bluuebunny/crossref_metadata_2025 huggingface dataset:
Reactivity and Mechanistic Issues in the Photocyclization of Dihalostyryl‐Naphthalenes towards Halo‐[4]helicenes: A Transposition on a Mallory Theme
Authors: Martin Kévin , Melan Caroline , Cauchy Thomas , Avarvari Narcis
Published: September 2021

One of the most straightforward strategies nowadays for the synthesis of carbo‐ and hetero‐helicenes is the oxidative photocyclization of stilbene derivatives under Mallory conditions. In this study, the reactivity of a series of 3,4‐dihalostyryl‐naphthalenes (Hal=Br, F and Cl) has been investigated using Mallory conditions towards the corresponding halogenated [4]helicene compounds. The difluoro precursor afforded the two isomeric 2,3‐ and 1,2‐difluoro‐[4]helicenes, resulting from the ring closure on the two possible positions of the substituted benzene ring, the dichloro compound led to the formation of a mixture of the two isomeric 2,3 and 1,2‐dichloro‐[4]helicenes together with the 2‐mono‐chloro derivative, while the dibromo precursor provided, unexpectedly, only 2,3‐dibromo‐[4]helicene and the 2‐mono‐bromo derivative. DFT calculations performed on the entire series of precursors, final helicenes and intermediate dihydrohelicenes, including the non‐halogenated congeners, reveal the highly energetically favorable formation of a second dihydrohelicene intermediate following a [1,9]‐hydrogen sigmatropic transposition. Whereas the existence of this transposed dihydrohelicene intermediate, more stable than the initially formed dihydrohelicene by 15–30 kcal/mol, was until now “hidden” in the non‐substituted series, it allows herein to explain its re‐aromatization through formal elimination of HX in order to provide the 2‐mono‐halogenated‐[4]helicene derivatives.
Photoredox‐Induced Deaminative Radical‐Cationic Three‐Component Couplings with N‐Alkylpyridinium Salts and Alkenes
Authors: Seefeldt Paul , Dasi Rajesh , Villinger Alexander , Brasholz Malte
Published: September 2021

N‐Benzyl‐ and N‐2°‐alkylpyridinium salts were engaged in visible‐light‐driven, photoredox‐induced radical‐cationic three‐component couplings with N‐methylmaleimide and acrylonitrile as radical acceptors, in combination with 1,1‐diarylethylenes as donor alkenes. These multicomponent coupling reactions could be achieved under mild conditions, with high efficiency, and to furnish diverse 3,4‐disubstituted pyrrolidin‐2,5‐dione products with high stereoselectivity. In addition, 2,3‐diaryl‐1,3‐butadienes could be utilized as alternative donor alkene components, to furnish diastereomerically pure 1,2,3‐trisubstituted 1,3‐butadienes as the coupling products.
Non‐Chromatographic Purification of Synthetic RNA Using Bio‐Orthogonal Chemistry
Authors: He Muhan , Wu Xunshen , Mao Song , Haruehanroengra Phensinee , Khan Irfan , Sheng Jia , Royzen Maksim
Published: September 2021

Solid‐phase synthesis of RNA oligonucleotides over 100 nt in length remains challenging due to the complexity of purification of the target strands from the failure sequences. This article describes a non‐chromatographic procedure that will enable routine solid‐phase synthesis and purification of long RNA strands. The optimized five‐step process is based on bio‐orthogonal inverse electron demand Diels‐Alder chemistry between trans‐cyclooctene (TCO) and tetrazine (Tz), and entails solid‐phase synthesis of RNA on a photo‐labile support. The target oligonucleotide strands are selectively tagged with Tz while on‐support. After photocleavage from the solid support, the target oligonucleotide strands can be captured and purified from the failure sequences using immobilized TCO. The approach can be applied for purification of 76‐nt long tRNA and 101‐nt long sgRNA for CRISPR experiments. Purity of the isolated oligonucleotides should be evaluated using gel electrophoresis, while functional fidelity of the sgRNA should be confirmed using CRISPR‐Cas9 experiments. © 2021 Wiley Periodicals LLC.

Basic Protocol: Five‐step non‐chromatographic purification of synthetic RNA oligonucleotides

Support Protocol 1: Synthesis of the components that are required for the non‐chromatographic purification of long RNA oligonucleotides.

Support Protocol 2: Solid‐phase RNA synthesis
c‐Myb facilitates immune escape of esophageal adenocarcinoma cells through the miR‐145‐5p/SPOP/PD‐L1 axis
Authors: Zhang Lan , Wang Xiaohui , Li Yunfei , Han Jing , Gao Xianzheng , Li Shenglei , Wang Feng
Published: September 2021

