in 6 M KOH at a current density of 1 and 10 A g−1, respectively. Notably, it delivered an excellent stability with capacity retention of 97.4 % at 20 A g−1after 6000 cycles.
Kinetic study of pyrolysis of high‐density polyethylene (HDPE) waste at different bed thickness in a fixed bed reactor
Authors: Li Haoyu , Mašek Ondřej , Harper Alan , Ocone Raffaella
Published: March 2021

The aim of this study is to investigate the kinetic characteristics of the high‐density polyethylene (HDPE) waste pyrolysis process based on thermogravimetric analysis (TGA) and using a fixed bed pyrolytic reactor (FBPR) at different temperatures. In addition, the influence of material bed thickness on the yield distribution and the composition of products was examined over a temperature range of 425–550°C. A higher wax fraction was obtained in the thin bed of the FBPR bed at 425°C. With temperature above 500°C, more oil and wax products were generated in the thick bed of the FBPR. Based on the experimental study, a discrete first‐order kinetic lumping model, comprising three independent parallel reactions (lumps), was developed to describe the yield distribution of gases, oil fractions, wax fractions, and solid residue, coupling with secondary cracking reactions of the wax fractions into lighter fractions (i.e., oil and gas). The overall apparent activation energy (Ea) and pre‐exponential factor (A0) of HDPE pyrolysis were estimated in the FBPR. The results showed that the thickness of the bed of plastics has a pronounced influence on the pyrolysis kinetics of HDPE.
Capacitive Impedance for Following In‐Situ Grafting Kinetics of Diazonium Salts
Authors: Shkirskiy Viacheslav , Levillain Eric , Gautier Christelle
Published: March 2021

A new method to follow in‐situ grafting kinetics of diazonium compounds based on imposing small amplitude high frequency AC oscillations at grafting potential, is outlined. This enables the time‐resolved measurements of capacitive impedance concomitantly with the growth of the organic layer at the working electrode. The impedance values were quantitatively correlated with the ex‐situ (from voltammograms) and in‐situ (from quartz crystal microbalance) measured surface coverages, providing a validation of the new methodology. The versatility of the developed approach was demonstrated on the grafting via reduction of 4‐nitrobenzenediazonium on Au and glassy carbon (GC) substrates and via deposition of in‐situ generated diazonium salts from 1‐aminoanthraquinone and 4‐ferrocenylaniline on GC. The capacitive impedance measurements are simple, fast, and non‐destructive, making it an appealing methodology for an exploration of grafting kinetics of a wide range of diazonium salts.
Efficient Photocatalytic CO2 Reformation of Methane on Ru/La‐g‐C3N4 by Promoting Charge Transfer and CO2 Activation**
Authors: Li Naixu , Li Xianhe , Pan Rui , Cheng Miao , Guan Jie , Zhou Jiancheng , Liu Maochang , Tang Junwang , Jing Dengwei
Published: March 2021

Artificial photosynthesis, in which solar energy drives CO2 to produce hydrocarbon fuels, is considered an effective way to solve the increasingly serious energy crisis and mitigate the greenhouse effect. Herein, layered porous Ru‐loaded and La‐doped g‐C3N4 nanosheets (Ru‐LGCNs) were prepared by one‐step calcination, followed by in situ photoreduction deposition of Ru. The layered Ru‐LGCN showed excellent photocatalytic CO2 reformation of methane performance under visible light, and the generation rates of CO, CH3CH3, CH3OH and CH3CH(OH)CH3 were 133, 154, 251 and 133 μmol h−1 g−1, respectively. The reason for the enhanced photocatalytic activity of Ru‐LGCN is the synergistic effect of bimetallic Ru and La. It is worth noting that the doped La can provide a good channel for charge transfer between LGCNs and CO2. This change in the charge behavior of the transport path is beneficial to break the C=O bonds on the active site La and generate methyl radicals on Ru, resulting in the generation of C2+ hydrocarbons.
Modification of Ti‐doped Hematite Photoanode with Quasi‐molecular Cocatalyst: A Comparison of Improvement Mechanism Between Non‐noble and Noble Metals
Authors: Wang Ruiling , Kuwahara Yasutaka , Mori Kohsuke , Qian Xufang , Zhao Yixin , Yamashita Hiromi
Published: March 2021

