bluuebunny/crossref_metadata_2025 huggingface dataset:
STROBE-MR: Guidelines for strengthening the reporting of Mendelian randomization studies
Authors: Davey Smith George , Davies Neil M , Dimou Niki , Egger Matthias , Gallo Valentina , Golub Robert , Higgins Julian PT , Langenberg Claudia , Loder Elizabeth W , Richards J Brent , Richmond Rebecca C , Skrivankova Veronika W , Swanson Sonja A , Timpson Nicholas J , Tybjaerg-Hansen Anne , VanderWeele Tyler J , Woolf Benjamin AR , Yarmolinsky James
Published: July 2019

While the number of studies using Mendelian randomization (MR) methods has grown exponentially in the last decade, the quality of reporting of these studies often has been poor. Similar to other reporting guidelines such as CONSORT (Consolidated Standards of Reporting Trials) for randomised trials and STROBE (STrenghtening the Reporting of Observational studies in Epidemiology) for observational studies in epidemiology, the STROBE-MR working group aims to provide guidance to authors on how to improve reporting of MR studies and help readers, reviewers, and journal editors to evaluate the quality of the presented evidence.

Empirical evidence indicates that many reports of MR studies do not clearly state or examine the various assumptions of MR methods and report insufficient details on the data sources, which makes it hard to evaluate the quality and reliability of the results. The STROBE-MR guidance covers both one sample and two sample MR studies. At present, the draft checklist consists of 20 items, organized into the title and abstract, introduction, methods, results and discussion sections of articles.

As these guidelines aim to reach the entire MR community, we would like to give everyone the opportunity to contribute their comments. The following draft of the STROBE-MR checklist is open for public discussion and all feedback will be taken into account during its next revision. For feedback, please use the comment section below this post on PeerJ Preprints.

We hope the final guidelines will serve the entire community and contribute to improving the reporting of MR studies in the future.
Rethinking the usage and experience of clustering markers in web mapping
Authors: Fürhoff Loïc
Published: July 2019

Although the notion of ‘too many markers’ have been mentioned in several research, in practice, displaying hundreds of Points of Interests (POI) on a web map in two dimensions with an acceptable usability remains a real challenge. Web practitioners often make an excessive use of clustering aggregation to overcome performance bottlenecks without successfully resolving issues of perceived performance. This paper tries to bring a broad awareness by identifying sample issues which describe a general reality of clustering, and provide a pragmatic survey of potential technologies optimisations. At the end, we discuss the usage of technologies and the lack of documented client-server workflows, along with the need to enlarge our vision of the various clutter reduction methods.
More homogeneous capillary flow and oxygenation in deeper cortical layers correlate with increased oxygen extraction
Authors: Li Baoqiang , Esipova Tatiana V , Sencan Ikbal , Kılıç Kıvılcım , Fu Buyin , Desjardins Michele , Moeini Mohammad , Kura Sreekanth , Yaseen Mohammad A , Lesage Frederic , Østergaard Leif , Devor Anna , Boas David A , Vinogradov Sergei A , Sakadžić Sava
Published: July 2019

Our understanding of how capillary blood flow and oxygen distribute across cortical layers to meet the local metabolic demand is incomplete. We addressed this question by using two-photon imaging of resting-state microvascular oxygen partial pressure (PO2) and flow in the whisker barrel cortex in awake mice. Our measurements in layers I-V show that the capillary red-blood-cell flux and oxygenation heterogeneity, and the intracapillary resistance to oxygen delivery, all decrease with depth, reaching a minimum around layer IV, while the depth-dependent oxygen extraction fraction is increased in layer IV, where oxygen demand is presumably the highest. Our findings suggest that more homogeneous distribution of the physiological observables relevant to oxygen transport to tissue is an important part of the microvascular network adaptation to local brain metabolism. These results will inform the biophysical models of layer-specific cerebral oxygen delivery and consumption and improve our understanding of the diseases that affect cerebral microcirculation.
Impaired skeletal muscle mitochondrial pyruvate uptake rewires glucose metabolism to drive whole-body leanness
Authors: Sharma Arpit , Oonthonpan Lalita , Sheldon Ryan D , Rauckhorst Adam J , Zhu Zhiyong , Tompkins Sean C , Cho Kevin , Grzesik Wojciech J , Gray Lawrence R , Scerbo Diego A , Pewa Alvin D , Cushing Emily M , Dyle Michael C , Cox James E , Adams Chris , Davies Brandon S , Shields Richard K , Norris Andrew W , Patti Gary , Zingman Leonid V , Taylor Eric B
Published: July 2019

Metabolic cycles are a fundamental element of cellular and organismal function. Among the most critical in higher organisms is the Cori Cycle, the systemic cycling between lactate and glucose. Here, skeletal muscle-specific Mitochondrial Pyruvate Carrier (MPC) deletion in mice diverted pyruvate into circulating lactate. This switch disinhibited muscle fatty acid oxidation and drove Cori Cycling that contributed to increased energy expenditure. Loss of muscle MPC activity led to strikingly decreased adiposity with complete muscle mass and strength retention. Notably, despite decreasing muscle glucose oxidation, muscle MPC disruption increased muscle glucose uptake and whole-body insulin sensitivity. Furthermore, chronic and acute muscle MPC deletion accelerated fat mass loss on a normal diet after high fat diet-induced obesity. Our results illuminate the role of the skeletal muscle MPC as a whole-body carbon flux control point. They highlight the potential utility of modulating muscle pyruvate utilization to ameliorate obesity and type 2 diabetes.
Comparison of integrated PET/MRI with PET/CT in evaluation of endometrial cancer: a retrospective analysis of 81 cases
Authors: Bian Li-hua , Wang Min , Gong Jing , Liu Hong-hong , Wang Nan , Wen Na , Fan Wen-sheng , Xu Bai-xuan , Wang Ming-yang , Ye Ming-xia , Meng Yuan-guang
Published: July 2019

