bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetic model and optimization for enzyme‐assisted hydrodistillation of d‐limonene‐rich essential oil from orange peel
Authors: Waheed Ammara , Akram Sumia , Ashraf Rizwan , Mushtaq Muhammad , Adnan Ahmad
Published: July 2020

The present research has been planned to evaluate the effect of enzymatic maceration on the recovery of essential oil during hydrodistillation of orange (Citrus sinensis L.) peel. In the execution phase, the orange peel was hydrolysed under different conditions regarding enzyme concentration, liquid‐to‐solid ratio, temperature and incubation time, which established that hydrolysis of orange peel with 3.9% (mL/100 g) Viscozyme L® at liquid/solid ratio of 4.0 (mL/g) and 55°C for 3.8 hours can produce essential oil fourfold higher as compared to untreated orange peel. The kinetic modelling of the data further established that the incorporation of enzymatic pretreatment can reduce the extraction time up to 4 hours without any loss of aroma compounds. The GC‐MS analysis of orange peel essential oil obtained under optimum conditions of enzyme‐assisted hydrodistillation (EAHD) revealed the presence of D‐limonene as a major constituent (66%) followed by β‐caryophyllene (23%) and isopropyl myristate (11%). Moreover, the orange peel essential oil expressed via EAHD showed a good tendency to neutralize free radicals and protect linoleic acid under ambient conditions. Henceforth, it might be brought forward that enzyme‐assisted hydrodistillation worked more efficiently and economically than the conventional counterpart.
Immune related proteins and tumor infiltratingCD8+ lymphocytes in hypopharyngeal cancer in relation to human papillomavirus (HPV) and clinical outcome
Authors: Landin David , Ährlund‐Richter Andreas , Mirzaie Leila , Mints Michael , Näsman Anders , Kolev Aeneas , Marklund Linda , Dalianis Tina , Munck‐Wikland Eva , Ramqvist Torbjörn
Published: July 2020

Background

Hypopharyngeal cancer (HPSCC) shows a poor clinical outcome, while HPSCC, caused by human papillomavirus (HPV), presents a better outcome. Here, HPCC, immune proteins, and tumor infiltrating CD8+ lymphocytes (CD8+ TILs) were evaluated in relation to HPV and outcome.

Methods

Fresh frozen tissue from four HPV‐positive HPSCC, 39 HPV‐negative HPSCC, and normal samples were analyzed for protein expression by the Proseek immuno‐oncology immunoassay. CD8+ TIL numbers evaluated by immunohistochemistry on 144 formalin‐fixed biopsies were analyzed in relation to clinical outcome.

Results

Proteins differing between HPV‐positive and negative HPSCC included CD8A, PD‐L1, Fas ligand, and chemokines. High CD8+ TIL numbers were correlated to improve clinical outcome in HPV‐negative HPSCC.

Conclusions

High expression of immune proteins in HPV‐positive HPSCC may explain the better clinical outcome. CD8+ TILs are of relevance for outcome of HPV‐negative HPSCC, while tumors with high immune activity but poor patient survival suggest a role for immune therapy.
Obstetric hemorrhage in resource‐limited locations: A quality improvement project after adoption of abdominopelvic compression devices
Authors: Kerr Nancy L. , Hauswald Mark , Tamrakar Suman R. , Kalit Solomon
Published: July 2020

Objective

To evaluate obstetric hemorrhage outcomes and present data specific to adoption of pneumatic circumferential abdominopelvic compression devices.

Methods

Two resource‐limited locations added low‐cost pneumatic compression devices to their standard protocols for obstetric hemorrhage between 2010 and 2019. Providers in rural Nepal and Papua New Guinea used devices that incorporated a bicycle tube or soccer ball (“Ball and Binder”) to provide abdominopelvic pressure after all available routine treatments had failed. Data were collected during the entire period as part of ongoing obstetric quality improvement. Data presented include obstetric event, etiology of bleeding, need for surgery, transfusion, transport, length of transports, maternal survival, and complications.

Results

Circumferential abdominopelvic compression was used 106 times. The devices were used primarily after vaginal birth with atony, but also for obstetrical lacerations, miscarriages, and post‐abortion bleeding. In all cases the bleeding stopped “promptly.” All women survived, none required hysterectomy, and no complications were reported resulting from device use. Only 15 (14%) patients were transported to a referral hospital.

Conclusion

In this quality improvement project, obstetric hemorrhage was controlled when circumferential pressure was applied after usual care had failed.
Repeated evolution of eye loss in Mexican cavefish: Evidence of similar developmental mechanisms in independently evolved populations
Authors: Sifuentes‐Romero Itzel , Ferrufino Estephany , Thakur Sunishka , Laboissonniere Lauren A. , Solomon Michael , Smith Courtney L. , Keene Alex C. , Trimarchi Jeffrey M. , Kowalko Johanna E.
Published: July 2020

