bluuebunny/crossref_metadata_2025 huggingface dataset:
Ciencia, tecnología, saberes locales e imperio en el mundo atlántico, siglos XV-XIX
Authors: Barrera-Osorio Antonio , Nieto Olarte Mauricio
Published: July 2019

Objective/context: With this introduction (and this dossier) we seek to encourage reflection and debate around new perspectives in the face of the problematized but, in some way, still predominant narratives of a history of science centered on northern and western Europe. In particular, we seek to encourage reflection and debate on the role of the Ibero-American hybrid world and the role of indigenous knowledge in the rise of modern science. Methodology: In the Atlantic World, from the 16th to the 19th century, the solutions to problems related to long distance trade, communication, and control over populations, resources and territories, came through practices and institutions that emphasized empirical knowledge and personal experience. These practices and institutions produced definitive scientific knowledge for the history of modern science. In this context, the authors of the articles included in the dossier employ multiple perspectives, methods and empirical evidence to analyze cultural exchanges, and to better understand how Christians expanded and corrected their knowledge of medicine, geography and natural history (to mention only a few domains of knowledge) beyond the dominant knowledge of classical antiquity and Christianity. It became clear that indigenous knowledge and its re-readings gave rise to new epistemological practices. Also, that the Atlantic world from the sixteenth to the nineteenth centuries was a space where meetings between Native Americans, Africans and Europeans created, among other things, new sciences and technologies. Originality: For about fifteen years, researchers in the United States, Latin America and Spain have proposed major arguments that aim to explain the connections between the Ibero-American world, indigenous knowledge, and the new knowledge practices that we call modern science. With this dossier we offer a sample of the state of these investigations, which question the notions of European modernity and globality that still define academic works on science in the Atlantic world. Conclusions: Although we don’t intended to offer an exhaustive state of the art, this work illustrates the importance of asking new questions about the production of knowledge in the context of the European exploration and conquest of the New World. We underscore the need for a better understanding of the encounters of European and American knowledge, and the importance of these knowledge production dynamics in the history of European modernity. This text briefly presents each of the contributions to this volume.
Artesanos, cartografía e imperio. La producción social de un instrumento náutico en el mundo ibérico, 1500-1650
Authors: Sánchez Martínez Antonio
Published: July 2019

Objective/context: Explaining how and under what conditions some of the most emblematic scientific instruments of the modern world were built remains a challenge for historians of science and technology. This principle also affects nautical instruments. Thus, the objective of this article is to consider the “how” and the “under what conditions”, in a broad sense, by examining one of these devices: the nautical charts developed during the European maritime expansion. Originality: The originality of this article lies not only in the reconstruction of this instrument in Portugal and Spain, providing new information about its development process and its manufacturers, but also in shedding light on old historiographical debates that underlie the genesis of modern science, such as the difficult collaboration between practical men and theoretical men; the contribution of artisan communities to the world of knowledge; the role that practical knowledge played in the establishment of new forms of standardization in science; the adoption of an empirical methodology for achieving mastery of the world or the construction of large global empires founded upon manual labor. Methodology: Analyzing these debates requires a methodological approach that addresses the main categories and concepts put into circulation by the most recent history and philosophy of science. In short, unveiling the conditions that enabled the establishment of epistemological agreements (and also disputes) between different knowledge communities by taking a nautical instrument as “mediator.” Conclusions: The article concludes that examining empirical knowledge cultures and their material achievements are a sine qua non condition to understand the genesis of European scientific modernity and the construction of a global world.
“Practical Botanists and Zoologists”: Contributions of Amazonian Natives to Natural History Expeditions (1846-1865)
Authors: Pereira Antunes Anderson , Massarani Luisa , De Castro Moreira Ildeu
Published: July 2019

Objective/context: This paper analyses the relations between 19th century travelling naturalists and the indigenous inhabitants of Brazilian Amazonia. The region was a favourite among travellers during the latter half of the 19th century. On their travel books, naturalists reported not only on local Nature, but also on local inhabitants and their contributions to the expeditions, making them valuable sources for understanding the interactions between them and the natives. Originality: The originality of the paper rests in the use of a diverse set of primary sources, in the form of 19th century travel books. The article contributes to the current historiography on Natural History expeditions while aiming specifically at the relations between naturalists and the indigenous inhabitants of the region. Methodology: The analysis relies on primary sources, which consist mainly of the travel books written and published by some of the most well-known 19th century travelling naturalists that visited the Brazilian Amazonia. It is from their personal reports and observations that we aim to understand, on the one hand, how these foreign naturalists interacted with the local indigenous inhabitants and, on the other, how the natives were able contribute to the scientific expeditions led by European naturalists. Conclusions: It is safe to conclude that the indigenous inhabitants of Brazilian Amazonia were a constant presence during 19th century expeditions in the region. The interactions between naturalists and natives, sometimes mediated by a third party, were often essential to the success of these expeditions. The principal contribution of the indigenous inhabitants, as stated by the naturalists themselves, was the aid in the collection of specimens. The natives’ expertise on the habits and habitats of animals and plants, paired with their hunting and to navigational skills through the region’s complex river system, seem to have been a subject of admiration as well as a source of information and specimens.
La huelga, el carnaval y los comicios: el mundo del trabajo portuario en Buenos Aires y la configuración de una comunidad obrera, verano de 1904
Authors: Caruso Laura
Published: July 2019