Background

The objective of this study was to compare the diagnostic value of integrated PET/MRI with PET/CT for assessment of regional lymph node metastasis and deep myometrial invasion detection of endometrial cancer.

Methods

Eighty-one patients with biopsy-proven endometrial cancer underwent preoperative PET/CT (n = 37) and integrated PET/MRI (n = 44) for initial staging. The diagnostic performance of PET/CT and integrated PET/MRI for assessing the extent of the primary tumor and metastasis to the regional lymph nodes was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. McNemar’s test was employed for statistical analysis.

Results

Integrated PET/MRI and PET/CT both detected 100% of the primary tumors. Integrated PET/MRI proved significantly more sensitivity and specificity than PET/CT in regional lymph node metastasis detection (P = 0.015 and P < 0.001, respectively). The overall accuracy of myometrial invasion detection for PET/CT and Integrated PET/MRI was 45.9% and 81.8%, respectively. Integrated PET/MRI proved significantly more accurate than PET/CT (P < 0.001).

Conclusion

Integrated PET/MRI, which complements the individual advantages of MRI and PET, is a valuable technique for the assessment of the lymph node metastasis and myometrial invasion in patients with endometrial cancer.
A green garlic (Allium sativum L.) based intercropping system reduces the strain of continuous monocropping in cucumber (Cucumis sativus L.) by adjusting the micro-ecological environment of soil
Authors: Xiao Xuemei , Cheng Zhihui , Lv Jian , Xie Jianming , Ma Ning , Yu Jihua
Published: July 2019

The continuous cropping obstacle of cucumber (Cucumis sativus L.) under facility cultivation is more prevalent in China. This is associated with an imbalance in soil microbial and ecological environment in long-term monocultures. It was postulated that intercropping with green garlic would relieve the continuous cropping obstacle of cucumber by altering the soil micro-ecology status. A pot-based experiment was conducted to investigate the green garlic-cucumber intercropping and cucumber monocropping systems. The results showed that the cucumber shoot biomass was improved by intercropping with green garlic. However, the population of soil bacteria and actinomycetes increased, while the fungal population decreased. The fatty acid methyl ester (FAME) profiles indicated that soil contained more fungal FAME biomarkers (18:1ω9c, 18:2ω6, 9) and higher fungal:bacterial ratio in the monoculture system, whereas clustering of more bacterial FAME biomarkers (cy17:0, cy19:0, 16:1ω7c10, Me16:0, 10Me17:0, 10Me18:0) was observed under intercropping conditions. Moreover, significantly (P < 0.05) higher soil invertase and alkaline phosphatase activities, organic matter, and available N, P and K contents were observed under intercropping systems. These were high in both bulk and rhizosphere soils in the intercropping system when compared to monocropping system. These findings suggest that intercropping with green garlic can alleviate continuous cropping obstacle of cucumber by improving the diverse composition of soil microbial community, enzyme activities, and nutrient availability.
Shoot and root traits of summer maize hybrid varieties with higher grain yields and higher nitrogen use efficiency at low nitrogen application rates
Authors: Su Wennan , Kamran Muhammad , Xie Jun , Meng Xiangping , Han Qingfang , Liu Tiening , Han Juan
Published: July 2019

Breeding high-yielding and nitrogen-efficient maize (Zea mays L.) hybrid varieties is a strategy that could simultaneously solve the problems of resource shortages and environmental pollution. We conducted a 2-year field study using four nitrogen application rates (0, 150, 225, and 300 kg N hm−2) and two maize hybrid varieties (ZD958 and QS101) to understand the plant traits related to high grain yields and high nitrogen use efficiency (NUE). We found that ZD958 had a higher grain yield and nitrogen accumulation in the shoots at harvest as well as a higher NUE at lower nitrogen application rates (0 and 150 kg hm–2) than QS101. The grain yields and NUE were almost identical for the two hybrid varieties at nitrogen application rates of 225 and 300 kg N hm–2. Compared with QS101, ZD958 had higher above-ground and below-ground biomass amounts, a deeper root distribution, longer root length, root active absorption area, greater grain filling rate, and higher photosynthetic NUE than QS101 at lower nitrogen application rates. Our results showed that ZD958 can maintain a higher grain yield at lower nitrogen rates in a similar manner to N-efficient maize hybrid varieties. The selection of hybrids such as ZD958 with a deeper root distribution and higher photosynthetic NUE can increase the grain yield and NUE under low nitrogen conditions.
Establishing an ecological security pattern for urban agglomeration, taking ecosystem services and human interference factors into consideration
Authors: Wang Dongchuan , Chen Junhe , Zhang Lihui , Sun Zhichao , Wang Xiao , Zhang Xian , Zhang Wei
Published: July 2019