Loading of molecular catalyst on the surface of semiconductors is an attractive way to boost the water oxidation activity. As active sites, molecular water oxidation cocatalysts show increasing attraction and application possibility. In order to compare the advantages between molecular catalysts with non‐noble and noble metals, the loading of the Fe(salen) and Ru(salen) as cocatalyst precursors on the surface of Ti−Fe2O3 was investigated Quasi‐Fe(salen) and Ru(salen) improved the photocurrent density by 1.5 and 1.7 times compared to that of the original Ti−Fe2O3 photoanode, respectively. The quasi‐Fe(salen) could improve the conductivity and reaction kinetics on the photoanode surface. By contrast, the notable advancements could be attributed to more reaction sites for quasi‐Ru(salen) as cocatalysts. Thus, non‐noble quasi‐Fe(salen) is a promising cocatalyst to replace the noble metal salen, and further optimization can be expected with regard to the precise control of reaction sites.
A novel soft‐switched interleaved high step‐up DC–DC converter for high‐efficiency conversion
Authors: Ghaffarpour Sadighi Hossein , Afjei Seyed Ebrahim , Salemnia Ahmad
Published: March 2021

The present study aims to present a new interleaved soft‐switched high step‐up DC–DC converter, which is suitable for renewable energy sources, by integrating built‐in transformer. A high conversion ratio is achieved by adjusting the turns ratio of the built‐in transformer and duty cycle. The proposed converter uses active clamped circuit, which provides zero‐voltage switching (ZVS) and a zero‐current switching (ZCS) operation for all switches and diodes, respectively. Therefore, the losses caused by reverse recovery are considerably alleviated by providing ZCS condition in the diodes. The proposed structure has some advantages such as low‐voltage stress across power switches, very low‐input current ripple, fewer components, and lower cost. The MOSFET with low drain‐source resistance can be used due to the low‐voltage stress, which could reduce conduction losses. Furthermore, a 500‐W, 48‐V input to 380‐V output laboratory prototype is built and tested to validate the performance of the proposed topology.
Optimal allocation of law enforcement patrol effort to mitigate poaching activities
Authors: Moore Jennifer F. , Udell Bradley J. , Martin Julien , Turikunkiko Ezechiel , Masozera Michel K.
Published: March 2021

Poaching is a global problem causing the decline of species worldwide. Optimizing the efficiency of ranger patrols to deter poaching activity at the lowest possible cost is crucial for protecting species with limited resources. We applied decision analysis and spatial optimization algorithms to allocate efforts of ranger patrols throughout a national park. Our objective was to mitigate poaching activity at or below management risk targets for the lowest monetary cost. We examined this trade‐off by constructing a Pareto efficiency frontier using integer linear programming. We used data from a ranger‐based monitoring program in Nyungwe National Park, Rwanda. Our measure of poaching risk is based on dynamic occupancy models that account for imperfect detection of poaching activities. We found that in order to achieve a 5% reduction in poaching risk, 622 ranger patrol events (each corresponding to patrolling 1‐km2 sites) were needed within a year at a cost of US$49,760. In order to attain a 60% reduction in poaching risk, 15,560 patrol events were needed at a cost of US$1,244,800. We evaluated the trade‐off between patrol cost and poaching risk based on our model by constructing a Pareto efficiency frontier and park managers found the solution for a 50% risk reduction to be a practical trade‐off based on funding constraints (comparable to recent years) and the diminishing returns between risk mitigation and cost. This expected reduction in risk required 8,558 patrol events per year at a cost of US$684,640. Our results suggest that optimal solutions could increase efficiency compared to the actual effort allocations from 2006 to 2016 in Nyungwe National Park (e.g., risk reductions of ~30% under recent budgets compared to ~50% reduction in risk under the optimal strategy). The modeling framework in this study took into account imperfect detection of poaching risk as well as the directional and conditional nature of ranger patrol events given the spatial adjacency relationships of neighboring sites and access points. Our analyses can help to improve the efficiency of ranger patrols, and the modeling framework can be broadly applied to other spatial conservation planning problems with conditional, multilevel, site selection.
Bone quality assessed by trabecular bone score in severe anorexia nervosa: A brief report
Authors: Watters Ashlie , Fielding Linda , Mehler Philip S.
Published: March 2021

Objective

Low bone mineral density (BMD) in anorexia nervosa (AN) leads to increased risk of fractures. Debate exists whether to medicinally treat young patients with AN based on abnormal dual‐energy x‐ray absorptiometry (DXA) scores or to weight restore and reassess when older. Trabecular bone score (TBS), a technology measuring bone quality, is used in conjunction with DXA. This report explores the potential additional value of TBS, in adults with severe AN, to augment the DXA diagnostic information.

