bluuebunny/crossref_metadata_2025 huggingface dataset:
Universal Bottom Contact Modification with Diverse 2D Spacers for High‐Performance Inverted Perovskite Solar Cells
Authors: Li Jun , Zuo Lijian , Wu Haotian , Niu Benfang , Shan Shiqi , Wu Gang , Chen Hongzheng
Published: June 2021

Although the 2D spacer modification is widely studied in perovskite solar cells (PVSCs), the energy level alignment between the 2D/3D interfaces makes it unfavorable for top surface passivation in the inverted p‐i‐n device structure. To address this issue, the effect of bottom interface modification is studied with three representative 2D spacers, i.e., the Ruddlesden‐Popper 2D spacer, Dion‐Jacobson 2D spacer, and strong passivation 2D spacer, in inverted p‐i‐n PVSCs. After optimization, the PVSCs with these 2D spacer modifications universally exhibit the best efficiencies of ≈21.6%, which constitutes dramatic improvement compared to the control device (20.7%). By lifting off the perovskite layer, the optoelectronic properties of the bottom surface are studied, and the mechanism underlying the improved device performance is unveiled to be uniformly originated from the formation of 2D/3D heterojunction, where the cascade valence band facilitates the hole collection and electron back scattering field suppresses the charge recombination at the anode interface. Besides, the unencapsulated device retains 90% of initial efficiency after 30 days of storage in ambient air with a relative humidity of 30 ± 5%, indicating excellent stability against moisture and oxygen. This study provides insight into the bottom interface modification with diverse 2D spacers for high‐performance p‐i‐n structured PVSC devices.
Dynamically Crosslinked Dry Ion‐Conducting Elastomers for Soft Iontronics
Authors: Zhang Panpan , Guo Wenbin , Guo Zi Hao , Ma Yuan , Gao Lei , Cong Zifeng , Zhao Xue Jiao , Qiao Lijie , Pu Xiong , Wang Zhong Lin
Published: June 2021

Soft ionic conductors show great promise in multifunctional iontronic devices, but currently utilized gel materials suffer from liquid leakage or evaporation issues. Here, a dry ion‐conducting elastomer with dynamic crosslinking structures is reported. The dynamic crosslinking structures endow it with combined advantageous properties simultaneously, including high ionic conductivity (2.04 × 10−4 S cm−1 at 25 °C), self‐healing capability (96% healing efficiency), stretchability (563%), and transparency (78%). With this ionic conductor as the electrode, two soft iontronic devices (electroluminescent devices and triboelectric nanogenerator tactile sensors) are realized with entirely self‐healing and stretchable capabilities. Due to the absence of liquid materials, the dry ion‐conducting elastomer shows wide operational temperature range, and the iontronic devices achieve excellent stability. These findings provide a promising strategy to achieve highly conductive and multifunctional soft dry ionic conductors, and demonstrate their great potential in soft iontronics or electronics.
Advances in Liquid‐Phase and Intercalation Exfoliations of Transition Metal Dichalcogenides to Produce 2D Framework
Authors: Raza Ali , Hassan Jahan Zeb , Ikram Muhammad , Ali Salamat , Farooq Umer , Khan Qasim , Maqbool Muhammad
Published: June 2021

A host of innovative developments in technology have led by 2D materials owing to their remarkable electronic and physical properties which opens doors for advanced research areas and horizons of material science. Among these materials, transitional metal dichalcogenides (TMDCs) e.g., MoS2, WS2, MoSe2, and WSe2, are reflected as promising candidates of 2D family. Despite significant achievements, the primary challenge is to produce these 2D materials with high purity, massive yield, and well‐controlled structure that lead to fundamental research as well as industrial applications in an efficient and scalable way. A variety of techniques have been employed to develop 2D‐TMDCs, such as mechanical exfoliation, chemical vapor deposition, and chemical exfoliations. Among state‐of‐the‐art synthetic protocols, chemical exfoliations including Liquid‐phase and intercalation isolations of TMDCs are deliberated as promising solutions for high yield, great performance, low cost, and excellent up‐scalability. Herein, a succinct and comprehensive survey of recent progress in chemical exfoliation routes is presented with the processing techniques, strategic design for exfoliations, and mechanisms of individual approaches. The focus of this review is to fulfill the gap in recent reviews such as underlying mechanisms, chemistries, and critical hurdles with effective solutions in performing chemical exfoliations and suggesting a framework for future studies of TMDCs’ advanced applications.
Hollow Carbon Fiber Decorated by Nano Structure Surface for High‐Efficiency Water Steam Generation
Authors: Suo Xidong , Yang Jie , Zhang Yanrong , Hao Yuting , Yang Jiahui , Qiao Hongtao
Published: June 2021

Utilization of carbon materials for harvesting solar energy is a green, feasible, sustainable, and promising way to manufacture freshwater from sewage and seawater. However, sunlight absorption efficiency, light to thermal conversion efficiency, and expensive cost are still limitations for large‐scale solar steam generation. Here, a solar steam evaporator which is fabricated by carbonized willow catkins films and activated by different metal chlorides under nitrogen at 800 °C is demonstrated. Under the light irradiation intensity of one sun (1000 W m−2), water evaporation rate of the prepared evaporator is up to ≈2.17 kg m−2 h−1, and the surface temperatures reach up to 50 and 91.7 °C under water‐saturated and dry situations, respectively, indicating good steam generation ability and heat localization performance of the fabricated evaporator. The SEM, BET, DSC, and ICP‐MS results show that such a high water evaporation rate of the prepared carbon materials is due to the typical tubular micro‐structure, which decreases water enthalpy of evaporation and the water evaporation in the form of molecular clusters. This method of carbonized and activated willow catkins films provides a sustainable way for efficiently harvesting solar energy to produce fresh water from seawater and sewage.
Population modification strategies for malaria vector control are uniquely resilient to observed levels of gene drive resistance alleles
Authors: Lanzaro Gregory C. , Sánchez C. Hector M. , Collier Travis C. , Marshall John M. , James Anthony A.
Published: June 2021