The assessment of ecological security patterns is a topic of conversation in landscape ecology in recent years. However, ecosystem services and human activities are seldom considered comprehensively in the assessment of ecological security patterns. The present study employs the Beijing–Tianjin–Hebei urban agglomeration as a study area, and uses ecological services to determine the ecological sources. The importance of ecological sources is classified based on logical coding and functional types of ecological services. The research combines regional characteristics to select and quantitatively calculate three human disturbance factors: soil erosion sensitivity, geological hazard sensitivity, and night lighting. Then the basic surface resistance of land use to limit migration is modified and ecological corridors are identified by combining these three disturbance factors. The results indicate that the sources of water production, soil and water conservation, and carbon fixation are mainly provided in mountainous areas, recreation sources are mostly distributed in the plains, and these ecological sources improve the maintenance of ecological corridors. The modification of resistance surfaces significantly changes the length of ecological corridors in Tianjin, Tangshan, Cangzhou, and Beijing, and the modified resistance surface improves the recognition of ecological corridors. This study provides a new research framework for identifying the ecological security patterns of urban agglomerations and provides scientific guidance related to ecological protection and urban planning for the Beijing−Tianjin−Hebei urban agglomeration.
Evaluation of five regions as DNA barcodes for identification of Lepista species (Tricholomataceae, Basidiomycota) from China
Authors: Wang Siyu , Guo Hongbo , Li JiaJia , Li Wei , Wang Qin , Yu Xiaodan
Published: July 2019

Background

Distinguishing among species in the genus Lepista is difficult because of their similar morphologies.

Methods

To identify a suitable DNA barcode for identification of Lepista species, we assessed the following five regions: internal transcribed spacer (ITS), the intergenic spacer (IGS), nuclear ribosomal RNA subunit, mitochondrial small subunit rDNA, and tef1. A total of 134 sequences from 34 samples belong to eight Lepista species were analyzed. The utility of each region as a DNA barcode was assessed based on the success rates of its PCR amplification and sequencing, and on its intra- and inter-specific variations.

Results

The results indicated that the ITS region could distinguish all species tested. We therefore propose that the ITS region can be used as a DNA barcode for the genus Lepista. In addition, a phylogenetic tree based on the ITS region showed that the tested eight Lepista species, including two unrecognized species, formed eight separate and well-supported clades.
University-School Scenarios and Voices from Classrooms. Rethinking Collaboration within the Framework of an Interuniversity Project
Authors: Fernández-Díaz Elia , Gutiérrez Esteban Prudencia , Fernández Olaskoaga Lorea
Published: July 2019

This work presents the analysis of a proposal designed in the field of initial teacher training, the aim of which is to promote the presence of schools in a university context. With the objective of enabling students to experience practical and reflective learning, we have designed a process of interuniversity collaboration focused on horizontally developing interaction and the generation of knowledge. The deconstruction of the process, based on a narrative approach, has allowed us to open a space to reflect on the actions that encourage participation and exchange between undergraduate students from different universities and promote links with schools. The results show the transformations of the protagonists of the experience and of those who participated indirectly, redefining personal stories in the context of collaborative work and the improvement of our professional development. It also shows the implications of an interuniversity project, recounting the richness inherent in the mixture of geographical and cultural contexts involved. The dilemmas and critical incidents allow us to guide the introduction of improvements in the next cycle of collaboration.
Constructing an Instrument with Behavioral Scales to Assess Teaching Quality in Blended Learning Modalities
Authors: Matosas-López Luis , Aguado-Franco Juan Carlos , Gómez-Galán José
Published: July 2019

The assessment of teaching quality in blended learning modalities has become a key element in the context of higher education. However, current evaluation systems present certain limitations. Behavioral scales overcome many of these limitations, offering an alternative for this task.

This study describes the process of constructing an assessment instrument with behavioral scales to evaluate university teachers in blended learning modalities, following the BARS (Behavioral Anchored Rating Scales) methodology. The design process included interviews and surveys involving a total of 477 students, as well as a panel of professors who were experts in this teaching modality.

The behavioral scales in the final instrument highlight the importance of certain particularly significant teaching-related aspects of blended learning models, namely: teacher-student communication; learning resources; course design; and the teacher’s technical competencies.

The authors conclude that the final instrument provides clear and unambiguous feedback, enables the teacher to take specific corrective measures, and reinforces the formative purpose of evaluation in these modalities.
Multicultural Competence and Cosmopolitan Citizenship in the Hispanic-Japanese Context of Higher Education
Authors: Delgado-Algarra Emilio José , Bernal-Bravo César , López-Meneses Eloy
Published: July 2019

The increase in the internationalization of universities has been accompanied by an increase in multiculturalism in classrooms. Due to this situation, with the objective of knowing the conceptions of university professors around pluricultural competence and attending to the connection with their positioning in relation to the models of cosmopolitan citizenship; a mixed research is developed in the Hispanic-Japanese context of higher education, focusing attention on education and social sciences professors. In general, it is concluded that there are connections between the positioning of multiculturalism and cosmopolitan citizenship. Thus, the university professors of both countries highlight the advantages of cultural plurality in educational environments and, despite the fact that there is governmental support for academic internationalization, in the sample of Japanese professors, there is a greater concern about the preservation of national identity in cultural plurality.
Lean Startup as a Learning Methodology for Developing Digital and Research Competencies
Authors: Ávalos Carolina , Pérez-Escoda Ana , Monge Luis
Published: July 2019

