bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidemiological, Clinical and Microbiological Characteristics of Patients with Post-Traumatic Osteomyelitis of Limb Fractures in Southwest China: A Hospital-Based Study
Authors: Peng Jiachen , Ren Youliang , He Wenbin , Li Zhengdao , Yang Jin , Liu Yi , Zheng Zhonghui , Kates Stephen L. , Schwarz Edward M. , Xie Chao , Xu Youjia
Published: May 2017

Abstract. Objective To determine the epidemiological, clinical and microbiological characteristics, of patients with post-traumatic osteomyelitis of extremity fractures, and provide evidence-based guidelines for early diagnosis and treatment, including empiric antibiotic therapy.Methods Human subject research was performed using institutional review board approved protocols. A retrospective chart review was conducted on 5,368 patients diagnosed with extremity traumatic fractures from January 1, 2012 to December 31, 2015, to identify osteomyelitis patients. Records from the Microbiology Department were reviewed, and patients with a positive wound culture, or bone biopsy culture, were selected for the study. Microbial suceptability was determined by the M-100-S22 protocol (Clinical & Laboratory Standards Institute® (CLSI) 2012 USA). Additional clinical information, including data on patients' baseline epidemiological, clinical, and microbiological records was collected from all available charts, and reviewed using a designed protocol.Results 84 (1.56%) patients were diagnosed with osteomyelitis based on a positive culture result. The most prevalent comorbidities in these patients were compartment syndrome, diabetes and hypertension. The most commonly involved infected site was the tibia-fibula (47.62%). 66 (78.57%) of these cases were monomicrobial, and 18 cases (21.43%) were polymicrobial. The infections were predominantly caused by Gram-positive bacteria (56, 53.85%). The most common Gram-positive bacteria were Staphylococcus aureus (39 cases, 37.50%) and S. epidermidis (6 cases, 5.77%), which were sensitive to ampicillin, synercid/ dalfopristin, linezolid, tigecycline, macrodantin, and vancomycin. S. aureus was the most common pathogen in both monomicrobial and polymicrobial cases. All 17 cases of MRSA infection were sensitive to Imezolid, ampicillin, synercid/ dalfopristin, linezolid, tigecycline, furadantin, piperacillin/yaz, rifampicin, and vancomycin, respectively. The most common Gram-negative bacteria were E. coli (16 cases, 15.38%) and Enterobacter cloacae (11 cases, 10.58%), which were sensitive to thienamycin.Conclusions In this study, the overall rate of post-traumatic osteomyelitis of limb fractures (1.56%) is lower than the national average rate (2.6-7.8%), for major medical centers in China. The main medical comorbidities were compartment syndrome, diabetes mellitus and hypertension. The most common infection was monomicrobial in lower extremities. S. aureus was the most common pathogen, which presented in 39 (37.50%) cases, and 17 of these (43.59%) were caused by MRSA. These findings can guide empiric antibiotic therapy in Southwest China for osteomyelitis in patients with traumatic limb fractures.
Metaphase chromosome structure is dynamically maintained by condensin I-directed DNA (de)catenation
Authors: Piskadlo Ewa , Tavares Alexandra , Oliveira Raquel A
Published: May 2017

Mitotic chromosome assembly remains a big mystery in biology. Condensin complexes are pivotal for chromosome architecture yet how they shape mitotic chromatin remains unknown. Using acute inactivation approaches and live-cell imaging in Drosophila embryos, we dissect the role of condensin I in the maintenance of mitotic chromosome structure with unprecedented temporal resolution. Removal of condensin I from pre-established chromosomes results in rapid disassembly of centromeric regions while most chromatin mass undergoes hyper-compaction. This is accompanied by drastic changes in the degree of sister chromatid intertwines. While wild-type metaphase chromosomes display residual levels of catenations, upon timely removal of condensin I, chromosomes present high levels of de novo Topoisomerase II (TopoII)-dependent re-entanglements, and complete failure in chromosome segregation. TopoII is thus capable of re-intertwining previously separated DNA molecules and condensin I continuously required to counteract this erroneous activity. We propose that maintenance of chromosome resolution is a highly dynamic bidirectional process.
Linguistic Precautions that to be Considered when Translating the Holy Quran
Authors: Gumaa Siddiek Ahmed
Published: May 2017

The present study is an attempt to raise some points that should be considered when translating the Quranic Text into English. We have looked into some samples of translations, selected from well known English translations of the Holy Quran and critically examined them. There were some errors in those translations, due to linguistic factors, owing to the differences between the Arabic and the English Language systems. Some errors were due to the cultural background of the translator which intentionally or unintentionally has affected the translation. Many samples were discussed and suggestions for corrections were made. Then further recommendations were given to be used as guidelines for similar future attempts. We concluded that the simulation of old words in drafting a translation does not fit with the English language as a target language. As this use of archaic stylistics would lead to further complications, which makes the language of translation look strange and complicated
Silence, an Eye of Knowledge
Authors: Aghamohammadi Mehdi
Published: May 2017

