bluuebunny/crossref_metadata_2025 huggingface dataset:
Modularized data‐driven reconstruction framework for nonideal focal spot effect elimination in computed tomography
Authors: Zhang Zhicheng , Yu Lequan , Zhao Wei , Xing Lei
Published: February 2021

Purpose

High‐performance computed tomography (CT) plays a vital role in clinical decision‐making. However, the performance of CT imaging is adversely affected by the nonideal focal spot size of the x‐ray source or degraded by an enlarged focal spot size due to aging. In this work, we aim to develop a deep learning‐based strategy to mitigate the problem so that high spatial resolution CT images can be obtained even in the case of a nonideal x‐ray source.

Methods

To reconstruct high‐quality CT images from blurred sinograms via joint image and sinogram learning, a cross‐domain hybrid model is formulated via deep learning into a modularized data‐driven reconstruction (MDR) framework. The proposed MDR framework comprises several blocks, and all the blocks share the same network architecture and network parameters. In essence, each block utilizes two sub‐models to generate an estimated blur kernel and a high‐quality CT image simultaneously. In this way, our framework generates not only a final high‐quality CT image but also a series of intermediate images with gradually improved anatomical details, enhancing the visual perception for clinicians through the dynamic process. We used simulated training datasets to train our model in an end‐to‐end manner and tested our model on both simulated and realistic experimental datasets.

Results

On the simulated testing datasets, our approach increases the information fidelity criterion (IFC) by up to 34.2%, the universal quality index (UQI) by up to 20.3%, the signal‐to‐noise (SNR) by up to 6.7%, and reduces the root mean square error (RMSE) by up to 10.5% as compared with FBP. Compared with the iterative deconvolution method (NSM), MDR increases IFC by up to 24.7%, UQI by up to 16.7%, SNR by up to 6.0%, and reduces RMSE by up to 9.4%. In the modulation transfer function (MTF) experiment, our method improves the MTF50% by 34.5% and MTF10% by 18.7% as compared with FBP, Similarly remarkably, our method improves MTF50% by 14.3% and MTF10% by 0.9% as compared with NSM. Also, our method shows better imaging results in the edge of bony structures and other tiny structures in the experiments using phantom consisting of ham and a bottle of peanuts.

Conclusions

A modularized data‐driven CT reconstruction framework is established to mitigate the blurring effect caused by a nonideal x‐ray source with relatively large focal spot. The proposed method enables us to obtain high‐resolution images with less ideal x‐ray source.
NMR visibility of deuterium‐labeled liver glycogen in vivo
Authors: De Feyter Henk M. , Thomas Monique A. , Behar Kevin L. , de Graaf Robin A.
Published: February 2021

Purpose

Deuterium metabolic imaging (DMI) combined with [6,6’‐2H2]‐glucose has the potential to detect glycogen synthesis in the liver. However, the similar chemical shifts of [6,6’‐2H2]‐glucose and [6,6’‐2H2]‐glycogen in the 2H NMR spectrum make unambiguous detection and separation difficult in vivo, in contrast to comparable approaches using 13C MRS. Here the NMR visibility of 2H‐labeled glycogen is investigated to better understand its potential contribution to the observed signal in liver following administration of [6,6’‐2H2]‐glucose.

Methods

Mice were provided drinking water containing 2H‐labeled glucose. High‐resolution NMR analyses was performed of isolated liver glycogen in solution, before and after the addition of the glucose‐releasing enzyme amyloglucosidase.

Results

2H‐labeled glycogen was barely detectable in solution using 2H NMR because of the very short T2 (<2 ms) of 2H‐labeled glycogen, giving a spectral line width that is more than five times as broad as that of 13C‐labeled glycogen (T2 = ~10 ms).

Conclusion

2H‐labeled glycogen is not detectable with 2H MRS(I) under in vivo conditions, leaving 13C MRS as the preferred technique for in vivo detection of glycogen.
4D quantification of alpine permafrost degradation in steep rock walls using a laboratory‐calibrated electrical resistivity tomography approach
Authors: Scandroglio Riccardo , Draebing Daniel , Offer Maike , Krautblatter Michael
Published: February 2021

The warming of rock permafrost affects mechanical stability and hydro‐cryostatic pressures in rock walls. The coincident decrease in slope stability frequently affects infrastructure by creep and subsidence and promotes the generation of rockfalls and rockslides. The increasing hazard posed by warming permafrost rock walls and the growing exposure of infrastructure and individuals create a demand for quantitative monitoring methods. Laboratory‐calibrated electrical resistivity tomography provides a sensitive record for frozen versus unfrozen bedrock, presumably being the most accurate quantitative monitoring technique in permafrost areas where boreholes are not available. The data presented here are obtained at the permafrost‐affected and unstable Steintaelli Ridge at 3100 m a.s.l. and allow the quantification of permafrost changes in the longest electrical resistivity tomography time series in steep bedrock. Five parallel transects across the rock ridge have been measured five times each, between 2006 and 2019, with similar hardware. Field measurements were calibrated using temperature‐resistivity laboratory measurements of water‐saturated rock samples from the site. A 3D time‐lapse inversion scheme is applied in the boundless electrical resistivity tomography (BERT) software for the inversion of the data. To assess the initial data quality, we compare the effect of data filtering and the robustness of final results with three different filters and two time‐lapse models. We quantify the volumetric permafrost distribution in the bedrock and its degradation in the last decades. Our data show mean monthly air temperatures to increase from −3.4°C to −2.6°C between 2005‒2009 and 2015‒2019, respectively, while simultaneously permafrost volume degraded on average from 6790 m3 (±640 m3 rock in phase‐transition range) in 2006 to 3880 m3 (±1000 m3) in 2019. For the first time, we provide a quantitative measure of permafrost degradation in unstable bedrock by using a temperature‐calibrated 4D electrical resistivity tomography. Our approach represents a fundamental benchmark for the evaluation of climate change effects on bedrock permafrost.
Leadership in Absentia: Negotiating Distance in Centralized Solomon Islands
Authors: Hobbis Stephanie Ketterer , Hobbis Geoffrey
Published: February 2021

