bluuebunny/crossref_metadata_2025 huggingface dataset:
Swimming toward solutions: Using fish and frogs as models for understandingRASopathies
Authors: Patterson Victoria L. , Burdine Rebecca D.
Published: June 2020

The RAS signaling pathway regulates cell growth, survival, and differentiation, and its inappropriate activation is associated with disease in humans. The RASopathies, a set of developmental syndromes, arise when the pathway is overactive during development. Patients share a core set of symptoms, including congenital heart disease, craniofacial anomalies, and neurocognitive delay. Due to the conserved nature of the pathway, animal models are highly informative for understanding disease etiology, and zebrafish andXenopusare emerging as advantageous model systems. Here we discuss these aquatic models of RASopathies, which recapitulate many of the core symptoms observed in patients. Craniofacial structures become dysmorphic upon expression of disease‐associated mutations, resulting in wider heads. Heart defects manifest as delays in cardiac development and changes in heart size, and behavioral deficits are beginning to be explored. Furthermore, early convergence and extension defects cause elongation of developing embryos: this phenotype can be quantitatively assayed as a readout of mutation strength, raising interesting questions regarding the relationship between pathway activation and disease. Additionally, the observation that RAS signaling may be simultaneously hyperactive and attenuated suggests that downregulation of signaling may also contribute to etiology. We propose that models should be characterized using a standardized approach to allow easier comparison between models, and a better understanding of the interplay between mutation and disease presentation.
Colorimetric sensing of iodide ions based on unmodified gold nanoparticles and the distinctive antiaggregation‐to‐aggregation process
Authors: Sun Xiaoxiao , Zhao Yuqi , Cui Xiaoqian , Liu Ruxin , Yu Miao , Fei Qiang , Liu Qingwen , Feng Guodong , Shan Hongyan , Huan Yanfu
Published: June 2020

A highly sensitive and selective colorimetric analysis method based on unmodified gold nanoparticles (AuNPs) to detect iodide ions (I−) in solution in the presence of hexadecyl trimethyl ammonium bromide (CTAB) and mercury ions (Hg2+) has been successfully developed. Hg2+ could form a gold amalgam with AuNPs to protect AuNPs from CTAB‐induced aggregation caused by the electrostatic attraction between CTAB and citrate ion‐covered AuNPs. When a mixture of Hg2+ and I− was added to the solution of AuNPs, the formation of the HgI2 complex destroyed the protection of Hg2+ for AuNPs, which led to the aggregation of AuNPs accompanied with the change in colour of the solution from red to grey black and decrease in the absorbance of AuNPs at 520 nm. There was a good linear relationship between A520nm and I− concentration from 0 to 800 nM with a low limit of detection (LOD) of 4.2 nM. Furthermore, this simple and reliable colorimetric sensor has been applied successfully to the detection of I− in practical samples.
Nanozyme‐based luminescence detection
Authors: Zhang Jinyi , Liu Juewen
Published: June 2020

Nanozymes refer to nanomaterial‐based enzyme mimics. Most nanozyme assays use chromogenic molecules as substrates that can produce an absorbance change in the visible region upon reaction. For certain applications, such as imaging, fluorescence and luminescence signals are required. Fluorescence detection is also advantageous for sensor development due to its low background signal and high sensitivity. A few substrates, such as Amplex Red and luminol, allow luminescence generation with many oxidative nanozymes. In addition, these substrates can work at neutral pH, useful for intracellular applications. In this review, we summarize luminescence signalling‐based nanozyme systems. We begin with the properties of commonly used substrates. A few specific nanozymes are highlighted, including metal nanoparticles, metal oxide nanomaterials, carbon‐based nanomaterials, and metal–organic frameworks. Finally, a few future research opportunities are discussed.
Modulatoren der Kanalfunktion
Authors: Düesberg Uta , Bend Jutta , Smaczny Christina
Published: June 2020

Diagnose und Therapie der Mukoviszidose sind in den letzten Jahren revolutioniert worden. Mit dem Neugeborenenscreening ist nun eine frühe Diagnose möglich, und die Behandlung mit CFTR‐Modulatoren bekämpft die Erbkrankheit am Basisdefekt. Bei einem frühen Einsatz könnten viele irreversible Schädigungen vermieden und Lebensqualität und Krankheitslast der Patienten deutlich reduziert werden. Laut dem Deutschen Mukoviszidose‐Register hat ein heute geborenes Kind mit Mukoviszidose eine durchschnittliche Lebenserwartung von 53 Jahren [2]. Schon heute gibt es mehr erwachsene Patienten als Kinder mit Mukoviszidose, die vor gar nicht allzu langer Zeit noch als reine Kinderkrankheit galt. Dieser Wandel führt aber auch zu Problemen in der Versorgung, denn die Strukturen im Gesundheitssystem halten nicht Schritt. Viele der erwachsenen Patienten müssen an Kinderkliniken behandelt werden, denn es gibt viel zu wenige Einrichtungen, die auf die Behandlung erwachsener Patienten spezialisiert sind. Hier gibt es bei aller Freude über den Fortschritt noch viele Herausforderungen. Auch der Dokumentation von Langzeitwirkungen der neuen Medikamente kommt eine große Bedeutung zu. Und schließlich dürfen die Patienten (ca. 10 %) nicht vergessen werden, die so seltene Mutationen des CFTR tragen, dass für sie derzeit noch keine der zugelassenen Therapien in Frage kommt. Hier könnte ein personalisierter Ansatz mittels Organoiden greifen, der mit dem HitCF‐Projekt bereits untersucht wird.
Experimente mit Gummibärchen
Authors: Sommer Isabell , Adrian Till , Katzarow‐Hermanns Maaike , Wiesmüller Christian
Published: June 2020

