bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectral Identification in the Attogram Regime through Laser‐Induced Emission of Single Optically Trapped Nanoparticles in Air
Authors: Purohit Pablo , Fortes Francisco J. , Laserna J. Javier 
Published: September 2017

AbstractCurrent trends in nanoengineering are bringing along new structures of diverse chemical compositions that need to be meticulously defined in order to ensure their correct operation. Few methods can provide the sensitivity required to carry out measurements on individual nano‐objects without tedious sample pre‐treatment or data analysis. In the present study, we introduce a pathway for the elemental identification of single nanoparticles (NPs) that avoids suspension in liquid media by means of optical trapping and laser‐induced plasma spectroscopy. We demonstrate spectroscopic detection and identification of individual 25(±3.7) to 70(±10.5) nm in diameter Cu NPs stably trapped in air featuring masses down to 73±35 attograms. We found an increase in the absolute number of photons produced as size of the particles decreased; pointing towards a more efficient excitation of ensembles of only ca. 7×105 Cu atoms in the onset plasma.
Accessing Stable Magnesium Acyl Compounds: Reductive Cleavage of Esters by Magnesium(I) Dimers
Authors: Boutland Aaron J. , Lamsfus Carlos A. , Maitland Brant , Maron Laurent , Stasch Andreas , Jones Cameron 
Published: September 2017

AbstractThe first examples of magnesium acyls, [(Nacnac)Mg{μ‐C(Ph)O}(μ‐OR)Mg(Nacnac)] (R=Me, tBu or Ph; Nacnac=[HC(MeCNAr)2]−; Ar=C6H2Me3‐2,4,6 (MesNacnac), C6H3Et2‐2,6 (DepNacnac), C6H3iPr2‐2,6 (DipNacnac)), have been prepared by reductive cleavage of a series of esters using dimeric magnesium(I) reducing agents, [{(Nacnac)Mg}2]. Crystallographic studies reveal the complexes to be dimeric, being bridged by both phenyl‐acyl and alkoxide/aryloxide fragments. The crystal structures, combined with results of spectroscopic and computational studies suggest that the nature of the acyl ligands within these complexes should be viewed as lying somewhere between anionic umpolung acyl and oxo‐carbene. However, reactions of the acyl complexes with a variety of organic electrophiles did not provide evidence of umpolung acyl reactivity. A number of attempts to prepare alkoxide free magnesium acyls were carried out, and while these were unsuccessful, they did lead to unusual products, the crystallographic and spectroscopic details of which are discussed.
Is the R3Si Moiety in Metal–Silyl Complexes a Z ligand? An Answer from the Interaction Energy
Authors: Binh Dang Ho , Milovanović Milan , Puertes‐Mico Julia , Hamdaoui Mustapha , Zarić Snežana D. , Djukic Jean‐Pierre 
Published: September 2017

AbstractThe computation of metal–silyl interaction energies indicates the existence of situations in which the silyl group behaves as a Z‐type ligand according to the Green method of covalent‐bond classification. There is a scale of relative intrinsic silylicityΠ, defined as the ratio of the intrinsic silyl‐to‐triflate interaction energy of a silyltriflate as a reference compound relative to the silyl‐to‐metal interaction of given complex, that can reveal in a straightforward manner the propensity of SiR3groups to behave chemically as metal‐bound “silylium” ions, namely, [SiR3]+. Emblematic cases, either taken from the Cambridge Structural Database (CSD) or constructed for the purpose of this study, were also investigated from the viewpoints of extended transition‐state natural orbitals for chemical valence (ETS‐NOCV) and quantum theory of atoms in molecules (QTAIM) analyses. It is shown in the case of POBMUP—which is the iridium 1,3‐bis[(di‐tert‐butylphosphino)oxy]benzene (POCOP) complex isolated by Brookhart et al.—how slight variations of molecular charge and structure can drastically affect the relative intrinsic silylicity of the SiEt3group that is weakly bonded to the hydrido–iridium motif.
Total Synthesis and Biological Assessment of Novel Albicidins Discovered by Mass Spectrometric Networking
Authors: von Eckardstein Leonard , Petras Daniel , Dang Tam , Cociancich Stéphane , Sabri Souhir , Grätz Stefan , Kerwat Dennis , Seidel Maria , Pesic Alexander , Dorrestein Pieter C. , Royer Monique , Weston John B. , Süssmuth Roderich D. 
Published: September 2017

