bluuebunny/crossref_metadata_2025 huggingface dataset:
Incomplete Ionization of a 110 meV Unintentional Donor in β-Ga2O3 and its Effect on Power Devices
Authors: Neal Adam T. , Mou Shin , Lopez Roberto , Li Jian V. , Thomson Darren B. , Chabak Kelson D. , Jessen Gregg H.
Published: October 2017

Understanding the origin of unintentional doping in Ga2O3 is key to increasing breakdown voltages of Ga2O3 based power devices. Therefore, transport and capacitance spectroscopy studies have been performed to better understand the origin of unintentional doping in Ga2O3. Previously unobserved unintentional donors in commercially available $$(\bar{2}01)$$
(

2
¯

01

)
Ga2O3 substrates have been electrically characterized via temperature dependent Hall effect measurements up to 1000 K and found to have a donor energy of 110 meV. The existence of the unintentional donor is confirmed by temperature dependent admittance spectroscopy, with an activation energy of 131 meV determined via that technique, in agreement with Hall effect measurements. With the concentration of this donor determined to be in the mid to high 1016 cm−3 range, elimination of this donor from the drift layer of Ga2O3 power electronics devices will be key to pushing the limits of device performance. Indeed, analytical assessment of the specific on-resistance (Ronsp) and breakdown voltage of Schottky diodes containing the 110 meV donor indicates that incomplete ionization increases Ronsp and decreases breakdown voltage as compared to Ga2O3 Schottky diodes containing only the shallow donor. The reduced performance due to incomplete ionization occurs in addition to the usual tradeoff between Ronsp and breakdown voltage.
TC-PTP regulates the IL-7 transcriptional response during murine early T cell development
Authors: Pike K. A. , Hatzihristidis T. , Bussières-Marmen S. , Robert F. , Desai N. , Miranda-Saavedra D. , Pelletier J. , Tremblay M. L.
Published: October 2017

Cytokines play a critical role in directing the discrete and gradual transcriptional changes that define T cell development. The interleukin-7 receptor (IL-7R), via its activation of the JAK-STAT pathway, promotes gene programs that change dynamically as cells progress through T cell differentiation. The molecular mechanism(s) directing differential gene expression downstream of the IL-7R are not fully elucidated. Here, we have identified T cell protein tyrosine phosphatase (TC-PTP), also known as PTPN2, as a negative regulator of IL-7R-STAT signaling in T cell progenitors, contributing to both the quantitative and qualitative nature of STAT-gene targeting. Novel genetic strategies used to modulate TC-PTP expression demonstrate that depletion of TC-PTP expression heightens the phosphorylation of STAT family members, causing aberrant expression of an interferon-response gene profile. Such molecular re-programming results in deregulation of early development checkpoints culminating in inefficient differentiation of CD4+CD8+double positive cells. TC-PTP is therefore shown to be required to safeguard the dynamic transcriptome necessary for efficient T cell differentiation.
A Study of the Brain Abnormalities of Post-Stroke Depression in Frontal Lobe Lesion
Authors: Shi Yu , Zeng Yanyan , Wu Lei , Liu Wei , Liu Ziping , Zhang Shanshan , Yang Jianming , Wu Wen
Published: October 2017

Post stroke depression (PSD) is a serious complication of stroke. Brain imaging is an important method of studying the mechanism of PSD. However, few studies have focused on the single lesion location. The aim of this study was to investigate the brain mechanism of frontal lobe PSD using combined voxel-based morphometry (VBM) and functional magnetic resonance imaging (fMRI). In total, 30 first-time ischemic frontal lobe stroke patients underwent T1 weighted MRI and resting-state fMRI scans. Clinical assessments included the 24-item Hamilton Rating Scale for Depression, the National Institutes of Health Stroke Scale, and the Mini-Mental State Examination. In our result, decreased gray matter (GM) volume in patients was observed in the prefrontal cortex, limbic system and motor cortex. The anterior cingulate cortex, selected as a seed to perform connectivity analyses, showed a greatly decreased functional connectivity with the prefrontal cortex, cingulate cortex, and motor cortex, but had an increased functional connectivity with the hippocampus gyrus, parahippocampa gyrus, insular, and amygdala. Stroke lesion location reduces excitability of brain areas in the ipsilateral brain. PSD affects mood through the brain network of the prefrontal-limbic circuit. Some brain networks, including motor cortex and the default mode network, show other characteristics of PSD brain network.
Amorphous lead oxide (a-PbO): suppression of signal lag via engineering of the layer structure
Authors: Semeniuk O. , Grynko O. , Juska G. , Reznik A.
Published: October 2017

Presence of a signal lag is a bottle neck of performance for many non-crystalline materials, considered for dynamic radiation sensing. Due to inadequate lag-related temporal performance, polycrystalline layers of CdZnTe, PbI2, HgI2 and PbO are not practically utilized, despite their superior X-ray sensitivity and low production cost (even for large area detectors). In the current manuscript, we show that a technological step to replace nonhomogeneous disorder in polycrystalline PbO with homogeneous amorphous PbO structure suppresses signal lag and improves time response to X-ray irradiation. In addition, the newly developed amorphous lead oxide (a-PbO) possesses superior X-ray sensitivity in terms of electron-hole pair creation energy $${W}_{\pm }$$

W

±

in comparison with amorphous selenium – currently the only photoconductor used as an X-ray-to-charge transducer in the state-of-the-art direct conversion X-ray medical imaging systems. The proposed advances of the deposition process are low cost, easy to implement and with certain customization might potentially be applied to other materials, thus paving the way to their wide-range commercial use.
Facile, general and template-free construction of monodisperse yolk–shell metal@carbon nanospheres
Authors: Xu Fei , Lu Yuheng , Ma Junhao , Huang Zhike , Su Quanfei , Fu Ruowen , Wu Dingcai
Published: October 2017

