bluuebunny/crossref_metadata_2025 huggingface dataset:
Holding Times and Preservation for Environmental Radiochemical Samples: An Evaluation of ISO Standard Guidelines
Authors: Hattink Jasper , Benzing Roger
Published: September 2019

The condition of a sample taken and stored before analysis is an important aspect in analytical measurements including in the field of environmental radiochemistry. The validity of the result from the test depends heavily on the sample integrity; a sample that is not well preserved might not be a true representative of what has been sampled. For example, the radionuclides in a water sample might be adsorbed by the wall of the container during transport and storage. This study summarises a range of shelf-life tests performed by SOCOTEC nuclear laboratory. Our studies suggest that the integrity of freshwater samples can be preserved for up to 1½ year when filtered and acidified for the analyses of gamma emitting radionuclides and at least 6 months for actinides. Tritium, either in its natural non-acidified state or acidified, can be stored for at least 3 years. For a minimum loss of the transuranium actinides, filtration and acidification should occur within 3 to 7 days of sampling. Cooling the samples during transport and interim storage is advised to suppress bacterial and algal growth.
Simplified Method for Determining Residual Specific Activity in Activated Concrete of a PET-cyclotron Room Using a Survey Meter
Authors: Matsumura Hiroshi , Yoshida Go , Toyoda Akihiro , Masumoto Kazuyoshi , Nishikawa Koichi , Nakabayashi Takayuki , Miyazaki Yoshiharu , Miura Taichi , Nakamura Hajime , Bessho Kotaro
Published: September 2019

An in situ method to determine the specific activity in concrete structures using a survey meter was established in this study for decommissioning accelerator rooms. This method is much simpler than the conventional sampling method that requires core boring. A survey meter (T-SP2, TAC Inc., Japan) was customised and equipped with a small detector probe, whose size allowed the design of a light-weight Pb shield. For dose rate measurement, a Pb shield thickness of 4.5 cm was enough to shield ambient γ-rays, and its weight (16 kg) was low enough for the device to be carried by a human. A calibration curve was obtained to quickly and easily convert the net contact dose rate on concrete into the specific activity in a PET cyclotron room. The specific activity detection limit for this device was lower than the clearance limit of 152Eu and 60Co in activated materials. Therefore, this method can be used for separating nonactivated concrete from activated concrete during decommissioning. A general correction factor for the slope of the calibration curve was also obtained for use at other accelerator facilities.
Investigation of Neutron-fluence Measurement Methods for Estimating Neutron-induced Activity from an Electrostatic Accelerator Source
Authors: Nakamura Hajime , Matsumura Hiroshi , Yoshida Go , Toyoda Akihiro , Masumoto Kazuyoshi , Miura Taichi , Sasa Kimikazu , Moriguchi Tetsuaki
Published: September 2019

Three methods to detect neutrons emitted from an electrostatic accelerator were examined. These were gold foil activation, thermoluminescent dosimeters (TLDs), and CR-39. The gold-foil activation method has previously been proven effective in the measurement of neutrons emitted from cyclotron sources. In the case of electrostatic accelerators, a greater amount of fast neutrons and a smaller amount of thermal neutrons are observed compared to a cyclotron accelerator. Therefore, the error in calculating the thermal neutron flux became unacceptably large. By comparison the CR-39 detectors were apparently unable to measure thermal neutrons well, because some tracks were also generated by fast neutrons causing a signal interference. In the case of TLDs, as the material was not sensitive to fast neutrons, it was not affected by them, and hence could adequately measure the thermal neutron flux. However, it was found that in some cases its measurements could be offset by the influence of high dose rate of gamma rays.
Assessment of Sr-90, Cs-137, Natural Radionuclides and Metals in Marine Fish Species Consumed in the City of São Paulo – Brazil
Authors: Nisti Marcelo Bessa , Saueia Cátia Heloisa Rosignoli , Castilho Bruna , Mazzilli Barbara Paci
Published: September 2019

The aim of this study is to quantify the concentration of the 90Sr, 137Cs, natural radionuclides (210Pb, 226Ra and 228Ra) and metals (As, Co, Cs, Rb, Se, Th, U and Zn) in the flesh of marine fish species most consumed in São Paulo city. The radionuclides and metals concentration were low (but close to the level of detection) or below the MDA of gamma spectrometry, liquid scintillation counting and instrumental neutron activation analysis. The radionuclides and metals concentrations are below limit adopted by the Brazilian Regulatory Agency.
Quantitative Evaluation of Radioactivity in Concrete at PET Cyclotron Facility with Simple and Non-destructive Measurement
Authors: Toyoda Akihiro , Matsumura Hiroshi , Masumoto Kazuyoshi , Yoshida Go , Miura Taichi , Nakamura Hajime , Bessho Kotaro , Nakabayashi Takayuki , Horitsugi Genki
Published: September 2019

Accelerator operations often generate neutrons that may activate concrete in the accelerator room. When accelerators are decommissioned, the concrete will remain as radioactive waste. Not all of concrete in the room will be radioactive wastes, but at place with large amount of neutrons will be radioactive wastes. Therefore, it is very important to determine where and how many neutrons are generated during accelerator operation. We used gold foils to obtain this information in positron emission tomography (PET) cyclotron facilities. We obtained concrete core samples from a PET cyclotron to determine the amount of radioactivity contained in concrete. We obtained the operational parameters (particle, radioactive product, current, and operation time) of the PET cyclotron facility and estimated the radioactivity generated in concrete using the operational parameters and gold foil results. A comparison of the estimated and core sampling measurement results showed good agreement.
Effect of chemical environment on the radiation chemistry of N,N-di-(2-ethylhexyl)butyramide (DEHBA) and plutonium retention
Authors: Horne Gregory P. , Zarzana Christopher A. , Grimes Travis S. , Rae Cathy , Ceder Joakim , Mezyk Stephen P. , Mincher Bruce J. , Charbonnel Marie-Christine , Guilbaud Philippe , Saint-Louis George , Berthon Laurence
Published: September 2019