Mit Gelatine in Form von Gummibärchen lassen sich durch einfache Experimente leicht die Unterschiede zu pflanzlichen Geliermitteln aufzeigen. Wie man diese Gummibärchen darüber hinaus zur Herstellung von nachhaltigen Etiketten nutzen kann, wird in diesem Beitrag gezeigt. Die dargestellten Experimente und Anleitungen sind Bestandteil eines Koffers mit Unterrichtsmaterialien für die Durchführung einer Projektwoche an Schulen mit dem Thema Nachhaltigkeit.
Die Haustaube: Friedenssymbol und Aufklärer
Authors: Eitner Pascal
Published: June 2020

In vielen Kulturen steht sie für Frieden, Freiheit, Liebe und Treue, aber die Taube war für den Menschen auch ‘mal Delikatesse, ‘mal fliegender Bote oder Spionagemittel. Für die Wissenschaft ist die Haustaube ein Modellorganismus zur Erforschung des Magnetsinns bei Vögeln, während für Privatleute das Vergnügen an Flugwettbewerben im Vordergrund steht.
Trousseau syndrome with intrahepatic cholangiocarcinoma that could be removed radically after endovascular treatment: Report of a case
Authors: Murahashi Shuei , Takeuchi Yosuke , Hayashida Shintaro , Ohya Yuki , Shindo Seigo , Terasaki Tadashi , Inomata Yukihiro , Hara Yasuyuki
Published: June 2020

Background

Trousseau syndrome is a poor prognosis. We report a case of Trousseau syndrome treated by radical resection after endovascular treatment.

Case

A 59‐year‐old woman presented to our department reporting spontaneous dizziness and pain of the upper abdomen. Magnetic resolution imaging (MRI) showed shower embolization of Brain. Contrast‐enhanced computer tomography (CT) showed renal infarction and splenic infarction, and a tumor was observed in the retrohepatic area. On day 9, sudden right side joint prejudice, neglect of left half space, and left hemiplegia were observed. MRI revealed obstruction of the right middle cerebral artery (MCA) perfusion zone. On the same day, endovascular treatment was performed and reperfusion was obtained. We decided on a radical surgery policy because there were a primary lesion and a high risk of new embolism, and no metastasis was seen.

Discussion

Trousseau syndrome generally has a poor prognosis, but active treatment should be considered as an option when we can expect the recovery of function.
Altered activation in sensorimotor network after applying rTMS over the primary motor cortex at different frequencies
Authors: Wang Xiaoyu , Li Lingyu , Wei Wei , Zhu Tingting , Huang Guo‐Feng , Li Xue , Ma Hui‐Bin , Lv Yating
Published: June 2020

Introduction

Repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex (M1) can modulate brain activity both in the stimulated site and remote brain areas of the sensorimotor network. However, the modulatory effects of rTMS at different frequencies remain unclear. Here, we employed finger‐tapping task‐based fMRI to investigate alterations in activation of the sensorimotor network after the application of rTMS over the left M1 at different frequencies.

Materials and Methods

Forty‐five right‐handed healthy participants were randomly divided into three groups by rTMS frequency (HF, high‐frequency, 3 Hz; LF, low‐frequency, 1 Hz; and SHAM) and underwent two task‐fMRI sessions (RH, finger‐tapping with right index finger; LH, finger‐tapping with left index finger) before and after applying rTMS over the left M1. We defined regions of interest (ROIs) in the sensorimotor network based on group‐level activation maps (pre‐rTMS) from RH and LH tasks and calculated the percentage signal change (PSC) for each ROI. We then assessed the differences of PSC within HF or LF groups and between groups.

Results

Application of rTMS at different frequencies resulted in a change in activation of several areas of the sensorimotor network. We observed the increased PSC in M1 after high‐frequency stimulation, while we detected the reduced PSC in the primary sensory cortex (S1), ventral premotor cortex (PMv), supplementary motor cortex (SMA), and putamen after low‐frequency stimulation. Moreover, the PSC in the SMA, dorsal premotor cortex (PMd), and putamen in the HF group was higher than in the LF group after stimulation.

Conclusion

Our findings suggested that activation alterations within sensorimotor network are dependent on the frequency of rTMS. Therefore, our findings contribute to understanding the effects of rTMS on brain activation in healthy individuals and ultimately may further help to suggest mechanisms of how rTMS could be employed as a therapeutic tool.
“Seat of the soul”? The structure and function of the pineal gland in women with alleged spirit possession—Results of two experimental studies
Authors: Bastos Marco Aurélio Vinhosa , Bastos Paulo Roberto Haidamus de Oliveira , e Paez Loyná Euá Flores , de Souza Edna Oliveira , Bogo Danielle , Perdomo Renata Trentin , Portella Renata Boschi , Ozaki Jorge Guilherme Okanobo , Iandoli Décio , Lucchetti Giancarlo
Published: June 2020

Background

Cultural traditions attribute to pineal gland an important role for spiritual experiences. Mediumship and spirit possession are cultural phenomena found worldwide which have been described as having dissociative and psychotic‐like characteristics, but with nonpathological aspects. A sympathetic activation pattern in response to spirit possession has been reported in some studies, but empirical data on pineal gland is scarce in this context.

