bluuebunny/crossref_metadata_2025 huggingface dataset:
Thoracic MRI evaluation of sarcoidosis in children
Authors: Gorkem Sureyya Burcu , Köse Seçil , Lee Edward Y. , Doğanay Selim , Coskun Ayse Seda , Köse Mehmet
Published: October 2016

Background

Childhood sarcoidosis is a very rare granulomatous disorder with an unknown etiology. Stage 1 disease is the most common whereas stages 2, 3, and 0 are rare in children.

Objective

To evaluate thoracic findings of pediatric pulmonary sarcoidosis on MRI and to compare them with CT findings.

Methods

Between August 2010 and May 2015, seven consecutive pediatric patients (four male, three female; age range: 8–18 years, mean age: 13.5 ± 3.01 years) who were diagnosed with sarcoidosis were enrolled in our study prospectively. Inclusion criterion was patients with stages 1–4 sarcoidosis who underwent contrast enhanced chest CT for initial diagnosis or follow‐up evaluation of thoracic findings and exclusion criteria were patients with stage 0 disease with extra‐pulmonary manifestations (n = 4).

Results

Two patients who recovered from stage 2 to stage 0 were interpreted as normal. Five patients had abnormal findings on chest CT, including hilar/mediastinal lymphadenopathy (n = 5, 71%), nodules larger than 3 mm (n = 4, 57%), ground glass opacity (n = 4, 57%), thickening of the pleura/fissure (n = 3, 42%), interlobular septal thickening (n = 2, 28%), atelectasis (n = 1, 14%), consolidation (n = 1, 14%), bronchiectasis (n = 1, 14%), intraparenchymal and subpleural cysts (n = 1,14%), fibrotic bands (n = 1, 14%), and enlarged pulmonary artery (n = 1, 14%). Findings that were detected on CT but not observed by lung MRI were nodules <3 mm (n = 4, 57%), mild bronchiectasis and mild ground glass opacity (n = 1, 14%), and subpleural and intraparenchymal cysts (n = 1, 14%). The sensitivity and specificity of MRI were 85.2% and 100%, respectively. There was no statistically significant difference between lung MRI and CT in detecting the thoracic findings in stages 1, 2, and 4 sarcoidosis (P = 0.1336, 95%Cl).

Conclusion

Contrast‐enhanced lung MRI with fast imaging sequences is a highly sensitive imaging modality and comparable with CT in evaluating both lung and cardiac abnormalities in pediatric sarcoidosis. Given there is no associated ionizing radiation, chest MRI is a promising imaging modality in this pediatric patient population. Pediatr Pulmonol. 2017;52:494–499. © 2016 Wiley Periodicals, Inc.
Janus Dendrimer from Poly(Aryl Ether) Linked PAMAM for Supergelation and Guest Release
Authors: Prabakaran Palani , Prasad Edamana
Published: October 2016

The present work reports an easy‐to‐make procedure of Janus dendrimers containing two most widely used dendrons [poly(aryl ether) and poly(amido amine) {PAMAM}], and utilize them, for the first time, to form a hydrogel with supergelation ability. The first generation (G1G1) Janus dendrimer forms hydrogel with a critical gelation concentration (CGC) of 6.5 mg/mL, whereas the CGC for G1G1.5 dendrimer went as low as 0.90 mg/mL in DMSO‐H2O mixture. Judicious choice of solvent medium (ethanol‐water) led to the formation of flexible morphology (long fibres to vesicles) by the Janus dendrimers, suggesting the possibility of tuning the mechanism of self‐assembly in the system. The dye (rhodamine B) loading efficiency in the gel was successfully carried out using different generations {G1G1 and G1G1.5} of the Janus dendrimer. Generation G1G1 hydrogel (1 wt%) showed maximum dye loading efficiency of 4 mg/mL. Rhodamine B release profiles from the Janus dendrimers were determined and the results indicate that slow release kinetics was observed in the case of G1G1, where the self‐assembly is robust.
Experimental investigation of the mechanical properties of basalt fiber‐reinforced concrete
Authors: Jalasutram Sruthi , Sahoo Dipti Ranjan , Matsagar Vasant
Published: October 2016

This paper presents an experimental investigation of how varying the volume fraction of chopped basalt fibers affects the mechanical properties of fiber‐reinforced concrete (FRC). The fiber content is varied in the range of 0–2%. The main parameters investigated are workability, compressive strength, splitting tensile strength, flexural strength, and flexural toughness. Test results showed that the compression strength of concrete decreased marginally with the addition of basalt fibers in comparison with plain concrete. However, the mode of failure of FRC under compression is changed from the brittle to ductile. The splitting tensile strength of concrete is improved by 15% when basalt fibers with 2% volume fraction are added to the concrete mix. A significant increase of up to 75% is noticed in the flexural tensile strength of basalt FRC, with better post‐peak residual strength compared with the plain concrete. Furthermore, the flexural toughness of basalt FRC is increased by nearly three times that of the plain concrete based on the round panel tests.
Orthorhombic HP‐REOF (RE = Pr, Nd, Sm – Gd) – High‐Pressure Syntheses and Single‐Crystal Structures (RE = Nd, Sm, Eu)
Authors: Glätzle Matthias , Schauperl Michael , Hejny Clivia , Tribus Martina , Liedl Klaus R. , Huppertz Hubert
Published: October 2016