One of the conspicuous features of the twentieth-century West was silence. This idea could be supported by examining reflections of Ludwig Wittgenstein, Fritz Mauthner, John Cage, Samuel Beckett, Ihab Hassan, Franz Kafka, Wassily Kandinsky, Jean-Paul Sartre, Virginia Woolf, Wolfgang Iser, Jacques Derrida, and Pierre Macherey. To me, silence is not a mere theory, but rather a phenomenon from which we can get practical benefits. I believe silence is an eye, eye of knowledge. We can broaden our knowledge of the world through silence. To convey the idea that silence is an eye, I have concocted the word slence, where  has replaced the letter i and stands for the eye. This means knowledge can enable us to see, thereby acquiring knowledge of, what used to be invisible, and accordingly unknowable. In other words, through silence, we can achieve a certain type of literacy. I substantiate this claim by exploring the Horus myth, Ojo de Dios, John Cage’s 4' 33", the nature of Expressionist paintings, Hinduism, thoughts of Hermes Trismegistus and Ibn al-Arabi, and practices of Mohammad, the prophet of Islam.
Outlook on Student Retention in Higher Education University Reforms in Morocco
Authors: Mansouri Zoulal , Moumine Mohamed El Amine
Published: May 2017

High student attrition rates at university have become one of the most challenging issues in higher education worldwide in the last five decades. Moroccan universities are no exception. At-risk students drop out of studies for a plethora of reasons, and the attrition rate is increasing despite the efforts made in education reforms carried out since 1999. This article reviews the most important components of the higher education reforms that have been adopted in Moroccan higher education in their endeavor to enhance student retention in university. These components are chronologically reviewed, first in the National Charter of Education and Training (NCET) launched in 1999, second in the Emergency Plan conducted in 2009-2012, and finally in the latest Strategic Vision of Reform 2015-2030. It is concluded that more efforts are necessary to strike a balance between quantity and quality in terms of student retention in university education.
Teachers and Learners’ Perceptions of Applying Translation as a Method, Strategy, or Technique in an Iranian EFL Setting
Authors: Mollaei Fatemeh , Taghinezhad Ali , Sadighi Firooz
Published: May 2017

It has been found that translation is an efficient means to teach/learn grammar, syntax, and lexis of a foreign language. Meanwhile, translation is good for beginners who do not still enjoy the critical level of proficiency in their target language for expression.  This study was conducted to examine the teachers and learners’ perceptions of employing translation in the foreign language classroom; i.e., the effects, merits, demerits, limitations, as well as its use as a method, strategy or technique. Both quantitative and qualitative methods were used to collect and analyze the data from graduate and undergraduate learners (n=56) and teachers (n=44), male and female, who responded to two questionnaires. Additionally, only the teachers were interviewed to gain richer insight into their perceptions and attitudes. According to the results of independent samples t-test, there was no significant difference between teachers and learners’ attitude to applying translation as a method, strategy, or technique in learning a foreign language.  Based on the interview results, some teachers believed that employing translation in the foreign language context was helpful but not constantly. They claimed that translation was only effective in teaching vocabulary and grammar apart from leaners’ proficiency level as it can clarify meaning. But some other teachers noted that mother tongue would interfere with learning foreign language; they considered translation as a time-consuming activity through which students cannot capture the exact meaning.
Students and Teachers’ Perceptions into the Viability of Mobile Technology Implementation to Support Language Learning for First Year Business Students in a Middle Eastern University
Authors: Tayan Bilal M.
Published: May 2017

Advancements in technology have enabled us to learn, adapt and exploit our skills and knowledge in new ways.  Appreciating the potential of technology may yet give growth and enrich the process of language education, particularly through a student-centred mobile learning environment. Consequently, a constructivist approach to learning can create tremendous possibilities for both language learners and teachers. By exploiting the affordances of mobile technologies and the Internet, a new platform of learning or Mobile Assisted Language Learning (MALL) can be realised, through which learners truly learn to learn.  Yet, while many of today’s language institutions and places of learning have begun to understand the potential presented by mobile technology as a tool and resource to content and language development, apprehension may still exist among educational practitioners, learners and senior management.  Such apprehension may stem from a lack of understanding in fully appreciating the opportunities and affordances posed by MALL in creating a support structure to learning and teaching excellence. This may be particularly true within developing countries such as those found in the Middle East. Consequently, set in a Saudi university context, the purpose of this study is to investigate learners’ and teachers’ perceptions towards the proposed implementation of a MALL programme, while exploring whether the promotion of mobile technologies could assist learning and become a viable support structure in teaching English as a second language.  Interviews were conducted with three English instructors who teach on the first year Business English programme at the university. The study also analysed 191 student participants who completed a Likert scale questionnaire designed to explore their mobile learning experiences, attitudes and perceptions towards the proposed MALL programme in their educational context. The findings from the student questionnaire and teacher interviews generally highlight positive attitudes and a receptiveness towards mobile learning implementation. This is perhaps due to the possibility of new pedagogical scaffoldings being created through MALL in their learning/teaching environment. The results further highlighted opportunities MALL presented in facilitating communication and affording learners greater motivation to engage in independent learning, thus facilitating learner autonomy and allowing for greater collaboration within a richer learner environment. However, while analysis highlighted a proposed MALL implementation could be a useful tool to support language acquisition for ESP/ESL learners (English for Specific Purposes/English as a Second Language), technical issues, network sustainability and comprehensive training were still significant factors of concern.
Benefits of Exercise Training For Computer-Based Staff: A Meta Analyses
Authors: Mohammed Mothna , Layth Naji Farah
Published: May 2017