Methods

We aimed to investigate pineal gland and pituitary volumes, as well as urinary 6‐sulfatoxymelatonin levels in 16 alleged mediums (Medium Group‐MG) compared with 16 healthy nonmedium controls (Control Group) (Experiment 1). Furthermore, we aimed to evaluate urinary 6‐sulfatoxymelatonin and stress reactivity in GM (n = 10) under different physiological conditions (Experiment 2).

Results

In Experiment 1, MG presented higher scores of anomalous experiences, but there were no between‐group differences regarding mental health or subjective sleep quality. Similar pineal gland and pituitary volumes were observed between groups. There were no between‐group differences in urinary 6‐sulfatoxymelatonin collected under equivalent baseline conditions. In Experiment 2, the rise of anxiety and heart rate in response to mediumistic experience was intermediate between a nonstressful control task (reading) and a stressful control task (Trier Social Stress Test—TSST). No significant differences were observed in 6‐sulfatoxymelatonin urinary levels between the three conditions. The pattern of stress reactivity during the TSST was normal, but with an attenuated salivary cortisol response.

Conclusion

The normal neuroimaging and stress reactivity findings in MG contrast with the abnormal results usually observed in subjects with psychotic and dissociative disorders.
Dynamic visual cortical connectivity analysis based on functional magnetic resonance imaging
Authors: Zhao Le , Zeng Weiming , Shi Yuhu , Nie Weifang , Yang Jiajun
Published: June 2020

Background

Studies of brain functional connectivity (FC) and effective connectivity (EC) using the functional magnetic resonance imaging (fMRI) have advanced our understanding of functional organization on visual cortex of human brain. The current studies mainly focus on static or dynamic connectivity, while the relationships between them have not been well characterized especially for static EC (sEC) and dynamic EC (dEC), as well as the consistency characteristics of changing trend of dFCs and dECs, which is of great importance to reveal the neural information processing mechanism in visual cortex region.

Method

In this study, we explore these relationships among several subareas of human visual cortex (V1–V5) by calculating the connection intensity and information flow among them over time by sliding window method, which are defined by Pearson correlation coefficient and Granger causality analysis, respectively, in each window.

Results

The results demonstrate that there are extensive connections existing in human visual network, which are time‐varying both in resting and task‐related states. sFC intensity is negatively correlated with the variance of dFC, while sEC intensity is positively correlated with the variance of dEC. Furthermore, we also find that dFC within visual cortex at rest shows more consistency, while dEC shows less compared with task state in changing trend.

Conclusion

Therefore, this study provides novel findings about dynamics of connectivity in human visual cortex from the perspective of functional and effective connectivity.
Eco‐innovation motivations and ecodesign tool implementation in companies in the Nordic textile and information technology sectors
Authors: Salo Hanna H. , Suikkanen Johanna , Nissinen Ari
Published: June 2020

The current sustainability challenges and the required systemic transformation highlight the need for innovations on multiple levels. Ecodesign integrates environmental aspects into product and process design to reduce environmental impacts, whereas eco‐innovation also concerns nontechnological solutions. In this paper, we formulate a model that combines eco‐innovation targets ad mechanisms with sustainability maturity, which also concerns stimuli and barriers faced by companies and ecodesign tools used. The results are based on a questionnaire sent to 902 textile and information technology (IT) companies (N = 104) in the Nordic countries. The tools that Nordic textile and IT companies use in particular are life cycle assessment, type I ecolabel, and carbon footprint. Internal stimuli, especially general willingness, were important for eco‐innovativeness, while legislation and customer demand also pushed companies forward. Specific no‐go barriers were not identified, although increase in costs was a common barrier. The respondents focus often on technological product innovations, but rarely on functional innovation, renting of products, and so forth. This highlights the need to address the availability of the right kind of tools to support a broader suite of innovation that can drive toward the circular economy.
Stabilization of immobilized l‐arabinose isomerase for the production of d‐tagatose from d‐galactose
Authors: Bortone Nadia , Fidaleo Marcello
Published: June 2020

The aim of this work was to develop a stable immobilized enzyme biocatalyst for the isomerization of d‐galactose to d‐tagatose at high temperature. l‐Arabinose isomerase from the hyperthermophilic bacterium Thermotoga maritima (TMAI) was produced as a (His)6‐tagged protein, immobilized on a copper–chelate epoxy support and subjected to several postimmobilization treatments aimed at increasing its operational and structural stability. Treatment with glutaraldehyde and ethylenediamine resulted in a more than twofold increase in the operational stability and in all enzyme subunits linked, directly or indirectly, to the support via covalent bonds. A postimmobilization treatment of the immobilized derivatives with mercaptoethanol for the removal of any remaining copper ions, determined a further increase of the operational biocatalytic activity. Immobilized derivatives subjected to both treatments were used for the bioconversion of 18 g/L d‐galactose to d‐tagatose at 80°C in a packed bed reactor in three repeated cycles and showed a better operational stability compared with the literature data. This study shows that a postimmobilization stabilization treatment with glutaraldehyde and ethylenediamine can stabilize the multi‐subunit structure of an enzyme immobilized on a metal‐chelate epoxy support with an increase of its operational stability, results that are not easily achievable with the sole immobilization on epoxy or metal chelate‐epoxy supports in the case of complex multimeric enzymes with geometric incongruence with the support.
An analysis of the professional preferences and choices of computer engineering students
Authors: Kabakus Abdullah Talha , Senturk Arafat
Published: June 2020

