bluuebunny/crossref_metadata_2025 huggingface dataset:
Seagrass structural and elemental indicators reveal high nutrient availability within a tropical lagoon in Panama
Authors: Gaubert-Boussarie Julie , Altieri Andrew H. , Duffy J. Emmett , Campbell Justin E.
Published: May 2021

Seagrass meadows are valued coastal habitats that provide ecological and economic benefits around the world. Despite their importance, many meadows are in decline, driven by a variety of anthropogenic impacts. While these declines have been well documented in some regions, other locations (particularly within the tropics) lack long-term monitoring programs needed to resolve seagrass trends over time. Effective and spatially-expansive monitoring within under-represented regions is critical to provide an accurate perspective on seagrass status and trends. We present a comprehensive dataset on seagrass coverage and composition across 24 sites in Bahía Almirante, a lagoon along the Caribbean coast of Panama. Using a single survey, we focus on capturing spatial variation in seagrass physical and elemental characteristics and provide data on key seagrass bio-indicators, such as leaf morphology (length and width), elemental content (% nitrogen and phosphorus) and stable isotopic signatures (δ13C andδ15N). We further explore relationships between these variables and water depth (proxy for light availability) and proximity to shore (proxy for terrestrial inputs). The seagrass assemblage was mostly monospecific (dominated by Thalassia testudinum) and restricted to shallow water (<3 m). Above-ground biomass varied widely, averaging 71.7 g dry mass m−2, yet ranging from 24.8 to 139.6 g dry mass m−2. Leaf nitrogen content averaged 2.2%, ranging from 1.76 to 2.57%, while phosphorus content averaged 0.19% and ranged from 0.15 to 0.23%. These values were high compared to other published reports for T. testudinum, indicating elevated nutrient availability within the lagoon. Seagrass stable isotopic characteristics varied slightly and were comparable with other published values. Leaf carbon signatures (δ13C) ranged from −11.74 to −6.70‰ and were positively correlated to shoreline proximity, suggesting a contribution of terrestrial carbon to seagrass biomass. Leaf nitrogen signatures (δ15N) ranged from −1.75 to 3.15‰ and showed no correlation with shoreline proximity, suggesting that N sources within the bay were not dominated by localized point-source discharge of treated sewage. Correlations between other seagrass bio-indicators and environmental metrics were mixed: seagrass cover declined with depth, while biomass was negatively correlated with N, indicating that light and nutrient availability may jointly regulate seagrass cover and biomass. Our work documents the response of seagrass in Bahía Almirante to light and nutrient availability and highlights the eutrophic status of this bay. Using the broad spatial coverage of our survey as a baseline, we suggest the future implementation of a continuous and spatially expansive seagrass monitoring program within this region to assess the health of these important systems subject to global and local stressors.
Genome-wide identification, classification and expression profile analysis of the HSF gene family in Hypericum perforatum
Authors: Zhou Li , Yu Xiaoding , Wang Donghao , Li Lin , Zhou Wen , Zhang Qian , Wang Xinrui , Ye Sumin , Wang Zhezhi
Published: May 2021

Heat shock transcription factors (HSFs) are critical regulators of plant responses to various abiotic and biotic stresses, including high temperature stress. HSFs are involved in regulating the expression of heat shock proteins (HSPs) by binding with heat stress elements (HSEs) to defend against high-temperature stress. The H. perforatum genome was recently fully sequenced; this provides a valuable resource for genetic and functional analysis. In this study, 23 putative HpHSF genes were identified and divided into three groups (A, B, and C) based on phylogeny and structural features. Gene structure and conserved motif analyses were performed on HpHSFs members; the DNA-binding domain (DBD), hydrophobic heptad repeat (HR-A/B), and exon-intron boundaries exhibited specific phylogenetic relationships. In addition, the presence of various cis-acting elements in the promoter regions of HpHSFs underscored their regulatory function in abiotic stress responses. RT-qPCR analyses showed that most HpHSF genes were expressed in response to heat conditions, suggesting that HpHSFs play potential roles in the heat stress resistance pathway. Our findings are advantageous for the analysis and research of the function of HpHSFs in high temperature stress tolerance in H. perforatum.
La Escuela Nacional de Electricidad y la educación técnica en Perú
Authors:   Universidad Nacional Mayor de San Marcos, Guizado Mercado Yenisa , Ragas José ,   Pontificia Universidad Católica de Chile
Published: May 2021

La Escuela Nacional de Electricidad fue un ambicioso proyecto educativo que tenía como fin último implementar una red eléctrica en el territorio peruano a inicios del siglo XX. Al unir los programas de dos entidades ―la Escuela de Artes y Oficios y la Escuela de Ingenieros― para crear una sola institución, quienes promovían la Escuela Nacional de Electricidad pretendían entrenar a los futuros técnicos y expertos con las ense­ñanzas más avanzadas provenientes del Norte Global. El análisis de entrevistas, no­tas de prensa y los trabajos de su principal impulsor (Emilio F. Guarini), así como otros materiales y recursos, permite sostener que la Escuela Nacional de Electricidad es un ejemplo de cómo los quiebres estructura­les de la sociedad local obstaculizaron los programas de modernización en el país. Pese a que el proyecto no se llevó a cabo, su estudio permite centrarnos en determina­dos aspectos de la educación técnica (y los límites de los mismos) y una determinada cultura institucional que privilegiaron una agresiva modernización tecnológica por encima del bienestar de los ciudadanos, especialmente de aquellos que vivían en las zonas rurales y más alejadas del país.
Historia del diseño, las técnicas y la tecnología
Authors:   Pontificia Universidad Católica de Chile, Escuela de Diseño, Álvarez Caselli Pedro , Palmarola Hugo ,   Pontificia Universidad Católica de Chile, Escuela de Diseño, Cristi Nicole ,   University College London, Departamento de Antropología
Published: May 2021