AbstractNatural products represent an important source of potential novel antimicrobial drug leads. Low production by microorganisms in cell culture often delays the structural elucidation or even prevents a timely discovery. Starting from the anti‐Gram‐negative antibacterial compound albicidin produced by Xanthomonas albilineans, we describe a bioactivity‐guided approach combined with non‐targeted tandem mass spectrometry and spectral (molecular) networking for the discovery of novel antimicrobial compounds. We report eight new natural albicidin derivatives, four of which bear a β‐methoxy cyanoalanine or β‐methoxy asparagine as the central α‐amino acid. We present the total synthesis of these albicidins, which facilitated the unambiguous determination of the (2 S,3 R)‐stereoconfiguration which is complemented by the assessment of the stereochemistry on antibacterial activity.
3D‐Druck: Chancen, Möglichkeiten, Risiken
Authors: Raddatz Lukas , Austerjost Jonas , Beutel Sascha 
Published: September 2017

ZusammenfassungDer 3D‐Druck wird als disruptive Technologie eingeschätzt, der die Art, wie Produkte hergestellt werden, stark verändern wird. Die neue Technologie unterscheidet sich fundamental von subtraktiven Verfahren, wie Fräsen, Schleifen oder formenden Verfahren wie Gießen, Pressen oder Biegen. Das herzustellende Objekt wird durch Hinzufügen oder Auftragen neuen Materials, also additiv, aufgebaut. Durch dieses generative Verfahren ergeben sich einige Vorteile gegenüber klassischen Methoden. Eine Reihe von Methoden und Materialien wurden entwickelt, andere stehen kurz vor der Marktreife.
Deuteration of Hyperpolarized 13C‐Labeled Zymonic Acid Enables Sensitivity‐Enhanced Dynamic MRI of pH
Authors: Hundshammer Christian , Düwel Stephan , Köcher Simone S. , Gersch Malte , Feuerecker Benedikt , Scheurer Christoph , Haase Axel , Glaser Steffen J. , Schwaiger Markus , Schilling Franz 
Published: September 2017

AbstractThe front cover artwork is provided by the groups of Dr. Christoph Scheurer, Prof. Axel Haase, Prof. Steffen J. Glaser, Prof. Markus Schwaiger and Dr. Franz Schilling from Technical University of Munich. The image shows deuterated zymonic acid, its pH‐sensitive 13C NMR resonances and examples of how this sensor can be used to non‐invasively image pH both in vitro and in vivo. Read the full text of the article at 10.1002/cphc.201700779.
Socioecological disparities in New Orleans following Hurricane Katrina
Authors: Lewis Joshua A. , Zipperer Wayne C. , Ernstson Henrik , Bernik Brittany , Hazen Rebecca , Elmqvist Thomas , Blum Michael J. 
Published: September 2017

AbstractDespite growing interest in urban resilience, remarkably little is known about vegetation dynamics in the aftermath of disasters. In this study, we examined the composition and structure of plant communities across New Orleans (Louisiana, USA) following catastrophic flooding triggered by levee failures during Hurricane Katrina in 2005. Focusing on eight neighborhoods that span a range of demographic and topographical conditions, we assessed whether plant communities in post‐Katrina New Orleans reflect flooding disturbance and post‐disaster landscape management policies. We then contextualized vegetation patterns and associated ecosystem services and disservices with census‐based demographic trends and in‐depth interviews to draw inferences about the drivers and outcomes of urban land abandonment in the aftermath of Hurricane Katrina. We found that areas subject to the greatest flooding disturbance exhibit the highest rates of vegetation response. Disturbance intensity and elevation, however, are relatively weak drivers of vegetation differences among the studied neighborhoods. Rather, we found that household income, racial demographics, and land abandonment are important drivers of vegetation community composition and structure across the city. Our findings indicate that resettlement and landscape management policies can mediate post‐flooding ecological outcomes and demonstrate that unmanaged, emergent vegetation on abandoned lands can be an environmental justice concern in underserved and historically marginalized communities.
Experimental study of aeolian sand ripples in a wind tunnel
Authors: Cheng Hong , Liu Chenchen , Li Jifeng , Liu Bo , Zheng Zhongquan , Zou Xueyong , Kang Liqiang , Fang Yi 
Published: September 2017