Objective/context: This paper inquires about the process of emergence of a working-class community in the port of Buenos Aires, resulting from actions by workers and inhabitants of the working-class neighborhood at the beginning of the 20th century. Originality: At the crossroads of diverse historiographies (social, cultural and political history), this paper proposes a joint regard at the labor dimension, worker disputes, carnival celebrations and electoral participation, and to use this multiplicity of events and experiences to think about the emergence of a radicalized worker community, with a particular identity gestated in the mobilization during a specific time at the beginning of the 20th century. Methodology: The months from late 1903 to early 1904 were an important juncture in the port district, and based on a diverse set of documents (commercial, neighborhood, trade and left-wing newspapers, news magazines, police reports, photographs, among others), this paper reconstructs the worker experience in three settings converging in the summer months: protest, carnival and legislative polls. At the same time, it ponders the territorial dimension of community configuration and the key places that formed the backdrop to a story of protest, celebration, and elections. Conclusions: This analysis shows us that worker sociabilities around the port consolidated a community based on family, corporate, partisan, neighborhood and worker solidarities, in times of labor, political and festive mobilization, and of radicalized confrontation with the State and with corporations.
A 90 años de la política de “cooperación constructiva”. Estados Unidos y el diferendo chileno-peruano por Tacna y Arica, 1925-1929
Authors: León Wöppke Consuelo , Jara Fernández Mauricio , Mancilla González Pablo
Published: July 2019

Objective/context: The objective of this article is to analyze the policy of constructive cooperation put in place by republican governments under Harding, Coolidge and, especially, Hoover, as a solution to the Chilean-Peruvian dispute over the Tacna and Arica regions between 1925 and 1929. Originality: Existing historiographical research has approached the Chilean-Peruvian border dispute in the Tacna and Arica regions from predominantly national perspectives and with documentation from one country or another, and there has not been a more complete and in-depth analysis of US actions and cooperation related to the dispute. The use of US documentation not only affords a more balanced perspective of the border problem, but also illuminates the role played by a number of American presidents. Methodology: Documentation provided by the State Department, held at the National Archives and Records Administration, together with other materials obtained at the Historical Archive of the Ministry of Foreign Affairs of Chile and the Chilean press of the period, led to a narrative and critical analysis of information pertaining to constructive cooperation by republican US governments to address the Chilean-Peruvian dispute between 1925 and 1929. Conclusions: During the 1920s, the United States pursued a foreign policy that would improve its image in Latin America. To this end, Hoover launched the Constructive Cooperation Doctrine, a US diplomatic effort to offer peaceful solutions to existing disputes in Latin American countries. The solution achieved for the Chilean-Peruvian border problem was one of its greatest triumphs in the continental scope.
The origins and relatedness structure of mixed infections vary with local prevalence of P. falciparum malaria
Authors: Zhu Sha Joe , Hendry Jason A , Almagro-Garcia Jacob , Pearson Richard D , Amato Roberto , Miles Alistair , Weiss Daniel J , Lucas Tim CD , Nguyen Michele , Gething Peter W , Kwiatkowski Dominic , McVean Gil ,   for the Pf3k Project
Published: July 2019

Individual malaria infections can carry multiple strains of Plasmodium falciparum with varying levels of relatedness. Yet, how local epidemiology affects the properties of such mixed infections remains unclear. Here, we develop an enhanced method for strain deconvolution from genome sequencing data, which estimates the number of strains, their proportions, identity-by-descent (IBD) profiles and individual haplotypes. Applying it to the Pf3k data set, we find that the rate of mixed infection varies from 29% to 63% across countries and that 51% of mixed infections involve more than two strains. Furthermore, we estimate that 47% of symptomatic dual infections contain sibling strains likely to have been co-transmitted from a single mosquito, and find evidence of mixed infections propagated over successive infection cycles. Finally, leveraging data from the Malaria Atlas Project, we find that prevalence correlates within Africa, but not Asia, with both the rate of mixed infection and the level of IBD.
N-chlorination mediates protective and immunomodulatory effects of oxidized human plasma proteins
Authors: Ulfig Agnes , Schulz Anton V , Müller Alexandra , Lupilov Natalie , Leichert Lars I
Published: July 2019

Hypochlorous acid (HOCl), a powerful antimicrobial oxidant, is produced by neutrophils to fight infections. Here, we show that N-chlorination, induced by HOCl concentrations encountered at sites of inflammation, converts blood plasma proteins into chaperone-like holdases that protect other proteins from aggregation. This chaperone-like conversion was reversible by antioxidants and was abrogated by prior methylation of basic amino acids. Furthermore, reversible N-chlorination of basic amino acid side chains is the major factor that converts plasma proteins into efficient activators of immune cells. Finally, HOCl-modified serum albumin was found to act as a pro-survival molecule that protects neutrophils from cell death induced by highly immunogenic foreign antigens. We propose that activation and enhanced persistence of neutrophils mediated by HOCl-modified plasma proteins, resulting in the increased and prolonged generation of ROS, including HOCl, constitutes a potentially detrimental positive feedback loop that can only be attenuated through the reversible nature of the modification involved.
Effects of Urban Expansion on Agricultural Resources: A Case Study of Embu Town in Kenya
Authors: Murimi Eliud K. , Njeru Lucy K. , Gichimu Bernard M. , Ndirangu Samuel N.
Published: July 2019

Aim: To determine the effect of urban development on agricultural resources in peri-urban areas of Embu town.