Esophageal adenocarcinoma (EAC), a subtype of esophageal carcinoma, is a severe health problem associated with high death rate and poor prognosis. Immunotherapy has proven to be effective in many solid tumors, including EAC, but immune escape blocks its effectiveness. Thus, we explored the mechanisms and functional role of c‐Myb in immune escape of EAC cells. Clinical EAC tissues were collected for determining the expression of c‐Myb, speckled POZ protein (SPOP), and miR‐145‐5p. Functional assays were then performed to detect the interactions between c‐Myb and SPOP as well as between SPOP and miR‐145‐5p. EAC cell invasion and migration were assessed. Next, T cells were sorted and cocultured with EAC cells with different treatments followed by detection of T‐cell viability. In addition, a mouse model of EAC was constructed for relevant in vivo assays. c‐Myb and miR‐145‐5p were highly expressed and SPOP had low expressions in EAC. c‐Myb activated the transcription of miR‐145‐5p, which in turn targeted SPOP. Further, SPOP accelerated the ubiquitination of PD‐L1 to enhance its expression. Overexpression of PD‐L1 suppressed T‐cell functions and promoted proliferative and migrative abilities of EAC cells to induce immune escape. The above findings were also confirmed in the ECA mouse model in vivo. Our findings uncovered that c‐Myb can promote the immune escape of EAC cells by favoring the transcription of miR‐145‐5p and inhibiting SPOP‐dependent ubiquitination and degradation of PD‐L1, thus, presenting new target for EAC adjunct therapy.
Cardiac remodelling predicts outcome in patients with chronic heart failure
Authors: Xu Lingyu , Pagano Joseph , Chow Kelvin , Oudit Gavin Y. , Haykowsky Mark J. , Mikami Yoko , Howarth Andrew G. , White James A. , Howlett Jonathan G. , Dyck Jason R.B. , Anderson Todd J. , Ezekowitz Justin A. , Thompson Richard B. , Paterson D. Ian
Published: September 2021

Aims

Surveillance imaging is often used to detect remodelling, a change in cardiac geometry, and/or function; however, there are limited data in patients with chronic heart failure (HF). We sought to characterize cardiac remodelling in patients with chronic HF and evaluate its association with outcome.

Methods and results

A prospective cohort of patients at risk for HF or with chronic HF underwent cardiac magnetic resonance (CMR) at baseline and 1 year. Ventricular function, volumes, mass, left atrial volume, global longitudinal strain, and myocardial scar were measured. The primary outcome was a composite of death or cardiovascular hospitalization up to 5 years from the 1 year scan. Cox regression was used to identify 1 year CMR predictors of outcome after adjusting for baseline risk. A total of 262 patients (median age 68 years, 57% males) including 96 at risk for HF, 97 with HF and preserved ejection fraction, and 69 with HF and reduced ejection fraction were included. In the patients with HF, 55 events were identified during follow‐up. After adjustment for baseline clinical risk, Cox proportion hazard regressions only identified 1 year change in left ventricular (LV) mass index as a CMR predictor of outcome, adjusted hazard ratio 1.21 (1.02, 1.44) per 10% increase, P = 0.031. Cardiac remodelling defined as a 1 year change in LV mass index ≥15% was observed in 35% of patients with HF. Patients with adverse remodelling of LV mass index had more events on Kaplan–Meier analyses compared to those with no remodelling, log‐rank P = 0.004 for overall cohort, P = 0.035 for heart failure with preserved ejection fraction and P = 0.035 for heart failure and reduced ejection fraction.

Conclusions

Cardiac remodelling is common during serial CMR assessment of patients with chronic HF. Change in LV mass predicted long‐term outcomes whereas change in left ventricular ejection fraction did not.
The Merger of Photocatalyzed Hydrogen Atom Transfer with Transition Metal Catalysis for C−H Functionalization of Alkanes and Cycloalkanes
Authors: Ye Ziqi , Lin Yu‐Mei , Gong Lei
Published: September 2021

Catalytic C(sp3)−H functionalization can convert abundant feedstock hydrocarbons into value‐added products in an atom‐ and step‐economic manner and is a powerful tool in organic synthesis. However, the intrinsic chemical inertness of ubiquitous aliphatic C−H bonds of alkanes and cycloalkanes makes their direct and selective functionalization extremely challenging. Recently, some elegant strategies have been developed to solve the problems based on the merger of photocatalyzed hydrogen atom transfer (HAT) with transition metal catalysis. Light‐induced HAT processes are employed to initiate the alkyl radical generation, which is synergistic with metal catalysis involving for example nickel, copper, cobalt, cerium, chromium, or manganese. The different metal catalysts provide redox adjustment, Lewis acid activation or other functionalities and tune the reactivity and selectivity of the radical‐mediated sequences, allowing the development of diverse chemo‐, site‐, and/or stereoselective synthetic reactions. In this minireview, we offer a brief summary of the recent advances in dual photo‐induced HAT and transition metal catalysis for C−H functionalization of alkanes and cycloalkanes. We expect that these methodologies will stimulate the applications in catalysis, pharmaceuticals, and other related fields.
Halide perovskite for low‐power consumption neuromorphic devices
Authors: Raifuku Itaru , Chao Yung‐Pin , Chen Hong‐Hsueh , Lin Chen‐Fu , Lin Pei‐En , Shih Li‐Chung , Chen Kuan‐Ting , Chen Jung‐Yao , Chen Jen‐Sue , Chen Peter
Published: September 2021

The rapid emergency of data science, information technology, and artificial intelligence (AI) relies on massive data processing with high computing efficiency and low power consumption. However, the current von‐Neumann architecture system requires high‐energy budget to process data computing and storage between central computing unit and memory. To overcome this problem, neuromorphic computing system which mimics the operation of human brain has been proposed to perform computing in an energy‐efficient manner. Recently, organic–inorganic halide perovskite compounds have been demonstrated as promising components for neuromorphic devices owing to their strong light absorption, solution processability, and unique properties such as ion migration, carrier trapping effects and phase transition. In this review paper, we report recent advances of neuromorphic devices which employed organic–inorganic halide perovskite compounds by analyzing their fundamental operating mechanisms, device architectures, applications and future prospective.

