bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regional land degradation assessment for dryland environments: The NamaqualandHardeveldbioregion of the SucculentKaroobiome as a case‐study
Authors: Bell Wesley D. , Hoffman Michael T. , Visser Vernon 
Published: February 2021

AbstractThere is growing consensus that land degradation assessments should occur at local to regional scales, as global assessments fail to capture the complexity of land degradation processes, and how they manifest in different social‐ecological contexts. We have tested a statistically rigorous method for regional land degradation assessment in drylands, using fuzzy classification theory and techniques, that results in the creation of a habitat condition archetype for the NamaqualandHardeveldbioregion of the SucculentKaroobiome in South Africa. The methodology initially groups field data into classes based on known indicators of land degradation, before predicting observed field cover with 16 remote sensing variables, derived from both LANDSAT 8 and SENTINEL‐2A satellite data. Using fuzzy classification techniques, projections of field cover from the resulting model are combined with variables representing a potential change in cover to produce a map of the habitat condition of the bioregion. Approximately 17% of the bioregion had habitat condition values less than one standard deviation smaller than the mean and could therefore be considered degraded. To provide context, this map is presented with potential drivers of change for the bioregion. The map, and accompanying drivers of change, is ultimately presented in a Google Earth Engine app for easy interpretation and use.
How Do the Purcell Factor, the Q‐Factor, and the Beta Factor Affect the Laser Threshold?
Authors: Khurgin Jacob B. , Noginov Mikhail A. 
Published: February 2021

AbstractAs lasers get more and more miniaturized and their dimensions become comparable to the wavelength, two interconnected phenomena take place: the fraction of spontaneous radiation going into a specific laser mode (β‐factor) increases and can ultimately reach unity, while the radiative lifetime gets shortened by the Purcell factor Fp. Often it is assumed that an increase of these two factors, along with the quality factor (Q‐factor), almost invariably causes reduction of the lasing threshold. This assumption is tested on various photonic and plasmonic lasers, demonstrating that, while there is obvious correlation between the aforementioned factors and the laser threshold, the dependence is far from being straightforward and omnipresent. Depending on specific laser material and geometry, the threshold can decrease, increase, or stay unchanged when β‐factor, Q‐factor, and Fp increase. For the most part, the reduction of threshold is achieved simply by reducing the laser volume and this volume reduction can concurrently cause the increase in β‐factor and/or Purcell factor, but it would be imprudent to say that the increase in either of these factors is the cause of the threshold reduction.
Nonlinear Mid‐Infrared Metasurface based on a Phase‐Change Material
Authors: Yue Fuyong , Piccoli Riccardo , Shalaginov Mikhail Y. , Gu Tian , Richardson Kathleen A. , Morandotti Roberto , Hu Juejun , Razzari Luca 
Published: February 2021

AbstractThe mid‐wave infrared (MWIR) spectral region (3–5 µm) is important to a vast variety of applications in imaging, sensing, spectroscopy, surgery, and optical communications. Efficient third‐harmonic generation (THG), converting light from the MWIR range into the near‐infrared, a region with mature optical detection and manipulation technologies, offers the opportunity to mitigate a commonly recognized limitation of current MWIR systems. In this work, the possibility of boosting THG in the MWIR through a metasurface design is presented. Specifically, a 30‐fold enhancement in a highly nonlinear phase‐change material Ge2Sb2Se4Te1 (GSST) is demonstrated by patterning arrays of subwavelength cylinders supporting a magnetic dipolar resonance. The unprecedented broadband transparency, large refractive index, and remarkably high nonlinear response, together with unique phase‐change properties, make GSST‐based metasurfaces an appealing solution for reconfigurable and ultra‐compact nonlinear devices operating in the MWIR.
Highly Responsive Photochromic Ceramics for High‐Contrast Rewritable Information Displays
Authors: Yang Zetian , Du Jiaren , Martin Lisa I. D. J. , Van der Heggen David , Poelman Dirk 
Published: February 2021