The acquisition of digital and research competencies for educating university students is a requirement that is becoming more relevant given the demands of today’s society. However, learning methodologies used by professors seem to be detached from reality, preventing the development of applicable learning, as well as the acquisition of those skills necessary in the twenty-first century. The main objective of the research is to analyze the Lean Startup method as a learning methodology in the creation of digital and research competencies in students from the UNED Costa Rica during the development of the course: Mixed Methods Research (MMR). The sample consisted of 531 individuals, teachers and students from different degrees of the School of Education from the UNED who took the course during the years 2015 to 2017. A mixed explanatory sequential design was used, with a theoretical part of an exploration of the method, a quantitative part (descriptive analysis and contrast of means) and another qualitative part by means of content analysis. The results showed the effectiveness of an innovative methodology such as Lean Startup in the development of digital and research skills, and the change of the teacher’s role in the teaching process.
Effect of Process Variables on the Transesterification Process of Palm Oil Sludge to Biodiesel
Authors: Aworanti O. A. , Ajani A. O. , Agarry S. E. , Babatunde K. A. , Akinwunmi O. D.
Published: July 2019

In this research work, the optimum process variables (catalyst, methanol to oil ratio and reaction time) for transesterification of palm oil sludge (POS) to biodiesel were studied. The transesterification process was carried by mixture of palm oil sludge, methanol and catalyst with the help of magnetic stirrer at 300 rpm and at temperature of 60ºC. The catalyst used for the process was potassium hydroxide (KOH). One-Factor-at-A-Time was used to select the possible optimum levels of process variable that gives high biodiesel yield. The study was evaluated by five levels  of methanol-to-oil ratio (1:1 – 12:1), catalyst (0.1- 2%) and reaction time (30 – 150 min).The optimum process variables for transesterification of palm oil sludge (POS) to achieved maximum biodiesel yield  were found to be methanol to oil molar ratio of 12:1, catalyst loading of 1.5wt% and reaction time of 30 min. At this optimum conditions the maximum biodiesel yield was 61.2%. The biodiesel produced from transesterification of palm oil sludge was characterized in order to determine the properties of the product. The density of POS is 857.0 kg/m3, kinematic viscosity of 5.38 mm2/s, flash point of 180°C, pour point of -5°C, and Acid value of 0.17 mgKOH/g. The biodiesel produced from transesterification of palm oil sludge meets the EN 14214 and ASTM 6751 standard. Thus, this study will be helpful to determine an efficient and economical procedure for biodiesel production from non-edible raw materials with high free fatty acid.
Revisiting Feller Diffusion: Derivation and Simulation
Authors: Munasinghe Ranjiva , Kanthan Leslie , Kossinna Pathum
Published: July 2019

We propose a simpler derivation of the probability density function of Feller Diffusion by using the Fourier Transform on the associated Fokker-Planck equation and then solving the resulting equation via the Method of Characteristics. We use the derived probability density to formulate an exact simulation algorithm whereby a sample path increment is drawn directly from the density. We then proceed to use the simulation to verify key statistical properties of the process such as the moments and the martingale property. The simulation is also used to confirm properties related to hitting time probabilities. We also mention potential applications of the simulation in the setting of quantitative finance.
Intra‐individual variation of circulating tumour DNA in lung cancer patients
Authors: Hojbjerg Johanne A. , Madsen Anne T. , Schmidt Hjordis H. , Sorensen Steffen F. , Stougaard Magnus , Meldgaard Peter , Sorensen Boe S.
Published: July 2019

Circulating tumour DNA (ctDNA) has been increasingly incorporated into the treatment of cancer patients. ctDNA is generally accepted as a powerful diagnostic tool, whereas the utility of ctDNA to monitor disease activity needs to be fully validated. Central to this challenge is the question of whether changes in longitudinal ctDNA measurements reflect disease activity or merely biological variation. Thus, the aim of this study was to explore the intra‐individual biological variation of ctDNA in lung cancer patients. We identified tumour‐specific mutations using next‐generation sequencing. Day‐to‐day and hour‐to‐hour variations in plasma concentrations of the mutant allele and wild‐type cell‐free DNA (cfDNA) were determined using digital PCR. The levels of the mutant alleles varied by as much as 53% from day to day and 27% from hour to hour. cfDNA varied up to 19% from day to day and up to 56% from hour to hour, as determined using digital PCR. Variations were independent of the concentration. Both mutant allele concentrations and wild‐type cfDNA concentrations showed considerable intra‐individual variation in lung cancer patients with nonprogressive disease. This pronounced biological variation of the circulating DNA should be investigated further to determine whether ctDNA can be used for monitoring cancer activity.
The etiologies and prognosis associated with spinal cord infarction
Authors: Hsu Jung Lung , Cheng Mei‐Yun , Liao Ming‐Feng , Hsu Hui‐Ching , Weng Yi‐Ching , Chang Kuo‐Hsuan , Chang Hong‐Shiu , Kuo Hung‐Chou , Huang Chin‐Chang , Lyu Rong‐Kuo , Lin Kun‐Ju , Ro Long‐Sun
Published: July 2019

Background

This study aims to investigate the etiology and prognosis of spinal cord infarction (SCI).