Esta edición se centra en las historias del diseño, de las técnicas y de la tecnología. Los estudios que las vinculan han generado un número creciente de investigaciones y publicaciones, revelando la diversidad y riqueza que presenta este cruce interdisciplinar. Este número recoge un entramado sobre las condiciones históricas, culturales y técnicas de objetos, imágenes e infraestructuras, integrando miradas diversas provenientes del diseño, así como de la historia de la tecnología, la ingeniería, los estudios de CTS (ciencia, tecnología y sociedad), de cultura material y de género. En muchos casos, estas perspectivas son superpuestas y combinadas de manera libre y poco ortodoxa por los análisis de y a través del diseño.
Decision Support Systems for Downy Mildew (Plasmopara viticola) Control in Grapevine: Short Comparison Review
Authors: Mian Giovanni , Buso Edoardo , Tonon Matteo
Published: May 2021

Plasmopara viticola, the aetiological agent of grapevine downy mildew (DM), is the most important pathology afflicting viticulture and requires a great number of fungicide treatments to avoid severe yield losses and quality decreasing. To date, great efforts have been made to reduce the use of plant defensive products. Resistant cultivars, new agrochemicals and, finally, epidemiological models have been elaborated to better manage plant phytoiatric treatments. Nowadays, models are widely used because they allow the cultivation of traditional varieties, limiting agrochemicals. Using such models, implemented in a DSS (Decision Support System), results in a lower risk of grapevine damage by diseases and pests and, in many cases, in a lower input of active substances. Thanks to the information reported in a DSS, users could become more conscious of the relations between weather conditions, pathogen’s cycle, and infections risk, which is an issue not yet well understood by lots of winegrowers. For this instance, DSSs have been established as important tools for the achievement of more sustainable agricultural practices. Hence, understanding their working principles might be really important. In fact, in this way, technicians and farmers can adopt the suitable system to fit their own agricultural reality, aiming at a better vineyard management under a sustainable point of view.
Development of Screening Method for Moisture Deficit Tolerance of Black Pepper Genotypes
Authors: Alagupalamuthirsolai M. , Srinivasan V. , Sarathambal C. , Thankamani C. K. , Krishnamurthy K. S. , Subila K. P.
Published: May 2021

Black pepper is basically a rainfed crop in India.  Drought is the chief abiotic stress causing up to 50-80% crop loss in black pepper. Lack of precise screening methodology to develop moisture stress tolerant lines is a limiting factor in black pepper productivity. To develop a rapid screening methodology, a laboratory experiment was conducted with rooted black pepper cuttings under hydroponic culture. The experiment was designed in a completely randomized with four replications. Moisture stress was imposed with six different concentrations of Polyethylene glycol-6000 (5, 8, 10, 12, 15 and 20 per cent) along with control in black pepper cv. Panniyur-1, IISR-Thevam, IISR-Sreekara and IISR-Girimunda. The results showed that Panniyur-1, IISR-Thevam, IISR-Sreekara and IISR-Girimunda at the PEG-6000 concentrations of 8%, 10%, 10%, 10% respectively reduced per cent cuttings survival almost by 50% Lethal dose (LD50) after 10 days of PEG stress and also, a signiﬁcant increase in proline was recorded up to 10% PEG-6000. Hence, 10% PEG-6000 appears to be an ideal concentration for screening black pepper genotypes for moisture stress tolerance.
Resourcing as an Antecedent of Effective Online Learning Adaptation in the Face of COVID-19: The Case of Papua New Guinea University of Technology (PNGUoT)
Authors: Nuru S. Tindi , Fred Ssemugenyi , Oyekola Peter , Ngene C. Tochukwu
Published: May 2021

This pandemic has utterly disrupted traditional education systems around the world. Even as a global search for sure-fire innovative solutions to the pandemic rages on, it is increasingly becoming clear that online teaching is no more of an option but, a necessity; changes that were occasioned by COVID-19 might be here to stay! While some are nervous that the abrupt unprecedented pivot to online delivery mode might result in a poor user experience that could stifle sustained growth, others are optimistic that a new normal of learning has emerged with significant takeaways. This study sought to examine how universities are adapting to the new normal of teaching online using a case study of PNGUoT. While acknowledging that the transition to online, asynchronous learning poses just as many challenges for students as it does academics,  the study delves into the potential confluence of forces that are antecedents to effective online learning such as institutional policies, media, instructors and learners, and seeks to establish whether they can meaningfully predict effective online learning. A systematic search from literature coupled with the study findings suggests a moderately strong positive effect of resourcing on effective online learning thereby rejecting a null hypothesis and accepting its alternate. The study concludes that the adoption of online learning will continue to persist in the post-pandemic era and as such, therefore, stakeholders in the education space must bolster their capabilities to provide quality online learning as a panacea.
Scientific Basis for the Innovative Uses of Henna (Lawsonia inermis L.) mentioned by Unani Scholars in different ailments
Authors: Akhtar Jamal , Bashir Fouzia , Bi Salma
Published: May 2021