This article examines a tension at the heart of national leadership in Solomon Islands today: a conviction that national leaders need to spend more time in rural environments to better represent rural interests, needs and values, while having to be in town to access the individuals and organizations that, essentially, make them national leaders in the first place. Drawing on fourteen months of ethnographic fieldwork in urban Honiara and the rural Lau Lagoon, Malaita, we are especially interested in how this tension shapes rural perceptions of the legitimacy of chiefs as national leaders. Given that development projects can only be negotiated in Honiara, where the required state institutions, international (N)GOs and major businesses are based, rural residents feel compelled to send their most important village leaders, especially clan chiefs, to town. However, the longer these leaders are away from their homes, the more they seem distracted by urban ‘luxuries’ and the less they appear committed to their rural homes. In particular, villagers complain about their chiefs' contributions to exchange relations. Villages, thus, find themselves in a double‐bind that exaggerates a broader ‘crisis of leadership’ alongside an urban‐rural divide which challenges the promise of chiefly leadership as solution to antipolitical sentiments and a centralized state.
A Review of Immunotherapy for Stage III and Metastatic Non-Small Cell Lung Cancer and the Rationale for the ECOG-ACRIN EA5181 Study
Authors: Varlotto John M. , Sun Zhuoxin , Ky Bonnie , Upshaw Jenica , Katz Sharyn I. , Fitzgerald Thomas J. , Wakelee Heather , Diehn Maximilian , Mankoff David A. , Lovely Christine , Belani Chandra , Oettel Kurt , Masters Gregory , Ramalingam Suresh , Pennell Nathan A.
Published: February 2021

ECOG-ACRIN EA5181 is a phase III prospective, randomized trial that randomizes patients undergoing chemo/radiation for locally advanced non-small cell lung cancer (LA-NSCLC) to concomitant durvalumab or no additional therapy, with both arms receiving 1 year of consolidative durvalumab. Radiation dose escalation failed to improve overall survival in RTOG 0617. However, conventionally fractionated radiation to 60 Gy with concomitant chemotherapy is associated with a high risk of local failure (38%–46%). It is hoped that concomitant immunotherapy during chemo/radiation can help decrease the risk of local failure, thereby improving overall survival and progression-free survival with acceptable toxicity. In this article, we review conventional chemo/radiation therapy for LA-NSCLC, as well as the quickly evolving world of immunotherapy in the treatment of non-small cell lung cancer and discuss the rationale and study design of EA5181.

Implications for Practice

This article provides an up-to-date assessment of how immunotherapy is reshaping the landscape of metastatic non-small cell lung cancer (NSCLC) and how the impact of this therapy is now rapidly moving into the treatment of patients with locally advanced NSCLC who are presenting for curative treatment. This article reviews the recent publications of chemo/radiation as well as those combining immunotherapy with chemotherapy and chemo/radiation, and provides a strategy for improving overall survival of patients with locally advanced NSCLC by using concomitant immunotherapy with standard concurrent chemo/radiation.
Iron Oxide Nanoparticles: Biosynthesis, Magnetic Behavior, Cytotoxic Effect
Authors: Miri Abdolhossein , Najafzadeh Hakimeh , Darroudi Majid , Miri Mohammad Javad , Kouhbanani Mohammad Amin Jadidi , Sarani Mina
Published: February 2021

Iron oxide nanoparticles have attracted much attention because of their superparamagnetic properties and their potential applications in many fields such as magnetic storage devices, catalysis, sensors, superparamagnetic relaxometry (SPMR), and high‐sensitivity biomolecule magnetic resonance imaging (MRI) for medical diagnosis and therapeutics. In this study, iron oxide nanoparticles (Fe2O3NPs) have been synthesized using ataranjabin(camelthorn or persian manna) aqueous solution. The synthesized Fe2O3NPs were identified through powder X‐ray diffraction (PXRD), X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT‐IR), field energy scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy‐dispersive spectroscopy (EDX), vibrating‐sample magnetometer (VSM) and Raman technics. The results show that the nanoparticles have a hexagonal structure with 20 to 60 nm in size. The cytotoxic effect of the synthesized nanoparticles has been tested upon application against lung cancer cell (A549) lines. It was found that there is no cytotoxic activity at lower concentrations of 200 μg/mL. The ability of the synthesized nanoparticles for lead removal in wastewaters was tested. Results show that highest concentration of adsorbent (50 mg/L) has maximum removal efficiency (96.73 %). So, synthesized Fe2O3NPs can be a good candidate to use as heavy metals cleaner from contaminated waters.
Ferroptosis‐Inhibitory Effect and Possible Mechanisms of Ellagitannin Geraniin
Authors: Chen Ban , Li Xican , Liu Jie , Li Yuling , Dai Wanjian , Chen Yingci , Chen Dongfeng
Published: February 2021