The revelation of the preferences and choices of students is critical for understanding which areas of the discipline they aim. Especially for final‐year undergraduate students, job prospects are an important concern. In this study, the graduation project choices of the final‐year undergraduate students in the department of computer engineering were investigated in light of their impact on both the industry and academia. A total of 1,693 course grades of 94 final‐year undergraduate students were retrieved from the Student Information System. These course grades were utilized as the features of the employed machine learning algorithms alongside the features that were deduced from them. In addition, the popularities of the graduation project topics on both GitHub and IEEE were investigated to reveal their impact on the industry and academia. To this end, we proposed an experimental study, using 14 machine learning techniques, that predicts the topics of the graduation projects that the final‐year undergraduate students chose. According to the experimental results, the accuracy of the proposed model was calculated to be as high as when it was utilized with the Bayes Net, Kleene Star, or J48 algorithm. This experimental result confirms the efficiency of the proposed model. Finally, the insights gained from the data are discussed to shed light on the reasons for the choices of the graduation projects as well as their relationships with the courses.
LncRNA‐XIST promotes the oxidative stress‐induced migration, invasion, and epithelial‐to‐mesenchymal transition of osteosarcoma cancer cells through miR‐153‐SNAI1 axis
Authors: Wen Ji‐Feng , Jiang Yong‐Qing , Li Chao , Dai Xian‐Kui , Wu Tong , Yin Wen‐Zhe
Published: June 2020

Osteosarcoma (OS) is the most common type of primary bone tumor that exhibits invasive growth and long‐distance organ metastasis. Thus, investigating the specifically targeted therapeutic agents against metastatic osteosarcoma depends on understanding the molecular mechanisms. The long noncoding RNAs (lncRNA) XIST (X‐inactive specific transcript) has been reported to have oncogenic roles in various malignant tumors including OS. However, its molecular mechanisms in OS migration and invasion are still under investigation. In the current study, we demonstrate that XIST is significantly upregulated in 30 pairs of OS tissues compared with their matched adjacent nontumor tissues by the quantitative reverse transcription polymerase chain reaction. Overexpression of XIST significantly induced the invasion, migration, and the epithelial‐to‐mesenchymal transition (EMT) phenotype. The epithelial marker, E‐cadherin was effectively suppressed by XIST overexpression. On the other way, the mesenchymal marker, Fibronectin, Snail, and Vimentin were significantly activated by exogenous XIST overexpression. Furthermore, we observed XIST was upregulated by the oxidative stress‐induced EMT. Bioinformatical analysis indicated that miR‐153 has multiple biding sites for XIST and miR‐153 was inversely suppressed by oxidative stress. XIST was verified to directly downregulate miR‐153 via sponging. We identified the mesenchymal marker, SNAI1 was a direct messenger RNA target of miR‐153. Importantly, inhibiting XIST successfully blocked the H2O2‐induced EMT of OS cells. In conclusion, this work demonstrates that lncRNA‐XIST promotes the oxidative stress‐induced OS cell invasion, migration, and EMT through the miR‐153/SNAI1 pathway, presenting lncRNA‐XIST as a promising therapeutic target for treating metastatic OS.
Effect of storage, initial grain moisture, and fumigation on rheological quality of wheat stored in hot steppe climate
Authors: Akhlaq Muhammad , Ali Shinawar Waseem
Published: June 2020

Background and objectives

As a seasonal crop, the government (Pakistan) and the milling industry purchase and store a reasonable quantity of wheat (T. aestivum) annually. After filling in jute/polypropylene bags, the major portion of this wheat is stacked in a room type warehouse under uncontrolled conditions. The aim of this study was to find the impact of the storage period, initial grain moisture, annual temperature variations, relative humidity, and fumigation on rheological changes in wheat stored in a hot steppe climate using the latest approach (mixolab).

Findings

During this study, the gluten index (GI) (72.4%–97.1%) and falling number (FN) (455–593.1 s) values increased for most of the storage months and showed a strong negative temperature correlation. Significant variability was also noted during the storage period in mixolab behavior and a strong correlation was found with the storage temperature. The starch gelatinization (C3) (1.824–2.063 Nm) and C3‐C2 (1.320–1.583 Nm) increased, while retrogradation (C5) (2.833–2.506 Nm) and cooling setback (C5‐C4) (1.265–0.840 Nm) decreased over most of the month. Pasting properties (C4) showed a mixed pattern during storage (1.7965–1.536 Nm). The GI and FN were positively correlated with C3 and C3‐C2, and negatively correlated with C5‐C4. Fumigation showed significant effect on GI and FN of the grains, while the initial grain moisture (<11%) showed non‐significant impact on most of the rheological characteristics during storage.

Conclusions

Most of the rheological characteristics of wheat (GI, FN, and mixolab) changed significantly during the storage period, while the fumigation and initial grain moisture did not show any significant impact.

