bluuebunny/crossref_metadata_2025 huggingface dataset:
Corrosion study and quantitative measurement of crystallite size of high strength aluminum hybrid composite developed via friction stir processing
Authors: Ikumapayi O.M. , Akinlabi E.T. , Majumdar J.D. , Fayomi O.S.I. , Akinlabi S.A.
Published: June 2020

This present study is centered on the corrosion behaviors and structural integrity of high strength aluminum‐alloy 7075‐T651 hybridized with carbonaceous coconut shell ash (CSA) and α+β titanium alloy powder in ratio of 50 : 50, fabricated during friction stir processing (FSP). The study examined the base metal – AA7075‐T651 as well as the friction stir processed AA7075‐T651 as control experiments. The Processing parameters used were plunge depth of 0.3 mm, travel speed of 20 mm/min, the tilt angle of 3° and rotational speed of 1500 min−1. The corrosion characteristics were examined with the Potentiodynamic Polarization method in 3.5 % NaCl medium while crystalline phases were studied with x‐ray diffraction (XRD). Results show that fabricated aluminum hybrid composite (AHC) AA7075‐T651/coconut shell ash (CSA)/titanium‐alloy has the highest percentage of inhibition performance efficiency (IPE) of 84.81 % resulting to 0.76938 mm/year corrosion rate and 356.51 Ω polarization resistance, whereas inhibition performance efficiency (IPE) for friction stir processed (FSPed) AA7075‐T651 was 63.99 % while the base metal – AA7075‐T651 was taken as the reference point. It was also revealed that the hybridized coconut shell ash (CSA)/titanium‐alloy powder on AA7075‐T651 enhanced the structural integrity, producing 38.5 nm crystallite size over friction stir processing (FSP) AA7075‐T651 with 41.2 nm and the base metal with 48.7 nm crystallite size.
Material characterization and corrosion behavior of hybrid coating Ti−Al−Si−Cu/Ti−6Al‐4V composite
Authors: Naidoo L.C , Fatoba O.S. , Akinlabi S.A. , Mahamood R.M. , Shatalov M.Y. , Murashkin E.V. , Hassan S. , Akinlabi E.T.
Published: June 2020

Titanium alloy grade 5 is a grade of the titanium material that is in‐demand in the marine, aerospace, biomedical and turbo machinery industries. It offers great properties such as being light weight, good corrosion performance and great strength. However, some of the other properties, namely: its low hardness and poor tribological performance, has limited its various industrial application. Developments have focused on the enhancement of the surface properties without altering the bulk of the material. This has led to the laser metal deposition technique categorized under the additive manufacturing processes. It is a feasible technique that operates on layer‐by‐layer additive processing to manufactures whole parts or repair local damages in components. This study aims to ascertain the optimum processing conditions of the process by varying the laser intensity and scanning speed between 0.9 kW–1 kW and 1.0 m/min–1.2 m/min, respectively, while maintaining all the other process parameters. The specimens were produced by utilizing the ytterbium laser system to conduct laser surface alloying of Ti−Al−Si−Cu/Ti‐6Al‐4 V. Metallographic preparations, characterizations to conduct laser metal deposition (LMD), microhardness and corrosion test were conducted. It was deduced that Ti‐9Si‐3Cu alloy had the best optimum performance at 1 kW and 1.0 m/min. The hardness and corrosion were optimum improved at reduced scan speeds and increased laser power.
Mechanical performance and biodegradability of polyvinyl alcohol nanocomposite films
Authors: Ong T.K. , Tshai K.Y. , Choo H.L. , Khiew P.S. , Chung S.L.
Published: June 2020

This study investigated the mechanical properties and biodegradability of polyvinyl alcohol (PVA) composite films. 3 wt.%, 5 wt.%, and 10 wt.% microcrystalline cellulose (MCC), commercial grade cellulose nanocrystals (NCCA), and nanocellulose (NCCB) extracted from oil palm fiber (OPF) were incorporated into polyvinyl alcohol by solvent casting. Field emission scanning electron microscopy (FESEM) images indicated that the average particle size of microcrystalline cellulose, commercial grade cellulose nanocrystals, and nanocellulose extracted from oil palm fiber are 12.63 μm±5.71 μm, 502.92 nm±196.10 nm, and 79.20 nm±11.69 nm, respectively. Nanofillers dispersed uniformly in polyvinyl alcohol matrix. Addition of microcrystalline cellulose up to 5 wt.% was able to improve the ultimate tensile strength (UTS) and yield strength of polyvinyl alcohol composite films but sacrificed the maximum elongation. Incorporation of 5 wt.% nanocellulose extracted from oil palm fiber is able to increase ultimate tensile strength, yield strength, and elastic modulus while maintaining the maximum elongation of polyvinyl alcohol composite films. Incorporation of commercial grade cellulose nanocrystals (up to 10 wt.%) increases ultimate tensile strength, yield strength, and maximum elongation while maintaining elastic modulus of polyvinyl alcohol composite films. Soil burial test result found that presence of moisture accelerated the degradation of the polyvinyl alcohol composite films drastically; the films were fully dissolved in the soil after 7 days. However, the weight of polyvinyl alcohol composite films did not change significantly after 28 days under controlled condition. This indicated that soil moisture is an important catalyst in biodegradation activity of polyvinyl alcohol composite films. Comparison with a commercially available biodegradable plastic bag (Bio‐PB) shows that the polyvinyl alcohol composite films developed in this study have superior mechanical performance and biodegradability, with potential to replace existing plastic bags.
Experts examine MH consequences of social distancing
Authors: Canady Valerie A.
Published: June 2020