Methods

Over a period of 16 years, we retrospectively analyzed 31 patients with SCI. Demographic features and symptom presentations were carefully documented. Etiology‐specific MRI features, such as the length and distribution of the lesions and owl’s eyes sign, were recorded and analyzed to determine their associations with the clinical signs/symptoms.

Results

In total, seven patients had aortic or vertebral artery dissections. We divided the patients with SCI into two groups: those with or without vessel dissection. Among SCI patients, the onset age was younger, and the proportion of patients with long‐segment lesions and posterior pattern involvement on axial view was higher in the group with dissection than in the group without dissection (all P < 0.05). The lesions were frequently located in the upper cervical or lower thoracic‐lumbar regions, and the lengths of the lesions were associated with 1‐month outcomes, suggesting that artery dissection may contribute to the longitudinal and posterior extension of SCI. In contrast, among patients without dissection, the range of longitudinal extensions of in spans of vertebral bodies was broader (range, 1–8). A higher proportion of patients had focal pain adjacent to the lesion (P = 0.05) and a poorer 1‐month outcome (P = 0.04) in the long‐segment lesion group than in the short‐segment lesion group.

Conclusions

A detailed history and the use of modern imaging tools may help clinicians search for vessel dissection and other etiologies, evaluate the spatial extension of lesions in SCI, and predict prognosis.
Functional consequences of a KCNT1 variant associated with status dystonicus and early‐onset infantile encephalopathy
Authors: Gertler Tracy S. , Thompson Christopher H. , Vanoye Carlos G. , Millichap John J. , George Alfred L.
Published: July 2019

Objective

We identified a novel de novo KCNT1 variant in a patient with early‐infantile epileptic encephalopathy (EIEE) and status dystonicus, a life‐threatening movement disorder. We determined the functional consequences of this variant on the encoded KNa1.1 channel to investigate the molecular mechanisms responsible for this disorder.

Methods

A retrospective case review of the proband is presented. We performed manual and automated electrophysiologic analyses of the KCNT1‐L437F variant expressed heterologously in Chinese hamster ovary (CHO) cells in the presence of channel activators/blockers.

Results

The KCNT1‐L437F variant, identified in a patient with refractory EIEE and status dystonicus, confers a gain‐of‐function channel phenotype characterized by instantaneous, voltage‐dependent activation. Channel openers do not further increase L437F channel function, suggesting maximal activation, whereas channel blockers similarly block wild‐type and variant channels. We further demonstrated that KCNT1 current can be measured on a high‐throughput automated electrophysiology platform with potential value for future screening of novel and repurposed pharmacotherapies.

Interpretation

A novel pathogenic variant in KCNT1 associated with early‐onset, medication‐refractory epilepsy and dystonia causes gain‐of‐function with rapid activation kinetics. Our findings extend the genotype–phenotype relationships of KCNT1 variants to include severe dystonia.
Impact of Layer Configuration and Doping on Electron Transport and Bias Stability in Heterojunction and Superlattice Metal Oxide Transistors
Authors: Khim Dongyoon , Lin Yen‐Hung , Anthopoulos Thomas D.
Published: July 2019

The astonishing recent progress in the field of metal oxide thin‐film transistors (TFTs) and their debut in commercial displays is accomplished using vacuum‐processed multicomponent oxide semiconductors. However, emulating this success with their solution‐processable counterparts poses numerous scientific challenges. Here, the development of high mobility n‐channel TFTs based on ultrathin (<10 nm) alternating layers of In2O3 and ZnO that are sequentially deposited to form heterojunction and superlattice channels is reported. The resulting TFTs exhibit high electron saturation mobility (13 cm2 V−1 s−1), excellent current on/off ratios (>108) with nearly zero onset voltages and hysteresis‐free operation despite the low temperature processing (≤200 °C). The enhanced performance is attributed to the formation of a quasi‐2D electron gas‐like system at the In2O3/ZnO heterointerface due to the conduction band offset. It is shown that altering the oxide deposition sequence has an adverse effect on electron transport due to formation of trap states. Optimized multilayer TFTs are shown to exhibit improved bias‐stress stability compared to single‐layer TFTs. Modulating the electron concentration within the superlattice channel via selective n‐doping of the ZnO interlayers leads to almost 100% saturation mobility increase (≈25 cm2 V−1 s−1) even when the TFTs are fabricated on flexible plastic substrates.
Heat‐Free Fabrication of Metallic Interconnects for Flexible/Wearable Devices
Authors: Martin Andrew , Chang Boyce S. , Martin Zachariah , Paramanik Dipak , Frankiewicz Christophe , Kundu Souvik , Tevis Ian D. , Thuo Martin
Published: July 2019