Cas9/guide RNA (gRNA)‐based gene drive systems are expected to play a transformative role in malaria elimination efforts., whether through population modification, in which the drive system contains parasite‐refractory genes, or population suppression, in which the drive system induces a severe fitness load resulting in population decline or extinction. DNA sequence polymorphisms representing alternate alleles at gRNA target sites may confer a drive‐resistant phenotype in individuals carrying them. Modeling predicts that, for observed levels of SGV at potential target sites and observed rates of de novo DRA formation, population modification strategies are uniquely resilient to DRAs. We conclude that gene drives can succeed when fitness costs incurred by drive‐carrying mosquitoes are low enough to prevent strong positive selection for DRAs produced de novo or as part of the SGV and that population modification strategies are less prone to failure due to drive resistance.
How does the early life environment influence the oral microbiome and determine oral health outcomes in childhood?
Authors: Adler Christina Jane , Cao Kim‐Anh Lê , Hughes Toby , Kumar Piyush , Austin Christine
Published: June 2021

The first 1000 days of life, from conception to 2 years, are a critical window for the influence of environmental exposures on the assembly of the oral microbiome, which is the precursor to dental caries (decay), one of the most prevalent microbially induced disorders worldwide. While it is known that the human microbiome is susceptible to environmental exposures, there is limited understanding of the impact of prenatal and early childhood exposures on the oral microbiome trajectory and oral health. A barrier has been the lack of technology to directly measure the foetal "exposome", which includes nutritional and toxic exposures crossing the placenta. Another barrier has been the lack of statistical methods to account for the high dimensional data generated by‐omic assays. Through identifying which early life exposures influence the oral microbiome and modify oral health, these findings can be translated into interventions to reduce dental decay prevalence.
Atypical resting state functional connectivity in mild traumatic brain injury
Authors: Amir Joelle , Nair Jay Kumar Raghavan , Del Carpio‐O'Donovan Raquel , Ptito Alain , Chen Jen‐Kai , Chankowsky Jeffrey , Tinawi Simon , Lunkova Ekaterina , Saluja Rajeet Singh
Published: June 2021

Objectives

This study aimed to investigate changes in three intrinsic functional connectivity networks (IFCNs; default mode network [DMN], salience network [SN], and task‐positive network [TPN]) in individuals who had sustained a mild traumatic brain injury (mTBI).

Methods

Resting‐state functional magnetic resonance imaging (rs‐fMRI) data were acquired from 27 mTBI patients with persistent postconcussive symptoms, along with 26 age‐ and sex‐matched controls. These individuals were recruited from a Level‐1 trauma center, at least 3 months after a traumatic episode. IFCNs were established based on seed‐to‐voxel, region‐of‐interest (ROI) to ROI, and independent component analyses (ICA). Subsequently, we analyzed the relationship between functional connectivity and postconcussive symptoms.

Results

Seed‐to‐voxel analysis of rs‐fMRI demonstrated decreased functional connectivity in the right lateral parietal lobe, part of the DMN, and increased functional connectivity in the supramarginal gyrus, part of the SN. Our TPN showed both hypo‐ and hyperconnectivity dependent on seed location. Within network hypoconnectivity was observed in the visual network also using group comparison. Using an ICA, we identified altered network functional connectivity in regions within four IFCNs (sensorimotor, visual, DMN, and dorsal attentional). A significant negative correlation between dorsal attentional network connectivity and behavioral symptoms score was also found.

Conclusions

Our findings indicate that rs‐fMRI may be of use clinically in order to assess disrupted functional connectivity among IFCNs in mTBI patients. Improved mTBI diagnostic and prognostic information could be especially relevant for athletes looking to safely return to play, as well for individuals from the general population with persistent postconcussive symptoms months after injury, who hope to resume activity.
Clipping versus coiling for the treatment of oculomotor nerve palsy induced by posterior communicating artery aneurysms: A comparison of effectiveness
Authors: Wang Zidong , Kang Xiaokui , Wang Qingdong
Published: June 2021

Background

A long debate has been going on in the clinical effectiveness to determine whether surgical clipping or coiling more favorable for oculomotor nerve palsy (ONP) caused by PcomAA. We aimed to perform a study, focusing on the effectiveness of ONP induced by PcomAA after treatment of surgical clipping and endovascular coiling.

Method

Potential studies were searched on PubMed, EMBASE, Web of Science, and Cochrane Library from database inception to February 2021, and STATA version 12.0 was exerted to process the pooled data.

