bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved event‐triggered control for a class of continuous‐time switched linear systems
Authors: Li Tai‐Fang , Fu Jun , Ma Zixiao
Published: March 2018

Both state‐based and observer‐based output feedback event‐triggered controls for continuous‐time switched linear systems are studied. An improved event‐triggered sampling mechanism is adopted in feedback control, under which Zeno behaviour can be easily excluded in sampling process. Meanwhile, it is shown that the closed‐loop switched system is stable in the sense of global uniform boundedness satisfying an average dwell time condition. A numerical example is finally given to verify the developed results.
Reactive power compensation using electric vehicles considering drivers’ reasons
Authors: Su Su , Hu Yong , Wang Shidan , Wang Wei , Ota Yutaka , Yamashita Koji , Xia Mingchao , Nie Xiaobo , Chen Lijiang , Mao Xia
Published: March 2018

The node voltage profile is more likely to be violated as the electric vehicles (EVs) charging load spreads in distribution network. Due to the stochastic nature of EV charging load spatially, more flexible reactive power compensation in different locations becomes important. However, the conventional reactive power compensation equipment has no flexibility spatially. Therefore, two kinds of reactive power compensation strategies using EVs considering drivers’ reasons are proposed. Drivers’ reasons contain charging demand, charging opportunity loss (time) and profit. In Strategy 1, EV chargers are used to fully compensate reactive power after finishing the unregulated charging. Thus, drivers’ charging behaviour is not influenced at all. In Strategy 2, the operating power factors of EV chargers are treated as variables for the optimisation. The constraint of operating power factors is derived from analysing the charging demand and the charging opportunity loss (time) for drivers. Then, in order to motivate drivers, an incentive method is introduced based on the quantification of each driver's contribution to the voltage. The case study shows that Strategy 1 performs well at nodes having the non‐significant voltage deviation without any constraint on driver's charging behaviour, while Strategy 2 performs well at nodes where the voltages deviation is significant.
Study on the lightning strike discharge characteristics of switchgear air gap at low air pressure condition
Authors: Zhang Zhijin , Wei Donghong , Zhang Dongdong , Zhu Junyu , Li Chen
Published: March 2018

The usage of medium‐voltage switchgear is more and more common in high altitude areas. Few relative standards about the selection of switchgear air gap in low air pressure conditions are currently available for referring. In this study, four different types of switchgear air gaps, as well as a typical rod‐plane gap, are taken as the samples, and their positive and negative lightning strike discharge characteristics under low air pressure are tested in the artificial climate chamber. The effects of the electrode structure, polarity, air pressure, humidity, and gap distance on the discharge performances are analysed as well. Research results indicate that the four switchgear air gaps and typical rod‐plane gap differs greatly in lightning impulse discharge performances and polarity effects. In low air pressure conditions, the lightning impulse breakdown voltage of either positive or negative polarity can be corrected by U50 = U50,0 × (P/P0)n. The discharge voltage under positive lightning impulse is more easily affected by air pressure than that under negative lightning impulse. Atmosphere humidity will cause dispersiveness of air‐gap lightning impulse discharge voltage, which performs to be non‐linear with a gap distance lower under 400 mm. Research results are referable for the design, selection and installation of medium‐voltage switchgear in high altitude areas.
Experimental analyses and clustering of travel choice behaviours by floating car big data in a large urban area
Authors: Fusco Gaetano , Bracci Agnese , Caligiuri Tommaso , Colombaroni Chiara , Isaenko Natalia
Published: March 2018

This study introduces a general methodology to process sparse floating car data, reconstruct the routes followed by the drivers, and cluster them to achieve suitable choice sets of significantly different routes for calibrating behavioural models. This methodology is applied to a large set of floating car data collected in Rome in 2010. Results underlined that routes assigned to different clusters are actually very different to each other. Nevertheless, as expected according to Wardrop's principle, the clusters belonging to the same origin–destination have rather similar average route travel times, even if there is a large range between their minimum and maximum values. A focus on drivers’ behaviour highlighted their propensity to follow the same route to their usual destination, though the 12% of the drivers switched to an alternative route. However, the analysis conducted over the 1 month of observations did not reveal the existence of any systematic correlation between neither the change of route nor the change of departure time and the travel time experienced the day before.
Multi‐carrier based phased antenna array design for directional modulation
Authors: Zhang Bo , Liu Wei
Published: March 2018

Directional modulation (DM) has been developed based on narrowband antenna arrays, which can form the desired constellation values in the directions of interest while scrambling the values and simultaneously maintaining a magnitude response as low as possible in other directions. In this study, for the first time, the authors develop a multi‐carrier based DM framework using antenna arrays, where simultaneous data transmission over multiple frequencies can be achieved, so that a much higher data rate can be obtained. In addition, such a framework allows possible frequency division based multi‐user access to the system and also provides the flexibility of using different modulation schemes at different frequencies. Then, they study the antenna location optimisation problem for multi‐carrier based DM using a compressive sensing based approach by employing the group sparsity concept. Examples are provided for both the design of weight coefficients and the optimisation of antenna locations.
Comparison of stability service cost in power grids considering different types of WTs
Authors: Hashemi Yashar , Shayeghi Hossein , Moradzadeh Mohammad
Published: March 2018