Gamma-radiolysis of the ligand DEHBA is accelerated under biphasic acidic conditions and yields one or more plutonium complexing degradation products.
Sponge-derived polybrominated diphenyl ethers and dibenzo-p-dioxins, irreversible inhibitors of the bacterial α-d-galactosidase
Authors: Utkina Natalia K. , Likhatskaya Galina N. , Balabanova Larisa A. , Bakunina Irina Y.
Published: September 2019

OH-PBDEs and OH-PBDDs from Dysideidae sponges at micro molar levels irreversibly inhibit the bacterial α-galactosidase of the GH36 family.
Structural characterization of novel comb-like branched α-d-glucan fromArca inflataand its immunoregulatory activitiesin vitroandin vivo
Authors: Li Chunlei , Peng Dan , Huang Weijuan , Ou Xiaozheng , Song Liyan , Guo Zhongyi , Wang Haoran , Liu Wanying , Zhu Jianhua , Yu Rongmin
Published: September 2019

In the current study, we identified and characterized a novel water-soluble polysaccharide (JNY2PW) with significant immunoregulatory effects and no apparent overall toxicity.
Banana flour phenolics inhibit trans-epithelial glucose transport from wheat cakes in a coupledin vitrodigestion/Caco-2 cell intestinal model
Authors: Pico Joana , Corbin Sydney , Ferruzzi Mario G. , Martinez Mario M.
Published: September 2019

A 10% replacement of wheat flour with banana flour subjected to different processing conditions resulted in from 45.0 to 54.5% higher glucose transport inhibition.
PbS quantum dots as additives in methylammonium halide perovskite solar cells: the effect of quantum dot capping
Authors: Ngo Thi Tuyen , Masi Sofia , Mendez Perla F. , Kazes Miri , Oron Dan , Seró Iván Mora
Published: September 2019

Colloidal PbS quantum dots (QDs) have been successfully employed as additives in halide perovskite solar cells (PSCs) acting as nucleation centers in the perovskite crystallization process.
Modeling nanoribbon peeling
Authors: Gigli L. , Vanossi A. , Tosatti E.
Published: September 2019

Lifting and peeling of 2D materials and nanoribbons off surfaces is common in nanoscience. Solution of an analytical model shows that structural lubricity makes the peeling of a nanoribbon or film radically different from the standard description of peeling of immobile, fully glued films.
A core–shell structure QRu-PLGA-RES-DS NP nanocomposite with photothermal response-induced M2 macrophage polarization for rheumatoid arthritis therapy
Authors: Chen Xu , Zhu Xufeng , Ma Litao , Lin Ange , Gong Youcong , Yuan Guanglong , Liu Jie
Published: September 2019

A novel therapeutic strategy for inducing macrophage M2 polarization by a core–shell QRu-PLGA-RES-DS NPs nanocomposite with photothermal response for RA therapy.
Photoacoustic ratiometric assessment of mitoxantrone release from theranostic ICG-conjugated mesoporous silica nanoparticles
Authors: Ferrauto Giuseppe , Carniato Fabio , Di Gregorio Enza , Botta Mauro , Tei Lorenzo
Published: September 2019

A nanosystem based on mesoporous silica functionalized with ICG and the chemotherapeutic drug mitoxantrone has been exploited to introduce an innovative photoacoustic ratiometric approach for the assessment of drug release bothin vitroandin vivo.
Which is the most effective pristine graphene electrode for energy storage devices: aerogel or xerogel?
Authors: Jung Sung Mi , Kim Dong Won , Jung Hyun Young
Published: September 2019

The morphological design of pristine graphene aerogel and xerogel in both supercapacitors and lithium-ion batteries was demonstrated.
Clickable styryl dyes for fluorescence labeling of pyrrolidinyl PNA probes for the detection of base mutations in DNA
Authors: Ditmangklo Boonsong , Taechalertpaisarn Jaru , Siriwong Khatcharin , Vilaivan Tirayut
Published: September 2019

Styryl dyes clicked to the backbone of pyrrolidinyl PNA probes show significant fluorescence enhancements in response to structural defects in PNA·DNA duplexes.
A computational study of regioselectivity in aluminum hydride ring-opening of cis- and trans-4-t-butyl and 3-methylcyclohexene oxides
Authors: Deora Nipa , Carlier Paul R.
Published: September 2019

Nucleophilic ring opening of cyclohexene oxides is known to proceed preferentially through the trans-diaxial pathway (the Fürst–Plattner rule).
Substrate-product analogue inhibitors of isoleucine 2-epimerase from Lactobacillus buchneri by rational design
Authors: Sorbara Noa T. , MacMillan Joshua W. M. , McCluskey Gregory D. , Bearne Stephen L.
Published: September 2019

Substrate-product analogues, designed based on partial movement of the sec-butyl side chain during catalysis, inhibit isoleucine 2-epimerase.
Well-defined CoP/Ni2P nanohybrids encapsulated in a nitrogen-doped carbon matrix as advanced multifunctional electrocatalysts for efficient overall water splitting and zinc–air batteries
Authors: Lv Xianwei , Tian Wenwen , Liu Yuping , Yuan Zhong-Yong
Published: September 2019

Well-defined core–shell CoP/Ni2P@NC nanohybrids for overall water splitting and rechargeable zinc–air batteries.
The supramolecular assemblies based on heteroatom-containing triangulenes
Authors: Winter Andreas , Schubert Ulrich S.
Published: September 2019

