bluuebunny/crossref_metadata_2025 huggingface dataset:
Wnt-Signalwege bei kutaner Wundheilung
Authors: Houschyar K.S. , Tapking C. , Puladi B. , Popp D. , Duscher D. , Rein S. , Reumuth G. , Grieb G. , Branski L.K. , Siemers F. , Lehnhardt M. , Yazdi A.S
Published: November 2019

Die menschliche Haut ist eine effiziente Barriere, die den Organismus vor Noxen schützt. Wunden zerstören diese Barriere. Die Wundheilung ist eine in Phasen ablaufende physiologische Regeneration des zerstörten Gewebes, die im Idealfall zum Verschluss einer Wunde, insbesondere durch Neubildung von Bindegewebe und Kapillaren, führt. Der Wnt-Signalweg ist eine im gesamten Tierreich stark konservierte Signaltransduktionskaskade, durch die grundlegende zelluläre Interaktionen in multizellulären Organismen gesteuert werden. Entsprechend werden durch den Wnt-Signalweg viele Prozesse, z. B. die Balance zwischen Proliferation und Differenzierung oder die Apoptose, koordiniert. Die Wnt-Signalisierung wird durch eine Wunde aktiviert und nimmt an jeder nachfolgenden Phase des Heilungsprozesses teil, beginnend mit der Entzündungskontrolle und des programmierten Zelltods bis zur Mobilisation von Stammzellen innerhalb der Wunde. Die endogene Wnt-Signalverstärkung stellt einen attraktiven therapeutischen Ansatz dar, um die Wiederherstellung von Hautwunden zu unterstützen, da die komplexen Mechanismen des Wnt-Signalwegs im Laufe der Jahre zunehmend verstanden wurden. In dieser Übersichtsarbeit werden die aktuellen Daten zusammengefasst, um die Rolle der Wnt-Signalgebung beim Wundheilungsprozess der Haut zu verdeutlichen.
Tissue-Specific Function of Thyroid Hormone Transporters: New
Insights from Mouse Models
Authors: Salveridou Eva , Mayerl Steffen , Sundaram Sivaraj Mohana , Markova Boyka , Heuer Heike
Published: November 2019

Thyroid hormone (TH) transporters are required for cellular transmembrane
passage of TH and are thus mandatory for proper TH metabolism and action.
Consequently, inactivating mutations in TH transporters such as MCT8 or
OATP1C1 can cause tissue- specific changes in TH homeostasis. As the most
prominent example, patients with MCT8 mutations exhibit elevated serum T3
levels, whereas their CNS appear to be in a TH deficient state. Here, we
will briefly summarize recent studies of mice lacking Mct8 alone or in
combination with the TH transporters Mct10 or Oatp1c1 that shed light on
many aspects and pathogenic events underlying global MCT8 deficiency and
also underscore the contribution of Mct10 and Oatp1c1 in tissue-specific TH
transport processes. Moreover, development of conditional knock-out mice
that allow a cell-specific inactivation of TH transporters in distinct
tissues, disclosed cell-specific changes in TH signaling, thereby
highlighting the pathophysiological significance of local control of TH
action.
Total Synthesis of Endolides A and B
Authors: Liu Langlang , Guo Yian , Liu Qingchao , Ratnayake Ranjala , Luesch Hendrik , Ye Tao
Published: November 2019

The total synthesis of endolides A and B has been achieved in a concise and highly stereoselective fashion (12 steps; 16.2 and 16.0% overall yield, respectively). Key features of the route include a modified Negishi coupling between 3-bromofuran and an organozinc reagent derived from an iodoalanine derivative for the synthesis of a 3-(3-furyl)alanine derivative, and a judicious choice of reaction conditions to overcome the conformational constraints placed by converting a linear peptide into the corresponding macrocycle.
Electrochemically Induced Thiocyanation of Enaminones: Synthesis of Functionalized Alkenes and Chromones
Authors: Yang Zan , Wang Yanhong , Hu Liping , Yu Jiangjing , Li An , Li Lijun , Yang Tao , Zhou Congshan
Published: November 2019

A simple and efficient electrochemically induced thiocyanation of enaminones under undivided electrolytic conditions has been developed. With this protocol, various polyfunctionalized alkenes and chromones could be obtained in good to excellent yields using readily available KSCN as the thiocyanation reagent under catalyst-, oxidant-, and transition-metal-free conditions.
Usability Testing of an Interactive Dashboard for Surgical Quality Improvement in a Large Congenital Heart Center
Authors: Wu Danny T. Y. , Vennemeyer Scott , Brown Kelly , Revalee Jason , Murdock Paul , Salomone Sarah , France Ashton , Clarke-Myers Katherine , Hanke Samuel P.
Published: November 2019

Background Interactive data visualization and dashboards can be an effective way to explore meaningful patterns in large clinical data sets and to inform quality improvement initiatives. However, these interactive dashboards may have usability issues that undermine their effectiveness. These usability issues can be attributed to mismatched mental models between the designers and the users. Unfortunately, very few evaluation studies in visual analytics have specifically examined such mismatches between these two groups.

Objectives We aimed to evaluate the usability of an interactive surgical dashboard and to seek opportunities for improvement. We also aimed to provide empirical evidence to demonstrate the mismatched mental models between the designers and the users of the dashboard.

