bluuebunny/crossref_metadata_2025 huggingface dataset:
A Mathematical Model for Amorphous Polymers Based on Concepts of Reptation Theory
Authors: Yang Lixiang
Published: October 2019

Mechanical behaviors of amorphous polymers have been investigated in all aspects from macroscopic thermodynamics to molecular dynamics in past five decades. Most models either have too complex mathematics or can only explain mechanical behaviors of specific materials under certain defined conditions. In this article, a mathematical model is proposed to understand mechanical behaviors of amorphous polymers with aid of the concepts of reptation theory. This new model is capable to match most experimental results of different amorphous polymers for a wide range of time and temperature effect from rubber zone to glassy zone. Above glass transitional temperature, the model shows hyperelastic behavior. Below glass transitional temperature, elastic–viscoplastic properties can be obtained. In the proposed model, no yielding surface is assumed. Hyperelasticity and Mullin's effect are illustrated in a different way without assuming strain energy function in advance. Yielding stress is controlled by Young's moduli, defect density, and defect velocity of molecular chains. Anisotropic plasticity is simply controlled by anisotropic Young's moduli. Therefore, no additional anisotropic parameters are needed to define anisotropic yielding surface. Strain rate, temperature, and hydrostatic pressure effects on yielding stress are through their effect on Young's moduli. Linear elastic, hyperelastic, viscoelastic, and viscoplastic models are put into one single equation, which makes the mathematical structure very easy to understand and easy to use. This model is validated by comparing with five existed experimental data. Proposed model also shares some features similar to the old well‐known large deformation models for amorphous polymers. POLYM. ENG. SCI., 59:2335–2346, 2019. © 2019 Society of Plastics Engineers
Wear of Biopolymers under Reciprocating Sliding Conditions against Different Counterfaces
Authors: Harsha A.P. , Wäsche Rolf , Joyce Thomas J.
Published: October 2019

The objective of this study was to investigate the wear resistance of ultrahigh‐molecular weight polyethylene (UHMWPE) and crosslinked polyethylene (XLPE) against different counterfaces. Friction and wear studies were evaluated under dry reciprocating sliding conditions at room temperature. Ti6Al4V discs finished in polished, lapped, and ground conditions were reciprocated against polymer cylinders. In addition, abrasive wear studies were conducted using different abrasive grit sizes. The friction and wear properties of the two polyethylenes were strongly affected by the different counterfaces. XLPE showed important friction and wear sensitivity with the change of surface roughness of the Ti6Al4V disc, as well as with the change in abrasive grit size. Scanning electron microscopy and energy‐dispersive X‐ray (EDX) analysis of the worn disc surfaces and the polymer pins indicated the wear mechanisms affecting the polyethylenes. POLYM. ENG. SCI., 59:2356–2366, 2019. © 2019 Society of Plastics Engineers
Adult attachment anxiety moderates the relation between self‐reported childhood maltreatment and borderline personality disorder features
Authors: Crow Thomas M. , Levy Kenneth N.
Published: October 2019

Childhood maltreatment is one of many risk factors for borderline personality disorder (BPD). However, not all individuals with BPD report histories of childhood maltreatment. Therefore, it is necessary to identify factors that contextualize the relation between childhood maltreatment and BPD features. With its emphasis on the developmental origins of emotion regulation, attachment theory provides a useful framework to understand how people are differentially affected by early life stress. The present study examined self‐reported adult attachment as a moderator in the relation between childhood maltreatment and BPD features in a large undergraduate sample (n = 1 033). Attachment anxiety, but not attachment avoidance, moderated the relation between childhood maltreatment and BPD features, and this relation was non‐significant among participants low (−1 standard deviation) in attachment anxiety. These results support the hypothesis that secure attachment in adulthood may buffer against the otherwise deleterious effects of distal risk factors on personality pathology. Future research should continue to examine this question across risk factors and across disorders. Furthermore, we suggest that researchers who have historically examined attachment as a mediator cross‐sectionally should re‐examine their data for evidence of a moderation effect. © 2019 John Wiley & Sons, Ltd.
Molecular dynamics study of polymeric chemical gels: Effect of persistence length and crosslinker density
Authors: Pereyra Rodolfo G. , Carignano Marcelo A.
Published: October 2019

Using molecular dynamics, we study the formation of chemical gels from an initial solution of reactive polymers that undergo a crosslinking reaction. We study the effect of the polymer persistence length and different densities of crosslinkers along the chains. As the reaction progresses, different structural features are identified in the system leading to the development of a percolated cluster. These features are (a) single strands, (b) double strands, and (c) bridges. We found that the total numbers of these three kinds of features are roughly independent of the persistence length; however, the average lengths of single and double strands grow with this variable. The average length of double strands strongly increases with increasing crosslinker density and the amount of single strands sharply falls as crosslinker density grows. We also found that general structural features of polymer networks are highly dependent on chain persistence length and crosslinker density. Fully flexible chains with high density of crosslinkers result in inhomogeneous network structures with large voids. In contrast, precursor chains with high rigidity and scarce number of crosslinkers result in homogeneous networks having small cavities. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 1343–1350
Preparation and Characterization of Cellulose/RDX Composite Aerogel Spheres
Authors: Bian Hongli , Wei Jie , Zhou Yi , Liu Jianxin , Shao Ziqiang , Wang Bo , Li Zhihua
Published: October 2019