This study presents a comparative study on dynamic behaviour of two different types of wind turbines (WTs) that are widely used in power systems. Mathematical modelling of two types of WTs in the multi‐machine power system is presented, and a suitable framework for the study is provided. To compare the cost of provision of stability service by each of two different WTs, a technical–economical two‐objective optimisation problem considering damping indices and generation cost will be formulated and solved by multi‐objective gravitational search algorithm method. The presented strategy is carried out for each WT and Pareto‐optimal curves are extracted. It is shown that in a system with poor dynamic situation, expensive production units are used that this phenomenon will increase generation cost. Generation costs are analysed by considering two WTs, doubly fed asynchronous generator and permanent magnet synchronous generator and dynamic condition for each type are evaluated. Two scenarios are assumed for evaluation; the first one without retuning of stabilisers and the second one with stabilisers retuned due to system generation situation. The proposed scheme is tested on modified 16‐machine 5‐area network and simulation results are compared.
Designing a wide area damping controller to coordinate FACTS devices in the presence of wind turbines with regard to time delay
Authors: Darabian Mohsen , Jalilvand1 Abolfazl
Published: March 2018

The main objective of this study is to increase the power system oscillation damping in the presence of wind farms using flexible alternating current transmission systems (FACTS) devices and predictive control. The desired design is conducted to coordinate static synchronous compensator–static synchronous series compensator and rotor side converter in doubly‐fed induction generator (DFIG). This design is done to compensate for the DFIG reactive power and increase power system oscillation damping in the presence of uncertainties in the wind turbine. The method proposed for coordinated design was based on the network predictive control (NPC) so that it could improve damping, and compensate for the time delays in sending wide area signals. In fact, NPC is based on generalised predictive control (GPC) which has the ability to compensate for time delays using model identification method. Using MATLAB software, the simulation results were conducted on a 16‐machine and 69‐bus power system under different scenarios; and the ability of NPC is well proven compared with GPC and the classic method of wide area controller.
Two‐stage cloud service optimisation model for cloud service middleware platform
Authors: Kung Hsu‐Yang , Kuo Ting‐Huan , Chen Chi‐Hua , Hsu Yu‐Lun
Published: March 2018

In this study, a cloud service optimisation model is presented for resource adaptation control, in which the cost to the user, various levels of virtual machine efficacy, and rental price are considered. A cloud service middleware that supports flexible web services by using heterogeneous platforms is proposed. Developers can conveniently register web services and deploy them to the middleware. The middleware provides an energy‐minimisation load balance (EM‐LB) mechanism, which considers the temperature of the machine, its power consumption, and the computing resources of virtual machines. The EM‐LB mechanism maintains a safe temperature threshold and minimises power usage, thereby reducing hotspots and conserving energy. Furthermore, a two‐stage cloud service optimisation model is proposed to analyse users’ requirements and existed computing resources for finding the Pareto optimality, and the aspirational level is found in accordance with the Pareto optimality for the lower cost and lower execution time. The simulation results show the efficiency of the proposed cloud service optimisation model and EM‐LB mechanism. Finally, the proposed EM‐LB mechanism is implemented to prove the feasibility of the model.
Research on space‐vector modulation and common‐mode voltage of four‐leg matrix converter
Authors: Xu Hanwei , Xu Lie , Li Yongdong
Published: March 2018

Four‐leg matrix converter (MC) is an AC–AC converter which has the ability to drive the unbalanced load. It can be used in many fields such as the ice protection system of More Electrical Aircraft to reach a considerably high power density. Detailed space‐vector modulation algorithm and circuit modelling are discussed in this study. Analysis, modelling, and characteristics of common‐mode voltage (CMV) are presented. The relationship between the peak value of CMV and circuit parameters is studied and quantitative results are provided. Simulation of a four‐leg MC driving system is built and an experimental platform based on DSP/CPLD control system is set up.
Initial rotor position estimation method for aircraft wound‐rotor synchronous starter/generators
Authors: Mao Shuai , Liu Weiguo , Ma Peng , Zhang Zan , Hu Ying
Published: March 2018

An initial rotor position estimation method which is independent of the magnetic saliency is proposed for the main generator (MG) of aircraft three‐stage wound‐rotor synchronous starter/generators. Voltage signals are injected into the stator of the MG and the field current response of the MG is evaluated in this method. Owing to the brushless excitation structure, the field current of the MG cannot be measured directly. Thus, estimation of the field current of the MG is performed first. Then, high‐frequency sinusoidal and pulse voltages are injected into the stator windings of the MG separately and the induced field current of the MG, estimated from the main exciter side, is regarded as the indicator for the initial rotor position of the MG. Simulation tests are carried out to verify the method and the results are presented and analysed.
Consideration and validation of flight control requirements under all engine failure conditions for MEA
Authors: Li Xiyu , Xu Shuhan , Bai Zhiqiang
Published: March 2018

Since the lower carbon emission and lower direct operating cost, MEA has drawn great attention worldwide. Considering and validating the flight control requirements under all engine failure conditions for MEA is the minimum design requirement, which is widely associated with aircraft characteristics, controllability and manoeuvrability, and system specialities such as electrical system, power plant system, hydraulic system, and avionics. Therefore, taking this topic as an example to illustrate a requirement validation process will be great interest to the aircraft design and integration, where the correctness and completeness of the requirements would be satisfied, the method and evidences of validation would be proposed, the requirement assumption validation and management should be presented, and scenario analysis and typical timeline analysis would be analysed. This paper presents the above processes from configuration, requirement definition and validation, to scenario analysis in compliance with SAE 4754A, which will be a fundamental process to the further verification and integration tasks.
Quantitative and Qualitative Assessment of Pulmonary Emphysema with T2-Weighted PROPELLER MRI in a High-Risk Population Compared to Low-Dose CT
Authors: Meier-Schroers Michael , Sprinkart Alois , Becker Manuel , Homsi Rami , Thomas Daniel
Published: March 2018

Purpose To determine the suitability of T2-weighted PROPELLER MRI for the assessment of pulmonary emphysema.