Methods An interactive dashboard was developed in a large congenital heart center. This dashboard provides real-time, interactive access to clinical outcomes data for the surgical program. A mixed-method, two-phase study was conducted to collect user feedback. A group of designers (N = 3) and a purposeful sample of users (N = 12) were recruited. The qualitative data were analyzed thematically. The dashboards were compared using the System Usability Scale (SUS) and qualitative data.

Results The participating users gave an average SUS score of 82.9 on the new dashboard and 63.5 on the existing dashboard (p = 0.006). The participants achieved high task accuracy when using the new dashboard. The qualitative analysis revealed three opportunities for improvement. The data analysis and triangulation provided empirical evidence to the mismatched mental models.

Conclusion We conducted a mixed-method usability study on an interactive surgical dashboard and identified areas of improvements. Our study design can be an effective and efficient way to evaluate visual analytics systems in health care. We encourage researchers and practitioners to conduct user-centered evaluation and implement education plans to mitigate potential usability challenges and increase user satisfaction and adoption.
Histological-subtypes and anatomical location correlated in meningeal brain tumors (meningiomas)
Authors: Bhat Abdul Rashid , Wani Muhammed Afzal , Kirmani Altaf Rehman , Ramzan Altaf Umar
Published: November 2019

Context: Not enough literature is available to suggest a link between the histological subtypes of intracranial meningeal brain tumors, called ‘meningiomas’ and their location of origin. Aim: The evidence of correlation between the anatomical location of the intracranial meningiomas and the histopathological grades will facilitate specific diagnosis and accurate treatment. Materials and Methods: The retrospective study was conducted in a single high-patient-inflow Neurosurgical Center, under a standard and uniform medical protocol, over a period of 30 years from December 1982 to December 2012. The records of all the operated 729 meningiomas were analyzed from the patient files in the Medical Records Department. The biodata, x-rays, angiography, computed tomography (CT) scans, imaging, histopathological reports, and mortality were evaluated and results drawn. Results: The uncommon histopathological types of meningiomas (16.88%) had common locations of origin in the sphenoid ridge, posterior parafalcine, jugular foramen, peritorcular and intraventricular regions, cerebellopontine angle, and tentorial and petroclival areas. The histopathological World Health Organization (WHO) Grade I (Benign Type) meningiomas were noted in 89.30%, WHO Grade II (Atypical Type) in 5.90%, and WHO Grade III (Malignant Type) in 4.80% of all meningiomas. Meningiomas of 64.60% were found in females, 47.32% were in the age group of 41-50 years, and 3.43% meningiomas were found in children. An overall mortality of 6.04% was noted. WHO Grade III (malignant meningiomas) carried a high mortality (25.71%) and the most common sites of meningiomas with high mortality were: The cerebellopontine angles, intraventricular region, sphenoid ridge, tuberculum sellae, and the posterior parafalcine areas. Conclusion: The correlation between the histological subtypes and the anatomical location of intracranial meningeal brain tumors, called meningiomas, is evident, but further research is required to establish the link.
Hematogenous pasteurella haemolytica brain abscess
Authors: Darmoul Mehdi , Nsir Atef Ben , Kilani Mohamed , Hattab Mohamed Nejib
Published: November 2019

Pasteurella infections are common in domestic animals and very rare in human. We report a hematogenously acquired Pasteurella haemolytica brain abscess, mimicking brain tumor on magnetic resonance imaging, in an 18-year-old female patient known with cardiac interventricular communication, without recent history of animal contact. The outcome was good after abscess complete removal and antimicrobials therapy for 6 weeks. To the best of our knowledge, this is the first reported case of P. haemolytica brain abscess.
Enhancing Asthma Patients' Self-Management through Smartphone-Based Application: Design, Usability Evaluation, and Educational Intervention
Authors: Farzandipour Mehrdad , Nabovati Ehsan , Heidarzadeh Arani Marzieh , Akbari Hossein , Sharif Reihane , Anvari Shima
Published: November 2019

Objective The aim of this study was to design and evaluate a smartphone-based application for improving self-management in patients with asthma and evaluate its effects on their knowledge.

Methods In this applied research, based on the Clinical Practice Guideline and a systematic review, a questionnaire was designed to determine the application information content and functionality requirements by 15 pediatric and adult asthma and allergy specialist. Then the application was designed and developed using Adobe Air software on the Android operating system. Usability evaluation of the mobile application was performed using the standard questionnaire for user interaction satisfaction (QUIS), which completed by 30 patients with asthma, 8 information technology (IT) specialists, and 2 asthma and allergy specialists. Self-management knowledge of 30 asthma patients was measured using a researcher-made questionnaire before and after using the application.

Results The number of specialists in the both Delphi rounds was 15 and the mean work experiences were 17.6 years. The most important elements for asthma self-management were avoiding exposure to allergen and triggers (96%), drug treatment (94.6%), and how to use the therapeutic tools (92.4%), and the most important functionalities were alerting the patients when they did not control asthma (92%), setting reminders for timely drug use (85.4%) and therapeutic tools (82.6%), recording prescription drugs (82.6%), and peak flow meter values (82%). Usability evaluation showed that 30 patients with asthma, 8 IT specialists, and 2 physicians evaluated the application at a “good” level. The mean score of the patients' knowledge before intervention was 2.43 ± 0.95 which after intervention was significantly increased to 4.3 ± 0.56 (p < 0.001).