The search for safe and effective ferroptosis‐inhibitors has become an important topic. Geraniin, an ellagitannin bearing hexahydroxydiphenoyl (HHDP) and dehydrohexahydroxydiphenoyl (DHHDP) groups, was observed to inhibit erastin‐induced ferroptosis in bone marrow‐derived mesenchymal stem cells (bmMSCs). To determine the mechanism, geraniin was further analyzed using UV‐vis spectra and several colorimetric assays, where its IC50 values were always much lower than that of the Trolox positive control. When interacted with several free radicals, geraniin gave no radical adduct formation (RAF) peak in the ultra‐performance liquid chromatography coupled with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry. In conclusion, geraniin exhibits ferroptosis‐inhibitory potential towards erastin‐treated bmMSCs; such potential may mainly stem from its strong lipid peroxidation (LPO)‐inhibition, Fe2+‐chelating, and antioxidant actions. Geraniin gives neither dimer nor radical adduct, owing to the bulky HHDP (or DHHDP) group; thus, it is considered as a safe and effective ferroptosis‐inhibitor.
Keep your distance: Using Instagram posts to evaluate the risk of anthroponotic disease transmission in gorilla ecotourism
Authors: Van Hamme Gaspard , Svensson Magdalena S. , Morcatty Thais Q. , Nekaris K. Anne‐Isola , Nijman Vincent
Published: February 2021

Mountain gorilla Gorilla beringei beringei trekking is a substantial source of revenue for the conservation of this threatened primate and its habitat. Trekking, however, may pose a threat of human‐to‐gorilla disease transmission that could have disastrous effects on wild gorillas.

We used 858 photographs posted on Instagram in 2013–2019 to analyse the proximity of tourists visiting mountain gorillas in the wild. We classified photographs of the encounters according to the distance between the closest gorilla and human, the age class of the gorilla, the trekking location and presence of a surgical face mask on the tourist. We ran a generalised linear mixed model to test whether these variables influenced the distance between the human and the wild gorillas in the photographs, and to test whether these distances have changed over time.

Most sampled photographs (86%) showed tourists within a critical 4 m of the gorillas, with 25 incidents of physical contact between a tourist and a gorilla, and only 3% at the recommended distance of 7 m or more. We only were able to record face mask use in the Democratic Republic of Congo, where these were present in 65% of uploaded photos.

Tourists and immature gorillas tended to get closer to each other than tourists and adult gorillas, and this is more pronounced in female tourists than male tourists. The mean distance between human and wild gorillas decreased by ~1 m between 2013 and 2019.

The results indicate that existing rules are not enforced and raise attention to this unsustainable aspect of mountain gorilla trekking as it is practiced today. These ever‐growing tourist attractions in the range countries pose risks of disease transmission in both directions between tourists and wildlife. The popularity of photograph‐based social media may stimulate closer contacts and influence people into risky behaviours.

We advocate the establishment and reinforcement of regulations relating to the distance between animals and tourists in any in situ wildlife ecotourism context, as well as campaigns to raise awareness regarding the risks of anthroponosis, and fines applied in case of non‐compliance.

A free Plain Language Summary can be found within the Supporting Information of this article.
Mechanical characteristics and hydrophobicity of alkyl ketene dimer compatibilized hybrid biopolymer composites
Authors: Caylak Sena , Ertas Murat , Donmez Cavdar Ayfer , Angin Naile
Published: February 2021

In this study, the effect of alkyl ketene dimer (AKD) on the mechanical and physical properties of natural fiber (NF) and glass fiber (GF) reinforced poly(lactic acid) (PLA) composites were investigated in detail. The hybrid PLA composites were manufactured by extrusion method followed by hot press molding. AKD was used to improve the hydrophobicity of hybrid PLA composites and compatibility of NF and PLA in the polymer matrix. The tensile and flexural tests, thickness swelling, water absorption, and contact angle measurements were accomplished for determining the performance of the hybrid PLA composites. The surface morphology of the hybrid PLA composites was also performed by scanning electron microscopy. The incorporation of AKD and NF into PLA matrix improved the mechanical strengths by 40% and above compared to those of samples without AKD. But, tensile and flexural moduli decreased as 7% and 14% of the samples with NF and AKD, respectively. Contact angle was higher for the hybrid PLA composites with AKD compared with the composites without AKD. However, the results revealed that in the presence of GF, AKD had no significant effect on overall properties of the hybrid PLA composites. In the light of the findings, AKD may have a potential usage as coupling agent in the NF filled PLA composites.
Synthesis of bio‐based poly(methacrylates) using SG1‐containing amphiphilic macroinitiators by nitroxide mediated miniemulsion polymerization
Authors: Tajbakhsh Saeid , Marić Milan
Published: February 2021