AbstractInspired by their excellent thermal stability and strong fatigue resistance, inorganic photochromic materials have been highlighted as promising candidates in various photonic applications ranging from photoswitches, anti‐counterfeiting, and encryption to information storage. However, the lack of suitable inorganic materials with both fast photoresponse and strong coloration contrast heavily restricts their applications. Herein, a new strategy is proposed to achieve high photochromic performance via constructing deep‐lying traps in ferroelectric ceramics. The obtained K0.5Na0.5NbO3‐Eu (KNN‐Eu) ceramic exhibits a reversible yellow–gray color change with high fatigue resistance upon alternating illumination (420 nm) and thermal stimulus (450 °C). A fast response time of around 1 s and a large reflectivity difference of 39.2% between the colored and bleached states are simultaneously achieved in KNN‐Eu ceramic, which is by far the best performance ever reported in inorganic photochromic materials. Benefiting from these excellent properties, KNN‐Eu is the first ferroelectric photochromic ceramic to support an instant and hand‐(re)writable information display. The enhanced photochromic performance is expected to facilitate the application of photochromic materials in numerous optical devices and provides a significant guidance to design other inorganic photochromic materials.
Horseradish Peroxidase‐Crosslinked Calcium‐Containing Silk Fibroin Hydrogels as Artificial Matrices for Bone Cancer Research
Authors: Pierantoni Lara , Ribeiro Viviana P. , Costa Lígia , Pina Sandra , da Silva Morais Alain , Silva‐Correia Joana , Kundu Subhas C. , Motta Antonella , Reis Rui L. , Oliveira Joaquim M. 
Published: February 2021

AbstractHydrogels, being capable of mimicking the extracellular matrix composition of tissues, are greatly used as artificial matrices in tissue engineering applications. In this study, the generation of horseradish peroxidase (HRP)‐crosslinked silk fibroin (SF) hydrogels, using calcium peroxide as oxidizer is reported. The proposed fast forming calcium‐containing SF hydrogels spontaneously undergo SF conformational changes from random coil to β‐sheet during time, exhibiting ionic, and pH stimuli responsiveness. In vitro response shows calcium‐containing SF hydrogels’ encapsulation properties and their ability to promote SaOs‐2 tumor cells death after 10 days of culturing, upon complete β‐sheet conformation transition. Calcium‐containing SF hydrogels’ angiogenic potential investigated in an in ovo chick chorioallantoic membrane (CAM) assay, show a high number of converging blood vessels as compared to the negative control, although no endothelial cells infiltration is observed. The in vivo response evaluated in subcutaneous implantation in CD1 and nude NCD1 mice shows that calcium‐containing SF hydrogels are stable up to 6 weeks after implantation. However, an increased number of dead cells are also present in the surrounding tissue. The results suggest the potential of calcium‐containing SF hydrogels to be used as novel in situ therapeutics for bone cancer treatment applications, particularly to osteosarcoma.
Tri‐Layer Laminated Fabric‐Induced Sweating Surfaces for Passive Cooling
Authors: Li Xiaoyan , Javed Muhammad , Luo Ming , Cai Zaisheng , Xu Bi 
Published: February 2021

AbstractFabrics which can keep people cool in a hot climate have attracted considerable attention in recent years. Among various cooling strategies, fabric cooling by water evaporation is proved to be very safe, simple and sustainable. Here, a tri‐layer laminated fabric (TLF) inspired by perspiration is designed to realize passive cooling of human body. An interlayer fabric which is coated with crosslinked sodium polyacrylate can absorb and store a large amount of water. A moisture‐absorbing and quick‐drying fabric is used as the outer layer while a waterproof breathable fabric is used on the inside of the laminate in contact with skin. The prepared TLF shows decent evaporative cooling performance under dry heat conditions. The water absorbency of TLF is about 400% higher than that of pristine cotton after 1 h soaking in water. Under a 1 sun irradiation (1000 W m−2), the indoor temperature of a simulated room can be reduced by ≈5–7 °C compared with the other without a cooling system. Meanwhile, the evaporative cooling effect can be maintained up to 5 h. This cooling fabric shows broad application prospects in the fields of thermal cooling to human and buildings.
FT‐ICR mass spectrometry: Superconducting magnet, external ion source, ion–molecule reactions, and ion–ion traps
Authors: Wanczek Karl Peter , Kanawati Basem 
Published: February 2021

