bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient fixation and conversion of CO2 into dimethyl carbonate catalyzed by an imidazolium containing tri-cationic ionic liquid/super base system
Authors: Chaugule Avinash A. , Tamboli Ashif H. , Kim Hern
Published: April 2016

The synthesis route used to prepare dimethyl carbonate from CO2 and methanol is a most attractive route from a green chemistry point of view.
Electrochemically self-doped hierarchical TiO2 nanotube arrays for enhanced visible-light photoelectrochemical performance: an experimental and computational study
Authors: Yang Yue , Liao Jianjun , Li Yanfang , Cao Xiankun , Li Na , Wang Caizhuang , Lin Shiwei
Published: April 2016

A two-step electrochemical anodization method was used to prepare typical hierarchical top-ring/bottom-tube TiO2 nanotube arrays (TNTAs).
Three-dimensional highly branched Pd3Cu alloy multipods as enhanced electrocatalysts for formic acid oxidation
Authors: Fan Yang , Zhang Yan , Li Huamin , Shen Wenmei , Wang Jiaoli , Wei Mengmeng
Published: April 2016

Pd3Cu alloy multipods with three-dimensional highly branched morphology were synthesized, which presents enhanced catalytic performance toward formic acid oxidation.
A modified Frenkel approach for viscometric prediction of binary and multicomponent liquid mixtures
Authors: Dey Ranjan , Saini Akanksha , Hingorani Hardik
Published: April 2016

Comparison of absolute average percentage deviations (AAPD) values of modified Frenkel with different approaches for binary, ternary and quaternary systems.
The inhibition of cytochrome P450 2A13-catalyzed NNK metabolism by NAT, NAB and nicotine
Authors: Liu Xingyu , Zhang Jie , Zhang Chen , Yang Bicheng , Wang Limeng , Zhou Jun
Published: April 2016

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is considered to be the most carcinogenic of the four tobacco-specific nitrosamines (TSNAs) and it needs to be metabolically activated to exert its carcinogenic effect on humans.
Fully differential switching topology for mm‐wave dual‐mode LO‐distribution circuitry
Authors: Hamidian A. , Barbin S.E. , Boeck G.
Published: April 2016

A novel switching circuitry for fully differential millimetre‐wave applications is presented. The structure of the proposed switching architecture includes 90 nm CMOS transistors and a distributed‐active‐transformer. To minimise the chip size, an innovative topology based on lumped components is investigated, resulting a total size of <0.025 mm2. The performance of the designed switch is validated within a dual‐mode local oscillator‐distribution circuitry of a V‐band transceiver.
Investigation of design methodology for non‐rare‐earth variable‐flux switched‐flux memory machines
Authors: Yang Hui , Lin Heyun , Zhuang Erxing , Fang Shuhua , Huang Yunkai
Published: April 2016

This study presents a design methodology for a newly emerged switched‐flux memory machine with low‐cost non‐rare‐earth. The adoption of aluminium–nickel–cobalt magnet with low‐coercive force enables the flexible air‐gap flux control without unnecessary excitation loss. Hence, the excellent flux variability and high‐efficiency sustainability within a wide‐speed range can be achieved. Since geometric constraints exist among major parameters, a design trade‐off should be established to facilitate the feasible design. Therefore, a simplified magnetic circuit is modelled to analytically determine the relationships among various parameters, and the generic design considerations including magnet grade selection and stator/rotor‐pole combination are addressed, respectively. The influences of design parameters on back‐electromotive force and torque capability are evaluated to aid the performance optimisation. A machine prototype is then fabricated to experimentally validate the theoretical analyses.
Optimum tie switches allocation and DG placement based on maximisation of system loadability using discrete artificial bee colony algorithm
Authors: Aman Muhammad Mohsin , Jasmon Ghauth B. , Mokhlis Hazlee , Bakar Ab Halim Abu
Published: April 2016

Due to an exponential increase in load demand and lack of capital resources to improve the existing transmission line infrastructure, power utilities are focusing on methods to increase the efficiency and loadability of existing infrastructure. This study presents a new approach for simultaneous optimum distributed generation (DG) placement and optimum tie‐switch allocation based on maximisation of system loadability using discrete artificial bee colony algorithm. The proposed algorithm is tested on 16‐Bus, 33‐Bus and 69‐Bus radial distribution test system. The obtained results show that with simultaneous optimum DG placement and optimum tie‐switch allocation, better results are achieved rather than solving two problems independently. Further it was also found that the proposed method has improved the efficiency of the system in terms of maximisation of system loadability, reduction in power system losses, improving the kVA margin to maximum loadability and voltage quality improvement.
How to solve the transmission expansion planning problem faster: acceleration techniques applied to Benders’ decomposition
Authors: Lumbreras Sara , Ramos Andrés
Published: April 2016