Method

Seventy‐one DXA scans were reanalyzed to obtain TBS results from patients (mean age: 36.3 years). Differences in laboratory, anthropometric values and concomitant DXA measurements in relation to TBS results are reported.

Results

For the cohort, mean body mass index (BMI) was 13.6 kg/m2 (SD: 2.1). The vast majority of patients had normal TBS with a mean of 1.395 (SD: 0.08) but, most patients (69%) had abnormal average DXA BMD Z‐scores of −2.2 (SD: 1.2). The patients who also demonstrated degraded bone quality on TBS had significantly lower percent ideal body weight and elevated alkaline phosphatase compared to patients with normal TBS (p's < .05).

Discussion

Low BMD treatment decisions in AN may be optimized by considering both DXA and TBS results.
In Her Wake: On Blackness and Being on Our Own Terms
Authors: Daniel Barnes Riché J.
Published: March 2021

In this reflective piece, scholar Riché Barnes tacks back and forth between her own biography as it intertwined with the biography of Leith Mullings, who was her first graduate student advisor. As an anthropologist invested in Black feminist thought, Barnes explores what it means to live in the wake of Leith Mullings.
Ultrahigh‐temperature mafic granulites from the Madurai Block, southern India: Constraints from conventional thermobarometry, pseudosection analysis, and rare earth element‐based thermometry
Authors: Ray Srijita , Tiwari Ashish Kumar , Sarkar Tapabrato
Published: March 2021

The determination of metamorphic pressure–temperature (P–T) conditions of granulites provides us a natural window into the composition, structure, and P–T conditions of the lower crust and process of continental growth. Here, we constrain the P–T evolution of a suite of mafic granulite from the eastern part of Madurai Block. Integrated results from mineral reactions, conventional thermobarometry, and pseudosection analysis suggest that the studied mafic granulites, with a peak assemblage of coarse‐grained garnet + coarse‐grained clinopyroxene + plagioclase + quartz + [rutile], were metamorphosed under granulite facies conditions of 830 ± 50°C and 9.5 ± 1 kbar. Subsequently, the rocks underwent near isothermal decompression leading to the formation of symplectic assemblages of clinopyroxene + orthopyroxene + plagioclase and orthopyroxene + ilmenite, within a P–T range of 9.0–5.5 kbar and 750–800°C. The estimated peak temperature conditions are somewhat lower than those obtained using characteristic ultra‐high temperature (UHT) mineral assemblages and non‐conventional thermometers (~1,000°C at ~10 kbar) from the co‐metamorphosed metapelitic granulites of the Madurai Block. This may be attributed to the high diffusion rate of divalent Fe and Mg, which often results in retrograde re‐equilibration leading to considerable underestimation of peak temperatures in mafic granulites. To overcome this problem, we have additionally determined peak metamorphic temperatures of the studied rocks using a recently developed garnet–clinopyroxene rare earth element (REE)‐based thermometer that takes advantage of much lower diffusion rate of trivalent REEs. Using the REE thermometer, we have obtained a peak temperature of 1,050 ± 50°C for the studied rocks, which is in reasonable agreement with the peak metamorphic temperature obtained from previous studies. The constrained P–T conditions and the clockwise P–T path suggest that the studied rocks were buried to lower crustal depths at UHT conditions in a convergent margin setting. The near isothermal decompression suggests rapid exhumation, most likely due to an extensional event. The peak UHT metamorphic conditions could have been attained at the core of a long‐lived orogenic plateau, as suggested by other studies.
When responsive and reactive meet organic? Treatment implications of language use in the era of #BanBPSD
Authors: Macfarlane Stephen , Atee Mustafa , Morris Thomas , Cunningham Colm
Published: March 2021