SG1‐based amphiphilic macroinitiators were synthesized from oligoethylene glycol methyl ether methacrylate and 10 mol% acrylonitrile or styrene (as the controlling comonomer) to conduct the nitroxide mediated polymerization of bio‐based methacrylic monomers (isobornyl methacrylate (IBOMA) and C13 alkyl methacrylate (C13MA)) in miniemulsion. The effect of the addition of surfactant (DOWFAX 8390), co‐stabilizer (n‐hexadecane) and different reaction temperatures (80, 90 and 100°C) on polymerization kinetics was studied. We found that the NMP of IBOMA/C13MA using amphiphilic macroalkoxyamines were most effective during miniemulsion polymerization (linear trend of Mn versus conversion and high latex stability) in presence of 2 wt% surfactant and 0.8 wt% co‐stabilizer (relative to monomer) at 90°C. The effect of surfactant, co‐stabilizer and temperature on particle size during the polymerization was studied and suggested a decrease in initial particle size with the addition of surfactant and co‐stabilizer. Finally, the thermal properties of IBOMA/C13MA polymers, prepared by amphiphilic macroinitiators, were examined thoroughly, indicating a Tg in the range of −44°C < Tg < 109°C.
Psychological symptoms in widowed parents with minor children, 2–4 years after the loss of a partner to cancer
Authors: Falk Megan W. , Angelhoff Charlotte , Alvariza Anette , Kreicbergs Ulrika , Sveen Josefin
Published: February 2021

Objectives

This study aimed to explore psychological symptoms in widowed parents with minor children, 2–4 years after the death of their partner. A second aim was to examine the associations between psychological symptoms and nonmodifiable and modifiable illness and healthcare‐related factors.

Methods

A cross‐sectional survey study on widowed parents with minor children after the loss of a partner to cancer. In total, 42 parents completed an online questionnaire including instruments for assessing symptoms of anxiety, depression, grief rumination, prolonged grief, and posttraumatic stress. Descriptive statistics, Spearman's correlation coefficients, Mann–Whitney U tests and Kruskal–Wallis tests were used to analyze differences in symptomology based on modifiable and nonmodifiable factors.

Results

Parents reported moderate–severe symptoms of anxiety, posttraumatic stress, and depression. Reporting having received more information during the partner's illness regarding how the illness could affect the partner's somatic and psychological health and where to turn for support were associated with fewer psychological symptoms.

Conclusions

A substantial proportion of widowed parents with minor children reported a moderate–severe symptom burden regarding depression, anxiety, and posttraumatic stress, and less so with prolonged grief symptoms. This study also highlighted the value of receiving information from healthcare personnel regarding the somatic and psychological effects of a partner's illness and where widowed parents can turn for support.
Examining fear of cancer recurrence in primary brain tumor patients and their caregivers using the Actor‐Partner Interdependence Model
Authors: Braun Sarah Ellen , Aslanzadeh Farah J , Thacker Leroy , Loughan Ashlee R
Published: February 2021

Objective

Fear of cancer recurrence (FCR) is related to psychological distress and poor quality of life in cancer patients and their caregivers. However, no studies have investigated FCR in neuro‐oncology. Given the varied prognosis, treatment, and disease trajectory of brain cancer, FCR may affect patients and their caregivers differently.

Methods

Eighty adult primary brain tumor (PBT) patients and 52 caregivers completed questionnaires assessing FCR and psychological distress (depressive symptoms, generalized anxiety, and death anxiety). Differences in patient and caregiver FCR by demographic and medical characteristics were examined. Using multilevel modeling, the Actor‐Partner Interdependence Model (APIM) was used to investigate the interrelationship between patient and caregiver FCR with demographics and psychological distress measures.

Results

Caregivers reported significantly higher FCR than patients. There were no effects of demographic or medical characteristics on patient FCR. Time since diagnosis was negatively related to caregiver FCR. All measures of psychological distress exerted a significant actor effect on FCR among both patients and caregivers. Two partner effects were found: caregiver depressive symptoms and death anxiety negatively predicted patients' FCR.

Conclusions

This is the first investigation of FCR in PBT patients and their caregivers. Most demographic and medical characteristics were not related to patient or caregiver FCR. Caregiver FCR may be higher at the time of diagnosis and decrease over time. APIMs revealed actor effects on patient and caregiver FCR for all measures of psychological distress. Results demonstrated the dyadic effects of a brain tumor diagnosis, emphasizing the need to include caregivers in psychotherapy for neuro‐oncology patients.
Reaching the highest shelf: A review of organic production, nutritional quality, and shelf life of kale (Brassica oleracea var. acephala)
Authors: Reda Tony , Thavarajah Pushaparajah , Polomski Robert , Bridges William , Shipe Emerson , Thavarajah Dil
Published: February 2021

Societal Impact Statement

Since its inception in the early 20th century, organic agriculture has grown increasingly popular due to its focus on a holistic, environmentally friendly approach to crop production. However, it is comparatively limited in biomass production, disease management, nutritional quality, and postharvest treatment compared to conventional agriculture. These challenges carry over into kale production, the majority of which is certified organic. This article reviews organic kale production, morphology, and shelf life, focusing on nutrition and plant breeding. It explores the shortcomings of organic output and potential areas of study to enhance shelf life in organic kale while maintaining nutritional quality.

Summary

Organic production has grown exponentially over the past few decades in both acreage and popularity worldwide. This review focuses specifically on kale produced in the USA. However, regulations limiting synthetic inputs leave organic produce at a disadvantage compared to conventional agriculture in terms of biomass, nutritional quality, disease management, and postharvest treatment. Organic agriculture requires significant improvements to be a viable means of production for a growing population. Kale (Brassica oleracea var. acephala) is a “nutritional powerhouse” leafy green vegetable. The high concentration of vitamins, minerals, and prebiotic carbohydrates in a low‐calorie food makes kale an important crop for combatting obesity‐related non‐communicable diseases. However, the short shelf life of organic kale and inevitable fresh food waste make developing new kale cultivars with increased shelf life essential. This review article aims to (a) review kale morphology, consumer preference, and production, and (b) review nutritional quality, its effect on shelf life, and current breeding efforts of kale. Future research could focus on developing a kale breeding pipeline following suitable kale germplasm selection adapted to organic agriculture with both superior shelf life and improved nutritional quality.
Deep learning pan‐specific model for interpretable MHC‐I peptide binding prediction with improved attention mechanism
Authors: Jin Jing , Liu Zhonghao , Nasiri Alireza , Cui Yuxin , Louis Stephen‐Yves , Zhang Ansi , Zhao Yong , Hu Jianjun
Published: February 2021