The practice of social distancing in countries all over the world, resulting in changes in national behavioral patterns and shutdowns of usual day‐to‐day functioning, will undoubtedly have consequences for mental health and well‐being in both the short and long term, according to authors of a JAMA Internal Medicine Viewpoint published online in April.
Resveratrol Alleviates Endoplasmic Reticulum Stress–Associated Hepatic Steatosis and Injury in Mice Challenged with Tunicamycin
Authors: Chen Yanan , Zhang Hao , Chen Yueping , Zhang Yuying , Shen Mingming , Jia Peilu , Ji Shuli , Wang Tian
Published: June 2020

Scope

Endoplasmic reticulum (ER) stress is widely recognized as a critical factor linked to lipid metabolic disorders in nonalcoholic fatty liver disease. However, its pathogenesis remains elusive, and therapeutic options are limited. This study investigates the potential of resveratrol (RSV) to alleviate hepatic steatosis and injury in a tunicamycin (TM)‐induced murine ER stress model and provides detailed evidence.

Methods and Results

Male C57BL/6J mice were orally administered either RSV or vehicle for 2 weeks before the TM challenge. Results indicated that TM induced ER morphological damage and severe unfolded protein reaction (UPR), accompanied by increases in lipid accumulation, oxidative damage, and inflammatory response. Administering RSV decreased the expression of ER stress markers, partially normalized the active levels of UPR sensors, and facilitated sirtuin 1 activity in the liver under ER stress. Notably, the TM‐induced hepatic steatosis was also alleviated by RSV, possibly by regulating the expression pattern of genes involving lipid oxidation and delivery. Consistently, RSV attenuated the TM‐induced increases in lipid peroxidation, hepatocyte apoptosis, and the overactivation of inflammatory signals.

Conclusion

RSV may have an auxiliary therapeutic potential to prevent the development of steatosis and its progression to steatohepatitis in the liver by alleviating severe ER stress.
Copper/benzocyclotene thin film technique based microstrip bandpass filter featured by thick dielectric layer for low insertion loss
Authors: Zhang Weibo , Gu Jiebin , Xu Gaowei , Luo Le , Li Xinxin
Published: June 2020

In this paper, a copper/benzocyclotene thin film based microstrip bandpass filter featured by a thick dielectric layer is presented. For thickening dielectric layer, a 30 μm‐deep micromachined groove with embedded benzocyclotene polymer is fabricated on the surface of silicon substrate. Mechanical polishing is utilized to planarize the benzocyclotene polymer embedded in the groove. Atomic Force Microscopy is used to characterize the surface roughness of benzocyclobutene (BCB) polymer film before and after polishing. With two additional BCB layer, a total thickness of 75.4 μm dielectric layer is realized, and the insertion loss of the filter can be reduced by 1.34 dB theoretically. The measured insertion loss of fabricated filter is −2.2 dB, which can be further reduced via tighter control of device parameters.
Compact triple‐band filter with adjustable passbands on one substrate integrated waveguide square resonant cavity
Authors: Liu Yi‐Jie , Zhang Gang , Liu Shi‐Cheng , Yang Ji‐Quan
Published: June 2020

A new compact triple‐band bandpass filter (BPF) with adjustable passbands based on only single substrate integrated waveguide (SIW) square resonant cavity is proposed in this letter. The first six resonant modes (the perturbed TE101′ mode and TE102′ mode, the perturbed TE201′ mode and TE202′ mode, the perturbed TE301′ mode and TE302′ mode) of the SIW cavity are controlled to constitute the three corresponding passbands by elaborately introducing metallic vias in the design. The three center frequencies and passband bandwidths can be effectively adjusted by only changing the location and sizes of these perturbations. For demonstration, a prototype SIW triple‐band BPF is designed, fabricated, and tested. Measured and simulated results are in good agreement, verifying the feasibility of the design concept.
Analysis and correction of off‐resonance artifacts in echo‐planar cardiac diffusion tensor imaging
Authors: van Gorkum Robbert J. H. , von Deuster Constantin , Guenthner Christian , Stoeck Christian T. , Kozerke Sebastian
Published: June 2020

Purpose

Cardiac diffusion tensor imaging using EPI readout is prone to image distortions in the presence of field inhomogeneities. In this work, a framework to analyze and correct image distortions in cardiac diffusion tensor imaging is presented.

Methods

A multi‐coil reconstruction framework was implemented to enable field map‐based off‐resonance correction. Numerical simulations were used to examine reconstruction performance for EPI phase‐encode directions blip up‐down and down‐up for different degrees of off‐resonance gradients and varying field map resolution. The impact of coil encoding was analyzed using the g‐factor and normalized RMSE. Finally, the proposed method was tested on free‐breathing in vivo cardiac diffusion tensor imaging data acquired in healthy subjects at 3 Tesla.

Results

Depending on the local field map gradient strength and polarity and the selected phase‐encode direction, field inhomogeneities lead to either local spatial compression or stretching with standard image reconstruction. Although spatial compression results in loss of image resolution upon field map‐based reconstruction, spatial stretching can be recovered once multiple receive coils are utilized. Multi‐coil reconstruction was found to reduce the normalized RMSE from 34.3% to 8.1% for image compression, and 33.6% to 1.8% for image stretching, with resulting average g‐factors 14.7 ± 2.9 and 1.2 ± 0.1, respectively. In vivo, multi‐coil field map‐based reconstruction yielded improved alignment of angle maps with anatomical cine data.

