bluuebunny/crossref_metadata_2025 huggingface dataset:
Protective Effects of Hypericum perforatum and Quercetin in a Rat Model of Ischemia/Reperfusion Injury of Testes
Authors: Tekin Leyla , Erdemli Mehmet , Erturk Nazile , Aksungur Zeynep , Aktas Serdar , Suzen Alev
Published: August 2017

Purpose This study aimed to compare the protective effects of Hypericum perforatum (Hp) and quercetin, a flavonoid, against ischemia/reperfusion (I/R) injury in rat testes.

Materials and Methods This study included 28 male Wistar albino rats that were divided into four groups. Except for the sham group, torsion was created by rotating both testes at an angle of 720 degrees clockwise for 2 hours. The Hp and quercetin groups received 25 mg/kg Hp and quercetin intraperitoneally 30 minutes before detorsion, respectively. Orchiectomy was performed for the measurement of markers of oxidative stress and histopathological examination.

Results In the Hp and quercetin groups, malondialdehyde (MDA) and nitric oxide (NO) levels and total oxidant capacity were significantly lower, the glutathione level and total antioxidant status were significantly higher, and Johnsen's testis biopsy scores were significantly higher than in the torsion/detorsion group (p ˂ 0.001). The markers of oxidative injury were significantly lower (p ˂ 0.001) and total antioxidant status was significantly higher (p ˂ 0.001), except for glutathione (p = 0.62) in the Hp group than in the quercetin group. Johnsen's score between Hp and quercetin groups was not significantly different (p = 0.80).

Conclusion Both Hp and quercetin have protective effects against I/R injury of the testes, but the protective effect of Hp was found to be stronger than that of quercetin.
Understanding Experiences of Youth Growing Up with Anorectal Malformation or Hirschsprung's Disease to Inform Transition Care: A Qualitative In-Depth Interview Study
Authors: Nah Shireen , Ong Caroline , Lie Desiree , Marimuttu Vicknesan , Hong Julian , Te-Lu Yap , Low Yee , Jacobsen Anette
Published: August 2017

Introduction The impact of anorectal malformation (ARM) or Hirschsprung's disease (HD) in children continues into adulthood despite early surgical correction. We aimed to explore the physical, social, and emotional impacts of these conditions on youth to inform best transition care strategies.

Materials and Methods Eligible participants were those aged between 14 and 21 years who had undergone surgery for ARM/HD in our institution. We conducted one-on-one in-depth interviews to saturation using a question guide developed from literature review and clinician expertise. Deidentified transcripts were coded by four coders (two pediatric surgeons, one psychiatrist, and one qualitative expert) for major themes using a constant comparison approach. A theoretical model for understanding the transition experience was developed using grounded theory.

Results Out of 120 patients identified as eligible, 11 youth (6 males) participated in the study. Interviews lasted from 50 to 60 minutes. Four major themes emerged: (1) social support (subthemes: family as core, friends as outer support), (2) cognitive and emotional change (subthemes: realization/recognition of illness, matching emotional response), (3) impact of physical symptoms (subthemes: adverse effects of abnormal bowel habits, gaining bowel continence control leading to overall feeling of control, need to keep disease private), and (4) healthcare providers (viewed as important information sources). Themes did not differ by gender.

Conclusion Our model suggests that participants' understanding of bowel disease evolved over time with a “lightbulb” moment in preteens or early teens accompanied by increasing disease ownership and self-management. Clinicians should independently engage with patients in late childhood to address evolving emotional and information needs and encourage increasing autonomy. Future studies should explore communication approaches to meet transition needs of patients.
Diagnosis and Management of Narcolepsy
Authors: Schneider Logan , Mignot Emmanuel
Published: August 2017

Type 1 narcolepsy is caused by deficient hypocretin signaling in the central nervous system (CNS), and is distinct from other primary CNS hypersomnias, which seem to lay along a spectrum from type 2 narcolepsy to idiopathic hypersomnia. There appears to be a strong autoimmune diathesis to the development of type 1 narcolepsy, as evidenced by the near universal presence of HLA-DQB1*06:02 in patients. Growing knowledge of the immunogenetic basis of the disease is supported by genetic studies and seasonal variation of type 1 narcolepsy incidence following winter upper respiratory infections (e.g., strep throat and influenza). Despite improved diagnostic accuracy of adding cerebrospinal fluid hypocretin measurement to the traditional workup, recognition of the disorder remains limited by its moderate prevalence and atypical manifestations in different ethnic groups. Treatments are currently symptom-based, and have been extended to other hypersomnias with mixed results.
Corticosteroid Therapy in Neonatal Septic Shock—Do We Prevent Death?
Authors: Altit Gabriel , Vigny-Pau Myriam , Barrington Keith , Dorval Véronique , Lapointe Anie
Published: August 2017

Objective The aim was to compare survival of patients with septic shock receiving or not hydrocortisone (HC) and to analyze the hemodynamic response to HC.

Study Design It is a retrospective study of 62 premature neonates with septic shock (confirmed bacteremia) and/or necrotizing enterocolitis (NEC) stage 2 and above receiving inotropes with or without HC. We analyzed survival and hemodynamic response to HC.

Results Thirty-nine (63%) premature neonates received HC and were compared with 23 (37%) who only received inotropes. Vasoactive index score (VAI) decreased and blood pressure, urine output, and oxygen requirements improved significantly following HC. Despite receiving more inotropes (VAI of 33 [20–53] vs 10 [8–20], p < 0.001), being more premature (26 ± 2 vs 27 ± 2 weeks, p = 0.02) and more frequently having NEC (64 vs 26%, p = 0.004), patients who received HC had similar survival from septic episode (death: 22% vs 41%, p = 0.12). However, patients receiving HC during their sepsis were less likely to survive at their 1-year postmenstrual age follow-up when accounted for gestational age (GA) at birth and duration of inotropes (hazard ratio 6.08 p = 0.01).