High‐pressure modifications of the rare earth oxide fluorides REOF (RE = Pr, Nd, Sm – Gd) were successfully synthesized under conditions of 11 GPa and 1200 °C applying the multianvil high‐pressure/high‐temperature technique. Single crystals of HP‐REOF (RE = Nd, Sm, Eu) were obtained making it possible to analyze the products by means of single‐crystal X‐ray diffraction. The compounds HP‐REOF (RE = Nd, Sm, Eu) crystallize in the orthorhombic α‐PbCl2‐type structure (space group Pnma, No. 62, Z = 4) with the parameters a = 632.45(3), b = 381.87(2), c = 699.21(3) pm, V = 0.16887(2) nm3, R1 = 0.0156, and wR2 = 0.0382 for HP‐NdOF, a = 624.38(3), b = 376.87(2), c = 689.53(4) pm, V = 0.16225(2) nm3, R1 = 0.0141, and wR2 = 0.0323 for HP‐SmOF, and a = 620.02(4), b = 374.24(3), c = 686.82(5) pm, V = 0.15937(2) nm3, R1 = 0.0177, and wR2 = 0.0288 for HP‐EuOF. Calculations of the bond valence sums clearly showed that the oxygen atoms occupy the tetrahedrally coordinated position, whereas the fluorine atoms are fivefold coordinated in form of distorted square‐pyramids. The crystal structures and properties of HP‐REOF (RE = Nd, Sm, Eu) are discussed and compared to the isostructural phases and the normal‐pressure modifications of REOF (RE = Nd, Sm, Eu). Furthermore, results of investigations by EDX and Raman measurements including quantum mechanical calculations are presented.
Reactive Nanocomposites as Versatile Additives for Composite Propellants
Authors: Tawfik Sayed M. , Saleh Ahmed , Elbeih Ahmed , Klapötke Thomas M.
Published: October 2016

A new approach to improve the performance of composite propellants was developed in which reactive nanocomposites (RNCs) are used as replacements for aluminum powders in composite solid rocket propellants. The new materials are mechanically activated nanothermites comprising of nano‐powders of aluminum as the fuel as well as oxides of copper, iron, molybdenum, or nickel as the oxidizer. The obtained RNCs were characterized using X‐ray diffraction, scanning electron microscopy, and laser diffraction particle size analyzer. The obtained RNCs were used for preparation of modified composite solid rocket propellants (CSRPs). Burning rate, thermal decomposition behavior, heat of combustion, sensitivity, and mechanical properties of CSRPs were determined. The results showed increases in the combustion energy and the burning rate of the modified propellants were achieved, and that RNCs can be considered to be promising multi‐function additives for composite solid rocket propellants. In addition, the mechanical properties and sensitivities of the modified propellants are within the desired range.
Implementation of the World Health Organization Trauma Care Checklist Program in 11 Centers Across Multiple Economic Strata: Effect on Care Process Measures
Authors: Lashoher Angela , Schneider Eric B. , Juillard Catherine , Stevens Kent , Colantuoni Elizabeth , Berry William R. , Bloem Christina , Chadbunchachai Witaya , Dharap Satish , Dy Sydney M. , Dziekan Gerald , Gruen Russell L. , Henry Jaymie A. , Huwer Christina , Joshipura Manjul , Kelley Edward , Krug Etienne , Kumar Vineet , Kyamanywa Patrick , Mefire Alain Chichom , Musafir Marcos , Nathens Avery B. , Ngendahayo Edouard , Nguyen Thai Son , Roy Nobhojit , Pronovost Peter J. , Khan Irum Qumar , Razzak Junaid Abdul , Rubiano Andrés M. , Turner James A. , Varghese Mathew , Zakirova Rimma , Mock Charles
Published: October 2016

Background

Trauma contributes more than ten percent of the global burden of disease. Initial assessment and resuscitation of trauma patients often requires rapid diagnosis and management of multiple concurrent complex conditions, and errors are common. We investigated whether implementing a trauma care checklist would improve care for injured patients in low‐, middle‐, and high‐income countries.

Methods

From 2010 to 2012, the impact of the World Health Organization (WHO) Trauma Care Checklist program was assessed in 11 hospitals using a stepped wedge pre‐ and post‐intervention comparison with randomly assigned intervention start dates. Study sites represented nine countries with diverse economic and geographic contexts. Primary end points were adherence to process of care measures; secondary data on morbidity and mortality were also collected. Multilevel logistic regression models examined differences in measures pre‐ versus post‐intervention, accounting for patient age, gender, injury severity, and center‐specific variability.

Results

Data were collected on 1641 patients before and 1781 after program implementation. Patient age (mean 34 ± 18 vs. 34 ± 18), sex (21 vs. 22 % female), and the proportion of patients with injury severity scores (ISS) ≥ 25 (10 vs. 10 %) were similar before and after checklist implementation (p > 0.05). Improvement was found for 18 of 19 process measures, including greater odds of having abdominal examination (OR 3.26), chest auscultation (OR 2.68), and distal pulse examination (OR 2.33) (all p < 0.05). These changes were robust to several sensitivity analyses.