Transmission expansion planning is receiving an increased attention, primarily due to the large‐scale grid upgrades that will be necessary to accommodate renewable generation or to increase cross‐border capacity. The intermittency of renewables, and the uncertainties inherent to long‐term planning, makes it advisable to use solution methods that cope with uncertainty explicitly. Stochastic Optimisation and, in particular, Benders’ decomposition, is one of the most widely applied approaches in this context. However, large‐scale planning can still present computational problems. Several techniques have been proposed to accelerate Benders’ decomposition. However, they appear disperse and usually without a clear application scope. Most of them have not been applied to TEP yet. This study presents a comprehensive view on TEP applied to Benders’ decomposition and the techniques available to accelerate its resolution, together with semi‐relaxed cuts, a technique proposed in the previous work by Lumbreras and Ramos in 2013. Then, for three case studies based on IEEE test cases, the most promising of these techniques are implemented and their effectiveness is compared. All test cases could save about 50% of solution time using simple and easy‐to‐implement techniques, showing that there is an interest in using these approaches in academic and practical TEP applications.
Analysis of frequently over‐threshold subsynchronous oscillation and its suppression by subsynchronous oscillation dynamic suppressor
Authors: Xiao Xiangning , Luo Chao , Zhang Jian , Yang Wenchao , Wu Yunsheng
Published: April 2016

To mitigate the frequently over‐threshold subsynchronous oscillation (FOSSO) phenomenon which occurred in Hulunbuir power plant in the northeast of China, a novel equipment based on voltage source converter (VSC), named subsynchronous oscillation dynamic suppressor (SSODS) is developed and installed. In this study, the root cause of FOSSO is revealed by analysing the response characteristics of the system. Then the control strategy of the developed SSODS is presented. Damping characteristics of SSODS are analysed by the complex torque coefficient method. To verify the effectiveness of the control strategy and the physical controller of VSC, as well as provide initially optimised controller parameters for the field tests, real‐time closed‐loop tests are carried out. A novel method of torsional modal frequency measure for onsite commissioning test is proposed. The operation and field verification test of SSODS is introduced, and test results demonstrate that SSODS can mitigate the new SSO phenomenon dramatically, proving the validity of SSODS.
Congestion mitigation using UPFC
Authors: K. Arun Kumar Reddy , Singh Shiv P.
Published: April 2016

Transmission congestion is one of the most challenging issues in operation of deregulated electricity markets of today. This study investigates into benefit of unified power flow controller (UPFC) as a viable solution to the problem of congestion management. A comprehensive load flow model for the UPFC is presented which has the capability to control active and reactive powers and voltage magnitude simultaneously. This study discusses about two different approaches for determination of suitable location of UPFC. One of them is sensitivity‐based approach and the other is pricing‐based method. Reduction in total system losses has been taken as objective in sensitivity‐based approach. Furthermore, sensitivity of total system losses with respect to control parameters of UPFC have been evaluated using two different methods. A pricing‐based approach which makes use of locational marginal price difference and congestion rent for determination of suitable location of UPFC. Minimisation of cost of rescheduling subjected to system operating constraints is the objective to be met for congestion management. Interior point method, a mathematical tool for non‐linear optimisation, is used to obtain the solution of above‐mentioned problem.
Robust wide‐area impedance‐based fault location method utilising LAV estimator
Authors: Hosseini Seyed Ali , Sadeh Javad , Mozafari Babak
Published: April 2016

This study presents a robust method for detecting the location of fault in the wide‐area power networks considering the limited number of synchronised phasor measurement units. In this manner, by employing the positive‐sequence components in the governing equations at pre‐ and post‐fault occurrence, the fault location (FL) problem is formulated as an optimisation problem. The constructed objective function consists of two terms that are dependent on the voltage and current changes so that each of them can be employed in the optimisation procedure, alone. Various factors, such as cyber attacks and measurement device failures, may lead to induce the bad data to the measurement set, and thus the results will not be valid. Automatic detection and elimination of erroneous measurements, contaminated with gross errors, from the measurement set, will be carried out utilising the least absolute value (LAV) estimator. This is the most important property of the LAV estimator, in which the bad measurements will be screened and suppressed during the iterative optimisation. An algorithm based on LAV estimation is presented to identify the FL. The efficiency of the proposed method is not affected by fault type and resistance. The method is tested on IEEE 14‐bus, 57‐bus and 118‐bus case studies and simulation results indicate the accuracy of the developed technique.
Thyroid Hormone in the Pediatric Intensive Care Unit
Authors: Radman Monique , Portman Michael
Published: April 2016

Thyroid hormones are key factors necessary for normal growth and development in children. They have tight control of metabolic rate and, as a result, frequently become altered in their synthesis and/or release during times of stress or critical illness. Disturbances in thyroid hormone homeostasis have been well described in several pathologic states, including sepsis/septic shock, renal failure, trauma, severe malnutrition, and following cardiopulmonary bypass. Specifically, a decrease in serum triiodothyronine (T3) and a concomitant increase in reverse triiodothyronine (rT3) levels are the most common changes observed. It is further noteworthy that serum thyroxine (T4), rT3, and T3 levels change in relation to severity of nonthyroidal illness. Many past investigators have speculated that these alterations are a teleological adaptation to severe illness and the increased metabolic demands that critical illness bears. However, this paradigm has been challenged through multiple avenues and has lost support over the past few years. Instead the “inflammatory hypothesis” has emerged implicating a cytokine surge as the mediator of thyroid hormone disruption. Overall, the demonstrated association between low thyroid hormone levels and poor clinical outcomes, the beneficial effects of thyroid hormone supplementation in multiple critically ill subpopulations, and the well-established safety profile of T3 therapy make thyroid hormone supplementation in the pediatric ICU worth consideration.
Hybrid Instrumentation in Lumbar Spinal Fusion
Authors: Obid Peter , Danyali Reza , Kueny Rebecca , Huber Gerd , Reichl Michael , Richter Alexander , Niemeyer Thomas , Morlock Michael , Püschel Klaus , Übeyli Hüseyin
Published: April 2016

Study Design

Ex vivo human cadaveric study.