Exploiting interfacial excess (Γ), Laplace pressure jump (ΔP), surface work, and coupling them to surface reactivity have led to the synthesis of undercooled metal particles. Metastability is maintained by a core–shell particle architecture. Fracture of the thin shell leads to solidification with concomitant sintering. Applying Scherer's constitutive model for load‐driven viscous sintering on the undercooled particles implies that they can form conductive traces. Combining metastability to eliminate heat and robustness of viscous sintering, an array of conductive metallic traces can be prepared, leading to plethora of devices on various flexible and/or heat sensitive substrates. Besides mechanical sintering, chemical sintering can be performed, which negates the need of either heat or load. In the latter, connectivity is hypothesized to occur via a Frenkel's theory of sintering type mechanism. This work reports heat‐free, ambient fabrication of metallic conductive interconnects and traces on all types of substrates.
Thermoreversible Siloxane Networks: Soft Biomaterials with Widely Tunable Viscoelasticity
Authors: Meng Yuan , Xu Weijing , Newman Maureen R. , Benoit Danielle S. W. , Anthamatten Mitchell
Published: July 2019

Polysiloxane elastomers represent a widely utilized soft material with excellent rubber‐like elasticity, biocompatibility, and biodurability; however, there is a lack of an effective and straightforward approach to manipulate the material's viscoelastic response. A facile hydrosilylation reaction is employed to integrate ureidopyrimidinone hydrogen‐bonding side‐groups into linear and crosslinked siloxane polymers to achieve biocompatible soft materials with a highly tunable viscoelastic relaxation timescale. Stacking of H‐bonded moieties is avoided in the designed macromolecular architectures with tight, side‐groups substituents. The obtained siloxane network features the presence of both covalent crosslinks and truly thermoreversible crosslinks, and can be formulated across a broad material design space including elastic solids, recoverable viscoelastic solids, and viscous liquids. The elastomers exhibit unique temperature‐dependent shape‐memory capability and show good cytocompatibility. Importantly, a deformed material's shape‐recovery occurs regardless of external triggering, and through manipulation of network formulations, the shape‐recovery timescale can be easily tuned from seconds to days, opening new possibilities for biomedical, healthcare, and soft material applications.
Direct‐Laser‐Writing of Metal Sulfide‐Graphene Nanocomposite Photoelectrode toward Sensitive Photoelectrochemical Sensing
Authors: Ge Lei , Hong Qing , Li Hui , Liu Changchun , Li Feng
Published: July 2019

Here, a facile approach for the in situ fabrication of metal sulfide (MS)‐graphene (G) nanocomposite, CdS‐G and PbS‐G, on indium−tin oxide (ITO) glass is demonstrated using a simple and scalable direct‐laser‐writing method in ambient air. Through the CO2 laser irradiation of a metal‐complex‐containing polyethersulfone layer on ITO glass, both the crystallization of laser‐induced MS (LIMS) and the formation of laser‐induced graphene (LIG) are synchronously achieved in one step, giving rise to a laser‐induced MS‐G nanocomposite photoelectrode, denoted as LI‐MS‐G@ITO. In such a laser‐scribing process, polyethersulfone not only acts as the carbon source to grow LIG but also provides an in situ source of S2− to produce LIMS with the aids of carbothermic reduction of sulfur element in polyethersulfone. The obtained LI‐MS‐G@ITO inherits the porous network architecture of polyethersulfone‐derived LIG, in which the LIMS nanocrystals uniformly decorate the multilayered graphene sheets with good dispersion, presenting a fast and stable photocurrent response with high reproducibility, which, as a proof‐of‐concept, further facilitates the use of a LI‐CdS‐G@ITO photoanode as an efficient transducer for photoelectrochemical detection of Cu2+ with high sensitivity and selectivity. This work can offer a universal and versatile protocol for the in situ and synchronous fabrication of novel MS‐G nanocomposites for sensitive photoelectrochemical analysis.
Independent Tuning of Optical Transparency Window and Electrical Properties of Epitaxial SrVO3 Thin Films by Substrate Mismatch
Authors: Mirjolet Mathieu , Vasili Hari Babu , López‐Conesa LLuís , Estradé Sònia , Peiró Francesca , Santiso José , Sánchez Florencio , Machado Pamela , Gargiani Pierluigi , Valvidares Manuel , Fontcuberta Josep
Published: July 2019

Transparent metallic oxides are pivotal materials in information technology, photovoltaics, or even in architecture. They display the rare combination of metallicity and transparency in the visible range because of weak interband photon absorption and weak screening of free carriers to impinging light. However, the workhorse of current technology, indium tin oxide (ITO), is facing severe limitations and alternative approaches are needed. AMO3 perovskites, M being a nd1 transition metal, and A an alkaline earth, have a genuine metallic character and, in contrast to conventional metals, the electron–electron correlations within the nd1 band enhance the carriers effective mass (m*) and bring the transparency window limit (marked by the plasma frequency, ωp*) down to the infrared. Here, it is shown that epitaxial strain and carrier concentration allow fine tuning of optical properties (ωp*) of SrVO3 films by modulating m* due to strain‐induced selective symmetry breaking of 3d‐t2g(xy, yz, xz) orbitals. Interestingly, the DC electrical properties can be varied by a large extent depending on growth conditions whereas the optical transparency window in the visible is basically preserved. These observations suggest that the harsh conditions required to grow optimal SrVO3 films may not be a bottleneck for their future application.
Stretchable ECM Patch Enhances Stem Cell Delivery for Post‐MI Cardiovascular Repair
Authors: Kim In Gul , Hwang Mintai P. , Park Jin Sil , Kim Su‐Hyun , Kim Jung‐Hyun , Kang Hyo Jin , Subbiah Ramesh , Ko Ung Hyun , Shin Jennifer H. , Kim Chong‐Hyun , Choi Donghoon , Park Kwideok
Published: July 2019