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Deep learning approaches for improving prediction of daily stream temperature in data‐scarce, unmonitored, and dammed basins
Authors: Rahmani Farshid , Shen Chaopeng , Oliver Samantha , Lawson Kathryn , Appling Alison
Published: September 2021

Basin‐centric long short‐term memory (LSTM) network models have recently been shown to be an exceptionally powerful tool for stream temperature (Ts) temporal prediction (training in one period and predicting in another period at the same sites). However, spatial extrapolation is a well‐known challenge to modelling Ts and it is uncertain how an LSTM‐based daily Ts model will perform in unmonitored or dammed basins. Here we compiled a new benchmark dataset consisting of >400 basins across the contiguous United States in different data availability groups (DAG, meaning the daily sampling frequency) with and without major dams, and studied how to assemble suitable training datasets for predictions in basins with or without temperature monitoring. For prediction in unmonitored basins (PUB), LSTM produced a root‐mean‐square error (RMSE) of 1.129°C and an R2 of 0.983. While these metrics declined from LSTM's temporal prediction performance, they far surpassed traditional models' PUB values, and were competitive with traditional models' temporal prediction on calibrated sites. Even for unmonitored basins with major reservoirs, we obtained a median RMSE of 1.202°C and an R2 of 0.984. For temporal prediction, the most suitable training set was the matching DAG that the basin could be grouped into (for example, the 60% DAG was most suitable for a basin with 61% data availability). However, for PUB, a training dataset including all basins with data was consistently preferred. An input‐selection ensemble moderately mitigated attribute overfitting. Our results indicate there are influential latent processes not sufficiently described by the inputs (e.g., geology, wetland covers), but temporal fluctuations can still be predicted well, and LSTM appears to be a highly accurate Ts modelling tool even for spatial extrapolation.
A robust and interpretable gene signature for predicting the lymph node status of primary T1/T2 oral cavity squamous cell carcinoma
Authors: Ghantous Yasmin , Omar Mohamed , Broner Esther Channah , Agrawal Nishant , Pearson Alexander T. , Rosenberg Ari J. , Mishra Vasudha , Singh Alka , El‐naaj Imad Abu , Savage Peter A. , Sidransky David , Marchionni Luigi , Izumchenko Evgeny
Published: September 2021

Oral cavity squamous cell carcinoma (OSCC) affects more than 30 000 individuals in the United States annually, with smoking and alcohol consumption being the main risk factors. Management of early‐stage tumors usually includes surgical resection followed by postoperative radiotherapy in certain cases. The cervical lymph nodes (LNs) are the most common site for local metastasis, and elective neck dissection is usually performed if the primary tumor thickness is greater than 3.5 mm. However, postoperative histological examination often reveals that many patients with early‐stage disease are negative for neck nodal metastasis, posing a pressing need for improved risk stratification to either avoid overtreatment or prevent the disease progression. To this end, we aimed to identify a primary tumor gene signature that can accurately predict cervical LN metastasis in patients with early‐stage OSCC. Using gene expression profiles from 189 samples, we trained K‐top scoring pairs models and identified six gene pairs that can distinguish primary tumors with nodal metastasis from those without metastasis. The signature was further validated on an independent cohort of 35 patients using real‐time polymerase chain reaction (PCR) in which it achieved an area under the receiver operating characteristic (ROC) curve and accuracy of 90% and 91%, respectively. These results indicate that such signature holds promise as a quick and cost effective method for detecting patients at high risk of developing cervical LN metastasis, and may be potentially used to guide the neck treatment regimen in early‐stage OSCC.
Leiomyoma of the round ligament in a postmenopausal woman: A rare case report
Authors: Bhatti Dimple , Mandrelle Kavita , Chander Ashima
Published: September 2021

Synopsis

Leiomyoma of the round ligament is a rare benign tumor that can be confused with an ovarian mass. Imaging and tumor markers can guide in the diagnosis.
Section 806 of the Sarbanes‐Oxley act: Can the fraud triangle prevent fraud in the finance sector?
Authors: Bertucci Ashley , Skufca Tyler , Boyer‐Davis Stacy
Published: September 2021

Section 806 of the Sarbanes‐Oxley Act of 2002 provided an important update to whistleblower protection laws in the United States. The fraud triangle can be an important aspect of corporate wrongdoing. The concern is whether the fraud triangle can actually prevent fraud. Special focus is placed on the finance sector in the Unites States. Three cases in the finance sector were examined based on their whistleblower complaints filed under the Sarbanes‐Oxley Act. Whistleblower protections following SOX were analyzed. The focus is on the Dodd‐Frank Act of 2010. A conclusion was reached explaining the effectiveness of whistleblower protections under the Sarbanes‐Oxley Act of 2002.
Seurat games on Stockmeyer graphs
Authors: Egrot Rob , Hirsch Robin
Published: September 2021

We define a family of vertex colouring games played over a pair of graphs or digraphs by players and . These games arise from work on a longstanding open problem in algebraic logic. It is conjectured that there is a natural number such that always has a winning strategy in the game with colours whenever . This is related to the reconstruction conjecture for graphs and the degree‐associated reconstruction conjecture for digraphs. We show that the reconstruction conjecture implies our game conjecture with for graphs, and the same is true for the degree‐associated reconstruction conjecture and our conjecture for digraphs. We show (for any ) that the 2‐colour game can distinguish certain nonisomorphic pairs of graphs that cannot be distinguished by the ‐dimensional Weisfeiler–Leman algorithm. We also show that the 2‐colour game can distinguish the nonisomorphic pairs of graphs in the families defined by Stockmeyer as counterexamples to the original digraph reconstruction conjecture.
Simulating the I‐V characteristics of an ultrathin IGZO‐based thin film transistor using finite element method
Authors: Hussien Salma A. , Abdellatif Sameh O.
Published: September 2021