Conclusion Considering the desirable outcomes of application evaluation and a positive impact of this educational intervention on asthma patients' knowledge, it is possible to use mobile-based self-management programs to help these patients to manage illness and gain knowledge and self-management skills.
Comparison of Wound Complications Between Two Closing Techniques Following Total Hip Arthroplasty Via the Direct Anterior Approach
Authors: Opanova Maria , Hasegawa Ian , Unebasami Emily , Tollefsen Cera-Nicole , Saito Sean , Andrews Samantha , Nakasone Cass
Published: November 2019

A higher rate of wound complications has been reported in the direct anterior approach (DAA) for total hip arthroplasty (THA), reportedly due to the location of the incision and poor surgical site exposure techniques. Therefore, the purpose of this study was to compare wound complications within the first 90 days between a zipper closing method (ZM) and subcuticular monocryl with dermabond skin closure (SMD). A total of 294 patients (352 hips) were closed using the SMD and 166 patients (206 hips) were closed via the ZM. All THAs via the DAA and postoperative care were performed based on the current standard of care for the treatment of symptomatic hip osteoarthritis, established by a single, high volume surgeon from 2016 to 2018. Any wound complications during the first 90 days were noted. Independent t-tests determined differences in descriptive variables. Additionally, a Fisher Exact test was performed to compare wound complication rate between groups (p < 0.05). Surgical time was significantly shorter for ZM (p < 0.001) for both unilateral and bilateral groups compared with SMD. Overall, there were four complications occurring in 558 cases (0.7%), with two cases (0.36%) requiring additional surgery. No wound complications were present in the SMD and four wound complications (1.9%), two requiring surgery, were reported for the ZM (χ2 [1, N = 558] = 6.884, p = 0.009). While no wound complications were reported in the SMD group, the ZM group sustained four wound complications, two of which required additional surgery. Two of these wound complications occurred within the first 14 cases following implementation of the ZM, perhaps indicating a short learning curve. The ZM is a quicker, perhaps easier closure method yet the added expense for materials and suggested increased risk for wound complications may moderate the enthusiasm of the ZM compared with the sutures following THA via the DAA.
A De Novo KCNQ2 Genomic Variant in an Infant with Early Infantile Epileptic Encephalopathy
Authors: Vélez-Galarraga María del Rosario , Coronel Melissa , Vaca Richard , Baquerizo Arianna , Sánchez-Carpintero Rocío
Published: November 2019

Early infantile epileptic encephalopathies (EIEEs) constitute a group of severe early onset epilepsies. Although still classified under syndromic clusters of clinical features, the genetic basis of several EIEEs leads to the definition of new types of epilepsies. We report a newborn male with seizures since his second day of life. The results of the first line diagnostic tests did not identify the cause of the seizures, which prompted a genetic study. A de novo KCNQ2 genomic variant that may explain the neonatal epileptic encephalopathy was found and led to more appropriate treatment. Genetic testing allows more specific treatment and more accurate prognosis, and also adds to the database of the phenotypes associated with the genomic variants.
People Who Once Had 40 Cattle Are Left Only with Fences: Coping with Persistent Drought in Awash, Ethiopia
Authors: Camfield Laura , Leavy Jen , Endale Senait , Tefera Tilahun
Published: November 2019

How to support those responding to environmental change in resource-constrained environments is central to literature on climate change adaption. Our research explores a gap in this literature relating to the negotiation of intra-household relations and resource access across different types of household in contexts of social and environmental transition. Using the example of the semi-arid Awash region in North-Eastern Ethiopia, which has experienced drought and alien plant invasion over the past decade, we explore how men and women use changes in household structures and relationships to adapt more effectively. We draw evidence from life histories with 35 pastoralists across three rural, peri-urban and urban communities. Using Dorward et al.’s taxonomy, we find Afar people are not only ‘stepping up’, but also ‘stepping out’: shifting from pastoralism into agriculture and salaried employment. As this often involves splitting households across multiple locations, we look at how these reconfigured households support pastoralists’ wellbeing.
Ground-to-satellite time and frequency synchronization link with active carrier phase compensation
Authors: Sun S. C. , Bai Y. , Liang H. J. , Wang S. G. , Wang L. J.
Published: November 2019

In this paper, a synchronization link between one ground station and one geostationary satellite is established. The ground station receives retransmitted signals from the satellite, measures phase delay along the propagation route, and actively compensates back to its sending signals, realizing real-time phase fluctuation compensation. The transmitted signal contains two frequencies to eliminate common-mode phase noise. The difference between their carrier phase delays is measured. Different modes of carrier phase variation are separated and compensated, achieving a remaining time jitter of ±200 ps. Major sources of error are analyzed, and potential methods for improvement are discussed. The proposed ground-to-satellite link and active compensation method has potential applications in frequency standard dissemination to remote receivers (including ground stations or satellites). These potential applications justify further study of this system.
Development of a compact laser-diode based frequency domain photoacoustic sensing system: Application of human breast cancer diagnosis
Authors: Gorey Abhijeet , Vasudevan Srivathsan , Ansari M. S. , Bhagat Priyanka , Phatak Satish , Sharma Norman , Chen George C. K.
Published: November 2019