Study Design:  Descriptive survey design involving observational and survey methods.

Place and Duration of Study: The study was carried out in three sub-locations lying within the peri-urban areas of Embu town, namely, Kamiu to the East, Njukiri to the West and Nthambo to the North of the town. The study was carried out from June to August 2018.

Methodology: Purposive stratified sampling was applied in this study where the three sub-locations were organized into three strata depending on their distance from the Central Business District i.e. 2, 4 and 6 Km for Kamiu, Njukiri and Nthambo respectively. A structured questionnaire was administered to 51 households per sub-location making a total of 153 respondents. Additional data was collected using personal observations and interviews with selected institutions with key information relating the study area. The data was analyzed using Statistical Package for Social Sciences. Descriptive analysis was carried out to generate frequencies and correlations. Quantitative data was subjected to Analysis of Variance where the three sub-locations were considered as treatments and means separated using Least Significant Difference at 95% level of confidence.

Results: The results indicated that urban development had encroached into hitherto agricultural areas exerting pressure into available agricultural resources such as land, water and labour thus contributing to reduced farming activities in the area. Significant differences between the three sub-locations were observed in average farm sizes, proportion of land allocated to farming, proportion of farmers in the area and availability of irrigation water and agricultural labour. The study recommends policy interventions to manage peri-urbanization in Embu and other towns with similar set up, in order to reduce degradation of agricultural resources and control unsustainable land sub-division and land use changes.
Phenology of ‘Magallanes’ Pummelo (Citrus maxima) Trees and Its Growth and Development as Influenced by Potassium Nutrition
Authors: Magbalot-Fernandez Alminda , Guzman Constancio C. De
Published: July 2019

This study aimed to determine the influence of potassium (K) fertilization on the vegetative growth, flowering and fruit development of 13-year old ‘Magallanes’ pummelo [Citrus maxima (Burm. Ex Rumph.) Merr.] trees. The experiment was conducted at South Davao Corporation (SODACO) farm, Davao city for 12-months duration. Five treatments were observed with increasing K levels were applied per tree: control (no fertilization), without K, 150 g K basal (recommended rate based on soil analysis), 225 g K basal, and 225 g K basal + foliar application. The critical stage of tree growth coincided with the months of May and August. Peak leaf flushing occurred in June and peak flowering with fruit set in April. The crucial stage of fruit development was noted two months after fruit set. Thus, optimum fertilization must be applied during these stages for maximum growth and production in ‘Magallanes’ pummelo. The vegetative growth of pummelo was not affected by increasing K rates. The recommended rate (150g K basal per tree) significantly increased canopy diameter by 76% but higher K rates did not increase tree height, due to the effect of fruit load and nutrient competition. On the other hand, increasing K rates to 50% higher than the recommended rate (225 g K per tree) increased the number of flushes by 36-100%. Flowering, fruit set and yield of ‘Magallanes’ pummelo were also enhanced by higher K rates. Flowering was increased by 4 times, fruit set by 86-100%, fruit number by 7 times, weight per fruit by 22-26%, and yields up to 9 times on trees composted with 225 g K rates.  The fruit size (diameter and length), however, did not increase by increasing the K level.
Comparative Study on Physicochemical Parameters Study of Oil Polluted Sites and Hydrocarbon Degradation Potentials of Heterotrophic Bacteria in Southern Nigeria
Authors: Akwukwaegbu R. N. , Okerentugba P. O. , Okpokwasili G. C. , Stanley H. O. , Ugboma C. J.
Published: July 2019

In this study, hydrocarbon degradation potentials of heterotrophic bacteria isolated from oil-polluted soil were examined; Samples were collected from Sakpenwa, an oil producing community in Tai LGA of Rivers State. The amounts of hydrocarbon in the soil samples were determined using Gas Chromatography-Flame Ionization Detector, GC- FID. The gravimetric analysis showed that the bacteria were capable of utilizing 96.9-99.7% the oil sample. Analysis of variance (ANOVA) carried out at 95% level of confidence showed that the degree of hydrocarbon degradation varied amongst isolates. Pseudomonas aeruginosa and Alcaligenes sp. showed highest degrading activities while Bacillus subtilis showed least activity. This study revealed that indigenous bacterial species possess the requisite gene necessary for hydrocarbon biodegradation. Biodegradation is most often the primary mechanism for contaminant destruction in the environment including petroleum contaminants.
Perception about Environmental Education in Agronomy Course in Agricultural Sciences Center of the Federal University of Alagoas
Authors: Keilla da Silva Alessandra , De Lima Silva Jonas Olimpio , Cabral e Sousa Luiggi Canario , Angelo Neto Orlando , Wilkson Batista Jhon , De Holanda Leite Maria José , De Sousa Silva Roberta Patrícia , Pereira Justino Sérvio Túlio
Published: July 2019