Thin film transistors (TFTs) are ranked as one of the promising field‐effect transistors in the electronic industry. TFTs showed a great potential in many applications where liquid crystal displays, touchscreens, and biosensors are of the leading. In the current study, we are demonstrating a numerical carrier transport model based on finite element method (FEM), to investigate InGaZnO (IGZO) based TFTs. Amorphous silicon TFT has been simulated as a bare device. The impact of scaling down the dimension of the TFT, up to 30 nm channel length, on the output performance characteristics of the transistor has been addressed. Additionally, the effects of active semiconductor layer doping concentration and oxide layer thickness have been investigated. Moreover, a novel approach is introduced to correlate the selected input design parameters with a set of characteristic outputs including threshold voltage, on/off current ratio, and subthreshold swing. The proposed model correlates input and outputs using a characteristic matrix with nine coefficients, making it possible to predict, that is, interpolate, the characteristic outputs within the system boundaries. The suggested model was verified with respect to input data as well as data from the literature showing a very acceptable agreement.
Organic material with balanced C‐nutrient stoichiometry and P addition could improve soil P availability with low C cost
Authors: Fei Chao , Zhang Shirong , Feng Xionghan , Ding Xiaodong
Published: September 2021

Background

Carbon (C) addition to promote phosphorus (P) turnover by microbes is recommended to increase soil P availability. The C‐nutrient stoichiometry of organic materials (OM) are the primary factors in controlling soil P availability and C storage.

Methods

A pot experiment was carried out to investigate the effects of different organic matter (OM) with equal carbon input [soybean dregs (SD), chicken manure (CM), and vermicompost (VC), 1000 mg C kg–1 soil] under three P levels (0, 10, and 20 mg P per kg dry soil) on soil P availability, C content, and plant growth in high P fixing soils.

Results

Plant biomass and shoot P content were significantly increased in P and OM addition treatment. Application of OM or P alone had no effect on soil available P (AP) but increased the microbial P (MBP). Compared with P addition alone, soil potential AP pool (the sum of soil AP and MBP content) was increased by 89%–200% in both OM and P addition soil. Soil potential AP pool and dissolved organic carbon (DOC) in VC treatment were significantly increased compared with those in CM and SD treatments. On day 60, compared with VC treatment, SD and VC treatments significantly increased alkaline phosphatase (ALP) but decreased soil organic carbon (SOC) content, in which ALP was negatively correlated with SOC and net C balance.

Conclusion

A small amount of P and vermicompost addition, which had a balanced carbon‐nutrient stoichiometric ratio, was an effective measurement in improving soil AP pool and C content in P‐fixing soil.
Potato root and leaf phosphatase activity in response to P deprivation
Authors: Kavka Mareike , Korn Kati , Hazarika Mousumi , Bachmann‐Pfabe Silvia , Uptmoor Ralf
Published: September 2021

Background

Plants are not able to take up organically bound phosphorus (P) before it is hydrolyzed by extracellular phosphatases while intracellular phosphatases play a role in P remobilization.

Aims

The aim of this study was to evaluate intra‐ and extracellular acid phosphatase activity as well as root and shoot growth of two modern starch potato cultivars at different levels of P deprivation.

Methods

In vitro propagated potato plantlets (cultivars Kuba and Cardoso) were grown in sand and fertigated with five different P concentrations, ranging from 1 to 0.05 mM P. Growth parameters, plant P concentrations, and acid phosphatase activities were determined after 40 days.

Results

Shoot and root biomass decreased gradually with decreasing P supply, while the root‐to‐shoot ratio increased. Shoot P concentration decreased steadily, but root P concentration remained constant at P levels below 0.5 mM. Root‐associated and root intracellular acid phosphatase activity increased in both cultivars with rising levels of P deprivation. The activity of acid phosphatases in old but not in young leaves was increased with P deprivation. Intracellular acid phosphatase activity was genotype dependent, with higher activity in the cultivar Kuba than in Cardoso.

Conclusions

Our results point to a tissue specific regulation of acid phosphatase activity depending on plant P status and potato genotype. Increasing root‐associated acid phosphatase activities may help P starved potato plants to ensure a sufficient P nutrition. Further research is needed to unravel the roles of leaf intracellular acid phosphatases in potato.
In‐Volume Laser Direct Writing of Silicon—Challenges and Opportunities
Authors: Chambonneau Maxime , Grojo David , Tokel Onur , Ilday Fatih Ömer , Tzortzakis Stelios , Nolte Stefan
Published: September 2021

Laser direct writing is a widely employed technique for 3D, contactless, and fast functionalization of dielectrics. Its success mainly originates from the utilization of ultrashort laser pulses, offering an incomparable degree of control on the produced material modifications. However, challenges remain for devising an equivalent technique in crystalline silicon which is the backbone material of the semiconductor industry. The physical mechanisms inhibiting sufficient energy deposition inside silicon with femtosecond laser pulses are reviewed in this article as well as the strategies established so far for bypassing these limitations. These solutions consisting of employing longer pulses (in the picosecond and nanosecond regime), femtosecond‐pulse trains, and surface‐seeded bulk modifications have allowed addressing numerous applications.
The Power of Musification: Sensor‐Based Music Feedback Improves Arm Swing in Parkinson's Disease
Authors: Mainka Stefan , Schroll Arno , Warmerdam Elke , Gandor Florin , Maetzler Walter , Ebersbach Georg
Published: September 2021

Background

Reduction of arm swing during gait is an early and common symptom in Parkinson's disease (PD). By using the technology of a mobile phone, acceleration of arm swing can be converted into a closed‐loop musical feedback (musification) to improve gait.