AbstractThe topographic parameters and propagation velocity of aeolian sand ripples reflect complex erosion, transport, and deposition processes of sand on the land surface. In this study, three Nikon cameras located in the windward (0–1 m), middle (4.5–5.5 m), and downwind (9–10 m) zones of a 10 m long sand bed are used to continuously record changes in sand ripples. Based on the data extracted from these images, this study reaches the following conclusions. (1) The initial formation and full development times of sand ripples over a flatbed decrease with wind velocity. (2) The wavelengths of full development sand ripples are approximately twice the wavelengths of initially formed sand ripples. Both wavelengths increase linearly with friction velocity. During the developing stage of sand ripples, the wavelength increases linearly with time. (3) The propagation velocity of full development sand ripples is approximately 0.6 times that of the initially formed sand ripples. The propagation velocity of both initial and full development of sand ripples increase as power functions with respect to friction velocity. During the developing stage of sand ripples, the propagation velocity decreases with time following a power law. These results provide new information for understanding the formation and evolution of aeolian sand ripples and help improve numerical simulations. Copyright © 2017 John Wiley & Sons, Ltd.
Security architecture and scheme of user‐centric ultra‐dense network (UUDN)
Authors: Chen Zhonglin , Chen Shanzhi , Xu Hui , Hu Bo 
Published: September 2017

AbstractUser‐centric ultra‐dense network (UUDN) is an inspiring approach of 5G, characterized by serving each user with dynamic access point group and designed to be independent of user's involvement. Contrast with traditional network‐centric cellular network, the UUDN architecture is based on the philosophy of network serving user. However, there is little systematic analysis of the security of UUDN, especially, the UUDN security architecture and key technologies challenges. After analysis of the main security challenges and requirements for the UUDN network architecture, we propose a new security architecture, details of its design, and the key security technologies for the UUDN security solutions and give performance evaluation for simulation. Finally, we discuss the future works in the fields of UUDN security.
Au Nanoparticles Modified Co/Titania Nanotubes as Electrocatalysts for Borohydride Oxidation
Authors: Balčiūnaitė A. , Tamašauskaitė‐Tamašiūnaitė L. , Santos D. M. F. , Zabielaitė A. , Jagminienė A. , Stankevičienė I. , Norkus E. 
Published: September 2017

AbstractGold‐cobalt catalysts were deposited on the surface of titania nanotubes (TiO2‐NTs) via galvanic displacement technique. The catalysts were characterized using field emission scanning electron microscopy, energy dispersive X‐ray spectroscopy and inductively coupled plasma optical emission spectroscopy. The electrocatalytic activity of the Au(Co)/TiO2‐NTs catalysts was examined in respect to the oxidation of BH4− ions in an alkaline media by cyclic voltammetry and chronoamperometry. It was found that the Au(Co)/TiO2‐NTs catalysts with Au loadings in the range of 10 up to 59 µgAu cm−2 had a higher activity compared to that of Co/TiO2‐NTs and bare Au. A direct NaBH4‐H2O2 single fuel cell was constructed with the Au(Co)/TiO2‐NTs catalysts as anode and Pt as the cathode. The fuel cell exhibited an open circuit voltage of ca. 1.9 V and peak power densities up to 217 mW cm−2 at 25 °C. The highest specific peak power density of 16.3 kW g−1Au was obtained when employing Au(Co)/TiO2‐NTs with the Au loading of 10 µgAu cm−2 as the anode catalyst.
Cops and docs: The challenges for ED physicians balancing the police, state laws, and EMTALA
Authors: Malcolm Kristin E. , Malcolm James G. , Wu Daniel T. , Spainhour Kevin A. , Race Kevin P. 
Published: September 2017