Key points

The aetiopathogenesis of behaviours and psychological symptoms of dementia (BPSD) is often subjective, complex and multifaceted, produced by an array of contributing factors, including biomedical, psychological, environmental and/or social factors

Alongside other contributing factors, organic aetiology of BPSD should be considered when devising therapeutic management plans

Although considered last resort, time‐limited antipsychotic treatment (≤3 months) may have a vital adjunct role in managing intractable, refractory, distressing and/or life‐threatening BPSD, such as delusions and hallucinations; but only after person‐centred psychosocial interventions are exhausted and fail to deliver any therapeutic response

If prescribed, careful monitoring of therapeutic responses and adverse effects of antipsychotics with de‐prescribing plans should be a top priority, as these agents have limited efficacies and serious adverse outcomes (e.g., mortality)
Suppression of NF‐κB‐induced chronic inflammation mitigates inflammatory osteolysis in the murine continuous polyethylene particle infusion model
Authors: Utsunomiya Takeshi , Zhang Ning , Lin Tzuhua , Kohno Yusuke , Ueno Masaya , Maruyama Masahiro , Huang Ejun , Rhee Claire , Yao Zhenyu , Goodman Stuart B.
Published: March 2021

Wear particle‐associated bone loss (periprosthetic osteolysis) constrains the longevity of total joint arthroplasty (TJA). Wear particles induce a prolonged upregulation of nuclear factor kappa B (NF‐κB) signaling in macrophages and osteoclasts. Synthetic double‐stranded oligodeoxynucleotides (ODNs) can prevent the binding of NF‐κB to the promoter regions of targeted genes and inhibit genetic activation. We tested the hypothesis that polyethylene‐particle induced chronic inflammatory bone loss could be suppressed by local delivery of NF‐κB decoy ODNs in murine in vivo model. Polyethylene particles were continuously infused into the medullary cavity of the distal femur for 6 weeks to induce chronic inflammation, and micro‐computational tomography and immunohistochemical analysis were performed. Particle‐induced chronic inflammation resulted in lower BMD values, an increase in osteoclastogenesis and nuclear translocation of p65, a prolonged M1 pro‐inflammatory macrophage phenotype, and a decrease of M2 anti‐inflammatory macrophage phenotype. Delayed timing of local infusion of NF‐κB decoy ODN for the last 3 weeks reversed polyethylene‐particle associated chronic inflammatory bone loss and facilitated bone healing. This study demonstrated that polyethylene‐particle associated chronic inflammatory osteolysis can be effectively modulated via interference with the NF‐κB pathway; this minimally invasive intervention could potentially be an efficacious therapeutic strategy for periprosthetic osteolysis after TJA.
The potential diagnosis role of TP53 mutation in advanced bladder cancer: A meta‐analysis
Authors: Liao Yihao , Tang Huiqin , Wang Miaomiao , Wang Keke , Wang Youzhi , Jiang Ning
Published: March 2021

Background

Bladder cancer is one of the most common urological cancers all over the world, and NMIBC occupies almost 80% of recently diagnosed bladder cancer cases. Progress and recurrence of bladder cancer are the main problems during the disease. The level of TP53 mutation is obviously higher in the high stage than the lower. This meta‐analysis is to evaluate the potential diagnosis feature of TP53 mutation by the expression of TP53 mutation of Ta stage vs high stage in bladder cancer.

Methods

A systematic search of databases was conducted, and some relevant articles were selected. Next, the meta‐analysis was carried out according to the standard guidelines.

Results

There were seven researches in which 677 participants were selected at the basis of inclusion standard. TP53 mutation was associated highly with increased diagnosis of bladder cancer. We found that the high stage of bladder cancer has obviously higher level of TP53 mutation than the lower stage, and these patients of MIBC have higher expression of TP53 mutation compared with NMIBC. No significant publication bias has been observed in this meta‐analysis. The expression of TP53 mutation might be a diagnose‐related biomarker for lots of patients with bladder cancer.