Conclusion

Multi‐coil, field map‐based image reconstruction for echo‐planar cardiac diffusion tensor imaging allows accurate image reconstruction provided that the phase‐encode direction and polarity is chosen to principally align with the direction and polarity of the prominent gradients of field inhomogeneities.
Rituximab for late onset myasthenia gravis: Evidence mounting but deliberations continue
Authors: Hehir Michael K. , Li Yuebing
Published: June 2020

See article on pages 377–380 in this issue.
Exact seismic response of smooth rigid retaining walls resting on stiff soil
Authors: Garcia‐Suarez Joaquin , Asimaki Domniki
Published: June 2020

The assessment of forces exerted on walls by the backfill is a recurrent problem in geotechnical engineering, owing to its relevance for both retaining systems and underground structures. In particular, the work by Arias and colleagues, and later also the one by Veletsos and Younan, among others, becomes pertinent when considering pressure increments on underground structures triggered by seismic events. As a first step, they studied the response of a rigid retaining wall resting on rigid bedrock subjected to SV waves, introducing some simplifying assumptions. This paper presents the exact solution to this reference problem. The solution is given in horizontal wavenumber domain; hence, it comes in terms of inverse Fourier transforms, which can be approximated numerically in Mathematica, which in turn are verified against finite‐element simulations. Specific features of this exact solution that were not captured by prior engineering approximations are highlighted and discussed.
Synchronizing pricing and replenishment to serve forward‐looking customers
Authors: Chen Ying‐Ju , Yang Chu Leon
Published: June 2020

We incorporate strategic customer waiting behavior in the classical economic order quantity (EOQ) setting. The seller determines not only the timing and quantities of the inventory replenishment, but also the selling prices over time. While similar ideas of market segmentation and intertemporal price discrimination can be carried over from the travel industries to other industries, inventory replenishment considerations common to retail outlets and supermarkets introduce additional features to the optimal pricing scheme. Specifically, our study provides concrete managerial recommendations that are against the conventional wisdom on “everyday low price” (EDLP) versus “high‐low pricing” (Hi‐Lo). We show that in the presence of inventory costs and strategic customers, Hi‐Lo instead of EDLP is optimal when customers have homogeneous valuations. This result suggests that because of strategic customer behavior, the seller obtains a new source of flexibility—the ability to induce customers to wait—which always leads to a strictly positive increase of the seller's profit. Moreover, the optimal inventory policy may feature a dry period with zero inventory, but this period does not necessarily result in a loss of sales as customers strategically wait for the upcoming promotion. Furthermore, we derive the solution approach for the optimal policy under heterogeneous customer valuation setting. Under the optimal policy, the replenishments and price promotions are synchronized, and the seller adopts high selling prices when the inventory level is low and plans a discontinuous price discount at the replenishment point when inventory is the highest.
A two‐grid method with backtracking for the mixed Navier–Stokes/Darcy model
Authors: Du Guangzhi , Li Qingtao , Zhang Yuhong
Published: June 2020

In this paper, we consider the effect of adding a coarse mesh correction to the two‐grid algorithm for the mixed Navier–Stokes/Darcy model. The method yields both L2 and H1 optimal velocity and piezometric head approximations and an L2 optimal pressure approximation. The method involves solving one small, coupled, nonlinear coarse mesh problem, two independent subproblems (linear Navier–Stokes equation and Darcy equation) on the fine mesh, and a correction problem on the coarse mesh. Theoretical analysis and numerical tests are done to indicate the significance of this method.
Hyaluronic acid for the treatment of airway diseases in children: Little evidence for few indications
Authors: Di Cicco Maria , Peroni Diego , Sepich Margherita , Tozzi Maria Giulia , Comberiati Pasquale , Cutrera Renato
Published: June 2020

Background

Hyaluronic acid (HA) is major physiological component of the extracellular matrix, which, in its high molecular weight form (HMW‐HA) has anti‐inflammatory properties. The diffusion of many different medical devices for inhalation therapy containing HA has led to an increase in their prescription, also in children. Here, we systematically review the published evidence on the efficacy and safety of HA for the treatment of upper and lower airway diseases in childhood.

Methods

Relevant published studies (randomized controlled trials) for the efficacy of HA inhalation in children with upper airways diseases, asthma, cystic fibrosis (CF), and non‐CF bronchiectasis were searched in Pubmed, Scopus, and Web of Knowledge databases by combining the adequate Medical Subject Headings terms and keywords, with no limit for the year of publication.

Results

We identified seven relevant publications for upper airways diseases, one for asthma, and five for CF, while we found no clinical trial including children with non‐CF bronchiectasis. Meta‐analysis was not conducted due to the heterogeneity of the included studies.

