bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the asphalt pavement's surface characteristics by field testing
Authors:   Dokuz Eylül University, Kaya Ozdemir Derya , Topal Ali , Kacmaz Bulent , Sengoz Burak
Published: May 2021

Pavement management systems are crucial because of monitoring the current pavement condition to supply safe, efficient, comfortable and durable riding surface for vehicles. Driving safety is the most important issue, which is closely related to pavement surface texture. The texture of the pavement surface and its ability to resist the polishing effect of heavy traffic is an important parameter in providing necessary skidding resistance during the service life. In this study, 4 different asphalt pavement sections located in Izmir/TURKEY with having different traffic characteristics were investigated every three months for two years aiming to evaluate the effect of traffic volume on the surface textural and frictional properties of the pavement. The textural properties were evaluated using sand patch test (SPT) and a 3D Laser Scanning System (LSS), while Dynamic Friction Tester (DFT) was employed to assess the frictional properties. As a result, lower Mean Texture Depth (MTD) and Mean Profile Depth (MPD) values were obtained for the increased traffic volumes. High correlation was derived between macro and micro textural properties of the asphalt pavement. Additionally, the textural and frictional properties were found highly related for the investigated asphalt pavement surfaces.
Study on the fractal model of water immersed collapse of Soft Rock
Authors:   Sichuan University, Ding Lujun , Liu Yuhong
Published: May 2021

Soft rock is a common rock mass in engineering, one of its characteristics is water swelling and disintegration. In this paper, the nonlinear fractal geometry is introduced and the correlation fractal dimension is used to study the characteristics of slate disintegration, based on the laboratory test of water immersion disintegration, the method of quality fractal dimension is used to solve the fractal dimension of the disintegration of slate, and the change of fractal dimension is used to reflect the characteristics of the softening and disintegration of slate when encountering water. The experimental results show that the fractal model can be used to fully understand the development and evolution of rock disintegration process, and to quantitatively link the relationship between rock expansion and disintegration. The conclusion has guiding significance for engineering practice.
Array of Services for Homeless Mentally Ill in Six Canadian Cities: Non-Governmental Organizations’ Contributions and Perspectives
Authors: Lesage Alain , Adair Carol E. , Fleury Marie-Josée , Grenier Guy , Gaucher Charles , Aubry Tim , Dewa Carolyn S. , Patterson Michelle , Somers Julian , Goering (deceased) Paula
Published: May 2021

During the period 2010–2011, when the At Home project was conducted, a questionnaire was sent to 420 non-governmental organization (NGO) key managers in six Canadian cities to enquire about their collaboration with public services and their perspective on the services for homeless people with serious mental illness (SMI). NGOs constituted a dense network of collaboration among themselves. With regard to public services, housing and shelters were two services that NGOs had frequent contact with, followed by the healthcare addiction sectors and, to a lesser extent, social service and the justice sectors. Education and employment were both located in the network periphery. In general, NGOs viewed housing availability and accessibility to health services as largely unsatisfactory. They called for better public support, coordination, and funding.
Mental Health, Suicidal Behaviour, and Primary Healthcare among Homeless Youth
Authors: Labelle Réal , Berthiaume Claude , Daigle Marc , Breton Jean-Jacques , Houle Janie
Published: May 2021

Youth homelessness is a complex psychosocial problem. It refers to the experience of young people who live without their parents or legal guardians and who do not have the means or the capacity to reside in a stable, secure, and permanent place. This exploratory study sought to examine the mental health and suicidal behaviour of 76 homeless Québec adolescents as part of a reflection on the mission of primary healthcare. Note that these adolescents are mostly in the first segment of the homelessness continuum and have voluntarily left their homes because of personal and family difficulties. These 43 girls and 33 boys aged 12 to 19 living temporarily in shelters completed a semi-structured interview and self-administered questionnaires regarding stressful events, psychosocial stress, and mental health. Of these, 38 reported suicidal behaviour, including attempted suicide in 19 cases. The results show that these young people exemplify a high degree of suffering and multiple problems. Evidence indicates that lost relationships and academic problems rooted in attention deficit/hyperactivity disorder are linked to suicidal behaviour. Finally, non-productive coping strategies centred on somatization and little reassurance of worth provided by the social support network are associated with suicidal behaviour. Caregivers in temporary shelters should look out for these factors and refer vulnerable youth to primarycare mental health professionals.
Principal Component Analysis for Yield in Blackgram(Vignamungo L. Hepper) under Organic and Inorganic Fertilizer Managements
Authors: Reddy A. Kavitha , Priya M. Shanthi , Reddy D. Mohan , Reddy B.Ravindra
Published: May 2021

The present investigation on thirty black gram diverse genotypes for 12 yield and yield attributing traits under organic and inorganic fertilizer managements was carried out to study genetic variation among traits and genotypes in the respective environments that would equip the selection criteria using principal Component Analysis. First four vectors with threshold Eigen value greater than one (>1) contributed to 77.56% and 70.74% variation under organic and inorganic fertilizer managements respectively. Characters viz., number of clusters per plant (0.395), number of seeds per pod (0.354), days to maturity (0.336), number of pods per plant (0.300), harvest index (0.244), plant height (0.073) and seed yield per plant (0.015), whereas under inorganic fertilizer management number of primary branches per plant (0.43), followed by number of pods per plant (0.43), seed yield per plant (0.31), number of pods per cluster (0.29), number of clusters per plant (0.29) explained the maximum variance in first principal component (PC1) under organic conditions. Based on comparison of trait contribution to total variability under PC1 under both the managements it can be concluded that the traits viz., number of clusters per plant, number of pods per plant and seed yield per plant were the potential traits that accounted for maximum share towards variability. These traits may be taken into consideration as selection criteria in breeding programmes aimed at developing high yielding varieties.
Effect of Steam Blanching on Carotenoids, Phenolic Compounds Content and Antioxidant Activity of Dried Pumpkin’s Pulp (Cucurbita moschata) Farmed with Three Biological Fertilizers
Authors: Vanessa Boudjeka Guemkam , William Djeukeu Asongni , Gisèle Loé-Etame , Fabien Dongho Dongmo Fabrice , Bolea Carmen , Stanciuc Nicoleta , Alice Tchiaze Ifoue , Iordachescu Gabriela , Inocent Gouado
Published: May 2021