Conclusions

Implementation of the WHO Trauma Care Checklist was associated with substantial improvements in patient care process measures among a cohort of patients in diverse settings.
Numerical responses of an avian predator to prey fluctuations in a temperate latitude: breeders vs. entire population
Authors: Panek Marek
Published: October 2016

Distinct numerical responses of predators to fluctuations in the abundance of their prey are often observed in northern regions but occur more rarely in temperate latitudes. This statement is, however, mostly based on observations of breeding populations, while in some predators, for example in raptors, numerous non‐breeding floaters can occur. I estimated the breeding density and reproductive performance (nest survey) as well as the density of entire population (transects with distance sampling) of the common buzzardButeo buteoin western Poland (52°N) in the years 2005–2014 to test the hypotheses that in temperate latitudes: (1) the breeding population of these birds does not show any numerical response, understood as annual changes in their abundance; (2) its reproductive success, however, changes with the abundance of main prey, the common voleMicrotus arvalis; and (3) hence the entire buzzard population (including potential immature floaters) present in a given area during the nesting period responds numerically with some time delay. The reproductive success of buzzards was positively correlated with their prey abundance. Contrary to my predictions, however, the breeding population of buzzards showed a slight numerical response with a 3‐year lag and the entire population tracked vole fluctuations without any time delay. The immediate numerical response of the entire buzzard population was probably caused by large‐scale movements of floaters. Such rapid numerical responses of some predators may contribute to the relative stability of prey populations in temperate latitudes compared to northern regions.
Unmet needs and current and future approaches for osteoporotic patients at high risk of hip fracture
Authors: Ferrari Serge , Reginster Jean-Yves , Brandi Maria Luisa , Kanis John A. , Devogelaer Jean-Pierre , Kaufman Jean-Marc , Féron Jean-Marc , Kurth Andreas , Rizzoli René
Published: October 2016

Summary

This review provides a critical analysis of currently available approaches to increase bone mass, structure and strength through drug therapy and of possible direct intra-osseous interventions for the management of patients at imminent risk of hip fracture.

Purpose

Osteoporotic hip fractures represent a particularly high burden in morbidity-, mortality- and health care-related costs. There are challenges and unmet needs in the early prevention of hip fractures, opening the perspective of new developments for the management of osteoporotic patients at imminent and/or at very high risk of hip fracture. Amongst them, preventive surgical intervention needs to be considered.

Methods

A European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO)/International Osteoporosis Foundation (IOF) working group reviewed the presently available intervention modalities including preventive surgical options for hip fragility. This paper represents a summary of the discussions.

Results

Prevention of hip fracture is currently based on regular physical activity; prevention of falls; correction of nutritional deficiencies, including vitamin D repletion; and pharmacological intervention. However, efficacy of these various measures to reduce hip fractures is at most 50% and may need months or years before becoming effective. To face the challenges of early prevention of hip fractures for osteoporotic patients at imminent and/or at very high risk of hip fracture, preventive surgical intervention needs further investigation.

Conclusion

Preventive surgical intervention needs to be appraised for osteoporotic patients at imminent and/or at very high risk of hip fracture.
Un cargamento de sigillatas en el entorno del Estrecho de Gibraltar: el pecio del Guadiaro
Authors: Bustamante Macarena , Navarro Ildefonso
Published: October 2016

Desde hace algunos años se ha producido la recopilación, por parte del Museo de Estepona (Málaga), de un conjunto de sigillatas extraído de contexto subacuático. Esto ha sido posible a partir del arrastre de las artes de pesca en una zona coincidente con la desembocadura del río Guadiaro. Esta colección presenta más de 200 individuos en casi perfecto estado de conservación y con un amplio elenco de sigilla en uno de los mayores conjuntos epigráficos de esta categoría en Hispania. La excepcionalidad del hallazgo, la variedad tipológica y epigráfica, y su localización hacen de su estudio una baza imprescindible para valorar el comercio de la vajilla fina en el sur de Hispania y su relación directa con el norte de la Mauritania Tingitana. Presentamos el primer avance del estudio que nos encontramos desarrollando sobre este voluminoso conjunto. La homogeneidad formal, el abultado número de piezas y la coincidente procedencia geográfica de las mismas han permitido lanzar la hipótesis de que estamos ante un pecio hundido en las cercanías del Estrecho de Gibraltar en época primo-trajanea, coincidiendo ampliamente las formas y los sellos con la denominada fosa Bassus de la Graufesenque. Planteamos una cronología ligeramente más tardía que el otro gran pecio localizado en aguas hispanas, el cala Culip IV, datado tradicionalmente entre el 78 y 82 d.C.
Boundaries and control in the Roman house
Authors: Berry Joanne
Published: October 2016

How should we read the structure of the atrium house? On the one hand, it is an open space; its rooms are arranged around the central courtyard or atrium. From its narrow entrance it is often possible to see straight through to the back of the garden or peristyle, and it is hardly surprising that scholars have claimed that the house was intentionally designed to allow people to see within, to guide their gaze to special features in order to demonstrate the wealth and status of the owner, or to make outsiders want to enter and see more. On the other hand, the house was also a sacred space that carried a potent symbolic value. It was protected by the household gods, and was sustained by religious, social and economic resources. Symbolically, the house was private even when it was used for public business. It was also strictly monitored and controlled.