Environmental education is an essential instrument for the formation of a critical conscience in society as a whole. The formation of the agronomy course must be intrinsically linked to environmental issues, since the activities developed by the future professional have direct consequences to nature, so the decisions must have as pillars, the understanding of environmental issues and the promotion of the sustainability in agroescosystems. The present research had as aim to perform a diagnosis on the environmental perception of students and professors of the agronomy undergraduate course of the Agricultural Sciences Center of the Federal University of Alagoas (CECA – UFAL). This work was carried out through a qualitative research, where the data collection was based on a questionnaire, with a sample of 95 students and 15 teachers. Therefore, a deficient and inconsistent approach regarding environmental education in the agronomy course of the CECA-UFAL, thus it is recommended that more disciplines be inserted for environmental education, not only in the course of agronomy, but in all the course of the area of agrarian sciences.
Organomineral Fertilizer in Pineapple Cultivars in the Acclimatization Stage of Seedlings Produced “In vitro”
Authors: Medeiros Mendonça Luciana Freitas de , Mendonça Vander , Castro Pereira Eduardo , Andrade Leite Grazianny , Da Silva Irineu Toni Halan , De Oliveira Luana Mendes , De Moura Elias Ariel , Freitas Celedônio Wilma , Monte de Andrade Alex Danilo
Published: July 2019

This study aimed at evaluating the effect of organomineral fertilizer doses on the growth and nutrition of seedlings of pineapple cultivars during the acclimatization stage. The trial was carried out in the University Federal Rural do Semi-Árido under greenhouse conditions, at Mossoró – Rio Grande do Norte, from July 2013 to April 2014. The trial was carried out in randomized blocks design in a 2x5 factorial scheme, with 2 pineapple cultivars (Imperial and Vitoria) and 5 doses of organomineral fertilizer (0; 2.5; 5; 7.5 and 10 g), amounting 10 treatments with 4 replications and 5 seedlings per plot. The qualitative data means were compared by Scott-Knott test at 5% of probability, and the quantitative data were submitted to regression analysis and the mathematical models were adjusted with a probability for the t-test of p<0.05 for the equation parameters. The cultivars reached appropriate growth for transferring to the field after 210 days. The doses of organomineral fertilizer that increased the biometrical characteristics were 10 g and 5 g for both ‘Vitoria’ and ‘Imperial’ cultivars, respectively.
The Effect of Honey Saffron Syrup on Labor Progression in Nulliparous Women
Authors: Ghaderi Sheno , Zaheri Farzaneh , Nouri Bijan , Shahoei Roonak
Published: July 2019

Background: Labor duration is one of the factors affecting the pregnancy outcome. Objective of the present study is to determine the effect of honey saffron syrup on the labor progression in nulliparous women.

Methods: The nulliparous women with inclusion criteria were randomly divided into three equal groups. For first group, the saffron syrup prepared with honey and for second group, saffron syrup prepared with sugar and in the control group the placebo were orally administered every two hours. Collected data were analyzed using Fisher’s test, ANOVA with Fisher’s post hos test and Repeated measure statistical method with p <0.05 as significant.

Results: The mean of labor duration in the two intervention groups was significantly shorter than the control group (p=0.000). The duration of the first stage of labor in the honey saffron syrup group was significantly shorter than the sugar saffron syrup group (p=0.016).

Conclusion: Administration of saffron syrup with honey shortened the time of first, second and third stage of labor.
Development and validation of the Eyewitness Metamemory Scale
Authors: Saraiva Renan Benigno , van Boeijen Inger Mathilde , Hope Lorraine , Horselenberg Robert , Sauerland Melanie , van Koppen Peter J.
Published: July 2019

Metamemory can be defined as the knowledge about one's memory capabilities and about strategies that can aid memory. In this paper, we describe the development and validation of the Eyewitness Metamemory Scale (EMS), tailored specifically for use in face memory and eyewitness identification settings. Participants (N = 800) completed the EMS and other measures on general metamemory. Results from exploratory and confirmatory factor analysis revealed good factorial validity, internal consistency, and content validity. The EMS items emerged into three distinct factors: memory contentment, memory discontentment, and memory strategies. The EMS is a brief and easily administrable questionnaire that might be used to assess self‐ratings of face recognition capacity and use of strategies to encode faces.
A passivity‐based simple adaptive synergetic control for a class of nonlinear systems
Authors: Mokhtari Khalil , Elhadri Abdelhafid , Abdelaziz Mourad
Published: July 2019

For a class of nonlinear systems with the representation {A(x), B(x), C} and where the system parameters and dynamics are unknown, a simple adaptive synergetic controller ensuring the asymptotic convergence of the system to a desired manifold is proposed based on the technique of simple adaptive control (SAC). It is well known that the design of the synergetic control (SC) law requires a thorough knowledge of the system parameters and dynamics. Such problem obstructs the synthesis of the SC law and the designer is prompted to pass through the estimation methods, which, in turn, poses a problem of increasing the computation time of the control algorithm. To cope with this problem, a solution is proposed by modifying the original SC law to develop an SAC‐like adaptive SC law without the need of prior knowledge of the system. The stability of the proposed adaptive controller is formally proven via the Lyapunov approach. Experimental application to a quadrotor system is given to validate the theoretical results.
Views on medication's role in treatment begin to converge amid deadly epidemic
Authors: Enos Gary
Published: July 2019