Significance and novelty

The quality characteristics of stored wheat vary depending on the geographical region. For millers, it will be important to understand these variations to produce a consistent quality flour.
Giant anal warts
Authors: Mulita Francesk , Tavlas Panagiotis , Iliopoulos Evangelos , Maroulis Ioannis
Published: June 2020

Anal lesions can occur due to infectious and neoplastic etiology, and a prompt and multidisciplinary approach may prevent poor outcomes.
High Voltage Stability and Characterization of P2‐Na0.66Mn1‐yMgyO2 Cathode for Sodium‐Ion Batteries
Authors: Or Tyler , Kaliyappan Karthikeyan , Bai Zhengyu , Chen Zhongwei
Published: June 2020

The development of sodium‐ion batteries is currently limited by the availability of high‐energy and low‐cost cathode materials. The energy density of cathodes can be maximized by expanding the voltage range for cycling, but this often leads to severe capacity degradation. Cathodes that demonstrate good long‐term cyclability at high voltage cut‐offs (>4.3 V vs Na/Na+) are scarce in the literature. In this work, layered P2‐Na0.66Mn1‐yMgyO2 was synthesized by using a modified Pechini method at various compositions (y=0, 0.05, 0.1) and characterized after extended cycling between 2–4.5, 4.6, and 4.7 V vs. Na/Na+. Na0.66Mn0.95Mg0.05O2 displayed a similar initial discharge capacity to Na0.66MnO2 with significant improvements in cycle retention. It was most promising when cycled between 2 and 4.5 V, retaining 140 mAh g−1 (82 % retention) and 116 mAh g−1 (68 % retention) after 50 and 100 cycles, respectively, at low current (40 mA g−1). A higher Mg dopant quantity led to improvements in cyclability and rate performance albeit with lower initial discharge capacity. Electrochemical and physical (ex situ XRD) characterizations were used to delineate the role of high‐voltage phase transitions, SEI layer formation, electrolyte solvent insertion into sodium slabs, and active material degradation/dissolution toward capacity loss.
Anion‐Immobilized and Fiber‐Reinforced Hybrid Polymer Electrolyte for Advanced Lithium‐Metal Batteries
Authors: Wang Zhitao , Zhou Hu , Meng Chunfeng , Zhang Lu , Cai Yueji , Yuan Aihua
Published: June 2020

3D‐skeleton‐reinforced hybrid polymer electrolytes (HPEs) are conducive to improving the electrochemical performance and mechanical strength, but their preparation methods are usually tedious and inappropriate for practical application. The simplification of the preparation process and the further optimization of 3D skeletons are urgent to develop high‐performance solid‐state batteries. In this work, glass fiber (GF) decorated with ZIF‐67 (GF@ZIF‐67) was originally selected as 3D skeleton to construct an anion‐immobilized and fiber‐reinforced polyethylene oxide (PEO)‐based HPE (GF@ZIF@PEO). The presence of GF@ZIF‐67 3D skeleton can enhance the mechanical strength, whereas Lewis‐acidic metal sites of ZIF‐67 can immobilize free anions of the polymer matrix, accelerating ion migration and facilitating long‐term cycling stability. Consequently, the assembled LiFePO4/Li solid‐state batteries delivered a reversible capacity of 132 mAh g−1 with the capacity retention of 92 % at 1 C after 200 cycles. Our universal approach paves the way for advanced solid‐state electrolytes.
The Diversity of a Polyclonal FluCell‐SELEX Library Outperforms Individual Aptamers as Emerging Diagnostic Tools for the Identification of Carbapenem Resistant Pseudomonas aeruginosa
Authors: Kubiczek Dennis , Raber Heinz , Bodenberger Nicholas , Oswald Thomas , Sahan Melis , Mayer Daniel , Wiese Sebastian , Stenger Steffen , Weil Tanja , Rosenau Frank
Published: June 2020

Textbook procedures require the use of individual aptamers enriched in SELEX libraries which are subsequently chemically synthesized after their biochemical characterization. Here we show that this reduction of the available sequence space of large libraries and thus the diversity of binding molecules reduces the labelling efficiency and fidelity of selected single aptamers towards different strains of the human pathogen Pseudomonas aeruginosa compared to a polyclonal aptamer library enriched by a whole‐cell‐SELEX involving fluorescent aptamers. The library outperformed single aptamers in reliable and specific targeting of different clinically relevant strains, allowed to inhibit virulence associated cellular functions and identification of bound cell surface targets by aptamer based affinity purification and mass spectrometry. The stunning ease of this FluCell‐SELEX and the convincing performance of the P. aeruginosa specific library may pave the way towards generally new and efficient diagnostic techniques based on polyclonal aptamer libraries not only in clinical microbiology.
Fluorinated PLGA Nanoparticles for Enhanced Drug Encapsulation and 19F NMR Detection
Authors: Neri Giulia , Mion Giuliana , Pizzi Andrea , Celentano Wanda , Chaabane Linda , Chierotti Michele R. , Gobetto Roberto , Li Min , Messa Piergiorgio , De Campo Floryan , Cellesi Francesco , Metrangolo Pierangelo , Baldelli Bombelli Francesca
Published: June 2020

In the continuous search for multimodal systems with combined diagnostic and therapeutic functions, several efforts have been made to develop multifunctional drug delivery systems. In this work, through a covalent approach, a new class of fluorinated poly(lactic‐co‐glycolic acid) co‐polymers (F‐PLGA) were designed that contain an increasing number of magnetically equivalent fluorine atoms. In particular, two novel compounds, F3‐PLGA and F9‐PLGA, were synthesized and their chemical structure and thermal stability were analyzed by solution NMR, DSC, and TGA. The obtained F‐PLGA compounds were proven to form in aqueous solution colloidal stable nanoparticles (NPs) displaying a strong 19F NMR signal. The fluorinated NPs also showed an enhanced ability to load hydrophobic drugs containing fluorine atoms compared to analogous pristine PLGA NPs. Preliminary in vitro studies showed high cell viability and the NP ability to intracellularly deliver and release a functioning drug.
Enantioseparation of citalopram enantiomers by capillary electrophoresis: Method development through experimental design and computational modeling
Authors: Budău Monica , Hancu Gabriel , Muntean Daniela Lucia , Papp Lajos Attila , Cârje Anca Gabriela , Garaj Vladimir
Published: June 2020