The Unani Medicine is a comprehensive medical system, which meticulously deals with the various states of health and disease. It provides promotive, preventive, curative and rehabilitative healthcare. The fundamentals, diagnosis and treatment modalities of the system are based on scientific principles and holistic concepts of health and healing. The history of Unani Medicine is traced back to ancient Egypt and Babylon, but Hippocrates (460–370 BC) is the father of Unani Medicine who set the ground for Medicine to develop it as a systematic science. Other scholars like Galen (129-200 AD); Rabban Ṭabarī (775-890 AD), al Rāzī (865-925 AD) and Ibn Sīnā (980-1037 AD) developed Unani Medicine to great heights. The system is enriched with detailed therapeutic uses of plant, mineral and animal origin drugs. Ibn Baytār’s classical pharmacopoeia describes 1400 medicinal plants and minerals, while the largest Indian compendium by Muḥammad Najm al Ghanī published in 1930, describes 2500 natural products. Unani scholars retain its traditional strength successfully and also benefitting from contemporary scientific development over the years. The system fully appropriated the paradigm of validation of existing knowledge on modern scientific parameters as well as new action of existing drugs was also discovered. Henna (Lawsonia inermis L.) is a commonly used medicinal plant of Unani Medicine which has Blood Purifier, Abortifacient, Analgesic, Astringent, Brain Tonic, Diuretic properties and used in the treatment of different diseases, e.g. Jarb-o-Hikka (Scabies), Juzaam (Leprosy), Bars (Leukoderma), Iltehaab-e-Mafasil (Arthritis), Dunbal (Boils) and Zarba-o-Saqta (bruises), Su'aal (Bronchitis), Harq-o-Salq (Burn and Scald), Humrah Dimaaghia (Erysipelas), Hasbah (Measles) and Judree (Small Pox) and Suda’ (Headache). This paper is a view to present a snapshot of the scientific aspects and the relevance of Henna (Lawsonia inermis L.) mentioned by Unani Physicians in the contemporary and emerging health scenario.
An Overview of Different Methods for Aminoglycoside Residue Determination
Authors: Morovatdar Sarah , Khameneh Bahman , Khashyarmanesh Zahra , Fazly Bibi Sedigheh
Published: May 2021

Aminoglycosides (AGs) are chemical substances that exist in the bacteriologic category of traditional antibiotic (AB) therapy. The importance of the determination of AG as has been described in many situations by researchers. Because of the narrow therapeutic ranges of AGs, considerable efforts have been attributed to the analysis of AGs in pharmaceutical preparations, serum, and urine specimens for therapeutic drug monitoring purposes. Residues of ABs in many different cases like environment and human food, causes a major concern, as prolonged exposure to ABs is a serious health hazard, related to both side effects of prolonged use and the risk of developing bacterial resistance to various ABs. The major challenge is finding a sensitive and reliable method to determine AGs in a complex matrix. The microbiological assay was a simple and old method for the determination of AGs. Chromatography and spectroscopy methods are the main instrumental methods for analysis that have been employed for these purposes. Biosensor based instrumental systems have been recently used to determine the AG residues in many cases. Each of these methods has its advantages and disadvantages. This review summarizes different ways (microbiological methods, instrumental methods, and biosensor) for the determination of AGs in all cases. Different databases including PubMed, Scopus, and Web of Science with the words of AGs determination and related words for antimicrobial keywords searched without time limitation.
Diabetes Mellitus: An Overview and Management with Herbs
Authors: Shaheen Ghazala , Fatima Iqra , Noor Raessa , Younus Muhammad , Sajid-Ur-Rehman M. , Ghaffar Saira , Rasool Shafqat , Zafar Farah , Khan Mohsin Abbas
Published: May 2021

Diabetes mellitus (DM) could be a typical disturbed throughout the globe. As of late, there are changed sorts of examinations and overview works region units considered. The individuals' Republic of Pakistan is that the place where there is magnificence while the common plants have selective meditative ayurvedic movement against inside emission Subordinate Diabetic Mellitus (IDDM) and Non-Insulin Subordinate Diabetic Mellitus (NIDDM). Among a few meds furthermore distinctive different meds, numerous herbs are praised to fix and the board diabetes; to boot they need no aspect impacts inside the prior some of the years, there must be an exponential development inside the arena of prescription then increasing quality each inside creating including created nations owing to their common source and fewer feature impacts during this audit work, we will in general essentially observe some potential plants therapeutic medication movement in the Individuals' Republic of Pakistan. A far-reaching audit of this paper is preliminary to a rundown of the plants with hostile to diabetic and associated valuable impacts beginning from entirely unexpected parts of the world. History indicated that meditative plants are utilized in old recuperating around the world for an all-inclusive chance to manage diabetes; here is frequently because of such herbs must manifestation characteristics moreover distinctive valuable features, while announced into logical writing. This effort increased this since quite a while ago run analyzers for extra exploration of the potential utilization of meditative plants having therapeutic medication potential just as indication action, inward emission mimetic movement, and cancer prevention agent action.
Usability of detecting delivery errors during treatment of prostate VMAT with a gantry‐mounted transmission detector
Authors: Honda Hirofumi , Tominaga Masahide , Sasaki Motoharu , Oita Masataka , Kanzaki Hiromitsu , Hamamoto Yasushi , Ishii Yoshiaki , Yamamoto Ryuji , Mochizuki Teruhito , Kido Teruhito , Uto Yoshihiro
Published: May 2021