Background: Office workers sit down to work for approximately 8 hours a day and, as a result, many of them do not have enough time for any form of physical exercise. This can lead to musculoskeletal discomforts, especially low back pain and recently, many researchers focused on home/office-based exercise training for prevention/treatment of low back pain among this population. Objective: This Meta analyses paper tried to discuss about the latest suggested exercises for the office workers based on the mechanisms and theories behind low back pain among office workers. Method: In this Meta analyses the author tried to collect relevant papers which were published previously on the subject. Google Scholar, Scopus, and PubMed were used as sources to find the articles. Only articles that were published using the same methodology, including office workers, musculoskeletal discomforts, low back pain, and exercise training keywords, were selected. Studies that failed to report sufficient sample statistics, or lacked a substantial review of past academic scholarship and/or clear methodologies, were excluded. Results: Limited evidence regarding the prevention of, and treatment methods for, musculoskeletal discomfort, especially those in the low back, among office workers, is available. The findings showed that training exercises had a significant effect (p<0.05) on low back pain discomfort scores and decreased pain levels in response to office-based exercise training. Conclusion: Office-based exercise training can affect pain/discomfort scores among office workers through positive effects on flexibility and strength of muscles. As such, it should be suggested to occupational therapists as a practical way for the treatment/prevention of low back pain among office workers.
Ambient noise tomography across Mount St. Helens using a dense seismic array
Authors: Wang Yadong , Lin Fan‐Chi , Schmandt Brandon , Farrell Jamie
Published: May 2017

We investigated upper crustal structure with data from a dense seismic array deployed around Mount St. Helens for 2 weeks in the summer of 2014. Interstation cross correlations of ambient seismic noise data from the array were obtained, and clear fundamental mode Rayleigh waves were observed between 2.5 and 5 s periods. In addition, higher‐mode signals were observed around 2 s period. Frequency‐time analysis was applied to measure fundamental mode Rayleigh wave phase velocities, which were used to invert for 2‐D phase velocity maps. An azimuth‐dependent traveltime correction was implemented to mitigate potential biases introduced due to an inhomogeneous noise source distribution. Reliable phase velocity maps were only obtained between 3 and 4 s periods due to limitations imposed by the array aperture and higher‐mode contamination. The phase velocity tomography results, which are sensitive to structure shallower than 6 km depth, reveal an ~10–15% low‐velocity anomaly centered beneath the volcanic edifice and peripheral high‐velocity anomalies that likely correspond to cooled igneous intrusions. We suggest that the low‐velocity anomaly reflects the high‐porosity mixture of lava and ash deposits near the surface of the edifice, a highly fractured magmatic conduit and hydrothermal system beneath the volcano, and possibly a small contribution from silicate melt.
Valles Marineris tectonic and volcanic history inferred from dikes in eastern Coprates Chasma
Authors: Brustel C. , Flahaut J. , Hauber E. , Fueten F. , Quantin C. , Stesky R. , Davies G. R.
Published: May 2017

Magmatic dikes have been proposed to have weakened and fractured the crust, allowing the formation of Valles Marineris. Hence, dikes were studied in the region of eastern Coprates Chasma in an area that includes a major transition between Hesperian‐aged volcanic deposits in the western walls and pristine Noachian crust in the eastern walls. Over a hundred dikes were identified. Dike widths are 13 m on average. Estimation of magma eruption rates are comparable with previous estimates for Hesperian lava flows on Mars (105 to 106 m3 s−1). Dikes dips range from 55° to 90°; orientations record two distinct main tectonic stress fields (90° and 70°) different from the Chasmata. Dikes striking 90° are only observed at elevations below 1500 m. Dikes striking 70° are observed at elevation below 0 m and are therefore considered older. However, linear features are also observed on the late Noachian/early Hesperian surrounding plateaus and could be related to the 70° dike group. In the western part of our study area, dikes (~10% of the total amount of dikes mapped) strike 110, subparallel to Valles Marineris, and suggest a relationship between dike emplacement and graben formation. The presence of preexisting faults in the two directions (90° and 70°) could explain the shape of eastern Valles Marineris and chaotic terrains, which have a different general orientation than the Valles Marineris main rift. Our results suggest a complex relationship between dike emplacement and the formation of Valles Marineris.
A process‐based insight into nonstationarity of the probability distribution of annual runoff
Authors: Jiang Cong , Xiong Lihua , Guo Shenglian , Xia Jun , Xu Chong‐Yu
Published: May 2017

In this paper, a process‐based analytical derivation approach is proposed to perform a nonstationary analysis for annual runoff distribution by taking into account the information of nonstationarities in both hydrological inputs and runoff generation processes. Under the Budyko hypothesis, annual runoff is simulated as a formulation of hydrological inputs (annual precipitation and potential evaporation) using an annual runoff model based on the Fu equation with a parameter w accounting for the runoff generation processes. The nonstationarity of the runoff generation process is captured by the dynamic Fu‐equation parameter w. Then the multivariate joint probability distribution among the hydrological inputs, the Fu‐equation parameter w, and the runoff model error k is constructed based on the nonstationary analysis for both the hydrological inputs and w. Finally, the annual runoff distribution is derived by integrating the multivariate joint probability density function. The derived distribution by the process‐based analytical derivation approach performs well in fitting distributions of the annual runoffs from both the Yangtze River and Yellow River, China. For most study watersheds in these two basins, the derived annual runoff distributions are found to be nonstationary, due to the nonstationarities in hydrological inputs (mainly potential evaporation) or the Fu‐equation parameter w.
Evaluating the role of watershed properties in long‐term water balance through a Budyko equation based on two‐stage partitioning of precipitation
Authors: Tang Yin , Wang Dingbao
Published: May 2017