AbstractState laws are awash with discord concerning whether a police officer's request or court order necessarily obligates physicians to perform a body fluid analysis of an arrested, conscious, nonconsenting suspect. Police typically bring arrestees directly to the emergency department (ED), and federal courts have begun to wrestle with the implications of the Emergency Medical Treatment and Labor Act (EMTALA), which requires that anyone presenting to the ED be screened for treatment. Some state laws require health care providers to comply with any police request for lab analysis, while other states offer more leeway to physicians. Recent trends in federal case law interpreting EMTALA suggest that a medical screening exam is not required for patients brought by police specifically for a blood or urine sample unless either the arrestee requests medical care or a prudent observer would believe medical care was indicated. This article answers two questions: What happens when a police officer presents to the ED requesting service on behalf of an arrestee? What does EMTLA require of physicians in response? We survey current state statutes, review recent state and federal case law, describe example policies from various hospitals, and conclude with recommendations for hospital risk managers.
Patient‐specific in silico models can quantify primary implant stability in elderly human bone
Authors: Steiner Juri A. , Hofmann Urs A.T. , Christen Patrik , Favre Jean M. , Ferguson Stephen J. , van Lenthe G. Harry 
Published: September 2017

ABSTRACTSecure implant fixation is challenging in osteoporotic bone. Due to the high variability in inter‐ and intra‐patient bone quality, ex vivo mechanical testing of implants in bone is very material‐ and time‐consuming. Alternatively, in silico models could substantially reduce costs and speed up the design of novel implants if they had the capability to capture the intricate bone microstructure. Therefore, the aim of this study was to validate a micro‐finite element model of a multi‐screw fracture fixation system. Eight human cadaveric humerii were scanned using micro‐CT and mechanically tested to quantify bone stiffness. Osteotomy and fracture fixation were performed, followed by mechanical testing to quantify displacements at 12 different locations on the instrumented bone. For each experimental case, a micro‐finite element model was created. From the micro‐finite element analyses of the intact model, the patient‐specific bone tissue modulus was determined such that the simulated apparent stiffness matched the measured stiffness of the intact bone. Similarly, the tissue modulus of a small damage region around each screw was determined for the instrumented bone. For validation, all in silico models were rerun using averaged material properties, resulting in an average coefficient of determination of 0.89 ± 0.04 with a slope of 0.93 ± 0.19 and a mean absolute error of 43 ± 10 μm when correlating in silico marker displacements with the ex vivo test. In conclusion, we validated a patient‐specific computer model of an entire organ bone‐implant system at the tissue‐level at high resolution with excellent overall accuracy. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:954–962, 2018.
Recommendations for Low‐Grade Carotid Stenosis Follow‐up Based on a Single‐Institution Database
Authors: Bennett Garrett M. , Bluth Edward I. , Larson Michael L. , Luo Qingyang 
Published: September 2017

ObjectivesThe purpose of this study was to determine the incidences and rates of progression of varying degrees of carotid stenosis that do not require intervention according to the Asymptomatic Carotid Atherosclerosis Study, the European Carotid Surgery Trial, and the North American Symptomatic Carotid Endarterectomy Trial, and from this information, to provide evidence‐based recommendations for follow‐up imaging.MethodsA retrospective review was performed of all carotid ultrasound examinations performed at a single institution from January 1995 through April 2015. Examinations following endarterectomy or stenting were excluded. Stenoses were classified by a modification of the criteria of Bluth et al (Radiographics 1988; 8:487–506). A Kaplan‐Meier survival analysis was performed for stenosis progression and to provide information for follow‐up recommendations.ResultsMost of the carotid arteries (91.6%) reviewed for this study showed 1% to 39% stenosis. However, only 6.8% of carotid arteries with 1% to 39% stenosis progressed compared to 38.9% of carotid arteries with 40% to 59% stenosis. A table of evidence‐based follow‐up recommendations is provided for patients with varying levels of stenosis.ConclusionsWe provide evidence‐based follow‐up recommendations for patients who have low degrees of carotid stenosis. Different degrees of carotid stenosis progress at different rates and therefore should be followed at different intervals. Additionally, the most patients in our database showed 1% to 39% stenosis and did not have any follow‐up imaging, suggesting that carotid ultrasound may not be overused for low degrees of stenosis.
Establishing an Ultrasound Curriculum in Undergraduate Medical Education: How Much Time Does It Take?
Authors: Siegel‐Richman Yonaton , Kendall John 
Published: September 2017