Citalopram (CIT) is a frequently used modern antidepressant that inhibits selectively serotonin reuptake in the brain. It has a chiral center in its structure and is used in therapy as both racemic mixture and pure enantiomer as its pharmacological effect is almost entirely associated with S‐CIT. The aim of this study was the development of a simple and rapid capillary electrophoresis (CE) method for the separation and quantification of CIT enantiomers. To establish the optimum chiral selector, several native and derivatized, neutral, and ionized cyclodextrins (CDs) were examined at different pH levels. An experimental design strategy was adopted for method optimization; a fractional factorial design was applied for screening purposes to identify significant experimental factors followed by a face‐centered central composite design used for optimization purposes. Computational modeling was used to obtain information on the interaction energy and the geometry of the complexes to aid in the understanding of chiral separation mechanism. The best results were obtained when using a 25‐mM phosphate buffer at pH 7.0, 3‐mM CM‐β‐CD as chiral selector, 17.5°C temperature, 15‐kV voltage, and 50 mbar/s hydrodynamic injection. The separation time was fast, below 3 min, and the migration order was S‐CIT followed by R‐CIT. The analytical performance of the method was verified in terms of precision, linearity, accuracy, sensibility, and robustness, and the method was applied for the determination of CIT enantiomers from pharmaceutical preparations.
Mancher Zimt kann auf die Leber schlagen
Authors: Emden Markus , Hild Pitt , Kallinna Kirsten , Murer Livia
Published: June 2020

Anliegen der in loser Folge erscheinenden Versuche ist es, Impulse für chemische Versuche zu geben, die gefahrlos zu Hause mit haushaltsüblichen Gegenständen durchgeführt werden können. Sie können damit als Quelle für das gemeinsame Ausprobieren mit Kindern zuhause dienen, in Kindergärten oder an Schulen sowie zur Verwendung bei Tagen der offenen Tür. Ein Stückweit sind sie zu verstehen als Antwort auf den oft gehörten Satz: „Ach, Du bist Chemiker/in!? Dann mach doch mal eben ein Experiment.“
Development of dissolved carbon dioxide‐driven‐and‐controlled repeated batch fermentation process for ethanol production
Authors: Feng Sijing , Lin Yen‐Han
Published: June 2020

We previously observed that as glucose is completely exhausted during ethanol fermentation, the dissolved carbon dioxide (DCO2) level in the fermenter will suddenly decline. This observation was implemented to design and develop a DCO2‐driven‐and‐controlled repeated batch fermentation process for ethanol production. The process was tested at four different glucose concentrations (~150 g/L, ~200 g/L, ~250 g/L, and ~300 g/L), and each glucose concentration was controlled under three respective DCO2 control levels (without DCO2 control, and DCO2 controlled at either 1000 mg/L or 750 mg/L). The results show that reported process features complete glucose utilization and is self‐driven. For glucose concentration less than 200 g/L, ~41%‐50% of fermentation time per batch was saved during the repeated batch operation. It took 12.1 ± 1.1 hours‐14.9 ± 1.9 hours to complete a batch with glucose feed at ~250 g/L and 21.7 ± 6 hours‐31.5 ± 7 hours to complete a batch with glucose feed at ~300 g/L. The reported process is time saving and stable, but the ethanol yield is ~20% lower than the operation without DCO2 control. Dissolved CO2 control became essential for glucose concentrations greater than 250 g/L if zero glucose discharge in each batch during the operation is desired.
Copper‐Catalyzed Modular Access to N‐Fused Polycyclic Indoles and 5‐Aroyl‐pyrrol‐2‐ones via Intramolecular N—H/C—H Annulation with Alkynes: Scope and Mechanism Probes
Authors: Liu Yan‐Hua , Song Hong , Zhang Chi , Liu Yue‐Jin , Shi Bing‐Feng
Published: June 2020

Summary of main observation and conclusion

Copper‐catalyzed intramolecular N—H/C—H annulation with alkynes has been developed. A variety of densely functionalized heterocycles, such as pyrrolo[1,2‐a]indoles, indolo[1,2‐c]quinazolin‐2‐ones, oxazolo[3,4‐a]indoles, and imidazo[1,5‐a]indoles, were synthesized in an atom‐ and step‐economical manner, owing to the high modularized feature of aniline moiety, the linker moiety, as well as the alkyne moiety. By simply changing the oxidant from di‐tert‐butyl peroxide (DTBP) to 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO), the reaction could readily be transformed to the aminooxygenation pathway, which grabs one oxygen atom from the TEMPO to generate 5‐aroyl‐pyrrol‐2‐ones. Mechanistic experiments indicate that vinyl radical is involved in this reaction and an amidyl‐radical‐initiated radical cascade might be responsible for this transformation.
Homogeneous Catalytic Ozonation of Lipids Involving Fe2+ and Mn2+: An Experimental and Modeling Study
Authors: Ramos Rúbia Martins Bernardes , Biz Ana Paula , Tavares Deolinda Alvarez , Kolicheski Mônica Beatriz , Dantas Tirzhá Lins Porto
Published: June 2020

