bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustainable architecture and urban design at Carnegie Mellon Qatar
Authors: Hutzell Kelly , el Samahy Rami
Published: April 2015

As Associate Teaching Professors of Architecture at Carnegie Mellon University, Rami El Samahy and I hold joint appointments, teaching at the Carnegie Mellon University main campus in Pittsburgh, Pennsylvania, in the US every fall semester, and at the branch campus in Doha, Qatar every spring semester. In Doha, we offer elective courses in architecture to non-majors, including students studying Business, Information Systems, and Computer Science. These students have the option to earn a minor in Architecture. One of the required courses for the minor in Architecture is a course titled Architecture for non-majors. In this course, students gain knowledge about the breadth of architectural practice through various forms of study, and assimilate these skills as they develop their own approach. In the first weeks, students learn how to measure, draw, and build models. Throughout the semester, students learn to sketch and design. They gain an understanding of local vernacular passive techniques and are encouraged to reinterpret these concepts in order to create responsible and sustainable contemporary architecture.Sustainability at the urban scale is the focus on an elective course titled Mapping Urbanism. This interdisciplinary seminar functions as an introductory workshop to urban design, information design, urban history, and theory. The aim of the course is two-fold: first, to develop an appreciation for the built environment and diverse history and cultures; and second, to educate students about the complex issues of urbanism through mapping. While the structure of the course is similar each year, the focus is always changing. Past courses have focused on examinations of international city typologies, regional sustainable mega-projects, and local public spaces.In addition to teaching architecture electives to non-majors, we’ve also led semester-long study abroad programs, whereby undergraduate architecture students from Carnegie Mellon University in Pittsburgh studied abroad in Doha. In 2010, fourth-year undergraduate Bachelor of Architecture students, who are required to take an architectural design studio that focuses on systems integration, redesigned the Qatar Green Building Council (QGBC) headquarters. The project was intended to reflect the needs, mission and organizational structure of the QGBC by showcasing a variety of sustainable strategies. Student projects included ideas such as opening the central atrium to create an exterior courtyard, redirecting the entrance; and have incorporated solar photovoltaic panels, wind turbines and evaporative cooling pools.
The Passivhaus concept for the Arabian Peninsula – An energetic-economical evaluation considering the thermal comfort
Authors: Göttsche Joachim , Korn Michael , Amato Alexandre
Published: April 2015

The Passivhaus building standard is a concept developed for the realization of energy-efficient and economical buildings with a simultaneous high utilization comfort under European climate conditions. Major elements of the Passivhaus concept are a high thermal insulation of the external walls, the use of heat and/or solar shading glazing as well as an airtight building envelope in combination with energy-efficient technical building installations and heating or cooling generators, such as an efficient energy-recovery in the building air-conditioning.
The objective of this research project is the inquiry to determine the parameters or constraints under which the Passivhaus concept can be implemented under the arid climate conditions in the Arabian Peninsula to achieve an energy-efficient and economical building with high utilization comfort. In cooperation between the Qatar Green Building Council (QGBC), Barwa Real Estate (BRE) and Kahramaa the first Passivhaus was constructed in Qatar and on the Arabian Peninsula in 2013. The Solar-Institut Jülich of Aachen University of Applied Science supports the Qatar Green Building Council with a dynamic building and equipment simulation of the Passivhaus and the neighbouring reference building. This includes simulation studies with different component configurations for the building envelope and different control strategies for heating or cooling systems as well as the air conditioning of buildings to find an energetic-economical optimum. Part of these analyses is the evaluation of the energy efficiency of the used energy recovery system in the Passivhaus air-conditioning and identification of possible energy-saving effects by the use of a bypass function integrated in the heat exchanger. In this way it is expected that on an annual basis the complete electricity demand of the building can be covered by the roof-integrated PV generator.
Smart building integrated photovoltaics BIPV for Qatar
Authors: Muehlbauer Maria
Published: April 2015

Retrofitting occupied villas with PV systems is only possible with the acceptance of the inhabitants.
The challenge is to make Building Integrated Photovoltaics BIPV and own-consumption of PV energy attractive and comfortable to the people. Providing Smart BIPV systems that consist of the PV system, an energy manager and a house management system adaptable to the individual lifestyle of the people could be a helpful motivation to support the PV micro grid generation.
In the Smart BIPV system the energy manager is monitoring all energy flows within the building, the consumed energy and the PV production. This detailed visualization makes the people sensible to their energy demands and gives them a real chance to improve their consumption habits. To achieve high own-consumption automatically switching of different appliances is necessary. The PV manager is able to switch appliances on and off according to the individual settings.
Flexible appliances with high energy demand (washing machine, dishwasher, and dryer) can be adapted to the own-produced energy. They are connected to different defined power sockets and the central unit will start them when enough PV energy is available. The inhabitants can change the settings individually to their needs, thus they can train their skills and gain experiences in coordinating different machines.
Other appliances must work independently from the PV energy (air conditioner, fan, blinds) and should be switched according to the inhabitant’s schedule. For example the air-conditioner should not run the whole day but before the inhabitants’ return, the central-unit can switch it on by settings or remotely to make a comfortable climate. This will not increase the own-consumption but reduces the demand of conventionally produced energy extensively and makes a good conscience.
The third group of appliances are all electrical devices with constant energy demand (refrigerator, freezer). These appliances are supplied by PV energy at first and during night by the public grid. That means a visible usage of renewable energy day by day.
The Smart BIPV systems can be introduced in new buildings and also in occupied villas. The PV manager is part of this system and the central unit is also connected to the electric meters, power sockets, switch sockets and several components like sensors for measuring temperature, humidity and motion in-house and outside. It must be built in by an electrician but the different applications can be installed successively and adjusted by the inhabitants.
Green Engineering for Sustainable Cities: Gardens by the Bay, Singapore
Authors: Bellew Patrick , Davey Meredith , Leanne Renn
Published: April 2015