Accurate prediction of peptide binding affinity to the major histocompatibility complex (MHC) proteins has the potential to design better therapeutic vaccines. Previous work has shown that pan‐specific prediction algorithms can achieve better prediction performance than other approaches. However, most of the top algorithms are neural networks based black box models. Here, we propose DeepAttentionPan, an improved pan‐specific model, based on convolutional neural networks and attention mechanisms for more flexible, stable and interpretable MHC‐I binding prediction. With the attention mechanism, our ensemble model consisting of 20 trained networks achieves high and more stabilized prediction performance. Extensive tests on IEDB's weekly benchmark dataset show that our method achieves state‐of‐the‐art prediction performance on 21 test allele datasets. Analysis of the peptide positional attention weights learned by our model demonstrates its capability to capture critical binding positions of the peptides, which leads to mechanistic understanding of MHC‐peptide binding with high alignment with experimentally verified results. Furthermore, we show that with transfer learning, our pan model can be fine‐tuned for alleles with few samples to achieve additional performance improvement. DeepAttentionPan is freely available as an open‐source software at https://github.com/jjin49/DeepAttentionPan.
Challenges to managing aging process equipment and infrastructure
Authors: Kelly Brian D.
Published: February 2021

Aging equipment has long been a reality in the chemical process industries. Plants built in the 1950s and 1960s, during an age of prosperity and growth, have since surpassed their life expectancy and many are still operating. Aging equipment is often more prone to failure than equipment built to current standards. Aging is recognized as a significant contributor to industrial accidents particularly in North America. CCPS published a concept book in 2018 highlighting best practices for dealing with aging equipment. In the current economic downturn coupled with the COVID‐19 pandemic there are some additional challenges in applying these best practices. This article discusses some of these challenges.
Defining distance thresholds for migration research
Authors: Lomax Nik , Norman Paul , Darlington‐Pollock Frances
Published: February 2021

There exists a large body of research focused on migration distance, where migration is either the outcome of interest or used as an input variable to model something else. However, there is little consistency in the distance thresholds used: these are often arbitrary, based on administrative boundaries or constrained by definitions available in the dataset. This causes problems with comparison across studies, and in some cases where migration distance is poorly defined could lead to issues with interpretation of results. Using Binary Logistic Regression and drawing on data from the 2011 Census Sample of Anonymised Records for England and Wales, we demonstrate that the odds of migrating vary when considering a range of population characteristics across 16 distance thresholds. We argue that the choice of distance cut‐offs needs to be population and context specific and that decisions about these cut‐offs should be made carefully as part of the study design.
Design and Characterization of ZnSe/GeO2 Heterojunctions as Bandstop Filters and Negative Capacitance Devices
Authors: Algarni Sabah E. , Qasrawi Atef F. , Khusayfan Najla M.
Published: February 2021

Herein, polycrystalline films of ZnSe which are coated onto Au substrates and recoated with amorphous layers of GeO2 are used as active material to perform as bandstop filters. The stacked layers of Au/ZnSe/GeO2 are coated under pressure of 10−5 mbar. The device is characterized by X‐ray diffraction, X‐ray photoelectron, X‐ray fluorescence, and impedance spectroscopy techniques. It is observed that when the device is contacted with carbon point contacts, it exhibits resonance–antiresonance phenomena near 1.0 GHz. The Au/ZnSe/GeO2/C devices display negative capacitance effect in the frequency domain of 0.96–1.80 GHz. Analyses of the conductivity and capacitance spectra in the frequency domain of 0.01–1.80 GHz reveal the domination of conduction by quantum mechanical tunneling below 0.58 GHz and by the correlated barriers hopping above 0.58 GHz. In addition, characterizations of the impedance, reflection coefficient, return loss () and voltage standing wave ratios () spectra of the device indicated ideal bandstop filter features. The notch frequency of the filter is 1.56 GHz. At this critical frequency, the Au/ZnSe/GeO2/C devices display ideal characteristics presented by VSWR of 1.0, value of 28.9 dB. These features make the Au/ZnSe/GeO2/C heterojunction devices promising for use in telecommunication technology.
The Moran forest
Authors: Bienvenu François , Duchamps Jean‐Jil , Foutel‐Rodier Félix
Published: February 2021

Starting from any graph on {1, … , n}, consider the Markov chain where at each time‐step a uniformly chosen vertex is disconnected from all of its neighbors and reconnected to another uniformly chosen vertex. This Markov chain has a stationary distribution whose support is the set of nonempty forests on {1, … , n}. The random forest corresponding to this stationary distribution has interesting connections with the uniform rooted labeled tree and the uniform attachment tree. We fully characterize its degree distribution, the distribution of its number of trees, and the limit distribution of the size of a tree sampled uniformly. We also show that the size of the largest tree is asymptotically , where , and that the degree of the most connected vertex is asymptotically .
Assessing the effectiveness of agricultural conservation practices in maintaining soil organic carbon under contrasting agroecosystems and a changing climate
Authors: Gollany Hero T. , DelGrosso Stephen J. , Dell Curtis J. , Adler Paul R. , Polumsky Robert W.
Published: February 2021