Aims: This study aims to assess the effect of steam blanching on the phytochemical composition and the antioxidant properties of Cucurbita moschata pulp, obtained with the use of three biological fertilizers. 

Study Design: The study was done on five samples of pumpkin pulp grown in different conditions. All the samples were evaluated before and after steam blanching treatment followed by hot                    air drying. The experimental design was a randomized complete block design with three replications. 

Place and Duration of Study: Laboratory of Biochemistry-University of Douala, Cameroon. The duration of study was seven months, from March to September 2018.

Methodology: Pumpkin were grown in May-September 2018 using the following fertilizers: ash at 10kg/25m2; bovine compost at 62.5 kg/25m2; ash + bovine compost (1:1). Besides negative control without fertilizers and positive control represented by NPK (20-10-10) at 2 kg/25m2 have been done. After harvesting, carotenoids, phenolic compounds, flavonoids contents, and antioxidant activities were determined using standard methods before and after a steam blanching treatment followed by hot air drying process. 

Results: Pumpkin pulp fertilized with ash, after a steam blanching treatment had the highest contents of total carotenoids, β-carotene, lycopene respectively of 696.03 ± 7.57; 584.86 ± 15.50 and 115.00 ± 1.25 mg/100g of edible portion and the lowest percentages of loss of these bioactive compounds. Pumpkin pulp fertilized with bovine compost and ash showed the lowest rates of loss of total phenolic compounds, respectively 0.62% and 4.25%, while those fertilized with the positive control (NPK) showed the highest rate of loss of total phenolic compounds (60%). Steam blanching treatment had a significant impact on phytonutrient contents and total phenolic compounds extracted from dried pumpkin pulp exert greater antioxidant activity. 

Conclusion: Pumpkin pulp fertilized with ash provides the highest carotenoids content after steam blanching treatment and this treatment increases the antioxidant activity and probably the shelf life of dried pumpkin pulp.
Saponins from the Pericarp of Albizia lebbeck (Benth) L. and Their Biological Screening on Laboratory Animals
Authors: Eid Basma G. , Sokkar Nadia M.
Published: May 2021

Aim: Albizia lebbeck L. is widely used to treat many diseases. Saponins are one of the major constituents that are found in the tissues of the tree. The purpose of this study was aimed at the phytochemical and biological investigation of the saponins of the pericarp.

Methodology: 50% ethanol extract of the dried powdered pericarp of A. lebbeck was fractionated with different organic solvents and examinated for their oxidative stress radical, anticonvulsant and analgesic effects. The highly potent fraction was subjected to chromatographic and spectroscopic analysis of its saponins.

Results: The n-butanol fraction expressed the best results regarding the biological activities. Chromatographic and spectroscopic analysis of this fraction revealed the identification of three oleanane-type saponins.

Conclusion: The present study constituted the first phytochemical analysis of the bioactive saponins content in the pericarp of A. lebbeck.

 

Graphical Abstract
Enhancement of Dissolution Rate and Bioavailability of Nifedipine by Chitosan Based Cocrystallization Technique
Authors: Reetu . , Yadav Ashutosh , Singh Anita , Garg Arun
Published: May 2021

The objective of present study was to enhance solubility and dissolution behaviour of nifedipine by using cocrystallization method. A significant increase in solubility and dissolution rate of nifedipine has been demonstrated by solvent change method using chitosan. In this method, chitosan was precipitated on nifedipine crystals using sodium citrate as a salting out agent. An accurately weighed chitosan was dissolved in 1% acetic acid and drug was added in the chitosan solution. This resulting solution was added drop wise into 1% sodium citrate solution with continuous stirring. Sodium citrate precipitate polymer on drug crystals. FTIR, DSC, XRD, SEM, In-vitro dissolution studies, were studied for characterization of prepared cocrystals. Stability studies showed a good stability character of prepared cocrystals. Design Expert® software version 10.0 was used to develop polynomial models which were analysed to delineate the main effects for each CQA (critical quality attributes) through Box-Bhenken design expert. Pharmacokinetic study clearly showed the enhancement of dissolution rate of cocrystals. The above investigation concluded that the significant dose reduction is possible for nifedipine with cocrystal formulation which leads to improve patient compliance.
Model for implementation of a modern journal club in medical physics residency programs
Authors: Cetnar Ashley J.
Published: May 2021

Journal clubs are a common educational experience for medical physics residents as a forum to discuss current research within the field. While journal clubs are valued by educational programs and accrediting bodies, there are a wide variety of ways in which these sessions are conducted. Unfortunately, there are currently few studies that have assessed the effectiveness of this educational method. This review defines journal club in the context of a medical physics residency and provides historical background for the meetings. Reasons why journal clubs are valued are presented, and several methods are described for conducting journal clubs. The format of journal clubs and scaffolding methods for guiding residents in gaining independence in critical reading skills are discussed. While the traditional journal club is a meeting, an alternative online virtual journal club is also described. Finally, a model of how a journal club can be applied in a medical physics residency is presented.
Childhood outcome analysis highlights risks of cannabis use in pregnancy
Authors: Enos Gary
Published: May 2021