Results

A total of 16 articles are included in the study, hailing from the United States, South Korea, the United Kingdom, France, Germany, Korea, China, Japan, Britain, and Singapore. The results showed that the clipping group was related to a higher incidence of complete ONP recovery at follow‐up (OR = 5.808, 95% CI 2.87 to 11.76, p < 0.001), the lower rates of partial ONP recovery (OR = 0.264, 95% CI 0.173 to 0.402, p < .001) and no improvement of ONP at follow‐up (RD = –0.149, 95% CI –0.247 to –0.051, p = .003). In the subgroup of complete ONP recovery based on the condition of patients, clipping was associated with a higher incidence of complete ONP recovery in patients with the incomplete initial ONP (OR = 3.579, p = .020) and ruptured aneurysm (OR = 5.38, p = .020). Regarding the subgroup of complete ONP recovery based on the quality of studies, similar results also appeared.

Conclusion

Surgical clipping was more favorable to the recovery from ONP caused by PcomAA endovascular coiling due to a higher rate of recovery and recovery degree of ONP. Besides that, more evidence‐based performance is necessary to supplement this opinion.
Effect of Citric Acid and Sodium Chloride on Characteristics of Sunflower Seed Shell‐Derived Activated Carbon
Authors: Bahiraei Ayoob , Behin Jamshid
Published: June 2021

Micro‐ and mesoporous activated carbons (ACs) with ultrahigh surface area were synthesized from sunflower seed shells (SSS) by carbonization followed by KOH activation. The effects of citric acid (CA) in both carbonization and activation and of sodium chloride (NaCl) in the activation step were evaluated through the response surface method. Na atoms produced during activation can diffuse in the carbon texture and intensify the role of K atoms in expanding and creating new microporosity, whereas its combination with CA results in a significant proportion of mesopores. CA sequestrates metal ions and facilitates the decomposition of lignocellulosics, which prevents the formation of heavy tar blocking the pores. A high capacity for CO2 adsorption was also observed for the NaCl‐activated sample which was higher than that reported previously.
REERS: Reliable and energy‐efficient route selection algorithm for heterogeneous Internet of things applications
Authors: Nayagi D. Salangai , G G Sivasankari , Ravi Vinayakumar , K R Venugopal , Sennan Sankar
Published: June 2021

Machine‐type communication (MTC) such as device‐to‐device and machine‐to‐machine communication is a technology used to realize the concept of Internet of things (IoT). The fifth generation (5G) IoT is composed of large density of wireless sensor device. The massive roll out of the MTC devices is a serious challenge for wireless communication networks from operational and management perspective, including massive access, route selection, energy efficiency and network congestion. Many proposals have been put forward by the research community to cater to the issues and difficulties of massive MTC (mMTC) access in large density sensor network‐enabled IoT communication environment. Recently, data aggregation with efficient route selection has attracted a lot of research attention owing to its robust ability to resolve the above‐mentioned challenges. Existing data routing and aggregation methodologies are not efficient when adopted to heterogeneous IoT applications as they fail to bring trade‐off between energy efficiency and latency minimization. This research work proposes reliable and energy‐efficient route selection (REERS) scheme to reduce energy dissipation and latency for catering both real‐time and non‐real‐time applications. Experiment outcomes shows the REERS schemes achieves much superior performance than existing routing and aggregation methodologies over latency reduction and energy efficiency.
Shennongjia–Wushan Mountains—One cryptic glacial refugium introduced by the phylogeographical study of the Geometridae moth Ourapteryx szechuana Wehrli
Authors: Cheng Rui , Han Hongxiang , Xue Dayong , Zhu Chaodong , Jiang Nan
Published: June 2021

The origin and evolution of biodiversity in the Shennongjia and Wushan Mountains, located in central China, are little known. In this study, we used Ourapteryx szechuana, which is widely distributed in China and northern Nepal, to explore whether these mountains acted as glacial refugia during climate oscillations of the Quaternary. In total, 192 samples of O. szechuana were collected throughout much of the distribution range. Phylogenetic analysis, molecular dating, demographic history reconstructions, and MAXENT were used to investigate the evolutionary history and differentiation mechanisms and predict the potential species distributions during four different periods. The phylogenetic tree and the star‐like median‐joining network strongly supported two reciprocally monophyletic and allopatric lineages. Lineage I was restricted to the Shennongjia and Wushan Mountains. The divergence time of O. szechuana from its sister species O. thibetaria was approximately 1.94 Ma. The differentiation processes of the two intraspecific lineages occurred at approximately 0.47 Ma. The demographic history reconstruction and the ecological niche model suggested that Lineage II experienced an expansion after the LGM (Last Glacial Maximum), whereas Lineage I did not experience any expansion. Our results suggested the Naynayxungla glaciation promoted the divergence of the two lineages by restricting them to different refugia. The valleys of the Shennongjia–Wushan Mountains may have kept stable and warm (thus ice‐free) environments during Quaternary glaciations, allowing this region to act as a glacial refugia. Our studies show that the Shennongjia and Wushan Mountains are likely to be important but little studied glacial refugia for the insect and thus worthy of more attention.
Electrochemiluminescence of Carbon‐based Quantum Dots: Synthesis, Mechanism and Application in Heavy Metal Ions Detection
Authors: Li Libo , Zhao Wanlin , Luo Lijun , Liu Xiaohong , Bi Xiaoya , Li Jiamin , Jiang Panao , You Tianyan
Published: June 2021