Objective

The development or progression of adjacent segment disease (ASD) after spine stabilization and fusion is a major problem in spine surgery. Apart from optimal balancing of the sagittal profile, dynamic instrumentation is often suggested to prevent or impede ASD. Hybrid instrumentation is used to gain stabilization while allowing motion to avoid hypermobility in the adjacent segment. In this biomechanical study, the effects of two different hybrid instrumentations on human cadaver spines were evaluated and compared with a rigid instrumentation.

Methods

Eighteen human cadaver spines (T11–L5) were subdivided into three groups: rigid, dynamic, and hook comprising six spines each. Clinical parameters and initial mechanical characteristics were consistent among groups. All specimens received rigid fixation from L3–L5 followed by application of a free bending load of extension and flexion. The range of motion (ROM) for every segment was evaluated. For the rigid group, further rigid fixation from L1–L5 was applied. A dynamic Elaspine system (Spinelab AG, Winterthur, Switzerland) was applied from L1 to L3 for the dynamic group, and the hook group was instrumented with additional laminar hooks at L1–L3. ROM was then evaluated again.

Results

There was no significant difference in ROM among the three instrumentation techniques.

Conclusion

Based on this data, the intended advantage of a hybrid or dynamic instrumentation might not be achieved.
Orbital spaces in the divide-expand-consolidate coupled cluster method
Authors: Ettenhuber Patrick , Baudin Pablo , Kjærgaard Thomas , Jørgensen Poul , Kristensen Kasper
Published: April 2016

The theoretical foundation for solving coupled cluster singles and doubles (CCSD) amplitude equations to a desired precision in terms of independent fragment calculations using restricted local orbital spaces is reinvestigated with focus on the individual error sources. Four different error sources are identified theoretically and numerically and it is demonstrated that, for practical purposes, local orbital spaces for CCSD calculations can be identified from calculations at the MP2 level. The development establishes a solid theoretical foundation for local CCSD calculations for the independent fragments, and thus for divide–expand–consolidate coupled cluster calculations for large molecular systems with rigorous error control. Based on this theoretical foundation, we have developed an algorithm for determining the orbital spaces needed for obtaining the single fragment energies to a requested precision and numerically demonstrated the robustness and precision of this algorithm.
Optimization of liquid jet system for laser-induced breakdown spectroscopy analysis
Authors: Skočovská Katarína , Novotný Jan , Prochazka David , Pořízka Pavel , Novotný Karel , Kaiser Jozef
Published: April 2016

A complex optimization of geometrical and temporal parameters of a jet system (developed in Laser-induced breakdown spectroscopy (LIBS) laboratory of Brno University of Technology) for direct elemental analysis of samples in a liquid state of matter using LIBS was carried out. First, the peristaltic pump was synchronized with the flashlamp of the ablation laser, which reduced variation of the ablated sample amount. Also, the fluctuation of the laser ray angle incident on the jet surface was diminished. Such synchronization reduced signal standard deviations and thus increased repeatability of the measurements. Then, laser energy and distance of the focusing lens from the sample were optimized. The gate delay time and the gate width were optimized for single pulse (SP) experiments; the gate delay time and the inter-pulse delay were optimized for the use of double pulse (DP) variant. Results were assessed according to the highest signal to noise ratios and the lowest relative standard deviations of the signal. The sensitivity of the single pulse and the double pulse LIBS for the detection of heavy metals traces, copper (Cu i at 324.754 nm) and lead (Pb i at 405.781 nm), in aqueous solution of copper (ii) sulfate and lead (ii) acetate, was estimated in terms of limits of detection (LODs). As a result, sensitivity improvement of DP LIBS system was observed, the LOD of Cu obtained with DP was calculated 40% lower than LOD gained from SP technique.
Solid polystyrene and deuterated polystyrene light output response to fast neutrons
Authors: Simpson R. , Danly C. , Glebov V. Yu. , Hurlbut C. , Merrill F. E. , Volegov P. L. , Wilde C.
Published: April 2016