Objectives

To assess arm swing in healthy subjects and the effects of musification on arm swing amplitude and other gait parameters in patients with PD.

Methods

Gait kinematics were analyzed in 30 patients during a 320 m walk in 3 different conditions comprising (1) normal walking; (2) focused swinging of the more affected arm; and (3) with musification of arm swing provided by the iPhone application CuraSwing. The acceleration of arm swing was converted into musical feedback. Arm swing range of motion and further gait kinematics were analyzed. In addition, arm swing in patients was compared to 32 healthy subjects walking at normal, slow, and fast speeds.

Results

Musification led to a large and bilateral increase of arm swing range of motion in patients. The increase was greater on the more affected side of the patient (+529.5% compared to baseline). In addition, symmetry of arm swing, sternum rotation, and stride length increased. With musical feedback patients with PD reached arm swing movements within or above the range of healthy subjects.

Conclusions

Musification has an immediate effect on arm swing and other gait kinematics in PD. The results suggest that closed‐loop musical feedback is an effective technique to improve walking in patients with PD.
Collusion in supply functions under technology licensing
Authors: Celen Ihsan , Saglam Ismail
Published: September 2021

We consider an infinitely lived duopoly with asymmetric costs and study the incentives of the firms to collude or compete in supply functions under the possibility of technology licensing. Simulating the subgame‐perfect Nash equilibria of alternative industry organizations, we show that licensing makes collusion harder; but it always has a positive effect on the welfares of consumers and the less efficient firm in the duopoly.
Evaluation of sleep quality among nursing faculty: Application of the Pittsburgh Sleep Quality Index—A descriptive correlational study
Authors: Cox Sonya D. , Benoit Julia S. , Brohard Cheryl L. , McIntyre Teresa M.
Published: September 2021

Aim

The aim of this study was to describe the overall sleep quality, sleep patterns and severity of sleep difficulties among nursing faculty using the Pittsburgh Sleep Quality Index (PSQI).

Design

Cross‐sectional descriptive and correlational study.

Methods

A survey of faculty recruited from Texas Board of Nursing approved colleges/schools was used. A purposive, convenience sample of 105 faculty completed the PSQI, a reliable and valid instrument, in an online setting. Data was collected from January 2019 through April 2019.

Results

Nursing faculty reported sleep difficulty across all components, with more problems in sleep latency, sleep disturbances and subjective sleep quality. Overall, 70.5% of participants were reportedly “poor” sleepers, a salient finding. Faculty experienced poor sleep quality across all academic ranks and age groups. Sleep latency and subjective sleep quality were components that presented higher in severity for the youngest faculty.
Primary thromboprophylaxis to prevent thrombotic events in pediatric oncology patients with a malignant mediastinal mass
Authors: Sarangi Susmita N. , Gaballah Marian , Nolfi‐Donegan Deirdre , Battaglia Maria , Amin Seema , Amodio John , Acharya Suchitra S.
Published: September 2021

Children with malignant mediastinal masses have increased thrombotic events (TE). Eligible subjects with malignant mediastinal masses between January 2000 and December 2017 were evaluated for TE, with 19 among 76 subjects receiving enoxaparin thromboprophylaxis. There were 13 TEs among 76 subjects for an incidence of 17.1%. Mediastinal compression directly led to TE in 9.2% of subjects who also had statistically significant superior vena cava compression at diagnosis. Primary thromboprophylaxis did not significantly affect TE occurrence; however, larger studies are warranted to consider strategic thromboprophylaxis guided by radiological monitoring of dynamic vascular compression to improve TE outcomes.
Beneficial and harmful outcomes of tocilizumab in severe COVID‐19: A systematic review and meta‐analysis
Authors: Rubio‐Rivas Manuel , Forero Carlos G. , Mora‐Luján José María , Montero Abelardo , Formiga Francesc , Homs Narcís A. , Albà‐Albalate Joan , Sánchez Laura , Rello Jordi , Corbella Xavier
Published: September 2021

Introduction

The results of studies of tocilizumab (TCZ) in COVID‐19 are contradictory. Our study aims to update medical evidence from controlled observational studies and randomized clinical trials (RCTs) on the use of TCZ in hospitalized patients with COVID‐19.

Methods

We searched the following databases from January 1, 2020 to April 13, 2021 (date of the last search): MEDLINE database through the PubMed search engine and Scopus, using the terms (“COVID‐19" [Supplementary Concept]) AND "tocilizumab" [Supplementary Concept]).

Results

Sixty four studies were included in the present study: 54 were controlled observational studies (50 retrospective and 4 prospective) and 10 were RCTs. The overall results provided data from 20,616 hospitalized patients with COVID‐19: 7668 patients received TCZ in addition to standard of care (SOC) (including 1915 patients admitted to intensive care units (ICU) with reported mortality) and 12,948 patients only receiving SOC (including 4410 patients admitted to the ICU with reported mortality). After applying the random‐effects model, the hospital‐wide (including ICU) pooled mortality odds ratio (OR) of patients with COVID‐19 treated with TCZ was 0.73 (95% confidence interval (CI) = 0.56–0.93). The pooled hospital‐wide mortality OR was 1.25 (95% CI = 0.74–2.18) in patients admitted at conventional wards versus 0.66 (95% CI = 0.59–0.76) in patients admitted to the ICU. The pooled OR of hospital‐wide mortality (including ICU) of COVID‐19 patients treated with TCZ plus corticosteroids (CS) was 0.67 (95% CI = 0.54–0.84). The pooled in‐hospital mortality OR was 0.71 (95% CI = 0.35–1.42) when TCZ was early administered (≤10 days from symptom onset) versus 0.83 (95% CI 0.48–1.45) for late administration (>10 days from symptom onset). The meta‐analysis did not find significantly higher risk for secondary infections in COVID‐19 patients treated with TCZ.