An analysis of results from the Adolescent Brain and Cognitive Development (ABCD) Study has added to the evidence base suggesting that the risks associated with marijuana use during pregnancy outweigh any potential benefits. However, it remains clear that amid the changing public perceptions about marijuana safety, many women who are pregnant or planning pregnancy are still likely to hear little or nothing about potential risks of use from their health care providers.
Light‐Activated Decellularized Extracellular Matrix‐Based Bioinks for Volumetric Tissue Analogs at the Centimeter Scale
Authors: Kim Hyeonji , Kang Byeongmin , Cui Xiaolin , Lee Se‐Hwan , Lee Kwangseok , Cho Dong‐Woo , Hwang Woonbong , Woodfield Tim B. F. , Lim Khoon S. , Jang Jinah
Published: May 2021

Tissue engineering requires not only tissue‐specific functionality but also a realistic scale. Decellularized extracellular matrix (dECM) is presently applied to the extrusion‐based 3D printing technology. It has demonstrated excellent efficiency as bioscaffolds that allow engineering of living constructs with elaborate microarchitectures as well as the tissue‐specific biochemical milieu of target tissues and organs. However, dECM bioinks have poor printability and physical properties, resulting in limited shape fidelity and scalability. In this study, new light‐activated dECM bioinks with ruthenium/sodium persulfate (dERS) are introduced. The materials can be polymerized via a dityrosine‐based cross‐linking system with rapid reaction kinetics and improved mechanical properties. Complicated constructs with high aspect ratios can be fabricated similar to the geometry of the desired constructs with increased shape fidelity and excellent printing versatility using dERS. Furthermore, living tissue constructs can be safely fabricated with excellent tissue regenerative capacity identical to that of pure dECM. dERS may serve as a platform for a wider biofabrication window through building complex and centimeter‐scale living constructs as well as supporting tissue‐specific performances to encapsulated cells. This capability of dERS opens new avenues for upscaling the production of hydrogel‐based constructs without additional materials and processes, applicable in tissue engineering and regenerative medicine.
Injectable Microfluidic Hydrogel Microspheres for Cell and Drug Delivery
Authors: Zhao Zhenyu , Wang Zhen , Li Gen , Cai Zhengwei , Wu Jiezhou , Wang Lei , Deng Lianfu , Cai Ming , Cui Wenguo
Published: May 2021

Microfluidic hydrogel microspheres have been broadly studied across a wide range of industries and applications, and their use in the medical field, including control cells and drug delivery, is increasing. The usual design of these materials is intended to enable the efficient and smart encapsulation of cells and/or drugs in microspheres in which the functionalities and features are effectively controlled, lending itself some unique properties. These characteristics promote exchanges and cooperation in multiple disciplines and boost the development of precision medicine, new manufacturing technologies, and applied materials. This review begins with a discussion of microfluidic hydrogel microspheres and then introduces the preparation equipment, main principles, and related characteristics of the microspheres. Furthermore, the medical applications of microfluidic hydrogel microspheres for delivering cells and drugs are emphasized. Finally, this review discusses perspectives and future directions for accelerating the development and application of microfluidic hydrogel microspheres for controlled delivery.
Metformin Carbon Dots for Promoting Periodontal Bone Regeneration via Activation of ERK/AMPK Pathway
Authors: Ren Chunxia , Hao Xinqing , Wang Lu , Hu Yue , Meng Lin , Zheng Shize , Ren Feilong , Bu Wenhuan , Wang Huan , Li Daowei , Zhang Kai , Sun Hongchen
Published: May 2021

The osteogenic potential of mesenchymal stem cells (MSCs) is severely impaired under persistent inflammation of periodontitis. A highly efficient way to promote or rescue osteogenic potential of MSCs under inflammation remains an unmet goal. Herein, metformin carbon dots (MCDs) with excellent biocompatibility are prepared from metformin hydrochloride and citric acid via a hydrothermal method. The MCDs can more effectively enhance the alkaline phosphatase (ALP) activity, calcium deposition nodules formation, expression of osteogenic genes and proteins in rat bone marrow mesenchymal stem cells (rBMSCs) than metformin under both inflammatory and normal conditions. Moreover, a novel pathway of extracellular signal‐regulated kinases (ERK)/AMP‐activated protein kinase (AMPK) signaling is involved in the MCDs‐induced osteogenesis. In periodontitis rats, MCDs can effectively regenerate the lost alveolar bone, but not the metformin. Taken together, MCDs can be the promising candidate nanomaterial for periodontitis treatment. This work may provide a new pharmacological target of ERK/AMPK pathway for treating bone loss and also give additional insights into developing nanodrugs from the numerous medications.
Effects of Hydrophobicity on Antimicrobial Activity, Selectivity, and Functional Mechanism of Guanidinium‐Functionalized Polymers
Authors: Tan Jason , Zhao Yanli , Hedrick James L. , Yang Yi Yan
Published: May 2021