Conclusion HC was used in infants with increased inotropic support. HC during septic shock was associated with similar survival from episode, but with decreased survival at 1-year postmenstrual age.
Results of the Universal 2 Prosthesis in Noninflammatory Osteoarthritic Wrists
Authors: Selles R. , Dias J. , Singh H. , Feitz R. , Moojen T. , Hovius S. , Brinkhorst M.
Published: August 2017

Background/Purpose Many treatment options are available for wrist osteoarthritis, with the objective of decreasing pain and preserving function. In later stages when midcarpal and radiocarpal osteoarthritis occur, two choices remain: total wrist arthrodesis or total wrist arthroplasty. The purpose of this study is to present the short-term functional changes following total wrist arthroplasty with the Universal 2 total wrist system (Integra Life Sciences) in patients with noninflammatory wrist osteoarthritis.

Patients and Methods Patients with severe noninflammatory wrist osteoarthritis were assessed preoperatively, 6 and 12 months after surgery using a range of motion, grip strength, pain, and the disabilities of the arm, shoulder, and hand (DASH) score. The additional assessment was performed after 1 year for a range of motion using a biaxial electrogoniometer, grip strength, DASH, and the Michigan hand questionnaire.

Results All range of motion directions and grip strength did not change from preoperative values. The DASH score improved from 53 preoperatively to 14 during latest follow-up. Median patients' satisfaction score decreased with approximately 20 points during the last follow-up.

Conclusion The relatively good DASH score combined with the partly maintained wrist range of motion indicates that reconstruction with the Universal 2 total wrist prosthesis should be considered in patients with end-stage noninflammatory wrist osteoarthritis.

Level of Evidence Level IV, therapeutic study.
NFU1-Related Disorders as Key Differential Diagnosis of Cavitating Leukoencephalopathy
Authors: de Souza Paulo , Bortholin Thiago , Burlin Stênio , Naylor Fernando , Oliveira Acary , Pinto Wladimir
Published: August 2017

Genetic leukoencephalopathies represent an expanding group of inherited disorders associated with involvement of brain white matter. Cystic degeneration has been previously described with some acquired or inherited leukoencephalopathies. We describe a 6-month-old Brazilian boy with a 2-month history of severe and rapidly progressive developmental and psychomotor regression and seizures. Neurological examination showed spastic tetraparesis and lethargy. Neuroimaging showed diffuse and symmetric cavitating cystic leukoencephalopathy. Whole-exome sequencing revealed compound heterozygous mutations in the NFU1 gene, providing definite genetic diagnosis of multiple mitochondrial dysfunction syndrome type 1. We report a rare presentation of early-onset cystic leukoencephalopathy in the context of multiple mitochondrial dysfunction syndrome type 1.
Mortality and its Causes in a German Cohort with Diabetes Mellitus Type 1 after 20 Years of Follow-Up: The JEVIN Trial
Authors: Heller Tabitha , Kloos Christof , Lehmann Thomas , Schiel Ralf , Lorkowski Stefan , Wolf Gunter , Müller Ulrich , Müller Nicolle
Published: August 2017

Background The JEVIN trial started as a cross-sectional study in 1989/90 in Jena. After a follow-up of more than 20 years, the mortality incidence of JEVIN participants with type 1 diabetes was surveyed.

Methods 103 (78.6%) of the 131 JEVIN patients participating at baseline could be examined. 38 persons (36.9%) had deceased. All JEVIN survey data and routine examinations documented in the electronic patient record EMIL® of surviving and deceased participants were used for analyses. We compared the data of the surviving with the deceased participants (follow-up time: 2,166 person-years).

Results The incidence rate of death was 1.75/100 person-years. Median observation time for all patients was 23.1 years (range 0.61–26.6 years). Mean age at death was 58.5 years (34.2–78.4 years), and diabetes duration 35 years (3.5–68.5 years). Most frequent causes of death were: cardiovascular diseases (48.2%, n=13) and infections (25.9%, n=7). There were no differences in age (p=0.302), diabetes duration (p=0.371), BMI (p=0.535), blood pressure (p=0.622/0.820), gender (p=0.566), and smoking status (p=0.709) between surviving and deceased persons. The mean HbA1c of the last year before death or last visit was higher in the deceased than surviving persons (7.5% vs. 7.0%; p=0.010). 57.4% of the surviving and 87.0% of the deceased participants had nephropathy (p=0.012), 79.7% vs. 89.7% retinopathy (p=0.241) and 61.4% vs. 63.3% neuropathy (p=0.860), but only nephropathy was significantly associated with increased mortality risk (HR=4.208, CI:1.226-14.440; HR=2.360, CI:0.696-8.004; HR=0.944, CI:0.436-2.043).

Conclusions In the JEVIN population with diabetes mellitus type 1 only, diabetic nephropathy was associated with higher mortality risk.
Strukturierte ambulante Patientenversorgung im Facharztvertrag Orthopädie: die Erfahrungen der Patienten als Qualitätskriterium
Authors: Klingenberg Anja , Kaufmann-Kolle Petra , Wensing Michel , Götz Katja , Jahed Jeanette , Lembeck Burkhard , Flechtenmacher Johannes , Kazmaier Tonia , Szecsenyi Joachim
Published: August 2017

Hintergrund Im Facharztvertrag (FaV) Orthopädie nach § 73c SGB V in Baden-Württemberg wurde im Jahr 2015 erstmals eine Patientenbefragung durchgeführt. Ziel war es, von den in das Facharztprogramm eingeschriebenen Patienten Rückmeldungen zur Versorgungsqualität und Hinweise auf Qualitätspotenziale, speziell auch im Hinblick auf die Ziele des FaV, zu erhalten. Praxen mit mehr als 20 auswertbaren Patientenfragebögen erhielten einen Feedbackbericht mit ihren praxisindividuellen Ergebnissen mit Vergleich zu den aggregierten, anonymisierten Ergebnissen aus allen Praxen.