Evolution in similar environments often leads to convergence of behavioral and anatomical traits. A classic example of convergent trait evolution is the reduced traits that characterize many cave animals: reduction or loss of pigmentation and eyes. While these traits have evolved many times, relatively little is known about whether these traits repeatedly evolve through the same or different molecular and developmental mechanisms. The small freshwater fish, Astyanax mexicanus, provides an opportunity to investigate the repeated evolution of cave traits. A. mexicanus exists as two forms, a sighted, surface‐dwelling form and at least 29 populations of a blind, cave‐dwelling form that initially develops eyes that subsequently degenerate. We compared eye morphology and the expression of eye regulatory genes in developing surface fish and two independently evolved cavefish populations, Pachón and Molino. We found that many of the previously described molecular and morphological alterations that occur during eye development in Pachón cavefish are also found in Molino cavefish. However, for many of these traits, the Molino cavefish have a less severe phenotype than Pachón cavefish. Further, cave–cave hybrid fish have larger eyes and lenses during early development compared with fish from either parental population, suggesting that some different changes underlie eye loss in these two populations. Together, these data support the hypothesis that these two cavefish populations evolved eye loss independently, yet through some of the same developmental and molecular mechanisms.
Regioselective synthesis of fused ring heterocyclic derivatives of ketene aminals and their biological activities
Authors: Yaqub Muhammad , Batool Javeria , Mahmood Khalid , Ashraf Abida , Perveen Ruqayia , Shafiq Zahid
Published: July 2020

A regioselective and convenient methodology was developed to synthesize heterocyclic derivatives, bearing imidazole, piperidines, and azepines rings. The N‐arylnitrones derived from 3‐formylchromones were selected to react with heterocyclic ketene aminal to furnish the structurally attractive and pharmacologically important fused ring heterocycles. The N‐arylnitrone moiety of 3‐formylchromone was used to activate the formyl group for regioselective fused ring heterocycles synthesis, whereas, the effect of substituents at aryl functionality of nitrones were studied to improve the yield of target fused ring heterocyclic products. The synthesized compounds (10‐12) were evaluated for their in vitro cytotoxic and antifungal influences. In cytotoxic (brine shrimp lethality) assay, compound 11e was found to be active with LD50 = 4.1 × 10−6 μg/mL.
MR‐Based Electrical Conductivity Imaging of Liver Fibrosis in an Experimental Rat Model
Authors: Kim Jin Woong , Kim Hyun Bum , Hur Young Hoe , Choi Bup Kyung , Katoch Nitish , Park Ji Ae , Kim Hyung Joong , Woo Eung Je
Published: July 2020

Background

Liver fibrosis is characterized by the excessive accumulation of extracellular matrix proteins. Electrical conductivity imaging at low frequency can provide novel contrast because the contrast mechanisms originate from the changes in the concentration and mobility of ions in the extracellular space.

Purpose

To evaluate the feasibility of an MR‐based electrical conductivity imaging that can detect the changes in a tissue condition associated with the progression of liver fibrosis.

Study Type

Prospective phantom and animal study.

Animal Model

Fibrosis was induced by weekly intraperitoneal injection of dimethylnitrosamine (DMN) in 45 male Sprague–Dawley rats.

Field Strength/Sequence

3T MRI with a multispin‐echo pulse sequence.

Assessment

The percentage change of conductivity (Δσ, %) in the same region‐of‐interest (ROI) was calculated from the DMN‐treated rats based on the values of the normal control rats. The percentage change was also calculated between the ROIs in each DMN‐treated group.

Statistical Tests

One‐way analysis of variance (ANOVA) and a two‐sample t‐test were performed.

Results

Liver tissues in normal control rats showed a uniform conductivity distribution of 56.6 ± 4.4 (mS/m). In rats more than 5 weeks after induction, the fibrous region showed an increased conductivity of ≥12% compared to that of the corresponding normal control rats. From regional comparisons in the same liver, the fibrous region showed an increased conductivity of ≥11% compared to the opposite, less induced region of rats more than 5 weeks after induction. Liver samples from the fibrous region represent tissue damages such as diffuse centrilobular congestion with marked dilatation of central veins from the histological findings. Immunohistochemistry revealed significant levels of attenuated fibrosis and increased inflammatory response.

Data Conclusion

The increased conductivity in the fibrous region is related to the changes of the extracellular space. The correlation between the collagen deposition and conductivity changes is essential for future clinical studies.

Level of Evidence 2

Technical Efficacy Stage 2

J. MAGN. RESON. IMAGING 2021;53:554–563.
Solvent‐resistant microfluidic paper‐based analytical device/spray mass spectrometry for quantitative analysis of C18‐ceramide biomarker
Authors: Azizov Shavkatjon , Sharipov Mirkomil , Lim Jae‐Min , Tawfik Salah M. , Kattaev Nuritdin , Lee Yong‐Ill
Published: July 2020

We developed a highly efficient and low‐cost organic solvents‐resistant microfluidic paper‐based analytical device (μPAD) coupled with paper spray mass spectrometry (PS‐MS) for quantitative determination of C18‐ceramide as a prognostic biomarker for several diseases. Several models of μPAD patterns have been examined to select the most resistant and efficient microchannel barriers, which can provide continuous spray at ionization zone and prevent “coffee ring” effect. Moreover, the developed μPAD has enabled the analysis of low concentration of C18‐ceramide because of the maximum supply of deposited analyte through microchannel. The MS results confirmed the formation of doubly and singly charged metal ion complexes between ceramide and different metal ions. Notably, the complexation that occurs between lithium ions and C18‐ceramide showed a high relative abundance compared with other formed complexes. Taking into account the relative abundance of complex [Cer + Li]+ at 572.8 m/z, it can be considered as a stable ion and therefore be used for the analysis of C18‐ceramide at low concentrations. Complexation of C18‐ceramide and lithium confirmed with quantum chemical calculations. The proposed method represents good linearity with a regression coefficient of 0.9956 for the analysis of C18‐ceramide and reaches a limit of detection to 0.84 nM. It has been adapted successfully for practical application in human serum samples with high recovery values in range of 92%–105%. The developed μPAD‐MS technique provides clear advantages by reducing the experimental steps and simplifying the operation process and enables to identify subnanomolar concentration of C18‐ceramide in human serum samples.
The influence of mesoscale land–seabreeze circulation on local wind climatology in the Svalbard fjords of Kongsfjorden and Hornsund
Authors: Kitowska Małgorzata , Makuch Przemysław , Petelski Tomasz , Piskozub Jacek
Published: July 2020