Conclusions

The results of this meta‐analysis provided further evidences that the expression of TP53 mutation was associated with the diagnosis efficiency of advanced bladder cancer. Higher expression of TP53 mutation was observed in the high stage of bladder cancer or the MIBC, and lower expression of TP53 mutation in the Ta stage of bladder cancer or the NMIBC. The expression level of TP53 mutation was probably a critical diagnosed biomarker in advanced bladder cancer.
Patient‐specific Virtual Temporal Bone Simulation Based on Clinical Cone‐beam Computed Tomography
Authors: Andersen Steven Arild Wuyts , Varadarajan Varun V. , Moberly Aaron C. , Hittle Bradley , Powell Kimerly A. , Wiet Gregory J.
Published: March 2021

Objectives

Patient‐specific surgical simulation allows presurgical planning through three‐dimensional (3D) visualization and virtual rehearsal. Virtual reality simulation for otologic surgery can be based on high‐resolution cone‐beam computed tomography (CBCT). This study aimed to evaluate clinicians' experience with patient‐specific simulation of mastoid surgery.

Methods

Prospective, multi‐institutional study. Preoperative temporal bone CBCT scans of patients undergoing cochlear implantation (CI) were retrospectively obtained. Automated processing and segmentation routines were used. Otologic surgeons performed a complete mastoidectomy with facial recess approach on the patient‐specific virtual cases in the institution's temporal bone simulator. Participants completed surveys regarding the perceived accuracy and utility of the simulation.

Results

Twenty‐two clinical CBCTs were obtained. Four attending otologic surgeons and 5 otolaryngology trainees enrolled in the study. The mean number of simulations completed by each participant was 16.5 (range 3–22). “Overall experience” and “usefulness for presurgical planning” were rated as “good,” “very good,” or “excellent” in 84.6% and 71.6% of the simulations, respectively. In 10.7% of simulations, the surgeon reported to have gained a significantly greater understanding of the patient's anatomy compared to standard imaging. Participants were able to better appreciate subtle anatomic findings after using the simulator for 60.4% of cases. Variable CBCT acquisition quality was the most reported limitation.

Conclusion

Patient‐specific simulation using preoperative CBCT is feasible and may provide valuable insights prior to otologic surgery. Establishing a CBCT acquisition protocol that allows for consistent segmentation will be essential for reliable surgical simulation.

Level of Evidence

3 Laryngoscope, 131:1855–1862, 2021
Characterization of common bean (Phaseolus vulgaris L.) germplasm for morphological and seed nutrient traits from Western Himalayas
Authors: Jan Sofora , Rather Irshad Ahmad , Sofi Parvaze Ahmad , Wani Mohd Altaf , Sheikh Farooq Ahmad , Bhat Mohammad Ashraf , Mir Reyazul Rouf
Published: March 2021

Common bean (Phaseolus vulgaris L.) is considered as one of the principle grain legume crops grown in Western Himalayas of Jammu and Kashmir, India. This region holds great diversity of common bean germplasm. The purpose of present study was to characterize 109 common bean genotypes collected from different hotspots for morphological traits—plant growth (growth habit, growth type, and twinning habit); leaf (color, size, and shape); flower (color, stripping on outer petal); pod (shape in relation to suture, shape of cross‐section, shape of distal part, and stringiness), seed (color and shape) traits, and quantitative morphological traits (seed weight, length, and breadth). The preliminary analysis of trait data showed wide variation for different morphological traits. Furthermore, diverse 60 genotypes were selected out of 109 genotypes and were evaluated for seed micronutrients (Fe, Zn, and Cu) and seed macronutrients (K, Ca, P, and Mg). The analysis of seed micronutrient and macronutrient data indicated substantial variation for these minerals in the germplasm. Seed Mg, P, K, and Ca concentrations varied from 1,220.5 to 2,737.5 ppm, 1,980–4,050 ppm, 8,344.5–14,794 ppm, and 300–5,350 ppm, respectively. Similarly, seed micronutrients Fe, Zn, and Cu concentrations ranged from 80.5–180.6 ppm, 14.64–104.08 ppm, and 0.9–13.4 ppm, respectively. The evaluation for seed micronutrient and macronutrient led to the identification of candidate genotypes possessing high seed micronutrient and macronutrient. The candidate genotypes identified during the present study will prove useful in common bean breeding programs as donor genotypes, in development of useful genetic resources and in gene discovery programs through functional genomics and transcriptomics.
Comparison of pedicled versus free flaps for reconstruction of extensive deep sternal wound defects following cardiac surgery: A retrospective study
Authors: Falkner Florian , Thomas Benjamin , Haug Valentin , Nagel Sarah S. , Vollbach Felix H. , Kneser Ulrich , Bigdeli Amir K.
Published: March 2021