As a high‐energy explosive, 1,3,5‐Trinitroperhydro‐1,3,5‐triazine (RDX) has been widely used in military and civilian applications such as explosives, rocket fuels and gun propellants due to its good comprehensive properties. However, at present, the application of RDX has been encumbered by its high sensitivity and crystal defects. Herein, inspired by the unique structure and eco‐friendliness of cellulose aerogel, for the first time, cellulose aerogel was introduced into RDX to prepare cellulose/RDX composite aerogel spheres by the solution impregnation method. The cellulose/RDX composite aerogel spheres were characterized by scanning electron microscopy (SEM), elemental analysis, thermogravimetric and differential scanning calorimetry (TG‐DSC), X‐ray diffractometer (XRD), and a vertical impact sensitivity tester. The material detonation speed was calculated using EXPLO5. The results showed that the surface of cellulose/RDX composite aerogel spheres was smooth, and the internal three‐dimensional cross‐linked void of the cellulose aerogel spheres was well filled with RDX particles. Compared with RDX raw materials, the particle size of RDX in the cellulose/RDX composite aerogel spheres was greatly reduced. The N content in the cellulose/RDX composite aerogel spheres was as high as 32.24 %. Thermal analysis results showed that the activation energy of cellulose/RDX composite aerogel spheres increased by 31.28 KJ/mol. The crystal structure of RDX in the cellulose/RDX composite aerogel spheres remained unchanged. Moreover, the impact sensitivity H50 of the cellulose/RDX composite aerogel spheres increased by more than 65 cm.
Assessment of chemical‐crosslink‐assisted protein structure modeling in CASP13
Authors: Fajardo J. Eduardo , Shrestha Rojan , Gil Nelson , Belsom Adam , Crivelli Silvia N. , Czaplewski Cezary , Fidelis Krzysztof , Grudinin Sergei , Karasikov Mikhail , Karczyńska Agnieszka S. , Kryshtafovych Andriy , Leitner Alexander , Liwo Adam , Lubecka Emilia A. , Monastyrskyy Bohdan , Pagès Guillaume , Rappsilber Juri , Sieradzan Adam K. , Sikorska Celina , Trabjerg Esben , Fiser Andras
Published: October 2019

With the advance of experimental procedures obtaining chemical crosslinking information is becoming a fast and routine practice. Information on crosslinks can greatly enhance the accuracy of protein structure modeling. Here, we review the current state of the art in modeling protein structures with the assistance of experimentally determined chemical crosslinks within the framework of the 13th meeting of Critical Assessment of Structure Prediction approaches. This largest‐to‐date blind assessment reveals benefits of using data assistance in difficult to model protein structure prediction cases. However, in a broader context, it also suggests that with the unprecedented advance in accuracy to predict contacts in recent years, experimental crosslinks will be useful only if their specificity and accuracy further improved and they are better integrated into computational workflows.
Giant Photoinduced Chirality in Thin Film Ge2Sb2Te5
Authors: Shanmugam Janaki , Borisenko Konstantin B. , Luers Andrew , Ewart Paul , Shah Priyav , Williams Benjamin A. O. , Craig Christopher , Hewak Daniel W. , Hussain Rohanah , Jávorfi Tamás , Siligardi Giuliano , Bosman Michel , Kirkland Angus I.
Published: October 2019

Induction, tuning, or amplification of chirality in various classes of materials and probing their chiral response are subjects of growing research. Herein, a large chiral signal that is rapidly imprinted in achiral amorphous Ge2Sb2Te5 (GST) thin films measured using synchrotron circular dichroism spectroscopy is reported. The chirality is induced by illuminating the films with pulsed circularly polarized (chiral) laser light for less than 2 μs in total. The effects of laser fluence and film thickness on the chiral response are described. The correlation of the optical results with structural studies by electron diffraction and model simulations suggests that alignment of reamorphized fragments in the crystallized film along the electric field vector of the light forms the centers that are responsible for the observed chirality. These results suggest opportunities for practical applications of this phenomenon and provide avenues for further studies of chirality induction in materials with impact in a wide range of disciplines.
Influence of deepening and mesoscale organization of shallow convection on stratiform cloudiness in the downstream trades
Authors: Vogel Raphaela , Nuijens Louise , Stevens Bjorn
Published: October 2019