Cooled Conservatories, Gardens by the Bay are the biggest cooled greenhouses in the world and a key project in the Singapore Government’s vision of transforming it into a ‘City in a Garden’. More significantly, the Prime Minister spoke of the lessons Singapore could learn from the green technologies employed within the Gardens so that once ‘economics’ allowed they could be implemented more widely within Singapore creating a green and more sustainable city. Behind the hyperbole, the gardens serve as a great educational tool providing learning points about acting and living in a more responsible manner, alongside demonstrating innovative sustainable technologies. As a national and international exemplar of sustainable practice, Gardens by the Bay was named World Building of the Year at the prestigious World Architecture Festival 2012, is a recipient of the 2013 RIBA Lubetkin Prize and CIBSE International Project of the Year 2014 and MIPIM Best Innovative Green Building 2014. The presenter will discuss the innovative technologies employed by the design team to deliver this award-winning project. He will also discuss the merits of creating such a facility in a sustainable city.
As part of a larger design team, Atelier Ten help develop a scheme based on first principles. Holistically integrated solutions were developed to meet the demanding brief to create artificial interior environments enabling Mediterranean and mountain plants to grow in the tropical urban heat of downtown Singapore. The project comprises 52 hectares of landscaped gardens on reclaimed ground. It features a 20,000m2 complex of cooled conservatories and 18 large structures supporting vertical gardens ranging in height from 25m to 50m known as Supertrees. The conservatories and the gardens have been designed to be symbiotic through the interaction of a number of energy and water processes. We have developed innovative strategies for controlling conditions within the two biomes while minimising energy demand to exemplar levels. External supertree structures coupled with liquid desiccant systems provide cool air to the biomes. These structures also incorporate photovoltaics, solar thermal panels and rainwater harvesting. Moreover, waste generated by Singapore’s National Parks will be diverted from landfill and used as a source of biomass to generate energy for use throughout. At present, this horticultural residue waste is land filled and so this installation acts to turn a waste stream into an active energy supply that results in carbon neutral operation.
Environmental benefits from Green Guildings - A case study of RasGas Headquarters building Doha, Qatar
Authors: Elias Mathew , Maseeh Bader Al , Philip Jose
Published: April 2015

This paper presents environmental benefits from green buildings based on a case study from the RasGas Headquarters building which is a LEED certified building under the Commercial Interiors Category. A comparison was made between utility costs of a typical commercial office building in Doha and the RasGas Headquarters building. The comparison shows substantial savings in utility costs for the green building. The authors encourage building owners and design consultants to be aware of the environmental and economic benefits from Green Buildings and include green features in the design of buildings. The authors believe that a good design is in fact a green design.
The efficacy of built morphology to create comfortable microclimates in a hot arid region
Authors: Francini Alberto
Published: April 2015

Sustainable city energy modelling for extreme climate areas such as hot arid climate zones require the knowledge of and the interaction with the territory in order to create a sustainable living for all inhabitants. To achieve this goal in an arid, dry area, we propose to modify buildings and microenvironment to affect, for example, temperatures and air humidity. To reduce energy costs and hence pollution, we need to find solutions that are more natural and capable of reducing energy costs and CO2 emissions, such as 1) the choice of an improved orientation of buildings and of the new urban area in order to reduce solar irradiation and facilitate cooling of buildings through convective air flows, 2) the implementation of green space in order to reduce CO2 emission, regulate air humidity and temperature, and to create a pleasant place to live.The method used is the study of alternative scenarios for settlement principles and built morphology as well as the assessment of energy costs and emissions.The first point that we must take in account for increasing the energy savings is the built morphology: examples are buildings shaped as inverted pyramids with few floors and therefore reducing energy costs and cost of vertical mobility. The shape acts like an umbrella to produce a shadow and allows the creation of green spaces and a pleasant movement through pedestrian focused facilities. The roof can host green spaces for the thermal insulation of the building and solar panels for environmentally friendly production of energy and reflection of solar rays.Floor orientation: the rotation of the various layers/floors allows to distribute the solar irradiation and facilitate the cooling (air-conditioning) of the buildings.Services and facilities for entertainment and recreation are integrated in the buildings. Interstices and green terraces in the building will help the natural air ventilation and create a perfect machine for living.The aggregation of inverted pyramid building types create a more interesting and enjoyable pedestrian and peaceful pathway in the building shadow to reach all available services and facilities housed in the various buildings and in the open space. Finally, the green space on the ground and roof will be useful to reduce the CO2 pollution through photosynthesis providing inhabitants with a high quality of life in a green microclimate.In addition to settlement principles, the built morphology creates comfortable microclimates for the human life.The objective of this research project is to identify a built typology able to define an urban model capable of improving the life of people living under extreme environmental conditions.
Bioclimatic principles towards sustainable, comfortable and energy efficient societies
Authors: El-Masry Diaa , Farag Eman , Salem Lamya , Katafygiotou Martha
Published: April 2015