The assemblies derived from the various types of heteroatom-containing triangulenes are reviewed with respect to their supramolecular structures, characterization, properties and potential application.
Facile synthetic approach towards vasorelaxant active 4-hydroxyquinazoline-4-carboxamides
Authors: Aziz Marian N. , Panda Siva S. , Shalaby ElSayed M. , Fawzy Nehmedo G. , Girgis Adel S.
Published: September 2019

A set of vasorelaxant active 4-hydroxyquinazoline-4-carboxamides was obtained in a novel synthetic approach via secondary amine nucleophilic reaction with 2,3-dioxoindoline-1-carboxamides.
Doxorubicin loaded ferritin nanoparticles for ferroptosis enhanced targeted killing of cancer cells
Authors: Yang Runlin , Li Yaoqi , Wang Xinyu , Yan Junjie , Pan Donghui , Xu Yuping , Wang Lizhen , Yang Min
Published: September 2019

DOX loaded ferritin selectively induces ferroptosis enhanced killing of transferrin receptor 1 overexpressed cancer cells.
A molecular electron density theory study of the mechanism, chemo- and stereoselectivity of the epoxidation reaction ofR-carvone with peracetic acid
Authors: Zeroual Abdellah , Ríos-Gutiérrez Mar , Amiri Ouafa , El Idrissi Mohammed , Domingo Luis R.
Published: September 2019

The epoxidation reaction ofR-carvone8with peracetic acid9has been studied within the molecular electron density theory at the B3LYP/6-311(d,p) computational level.
Study on noise-vibration coupling characteristics of premixed methane–air flame propagation in a tube with an acoustic absorption material
Authors: Wang Quan , Chang Weida , Liu Shanghao , Li Zhimin , Zhu Kaibo
Published: September 2019

To study the influence of an acoustic absorbing material on the noise and vibration of a methane–air flame, the flame propagation velocity, overpressure, noise and wall vibration characteristics were investigated in a square plexiglass tube.
Triphala inhibits alpha-synuclein fibrillization and their interaction study by NMR provides insights into the self-association of the protein
Authors: Bopardikar Mandar , Bhattacharya Anusri , Rao Kakita Veera Mohana , Rachineni Kavitha , Borde Lalit C. , Choudhary Sinjan , Koti Ainavarapu Sri Rama , Hosur Ramakrishna V.
Published: September 2019

Triphala inhibits αSyn self-association by interacting with anchoring regions which are responsible for αSyn oligomerization.
Plasmonic Ag decorated CdMoO4 as an efficient photocatalyst for solar hydrogen production
Authors: Sethi Yogesh A. , Kulkarni Aniruddha K. , Khore Supriya K. , Panmand Rajendra P. , Kanade Sandip C. , Gosavi Suresh W. , Kulkarni Milind V. , Kale Bharat B.
Published: September 2019

Plasmonic enhancement of photocatalytic hydrogen generation is demonstrated using hierarchical Ag decorated CdMoO4 synthesized using a hydrothermal method.
Role of torsional strain in the ring-opening polymerisation of low strain [n]nickelocenophanes
Authors: Musgrave Rebecca A. , Hailes Rebekah L. N. , Annibale Vincent T. , Manners Ian
Published: September 2019

We investigate types of ring strain responsible for the ring-opening polymerisation of [n]nickelocenophanes with carbon and silicon-based ansa bridges.
Chemoselective formal β-functionalization of substituted aliphatic amides enabled by a facile stereoselective oxidation event
Authors: Bauer Adriano , Maulide Nuno
Published: September 2019

A facile dehydrogenation event enables the functionalization of aliphatic amides at different positions in a one-pot fashion.
The hydrogen evolution reaction: from material to interfacial descriptors
Authors: Dubouis Nicolas , Grimaud Alexis
Published: September 2019

This perspective provides a new look into how electrolyte structure at the interface controls the kinetics of water reduction.
Rhodium-catalyzed asymmetric intramolecular hydroarylation of allenes: access to functionalized benzocycles
Authors: Berthold Dino , Klett Johannes , Breit Bernhard
Published: September 2019

A rhodium-catalyzed regio- and enantioselective cyclization of tethered allenylbenzenes is reported.
Atmospheric pressure synthesis of nano-scale SAPO-34 catalysts for effective conversion of methanol to light olefins
Authors: Lyu Meng , Yang Chengguang , Liu Ziyu , Wang Ting , Liu Hongjiang , Chen Xinqing , Sun Yuhan
Published: September 2019

Nano-scale SAPO-34 zeolites were synthesized in an open reactor under atmospheric pressure.
Rheological properties and failure of alginate hydrogels with ionic and covalent crosslinks
Authors: Hashemnejad Seyed Meysam , Kundu Santanu
Published: September 2019

Non-linear rheological properties and failure behavior of ionic and chemically crosslinked alginate hydrogels are investigated.
Atomically dispersed metal dimer species with selective catalytic activity for nitrogen electrochemical reduction
Authors: Li Yang , Zhang Qi , Li Can , Fan Hai-Ning , Luo Wen-Bin , Liu Hua-Kun , Dou Shi-Xue
Published: September 2019

An atomic Fe/Mo-metal dimer in situ anchored on defect-rich graphene layers realizes selective electroreduction of nitrogen to ammonia by numerous FeMoN6 active sites.
An “electronegative” bifunctional coating layer: simultaneous regulation of polysulfide and Li-ion adsorption sites for long-cycling and “dendrite-free” Li–S batteries
Authors: Lu Qian , Zou Xiaohong , Ran Ran , Zhou Wei , Liao Kaiming , Shao Zongping
Published: September 2019

Liquid-phase delaminated HxMnO2+x nanosheets can be utilized to create an “electronegative” coating layer for Li–S batteries to suppress the polysulfide shuttling and Li-dendrite growth.
Nonacyclic carbazole-based non-fullerene acceptors enable over 12% efficiency with enhanced stability for organic solar cells
Authors: Wang Hongtao , Zhang Zhuohan , Yu Jiangsheng , Liu Xin , Qu Shenya , Guang Shun , Tang Weihua
Published: September 2019