In this study we use large‐eddy simulation to explore the factors controlling stratiform cloudiness in the downstream trades. We perform sensitivity experiments with different large‐scale forcings, radiation specifications and domain sizes, which isolate the influence of convective deepening, moisture–radiation interactions and mesoscale organization, respectively. Across the simulations with different large‐scale forcings, we find that the deepening of the cloud layer and the associated increase in precipitation strongly correlate with decreasing inversion strength and stratiform cloudiness. The relationship between cloud‐layer depth and cloud amount is largely independent of the way a specific change in the large‐scale forcing induces the deepening. The interaction of radiation with the domain‐averaged humidity and cloud profile is necessary for stratiform cloudiness to form. Strong radiative cooling experienced by updraughts overshooting a strong inversion induces the formation of detrained stratiform layers, and strong long‐wave cooling associated with the stratiform layers stabilizes the inversion. Interactive radiation is also important for exposing differences in shallow convection under different free‐tropospheric humidities. A drier initial free troposphere leads to both increased cloud‐layer and free‐tropospheric radiative cooling and increased surface evaporation, which forces deeper convection and more precipitation compared to a moister initial free troposphere. The simulations with a drier initial free troposphere thus have weaker inversions and less stratiform cloud. The organization of convection into larger clusters in large‐domain simulations increases precipitation and weakens the inversion compared to a simulation on a 16‐fold smaller domain, which does not support convective organization. Organized updraught clusters carry more moisture and liquid to the inversion, so that the same amount of stratiform cloudiness forms, despite the inversion being weaker. The simulations presented here suggest that the deepening and organization of shallow convection plays an important role in regulating stratiform cloudiness and thus total cloud cover in the downstream trades.
Mucormycosis: an unusual masquerader of an endobronchial tumour
Authors: Jaganathan Venugopal , Madesh Vijaya Prakash , Subramanian Santhakumar , Muthusamy Rajeshwari K. , Mehta Sangita S.
Published: October 2019

Pulmonary mucormycosis is a life‐threatening invasive fungal infection usually seen in the background of immunosuppression, haematological malignancies, or uncontrolled diabetes. Immunocompetent hosts can also be affected. Isolated endobronchial mucormycosis is rare with only a few cases reported in the literature. Here, we present a case of an endobronchial mass masquerading as a tumour that was later diagnosed as invasive mucormycosis by histopathological examination.
Black pleural effusion: an unusual presentation of metastatic melanoma diagnosed by medical thoracoscopy
Authors: Sumalani Kamran Khan , Rehman Uneeba , Akhter Nousheen , Rizvi Nadeem Ahmed
Published: October 2019

Melanoma presenting with black pleural effusion is rare, with only five cases reported till date. In distinction to others, this is the only case where patient did not have a prior diagnosis of melanoma and was diagnosed by thoracoscopy. Reported is the case of a 49‐year‐old male who presented with dyspnoea and weight loss. Patient had a large left‐sided pleural effusion. Ultrasound showed thickened irregular pleura and multiloculated pleural effusion. Diagnostic pleural aspiration was performed, and fluid was black in colour and was exudative lymphocytic. Atypical cells were noted on pleural fluid cytology. Medical thoracoscopy was carried out and histopathology suggested metastatic melanoma. Patient had multiple nevi all over the body, but clinically none was indicative of melanoma. He refused skin biopsy. The case was referred to medical oncology where palliative management was planned. Patient died within two weeks of diagnosis.
Experimental analysis of low‐altitude terrain following for hover‐capable flight‐style autonomous underwater vehicles
Authors: Schillai Sophia M. , Turnock Stephen R. , Rogers Eric , Phillips Alexander B.
Published: October 2019

Operating an autonomous underwater vehicle (AUV) in close proximity to terrain typically relies solely on the vehicle sensors for terrain detection, and challenges the manoeuvrability of energy efficient flight‐style AUVs. This paper gives new results on altitude tracking limits of such vehicles by using the fully understood environment of a lake to perform repeated experiments while varying the altitude demand, obstacle detection and actuator use of a hover‐capable flight‐style AUV. The results are analysed for mission success, vehicle risk and repeatability, demonstrating the terrain following capabilities of the overactuated AUV over a range of altitude tracking strategies and how these measures better inform vehicle operators. A major conclusion is that the effects of range limits, bias and false detections of the sensors used for altitude tracking must be fully accounted for to enable mission success. Furthermore it was found that switching between hover‐ and flight‐style actuations based on speed, whilst varying the operation speed, has advantages for performance improvement over combining hover‐ and flight‐style actuators at high speeds.
The evolution of the curiosity rover sampling chain
Authors: Verma Vandi , Carsten Joseph , Kuhn Stephen
Published: October 2019

The Mars Science Laboratory (MSL) Curiosity rover landed in Gale crater in August of 2012 on its mission to explore Mt. Sharp as the first planetary rover to collect and analyze rock and regolith samples. On this new mission, sampling operations were conceived to be executed serially and in situ, on a “sample chain” along which sample would be collected, then processed, then delivered to sample analysis instruments, analyzed there, and then discarded so the chain could be repeated. This paper describes the evolution of this relatively simple chain into a richer sampling network, responding to science and engineering desires that came into focus only as the mission matured, scientific discoveries were made, and anomalies were encountered. The rover flight and ground system architectures retained significant heritage from past missions, while extending capabilities in anticipation of the need for adaptation. As evolution occurred, the architecture permitted nimble extension of sampling behavior without time‐consuming flight software updates or significant impact to daily operations. This paper presents the major components of this architecture and discusses some of the results of successful adaptation across thousands of Sols of Mars operations.
π‐Hydrogen Bonding Probes Chemical Reactivity: Bromination of a CC Double Bond and Electrophilic Aromatic Benzylation
Authors: Galabov Boris , Koleva Gergana , Hadjieva Boriana , Schaefer Henry F.
Published: October 2019