We present the development of a laser diode based photoacoustic spectral response (PASR) setup capable of diagnosing human breast cancer tissues through the use of mechanobiological properties of the tissue. A detailed description of the laser driver is provided, highlighting the important characteristics of the developed driver. Furthermore, the amplifier development is described. The developed laser diode based PASR system has been characterized using standard samples. Subsequently, the developed experiment has been applied onto diagnosis of human breast tumors. Energy has been used as a parameter to differentiate between normal and malignant tissues. The results were statistically consistent and then compared with standard histopathology for correlation.
Lasing without population inversion in N2+
Authors: Mysyrowicz A. , Danylo R. , Houard A. , Tikhonchuk V. , Zhang X. , Fan Z. , Liang Q. , Zhuang S. , Yuan L. , Liu Y.
Published: November 2019

We experimentally demonstrate the existence of long-lived coherent polarizations coupling simultaneously ground state X (X2Σg+) to excited states A (A2Πu) and B (B2Σu+) of N2+ inside a plasma created by a short intense laser pulse at 800 nm. This three-level V-scheme arrangement is responsible for a strong optical gain without population inversion at the B–X transition at 391.4 nm. Simulations based on Maxwell-Bloch equations reproduce well the kinetics and the pressure dependence of the gain.
Quantitative infrared spectroscopy of environmentally sensitive and rough materials
Authors: Xu Beibei , Peng Zhiwei , Wu Zupeng , Zhang Xu A. , Wang YuHuang
Published: November 2019

Fourier transform infrared (FTIR) spectroscopy is a widely used characterization technique for studying chemical compositions and light-matter interactions in the infrared range. However, it remains challenging to use conventional FTIR equipment to characterize materials that are environmentally sensitive and/or have rough surfaces due to their dynamic response to external stimuli (e.g., humidity) and light scattering from the sample surface. Here, we describe an approach enabling quantitative infrared spectroscopy measurements of these challenging samples, including transmittance, reflectance, and emissivity. We designed and 3D-printed a miniaturized environmental chamber that can be directly inserted into the sample holder of a conventional integrating sphere to perform total transmission and reflection measurements in controlled environments. Moreover, a calibration method was developed to exclude light scattering from rough surfaces of the sample and the distortion created by infrared windows. To illustrate the potential application of this method, we have performed quantitative infrared measurements, both specular and diffusive, on a sapphire standard reference with a specular surface, as well as a textile sample that has a rough surface and is dynamically responsive to changes in humidity. The calibrated results measured with the equipped chamber match those measured without the IR windows, demonstrating the viability of our environmental chamber and the proposed calibration method. This quantitative infrared spectroscopy measurement technique may help advance fields such as metasurfaces and adaptive textiles, where samples are often rough, dynamically responsive, and/or environmentally sensitive.
Numerical simulation of the influence of electron injections on the short-term annealing in pulse-neutron-irradiated p-type Si
Authors: Bai Xiaoyan , Liu Yan , Chen Wei , Qi Chao , Jin Xiaoming , Wang Guizhen , Li Ruibin , Wang Chenhui , Li Junlin
Published: November 2019

The physical reason behind the much more rapid short-term annealing progress in the presence of electrons in P-type silicon irradiated by pulse neutrons is investigated. Continuum equations coupled with defect reactions are used for the numerical simulation on the temporary evolutions of defects at different electron injection ratios. It is indicated that electron injections can significantly accelerate the creations of boron and carbon interstitials, but may have little influence on the creation of the vacancy-oxygen complex. The calculations on the relative concentrations of interstitials and vacancies in different charge states via the electron injection ratio show that more and more interstitials in the doubly positive charge state change into neutral ones, and neutral vacancies are always dominant with an increase in the electron concentration. The thermal diffusion coefficient of neutral interstitials is much larger than the ones of interstitials in other charge states. As a consequence, normal ionization enhanced diffusion for interstitials in the presence of electrons can significantly accelerate the short-term annealing progress in P-type silicon. Ionization enhanced diffusion coefficients for interstitials due to athermal diffusion are further estimated using the Bourgoin mechanism, and results indicate that the diffusion coefficients of positively charged interstitials are improved by several orders of magnitude when compared to their corresponding thermal diffusion coefficients. However, the production of boron and carbon interstitials is only accelerated by about one order of magnitude, which would be ascribed into such large thermal diffusion coefficients of neutral interstitials.
Molecular dynamics simulation of Y-type nanomotors with different angles in aqueous solution
Authors: Fu Zhongyu , Liang Dong , Jiang Shuanlei , Zhao Pengde , Han Kaixin , Xu Zhen
Published: November 2019

Nanomotors are of great importance when studying nanoelectromechanical systems that contain carbon nanotube (CNT) based nanomotors for controlled motion in water using a rotating electric field. In this paper, Y-type nanomotor structures based on CNTs immersed in an aqueous solution are designed, and systems with different Y-type structure angles are simulated using molecular dynamics. The simulation results suggest that when the rotating electric field speed is appropriate, changing the Y-type structure angle can adjust the hysteresis (forward and backward motion) of nanomotor rotors during rotation. Precise control over the rotation angle of the nanomotor rotor improves its working efficiency. The enclosed simulation results are an important reference when designing nanoscale propellers and complex structured nanogear systems in aqueous solutions.
Broadband waveplate operation by orthotropic metasurface reflector
Authors: Mustafa Meraj-E- , Tahir Farooq A. , Amin Muhammad
Published: November 2019