Materials and Methods 60 participants in a lung cancer screening program (30 subjects with pulmonary emphysema, and 30 control subjects without emphysema) were included for this retrospective study. All subjects were examined with low-dose CT (LDCT) and MRI within the screening program. The use of a T2-weighted PROPELLER sequence for the assessment of emphysema was analyzed and correlated with the results of LDCT. The presence and the extent of pulmonary emphysema were first assessed qualitatively using a three-point score, and then quantitatively with a semi-automated software program to obtain emphysema indices.

Results All 30 cases with pulmonary emphysema were accurately detected by MRI. There were 3 cases with emphysema according to MRI without emphysematous changes on LDCT (false-positive results). The qualitative scores as well as the emphysema indices were significantly higher in the emphysema group compared to the control group for MRI and LDCT (p < 0.001). Both the scores and the indices correlated significantly between MRI and LDCT (qualitative score of severity: r = 0.912/p < 0.001 in the emphysema group and r = 0.668/p < 0.001 in the control group; emphysema index: r = 0.960/p < 0.001 in the emphysema group and r = 0.746/p < 0.001 in the control group).

Conclusion The presence and the extent of pulmonary emphysema may be assessed qualitatively and quantitatively by T2-weighted PROPELLER MRI with very good correlation to LDCT.

Key Points: 

Citation Format
Claisen Rearrangements of Benzyl Vinyl Ethers and Heterobenzyl Vinyl Ethers
Authors: McGeary Ross , Burns Jed , Krenske Elizabeth
Published: March 2018

The Claisen rearrangement of benzylic substrates (benzyl vinyl­ ethers) has received considerably less attention than its well-known aliphatic and normal aromatic variants. Here, we review the rearrangement of both benzylic and heterobenzylic substrates, with examples of the reaction’s use in the synthesis of natural products and drug-like molecules.

1 Introduction

2 Early Attempts at the Benzyl-Claisen Rearrangement

3 Successful Benzylic Examples

4 Heterobenzylic Examples

5 Conclusion
One-Pot Synthesis of Isoquinuclidines via 2,6-Diaryl-1,2-dihydropyridines using (E,E)-Cinnamylideneacetophenones as Templates
Authors: Varandas Pedro , Rocha Djenisa , Paz Filipe , Silva Eduarda , Silva Artur
Published: March 2018

Diastereoselective Diels–Alder reactions of 2,6-diaryl-1,2-dihydropyridines with N-methylmaleimide afford highly substituted isoquinuclidines in good chemical yield (30–50%). This sequential one-pot synthesis is performed under microwave irradiation and involves, primarily, the synthesis of 2,6-diaryl-1,2-dihydropyridines by a 6π-azaelectrocyclisation involving an intermediate α,β,γ,δ-di-unsaturated imine, obtained by condensation of (E,E)-cinnamylideneacetophenones with amines. This procedure easily converts unstable 2,6-diaryl-1,2-dihydropyridines into, otherwise inaccessible, isoquinuclidines without any kind of manipulation.
Unicompartmental Knee Arthroplasty: The Past, Current Controversies, and Future Perspectives
Authors: Johal Sim , Nakano Naoki , Baxter Mark , Hujazi Ihab , Pandit Hemant , Khanduja Vikas
Published: March 2018

Unicompartmental knee arthroplasty (UKA) is a bone conserving and ligament-sparing procedure that reliably restores normal knee kinematics and function for arthritis limited either to the medial or the lateral compartment of the knee. Although there is enough evidence to demonstrate that the UKA offers good medium to long-term success given the correct patient selection, prosthesis design, and implantation technique, there are several reports to suggest inferior survival rates in comparison with the total knee arthroplasty (TKA). Furthermore, it is a specialized procedure which works well in the hands of the experienced operator and therefore different authors' tend to draw different conclusions based on the same evidence, and as a result, there is great variability in the usage of the UKA. The aim of this current concept's review is to present to the readers the history of the UKA especially with reference to implant design, discuss current controversies, and outline the future perspectives of this novel procedure.
The Reliability of Electronic Health Record Data Used for Obstetrical Research
Authors: Altman Molly , Colorafi Karen , Daratha Kenn
Published: March 2018

Background Hospital electronic health record (EHR) data are increasingly being called upon for research purposes, yet only recently has it been tested to examine its reliability. Studies that have examined reliability of EHR data for research purposes have varied widely in methods used and field of inquiry, with little reporting of the reliability of perinatal and obstetric variables in the current literature.

Objective To assess the reliability of data extracted from a commercially available inpatient EHR as compared with manually abstracted data for common attributes used in obstetrical research.

Methods Data extracted through automated EHR reports for 3,250 women who delivered a live infant at a large hospital in the Pacific Northwest were compared with manual chart abstraction for the following perinatal measures: delivery method, labor induction, labor augmentation, cervical ripening, vertex presentation, and postpartum hemorrhage.