Conclusions

TCZ prevented mortality in patients hospitalized for COVID‐19. This benefit was seen to a greater extent in patients receiving concomitant CS and when TCZ administration occurred within the first 10 days after symptom onset.
Clinical features of Chinese children with COVID‐19 and other viral respiratory infections
Authors: Zhang Zhen‐Zhen , Chen Da‐Peng , Liu Quan‐Bo , Gan Chuan , Jiang Li , Zhu Kun , Zhang Xia‐Yi , Xu Hong‐Mei , Huang Ai‐Long , Long Quan‐Xin , Deng Hai‐Jun , Chen Juan
Published: September 2021

Objective

Few studies have explored the clinical features in children infected with SARS‐CoV‐2 and other common respiratory viruses, including respiratory syncytial virus (RSV), Influenza virus (IV), and adenovirus (ADV). Herein, we reported the clinical characteristics and cytokine profiling in children with COVID‐19 or other acute respiratory tract infections (ARTI).

Methods

We enrolled 20 hospitalized children confirmed as COVID‐19 positive, 58 patients with ARTI, and 20 age and sex‐matched healthy children. The clinical information and blood test results were collected. A total of 27 cytokines and chemokines were measured and analyzed.

Results

The median age in the COVID‐19 positive group was 14.5 years, which was higher than that of the ARTI groups. Around one‐third of patients in the COVID‐19 group experienced moderate fever, with a peak temperature of 38.27°C. None of the patients displayed wheezing or dyspnea. In addition, patients in the COVID‐19 group had lower white blood cells, platelet counts as well as a neutrophil‐lymphocyte ratio. Lower serum concentrations of 14 out of 27 cytokines were observed in the COVID‐19 group than in healthy individuals. Seven cytokines (IL‐1Ra, IL‐1β, IL‐9, IL‐10, TNF‐α, MIP‐1α, and VEGF) changed serum concentration in COVID‐19 compared with other ARTI groups.

Conclusion

Patients with COVID‐19 were older and showed milder symptoms and a favorable prognosis than ARTI caused by RSV, IV, and ADV. There was a low grade or constrained innate immune reaction in children with mild COVID‐19.
Reaction Dynamics Study of Hypergolic Bipropellants: Azide Amine and Dinitrogen Tetroxide
Authors: Zhao Jian‐Shuo , Huang Zhi‐Yong , Jin Guo‐Feng , Gao Min‐Na , Zhu Hui‐Xin
Published: September 2021

In order to analyze the reaction mechanism between N,N‐dimethyl‐2‐azide‐ethylamine (DMAZ) and nitrogen tetroxide (NTO), a stable conformation of DMAZ molecule was first searched. Then, the changes of the potential energy and the products generated in the simulation process were analyzed by the reaction molecular dynamics. Finally, the potential energy surface, reaction rate constant and activation energy of H atom abstraction were calculated based on density functional theory. The results show that the stable conformation of DMAZ looks like a scorpion. In the simulation, the potential energy of the system increased sharply in the endothermic reaction, and then decreased in the exothermic chemical reaction. Compared with N,N,N’,N’‐tetramethyl ethylenediamine (TMEDA), the reaction speed of DMAZ/NTO was higher, and the energy released was also higher. The reaction products of DMAZ/NTO and TMEDA/NTO were mainly H2O, N2 and CO2.With the increase of temperature, the rate constant of H atom abstraction increased exponentially. The rate of increase in path H3(it means that NO2 reacts with the H3 atom of DMAZ) was much higher than that of path H14 (it means that NO2 reacts with the H14 atom of DMAZ). The activation energies of H atom abstraction in path H3 and H14 were 16.60 kJ mol−1 and 61.08 kJ mol−1 respectively.
Effect of Pressure of Supercritical CO2 on Perfusion Explosive with Foamed SF‐3 Propellant
Authors: Tan Daquan , Zhang Di , Wang Yingbo , Xiao Fangci , Chen Feiyun , Wei Xiaoan
Published: September 2021

In this paper, an SF‐3 double‐base propellant was treated by a supercritical carbon dioxide foaming process. Effects of the pressure of supercritical carbon dioxide on the morphology, energy level, and ingredients of the foamed SF‐3 double‐base propellant and the detonation performance of a perfusion explosive with the foamed SF‐3 double‐base propellant were studied. Results show that, with the increase of the pressure, the number of pores in the foamed SF‐3 double‐base propellant gradually increased, and some of the pores were connected to form a small amount of cracks. In the foaming process, the pressure had a small effect on the energy of foamed SF‐3, and the formation of dense pores increased the volume of the sample. The dense pores acted as “hotspots” during the detonation process of the perfusion explosive, allowing the explosive to have better detonation performance, as compared with the perfusion explosive with unfoamed SF‐3 which could not detonate effectively. When the pressure of supercritical CO2 was 8 MPa, the perfusion explosive with foamed SF‐3 had a shock wave energy of 1.06 kJ g−1 and a detonation velocity of 6521 m s−1. When the pressure was 11 MPa, the detonation velocity and shock wave energy of the perfusion explosive were 2.9 % and 6.6 % respectively higher than those under the pressure of 8 MPa. Therefore, with the increase of pressure, the detonation velocity and the shock wave energy of the perfusion explosive with foamed SF‐3 were increased, proving that increasing the pressure can effectively improve the detonation performance of perfusion explosives with foamed SF‐3.
Assessment of prediction methods for protein structures determined by NMR in CASP14: Impact of AlphaFold2
Authors: Huang Yuanpeng Janet , Zhang Ning , Bersch Beate , Fidelis Krzysztof , Inouye Masayori , Ishida Yojiro , Kryshtafovych Andriy , Kobayashi Naohiro , Kuroda Yutaka , Liu Gaohua , LiWang Andy , Swapna G.V.T , Wu Nan , Yamazaki Toshio , Montelione Gaetano T.
Published: September 2021