Volumetric‐modulated arc therapy (VMAT) requires highly accurate control of multileaf collimator (MLC) movement, rotation speed of linear accelerator gantry, and monitor units during irradiation. Pretreatment validation and monitoring of these factors during irradiation are necessary for appropriate VMAT treatment. Recently, a gantry mounted transmission detector “Delta4 Discover® (D4D)” was developed to detect errors in delivering doses and dose distribution immediately after treatment. In this study, the performance of D4D was evaluated. Simulation plans, in which the MLC position was displaced by 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm from the clinically used original plans, were created for ten patients who received VMAT treatment for prostate cancer. Dose deviation (DD), distance‐to‐agreement (DTA), and gamma index analysis (GA) for each plan were evaluated by D4D. These results were compared to the results (DD, DTA and GA) measured by Delta4 Phantom + (D4P). We compared the deviations between the planned and measured values of the MLC stop positions A‐side and B‐side in five clinical cases of prostate VMAT during treatment and measured the GA values. For D4D, when the acceptable errors for DD, DTA, and GA were determined to be ≤3%, ≤2 mm, and ≤3%/2 mm, respectively, the minimum detectable errors in the MLC position were 2.0, 1.5, and 1.5 mm based on DD, DTA, and GA respectively. The corresponding minimum detectable MLC position errors were 2.0, 1.0, and 1.5 mm, respectively, for D4P. The deviation between the planned and measured position of MLC stopping point of prostate VMAT during treatment was stable at an average of −0.09 ± 0.05 mm, and all GA values were above 99.86%. In terms of delivering doses and dose distribution of VMAT, error detectability of D4D was comparable to that of D4P. The transmission‐type detector “D4D” is thus suitable for detecting delivery errors during irradiation.
Brain MRS correlates with mitochondrial dysfunction biomarkers in MELAS‐associated mtDNA mutations
Authors: Gramegna Laura L. , Evangelisti Stefania , Di Vito Lidia , La Morgia Chiara , Maresca Alessandra , Caporali Leonardo , Amore Giulia , Talozzi Lia , Bianchini Claudio , Testa Claudia , Manners David N. , Cortesi Irene , Valentino Maria L. , Liguori Rocco , Carelli Valerio , Tonon Caterina , Lodi Raffaele
Published: May 2021

Objective

The purpose of this study was to investigate correlations between brain proton magnetic resonance spectroscopy (1H‐MRS) findings with serum biomarkers and heteroplasmy of mitochondrial DNA (mtDNA) mutations. This study enrolled patients carrying mtDNA mutations associated with Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke‐like episodes (MELAS), and MELAS‐Spectrum Syndrome (MSS).

Methods

Consecutive patients carrying mtDNA mutations associated with MELAS and MSS were recruited and their serum concentrations of lactate, alanine, and heteroplasmic mtDNA mutant load were evaluated. The brain protocol included single‐voxel 1H‐MRS (1.5T) in the medial parieto‐occipital cortex (MPOC), left cerebellar hemisphere, parieto‐occipital white matter (POWM), and lateral ventricles. Relative metabolite concentrations of N‐acetyl‐aspartate (NAA), choline (Cho), and myo‐inositol (mI) were estimated relative to creatine (Cr), using LCModel 6.3.

Results

Six patients with MELAS (age 28 ± 13 years, 3 [50%] female) and 17 with MSS (age 45 ± 11 years, 7 [41%] female) and 39 sex‐ and age‐matched healthy controls (HC) were enrolled. These patients demonstrated a lower NAA/Cr ratio in MPOC compared to HC (p = 0.006), which inversely correlated with serum lactate (p = 0.021, rho = −0.68) and muscle mtDNA heteroplasmy (p < 0.001, rho = −0.80). Similarly, in the cerebellum patients had lower NAA/Cr (p < 0.001), Cho/Cr (p = 0.002), and NAA/mI (p = 0.001) ratios, which negatively correlated with mtDNA blood heteroplasmy (p = 0.001, rho = −0.81) and with alanine (p = 0.050, rho = −0.67). Ventricular lactate was present in 78.3% (18/23) of patients, correlating with serum lactate (p = 0.024, rho = 0.58).

Conclusion

Correlations were found between the peripheral and biochemical markers of mitochondrial dysfunction and brain in vivo markers of neurodegeneration, supporting the use of both biomarkers as signatures of MELAS and MSS disease, to evaluate the efficacy of potential treatments.
Interictal spike networks predict surgical outcome in patients with drug‐resistant focal epilepsy
Authors: Azeem Abdullah , von Ellenrieder Nicolas , Hall Jeffery , Dubeau Francois , Frauscher Birgit , Gotman Jean
Published: May 2021

Objective

To determine if properties of epileptic networks could be delineated using interictal spike propagation seen on stereo‐electroencephalography (SEEG) and if these properties could predict surgical outcome in patients with drug‐resistant epilepsy.

Methods

We studied the SEEG of 45 consecutive drug‐resistant epilepsy patients who underwent subsequent epilepsy surgery: 18 patients with good post‐surgical outcome (Engel I) and 27 with poor outcome (Engel II–IV). Epileptic networks were derived from interictal spike propagation; these networks described the generation and propagation of interictal epileptic activity. We compared the regions in which spikes were frequent and the regions responsible for generating spikes to the area of resection and post‐surgical outcome. We developed a measure termed source spike concordance, which integrates information about both spike rate and region of spike generation.

Results

Inclusion in the resection of regions with high spike rate is associated with good post‐surgical outcome (sensitivity = 0.82, specificity = 0.73). Inclusion in the resection of the regions responsible for generating interictal epileptic activity independently of rate is also associated with good post‐surgical outcome (sensitivity = 0.88, specificity = 0.82). Finally, when integrating the spike rate and the generators, we find that the source spike concordance measure has strong predictability (sensitivity = 0.91, specificity = 0.94).