ObjectivesOver the years, the use of ultrasound in the medical profession has become a common occurrence. As a result, many medical schools are considering an ultrasound curriculum for first‐ and second‐year medical students. The question posed by many of these programs is how much time and effort are required to establish such a curriculum. We at the University of Colorado School of Medicine sought to quantify the resources and time required.MethodsWe conducted a cohort study that analyzed the time spent teaching, as well as the types of instructors (eg, faculty, resident, and peer student) that contributed to our ultrasound curriculum. The study population consisted of instructors who participated in the curriculum during the 2014–2015 academic year. We analyzed the amount of time that facilitators spent teaching and tabulated these data using their specialty.ResultsOur data revealed that within an academic year, a combined total of 484 hours were spent teaching ultrasound to first‐ and second‐year medical students combined. A total of 6 days were required to teach ultrasound to first‐year medical students, and a total of 5 days were required for second‐year medical students. It required 1 instructor for every 8 students, and most the faculty who volunteered time were from the field of emergency medicine, followed by family medicine and radiology.ConclusionsWe describe the number of hours and instructors required to implement an ultrasound curriculum for undergraduate medical education.
Utility of Transfacial Dental Ultrasonography in Evaluation of Cystic Jaw Lesions
Authors: Gad Khaled , Ellabban Mohamed , Sciubba James 
Published: September 2017

ObjectivesPlain radiography has been widely used in dentistry. Because of the variability of the quality of equipment, radiographic technique, accuracy of interpretation, and radiation risk to the patients, the field is ripe for the introduction of other newer diagnostic modalities. In this report, we demonstrate the utility of ultrasonography in the diagnostic workup of cystic or cystlike lesions of the jaw.MethodsWe used a transfacial ultrasonographic scanning approach to examine 32 patients with clinical or radiographic presentation of a jaw cyst. Computed tomography and histopathologic analysis were used as the reference standards to confirm the findings.ResultsUltrasonography could establish the presence or absence of a lesion, erosion of the buccal cortical plate, and identification of associated soft tissue involvement in all cases (sensitivity and specificity, 100% and 100%, respectively; area under the receiver operating characteristic curve, 1.0; P < .001).ConclusionsOur observations revealed the usefulness of ultrasonography and demonstrated its potential value when introduced as a routine office‐based imaging method for dentistry.
Lung Ultrasonography in Patients With Idiopathic Pulmonary Fibrosis: Evaluation of a Simplified Protocol With High‐Resolution Computed Tomographic Correlation
Authors: Vassalou Evangelia E. , Raissaki Maria , Magkanas Eleftherios , Antoniou Katerina M. , Karantanas Apostolos H. 
Published: September 2017

ObjectivesTo compare a simplified ultrasonographic (US) protocol in 2 patient positions with the same‐positioned comprehensive US assessments and high‐resolution computed tomographic (CT) findings in patients with idiopathic pulmonary fibrosis.MethodsTwenty‐five consecutive patients with idiopathic pulmonary fibrosis were prospectively enrolled and examined in 2 sessions. During session 1, patients were examined with a US protocol including 56 lung intercostal spaces in supine/sitting (supine/sitting comprehensive protocol) and lateral decubitus (decubitus comprehensive protocol) positions. During session 2, patients were evaluated with a 16–intercostal space US protocol in sitting (sitting simplified protocol) and left/right decubitus (decubitus simplified protocol) positions. The 16 intercostal spaces were chosen according to the prevalence of idiopathic pulmonary fibrosis–related changes on high‐resolution CT. The sum of B‐lines counted in each intercostal space formed the US scores for all 4 US protocols: supine/sitting and decubitus comprehensive US scores and sitting and decubitus simplified US scores. High‐resolution CT–related Warrick scores (J Rheumatol 1991; 18:1520–1528) were compared to US scores. The duration of each protocol was recorded.ResultsA significant correlation was found between all US scores and Warrick scores and between simplified and corresponding comprehensive scores (P < .0001). Decubitus simplified US scores showed a slightly higher correlation with Warrick scores compared to sitting simplified US scores. Mean durations of decubitus and sitting simplified protocols were 4.76 and 6.20 minutes, respectively (P < .005).ConclusionsSimplified 16–intercostal space protocols correlated with comprehensive protocols and high‐resolution CT findings in patients with idiopathic pulmonary fibrosis. The 16–intercostal space simplified protocol in the lateral decubitus position correlated better with high‐resolution CT findings and was less time‐consuming compared to the sitting position.