Material und Methoden Die Patientenbefragung wurde mit einem speziell für das Projekt entwickelten Fragebogen im Inhouse-Verfahren (Fragebögen, versiegelte Sammelbox) und für die Patienten anonym in den orthopädischen und chirurgischen Facharztpraxen durchgeführt.

Ergebnisse Insgesamt 10 010 Patienten aus 267 Praxen nahmen an der Befragung teil. Im Praxisvergleich ausgewertet wurden die Rückmeldungen von 8988 Patienten aus 183 Praxen mit mindestens 20 auswertbaren Fragebögen (Rücklaufquote 49,1%). Befragungsergebnisse zu den Themen Arzt-Patient-Kommunikation, Terminvergabe, Wartezeiten, Zusammenarbeit mit dem Hausarzt und Überweisungen sowie veranlasste Behandlungsmaßnahmen werden dargestellt. Die Zufriedenheit der Patienten mit der Versorgung bei ihren niedergelassenen Orthopäden und Chirurgen im FaV war insgesamt hoch. Zwischen den Praxen zeigten sich große Unterschiede bez. der soziodemografischen Merkmale und auch der Rückmeldungen der Patienten zur gesundheitlichen Versorgung. Den stärksten Zusammenhang zur Gesamtzufriedenheit zeigte die Bewertung der ärztlichen Beratung. Die Überweisung durch den Hausarzt hatte einen positiven Einfluss auf die Bindung der Patienten an ihre Facharztpraxis (die geäußerte Absicht, ihren Orthopäden/Chirurgen wieder aufzusuchen). Das größte Qualitätspotenzial bestand aus Patientensicht bei der Beratung zu Selbsthilfeangeboten (z. B. Ernährung, Bewegung).

Schlussfolgerungen Die Befragungsergebnisse bestätigen die Bedeutung von Beratung und Motivation, insbesondere zu richtigen körperlichen Aktivitäten und zum Selbstmanagement als Zielsetzung des FaV Orthopädie Baden-Württemberg (biopsychosoziale Ausrichtung). Sie bieten eine Grundlage für die Weiterentwicklung der Versorgungsqualität, orientiert an den Vertragszielen und an den Bedürfnissen der Patienten.
Bio-psycho-soziale Charakteristika und therapeutische Aspekte bei Methamphetamin-abhängigen Frauen – Gendersensible Ergebnisse einer systematischen Literaturrecherche
Authors: Neumann Stefanie , Soyka Michael , Franke Andreas
Published: August 2017

Gegenstand Methamphetamin (MethA) wird im Verhältnis zu anderen illegalen Drogen tendenziell häufiger von Frauen als Männern konsumiert. Unter Annahme des bio-psycho-sozialen Ätiologie-Modells beruht die Abhängigkeit auf biologischen, psychischen und sozialen Faktoren, in denen sich Frauen und Männer unterscheiden. Systematische genderdifferenzierte Erkenntnisse, die einen wichtigen Einfluss auf therapeutische Maßnahmen haben, fehlen allerdings noch.

Methode Die Übersicht basiert auf einer Datenbank-Recherche (PUBMED) zu biologischen, psychischen, sozialen sowie therapeutischen Aspekten bei von MethA abhängigen Frauen.

Ergebnisse MethA-induzierte kognitive Störungen scheinen bei Frauen stärker ausgeprägt zu sein als bei Männern. Ihr Lebensstil ist oft von aktiver und passiver (sexualisierter) Gewalt geprägt. Sie zeigen ein erhöhtes sexuelles Risikoverhalten; v. a. durch ungeschützten Verkehr mit mehreren Partnern. Psychiatrische Komorbiditäten scheinen quantitativ ausgeprägter zu sein und betreffen v. a. Angststörungen und depressive Syndrome.

Schlussfolgerung und Klinische Relevanz Missbrauch und Abhängigkeit von MethA werden bei Frauen von psychischen als auch sozialen Faktoren determiniert. Es bedarf aber weiterer gendersensibler Forschungen, um die Prävention, Beratung und Therapie zu verbessern.
Operieren wir die Glaukome zu spät?
Authors: Stürmer Jörg , Faschinger Christoph
Published: August 2017

Aus der Sicht des operativen Glaukomatologen fragt man sich, warum die Patienten erst sehr spät zur Operation zugewiesen werden. Meist besteht schon zur Zeit der Zuweisung zur filtrierenden Operation nach vielen Jahren der konventionellen Therapie ein sowohl funktionell als auch morphologisch fortgeschrittener Glaukomschaden, zusätzlich ist auch oft noch der Augeninnendruck unter einer lokalen Maximaltherapie dekompensiert. Zusätzlich kommt hinzu, dass die Patienten oft ein fortgeschrittenes Alter aufweisen und schon viele Jahre lang mit verschiedenen Kombinationen aus Tropfen therapiert wurden. Sehr spät gestellte Diagnosen stellen eher die Ausnahme dar. Die Gründe für diese späte Zuweisung sind vielfältig. Neben der immer besseren (besser verträglichen und wirksamen) medikamentösen Glaukomtherapie spielen die Abneigung der Patienten gegen den operativen Eingriff (da keine Verbesserung des Sehvermögens zu erwarten ist) und die bis jetzt (noch) nicht verfügbare optimale Glaukomoperation eine entscheidende Rolle. Anhand einer kleinen retrospektiven Studie der letzten 274 zur filtrierenden Glaukomoperation zugewiesenen Patienten sollen die Kriterien für eine rechtzeitige Indikationsstellung erarbeitet und kritisch analysiert werden. In dieser Studie zeigt sich, dass rund ¾ aller Glaukompatienten spät oder zu spät zur Glaukomoperation zugewiesen werden. Für den niedergelassenen Ophthalmologen ohne Spezialisierung im Glaukombereich werden Kriterien formuliert, wann ein Patient zur Glaukomoperation zugewiesen werden sollte. Diese Kriterien sind grundsätzlich für alle Glaukomoperationen anzuwenden. Die Vor- und Nachteile einer filtrierenden Glaukomoperation werden jedoch besonders hervorgehoben, da dieser Eingriff nach wie vor den Goldstandard darstellt. Da aber die Trabekulektomie leider kein optimaler Glaukomeingriff ist, bestehen berechtigte Hoffnungen, dass die moderneren, weniger invasiven und damit auch weniger risikobehafteten Glaukomeingriffe (MIGS) die Indikationen für einen drucksenkenden Eingriff erweitern und damit die Hemmschwelle für die Zuweisung zur Glaukomoperation herabsetzen.
Differenzialdiagnostik der pulmonalen Hypertonie
Authors: Halank Michael , Dumitrescu Daniel , Leuchte Hanno
Published: August 2017