A versatile, general and template-free strategy for the construction of well-defined yolk–shell metal@carbon nanostructures is described.
Novel activity-based probes for N-acylethanolamine acid amidase
Authors: Petracca Rita , Romeo Elisa , Baggelaar Marc P. , Artola Marta , Pontis Silvia , Ponzano Stefano , Overkleeft Herman S. , van der Stelt Mario , Piomelli Daniele
Published: October 2017

Two NAAA activity-based probes were generated as tool for the identification of new inhibitors and the investigation of NAAA physiology.
Nickel-catalyzed acetamidation and lactamization of arylboronic acids
Authors: Huang Bo , Zeng Linwei , Shen Yangyong , Cui Sunliang
Published: October 2017

A nickel-catalyzed acetamidation and lactamization of arylboronic acids via a one-pot reaction with ynamides and N-hydroxyphthalimide is described.
Surface phase diagram prediction from a minimal number of DFT calculations: redox-active adsorbates on zinc oxide
Authors: Hellström Matti , Behler Jörg
Published: October 2017

We develop a simple model capable of predicting coverage-dependent adsorption energies for redox-active adsorbates on semiconductor surfaces.
A ring polymer molecular dynamics study of the OH + H2(D2) reaction
Authors: Castillo J. F. , Suleimanov Y. V.
Published: October 2017

Using ring polymer molecular dynamics we have calculated the rate coefficients for the OH + H2 reaction.
Towards a taxonomy of topology for polynuclear aromatic hydrocarbons: linking electronic and molecular structure
Authors: Adkins Erin M. , Miller J. Houston
Published: October 2017

Trends linking topology of PAH to their electronic properties are reported, evaluating how HOMO–LUMO gap depends on structure and size.
Study of the remarkable reactivity of HNCO/urea with NO2 in the NOx SCR by urea process over an oxide-based catalyst
Authors: Seneque M. , Can F. , Barreau M. , Duprez D. , Courtois X.
Published: October 2017

An exceptional reactivity between NO2 and the reductant species was demonstrated during NO2-SCR experiments with urea, when only NO2 was used as NOx.
Retracted Article: Alterations in lipid metabolism due to a protein-restricted diet in rats during gestation and/or lactation
Authors: Sosa-Larios T. C. , A. Miliar-Garcia A. , Reyes-Castro L. A. , Morimoto S. , Jaramillo-Flores M. E.
Published: October 2017

Perinatal malnutrition affects not only fetal and neonatal growth, but also the health of offspring in adulthood, as suggested by the concept of metabolic programming.
Recycling of homogeneous catalysts in reactive ionic liquid – solvent-free aminofunctionalizations of alkenes
Authors: Faßbach Thiemo A. , Kirchmann Robin , Behr Arno , Vorholt Andreas J.
Published: October 2017

Turning down the bed for homogenous catalysts: the use of dimcarb as a reactive ionic liquid, offers the opportunity to carry out different homogeneously transition metal catalyzed aminations without using any solvent, while at the same time efficient catalyst recycling is possible.
Orthoester functionalizedN-guanidino derivatives of 1,5-dideoxy-1,5-imino-d-xylitol as pH-responsive inhibitors of β-glucocerebrosidase
Authors: Sevšek Alen , Sastre Toraño Javier , Quarles van Ufford Linda , Moret Ed E. , Pieters Roland J. , Martin Nathaniel I.
Published: October 2017

Alkylated guanidinium iminosugar derivatives bearing a pH sensitive orthoester moiety are potent and selective β-glucosidase inhibitors.
Exploring the binding mechanism of paraquat to DNA by a combination of spectroscopic, cellular uptake, molecular docking and molecular dynamics simulation methods
Authors: Jafari Fataneh , Moradi Sajad , Nowroozi Amin , Sadrjavadi Komail , Hosseinzadeh Leila , Shahlaei Mohsen
Published: October 2017

The possibility that paraquat may exert its toxicity also by interaction with DNA is studied using a combination of different computational and experimental techniques.
Construction of a selective electrochemical sensing solid–liquid interface for the selective detection of fluoride ion in water with bis(indolyl)methane-functionalized multi-walled carbon nanotubes
Authors: Ni Yue , Liu Hong , Xu Jian , Yue Ying , Shao Shijun
Published: October 2017

A new solid–liquid interface for selective recognition of fluoride ions in water was fabricated based on the Nbim/MWCNT/GCE.
Facile spectroscopic approach to obtain the optoelectronic properties of few-layered graphene oxide thin films and their role in photocatalysis
Authors: Jilani Asim , Othman Mohd Hafiz Dzarfan , Ansari Mohammad Omaish , Kumar Rajeev , Alshahrie Ahmed , Ismail Ahmad Fauzi , Khan Imran Ullah , Sajith Vattam Kandathil , Barakat M. A.
Published: October 2017

Herein, we report the synthesis of few-layered graphene oxide (GO), reduced graphene oxide (rGO), and rGO/ZnO thin films on a glass substrate.
Attomolar detection of extracellular microRNAs released from living prostate cancer cells by a plasmonic nanowire interstice sensor
Authors: Yang Siyeong , Kim Hongki , Lee Kyung Jin , Hwang Seul Gee , Lim Eun-Kyung , Jung Juyeon , Lee Tae Jae , Park Hee-Sung , Kang Taejoon , Kim Bongsoo
Published: October 2017

Extracellular miR141 and miR375 released from living human prostate cancer cell lines were clearly verified by using an extremely sensitive and specific PNI sensor.
Dual stimuli responsive self-healing and malleable materials based on dynamic thiol-Michael chemistry
Authors: Chakma Progyateg , Rodrigues Possarle Luiz Henrique , Digby Zachary A. , Zhang Borui , Sparks Jessica L. , Konkolewicz Dominik
Published: October 2017

Thiol-maleimide adducts are incorporated as crosslinkers into polymer networks and act as pH-responsive and thermoresponsive dynamic crosslinkers, imparting malleability and self-healing properties into the material.
Photothermal effect: an important aspect for the enhancement of photocatalytic activity under illumination by NIR radiation
Authors: Neelgund Gururaj M. , Oki Aderemi
Published: October 2017