Interpretations

Epileptic networks derived from interictal spikes can determine the generators of epileptic activity. Inclusion of the most active generators in the resection is strongly associated with good post‐surgical outcome. These epileptic networks may aid clinicians in determining the area of resection during pre‐surgical evaluation.
Ternary Nanoswitches Realized with Multiresponsive PMMA‐b‐PNIPMAM Films in Mixed Water/Acetone Vapor Atmospheres
Authors: Geiger Christina , Reitenbach Julija , Henschel Cristiane , Kreuzer Lucas P. , Widmann Tobias , Wang Peixi , Mangiapia Gaetano , Moulin Jean-François , Papadakis Christine M. , Laschewsky André , Müller-Buschbaum Peter
Published: May 2021

To systematically add functionality to nanoscale polymer switches, an understanding of their responsive behavior is crucial. Herein, solvent vapor stimuli are applied to thin films of a diblock copolymer consisting of a short poly(methyl methacrylate) (PMMA) block and a long poly(N‐isopropylmethacrylamide) (PNIPMAM) block for realizing ternary nanoswitches. Three significantly distinct film states are successfully implemented by the combination of amphiphilicity and co‐nonsolvency effect. The exposure of the thin films to nitrogen, pure water vapor, and mixed water/acetone (90 vol%/10 vol%) vapor switches the films from a dried to a hydrated (solvated and swollen) and a water/acetone‐exchanged (solvated and contracted) equilibrium state. These three states have distinctly different film thicknesses and solvent contents, which act as switch positions “off,” “on,” and “standby.” For understanding the switching process, time‐of‐flight neutron reflectometry (ToF‐NR) and spectral reflectance (SR) studies of the swelling and dehydration process are complemented by information on the local solvation of functional groups probed with Fourier‐transform infrared (FTIR) spectroscopy. An accelerated responsive behavior beyond a minimum hydration/solvation level is attributed to the fast build‐up and depletion of the hydration shell of PNIPMAM, caused by its hydrophobic moieties promoting a cooperative hydration character.
All‐Printed Green Micro‐Supercapacitors Based on a Natural‐derived Ionic Liquid for Flexible Transient Electronics
Authors: Migliorini Lorenzo , Piazzoni Claudio , Pohako‐Esko Kaija , Di Girolamo Marta , Vitaloni Andrea , Borghi Francesca , Santaniello Tommaso , Aabloo Alvo , Milani Paolo
Published: May 2021

The fabrication and characterization of green, flexible, and ultra‐thin supercapacitors that are able to operate above 1.5 V is reported, using an all‐printed fabrication process. The devices are produced by aqueous spray casting of a natural‐derived electrolyte ionogel composed by 2‐hydroxyethyl cellulose and by the ionic liquid choline lactate, while the electrodes are composed of highly porous nanostructured carbon films deposited by supersonic cluster beam deposition (SCBD). The obtained supercapacitors (device thickness < 10 μm) are stable to bending and they possess power values up to 120 kW kg–1. The combination of aqueous spray casting and SCBD constitutes a versatile, scalable, and eco‐friendly fabrication process able to directly print interconnected elements suitable for transient electronic systems.
Controlling Structure with Injectable Biomaterials to Better Mimic Tissue Heterogeneity and Anisotropy
Authors: Babu Susan , Albertino Filippo , Omidinia Anarkoli Abdolrahman , De Laporte Laura
Published: May 2021

Tissue regeneration of sensitive tissues calls for injectable scaffolds, which are minimally invasive and offer minimal damage to the native tissues. However, most of these systems are inherently isotropic and do not mimic the complex hierarchically ordered nature of the native extracellular matrices. This review focuses on the different approaches developed in the past decade to bring in some form of anisotropy to the conventional injectable tissue regenerative matrices. These approaches include introduction of macroporosity, in vivo pattering to present biomolecules in a spatially and temporally controlled manner, availability of aligned domains by means of self‐assembly or oriented injectable components, and in vivo bioprinting to obtain structures with features of high resolution that resembles native tissues. Toward the end of the review, different techniques to produce building blocks for the fabrication of heterogeneous injectable scaffolds are discussed. The advantages and shortcomings of each approach are discussed in detail with ideas to improve the functionality and versatility of the building blocks.
Encapsulation of Hydrophilic Compounds in Small Extracellular Vesicles: Loading Capacity and Impact on Vesicle Functions
Authors: Hettich Britta Franziska , Bader Johannes Josua , Leroux Jean‐Christophe
Published: May 2021

Their natural functions in intercellular communication render extracellular vesicles (EV) highly attractive for drug delivery applications. However, the loading efficiency of present methods to incorporate particularly hydrophilic low molecular weight drugs of biomedical interest is largely unexplored, as is the impact these methods may have on the intrinsic structural and biological vesicle properties. Here, different methods are exploited to incorporate hydrophilic non‐membrane permeable compounds into stem cell‐derived small EV, and to assess the vesicle characteristics after the different loading processes. When comparing several methods head‐to‐head, the loading capacity increases in the order saponin ≤ sonication < fusion < freeze‐thawing ≤ osmotic shock. Interestingly, the structural and biological functions of small EV are dependent on the applied encapsulation process, with the functional properties being altered at a greater extent. Therefore, the importance of including additional characterization parameters to probe alterations of the biological functionality of small EV is clearly demonstrated. Here, freeze‐thawing and particularly the osmotic shock have proven to be the most appropriate methods for EV loading, as they achieve a high drug encapsulation and yet preserve the investigated structural and biological vesicle characteristics.
Atomically Thin Sheets of Lead‐Free 1D Hybrid Perovskites Feature Tunable White‐Light Emission from Self‐Trapped Excitons
Authors: Klement Philip , Dehnhardt Natalie , Dong Chuan‐Ding , Dobener Florian , Bayliff Samuel , Winkler Julius , Hofmann Detlev M. , Klar Peter J. , Schumacher Stefan , Chatterjee Sangam , Heine Johanna
Published: May 2021