Background

Myocutaneous pedicled flaps are the method of choice for sternal reconstruction after deep sternal wound infection (DSWI) following cardiac surgery. We set out to investigate whether free flaps provide a superior alternative for particularly extended sternal defects.

Methods

Between October 2008 and February 2020, 86 patients with DSWI underwent sternal reconstruction with myocutaneous flaps at our institution. Patients were retrospectively grouped into pedicled (A; n = 42) and free flaps (B, n = 44). The objective was to compare operative details, outcome variables, surgical as well as medical complication rates between both groups, retrospectively. Binary logistic regression analysis was applied to determine the effect of increasing defect size on flap necrosis.

Results

Rates of partial flap necrosis (>5% of the skin island) were significant higher in pedicled flaps (n = 14), when compared to free flaps (n = 4) (OR: 5.0; 33 vs. 9%; p = .008). Increasing defect size was a significant risk factor for the incidence of partial flap necrosis of pedicled flaps (p = .012), resulting in a significant higher rate of additional surgeries (p = .036). Binary regression model revealed that the relative likelihood of pedicled flap necrosis increased by 2.7% with every extra square‐centimeter of defect size.

Conclusion

To avoid an increased risk of partial flap necrosis, free flaps expand the limits of extensive sternal defect reconstruction with encouragingly low complication rates and proved to be a superior alternative to pedicled flaps in selected patients.
An empirical study on the materiality calculation at financial statements level
Authors: Azad Abdollah , Salehi Mahdi , Lari Dashtbayaz Mahmoud
Published: March 2021

This study aims to find an answer to the question that “whether there is a significant difference between quantitative thresholds of materiality (at the financial statement level) calculated according to the method used in Iran and the method employed by big audit firms.” The calculated quantitative threshold of materiality according to the method used in Iran and the method employed by big audit firms (based on the study of Eilifsen & Messier, Auditing: A Journal of Practice & Theory, 2015, 34, pp. 3–26) compared by using the information of 342 listed firms on the Tehran Stock Exchange during 2014–2018 by comparing test means. The difference between the calculated quantitative threshold of materiality based on the method used in Iran and the method employed by big audit firms is significant. About two decades just passed from the compilation of the method of assessing the quantitative threshold of materiality in Iran, and despite the change in related audit standards, it seems that the guideline requires revision, and professional authorities should pay considerable attention to the issue. To be informed of the manner of evaluating the quantitative threshold of materiality by big audit firms and comparing that with the method used in Iran can provide a better understanding of materiality and its assessment for professional authorities, auditors, scholars, and other users of financial statements. International audit firms are not very active in Iran. Comparing Iranian auditors' materiality thresholds with international audit firms contributes and expands the materiality literature about materiality judgment in developing countries with no or little relevance to international audit firms.
Star‐shaped copolymers with PLA–PEG arms and their potential applications as biomedical materials
Authors: Kubisa Przemyslaw , Lapienis Grzegorz , Biela Tadeusz
Published: March 2021

This review is devoted to the star‐shaped polylactide‐b‐poly(ethylene glycol) (PLA‐b‐PEG) polymers with hydrophobic‐hydrophilic arms. Star‐shaped polymers have a more compact structure as compared to linear counterparts but what is more important contain more end‐groups. If end‐groups are hydrophilic (such as hydroxyl groups), it may shift the hydrophilic‐hydrophobic balance of hydrophobic polymer such as PLA. Additional improvement of hydrophilicity may be achieved by introducing poly(ethylene glycol) segments. In this review, we are discussing synthetic approaches and basic properties of star‐shaped polylactide‐b‐poly(ethylene glycol) (PLA‐b‐PEG). The introduction of hydrophilic fragments (PEG) into hydrophobic chains (PLA) causes the considerable change of many properties of PLA polymers and extends their applications, particularly biomedical. The influence of the architecture and the number of arms of synthesized polymers as well as the content of hydrophilic and hydrophobic blocks on their properties is also discussed. Particular emphasis is placed on researches on the obtained polymers (in vitro and in vivo) as potential materials for biomedical applications.
Preparation and characterization of poly(vinyl alcohol)/halloysite nanotubes composite sponges with improved mechanical properties
Authors: Chen Tianxiang , Chen Sina , Wang Jinyun , Lin Tengfei , Wu Weihang , Yang Weijin , Wang Yu
Published: March 2021