In this study, a series of guanidinium‐functionalized polycarbonate random co‐polymers is prepared from organocatalytic ring‐opening polymerization to investigate the effect of the hydrophobic side chain (ethyl, propyl, isopropyl, benzyl, and hexyl) on their antimicrobial activity and selectivity. Although the polymers exhibit similar minimum inhibitory concentrations, the more hydrophobic polymers exhibit a faster rate of bacteria elimination. At higher percentage content (20 mol%), polymers with more hydrophobic side chains suffer from poor selectivity due to their high hemolytic activity. The highly hydrophobic co‐polymer, containing the hydrophobic hexyl‐functionalized cyclic carbonate, kills bacteria via a membrane‐disruptive mechanism. Micelle formation leads to a lower extent of membrane disruption. This study unravels the effects of hydrophobic side chains on the activities of the polymers and their killing mechanism, providing insights into the design of new antimicrobial polymers.
Liquid‐Crystal‐Elastomer‐Actuated Reconfigurable Microscale Kirigami Metastructures
Authors: Zhang Mingchao , Shahsavan Hamed , Guo Yubing , Pena‐Francesch Abdon , Zhang Yingying , Sitti Metin
Published: May 2021

Programmable actuation of metastructures with predesigned geometrical configurations has recently drawn significant attention in many applications, such as smart structures, medical devices, soft robotics, prosthetics, and wearable devices. Despite remarkable progress in this field, achieving wireless miniaturized reconfigurable metastructures remains a challenge due to the difficult nature of the fabrication and actuation processes at the micrometer scale. Herein, microscale thermo‐responsive reconfigurable metasurfaces using stimuli‐responsive liquid crystal elastomers (LCEs) is fabricated as an artificial muscle for reconfiguring the 2D microscale kirigami structures. Such structures are fabricated via two‐photon polymerization with sub‐micrometer precision. Through rationally designed experiments guided by simulations, the optimal formulation of the LCE artificial muscle is explored and the relationship between shape transformation behaviors and geometrical parameters of the kirigami structures is build. As a proof of concept demonstration, the constructs for temperature‐dependent switching and information encryption is applied. Such reconfigurable kirigami metastructures have significant potential for boosting the fundamental small‐scale metastructure research and the design and fabrication of wireless functional devices, wearables, and soft robots at the microscale as well.
Nanoparticle‐Mediated siRNA Delivery and Multifunctional Modification Strategies for Effective Cancer Therapy
Authors: Chen Mengyao , Dong Chunyan , Shi Shuo
Published: May 2021

RNA interference (RNAi), which can inhibit the expression or transcription of specific genes, is considered to be a revolutionary tool for mediating gene therapy. Small interfering RNA (siRNA) is an important therapeutic agent for RNAi. However, the clinical application of siRNA‐based gene silencing is still limited due to the easy degradation of siRNA during the circulation in the body and the difficulty in delivering siRNA to desired tissues and cells. The rapid development of nanotechnology provides new ideas for siRNA delivery and a large variety of nanocarriers have been designed to solve the problems of siRNA delivery including easy degradation, lack of targeting ability, poor internalization ability, easy to cause induction of immune response and so on. Here, this review introduces the mechanism of RNAi in gene therapy, then summarizes the developments on nanocarriers for siRNA delivery, and specially focuses on the functional modification strategies of nanocarriers to construct multifunctional siRNA delivery vectors. Lastly, the future development and challenges of siRNA delivery vector are discussed, along with the current application of siRNA in tumor treatment clinical trials. It is hoped that this review can provide useful information to help transform siRNA‐mediated gene therapy into clinical application.
A Lab‐On‐chip Tool for Rapid, Quantitative, and Stage‐selective Diagnosis of Malaria
Authors: Giacometti Marco , Milesi Francesca , Coppadoro Pietro Lorenzo , Rizzo Alberto , Fagiani Federico , Rinaldi Christian , Cantoni Matteo , Petti Daniela , Albisetti Edoardo , Sampietro Marco , Ciardo Mariagrazia , Siciliano Giulia , Alano Pietro , Lemen Brigitte , Bombe Joel , Nwaha Toukam Marie Thérèse , Tina Paul Fernand , Gismondo Maria Rita , Corbellino Mario , Grande Romualdo , Fiore Gianfranco Beniamino , Ferrari Giorgio , Antinori Spinello , Bertacco Riccardo
Published: May 2021

Malaria remains the most important mosquito‐borne infectious disease worldwide, with 229 million new cases and 409.000 deaths in 2019. The infection is caused by a protozoan parasite which attacks red blood cells by feeding on hemoglobin and transforming it into hemozoin. Despite the WHO recommendation of prompt malaria diagnosis, the quality of microscopy‐based diagnosis is frequently inadequate while rapid diagnostic tests based on antigens are not quantitative and still affected by non‐negligible false negative/positive results. PCR‐based methods are highly performant but still not widely used in endemic areas. Here, a diagnostic tool (TMek), based on the paramagnetic properties of hemozoin nanocrystals in infected red blood cells (i‐RBCs), is reported on. Exploiting the competition between gravity and magnetic forces, i‐RBCs in a whole blood specimen are sorted and electrically detected in a microchip. The amplitude and time evolution of the electrical signal allow for the quantification of i‐RBCs (in the range 10–105 i‐RBC µL−1) and the distinction of the infection stage. A preliminary validation study on 75 patients with clinical suspect of malaria shows on‐field operability, without false negative and a few false positive results. These findings indicate the potential of TMek as a quantitative, stage‐selective, rapid test for malaria.
Phase‐Change‐Memory Process at the Limit: A Proposal for Utilizing Monolayer Sb2Te3
Authors: Wang Xue‐Peng , Li Xian‐Bin , Chen Nian‐Ke , Chen Bin , Rao Feng , Zhang Shengbai
Published: May 2021