AbstractThe world of Fourier‐transform ion cyclotron resonance (FT‐ICR) mass spectrometry has witnessed, especially in the last 30 years significant advances in many fields of science, such as electronics, magnets, new ICR cell designs, developed ICR event sequences, modern external ionization sources, and linear ion beam guides, as well as modern vacuum technology. In this review, a brief account is given focusing especially on the studies performed in Wanczek's group and ICR research laboratory at the University of Bremen. An FT‐ICR mass spectrometer has been developed with a high magnetic field superconducting magnet, operating at 4.7 T. At this magnetic field, a trapping time of 13.5 h was obtained with 30% efficiency. For the tetrachloromethane molecular ion, m/z 166, a mass‐resolving power m/Δm = 1.5 × 106 was measured at a pressure of 2 × 10−8 Torr. The transition from magnet sweep to frequency sweep and the application of Fourier‐transform has greatly enhanced the ICR technology. External ion sources were invented and differential pumping schemes were developed for enabling ultrahigh vacuum condition for ICR detection, while guiding ions at relatively higher pressures, during their flight to the ICR cell. With the external ion source, a time‐of‐flight ICR tandem instrument is built. A method to measure the ion flight time and to trap the ions in the ICR cell is described. Many ICR cell characteristics such as z‐axis ion ejection and coupling of radial and axial ion motions in a superposed homogeneous magnetic and inhomogeneous trapping electric field were extensively studied. Gas‐phase ion–molecule reactions of several reactive inorganic compounds with a focus on phosphorous and sulfur as well as silicon chemistry were also studied in great detail. The gas‐phase ion chemistry of several trifluoromethyl‐reagents such as trifluoromethyltrimethylsilane and tris(trifluoromethyl)phosphine were also investigated in ICR. Dual polarities multisegmented ICR cells were invented and deeply characterized. Sophisticated ICR pulse event programs were developed to enable long‐range ion–ion interactions between simultaneously trapped positive and negative ions.
Adipose‐derived stromal cells for nonhealing wounds: Emerging opportunities and challenges
Authors: Deptuła Milena , Brzezicka Agnieszka , Skoniecka Aneta , Zieliński Jacek , Pikuła Michał 
Published: February 2021

AbstractWound healing complications affect thousands of people each year, thus constituting a profound economic and medical burden. Chronic wounds are a highly complex problem that usually affects elderly patients as well as patients with comorbidities such as diabetes, cancer (surgery, radiotherapy/chemotherapy) or autoimmune diseases. Currently available methods of their treatment are not fully effective, so new solutions are constantly being sought. Cell‐based therapies seem to have great potential for use in stimulating wound healing. In recent years, much effort has been focused on characterizing of adipose‐derived mesenchymal stromal cells (AD‐MSCs) and evaluating their clinical use in regenerative medicine and other medical fields. These cells are easily obtained in large amounts from adipose tissue and show a high proregenerative potential, mainly through paracrine activities.In this review, the process of healing acute and nonhealing (chronic) wounds is detailed, with a special attention paid to the wounds of patients with diabetes and cancer. In addition, the methods and technical aspects of AD‐MSCs isolation, culture and transplantation in chronic wounds are described, and the characteristics, genetic stability and role of AD‐MSCs in wound healing are also summarized. The biological properties of AD‐MSCs isolated from subcutaneous and visceral adipose tissue are compared. Additionally, methods to increase their therapeutic potential as well as factors that may affect their biological functions are summarized. Finally, their therapeutic potential in the treatment of diabetic and oncological wounds is also discussed.
Observation and evaluation of dynamic population gratings formed by two‐wave mixing in an erbium‐doped fiber amplifier
Authors: Kuroda Keiji 
Published: February 2021