Conclusions

The evidence of HA efficacy in the treatment of the upper and lower airways is still limited in children. Available data suggest that inhaled HMW‐HA could be useful in the treatment of recurrent upper respiratory infections and chronic or recurrent inflammation of the middle ear and adenoids as well as of the lower airways in cystic fibrosis in association with hypertonic saline solution. Studies on larger populations and on the different formulations and nebulization methods, especially in pediatric age, are urgently needed.
New fusion and selection approaches for estimating the remaining useful life using Gaussian process regression and induced ordered weighted averaging operators
Authors: Bouzenita Mohammed , Mouss Leila‐Hayet , Melgani Farid , Bentrcia Toufik
Published: June 2020

In this paper, we propose new fusion and selection approaches to accurately predict the remaining useful life. The fusion scheme is built upon the combination of outcomes delivered by an ensemble of Gaussian process regression models. Each regressor is characterized by its own covariance function and initial hyperparameters. In this context, we adopt the induced ordered weighted averaging as a fusion tool to achieve such combination. Two additional fusion techniques based on the simple averaging and the ordered weighted averaging operators besides a selection approach are implemented. The differences between adjacent elements of the raw data are used for training instead of the original values. Experimental results conducted on lithium‐ion battery data report a significant improvement in the obtained results. This work may provide some insights regarding the development of efficient intelligent fusion alternatives for further prognostic advances.
Infusion of human umbilical cord tissue mesenchymal stromal cells in children with autism spectrum disorder
Authors: Sun Jessica M. , Dawson Geraldine , Franz Lauren , Howard Jill , McLaughlin Colleen , Kistler Bethany , Waters-Pick Barbara , Meadows Norin , Troy Jesse , Kurtzberg Joanne
Published: June 2020

Ongoing neuroinflammation may contribute to symptoms of autism spectrum disorder (ASD) in at least a portion of affected individuals. Mesenchymal stromal cells (MSCs) have demonstrated the capacity to modulate neuroinflammation, but safety and feasibility of MSC administration in children with ASD have not been well established. In this open-label, phase I study, 12 children with ASD between 4 and 9 years of age were treated with intravenous (IV) infusions of human cord tissue mesenchymal stromal cells (hCT-MSCs), a third-party MSC product manufactured from unrelated donor umbilical cord tissue. Children received one, two, or three doses of 2 × 106 cells per kilogram at 2-month intervals. Clinical and laboratory evaluations were performed in person at baseline and 6 months and remotely at 12 months after the final infusion. Aside from agitation during the IV placement and infusion in some participants, hCT-MSCs were well tolerated. Five participants developed new class I anti-human leukocyte antigen (HLA) antibodies, associated with a specific lot of hCT-MSCs or with a partial HLA match between donor and recipient. These antibodies were clinically silent and not associated with any clinical manifestations to date. Six of 12 participants demonstrated improvement in at least two ASD-specific measures. Manufacturing and administration of hCT-MSCs appear to be safe and feasible in young children with ASD. Efficacy will be evaluated in a subsequent phase II randomized, placebo-controlled clinical trial.
Pharmacology Profile of Recently Developed Multi‐Functional Azoles; SAR‐Based Predictive Structural Modification
Authors: Dorababu Atukuri
Published: June 2020

Fungal infections have become ubiquitous diseases and their persistent nature and development of drug resistance have led to a global threat. Thereby urgent need to develop efficient antifungal agents is a must. Menace of protozoal diseases cannot be ruled out as the vaccines are not available currently and available anti‐protozoal drugs are of low efficacy. Multidrug‐resistant tuberculosis is responsible for the inefficient treatment of tuberculosis. Regarding cancer control, the five‐membered heterocyclic compounds such as triazoles and tetrazoles are significant pharmacores that play prominent roles in drug design. In this regard, the research is being carried out in the field of drug design and synthesis considering azole‐containing scaffolds as promising target molecules. In this review, the research on azoles having inhibitory properties against various disease causative factors such as fungi, protozoa, bacteria, mycobacteria, etc and various cancer cell lines is described. The whole research is classified on the basis of the type of the azole pharmacore on which the drug molecules are synthesized. The pharmacology of the designed molecules is expressed alongside emphasizing the moieties responsible for the potent activity. Besides, possible structural modification speculating higher biological properties is demonstrated based on SAR.
Vanadium Oxyacetylacetonate Grated on Metal Organic Framework as Catalyst for the Direct Hydroxylation of Benzene to Phenol
Authors: Zhao Qianqian , Zhang Liuxue , Zhao Meiyan , Xu Panpan , Wang Xiulian , Jia Xu , Zhang Jie
Published: June 2020

A high‐performance NH2‐MIL‐88B(Fe)‐SA−V for the direct catalytic oxidation of benzene hydroxylation using hydrogen peroxide as the oxidant was designed and prepared. The synthesized material was characterized by scanning electron microscopy, x‐ray powder diffraction, flourier transform infrared spectroscopy and nitrogen adsorption‐desorption. The influence of different parameters on the catalytic performance of NH2‐MIL‐88B(Fe)‐SA−V for benzene hydroxylation was researched. Under optimized condition, the high yield of 22.2% and selectivity of 98.6% were obtained, while the pure NH2‐MIL‐88B(Fe) only gained the yield of 1.2%. Furthermore, the V/Fe3O4 catalyst was obtained by calcination of NH2‐MIL‐88B(Fe)‐SA−V in N2 for photocatalytic recycle, and the yield and selectivity of phenol were 20.2% and 98.2% respectively. And the V/Fe3O4 has good photocatalytic efficiency after several recycling tests in the acid reaction condition.
Recent Advances in Energy Conversion Applications of Carbon Dots: From Optoelectronic Devices to Electrocatalysis
Authors: Feng Tanglue , Tao Songyuan , Yue Da , Zeng Qingsen , Chen Weihua , Yang Bai
Published: June 2020