Die pulmonale Hypertonie (PH) ist per se keine Erkrankung, sondern ein hämodynamischer Zustand, der eine Druckerhöhung im kleinen Kreislauf
in Ruhe beschreibt. Ursächlich können hierfür viele Erkrankungen verantwortlich sein. Unabhängig von der Ätiologie der PH ist deren
führendes Symptom die progrediente Dyspnoe, die nicht selten gleichzeitig mit Müdigkeit und Abgeschlagenheit einhergeht. Aufgrund des
unspezifischen Charakters der Beschwerden vergehen häufig Monate bis Jahre bis zur Diagnosestellung. Bei kardialer Dekompensation sind
Halsvenenstauung, Beinödeme und Aszites typische klinische Zeichen der rechtskardialen Vorlast-Erhöhung. Die wichtigste nichtinvasive
Untersuchungsmethode zur Verdachts­diagnose der PH ist in den meisten Fällen die Echokardiografie. Zur Basisdiagnostik der Belastungsdyspnoe
unklarer Ätiologie zählen neben der körperlichen Untersuchung und Anamnese, die Lungenfunktions-Untersuchung einschließlich
alveolo-kapillärer Diffusionsmessung, die Bestimmung der kapillären oder arteriellen Blutgase, die Röntgenaufnahme der Lunge, das EKG,
laborchemische Herzinsuffizienzmarker und die Spiroergometrie. Die häufigsten Ursachen der PH sind Linksherz- und/oder Lungenerkrankungen.
Aktuell erfolgt eine klinische Einteilung der pulmonalen Hypertonie in 5 Gruppen. Da die PH unabhängig von der Ätiologie mit einer
Beeinträchtigung der Prognose assoziiert ist, sind die Hauptziele der Diagnostik die exakte Klassifikation der Erkrankung und deren
Früherkennung, um einen verzögerten Therapiebeginn zu verhindern. Nicht immer ist die exakte Klärung der Ursache der PH im Einzelfall
möglich. Wenn Lungen- und Linksherzerkrankungen als Ursachen der PH ausgeschlossen sind, sollte eine Ventilations-/Perfussionszintigrafie
und eine Überweisung an ein PH-Zentrum erfolgen. Dort sollte dann nach den seltenen Ursachen einer PH wie pulmonal arterielle Hypertonie
(PAH) oder chronisch thromboembolische pulmonale Hypertonie (CTEPH) gefahndet werden. Zur Diagnosestellung der PH ist dann letztendlich eine
vollständige Rechtsherzkatheter-Untersuchung unabdingbar.
Microscopic and Phytochemical Comparison of the Three Leonurus Species L. cardiaca, L. japonicus, and L. sibiricus
Authors: Pitschmann Anna , Waschulin Christine , Sykora Christina , Purevsuren Sodnomtseren , Glasl Sabine
Published: August 2017

At least three Leonurus species, Leonurus cardiaca, Leonurus japonicus, and Leonurus sibiricus, are used in various traditional medicinal systems for different therapeutic purposes. The plant names “L. sibiricus” and “L. japonicus” are often used as synonyms, which causes confusion in literature and implies that several studies may be based on improperly identified plant material. To avoid further confusion, the current status of the identification of these three species is illustrated. Characteristics for their unequivocal identification are presented using stereo and light microscopy as well as HPTLC.

The establishment of the species-specific anatomical, morphological, and phytochemical characters was based on reference specimens in comparison with wild collected or commercially obtained material. Morphologically, the species differed in shape and length ratio of the upper and lower lip of the corolla. Differentiating anatomical characters involve the presence, density, and dimension of trichomes on different organs. Detailed anatomical descriptions of the leaves and corollae of L. japonicus and L. sibiricus are given and compared to L. cardiaca. These three sets of characters facilitate fast and reliable identification. Complementary HPTLC fingerprints show type-specific patterns that allow the differentiation of L. japonicus from the other two species. For the distinction of L. cardiaca and L. sibiricus, flower morphology has to be considered.