The reactivity trends for two basic organic reactions – addition of bromine to a CC double bond in alkenes and electrophilic aromatic benzylation of alkyl‐ and halobenzenes – are rationalized using both experimental and theoretical quantities. Literature kinetic data are employed. The shifts of phenol O–H stretching frequency upon π‐hydrogen bonding (Δν(OH)exp) with the nucleophilic reactants are shown to provide a quantitative measure of the reactivity for the considered reactions. Very good correlations between Δν(OH)exp and theoretically estimated charge density parameters (atomic charges and shifts of molecular electrostatic potential) show that the O–H frequency shifts reflect the variations of nucleophilic properties in the reaction centers upon structural changes. The Δν(OH)exp shifts perform much better in quantifying reactivity trends than usually employed experimental quantities, such as gas‐phase basicities and proton affinities.
Structural Reorganization–Based Nanomaterials as Anodes for Lithium‐Ion Batteries: Design, Preparation, and Performance
Authors: Han Yu , Huang Guoyong , Xu Shengming
Published: October 2019

In recent years, with the growing demand for higher capacity, longer cycling life, and higher power and energy density of lithium ion batteries (LIBs), the traditional insertion‐based anodes are increasingly considered out of their depth. Herein, attention is paid to the structural reorganization electrode, which is the general term for conversion‐based and alloying‐based materials according to their common characteristics during the lithiation/delithiation process. This Review summarizes the recent achievements in improving and understanding the lithium storage performance of conversion‐based anodes (especially the most widely studied transition metal oxides like Mn‐, Fe‐, Co‐, Ni‐, and Cu‐based oxides) and alloying‐based anodes (mainly including Si‐, Sn‐, Ge‐, and Sb‐based materials). The synthesis schemes, morphological control and reaction mechanism of these materials are also included. Finally, viewpoints about the challenges and feasible improvement measures for future development in this direction are given. The aim of this Review is to shed some light on future electrode design trends of structural reorganization anode materials for LIBs.
The Tax Paradox and Weak Tax Neutrality
Authors: López Ramón E. , Gutiérrez Cubillos Pablo , Figueroa Eugenio
Published: October 2019

We introduce the concept of weak tax neutrality that establishes that the relationship between the tax rate and the user cost of capital may be non‐monotonic. We show that most existing corporate tax systems allow for weak neutrality. That is, given the tax allowances permitted by these systems, it is possible that neutrality may arise for at least one positive corporate tax rate. Moreover, we show the practical relevance of weak neutrality in realistic situations where there are several asset types and heterogeneous levels of firms' debt ratios.
Comparing and co‐analysing microsatellite and morphological data for species delimitation in the New Zealand native Myosotis pygmaea species group (Boraginaceae)
Authors: Prebble Jessica M. , Meudt Heidi M. , Tate Jennifer A. , Symonds V. Vaughan
Published: October 2019

Delimiting species boundaries in recent plant radiations can be challenging. The New Zealand native Myosotis pygmaea (Boraginaceae) species group is a case in point. This species complex is of interest as it includes threatened species as well as possibly threatened unnamed putative taxa. Integrative taxonomic approaches using multiple lines of evidence are frequently used to overcome the difficulties of identifying lineages resulting from recent radiations. Here we analyse genotypic data from nearly 500 Myosotis individuals using microsatellite markers, and compare and co‐analyse this dataset with previously published morphological data. Within the M. pygmaea group, several genetic clusters can be identified, none of which align exactly with the current taxonomy and morphological variation previously identified. When co‐analysing the molecular and morphological data, M. brevis can be distinguished from the remainder of the M. pygmaea species group, but no other species or previously recognised morphological groups are supported. Other groupings within the molecular dataset appear to reflect geographic structure. Within the M. pygmaea species group, the resulting pattern of low within, and high between, population genetic variation is consistent with self‐fertilization and low levels of seed dispersal.
The Effect of Sputter Cathode Design on Deposition Parameters
Authors: Gaines J.R.
Published: October 2019

Recent advances in the classic magnetron sputter cathode design have enabled higher quality thin films and improved deposition rates. New designs that have eliminated traditional sputter target hold down fixtures and the retraction of the dark space shield have greatly increased the available sputter target surface area while reducing the probability of re‐deposition of target material on cathode components that could lead to shorting and contamination. Hermetic sealing strategies have mitigated gas permeation through the sputter cathode and enabled lower operating pressures which substantially reduces process gas inclusions in sputtered films.
Molecular characterization of Mycobacterium bovis infection in cattle and buffalo in Amazon Region, Brazil
Authors: Carneiro Paulo A. M. , Pasquatti Taynara. N. , Takatani Haruo , Zumárraga Martin J. , Marfil Maria. J. , Barnard Christian , Fitzgerald Scott D. , Abramovitch Robert B. , Araujo Flábio R. , Kaneene John B.
Published: October 2019