Bioclimatic architecture has developed over many years to address the problems inherent in buildings. Through a process of trial and error our ancestors have found effective ways to handle the different climatic conditions. All through history, people were trying to adapt their buildings with the environment in order to create better living conditions. Traditionally, dwellings and other buildings have been constructed with full respect to the characteristics of a particular geographical location in order to control its local climatic conditions. Consequently, different types of architecture have arisen to adapt different climatic and cultural conditions, which vary from region to region. Traditional and vernacular buildings showed real sustainability through employing native construction materials and techniques, which efficiently enabled them to minimize their negative environmental impacts, reduce the energy required to supply different climatic controllers and provide indoor thermal comfort.Nowadays, the trend towards an internationalized style of building could result in a reduction in the traditional solutions, which have served several cultures well for many centuries. Of course, people quite rightly demand new architectural designs and high standards of comfort in buildings. These demands are also achievable through the careful combination of traditional and modern bioclimatic principles. The advantages of this option are clear; there is a dramatic reduction of energy needs and an increased use of the architectural style with which people feel at ease. Green buildings and bioclimatic architecture may also promote the preservation of heritage and cultural identity which is a very important matter for the evolving societies. Furthermore while the preservation of natural resources is a universal issue, the specific importance of sustainability and passive design is an up to date topic. Therefore this review paper examines the integration of bioclimatic strategies and passive techniques in modern architecture towards a sustainable, comfortable and energy efficient built environment focusing on the warm climatic regions of the world.
State of the art on indoor comfort and occupants behavior in warm climatic regions
Authors: El-Masry Diaa , Farag Eman , Salem Lamya , Katafygiotou Martha
Published: April 2015

Indoor thermal comfort is essential for occupants well-being, productivity and efficiency. Comfort standards state criteria in order to create adequate thermal comfort conditions in buildings. Early on, humans tended to create a thermally neutral environment in which they can feel comfortable to spend the most creative hours of their life. One of the greatest challenges of modern architecture is to create a thermally comfortable environment inside buildings, studying in detail all the factors that contribute to it. Nowadays the aim is also to achieve the preeminent indoor air quality and specifically thermal comfort with the minimum possible energy cost and environmental impact.This paper is a literature review of the thermal comfort requirements based on international standards and occupants behavioral trends with their effect especially on the energy consumption. The study focuses in the warm humid climatic regions particularly the Gulf area where comfort preservation and sustainability of a building could be very challenging. Extremely high temperatures and intense solar radiation are on the rise in this era of climate change and global warming. Thus achieving indoor thermal comfort and reducing energy usage in buildings is becoming increasingly difficult. Passive strategies and bioclimatic techniques may serve well and in combination with the growing environmental awareness of occupants may conclude to a more comfortable and sustainable built environment.
Cemfree: The development of non-Portland cement based concretes
Authors: Liska Martin , Bartholomew Deirdra
Published: April 2015

This paper outlines the development of a cement-free structural concrete known as Cemfree. From concept through to laboratory testing and large-scale field trials, this paper focusses on the scale-up of the technology and the advances in sustainable and durable construction that this innovative material allows.Such concretes are produced using conventional materials, equipment and practices, except that it is now possible to produce structural-grade concrete using a highly sustainable, highly durable alternative binder in place of conventional Portland cement - this binder is known as Cemfree Binder.This paper details the results and data recorded during our internal lab investigations and subsequent field trials; as well as the results and findings of other parties who have had access to the material for independent testing and evaluation.The Cemfree concept has been recognised by Shell in their Springboard Awards 2013, and by Crossrail as Innovation #001 in their Innov18 programme. Cemfree is set to radically change our approach to sustainable construction without the need to change or modify any of our fundamental working practices.
Context
Authors: van Dijk Teun A.
Published: April 2015

The vague and ambiguous concept of “context” is widely used in the humanities and social sciences, in general, and in the study of language and discourse, in particular. After a brief discussion of some classical definitions of context in the language sciences, this article presents a summary of a theory of context in terms of mental models of the communicative situation. These mental models control the appropriateness of discourse in such situations and hence also offer a basis for pragmatics.
Apology Discourse
Authors: Ogiermann Eva
Published: April 2015