In recent years, carbon‐based quantum dots as luminophores and co‐reactants have aroused broad interest for their ability to function in electrochemiluminescence (ECL) sensors due to their unique features, including excellent biocompatibility, low toxicity, and water solubility. In this mini review, the synthesis methods of carbon‐based quantum dots are firstly introduced. Then, the mechanism of carbon‐based quantum dots as luminophores and co‐reactants and their latest progress application in the detection of heavy metal ions are explored. Finally, the current challenges and potential future development directions of carbon‐based quantum dots in ECL sensing filed for heavy metal ions analysis are summarized.
Novel engineering of ruthenium‐based electrocatalysts for acidic water oxidation: A mini review
Authors: Zhou Feng , Zhang Lijie , Li Juan , Wang Qi , Chen Yurou , Chen Hailun , Lu Guolong , Chen Guang , Jin Huile , Wang Shun , Wang Jichang
Published: June 2021

The oxygen evolution reaction (OER) is pivotally involved in proton exchange membrane water electrolyzers (PEMWEs). However, the commercialized iridium‐based catalysts often suffer from severe sluggish kinetics, eventually deteriorating the polarization and overall PEMWEs performance. Therefore, to develop OER electrocatalysts with promising reaction kinetics and high stability is of great significance for PEMWEs. Compared to iridium, the ruthenium‐based catalysts possess lower price and higher activity in acidic water oxidation, which promises Ru‐based materials to replace the state‐of‐the‐art IrOx. Yet, the less stable ruthenium than iridium impedes its real applications. In this mini review, recent knowledge of feasible engineering strategies for migrating the Ru‐based electrocatalysts' stability is summarized. In order to improve performance and durability, basic fundamentals of acidic OER on nanoscale and molecular engineered Ru‐based electrocatalysts are briefly introduced. In the end, the challenges and outlook for engineering novel Ru‐based electrocatalysts are presented.
Thermal and electrical performance analysis of induction heating based‐thermochemical reactor for heat storage integration into power systems
Authors: Bio Gassi Karim , Guene Lougou Bachirou , Baysal Mustafa , Ahouannou Clément
Published: June 2021

In this study, the thermal and electrical performance analysis of an induction heating based‐thermochemical reactor is investigated for high‐temperature heat storage. The induction‐heating model is built with Maxwell equations, and the surface‐to‐surface (S2S) radiation model is used for the induced and diffused thermal energy flow transport in the fluid phase within the reactor inner cavity. The effects of operating and structural parameters in terms of the coil turn number, coil current intensity and frequency, the conductive plate, and the coil's relative permeability, electrical conductivity, and emissivity could affect the heat generation, input power demand, and energy consumption of the proposed reactor performance are sufficiently investigated. It is found that the reactor temperature distribution resulted from the homogenized multi‐turn coil magnetomotive force and frequency with the current intensity 48% more effective in reaching the desired temperature at the heat storage medium. However, the conductive plate relative permeability, electrical conductivity, and surface emissivity significantly affect the induction heating system's thermal power, with the relative permeability having the highest impact of 13% in the storage medium's temperature increasing at low current intensity. Moreover, the surface emissivity shows remarkable effects when the inducting heating operates at a high current. Significant energy consumption, more than 159%, is observed when the induction heating generator operates at steady‐state mode. The reactor heating region temperature increases when the reactor operating current and frequency get high. It is observed that the more the induced heat was applied to the reactor, the more the reactor is heating up to a steady‐state. The instantaneous temperature distribution inside the reactor depicted the rise in the temperature is caused by convection and radiation heat transfer. Higher and more uniform temperature distribution inside the reactor is obtained by optimizing the reactor operating and structural parameters.
Risk of epithelial ovarian cancer Type I and II after hysterectomy, salpingectomy and tubal ligation—A nationwide case‐control study
Authors: Darelius Anna , Kristjansdottir Björg , Dahm‐Kähler Pernilla , Strandell Annika
Published: June 2021

The proposed different origins and pathways to of the dualistic model of epithelial ovarian cancer (EOC) may affect and alter the potential risk reduction related to hysterectomy, salpingectomy and tubal ligation. The aim of our study was to analyze associations between hysterectomy, salpingectomy or tubal ligation and risk reduction of EOC Type I and II. In this nationwide register‐based case‐control study, women diagnosed with EOC, Fallopian tube or primary peritoneal cancer between 2008 and 2014 were included. Cases were classified into Type I and II according to histology and predefined criteria. The exposure variables: hysterectomy, salpingectomy and tubal ligation were identified from national registries. Conditional logistic regression analyses were performed to evaluate associations between Type I and II EOC and the exposure variables. Among 4669 registered cases, 4040 were eligible and assessed for subtyping resulting in 1033 Type I and 3007 Type II. Ten controls were randomly assigned to each case from the register of population. In regression analyses, women with previous salpingectomy had a significantly lower risk of EOC Type II (odds ratio [OR] 0.62; 95% confidence interval [95%CI] 0.45‐0.85) but not Type I (OR 1.16; 95%CI 0.75‐1.78). Hysterectomy was associated with a reduced risk of both EOC Type I (OR 0.71; 95%CI 0.52‐0.99) and Type II (OR 0.81; 95%CI 0.68‐0.96). Similar estimates were obtained for tubal ligation, although without statistical significance. The association between salpingectomy and reduced risk of EOC Type II supports the proposed theory of high‐grade serous cancer originating from the tubal fimbriae.
The role of information and communications technology in refugee entrepreneurship: A critical realist case study
Authors: Brown Suzana , Saxena Deepak , Wall P. J.
Published: June 2021