Current cell‐based therapies administered after myocardial infarction (MI) show limited efficacy due to subpar cell retention in a dynamically beating heart. In particular, cardiac patches generally provide a cursory level of cell attachment due to the lack of an adequate microenvironment. From this perspective, decellularized cell‐derived ECM (CDM) is attractive in its recapitulation of a natural biophysical environment for cells. Unfortunately, its weak physical property renders it difficult to retain in its original form, limiting its full potential. Here, a novel strategy to peel CDM off from its underlying substrate is proposed. By physically stamping it onto a polyvinyl alcohol hydrogel, the resulting stretchable extracellular matrix (ECM) membrane preserves the natural microenvironment of CDM, thereby conferring a biological interface to a viscoelastic membrane. Its various mechanical and biological properties are characterized and its capacity to improve cardiomyocyte functionality is demonstrated. Finally, evidence of enhanced stem cell delivery using the stretchable ECM membrane is presented, which leads to improved cardiac remodeling in a rat MI model. A new class of material based on natural CDM is envisioned for the enhanced delivery of cells and growth factors that have a known affinity with ECM.
1D Supercapacitors for Emerging Electronics: Current Status and Future Directions
Authors: Zhai Shengli , Karahan H. Enis , Wang Chaojun , Pei Zengxia , Wei Li , Chen Yuan
Published: July 2019

1D supercapacitors (SCs) have emerged as promising candidates to power emerging electronics in recent years because of their unique advantages in energy storage and mechanical flexibility. There are four main research fronts in the development of 1D SCs: 1) enhancing mechanical characteristics, 2) achieving superior electrochemical performance, 3) enabling multiple device integration, and 4) demonstrating multifunctionality. Here, a brief history of 1D SCs is presented and significant research achievements regarding the four fronts identified as the main pillars of the development of 1D SCs are highlighted. The current challenges of the fabrication and utilization of 1D SCs are critically examined and potential solutions are analyzed. Plus, the performance inconsistencies arising from the improper use and extreme diversity of performance evaluation and reporting methods are highlighted. Beyond, perspectives on future efforts are provided and goals regarding the four research fronts are set, to further push 1D SCs toward practical applications. The development of 1D SCs is summarized here, with existing obstacles diagnosed, corresponding solutions proposed, and future directions indicated accordingly.
Lipidic Aminoglycoside Derivatives: A New Class of Immunomodulators Inducing a Potent Innate Immune Stimulation
Authors: Colombani Thibault , Haudebourg Thomas , Decossas Marion , Lambert Olivier , Ada Da Silva Grace , Altare Frederic , Pitard Bruno
Published: July 2019

Development of simple and fully characterized immunomodulatory molecules is an active area of research to enhance current immunotherapies. Monophosphoryl lipid A (MPL), a nontoxic lipidic derivative from bacteria, is the first and currently only adjuvant approved in humans. However, its capacity to induce a potent response against weak immunogenic tumoral‐associated antigens remains limited. Herein, a new generation of lipidic immunomodulators to conduct a structure–activity relationship study to determine the minimal structural elements conferring immunomodulatory properties is introduced. Two lead molecules characterized by a short succinyl linker between two oleyl chains and a polar headgroup consisting of either naturally occurring tobramycin (DOST) or kanamycin (DOSK) are identified. These two lipoaminoglycosides self‐assemble in very small vesicles. In a wide variety of cells including 3D human cell culture, DOST and DOSK induce the upregulation of proinflammatory cytokines and interferon‐inducible proteins in a dose and time‐dependent manner via a caveolae‐dependent proinflammatory mechanism and phosphatidylinositol phospholipase C activation. Furthermore, after intratumoral administration, these lipoaminoglycosides induce an efficient immune response leading to significant antitumor activity in a mouse breast cancer model. Altogether, these findings indicate that DOST and DOSK are two groundbreaking synthetic lipid immunostimulators that can be used as adjuvants to enhance current immunotherapeutic treatments.
Efficient Red/Near‐Infrared‐Emissive Carbon Nanodots with Multiphoton Excited Upconversion Fluorescence
Authors: Liu Kai‐Kai , Song Shi‐Yu , Sui Lai‐Zhi , Wu Si‐Xuan , Jing Peng‐Tao , Wang Ruo‐Qiu , Li Qing‐Yi , Wu Guo‐Rong , Zhang Zhen‐Zhong , Yuan Kai‐Jun , Shan Chong‐Xin
Published: July 2019

Red/near‐infrared (NIR) emissive carbon nanodots (CNDs) with photoluminescence (PL) quantum yield (QY) of 57% are prepared via an in situ solvent‐free carbonization strategy for the first time. 1‐Photon and 2‐photon cellular imaging is demonstrated by using the CNDs as red/NIR fluorescence agent due to the high PL QY and low biotoxicity. Further study shows that the red/NIR CNDs exhibit multiphoton excited (MPE) upconversion fluorescence under excitation of 800–2000 nm, which involves three NIR windows (NIR‐I, 650–950 nm; NIR‐II, 1100–1350; NIR‐III, 1600–1870 nm). 2‐Photon, 3‐photon, and 4‐photon excited fluorescence of the CNDs under excitation of different wavelengths is achieved. This study develops an in situ solvent‐free carbonization method for efficient red/NIR emissive CNDs with MPE upconversion fluorescence, which may push forward the application of the CNDs in bioimaging.
Multifunctional Magnetocontrollable Superwettable‐Microcilia Surface for Directional Droplet Manipulation
Authors: Ben Shuang , Zhou Tiantian , Ma Han , Yao Jinjia , Ning Yuzhen , Tian Dongliang , Liu Kesong , Jiang Lei
Published: July 2019