The aim of this study was to characterize Mycobacterium bovis from cattle and buffalo tissue samples, from two Brazilian states, and to analyse their genetic diversity by spoligotyping. Tissue samples from tuberculosis suspect animals, 57 in Amazonas State (12 cattle and 45 buffaloes) and six from Pará State (5 cattle and one buffalo) from slaughterhouses under State Veterinary Inspection, were isolated in culture medium Stonebrink. The positive cultures were confirmed by PCR and analysed by the spoligotyping technique and the patterns (spoligotypes) were identified and compared at the Mycobacterium bovis Spoligotype Database (http://www.mbovis.org/). There was bacterial growth in 44 (69.8%) of the tissues of the 63 animals, of which PCR for region of differentiation 4 identified 35/44 (79.5%) as Mycobacterium bovis. Six different spoligotypes were identified among the 35 Mycobacterium bovis isolates, of which SB0295, SB1869, SB0121 and SB1800 had already been described in Brazil, and SB0822 and SB1608 had not been described. The most frequent spoligotype in this study (SB0822) had already been described in buffaloes in Colombia, a neighbouring country of Amazonas state. The other identified spoligotypes were also described in other South American countries, such as Argentina and Venezuela, and described in the Brazilian states of Rio Grande do Sul, Santa Catarina, São Paulo, Minas Gerais, Mato Grosso do Sul, Mato Grosso and Goiás, indicating an active movement of Mycobacterium bovis strains within Brazil.
Molecular identification and chromosomal localization of new powdery mildew resistance gene Pm11 in oat
Authors: Ociepa Tomasz , Okoń Sylwia , Nucia Aleksandra , Leśniowska-Nowak Justyna , Paczos-Grzęda Edyta , Bisaga Maciej
Published: October 2019

The appropriate selection of various traits in valuable plants is very important for modern plant breeding. Effective resistance to fungal diseases, such as powdery mildew, is an example of such a trait in oats. Marker-assisted selection is an important tool that reduces the time and cost of selection. The aims of the present study were the identification of dominant DArTseq markers associated with a new resistance gene, annotated as Pm11 and derived from Avena sterilis genotype CN113536, and the subsequent conversion of these markers into a PCR-based assay. Among the obtained 30,620 silicoDArT markers, 202 markers were highly associated with resistance in the analysed population. Of these, 71 were selected for potential conversion: 42 specific to resistant and 29 to susceptible individuals. Finally, 40 silicoDArT markers were suitable for primer design. From this pool, five markers, 3 for resistant and 2 for susceptible plants, were selected for product amplification in the expected groups. The developed method, based on 2 selection markers, provides certain identification of resistant and susceptible homozygotes. Also, the use of these markers allowed the determination of heterozygotes in the analysed population. Selected silicoDArT markers were also used for chromosomal localization of new resistance genes. Five out of 71 segregating silicoDArT markers for the Pm11 gene were found on the available consensus genetic map of oat. Five markers were placed on linkage groups corresponding to Mrg12 on the Avena sativa consensus map.
Smartphone‐Based Application for Tele‐follow‐up of Patients with Endocrine Disorders in Context of a LMIC: A Compliance, Satisfaction, Clinical Safety and Outcome Assessment
Authors: Yadav Sanjay Kumar , Jha Chandan Kumar , Mishra Saroj Kanta , Mishra Anjali
Published: October 2019

Background

Remote video consultations are increasingly used in clinical practice, and a lot of data are emerging on its feasibility and acceptability. This study aims to bring out qualitative and quantitative data which will enhance our understanding of strengths and limitations of this media in the setting of a low‐ and middle‐income country (LMIC).

Materials and methods

This was a prospective study conducted from January 2017 to May 2018, at the Department of Endocrine Surgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Lucknow, India. A total of 107 patients were selected who chose remote follow‐up care through social media (WhatsApp). Data were analyzed on feasibility, clinical safety, satisfaction and economic burden.

Results

A total of 107 postoperative patients were followed up using a social media tool. A total of 396 tele‐sessions were held. The average number of tele‐consultations per patient was 3.7 (range 2–6). Reasons for tele‐follow‐up included: confirmation of histology report (n = 92), medication dosage adjustments (n = 148), wound evaluation (n = 102), reporting of serum TSH and serum calcium levels (n = 296) and medical fitness certificate (n = 13). Wound evaluation through tele‐follow‐up was on par with the outpatient department (OPD) follow‐up as no patient had to report to OPD for wound infection. Satisfaction level was excellent in 55% of patients and very good in 25%. 20% of the patients reported an average satisfaction level. If all of these 107 patients would have come to our OPD follow‐up, they would have traveled 613.2 miles (908 km) per patient on an average, apart from losing work hours. Average cost and workdays saved per visit were $78 and 5.4 days, respectively.

Conclusion

Video consultation using social media tools is clinically safe and cost effective. Economic benefits far outweigh the risk of missing an adverse event, especially in the setting of low‐ and middle‐income countries.
Should 68Ga‐DOTATATE PET/CT be Performed Routinely in Patients with Neuroendocrine Tumors Before Surgical Resection?
Authors: Babazadeh Nasim T. , Schlund Devan J. , Cornelius Tyler , Singh Jagadeesh S. , Tierney John F. , Chen Meri , Keutgen Xavier M.
Published: October 2019

Background

The only potential cure for neuroendocrine tumors (NETs) is operative resection, which may also offer a survival benefit for advanced disease. We aimed to assess the role of 68Ga‐DOTATATE PET/CT in preoperative planning and compared its performance to CT with IV contrast and MRI with Eovist®, for abdominal NETs.