Organic solar cells based on a nonacyclic carbazole-cored non-fullerene acceptor exhibited a high power conversion efficiency of 12.07% with enhanced stability.
A multi-input light-stimulated synaptic transistor for complex neuromorphic computing
Authors: He Weixin , Fang Yuan , Yang Huihuang , Wu Xiaomin , He Lihua , Chen Huipeng , Guo Tailiang
Published: September 2019

Multi-input synaptic devices that can imitate multi-synaptic connection and integration in the human brain are crucial for the construction of ideal brain-like computing systems with parallelism, low power consumption, and robustness.
Kaempferol derivatives isolated from Lens culinaris Medik. reduce DNA damage induced by etoposide in peripheral blood mononuclear cells
Authors: Kluska Magdalena , Juszczak Michał , Wysokiński Daniel , Żuchowski Jerzy , Stochmal Anna , Woźniak Katarzyna
Published: September 2019

Bioactive compounds isolated from plants are considered to be attractive candidates for cancer therapy. In this study, we examined the effect of kaempferol, its derivatives, the polyphenol fraction (PF) and an extract (EX) isolated from the aerial parts of Lens culinaris Medik. on DNA damage induced by etoposide in human cells. We also studied the effect of these compounds and their combinations on cell viability. The studies were conducted on HL-60 cells and human peripheral blood mononuclear cells (PBMCs). We used the comet assay in the alkaline version to evaluate DNA damage. To examine cell viability we applied the trypan blue exclusion assay. We demonstrated that kaempferol glycoside derivatives isolated from the aerial parts of Lens culinaris Medik. reduce DNA damage induced by etoposide in PBMCs, but do not have an impact on DNA damage in HL-60 cells. We also showed that kaempferol induces DNA damage in HL-60 cells and leads to an increase of DNA damage provoked by etoposide. Our data suggest that kaempferol derivatives can be further explored as a potential agent protecting normal cells against DNA damage induced by etoposide. Moreover, kaempferol's ability to induce DNA damage in cancer cells and to increase DNA damage caused by etoposide may be useful in designing and improving anticancer therapies.
Origin of the system of globular clusters in the Milky Way
Authors: Massari D. , Koppelman H. H. , Helmi A.
Published: September 2019

Context. The assembly history experienced by the Milky Way is currently being unveiled thanks to the data provided by the Gaia mission. It is likely that the globular cluster system of our Galaxy has followed a similarly intricate formation path.

Aims. To constrain this formation path, we explore the link between the globular clusters and the known merging events that the Milky Way has experienced.

Methods. To this end, we combined the kinematic information provided by Gaia for almost all Galactic clusters, with the largest sample of cluster ages available after carefully correcting for systematic errors. To identify clusters with a common origin we analysed their dynamical properties, particularly in the space of integrals of motion.

Results. We find that about 40% of the clusters likely formed in situ. A similarly large fraction, 35%, appear to be possibly associated to known merger events, in particular to Gaia-Enceladus (19%), the Sagittarius dwarf galaxy (5%), the progenitor of the Helmi streams (6%), and to the Sequoia galaxy (5%), although some uncertainty remains due to the degree of overlap in their dynamical characteristics. Of the remaining clusters, 16% are tentatively associated to a group with high binding energy, while the rest are all on loosely bound orbits and likely have a more heterogeneous origin. The resulting age–metallicity relations are remarkably tight and differ in their detailed properties depending on the progenitor, providing further confidence on the associations made.

Conclusions. We provide a table listing the likely associations. Improved kinematic data by future Gaia data releases and especially a larger, systematic error-free sample of cluster ages would help to further solidify our conclusions.
GALACTICNUCLEUS: A high-angular-resolution JHKs imaging survey of the Galactic centre
Authors: Nogueras-Lara F. , Schödel R. , Gallego-Calvente A. T. , Dong H. , Gallego-Cano E. , Shahzamanian B. , Girard J. H. V. , Nishiyama S. , Najarro F. , Neumayer N.
Published: September 2019

Context. The high extinction and extreme source crowding of the central regions of the Milky Way are serious obstacles to the study of the structure and stellar population of the Galactic centre (GC). Existing surveys that cover the GC region (2MASS, UKIDSS, VVV, SIRIUS) do not have the necessary high angular resolution. Therefore, a high-angular-resolution survey in the near infrared is crucial to improve the state of the art.

Aims. Here, we present the GALACTICNUCLEUS catalogue, a near infrared JHKs high-angular-resolution (0.2″) survey of the nuclear bulge of the Milky Way.

Methods. We explain in detail the data reduction, data analysis, calibration, and uncertainty estimation of the GALACTICNUCLEUS survey. We assess the data quality comparing our results with previous surveys.

Results. We obtained accurate JHKs photometry for ∼3.3 × 106 stars in the GC detecting around 20% in J, 65% in H, and 90% in Ks. The survey covers a total area of ∼0.3 deg2, which corresponds to ∼6000 pc2. The GALACTICNUCLEUS survey reaches 5σ detections for J ∼ 22 mag, H ∼ 21 mag, and Ks ∼ 21 mag. The uncertainties are below 0.05 mag at J ∼ 21 mag, H ∼ 19 mag, and Ks ∼ 18 mag. The zero point systematic uncertainty is ≲0.04 mag in all three bands. We present colour–magnitude diagrams for the different regions covered by the survey.
Efficient Robust Design Optimization of Optical Systems
Authors: Kunath Stephanie
Published: September 2019