The presented data contribute to the quality control of the three Leonurus species and additionally meet a definite and timely need regarding the introduction of L. japonicus to the European Pharmacopoeia in addition to the already existing monograph of L. cardiaca.
Calcium effect on membrane of an optically trapped erythrocyte studied by digital holographic microscopy
Authors: Farzam Rad Vahideh , Tavakkoli Rahim , Moradi Ali-Reza , Anand Arun , Javidi Bahram
Published: August 2017

The calcium level in blood affects the morphological and rheological properties of red blood cell (RBC) membranes. In this paper, we present an integrated optical system for a single cell study of hypercalcemia. The system consists of holographic optical tweezers and blinking optical tweezers, for photo-damage-free immobilization of the cells, combined with digital holographic microscopy, for quantitative analysis and live visualization of the cells. Digital holograms were recorded live, while the concentration of calcium ions in the buffer is gradually increased. Full morphometric data of RBCs were obtained by numerical reconstruction of the holograms. Morphological changes are expressed in terms of various parameters such as root mean square, skewness, and kurtosis of the cell membrane thickness distribution. We have observed dramatic changes of the cell morphology, which are attributed to the formation of calcium-induced hydrophobic aggregates of phospholipid molecules in the RBC membrane, resulting in a net change in membrane rigidity. Our experimental results are in agreement with previous biological studies of RBCs under the Ca2+ influence.
A nonlinear electromagnetics model of an asymmetrically-driven, low pressure capacitive discharge
Authors: Wen De-Qi , Kawamura E. , Lieberman M. A. , Lichtenberg A. J. , Wang You-Nian
Published: August 2017

It is well-known that standing waves having radially center-high voltage profiles exist in high frequency driven capacitive discharges. Capacitive sheaths can also nonlinearly excite driving frequency harmonics near the series resonance that can be spatially near-resonant, and therefore enhance the on-axis power deposition. The powered-electrode/plasma/grounded-electrode sandwich structure of an asymmetrically excited cylindrical discharge forms a three electrode system in which both z-symmetric and z-antisymmetric radially propagating wave modes can exist. We develop a nonlinear electromagnetics model for this system with radially- and time-varying sheath widths, incorporating both symmetric and antisymmetric modes, and the plasma skin effect. Waves generated in the electrostatic wave limit are also treated. The discharge is modeled as a uniform density bulk plasma with either homogeneous or Child law sheaths at the electrodes, incorporating their nonlinear voltage versus charge relations. The model includes a finite power source resistance and a self-consistent calculation of the dc bias voltages. The resulting set of nonlinear partial differential equations is solved numerically to determine the symmetric and antisymmetric mode amplitudes and the nonlinearly-excited radially-varying harmonics. Two examples driven at lower frequency (30 MHz) or at higher frequency (60 MHz) are examined. The first case displays the excited dominant ninth harmonic near the series resonance frequency with the fundamental frequency having a weak standing wave. The higher frequency case shows a more obvious standing wave effect, enhanced by the nonlinear harmonics. The symmetric and antisymmetric modes are of similar amplitudes over the driving electrode, summing to give a larger bottom sheath.
Directional emission of quantum dot scintillators controlled by photonic crystals
Authors: Liu Bo , Wu Qiang , Zhu Zhichao , Cheng Chuanwei , Gu Mu , Xu Jun , Chen Hong , Liu Jinliang , Chen Liang , Zhang Zhongbing , Ouyang Xiaoping
Published: August 2017

We have demonstrated enhanced light emission from a CdSe/ZnS quantum dot scintillator film in the normal direction by photonic crystal structures. With the control of the photonic crystal structures, a two-fold enhancement was achieved for the wavelength-integrated emission spectra under the excitation of both ultra-violet and X-rays, which is beneficial to radiation detection applications. Furthermore, it is found that the optical properties such as the bandwidth and peak wavelength can be controlled by adjusting the thickness of a TiO2 conformal layer which was deposited on the surface of the photonic crystal slab formed from solidified resist.
Ultrafast switching of valence and generation of coherent acoustic phonons in semiconducting rare-earth monosulfides
Authors: Punpongjareorn Napat , He Xing , Tang Zhongjia , Guloy Arnold M. , Yang Ding-Shyue
Published: August 2017

We report on the ultrafast carrier dynamics and generation of coherent acoustic phonons in YbS, a semiconducting rare-earth monochalcogenide, using two-color pump–probe reflectivity. Compared to the carrier relaxation processes and lifetimes of conventional semiconductors, recombination of photoexcited electrons with holes in localized f orbitals is found to take place rapidly with a density-independent time constant of <500 fs in YbS. Such carrier annihilation signifies the unique and ultrafast nature of valence restoration of ytterbium ions after femtosecond photoexcitation switching. Following transfer of the absorbed energy to the lattice, coherent acoustic phonons emerge on the picosecond timescale as a result of the thermal strain in the photoexcited region. By analyzing the electronic and structural dynamics, we obtain the physical properties of YbS including its two-photon absorption and thermooptic coefficients, the period and decay time of the coherent oscillation, and the sound velocity.
Effect of crystal orientation and nanofiller alignment on dielectric breakdown of polyethylene/montmorillonite nanocomposites
Authors: Li Bo , Xidas Panagiotis I. , Triantafyllidis Kostas S. , Manias Evangelos
Published: August 2017

Extrusion blown polyethylene and polyethylene/montmorillonite nanocomposite films were cold stretched to various ratios to quantify the influence of the crystal orientation and the nanofiller alignment on their dielectric breakdown performance. It was found that the crystal orientation could increase the breakdown strength (EBD) in the stretched blown films. The aligned pseudo-2D inorganic nanoclays provided additional strong improvements in EBD that can be superimposed to any EBD enhancement due to the polymer crystal orientation. At high filler loadings and high stretching ratios, the onset of percolation was observed through a substantial improvement in the dielectric breakdown strength.
Analytical investigation of electrokinetic effects of micropolar fluids in nanofluidic channels
Authors: Ding Zhaodong , Jian Yongjun , Wang Lin , Yang Liangui
Published: August 2017