We analyse data series (1992–2013) of wind measurements from meteorological stations in Ny‐Ålesund and Hornsund on Svalbard and then have them compared to surface layer winds from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis. We find significant discrepancies between the local wind direction and directions of wind compatible with the analysis of large‐scale pressure fields. We argue that one of the most important factors controlling wind directions in the Svalbard fjords is the difference in temperature between the neighbouring glaciers and surface sea temperatures of open waters warmed by the west Spitsbergen current. This creates atmospheric circulation patterns similar to the land breeze in temperate climates. We show that the frequency of simultaneous breeze‐type circulation events on the northern and southern fjords of Spitsbergen is highly correlated with sea–land temperature difference on monthly timescales. A Monte Carlo analysis of breeze probabilities rejects the null hypothesis of independent breeze events in both fjords. This result shows that breeze events are not independent where two fjords placed at opposite ends of Spitsbergen's west coast are concerned, and we also posit that the breeze occurrence is largely controlled by the synoptic situation. Such large‐scale wind phenomena should have an impact on air–sea heat fluxes to the east of Spitsbergen.
Comparison of Er,Cr:YSGG laser to minimally invasive surgical technique in the treatment of intrabony defects: Six‐month results of a multicenter, randomized, controlled study
Authors: Clem Donald , Heard Rick , McGuire Michael , Scheyer E. Todd , Richardson Chris , Toback Gregory , Gwaltney Chad , Gunsolley John C.
Published: July 2020

Background

The purpose of this publication is to report on the six‐month clinical results and patient‐reported outcomes (PROs) comparing the surgical use of the erbium, chromium‐doped: yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser (ERL) and minimally invasive surgical technique (MIST) for the treatment of intrabony defects in subjects with generalized periodontitis stage III, grade B.

Methods

Fifty‐three adults (29 females and 24 males; aged 19 to 73 years) with 79 intrabony defects were randomized following scaling and root planing (SRP) to receive ERL monotherapy (n = 27) or MIST (n = 26). Recession, probing depth (PD), clinical attachment level (CAL), treatment time, and PROs were assessed and compared for each treatment group. Clinical measurements were recorded at baseline, 4 to 6 weeks following SRP, and 6 months following surgical therapy.

Results

The following primary and secondary outcome variables were non‐inferior with the following margins: CAL with a non‐inferiority margin of 0.6 mm (p = 0.05), PD with a non‐inferiority margin of 0.5 mm (p = 0.05). Recession with a non‐inferiority margin of 0.4 mm (p = 0.05). Faster procedure times were found for ERL (16.39 ± 6.21 minutes) versus MIST (20.17 ± 5.62 minutes), p = 0.0002. In the first 2 to 3 days of post‐therapeutic diary outcomes, subjects reported less bruising, facial swelling, and use of ice pack for the ERL group.

Conclusions

This is the first multicenter, randomized, masked, and controlled study demonstrating the ERL is not inferior to MIST in terms of clinical outcomes but is superior in PROs for the surgical treatment of intrabony defects.
Choosing the left fork: Steven Offenbacher and understanding maternal periodontal disease and adverse pregnancy outcomes
Authors: Boggess Kim A.
Published: July 2020

Steven Offenbacher was one of the first researchers to identify periodontal disease as a risk factor for various adverse pregnancy outcomes. Cohort and case‐controlled studies of pregnant women have demonstrated periodontal disease as a risk factor for preterm birth, preeclampsia, and fetal growth restriction. Periodontal therapy during the second trimester improves maternal oral health but fails to reduce the risk of preterm birth. A possible association between periodontal disease and gestational diabetes has also been reported. In one model, periodontal bacteria gain access to the systemic circulation, and thereby the placenta, resulting in local inflammation, placental dysfunction, and, consequently, adverse pregnancy outcomes. It is crucial to increase awareness of the links between maternal periodontal and adverse pregnancy outcomes and to promote oral health prophylaxis during pregnancy.
On the productive function of furnaces in archaeological sites
Authors: Rossi Manuela , De Riso Nunzia , Caterino Marco , Ferraro Giarita , Cicala Luigi , Ferrara Bianca , Gassner Verena , Vergara Alessandro
Published: July 2020

The knowledge on the material production from archaeological sites contains valuable information on the technological advances and on the commercial routes of a civilization. Archaeologists can face some ambiguities in the assessment of the productive function of furnaces emerging from excavation when archaeological markers are not available due to a poor conservation state. A protocol to discriminate among the production of lime and ceramics is the major aim of this work. Indeed, herein, we address the possibility to assist archaeologists by a vibrational spectroscopy‐based identification of furnace productive function using a proper sampling, particularly to discriminate between kiln for ceramics from calcara. The proposed analytical procedure supported by a geological survey of the area was established, defining also the application limits, by investigating four cases, one from the sanctuary of Hera at the mouth of river Sele (Paestum), two from Velia (Eastern and Southern quarters), and the fourth from Roscigno. Some care during sampling from furnaces and in the interpretation of possible interferences in Raman and FT‐IR spectra are also discussed.
Wind erosion of soil influenced by clay amendment in the inland Pacific Northwest, USA
Authors: Pi Huawei , Huggins David R. , Sharratt Brenton
Published: July 2020