One central task of developing nonvolatile phase change memory (PCM) is to improve its scalability for high‐density data integration. In this work, by first‐principles molecular dynamics, to date the thinnest PCM material possible (0.8 nm), namely, a monolayer Sb2Te3, is proposed. Importantly, its SET (crystallization) process is a fast one‐step transition from amorphous to hexagonal phase without the usual intermediate cubic phase. An increased spatial localization of electrons due to geometrical confinement is found to be beneficial for keeping the data nonvolatile in the amorphous phase at the 2D limit. The substrate and superstrate can be utilized to control the phase change behavior: e.g., with passivated SiO2 (001) surfaces or hexagonal Boron Nitride, the monolayer Sb2Te3 can reach SET recrystallization in 0.54 ns or even as fast as 0.12 ns, but with unpassivated SiO2 (001), this would not be possible. Besides, working with small volume PCM materials is also a natural way to lower power consumption. Therefore, the proposed PCM working process at the 2D limit will be an important potential strategy of scaling the current PCM materials for ultrahigh‐density data storage.
Downregulation of a Dorsal Root Ganglion‐Specifically Enriched Long Noncoding RNA is Required for Neuropathic Pain by Negatively Regulating RALY‐Triggered Ehmt2 Expression
Authors: Pan Zhiqiang , Du Shibin , Wang Kun , Guo Xinying , Mao Qingxiang , Feng Xiaozhou , Huang Lina , Wu Shaogen , Hou Bailing , Chang Yun‐Juan , Liu Tong , Chen Tong , Li Hong , Bachmann Thomas , Bekker Alex , Hu Huijuan , Tao Yuan‐Xiang
Published: May 2021

Nerve injury‐induced maladaptive changes of gene expression in dorsal root ganglion (DRG) neurons contribute to neuropathic pain. Long non‐coding RNAs (lncRNAs) are emerging as key regulators of gene expression. Here, a conserved lncRNA is reported, named DRG‐specifically enriched lncRNA (DS‐lncRNA) for its high expression in DRG neurons. Peripheral nerve injury downregulates DS‐lncRNA in injured DRG due, in part, to silencing of POU domain, class 4, transcription factor 3, a transcription factor that interacts with the DS‐lncRNA gene promoter. Rescuing DS‐lncRNA downregulation blocks nerve injury‐induced increases in the transcriptional cofactor RALY‐triggered DRG Ehmt2 mRNA and its encoding G9a protein, reverses the G9a‐controlled downregulation of opioid receptors and Kcna2 in injured DRG, and attenuates nerve injury‐induced pain hypersensitivities in male mice. Conversely, DS‐lncRNA downregulation increases RALY‐triggered Ehmt2/G9a expression and correspondingly decreases opioid receptor and Kcna2 expression in DRG, leading to neuropathic pain symptoms in male mice in the absence of nerve injury. Mechanistically, downregulated DS‐lncRNA promotes more binding of increased RALY to RNA polymerase II and the Ehmt2 gene promoter and enhances Ehmt2 transcription in injured DRG. Thus, downregulation of DS‐lncRNA likely contributes to neuropathic pain by negatively regulating the expression of RALY‐triggered Ehmt2/G9a, a key neuropathic pain player, in DRG neurons.
Marriage of Virus‐Mimic Surface Topology and Microbubble‐Assisted Ultrasound for Enhanced Intratumor Accumulation and Improved Cancer Theranostics
Authors: Meng Zheying , Zhang Yang , Shen E , Li Wei , Wang Yanjie , Sathiyamoorthy Krishnan , Gao Wei , C. Kolios Michael , Bai Wenkun , Hu Bing , Wang Wenxing , Zheng Yuanyi
Published: May 2021

The low delivery efficiency of nanoparticles to solid tumors greatly reduces the therapeutic efficacy and safety which is closely related to low permeability and poor distribution at tumor sites. In this work, an “intrinsic plus extrinsic superiority” administration strategy is proposed to dramatically enhance the mean delivery efficiency of nanoparticles in prostate cancer to 6.84% of injected dose, compared to 1.42% as the maximum in prostate cancer in the previously reported study. Specifically, the intrinsic superiority refers to the virus‐mimic surface topology of the nanoparticles for enhanced nano–bio interactions. Meanwhile, the extrinsic stimuli of microbubble‐assisted low‐frequency ultrasound is to enhance permeability of biological barriers and improve intratumor distribution. The enhanced intratumor enrichment can be verified by photoacoustic resonance imaging, fluorescence imaging, and magnetic resonance imaging in this multifunctional nanoplatform, which also facilitates excellent anticancer effect of photothermal treatment, photodynamic treatment, and sonodynamic treatment via combined laser and ultrasound irradiation. This study confirms the significant advance in nanoparticle accumulation in multiple tumor models, which provides an innovative delivery paradigm to improve intratumor accumulation of nanotherapeutics.
Bio‐Inspired Motion Mechanisms: Computational Design and Material Programming of Self‐Adjusting 4D‐Printed Wearable Systems
Authors: Cheng Tiffany , Thielen Marc , Poppinga Simon , Tahouni Yasaman , Wood Dylan , Steinberg Thorsten , Menges Achim , Speck Thomas
Published: May 2021