A key auxiliary role of the photothermal effect (PTE) in the enhancement of photocatalytic activity under illumination by near-infrared (NIR) radiation has been experimentally revealed.
Interfacial solar heating by self-assembled Fe3O4@C film for steam generation
Authors: Chen Rong , Zhu Kehang , Gan Qimao , Yu Yongqiang , Zhang Tuqiao , Liu Xiaowei , Ye Miaomiao , Yin Yadong
Published: October 2017

Fe3O4@C core–shell nanocrystals are self-assembled into a uniform floating film on water surface for promoting interfacial solar heating toward steam generation.
Thiophene-fused 1,10-phenanthroline toward a far-red emitting conjugated polymer and its polymer dots: synthesis, properties and subcellular imaging
Authors: Yan Chunmei , Sun Zezhou , Guo Hongshuang , Wu Changfeng , Chen Yulan
Published: October 2017

A new far-red emitter based on a conjugated block copolymer was developed, leading to the formation of compact Pdots for specific subcellular imaging.
Facile synthesis of carbo- and heterocycles via Fe(iii)-catalyzed alkene hydrofunctionalization
Authors: Qi Jifeng , Zheng Jing , Cui Sunliang
Published: October 2017

A facile synthesis of carbo- and heterocycles via Fe(iii)-catalyzed alkene hydrofunctionalization has been developed.
Influence of lead-free glass frit in the front contact paste on the conversion efficiency of polycrystalline silicon solar cells
Authors: Ma Qian , Ma Shenghua , Bai Jintao , Wang Hui
Published: October 2017

Due to the demand for a new environmentally friendly silver front conductive paste, it is imperative for silicon solar cells to use nontoxic lead-free glass frits.
Light induced construction of porous covalent organic polymeric networks for significant enhancement of CO2 gas sorption
Authors: Bhowmik Soumitra , Konda Maruthi , Das Apurba K.
Published: October 2017

Porous covalent organic polymers were prepared from self-assembled fibers using a topochemical polymerization reaction and their four times higher CO2 sorption behaviour is demonstrated.
DNA-based nanoscale walking devices and their applications
Authors: Xing Yikang , Liu Bing , Chao Jie , Wang Lianhui
Published: October 2017

Herein we review DNA-based nanoscale walking devices including unipedal, bipedal, multipedal, and other novel walking devices and their applications.
A benzylic linker promotes methyltransferase catalyzed norbornene transfer for rapid bioorthogonal tetrazine ligation
Authors: Muttach F. , Muthmann N. , Reichert D. , Anhäuser L. , Rentmeister A.
Published: October 2017

Benzylic AdoMet analogs enable highly efficient enzymatic transfer of norbornenes to nucleic acids and subsequent tetrazine ligation.
Direct structural identification of carbenium ions and investigation of host–guest interaction in the methanol to olefins reaction obtained by multinuclear NMR correlations
Authors: Xiao Dong , Xu Shutao , Han Xiuwen , Bao Xinhe , Liu Zhongmin , Blanc Frédéric
Published: October 2017

Structural identification of carbenium ion intermediates and quantitative investigation of their interactions with zeolite H-ZSM-5 by multinuclear MAS NMR.
Generalised transmit–receive joint spatial modulation
Authors: Cheng Qian , Zhu Jiang
Published: October 2017

A generalised transmit–receive joint spatial modulation (GTRSM) scheme is proposed, which amalgamates both transmitter‐ and receiver‐side spatial modulation (SM) schemes. The proposed GTRSM jointly employs the combinations of multiple instead of a single activated transmit and receive antennas and baseband symbols to transmit information. The optimal maximum‐likelihood detector for GTRSM is formulated, and the channel capacity of GTRSM is also analysed. Simulated results demonstrate that the proposed GTRSM behaves good BER performance and can significantly improve the channel capacity compared with conventional SMs.
Sub‐sampling of RF and THz waves using LT‐GaAs photoconductors under 1550 nm light excitation
Authors: Billet M. , Desmet Y. , Bavedila F. , Barbieri S. , Hänsel W. , Holzwarth R. , Ducournau G. , Lampin J.‐F. , Peytavit E.
Published: October 2017

Low‐temperature‐grown GaAs (LT‐GaAs)‐based Fabry–Pérot cavity photoconductors, designed for RF and THz optoelectronics applications using1550 nm lasers, are studied. The sub‐sampling of continuous waves at frequencies up to 300 GHz is presented. The duty‐cycle‐limited conversion losses measured up to 67 GHz show that this GaAs‐based photoconductor behaves as a nearly perfect photoswitch controlled by a 1550 nm pulsed laser.
Triple‐mode cavity bandpass filter under excitation via U‐shaped slots
Authors: Guo Zai‐Cheng , Wong Sai‐Wai , Lin Jing‐Yu , Zhu Lei , Chu Qing‐Xin
Published: October 2017

A triple‐mode narrow‐band bandpass filter is presented by exploiting three fundamental resonant modes, TE101, TE011 and TM110 modes, in a single air‐filled rectangular cavity. Compared with the conventional multimode cavity filter, the proposed filter is to simultaneously excite these three resonant modes without installing any cuts or screws inside the cavity, so as to keep the integrity of the cavity and decrease the fabrication cost. In particular, an inclined U‐shaped slot is utilised at each of the microstrip feed line to properly excite these three modes such that not only three poles are achieved within the desired passband but also a pair of transmission zeros are generated in the lower and upper stop‐bands. A single metal rectangular filter is finally fabricated and tested. The measured results have well validated the simulated results.
Precise dq model development of linear flux switching motors with segmented secondary for rail transportation applications
Authors: Hosseini Monir Sadat , Javadi Hamid , Vaez‐Zadeh Sadegh , Abdollahi Seyed Ehsan
Published: October 2017