The effects of microstructure of fluid particles on the electrokinetic phenomena are investigated analytically based on a micropolar fluid model, where micro-rotation of fluid particles and material parameters like viscosity and angular viscosity coefficients are involved. Meanwhile, the influences of velocity slip at the surface of a nanofluidic channel and overlapped electrical double layers (EDLs) are incorporated. Results indicate that the introduction of micropolarity will significantly affect the electrokinetic effects, especially in the case of overlapped EDLs. Qualitatively, it leads to evident reductions in the flow rate, streaming current, and streaming potential relative to Newtonian fluids. The velocity slip is an opposing and competitive mechanism which tends to increase the flow rate, streaming current, and potential. Furthermore, the interplay between the micropolarity and slip effects is studied in detail. The influence of micropolarity on the electrokinetic energy conversion (EKEC) efficiency depends on the ionic Peclet number R. For small values of R (e.g., R = 0.1), the EKEC efficiency for micropolar fluids may exceed that for Newtonian fluids in some range of parameter K in the case of overlapped EDLs for nanochannels. However, for R ≥ 0.2, the EKEC efficiency for micropolar fluids is always less than that for Newtonian fluids.
Amplification of coherent synchrotron high harmonic emission from ultra-thin foils in relativistic light fields
Authors: Braenzel J. , Andreev A. A. , Platonov K. Y. , Ehrentraut L. , Schnürer M.
Published: August 2017

We report on a remarkable enhancement of high harmonic (HH) radiation emitted from the interaction of an ultra-intense laser pulse with ultra-thin foils by a manipulation of foil pre-plasma conditions. With a strong counter-propagating pre-pulse, we introduce a concerted expansion of the ultrathin foil target, and this significantly raises the efficiency of the HH generation process. Our experimental results show how the emission efficiency can be easily controlled by the intensity and delay time of the pre-pulse. The results give an important insight into the high harmonic generation process from solid dense plasmas when spatially limited. 1D particles in cell simulations confirm our experimental findings and show a significant dependency of the HH emission efficiency on the plasma density. The simplicity of the ultra-thin foil target and interaction geometry hold promise for specifically compact realization of imaging experiments with ultra-short and bright extreme ultra violet-pulses.
Systematic reduction of a detailed atrial myocyte model
Authors: Lombardo Daniel M. , Rappel Wouter-Jan
Published: August 2017

Cardiac arrhythmias are a major health concern and often involve poorly understood mechanisms. Mathematical modeling is able to provide insights into these mechanisms which might result in better treatment options. A key element of this modeling is a description of the electrophysiological properties of cardiac cells. A number of electrophysiological models have been developed, ranging from highly detailed and complex models, containing numerous parameters and variables, to simplified models in which variables and parameters no longer directly correspond to electrophysiological quantities. In this study, we present a systematic reduction of the complexity of the detailed model of Koivumaki et al. using the recently developed manifold boundary approximation method. We reduce the original model, containing 42 variables and 37 parameters, to a model with only 11 variables and 5 parameters and show that this reduced model can accurately reproduce the action potential shape and restitution curve of the original model. The reduced model contains only five currents and all variables and parameters can be directly linked to electrophysiological quantities. Due to its reduction in complexity, simulation times of our model are decreased more than three-fold. Furthermore, fitting the reduced model to clinical data is much more efficient, a potentially important step towards patient-specific modeling.
Assessing many-body contributions to intermolecular interactions of the AMOEBA force field using energy decomposition analysis of electronic structure calculations
Authors: Demerdash Omar , Mao Yuezhi , Liu Tianyi , Head-Gordon Martin , Head-Gordon Teresa
Published: August 2017

In this work, we evaluate the accuracy of the classical AMOEBA model for representing many-body interactions, such as polarization, charge transfer, and Pauli repulsion and dispersion, through comparison against an energy decomposition method based on absolutely localized molecular orbitals (ALMO-EDA) for the water trimer and a variety of ion-water systems. When the 2- and 3-body contributions according to the many-body expansion are analyzed for the ion-water trimer systems examined here, the 3-body contributions to Pauli repulsion and dispersion are found to be negligible under ALMO-EDA, thereby supporting the validity of the pairwise-additive approximation in AMOEBA’s 14-7 van der Waals term. However AMOEBA shows imperfect cancellation of errors for the missing effects of charge transfer and incorrectness in the distance dependence for polarization when compared with the corresponding ALMO-EDA terms. We trace the larger 2-body followed by 3-body polarization errors to the Thole damping scheme used in AMOEBA, and although the width parameter in Thole damping can be changed to improve agreement with the ALMO-EDA polarization for points about equilibrium, the correct profile of polarization as a function of intermolecular distance cannot be reproduced. The results suggest that there is a need for re-examining the damping and polarization model used in the AMOEBA force field and provide further insights into the formulations of polarizable force fields in general.
Net electron energy gain induced by superluminal phase velocity and subluminal group velocity of a laser in a plasma channel
Authors: Cheng Li-Hong , Yao Zheng-Wei , Zhang Xiao-Bo , Xue Ju-Kui
Published: August 2017

We examine electron dynamics induced by laser-plasma interaction in a two-dimensional plasma channel, taking into action the laser phase velocity as well as the group velocity. The coupled effects of phase velocity, group velocity, and plasma channel on electron dynamics are discussed in detail. The superluminal phase velocity and the corresponding subluminal group velocity of the laser result in rich and complex electron dynamics, which are depicted in the plane of the phase velocity and plasma charge density. For weak superluminosity of the phase velocity, the effects of the phase velocity and the group velocity can be neglected. For moderate superluminosity of the phase velocity, a cross-over region can exist, where the highly energetic electron could be found and the net energy gain is several times greater than the energy gain in vacuum. For strong superluminosity of the phase velocity, the dephasing rate increases and thus limits the electron energy gain from the laser. However, the asymmetric laser pulse, attributed by the superluminal phase velocity and the subluminal group velocity, results in the electron getting adjustable net energy gain from the laser. The electron oscillations are no longer limited by the charge density threshold and the electron can always get net energy from the laser. These electron dynamics can also be modified by adjusting the polarization of the laser.
Influence of off-stoichiometry on magnetoresistance characteristics of Co2MnSi/Ag-based current-perpendicular-to-plane spin valves
Authors: Inoue Masaki , Hu Bing , Moges Kidist , Inubushi Kazuumi , Nakada Katsuyuki , Yamamoto Masafumi , Uemura Tetsuya
Published: August 2017