Soil clay content is one of the primary intrinsic soil properties affecting soil erodibility and ecological processes, but few studies have tested the effects of clay amendment on wind erosion of soil. The objective of this study was therefore to evaluate the effect of progressive clay amendment on wind erosion of soil in the inland Pacific Northwest, where there is a high soil erodibility risk due to the arid and semiarid environment and sandy soils. Clay amendment significantly increased crust crushing energy when physical soil crusts formed after simulated rainfall. Crusts were then subject to simulated tillage to create an erodible soil surface before determining wind erosion in a wind tunnel. Soil loss significantly decreased with increasing clay amendment, even for low clay amendments (2%), soil loss at this percentage of clay amendment was 13.1–99.7% lower as compared with a soil surface devoid of clay amendment for the four soil types. The rate of change in erosion decreased with increasing amounts of clay amendment. Clay amendment was more effective in decreasing soil loss for two sandy loams or soil types with lower clay content. Clay amendment decreased soil loss primarily due to its impact on increasing aggregate geometric mean diameter (GMD), but aggregate crushing energy is also important in decreasing soil loss in terms of decreasing abrasion flux. Clay amendment is thus an effective way to restrain land deterioration in terms of increasing crust crushing energy, aggregate GMD, and decreasing abrasion flux.
Machine Learning‐Based Optoacoustic Tissue Classification Method for Laser Osteotomes Using an Air‐Coupled Transducer
Authors: Nguendon Kenhagho Hervé , Canbaz Ferda , Gomez Alvarez‐Arenas Tomas E. , Guzman Raphael , Cattin Philippe , Zam Azhar
Published: July 2020

Background and Objectives

Using lasers instead of mechanical tools for bone cutting holds many advantages, including functional cuts, contactless interaction, and faster wound healing. To fully exploit the benefits of lasers over conventional mechanical tools, a real‐time feedback to classify tissue is proposed.

Study Design/Materials and Methods

In this paper, we simultaneously classified five tissue types—hard and soft bone, muscle, fat, and skin from five proximal and distal fresh porcine femurs—based on the laser‐induced acoustic shock waves (ASWs) generated. For laser ablation, a nanosecond frequency‐doubled Nd:YAG laser source at 532 nm and a microsecond Er:YAG laser source at 2940 nm were used to create 10 craters on the surface of each proximal and distal femur. Depending on the application, the Nd:YAG or Er:YAG can be used for bone cutting. For ASW recording, an air‐coupled transducer was placed 5 cm away from the ablated spot. For tissue classification, we analyzed the measured acoustics by looking at the amplitude‐frequency band of 0.11–0.27 and 0.27–0.53 MHz, which provided the least average classification error for Er:YAG and Nd:YAG, respectively. For data reduction, we used the amplitude‐frequency band as an input of the principal component analysis (PCA). On the basis of PCA scores, we compared the performance of the artificial neural network (ANN), the quadratic‐ and Gaussian‐support vector machine (SVM) to classify tissue types. A set of 14,400 data points, measured from 10 craters in four proximal and distal femurs, was used as training data, while a set of 3,600 data points from 10 craters in the remaining proximal and distal femur was considered as testing data, for each laser.

Results

The ANN performed best for both lasers, with an average classification error for all tissues of 5.01 ± 5.06% and 9.12 ± 3.39%, using the Nd:YAG and Er:YAG lasers, respectively. Then, the Gaussian‐SVM performed better than the quadratic SVM during the cutting with both lasers. The Gaussian‐SVM yielded average classification errors of 15.17 ± 13.12% and 16.85 ± 7.59%, using the Nd:YAG and Er:YAG lasers, respectively. The worst performance was achieved with the quadratic‐SVM with a classification error of 50.34 ± 35.04% and 69.96 ± 25.49%, using the Nd:YAG and Er:YAG lasers.

Conclusion

We foresee using the ANN to differentiate tissues in real‐time during laser osteotomy. Lasers Surg. Med. © 2020 Wiley Periodicals LLC
New chaotic attractors: Application of fractal‐fractional differentiation and integration
Authors: Gómez‐Aguilar J.F. , Atangana Abdon
Published: July 2020

Very recently, the concept of fractal differentiation and fractional differentiation has been combined to produce new differentiation operators. The new operators were constructed using three different kernels, namely, power law, exponential decay, and the generalized Mittag‐Leffler function. The new operators have two parameters: the first is considered as fractional order and the second as fractal dimension. In this work, we applied these new operators to model some chaotic attractors, and the models were solved numerically using a new and very efficient numerical scheme. We presented numerical simulations for some specific fractional order and fractal dimension. The classical fractional differential models could be recovered when the fractal dimension is equal to 1; in these cases, the obtained attractors with power law presented no similarities. Nevertheless, those obtained via Caputo‐Fabrizio and the Atangana‐Baleanu derivative show some crossover effects, which is due to non‐index law property. However, those obtained from fractal‐fractional, in particular, those with the Mittag‐Leffler kernel, show very strange and new attractors with self‐similarities; these results are obtained for the first time. We conclude that this new concept is the future to modelling complexities with self‐similarities.
Numerical Techniques for the Solution of the Molecular Weight Distribution in Polymerization Mechanisms, State of the Art
Authors: Saldívar‐Guerra Enrique
Published: July 2020