NMR studies can provide unique information about protein conformations in solution. In CASP14, three reference structures provided by solution NMR methods were available (T1027, T1029, and T1055), as well as a fourth data set of NMR‐derived contacts for an integral membrane protein (T1088). For the three targets with NMR‐based structures, the best prediction results ranged from very good (GDT_TS = 0.90, for T1055) to poor (GDT_TS = 0.47, for T1029). We explored the basis of these results by comparing all CASP14 prediction models against experimental NMR data. For T1027, NMR data reveal extensive internal dynamics, presenting a unique challenge for protein structure prediction methods. The analysis of T1029 motivated exploration of a novel method of “inverse structure determination,” in which an AlphaFold2 model was used to guide NMR data analysis. NMR data provided to CASP predictor groups for target T1088, a 238‐residue integral membrane porin, was also used to assess several NMR‐assisted prediction methods. Most groups involved in this exercise generated similar beta‐barrel models, with good agreement with the experimental data. However, as was also observed in CASP13, some pure prediction groups that did not use any NMR data generated models for T1088 that better fit the NMR data than the models generated using these experimental data. These results demonstrate the remarkable power of modern methods to predict structures of proteins with accuracies rivaling solution NMR structures, and that it is now possible to reliably use prediction models to guide and complement experimental NMR data analysis.
Density Functional Theory Study on the Interfacial Properties of CuS/Bi2S3 Heterostructure
Authors: Shan Bao-Feng , Deng Jie , Zhao Zong-Yan
Published: September 2021

Composite heterostructure photocatalysts can effectively improve photocatalytic performance. For narrow‐bandgap semiconductors, such as Bi2S3, constructing heterostructures with other semiconductors can obviously promote the separation of photogenerated electron−hole pairs and improve their photocatalytic performance. However, some basic and important parts of this technology still require further clarification. Herein, the interface properties of CuS/Bi2S3 heterostructure was studied using density functional theory calculations. The results show that the electronic structure of the interface model shows some different characteristics compared with the bulk and surface models due to the different bonding modes and chemical environments at the interface. At the interface of the CuS/Bi2S3 heterostructure, the band edge of CuS is bent downward relative to Bi2S3 to form a type II heterostructure. In addition, in the equilibrium state, the direction of the built‐in electric field of the heterostructure is from Bi2S3 to CuS. Therefore, the photogenerated electron−hole pairs can be separated by the CuS/Bi2S3 interface, which is extremely advantageous for the improvement of photocatalytic performance. The formation of the CuS/Bi2S3 heterostructure not only broadens the light absorption of CuS but also suppresses the recombination of photogenerated electron−hole pairs of the narrow‐bandgap semiconductor Bi2S3.
Culverts delay upstream and downstream migrations of river herring (Alosa spp.)
Authors: Alcott Derrick , Goerig Elsa , Castro‐Santos Theodore
Published: September 2021

Alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis) are iteroparous anadromous fish found throughout the East Coast of North America. The phenology of anadromous fish migrations is important for fitness, and the duration of spawning migrations has been compressed in recent years in response to climate change. Anthropogenic barriers to movement, such as dams and culverts at road‐stream crossings, can further disrupt migration phenology by delaying movement and increasing predation risk. We used passive integrated transponder (PIT) telemetry to quantify upstream and downstream migratory delay at five road‐stream‐crossing culverts on the Herring River (MA, USA). Groundspeeds were reduced at all culverts in both directions, confirming that the culverts impede movement despite high passage proportions. The cumulative delay of the culverts on the upstream migration was sufficient to more than double the amount of time required to traverse the river if the culverts had been absent. Furthermore, the presence of snapping turtles (Chelydra serpentina) ambushing river herring within one of the culverts resulted in reduced passage rates beyond the reduction in movement caused by the physical structure itself. This highlights that physical barriers can create cascading ecological consequences and the importance of taking a holistic approach to understanding barrier effects.
Thriving on contradiction: Toward a dialectical alternative to fit‐based models in strategy (and beyond)
Authors: Farjoun Moshe , Fiss Peer C.
Published: September 2021

Research Summary

While the established, coherence view of internal fit provides a compact representation of firms and strategy, it also discounts the strategic benefits of tensions and contradictions, and downplays strategy creation and change. Here, we develop a novel dialectical alternative to fit‐based models of strategy. Within our model, contradictions and tensions serve as a key engine for strategic renewal and transformation. If carefully harnessed through what we call “disciplined incoherence,” contradictions can help firms establish and change their strategies and business models, adapt to and shape their environment, and enhance and sustain their competitive advantage. We offer a dynamic, endogenous view of how configurations are generated, transformed, and maintained, and present a processual alternative to current strategy models that are grounded in equilibrium and coherence assumptions.