Scholars are increasingly challenging the idea that the inhabitants of Roman houses were more concerned with display than with privacy, and are suggesting methods by which privacy was established. I will argue here that in the Roman house display and privacy are not mutually exclusive, but of equal importance. Within the open atrium plan there were both physical and symbolic boundaries that functioned to control movement and protect the home from visitors who were not members of the household or family. My aim is to explore the creation and deployment of such boundaries in a society that often used aesthetic markers to control space, and to discuss how what may seem to have been free movement within the atrium house may actually have been restricted.
Hadrian, Hercules and griffins: a group of cuirassed statues from Latium and Pamphylia
Authors: Wood Susan
Published: October 2016

Three cuirassed statues and one fragmentary torso, all probably of the Hadrianic/early Antonine era, bear a rare breastplate relief. The heraldic design combines a muscular youth, nude except for a lionskin over his head and shoulders, and a pair of lion-griffins, whom he grasps by their horns. His iconography conforms to that of a youthful Hercules, whom we see here in the ancient formula for a “Master of the animals”. The composition has been mistakenly identified as a combat between griffins and an Arimaspos, but the central figure displays domination over the two creatures, rather than vice versa. A closely related device that appeared on some cuirassed statues during the same period represented the vegetal god Dionysus-Sabazios between a pair of his sacred panthers. The similarity of the two breastplate devices is no accident, although the two groups represent different deities and animals. Both these heraldic devices seem to have been popular only for a limited time but the device of Hercules with griffins does appear in works from both Italy and Asia Minor. One of these statues certainly represents the deified Hadrian, another is today restored with a head of the same emperor, which may or may not belong to the torso, and the third almost certainly once portrayed Trajan, although the portrait face underwent later recutting; the head of the fourth is lost.
A new Republican temple on the via Appia, at the borders of Rome's urban space
Authors: Dubbini Rachele
Published: October 2016

On May 27, 1970, during construction of the Caffarella sewer system which was to serve new districts in the sprawling suburbs of Rome, the Municipality of Rome alerted the Soprintendenza to the discovery of some ancient structures near the via Appia.The area affected by the passage of the sewer system lies just beyond the Almo river, between the Appia's first and second mile, in a place where, at the end of the 19th c., P. Cartoni built a rather large barn for his estate (vigna). On the W side of the road, excavators discovered a concrete pedestal reveted with tuff blocks that was interpreted as the foundation of a sepulchral monument, the ruderatio of the via Appia, and a secondary paved road leading southeast, as published by L. Spera (see fig. 1, trench A). However, the excavations on the E side of the via Appia have never been published. The aim of this paper is to describe and interpret the remarkable discovery. My examination of documentation stored in the archives of the Soprintendenza identified photographs and sketches of the 1970 excavation, providing evidence for the existence of a Republican-era monumental architectural complex situated behind the barn of Vigna Cartoni. Since it was impossible unfortunately to locate any written reports, the research was based mostly on illustrations and administrative documents, but a fairly accurate history of the excavation could be reconstructed based on the latter.
Egyptian blue: modern myths, ancient realities
Authors: Skovmøller Amalie , Brøns Cecilie , Sargent Maria Louise
Published: October 2016

Colours containing bright and saturated blue hues were popular for painterly effects in most of the Mediterranean cultures dating from the Bronze Age to the fall of the Roman Empire. Pigments providing the desired blue were produced from precious minerals such as azurite and lapis lazuli, but bright blue hues also came from pigments produced by merging other naturally occurring sources. This large group of synthetically-generated blue frits is referred to as Egyptian blue. Egyptian blue is a calcium copper tetrasilicate compound, a synthetic pigment made by heating a calcium compound (such as powdered limestone and sand rich in calcium carbonate) together with copper and quartz (fig. 1), although synthetic blue pigments based on cobalt are also known, so far mainly in Egypt (such as “Amarna-blue”). The hue of Egyptian blue pigments ranges from a saturated, almost black blue to light blue, bluish-green, and purple, each being dependent on the materials employed for its production and manufacturing process. Its material properties are crystal-like, resembling finely shattered glass. It ranges in saturation and brightness (which can be enhanced by secondary heating), and it has a relatively low covering power. It seems to have ceased being widely applied sometime after the fall of the empire, which added a certain mystery to it.
Exploiting excavation archives: Herculaneum from 1927 to 1961 as a case-study
Authors: Monteix Nicolas
Published: October 2016

“Questi giornali di scavo di Ercolano sono una miseria di forma e di sostanza”

“The only source of information for most of the finds of the site [Pompeii] remains the pages of the Giornali degli Scavi”

With the multiplication of excavations, archaeological research (and even rescue archaeology) increasingly faces sites previously explored and thereby has to deal with documentation made with different methods and of different scopes than those of today. Beyond the historiographical issues and differences in ways of describing the past as viewed from the present, such an archival documentation is generally fragmentary, often scattered between various institutions or in private archives. The aim of this paper is to contribute to a debate on an important issue: how might we best make use of previous material, from archival documents to publications?