The potential of conservation practices to maintain soil organic C (SOC) and reduce climate change impacts on yields is unknown. This study aimed to validate the DayCent model with observed yield data and the CQESTR model with measured SOC in two agroecosystems, and predict the best practices to sustain SOC under projected climate change. Data were from a conventional tillage (CT) wheat (Triticum aestivum L.)–fallow rotation without N or with 135 kg N ha–1 fertilizer, and no‐till (NT) experiments, NTA (NTA0W‐F and NTA135W‐F) and NTB with a wheat–pea (Pisum sativum L.) cover crop (NTB0W‐P and NTB135W‐P) in Oregon; and crop rotations with CT and NT silage or grain corn (Zea mays L.)–soybean [Glycine max (L.) Merr.]–alfalfa (Medicago sativa L.) with or without manure or stover removal or a cover crop in Pennsylvania. Measured and CQESTR‐simulated SOC were significantly (p < .0001) correlated (r = .90). In Oregon, predicted SOC to 60 cm increased under NTA135W‐F and NTB135W‐P at 0.05 and 0.08 Mg ha–1 yr–1 under projected climate change, respectively. The NT management under dryland production provided a limited SOC increase. In Pennsylvania, predicted SOC to 1 m decreased at 0.07 Mg ha–1 yr–1 in corn–soybean under CT or NT with stover removal, but increased by 0.71 Mg ha–1 yr–1 in dairy forage NT and manure added under climate change. The responses of SOC to climate change were affected by management, biomass type, edaphic properties, local climate, and agroecosystem.
Tannic Acid as a Natural Ferroptosis Inhibitor: Mechanisms and Beneficial Role of 3’‐O‐Galloylation
Authors: Liu Yangping , Li Xican , Hua Yujie , Zhang Wenhui , Zhou Xianxi , He Jianfeng , Chen Dongfeng
Published: February 2021

Ferroptosis is a recently reported cellular apoptosis form. Screening for safe ferroptosis inhibitors and elucidation of the mechanisms have recently attracted significant attention. In this study, the ferroptosis‐inhibitory activities of gallotannin tannic acid and its parent, 1,2,3,4,6‐penta‐O‐galloyl‐β‐D‐glucopyranose (β‐PGG), were comparatively evaluated using an erastin‐mediated bone marrow‐derived mesenchymal stem cell (bmMSC) model, employing ferrostatin‐1 (Fer‐1) as a positive control. The relative inhibitory levels decreased in the following order: Fer‐1>tannic acid>β‐PGG. In the radical‐trapping assays, the relative levels decreased in the order of tannic acid>β‐PGG >Fer‐1. When mixed with ferrous ions, the UV‐visible spectra of tannic acid, β‐PGG, and Fer‐1 changed. In conclusion, natural tannic acid could undergo radical trapping and ferrous complexation pathways to inhibit ferroptosis in the bmMSCs. In contrast to Fer‐1, which utilized ferrous complexation to initiate its catalytic recycle, tannic acid mediated ferrous complexation to indirectly trap the radicals. The 3’‐O‐galloylation reaction enhanced the radical trapping and indirect radical trapping of tannic acid to enhance ferroptosis inhibition.
A Theoretical Study on the Degenerate Cope Rearrangement of Hypostrophene Using the RRKM Theory and Topological Approaches
Authors: Khojandi Mahya , Zahedi Ehsan , Seif Ahmad , Taghvamanesh Afshin , Karimkhani Mehrnoosh
Published: February 2021

The CBS‐APNO and CBS‐QB3 model chemistries have been used to study the temperature‐ and pressure‐dependent kinetics of degenerate Cope rearrangement of hypostrophene. The rate constants are calculated by means of RRKM theory and corrected by the Wigner tunneling correction. The high‐ and low‐pressure limits of the rate constants reveal that the TST is valid to estimate the rate constant at 1 bar and the reaction in the bimolecular region cannot be observed experimentally. The estimated rate constant and activation energy at 1 bar and 308 K are 10−2 s−1 and 89 kJ.mol−1, respectively, such that the homoaromatic transition structure is stabilized by 85 kJ.mol−1 because of the interactions between the allyl moieties. Evolution of chemical events along the reaction has been analyzed by the BET together with the NCI and AIM topological approaches at the B3LYP with 6‐311G(d,p) basis set. The progress of reaction was monitored by five SSDs and controlled by the succession of catastrophes C†[F]2TS[F†]2C. The sequential chemical events consist of homolytic rupture of C−C bond and formation of pseudoradical centers on carbon atoms, disappearance of the generated pseudoradical centers, formation of new pseudoradical centers on two carbon, and formation of new C−C single bond through the C− to −C coupling of the generated pseudoradical centers. The NCI and AIM analyses have been performed to study the nature of the interaction in the regions where bond rupture/formation occur.
Structural Phase Transitions to 2D and 3D Oxygen Vacancy Patterns in a Perovskite Film Induced by Electrical and Mechanical Nanoprobing
Authors: Yao Lide , Inkinen Sampo , Komsa Hannu‐Pekka , van Dijken Sebastiaan
Published: February 2021