Results Almost perfect agreement was observed for all four modes of delivery (vacuum assisted: kappa = 0.92; 95% confidence interval [CI] = 0.88–0.95, forceps assisted: kappa = 0.90; 95%CI = 0.76–1.00, cesarean delivery: kappa = 0.91; 95%CI = 0.90–0.93, and spontaneous vaginal delivery: kappa = 0.91; 95%CI = 0.90–0.93). Cervical ripening demonstrated substantial agreement (kappa = 0.77; 95%CI = 0.73–0.80); labor induction (kappa = 0.65; 95%CI = 0.62–0.68) and augmentation (kappa = 0.54; 95%CI = 0.49–0.58) demonstrated moderate agreement between the two data sources. Vertex presentation (kappa = 0.35; 95%CI = 0.31–0.40) and post-partum hemorrhage (kappa = 0.21; 95%CI = 0.13–0.28) demonstrated fair agreement.

Conclusion Our study demonstrates variability in the reliability of obstetrical data collected and reported through the EHR. While delivery method was satisfactorily reliable in our sample, other examined perinatal measures were less so when compared with manual chart abstraction. The use of multiple modalities for assessing reliability presents a more consistent and rigorous approach for assessing reliability of data from EHR systems and underscores the importance of requiring validation of automated EHR data for research purposes.
The Value of Monitoring Clinical Decision Support Interventions
Authors: Yoshida Eileen , Fei Shirley , Bavuso Karen , Lagor Charles , Maviglia Saverio
Published: March 2018

Background Well-functioning clinical decision support (CDS) can facilitate provider workflow, improve patient care, promote better outcomes, and reduce costs. However, poorly functioning CDS may lead to alert fatigue, cause providers to ignore important CDS interventions, and increase provider dissatisfaction.

Objective The purpose of this article is to describe one institution's experience in implementing a program to create and maintain properly functioning CDS by systematically monitoring CDS firing rates and patterns.

Methods Four types of CDS monitoring activities were implemented as part of the CDS lifecycle. One type of monitoring occurs prior to releasing active CDS, while the other types occur at different points after CDS activation.

Results Two hundred and forty-eight CDS interventions were monitored over a 2-year period. The rate of detecting a malfunction or significant opportunity for improvement was 37% during preactivation and 18% during immediate postactivation monitoring. Monitoring also informed the process of responding to user feedback about alerts. Finally, an automated alert detection tool identified 128 instances of alert pattern change over the same period. A subset of cases was evaluated by knowledge engineers to identify true and false positives, the results of which were used to optimize the tool's pattern detection algorithms.

Conclusion CDS monitoring can identify malfunctions and/or significant improvement opportunities even after careful design and robust testing. CDS monitoring provides information when responding to user feedback. Ongoing, continuous, and automated monitoring can detect malfunctions in real time, before users report problems. Therefore, CDS monitoring should be part of any systematic program of implementing and maintaining CDS.
Contemporary Perioperative Analgesia in Total Knee Arthroplasty: Multimodal Protocols, Regional Anesthesia, and Peripheral Nerve Blockade
Authors: Neilio Jonathan , Kunze Lisa , Drew Jacob
Published: March 2018

Perioperative care of the total knee arthroplasty (TKA) patient has evolved considerably over the past decade. Among the changes driving this evolution toward shorter hospitalization and accelerated rehabilitation have been regional anesthesia, peripheral nerve blockade, and multimodal analgesia protocols. These complementary techniques are increasingly supported by scientific evidence, though considerable uncertainty persists regarding the optimal combination of strategies. Continued refinement of technique and critical evaluation is trending toward greater characterization of the comparative effectiveness of myriad options. Contemporary interdisciplinary arthroplasty care teams have the opportunity to individualize the TKA patient's perioperative pain control to optimize not only the clinical outcome but also patient satisfaction.
Patient-Specific Instrument Can Improve Functional and Radiographic Results during Learning Curve for Oxford Unicompartmental Knee Arthroplasty
Authors: Matas-Diez Jose , Carbo-Laso Esther , Perez-Mañanes Ruben , Vaquero-Martín Javier , Sanz-Ruiz Pablo
Published: March 2018

The true value of use of patient-specific instrumentation (PSI) systems by inexperienced surgeons during their learning curve to improve the clinical and radiographic outcome of unicompartmental knee arthroplasty (UKA) has not been previously studied. Fifty patients with a mean age of 64.3 years undergoing surgery for Oxford UKA were prospectively divided into two groups. Twenty-five patients were operated on by a surgeon with no prior experience in UKA using a PSI system and the other 25 patients by an experienced surgeon using a conventional procedure. Patients were scored using joint range of motion (ROM), the Knee Society Score (KSS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the 12-item Short-Form (SF-12) before and 3 months and 2 years after surgery. Impact of use of PSI was measured by comparing clinical and radiographic outcome, complications, and implant survival. No evidence of poorer clinical outcome was seen in any subscale of KSS, KOOS, and SF-12 for inexperienced surgeons using PSI (p = 0.45, p = 0.32, and p = 0.61, respectively). No difference was found between the two procedures in precision of radiographic alignment of components (p = 0.53). No complication occurred in any group. PSI may improve precision of component alignment during the learning curve of surgeons, thus achieving functional results similar to those of more experienced surgeons using a conventional procedure.
Long-Term Clinical Results of Double Bundle Reconstruction of the Medial Patellofemoral Ligament for Patellar Instability
Authors: Zhang Lei , Li Zhiyao
Published: March 2018