Low‐dimensional organic–inorganic perovskites synergize the virtues of two unique classes of materials featuring intriguing possibilities for next‐generation optoelectronics: they offer tailorable building blocks for atomically thin, layered materials while providing the enhanced light‐harvesting and emitting capabilities of hybrid perovskites. This work goes beyond the paradigm that atomically thin materials require in‐plane covalent bonding and reports single layers of the 1D organic–inorganic perovskite [C7H10N]3[BiCl5]Cl. Its unique 1D–2D structure enables single layers and the formation of self‐trapped excitons, which show white‐light emission. The thickness dependence of the exciton self‐trapping causes an extremely strong shift of the emission energy. Thus, such 2D perovskites demonstrate that already 1D covalent interactions suffice to realize atomically thin materials and provide access to unique exciton physics. These findings enable a much more general construction principle for tailoring and identifying 2D materials that are no longer limited to covalently bonded 2D sheets.
Lewis Acid‐Catalyzed Formal (4+2)‐ and (2+2+2)‐Cycloaddition Between 1‐Azadienes and Styrylmalonates as Analogues of Donor‐Acceptor Cyclopropanes
Authors: Sergeev Pavel G. , Novikov Roman A. , Tomilov Yury V.
Published: May 2021

The reactions of donor‐acceptor cyclopropanes (DACs) and isomeric β‐styrylmalonates with conformationally non‐rigid α,β‐unsaturated imines in the presence of Lewis acids were studied. The effect of the structural features of starting compounds on the process course was determined. The main attention was focused to discover the reaction conditions for the formal (4+2)‐cycloaddition pathway with the possibility of variation of the α‐substituent in azadiene instead of known (3+2)‐cycloaddition synthetic methodology. Based on the results obtained, a method for the diastereoselective synthesis of substituted trans,trans‐tetrahydropyridines was developed. Three substrate‐sensitive diverse Lewis acid catalytic systems have been employed based on Sc(OTf)3, Sn(OTf)2, and GaCl3. The use of GaCl3 as a Lewis acid allows to obtain a minor product of the formal (2+2+2)‐cycloaddition, which represents a fully 1,2,3,4,5,6‐hexasubstituted cyclohexane derivative produced with diastereoselectivity >30:1. Appropriate mechanistic and stereochemical models have been suggested.

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The Use of Green‐Solvent Processable Molecules with Large Dipole Moments in the Electron Extraction Layer of Inverted Organic Solar Cells as a Universal Route for Enhancing Stability
Authors: Sadeghianlemraski Mozhgan , Nouri Mohammad , Wong William S. , Aziz Hany
Published: May 2021

Employing a large dipole interlayer has recently been one of the most captivating interfacial engineering approaches in organic solar cells (OSCs). In this work, the effect of using green‐solvent processable molecules with large dipole moments as electron extraction layers (DM‐EELs) on OSCs’ stability is investigated. The inverted OSCs are based on two donor–acceptor systems, with histidine and sarcosine as representative DM‐EELs and with ZnO as a control EEL. Stability results illustrate that while the dominant degradation mechanism depends on the donor–acceptor system (photoinduced degradation vs temporal degradation), using DM‐EELs substantially suppresses degradation and enhances stability in both cases. The voltage‐dependent ideality factor characteristics show that the DM‐EEL OSCs exhibit minimal recombination mechanism changes even after UV exposure. By contrast, ZnO cells are limited by significant shunt formation and UV‐induced surface recombination. Low‐temperature measurements verify that unlike the indium tin oxide (ITO)/ZnO contact, the ITO/DM‐EEL contact is not affected by trap states or work function variations. As a result, the ITO/DM‐EEL contact maintains its electron‐selectivity and resists UV‐induced surface recombination observed in the ZnO cells. The results show that using green‐solvent processable materials with large dipole moments as EELs can provide a universal route for enhancing the stability of inverted OSCs.
Charge Traps in All‐Inorganic CsPbBr3 Perovskite Nanowire Field‐Effect Phototransistors
Authors: Winterer Felix , Walter Lisa Sophie , Lenz Jakob , Seebauer Stefan , Tong Yu , Polavarapu Lakshminarayana , Weitz Ralf Thomas
Published: May 2021

All‐inorganic halide perovskite materials have recently emerged as outstanding materials for optoelectronic applications. However, although critical for developing novel technologies, the influence of charge traps on charge transport in all‐inorganic systems still remains elusive. Here, the charge transport properties in cesium lead bromide, nanowire films are probed using a field‐effect transistor geometry. Field‐effect mobilities of μFET = 4 × 10−3 cm−2 V−1 s−1 and photoresponsivities in the range of R = 25 A W−1 are demonstrated. Furthermore, charge transport both with and without illumination is investigated down to cryogenic temperatures. Without illumination, deep traps dominate transport and the mobility freezes out at low temperatures. Despite the presence of deep traps, when illuminating the sample, the field‐effect mobility increases by several orders of magnitude and even phonon‐limited transport characteristics are visible. This can be seen as an extension to the notion of “defect tolerance” of perovskite materials that has solely been associated with shallow traps. These findings provide further insight in understanding charge transport in perovskite materials and underlines that managing deep traps can open up a route to optimizing optoelectronic devices such as solar cells or phototransistors operable also at low light intensities.
Reflections on the history of genetic medicine at Johns Hopkins University
Authors: Migeon Barbara R. , Kazazian Haig H.
Published: May 2021