Oxygen vacancy migration and ordering in perovskite oxides enable manipulation of material properties through changes in the cation oxidation state and the crystal lattice. In thin‐films, oxygen vacancies conventionally order into equally spaced planes. Here, it is shown that the planar 2D symmetry is broken if a mechanical nanoprobe restricts the chemical lattice expansion that the vacancies generate. Using in situ scanning transmission electron microscopy, a transition from a perovskite structure to a 3D vacancy‐ordered phase in an epitaxial La2/3Sr1/3MnO3–δ film during voltage pulsing under local mechanical straining is imaged. The never‐before‐seen ordering pattern consists of a complex network of distorted oxygen tetrahedra, pentahedra, and octahedra that, together, produce a corrugated atomic structure with lattice constants varying between 3.5 and 4.6 Å. The giant lattice distortions respond sensitively to strain variations, offering prospects for non‐volatile nanoscale physical property control driven by voltage and gated by strain.
Highly Active Hollow RhCu Nanoboxes toward Ethylene Glycol Electrooxidation
Authors: Qiao Bin , Yang Ting , Shi Shufeng , Jia Nan , Chen Yu , Chen Xinbing , An Zhongwei , Chen Pei
Published: February 2021

The efficient electrocatalysts toward the ethylene glycol oxidation reaction (EGOR) are highly desirable for direct ethylene glycol fuel cells because of the sluggish kinetics of anodic EGOR. Herein, porous RhCu nanoboxes are successfully prepared through facile galvanic replacement reaction and succedent sodium borohydride reduction strategy. Benefiting from hierarchical pore structure, RhCu nanoboxes display excellent electrocatalytic performance toward the EGOR in alkaline medium with a mass activity of 775.1 A gRh−1, which is 2.8 times as large as that of commercial Rh nanocrystals. Moreover, the long‐term stability of RhCu nanoboxes is better than that of commercial Rh nanocrystals. Furthermore, the theoretical calculations demonstrate that RhCu nanoboxes possess lower adsorption energy of CO and lower reaction barrier (0.27 eV) for the COads oxidation with aid of the adsorbed OHads species, resulting in the outstanding electrocatalytic performance toward the EGOR. This work provides a meaningful reference for developing highly effective electrocatalysts toward the EGOR.
Immune Stimulating Antibody‐Photosensitizer Conjugates via Fc‐Mediated Dendritic Cell Phagocytosis and Phototriggered Immunogenic Cell Death for KRAS‐Mutated Pancreatic Cancer Treatment
Authors: Kim Dahye , Lee Sanghee , Na Kun
Published: February 2021

Although cetuximab (CTX) is a chimeric epidermal growth factor receptor (EGFR) antibody, the antitumor efficacy of CTX has a negligible effect in patients with Kirsten rat sarcoma 2 viral oncogene homolog (KRAS) mutated pancreatic adenocarcinoma. Given that all extant treatments are ineffective due to the undruggable characteristics of KRAS‐mutated cancer, alternative strategies have been investigated. In this work, CTX‐conjugated maleimide‐polyethylene glycol‐chlorin e6 (CMPC) is designed to strengthen its antitumor efficacy. With strong affinity for EGFR overexpressing Aspc‐1 cells, CMPC with laser exerts the greatest cytotoxicity (90%) and induction of immunogenic cell death. Through a combination of fragment crystallizable region‐mediated antigen uptake by CTX and danger‐associated molecular patterns released by photodynamic therapy (PDT), phagocytosis and maturation of dendritic cells treated with CMPC plus laser show dramatic increases. In vivo biodistribution and antitumor effect also demonstrate that CMPC has significant tumor selectivity and tumor ablation efficacy upon laser irradiation. Furthermore, a large number of CD4+, CD8+ T cells and mature DCs and natural killer cells are infiltrated in CMPC with laser‐treated tumor tissues and tumor‐draining lymph nodes, revealing both innate and adaptive cellular immune stimulation. This synergistic effect with CMPC and laser treatment provides an effective approach for pancreatic cancer immunotherapy attributed to both CTX and PDT.
A Powder Self‐Healable Hydrogel Electrolyte for Flexible Hybrid Supercapacitors with High Energy Density and Sustainability
Authors: Huang Hailong , Han Lu , Fu Xiaobin , Wang Yanling , Yang Zhongli , Pan Likun , Xu Min
Published: February 2021

Ionic conductive hydrogel electrolyte is considered to be an ideal electrolyte candidate for flexible supercapacitor due to its flexibility and high conductivity. However, due to the lack of effective recycling methods, a large number of ineffective flexible hydrogel supercapacitors caused by some irreversible damages and dryness of hydrogel electrolyte are abandoned, which would induce heavy economic and environmental protection problems. Herein,a smart ionic conductive hydrogel (SPMA‐Zn: ZnSO4/sodium alginate/polymethylacrylic acid) is developed for flexible hybrid supercapacitor (SPMA‐ZHS). The SPMA‐Zn exhibits an excellent self‐healing ability and can recover its electrochemical performance after multiple mechanical damages. More importantly, it possesses an outstanding powder self‐healable property, which could easily regenerate the hydrogel electrolyte after powdering, and maintain stable electrochemical performance of SPMA‐ZHS. Besides, the SPMA‐ZHS displays excellent electrochemical performance with a wide and stable working voltage range of 0–2.2 V, high energy density of 164.13 Wh kg−1 at the power density of 1283.44 Wh kg−1 and good stability with a capacity retention of 95.3% after 5000 charge/discharge cycles at 10 A g−1. The strategy in this work would provide a new insight in exploring flexible hydrogel electrolyte‐based supercapacitor with good sustainability and high energy density for flexible wearable electronic devices.
De Novo Designed Peptide and Protein Hairpins Self‐Assemble into Sheets and Nanoparticles
Authors: Galloway Johanna M. , Bray Harriet E. V. , Shoemark Deborah K. , Hodgson Lorna R. , Coombs Jennifer , Mantell Judith M. , Rose Ruth S. , Ross James F. , Morris Caroline , Harniman Robert L. , Wood Christopher W. , Arthur Christopher , Verkade Paul , Woolfson Derek N.
Published: February 2021