The Neutron Imaging System has proven to be an important diagnostic in studying DT implosion characteristics at the National Ignition Facility. The current system depends on a polystyrene scintillating fiber array, which detects fusion neutrons born in the DT hotspot as well as neutrons that have scattered to lower energies in the surrounding cold fuel. Increasing neutron yields at NIF, as well as a desire to resolve three-dimensional information about the fuel assembly, have provided the impetus to build and install two additional next-generation neutron imaging systems. We are currently investigating a novel neutron imaging system that will utilize a deuterated polystyrene (CD) fiber array instead of standard hydrogen-based polystyrene (CH). Studies of deuterated xylene or deuterated benzene liquid scintillator show an improvement in imaging resolution by a factor of two [L. Disdier et al., Rev. Sci. Instrum. 75, 2134 (2004)], but also a reduction in light output [V. Bildstein et al., Nucl. Instrum. Methods Phys. Res., Sect. A 729, 188 (2013); M. I. Ojaruega, Ph.D. thesis, University of Michigan, 2009; M. T. Febbraro, Ph.D. thesis, University of Michigan, 2014] as compared to standard plastic. Tests of the relative light output of deuterated polystyrene and standard polystyrene were completed using 14 MeV fusion neutrons generated through implosions of deuterium-tritium filled capsules at the OMEGA laser facility. In addition, we collected data of the relative response of these two scintillators to a wide energy range of neutrons (1-800 MeV) at the Weapons Neutrons Research Facility. Results of these measurements are presented.
Ion beam synthesis of ZrCxOy nanoparticles in cubic zirconia
Authors: Velişa Gihan , Mylonas Stamatis , Trocellier Patrick , Thomé Lionel , Debelle Aurélien , Vaubaillon Sylvain , Bachelet Cyril
Published: April 2016

{110}-oriented yttria-stabilized zirconia single crystals have been implanted with low-energy C ions in an axial direction, at room temperature and at 550 °C. Room temperature ion implantation generated a damage layer that contains the expected dislocation loop clusters. Strikingly, the high temperature implantation produced zirconium oxycarbide nanoparticles (ZrCxOy) at a shallow depth in the yttria-stabilized cubic zirconia crystal, with a diameter in the range of 4–10 nm. Moreover, in the high concentration region of implanted C ions, between 100 and 150 nm below the surface, a number of large precipitates, up to 20 nm, were observed.
Nonextensivity effect on radio-wave transmission in plasma sheath
Authors: Mousavi A. , Esfandiari-Kalejahi A. , Akbari-Moghanjoughi M.
Published: April 2016

In this paper, new theoretical findings on the application of magnetic field in effective transmission of electromagnetic (EM) waves through a plasma sheath around a hypersonic vehicle are reported. The results are obtained by assuming the plasma sheath to consist of nonextensive electrons and thermal ions. The expressions for the electric field and effective collision frequency are derived analytically in the framework of nonextensive statistics. Examination of the reflection, transmission, and absorption coefficients regarding the strength of the ambient magnetic field shows the significance of q-nonextensive parameter effect on these entities. For small values of the magnetic field, the transmission coefficient increases to unity only in the range of −1<q<1. It is also found that the EM wave transmission through the nonextensive plasma sheath can take place using lower magnetic field strengths in the presence of superthermal electrons compared with that of Maxwellian ones. It is observed that superthermal electrons, with nonextensive parameter, q < 1, play a dominant role in overcoming the radio blackout for hypersonic flights.
Enhanced actuation of nanocrystalline diamond microelectromechanical disk resonators with AlN layers
Authors: Yoshikawa Taro , Reusch Markus , Holc Katarzyna , Iankov Dimitre , Zuerbig Verena , Zukauskaite Agne , Nebel Christoph E. , Ambacher Oliver , Lebedev Vadim
Published: April 2016

A great potential of the use of aluminum nitride (AlN) to enhance the actuation of nanocrystalline diamond (NCD) microelectromechanical system disk resonators is revealed. A disk resonator with a unimorph (AlN/NCD) structure is fabricated by depositing a c-axis oriented AlN on a capacitive NCD disk resonator. The unimorph resonator is piezoelectrically actuated with flexural whispering gallery modes with a relatively large electrode gap spacing, i.e., the spacing which is greater than 1 μm, although this is not possible for the capacitive NCD disk resonator. This result is explained by a finite element method simulation where the piezoelectric actuation turns out to be more effective than the capacitive actuation when the electrode gap spacing is >0.8 μm. The simulation also shows that the electrode gap spacing required for the capacitive actuation to be more effective than the piezoelectric actuation exponentially decreases when the resonator dimension is scaled down for higher frequency operations. Our study indicates that the use of AlN is promising to decrease impedance levels of NCD disk resonators especially for their higher frequency operations.
Thermal radiative near field transport between vanadium dioxide and silicon oxide across the metal insulator transition
Authors: Menges F. , Dittberner M. , Novotny L. , Passarello D. , Parkin S. S. P. , Spieser M. , Riel H. , Gotsmann B.
Published: April 2016

The thermal radiative near field transport between vanadium dioxide and silicon oxide at submicron distances is expected to exhibit a strong dependence on the state of vanadium dioxide which undergoes a metal-insulator transition near room temperature. We report the measurement of near field thermal transport between a heated silicon oxide micro-sphere and a vanadium dioxide thin film on a titanium oxide (rutile) substrate. The temperatures of the 15 nm vanadium dioxide thin film varied to be below and above the metal-insulator-transition, and the sphere temperatures were varied in a range between 100 and 200 °C. The measurements were performed using a vacuum-based scanning thermal microscope with a cantilevered resistive thermal sensor. We observe a thermal conductivity per unit area between the sphere and the film with a distance dependence following a power law trend and a conductance contrast larger than 2 for the two different phase states of the film.
When undone science stifles innovation: the case of the Tasmanian devil cancer
Authors: Warren Josephine
Published: April 2016