The influence of off-stoichiometry of Co2MnSi (CMS) spin sources on giant magnetoresistance characteristics was investigated for CMS/Ag-based current-perpendicular-to-plane spin valves prepared with various Mn compositions α in Co2MnαSi0.82 electrodes. The magnetoresistance ratio of the prepared CMS/Co50Fe50 (CoFe) (1.1 nm)/Ag/CoFe (1.1)/CMS spin valves systematically increased with α from 11.4% for Mn-deficient α = 0.62 to 20.7% for Mn-rich α = 1.45 at 290 K. This result suggests that increasing α from a Mn-deficient to Mn-rich value increases the spin polarization by suppressing CoMn antisites harmful to the half-metallicity. Thus, our results demonstrate that appropriately controlling the film composition toward a Mn-rich one is highly effective for enhancing the half-metallicity of CMS in CMS-based spin valves, as it is in CMS-based magnetic tunnel junctions.
New research on reflectin proteins sheds light on cephalopods’ camouflage
Authors: Kim Meeri
Published: August 2017

Squid and other cephalopods use reflectin proteins within their skin as a molecular machine to manipulate body coloration.
Differing mortality rates in two concurrently radio-tracked populations of koala (Phascolarctos cinereus)
Authors: Phillips Stephen
Published: August 2017

Radio-tracking studies enable insights into factors that contribute to koala mortality. Two radio-tracking studies investigating the impacts of disturbance events on koalas were undertaken in different areas over the same period. Both studies employed similar techniques for koala capture, processing and monitoring. In one study, none of nine koalas died during a 5-month monitoring program following their translocation into a new habitat area, while in the second study 6 of 11 koalas died over the same period during an in situ impact-monitoring study. The two populations differed morphologically and genetically: that with the higher mortality rate notable for a smaller head and neck circumference and lower genetic diversity. Differing outcomes from the two studies lend support to a hypothesis that inbreeding and the loss of genetic information may predispose some individuals and/or populations of koalas to an elevated stress response and/or increased susceptibility to disease, the expression of which may become exacerbated in the presence of ongoing disturbance or novel stressors that can include research activities. If this is the case, the endocrinology and genetic structure of free-ranging koala populations needs to be afforded greater consideration in terms of predicting a given population’s immunological response to potential isolation and/or disturbance events.
Cobalt Species Active for Nitrous Oxide (N2O) Decomposition within a Temperature Range of 300–600°C
Authors: Khan Naseer A. , Kennedy Eric M. , Dlugogorski Bogdan Z. , Adesina Adesoji A. , Stockenhuber Michael
Published: August 2017

This article presents a novel study of the role of the catalyst support towards the formation of active cobalt sites for N2O conversion reactions within a temperature range of 300–600°C. These reactions were examined in a fixed bed tubular reactor. ZSM-5 (Si/ Al = 15), TS-1, and amorphous silicates were used as catalyst supports for cobalt loadings. All catalysts were prepared by following standard methods and recipes. In general, cobalt loading on supports was varied between 0.78 and 5.40 wt.-% (as determined from inductively coupled plasma (ICP) analysis). ICP, temperature programmed desorption, X-ray diffraction, and N2 adsorption/desorption isotherms were used for the characterization of prepared catalysts. Cobalt on ZSM-5 support generates weak and strong acid sites. Furthermore, for the Co-ZSM-5 catalyst, prepared by a wet deposition method, the N2O decomposition reaction is first order with an activation energy of ~132 kJ mol−1. Co2+ and Co3+ are the suggested active species for the N2O conversions in the studied range of temperatures.
Production of inbred offspring by intracytoplasmic sperm injection of oocytes from juvenile female mice
Authors: Zhu Jie , Cui Wei , Dai Yan-Feng
Published: August 2017

The aim of the present study was to determine whether the use of oocytes from juvenile female mice would improve the efficiency of intracytoplasmic sperm injection (ICSI). In the present study, 15 adult and 14 juvenile C57BL6/J female mice were superovulated, with 17.8 oocytes per mouse harvested from adults, significantly lower than the 40.2 harvested from juveniles (P < 0.01). Sixty and 233 oocytes were harvested from C57BL/6J adult and juvenile mice respectively, activated in 10 mM SrCl2 + 5 μg mL−1 cytochalasin B for 5–6 h and cultured in potassium simplex optimisation medium (KSOM) for 3.5 days, with no differences in morula and blastocyst rates between groups (91.7% vs 96.6%; P > 0.05). Twelve hours after injection of human chorionic gonadotrophin, oocytes were harvested from C57BL/6J juvenile mice into KSOM, randomly divided into groups and activated with the same method mentioned above at 0, 2, 4 or 6 h and then cultured in KSOM for 3.5 days. There was no significant difference in morula and blastocyst rates among the different groups (P > 0.05). Oocytes from juvenile mice activated in 10 mM SrCl2 for 2 h were subjected to ICSI and the rates of pronuclear formation and Day 1 cleavage were significantly improved compared with the control group (P < 0.01). ICSI combined with activation of oocytes from inbred mouse strains (C57BL/6J, C57BL/6N and 129Svev) successfully produced pups. The fertility of some these mice resulting from ICSI was tested, and the animals proved fertile. In conclusion, superovulated juvenile mice can yield more useable oocytes than adult mice, but additional activation is essential for full development of ICSI oocytes harvested from juvenile inbred mice.
Genomic diversification of giant enteric symbionts reflects host dietary lifestyles
Authors: Ngugi David Kamanda , Miyake Sou , Cahill Matt , Vinu Manikandan , Hackmann Timothy J. , Blom Jochen , Tietbohl Matthew D. , Berumen Michael L. , Stingl Ulrich
Published: August 2017