Medial patellofemoral ligament (MPFL) reconstruction is a satisfactory technique for patellar instability, and the anatomical double bundle variant is recommended for better clinical results. However, long-term outcomes are still uncharacterized. This study aimed to assess the effectiveness of double bundle reconstruction of the MPFL for patellar instability by means of established scores. A total of 68 patients with chronic patellar instability who underwent surgery from May 2005 to February 2010 were included prospectively. Anatomical double reconstruction of the MPFL with the semitendinosus tendon was conducted. Tegner Activity Scale (TAS), Kujala score, Lysholm knee score, and objective physical examination were assessed during follow-up. Median follow-up time for the patients was 8 (range, 6–10) years. Eight patients were lost to follow-up after 2 years. Preoperative mean TAS was 2.85 ± 0.78, increased to 4.91 ± 0.84 at 6 months and 7.26 ± 0.78 at 2 years postoperatively, and was 7.82 ± 0.89 at last follow-up. At last follow-up, pain free at rest was achieved in all patients; and 8 patients had knee pain in activities of daily living. Mean Kujala score was 57.53 ± 8.59 preoperatively, and increased to 61.22 ± 6.46, 89.51 ± 3.90, and 88.92 ± 3.84 at 6 months, 2 years postoperatively, and at last follow-up, respectively. Lysholm scores were also increased from preoperative values of 43.53 ± 10.20 to 58.22 ± 6.80, 89.37 ± 4.38, and 89.67 ± 4.13 at 6 months, 2 years postoperatively, and at last follow-up, respectively. Range of motion was 121.44 ± 12.69, 129.71 ± 6.39, 130.93 ± 5.67, and 130.78 ± 5.80 at preoperative point, 6 months, 2 years postoperatively, and at last follow-up, respectively. Long-term clinical results of double bundle reconstruction of the MPFL for patellar instability were encouraging.
Factors Affecting Subjective and Objective Outcomes and Return to Play in Anterior Cruciate Ligament Reconstruction: A Retrospective Cohort Study
Authors: Rosso Federica , Bonasia Davide , Cottino Umberto , Cambursano Simone , Dettoni Federico , Rossi Roberto
Published: March 2018

Purpose To analyze the prognostic factors influencing subjective and objective outcomes and return to play (RTP) after anterior cruciate ligament reconstruction (ACL-R).

Methods Primary ACL-Rs using a transtibial technique performed between 2008 and 2012 were included. Data regarding patients, surgery, sports, and rehabilitation, including an on-field rehabilitation (OFR) and duration of the rehabilitation program, were collected. The International Knee Documentation Committee (IKDC) subjective and objective evaluation forms, and the Knee Injury and Osteoarthritis Outcome Score and Lysholm questionnaires were used for the assessment of subjective and objective outcomes. The Subjective Patient Outcome for Return to Sports and ACL–return to sport after injury (RSI) scores were used for RTP evaluation. Several potential predictors of outcome were tested with a univariate analysis. All the variables with p < 0.1 were retested in a logistic regression model to evaluate their association with the outcomes.

Results In total, 176 cases were included with an average follow-up of 44.1 months. Of the patients, 92.2% were rated as normal or nearly normal at the IKDC evaluation. In addition, 90.1% of the patients returned to sport, with 57.6% returning to the same preinjury level. Objective outcomes were negatively influenced by late rehabilitation (odds ratio [OR] = 2.75). Performing an OFR phase during the rehabilitation was associated with better subjective outcomes (OR = 2.71). Length of rehabilitation strongly influenced the RTP rate (OR = 13.16). Conversely, higher ACL-RSI score was inversely related to RTP. Objective IKDC score was inversely related to the ACL-RSI (OR = 0.31), whereas subjective score was correlated with both the total ACL-RSI score (OR = 0.15) and the level of activity (OR = 0.20).

Conclusion This study confirmed the role of rehabilitation on subjective and objective outcomes and on RTP. Particularly, the complete adherence to a rehabilitation program, including an OFR phase, resulted in better subjective outcomes and higher RTP rate. The relationship between psychological factors, measured through the ACL-RSI score, and RTP was confirmed.

Level of Evidence Level III, observational study without a control group.
Local Experience in using Hormonal Therapies according to the UKISS Studies in the Treatment of Infantile Spasms in Hong Kong
Authors: Mo Chung Yin , Yuen Chi Lap
Published: March 2018

Infantile spasms constitute severe epileptic encephalopathy in infancy with characteristic seizure semiology and electroencephalographic patterns. Besides the spasms, the most detrimental effect is the impact on future developmental outcomes. Different treatment methods are used, but hormonal therapy is the most well-accepted method for treating infantile spasms in nontuberous sclerosis cases. After the launch of the original United Kingdom Infantile Spasms Study (UKISS) and the two follow-up articles, the regimens of hormonal therapy became more structured and the expected treatment outcomes were studied better. We would like to share our local experience using this protocol to treat patients with infantile spasms in Hong Kong with a case series of four patients.
Surgical Treatment of Objective Patellar Instability: Long-Term Results
Authors: Berruto Massimo , Uboldi Francesco , Ferrua Paolo , Vergottini Giovanni , Manunta Andrea
Published: March 2018

Purpose To evaluate the long-term results of classical “à la carte” surgical treatment of objective patellar instability as proposed by Dejour in 1987.