AbstractDynamic population gratings formed by two‐wave mixing in an erbium‐doped fiber amplifier are reported. One of the counter‐propagating fields is intensity‐modulated to distinguish reflection from the grating from amplified transmission fields. The modulation‐frequency dependence of the reflection is studied under single‐wavelength and two‐wavelength input conditions to separate reflection from transient gain. The results are analyzed by measuring the gain saturation and recovery times using self‐probe and pump–probe techniques.
In vitro ameliorative effects of ellagic acid on vitality, motility and DNA quality in human spermatozoa
Authors: Iovine Concetta , Mottola Filomena , Santonastaso Marianna , Finelli Renata , Agarwal Ashok , Rocco Lucia 
Published: February 2021

AbstractOxidative stress (OS) plays a significant role in the etiology of male infertility, resulting in the impairment of male reproduction. This condition, characterized by an imbalance in the levels of oxidizing and antioxidant species in the seminal fluid, has a harmful impact on sperm functions and DNA integrity. The present study aimed to evaluate the anti‐genotoxic action of ellagic acid, a polyphenolic molecule of natural origin having a powerful antigenotoxic, anti‐inflammatory and antiproliferative role. An OS condition was induced in vitro by incubating normozoospermic human semen samples in benzene for 45, 60 and 90 min. DNA integrity was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling assay, RAPD‐PCR was performed to calculate the genome template stability, while the percentage of intracellular reactive oxygen species (ROS) was assessed by the 2ʹ, 7ʹ‐dichlorofluorescein assay. Our results showed that ellagic acid has a consistent protective effect on DNA integrity, as well as on sperm vitality and motility, by counteracting generation of intracellular ROS. The results of this study suggest ellagic acid as a suitable molecule to protect sperm DNA from oxidative stress, with a potentially significant translational impact on the management of the male infertility.
Adaptive functioning and academic achievement in survivors of childhood acute lymphoblastic leukemia: A report from the Children's Oncology Group
Authors: Jacola Lisa M. , Baran Julie , Noll Robert B. , Willard Victoria W. , Hardy Kristina K. , Embry Leanne , Hullmann Stephanie E. , Larsen Eric C. , Winick Naomi , Kairalla John A. 
Published: February 2021

AbstractPurposeTo characterize academic and adaptive skill outcomes in survivors of high‐risk B‐lineage acute lymphoblastic leukemia (HR B‐ALL).MethodsParticipants were 178 patients enrolled on a nontherapeutic clinical trial that aimed to characterize neurocognitive and functional outcomes (ie, academic achievement and adaptive skills) following treatment for childhood HR B‐ALL. Eligible patients were treated on Children's Oncology Group AALL0232 clinical trial that included two treatment randomizations: methotrexate delivery (high or escalating dose) and corticosteroid (dexamethasone or prednisone). Academic achievement and adaptive skills were evaluated at one time point, 8‐24 months after completing treatment.ResultsMultivariable logistic regression showed no significant association between treatment variables and outcomes after accounting for age at diagnosis, sex, and insurance status. In multivariable analyses accounting for sex and insurance status, survivors <10 years old at diagnosis had significantly lower scores in Math (P = .02). In multivariable analyses accounting for sex and age at diagnosis, scores for children with US public health insurance were significantly lower than those with US private or military insurance across all academic and adaptive skills (all P‐values ≤.04). Results from univariate analyses showed that boys had significantly lower scores than girls across all adaptive skill domains (all P‐values ≤.04).ConclusionRegardless of treatment randomization, survivors of HR B‐ALL <10 years at diagnosis are at risk for deficits in Math and overall adaptive functioning; overall adaptive skills for boys were significantly poorer. Screening and early intervention for patients at highest risk, particularly young patients and lower resourced families, should be prioritized.
Compatibilized polypropylene nanocomposites containing expanded graphite and graphene nanoplatelets
Authors: Ho Quang Binh , Kontopoulou Marianna 
Published: February 2021