Herculaneum can exemplify the main processes one might face while studying a site excavated in the past. Initially explored through tunnels, it was excavated in open-area excavations in four periods (1828-55; 1869-75; 1927-61; 1996-98). Most of the city as we know it was uncovered by A. Maiuri (1886-1963) while he was Soprintendente and director of the Museum of Naples (1924-61). He managed to pass himself off as the only excavator of Herculaneum, and such a view was consolidated by the (incomplete) publication of his excavations in 1958. Up until the late 1990s, anything written about Herculaneum relied on his synthesis, with only a few re-interpretations based on observations made on a site that had been restored and presented by him. S. Mols was the first to use other sources to understand better the context of the wooden furniture discovered throughout the town, namely the daybooks (Giornale degli scavi di Ercolano [henceforth GSE]) composed during the excavation. Since then, slowly but surely, many of those involved in the study of Herculaneum started using those diaries, hoping to have a more complete and less subjective perception of the excavation — at least, one less influenced by Maiuri.
Light on the water: ritual deposit of lamps in Lake Nemi
Authors: Diosono Francesca , Cinaglia Tiziano
Published: October 2016

Lake Nemi, in a crater of volcanic origins, lies along the via Appia c.30 km south of Rome in the region of the Alban Hills. The basin as a whole has a high density of archeological evidence, most noticeably the sanctuary of Diana on the NE and the imperial villa on the SW sides. Famously, two large ships belonging to Caligula were long preserved in the lake bed. Following repeated attempts beginning in Renaissance times, in 1927 the recovery of the two ships became a matter of national prestige and propaganda for the Fascist government. The decision was taken to lower the level of the lake by c.22 m to the lake floor where the hulls lay, using powerful pumps that sucked and directed the water through the ancient emissary that was re-opened (figs. 2-3). These operations, conducted between 1928 and 1932, concluded in 1936 with the grand opening on the NW shore of the Museo Nazionale delle Navi Romane, where the ships were displayed. But the tragic epilogue came just a few years later in 1944 during the Second World War when the ships, symbols of a régime that was as boastful as it was fragile, were completely destroyed.
The manufacturing process of the gold bust of Marcus Aurelius: evidence from neutron imaging
Authors: de Pury-Gysel Anne , Lehmann Eberhard H. , Giumlia-Mair Alessandra
Published: October 2016

This paper presents the results of applying neutron imaging methods to the gold bust of Marcus Aurelius, an analytical procedure that was carried out in 2006 at the Paul Scherrer Institut in Villigen (Switzerland). The results have produced a better understanding of the gold repoussé manufacturing techniques for large pieces.

Given the number of gold statues that existed at Rome and in its provinces, the preserved pieces represent only a tiny fraction; to recover the precious metal, most gold objects were eventually melted down, with the result that only a very small number of pieces are left. That scarcity explains our difficulties in studying the characteristics of this category. Just 6 gold busts of the Roman period have been documented. The bust of Marcus Aurelius was found in a sewer running beneath a sanctuary of Aventicum (figs. 1, 6a and 16). Then there is the bust of Septimius Severus discovered at Didymoteichon (NE Greece), a small fragment from the shoulder pteriges of a breastplated bust of the 2nd c. A.D. found at the fort of Dambach (Germany), the Late Roman head inserted into the 9th-10th c. statue of St. Fides in the Abbeye of Conques (France), and the much smaller busts of (possibly) Licinius I and of Licinius II probably of the early 4th c.
Tracking mass death during the fall of Rome's empire (II): a first inventory of mass graves
Authors: McCormick Michael
Published: October 2016

Part I of this study synthesized what archaeological features and written evidence indicate about human mortality crises during the later Roman Empire. It argued that one could test competing ideas about mortality crises by assembling and analyzing the archaeological evidence of mass graves of our Type 1, defined as the resting place of more than 5 individuals who were interred more or less simultaneously. Such an archaeological data-set would clarify whether mass death figured significantly in the demographic and cultural landscape of late antiquity. It should, moreover, begin to elucidate when, where, and to what varying extent mortality crises may have been induced by violence, disease, or economic and environmental conditions. Part I reviewed the aggregate patterns of 85 archaeological features in 55 sites. Ten were very large burials (50-526 individuals); burials of between 5 and 9 individuals were most frequent (31 cases). Very large graves were predominantly urban, although large military burials occurred in the countryside. Eyewitnesses described huge mass graves in some of the empire's great cities, but few have been archaeologically documented until now. Nonetheless, the late Roman city that has been most carefully investigated, Jerusalem, has yielded 8 such sites. A third (10) of 29 burials that provide useful evidence document violent death. Although the dating of many features is imperfect, mass graves identified so far peaked in the 6th (24) and 7th (32) c.
Hair cell force generation does not amplify or tune vibrations within the chicken basilar papilla
Authors: Xia Anping , Liu Xiaofang , Raphael Patrick D. , Applegate Brian E. , Oghalai John S.
Published: October 2016

Frequency tuning within the auditory papilla of most non-mammalian species is electrical, deriving from ion-channel resonance within their sensory hair cells. In contrast, tuning within the mammalian cochlea is mechanical, stemming from active mechanisms within outer hair cells that amplify the basilar membrane travelling wave. Interestingly, hair cells in the avian basilar papilla demonstrate both electrical resonance and force-generation, making it unclear which mechanism creates sharp frequency tuning. Here, we measured sound-induced vibrations within the apical half of the chicken basilar papilla in vivo and found broadly-tuned travelling waves that were not amplified. However, distortion products were found in live but not dead chickens. These findings support the idea that avian hair cells do produce force, but that their effects on vibration are small and do not sharpen tuning. Therefore, frequency tuning within the apical avian basilar papilla is not mechanical, and likely derives from hair cell electrical resonance.
Solar water splitting by photovoltaic-electrolysis with a solar-to-hydrogen efficiency over 30%
Authors: Jia Jieyang , Seitz Linsey C. , Benck Jesse D. , Huo Yijie , Chen Yusi , Ng Jia Wei Desmond , Bilir Taner , Harris James S. , Jaramillo Thomas F.
Published: October 2016