Research on apologies is: highly cross‐disciplinary; conducted mainly in different areas of sociology and linguistics, and focusing on both apology expressions and accounts. Goffman's work on remedial interchanges, based on observations of everyday public encounters, has examined the role of apologies in preserving the “territories of the self.” It has also inspired the view on apologies offered by politeness theory, where apologies are viewed as strategies acknowledging the other's right to nondistraction. At the same time, scholars working in the area of conflict resolution in private as well as in legal contexts have focused on the role of responsibility acceptance and remorse in apologizing. Cross‐cultural research on apologies has established a taxonomy that has been applied to numerous languages, revealing culture‐specific preferences in apologizing, while scholars studying public apologies addressed to large audiences have pointed out their function as symbolic and persuasive acts.
Anodic Electrochromism for Energy‐Efficient Windows: Cation/Anion‐Based Surface Processes and Effects of Crystal Facets in Nickel Oxide Thin Films
Authors: Wen Rui‐Tao , Granqvist Claes G. , Niklasson Gunnar A.
Published: April 2015

Anodic electrochromic (EC) oxides are of major interest as counter electrodes for smart window applications owing to their unique optical properties upon charge insertion and extraction. However, performance optimization of such oxides has been hampered by limited understanding of their EC mechanism, particularly in Li+‐conducting electrolytes. This paper reports on NiOx films with 1.16 ≤ x ≤ 1.32, prepared by sputter deposition. These films are immersed in an electrolyte of lithium perchlorate in propylene carbonate, and EC properties are studied by cyclic voltammetry and in situ optical transmittance measurements. The electrochromism is significantly enhanced at large values of x. It has been found that charge exchange in Ni oxide is mainly due to surface processes and involves both cations and anions from the electrolyte, which is different from the case of cathodic EC materials such as WO3. Whereas previous studies of Ni oxide have focused on cation intercalation, the cation/anion‐based mechanism presented here offers a new paradigm for designing and developing EC devices such as smart windows for energy efficient buildings.
Fabrication of Patterned Concave Microstructures by Inkjet Imprinting
Authors: Bao Bin , Jiang Jieke , Li Fengyu , Zhang Pengchao , Chen Shuoran , Yang Qiang , Wang Shutao , Su Bin , Jiang Lei , Song Yanlin
Published: April 2015

Concave microstructures such as microwells and microgrooves are widely utilized in fields such as biochips, microfluidics, and functional devices. Previously, concave microstructure fabrication was mostly based on laser etching or lithography which is either costly or of multisteps. The inkjet etching method is a direct structuring technique, but limited by its inherent transverse ink diffusion that leads to low feature resolution. Nanoimprint lithography can reach submicro and even nano ranges, whereas an elaborate template is needed. Thus, it is still a challenge to realize controllable fabrication of concave microstructures in large areas with high efficiency and resolution. Here, a template‐free strategy to fabricate concave microstructures with high resolution by inkjet imprinting is provided. In this method, a sacrificial ink is inkjet‐printed onto a precured viscoelastic surface and imprints its shapes to construct concave microstructures. The morphology of the microstructures could be adjusted by controlling the interaction between the two immiscible phases. The microwells/microgrooves could be used to pattern single cells and functional materials such as optical, electronic, and magnetic nanoparticles. These results will open a new pathway to fabricate concave microstructures and broaden their applications in various functional devices.
Collagen‐Coated Lapatinib‐Loaded Poly(lactic acid) Microspheres for Breast Cancer in Biomedical Applications
Authors: Prabhakar M. N. , Song Jung‐Il , Chowdoji Rao K.
Published: April 2015

A novel micro in situ drug loaded with poly(lactic acid) (PLA) microspheres coated with collagen by a simple adsorption technique through the water‐in‐oil emulsion method is introduced to reduce inflammatory responses at the site of implants and enhance the bioactiveness for several applications in the medical field including tissue engineering. The surface modification technique was the current scenario; hence, the protein adsorption principle is used for coating of collagen onto the surface of PLA microspheres. The study was conducted in two steps: (1) Lapatinib drug loaded PLA microspheres were prepared and characterized and (2) the drug‐loaded PLA microspheres were dispersed in a collagen solution, yielding the modified microspheres. The surface morphology of the prepared PLA microspheres was verified by using a scanning electron microscope, and it is concluded that the microspheres are spherical in shape. The PLA microspheres are studied through attenuated total reflectance Fourier transform infrared spectroscopy, and through the differential scanning calorimetry–thermal gravimetric analysis technique it is observed that there is no interaction between polymer and the drug. The in vitro release study of modified PLA microspheres was conducted at pH 7.4, and the results indicated that the adsorption technique can be the simple strategy to coat collagen on the surface of polyester implants to develop the stealth implant in shorter time with low cost technology.
Recent Advances in Electrolytes for Lithium–Sulfur Batteries
Authors: Zhang Shiguo , Ueno Kazuhide , Dokko Kaoru , Watanabe Masayoshi
Published: April 2015