A dq model representation of segmented secondary linear flux switching motors (SSLFSMs) is investigated. In these motors, the armature and field windings are both mounted in the primary slots and the secondary is only composed of simple laminated segments. This type of motors inherits both merits of high force density from linear synchronous motors and simple secondary structure from linear induction motors. Due to its simple and consequently low‐cost secondary structure, it is applicable to transportation systems like Maglev. Position and speed control of this motor is essential for rail transportation applications. Therefore, derivation of an appropriate analytical model for control purposes is needed. An analytical method to represent the dq model of SSLFSMs is presented. Employing this method, the d‐ and q‐axis inductances and the developed electromagnetic thrust and normal force are calculated. To verify the proposed model, three different finite‐element method‐based models are studied and one is chosen as the basis for comparison. All results obtained by the analytical model are verified by this finite‐element method‐based model. Moreover, a prototype of SSLFSMs is built to validate the study.
Least error squared phasor estimation with identification of a decaying DC component
Authors: Hwang Jin Kwon
Published: October 2017

A fault current in a power system contains both harmonics and a decaying DC component, which can produce a severe error in phasor estimation of fundamental frequency. Currently, full‐cycle discrete Fourier transform phasor estimation is widely used in numerical relays owing to harmonics immunity, which produces easy identification of the decaying DC component. It is desirable to promptly estimate the phasor for a fast protection of the power system. Such promptness is dependent on the data window length of the phasor estimation. The least error squares (LESs) method is effective to achieve this promptness as it can estimate the phasor with a data window length of less than one cycle. This study proposes a phasor estimation method using LES with the data window length less than one cycle. The time constant of the decaying DC is identified through Prony analysis, while the noise effect on the phasor estimation is investigated according to the data window length. The performances of the proposed method are investigated through simulations on time constants of the decaying DC, frequency deviations of the power system, and signal‐to‐noise ratio. The feasibility of the proposed method is verified to estimate the phasor of a fault transmission line in a MATLAB/Simulink.
Out‐of‐step protection of synchronous generators based on a digital phase comparison in the time domain
Authors: Ostojić Mladen M. , Djurić Milenko B.
Published: October 2017

The study presents a new out‐of‐step algorithm used for the protection of synchronous generators. The algorithm is implemented on the principle of a digital phase comparison in the time domain. Phase voltages and currents measured at the generator bus bars are used as input signals. On the basis of the measured phase voltages and currents and known generator parameters, the internal voltages of the generator in the time domain are calculated. The algorithm compares the phase and internal voltages of synchronous generator and on the basis of the out‐of‐step index it detects a disturbance. Model of the test network is implemented in MATLAB/Simulink software package. The algorithm was tested on turbo and hydro‐generator models. The proposed algorithm test results were compared with a conventional method based on measurement of the impedance. The obtained results show good properties of the proposed algorithm.
Improving power system stability in the presence of wind farms using STATCOM and predictive control strategy
Authors: Darabian Mohsen , Jalilvand Abolfazl
Published: October 2017

In this study, a multi‐objective predictive control strategy is presented for the stability improvement of a power system in the presence of wind farms and STATCOM. The main contribution of this study is in the multi‐objective consideration for controlling the active and reactive powers of the rotor‐side converter in each of the induction generators, controlling the voltage of the synchronous generators’ excitation system, and designing the damping controller of STATCOM using the predictive strategy. To reduce the computational burden, and to accurately choose the input paths into the predictive control, the Laguerre functions are used. Also, for reducing the sampling time in the selection of large prediction horizons, the exponential data weighting has been employed. The simulation results were evaluated using MATLAB software in the field of time and frequency under different scenarios. Moreover, the obtained results of each domain are compared using the two techniques of the predictive strategy, i.e. the classic model, Laguerre functions, and also the conventional proportional integral controller. The comparison of these three methods reveals that the functional predictive control outfits the two other controllers in damping of the oscillations.
Flaring of blazars from an analytical, time-dependent model for combined synchrotron and synchrotron self-Compton radiative losses of multiple ultrarelativistic electron populations
Authors: Röken Christian , Schuppan Florian , Proksch Katharina , Schöneberg Sebastian
Published: October 2017

We present a fully analytical, time-dependent leptonic one-zone model that describes a simplified radiation process of multiple interacting ultrarelativistic electron populations and accounts for the flaring of GeV blazars. In this model, several mono-energetic, ultrarelativistic electron populations are successively and instantaneously injected into the emission region, that is, a magnetized plasmoid propagating along the blazar jet, and subjected to linear, time-independent synchrotron radiative losses, which are caused by a constant magnetic field, and nonlinear, time-dependent synchrotron self-Compton radiative losses in the Thomson limit. Considering a general (time-dependent) multiple-injection scenario is, from a physical point of view, more realistic than the usual (time-independent) single-injection scenario invoked in common blazar models, as blazar jets may extend over tens of kiloparsecs and thus most likely pick up several particle populations from intermediate clouds. We analytically compute the electron number density by solving a kinetic equation using Laplace transformations and the method of matched asymptotic expansions. Moreover, we explicitly calculate the optically thin synchrotron intensity, the synchrotron self-Compton intensity in the Thomson limit, as well as the associated total fluences. In order to mimic injections of finite duration times and radiative transport, we model flares by sequences of these instantaneous injections, suitably distributed over the entire emission region. Finally, we present a parameter study for the total synchrotron and synchrotron self-Compton fluence spectral energy distributions for a generic three-injection scenario, varying the magnetic field strength, the Doppler factor, and the initial electron energy of the first injection in realistic parameter domains, demonstrating that our model can reproduce the typical broadband behavior seen in observational data.
Developing a Bench-Scale Green Diboration Reaction toward Industrial Application
Authors: Pubill-Ulldemolins Cristina , Bonet Amadeu , Farre Albert , Briggs Rachel
Published: October 2017

We report a new methodology for the organocatalytic diboration reaction using inexpensive, sustainable, nontoxic, commercially available halogen salts. This is an educative manuscript for the transformation of laboratory scale reactions into a sustainable approach of appeal to industry.
Vitamin E in the Preterm Infant: A Forgotten Cause of Hemolytic Anemia
Authors: Hatfield Emily , Garlitz Karen , Westgate Philip , Bada Henrietta , Gomez-Pomar Enrique
Published: October 2017

Objective Vitamin E deficiency in premature infants has been associated with hemolytic anemia. Its incidence decreased after the supplementation of preterm formulas and parenteral nutrition with vitamin E. Despite this, some infants still develop hemolytic anemia and receive vitamin E.