Methods A multicentric retrospective study was conducted evaluating patients that underwent surgical procedure with a 10-year minimum follow-up (mean 12.7; range, 10–15). Surgical procedures were medial transfer of the tibial tubercle transfer according to Elmslie and Trillat et al in 38 cases, plasty of the vastus medialis obliquus according to Insall in 15 cases, open lateral retinacular release in 13 cases, capsuloplasty in 3 cases, and trochleoplasty in 1 case. Different combinations of surgical procedures were adopted according to the pathological features. Subjective outcome was assessed with the visual analog scale (VAS), Kujala score, subjective International Knee Documentation Committee (IKDC) score, Tegner score, and Crosby and Insall scale. Radiographic exams were used to assess the patellar tilt by the Laurin's angle and patellofemoral osteoarthritis (OA) according to the Iwano radiological OA scale.

Results Forty patients were evaluated. Subjectively, 60% of patients achieved a result judged good, 34% sufficient, and 6% poor. There were only two cases of recurrence of instability. Mean score results were Kujala score 73.4 ± 9.9 (range, 55–95), VAS 4.5 ± 1.2 (range, 1–6), IKDC 64.8 ± 7.9 (range, 51–88), and Tegner score 4. Only nine patients returned to sports activities). Ten patients developed a grade I patellofemoral OA, 8 patients a grade II, and 22 patients a grade III. Average patellar tilt was 10° ±  3.9°.

Conclusion This retrospective study showed that the traditional surgical procedure was successful for the treatment of patellar instability, but it did not prevent symptomatic patellofemoral OA.

Level of Evidence Level IV, retrospective case series.
Einmalige Applikation für eine effektive Prophylaxe
Authors: Žatecky Adela
Published: March 2018

Die Tripel-Kombinationstherapie ans NK1-Rezeptorantagonist, 5-HT3-Rezeptorant agonist und Dexamethason setzt sich als Begleittherapie zu hoch emetogenen und einigen moderat emetogenen Chemotherapien immer mehr durch und wird auch in verschiedenen Leitlinien entsprechend empfohlen.
EUS-guided gastroenterostomy in management of benign gastric outlet obstruction
Authors: Chen Yen-I , James Theodore , Agarwal Amol , Baron Todd , Itoi Takao , Kunda Rastislav , Nieto Jose , Bukhari Majidah , Gutierrez Olaya , Sanaei Omid , Moran Robert , Fayad Lea , Khashab Mouen
Published: March 2018

Background and study aims Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) in malignant gastric outlet obstruction (GOO) appears to be promising; however, its role in benign GOO is unclear. The aim of this study was to ascertain the clinical efficacy and safety of EUS-GE in benign GOO.

Patients and methods This was an international retrospective series involving 5 tertiary centers. Consecutive patients who underwent EUS-GE between 1/2013 – 10/2016 for benign GOO were included. The primary endpoint was the rate of clinical success defined as ability to tolerate oral intake without vomiting. Secondary endpoints included technical success and rate of adverse events (AE).

Results Overall, 26 patients (46.2 % female; mean age 57.7 ± 13.9 years) underwent EUS-GE for benign GOO due to strictures from chronic pancreatitis (n = 11), surgical anastomosis (n = 6), peptic ulcer disease (n = 5), acute pancreatitis (n = 1), superior mesentery artery syndrome (n = 1), caustic injury (n = 1), and hematoma (n = 1). Technical success was achieved in 96.2 %. Dilation of the lumen apposing metal stent was performed in 13/25 (52 %) with a mean maximum diameter of 14.6 ± 1.0 mm. Mean procedure time was 44.6 ± 26.1 min. Clinical success was observed in 84.0 % with a mean time to oral intake of 1.4 ± 1.9 days and a median follow-up of 176.5 (IQR: 47 – 445.75) days. Rate of unplanned re-intervention was 4.8 %. 3 AE were noted including 2 misdeployed stents and 1 gastric leak needing surgical intervention following elective GE stent removal.

Conclusions EUS-GE is a promising treatment for benign GOO. Larger and prospective data are needed to further validate this novel endoscopic technique in treating benign GOO of various etiologies.
Linked color imaging enhances endoscopic detection of sessile serrated adenoma/polyps
Authors: Fujimoto Daisaku , Muguruma Naoki , Okamoto Koichi , Fujino Yasuteru , Kagemoto Kaizo , Okada Yasuyuki , Takaoka Yoshifumi , Mitsui Yasuhiro , Kitamura Shinji , Kimura Tetsuo , Miyamoto Hiroshi , Bando Yoshimi , Sonoda Tomoko , Takayama Tetsuji
Published: March 2018

Background and study aims Although new image-enhanced endoscopy (IEE) technologies such as blue laser imaging (BLI), BLI-bright, and linked color imaging (LCI) have been developed, their utility for the detection of sessile serrated adenoma/polyps (SSA/Ps) is still unclear. This study aimed to evaluate the utility of BLI, BLI-bright, and LCI for SSA/P detection in still image examinations and in a prospective randomized controlled trial (RCT).

Patients and methods A group of 6 expert and non-expert endoscopists read 200 endoscopic still images containing SSA/P lesions using white light image (WLI), BLI, BLI-bright, and LCI. Color differences were calculated using the color space method. A prospective RCT of tandem colonoscopy with WLI and LCI was performed. Patients with SSA/P and those with a history of SSA/P that had been endoscopically removed were enrolled and randomly allocated to WLI-LCI or LCI-WLI groups. Additional endoscopic detection rates for SSA/P were compared between the 2 groups.