Given the issue of lipids in effluent treatment systems and their negative impact on the environment, this study aimed to examine lipid degradation by homogenous catalytic ozonation with the aid of iron and manganese ions. This technology presents the possibility of completely mineralizing pollutants using hydroxyl radicals. Milk is chosen as the lipid source because of the high concentration of triglycerides in its matrix, this kind of lipid being the one found most frequently in food and, consequently, in effluent treatment systems. The milk pH value is controlled, and acidic, neutral, and basic conditions are evaluated. The rates of pseudo‐first‐order reactions and the effective value are estimated. It is shown that under acidic conditions low catalyst dosages are enough to cause the complete degradation of lipids. Under neutral conditions, a similar behavior is observed. Under basic conditions, higher catalyst dosages give higher reaction rates. The order of effectiveness of the catalysts under acidic and basic conditions is Fe2+ > Mn2+, with Mn2+ > Fe2+ under neutral conditions. Homogeneous catalytic ozonation is therefore efficient at lipid degradation. This technique is viable economically, since the lipid removal occurred at low ozone levels. In addition, the ions used as catalysts are naturally abundant.
Impact of the adapted white point and the cultural background on memory color assessments
Authors: Babilon Sebastian , Khanh Tran Quoc
Published: June 2020

With their inherent ability of serving as an internal reference, memory colors provide a very powerful concept in the evaluation of color rendering properties of white light sources with respect to visual appreciation. Recent results for example suggest fairly good correlations between memory‐based color quality metrics and the observers' general color preferences. However, due to technical limitations in the design of the underlying psychophysical experiments, they generally lack the explicit inclusion of realistic viewing and adaptation conditions, which is supposed to have a nonnegligible impact on the model prediction performance. In addition, intercultural effects might play a crucial role in the context of memory colors. For these reasons, the current article investigates the impact of both the adapted white point and the observers' cultural background on memory color assessments in order to contribute to a better understanding of these dependencies and their interactions. For this purpose, the color appearance rating results of Chinese and German observers were collected for a selection of 12 different familiar test objects assessed under two different adaptation conditions at 3200 K and 5600 K, respectively. From the statistical analysis of the experimental data, it is shown, in accordance to previous studies, that the impact of the observed intercultural deviations is likely to be of no practical importance even though significance is found. Despite considerably larger effect sizes, the same must be concluded for the two tested adaptation conditions.
A verifiable ranked ciphertext retrieval scheme based on bilinear mapping
Authors: Huang Baohua , Huang Pirong , Yuan Hong , Liang Sheng
Published: June 2020

It is prevalent nowadays for data owners to outsource their data to the cloud. Most of the traditional searchable schemes are proposed under the honest and curious model, lacking verification of integrity and correctness of the retrieval results. Because the cloud server is not completely trustworthy and there may be improper execution of the users' retrieval requests, it is necessary to verify the retrieval results returned by the cloud server. In order to address these issues, we propose a verifiable ranked ciphertext retrieval scheme (VRCRS) based on bilinear mapping. For the purpose of ranking the keywords and improving the security of ciphertext retrieval scheme, we utilize the lucene search engine toolkit to score keywords, and improve the traditional inverted index structure for building a secure inverted index structure. By adding dummy words into the dictionary of keywords, the proposed scheme can resist the keywords statistics attack of malicious server. To ensure the correctness and integrity of returned ciphertext, we apply bilinear mapping to generate validation tags for keywords. The theoretical analysis and experimental results show that the proposed scheme is secure and efficient. VRCRS can actually identify the illegal behavior of cloud server such as tampering and forgery.
Dengue Fever, COVID‐19 (SARS‐CoV‐2), and Antibody‐Dependent Enhancement (ADE): A Perspective
Authors: Ulrich Henning , Pillat Micheli M. , Tárnok Attila
Published: June 2020

SARS‐CoV‐2 pandemic and recurrent dengue epidemics in tropical countries have turned into a global health threat. While both virus‐caused infections may only reveal light symptoms, they can also cause severe diseases. Here, we review the possible antibody‐dependent enhancement (ADE) occurrence, known for dengue infections, when there is a second infection with a different virus strain. Consequently, preexisting antibodies do not neutralize infection, but enhance it, possibly by triggering Fcγ receptor‐mediated virus uptake. No clinical data exist indicating such mechanism for SARS‐CoV‐2, but previous coronavirus infections or infection of SARS‐CoV‐2 convalescent with different SARS‐CoV‐2 strains could promote ADE, as experimentally shown for antibodies against the MERS‐CoV or SARS‐CoV spike S protein. © 2020 International Society for Advancement of Cytometry
Thymus aging in mice deficient in either EphB2 or EphB3, two master regulators of thymic epithelium development
Authors: García‐Ceca Javier , Montero‐Herradón Sara , Zapata Agustín G.
Published: June 2020

Background

The epithelial microenvironment is involved in thymus aging, but the possible role of EphB receptors that govern the thymic epithelium development has not been investigated. Herein, we study the changes undergone by the thymus of EphB‐deficient mice throughout their life.

Results

Immune alterations occurring throughout life were more severe in mutant than in wild‐type (WT) mice. Mutant thymuses exhibit lower cellularity than WT ones, as well as lower proportions of early thymic progenitors cells and double‐positive (CD4+CD8+) thymocytes, but higher of double‐negative (CD4−CD8−) and single‐positive (CD4+CD8−, CD4−CD8+) cells. Throughout life, CD4+ naïve cells decreased particularly in mutant mice. In correlation, memory T cells, largely CD8+ cells, increased. Aged thymic epithelium undergoes changes including appearance of big epithelial free areas, decrease of K8+K5− areas, which, however, contain higher proportions of Ly51+UEA1− cortical epithelial cells, in correlation with reduced Aire+ medullary epithelial cells. Also, aged thymuses particularly those derived from mutant mice exhibited increased collagen IV, fat‐storing cells, and connective cells.