This paper presents a material programming approach for designing 4D‐printed self‐shaping material systems based on biological role models. Plants have inspired numerous adaptive systems that move without using any operating energy; however, these systems are typically designed and fabricated in the form of simplified bilayers. This work introduces computational design methods for 4D‐printing bio‐inspired behaviors with compounded mechanisms. To emulate the anisotropic arrangement of motile plant structures, material systems are tailored at the mesoscale using extrusion‐based 3D‐printing. The methodology is demonstrated by transferring the principle of force generation by a twining plant (Dioscorea bulbifera) to the application of a self‐tightening splint. Through the tensioning of its stem helix, D. bulbifera exhibits a squeezing force on its support to provide stability against gravity. The functional strategies of D. bulbifera are abstracted and translated to customized 4D‐printed material systems. The squeezing forces of these bio‐inspired motion mechanisms are then evaluated. Finally, the function of self‐tightening is prototyped in a wrist‐forearm splint—a common orthotic device for alignment. The presented approach enables the transfer of novel and expanded biomimetic design strategies to 4D‐printed motion mechanisms, further opening the design space to new types of adaptive creations for wearable assistive technologies and beyond.
Mechanistic Insights into the Pre‐Lithiation of Silicon/Graphite Negative Electrodes in “Dry State” and After Electrolyte Addition Using Passivated Lithium Metal Powder
Authors: Bärmann Peer , Mohrhardt Marvin , Frerichs Joop Enno , Helling Malina , Kolesnikov Aleksei , Klabunde Sina , Nowak Sascha , Hansen Michael Ryan , Winter Martin , Placke Tobias
Published: May 2021

Because of its high specific capacity, silicon is regarded as the most promising candidate to be incrementally added to graphite‐based negative electrodes in lithium‐ion batteries. However, silicon suffers from significant volume changes upon (de‐)lithiation leading to continuous re‐formation of the solid electrolyte interphase (SEI) and ongoing active lithium losses. One prominent approach to compensate for active lithium losses is pre‐lithiation. Here, the “contact pre‐lithiation” of silicon/graphite (Si/Gr) negative electrodes in direct contact with passivated Li metal powder (PLMP) is studied, focusing on the pre‐lithiation mechanism in “dry state” and after electrolyte addition. PLMP is pressed onto the electrode surface to precisely adjust the degree of pre‐lithiation (25%, 50%, and 75%). By in situ XRD and ex situ 7Li NMR studies, it is proven that significant lithiation of Si/Gr electrodes occurs by direct contact to Li metal, that is, without electrolyte. After electrolyte addition, de‐lithiation of silicon and graphite is confirmed, resulting in SEI formation. The amount of Li metal highly impacts the presence and durability of the LixC and LixSi phases. Finally, the challenges for homogeneous pre‐lithiation and SEI formation are identified, and the impact of electrolyte addition is assessed by analysis of the lateral and in‐depth lithium distribution within the Si/Gr electrode.
Nonpolar Liquid Lubricant Submerged Triboelectric Nanogenerator for Current Amplification via Direct Electron Flow
Authors: Chung Seh‐Hoon , Chung Jihoon , Song Myunghwan , Kim Seonwoo , Shin Dongjun , Lin Zong‐Hong , Koo Bonwook , Kim Dongseob , Hong Jinkee , Lee Sangmin
Published: May 2021

Triboelectric nanogenerators (TENGs) can convert a mechanical energy input to an electric energy output through Maxwell's displacement current. By increasing the electrical output and overcoming the mechanical limitations of TENGs, such devices can be used as an auxiliary power source for portable electronics. Nevertheless, the generation mechanism and structure must be optimized to compensate for the electrical and mechanical limitations of TENGs. This paper reports on a nonpolar liquid lubricant submerged TENG (LLS‐TENG), which can overcome the existing electrical and mechanical limitations of the TENG. When a nonpolar liquid lubricant is filled in the LLS‐TENG, the air breakdown can be effectively blocked owing to the large Debye length of such lubricants. In addition, the rolling friction and lubrication present in the LLS‐TENG can significantly reduce the friction wear of the device. Consequently, the LLS‐TENG can charge a commercial capacitor and battery by generating a high voltage and current output of up to 200 V and 170 mA, respectively.
Interfacial Tension Modulation of Liquid Metal via Electrochemical Oxidation
Authors: Song Minyung , Daniels Karen E. , Kiani Abolfazl , Rashid‐Nadimi Sahar , Dickey Michael D.
Published: May 2021

Herein, this progress report summarizes recent studies of electrochemical oxidation to modulate the interfacial tension of gallium‐based alloys. These liquid alloys have the largest interfacial tension of any liquid at room temperature. The ability to modulate the tension offers the possibility to create forces that change the shape and position of small volumes of liquid metal. It has been known since the late 1800s that electrocapillarity—the use of potential to modulate the electric double layer on the surface of metals in electrolyte—lowers the interfacial tension of liquid metals. This phenomenon, however, can only achieve modest changes in interfacial tension since it is limited to potentials that avoid Faradaic reactions. A recent discovery suggests reactions driven by the electrochemical oxidation of gallium alloys cause the interfacial tension to decrease from ≈500 mN m−1 at 0 V to ≈0 mN m−1 at less than 1 V. This change in interfacial tension is reversible, controllable, and goes well‐beyond what is possible via conventional electrocapillarity or surfactants. This report aims to introduce beginners to this field and address misconceptions. The report discusses applications that utilize modulations in interfacial tension of liquid metal and concludes with remaining opportunities and challenges needing further investigation.
Striking developmental convergence in angiosperm endoparasites
Authors: Teixeira‐Costa Luiza , Davis Charles C. , Ceccantini Gregorio
Published: May 2021

Premise

A subset of parasitic plants bear extremely reduced features and grow nearly entirely within their hosts. Until recently, most of these endoparasites were thought to represent a single clade united by their reduced morphology. Current phylogenetic understanding contradicts this assumption and indicates these plants represent distantly related clades, thus offering an opportunity to examine convergence among plants with this life history.