We present an anisotropic metasurface offering a simultaneous linear to cross-polarization conversion and linear to circular polarization conversion operations on large bandwidths of microwave frequencies. The proposed orthotropic structure consists of metallic bow tie shaped patches with embedded circular patches enabling diagonal structure symmetry. We demonstrate through numerical simulations and experiments that the metasurface can be used as a high efficiency linear to cross-polarization reflective converter within the two broad frequency bands of 7.48–10.55 GHz and 18.47–19.52 GHz with a polarization conversion ratio above 90%. Simultaneously, the designed metasurface acts as a circular polarizer for linearly polarized incident waves in triple frequency bands of 6.10–7.46 GHz, 10.55–18.42 GHz, and 19.60–22.39 GHz with an axial ratio below the 3 dB threshold. To the best of our knowledge, the second band from 10.55 to 18.42 GHz of circular polarization conversion “has the highest reported (to date) bandwidth of 54.3% for an axial ratio below 3 dB.” The designed metasurface remains angular stable up to 75° over most of the part of the above-mentioned operating bands for both transverse-electric and transverse-magnetic polarized wave incidences.
Measurement of intrinsic thermal conductivity of carbon fiber using direct electrical heating method
Authors: Yang Juekuan , Kong Long , Mu Bokang , Zhang Hongze , Li Yong , Cao Weiyu
Published: November 2019

It is usually very difficult to measure the intrinsic thermal conductivity of fibers using direct electrical heating method, due to the presence of lateral heat loss. In this study, we demonstrate that the intrinsic thermal conductivity and lateral heat transfer coefficient of fibers can be extracted simultaneously via multiple measurements on the same fiber. In our experiments, three samples of various lengths were prepared from an individual polyacrylonitrile-based carbon fiber of 5.6 µm in diameter and measured with the direct electrical heating method. From each sample, we can get a curve of thermal conductivity vs lateral heat transfer coefficient. We showed that the intrinsic thermal conductivity and lateral heat transfer coefficient can be extracted from the intersection of these curves. Our results also showed that ignoring the lateral heat loss can result in an overestimation in thermal conductivity of carbon fibers by more than 3 times.
Velocity map imaging of inelastic and elastic low energy electron scattering in organic nanoparticles
Authors: Kostko O. , Jacobs M. I. , Xu B. , Wilson K. R. , Ahmed M.
Published: November 2019

Electron transport is of fundamental importance and has application in a variety of fields. Different scattering mechanisms affect electron transport in the condensed phase; hence, it is important to comprehensively understand these mechanisms and their scattering cross sections to predict electron transport properties. Whereas electron transport is well understood for high kinetic energy (KE) electrons, there is a discrepancy in the experimental and theoretical values for the Inelastic Mean Free Path (IMFP) in the low KE regime. In this work, velocity map imaging soft X-ray photoelectron spectroscopy is applied to unsupported organic nanoparticles (squalene) to extract experimental values of inelastic and elastic mean free paths (EMFPs). The obtained data are used to calculate corresponding scattering cross sections. The data demonstrate a decrease in the IMFP and increase in the EMFP with increasing electron KE between 10 and 50 eV.
Quantitative estimation of inter-dipole interaction energy in giant-permittivity CaCu3Ti4O12 solid bulks
Authors: Ma Ran , Li Yongqiang , Huang Yicheng , Dong Shicheng , Yang Qirui , Jin Yazhou , Zhang Zhengjun , Yan Meng , Chen Kai , Liu Junming , Zhu Jinsong
Published: November 2019

In the CaCu3TiO4 solid bulks with the giant permittivity of ∼104, the 100-fold permittivity-drop below 200 K has been observed without any long-range structural transition. In the frame of the comprehensive model, the Ising-model analysis of dielectric polarization is applied and the energy of the nearest interaction among the dipoles is deduced from the experiments by utilizing the particle swarm optimization. The interaction energy of ∼56 meV is reasonably smaller than the experimental value of the thermal activation energy of ∼88 meV. The interaction energy is independent of the temperatures, the dipole-chain lengths, and the frequencies of the applied AC electric field. Therefore, such appropriate, stable, and intrinsic interaction energy makes the many-body dielectric relaxation rather than the structural transition responsible for the permittivity drop.
Intrinsic viscosities of non-spherical colloids by Brownian dynamics simulations
Authors: Palanisamy Duraivelan , den Otter Wouter K.
Published: November 2019

A numerical study is presented on the intrinsic viscosities of sheared dilute suspensions of nonspherical Brownian colloidal particles. The simulations confirm theoretical predictions on the intrinsic viscosities of highly oblate and highly prolate spheroids in the limits of weak and strong Brownian noise (i.e., for low and high Péclet numbers). Numerical data and fit functions are provided covering the entire shear-thinning regime, for spheroids ranging from highly oblate to highly prolate. The tumbling motion and intrinsic viscosities of a hemispherical cap and a helix are briefly discussed.
Leaf micromorphology of 19 Mentha taxa
Authors: Hanafy Doaa M. , Prenzler Paul D. , Hill Rodney A. , Burrows Geoffrey E.
Published: November 2019