Methods

Records of patients who underwent 68Ga‐DOTATATE PET/CT in addition to MRI with Eovist® and/or CT with IV contrast were retrospectively evaluated. The effect of imaging findings on surgical management and characteristics of detected lesions were analyzed. Descriptive statistics were used.

Results

Of 21 patients who underwent 68Ga‐DOTATATE PET/CT prior to surgical resection, five (24%) had a change in surgical management due to findings. In three patients, 68Ga‐DOTATATE PET/CT identified the primary tumor. In two patients, 68Ga‐DOTATATE PET/CT helped clarify equivocal hepatic lesions seen on MRI with Eovist®. MRI with Eovist® had the highest number of lesions found (median 13, versus 9 on CT and 9.5 on 68Ga‐DOTATATE PET/CT). DOTATATE‐avid lesions were on average larger than lesions seen only on MRI with Eovist® (1.6 cm versus 0.6 cm, p = 0.0002). The optimal cutoff point for detection by 68Ga‐DOTATATE PET/CT was a size of 0.95 cm, with a sensitivity of 56% and specificity of 98%.

Conclusions

Preoperative 68Ga‐DOTATATE PET/CT is useful only in a subset of patients undergoing surgical resection for NETs. MRI with Eovist® is superior at identifying liver metastases when compared to 68Ga‐DOTATATE PET/CT and should therefore be used routinely before hepatic cytoreduction of NETs.
Norm emergence in multiagent systems: a viewpoint paper
Authors: Morris-Martin Andreasa , De Vos Marina , Padget Julian
Published: October 2019

Norms are utilised in agent societies to encourage acceptable behaviour by the participating agents. They can be established or revised from the top-down (authority) or from the bottom-up (populace). The study of norm creation from the bottom-up—or norm emergence/convergence—shows evidence of increasing activity. In consequence, we seek to analyse and categorize the approaches proposed in the literature for facilitating norm emergence. This paper makes three contributions to the study of norm emergence. Firstly, we present the different perspectives of norms and their impact on the norm emergence process, with the aim of comparing their similarities and differences in implementing the norm life cycle. Secondly, we identify the characteristics that support norm emergence that are observed in the emergence literature. Finally, we identify and propose future topics for study for the community, through a discussion of the challenges and opportunities in norm emergence.
Predictors affecting myopic regression in − 6.0D to − 10.0D myopia after laser-assisted subepithelial keratomileusis and laser in situ keratomileusis flap creation with femtosecond laser-assisted or mechanical microkeratome-assisted
Authors: Zhou Jihong , Gu Wei , Li Shaowei , Wu Lijuan , Gao Yan , Guo Xiuhua
Published: October 2019

Purpose

To investigate the predictive factors of postoperative myopic regression among subjects who have undergone laser-assisted subepithelial keratomileusis (LASEK), laser-assisted in situ keratomileusis (LASIK) flap created with a mechanical microkeratome (MM), and LASIK flap created with a femtosecond laser (FS). All recruited patients had a manifest spherical equivalence (SE) from − 6.0D to − 10.0D myopia.

Methods

This retrospective, observational case series study analyzed outcomes of refraction at 1 day, 1 week, and 1, 3, 6, and 12 months postoperatively. Predictors affecting myopic regression and other covariates were estimated with the Cox proportional hazards model for the three types of surgeries.

Results

The study enrolled 496 eyes in the LASEK group, 1054 eyes in the FS-LASIK group, and 910 eyes in the MM-LASIK group. At 12 months, from − 6.0D to − 10.0D myopia showed that the survival rates (no myopic regression) were 52.19%, 59.12%, and 58.79% in the MM-LASIK, FS-LASIK, and LASEK groups, respectively. Risk factors for myopic regression included thicker postoperative central corneal thickness (P ≦ 0.01), older age (P ≦ 0.01), aspherical ablation (P = 0.02), and larger transitional zone (TZ) (P = 0.03). Steeper corneal curvature (Kmax) (P = 0.01), thicker preoperative central corneal thickness (P < 0.01), smaller preoperative myopia (P < 0.01), longer duration of myopia (P = 0.02), with contact lens (P < 0.01), and larger optical zone (OZ) (P = 0.02) were protective factors. Among the three groups, the MM-LASIK had the highest risk of postoperative myopic regression (P < 0.01).

Conclusions

The MM-LASIK group experienced the highest myopic regression, followed by the FS-LASIK and LASEK groups. Older age, aspheric ablation used, thicker postoperative central corneal thickness, and enlarging TZ contribute to myopic regression; steeper preoperative corneal curvature (Kmax), longer duration of myopia, with contact lens, thicker preoperative central corneal thickness, lower manifest refraction SE, and enlarging OZ prevent postoperative myopic regression in myopia from − 6.0D to − 10.0D.
Second and third order nonlinear optical, mechanical, surface characteristics of bis(thiourea) manganese chloride (BTMC) grown by slow cooling technique used for frequency conversion applications
Authors: Kubendiran T. , Ravi Kumar S. M. , Allen Moses S. E. , Nasareena Banu A. , Shanthi C. , Sivaraj S.
Published: October 2019