Gaps or deficits in knowledge present opportunities for new and innovative research, but when studies are undone much is lost. The concept of ‘undone science’ can be understood within related concepts, including ignorance, nescience, non-knowledge and the chilling effect. The Tasmanian devil cancer, devil facial tumour disease (DFTD), is a new and novel cancer, potentially providing many opportunities for innovative research. The contagious cancer hypothesis for DFTD is also novel. In the research it has sponsored, the Tasmanian government elected to follow this pathway, neglecting an alternative plausible hypothesis that toxins in the devils’ environment may have played a role in the initiation or progression of the cancer. The studies were not viewed as opportunities to fill gaps in devil cancer knowledge, and remain undone.
Development and usage of wiki-based software for point-of-care emergency medical information
Authors: Donaldson Ross I , Ostermayer Daniel G , Banuelos Rosa , Singh Manpreet
Published: April 2016

Objective To describe the creation and evaluate the usage of the first medical wiki linked to dedicated mobile applications.

Methods With the support of multiple current and past contributors, we developed an emergency medicine wiki linked to offline mobile applications (WikEM) in 2009. First deployment was at the Harbor-UCLA Medical Center emergency medicine residency program, with the wiki later opened to public use. To evaluate the project, we performed a post hoc analysis of system use and surveyed 8 years of current and past residents. Outcomes included website and application analytics, as well as survey analysis by composite response categories.

Results Over the 6-year period of this project, the wiki grew to over 7250 pages and 45 500 edits. The website receives more than 85 000 user sessions per month, with over 150 million page views to date. There have been over 200 000 installs of the mobile applications, progressing to produce over 5000 mobile sessions daily. Of potential survey respondents, 87.7% (107) completed the Internet-based survey. Among those who contributed to the wiki, 74.6% reported that it benefited their understanding of core emergency medicine content. Of program graduates, the vast majority reported use of the wiki as a resource after residency (93.8%) along with improvement in clinical efficiency (89.7%). Residents reported higher use and a more favorable opinion of wiki usefulness compared to graduates ( P < .001).

Conclusions A wiki paired with mobile applications is beneficial for resident education and useful in post-residency clinical practice.
Insulin and oral anti-hyperglycaemic agents in critical illness
Authors: van Hooijdonk Roosmarijn T. M. , Schultz Marcus J.
Published: April 2016

Dysglycaemia is frequently seen in the intensive care unit (ICU). Hyperglycaemia, hypoglycaemia and glycaemic variability are all independently associated with mortality and morbidity in critically-ill patients. It is common practice to treat hypergycaemia in these patients, while at the same time preventing hypoglycaemia and glycaemic variability. Insulin infusion is preferred over oral anti–hyperglycaemic agents for glucose control in the ICU because of the highly unpredictable biological availability of oral anti-hyperglycaemic agents during critical illness. Many oral anti–hyperglycaemic agents are relatively contraindicated in critically-ill patients. Intravenously-administered insulin has a predictable effect on blood glucose levels, in particular because of its short half-life. Notably, effective and safe insulin titration requires frequent blood glucose measurements, a dedicated lumen of a central venous catheter for infusion of insulin, an accurate syringe pump, and trained nurses for delicate adoptions of the infusion rate. Insulin infusion increases the risk of hypoglycaemia, which should be prevented at all times. In addition, precautions should be taken against overcorrection of hypoglycaemia, using only small amounts of glucose. Whether glycaemic variability can be kept minimal is uncertain. Use of continuous glucose measuring devices has the potential to improve glycaemic control in critically-ill patients.
Management of pleural effusion and haemothorax
Authors: Chiumello Davide , Coppola Silvia
Published: April 2016

The main goal of management of pleural effusion is to provide symptomatic relief removing fluid from the pleural space. The options depend on type, stage, and underlying disease. The first diagnostic instrument is the chest radiography, while ultrasound can be very useful to guide thoracentesis. Pleural effusion can be a transudate or an exudate. Generally, a transudate is uncomplicated effusion treated by medical therapy, while an exudative effusion is considered complicated effusion and should be managed by drainage. Refractory non-malignant effusions can be transudative (congestive heart failure, cirrhosis, nephrosis) or exudative (pancreatitis, connective tissue disease, endocrine dysfunction), and the management options include repeated therapeutic thoracentesis, in-dwelling pleural catheter for intermittent external drainage, pleuroperitoneal shunts for internal drainage, or surgical pleurectomy. Parapneumonic pleural effusions can be classified as complicated when there is persistent bacterial invasion of the pleural space, uncomplicated and empyema with specific indications for pleural fluid drainage. Malignancy is the most common cause of exudative pleural effusions in patients aged >60 years and the decision to treat depends upon the presence of symptoms and the underlying tumour type. Options include in-dwelling pleural catheter drainage, pleurodesis, pleurectomy, and pleuroperitoneal shunt. Haemothorax needs to be differentiated from a haemorrhagic pleural effusion and, when suspected, the essential management is intercostal drainage. It achieves two objectives to drain the pleural space allowing expansion of the lung and to allow assessment of rates of blood loss to evaluate the need for emergency or urgent thoracotomy.
Antibiotic resistance in the ICU
Authors: Edgeworth Jonathan
Published: April 2016