Exploitation and utilization of sustainable energy sources has increasingly become the common theme of global social development, which has promoted tremendous development of energy conversion devices/technologies. Owing to excellent and unique optical/electrical properties, carbon dots (CDs) have attracted extensive research interest for numerous energy conversion applications. Strong absorption, downconversion photoluminescence, electron acceptor/donor characteristics, and excellent electron conductivity endow CDs with enormous potential for applications in optoelectronic devices. Furthermore, excellent electron transfers/transport capacities and easily manipulable structural defects of CDs offer distinct advantages for electrocatalytic applications. Recent advances in CD‐based energy conversion applications, including optoelectronic devices such as light‐emitting diodes and solar cells, and electrocatalytic reactions including the hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, and carbon dioxide reduction reaction, are summarized. Finally, current challenges and future prospects for CD‐based energy conversion applications are proposed, highlighting the importance of controllable structural design and modifications.
Phenylbutyrate ameliorates prefrontal cortex, hippocampus, and nucleus accumbens neural atrophy as well as synaptophysin and GFAP stress in aging mice
Authors: Carvajal‐Flores Fabiola Natividad , Díaz Alfonso , Flores‐Gómez Gabriel D. , de la Cruz Fidel , Flores Gonzalo
Published: June 2020

Recent reports on brain aging suggest that oxidative stress and inflammatory processes contribute to aging. Interestingly, sodium phenylbutyrate (PBA) is an inhibitor of histone deacetylase, which has anti‐inflammatory properties. Several reports have suggested the effect of PBA on learning and memory processes, however there are no studies of the effect of this inhibitor of histone deacetylase on aging. Consequently, in the present study, the effect of PBA was studied in 18‐month‐old mice. The animals were administered PBA for 2 months after locomotor activity treatment and Morris water maze tests were performed. The Golgi‐Cox staining technique and immunohistochemistry for glial fibrillary acidic protein (GFAP) and synaptophysin were performed for the morphological procedures. The administration of PBA improves learning and memory according to the Morris water maze test compared to vehicle‐treated animals, which had unchanged locomotor activity. Using Golgi‐Cox staining, dendritic length and the number of dendritic spines were measured in limbic regions, such as the nucleus accumbens (NAcc), prefrontal cortex (PFC) layer 3, and the CA1 of the dorsal hippocampus. In addition, PBA increased the number of dendritic spines in the PFC, NAcc, and CA1 subregions of the hippocampus with an increase in dendritic length only in the CA1 region. Moreover, PBA reduced the levels of the GFAP and increased the levels of synaptophysin in the studied regions. Thus, PBA can be a useful pharmacological tool to prevent or delay synaptic plasticity damage and cognitive impairment caused by age.
Indian Ocean Warming
Authors: Roxy M. K. , Gnanaseelan C. , Parekh Anant , Chowdary Jasti S. , Singh Shikha , Modi Aditi , Kakatkar Rashmi , Mohapatra Sandeep , Dhara Chirag , Shenoi S. C. , Rajeevan M.
Published: June 2020

Sea surface temperature (SST) and upper ocean heat content (OHC, upper 700 m) in the tropical Indian Ocean underwent rapid warming during 1950–2015, with the SSTs showing an average warming of about 1 °C. The SST and OHC trends are very likely to continue in the future, under different emission scenarios. Climate models project a rise in tropical Indian Ocean SST by 1.2–1.6 °C and 1.6–2.7 °C in the near (2040–2069) and far (2070–2099) future across greenhouse gas (GHG) emissions scenarios RCP4.5 and RCP8.5, relative to the reference period of 1976–2005. Indian Ocean warming has very likely resulted in decreasing trend in oxygen (O2) concentrations in the tropical Indian Ocean, and declining trends in pH and marine phytoplankton over the western Indian Ocean. The observed trends in O2, pH and marine phytoplankton are projected to increase in the future with continued GHG emissions.
Comparative Study of Immunomodulatory Agents to Induce Human T Regulatory (Treg) Cells: Preferential Treg-Stimulatory Effect of Prednisolone and Rapamycin
Authors: Janyst Michał , Kaleta Beata , Janyst Karolina , Zagożdżon Radosław , Kozlowska Ewa , Lasek Witold
Published: June 2020

T regulatory (Treg) cells play a critical role in the maintenance of self-tolerance, as well as in inhibition of inflammation and exaggerated immune response against exogenous antigens. They develop in the thymus (tTreg cells) but also may be generated at the peripheral tissues, including tumor microenvironment (pTreg cells), or induced in vitro in the presence of transforming growth factor (TGF)-β (iTreg cells). Since tTreg cells constitute a minor fraction of peripheral blood lymphocytes in physiological conditions, an alternative way to obtain high number of functional Treg cells for therapeutic purposes is their generation in vitro from conventional T cells. In our studies, we compared effectiveness of several pharmacological agents with suggested immunomodulatory effects on Treg development (rapamycin, prednisolone, inosine pranobex, glatiramer acetate, sodium butyrate, and atorvastatin) to optimize Treg-inducing protocols. All but one (atorvastatin) immunomodulators augmented induction of polyclonal Treg cells in cultures. They were effective both in increasing the number of CD4+CD25highFoxp3high cells and Foxp3 expression. Rapamycin and prednisolone were found the most effective. Both drugs prolonged also phenotypic stability of Treg cells and induced fully active Treg cells in a functional assay. In the assay, prednisolone appeared superior versus rapamycin. The results, on the one hand, may be helpful in planning optimal protocols for generation of Treg cells for clinical application and, on the other hand, shed some light on mechanisms of the immunomodulatory activity of some tested agents observed in vivo.
PJI-TNM als neues Klassifikationssystem für Endoprotheseninfektionen
Authors: Rupp Markus , Kerschbaum Maximilian , Freigang Viola , Bärtl Susanne , Baumann Florian , Trampuz Andrej , Alt Volker
Published: June 2020

Hintergrund

Bisherige Klassifikationen für Protheseninfektionen beurteilen die Heterogenität der Infektion nur unzureichend. Die PJI-TNM-Klassifikation berücksichtigt auf Basis der onkologischen TNM-Klassifikation folgende entscheidende Kriterien bei Protheseninfektionen: Implantatart und -stabilität, Weichteilverhältnisse, Biofilmreife, Erregerart, Komorbiditäten des Patienten und Infektrezidive. Ziel dieser Arbeit ist es, die neue PJI-TNM-Klassifikation auf deren Anwendbarkeit in der klinischen Praxis zu überprüfen.