Study Design Retrospective analysis of 70 infants admitted to a level IV intensive care unit and who developed hemolytic anemia and were treated with vitamin E. Infants were classified into two groups based on whether or not they responded to vitamin E therapy. Statistical methods included the use of descriptive statistics and marginal logistic regression models.

Results Low hematocrit and reticulocytosis before vitamin E administration were associated with adequate response to treatment. Thrombocytosis, iron treatment (duration and dose), gestational age, birth weight, and type of feedings were not. Infants who received a short duration of parenteral nutrition and were on oxygen responded to vitamin E therapy. Infants with a hematocrit ≤ 26% and reticulocyte of 36.1% were more likely to respond to vitamin E.

Conclusion Although formulas and parenteral nutrition are supplemented with vitamin E; some preterm infants may still develop hemolytic anemia. Those with anemia, reticulocytosis, and oxygen requirement may benefit from additional vitamin E.
Non-operative Management for Uncomplicated Appendicitis: An Option to Consider
Authors: Trabanino Carmen , Pinnagoda Kalitha , Ait Kaci Amir , Carfagna Luana , Mouttalib Sofia , Combelles Sophie , Vial Julie , Galinier Philippe , Abbo Olivier
Published: October 2017

Aim The main goal of our study was to assess a 7 days long course of antibiotics for acute uncomplicated appendicitis.

Materials and Methods From March 2014 to November 2015, all patients diagnosed with acute appendicitis have been considered to be treated by only antibiotics. Inclusion criteria included clinical (tenderness), biological (C-reactive protein [CRP] < 50), and radiological features (diameter > 6 mm). All patients were treated with intravenous amoxicillin and clavulanic acid (100 mg/kg/day) for 2 days (six doses). At the end of the treatment, clinical and paraclinical examinations included blood samples at day 7 and ultrasound (US) scan at 3 months.

Results A total of 166 patients were treated and followed up prospectively during the study period. Mean age at diagnosis was 10.8 ± 0.6 years. All children, but four were discharged with a clinical improvement after 48 hours and six intravenous antibiotics injection according to our protocol. Four children required surgery during the initial hospitalization period.

Initial ultrasound scan showed a mean diameter of 7.85 ± 1.6 mm, with inflamed fat in 124 patients (74.7%). At Day 7, the diameter was 5.2 ± 1.6 mm (p < 0.0001).

During a median follow-up of 18.8 months (3.5–18), 22 patients (13.25%) had to be managed for a novel episode of acute appendicitis after a median period of 138 days (13–270). None had to be managed for a complicated appendicitis.

Conclusion Non-operative treatment (NOT) is a safe alternative for the management of uncomplicated acute appendicitis in children. Further study should be conducted to determine relapse risk factors.
Intensivmedizinische Aspekte der interventionellen Therapie von Herzklappenerkrankungen
Authors: Reith Sebastian , Marx Nikolaus
Published: October 2017

Was ist neu?

Intensivmedizinische Nachbehandlung der interventionellen Aortenklappenintervention (TAVI) Durch die Indikationsausweitung der TAVI auf Patienten mit intermediären Operationsrisiko und der gleichzeitigen Vorgabe zur Einhaltung struktureller Voraussetzungen für die postinterventionelle intensivmedizinische Versorgung durch den GBA werden zukünftig große logistische, kapazitäre und personelle Herausforderungen an die Intensivmedizin gestellt.

Interventionelle Mitralklappentherapie mittels MitraClip-Verfahren Mit der hauptsächlichen MitraClip®-Behandlung von Patienten mit funktioneller Mitralinsuffizienz auf dem Boden einer eingeschränkten linksventrikulären Funktion im klinischen Alltag stellt dieses interventionelle Therapieverfahren eine intensivmedizinische Herausforderung in der frühen postinterventionellen Phase dar.
Einflussfaktoren auf chronische Rückenschmerzen bei Pflegekräften in der Altenpflege in Rheinland-Pfalz
Authors: Frey Dorothee , Rieger Sandra , Diehl Elisabeth , Pinzon Luis
Published: October 2017

Einleitung Die vorliegende Studie ermittelt die Lebenszeitprävalenz chronischer Rückenschmerzen bei Altenpflegekräften in rheinland-pfälzischen Einrichtungen und identifiziert potentielle Einflussfaktoren.

Methodik Im Rahmen einer Querschnittserhebung wurden 155 Pflegekräfte aus 5 Altenpflegeeinrichtungen untersucht und schriftlich befragt. Ausschnitte aus verschiedenen standardisierten Fragebögen wurden mit eigenen Fragen kombiniert und ergänzt durch eine körperliche Untersuchung mit 2 standardisierten Belastungstests. Die Daten wurden deskriptiv und bivariat sowie mittels binärlogistischer Regressionsanalyse ausgewertet.

Ergebnisse Die Pflegekräfte waren zu 83,8% weiblich, das Durchschnittsalter lag bei 41 Jahren. Die Lebenszeitprävalenz chronischer Rückenschmerzen bei weiblichen Pflegekräften betrug 50,8%, bei männlichen Pflegekräften lag sie bei 20,0%. Als potentielle Einflussfaktoren für chronische Rückenschmerzen konnten ein schlechter subjektiver Gesundheitszustand und eine schwache Ausdauer der Rückenmuskulatur identifiziert werden.