In this paper, a four‐parameter Budyko equation is derived for mean annual water balance by applying the proportionality relationship to a two‐stage partitioning of precipitation. The four dimensionless parameters include the Horton index (H, defined as the ratio of evaporation to total wetting) and λ (the ratio of initial evaporation to total wetting) for slow runoff, and β (the ratio of initial wetting to total wetting) and γ (the ratio of total wetting to its potential) for fast runoff. The derived four‐parameter equation balances model parsimony and representation of dominant hydrologic processes and provides a framework to disentangle the roles of climate variability, vegetation, soil, and topography on long‐term water balance in gauged watersheds. The four parameters are determined for 165 watersheds by using observations of precipitation, potential evaporation, streamflow, and soil properties. Based on the principal component regression analysis, average time interval between rainfall events, slope, normalized difference vegetation index, and wilting point are identified as the dominant controlling factors on H and λ; saturated hydraulic conductivity and the difference between field capacity and residual soil moisture are identified as the dominant controlling factors on β; and γ is controlled by effective soil water storage capacity, frequency of rainfall events, and climate seasonality. The combination of four‐parameter Budyko equation and the principal component regression equations provides a model to assess the long‐term responses of evaporation and runoff to climate and watershed property changes in ungauged watersheds.
On the seasonal variability of the Canary Current and the Atlantic Meridional Overturning Circulation
Authors: Vélez‐Belchí Pedro , Pérez‐Hernández M. Dolores , Casanova‐Masjoan María , Cana Luis , Hernández‐Guerra Alonso
Published: May 2017

The Atlantic Meridional Overturning Circulation (AMOC) is continually monitored along 26°N by the RAPID‐MOCHA array. Measurements from this array show a 6.7 Sv seasonal cycle for the AMOC, with a 5.9 Sv contribution from the upper mid‐ocean. Recent studies argue that the dynamics of the eastern Atlantic is the main driver for this seasonal cycle; specifically, Rossby waves excited south of the Canary Islands. Using inverse modeling, hydrographic, mooring, and altimetry data, we describe the seasonal cycle of the ocean mass transport around the Canary Islands and at the eastern boundary, under the influence of the African slope, where eastern component of the RAPID‐MOCHA array is situated. We find a seasonal cycle of −4.1 ± 0.5 Sv for the oceanic region of the Canary Current, and +3.7 ± 0.4 Sv at the eastern boundary. This seasonal cycle along the eastern boundary is in agreement with the seasonal cycle of the AMOC that requires the lowest contribution to the transport in the upper mid‐ocean to occur in fall. However, we demonstrate that the linear Rossby wave model used previously to explain the seasonal cycle of the AMOC is not robust, since it is extremely sensitive to the choice of the zonal range of the wind stress curl and produces the same results with a Rossby wave speed of zero. We demonstrate that the seasonal cycle of the eastern boundary is due to the recirculation of the Canary Current and to the seasonal cycle of the poleward flow that characterizes the eastern boundaries of the oceans.
Fluoride resistance capacity in mammalian cells involves complex global gene expression changes
Authors: Ran Shujun , Sun Ning , Liu Yun , Zhang Wu , Li Yiming , Wei Limin , Wang Jia , Liu Bin
Published: May 2017

Fluorine is a bone‐seeking element ubiquitously present in the environment and widely used in many oral hygiene products. In humans, excessive intake of fluoride may cause dental and skeletal fluorosis. However, endemic fluorosis does not appear to develop in a proportion of individuals exposed to the same levels of fluoride. The mechanisms by which mammalian cells resist fluoride are still unclear. In this study, we developed strains of mouse L‐929 cells resistant to different levels of fluoride. High‐throughput RNA‐sequencing analyses of the fluoride‐resistant L‐929 cells indicated that massive changes in global gene expression occurred, compared with the wild‐type L‐929 cells. The main biological processes and functions changed were associated with the extracellular region and matrix, response to stress, receptor binding, and signal transduction. This indicated that high doses of fluoride not only exerted stress on L‐929 cells but also induced functional pathways that helped them adapt to the presence of fluoride or to expel it. These data should prove useful in identifying cellular processes or transporters/channels that play central roles in adaptation to or expulsion of fluoride in humans.
Effects of Long‐Term Etanercept Treatment on Clinical Outcomes and Objective Signs of Inflammation in Early Nonradiographic Axial Spondyloarthritis: 104‐Week Results From a Randomized, Placebo‐Controlled Study
Authors: Dougados Maxime , van der Heijde Désirée , Sieper Joachim , Braun Jürgen , Citera Gustavo , Lenaerts Jan , van den Bosch Filip , Wei James Cheng‐Chung , Pedersen Ron , Bonin Randi , Jones Heather , Marshall Lisa , Logeart Isabelle , Vlahos Bonnie , Bukowski Jack F. , Maksymowych Walter P.
Published: May 2017

Objective

To evaluate the long‐term clinical and imaging efficacy of etanercept in patients with early, active nonradiographic axial spondyloarthritis (SpA).