The design and assembly of peptide‐based materials has advanced considerably, leading to a variety of fibrous, sheet, and nanoparticle structures. A remaining challenge is to account for and control different possible supramolecular outcomes accessible to the same or similar peptide building blocks. Here a de novo peptide system is presented that forms nanoparticles or sheets depending on the strategic placement of a “disulfide pin” between two elements of secondary structure that drive self‐assembly. Specifically, homodimerizing and homotrimerizing de novo coiled‐coil α‐helices are joined with a flexible linker to generate a series of linear peptides. The helices are pinned back‐to‐back, constraining them as hairpins by a disulfide bond placed either proximal or distal to the linker. Computational modeling indicates, and advanced microscopy shows, that the proximally pinned hairpins self‐assemble into nanoparticles, whereas the distally pinned constructs form sheets. These peptides can be made synthetically or recombinantly to allow both chemical modifications and the introduction of whole protein cargoes as required.
Wide and Tunable Bandgap MAPbBr3−xClx Hybrid Perovskites with Enhanced Phase Stability: In Situ Investigation and Photovoltaic Devices
Authors: Tang Ming-Chun , Dang Hoang X. , Lee Sehyun , Barrit Dounya , Munir Rahim , Wang Kai , Li Ruipeng , Smilgies Detlef-M. , De Wolf Stefaan , Kim Dong-Yu , Anthopoulos Thomas D. , Amassian Aram
Published: February 2021

The current understanding of the crystallization, morphology evolution, and phase stability of wide‐bandgap hybrid perovskite thin films is very limited, as much of the community's focus is on lower bandgap systems. Herein, the crystallization behavior and film formation of a wide and tunable bandgap MAPbBr3−xClx system are investigated, and its formation and phase stability are contrasted to the classical MAPbI3−xBrx case. A multiprobe in situ characterization approach consisting of synchrotron‐based grazing incidence wide‐angle X‐ray scattering and laboratory‐based time‐resolved UV–Vis absorbance measurements is utilized to show that all wide‐bandgap perovskite compositions of MAPbBr3−xClx studied (0 < x < 3) crystallize the same way: the perovskite phase forms directly from the colloidal sol state and forms a solid film in the cubic structure. This results in significantly improved alloying and phase stability of these compounds compared with MAPbI3−xBrx systems. The phase transformation pathway is direct and excludes solvated phases, in contrast to methylammonium lead iodide (MAPbI3). The films benefit from antisolvent dripping to overcome the formation of discontinuous layers and enable device integration. Pin‐hole‐free MAPbBr3−xClx hybrid perovskite thin films with a tunable bandgap are, thus, integrated into working single‐junction solar cell devices and achieve a tunable open‐circuit voltage as high as 1.6 V.
Dimensions of corruption in Pakistan: A systems thinking approach and qualitative analysis
Authors: Ullah Muhammad Aman , Urquhart Cathy , Arthanari Tiru , Ahmed Eatzaz
Published: February 2021

Over the past few decades, many studies of corruption have been carried out. These studies have mainly focused on specific aspects of corruption such as economic issues, legal issues, social propositions, national development and economic policy. This study builds a systems thinking model of corruption, which helps in the understanding of corruption and acts as an input into future policymaking on corruption. Data for the qualitative analysis come from 198 interviews (including 43 in‐depth interviews) conducted in Pakistan. The main contribution of the study is the increased understanding and insights about issues of values, social aspects, inflation, government size and political norms when considering perceptions of corruption in Pakistan. Some of our key findings, such as the effect of inflation, government size, transparency in international negotiations and the juxtaposition of religious values with corruption, have not been widely discussed in the literature.
Approximation of the quasi‐deviance function for the time‐changed Lévy processes by the first‐exit time of the inverse Gaussian subordinator
Authors: Mselmi Farouk
Published: February 2021

In this paper, we approximate the link and variance functions of the natural exponential family generated by the distribution of the class of time‐changed Lévy processes by the first‐exit time of the inverse Gaussian subordinator. These results lead us to get an approximation for the quasi‐deviance function.
Study of Activated Carbon Sheets Used for Air‐Cathodes of Portable Quasi‐Solid Aluminum‐Air Batteries
Authors: Iwai Toshiki , Nguyen Dang‐Trang , Taguchi Kozo
Published: February 2021

The air‐cathode is investigated for the development and optimization of low‐cost, miniaturized, portable, quasi‐solid aluminum‐air batteries. The battery used aluminum as the anode and gelation sodium chloride as the electrolyte. The air‐cathode was activated carbon sheet made of carbon fiber, cellulose, and activated carbon powder. The air‐cathode requires a large surface area. Activated carbon (AC) has the property of porosity and large surface area. In this study, this property was utilized for enhancing the performance of the air‐cathode. The performance of AC sheets with AC ratio in the range of 0–75 wt% was compared. 60 wt% sample generated the highest maximum power density of 3.5 mW/cm−2 with an energy density of 1.0 kWh/kg. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.