It is widely claimed that information and communications technology (ICT) enables entrepreneurship among refugees. However, the specific impact ICT has on refugee entrepreneurship is not fully understood. This study addresses the research gap by investigating the role ICT plays in enabling entrepreneurial activities among refugees in the Dzaleka refugee camp in Malawi. Drawing on 25 structured interviews we explore the opportunities and challenges faced by refugee entrepreneurs in this context. A critical realist approach is leveraged to identify the stages of business growth where ICT is an important driver and uncover other mechanisms that both enable and/or constrain entrepreneurship. Analysis suggests four generative mechanisms that either enable or constrain refugee business entrepreneurship. The most important finding is that the survival of refugee businesses is facilitated by the market mechanism, with only the growth stage significantly influenced by ICT. Our findings directly conflict with the existing literature that suggests ICT is essential for fostering business entrepreneurship among refugees. This work offers a unique framework for policy interventions that provides guidance on the circumstances, the type of technology and the way it should be leveraged in order to facilitate entrepreneurship.
Salvage neck dissection for isolated neck recurrences in head and neck tumors: Intra and postoperative complications
Authors: Molteni Gabriele , Comini Lara , Le Pera Beatrice , Bassani Sara , Ghirelli Michael , Martone Andrea , Mattioli Francesco , Nocini Riccardo , Santoro Roberto , Spinelli Giuseppe , Presutti Livio , Marchioni Daniele , Mannelli Giuditta
Published: June 2021

Background and Objectives

The current evidence regarding complications after salvage neck dissection (ND) for isolated regional recurrences (IRRs) in head and neck cancers is poor. The aim of this study is to evaluate the incidence and differences in complication rates of salvage ND after primary surgery, radiotherapy, chemoradiotherapy, or combined treatments.

Methods

This was a multicentric retrospective study on 64 patients who underwent salvage ND for IRR in three Italian institutes between 2008 and May 2020.

Results

Complications were detected in 7 of the 34 patients (20.8%) and surgeons described difficult dissection in 20 patients (58.82%). Accidental vascular ligations or nervous injury during surgery were never detected. None of the variables analyzed were statistically significant in predicting the risk of complications, disease‐free survival, or overall survival.

Conclusions

IRR represents a rare entity among total relapses. The incidence of complications after salvage ND for IRR is higher than after primary surgery but at an acceptable rate in experienced hands. However, an adequate balance between functional and oncological outcomes is mandatory.
Tracheal Macrophages During Regeneration and Repair of Long‐Segment Airway Defects
Authors: Tan Zheng Hong , Dharmadhikari Sayali , Liu Lumei , Wolter Gabrielle , Shontz Kimberly M. , Reynolds Susan D. , Johnson Jed , Breuer Christopher K. , Chiang Tendy
Published: June 2021

Objectives/Hypothesis

Tissue‐engineered tracheal grafts (TETGs) offer a potential solution for repair of long‐segment airway defects. However, preclinical and clinical TETGs have been associated with chronic inflammation and macrophage infiltration. Macrophages express great phenotypic heterogeneity (generally characterized as classically activated [M1] vs. alternatively activated [M2]) and can influence tracheal repair and regeneration. We quantified and characterized infiltrating host macrophages using mouse microsurgical tracheal replacement models.

Study Design

Translational research, animal model.

Methods

We assessed macrophage infiltration and phenotype in animals implanted with syngeneic tracheal grafts, synthetic TETGs, or partially decellularized tracheal scaffolds (DTSs).

Results

Macrophage infiltration was observed following tracheal replacement with syngeneic trachea. Both M1 and M2 macrophages were present in native trachea and increased during early tracheal repair (P = .014), with an M1/M2 ratio of 0.48 ± 0.15. In contrast, orthotopic implantation of synthetic TETGs resulted in a shift to M1 predominant macrophage phenotype with an increased M1/M2 ratio of 1.35 ± 0.41 by 6 weeks following implant (P = .035). Modulation of the synthetic scaffold with the addition of polyglycolic acid (PGA) resulted in a reduction of M1/M2 ratio due to an increase in M2 macrophages (P = .006). Using systemic macrophage depletion, the M1/M2 ratio reverted to native values in synthetic TETG recipients and was associated with an increase in graft epithelialization. Macrophage ratios seen in DTSs were similar to native values.

Conclusions

M1 and M2 macrophages are present during tracheal repair. Poor epithelialization with synthetic TETG is associated with an elevation of the M1/M2 ratio. Macrophage phenotype can be altered with scaffold composition and host‐directed systemic therapies. DTSs exhibit M1/M2 ratios similar to those seen in native trachea and syngeneic tracheal replacement.