Hydrogen production via electrochemical water splitting is a promising approach for storing solar energy. For this technology to be economically competitive, it is critical to develop water splitting systems with high solar-to-hydrogen (STH) efficiencies. Here we report a photovoltaic-electrolysis system with the highest STH efficiency for any water splitting technology to date, to the best of our knowledge. Our system consists of two polymer electrolyte membrane electrolysers in series with one InGaP/GaAs/GaInNAsSb triple-junction solar cell, which produces a large-enough voltage to drive both electrolysers with no additional energy input. The solar concentration is adjusted such that the maximum power point of the photovoltaic is well matched to the operating capacity of the electrolysers to optimize the system efficiency. The system achieves a 48-h average STH efficiency of 30%. These results demonstrate the potential of photovoltaic-electrolysis systems for cost-effective solar energy storage.
Ultrafast photocurrents at the surface of the three-dimensional topological insulator Bi2Se3
Authors: Braun Lukas , Mussler Gregor , Hruban Andrzej , Konczykowski Marcin , Schumann Thomas , Wolf Martin , Münzenberg Markus , Perfetti Luca , Kampfrath Tobias
Published: October 2016

Three-dimensional topological insulators are fascinating materials with insulating bulk yet metallic surfaces that host highly mobile charge carriers with locked spin and momentum. Remarkably, surface currents with tunable direction and magnitude can be launched with tailored light beams. To better understand the underlying mechanisms, the current dynamics need to be resolved on the timescale of elementary scattering events (∼10 fs). Here, we excite and measure photocurrents in the model topological insulator Bi2Se3 with a time resolution of 20 fs by sampling the concomitantly emitted broadband terahertz (THz) electromagnetic field from 0.3 to 40 THz. Strikingly, the surface current response is dominated by an ultrafast charge transfer along the Se–Bi bonds. In contrast, photon-helicity-dependent photocurrents are found to be orders of magnitude smaller than expected from generation scenarios based on asymmetric depopulation of the Dirac cone. Our findings are of direct relevance for broadband optoelectronic devices based on topological-insulator surface currents.
Atomic intercalation to measure adhesion of graphene on graphite
Authors: Wang Jun , Sorescu Dan C. , Jeon Seokmin , Belianinov Alexei , Kalinin Sergei V. , Baddorf Arthur P. , Maksymovych Petro
Published: October 2016

The interest in mechanical properties of two-dimensional materials has emerged in light of new device concepts taking advantage of flexing, adhesion and friction. Here we demonstrate an effective method to measure adhesion of graphene atop highly ordered pyrolytic graphite, utilizing atomic-scale ‘blisters’ created in the top layer by neon atom intercalates. Detailed analysis of scanning tunnelling microscopy images is used to reconstruct atomic positions and the strain map within the deformed graphene layer, and demonstrate the tip-induced subsurface translation of neon atoms. We invoke an analytical model, originally devised for graphene macroscopic deformations, to determine the graphite adhesion energy of 0.221±0.011 J m−2. This value is in excellent agreement with reported macroscopic values and our atomistic simulations. This implies mechanical properties of graphene scale down to a few-nanometre length. The simplicity of our method provides a unique opportunity to investigate the local variability of nanomechanical properties in layered materials.
Thick filament mechano-sensing is a calcium-independent regulatory mechanism in skeletal muscle
Authors: Fusi L. , Brunello E. , Yan Z. , Irving M.
Published: October 2016

Recent X-ray diffraction studies on actively contracting fibres from skeletal muscle showed that the number of myosin motors available to interact with actin-containing thin filaments is controlled by the stress in the myosin-containing thick filaments. Those results suggested that thick filament mechano-sensing might constitute a novel regulatory mechanism in striated muscles that acts independently of the well-known thin filament-mediated calcium signalling pathway. Here we test that hypothesis using probes attached to the myosin regulatory light chain in demembranated muscle fibres. We show that both the extent and kinetics of thick filament activation depend on thick filament stress but are independent of intracellular calcium concentration in the physiological range. These results establish direct control of myosin motors by thick filament mechano-sensing as a general regulatory mechanism in skeletal muscle that is independent of the canonical calcium signalling pathway.
The pseudokinase CaMKv is required for the activity-dependent maintenance of dendritic spines
Authors: Liang Zhuoyi , Zhan Yi , Shen Yang , Wong Catherine C. L. , Yates John R. , Plattner Florian , Lai Kwok-On , Ip Nancy Y.
Published: October 2016