The molecular weight distribution (MWD) is possibly the most important characteristic of a polymer. Polymers derive many of their physical properties from their MWD. Therefore, since the origins of polymer science, the theory provides a link between the kinetic mechanism and the mathematical expression of the MWD, and there are analytical solutions for ideal cases. However, the MWD formed in real‐life polymerization processes is usually more complex; the solution of the mathematical models that describe them can be quite challenging and has been the focus of enormous research efforts. These models may consist of systems of very large dimension: thousands of differential equations, often stiff, which demand special numerical techniques for their solution. In this paper the numerical techniques that can be used to solve this challenging problem are reviewed and contrasted, including weighted residual methods, direct integration, numerical inversion of transformed equations, and lumping methods. Stochastic techniques are also surveyed.
Job strain in nonprofit human service agencies: Job demands and job control's additive effects, and goal‐related feedback's mediating role
Authors: Preston Mark S.
Published: July 2020

Few quantitative studies in the nonprofit literature have examined job demands' strain‐inducing impact. The classic demand‐control (DC) model predicts a positive main effect for job demands and a negative main effect for job control on job strain, respectively. However, four decades of DC model studies have uncovered modest support for this additive model. As a means of addressing both issues, the present study tested a recently introduced modified additive model using 621 employees from two different types of nonprofit human service agencies located in the city of New York. Two mediational analyses, structural equation modelling and bootstrapping, corroborated goal‐related feedback's intervening role on the control‐strain relationship. Findings not only replicate and extend prior research, but also make a unique contribution to the nonprofit literature. Implications for the stress management of nonprofit human service employees, as well as recommendations for the DC model literature are also discussed.
Applying the three‐dimensional block‐pulse functions to solve system of Volterra–Hammerstein integral equations
Authors: Xie Jiaquan , Gong Xiaoyuan , Shi Wei , Li Ruili , Zhao Weici , Wang Tao
Published: July 2020

In this paper, a numerical scheme is utilized to solve three‐dimensional nonlinear system of Volterra‐Hammerstein integrals equations, which is based on the three‐dimensional block‐pulse functions (3D‐BPFs) and their operational matrices. Then the primary nonlinear system is transferred into a linear system of algebraic equations by applying the approximate expression and operational matrices, which can be easily solved through any numerical techniques. According to the convergence of 3D‐BPFs, the new convergence analysis and error estimation theorem of the research system is detailed investigated. Lastly illustrative examples are included to demonstrate the validity and applicability of the technique.
Synergistic toughening of iso‐polypropylene with high‐density polyethylene and polycyclooctene synthesized by ROMP
Authors: Zhou Fuqiang , Qi Lucheng , He Xuelian
Published: July 2020

A series of different molecular weight Polycyclooctene(PCOE) rubber were synthesized via ROMP with G2 catalyst and Iso‐polypropylene (iPP), PCOE and high density polyethylene (HDPE) blends were prepared by micro twin‐screw extruder. The effects of PCOE molecular weight and content were investigated by studying the thermal, rheological and mechanical properties of the blends. We observed that the low molecular weight PCOE promoted the dispersion of HDPE, and as the molecular weight and content of PCOE rising, PCOE encapsulated HDPE particles entirely to form a connected core‐shell network structure in PP matrix and a certain degree of micro‐crosslinked structure which connected the PCOE ‘shell’. Micrographs of the fracture surfaces support the finding that PCOE promoted a finer dispersion and improved the morphological stability of the ternary blends as a compatibillizer. The increasing molecular weight of PCOE enhanced the molecular chains entanglement of the blends resulting in an increase on blends viscosity. The interfacial adhesion of PP/PCOE/HDPE ternary blends improved significantly as PCOE molecular weight increased from 12 kg/mol to 270 kg/mol. The impact strength of the PP/PCOE/HDPE blends increased by 3 times as compared with PP/HDPE blends owing to the addition of 15 wt% HDPE and 15 wt% PCOE(Mn = 270 kg/mol).
A retrospective analysis of recurrent pediatric ependymoma reveals extremely poor survival and ineffectiveness of current treatments across central nervous system locations and molecular subgroups
Authors: Ritzmann Timothy A. , Rogers Hazel A. , Paine Simon M.L. , Storer Lisa C.D. , Jacques Thomas S. , Chapman Rebecca J. , Ellison David , Donson Andrew M. , Foreman Nicholas K. , Grundy Richard G.
Published: July 2020

Background

Relapse occurs in 50% of pediatric ependymoma cases and has poor prognosis. Few studies have investigated the clinical progress of relapsed disease, and treatment lacks a standardized approach.

Methods and materials

We analyzed 302 pediatric ependymoma cases. Tumor, demographic, and treatment variables were investigated for association with relapse risk, time to recurrence, and survival after relapse. DNA methylation profiling was performed for 135/302 cases, and predominant subgroups were EPN_PFA (n = 95) and EPN_RELA (n = 24). Chromosome 1q status was ascertained for 185/302 cases by fluorescent in‐situ hybridization (FISH), multiplex ligation‐dependent probe amplification (MLPA), and DNA methylation profiles.

Results

Sixty‐two percent of cases relapsed, with a median of two recurrences with no difference between posterior fossa and supratentorial locations (66% vs 55% relapse rate). One hundred seventeen (38%) cases relapsed within two years and five (2%) beyond 10 years. The late relapses were clinically heterogeneous. Tumor grade and treatment affected risk and time to relapse variably across subgroups. After relapse, surgery and irradiation delayed disease progression with a minimal impact on survival across the entire cohort. In the EPN_PFA and EPN_RELA groups, 1q gain was independently associated with relapse risk (subhazard ratio [SHR] 4.307, P = 0.027 and SHR 1.982, P = 0.010, respectively) while EPN_PFA had increased relapse risk compared with EPN_RELA (SHR = 0.394, P = 0.018).