To accelerate the virtual product development of using optical simulation software, the Robust Design Optimization approach is very promising. Optical designs can be explored thoroughly by means of sensitivity analysis. This includes the identification of relevant input parameters and the modelling of inputs vs. outputs to understand their dependencies and interactions. Furthermore, the intelligent definition of objective functions for an efficient subsequent optimization is of high importance for multi-objective optimization tasks. To find the best trade-off between two or more merit functions, a Pareto optimization is the best choice. As a result, not only one design, but a front of best designs is obtained and the most appropriate design can be selected by the decision maker. Additionally, the best trade-off between output variation of the robustness (tolerance) and optimization targets can be found to secure the manufacturability of the optical design by several advanced approaches. The benefit of this Robust Design Optimization approach will be demonstrated.
Optical freeform generation by laser machining and plasma-assisted polishing
Authors: Arnold Thomas , Maiwald Anne , Böhm Georg , Erhrhard Martin , Zimmer Klaus
Published: September 2019

Tailored optical freeform lenses are required for different applications. Sub-aperture deterministic machining techniques such as plasma jet machining have shown great potential to generate freeform surfaces. However, depending on the required local slopes of the surface shape geometrical limitations occur due to the lateral tool function width. In the paper an alternative approach to fabricate freeform shapes exhibiting steep local slopes is presented. A first step involves a dwell time based fs-laser ablation process to generate the surface contour on a fused silica sample. Since the resulting roughness after laser machining lies in the range of 400 nm RMS which does not match optical requirements a subsequent plasma jet based polishing step is performed where micro-roughness is drastically reduced to values below 0.3 nm RMS.
Realization of depth reference samples with surfaces amplitudes between 0.1 nm and 5 nm
Authors: Finzel Annemarie , Dornberg Gregor , Görsch Stephan , Mitzschke Martin , Bauer Jens , Frost Frank
Published: September 2019

A new approach for the realization of depth reference samples is presented. By a combination of photolithography, reactive ion beam etching, surface planarization with photoresists and a subsequent coating with non-transparent materials, defined sinusoidal surface profiles are generated which can be used as depth references for the comparison and calibration of different surface profile measurements. The smallest realized surface amplitudes are in the range of less than 0.1 nm.
Splicing fluoride glass and silica optical fibers
Authors: Cozic Solenn , Boivinet Simon , Pierre Christophe , Boulet Johan , Poulain Samuel , Poulain Marcel
Published: September 2019

Splicing fluoride glass fibers and silica fibers is a critical point for manufacturing all fibered laser modules. As these materials are extremely different, various problems must be considered: thermal, expansion, mechanical, chemical. Reliability and power handling make priority concerns. We report splices made on a 200/220 multimode silica fiber and a double clad 15/250/290 ZBLAN fiber. Splices are proof tested at 300 g tensile strength. No damage is observed after thermal cycling from -30 °C to 85 °C, at 40 % RH during 24 hours. Typical optical splice loss is about 0.2 dB. They withstand 220 W input power at 976 nm without any damage and drastic temperature increasing.
Measurement and correction of two-sided freeform optical elements with combined tactile-optical metrology equipment
Authors: Hartung Johannes , von Lukowicz Henrik , Rohde Mathias , Kleinbauer Knut , Heidler Nils , Risse Stefan
Published: September 2019

Freeform optical elements are state of the art for several years to fabricate very high performance optical systems with the necessity of, e.g., strong folding in mirror system or correction of typical asymmetric aberrations in mirror systems as well as lens systems. For freeform mirror systems, in particular for metal mirrors, the metrology is well understood and iterative process chains are well established. For transmission elements with a freeform surface on both sides, manufacturing, metrology, and correction for both sides in a parallel manner is quite difficult. The article presents a method to measure such an optical element and correct it with a well-defined correction step to have both sides in a well-defined position to each other.
Computer Generated Holograms (CGH) for Testing, Alignment and Positioning of Astronomical and Space Mirrors Aspherical Surfaces
Authors: Semenov Aleksandr , Abdulkadyrov Magomed , Dobrikov Nikolay , Ignatov Aleksandr , Patrikeev Vladimir , Pridnya Vitaliy , Polyanchikov Andrey , Nasyrov Ruslan
Published: September 2019

JSC LZOS successfully applies Computer Generated Holograms (CGH) for testing of on- and off-axis surfaces of large-dimensioned optical components for their alignment with respect to interferometer, for defining of aspherical surface optical vertex position with respect to the geometrical center and for optical systems alignment. All this allows producing of large-dimensioned aspherical on- and off-axis astronomical and space mirrors with high accuracy.
Laser printed flat lenses for optofluidics
Authors: Žukauskas Airidas , Stilling-Andersen Andreas R. , Zhu Xiaolong , Kristensen Anders
Published: September 2019

Conventional three-dimensional optics requires curvature to control the wave front of light thus making it diﬃcult to reduce the size of the optical systems. Furthermore, for correction of optical aberrations, complex optical systems comprising more than one lens are used. This adds additional bulk, mass and complexity to the optical systems. Recent development in diﬀractive optics has enabled new thin lightweight optical elements such as metalenses. We introduce resonant laser printing technique as a flexible photo-thermal technology for metalens fabrication with the ability to control the light with microscale precision. Our laser printed metalenses can be integrated in bio-sensors, bio-imaging systems, and optofluidical devices.
Addressing the Fabrication Difficulties of Femtosecond Laser Written Surface Waveguides for Enhanced Evanescent Coupling
Authors: Amorim Vítor A. , Maia João M. , Viveiros Duarte , Marques P. V. S.
Published: September 2019