One of the most prominent byproducts of the opioid crisis has been experienced as a narrowing, but not an elimination, of the separation between adherents to medication‐ or abstinence‐based approaches to substance use treatment. At least some of the industry's old guard of treatment organizations is increasingly seeing agonist medications as having an important role in treatment, though they also view psychosocial treatment as a critical component to maximizing outcomes in treating a multidimensional illness.
NY bill would limit copays for OTP treatment
Authors: Knopf Alison
Published: July 2019

A bill in the New York State Assembly would limit copays for commercially insured patients who get services from opioid treatment programs (OTPs). While commercial insurance companies are accustomed to building in copays — as high as $50 or more — per visit to a health care provider, this clearly is not feasible for patients who have to go to OTPs six days a week, which is what is required in early treatment (the first 90 days) under federal law. The bill (A. 972‐A/S. 4643‐A) would change the current situation in New York, under which treatment providers are prohibited by state law from waiving those copays.
Effect of High‐Pressure Torsion on Hardness and Electrical Resistivity of Commercially Pure Cu
Authors: Rijal Ajay , Singh Shobhit P. , Han Jae-Kyung , Kawasaki Megumi , Kumar Praveen
Published: July 2019

Commercially pure Cu is processed through high‐pressure torsion (HPT) at 6 GPa up to 50 turns and stored under the ambient condition for 21 months. Subsequently, microhardness and electrical resistivity of the Cu samples are measured and correlated with the microstructure. Grain size monotonically decreases with the number of HPT turns and becomes saturated at ≈300 nm after an equivalent strain of ≈40. Considerable fractions of low‐angle grain and twin boundaries are observed in the samples processed through HPT to low strains; however, their fractions decrease with increasing HPT turns. Consistently, although the hardness of the processed samples is greater than that of the annealed coarse‐grained sample, it first decreases with HPT straining and subsequently increases to a saturated value of ≈160 HV. In contrast, the electrical resistivity of Cu first increases with HPT processing, then decreases and finally becomes saturated at a value of ≈22 nΩ m, which is slightly higher than the least value obtained in this study. The obtained results are compared with the literature on HPT processing of Cu, and the usefulness of the ambient ageing for optimizing the hardness‐conductivity relationship is discussed.
The Evolution in Catalytic Activity Driven by Periodic Transformation in the Inner Sites of Gold Clusters
Authors: Sun Yongnan , Wang Endong , Ren Yujing , Xiao Kang , Liu Xu , Yang Dan , Gao Yi , Ding Weiping , Zhu Yan
Published: July 2019

It is extremely difficult to distinguish the contributions of different sites on the surface and in the inner sites of a catalyst to the overall catalytic performance, as the observed catalytic results reflect an ensemble average from almost all the active sites. How do the inner sites of a catalyst that seem to be not directly involved in a catalytic process exactly contribute to the catalytic performance? Toward this goal, herein the studies not only provide fundamental insights into how the alteration of Au8n+4(SR)4n+8 clusters by only the inner structure can dramatically change the intrinsic catalytic properties, where Au8n+4(SR)4n+8 (n = 3, 4, 5) clusters have the same surface motifs but share a periodic kernel structure, but also further demonstrate that the evolution in catalytic activity can potentially be determined by periodic transformation in the inner kernels.
Biomimetic Locomotion of Electrically Powered “Janus” Soft Robots Using a Liquid Crystal Polymer
Authors: Xiao Yao‐Yu , Jiang Zhi‐Chao , Tong Xia , Zhao Yue
Published: July 2019

Oriented liquid crystal networks (LCNs) can undergo reversible shape change at the macroscopic scale upon an order–disorder phase transition of the mesogens. This property is explored for developing soft robots that can move under external stimuli, such as light in most studies. Herein, electrically driven soft robots capable of executing various types of biomimetic locomotion are reported. The soft robots are composed of a uniaxially oriented LCN strip, a laminated Kapton layer, and thin resistive wires embedded in between. Taking advantage of the combined attributes of the actuator, namely, easy processing, reprogrammability, and reversible shape shift between two 3D shapes at electric power on and off state, the concept of a “Janus” soft robot is demonstrated, which is built from a single piece of the material and has two parts undergoing opposite deformations simultaneously under a uniform stimulation. In addition to complex shape morphing such as the movement of oarfish and sophisticated devices like self‐locking grippers, electrically powered “Janus” soft robots can accomplish versatile locomotion modes, including crawling on flat surfaces through body arching up and straightening down, crawling inside tubes through body stretching and contraction, walking like four‐leg animals, and human‐like two‐leg walking while pushing a load forward.
Active Posts in Deterministic Lateral Displacement Devices
Authors: Beech Jason P. , Keim Kevin , Ho Bao Dang , Guiducci Carlotta , Tegenfeldt Jonas O.
Published: July 2019