The rapidly increasing demand for electrical and hybrid vehicles and stationary energy storage requires the development of “beyond Li‐ion batteries” with high energy densities that exceed those of state‐of‐the‐art Li‐ion batteries. Li–S batteries, which have very high theoretical capacities and energy densities, are believed to be one of the most promising candidates. The sulfur‐based electrochemical reaction requires novel electrolytes to replace the classical carbonate‐based electrolyte systems inherited from Li‐ion batteries because carbonates are incompatible with the intermediate polysulfides in Li–S batteries. In addition, the theoretical specific capacities and projected energy densities of Li–S batteries are difficult to achieve experimentally, mainly because of the electronically insulating nature of sulfur and lithium sulfide cathodes, and the shuttle effect; this is a serious issue associated with the dissolution and diffusion of soluble polysulfides in most potential electrolytes and causes rapid capacity fading. It is therefore highly desirable to explore, modify, and/or optimize electrolytes for Li–S batteries to address these issues and improve their capacities, cycling stabilities, rate performances, and energy densities. An overview of recent developments in electrolytes for Li–S batteries is provided with a focus on the chemistry of polysulfides in different electrolyte media, including polysulfide solubility and its relevance to battery performance.
Validity of the effort/reward imbalance questionnaire in health professionals from six Latin‐American countries
Authors: Juárez‐García Arturo , Vera‐Calzaretta Aldo , Blanco‐Gomez Gisela , Gómez‐Ortíz Viviola , Hernández‐Mendoza Elena , Jacinto‐Ubillus José , Choi Bongkyoo
Published: April 2015

Background

This study tests the validity and the invariance of ERI questionnaire (ERIQ) data from health professionals in six different Latin‐American countries.

Methods

One thousand two hundred ninety‐two (1292) participants who worked in hospitals in Argentina, Chile, Colombia, Mexico, Peru and Venezuela completed the ERI and GHQ questionnaires. Partial correlations were carried out as well as reliability statistics and confirmatory factor analyses to examine factor structure and invariance of ERIQ in each subsample.

Results

Overall confirmatory factor analyses confirmed the theoretical structure of the ERIQ. The effort and overcommitment scales were invariant (equivalent) across the six countries, but the reward scale was only partially invariant. Several associations between ERIQ and mental health remain significant after controlling for sociodemographic variables.

Conclusions

Although the validity of the ERIQ’ scales were generally satisfactory in most Latin‐American samples, future research should examine in depth the equivalence of reward scale across Latin‐American cultures. Am. J. Ind. Med. 58:636–649, 2015. © 2015 Wiley Periodicals, Inc.
Combination of blunt cardiac and pericardial injury presenting a massive hemothorax without hemopericardium
Authors: Kittaka Hirotada , Yagi Yoshiki , Zushi Ryosuke , Hazui Hiroshi , Akimoto Hiroshi
Published: April 2015

Case

A 64‐year‐old man was injured after falling from a height of 5 m and was transported to our institution. On presentation, his hemodynamic state was unstable, and both focused assessment with sonography for trauma and enhanced computed tomography imaging revealed massive left pleural effusion, but no pericardial effusion. He went into cardiopulmonary arrest just before surgery, so an urgent left anterolateral thoracotomy followed by open chest cardiac massage and aortic clamping were carried out. By performing an additional right anterior thoracotomy, a left pleuropericardial laceration and a perforation measuring 1 cm in diameter at the left ventricle were found. The patient's dynamic state stabilized following the restoration of hemostasis by suturing the rupture site.

Outcome

The patient's postoperative course was favorable, and he was discharged after 20 days of hospitalization.

Conclusion

Blunt cardiac and pericardial injury rarely causes massive hemothorax with no hemopericardium, resulting in hemorrhagic shock.
Metallo‐β‐lactamase‐producing Klebsiella pneumoniae infection in a non‐hospital environment
Authors: Okazaki Rumi , Hagiwara Shuichi , Kimura Takao , Tokue Yutaka , Kambe Masahiko , Murata Masato , Aoki Makoto , Kaneko Minoru , Oshima Kiyohiro , Murakami Masami
Published: April 2015

Case

A 92‐year‐old female resident at a nursing home was transported to the emergency department unconscious, hypotensive, and febrile. Chest X‐rays and computed tomography revealed a permeation shadow in the right lung. The patient was diagnosed with sepsis due to pneumonia. At the time of admission, she had not received antibiotics or treatment using medical devices over the past 6 months. Two sets of samples were taken for blood and sputum cultures, and Klebsiella pneumoniae was isolated from all cultures. The strain was identified as metallo‐β‐lactamase‐producing K. pneumoniae, and the patient was successfully treated with tazobactam–piperacillin. This case indicates that metallo‐β‐lactamase‐producing K. pneumoniae infection occurred in a non‐hospital environment.

Outcome

After tazobactam–piperacillin treatment, the patient was transferred to another hospital.

Conclusion

Emergency physicians should be aware of multidrug‐resistant bacterial infection even in a non‐hospital setting.
Assembly and Purification of Enzyme‐Functionalized DNA Origami Structures
Authors: Timm Christopher , Niemeyer Christof M.
Published: April 2015

The positioning of enzymes on DNA nanostructures for the study of spatial effects in interacting biomolecular assemblies requires chemically mild immobilization procedures as well as efficient means for separating unbound proteins from the assembled constructs. We herein report the exploitation of free‐flow electrophoresis (FFE) for the purification of DNA origami structures decorated with biotechnologically relevant recombinant enzymes: the S‐selective NADP+/NADPH‐dependent oxidoreductase Gre2 from S. Cerevisiae and the reductase domain of the monooxygenase P450 BM3 from B. megaterium. The enzymes were fused with orthogonal tags to facilitate site‐selective immobilization. FFE purification yielded enzyme–origami constructs whose specific activity was quantitatively analyzed. All origami‐tethered enzymes were significantly more active than the free enzymes, thereby suggesting a protective influence of the large, highly charged DNA nanostructure on the stability of the proteins.
An Organic Microlaser Array Based on a Lateral Microcavity of a Single J‐aggregation Microbelt
Authors: Liao Qing , Jin Xue , Zhang Haihua , Xu Zhenzhen , Yao Jiannian , Fu Hongbing
Published: April 2015