In this work, the fabrication of optical waveguides embedded in fused silica (Suprasil1) and boro-aluminosilicate glass (Eagle2000) is demonstrated with femtosecond laser direct writing, as well as their suitability to be brought to the surface, through wet etching, for enhanced evanescent coupling with the external dielectric medium. Fused silica demonstrated to be inappropriate in this particular application, as the guiding region is at the bottom of the induced modification, creating a barrier between the guided mode and the substrate’s boundary. Furthermore, the existence of nanogratings meant that, upon contact of the top of the induced modification with the substrate’s boundary, the waveguide is quickly etched. Eagle2000 demonstrated to be superior to fused silica due to its characteristic modification cross-section and absence of nanogratings, which allowed the placement of the guiding region as close to the substrate’s surface as required. However, surface roughness arising from the creation of insoluble products in the HF solution was found. The addition of HCl to dissolve these products was implemented.
MRI Brain Changes After Marathon Running: Results of the Berlin Beat of Running Study
Authors: Herm Juliane , Haeusler Karl Georg , Kunze Claudia , Krüll Matthias , Brechtel Lars , Lock Jürgen , Heuschmann Peter U. , Haverkamp Wilhelm , Heekeren Hauke , Liman Thomas , Endres Matthias , Fiebach Jochen B. , Jungehulsing Gerhard Jan
Published: September 2019

Several studies report neurological complications such as brain injury induced by ischemia or edema following exhaustive endurance sport. We aimed to detect the frequency of acute brain lesions after a marathon race. In the prospective observational Berlin Beat of Running study, 110 experienced endurance athletes underwent 3-Tesla brain MRI exams 2–3 days prior and within 2 days after a marathon run. MRI results were compared to an age- and sex-matched control group of 68 non-athletes, including the “Age-Related White Matter Changes” (ARWMC) scale to assess white matter lesions (WML) in the brain. 108 athletes (median age 48 years, 24% female, 8% with hypertension; 0% with diabetes) completed the race. No athlete reported neurological deficits, but a single acute ischemic lesion was detected in diffusion-weighted MRI after the race in one athlete. No other acute brain lesions compared to prior MRI were found. An ARWMC score ≥4 was found in 15% of athletes and 12% of non-athletic controls (p=0.7). Chronic ischemic lesions were not found in athletes but in four controls (6%) (p=0.02). In conclusion, acute ischemic brain lesions may be found in endurance runners. Every seventh endurance athlete and every ninth control showed evidence for substantial white matter lesions.
Die kognitive, sprachliche und motorische Entwicklung pränatal methamphetamin- und opioid-exponierter Kinder
Authors: Schreiter Juliane , Vogel Mandy , Kiep Henriette , Thome Ulrich , Bläser Annett , Nickel Petra , Kiess Wieland , Bernhard Matthias K.
Published: September 2019

Hintergrund Der Konsum illegaler Substanzen in der Schwangerschaft ist eine große gesellschaftliche und medizinische Herausforderung. Hauptproblemsubstanzen der pränatalen Drogenexposition sind neben Tetrahydrocannabinol (THC) Opioide und Methampehtamin. Die Wirkung dieser Substanzen auf die langfristige Entwicklung der Kinder ist noch vielfach unbekannt.

Methoden Seit 2012 werden am Universitätsklinikum Leipzig geborene Kinder mit pränataler Substanzexposition in der Kinderschutzambulanz langfristig nachbetreut. Von 42 Kindern mit pränataler Opioid- oder Methamphetaminexposition wurde im Alter von 2–3 Jahren eine Entwicklungsdiagnostik anhand der Bayley Scales (BSID III) durchgeführt. Als Kontrolle dienten 84 nicht exponierte Kinder. Das Matching erfolgte 1:2, adaptiert nach Alter, Geschlecht, Gestationsalter und Geburtsgewicht.

Ergebnisse Die motorische Entwicklung zwischen pränatal methamphetamin-, opioidexponierten Kindern und der Kontrollgruppe unterscheidet sich nicht signifikant. Die Kinder mit pränataler Methamphetaminexposition (n=23) zeigen jedoch signifikant geringere Skalenwerte in Kognition und Sprache (79,1 gegenüber 95,9 der Kontrollgruppe), pränatal opioidexponierte Kinder eine leichtere kognitive Einschränkung mit einem Skalenwert von 91,7 (n=19). 56% der Kinder der Methamphetamin-Gruppe hatten formal eine Entwicklungsverzögerung zum Testzeitpunkt. Zusätzlich erreichten Kinder signifikant niedrigere Skalenwerte, deren Bezugsperson alleinerziehend und/oder eine geringe schulische und berufliche Bildung hatten. Beide Substanzen erhöhten trotz gleichem Gestationsalter in allen Gruppen (37,4–38,5 SSW) das Auftreten postnataler Adaptionsstörungen erheblich (46–53%).

Schlussfolgerung Aus dieser Studie ergeben sich Hinweise darauf, dass Kinder mit pränataler Exposition gegenüber Methamphetamin oder Opioiden kognitive und sprachliche Defizite mit 2–3 Jahren zeigen und Methamphetamin einen stärkeren negativen Einfluss zu haben scheint. Die mit elterlichen Drogenabusus verbundenen psychosozialen Risikofaktoren haben dabei eine entscheidende Bedeutung für das Erreichen einer altersgerechten Entwicklung.
ERCP assessment tool: evidence of validity and competency development during training
Authors: Siau Keith , Dunckley Paul , Feeney Mark , Johnson Gavin ,   on behalf of the Joint Advisory Group on Gastrointestinal Endoscopy
Published: September 2019

Background The endoscopic retrograde cholangiopancreatography (ERCP) direct observation of procedural skills (DOPS) is a 27-item competency assessment tool that was developed to support UK ERCP training. We evaluated validity of ERCP DOPS and competency development during training.

Methods This prospective study analyzed ERCP DOPS performed in the UK between July 2016 and October 2018. Reliability was measured using Cronbach’s alpha, and DOPS scores were benchmarked using the contrasting groups method. The percentage of competent scores was averaged for each item, domain, and overall rating, and stratified by lifetime procedure count to evaluate learning curves. Multivariable analyses were performed to identify predictors of DOPS competence.