A novel polyvinyl alcohol (PVA)/halloysite nanotubes (HNTs) composite sponge with preferable properties was fabricated via water solution mixing and casting technique with a fixed PVA ratio and the various contents of nano‐fillers. The morphology and physical properties of all the samples have been studied and characterized extensively. The results showed that HNTs were uniformly aligned along in the PVA matrix depending on good interfacial interactions between HNTs and PVA matrix. The addition of HNTs decreased the pore sizes and porosity of the sponges. Mechanical tests indicated that the incorporation of HNTs contribute to the reinforcement in mechanical properties of composite sponges under both dry and moist conditions. In addition, the composites showed better performances in thermal stability and water absorption capacity than pure PVA sponges. Rhodamine B and ibuprofen were employed to evaluate the control release ability. The results illustrated that increasing HNT contents can enhance the sustained release ability of PVA sponges.
Internal structure and palsa development at Orravatnsrústir Palsa Site (Central Iceland), investigated by means of integrated resistivity and ground‐penetrating radar methods
Authors: Emmert Adrian , Kneisel Christof
Published: March 2021

The natural cyclical development of palsas makes it difficult to use visible signs of decay as reference points for environmental change. Thus, to determine the actual development stage of a palsa, investigations of the internal structure are crucial. Our study presents 2‐D and 3‐D electrical resistivity imaging (ERI) and 2‐D ground‐penetrating radar (GPR) results, measurements of surface and subsurface temperatures, and of the soil matric potential from Orravatnsrústir Palsa Site in Central Iceland. By a joint interpretation of the results, we deduce the internal structure (i.e., thickness of thaw zone and permafrost, ice/water content) of five palsas of different size and shape. The results differentiate between initial and mature development stages and show that palsas of different development stages can exist in close proximity. While internal characteristics indicate undisturbed development of four palsas, one palsa shows indications of environmental change. Our study shows the value of the multimethod geophysical approach and introduces measurements of the soil matric potential as a promising method to assess the current state of the subsurface.
Protein secondary structure assignment using pc‐polyline and convolutional neural network
Authors: Wang Lincong , Cao Chen , Zuo Shuxue
Published: March 2021

Motivation

The assignment of protein secondary structure elements (SSEs) underpins structural analysis and prediction. The backbone of a protein could be adequately represented using a pc‐polyline that passes through the centers of its peptide planes. One salient feature of pc‐polyline representation is that the secondary structure of a protein becomes recognizable in a matrix whose elements are the pairwise distances between two peptide plane centers. Thus, a pc‐polyline could in turn be used to assign SSEs.

Results

Using convolutional neural network (CNN) here we confirm that a pc‐polyline indeed contains enough information for it to be used for the accurate assignments of the six SSE types: α‐helix, β‐sheet, β‐bulge, 310‐helix, turn and loop. The applications to three large data sets show that the assignments by our CNN‐based p2psse program agree very well with those by dssp, stride and quite well with those by five other programs. The analyses of their SSE assignments raise some general questions about the characterizations of protein secondary structure. In particular the analyses illustrate the difficulty with giving a quantitative and consistent definition for each of the six SSE types especially for 310‐helix, β‐bulge, turn or loop in terms of either backbone H‐bond patterns, or backbone dihedral angles, or Cα‐polyline or pc‐polyline. The difficulty suggests that the SSE space though being dominated by the regions for the six SSE types is to a certain degree continuous.