Methoden

Im Rahmen einer Konzeptionsstudie wurde die PJI-TNM-Klassifikation bei 20 Patienten mit periprothetischen Schulter‑, Hüfte- oder Kniegelenksinfektion angewandt. Anhand der Patientenakte wurde die PJI-TNM-Klassifikation mit den übergeordneten Parametern T („tissue and implants“), N („non-eucaryotic cells and fungi“), M („morbidity“) und r („reinfection“), klassifiziert.

Ergebnisse

Alle 20 Fälle (12 männlich, 8 weiblich, mittleres Alter 72,2 [40–88 Jahre]), darunter 13 Hüft-, 6 Knie- und eine Schulterprotheseninfektion, konnten mit der PJI-TNM-Klassifikation klassifiziert werden. Insgesamt zeigte sich eine große Heterogenität der Fälle: 12 Prothesen waren fest (T0), 6 gelockert (T1) und bei zwei Prothesen ein Weichteildefekt (T2) vorhanden. Bei 7 Prothesen wurde von unreifem Biofilm (N0) ausgegangen. 13 Prothesen wurden entsprechend eines reifen Biofilms klassifiziert (N1+N2). 9 Patienten waren nur geringgradig (M0), 7 Patienten mäßig (M1) und 3 Patienten schwer vorerkrankt (M2). Ein Patient lehnte die chirurgische Therapie ab (M3a). Bei 3 Fällen handelte es sich um eine Reinfektion (r).

Schlussfolgerungen

Die aus der Onkologie stammenden Prinzipien der TNM-Klassifikation lassen sich auch bei periprothetischen Infektionen anwenden. Schon bei einer geringen Fallzahl ist eine deutliche Heterogenität periprothetischer Infektionen, wie sie auch im klinischen Alltag generell beobachtet wird, feststellbar. Diese wird durch die PJI-TNM-Klassifikation gut abgebildet und kann dadurch zukünftig eventuell zur Verbesserung bei der Therapieentscheidung beitragen.
Duration of female parental care and their survival in the little auk Alle alle - are these two traits linked?
Authors: Wojczulanis-Jakubas Katarzyna , Jiménez-Muñoz Marina , Jakubas Dariusz , Kidawa Dorota , Karnovsky Nina , Cole Diana , Matechou Eleni
Published: June 2020

Desertion of offspring before its independence by one of the parents is observed in a number of avian species with bi-parental care but reasons for this strategy are not fully understood. This behaviour is particularly intriguing in species where bi-parental care is crucial to raise the brood successfully. Here, we focus on the little auk,Alle alle, a small seabird with intensive bi-parental care, where the female deserts the brood at the end of the chick rearing period. The little auk example is interesting as most hypotheses to explain desertion of the brood by females (e.g. “re-mating hypothesis”, “body condition hypothesis”) have been rejected for this species. Here, we analysed a possible relationship between the duration of female parental care over the chick and her chances to survive to the next breeding season. We performed the study in two breeding colonies on Spitsbergen with different foraging conditions – more favourable in Hornsund and less favourable in Magdalenefjorden. We predicted that in Hornsund females would stay for shorter periods of time with the brood and would have higher survival rates in comparison with birds from Magdalenefjorden. We found that indeed in less favourable conditions of Magdalenefjorden, females stay longer with the brood than in the more favourable conditions of Hornsund. Moreover, female survival was negatively affected by the length of stay in the brood. Nevertheless, duration of female parental care over the chick was not related to their parental efforts, earlier in the chick rearing period, and survival of males and females was similar. Thus, although females brood desertion and winter survival are linked, the relationship is not straightforward.

Significance statement

When bi-parental care is crucial to raise the brood successfully, one parent desertion raises the question of why this happens. We examined this issue in the little auk, a small seabird with females deserting the brood at the end of the chick rearing period. We hypothesised that females deserting the brood save residual energy and, in this way, increases their chance to survive to the next breeding season. We found that duration of female parental care depends on environmental conditions, with longer staying with the brood in less favourable conditions. As expected, female survival decreased with duration of their staying with the brood but it was not related to their parental efforts (i.e. number of chick feedings, duration of foraging flights). In addition, survival of males and females was similar. Thus, although little auk females brood desertion and winter survival are linked, the relationship is not straightforward.
Is Extended‐Duration (Post‐Hospital Discharge) Venous Thromboembolism Chemoprophylaxis Safe and Efficacious in High‐Risk Surgery Patients? A Systematic Review
Authors: Shaikh Saamia , Reddy Melanie , McKenney Mark , Elkbuli Adel
Published: June 2020

Background

The risk of venous thromboembolism (VTE) persists beyond hospitalization in surgical patients, yet post‐hospital discharge chemoprophylaxis regimens are not common. The purpose of this study is to systematically review the literature regarding extended‐duration (post‐hospital discharge) venous thromboembolism chemoprophylaxis and to determine whether it is warranted in high‐risk surgical patients, as determined by its safety and efficacy.