Results 818 DOPS (109 trainees, 80 UK centers) were analyzed. Overall Cronbach’s alpha was 0.961. Attaining competency in 87 % of assessed DOPS items provided the optimal competency benchmark. This was achieved in the domain sequence of: pre-procedure, post-procedure management, endoscopic non-technical skills, cannulation & imaging, and execution of selected therapy, and across all items after 200 – 249 procedures (89 %). After 300 procedures, the benchmark was reached for selective cannulation (89 %), but not for stenting (plastic 73 %; metal 70 %), sphincterotomy (80 %), and sphincteroplasty (56 %). On multivariable analysis, lifetime procedure count (P = 0.002), easier case difficulty (P < 0.001), trainee grade (P = 0.03), and higher lifetime DOPS count (P = 0.01) were predictors of DOPS competence.

Conclusion This study provides novel validity, reliability, and learning curve data for ERCP DOPS. Trainees should have a minimum of 300 hands-on ERCP procedures before undertaking summative assessment for independent practice.
A study of non-iterative triples contributions in relativistic equation-of-motion coupled-cluster calculations using an exact two-component Hamiltonian with atomic mean-field spin-orbit integrals: Application to uranyl and other heavy-element compounds
Authors: Cheng Lan
Published: September 2019

The implementation of an equation-of-motion coupled-cluster singles and doubles augmented with a noniterative triples correction [EOM-CCSD(T)(a)*] method [D. A. Matthews and J. F. Stanton, J. Chem. Phys. 145, 124102 (2016)] with an exact two-component Hamiltonian using atomic mean-field spin-orbit integrals (X2CAMF) is reported. Benchmark calculations show that both the correction from triple excitations in the cluster operator to the similarity-transformed Hamiltonian and the contribution from triple excitations in excited-state eigenvalue equations make important contributions to computed excitation energies of molecules containing heavy elements. X2CAMF-EOM-CCSD(T)(a)* excitation energies and excited-state properties for low-lying excited states of As2, Sb2, and Bi2 are in significantly better agreement with corresponding experimental values than EOM-CCSD ones. X2CAMF-EOM-CCSD(T)(a)* calculations have also been demonstrated to provide accurate results for excitation energies of low-lying excited states of bare uranyl ion UO22+, hereby resolving a long-standing debate on this topic.
Strong dependence of the nano-bio interactions on core morphology and layer composition of ultrasmall nanostructures
Authors: Hassan Sergio A.
Published: September 2019

The interactions between nanoparticles (NPs) and proteins, cells, and tissues, broadly known as nano-bio interactions, depend on the NP size and shape and on the characteristics of the NP coating layer, such as density, thickness, and chemical makeup. The dependence of nano-membrane interactions on the design parameters of ultrasmall nanostructures is studied by computer simulations. Considered here are spheres, plates, rings, rods, tubes, and helices made up of either bare magnetite or passivated gold, interacting with charged or zwitterionic membranes. The analysis reveals a strong dependence on shape, size, and layer composition of various quantities that characterize the nano-bio behavior, including binding modes and affinities. This sensitivity can be exploited to design nanostructures that bind preferentially to membranes or that stabilize or disrupt membrane structural integrity. The method used here is general and not limited to the ultrasmall regime, so it can be adopted to study other nano-bio interactions systematically. The implications for the distribution of NPs in cells and tissues (biodistribution) and for passive and active transmembrane transport are discussed, both important processes in biomedicine.
Detonation wave propagation in micro-scale groove charges
Authors: Liu Rongqiang , Nie Jianxin , Song Haitong , Jiao Qingjie , Wen Yuquan
Published: September 2019

The detonation wave propagation characteristics in micro-scale groove charges are very important for optimizing the structure of the Micro-Electro-Mechanics System explosive train and improving its detonation reliability. Focusing on the problem of detonation wave propagation of micro-scale groove charges under strong confinement, the effects of charge density, groove size and confinement are considered. A theoretical model of curved detonation wave propagation in a micro-scale groove charge under a strong confinement was established by means of equivalent mass correction. The mathematical expression for the detonation velocity was derived and a numerical calculation method of detonation velocity and shock front shape was given using MATLAB software. An experiment was designed to test the detonation velocities for micro-scale groove charges with a booster explosive. The results closely agreed with the calculations, validating the propagation model of curved detonation waves. The results show that the smaller the groove size, the bigger the detonation velocity loss and the curvature of shock front in the central axis. When the charge size was 0.6×0.6mm, the detonation velocity loss was 11.49%. The detonation velocity and maximum streamline deflection angle increase with increasing charge density and size. The increase of streamline deflection angle reduces the detonation velocity of the explosive. However, the streamline deflection angle changes by only a small amount in the micro-scale with an effect on the detonation velocity of less than 1%. The detonation velocity has a strong correlation with charge size and density. This paper contains theoretical guidance for the design and performance optimization of charge structures in the MEMS explosive train.
Liquid-hexatic-solid phase transition of a hard-core lattice gas with third neighbor exclusion
Authors: Darjani Shaghayegh , Koplik Joel , Banerjee Sanjoy , Pauchard Vincent
Published: September 2019

The determination of phase behavior and, in particular, the nature of phase transitions in two-dimensional systems is often clouded by finite size effects and by access to the appropriate thermodynamic regime. We address these issues using an alternative route to deriving the equation of state of a two-dimensional hard-core particle system, based on kinetic arguments and the Gibbs adsorption isotherm, by the use of the random sequential adsorption with a surface diffusion model. Insight into coexistence regions and phase transitions is obtained through direct visualization of the system at any fractional surface coverage via local bond orientation order. The analysis of the bond orientation correlation function for each individual configuration confirms that first-order phase transition occurs in a two-step liquid-hexatic-solid transition at high surface coverage.
A tiny swimmer generates rapid, far-reaching signals in water
Authors: Berkowitz Rachel
Published: September 2019