A laser array on the nano‐ and microscale is a key component for integration in photonic devices, but remains a challenge when using semiconductor nanowire lasers. Here we report a low‐threshold lateral‐cavity microlaser, formed between two lateral‐faces of a single‐crystalline organic microbelt (OMB) of 1,4‐dimethoxy‐2,5‐di[4′‐(cyano)styryl]benzene (COPV). By cutting a single OMB into six pieces by a top‐down two‐photon processing technique, we successfully fabricated a compact and uniform 1×6 microlaser array along the length direction of the OMB. The microlasers had excellent reproducibility and addressable high precision, thus making them attractive candidates as miniaturized coherent light sources for future nanophotonics.
Polyimide Dendrimers Containing Multiple Electron Donor–Acceptor Units and Their Unique Photophysical Properties
Authors: Toma Francesca M. , Puntoriero Fausto , Pho Toan V. , La Rosa Marcello , Jun Young‐Si , Tremolet de Villers Bertrand J. , Pavlovich James , Stucky Galen D. , Campagna Sebastiano , Wudl Fred
Published: April 2015

A high‐yielding synthesis of a series of polyimide dendrimers, including decacyclene‐ and perylene‐containing dendrimer D6, in which two types of polyimide dyes are present, is reported. In these constructs, the branching unit is represented by trisphenylamine, and the solubilizing chains by N‐9‐heptadecanyl‐substituted perylene diimides. The photophysical properties of the dendrimers have been studied by absorption, steady‐state, and time‐resolved emission spectroscopy and pump–probe transient absorption spectroscopy. Photoinduced charge‐separated (CS) states are formed on the femtosecond timescale upon visible excitation. In particular, in D6, two different CS states can be formed, involving different subunits that decays independently with different lifetimes (ca. 10–100 ps).
Distinct Proton and Water Reduction Behavior with a Cobalt(III) Electrocatalyst Based on Pentadentate Oximes
Authors: Basu Debashis , Mazumder Shivnath , Shi Xuetao , Staples Richard J. , Schlegel H. Bernhard , Verani Cláudio N.
Published: April 2015

A new pentadentate oxime has been designed to drive the preferential coordination favored by CoI in catalysts used for proton/water reduction. The ligand incorporates water upon metal coordination and is water soluble. This CoIII species is doubly reduced to CoI and exhibits H+ reduction activity in the presence of weak acids in MeCN and evolves H2 upon protonation suggesting that the ligand design increases catalyst effectiveness. Superior catalysis is observed in water with a turnover number (TON) of 5700 over 18 h. However, the catalyst yields Co‐based nanoparticles, indicating that the solvent media may dictate the nature of the catalyst.
The Mechanism of Color Change in the Neon Tetra Fish: a Light‐Induced Tunable Photonic Crystal Array
Authors: Gur Dvir , Palmer Benjamin A. , Leshem Ben , Oron Dan , Fratzl Peter , Weiner Steve , Addadi Lia
Published: April 2015

The fresh water fish neon tetra has the ability to change the structural color of its lateral stripe in response to a change in the light conditions, from blue‐green in the light‐adapted state to indigo in the dark‐adapted state. The colors are produced by constructive interference of light reflected from stacks of intracellular guanine crystals, forming tunable photonic crystal arrays. We have used micro X‐ray diffraction to track in time distinct diffraction spots corresponding to individual crystal arrays within a single cell during the color change. We demonstrate that reversible variations in crystal tilt within individual arrays are responsible for the light‐induced color variations. These results settle a long‐standing debate between the two proposed models, the “Venetian blinds” model and the “accordion” model. The insight gained from this biogenic light‐induced photonic tunable system may provide inspiration for the design of artificial optical tunable systems.
From the Bench to the Field in Low‐Cost Diagnostics: Two Case Studies
Authors: Kumar Ashok A. , Hennek Jonathan W. , Smith Barbara S. , Kumar Shailendra , Beattie Patrick , Jain Sidhartha , Rolland Jason P. , Stossel Thomas P. , Chunda‐Liyoka Catherine , Whitesides George M.
Published: April 2015

Despite the growth of research in universities on point‐of‐care (POC) diagnostics for global health, most devices never leave the laboratory. The processes that move diagnostic technology from the laboratory to the field—the processes intended to evaluate operation and performance under realistic conditions—are more complicated than they might seem. Two case studies illustrate this process: the development of a paper‐based device to measure liver function, and the development of a device to identify sickle cell disease based on aqueous multiphase systems (AMPS) and differences in the densities of normal and sickled cells. Details of developing these devices provide strategies for forming partnerships, prototyping devices, designing studies, and evaluating POC diagnostics. Technical and procedural lessons drawn from these experiences may be useful to those designing diagnostic tests for developing countries, and more generally, technologies for use in resource‐limited environments.
Graft‐Copolymer‐Based Approach to Clear, Durable, and Anti‐Smudge Polyurethane Coatings
Authors: Rabnawaz Muhammad , Liu Guojun
Published: April 2015