Managerial Summary

Prior thinking suggests that firm strategies should focus on achieving fit between the firm's different elements such as activities, organizational structures, and policies, and that tensions and inconsistencies should be eliminated or minimized. We argue that this view overlooks the important role of contradictions in fostering innovation and competitive advantage and driving strategic change and renewal. Conflicts and contradictions pose their own risks. Yet, given the potential for their firms to thrive on contradictions, managers and strategists should neither dismiss these challenges nor be paralyzed by them. Instead of stamping out tensions and contradictions, managers can apply a process of “disciplined incoherence” where they relinquish some control while drawing on organizational arrangements and their own creativity and skills to allow contradictions to develop.
Exciton‐Dominated Ultrafast Optical Response in Atomically Thin PtSe2
Authors: Bae Seongkwang , Nah Sanghee , Lee Doeon , Sajjad Muhammad , Singh Nirpendra , Kang Ku Min , Kim Sanghoon , Kim Geun‐Ju , Kim Jaekyun , Baik Hionsuck , Lee Kyusang , Sim Sangwan
Published: September 2021

Strongly bound excitons are a characteristic hallmark of 2D semiconductors, enabling unique light–matter interactions and novel optical applications. Platinum diselenide (PtSe2) is an emerging 2D material with outstanding optical and electrical properties and excellent air stability. Bulk PtSe2 is a semimetal, but its atomically thin form shows a semiconducting phase with the appearance of a band‐gap, making one expect strongly bound 2D excitons. However, the excitons in PtSe2 have been barely studied, either experimentally or theoretically. Here, the authors directly observe and theoretically confirm excitons and their ultrafast dynamics in mono‐, bi‐, and tri‐layer PtSe2 single crystals. Steady‐state optical microscopy reveals exciton absorption resonances and their thickness dependence, confirmed by first‐principles calculations. Ultrafast transient absorption microscopy finds that the exciton dominates the transient broadband response, resulting from strong exciton bleaching and renormalized band‐gap‐induced exciton shifting. The overall transient spectrum redshifts with increasing thickness as the shrinking band‐gap redshifts the exciton resonance. This study provides novel insights into exciton photophysics in platinum dichalcogenides.
Scalable Preparation of High‐Performance ZnO–SnO2 Cascaded Electron Transport Layer for Efficient Perovskite Solar Modules
Authors: He Ruiqin , Nie Siqing , Huang Xiaofeng , Wu Yazhuo , Chen Ruihao , Yin Jun , Wu Binghui , Li Jing , Zheng Nanfeng
Published: September 2021

Perovskite solar cells are the fastest‐growing photovoltaic technology in recent years. However, together with the stability, the low‐cost and high‐quality preparation of large‐area modules still limits their commercialization process. Herein, a scalable and high‐performance ZnOSnO2 cascade double‐layer electron transport layer (ETL) for efficient and stable perovskite modules is reported. The cascaded ETL is fabricated using a simple spray pyrolysis coating combined with the blade coating process, which not only effectively improves the interface stability by avoiding the protonation of ZnO to maintain its high electron mobility, but also provides a much smoother surface for the crystallization of perovskites. In addition, the well‐matched conduction band level between SnO2 and perovskites ensures the improvement of open‐circuit voltage. Subsequently, combined with the blade‐coated perovskite layer and hole transport layer film, large‐area planar perovskite modules are successfully prepared. These high‐quality films enable the perovskite solar modules to achieve impressive efficiencies of 17.8% in the module size 6 × 6 cm2 and 16.6% in a size of 10 × 10 cm2. The obtained module also shows excellent reproducibility and stability. The high‐performance ETL and the related deposition method developed in this work are promising for applications in the industrial scalable perovskite modules’ fabrication.
The economic logic of OR consulting practice: Towards a foundational view
Authors: Ormerod Richard John
Published: September 2021

The establishment of foundations for operational research (OR) enables OR academic researchers to ground their theoretical research. As OR consultants, we compete for commercial contracts with clients based on our practical expertise. The paper seeks to identify the economic foundations of this contracting process, to separate those aspects most likely to endure from those that are more ephemeral. The focus of the analysis is on the behaviour of the players in the consulting services market. The market for consultancy thrives despite the fact that it is difficult for both consultants and clients to understand what is being sought and what is being offered. A key question for everyone concerned is how this problem is resolved in practice. The paper distils existing theories into a set of foundational statements that inform OR research aimed at improving the practice of OR consultants and client interactions. Eight economic foundational statements are derived.
Genetic Dielectric Genes Inside 2D Carbon‐Based Materials with Tunable Electromagnetic Function at Elevated Temperature
Authors: Cao Mao-Sheng , Shu Jin-Cheng , Wen Bo , Wang Xi-Xi , Cao Wen-Qiang
Published: September 2021

Understanding the nature of dominating electromagnetic response and energy conversion is quietly pivotal to achieve tunable electromagnetic function at elevated temperature. Herein, the dielectric genes, especially genetic genes, inside 2D carbon‐based materials are deeply dissected based on previous work, and the contribution of conduction and relaxation to electromagnetic response is highly excavated. The evolution of dielectric genes related to ferroferric oxide (Fe3O4) content, temperature, and spatial distribution is described in detail, which creates an available approach for tunable microwave absorption performance. At 373 K, the 20 wt% product realizes the optimal reflection loss of −59 dB, with a small matching thickness of 1.17 mm. In the coming fifth‐generation (5 G) era, the cognition on dielectric genes furnishes a solid platform for the design and manufacture of high‐efficiency electromagnetic functional materials and devices, vigorously promoting the research of electromagnetic protection in high‐temperature environment.