Methods

Adult patients who satisfied the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial SpA (but not the modified New York radiographic criteria), with symptom duration >3 months to <5 years, and who were unresponsive to ≥2 nonsteroidal antirheumatic drugs (NSAIDs) received double‐blind etanercept 50 mg/week or placebo for 12 weeks, followed by open‐label etanercept 50 mg/week to week 104. Clinical, magnetic resonance imaging (MRI; Spondyloarthritis Research Consortium of Canada [SPARCC] scores), and safety outcomes at 104 weeks were analyzed.

Results

Of 215 randomized patients (etanercept: n = 106; placebo: n = 109), 205 entered the study (etanercept/etanercept: n = 100; placebo/etanercept: n = 105) and 169 completed the open‐label period (etanercept/etanercept: n = 83; placebo/etanercept: n = 86). At week 104, 61 of 81 (75%), 49 of 81 (61%), 48 of 80 (60%), and 57 of 81 (70%) patients who received etanercept throughout the trial achieved ASAS20, ASAS40, Ankylosing Spondylitis Disease Activity Score (ASDAS) inactive disease, and Bath Ankylosing Spondylitis Disease Activity Index criteria for 50% improvement (BASDAI 50) scores, respectively (observed). From baseline to week 104, continued improvements in clinical outcomes (ASDAS–C‐reactive protein: −1.5 and −1.7; BASDAI: −3.3 and −3.8 [last observation carried forward]), and SPARCC MRI scores (sacroiliac joint: −6.0 and −3.4; spinal: −2.1 and −0.8 [observed]) were seen in patients receiving etanercept/etanercept and placebo/etanercept. During the study, 8% in the etanercept/etanercept group and 7% in the placebo/etanercept group had serious adverse events; no new safety signals were seen.

Conclusion

Patients with early, active nonradiographic axial SpA and an inadequate response to at least 2 NSAIDs demonstrated improvement in clinical and imaging outcomes that were sustained through 104 weeks of etanercept treatment.
Impact Testing of Polymer‐filled Auxetics Using Split Hopkinson Pressure Bar
Authors: Fíla Tomáš , Zlámal Petr , Jiroušek Ondřej , Falta Jan , Koudelka Petr , Kytýř Daniel , Doktor Tomáš , Valach Jaroslav
Published: May 2017

In this paper, impact testing of auxetic structures filled with strain rate sensitive material is presented. Two dimensional missing rib, 2D re‐entrant honeycomb, and 3D re‐entrant honeycomb lattices are investigated. Structures are divided into three groups according to type of filling: no filling, low expansion polyurethane foam, and ordnance gelatine. Samples from each group are tested under quasi‐static loading and dynamic compression using Split Hopkinson Pressure Bar. Digital image correlation is used for assessment of in‐plane displacement and strain fields. Ratios between quasi‐static and dynamic results for plateau stresses and specific energy absorption in the plateau are calculated. It is found out that not only the manufactured structures, but also the wrought material exhibit strain rate dependent properties. Evaluation of influence of filling on mechanical properties shows that polyurethane increases specific absorbed energy by a factor of 1.05–1.4, whereas the effect of gelatine leads to increase of only 5–10%. Analysis of the Poisson's function reveals influence of filling on achievable (negative) values of Poisson's ratio, when compared to unfilled specimens. The results for the Poisson's function yielded apparently different values as the assessed minima of quasi‐static Poisson's ratio in small deformations are constrained by a factor of 15.
Prediction of New Structure, Phase Transition, Mechanical, and Thermodynamic Properties of Nb3Si
Authors: Pan Yong
Published: May 2017

Although Nb‐based silicides are promising high temperature materials, the high temperature application of Nb‐based silicides is markedly influenced by Nb3Si phase. However, the structure and relevant properties of Nb3Si are not completely clear. To solve these problems, in this paper, we systematically investigate the structure, elastic properties, brittle or ductile behavior, and thermodynamic properties of Nb3Si based on the first‐principle calculations. Additionally, phase transition of Nb3Si under high pressure is studied in detail. The calculated results show that two new Nb3Si phases: Br3Sm‐type (space group: Cmcm, No.63) and Sc3In‐type (space group: P63/mmc, No.194) are predicted. Although Nb3Si with Ta3Si‐type is the most stable structure, pressure leads to phase transition from Ta3Si‐type structure to V3Si‐type structure at ≈60 GPa. We further demonstrate that Nb3Si is a ductile material. Importantly, we find that the heat capacity of Nb3Si with tetragonal structure is about 190 J (mol K)−1, which is two times larger than that of other structures.
Transferable Organic Semiconductor Nanosheets for Application in Electronic Devices
Authors: Noever Simon J. , Eder Michael , del Giudice Fabio , Martin Jan , Werkmeister Franz X. , Hallwig Stefan , Fischer Stefan , Seeck Oliver , Weber Nils‐Eike , Liewald Clemens , Keilmann Fritz , Turchanin Andrey , Nickel Bert
Published: May 2017