Availability

The program is available at https://github.com/wlincong/p2pSSE.
Greater celandine (Chelidonium majus L.) for COVID‐19: A twenty‐case series
Authors: Gardin Nilo E. , Braga Anne Jacqueline
Published: March 2021

In December 2019, an outbreak of coronavirus disease 2019 (COVID‐19) occurred in Wuhan, China, with a rapid increase in cases worldwide. Until now, among several drugs tested, none demonstrated sufficient efficacy for its etiological treatment. Greater celandine (Chelidonium majus L.) is a well‐known medicinal plant, traditionally indicated for digestive disorders and topically to remove warts. This study, performed at private offices in São Paulo and Aracaju (Brazil), describes 20 consecutive COVID‐19 outpatients treated with greater celandine and their clinical evolution. The patients, aged 14–71 years (median of 41 years), were treated with Chelidonium majus 10% mother tincture, 20–30 drops three times a day for 3–12 days (median of 5 days). Clinical features were assessed during the treatment and at least until 1 week after its end. These cases were considered mild, as most COVID‐19 cases. The symptoms were mainly fever, fatigue, cough, sore throat, coryza, anosmia, ageusia, and headache. Ten patients had comorbidities, such as hypertension, diabetes, and overweight. Complete or almost complete clinical improvement occurred within 1–9 days of treatment (median of 3 days). There were no adverse events. This casuistry, although small, may inspire other researchers to continue investigating Chelidonium majus as a healing treatment for COVID‐19.
Protocatechualdehyde inhibitsreceptor activator of nuclear factor kappa‐B ligand‐induced osteoclastogenesis and attenuates lipopolysaccharide‐induced inflammatory osteolysis
Authors: Huang Hao , Jiang Wenli , Hong Kehua , Cai Jie , He Yongchao , Ma Xuming , Wu Peng , Lang Junzhe , Ma Yuegang , Huang Caiguo , Yuan Jiandong
Published: March 2021

Inflammatory osteolysis as a consequence of chronic bacterial infection underlies several lytic bone conditions, such as otitis media, osteomyelitis, septic arthritis, periodontitis, periprosthetic infection, and aseptic loosening of orthopedic implants. In consideration of the lack of effective preventive or treatments options against infectious osteolysis, the exploitation of novel pharmacological compounds/agents is critically required. The present study assessed the effect of protocatechualdehyde (PCA), a natural occurring polyphenolic compound with diverse biological activities including but not limited to antibacterial and antiinflammatory properties, on nuclear factor‐κB ligand (RANKL)‐induced osteoclastogenesis in vitro and lipopolysaccharide (LPS)‐induced bone loss in vivo. In the present study, it was found that PCA potently inhibited RANKL‐induced osteoclast formation, fusion, and activation toward bone resorption in a dose‐dependent manner via the suppression of the ERK/c‐Fos/nuclear factor of activated T‐cells, cytoplasmic 1 signaling axis. It was further demonstrated that the in vivo administration of PCA could effectively protect mice against the deleterious effects of LPS‐induced calvarial bone destruction by attenuating osteoclast formation and activity in a dose‐dependent manner. Collectively, these findings provided evidence for the potential therapeutic application of PCA in the prevention and treatment of infectious osteolytic conditions, and potentially other osteoclast‐mediated bone diseases.
Disjunctive luminosity
Authors: Johnson Drew ,   Philosophy Documentation Center
Published: March 2021

Williamson's influential anti-luminosity argument aims to show that our own mental states are not “luminous,” and that we are thus “cognitively homeless.” Among other things, this argument represents a significant challenge to the idea that we enjoy basic self-knowledge of our own occurrent mental states. In this paper, I summarize Williamson's anti-luminosity argument, and discuss the role that the notion of “epistemic basis” plays in it. I argue that the anti-luminosity argument relies upon a particular version of the basis-relative safety condition on knowledge. This commitment is significant because basic self-knowledge seemingly lacks any kind of distinct epistemic basis, such as inference, observation, testimony, etc., despite representing a genuine kind of knowledge of contingent matters of fact. I consider a disjunctivist account (due to Bar-On and Johnson), according to which true basic self-beliefs indeed lack an epistemic basis in any kind of epistemic method (such as inference), yet are still epistemically grounded in the mental states they concern. I argue that this account of self-knowledge is compatible with standard understandings of the basis relative safety condition on knowledge, but rejects the particular version required by the anti-luminosity argument.