AbstractWe present a non‐covalent compatibilization approach to prepare polypropylene (PP) composites containing expanded graphite (EG) and graphene nanoplatelets (GNPs) by melt compounding. This method involves PP matrix functionalization with pyridine (Py) moieties, which are capable of engaging in π‐π interactions with the surface of the EG and GNPs. The addition of 10 wt% of PP grafted with amino‐pyridine (PP‐g‐Py) to neat PP facilitated the break‐up of EG particles, by intercalating between their layers and facilitating their separation into smaller tactoids. GNPs were prepared starting from EG through a thermomechanical exfoliation method. Addition of GNPs to PP resulted in well‐dispersed platelets having aspect ratios as high as 40, whereas in the presence of the PP‐g‐Py compatibilizer the matrix contained sub‐micron scale platelets. The electrical percolation thresholds were in the vicinity of 6 and 10 vol% in the compatibilized PP‐EG and PP‐GNP composites, respectively, and the maximum value of the electrical conductivity achieved was 10−1 S/m for the compatibilized GNP composites. Addition of GNPs resulted in increases in the flexural moduli by as much as 95% compared to the unfilled PP, whereas the impact strength remained unaffected up to 10 wt% GNP content.
Standards development for modules in high temperature micro‐environments
Authors: Kempe Michael D. , Holsapple Derek , Whitfield Kent , Shiradkar Narendra 
Published: February 2021

AbstractPhotovoltaic (PV) module qualification standards, IEC 61215 and IEC 61730, were designed to apply to “general open‐air climates” and IEC 61730 specifically indicated applicability of ambient air temperature of 40°C. Additionally, these standards provided allowances for so‐called “open rack mounted PV modules” without a clear definition of “open‐rack.” These implied restrictions and allowances meant that hotter climates or thermally restrictive installation methods may not be covered by these often customer‐mandated certification standards. This is particularly salient for the significant growth regions of the Middle East and India that would be expected to operate at significantly higher temperatures. The applicability of these documents raised issues over the definition of “open rack” and the fact that the geographic location is just as important as the mounting configuration in assessing the impact of the micro‐environment of a PV module. This work summarizes the scientific background for IEC Technical Specification 63126:2020 ED1, titled “Guidelines for qualifying PV modules components and materials for operation at high temperatures.” This standard was recently published by the IEC and is the first step in a systematic effort to rework these standards to address the question of temperature more directly. Instead of specifying a mounting condition, we specify different suites of tests suitable for a system (PV module, mounting style, and location) defined by the 98th percentile cell temperature. With a defined temperature regime to work from, this allowed us to use existing literature research combined with additional modeling work to determine, which tests would need to be modified. This resulted in suggested changes to material thermal indices, thermal cycling temperatures, hot spot testing, ultraviolet testing, and bypass diode testing among other tests and characteristics described herein.
Social and emotional learning during early adolescence: Effectiveness of a classroom‐based SEL program for middle school students
Authors: Green Amy L. , Ferrante Stephen , Boaz Timothy L. , Kutash Krista , Wheeldon‐Reece Brooke 
Published: February 2021

AbstractEarly adolescence and the transition to middle school bring about many challenges for students and negative outcomes are not uncommon, including academic decline and social maladjustment. This developmental period is also marked by increased risk of mental health‐related difficulties. Strengthening students’ social and emotional competencies through the delivery of school‐based Social and Emotional Learning (SEL) programs has been suggested as one strategy for promoting positive development and preventing negative outcomes. In particular, the delivery of developmentally appropriate and evidence‐based SEL programs at the universal level of tiered supports has the potential to benefit many students. The current study presents findings from a randomized controlled trial of the Speaking to the Potential, Ability, and Resilience Inside Every Kid (SPARK) Pre‐Teen Mentoring Curriculum for 357 students from two schools. Results revealed that students who received the curriculum showed significant improvements in knowledge of curriculum content and principles; communication, decision‐making, and problem‐solving skills; emotional regulation; and resilience compared to students in the comparison condition. Results provide initial evidence for the efficacy of the SPARK Pre‐Teen Mentoring Curriculum for middle school students. Study strengths and limitations as well as directions for future research and program development are discussed.