Mentha (mint) is a genus in the Lamiaceae with a worldwide distribution. It has a complex classification due to frequent hybridisation at the interspecific level, variation in basic chromosome number and the occurrence of polyploidy (diploid to nonaploid). Although there have been many studies of Mentha leaf micromorphology, usually only a few taxa were described. The aim of this study was to characterise the micromorphology of Mentha leaves. Nineteen Mentha taxa, covering all four sections of the genus, were grown under controlled conditions and adaxial and abaxial leaf surfaces were examined using stereo and scanning electron microscopes. This study included examination of the previously uninvestigated Australian species, M. australis and M. diemenica. The study revealed that average lamina length varied from 3 mm (M. requienii) to 34 mm (M. × niliaca) and leaves were sessile (M. spicata) to where petiole length was 50% of total leaf length (M. requienii). Peltate and capitate glandular trichomes were found on the adaxial and abaxial leaf surfaces of almost all taxa. Most taxa were hypostomatous. A few taxa had amphistomatous leaves which was interesting given that Mentha is a mesophytic genus naturally found in moist environments beside streambanks and lake shores. Average guard cell length varied from 14 µm (M. suaveolens) to 27 µm (M. × piperita f. citrata ‘Basil’) with larger guard cell length correlated with larger DNA content and chromosome number. Two species in section Pulegium (M. requienii and M. pulegium) had small laminas, relatively long petioles and high adaxial stomatal density which distinguished them from taxa in the other three sections. Larger DNA content in plants can be associated with larger cell size. Most studies of Mentha leaf micromorphology make no mention of ploidy. The present study indicates this should be considered when comparing relative cell size between species.
Genomic sites hypersensitive to ultraviolet radiation
Authors: Premi Sanjay , Han Lynn , Mehta Sameet , Knight James , Zhao Dejian , Palmatier Meg A. , Kornacker Karl , Brash Douglas E.
Published: November 2019

If the genome contains outlier sequences extraordinarily sensitive to environmental agents, these would be sentinels for monitoring personal carcinogen exposure and might drive direct changes in cell physiology rather than acting through rare mutations. New methods, adductSeq and freqSeq, provided statistical resolution to quantify rare lesions at single-base resolution across the genome. Primary human melanocytes, but not fibroblasts, carried spontaneous apurinic sites and TG sequence lesions more frequent than ultraviolet (UV)-induced cyclobutane pyrimidine dimers (CPDs). UV exposure revealed hyperhotspots acquiring CPDs up to 170-fold more frequently than the genomic average; these sites were more prevalent in melanocytes. Hyperhotspots were disproportionately located near genes, particularly for RNA-binding proteins, with the most-recurrent hyperhotspots at a fixed position within 2 motifs. One motif occurs at ETS family transcription factor binding sites, known to be UV targets and now shown to be among the most sensitive in the genome, and at sites of mTOR/5′ terminal oligopyrimidine-tract translation regulation. The second occurs at A2–15TTCTY, which developed “dark CPDs” long after UV exposure, repaired CPDs slowly, and had accumulated CPDs prior to the experiment. Motif locations active as hyperhotspots differed between cell types. Melanocyte CPD hyperhotspots aligned precisely with recurrent UV signature mutations in individual gene promoters of melanomas and with known cancer drivers. At sunburn levels of UV exposure, every cell would have a hyperhotspot CPD in each of the ∼20 targeted cell pathways, letting hyperhotspots act as epigenetic marks that create phenome instability; high prevalence favors cooccurring mutations, which would allow tumor evolution to use weak drivers.
CRIg plays an essential role in intravascular clearance of bloodborne parasites by interacting with complement
Authors: Liu Gongguan , Fu Yong , Yosri Mohammed , Chen Yanli , Sun Peng , Xu Jinjun , Zhang Mingshun , Sun Donglei , Strickland Ashley B. , Mackey Zachary B. , Shi Meiqing
Published: November 2019

Significance

Bloodborne parasites develop very sophisticated mechanisms to survive in the bloodstream, causing serious diseases. The mechanisms involved in intravascular clearance of bloodborne parasites are largely unknown. Understanding the underlying mechanisms is fundamental for developing strategies to treat the diseases. In the current study, we reveal that CRIg, a macrophage receptor previously shown to bind C3b/iC3b in vitro, plays an essential role in intravascular clearance of the bloodborne parasites African trypanosomes. More importantly, we demonstrate that CRIg, through interactions with complement deposited on the parasites in vivo, rather than parasites themselves, captures parasites under flow conditions. Thus, CRIg functions as a complement receptor in vivo to capture bloodborne pathogens and may represent a target for treatment.
Dysregulation of different classes of tRNA fragments in chronic lymphocytic leukemia
Authors: Veneziano Dario , Tomasello Luisa , Balatti Veronica , Palamarchuk Alexey , Rassenti Laura Z. , Kipps Thomas J. , Pekarsky Yuri , Croce Carlo M.
Published: November 2019

Chronic lymphocytic leukemia (CLL) is the most common human leukemia, and dysregulation of tRNA-derived short noncoding RNA (tsRNA) (tRF-1) expression is an accompanying event in the development of this disease. tsRNAs are fragments originating from the 3′ end of tRNA precursors and do not contain mature tRNA sequences. In contrast to tsRNAs, mature tRFs (tRF-3s, tRF-5s, and internal tRFs) are produced from mature tRNA sequences and are redundant fragments. We investigated tsRNA expression in CLL and determined tsRNA signatures in indolent CLL and aggressive CLL vs. normal B cells. We noticed that both
ts-43
and
ts-44
are derived from distinct genes of pre-tRNA
His
, and are down-regulated in CLL 3- to 5-fold vs. normal B cells. Thus, we investigated expression levels of tRF-5 fragments from tRNA
His
in CLL samples and healthy controls, and determined that such fragments are down-regulated by 5-fold in CLLs vs. normal controls. Given these results, we investigated the expression of all mature tRFs in CLLs vs. normal controls. We found a drastic dysregulation of the expression of mature tRFs in CLL. In aggressive CLL, for the top 15 up-regulated fragments, linear fold change varied from 2,053- to 622-fold. For the top 15 down-regulated fragments in CLL, linear fold change varied from 314- to 52-fold. In addition, 964 mature tRFs were up-regulated at least 2-fold in CLL, while 701 fragments were down-regulated at least 2-fold. Similar results were obtained for indolent CLL. Our results suggest that mature tRFs may have oncogenic and/or tumor suppressor function in CLL.
Antidiabetic components from the hexane extract of red kidney beans (Phaseolus vulgaris L.): isolation and structure determination
Authors: Sutedja Anita Maya , Yanase Emiko , Batubara Irmanida , Fardiaz Dedi , Lioe Hanifah Nuryani
Published: November 2019