Methods

We sampled species from Apodanthaceae, Cytinaceae, Mitrastemonaceae, and Rafflesiaceae spanning a range of developmental stages. To provide a broader comparative framework, Santalaceae mistletoes with a similar lifestyle were also analyzed. Microtomography and microscopy were used to analyze growth patterns and the ontogeny of host–parasite vascular connections.

Results

Apodanthaceae, Cytinaceae, Mitrastemonaceae, and Rafflesiaceae species demonstrated a common development characterized by late cell differentiation. These species were also observed to form direct connections to host vessels and to cause severe alterations of host xylem development. Apodanthaceae and Rafflesiaceae species were additionally observed to form sieve elements, which connect with the host phloem. Endophytic Santalaceae species demonstrated a dramatically different developmental pattern, featuring early cell differentiation and tissue organization, and little effect on host anatomy and cambial activity.

Conclusions

Our results illuminate two distinct developmental trajectories in endoparasites. One involves the retention of embryonic characteristics and late connection with host vessels, as demonstrated in species of Apodanthaceae, Cytinaceae, Mitrastemonaceae, and Rafflesiaceae. The second involves tissue specialization and early connection with host xylem, as exemplified by Santalaceae species. These differences are hypothesized to be related to the absence/presence of photosynthesis in these plants.
Congenital chromoanagenesis in the routine postnatal chromosomal microarray analyses
Authors: Villela Darine , Mazzonetto Patricia C. , Migliavacca Michele P. , Perrone Eduardo , Guida Gustavo , Milanezi Maria Fernanda G. , Jorge Alexander A. L. , Ribeiro‐Bicudo Lucilene A. , Kok Fernando , Campagnari Francine , de Rosso‐Giuliani Liane , da Costa Silvia Souza , Vianna‐Morgante Angela M. , Pearson Peter L. , Krepischi Ana C. V. , Rosenberg Carla
Published: May 2021

Chromosomal microarray analyses (CMA) have greatly increased both the yield and diagnostic accuracy of postnatal analysis; it has been used as a first‐tier cytogenetic test in patients with intellectual disability, autism spectrum disorder, and multiple congenital abnormalities. During the last 15 years, we performed CMA in approximately 8,000 patients with neurodevelopmental and/or congenital disorders, of which 13 (0.16%) genetically catastrophic complex chromosomal rearrangements were identified. These ultrarare rearrangements showed clustering of breakpoints, characteristic of chromoanagenesis events. Al1 13 complex events display underlying formation mechanisms, originating either by a synchronization of the shattering of clustered chromosome regions in which regional asynchrony of DNA replication may be one of the main causes of disruption. We provide an overview of the copy number profiling in these patients. Although several previous studies have suggested that chromoanagenesis is often a genetic disease source in postnatal diagnostic screening, due to either the challenge of clinical interpretation of these complex rearrangements or the limitation of microarray resolution relative to the small size and complexity of chromogenic induced chromosome abnormalities, bringing further attention and to study its occurrence in the clinical setting is extremely important.
Symptomatic mosaicism for a novel FBN1 splice site variant in a parent causing inherited neonatal Marfan syndrome
Authors: Postma Julianne K. , Altamirano‐Diaz Luis , Rupar C. Anthony , Siu Victoria M.
Published: May 2021

Neonatal Marfan syndrome is a severe, early onset presentation of pathogenic variants in FBN1. Because of the significant cardiac involvement and early mortality, nearly all reported cases have been de novo, and the disorder has not been documented to be inherited from a symptomatic parent. Here, we present a female infant with neonatal Marfan syndrome who was born to a father with Marfan syndrome. Prior to the birth of his daughter, the father had been found to have an FBN1 missense variant of uncertain clinical significance. Initial familial variant testing of the infant did not reveal the same missense variant, but Sanger sequencing of FBN1 subsequently identified a pathogenic splice site variant. The father was then found to have 10%–20% mosaicism for the same splice site variant.
Organophotoredox‐Catalyzed Late‐Stage Functionalization of Heterocycles
Authors: Kumar Hota Sudhir , Jinan Dilsha , Prakash Panda Satya , Pan Rittwika , Sahoo Basudev , Murarka Sandip
Published: May 2021

In the last decade, visible light photoredox catalysis promoting radical‐based organic transformations has received enormous synthetic applicability, as they allow unfolding of site‐selective reactivities under mild reaction conditions. Moreover, the photoredox transformations utilizing organic dyes as photocatalysts are attractive with regard to low cost, less toxicity, easy availability and high functional group tolerance. The organophotoredox‐catalyzed reaction technologies enabling direct, efficient and selective late‐stage functionalization of various heterocycles leading to the formation of various C−C and C−X (X=N, P, O, S, Se, Br) bonds have emerged at the forefront of synthetic methodologies available to synthetic chemists. This minireview summarizes the developments made in the last five years in the field of late‐stage functionalization of heterocycles governed by various organophotocatalysts and intends to provide the readers a comprehensive overview of this research field with representative examples and mechanistic insights.
Non‐invasive Regulation of Cellular Morphology Using a Photoswitchable Mechanical DNA Polymer
Authors: Sethi Soumya , Hidaka Kumi , Sugiyama Hiroshi , Endo Masayuki
Published: May 2021