A method has been developed to stabilize and transfer nanofilms of functional organic semiconductors. The method is based on crosslinking of their topmost layers by low energy electron irradiation. The films can then be detached from their original substrates and subsequently deposited onto new solid or holey substrates retaining their structural integrity. Grazing incidence X‐ray diffraction, X‐ray specular reflectivity, and UV–Vis spectroscopy measurements reveal that the electron irradiation of ≈50 nm thick pentacene films results in crosslinking of their only topmost ≈5 nm (3–4 monolayers), whereas the deeper pentacene layers preserve their pristine crystallinity. The electronic performance of the transferred pentacene nanosheets in bottom contact field‐effect devices is studied and it is found that they are fully functional and demonstrate superior charge injection properties in comparison to the pentacene films directly grown on the contact structures by vapor deposition. The new approach paves the way to integration of the organic semiconductor nanofilms on substrates unfavorable for their direct growth as well as to their implementation in hybrid devices with unusual geometries, e.g., in devices incorporating free‐standing sheets.
Hot‐Wire Assisted ALD: A Study Powered by In Situ Spectroscopic Ellipsometry
Authors: Kovalgin Alexey Y. , Yang Mengdi , Banerjee Sourish , Apaydin Ramazan O. , Aarnink Antonius A. I. , Kinge Sachin , Wolters Rob A. M.
Published: May 2017

Hot‐wire assisted atomic layer deposition (HWALD) is a novel energy‐enhancement technique. HWALD enables formation of reactive species (radicals) at low substrate temperatures, without the generation of energetic ions and UV photons as by plasma. This approach employs a hot wire (tungsten filament) that is heated up to a temperature in the range of 1300–2000 °C to dissociate precursor molecules. HWALD has the potential to overcome certain limitations of plasma‐assisted processes. This work investigates the ability of a heated tungsten filament to catalytically crack molecular hydrogen or ammonia into atomic hydrogen and nitrogen‐containing radicals. The generation of these radicals and their successful delivery to the wafer (substrate) surface are experimentally confirmed by dedicated tellurium‐etching and silicon‐nitridation experiments. It further reports on deposition of low‐resistivity oxygen‐free tungsten films by using HWALD, as well as on the effect of hot‐wire‐generated nitrogen radicals and atomic hydrogen in deposition of aluminum nitride and boron nitride films. In parallel, this work provides important illustrative examples of using in situ real‐time monitoring of deposition and etching processes, together with extracting a variety of film properties, by spectroscopic ellipsometry technique.
Manipulating III–V Nanowire Transistor Performance via Surface Decoration of Metal‐Oxide Nanoparticles
Authors: Wang Fengyun , Yip SenPo , Dong Guofa , Xiu Fei , Song Longfei , Yang Zaixing , Li Dapan , Hung Tak Fu , Han Ning , Ho Johnny C.
Published: May 2017

Recently, III–V semiconductor nanowires (NWs) are widely investigated as field‐effect transistors (FETs) for high‐performance electronics, optoelectronic, and others; nevertheless, effective control in their device performances, especially the threshold voltage is still not well attained, which can potentially limit their practical uses for technological applications. This study reports a simple but highly reliable metal‐oxide nanoparticle (NP) surface decoration approach onto the device channel in order to manipulate electrical characteristics of III–V NWFETs, such as the threshold voltage and transistor operation, through the manipulation of free electrons in the NW channel (i.e., InAs, InP, and In0.7Ga0.3As) via depositing various metal‐oxide NPs with different work functions. Without any passivation layer, this decoration approach can yield the stable NW device characteristics in ambient. Notably, the versatility of our decoration scheme has also been illustrated through the realization of high‐performance enhancement‐mode InAs NW‐paralleled‐arrayed devices as well as the configuration of highly efficient InAs NW NMOS inverters, comprising of both depletion and enhancement mode devices. All these results further elucidate the technological potential of this decoration approach for future high‐performance, low‐power nanoelectronic device fabrication, and circuit integration.
Photonic Spring‐Like Shell Templated from Cholesteric Liquid Crystal Prepared by Microfluidics
Authors: Kim Jong‐Gyu , Park Soo‐Young
Published: May 2017

Solid‐state photonic shells are prepared with a reactive cholesteric liquid crystal (CLC) mixture that consists of a reactive mesogen mixture and the nonreactive chiral dopant. The shells are prepared using a microfluidic glass‐capillary chip, followed by UV‐curing and extraction of the chiral dopant. CLC shells with relatively uniform thickness are produced by density matching and annealing. The produced solid‐state CLC (CLCsolid) shells show a good reversible swelling/shrinkage behavior that is dependent on the solvent quality and temperature. The swelling or shrinkage simultaneously induces a color change in the reflection point at the center and in the cross‐communication dots. Encapsulation and release from the CLCsolid‐shell cores are successfully tested with Rhodamine 6G by controlling the solvent quality and temperature. Nanosized Fe3O4 particles encapsulated in the core give the CLCsolid shells mobility, and are assembled at the desired location using a magnet. The color changes caused by external stimuli can be applied to new types of small hollow sensors that will respond to changes in temperature, and solvent quality. The shells can be used, for example, as a chemical container that can be triggered by temperature to release for a delayed reaction, or in a security patch controlled by tuneable multicolored patterns.
Challenges of Mechanochemistry: Is In Situ Real‐Time Quantitative Phase Analysis Always Reliable? A Case Study of Organic Salt Formation
Authors: Michalchuk Adam A. L. , Tumanov Ivan A. , Konar Sumit , Kimber Simon A. J. , Pulham Colin R. , Boldyreva Elena V.
Published: May 2017