Level of Evidence

NA Laryngoscope, 132:737–746, 2022
Synthesis and characterization of bacterial cellulose/graphene oxide nano‐biocomposites
Authors: Rashidian Elmira , Babaeipour Valiollah , Chegeni Asma , Khodamoradi Niloofar , Omidi Meisam
Published: June 2021

Bacterial cellulose/graphene oxide (BC/GO) nano‐biocomposites constructed using two methods of in situ and immersion. Scanning electron microscopy showed that a lower amount of GO formed a stronger composite with smaller pores. The in situ method formed a nanostructured composite with an ultrafine particle size distribution. X‐ray diffraction peaks indicated that GO embedded in BC network uniformly. The Young's modulus of the fabricated composites for both methods increased compared to pure BC. DSC analysis showed that the prepared samples were endothermic and in the 350–370°C, the BC/GO sample experienced a 46.9% weight loss. The immersion method formed a composite with higher thermal stability.
A proteomic investigation of isogenic radiation resistant prostate cancer cell lines
Authors: Kurganovs Natalie , Wang Hanzhi , Huang Xiaoyong , Ignatchenko Vladimir , Macklin Andrew , Khan Shahbaz , Downes Michelle R. , Boutros Paul C. , Liu Stanley K. , Kislinger Thomas
Published: June 2021

To model the problem of radiation resistance in prostate cancer, cell lines mimicking a clinical course of conventionally fractionated or hypofractionated radiotherapy have been generated. Proteomic analysis of radiation resistant and radiosensitive DU145 prostate cancer cells detected 4410 proteins. Over 400 proteins were differentially expressed across both radiation resistant cell lines and pathway analysis revealed enrichment in epithelial to mesenchymal transition, glycolysis and hypoxia. From the radiation resistant protein candidates, the cell surface protein CD44 was identified in the glycolysis and epithelial to mesenchymal transition pathways and may serve as a potential therapeutic target.
Distilling the mechanism for the Madden–Julian Oscillation into a simple translating structure
Authors: Vallis Geoffrey K.
Published: June 2021

This article presents a minimal model of the Madden–Julian Oscillation (MJO), isolating a robust mechanism that leads to the observed characteristic pattern and eastward propagation. A localized heat source at the Equator leads to a Gill‐like pattern in the geopotential, with moist air converging toward the heat source. Over a fairly wide range of parameters, the moisture convergence is found to be slightly to the east of the heat source, with moist air advected in from the east along the Kelvin lobe meeting slightly drier air advected meridionally around the Rossby lobes. The associated condensation then gives rise to a heat source that also is east of the original one, thus causing the pattern itself to propagate east with dryer regions both to the east and west of the region of precipitation. The speed of the propagation is limited by the ability of the moisture advection to move the condensational heat source; it thus scales with the fluid speed which is induced by the convective heat source, and so with the strength of the convective heating, and not with a gravity wave speed. The propagation speed also increases with the nominal offset between the centre of the pattern and the subsequent moistening and condensation. In the real world this distance, as well as the level and coherence of condensation, are determined not only by the location of moisture convergence but also by the complex physics of convection in the tropical environment. Thus, even though the underlying MJO mechanism is itself not complicated, its reproduction will depend rather sensitively on model parameters in simulations with comprehensive numerical models.
Effect of external electric field on the tautomeric equilibrium and structure of 2‐carbamido‐1,3‐indandione
Authors: Enchev Venelin , Markova Nadezhda
Published: June 2021

2‐Carbamido‐1,3‐indandione (CAID) is a new reliable fluorescent biomarker and it exists in two tautomeric forms: 2‐(hydroxyl‐aminomethylidene)‐indan‐1,3‐dione (A) and 2‐carboamide‐1‐hydroxy‐3‐oxo‐indan (B). The structures of the tautomers and the transition state for intramolecular proton transfer are located at MP2/6‐31+G(d) level for each magnitude and for opposite directions of the applied electric field. According to our SCS‐MP2/6‐31+G(d) field‐free calculations tautomer A prevails (59.3%) while variation of the electric field strength along the direction from the indandione moiety to the carbamido fragment (+x‐direction) leads to stabilization of tautomer B. The two tautomeric forms become isoenergetic at 2.571 V/Å when the applied electric field is parallel to the direction from amino to the hydroxyl group (−y‐direction) in CAID, and at 3.085 V/Å tautomer B (51.9%) is slightly favored. Apparently, an external electric field has a strong influence on the tautomeric equilibrium in the CAID molecule.
Distributed observers design for a class of nonlinear systems to achieve omniscience asymptotically via differential geometry
Authors: Xu Haotian , Wang Jingcheng , Wang Hongyuan , Wang Bohui
Published: June 2021

Distributed observers are the framework of fusing observed data by constructing a cooperative observer network. This article renders a scheme of distributed observers for a class of nonlinear system. With this scheme, each local nonlinear observer in the cooperative network can estimate the whole states of the underlying system by their own output measurements and information obtained from their neighbor via communication network. The proposed distributed observers are constructed with Partial Observable Canonical Form, which is a technology studied in differential geometry. The common observable subspace pruning and the weight matrix with spatial transformation are innovatively developed to solve the problem that each local observer is not in the same space. The sufficient conditions are proposed to guarantee the achievement of asymptotical omniscience of distributed nonlinear observers. Furthermore, our distributed observers can also be applied to linear systems and systems with some zero outputs. In addition, comparing with some existing methods of distributed nonlinear observers, our method admits some unbounded systems. Four simulations including multi‐Wen‐bridge oscillator systems, multi‐manipulators systems, unbounded nonlinear system and a linear system are employed to show the validity of the main result.
Nested adaptive integral terminal sliding mode control for high‐order uncertain nonlinear systems
Authors: Shao Ke
Published: June 2021