Schlussfolgerung Die Lebenszeitprävalenz chronischer Rückenschmerzen war bei den Pflegekräften höher als in den Daten zur Allgemeinbevölkerung. Diskutierte Einflussfaktoren für Rückenschmerzen, wie z. B. zu viele patientenferne Aufgaben, Zeitdruck oder die Arbeit mit zu vielen Bewohnern erwiesen sich als nicht signifikant. Der subjektive Gesundheitszustand und die Ausdauer der Rückenmuskulatur standen dagegen in Zusammenhang mit Rückenschmerzen. Prospektive Studien zu physischen und psychischen Belastungen, Beanspruchungen und Ressourcen sind notwendig, um die Kausalität der hohen Lebenszeitprävalenz von chronischen Rückenschmerzen bei Altenpflegekräften besser verstehen zu können.
Morbus Behçet
Authors: Kötter Ina
Published: October 2017

Was ist neu?

Epidemiologie Die Prävalenz bei deutschstämmigen Patienten ist 0,9/100 000, bei türkischstämmigen 77/100 000. HLA-B51 ist mit der Augenbeteiligung assoziiert, Männer haben schwerere Verläufe.

Pathogenese Neben HLA-B51 ist auch HLA-A26 mit der Erkrankung assoziiert. Zusätzlich gibt es Assoziationen mit Mutationen im IL12/23-Rezeptor-Gen. Der M. Behçet wird inzwischen als intermediäre, partiell autoinflammatorische Erkrankung betrachtet.

Therapie In den neuen EULAR-Empfehlungen wird für die schwere Augenbeteiligung Adalimumab gleichrangig mit Infliximab und Interferon-alpha empfohlen. Adalimumab ist für die schweren (nicht anterioren) Uveitiden inklusive der bei M. Behçet zugelassen. Infliximab wird als Primärtherapie bei ZNS-Beteiligung empfohlen. Bei Thrombosen im Rahmen der Erkrankung muss vorrangig die Entzündungsaktivität beherrscht werden, eine Antikoagulation wird nicht mehr bzw. nur noch vorübergehend empfohlen. Apremilast wird aktuell in Studien für die mukokutanen Manifestationen untersucht und wird für diese ebenfalls bereits empfohlen.
Das Konzept der umweltbedingten Krankheitslast
Authors: Tobollik Myriam , Plaß Dietrich , Steckling Nadine , Zeeb Hajo , Wintermeyer Dirk , Hornberg Claudia
Published: October 2017

Ziel der Studie Umweltrisikofaktoren haben häufig eine hohe gesundheitliche Relevanz mit einem großen und z. T. nicht ausreichend genutzten Präventionspotenzial. Das Wissen über die komplexen Wirkungszusammenhänge zwischen Umwelt und Gesundheit ist für einige Umweltrisikofaktoren begrenzt. Ein Instrument, das bestehende Evidenz nutzt, um die gesundheitlichen Auswirkungen für eine Bevölkerung oder Bevölkerungsgruppe zu quantifizieren, ist das Konzept der umweltbedingten Krankheitslast (Environmental Burden of Disease, EBD). Ziel des Beitrages ist es, das Konzept der umweltbedingten Krankheitslast vorzustellen sowie den Nutzen aber auch die Kritikpunkte zu benennen.

Methodik EBD fasst Morbiditäts- und Mortalitätsdaten in einem Summenmaß, dem Disability-Adjusted Life Year (DALY), zusammen und ermöglicht eine vergleichende Darstellung von Krankheitslasten. Hierfür werden Lebensjahre als Einheit genutzt. Mithilfe des attributablen Anteils kann ermittelt werden, welcher Anteil der Gesamtkrankheitslast auf umweltbedingte Risikofaktoren zurückzuführen ist.

Ergebnisse Das EBD-Konzept wird, trotz seiner zunehmenden Anwendung im internationalen Raum, häufig kritisch diskutiert, da die Einschränkung des mehrdimensionalen Konstrukts Gesundheit in einer Maßzahl zusammengefasst wird. Weitere Kritik bezieht sich auf die sozialen und normativen Konventionen, die das Konzept beinhaltet. Fehlende oder unzureichende Eingangsdaten können zudem die Qualität und Aussagekraft von EBD-Schätzungen limitieren.

Schlussfolgerung Es bedarf eines wissenschaftlichen Diskurses, in welchem Rahmen das Konzept in Deutschland genutzt werden kann und sollte.
Kombinierte chirurgische Therapie von Shuntinfekt und
zentralvenöser Stenose
Authors: Krönung Gerhard
Published: October 2017

Die einzeitige Sanierung eines segmentalen Shuntveneninfektes erkauft den
Funktionserhalt um den Preis eines erhöhten Risikos einer Infektpersistenz oder
Infektexazerbation. Die hetero tope Shuntrekonstruktion ist hier im Einzelfall
ein eleganter, alternativer Lösungsweg.
Herpes Zoster – Empfehlungen der konsensbasierten Europäischen Leitlinie
Authors: Werner Ricardo , Eisert Lisa , Nast Alexander
Published: October 2017

Was ist neu?

Diagnosestellung Bei diagnostischer Unsicherheit wird die Anwendung molekulargenetischer Untersuchungen oder alternativ Antigen-basierter Tests empfohlen.

Weiterführende Diagnostik Risikofaktoren und klinische Zeichen für komplizierte Verläufe sollten erfasst werden und erfordern ggf. weiterführende diagnostische Maßnahmen.

Therapieziele und Indikationen zur systemischen antiviralen Behandlung Insbesondere Patienten mit Risikofaktoren für eine kompliziert verlaufende Erkrankung sollten eine systemische antivirale Therapie erhalten. Für junge Patienten ohne Risikofaktoren wurde eine relative Therapieindikation ausgesprochen.

Wie sollte behandelt werden? Die Auswahl der antiviralen Medikation sollte gemeinsam mit dem Patienten unter Berücksichtigung der Praktikabilität, Therapiekosten, Kontraindikationen und Komorbiditäten erfolgen. Patienten mit Risikofaktoren für komplizierte Verläufe sollten bevorzugt mit parenteralem Aciclovir behandelt werden.

Spezifische Situationen Die ergänzende systemische Verabreichung von Kortikosteroiden wird nur in spezifischen Situationen (z. B. akute Retinanekrose, Ramsay-Hunt-Syndrom) und in Konsultation mit den entsprechenden Fachdisziplinen empfohlen.