Results LCI showed the highest SSA/P detection rate among the 4 modes for both expert and non-expert endoscopists. The detection rate with LCI for the 6 expert endoscopists (mean 98.3 ± standard deviation 2.0 %) was significantly higher than that with WLI (86.7 ± 6.0 %, P < 0.01). Likewise, the detection rate with LCI for the 6 non-expert endoscopists (92.3 ± 2.9 %) was significantly higher than that with WLI (72.7 ± 11.5 %, P < 0.01). The color difference of SSA/P with LCI was the highest among the 4 modes, and was significantly higher than with WLI (median 15.9, (interquartile range 13.7 – 20.6) vs. 10.2, (7.6 – 14.2); P < 0.0001). In the RCT, a total of 44 patients (WLI-LCI 22 vs. LCI-WLI 22) underwent colonoscopy. The additional detection rate for SSA/P in the second inspection in the WLI-LCI group (21.6 %, 8/37) was significantly higher than in the LCI-WLI group (3.2 %, 1/31; P = 0.02). The small, flat, non-mucus and isochromatic SSA/Ps in the transverse colon were detected more frequently in the second inspection with LCI.

Conclusions LCI was the most sensitive mode for SSA/P detection among WLI, BLI, BLI-bright, and LCI in the still image examinations. Our RCT strongly suggests that LCI is superior to conventional WLI for SSA/P detection during colonoscopy. UMIN000017599.
Im Wandel der Zeit
Authors: Beister Bianca , Quensel Tom , Zilezinski Max
Published: March 2018

Berufseinsteiger auf der Intensivstation Zur Nachwuchsförderung in der
Intensivpflege hat die Charité – Universitätsmedizin Berlin im Jahr 2012 ein
Trainee-Programm gestartet. Jetzt liegen erste Resümees der Teilnehmer vor.
Magnifying endoscopy with narrow-band imaging for gastric heterotopic pancreas
Authors: Oh Heetaek , Kim Gwang , Lee Moon , Jeon Hye , Baek Dong , Lee Bong
Published: March 2018

Background and study aims Heterotopic pancreas is a common subepithelial lesion in the stomach. However, its histological diagnosis is difficult when tissue samples are obtained with a conventional biopsy forceps. This study aimed to describe the magnifying endoscopy with narrow-band imaging (ME-NBI) features of gastric heterotopic pancreas.

Patients and methods We retrospectively analyzed a database of all patients who underwent endoscopic ultrasonography (EUS) at Pusan National University Hospital from January 2010 to December 2010. Thirty-six patients with endosonographically diagnosed heterotopic pancreas who underwent ME-NBI and endoscopic ultrasonography (EUS) simultaneously were studied. The ME-NBI features of their lesions were analyzed.

Results Thirty lesions were located in the antrum and six in the body. Six lesions (17 %) showed umbilication or central dimpling on the surface, and nine (25 %) had a macroscopic opening on the surface. On ME-NBI, a microscopic opening was identified in 22 (81 %) of 27 lesions wherein a macroscopic opening was not observed during conventional endoscopy. Macroscopic or microscopic opening was observed in 31 lesions (86 %). The frequency of macroscopic or microscopic opening was higher in lesions with anechoic duct-like structures than in lesions without such structures on EUS (91 % [29/32] vs 50 % [2/4], P = 0.027). Focal loss of microsurface structure and presence of a thickened submucosal vessel were observed in 6 (17 %) and 5 lesions (14 %), respectively.

Conclusions The characteristic ME-NBI feature of heterotopic pancreas is presence of a microscopic opening on its surface. This ME-NBI feature is potentially useful for differentiating heterotopic pancreas from other gastric subepithelial tumors.
Externally Acquired Radiological Image Data and Reporting for the Clinical Routine, Conference and Boards – Legal Aspects of the Second Opinion in Germany
Authors: Schreyer Andreas , Rosenberg Britta , Steinhäuser René
Published: March 2018

Background Because of an increasing number of boards and conferences, the number of second opinion readings of externally acquired image data is growing dramatically. In this review article we intend to give medical and legal recommendations for the documentation and interpretation of externally acquired radiological data for second opinions and board presentations based on German jurisdiction.

Method Using the FAQ format as a dialog between radiologists and medical legal experts, we answer the most crucial questions regarding correct documentation and interpretation for externally acquired radiological image data based on an up-to-date literature search.

Results Based on the unity of radiological image data and the corresponding written report according to the radiation protection law, the primary report should be present when composing a second opinion. If the primary external report is not present, this should be mentioned as a limitation. All radiological second opinions should be documented in written form. This is especially important in cases of discrepant findings. Legally, the attending physician is responsible for selecting the radiological opinion. The radiologist should not rely on the written primary report without personal reevaluation. Legally, it would be considered radiological malpractice if the external image data and previous image data are not evaluated personally.

Conclusion From a legal point of view, there are explicit recommendations regarding thorough documentation of a second opinion as an independent medical service in all cases.