Red kidney beans (Phaseolus vulgaris L.) contain bioactive compounds that are known to exhibit antidiabetic effects via inhibition of α-glucosidase. However, information on the nonpolar components that exhibit antidiabetic activity is limited. Here, we report the isolation and structure determination of components with α-glucosidase inhibitory activity, which were obtained from the hexane extract of red kidney beans. Triacylglycerols (TAGs) were identified as the major components exhibiting inhibitory activity against α-glucosidase. The chemical structure of TAGs was determined by a combination of GC-MS and UPLC-MS/MS. The primary TAGs identified were LnLnLn (trilinolenin) and LnLLn (1,3-dilinolenoyl-2-linoleoyl glycerol). The major fatty acids present in these TAGs were α-linolenic acid (ω-3) and linoleic acid (ω-6). These TAGs were also found to inhibit the α-glucosidase activity in a similar fashion as acarbose. These results suggest that TAGs have potency as antidiabetics and support the potential suitability of red kidney beans for diabetes treatment.
Cryo-EM structure of the complete and ligand-saturated insulin receptor ectodomain
Authors: Gutmann Theresia , Schäfer Ingmar B. , Poojari Chetan , Brankatschk Beate , Vattulainen Ilpo , Strauss Mike , Coskun Ünal
Published: November 2019

Glucose homeostasis and growth essentially depend on the hormone insulin engaging its receptor. Despite biochemical and structural advances, a fundamental contradiction has persisted in the current understanding of insulin ligand–receptor interactions. While biochemistry predicts two distinct insulin binding sites, 1 and 2, recent structural analyses have resolved only site 1. Using a combined approach of cryo-EM and atomistic molecular dynamics simulation, we present the structure of the entire dimeric insulin receptor ectodomain saturated with four insulin molecules. Complementing the previously described insulin–site 1 interaction, we present the first view of insulin bound to the discrete insulin receptor site 2. Insulin binding stabilizes the receptor ectodomain in a T-shaped conformation wherein the membrane-proximal domains converge and contact each other. These findings expand the current models of insulin binding to its receptor and of its regulation. In summary, we provide the structural basis for a comprehensive description of ligand–receptor interactions that ultimately will inform new approaches to structure-based drug design.
B cell tolerance and antibody production to the celiac disease autoantigen transglutaminase 2
Authors: du Pré M. Fleur , Blazevski Jana , Dewan Alisa E. , Stamnaes Jorunn , Kanduri Chakravarthi , Sandve Geir Kjetil , Johannesen Marie K. , Lindstad Christian B. , Hnida Kathrin , Fugger Lars , Melino Gerry , Qiao Shuo-Wang , Sollid Ludvig M.
Published: November 2019

Autoantibodies to transglutaminase 2 (TG2) are hallmarks of celiac disease. To address B cell tolerance and autoantibody formation to TG2, we generated immunoglobulin knock-in (Ig KI) mice that express a prototypical celiac patient–derived anti-TG2 B cell receptor equally reactive to human and mouse TG2. We studied B cell development in the presence/absence of autoantigen by crossing the Ig KI mice to Tgm2−/− mice. Autoreactive B cells in Tgm2+/+ mice were indistinguishable from their naive counterparts in Tgm2−/− mice with no signs of clonal deletion, receptor editing, or B cell anergy. The autoreactive B cells appeared ignorant to their antigen, and they produced autoantibodies when provided T cell help. The findings lend credence to a model of celiac disease where gluten-reactive T cells provide help to autoreactive TG2-specific B cells by involvement of gluten–TG2 complexes, and they outline a general mechanism of autoimmunity with autoantibodies being produced by ignorant B cells on provision of T cell help.
Morphology modification of Si nanopillars under ion irradiation at elevated temperatures: plastic deformation and controlled thinning to 10 nm
Authors: Xu Xiaomo , Heinig Karl-Heinz , Möller Wolfhard , Engelmann Hans-Jürgen , Klingner Nico , Gharbi Ahmed , Tiron Raluca , Borany Johannes von , Hlawacek Gregor
Published: November 2019