Schmerztherapie Eine suffiziente Schmerztherapie unter Berücksichtigung des WHO-Stufenschemas und Einbezug von Komedikation soll frühzeitig erfolgen.

Lokalbehandlung Die Studienlage für spezifische Ansätze der Lokaltherapie ist unzureichend und es konnte innerhalb des Expertengremiums keine Einigung für eine spezifische Empfehlung erzielt werden.
Hörverbesserung durch Tympanoplastik
Authors: Plontke Stefan K. , Zirkler Jonas
Published: October 2017

Die grundlegenden Techniken der Tympanoplastik wurden Anfang der 1950er Jahre
entwickelt und seitdem verfeinert und modifiziert; die Grundprinzipien haben
aber auch heute noch ihre Bedeutung. Als Transplantatmaterialien finden
überwiegend Knorpel und Perichondrium Verwendung. Zur Ossikelrekonstruktion
haben sich insbesondere Titanprothesen als vorteilhaft erwiesen.
Leitlinien in der Praxis: Die neue S3-Leitlinie „Nicht
erholsamer Schlaf/Schlafstörungen“ – Kapitel „Schlafbezogene
Atmungsstörungen“
Authors: Gerlach Martin , Sanner Bernd
Published: October 2017

Zu den schlafbezogenen Atmungsstörungen zählen die zentrale Schlafapnoe (ZSA),
die obstruktive Schlafapnoe (OSA) und die schlafbezogene Hypoventilation bzw.
Hypoxämie. Sie sind häufig und von zunehmender klinischer Relevanz. Das Kapitel
zu dieser Krankheitsgruppe aus der S3-Leitlinie „Nicht erholsamer
Schlaf/Schlafstörungen“ der Deutschen Gesellschaft für Schlafmedizin wurde am
29. November 2016 aktualisiert und bietet Neuerungen zu Epidemiologie,
Diagnostik, Therapie und Systematik. Zur Epidemiologie wird die deutlich erhöhte
Mortalität schwangerer Frauen mit OSA herausgestellt. In der Diagnostik der OSA
wird betont, dass die Polygrafie unter bestimmten Voraussetzungen ausreichen
kann. Änderungen der diagnostischen Empfehlungen zur ZSA erlauben nun die
Diagnosestellung auch bei geringer Apnoerate unter der Voraussetzung einer
typischen klinischen Situation. Entscheidende therapeutische Unterschiede haben
sich bei der ZSA mit Herzinsuffizienz ergeben. Ferner wird differenziert
zwischen schlafbezogener Hypoventilation und schlafbezogener Hypoxämie. Das
Obesitas-Hypoventilations-Syndrom wird insgesamt breiter besprochen. Der
vorliegende Artikel fasst die Änderungen zusammen und kommentiert sie.
Management der Unterschenkelvenenthrombose
Authors: Schellong Sebastian
Published: October 2017

Was ist neu?

Natürlicher Verlauf der ICVT Die isolierte Wadenvenenthrombose hat ein bewiesenermaßen geringeres Schadenspotenzial für den Patienten als eine proximale Beinvenenthrombose.

Evidenz für die Therapie Für die Gesamtheit aller Fälle von ICVT wächst die Evidenz, dass die Antikoagulation weitere VTE-Ereignisse in der Häufigkeit reduziert. Die „number needed to treat“ ist jedoch bedeutend höher als für die proximale TVT. Es gibt eine Patientengruppe von ICVT mit so niedrigem Risiko, dass sie keiner Behandlung bedarf. Ihre Charakterisierung ist wenig datenbasiert.

Aktueller Stand der Leitlinien Aktuelle Leitlinien lassen einen Korridor, Patienten mit ICVT nicht zu antikoagulieren.
Asymptomatische Hyperurikämie: Risikofaktor für die Entstehung und Progression einer chronischen Nierenerkrankung
Authors: Kälsch Anna-Isabelle , Krüger Bernd
Published: October 2017

Was ist neu?

Auftreten einer chronischen Niereninsuffizienz Epidemiologische Studien deuten klar auf einen Einfluss der asymptomatischen Hyperurikämie in der Entwicklung einer chronischen Niereninsuffizienz hin. Allerdings ist die Frage, ob eine erhöhte Harnsäure ursächlich für die Ausbildung einer Niereninsuffizienz ist oder lediglich einen Surrogatparameter darstellt, noch nicht abschließend geklärt.

Progression der chronischen Niereninsuffizienz und Mortalität Der Zusammenhang der asymptomatischen Hyperurikämie mit einer Progression einer bestehenden chronischen Niereninsuffizienz ist weit weniger eindeutig, gut belegt ist jedoch die Assoziation mit einer erhöhten Mortalität.

Transplantatfunktion und Mortalität nach Nierentransplantation Neben einer Assoziation mit einem Progress einer chronischen Niereninsuffizienz finden sich vergleichbare Daten bzgl. eines Transplantatverlustes nach Nierentransplantation.

Einfluss der Intervention auf die Progression Neben der Therapie der Gicht erscheint die Senkung des Harnsäurespiegels ebenfalls positive Effekte auf die renale Funktion zu haben. Ergebnisse kleinerer Studien sind hierzu sehr vielversprechend, müssen aber in größeren, randomisierten Studien, bestätigt werden, um verbindliche Empfehlungen zur Therapie der asymptomatischen Hyperurikämie aussprechen zu können.