Conclusions

The absence of EphB accelerates the alterations undergone throughout life by both thymic epithelium and thymocytes, and the proportions of peripheral naïve and memory T cells, all of which are hallmarks of immune aging.
Quantifying natural disturbances using a large‐scale dendrochronological reconstruction to guide forest management
Authors: Čada Vojtěch , Trotsiuk Volodymyr , Janda Pavel , Mikoláš Martin , Bače Radek , Nagel Thomas A. , Morrissey Robert C. , Tepley Alan J. , Vostarek Ondřej , Begović Krešimir , Chaskovskyy Oleh , Dušátko Martin , Kameniar Ondrej , Kozák Daniel , Lábusová Jana , Málek Jakub , Meyer Peter , Pettit Joseph L. , Schurman Jonathan S. , Svobodová Kristýna , Synek Michal , Teodosiu Marius , Ujházy Karol , Svoboda Miroslav
Published: June 2020

Estimates of historical disturbance patterns are essential to guide forest management aimed at ensuring the sustainability of ecosystem functions and biodiversity. However, quantitative estimates of various disturbance characteristics required in management applications are rare in longer‐term historical studies. Thus, our objectives were to (1) quantify past disturbance severity, patch size, and stand proportion disturbed and (2) test for temporal and subregional differences in these characteristics. We developed a comprehensive dendrochronological method to evaluate an approximately two‐century‐long disturbance record in the remaining Central and Eastern European primary mountain spruce forests, where wind and bark beetles are the predominant disturbance agents. We used an unprecedented large‐scale nested design data set of 541 plots located within 44 stands and 6 subregions. To quantify individual disturbance events, we used tree‐ring proxies, which were aggregated at plot and stand levels by smoothing and detecting peaks in their distributions. The spatial aggregation of disturbance events was used to estimate patch sizes. Data exhibited continuous gradients from low‐ to high‐severity and small‐ to large‐size disturbance events. In addition to the importance of small disturbance events, moderate‐scale (25–75% of the stand disturbed, >10 ha patch size) and moderate‐severity (25–75% of canopy disturbed) events were also common. Moderate disturbances represented more than 50% of the total disturbed area and their rotation periods ranged from one to several hundred years, which is within the lifespan of local tree species. Disturbance severities differed among subregions, whereas the stand proportion disturbed varied significantly over time. This indicates partially independent variations among disturbance characteristics. Our quantitative estimates of disturbance severity, patch size, stand proportion disturbed, and associated rotation periods provide rigorous baseline data for future ecological research, decisions within biodiversity conservation, and silviculture intended to maintain native biodiversity and ecosystem functions. These results highlight a need for sufficiently large and adequately connected networks of strict reserves, more complex silvicultural treatments that emulate the natural disturbance spectrum in harvest rotation times, sizes, and intensities, and higher levels of tree and structural legacy retention.
Shifting trophic control of fishery–ecosystem dynamics following biological invasions
Authors: Goto Daisuke , Dunlop Erin S. , Young Joelle D. , Jackson Donald A.
Published: June 2020

Increasing human population size and mobility have accelerated the translocation of nonnative species globally, which has become a major threat to conservation of biodiversity and ecosystem services. Introduced species can disrupt species interactions of the recipient ecosystem, triggering system‐wide events, and amplify or dampen effects of existing pressures. We show how two pervasive intercontinental invasive consumers in North American lakes, dreissenids (filter‐feeding mussels) and Bythotrephes (carnivorous zooplankton), nonlinearly modify consumer–resource dynamics and undermine management interventions to rebuild cold‐water predatory fish biomass. Synthesizing 30 yr (1986–2015) of lake‐wide monitoring data with a dynamic mass‐balance food‐web model (consisting of 61 species and trophic groups), we reconstructed historical food‐web dynamics of Lake Simcoe, a large, temperate lake in Ontario, Canada that has shifted from a turbid to clear‐water state. We then analyzed patterns of biomass fluctuations of three recreationally harvested, ecologically connected populations; lake trout (Salvelinus namaycush, a piscivore), lake whitefish (Coregonus clupeaformis, a benthivore), and cisco (C. artedi, a planktivore) before and after the invasions by testing hypotheses on their delayed recoveries under management interventions–predator manipulations (fishery removal and stocking) and nutrient (phosphorus) load reduction. Analyses suggest that fishery harvest primarily regulated early recovery trajectories of the piscivore and planktivore, weakening top‐down control prior to the establishment of the invasive consumers. By contrast, the benthivore biomass patterns were shaped, in part, by the invasive mussels (via diet shift), independently of management actions. Although improved water quality (with reduced hypoxia in deeper water) and, in turn, higher macrophyte production are projected to expand the predation refuge for young fish, intensified planktivory (by Bythotrephes) and herbivory (by dreissenids) have triggered shifts in community composition (from pelagic to demersal dominance). These system‐wide shifts, in turn, have substantially diminished ecosystem productivity, thereby shrinking fishery yields. Novel consumers can rewire food webs, disrupt energy flows, and suppress predator recoveries, underscoring the need to account for altered ecological reality when sustainably managing fishery resources in invaded ecosystems.