The extracellular matrix (ECM) in which the cells reside provides a dynamic and reversible environment. Spatiotemporal cues are essential when cells are undergoing morphogenesis, repair and differentiation. Emulation of such an intricate system with reversible presentation of nanoscale cues can help us better understand cellular processes and can allow the precise manipulation of cell function in vitro. Herein, we formulated a photoswitchable DNA mechanical nanostructure containing azobenzene moieties and dynamically regulated the spatial distance between adhesion peptides using a photoswitchable DNA polymer with photoirradiation. We found that the DNA polymer reversibly forms two different structures, a relaxed linear and shrunken compact form, observed by AFM. Using the mechanical properties of this DNA polymer, UV and visible light irradiation induced a significant morphology change of the cells between a round shape and spindle shape, thus providing a tool to decipher the language of the ECM better.
Der derzeitige Stand von MOF‐ und COF‐Anwendungen
Authors: Freund Ralph , Zaremba Orysia , Arnauts Giel , Ameloot Rob , Skorupskii Grigorii , Dincă Mircea , Bavykina Anastasiya , Gascon Jorge , Ejsmont Aleksander , Goscianska Joanna , Kalmutzki Markus , Lächelt Ulrich , Ploetz Evelyn , Diercks Christian S. , Wuttke Stefan
Published: May 2021

Die Verschmelzung verschiedener Disziplinen ist das Herzstück der retikulären Chemie und hat durch die Eröffnung eines unendlichen Raums der chemischen Zusammensetzung, Struktur und Materialeigenschaften die Grenzen der Chemie geweitet. Das retikuläre Design hat die präzise Vorhersage von kristallinen Gerüststrukturen, die Abstimmbarkeit der chemischen Zusammensetzung, den Einbau verschiedener Funktionalitäten in das Gerüstgerüst und als Folge davon die Feinabstimmung der Eigenschaften von Metall‐organischen Gerüsten (MOFs) und kovalenten organischen Gerüsten (COFs) ermöglicht, wie sie von keiner anderen Materialklasse erreicht wird. Die Nutzung der einzigartigen Eigenschaften retikulärer Materialien hat zu bedeutenden Fortschritten aus fundamentaler wie auch aus angewandter Sicht geführt. Hier möchten wir die Meilensteine in der MOF‐ und COF‐Forschung beleuchten und einen kritischen Blick auf die Fortschritte in deren realen Anwendungen geben. Abschließend diskutieren wir kurz die großen Herausforderungen, die angegangen werden müssen, um den Weg für industrielle Anwendungen zu ebnen.
NovelN,N‐dimethylacrylamidecopolymer containing multiple rigid comonomers as a filtrate reducer inwater‐baseddrilling fluids and mechanism study
Authors: Wang Guoshuai , Jiang Guancheng , Yang Jun , Yang Lili , Li Xinliang , He Yinbo , Chang Xiangyang
Published: May 2021

Ultra‐high temperature dramatically deteriorates rheological properties and filtration performance of water‐based drilling fluids (WBDFs), especially for a salt‐gypsum formation that greatly restricts the application of WBDFs in ultra‐deep well drilling operations. Hence, the research in this article used an anionic copolymer (DANS) prepared byN,N‐dimethylacrylamide, 2‐acrylamide‐2‐methylpropanesulfonic acid,N‐vinylpyrrolidone, and sodium 4‐styrenesulfonate as an anti‐ultra‐high temperature and anti‐salt contamination filtrate reducer. Due to its multiple bulky cyclic structures in the side chain, DANS exhibits excellent thermal stability in the thermal gravimetric, rheological, and filtration tests. By adding 1.0 wt% DANS, the American Petroleum Institute (API) filtration volume of sodium bentonite‐based fluids (SBT‐BFs) decreased from 56.0 to 9.2 ml after aging at 240°C. Even under both 20 wt% NaCl contamination and 240°C aging, SBT‐BFs with 2.0 wt% DANS could maintain a filtration volume of 9.4 ml, whereas SBT‐BFs without DANS reached a filtration volume of 203.0 ml. The possible filtration control mechanism of DANS was further investigated via the Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), ζ potential, particle size distribution, filter cake micro‐morphology, and transmission electron microscopy (TEM). Confirmed by FTIR and AFM results, the effective adsorption was formed between DANS and bentonite even under a high‐salinity environment. Thus, a firm “dot net” structure formed by bentonite/DANS was observed by TEM, significantly improving the colloidal stability, dispersibility, and filter cake compactness of SBT‐BFs. Finally, by utilizing DANS as the core treatment agent, a high‐density WBDFs system with a temperature resistance of 240°C and a salt‐tolerance of 20 wt% has been successfully prepared.
Insights into an undescribed high‐elevation lake (6,170 m a.s.l.) on Volcán Llullaillaco: A physical and microbiological view
Authors: Aran Pablo , Aguilar Pablo , Bowen Thomas , Farson Matthew , Tapia Joseline , Vimercati Lara , Darcy John L. , Solon Adam J. , Porazinska Dorota , Schmidt Steven K. , Dorador Cristina
Published: May 2021

High elevation lakes are extreme ecosystems and serve as sentinels of various global changes.

An expedition to Volcán Llullaillaco in 1996 discovered an unstudied high‐elevation lake (6,170 m a.s.l.) that probably was formed as a result of the past eruptive events or climatic processes such as glacial retreat in the lake basin.

This article describes an initial physical characterization of the lake and its microbial communities derived from two sampling expeditions in 2013 and 2016.

The microbial community in the lake, with an area between 1.2 and 1.4 ha and a depth of 6.8 m, was dominated by Proteobacteria, Actinobacteria and Haloarchaea. In addition, 26 bacterial isolates were identified within the genera Subtercola, Xylophilus, Rhodanobacter, Mesorhizobium and Pseudomonas.

Lago Llullaillaco is one of the highest recorded lakes in the world, and this study highlights the unique microbial diversity of this aquatic ecosystem and the importance of its preservation to understand the complex biological processes under polyextreme conditions.