Senkung der Harnsäure durch SLGT2-Inhibitoren Subgruppenanalysen zeigen, dass SLGT2-Inhibitoren neben ihrer glukosurischen auch eine urikosurische Wirkung besitzen und den Harnsäurespiegel signifikant senken können. Inwieweit dies zum nephroprotektiven Effekt dieser Substanzen beiträgt, müssen weitere Subgruppenanalysen und/oder Studien noch beantworten.
Linked color imaging (LCI), a novel image-enhanced endoscopy technology, emphasizes the color of early gastric cancer
Authors: Kanzaki Hiromitsu , Takenaka Ryuta , Kawahara Yoshiro , Kawai Daisuke , Obayashi Yuka , Baba Yuki , Sakae Hiroyuki , Gotoda Tatsuhiro , Kono Yoshiyasu , Miura Ko , Iwamuro Masaya , Kawano Seiji , Tanaka Takehiro , Okada Hiroyuki
Published: October 2017

Background and study aims Linked color imaging (LCI) and blue laser imaging (BLI) are novel image-enhanced endoscopy technologies with strong, unique color enhancement. We investigated the efficacy of LCI and BLI-bright compared to conventional white light imaging (WLI) by measuring the color difference between early gastric cancer lesions and the surrounding mucosa.

Patients and methods Images of early gastric cancer scheduled for endoscopic submucosal dissection were captured by LCI, BLI-bright, and WLI under the same conditions. Color values of the lesion and surrounding mucosa were defined as the average of the color value in each region of interest. Color differences between the lesion and surrounding mucosa (ΔE) were examined in each mode. The color value was assessed using the CIE L*a*b* color space (CIE: Commission Internationale d’Eclairage).

Results We collected images of 43 lesions from 42 patients. Average ΔE values with LCI, BLI-bright, and WLI were 11.02, 5.04, and 5.99, respectively. The ΔE was significantly higher with LCI than with WLI (P < 0.001). Limited to cases of small ΔE with WLI, the ΔE was approximately 3 times higher with LCI than with WLI (7.18 vs. 2.25). The ΔE with LCI was larger when the surrounding mucosa had severe intestinal metaplasia (P = 0.04). The average color value of a lesion and the surrounding mucosa differed. This value did not have a sufficient cut-off point between the lesion and surrounding mucosa to distinguish them, even with LCI.

Conclusion LCI had a larger ΔE than WLI. It may allow easy recognition and early detection of gastric cancer, even for inexperienced endoscopists.
Comparative evaluation of two porcine ex vivo models for training in endoscopic ultrasound-guided drainage of pancreatic fluid collections
Authors: Moryoussef Frederick , Leblanc Sarah , Bertucat Alice , Laquiere Arthur , Coron Emmanuel , Mangialavori Luigi , Duchmann Jean-Christophe , Le Baleur Yann , Prat Frederic
Published: October 2017

Introduction EUS-guided cystoenterostomy (EUCE), a technique used for the drainage of pancreatic pseudocysts and peri-enteric collections, requires specific skills for which dedicated models are needed. Based on a compact EASIE model (Erlangen Active Simulator for Interventional Endoscopy), we developed two ex vivo porcine models of retrogastric cysts and evaluated learning performance within the frame of a structured training program.

Material and methods The first model was made of porcine colon (i. e. “natural cyst”), the second one with an ostomy bag (i. e. “artificial cyst”). All procedures were achieved with an EUS scope under fluoroscopy. Both models were evaluated prospectively over a 2-day session involving 14 students and five experts. The primary end point was overall satisfaction with each model.

Results The “natural cyst” and “artificial cyst” were prepared within 10 and 16.5 minutes (P = 0.78), respectively. Model grading showed a non-significant trend for overall satisfaction in favor of the artificial model (P = 0.06). As secondary end points, difference was not significant for impression of realism (P = 0.75) whereas the “artificial cyst” was graded significantly better by experts and students in terms of ability to teach procedural steps (P = 0.01) and ease of puncture (P = 0.03). Moreover, experts considered the ability to improve students’ proficiency to be superior with the “artificial cyst” (P = 0.008).

Conclusion Both “artificial” and “natural cysts” are efficient for EUCE training in terms of overall satisfaction. However, the “artificial cyst” model appears to make the procedure easier with a higher ability to teach procedural steps and improve the students’ proficiency. Larger applications of this model are needed to validate as a standard of training.
Antikörpergesteuerte Transplantatabstoßung nach
Nierentransplantation
Authors: Thorban Stefan , Hüser Norbert , Aßfalg Volker , Renders Lutz , Matevossian Edouard
Published: October 2017

Die antikörpervermittelte Abstoßung nach einer Nierentransplantation mit dem
Nachweis von (de novo) donorspezifischen HLA-Antikörpern gehört derzeit zu den
größten Herausforderungen bei der Nierentransplantation. Ungeklärt bleiben
letztlich die Bedeutung von Persistenz oder Verlust der donorspezifischen
Antikörper und wie die Therapie bei gefährdeten Patienten aussehen sollte. Wer
sollte zu welchem Zeitpunkt und mit welchem Medikamentenprotokoll eine
Desensibilisierung erhalten? In dieser Übersicht werden diagnostische und
therapeutische Verfahrensweisen bezüglich der antikörpervermittelten Abstoßung
und bei hochimmunisierten Patienten bei Nierentransplantation dargestellt und
Strategien zur Vermeidung einer antikörpervermittelten Rejektion aufgezeigt.
Simplified expressions that incorporate finite pulse effects into coherent two-dimensional optical spectra
Authors: Do Thanh Nhut , Gelin Maxim F. , Tan Howe-Siang
Published: October 2017

We derive general expressions that incorporate finite pulse envelope effects into a coherent two-dimensional optical spectroscopy (2DOS) technique. These expressions are simpler and less computationally intensive than the conventional triple integral calculations needed to simulate 2DOS spectra. The simplified expressions involving multiplications of arbitrary pulse spectra with 2D spectral response function are shown to be exactly equal to the conventional triple integral calculations of 2DOS spectra if the 2D spectral response functions do not vary with population time. With minor modifications, they are also accurate for 2D spectral response functions with quantum beats and exponential decay during population time. These conditions cover a broad range of experimental 2DOS spectra. For certain analytically defined pulse spectra, we also derived expressions of 2D spectra for arbitrary population time dependent 2DOS spectral response functions. Having simpler and more efficient methods to calculate experimentally relevant 2DOS spectra with finite pulse effect considered will be important in the simulation and understanding of the complex systems routinely being studied by using 2DOS.