Using electrically connected metal‐coated posts in a deterministic lateral displacement (DLD) device and applying electric fields, electrokinetics is used to tune separations, significantly decrease the critical size for separation, and increase the dynamic range with switching times on the order of seconds. The strength of DLD stems from its binary behavior. To first approximation, particles move in one out of two trajectories based on their effective size. For particles that are close to the threshold size, a small external force is sufficient to nudge the particles from one trajectory to another. The devices consist of arrays of cylindrical metal‐coated SU‐8 posts connected by an underlying metal layer. This allows the application of voltages at the post surfaces and the generation of electric field gradients between neighboring posts, causing polarizable particles to experience a dielectrophoretic (DEP) force. This force, which depends on the volume and polarizability of the particle, can be made sufficient to push particles from one trajectory into another. In this way, the critical size in a device, normally fixed by the geometry, can be tuned. What's more, adding DEP in this way allows for the simultaneous creation of multiple size fractions.
Hybrid Graphene/Cu2O Quantum Dot Photodetectors with Ultrahigh Responsivity
Authors: Liu Qiaoli , Tian Huijun , Li Jingwei , Hu Anqi , He Xiaoying , Sui Manling , Guo Xia
Published: July 2019

Flexible high‐sensitivity photodetectors are desirable for use in future wearable optoelectronics. Graphene is attracting considerable attention because of its outstanding electrical, optical, and mechanical properties, which make graphene appealing in flexible optoelectronics and photodetection applications. In this paper, an internal current gain mechanism is proposed based on a 2D/0D photodetection system. The carrier density in the 2D material can be amplified via Fermi level modulation when a 0D quantum dot absorbs photons. An ultrahigh responsivity of more than 1010 A W−1 and fW‐scale light detectivity are achieved at room temperature using the flexible transfer‐free hybrid graphene/Cu2O quantum dot photodetector developed in this work. After excessive bending, the responsivity of the photodetector still reaches 106 A W−1, thus demonstrating the promising flexibility of the device.
Direct Imprint of Optical Functionalities on Free‐Form Chalcogenide Glasses
Authors: Ostrovsky Natali , Yehuda Dor , Tzadka Sivan , Kassis Evyatar , Joseph Shay , Schvartzman Mark
Published: July 2019

Scalable surface patterning of chalcogenide glasses is the crux for many optical applications of these promising optical materials. Here, a novel, resist‐free surface patterning of chalcogenide glasses with 3D relief microstructures is introduced, using direct radiation‐assisted thermal imprint. The imprint is based on a nanocomposite mold made of a carbon nanotube matrix and polydimethylsiloxane resin. To allow nanoimprint, the mold and glass substrate are confined between two elastic membranes, pneumatically pressed against each other, and controllably radiated by an infrared bulb. Since chalcogenide glass is transparent to infrared radiation, the radiation is mostly absorbed in the mold due to the embedded carbon nanotubes, so that the glass–mold interface is heated to the imprint temperature. By using this approach, the first of its type direct imprint of chalcogenide glass of any arbitrary form is demonstrated, including flat substrates and convex aspheric lenses. The composition and structure of imprinted chalcogenide glass are analyzed, and it is demonstrated that they are well maintained throughout the imprint. It is optically characterized both in transmission and reflection modes. It is believed that the innovation provides a quantum leap in the micro‐ and nano‐scale processing of chalcogenide glasses, and opens the pathway to their numerous applications.
All‐Dielectric Silicon Metasurface with Strong Subterahertz Toroidal Dipole Resonance
Authors: Zografopoulos Dimitrios C. , Ferraro Antonio , Algorri José Francisco , Martín‐Mateos Pedro , García‐Cámara Braulio , Moreno‐Oyervides Aldo , Krozer Viktor , Acedo Pablo , Vergaz Ricardo , Sánchez‐Pena José Manuel , Beccherelli Romeo
Published: July 2019

A single‐layer, all‐dielectric metasurface exhibiting a strong toroidal resonance in the low‐atmospheric loss radio window of the subterahertz W‐band is theoretically proposed and experimentally demonstrated. The metasurface is fabricated on a high‐resistivity floating‐zone silicon wafer by means of a single‐process, wet anisotropic etching technique. The properties of the toroidal mode of both the constituent dielectric elements and the metasurface are rigorously investigated by means of the multipole decomposition technique and full‐wave simulations. The experimental demonstration of such a compact, all‐silicon metasurface opens new venues of research in the investigation of toroidal modes and the engineering of functional millimeter‐wave components, which can be scaled to terahertz and higher frequencies of the electromagnetic spectrum.
SSBP1 mutations in dominant optic atrophy with variable retinal degeneration
Authors: Jurkute Neringa , Leu Costin , Pogoda Hans‐Martin , Arno Gavin , Robson Anthony G. , Nürnberg Gudrun , Altmüller Janine , Thiele Holger , Motameny Susanne , Toliat Mohammad Reza , Powell Kate , Höhne Wolfgang , Michaelides Michel , Webster Andrew R. , Moore Anthony T. , Hammerschmidt Matthias , Nürnberg Peter , Yu‐Wai‐Man Patrick , Votruba Marcela
Published: July 2019

Objective

Autosomal dominant optic atrophy (ADOA) starts in early childhood with loss of visual acuity and color vision deficits. OPA1 mutations are responsible for the majority of cases, but in a portion of patients with a clinical diagnosis of ADOA, the cause remains unknown. This study aimed to identify novel ADOA‐associated genes and explore their causality.

Methods

Linkage analysis and sequencing were performed in multigeneration families and unrelated patients to identify disease‐causing variants. Functional consequences were investigated in silico and confirmed experimentally using the zebrafish model.