Clear anti‐smudge coatings with a thickness of up to tens of micrometers have been prepared through a graft‐copolymer‐based approach from commercial precursors. The coatings repel water, diiodomethane, hexadecane, ink, and an artificial fingerprint liquid. In addition, they can be readily applied onto different substrates using different coating methods. These coatings could find applications in protecting hand‐held electronic devices from fingerprints, windows from stains, and buildings from graffiti.
Unprecedented Mechanism Employed by the Salmonella enterica EutT ATP:CoIrrinoid Adenosyltransferase Precludes Adenosylation of Incomplete CoIIrrinoids
Authors: Park Kiyoung , Mera Paola E. , Moore Theodore C. , Escalante‐Semerena Jorge C. , Brunold Thomas C.
Published: April 2015

Three distinct families of ATP:corrinoid adenosyltransferases (ACATs) exist that are capable of converting vitamin B12 derivatives into coenzyme B12 by catalyzing the thermodynamically challenging reduction of CoIIrrinoids to form “supernucleophilic” CoI intermediates. While the structures and mechanisms of two of the ACAT families have been studied extensively, little is known about the EutT enzymes beyond the fact that they exhibit a unique requirement for a divalent metal cofactor for enzymatic activity. In this study we have obtained compelling evidence that EutT converts cob(II)alamin into an effectively four‐coordinate CoII species so as to facilitate CoII→CoI reduction. Intriguingly, EutT fails to promote axial ligand dissociation from the substrate analogue cob(II)inamide, a natural precursor of cob(II)alamin. This unique substrate specificity of EutT has important physiological implications.
Cobalt‐Catalyzed Hydrogenation of Esters to Alcohols: Unexpected Reactivity Trend Indicates Ester Enolate Intermediacy
Authors: Srimani Dipankar , Mukherjee Arup , Goldberg Alexander F. G. , Leitus Gregory , Diskin‐Posner Yael , Shimon Linda J. W. , Ben David Yehoshoa , Milstein David
Published: April 2015

The atom‐efficient and environmentally benign catalytic hydrogenation of carboxylic acid esters to alcohols has been accomplished in recent years mainly with precious‐metal‐based catalysts, with few exceptions. Presented here is the first cobalt‐catalyzed hydrogenation of esters to the corresponding alcohols. Unexpectedly, the evidence indicates the unprecedented involvement of ester enolate intermediates.
Effect of the intermediate layer–core ratio on the morphology and opacity ability of hollow latex particles
Authors: Yuan Teng , Shao Qinghui , Hu Jianqing , Wang Feng , Tu Weiping
Published: April 2015

In this study, well‐monodispersed hollow latex particles were synthesized through semicontinuous seed emulsion polymerization, and the effect of the hollow latex particles' intermediate layer–core ratios on their morphology and opacity ability were studied. The results show that when the intermediate layer–core ratios increased from 6 to 10, the swelling degree of the hollow latex particles decreased, and the intensity gradually increased, but the opacity ability increased first and then decreased. When the intermediate layer–core ratio was 8, the opacity ability of the hollow latex particles was the best. When the intermediate layer–core ratios were 6 and 7, the surface of the hollow latex particles was rough, and they showed a great swelling degree, big cavity, and thin shell, and few of latex particles collapsed or ruptured. When the intermediate layer–core ratios were 9 and 10, the hollow latex particles had a smooth surface, thick shell, and small swelling degree and cavity, and roughly, there was no collapse or rupture of the hollow latex particles. When the intermediate layer–core ratio was 8, the swelling degree of the hollow latex particles was moderate. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42268.
Degradation in soil behavior of artificially aged polyethylene films with pro‐oxidants
Authors: Briassoulis Demetres , Babou Epifaneia , Hiskakis Miltiadis , Kyrikou Ioanna
Published: April 2015

Bio‐based, biodegradable in soil, as well as degradable polyethylene mulching films with pro‐oxidants, have been introduced in the market in an effort to deal with the serious problem of managing plastic waste streams generated from conventional mulching films. In a previous experimental investigation, a series of naturally degraded under water melon cultivation conditions linear low density polyethylene (LLDPE) mulching films with pro‐oxidants, buried in the field for 8.5 years, were recovered intact even though undergoing a continuous slow abiotic degradation in soil. The aim of the present article was to simulate the behavior of the LLDPE mulching films with pro‐oxidants under a much longer time‐scale (e.g. some decades). Toward this purpose, samples of LLDPE with pro‐oxidants film were artificially degraded to simulate severe degradation/fragmentation of these films while been buried in the soil for many years, following the end of the cultivation season. Further degradation of these severely degraded samples was investigated by burying them in the soil over a period of seven years. During this burial period, all degradation parameters and their evolution with time were measured. The artificially degraded LLDPE film samples with pro‐oxidants, in contrast to the naturally degraded film that remained intact for 8.5 years, were gradually transformed into tiny micro‐fragments in the soil. These fragments, through a continuing abiotic degradation process under natural soil conditions are eventually transformed into invisible micro‐fragments. The fate of these micro‐fragments and their long‐term impact to the environment and human health is unpredictable. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42289.
In situ injectable poly(γ‐glutamic acid) based biohydrogel formed by enzymatic crosslinking
Authors: Fan Zhiping , Zhang Yemin , Zhang Wei , Li Xinsong
Published: April 2015