The two objectives of ensuring early appropriate antimicrobial treatment for septic patients on the intensive care unit (ICU), and limiting emergence and spread of antimicrobial resistance are both complicated and potentially conflicting. Increasingly unpredictable resistance, particularly amongst Gram-negative bacteria, through both local selection and transmission, and importation of globally successful resistant clones encourages the use of broad-spectrum empiric antimicrobials for septic patients, including in combination. This may lead to a vicious cycle whereby increasing antibiotic use increases resistance, which in turn leads to higher levels of inappropriate therapy. In response, the multi-disciplinary ICU-team implements infection prevention and control, and antimicrobial stewardship programmes. Antimicrobial stewardship programmes provide interventions and guidance to optimize appropriate therapy,whilelimiting unnecessary use through a variety of measures. The development of rapid molecular testing for bacterial identification and antimicrobial susceptibility prediction could potentially bring useful microbiological information to the bedside at the time of therapeutic decision making.
Adult orbital wall fracture repair
Authors: Burnham Richard , Bridle Christopher
Published: April 2016

The orbit, consisting of the outer frame and inner pyramidal vault, provides support and protection for the orbital contents. Any disruption to this structure may result in the loss of normal binocular vision. We present a case of a fracture of the orbital floor and medial orbital wall. The chapter discusses current thinking on the paradigm shift from ‘safe distances’ to the use of anatomical structures within the orbit to guide reconstruction. Emphasis is placed on the early diagnosis of orbital compartment syndrome that represents a maxillofacial emergency and requires expedient surgical treatment. The close liaison with ophthalmology and orthoptic colleagues is also vital in order to achieve optimum outcomes.
High-energy ballistic injuries to the face
Authors: Breeze John , Parmar Sat , Monaghan Andrew
Published: April 2016

High-velocity bullets damage the facial skeleton both as a result of their direct tissue crushing effect as well as high-energy transfer. This produces wounds that may be unfamiliar to the practice of many maxillofacial surgeons. We describe the case of a UK soldier hit in the face by a high-velocity bullet resulting in a complex mandibular fracture with overlying soft tissue maceration. Following securing of the airway by surgical tracheostomy, his mandible was reduced and stabilized using an external fixator. Subsequent rehabilitation involved an iliac bone graft to enable implant placement followed by vestibuloplasty to improve vestibular contour. These types of battle wounds are unusual in civilian practice and we believe this case illustrates some of the diagnostic and treatment decisions required to produce a successful outcome.
Low-energy explosive fragmentation injuries to the neck and face
Authors: Breeze John , Gibbons Andrew , Sharp Ian
Published: April 2016

Explosively propelled fragments cause significant damage to unprotected areas of the body, producing wounds that may be unfamiliar to the practice of many maxillofacial surgeons. We describe the case of a UK soldier who stood on an improvised explosive device. He sustained traumatic amputation of both legs and multiple fragments penetrating the face and neck with a partial avulsive injury to the right side of his mandible. Following serial debridement of the wounds both in Afghanistan and back in the UK, a custom-made reconstruction plate was used to support the comminuted mandible. A bone graft was contraindicated due to his limb injuries and therefore distraction osteogenesis was used to generate bone for subsequent implant placement. These types of battle wounds are unusual in civilian practice and we believe this case illustrates some of the diagnostic and treatment decisions required to produce a successful outcome.
Management of the Wilkes Grade III temporomandibular joint
Authors: Mihalache Grigore , Messahel Ahmed
Published: April 2016

Temporomandibular joint (TMJ) dysfunction is a broad and multifactorial topic. It occurs more commonly in men than women with the average age of presentation being around 30 years of age. Internal derangement of the TMJ has been very eloquently classified by Wilkes according to the degree of clinical, radiological, and surgical abnormality. We present a case of a 28-year-old female with a 12-month history of pain and clicking from her right TMJ. Cross-sectional imaging demonstrated anterior displacement of the disc with reduction. This chapter predominantly describes non-surgical management of this disease process. However, acknowledgement is given to those cases where surgical intervention is required.
Sagittal split osteotomy for the removal of a lower third molar
Authors: Idle Matthew , Dover Stephen
Published: April 2016

In the UK the National Institute for Health and Care Excellence has provided comprehensive guidance for removal of third molars. These have been compiled to prevent unnecessary morbidity to the patient in the form of inferior alveolar and lingual nerve injuries. We present a case of a 48-year-old male with recurrent episodes of pericoronitis around the lower eight necessitating its removal. An orthopantomogram and computed tomogram demonstrated that the tooth was deeply buried in the ramus of the mandible and in close proximity to the inferior alveolar nerve. Thus a sagittal split osteotomy was performed to allow removal of this source of infection. Despite this being an unconventional technique oral and maxillofacial surgeons should be familiar with this as a potential treatment option.
Is there an exoplanet in the Solar system?
Authors: Mustill Alexander J. , Raymond Sean N. , Davies Melvyn B.
Published: April 2016