Results

We defined a new ADOA locus on 7q33‐q35 and identified 3 different missense variants in SSBP1 (NM_001256510.1; c.113G>A [p.(Arg38Gln)], c.320G>A [p.(Arg107Gln)] and c.422G>A [p.(Ser141Asn)]) in affected individuals from 2 families and 2 singletons with ADOA and variable retinal degeneration. The mutated arginine residues are part of a basic patch that is essential for single‐strand DNA binding. The loss of a positive charge at these positions is very likely to lower the affinity of SSBP1 for single‐strand DNA. Antisense‐mediated knockdown of endogenous ssbp1 messenger RNA (mRNA) in zebrafish resulted in compromised differentiation of retinal ganglion cells. A similar effect was achieved when mutated mRNAs were administered. These findings point toward an essential role of ssbp1 in retinal development and the dominant‐negative nature of the identified human variants, which is consistent with the segregation pattern observed in 2 multigeneration families studied.

Interpretation

SSBP1 is an essential protein for mitochondrial DNA replication and maintenance. Our data have established pathogenic variants in SSBP1 as a cause of ADOA and variable retinal degeneration. ANN NEUROL 2019;86:368–383
Selective Excitation of Band Extrema in Valley Photonic Crystals
Authors: Yuan Jia‐Jun , He Xin‐Tao , Zhao Fu‐Li , Dong Jian‐Wen
Published: July 2019

Flexible control of building blocks of photonic crystals enables achieving desirable band structures. Exploration of photonic band extrema has brought many fantastic features to design artificial optical materials, such as Brillouin‐zone‐corner extrema for valley photonic materials and zone‐center extremum for zero‐index metamaterials. However, two such kinds of extrema are always found independently in different photonic crystals. In this work, a kind of valley photonic crystals possessing both zone‐center and zone‐corner band extrema almost at the same frequency is proposed. Inspired by antennas theory, a three‐antenna array (TAA) source is devoted to individually manipulate each extremum. The correlation coefficient is given to determine the coupling efficiency between the TAA source and extrema eigenmodes. By using a source with a high correlation coefficient, these extrema bulk states are selectively excited consistent with their eigenfields. Furthermore, three control cases are shown that multiple extrema points are simultaneously excited, in order to confirm the validity of the correlation coefficient. Finally, a potential application of a beam‐steering device is proposed through selective excitation of ternary extrema. This work develops binary valley states into ternary mix states, rendering more degrees of freedom for on‐chip optical information transport, particularly for beam steering and mode division multiplexing.
Phase‐Dependent Quantum Correlation in a Cavity‐Atom System
Authors: Guo Miaodi , Li Hongmei , Zhang Rui , Su Xuemei
Published: July 2019

A scheme to manipulate quantum correlation between output lights of a cavity‐atom system by phase control is proposed. A driving‐field phase is introduced which has a similar value with that of building up quantum correlation in a Hanbury–Brown–Twiss setup. A closed‐loop phase is formed to improve quantum coherence by phase‐dependent electromagnetically induced transparency. The closed‐loop phase has been utilized to realize quantum correlation and even quantum entanglement in the atomic system of previous work. With these two phases, a steady and maximum quantum correlation has been obtained in the scheme here. Moreover, the maximum quantum correlation is free to decoherence of this cavity‐atom system. The study on field‐intensity correlation (quantum correlation) has potential applications on correlated imaging, image encryption transmission, and the improvement of noise resistance in a quantum network.
Umformung von Metallnanopartikeln unter Reaktionsbedingungen
Authors: Zhu Beien , Meng Jun , Yuan Wentao , Zhang Xun , Yang Hangsheng , Wang Yong , Gao Yi
Published: July 2019

Die Form metallischer Nanopartikel (NPs) ist einer der Schlüsselfaktoren für die katalytische Reaktivität. Die jüngsten In‐situ‐TEM‐Beobachtungen zeigen, dass eine dynamische Umformung von Metall‐NPs unter Reaktionsbedingungen erfolgt, was zu einem Haupthindernis für das umfassende Verständnis des katalytischen Mechanismus auf molekularer Ebene wird. In diesem Kurzaufsatz geben wir einen Überblick über die neuesten Fortschritte bei der Charakterisierung und Modellierung der Gleichgewichtsform von Metall‐NPs in verschiedenen reaktiven Umgebungen mithilfe einer Kombination hochmoderner Experimente in Form von In‐situ‐Umgebungs‐Transmissionselektronenmikroskopie und eines neu entwickelten Multiskalen‐Strukturrekonstruktions‐Modells. Die erzielte quantitative Übereinstimmung zwischen den experimentellen Beobachtungen und der theoretischen Modellierung zeigt, dass der grundlegende Mechanismus für das Umformungsphänomen durch anisotrop veränderte Oberflächenenergien unter Gasadsorption angetrieben wird. Die voraussagbare Umformung von Metall‐NPs ebnet den Weg für das rationale Design von wirklich effizienten Nanokatalysatoren in realen Reaktionen.
Effects of substituents on water vapor sorption in liquid–water‐soluble polysaccharides
Authors: Shimanuki Niina , Nagai Kazukiyo
Published: July 2019