Conclusions

Recurrent pediatric ependymoma is an aggressive disease with poor outcomes, for which current treatments are inadequate. We report that chromosome 1q gain increases relapse risk in common molecular subgroups in children but a deeper understanding of the underlying biology at relapse and novel therapeutic approaches are urgently needed.
Functionalized‐graphene reinforced polyethersulfone nanocomposites with improved physical and mechanical properties
Authors: Ahmad Md. Wasi , Dey Baban , Al Saidi Abdullah Khamis Ali , Choudhury Arup
Published: July 2020

We have explored graphene oxide (GO) and sulfonic acid‐functionalized graphene oxides (GOSO3H) as efficient reinforcements to improve the performances of the polyethersulfone (PES). In contrast to GO, the numerous terminal SO3− groups in GOSO3H nanosheets not only promoted the filler dispersion in PES matrix, but also formed strong interfacial adhesion via H‐bonding and dipole‐dipole interactions. The tensile strength of PES was enhanced by around 3‐folds and 5‐folds upon incorporation 5 wt% GO and GOSO3H nanosheets, respectively. The improvement of tensile modulus of PES is considerably higher with GOSO3H nanosheets compared to GO. The superior tensile properties of the PES/GOSO3H nanocomposites could be ascribed to the better dispersion of GOSO3H nanosheets and the efficient stress transfer between PES matrix and GOSO3H nanosheets, which is well supported by X‐ray diffraction and morphological analyses. The loading capacity of the GOSO3H was found be higher than that of GO. The dc conductivity of the PES/GOSO3H nanocomposites was recorded greater than that of the GO‐reinforced nanocomposites. The thermo‐oxidative stability of the PES matrix was substantially improved upon inclusion of both the GO and GOSO3H, but the GOSO3H showed better effects. Overall, the as‐prepared PES/GOSO3H hybrid nanocomposite can be used as potential material in different membrane applications.
Der kontrollierte Stoß
Authors: Mathelitsch Leopold , Thaller Sigrid
Published: July 2020

Das Billardspiel ist über ein halbes Jahrtausend alt. Seine Physik fasziniert die Forschung seit Huygens bis heute. Die aus der Perspektive der Physik entscheidenden Elemente sind der Stoß mit dem Queue, der Kontakt zwischen den Bällen und der Kontakt zwischen Ball und Bande. Gestoßen werden kann die Kugel zentral, ober‐ oder unterhalb ihres Mittelpunkts sowie seitlich versetzt. Davon hängt ihr Verhalten ab, ob sie rollt, gleitet, etwa einen Topspin oder einen sonstigen Effet mitbekommt. Während der Kontakt zwischen zwei Bällen wegen der geringen Reibung wie ein elastischer Stoß behandelbar ist, spielt der Effet beim Kontakt mit der Bande eine wichtige Rolle. Beim Sinai‐Billard besitzt der Tisch runde Ecken oder ein rundes Hindernis, die Folge ist chaotisches Verhalten. Das wurde mit ultrakalten Atomen in entsprechend geformten Lichtpotentialen demonstriert.
Mit Ionen ist zu rechnen
Authors: Linke Norbert , Müller Markus
Published: July 2020

Quantencomputer versprechen, spezielle, für Anwendungen hochinteressante Aufgaben zu lösen. An diesen NP‐harten Problemen scheitern herkömmliche Supercomputer. Eine Technik, die intensiv erforscht wird, ist der Ionen‐Quantencomputer. An ihm demonstriert dieser Artikel, wie der Quanten‐Suchalgorithmus von Lov Grover funktioniert. Programmiert werden solche Quantencomputer über einen Software‐Stack. Er übersetzt die Befehle der Nutzeroberfläche über verschiedene Stufen in die Laser‐Manipulation der Ionen‐Qubits. Bei den aktuell in Laboren laufenden Quantencomputern sind etwa zehn Ionen die Grenze, ab der das Rauschen der Quantengatter für zu große Fehler in den Rechnungen sorgt. In Zukunft soll eine Quantenfehlerkorrektur, die mehrere physische Qubits zu einem logischen Qubit verknüpft, Fehler erkennen können. Um die Zahl der Ionen zu steigern, soll die Kontrolle über die Laserpulse und die Fallenpotenziale verbessert werden. Zudem wird daran geforscht, mehrere Ionenfallen zum Beispiel via Photonenverschränkung miteinander zu verbinden. Mikrochip‐Ionenfallen sollen Ionen‐Quantencomputer miniaturisieren.
Pas de Deux in der Nanowelt
Authors: Doster Juliane , Weig Eva
Published: July 2020

Benachbarte Nanosäulen können durch ein gemeinsames Substrat gekoppelt werden. Hierfür müssen die Säulen zu Biegeschwingungen angeregt werden. Die dabei entstehende Verspannung im Substrat vermittelt den Energieaustausch zwischen den Säulen und soll in Zukunft die Untersuchung deutlich komplexerer gekoppelter Systeme ermöglichen [1].
Specific Features of Formation of Laser‐Induced Periodic Surface Structures on Ge2Sb2Te5 Amorphous Thin Films under Illumination by Femtosecond Laser Pulses
Authors: Kozyukhin Sergey , Smayev Mikhail , Sigaev Vladimir , Vorobyov Yuri , Zaytseva Yuliya , Sherchenkov Alexey , Lazarenko Petr
Published: July 2020