This paper aims to develop a nested adaptive integral terminal sliding mode control scheme for high‐order uncertain nonlinear systems. To achieve this goal, a recursive‐structure integral terminal sliding mode (ITSM) is presented, which consists of a nonsingular terminal sliding mode and a fractional power integral terminal sliding mode. Based on the ITSM, the reaching phase is eliminated and simultaneously, the system is stabilized in finite time. Moreover, due to the full‐order sliding mode inherent in ITSM, the reaching control input is obtained in an integral form instead of a signum function. To remove the needs for the upper bounds of the disturbance or its derivatives, a nested dual‐layer adaptive law is introduced to update the level of the control gain according to the disturbance variations without overestimation. Stability analysis demonstrates that under the proposed control, the system state starts on the sliding surface and then converges to the origin in finite time in the presence of system uncertainties. The novelty of the proposed method lies in its finite‐time origin convergence without reaching phase, nonoverestimation, nonsingular and chattering‐free control signal, and those properties have not yet been achieved by any other existing methods. A simulation example is provided to illustrate the superiorities of the proposed control by comparison to conventional method.
Latent profiles of emotion regulation strategies associated with alexithymia, nonsuicidal self‐injury and resilience among nursing students
Authors: Mao Cui , Lin Mingjing , Shen Shiyu , Li Yuanyuan , Xie Zihui , Li Ping
Published: June 2021

The present study sought to better understand the complex nature of emotion regulation in nursing students by exploring patterns of emotion regulation strategies (ERSs), and to examine the relationships between these unique profiles with alexithymia, nonsuicidal self‐injury (NSSI) and resilience. A total of 1960 nursing students (Mage = 19.56, SD = 1.13 years) were recruited. Using latent profile analysis, nursing students were classified into four profiles based on their ERS use: high reaction profile (HRP; 11.53%), medium reaction profile (MRP; 55.46%), adaptive reaction profile (ARP; 22.86%) and low reaction profile (LRP; 10.15%). This study found that relative to HRP and MRP, ARP and LRP showed a lower incidence of NSSI and alexithymia; HRP and ARP showed a higher level of resilience than MRP and LRP. Furthermore, LRP had the lowest level of resilience. This study highlights the importance of identifying the different ERS profiles among nursing students. Targeted programs are needed to enhance adaptive strategies and reduce maladaptive strategies to improve nursing students' psychological and behavioural performance.
Tailoring Unsymmetrical‐Coordinated Atomic Site in Oxide‐Supported Pt Catalysts for Enhanced Surface Activity and Stability
Authors: Xue Zhenggang , Yan Muyu , Wang Xiaolin , Wang Zhiyuan , Zhang Yan , Li Yuhuan , Xu Wenjie , Tong Yujing , Han Xiao , Xiong Can , Wang Wenyu , Chen Min , Ye Bangjiao , Hong Xun , Song Li , Zhang Hongjun , Yang Li‐Ming , Wu Yuen
Published: June 2021

The catalytic properties of supported metal heterostructures critically depend on the design of metal sites. Although it is well‐known that the supports can influence the catalytic activities of metals, precisely regulating the metal–support interactions to achieve highly active and durable catalysts still remain challenging. Here, the authors develop a support effect in the oxide‐supported metal monomers (involving Pt, Cu, and Ni) catalysts by means of engineering nitrogen‐assisted nanopocket sites. It is found that the nitrogen‐permeating process can induce the reconstitution of vacancy interface, resulting in an unsymmetrical atomic arrangement around the vacancy center. The resultant vacancy framework is more beneficial to stabilize Pt monomers and prevent diffusion, which can be further verified by the density functional theory calculations. The final Pt–N/SnO2 catalysts exhibit superior activity and stability for HCHO response (26.5 to 15 ppm). This higher activity allows the reaction to proceed at a lower operating temperature (100 °C). Incorporated with wireless intelligent‐sensing system, the Pt–N/SnO2 catalysts can further achieve continuous monitoring of HCHO levels and cloud‐based terminal data storage.
Aligned Millineedle Arrays for Solar Power Seawater Desalination with Site‐Specific Salt Formation
Authors: Huang Zhongming , Wei Jinchao , Wan Yingpeng , Li Peng , Yu Jie , Dong Jiayi , Wang Shuangpeng , Li Shengliang , Lee Chun‐Sing
Published: June 2021

As a sustainable and clean water production technology, solar thermal water evaporation has been extensively studied in the past few years. One challenge is that upon operation, salt would form on surface of the solar absorbers leading to inefficient water supply and light absorption and thus much reduced water vaporization rate. To address this problem, a simple solar evaporator based on an array of aligned millineedles for efficient solar water evaporation and controlled site‐specific salt formation is demonstrated. The maximum solar evaporation rate achieved is 2.94 kg m−2 h−1 under one Sun irradiation in brine of high salinity (25 wt% NaCl), achieving energy conversion efficiency of 94.5% simultaneously. More importantly, the spontaneously site‐specific salt formation on the tips of millineedles endows this solar evaporator with salt harvesting capacity. Rationally separating the clean water and salt from brine by condensation and gravity assistance, this tip‐preferential crystallization solar evaporator is not affected by the salt clogging compared with conventional 2D solar evaporators. This study provides new insights on the design of solar evaporators and advances their applications in sustainable seawater desalination and wastewater management.
Diurnal variation in serum concentrations of cortisol in captive African (Loxodonta africana) and Asian (Elephas maximus) elephants
Authors: Bechert Ursula , Hixon Sean , Schmitt Dennis
Published: June 2021