Dendritic spine stabilization depends on afferent synaptic input and requires changes in actin cytoskeleton dynamics and protein synthesis. However, the underlying molecular mechanism remains unclear. Here we report the identification of ‘calmodulin kinase-like vesicle-associated’ (CaMKv), a pseudokinase of the CaMK family with unknown function, as a synaptic protein crucial for dendritic spine maintenance. CaMKv mRNA localizes at dendrites, and its protein synthesis is regulated by neuronal activity. CaMKv function is inhibited upon phosphorylation by cyclin-dependent kinase 5 (Cdk5) at Thr345. Furthermore, CaMKv knockdown in mouse hippocampal CA1 pyramidal neurons impairs synaptic transmission and plasticity in vivo, resulting in hyperactivity and spatial memory impairment. These findings collectively indicate that the precise regulation of CaMKv through activity-dependent synthesis and post-translational phosphorylation is critical for dendritic spine maintenance, revealing an unusual signalling pathway in the regulation of synaptic transmission and brain function that involves a pseudokinase.
Monitoring peripheral nerve degeneration in ALS by label-free stimulated Raman scattering imaging
Authors: Tian Feng , Yang Wenlong , Mordes Daniel A. , Wang Jin-Yuan , Salameh Johnny S. , Mok Joanie , Chew Jeannie , Sharma Aarti , Leno-Duran Ester , Suzuki-Uematsu Satomi , Suzuki Naoki , Han Steve S. , Lu Fa-Ke , Ji Minbiao , Zhang Rosanna , Liu Yue , Strominger Jack , Shneider Neil A. , Petrucelli Leonard , Xie X. Sunney , Eggan Kevin
Published: October 2016

The study of amyotrophic lateral sclerosis (ALS) and potential interventions would be facilitated if motor axon degeneration could be more readily visualized. Here we demonstrate that stimulated Raman scattering (SRS) microscopy could be used to sensitively monitor peripheral nerve degeneration in ALS mouse models and ALS autopsy materials. Three-dimensional imaging of pre-symptomatic SOD1 mouse models and data processing by a correlation-based algorithm revealed that significant degeneration of peripheral nerves could be detected coincidentally with the earliest detectable signs of muscle denervation and preceded physiologically measurable motor function decline. We also found that peripheral degeneration was an early event in FUS as well as C9ORF72 repeat expansion models of ALS, and that serial imaging allowed long-term observation of disease progression and drug effects in living animals. Our study demonstrates that SRS imaging is a sensitive and quantitative means of measuring disease progression, greatly facilitating future studies of disease mechanisms and candidate therapeutics.
In situ electrochemical quantification of active sites in Fe–N/C non-precious metal catalysts
Authors: Malko Daniel , Kucernak Anthony , Lopes Thiago
Published: October 2016

The economic viability of low temperature fuel cells as clean energy devices is enhanced by the development of inexpensive oxygen reduction reaction catalysts. Heat treated iron and nitrogen containing carbon based materials (Fe–N/C) have shown potential to replace expensive precious metals. Although significant improvements have recently been made, their activity and durability is still unsatisfactory. The further development and a rational design of these materials has stalled due to the lack of an in situ methodology to easily probe and quantify the active site. Here we demonstrate a protocol that allows the quantification of active centres, which operate under acidic conditions, by means of nitrite adsorption followed by reductive stripping, and show direct correlation to the catalytic activity. The method is demonstrated for two differently prepared materials. This approach may allow researchers to easily assess the active site density and turnover frequency of Fe–N/C catalysts.
Imparting amphiphobicity on single-crystalline porous materials
Authors: Sun Qi , He Hongming , Gao Wen-Yang , Aguila Briana , Wojtas Lukasz , Dai Zhifeng , Li Jixue , Chen Yu-Sheng , Xiao Feng-Shou , Ma Shengqian
Published: October 2016

The sophisticated control of surface wettability for target-specific applications has attracted widespread interest for use in a plethora of applications. Despite the recent advances in modification of non-porous materials, surface wettability control of porous materials, particularly single crystalline, remains undeveloped. Here we contribute a general method to impart amphiphobicity on single-crystalline porous materials as demonstrated by chemically coating the exterior of metal-organic framework (MOF) crystals with an amphiphobic surface. As amphiphobic porous materials, the resultant MOF crystals exhibit both superhydrophobicity and oleophobicity in addition to retaining high crystallinity and intact porosity. The chemical shielding effect resulting from the amphiphobicity of the MOFs is illustrated by their performances in water/organic vapour adsorption, as well as long-term ultrastability under highly humidified CO2 environments and exceptional chemical stability in acid/base aqueous solutions. Our work thereby pioneers a perspective to protect crystalline porous materials under various chemical environments for numerous applications.
Structural basis of checkpoint blockade by monoclonal antibodies in cancer immunotherapy
Authors: Lee Ju Yeon , Lee Hyun Tae , Shin Woori , Chae Jongseok , Choi Jaemo , Kim Sung Hyun , Lim Heejin , Won Heo Tae , Park Kyeong Young , Lee Yeon Ji , Ryu Seong Eon , Son Ji Young , Lee Jee Un , Heo Yong-Seok
Published: October 2016

Cancer cells express tumour-specific antigens derived via genetic and epigenetic alterations, which may be targeted by T-cell-mediated immune responses. However, cancer cells can avoid immune surveillance by suppressing immunity through activation of specific inhibitory signalling pathways, referred to as immune checkpoints. In recent years, the blockade of checkpoint molecules such as PD-1, PD-L1 and CTLA-4, with monoclonal antibodies has enabled the development of breakthrough therapies in oncology, and four therapeutic antibodies targeting these checkpoint molecules have been approved by the FDA for the treatment of several types of cancer. Here, we report the crystal structures of checkpoint molecules in complex with the Fab fragments of therapeutic antibodies, including PD-1/pembrolizumab, PD-1/nivolumab, PD-L1/BMS-936559 and CTLA-4/tremelimumab. These complex structures elucidate the precise epitopes of the antibodies and the molecular mechanisms underlying checkpoint blockade, providing useful information for the improvement of monoclonal antibodies capable of attenuating checkpoint signalling for the treatment of cancer.
Exploiting the speckle-correlation scattering matrix for a compact reference-free holographic image sensor
Authors: Lee KyeoReh , Park YongKeun
Published: October 2016