Method

We searched four online databases for articles evaluating extended‐duration (post‐hospital discharge) VTE chemoprophylaxis regimens in surgical patients between the years January 2000 and February 2020. The Preferred Reporting Items for Systematic Reviews and Meta‐Analysis (PRISMA) guidelines were used. GRADE methodology and the Cochrane Risk of Bias Assessment Tool for Randomized Controlled Trials were used to grade the quality of evidence and assess risk of bias.

Results

Nineteen studies with 10,544 patients were analyzed. The duration for extended‐duration VTE chemoprophylaxis ranged from 7 to 42 days. In our study cohort, high‐risk patients not prescribed extended‐duration VTE chemoprophylaxis had a mean VTE incidence rate of 12.23%, while patients receiving 28–30 days of chemoprophylaxis had a mean VTE incidence rate of 4.37% (p = 0.006). The risk of bleeding events did not correlate with the duration of chemoprophylaxis.

Conclusion

Extended‐duration VTE chemoprophylaxis in high‐risk surgical patients decreased the incidence of thrombotic complications without increasing the risk of bleeding events. Further research is needed to establish guidelines for the optimal duration of VTE chemoprophylaxis in high‐risk surgical patients.

Level of evidence

III.
Treatment decision satisfaction and regret after focal HIFU for localized prostate cancer
Authors: Westhoff Niklas , Ernst Ramona , Kowalewski Karl Friedrich , Schmidt Laura , Worst Thomas Stefan , Michel Maurice Stephan , von Hardenberg Jost
Published: June 2020

Purpose

Focal therapies (FTs) are investigated within prospective studies on selected patients treated for localized prostate cancer (PCa). Benefits are preservation of genitourinary function and reduced complications, but follow-up is elaborate and is associated with uncertainty as cancer-free survival appears to be lower compared to standard radical treatments. The aim of this study was to analyse patient-reported acceptance of FT and evaluate factors associated with treatment decision regret.

Methods

52 patients who received focal high-intensity focused ultrasound for low- to intermediate-risk PCa between 2014 and 2019 within two prospective trials were eligible for a survey regarding PCa-related treatment regret and quality-of-life (Clark’s scale) and the following potential predictors: sociodemographic variables, Charlson Comorbidity Index, subjective aging (AARC-10 SF), and general health-related quality-of-life (SF-12). Cancer persistence/recurrence (multiparametric MRI and fusion biopsy after 12 months) and functional outcomes (EPIC-26 UI/UIO/S) data were also included in this study.

Results

The overall survey response rate was 92.3% (48/52 patients). Median follow-up was 38 months (interquartile range = 25–50 months). In total, ten patients (20.8%) reported treatment decision regret. In univariable analyses, a clinically meaningful increase in urinary incontinence showed a significant association (OR 4.43; 95% CI 0.99–20.53; p = 0.049) with regret. Cancer recurrence (OR 12.31; 95% CI 1.78–159.26; p = 0.023) and general health worry as a domain of Clark’s scale (OR 1.07; 95% CI 1.03–1.14; p < 0.01) were predictors of regret in a multivariable logistic regression model (AUC = 0.892).

Conclusion

Acceptance of FT is comparable to standard treatments. Extensive follow-up including regular PSA testing does not cause additional regret but careful patient selection and information before FT is crucial.
Experimental characterization of the hypersonic flow around a cuboid
Authors: Rees Thomas W. , Fisher Tom B. , Bruce Paul J. K. , Merrifield Jim A. , Quinn Mark K.
Published: June 2020

Understanding the hypersonic flow around faceted shapes is important in the context of the fragmentation and demise of satellites undergoing uncontrolled atmospheric entry. To better understand the physics of such flows, as well as the satellite demise process, we perform an experimental study of the Mach 5 flow around a cuboid geometry in the University of Manchester High SuperSonic Tunnel. Heat fluxes are measured using infrared thermography and a 3D inverse heat conduction solution, and flow features are imaged using schlieren photography. Measurements are taken at a range of Reynolds numbers from $${40.0 \times 10^3}$$

40.0
×

10
3

to $${549 \times 10^3}$$

549
×

10
3

. The schlieren results suggest the presence of a separation bubble at the windward edge of the cube at high Reynolds numbers. High heat fluxes are observed near corners and edges, which are caused by boundary-layer thinning. Additionally, on the side (off-stagnation) faces of the cube, we observe wedge-shaped regions of high heat flux emanating from the windward corners of the cube. We attribute these to vortical structures being generated by the strong expansion around the cube’s corners. We also observe that the stagnation point of the cube is off-centre of the windward face, which we propose is due to sting flex under aerodynamic loading. Finally, we propose a simple method of calculating the stagnation point heat flux to a cube, as well as relations which can be used to predict hypersonic heat fluxes to cuboid geometries such as satellites during atmospheric re-entry.

Graphic abstract
Clinical characterization of children and adolescents with NF1 microdeletions
Authors: Kehrer-Sawatzki Hildegard , Kluwe Lan , Salamon Johannes , Well Lennart , Farschtschi Said , Rosenbaum Thorsten , Mautner Victor-Felix
Published: June 2020

Purpose

An estimated 5–11% of patients with neurofibromatosis type 1 (NF1) harbour NF1 microdeletions encompassing the NF1 gene and its flanking regions. The purpose of this study was to evaluate the clinical phenotype in children and adolescents with NF1 microdeletions.