Mechanochemical methods offer unprecedented academic and industrial opportunities for solvent‐free synthesis of novel materials. The need to study mechanochemical mechanisms is growing, and has led to the development of real‐time in situ X‐ray powder diffraction techniques (RI‐XRPD). However, despite the power of RI‐XRPD methods, there remain immense challenges. In the present contribution, many of these challenges are highlighted, and their effect on the interpretation of RI‐XRPD data considered. A novel data processing technique is introduced for RI‐XRPD, through which the solvent‐free mechanochemical synthesis of an organic salt is followed as a case study. These are compared to ex situ studies, where notable differences are observed. The process is monitored over a range of milling frequencies, and a nonlinear correlation between milling parameters and reaction rate is observed. Kinetic analysis of RI‐XRPD allows, for the first time, observation of a mechanistic shift over the course of mechanical treatment, resulting from time evolving conditions within the mechanoreactor.
High Efficiency Photocatalytic Water Splitting Using 2D α‐Fe2O3/g‐C3N4 Z‐Scheme Catalysts
Authors: She Xiaojie , Wu Jingjie , Xu Hui , Zhong Jun , Wang Yan , Song Yanhua , Nie Kaiqi , Liu Yang , Yang Yingchao , Rodrigues Marco‐Tulio F. , Vajtai Robert , Lou Jun , Du Daolin , Li Huaming , Ajayan Pulickel M.
Published: May 2017

Photocatalysis is the most promising method for achieving artificial photosynthesis, but a bottleneck is encountered in finding materials that could efficiently promote the water splitting reaction. The nontoxicity, low cost, and versatility of photocatalysts make them especially attractive for this application. This study demonstrates that small amounts of α‐Fe2O3 nanosheets can actively promote exfoliation of g‐C3N4, producing 2D hybrid that exhibits tight interfaces and an all‐solid‐state Z‐scheme junction. These nanostructured hybrids present a high H2 evolution rate >3 × 104 µmol g‐1 h‐1 and external quantum efficiency of 44.35% at λ = 420 nm, the highest value so far reported among the family of g‐C3N4 photocatalysts. Besides effectively suppressing the recombination of electron–hole pairs, this Z‐scheme junction also exhibits activity toward overall water splitting without any sacrificial donor. The proposed synthetic route for controlled production of 2D g‐C3N4‐based structures provides a scalable alternative toward the development of highly efficient and active photocatalysts.
Investigation of interfacial debonding between steel wire and adhesive resin
Authors: Zhang Jie , Shi Jianfeng , Xu Ping
Published: May 2017

Plastic pipes reinforced by cross helically wound steel wire (PSPs) have been widely used in the transportation of petroleum, natural gas, municipal water, and so on. With the applications of PSPs in high‐temperature and high‐pressure environments, the problem of PSP joints has begun to appear. The bulging failure of PSP joints is the main failure mode, and steel–polymer interfacial debonding is the major factor causing bulging failure. Thus, it is crucial to understand the failure criterion of steel–polymer interfacial debonding. In this study, pull‐out tests were carried out at different temperatures and loading rates. A finite element (FE) model was developed on the basis of the cohesive element. We proposed that the key parameter for the bugling failure of PSPs was the shear stress of the steel–polymer interface. We assumed that when the shear stress exceeded the shear strength, this led to the degradation of the interface. By iteratively presetting the shear strength and calculation of the FE model, the FE results were verified with experimental results. We found that the shear stress of the front part of the FE model first reached its peak value; its interface began to degrade, and then, the shear stress decreased. The peak value of the shear stress moved toward the end part of the FE model, and the shear strength could be obtained. Finally, the effects of the temperature and failure time on the shear strength were investigated. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45064.
Effect of the sodium dodecyl sulfate/monomer ratio on the network structure of hydrophobic association hydrogels with adjustable mechanical properties
Authors: Lv Xue , Sun Shulin , Yang Haidong , Gao Ge , Liu Fengqi
Published: May 2017

The study of gel‐network structure is not as extensive as the study of the application of hydrogels. However, the distribution of the inner structure is crucial for designing hydrogels with tunable mechanical properties to meet certain kinds of demands. In this study, a series of hydrophobic association hydrogels (HA‐gels) were synthesized by free‐radical micellar copolymerization in a sodium dodecyl sulfate (SDS) surfactant solution. The hydrophobic monomer was palmityl alcohol poly(oxyethylene acrylate) (AEO–AC), which is an ecofriendly alternative to the traditional octyl phenol poly(oxyethylene acrylate). Interestingly, we found that the molar ratio [or ratio point (R)] of SDS to AEO–AC played a key role in tuning the mechanical properties. All series HA‐gels denominated a similar down–up–down tendency with increasing R, and the best R is 3. This result was consistent with the microscopic network structure number of the hydrophobic monomer (NH = 21–24), and this indicated that each hydrophobic monomer associated three SDS monomers in its internal networks. The resulting AEO–AC–acrylamide gels exhibited the best mechanical strength (yield maximum broken stress = 218 kPa) and the maximum effective crosslink density. Moreover, the relationship between the network structure and the mechanical properties of the HA‐gels was investigated with various Rs. Two different interaction effects of distribution between SDS and AEO–AC are discussed in detail. The HA‐gels exhibited self‐healing properties and maintained their shape in water over 160 days. The results indicate that changing R is an effective method for tuning the mechanical properties of HA‐gels as a type of prospective biomedical material. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45196.
Self‐assembled acrylamide‐based copolymer/surfactant with high‐temperature resistance for enhanced oil recovery
Authors: Gou Shaohua , Zhang Qin , Ma Yongtao , Li Shiwei , Zhou Yanting , Fei Yumei , Wu Yuanpeng , He Zhenyan
Published: May 2017