The word ‘holography’ means a drawing that contains all of the information for light—both amplitude and wavefront. However, because of the insufficient bandwidth of current electronics, the direct measurement of the wavefront of light has not yet been achieved. Though reference-field-assisted interferometric methods have been utilized in numerous applications, introducing a reference field raises several fundamental and practical issues. Here we demonstrate a reference-free holographic image sensor. To achieve this, we propose a speckle-correlation scattering matrix approach; light-field information passing through a thin disordered layer is recorded and retrieved from a single-shot recording of speckle intensity patterns. Self-interference via diffusive scattering enables access to impinging light-field information, when light transport in the diffusive layer is precisely calibrated. As a proof-of-concept, we demonstrate direct holographic measurements of three-dimensional optical fields using a compact device consisting of a regular image sensor and a diffusor.
Genome reduction in an abundant and ubiquitous soil bacterium ‘Candidatus Udaeobacter copiosus’
Authors: Brewer Tess E. , Handley Kim M. , Carini Paul , Gilbert Jack A. , Fierer Noah
Published: October 2016

Although bacteria within the Verrucomicrobia phylum are pervasive in soils around the world, they are under-represented in both isolate collections and genomic databases. Here, we describe a single verrucomicrobial group within the class Spartobacteria that is not closely related to any previously described taxa. We examined more than 1,000 soils and found this spartobacterial phylotype to be ubiquitous and consistently one of the most abundant soil bacterial phylotypes, particularly in grasslands, where it was typically the most abundant. We reconstructed a nearly complete genome of this phylotype from a soil metagenome for which we propose the provisional name ‘Candidatus Udaeobacter copiosus’. The Ca. U. copiosus genome is unusually small for a cosmopolitan soil bacterium, estimated by one measure to be only 2.81 Mbp, compared to the predicted effective mean genome size of 4.74 Mbp for soil bacteria. Metabolic reconstruction suggests that Ca. U. copiosus is an aerobic heterotroph with numerous putative amino acid and vitamin auxotrophies. The large population size, relatively small genome and multiple putative auxotrophies characteristic of Ca. U. copiosus suggest that it may be undergoing streamlining selection to minimize cellular architecture, a phenomenon previously thought to be restricted to aquatic bacteria. Although many soil bacteria need relatively large, complex genomes to be successful in soil, Ca. U. copiosus appears to use an alternative strategy, sacrificing metabolic versatility for efficiency to become dominant in the soil environment.
Understanding Longitudinal Wood Fiber Ultra-structure for Producing Cellulose Nanofibrils Using Disk Milling with Diluted Acid Prehydrolysis
Authors: Qin Yanlin , Qiu Xueqing , Zhu J.Y.
Published: October 2016

Here we used dilute oxalic acid to pretreat a kraft bleached Eucalyptus pulp (BEP) fibers to facilitate mechanical fibrillation in producing cellulose nanofibrils using disk milling with substantial mechanical energy savings. We successfully applied a reaction kinetics based combined hydrolysis factor (CHFX) as a severity factor to quantitatively control xylan dissolution and BEP fibril deploymerization. More importantly, we were able to accurately predict the degree of polymerization (DP) of disk-milled fibrils using CHFX and milling time or milling energy consumption. Experimentally determined ratio of fibril DP and number mean fibril height (diameter d), DP/d, an aspect ratio measurer, were independent of the processing conditions. Therefore, we hypothesize that cellulose have a longitudinal hierarchical structure as in the lateral direction. Acid hydrolysis and milling did not substantially cut the “natural” chain length of cellulose fibrils. This cellulose longitudinal hierarchical model provides support for using weak acid hydrolysis in the production of cellulose nanofibrils with substantially reduced energy input without negatively affecting fibril mechanical strength.
Nanocellulose size regulates microalgal flocculation and lipid metabolism
Authors: Yu Sun Il , Min Seul Ki , Shin Hwa Sung
Published: October 2016

Harvesting of microalgae is a cost-consuming step for biodiesel production. Cellulose has recently been studied as a biocompatible and inexpensive flocculant for harvesting microalgae via surface modifications such as cation-modifications. In this study, we demonstrated that cellulose nanofibrils (CNF) played a role as a microalgal flocculant via its network geometry without cation modification. Sulfur acid-treated tunicate CNF flocculated microalgae, but cellulose nanocrystals (CNC) did not. In addition, desulfurization did not significantly influence the flocculation efficiency of CNF. This mechanism is likely related to encapsulation of microalgae by nanofibrous structure formation, which is derived from nanofibrils entanglement and intra-hydrogen bonding. Moreover, flocculated microalgae were subject to mechanical stress resulting in changes in metabolism induced by calcium ion influx, leading to upregulated lipid synthesis. CNF do not require surface modifications such as cation modified CNC and flocculation is derived from network geometry related to nanocellulose size; accordingly, CNF is one of the least expensive cellulose-based flocculants ever identified. If this flocculant is applied to the biodiesel process, it could decrease the cost of harvest, which is one of the most expensive steps, while increasing lipid production.