Methods

We retrospectively analysed 30 children and adolescents with NF1 microdeletions pertaining to externally visible neurofibromas. The internal tumour load was determined by volumetry of whole-body magnetic resonance imaging (MRI) in 20 children and adolescents with NF1 microdeletions. Furthermore, the prevalence of global developmental delay, autism spectrum disorder and attention deficit hyperactivity disorder (ADHD) were evaluated.

Results

Children and adolescents with NF1 microdeletions had significantly more often cutaneous, subcutaneous and externally visible plexiform neurofibromas than age-matched patients with intragenic NF1 mutations. Internal neurofibromas were detected in all 20 children and adolescents with NF1 microdeletions analysed by whole-body MRI. By contrast, only 17 (61%) of 28 age-matched NF1 patients without microdeletions had internal tumours. The total internal tumour load was significantly higher in NF1 microdeletion patients than in NF1 patients without microdeletions. Global developmental delay was observed in 28 (93%) of 30 children with NF1 microdeletions investigated. The mean full-scale intelligence quotient in our patient group was 77.7 which is significantly lower than that of patients with intragenic NF1 mutations. ADHD was diagnosed in 15 (88%) of 17 children and adolescents with NF1 microdeletion. Furthermore, 17 (71%) of the 24 patients investigated had T-scores ≥ 60 up to 75, indicative of mild to moderate autistic symptoms, which are consequently significantly more frequent in patients with NF1 microdeletions than in the general NF1 population. Also, the mean total T-score was significantly higher in patients with NF1 microdeletions than in the general NF1 population.

Conclusion

Our findings indicate that already at a very young age, NF1 microdeletions patients frequently exhibit a severe disease manifestation which requires specialized long-term clinical care.
Individual tubular J-aggregates stabilized and stiffened by silica encapsulation
Authors: Herman Katherine , Kirmse Holm , Eljarrat Alberto , Koch Christoph T. , Kirstein Stefan , Rabe Jürgen P.
Published: June 2020

Amphiphilic cyanine dyes in aqueous solution self-assemble into J-aggregates with diverse structures. In particular, the dye 3,3′-bis(3-sulfopropyl)-5,5′,6,6′-tetrachloro-1,1′-dioctylbenzimida-carbo-cyanine (C8S3) forms micrometer long double walled tubular J-aggregates with a uniform outer diameter of 13 ± 0.5 nm. Interestingly, these J-aggregates exhibit strong exciton delocalization and migration, similar to natural light harvesting systems. However, their structural integrity and hence their optical properties are very sensitive to their chemical environment as well as to mechanical deformation, rendering detailed studies on individual tubular J-aggregates difficult. We addressed this issue and examined a previously published route for their chemical and mechanical stabilization by in situ synthesis of a silica coating that leaves their absorbance and emission unaltered in solution. Here, we demonstrate that the silica shell with a thickness of a few nanometers is able to stabilize the tubular J-aggregates of C8S3 against changes of pH of solutions down to values where pure aggregates are oxidized, against drying under ambient conditions, and even against the vacuum conditions within an electron microscope. Dried silica–covered aggregates are brittle, as demonstrated by manipulation with a scanning force microscope on a surface. Transmission electron microscope images confirm that the thickness of the coatings is homogeneous and uniform with a thickness of less than 5 nm; scanning TEM energy dispersive X-ray spectroscopy confirms the chemical composition of the shell as SiO2; and electron energy loss spectra could be recorded across a single freely suspended aggregate. Such a silica shell may not only serve for stabilization but also could be the base for further functionalization of the aggregates by either chemical attachment of other units on top of the shell or by inclusion during the synthesis.
Altered microvascular density in patients with systemic lupus erythematosus treated with hydroxychloroquine—an optical coherence tomography angiography study
Authors: Mihailovic Nataša , Leclaire Martin Dominik , Eter Nicole , Brücher Viktoria C.
Published: June 2020

Purpose

To evaluate the retinal microvascular density using optical coherence tomography angiography (OCTA) in patients with systemic lupus erythematosus (SLE) treated with hydroxychloroquine (HCQ).

Methods

Nineteen eyes of 19 patients with SLE (study group) without HCQ retinopathy and 19 eyes of 19 healthy subjects (control group) were included in this study. The study group was divided into patients using HCQ for > 5 years (high-risk group) and < 5 years (low-risk group). The VD data of the 3 × 3 mm OCT angiogram of the superficial capillary plexus (SCP) and the choriocapillaris (VD-CC), the foveal avascular zone (FAZ) area and the central retinal thickness (CRT) were extracted and analyzed.

Results

VD in the en face SCP was significantly reduced in the high-risk group and the low-risk group compared with that in the control group (p < 0.001, p = 0.001) and in the high-risk group compared with the low-risk group (p = 0.007). Correlation analysis between the cumulative dose of HCQ and the VD of the study group revealed a negative correlation, but no statistical significance (p = 0.074). However, a significant positive correlation was observed for the low-risk group (p = 0.035). In patients with SLE, VD-CC was lower (p = 0.042) and the FAZ area larger (p = 0.019). CRT showed no difference between the groups (p = 0.183).

Conclusion

In this study, SLE patients showed a reduced VD in both groups. In patients treated with HCQ < 5 years, HCQ might have a protective effect on retinal microvasculature. Analysis of retinal microvascular density using OCTA could be useful in the diagnosis and monitoring of vascular alteration in patients with SLE.