A semiorganic nonlinear optical (NLO) single crystal of bis(thiourea) manganese chloride (BTMC) is grown successfully by slow cooling technique using water as solvent at temperature 45 °C. The optically good quality crystal of BTMC was grown with dimension up to 8 × 8 × 2 mm3in a period of 2–3 weeks. The grown crystal crystallizes in orthorhombic crystal system which was confirmed by single crystal X-ray diffraction analysis. The various functional groups of BTMC were identified through FT-IR spectroscopic analysis. The lower cut-off wavelength of 280 nm was revealed from optical transmittance spectrum of UV. The mechanical behavior of BTMC crystal was analyzed by Vicker’s microhardness study and also the various mechanical parameters were determined. Vickers micro hardness test revealed, the titular crystal belongs to harder material category. The SHG efficiency is estimated from Kurtz-Perry powder method and it found to be 0.33 times than the reference material. The dielectric behavior, photo conducting nature and surface properties have been analyzed for grown BTMC crystal. The presence of synthesized elements was confirmed by EDAX study. The third order nonlinear optical susceptibility$$\chi^{\left(3 \right)}$$χ3of the material is measured using Z-scan technique and it is found to be 5.1202 × 10−14esu.
Optimization of CCT Equations Using Calculated Grain Boundary Soluble Compositions for the Simulation of Austenite Decomposition of Steels
Authors: Miettinen Jyrki , Koskenniska Sami , Somani Mahesh , Louhenkilpi Seppo , Pohjonen Aarne , Larkiola Jari , Kömi Jukka
Published: October 2019

New CCT equations have been developed and optimized to simulate the start temperatures of the austenite decomposition process in low-alloyed steels using experimental CCT data published in the literature. Exceptionally, this optimization does not apply the nominal compositions of the steels, but the corresponding soluble compositions of the grain boundaries calculated using IDS software, depending on the reported austenitization treatments of the steels. These compositions, rather than the nominal ones, are expected to control the start of the austenite decomposition, which usually initiates at the grain boundaries. The new optimization treatment takes into account the solute microsegregation and the possible precipitate formation. Using IDS software, the new equations were validated with new experimental CCT data. Agreement was good not only for the austenite decomposition start temperatures, but also for the final phase fractions, indicating fairly reasonable predictions of phase transformation kinetics by the IDS. In addition, IDS simulations were compared with the experimental CCT data of five high-carbon steels, applying both the new equations based on grain boundary soluble compositions as well as the equations based on the nominal compositions. With the same experimental CCT data used in optimization, better agreement was obtained with the new equations, indicating the importance of determining the soluble compositions at the grain boundaries where the austenite decomposition process is likely to begin.
A preliminary pollution appraisal of western backwater at Karachi Coastal area
Authors: Alamgir Aamir , Fatima Noor , Khan Moazzam Ali , Rehman Muttiur , Shaukat Syed Shahid
Published: October 2019

This study aims at preliminary analysis of pollution profile of western backwater. The site is very important from the ecological perspective. The mangrove ecosystem of the study area is of prime significance, whilst the study area is receiving heavy pollution load from Lyari River. The water samples were collected from the pre-designated locations and analyzed for physical and biochemical characteristics. The BOD and COD concentrations of the samples were extremely higher from the environmental and ecological viewpoint. The heavy inorganic and organic load is coming from the domestic and industrial effluents coming from Lyari River. Oil and grease concentrations were also extremely higher in all these sites indicating the hampering of natural purification system of water. The concentration of phenol also indicates the emptying of industrial effluent at the Lyari River outfall. The heavy influx of the nutrients in the form of nitrogen and phosphate represents the problem of eutrophication at the study area. Out of all 7 sites, L-7 was most polluted as it was closed to the Lyari River outfall. The extent of pollution is at the following order L-7 > L-5 > L-6 > L-4 > L-3 > L-2 > L-1.
Modal identification of localised damage in beams and trusses: experimental and numerical results
Authors: Diaferio Mariella , Sepe Vincenzo , Bellizzotti Gabriele
Published: October 2019

The paper discusses the possibility of detecting local damages in complex structures typical of civil engineering, as multispan beams and trusses. Namely, it describes a procedure to identify localised cracks in structures in the elastic range of behaviour using only the values of natural frequencies in the intact configuration and in the damaged one evaluated by means of dynamic tests. The error minimisation procedure described in the paper selects the solution within a set of finite element models that simulate a range of positions and levels of damage, by identifying the damaged configuration as the one whose modal frequencies minimise the least-square difference with the measured data. The accuracy of the method is first investigated by applying it to the damage detection of a two-span steel beam, whose modal frequencies were obtained by means of experimental tests. To explore the accuracy of the proposed procedure, numerically simulated data with random noise were also generated for several positions and levels of damage and for different values of the random noise. The procedure was then extended, by means of numerical simulations, to the case of a beam with two localised damages. Finally, the procedure proposed for multispan beams is adapted to the damage identification of plane truss structures.
Sildenafil Protects Endothelial Cells From Radiation-Induced Oxidative Stress
Authors: Wortel R.C. , Mizrachi A. , Li H. , Markovsky E. , Enyedi B. , Jacobi J. , Brodsky O. , Cao J. , Lippert A.R. , Incrocci L. , Mulhall J.P. , Haimovitz-Friedman A.
Published: October 2019

Introduction

The etiology of radiation-induced erectile dysfunction (ED) is complex and multifactorial, and it appears to be mainly atherogenic.