Colonies of a single-celled organism synchronize their contractions to release toxins that may deter predators.
Effect of a mixed silage of king grass (Cenchrus purpureus) and forage legumes (Leucaena leucocephala or Gliricidia sepium) on sheep intake, digestibility and nitrogen balance
Authors: Santana A. A. , Cheng L. , Verdecia D. M. , Ramírez J. L. , López S. , Cisneros M. V. , Rugoho I. , Maxwell T. M. R. , Al-Marashdeh O.
Published: September 2019

Ensiled king grass (Cenchrus purpureus (Schumach.) Morrone) is commonly used as feed in tropical ruminant production. However, ruminant performance can be limited by low nitrogen (N) content in tropical grass silage. A mixed feed of legume–king grass silage may be an option to improve ruminant production. We investigated the effects of feeding an ensiled mixture of king grass forage and foliage of a browse tree legume, either leucaena (Leucaena leucocephala (Lam.) de Wit) or gliricidia (Gliricidia sepium (Jacq.) Walp), on dry matter (DM) intake, DM digestibility, organic matter (OM) digestibility and N balance of Pelibuey sheep. Twelve male lambs 9–11 months old were blocked by initial bodyweight (33 ± 3 kg, mean ± s.d.) into three groups of four lambs and randomly assigned to one of three feed treatments: king grass silage (KS); mixed king grass and leucaena silage (KLS); and mixed king grass and gliricidia silage (KGS). Results showed that DM and OM were similar among silages. The N content was higher (P < 0.001) in KLS and KGS than in KS. DM intake and DM digestibility were higher (P < 0.001) in KLS and KGS than in KS. OM digestibility was higher (P < 0.001) in KLS than in KS. Nitrogen intake, faecal N, urine volume, urinary N, digested N, N digestibility, N retention and retained N:N intake ratio from KLS and KGS treatments were higher (P < 0.05) than from KS. A lower (P < 0.01) urinary N:N intake ratio was detected from KGS and KLS than from KS. This study demonstrated that, compared with silage made from king grass alone, legume–king grass silage mixtures can improve intake and nutrient digestibility in Pelibuey lambs. Further, N retention can be enhanced when legume–king grass silages are used as feed compared with king grass silage alone.
Atmosphere–ocean oxygen and productivity dynamics during early animal radiations
Authors: Dahl Tais W. , Connelly James N. , Li Da , Kouchinsky Artem , Gill Benjamin C. , Porter Susannah , Maloof Adam C. , Bizzarro Martin
Published: September 2019

Significance

We have discovered 2 major oceanic anoxic events (OAEs) in the early Cambrian at the time when animals markedly diversified. We present a multiproxy constraint on the global biogeochemical cycles to show that these events, in contrast to most younger OAEs, could have been driven by declining atmospheric O
2
levels, plausibly set off by the appearance of bioturbating animals. Pulses of animal appearances may have occurred at different times on different continents, but the last pulse occurred after the OAEs and at a time when we predict higher marine productivity and O
2
levels in the surface oceans suggesting energy supply into the marine food chain was maximal.
Gold nanoshell-localized photothermal ablation of prostate tumors in a clinical pilot device study
Authors: Rastinehad Ardeshir R. , Anastos Harry , Wajswol Ethan , Winoker Jared S. , Sfakianos John P. , Doppalapudi Sai K. , Carrick Michael R. , Knauer Cynthia J. , Taouli Bachir , Lewis Sara C. , Tewari Ashutosh K. , Schwartz Jon A. , Canfield Steven E. , George Arvin K. , West Jennifer L. , Halas Naomi J.
Published: September 2019

Significance

Prostate cancer is the most common nonskin cancer in the United States, where approximately 1 in 9 men will be diagnosed in their lifetime. The prostate is near several vital structures, such as the urethra and neurovascular bundle, and whole gland treatments for prostate cancer can disrupt normal urinary, bowel, and sexual functioning. Here we report the initial results of a clinical trial for nanoparticle-based photothermal cancer therapy. The trial was designed to perform ultrafocal photothermal ablation of cancerous tumors within the prostate. Gold-silica nanoparticles designed to absorb near-infrared light at wavelengths of high tissue transparency provide a highly localized light-based strategy for the treatment of prostate cancer, with substantially reduced risks for deleterious treatment-related side effects.
NEEDLE1
encodes a mitochondria localized ATP-dependent metalloprotease required for thermotolerant maize growth
Authors: Liu Qiujie , Galli Mary , Liu Xue , Federici Silvia , Buck Amy , Cody Jon , Labra Massimo , Gallavotti Andrea
Published: September 2019

Meristems are highly regulated structures ultimately responsible for the formation of branches, lateral organs, and stems, and thus directly affect plant architecture and crop yield. In meristems, genetic networks, hormones, and signaling molecules are tightly integrated to establish robust systems that can adapt growth to continuous inputs from the environment. Here we characterized
needle1
(
ndl1
), a temperature-sensitive maize mutant that displays severe reproductive defects and strong genetic interactions with known mutants affected in the regulation of the plant hormone auxin.
NDL1
encodes a mitochondria-localized ATP-dependent metalloprotease belonging to the FILAMENTATION TEMPERATURE-SENSITIVE H (FTSH) family. Together with the hyperaccumulation of reactive oxygen species (ROS),
ndl1
inflorescences show up-regulation of a plethora of stress-response genes. We provide evidence that these conditions alter endogenous auxin levels and disrupt primordia initiation in meristems. These findings connect meristem redox status and auxin in the control of maize growth.