We investigate the prospects for the capture of the proposed Planet 9 from other stars in the Sun's birth cluster. Any capture scenario must satisfy three conditions: the encounter must be more distant than ∼150 au to avoid perturbing the Kuiper belt; the other star must have a wide-orbit planet (a ≳ 100 au); the planet must be captured on to an appropriate orbit to sculpt the orbital distribution of wide-orbit Solar system bodies. Here we use N-body simulations to show that these criteria may be simultaneously satisfied. In a few per cent of slow close encounters in a cluster, bodies are captured on to heliocentric, Planet 9-like orbits. During the ∼100 Myr cluster phase, many stars are likely to host planets on highly eccentric orbits with apastron distances beyond 100 au if Neptune-sized planets are common and susceptible to planet–planet scattering. While the existence of Planet 9 remains unproven, we consider capture from one of the Sun's young brethren a plausible route to explain such an object's orbit. Capture appears to predict a large population of trans-Neptunian objects (TNOs) whose orbits are aligned with the captured planet, and we propose that different formation mechanisms will be distinguishable based on their imprint on the distribution of TNOs.
Structure and superconductivity of hydrides at high pressures
Authors: Duan Defang , Liu Yunxian , Ma Yanbin , Shao Ziji , Liu Bingbing , Cui Tian
Published: April 2016

Hydrogen atoms can provide high phonon frequencies and strong electron–phonon coupling in hydrogen-rich materials, which are believed to be potential high-temperature superconductors at lower pressure than metallic hydrogen. Especially, recently both of theoretical and experimental reports on sulfur hydrides under pressure exhibiting superconductivity at temperatures as high as 200 K have further stimulated an intense search for room-temperature superconductors in hydrides. This review focuses on crystal structures, stabilities, pressure-induced transformations, metallization, and superconductivity of hydrogen-rich materials at high pressures.
Neither Neoplasia Nor Tuberculosis, but Francisella
Authors: Mambie Adeline , Wallet Frédéric , Scherman Laurine , Armand Sylvie , Vervelle Christine , Faure Karine , Guery Benoit , Titécat Marie , Loïez Caroline
Published: April 2016

Tularaemia is an emerging anthropozoonosis transmitted by contact with infected animals and through arthropod bites, inhalation, or ingestion. We describe a pulmonary nodule suggesting cancer in a 70-year-old man. Histological analysis excluded neoplasia, and bacteriological culture excluded tuberculosis. Serological testing and PCR Francisella were positive for this hunter patient, then treated by ciprofloxacin with a favourable outcome.
Cellular Dynamics of Mouse Trophoblast Stem Cells: Identification of a Persistent Stem Cell Type1
Authors: Motomura Kaori , Oikawa Mami , Hirose Michiko , Honda Arata , Togayachi Sumie , Miyoshi Hiroyuki , Ohinata Yasuhide , Sugimoto Michihiko , Abe Kuniya , Inoue Kimiko , Ogura Atsuo
Published: April 2016

Mouse trophoblast stem cells (TSCs) proliferate indefinitely in vitro, despite their highly heterogeneous nature. In this study, we sought to characterize TSC colony types by using methods based on cell biology and biochemistry for a better understanding of how TSCs are maintained over multiple passages. Colonies of TSCs could be classified into four major types: type 1 is compact and dome-shaped, type 4 is flattened but with a large multilayered cell cluster, and types 2 and 3 are their intermediates. A time-lapse analysis indicated that type 1 colonies predominantly appeared after passaging, and a single type 1 colony gave rise to all other types. These colony transitions were irreversible, but at least some type 1 colonies persisted throughout culture. The typical cells comprising type 1 colonies were small and highly motile, and they aggregated together to form primary colonies. A hierarchical clustering based on global gene expression profiles suggested that a TSC line containing more type 1 colony cells was similar to in vivo extraembryonic tissues. Among the known TSC genes examined, Elf5 showed a differential expression pattern according to colony type, indicating that this gene might be a reliable marker of undifferentiated TSCs. When aggregated with fertilized embryos, cells from types 1 and 2, but not from type 4, distributed to the polar trophectoderm in blastocysts. These findings indicate that cells typically found in type 1 colonies can persist indefinitely as stem cells and are responsible for the maintenance of TSC lines. They may provide key information for future improvements in the quality of TSC lines.
A Comparison of Three C-Arm Draping Techniques to Minimize Contamination of the Surgical Field
Authors: Gershkovich Grigory E. , Tiedeken Nathan C. , Hampton David , Budacki Ross , Samuel Solomon P. , Saing Minn
Published: April 2016

The use of intraoperative fluoroscopy has become a routine and useful adjunct within orthopaedic surgery. However, the fluoroscopy machine may become an additional source of contamination in the operating room, particularly when maneuvering from the anterior–posterior position to the lateral position. Consequently, draping techniques were developed to maintain sterility of the operative field and surgeon. Despite a variety of methods, no studies exist to compare the sterility of these techniques specifically when the fluoroscopy machine is in the lateral imaging position. We evaluated the sterility of 3 c-arm draping techniques in a simulated operative environment. The 3 techniques consisted of a traditional 3-quarter sterile sheet attached to the side of the operative table, a modified clip-drape method, and a commercially available sterile pouch. Our study demonstrated that the traditional method poses a high risk for sterile field contamination, whereas the modified clip-drape method and commercially available sterile pouch kept floor contamination furthest from the surgical field. With the current data, we urge surgeons to use modified techniques rather than the traditional draping method.
The Association of Central-Line–Associated Bloodstream Infections With Central-Line Utilization Rate and Maintenance Bundle Compliance Among Types of PICUs*
Authors: Affolter Jeremy T. , Huskins W. Charles , Moss Michele , Kuhn Evelyn M. , Gedeit Rainer , Rice Thomas B.
Published: April 2016

Objective:

Central-line–associated bloodstream infections comprise 25% of device-associated infections. Compared with other units, PICUs demonstrate a higher central-line–associated bloodstream infections prevalence. Prior studies have not investigated the association of central-line–associated bloodstream infections prevalence, central-line utilization, or maintenance bundle compliance between specific types of PICUs.