In nature, fluid manipulations are ubiquitous in organisms, and they are crucial for many of their vital activities. Therefore, this process has also attracted widescale research attention. However, despite significant advances in fluid transportation research over the past few decades, it is still hugely challenging to achieve efficient and nondestructive droplet transportation owing to contamination effects and controllability problems in liquid transportation applications. To this end, inspired by the motile microcilia of micro‐organisms, the superhydrophobicity of lotus leaves, the underwater superoleophobicity of filefish skin, and pigeons' migration behavior, a novel manipulation strategy is developed for droplets motion. Specifically, herein, a superwettable magnetic microcilia array surface with a structure that is switchable by an external magnetic field is constructed for droplet manipulation. It is found that under external magnetic fields, the superhydrophobic magnetic microcilia array surface can continuously and directionally manipulate the water droplets in air and that the underwater superoleophobic magnetic microcilia array surface can control the oil droplets underwater. This work demonstrates that the nondestructive droplet transportation mechanism can be used for liquid transportation, droplet reactions, and micropipeline transmission, thus opening up an avenue for practical applications of droplet manipulation using intelligent microstructure surfaces.
Quantifying the Nongeminate Recombination Dynamics in Nonfullerene Bulk Heterojunction Organic Solar Cells
Authors: Vollbrecht Joachim , Brus Viktor V. , Ko Seo‐Jin , Lee Jaewon , Karki Akchheta , Cao David Xi , Cho Kilwon , Bazan Guillermo C. , Nguyen Thuc‐Quyen
Published: July 2019

In this study, a comprehensive analytical model to quantify the total nongeminate recombination losses, originating from bimolecular as well as bulk and surface trap‐assisted recombination mechanisms in nonfullerene‐based bulk heterojunction organic solar cells is developed. This proposed model is successfully employed to obtain the different contributions to the recombination current of the investigated solar cells under different illumination intensities. Additionally, the model quantitatively describes the experimentally measured open‐circuit voltage versus light intensity dependence. Most importantly, it is possible to calculate the experimental results with the same fitting parameter values from the presented model. The validity of this model is also proven by a combination of other independent, steady‐state, and transient experimental techniques. This new powerful analytical tool will enable researchers in the photovoltaic community to take into account the synergetic contribution from all relevant types of nongeminate recombination losses in different optoelectronic systems and target their analysis of recombination dynamics at any operating voltage.
Preparation and photocatalytic activity of carbon dot/Ag/AgCl
Authors: Song Limin , Zhao Xiaofei , Zhang Shujuan
Published: July 2019

CD (carbon dot)/Ag/AgCl compound photocatalysts with different compounding degrees were prepared via a precipitation method, and their physiochemical properties were characterized by X‐ray diffraction, FE‐SEM, UV–vis and the like. Through the degradation experiment of methyl orange (MO), the effects of different compounding amount and methyl orange concentration on photocatalytic degradation were investigated to find the best ratio. It was found the photocatalytic activity of CD/Ag/AgCl was significantly higher than Ag/AgCl, and the best compounding dosage was 6 mg/l carbon dot. The degradation rate of CD/Ag/AgCl was lower when the initial MO concentration was higher. Five repeated experiments were conducted to test the stability of the catalysts, and showed the MO degradation rates were all above 85%, indicating the CD/Ag/AgCl compound photocatalysts all showed high stability and repeatability. The reaction mechanism of CD/Ag/AgCl photocatalyst was studied by electrochemical experiments and ESR experiments. The results show that the doping of CD effectively improves the photocatalytic degradation ability of MO.
Isothermal Curing Kinetics of Epoxidized Fatty Acid Methyl Esters and Triacylglycerols
Authors: Li Yonghui , Li Cong , Sun Xiuzhi Susan
Published: July 2019

Plant oil triacylglycerols are attractive renewable resources for biobased epoxy resins. We investigated the curing kinetics of three model epoxidized fatty acid methyl esters and representative epoxidized triacylglycerols with varied epoxide functionalities and distributions in the presence of a latent cationic initiator. Isothermal differential scanning calorimetry (DSC) was used to analyze the curing kinetics of the epoxy systems, and kinetic parameters (i.e., rate constants, reaction orders) were determined. Both epoxidized fatty esters and triacylglycerols followed the autocatalytic curing mechanism, and the DSC data were analyzed according to the Kamal autocatalytic model. Epoxidized methyl linoleate (EMLO) had the highest maximum curing rate, followed by epoxidized methyl linolenate (EMLON), and epoxidized methyl oleate (EMO) had the lowest maximum curing rate. We conclude that EMLO with two epoxide groups has the highest reactivity in this curing system, while the EMO with one epoxide group has the lowest reactivity. For epoxidized triacylglycerols, epoxidized camelina oil had the highest curing reactivity at higher temperatures, followed by epoxidized linseed oil and soybean oil.