In this study, we investigated the influence of the difference in the chemical structures of hyaluronic acid (HA), sodium hyaluronate (Na‐HA), and starch water‐soluble polysaccharides and the difference in sample shape (as‐received samples and membranes) on water vapor solubility. The sorption at this time was characterized by a Fickian diffusion increase at one stage, but HA and starch had a non‐Fickian diffusion increase at the two stages in the high humidity region of 52% or more. In addition, all sorption isotherms of HA, Na‐HA, and starch did not depend on the sample shape and had an extended dual‐mode sorption type behavior consisting of Flory–Huggins and dual‐mode sorption types. Furthermore, the infinite dilution solubility coefficient for water molecules increased with increasing surface free energy and correlates with the surface free energy obtained from the contact angle of water of HA, Na‐HA, and starch membranes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48223.
UV‐activated hydrosilylation of (Me‐Cp)Pt(Me)3: Enhanced photocatalytic activity, polymerization kinetics, and photolithography
Authors: Xi Lu , Liu Zhu , Su Jiahui , Bei Yiling , Xiang Hongping , Liu Xiaoxuan
Published: July 2019

Hydrosilylation is commonly known as a thermally induced addition reaction between unsaturated bonds and SiH bonds to synthesize or crosslink organosilanes and organosilicones, while it has emerged that it can also be activated under the coaction of UV irradiation and specific platinum catalyst. For higher photopolymerization conversion, excessive platinum catalyst is always required; however, this inevitably causes the significant increase of production cost and decrease of operation time. In this study, traces of trimethyl(methylcyclopentadienyl) platinum (IV) (Me‐Cp)Pt(Me)3 catalysts is combined with different photosensitizers (PSs) to efficiently promote the UV‐activated hydrosilylation. Naphthalene is found to be the most applicable PS, because it improves the photopolymerization conversion from about 70 to 100% for the crosslinking of silicone rubbers. This UV‐activated hydrosilylation is more likely to follow the first‐order reaction kinetics, and its activation energy is 30.9 kJ mol−1. The mechanical properties and thermostability of UV‐crosslinked silicone rubbers are also enhanced with the incorporation of naphthalene. Moreover, this UV‐activated hydrosilylation of silicone rubbers reveals a potential role to prepare complicated geometry shapes by photolithography. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48251.
Schools, student health and family welfare: Exploring teachers’ work as boundary spanners
Authors: McCuaig Louise , Rossi Tony , Enright Eimear , Shelley Karen
Published: July 2019

Young people's health and welfare is an enduring, and sometimes contested, underpinning rationale for compulsory schooling. However, a contemporary culture of austerity and accountability has challenged the capacity of schools to address health‐related agendas. This article reports on how four Australian teachers negotiate the network of partnerships within and beyond the school when attempting to solve their students’ particular health and welfare needs. Drawing on interview data collected as part of a larger government‐funded project, we reveal the labour‐intensive, typically risky and often emotionally charged nature of this work. To better understand this ‘health work’ we drew on the idea of ‘teacher as boundary spanner’ to get a clearer sense of the type of work undertaken within an education sector that operates under the conditions of what Fraser calls progressive neoliberalism. We conclude that there is a compelling need to better support those particular teachers who are, to all intents and purposes, human safety nets called upon to care for some of the most vulnerable children in our schools.
A flexible design for advanced Phase I/II clinical trials with continuous efficacy endpoints
Authors: Mozgunov Pavel , Jaki Thomas
Published: July 2019

There is growing interest in integrated Phase I/II oncology clinical trials involving molecularly targeted agents (MTA). One of the main challenges of these trials are nontrivial dose–efficacy relationships and administration of MTAs in combination with other agents. While some designs were recently proposed for such Phase I/II trials, the majority of them consider the case of binary toxicity and efficacy endpoints only. At the same time, a continuous efficacy endpoint can carry more information about the agent's mechanism of action, but corresponding designs have received very limited attention in the literature. In this work, an extension of a recently developed information‐theoretic design for the case of a continuous efficacy endpoint is proposed. The design transforms the continuous outcome using the logistic transformation and uses an information–theoretic argument to govern selection during the trial. The performance of the design is investigated in settings of single‐agent and dual‐agent trials. It is found that the novel design leads to substantial improvements in operating characteristics compared to a model‐based alternative under scenarios with nonmonotonic dose/combination–efficacy relationships. The robustness of the design to missing/delayed efficacy responses and to the correlation in toxicity and efficacy endpoints is also investigated.
Cu‐doped quantum dots: a new class of near‐infrared emitting fluorophores for bioanalysis and bioimaging
Authors: Li Chenghui , Wu Peng
Published: July 2019

Transition metal ion‐doped quantum dots (QDs) exhibit unique optical and photophysical properties that offer significant advantages over undoped QDs, such as larger Stokes shift to avoid self‐absorption/energy transfer, longer excited‐state lifetimes, wider spectral window, and improved chemical and thermal stability. Among the doped QDs emitters, Cu is widely introduced into the doped QDs as novel, efficient, stable, and tunable optical materials that span a wide spectrum from blue to near‐infrared (NIR) light. Their unique physical and chemical characteristics enable the use of Cu‐doped QDs as NIR labels for bioanalysis and bioimaging. In this review, we discuss doping mechanisms and optical properties of Cu‐doped QDs that are capable of NIR emission. Applications of Cu‐doped QDs in in vitro biosensing and in in vivo bioimaging are highlighted. Moreover, a prospect of the future of Cu‐doped QDs for bioanalysis and bioimaging are also summarized.