Two members of the faculty—who witnessed the birth of Genetic Medicine and remained to see it evolve—present their reflections about the history of genetic medicine at the Johns Hopkins Medical Institutions. They tell how the genetic units in Pediatrics and Medicine that were initiated by Barton Childs and Victor McKusick, respectively, became the McKusick Nathans Department of Genetic Medicine in 2020.
Disauerstoffaktivierung und Pyrrol‐α‐Spaltung mit Calix[4]pyrrolatoaluminaten: Enzymmodell durch strukturellen Zwang
Authors: Sigmund Lukas Maximilian , Ehlert Christopher , Enders Markus , Graf Jürgen , Gryn'ova Ganna , Greb Lutz
Published: May 2021

Die vorliegende Arbeit beschreibt die Reaktion von Triplett‐Disauerstoff mit den porphyrinogenen Calix[4]pyrrolatoaluminaten hin zu Alkylperoxidoaluminaten mit hoher Selektivität. Multikonfigurationsquantenchemische Berechnungen beleuchten den spinverbotenen Prozess. Ungeachtet einer vernachlässigbaren Spin‐Bahn‐Kopplungskonstante wird die Interkombination (intersystem crossing) durch die Entartung des Singulett‐ und Triplett‐Zustands sowie durch spinvibronische Kopplung ermöglicht. Die gebildeten Peroxide sind stabil gegenüber externen Substraten, gehen allerdings eine beispiellose oxidative Pyrrol‐α‐Spaltung mittels einer durch Ligand‐Aromatisierung/‐dearomatisierung initiierten Spaltung der O‐O‐σ‐Bindung ein. Ein detaillierter Vergleich der Calix[4]pyrrolatoaluminate mit disauerstoffbezogener Enzymologie liefert Einblicke in die Arbeitsweise von metall‐ und cofaktorfreien Enzymen. Diese Zusammenhänge bekräftigen die Wichtigkeit von strukturellem Zwang und Element‐Ligand‐Kooperativität für die Funktionen des aeroben Lebens.
A micro‐to‐macro approach to returns, volumes and waiting times
Authors: D'Amico Guglielmo , Petroni Filippo
Published: May 2021

Modelling stock prices has been a research topic for many decades and it is still an open question. Different approaches have been used in the literature, the majority of which can be classified within the so‐called econometric framework and sometimes also referred to as the macro‐to‐micro approach. Another strand of literature relies on the modelling of directly observable quantities, the so‐called micro‐to‐macro approach. Based on this second line of research, we propose a new multivariate stochastic process to model simultaneously price returns, trading volumes and the time interval between changes in trades, price and volume. The proposed model is based on a generalization of semi‐Markov chain models and copulas and is motivated by empirical evidence that the three mentioned variables are correlated and long‐range autocorrelated. Utilizing Monte Carlo simulations, we compared our model with real data from the Italian stock market and show that it can reproduce many empirical pieces of evidence. The proposed model can be used in the field of portfolio optimization, development of risk measure and volatility forecasting.
Simultaneous determination of cellular adenosine nucleotides, malondialdehyde, and uric acid using HPLC
Authors: Chen Yanjie , Ji Peng , Ma Guangyin , Song Zehua , Tang Bruce Qing , Li Tongju
Published: May 2021

Adenine nucleotides and malondialdehyde (MDA) are key components involved in energy metabolism and reactive oxygen species (ROS) production. Measuring the levels of these components at the same time would be critical in studying mitochondrial functions. We have established a HPLC method to simultaneously measure adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, MDA, and uric acid (UA). The samples were treated with perchloric acid followed by centrifugation. After neutralization, the supernatant was subjected to HPLC determination. HPLC was performed using a C18 chromatographic column, isocratic elusion, and UV detection. The detection and quantification limits for these components were determined with standard solutions. The precision, repeatability, and 24‐h stability were evaluated using cellular samples, and their relative standard deviations were all within 2%. The reproducibility and efficiency were confirmed with sample recovery tests and the observed oxidative effects of H2O2 on Jurkat cells. With this method, we discovered the dependence of energy and oxidative states on the density of Jurkat cells cultured in suspension. We also found a significant correlation between UA in serum and that in saliva. These results indicate that this method has good accuracy and applicability. It can be used in biological, pharmacological, and clinical studies, especially those involving mitochondria, ROS, and purinergic signaling.
Association between neurological outcome and poststroke comorbid mood and anxiety disorders: A real‐life experience
Authors: Rabat Yolaine , Houeze Richard , Sagnier Sharmila , Olindo Stephane , Poli Mathilde , Debruxelles Sabrina , Renou Pauline , Rouanet François , Berthoz Sylvie , Sibon Igor
Published: May 2021

Introduction

Poststroke depression (PSD) and anxiety (PSA) are prevalent and have a strong impact on functional outcome. Beside stroke severity, little is known on their clinical determinants. This study investigated the association between stroke mechanism, neurological poststroke complications and remaining vascular risk factors and the presence of comorbid PSD and PSA, termed poststroke emotional distress (PSED).

Methods

This was a retrospective analysis of a prospectively compiled medical records database of consecutive patients evaluated during a follow‐up visit 3‐ to 4‐month poststroke. HAD scale was used to define PSED category (PSD+PSA vs. NoPSD+NoPSA). Stroke mechanism and poststroke complications were identified clinically or using appropriate scales. Their association with PSED was tested using a multivariate logistic regression model.