Cortisol is involved in a broad range of physiological processes and enables animals to adapt to new situations and challenges. Diurnal fluctuations in circulating cortisol concentrations in elephants have been demonstrated based on samples from urine and saliva. The aims of this study were to demonstrate diurnal cortisol fluctuations based on blood samples and compare concentrations between seasons, species, and changes in reproductive hormone concentrations. Nine African (Loxodonta africana) and three Asian (Elephas maximus) elephants at two facilities in the United States were included in this study. Blood samples were collected every 2–3 h at one location and every 1–6 h at another. Peak serum concentrations of cortisol averaged 28 ng/ml for both African and Asian elephants, and diurnal cycles included a fivefold decrease from morning peak to evening nadir concentrations. Diurnal cortisol profiles varied uniquely among individual elephants. During the winter, nadir concentrations of cortisol were slightly higher, and the timing of peak concentrations was less predictable. There was no correlation between diurnal serum concentrations of progesterone and cortisol; however, a significant correlation (p = .02) was identified between serum concentrations of testosterone and cortisol when a time lag of ~2–3 h was considered. The physiological significance of the positive correlations between diurnal serum concentrations of cortisol and testosterone in male elephants remains to be determined. If cortisol concentrations are being used to evaluate elephant health or welfare, samples should be obtained at the same time each day to minimize variation due to diurnal fluctuations, and ideally seasonal variations and individuality in diurnal profiles should also be considered.
Correction to: Method development for on-line species-specific sulfur isotopic analysis by means of capillary electrophoresis/multicollector ICP-mass spectrometry
Authors: Faßbender Sebastian , Rodiouchkina Katerina , Vanhaecke Frank , Meermann Björn
Published: June 2021

A Correction to this paper has been published: 10.1007/s00216-021-03474-6
Improving Global Surgical Oncology Benchmarks: Defining the Unmet Need for Cancer Surgery in Ghana
Authors: Gaskill Cameron E. , Gyedu Adam , Stewart Barclay , Quansah Robert , Donkor Peter , Mock Charles
Published: June 2021

Background

The Lancet Commission on Global Surgery (LCoGS) recommended an annual surgical rate at which low‐ and middle‐income countries (LMICs) could achieve most of the population‐wide benefits of surgery. However, condition‐specific guidelines were not proposed. To inform rates of surgery for cancer, we sought to assess the current met and unmet need for oncologic surgery in Ghana.

Methods

Data on all operations performed in Ghana over a one‐year period (2014–15) were obtained from representative samples of 48/124 first‐level and 12/16 referral hospitals and scaled‐up for nationwide estimates. Procedures for cancer were identified by indication. Using modified LCoGS methodology with disease prevalence, Ghana's annual rate of cancer surgery was compared to that of New Zealand to quantify current unmet needs.

Results

232,776 surgical procedures were performed in Ghana; 2,562 procedures (95%UI 1878–3255) were for cancer. Of these, 964 (37%) were surgical biopsies. The annual rate of procedures treating cancer was 2115 surgeries/100,000 cancer cases, or 21% of the New Zealand benchmark. Cervical, breast, and prostate cancer were found to meet 2.1%, 17.2%, and 32.1% of their respective surgical need.

Conclusions

There is a large unmet need for cancer surgery in Ghana. Cancer surgery constitutes under 2% of the total surgeries performed in Ghana, an important proportion of which are used for biopsies. Therapeutic operative rate is deficient across most cancer types, and may lag behind improvements in screening efforts. As cancer prevalence and diagnosis increase in LMICs, cancer‐specific surgical capacity must be increased to meet these evolving needs.
Prognostic Significance of Preoperative Osteopenia in Patients Undergoing Esophagectomy for Esophageal Cancer
Authors: Takahashi Keita , Nishikawa Katsunori , Furukawa Kenei , Tanishima Yuichiro , Ishikawa Yoshitaka , Kurogochi Takanori , Yuda Masami , Tanaka Yujiro , Matsumoto Akira , Mitsumori Norio , Ikegami Toru
Published: June 2021

Background

Osteopenia, which exhibits low bone mineral density (BMD), has been linked to sarcopenia and recently reported as a prognostic factor in various cancers. However, the prognostic significance of osteopenia in esophageal cancer remains unclear. Hence, this study aimed to clarify the impact of osteopenia on the prognosis of patients undergoing esophagectomy for esophageal cancer.

Methods

We included 229 patients who underwent esophagectomy. BMD was calculated as the average pixel density (Hounsfield unit) within a circle in midvertebral core at the 11th thoracic vertebra on preoperative computed tomography. We then divided the patients into the Osteopenia group (n = 159) and the Non‐Osteopenia group (n = 70) according to the optimal cutoff value obtained from the receiver operating characteristic curve. Their clinicopathological data, prognosis, and recurrence were analyzed.

Results

The mean age was significantly older in the Osteopenia group (p = 0.047). The Osteopenia group had significantly worse overall survival (OS) and relapse‐free survival (RFS) than the Non‐Osteopenia group (p = 0.001 and p = 0.012, respectively). Multivariate analysis revealed osteopenia was an independent prognostic factor for OS (p < 0.001; hazard ratio [HR], 2.243; 95% confidence interval [CI], 1.422–3.538) and RFS (p = 0.008; HR, 1.739; 95% CI, 1.154–2.620). In logistic regression model, advanced age and cStage III‐IV were independent risk factors for preoperative osteopenia.

Conclusions

Preoperative osteopenia is associated with poor survival and recurrence in patients undergoing esophagectomy for esophageal cancer.