Enzymatic crosslinking was developed to prepare in situ forming poly(γ‐glutamic acid) (γ‐PGA) based hydrogel in this study. First, the precursor of poly(γ‐glutamic acid)–tyramine (γ‐PGA–Ty) was synthesized through the reaction of carboxyl groups from a γ‐PGA backbone with tyramine. The structure of the grafted precursor was confirmed by 1H‐NMR and Fourier transform infrared spectroscopy. After that, the crosslinking of the phenol‐containing γ‐PGA–Ty precursor was triggered by horseradish peroxidase in the presence of H2O2; this resulted in the formation of the γ‐PGA–Ty hydrogels. The equilibrium water content, morphology, enzymatic degradation rate, and mechanical properties of the hydrogels were characterized in detail. The data revealed that the well‐interconnected hydrogels had tunable water contents, mechanical properties, and degradability through adjustments of the composition. Furthermore, cell experiments proved the biocompatibility of the hydrogels by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. These characteristics provide an opportunity for the in situ formation of injectable biohydrogels as potential candidates in cell encapsulation and drug delivery. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42301.
MicroRNA‐9 Promotion of Interleukin‐6 Expression by Inhibiting Monocyte Chemoattractant Protein–Induced Protein 1 Expression in Interleukin‐1β–Stimulated Human Chondrocytes
Authors: Makki Mohammad S. , Haseeb Abdul , Haqqi Tariq M.
Published: April 2015

Objective

Enhanced expression of interleukin‐6 (IL‐6) plays an important role in the pathogenesis of osteoarthritis (OA). Monocyte chemoattractant protein–induced protein 1 (MCPIP‐1) is a novel posttranscriptional regulator of IL‐6 expression and is targeted by microRNA‐9 (miR‐9). We investigated the expression of MCPIP‐1 in OA cartilage and explored whether targeting of MCPIP‐1 by miR‐9 contributes to enhanced IL‐6 expression in OA.

Methods

Gene and protein expression in IL‐1β–stimulated human OA chondrocytes/cartilage was determined by TaqMan assay and immunoblotting, respectively. Messenger RNA (mRNA) for MCPIP‐1 and IL‐6 expression at the single‐cell level was analyzed using RNAscope. MCPIP‐1 protein interaction with IL‐6 mRNA was investigated using RNA immunoprecipitation. Transient transfections were used for the small interfering RNA (siRNA)–mediated knockdown and overexpression of MCPIP‐1, its RNase‐defective mutant miR‐9, or antagomir. The role of signaling pathways was evaluated using small‐molecule inhibitors. Binding of miR‐9 with the “seed sequence” in the 3′‐untranslated region of MCPIP‐1 mRNA was investigated using a luciferase reporter assay.

Results

MCPIP‐1 mRNA expression was low, but expression of miR‐9 and IL‐6 was high, in damaged OA cartilage. In IL‐1β–stimulated OA chondrocytes, the expression of miR‐9 and MCPIP‐1 was mutually exclusive, and increased expression of miR‐9 correlated with reduced MCPIP‐1 expression and enhanced IL‐6 expression. MCPIP‐1 protein directly binds with IL‐6 mRNA, and overexpression of wild‐type MCPIP‐1 destabilized the IL‐6 mRNA. MCPIP‐1 expression was altered by overexpression or inhibition of miR‐9. Transfection with miR‐9 mimics inhibited the reporter activity, and mutation of the “seed sequence” abolished the repression of reporter activity.

Conclusion

These findings implicate miR‐9–mediated suppression of MCPIP‐1 in the pathogenesis of OA via up‐regulation of IL‐6 expression in IL‐1β–stimulated human OA chondrocytes.
A relational altmetric? Network centrality onResearchGate as an indicator of scientific impact
Authors: Hoffmann Christian Pieter , Lutz Christoph , Meckel Miriam
Published: April 2015

Social media are becoming increasingly popular in scientific communication. A range of platforms, such as academic social networking sites (SNS), are geared specifically towards the academic community. Proponents of the altmetrics approach have pointed out that new media allow for new avenues of scientific impact assessment. Traditional impact measures based on bibliographic analysis have long been criticized for overlooking the relational dynamics of scientific impact. We therefore propose an application of social network analysis to researchers' interactions on an academic social networking site to generate potential new metrics of scientific impact. Based on a case study conducted among a sample ofSwiss management scholars, we analyze how centrality measures derived from the participants' interactions on the academicSNS ResearchGate relate to traditional, offline impact indicators. We find that platform engagement, seniority, and publication impact contribute to members' indegree and eigenvector centrality on the platform, but less so to closeness or betweenness centrality. We conclude that a relational approach based on social network analyses of academicSNS, while subject to platform‐specific dynamics, may add richness and differentiation to scientific impact assessment.