Results

The sample included 2,300 patients (male: 64.8%); 19% had a PSED and 56.39% were free of any depression or anxiety. The most frequent poststroke complications were fatigue/fatigability (58.4%), sleep problems (26.7%), and pain (20.4%). While no association was observed between PSED and stroke mechanism, higher functional disability (OR:1.572), lower cognitive abilities (OR:0.953), sleep problems (OR:2.334), pain (OR:1.478), fatigue/fatigability (OR:2.331), and abnormal movements (OR:2.380) were all independent risk factors. Persisting tobacco consumption (OR:1.360) was the only vascular significant risk factor.

Conclusions

The frequency of comorbid PSED remains high (1/5 patient) despite improved awareness of these conditions. The association between poststroke complications and the presence of PSED emphasizes the need for standardized neurological and psychological evaluations at follow‐up. These results foster the need to improve the management of addictive behaviors to reduce the burden of PSED.
Multicenter clinical evaluation of a piezoresistive‐MEMS‐sensor rapid‐exchange pressure microcatheter system for fractional flow reserve measurement
Authors: Li Chenguang , Yang Junqing , Dong Shaohong , Dong Liang , Chen Jiyan , Shen Li , Zhang Feng , Li Changling , Liu Huadong , Hu Xinyang , Hau William Kongto , Qian Juying , Jeremias Allen , Wang Jian'an , Ge Junbo ,   for the SUPREME Study Investigators
Published: May 2021

Objectives

This multicenter, prospective clinical study investigates whether the microelectromechanical‐systems‐(MEMS)‐sensor pressure microcatheter (MEMS‐PMC) is comparable to a conventional pressure wire in fractional flow reserve (FFR) measurement.

Background

As a conventional tool for FFR measurement, pressure wires (PWs) still have some limitations such as suboptimal handling characteristics and unable to maintain the wire position during pullback assessment. Recently, a MEMS‐PMC compatible with any 0.014″ guidewire is developed. Compared with the existing optical‐sensor PMC, this MEMS‐PMC has smaller profiles at both the lesion crossing and sensor packaging areas.

Methods

Two hundred and forty‐two patients with visually 30–70% coronary stenosis were enrolled at four centers. FFR was measured first with the MEMS‐PMC, and then with the PW. The primary endpoint was the Bland–Altman mean bias between the MEMS‐PMC and PW FFR.

Results

From the 224‐patient per‐protocol data, quantitative coronary angiography showed 17.9% and 55.9% vessels had diameter < 2.5 mm and stenosis >50%, respectively. The two systems' mean bias was −0.01 with [−0.08, 0.06] 95% limits‐of‐agreement. Using PW FFR≤0.80 as cutoff, the MEMS‐PMC per‐vessel diagnostic accuracy was 93.4% [95% confidence interval: 89.4–96.3%]. The MEMS‐PMC's success rate was similar to that of PW (97.5 vs. 96.3%, p = .43) with no serious adverse event, and its clinically‐significant (>0.03) drift rate was 43% less (9.5 vs. 16.7%, p = .014).

Conclusions

Our study showed the MEMS‐PMC is safe to use and has a minimal bias equal to the resolution of current FFR systems. Given the MEMS‐PMC's high measurement accuracy and rapid‐exchange nature, it may become an attractive new tool facilitating routine coronary physiology assessment.
Impact of stent length and diameter on 10‐year mortality in the SYNTAXES trial
Authors: Hara Hironori , Ono Masafumi , Kawashima Hideyuki , Kogame Norihiro , Mack Michael J. , Holmes David R. , Morice Marie‐Claude , Davierwala Piroze M. , Mohr Friedrich W. , Thuijs Daniel J.F.M. , Head Stuart J. , Kappetein Arie Pieter , Onuma Yoshinobu , Serruys Patrick W. ,   for the SYNTAX Extended Survival Investigators
Published: May 2021

Objectives

We investigated the impact of total stent length (TSL) and average nominal stent diameter (ASD) on 10‐year mortality after percutaneous coronary intervention (PCI) in the SYNTAXES trial.

Background

TSL and ASD in patients treated with PCI are associated with major adverse cardiovascular events. However, the treatment effect of PCI with extensive and/or small stenting as compared with coronary artery bypass grafting (CABG) for complex coronary artery disease has not been fully evaluated.

Methods

Impacts on mortality of extensive stenting defined as TSL >100 mm and small stenting as ASD <3 mm were analyzed in 893 PCI patients and were compared to 865 CABG patients.

Results

TSL as a continuous variable was significantly associated with 10‐year mortality (adjusted hazard ratio [HR], 1.05 [1.01–1.09] per 10 mm increase). PCI patients with extensive stenting had a higher 10 year mortality than CABG patients (adjusted HR, 1.97 [1.41–2.74]) or not‐ extensive stenting PCI (adjusted HR, 1.94 [1.36–2.77]). Although ASD did not have a significant association with 10 year mortality (adjusted HR, 0.97 [0.85–1.11] per 0.25 mm increase), PCI with small stents was associated with a higher 10 year mortality, compared to CABG (adjusted HR, 1.66 [1.23–2.26]) and PCI performed with large stents (adjusted HR, 1.74 [1.19–2.53]). Patients treated with not‐extensive and large stents had similar mortality rates (24.0 versus 23.8%) as those treated with CABG.

Conclusions

Extensive and small stenting were associated with higher 10 year mortality, compared with CABG. When patients have to be treated with extensive or small stenting, revascularization with CABG should be preferred.