Design:

This study analyzed monthly aggregate data regarding central-line–associated bloodstream infections prevalence, central-line utilization, and maintenance bundle compliance between three types of PICUs: 1) PICUs that do not care for cardiac patients (PICU); 2) PICUs that provide care for cardiac and noncardiac patients (C/PICU); or 3) designated cardiac ICUs (CICU).

Setting:

The included units submitted data as part of The Children’s Hospital Association PICU central-line–associated bloodstream infections collaborative from January 1, 2011, to December 31, 2013.

Patients:

Patients admitted to PICUs in collaborative institutions.

Interventions:

None.

Measurements and Main Results:

The overall central-line–associated bloodstream infections prevalence was low (1.37 central-line–associated bloodstream infections events/1,000 central-line days) and decreased over the time of the study. Central-line–associated bloodstream infections prevalence was not related to the type of PICU although C/PICU tended to have a higher central-line–associated bloodstream infections prevalence (p = 0.055). CICU demonstrated a significantly higher central-line utilization ratio (p < 0.001). However, when examined on a unit level, central-line utilization was not related to the central-line–associated bloodstream infections prevalence. The central-line maintenance bundle compliance rate was not associated with central line–associated bloodstream infections prevalence in this unit-level investigation. Neither utilization rate nor compliance rate changed significantly over time in any of the types of units.

Conclusions:

Although this unit-level analysis did not demonstrate an association between central-line–associated bloodstream infections prevalence and central-line utilization and maintenance bundle compliance, optimization of both should continue, further decreasing central-line–associated bloodstream infections prevalence. In addition, investigation of patient-specific factors may aid in further central-line–associated bloodstream infections eradication.
Volumetric Planning Using Computed Tomographic Angiography Improves Clinical Outcomes in DIEP Flap Breast Reconstruction
Authors: Lee Kyeong-Tae , Mun Goo-Hyun
Published: April 2016

Background:

The present study evaluated outcomes of deep inferior epigastric perforator (DIEP) flap breast reconstruction using volumetric planning—which is preoperative planning based on volumetric data of the breast and flap estimated from computed tomographic angiography.

Methods:

A prospective review of three patient cohorts undergoing DIEP flap breast reconstruction from June of 2009 to February of 2015 was performed. Cohort 1 comprised 48 cases in which no volumetric planning was used. Cohort 2 included the next 101 consecutive cases undergoing breast reconstruction according to an algorithm based on volumetric planning. Cohort 3 consisted of the next 109 consecutive cases using a modified algorithm. The inset rate (weight ratio of the inset flap to harvested flap) was estimated during volumetric planning, and specific surgical strategies, such as incorporating multiple perforators, conducting venous augmentation (cohort 2), or harvesting bipedicled flaps (cohort 3), were used with reference to it. Rates of perfusion-related complications were compared.

Results:

All but one flap survived completely. Fat necrosis occurred in 9.7 percent. Overall, the perfusion-related complication rate was 22.9 percent of cohort 1, 10.9 percent in cohort 2, and 5.6 percent in cohort 3 (p = 0.006). The fat necrosis rates were 19.1, 9.9, and 5.6 percent in cohorts 1, 2, and 3, respectively (p = 0.032). A multivariate analysis demonstrated that volumetric planning had independent benefits for preventing perfusion-related complications (p = 0.003).

Conclusion:

The authors’ results suggest that volumetric planning can facilitate elaborate planning and reduce perfusion-related complications, enabling reliable breast reconstruction using DIEP flaps.

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Therapeutic, III.
Making Master Surgeons Out of Trainees: Part I. Teaching Surgical Judgment
Authors: Kempton Steve J. , Bentz Michael L.
Published: April 2016

The training of competent and ethical plastic surgery residents has become more difficult, as surgeons face increasing clinical and research demands, concern for medicolegal liability, and pressure to increase efficiency to decrease health care expenditures. The resulting variation in operative experience among plastic surgery trainees exemplifies the need for educational reform to accommodate change. Although the Accreditation Council for Graduate Medical Education has mandated a transition to competency-based training, and state-of-the-art technologies in surgical simulation are being developed to improve operative skills, the construction of a system to teach and assess operative judgment is deficient and should be thoughtfully created and implemented. Established educational methods and curriculums can be used in this effort and include apprenticeship operative teaching, surgical simulation, morbidity and mortality conferences, and resident clinics. The first step in this effort is to require trainees to make decisions, communicating their judgments and recommendations using language that demonstrates clear thinking and thoughtful analysis. For faculty, this means carving out dedicated preoperative teaching time in addition to efficient use of intraoperative time and sharing of postoperative outcomes. For programs, this means developing metrics to evaluate progress and build procedure-specific simulations. The goal should be not just to settle for training safe and ethical surgeons but to produce masterful surgeons with mature judgment.