This article presents the results of irradiation treatment by the 180 fs laser pulses at the wavelength of 1030 nm of Ge2Sb2Te5 amorphous thin films. It is shown that high‐quality laser‐induced periodic surface structures (LIPSS) are formed at certain parameters of irradiation with a period corresponding to the laser wavelength. A distinctive feature of the observed LIPSS is the alternation of amorphous and crystalline regions corresponding to the ridges and valleys of the periodic structures which are perpendicular to the polarization of the femtosecond light beam. These surface crystalline–amorphous alternating structures are characterized by significantly less pronounced surface relief than for previously observed LIPSS formed by femtosecond laser pulses at the wavelength of 515 nm. Possible mechanisms are considered for the LIPSS formation including the formation of surface plasmon polariton and its subsequent interference with the incident beam resulting in spatial modulation of the temperature on the film surface. As the results indicate, the formation of alternating structure has a threshold nature with the threshold laser fluence for LIPSS formation depending logarithmically on the number of laser pulses, which is attributed to the transient nature of the crystallization process.
Preparation of polypropylene/poly (butylene adipate‐co‐terephthalate) composite films incorporated with melanin for prevention of greening of potatoes
Authors: Bang Yeong‐Ju , Shankar Shiv , Rhim Jong‐Whan
Published: July 2020

Polypropylene (PP) and poly (butylene adipate‐co‐terephthalate) (PBAT) blend films incorporated with melanin (Mel) were prepared using an extrusion casting method. Scanning electron microscopy results showed that Mel was evenly dispersed to form a well‐blended film. The PP/PBAT/Mel composite films prevented UV light transmittance, especially UV‐B rays. The addition of Mel influenced the surface color, water vapor transmission rate, oxygen transmission rate, and water contact angle of the composite films. After the addition of Mel, the tensile strength and elongation at break in the machine direction of the composite film increased by 30% and 27%, respectively. Packaging potatoes with PP/PBAT/Mel film and storing them under fluorescent light for 6 days effectively prevented the greening of potatoes caused by the production of chlorophyll. The PP/PBAT/Mel films have a high potential for the prevention of greening of potatoes during storage and distribution.
Time‐based replacement policies for a fault tolerant system subject to degradation and two types of shocks
Authors: Dong Wenjie , Liu Sifeng , Cao Yingsai , Bae Suk Joo
Published: July 2020

A single component nonrepairable system suffering from both an internal stochastic degradation process and external random shocks is investigated in this paper. More specifically, the Wiener process with a positive drift coefficient is introduced to describe the gradual deterioration and the arrival number of external shocks is counted with a nonhomogeneous Poisson process (NHPP). Meanwhile, fault tolerant design is incorporated into the stochastically deterioration system so as to protect it from shock failures to some extent and is consummately addressed via a generalized m − δ shock model. From the actual engineering point of view, external shocks are typically classified into two distinct categories in this current research, that is, a minor shock (Type I shock) increasing the damage load on current degradation level and a traumatic shock (Type II shock) resulting in system catastrophic failure immediately. The closed‐form expression of system survival function is derived analytically and is viewed as the generalization of existing reliability function for systems subject to dependent and competing failure processes. Based on which, two time‐based maintenance (TBM) policies including an age replacement model and a block replacement model are scheduled, where the expected long‐run cost rate (ELRCR) in each model is, respectively, optimized to seek the optimal replacement interval. In the illustrative example part, a subsea blowout preventer (BOP) control system is arranged to validate the theoretical results numerically. To compare which policy is more profitable under different conditions, the relative gain on optimal maintenance cost rate of the two TBM policies is presented.
Consensus of linear multi‐agent systems with stochastic noises and binary‐valued communications
Authors: Wang Ting , Hu Min , Zhao Yanlong
Published: July 2020

This article studies consensus problems of discrete‐time linear multi‐agent systems with stochastic noises and binary‐valued communications. Different from quantized consensus of first‐order systems with binary‐valued observations, the quantized consensus of linear multi‐agent systems requires that each agent observes its neighbors' states dynamically. Unlike the existing quantized consensus of linear multi‐agent systems, the information that each agent in this article gets from its neighbors is only binary‐valued. To estimate its neighbors' states dynamically by using the binary‐valued observations, we construct a two‐step estimation algorithm. Based on the estimates, a stochastic approximation‐based distributed control is proposed. The estimation and control are analyzed together in the closed‐loop system, since they are strongly coupled. Finally, it is proved that the estimates can converge to the true states in mean square sense and the states can achieve consensus at the same time by properly selecting the coefficient in the estimation algorithm. Moreover, the convergence rate of the estimation and the consensus speed are both given by O(1/t). The theoretical results are illustrated by simulations.
Spatiotemporally Controlling the Release of Biological Effectors Enhances Their Effects on Cell Migration and Neurite Outgrowth
Authors: Xue Jiajia , Wu Tong , Qiu Jichuan , Xia Younan
Published: July 2020