Si nanopillars of less than 50 nm diameter have been irradiated in a helium ion microscope with a focused Ne+ beam. The morphological changes due to ion beam irradiation at room temperature and elevated temperatures have been studied with the transmission electron microscope. We found that the shape changes of the nanopillars depend on irradiation-induced amorphization and thermally driven dynamic annealing. While at room temperature, the nanopillars evolve to a conical shape due to ion-induced plastic deformation and viscous flow of amorphized Si, simultaneous dynamic annealing during the irradiation at elevated temperatures prevents amorphization which is necessary for the viscous flow. Above the critical temperature of ion-induced amorphization, a steady decrease of the diameter was observed as a result of the dominating forward sputtering process through the nanopillar sidewalls. Under these conditions the nanopillars can be thinned down to a diameter of ∼10 nm in a well-controlled manner. A deeper understanding of the pillar thinning process has been achieved by a comparison of experimental results with 3D computer simulations based on the binary collision approximation.
Mercator: uncovering faithful hyperbolic embeddings of complex networks
Authors: García-Pérez Guillermo , Allard Antoine , Serrano M Ángeles , Boguñá Marián
Published: November 2019

We introduce Mercator, a reliable embedding method to map real complex networks into their hyperbolic latent geometry. The method assumes that the structure of networks is well described by the popularity × similarity

S

1

/

H

2

static geometric network model, which can accommodate arbitrary degree distributions and reproduces many pivotal properties of real networks, including self-similarity patterns. The algorithm mixes machine learning and maximum likelihood (ML) approaches to infer the coordinates of the nodes in the underlying hyperbolic disk with the best matching between the observed network topology and the geometric model. In its fast mode, Mercator uses a model-adjusted machine learning technique performing dimensional reduction to produce a fast and accurate map, whose quality already outperforms other embedding algorithms in the literature. In the refined Mercator mode, the fast mode embedding result is taken as an initial condition in a ML estimation, which significantly improves the quality of the final embedding. Apart from its accuracy as an embedding tool, Mercator has the clear advantage of systematically inferring not only node orderings, or angular positions, but also the hidden degrees and global model parameters, and has the ability to embed networks with arbitrary degree distributions. Overall, our results suggest that mixing machine learning and ML techniques in a model-dependent framework can boost the meaningful mapping of complex networks.
Non-parabolic effect for femtosecond laser-induced ultrafast electro-absorption in solids*
Authors: Liu Li-Bo , Deng Hong-Xiang , Zu Xiao-Tao , Yuan Xiao-Dong , Zheng Wan-Guo
Published: November 2019

A theoretical study for femtosecond laser-induced ultrafast electro-absorption of bulk solids is presented. Our numerical results show that, in the case of low intensity of the pump laser where the interaction between the pump laser and solids is in the multi-photon regime, the energy band of solids can be approximately taken as a parabolic band and electro-absorption spectrums from the parabolic band and real band are nearly the same. While, in the case of high intensity where the interaction is in the tunneling regime, spectrums from the parabolic band and real band are quite different. The physical mechanism for the difference in the tunneling regime is found. We find that the non-parabolic parts of the real energy band and Bragger scattering of electrons near the first Brillouin zone boundaries, which are neglected in previous studies, strongly influence the electro-absorption spectrum in the tunneling regime. These two physical processes cause the difference of spectrums. Our theoretical results are in accordance with the experiment result.
Electron capture in collisions of Li3+ ions with ground and excited states of Li atoms*
Authors: Ma M X , Kou B H , Liu L , Wu Y , Wang J G
Published: November 2019

The electron capture processes in collisions of Li3+ ion with Li(1s22s) and Li(1s22p0,1) are investigated by using the two-center atomic orbital close-coupling method in the energy range from 0.1 keV/u to 300 keV/u. The interaction of the active electrons with the target ion is represented by a model potential. The present results for the Li3+–Li(1s22s) system are compared with the available theoretical data and general agreement is obtained for the high collision energies. It is also found that the total and partial electron capture cross sections are sensitive to the initial charge cloud alignment in the low energy region.
Noise properties of multi-combination information in x-ray grating-based phase-contrast imaging*
Authors: Faiz Wali , Li Ji , Gao Kun , Wu Zhao , Lei Yao-Hu , Huang Jian-Heng , Zhu Pei-Ping
Published: November 2019

Grating-based x-ray phase contrast imaging has attracted increasing interest in recent decades as multimodal and laboratory source usable method. Specific efforts have been focused on establishing a new extraction method to perform practical applications. In this work, noise properties of multi-combination information of newly established information extraction method, so-called angular signal radiography method, are investigated to provide guidelines for targeted and specific applications. The results show that how multi-combination of images can be used in targeted practical applications to obtain a high-quality image in terms of signal-to-noise ratio. Our conclusions can also hold true for upcoming targeted practical applications such as biomedical imaging, non-destructive imaging, and materials science.
Evaporation of saline colloidal droplet and deposition pattern*
Authors: Sun Hong-Hui , Li Wei-Bin , Ji Wen-Jie , Dai Guo-Liang , Huan Yong , Wang Yu-Ren , Lan Ding
Published: November 2019

The dynamic process of the evaporation and the desiccation of sessile saline colloidal droplets, and their final deposition are investigated. During the evaporation, the movement of the colloidal particles shows a strong dependence on the salt concentration and the droplet shape. The final deposition pattern indicates a weakened coffee-ring effect in this mixed droplet system. The microscopic observation reveals that as evaporation proceeds, the particle motion trail is affected by the salt concentration of the droplet boundary. The Marangoni flow, which is induced by surface tension gradient originating from the local evaporative peripheral salt enrichment, suppresses the compensation flow towards the contact line of the droplet. The inhomogeneous density and concentration field induced by evaporation or crystallization can be the major reason for various micro-flows. At last stage, the distribution and crystallization of NaCl are affected by the colloidal particles during the drying of the residual liquid film.