Aim

To focus on vascular aspects of radiation-induced ED and to elucidate whether the protective effects of sildenafil are mediated by attenuation of oxidative stress and apoptosis in the endothelial cells.

Methods

Bovine aortic endothelial cells (BAECs), with or without pretreatment of sildenafil (5 μM at 5 minutes before radiation), were used to test endothelial dysfunction in response to external beam radiation at 10–15 Gy. Generation of reactive oxygen species (ROS) was studied. Extracellular hydrogen peroxide (H2O2) was measured using the Amplex Red assay and intracellular H2O2 using a fluorescent sensor. In addition, ROS superoxide (O2•-) was measured using a O2•- chemiluminescence enhancer. Both H2O2 and O2•- are known to reduce the bioavailability of nitric oxide, which is the most significant chemical mediator of penile erection. Generation of cellular peroxynitrite (ONOO−) was measured using a chemiluminescence assay with the PNCL probe. Subsequently, we measured the activation of acid sphingomyelinase (ASMase) enzyme by radioenzymatic assay using [14C-methylcholine] sphingomyelin as substrate, and the generation of the proapoptotic C16-ceramide was assessed using the diacylglycerol kinase assay. Endothelial cells apoptosis was measured as a readout of these cells’ dysfunction.

Main Outcome Measures

Single high-dose radiation therapy induced NADPH oxidases (NOXs) activation and ROS generation via the proapoptotic ASMase/ceramide pathway. The radio-protective effect of sildenafil on BAECs was due to inhibition of this pathway.

Results

Here, we demonstrate for the first time that radiation activated NOXs and induced generation of ROS in BAECs. In addition, we showed that sildenafil significantly reduced radiation-induced O2•- and as a result there was reduction in the generation of peroxynitrite in these cells. Subsequently, sildenafil protected the endothelial cells from radiation therapy-induced apoptosis.

Strengths and Limitations

This is the first study demonstrating that single high-dose radiation therapy induced NOXs activation, resulting in the generation of O2•- and peroxynitrite in endothelial cells. Sildenafil reduced ROS generation by inhibiting the ASMase/ceramide pathway. These studies should be followed in an animal model of ED.

Conclusions

This study demonstrated that sildenafil protects BAECs from radiation-induced oxidative stress by reducing NOX-induced ROS generation, thus resulting in decreased endothelial dysfunction. Therefore, it provides a potential mechanism to better understand the atherogenic etiology of postradiation ED.
Transcendental Monsters, Animism and the Critique of Hyperobjects
Authors: Bradley Joff P.N.
Published: October 2019

This transversal and transilient thought-experiment explores the application and significance of Japanese animism for environmental education and environmental philosophy. Through the exploration of indigenous knowledge found in Japanese folklore and Japanese Buddhism, the thought-experiment offers a critique of a certain strand of contemporary fatalistic and nihilistic thinking regarding the Anthropocene. At its simplest it questions the trend toward mysticism and obfuscation in environmental education and demands a response to the environmental crisis precisely through reason and rationality. How shall this be undertaken? On one level, the hauntings of 妖怪 (Yōkai) and 幽霊 (Yūrei) in Japanese folklore shall act as a prism through which to understand the impact of the fantastical on the contemporary imagination, and on another level, I shall critique the fantastical as such to question the so-called inaccessibility of the hyperobject (Morton, 2014), which in the end leaves us despairingly passive and without the possibility of response. It is in the work of the Japanese philosopher 井上円了 (Inoue Enryō) and especially his defence of Western Enlightenment beliefs during Japan’s modernisation period (1868–1912) that a curious method and heuristic tool is found that may be used to address not only the problem of mystification in Japanese philosophy but also the obfuscation of the ecological object of recent Western thought. Seemingly sacrilegiously, it is through reason and at the limits of the rational that one may approach the hyperobject-in-itself, which is to say, the unfathomable as such.
Modern Slavery in Global Supply Chains: Can National Action Plans on Business and Human Rights Close the Governance Gap?
Authors: HAMPTON Diane Bulan
Published: October 2019

Following the 2011 endorsement of the UN Guiding Principles on Business and Human Rights (UNGPs), states have begun to implement National Action Plans (NAPs) to operationalize the UNGPs. Using a case study approach and applying a conceptual framework for polycentric governance, this article aims to provide an early assessment of the effectiveness of NAPs adopted by the United Kingdom and the United States to combat one of the worst human rights abuses in global supply chains: modern slavery. This study demonstrates that both NAPs contain elements addressing the governance gaps surrounding modern slavery, such as enacting new laws, adapting existing regulations, strengthening multi-stakeholder mechanisms for business accountability, and promoting innovation. However, it is argued that the NAPs themselves were not the catalysts for the majority of these measures. This article concludes that states should optimize the five characteristics of polycentric governance outlined in this study to improve the relevance and effectiveness of NAPs as drivers of change.