Key Points 

Citation Format
Dynamic modes in a network of five oscillators with inhibitory all-to-all pulse coupling
Authors: Vanag Vladimir K. , Yasuk Vitaly O.
Published: March 2018

The dynamic modes of five almost identical oscillators with pulsatile inhibitory coupling with time delay have been studied theoretically. The models of the Belousov–Zhabotinsky reaction and phase oscillators with all-to-all coupling have been considered. In the parametric plane Cinh–τ, where Cinh is the coupling strength and τ is the time delay between a spike in one oscillator and pulsed perturbations of all other oscillators, three main regimes have been found: regular modes, when each oscillator gives only one spike during the global period T, C (complex) modes, when the number of pulses of different oscillators is different, and OS (oscillations-suppression) modes, when at least one oscillator is suppressed. The regular modes consist of several cluster modes and are found at relatively small Cinh. The C and OS modes observed at larger Cinh intertwine in the Cinh–τ plane. In a relatively narrow range of Cinh, the dynamics of the C modes are very sensitive to small changes in Cinh and τ, as well as to the initial conditions, which are the characteristic features of the chaos. On the other hand, the dynamics of the C modes are periodic (but with different periods) and well reproducible. The number of different C modes is enormously large. At still larger Cinh, the C modes lose sensitivity to small changes in the parameters and finally vanish, while the OS modes survive.
Adiabatic bulk modulus of elasticity for 2D liquid dusty plasmas
Authors: Feng Yan , Huang Dong , Li Wei
Published: March 2018

From the recently obtained equation of state (EOS) for two-dimensional (2D) liquid dusty plasmas, their various physical quantities have been derived analytically, such as the specific heat CV, the Grüneisen parameter, the bulk modulus of elasticity, and the isothermal compressibility. Here, the coefficient of volumetric thermal expansion αV and the relative pressure coefficient αP of 2D liquid dusty plasmas are derived from their EOS. Using the obtained CV, αV, and αP, the analytical expression of their heat capacity under constant-pressure conditions CP is obtained. Thus, the heat capacity ratio, expressed as CP/CV, is analytically achieved. Then the adiabatic bulk modulus of elasticity is derived, so that the adiabatic sound speeds are obtained. These obtained results are compared with previous findings using a different approach.
Electrical tuning of the band alignment and magnetoconductance in an n-type ferromagnetic semiconductor (In,Fe)As-based spin-Esaki diode
Authors: Anh Le Duc , Hai Pham Nam , Tanaka Masaaki
Published: March 2018

We report a strong bias dependence of the magnetoconductance (MC) of a spin-Esaki diode composed of n+-type ferromagnetic semiconductor (FMS) (In,Fe)As and p+-type Be doped InAs grown on a p+-InAs (001) substrate by molecular beam epitaxy. When the bias voltage V is increased above 450 mV in the forward bias, we found that the MC, measured at 3.5 K under a magnetic field H of 1 T in the in-plane [110] direction, changes its sign from positive to negative and its magnitude rises rapidly from 0.5% at V < 450 mV to −7.4% at V = 650 mV. Furthermore, the MC magnitude decreases as cos2(θ) when rotating H from the in-plane [110] direction to the perpendicular [001] direction, where θ is the angle between H and the [110] axis. Using a two-fluid model, we explain both the magnitude and the anisotropy of the MC based on the evolution of the spin-Esaki diode's band profile with V. This analysis provides insights into the density of states and spin-polarization of the conduction band and the Fe-related impurity band in n-type FMS (In,Fe)As.
Design and optimization of G-band extended interaction klystron with high output power
Authors: Li Renjie , Ruan Cunjun , Zhang Huafeng
Published: March 2018

A ladder-type Extended Interaction Klystron (EIK) with unequal-length slots in the G-band is proposed and designed. The key parameters of resonance cavities working in the π mode are obtained based on the theoretical analysis and 3D simulation. The influence of the device fabrication tolerance on the high-frequency performance is analyzed in detail, and it is found that at least 5 μm of machining precision is required. Thus, the dynamic tuning is required to compensate for the frequency shift and increase the bandwidth. The input and output coupling hole dimensions are carefully designed to achieve high output power along with a broad bandwidth. The effect of surface roughness of the metallic material on the output power has been investigated, and it is proposed that lower surface roughness leads to higher output power. The focusing magnetic field is also optimized to 0.75 T in order to maintain the beam transportation and achieve high output power. With 16.5 kV operating voltage and 0.30 A beam current, the output power of 360 W, the efficiency of 7.27%, the gain of 38.6 dB, and the 3 dB bandwidth of 500 MHz are predicted. The output properties of the EIK show great stability with the effective suppression of oscillation and mode competition. Moreover, small-signal theory analysis and 1D code AJDISK calculations are carried out to verify the results of 3D PIC simulations. A close agreement among the three methods proves the relative validity and the reliability of the designed EIK. Thus, it is indicated that the EIK with unequal-length slots has potential for power improvement and bandwidth extension.
Development of high intensity X-ray sources at the National Ignition Facility
Authors: May M. J. , Colvin J. D. , Kemp G. E. , Barrios M. A. , Widmann K. , Benjamin R. , Thorn D. , Poole P. , Blue B.
Published: March 2018

Laser heated plasmas have provided recently some of the most powerful and energetic nanosecond length laboratory sources of x-ray photons (Ephoton = 1–30 keV). The highest x-ray to laser conversion is currently accessible by using underdense (ne ∼ 0.25 nc) plasmas since optimal laser coupling is obtained in millimeter scale targets. The targets can have conversion efficiencies of up to 10%. Several types of targets can be used to produce underdense plasmas: metal lined cylindrical cavities, gas pipes, and most recently nano-wire foams. Both the experimental and simulation details of these high intensity x-ray sources are discussed.