In this article, we report on a water‐soluble self‐assembled system that consisted of an acrylamide (AM)‐based copolymer and a nonionic surfactant for enhancing oil recovery. The copolymer, denoted as poly(acrylamide–acrylic acid–diallyl dimethyl ammonium chloride–N‐allyl benzamide) (PMADN), was synthesized with AM, acrylic acid, diallyl dimethyl ammonium chloride, and N‐allyl benzamide, and the nonionic surfactant was Tween 40. The results of our investigation of the ratio of the copolymer to Tween 40 show that the optimal concentrations of PMADN and Tween 40 were 1000 and 500 mg/L, respectively. When it was heated to 115–120 °C for 15 min, the apparent viscosity of the self‐assembly system increased 19.2%, and its viscosity retention rate remained at 11.6% under 1000 s−1. When the system was dissolved in 12,000 mg/L NaCl, 2000 mg/L CaCl2, and 2000 mg/L MgCl2 solutions, the viscosity retention rates were 22.3%, 12.1%, and 17.6%, respectively. In addition, a 2000 mg/L PMADN–Tween 40 solution dramatically enhanced the oil recovery up to 13.4%. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45202.
A Prospective Study of the Impact of Current Poverty, History of Poverty, and Exiting Poverty on Accumulation of Disease Damage in Systemic Lupus Erythematosus
Authors: Yelin Edward , Trupin Laura , Yazdany Jinoos
Published: May 2017

Objective

To estimate the effect of current poverty, number of years in poverty, and exiting poverty on disease damage accumulation in systemic lupus erythematosus (SLE).

Methods

For this study, 783 patients with SLE were followed up from 2003 to 2015 through annual structured interviews. Respondents were categorized in each year by whether they had a household income of ≤125% of the US federal poverty level. Linear and logistic regression analyses were used to assess the impact of poverty in 2009, number of years in poverty between 2003 and 2009, and permanent exits from poverty as of 2009 on the extent of disease damage (according to the Brief Index of Lupus Damage [BILD] score) or accumulation of a clinically meaningful increase in disease damage (defined as a minimum 2‐point increase in the BILD damage score) by 2015.

Results

After adjustment for sociodemographic features, health care characteristics, and health behaviors, poverty in 2009 was associated with an increased level of accumulated disease damage in 2015 (mean difference in BILD damage score between poor and non‐poor 0.62 points, 95% confidence interval [95% CI] 0.25–0.98) and increased odds of a clinically important increase in damage (odds ratio [OR] 1.67, 95% CI 0.98–2.85). Being poor in every year between 2003 and 2009 was associated with greater damage (mean change in BILD score 2.45, 95% CI 1.88–3.01) than being poor for one‐half or more of those years (mean change in BILD score 1.45, 95% CI 0.97–1.93), for fewer than one‐half of those years (mean change in BILD score 1.49, 95% CI 1.10–1.88), or for none of those years (mean change in BILD score 1.34, 95% CI 1.20–1.49). Those exiting poverty permanently had similar increases in disease damage (mean change in BILD score 1.30, 95% CI 0.90–1.69) as those who were never in poverty (mean change in BILD score 1.36, 95% CI 1.23–1.50) but much less damage than those who remained in poverty (mean change in BILD score 1.98, 95% CI 1.59–2.38).

Conclusion

The effects of current poverty, “dose” of poverty, and exiting poverty suggest that poverty plays a critical role in the accumulation of damage in patients with SLE.
Assimilating GPM hydrometeor retrievals in HWRF: choice of observation operators
Authors: Wu Ting‐Chi , Zupanski Milija
Published: May 2017

A recent study investigated the capability to assimilate hydrometeor retrievals in the National Oceanic and Atmospheric Administration (NOAA) Hurricane Weather Research and Forecasting (HWRF) system. Hydrometeor retrievals were obtained from a hurricane‐specific retrieval that utilizes data from the Global Measurement Mission Microwave Imager. Data assimilation system used in HWRF is the hybrid ensemble‐variational Gridpoint Statistical Interpolation (GSI). As a first attempt to assimilate hydrometeor retrievals in HWRF, observation operators for solid and liquid integrated water content were developed using the GSI standard control variables, such as temperature, pressure, and specific humidity, under the assumption that all water vapor in excess of saturation is condensed out. To improve the usefulness of assimilating hydrometeor retrievals in HWRF, this study extends this previous work by introducing new observation operators that (1) directly use hydrometeor species estimated from HWRF microphysics and (2) include total cloud condensate as a control variable. Hurricane Gonzalo (2014) was used to examine the performance of the old and new observation operators on HWRF analysis and subsequent forecasts with three pairs of experiments. Results suggest that when new observation operators are used the analysis is an improved fit to observations and realistic adjustments to control variables are evident as seen in analysis increment. In addition, the forecasts also indicate some improvements in hurricane intensity.