It is a major challenge to coordinate topographic cues from scaffolds with the on‐demand, sustained release of biological effectors to maximize their performance in tissue regeneration. Here, a system involving masked, photo‐triggered release of biological effectors from a temperature‐sensitive scaffold for augmented cell migration and neurite outgrowth is reported. The scaffold contains microparticles of a phase‐change material (PCM) sandwiched between two layers of electrospun fibers. The biological effectors are co‐loaded with a photothermal dye in the PCM microparticles. Under irradiation with a near‐infrared laser, the PCM will be melted to swiftly release the biological effectors. By imposing a photomask between the scaffold and the laser, only those microparticles in the irradiated region are melted, enabling a spatial control over the release. By adjusting the photomask, different regions of the scaffold can be sequentially irradiated at designated times, realizing on‐demand and sustained release of the biological effectors with spatiotemporal controls. In one demonstration, this method is used to accelerate the directional migration of NIH‐3T3 fibroblasts along the uniaxial or radial direction of fiber alignment by controlling the release of epidermal growth factor. In another demonstration, the release of nerve growth factor is managed to significantly promote neurite outgrowth from PC12 cells.
Competitive blind spots and the cyclicality of investment: Experimental evidence
Authors: Rodet Cortney S. , Smyth Andrew
Published: July 2020

We report laboratory experiments investigating the cyclicality of profit‐enhancing investment in a competitive environment. In our setting, optimal investment is counter‐cyclical when investment costs fall following market downturns. However, we do not observe counter‐cyclical investment. Instead, we see much less strategic behavior than our rational investment model anticipates. Our participants exhibit what Porter (1980) terms a competitive blind spot, and heuristic investment models where individuals invest a fixed percentage of their liquidity, or a fixed percentage of anticipated market demand, better fit our data than does optimal investment. We also report a control treatment without cost changes and a treatment with asymmetric investment liquidity. Both of these extensions support our main result.
Report of the Nomenclature Committee for Algae: 21
Authors: Andersen Robert A.
Published: July 2020

The names Microtheca and Anuraea octoceras are not recommended for rejection.
Biosorption of chromium (VI) from textile waste water using luffa cylindrica activated carbon
Authors: Nwosu‐Obieogu Kenechi , Okolo Bernard I
Published: July 2020

Luffa cylindrica was applied as a low‐cost adsorbent for removing chromium (VI) from textile industry effluent in this study. The adsorbent was characterized using scanning electron micrograph (SEM). A batch mode experiment was conducted to study the effect of pH, contact time, and adsorbent dosage on the adsorptive potential of the prepared luffa cylindrica activated carbon. The characterization results from SEM indicate that the adsorbents' potential was fully exploited in this study. A significance test conducted using ANOVA indicated that contact time and adsorbent dosage had the most effect on the adsorptive removal of Cr (VI). The optimum removal efficiency was 99.90% at pH 8.0, 99.8% at 60 min of contact time, and 99.82% at an adsorbent dosage of 1.0 g. The experimental results were analyzed using the Langmuir and Freundlich adsorption isotherm models, and the Freundlich isotherm provided a better correlation for Cr (VI) adsorption. The kinetic data by the pseudo‐first‐order kinetic model gave a better fit than the pseudo‐second‐order kinetic model.
Mass deformations of unoriented quiver theories
Authors: Bianchi Massimo , Bufalini Davide , Mancani Salvo , Riccioni Fabio
Published: July 2020

Abstract

We study the interplay between mass deformations and unoriented projections of super-conformal quiver gauge theories resulting from D3-branes at (toric) Calabi-Yau singularities. We focus on simple orbifold cases (ℂ3/ℤ3 and ℂ3/ℤ4) and their non-orbifold descendants. This allows us to generalize the construction rules and clarify points that have been previously overlooked. In particular we spell out the conditions of anomaly cancellations as well as super-conformal invariance that typically require the introduction of flavour branes, which in turn may spoil toric symmetry. Finally, we discuss duality cascades in this context and the interplay between Seiberg/toric duality and unoriented projection with (or without) mass deformations.
High-Degree Middle Cerebral Artery Stenosis
Authors: Guan Min , Lin Jia’xing , Huang Sheng’ming , Leng Xin’yi , Shi Chang’zheng , Qiao Hong’yu , Wang Xiang’yu , Huang Li’an
Published: July 2020

Purpose

Endovascular treatment in severe middle cerebral artery (MCA) stenosis is controversial owing to high rates of periprocedural complications, especially occlusion of the lenticulostriate arteries (LSA). The characteristics of LSAs and the spatial relationships between MCA plaques and LSAs using the fusion of three-dimensional (3D) digital subtraction angiography (DSA) and magnetic resonance imaging (3D DSA-MRI fusion) were investigated.

Methods

We retrospectively analyzed data from 32 ischemic stroke or transient ischemic attack patients with severe MCA stenosis, who underwent MRI and DSA within 2 weeks after symptom onset. The patients were divided into culprit and non-culprit MCA stenosis groups. The 3D DSA-MRI fusion was performed on dedicated workstations, which allowed automated overlays of the target vessels. The characteristics of LSAs, plaque distribution and lesion patterns, and their relationships were evaluated.

Results

The 3D DSA-MRI fusion image was able to illustrate the spatial relationships between MCA plaques and LSA orifices. Of 42 LSA stems in 32 patients, 10 had MCA plaque over the LSA orifice and were all found in the culprit MCA stenosis group. Over half (51.9%) of the LSA stems in patients with culprit MCA stenosis originated from the stenotic MCA segment. The MCA plaque-LSA orifice spatial relationships were classified into four types, which were significantly different between the two groups (p = 0.016).

Conclusion

The 3D DSA-MRI fusion technique enables visualization of the LSA orifice and MCA plaque and their spatial relationships. This classification of the type of spatial relationships can provide insights into the pathogenesis of MCA stroke and useful guides for treatment strategies.