Significance

Gastrointestinal symbionts of organisms are important in the breakdown of food for the host, particularly for herbivores requiring exogenous enzymes to digest complex polysaccharides in their diet. However, their role in the digestion of algae in marine piscine herbivores remains unresolved. Here, we show that the diversity of food sources available to herbivorous surgeonfishes is directly linked with the genetic makeup of their enteric microbiota. Importantly, the genomic blueprint of dominant enteric symbionts belonging to diverse
Epulopiscium
clades differs according to the host diet. Thus, the acquisition of a unique enteric microbiota specialized to their diets likely shapes the nutritional ecology of piscine herbivores, in turn facilitating the coexistence of a high diversity of marine species within coral reefs.
Distinct PKC-mediated posttranscriptional events set cytokine production kinetics in CD8+T cells
Authors: Salerno Fiamma , Paolini Nahuel A. , Stark Regina , von Lindern Marieke , Wolkers Monika C.
Published: August 2017

Significance

A hallmark of effective T cell responses against invading pathogens is the production of effector molecules. Effector molecules such as cytokines not only kill infected cells, but they also recruit innate immune cells and alter the environment to optimally respond to microbial infections. However, because effector molecules are very potent, they can pose a health risk. When produced excessively or when generated at the wrong time, this aberrant production can induce immunopathology. Here, we uncover that each cytokine employs a private regulation of transcriptional and posttranscriptional events to guarantee appropriate production kinetics.
XFEL structures of the influenza M2 proton channel: Room temperature water networks and insights into proton conduction
Authors: Thomaston Jessica L. , Woldeyes Rahel A. , Nakane Takanori , Yamashita Ayumi , Tanaka Tomoyuki , Koiwai Kotaro , Brewster Aaron S. , Barad Benjamin A. , Chen Yujie , Lemmin Thomas , Uervirojnangkoorn Monarin , Arima Toshi , Kobayashi Jun , Masuda Tetsuya , Suzuki Mamoru , Sugahara Michihiro , Sauter Nicholas K. , Tanaka Rie , Nureki Osamu , Tono Kensuke , Joti Yasumasa , Nango Eriko , Iwata So , Yumoto Fumiaki , Fraser James S. , DeGrado William F.
Published: August 2017

Significance

The influenza M2 channel is among the smallest proton-selective channels found in nature. High-resolution structures of this channel further our understanding of how protons are transported across a membrane bilayer through a constricted membrane protein environment. This study also has broader implications for the structural interpretation of water in channels using X-ray crystallographic techniques. Previous crystallographic structure determined using synchrotron radiation with cryocooling were biased by the low temperature, and room temperature data collection was limited by radiation damage. These problems have been avoided through room temperature diffraction at an X-ray free-electron laser (XFEL) source.
Performance of Fast Absorbable Sutures and Histo‐Glue for Closing Incisions in Brown Trout
Authors: Jepsen Niels , Larsen Martin H. , Aarestrup Kim
Published: August 2017

Telemetry has become a standard tool in fish research, but tagging methods still need refinement to achieve better results and to improve animal welfare. One of the problems reported from evaluations of surgical implants is unsatisfactory wound closure. Thus, researchers struggle to find better ways to close incisions, typically for tags implanted under field conditions. Problems are regularly encountered when closing incisions with traditional absorbable or nonabsorbable sutures, including decreased growth, slow wound healing, and erythema and necrosis at the suture site. We compared survival, growth, tag expulsion rate, and incision healing among three groups of dummy transmitter‐tagged wild Brown Trout Salmo trutta for which incisions were closed with two types of suture material (absorbable and fast absorbable) and histo‐glue. The tagged fish were kept in seminatural ponds for 20 d. Survival did not differ among groups, but growth of the tagged fish was lower than that of the control group. Histo‐glue gave the best healing but resulted in a high tag loss rate (33%). The fast absorbable sutures did not disappear faster than normal absorbable sutures, and healing and tag loss were similar. The use of fast absorbable sutures may hold potential for improving the procedure and should be further tested.
CD55 regulates self-renewal and cisplatin resistance in endometrioid tumors
Authors: Saygin Caner , Wiechert Andrew , Rao Vinay S. , Alluri Ravi , Connor Elizabeth , Thiagarajan Praveena S. , Hale James S. , Li Yan , Chumakova Anastasia , Jarrar Awad , Parker Yvonne , Lindner Daniel J. , Nagaraj Anil Belur , Kim J. Julie , DiFeo Analisa , Abdul-Karim Fadi W. , Michener Chad , Rose Peter G. , DeBernardo Robert , Mahdi Haider , McCrae Keith R. , Lin Feng , Lathia Justin D. , Reizes Ofer
Published: August 2017

Effective targeting of cancer stem cells (CSCs) requires neutralization of self-renewal and chemoresistance, but these phenotypes are often regulated by distinct molecular mechanisms. Here we report the ability to target both of these phenotypes via CD55, an intrinsic cell surface complement inhibitor, which was identified in a comparative analysis between CSCs and non-CSCs in endometrioid cancer models. In this context, CD55 functions in a complement-independent manner and required lipid raft localization for CSC maintenance and cisplatin resistance. CD55 regulated self-renewal and core pluripotency genes via ROR2/JNK signaling and in parallel cisplatin resistance via lymphocyte-specific protein tyrosine kinase (LCK) signaling, which induced DNA repair genes. Targeting LCK signaling via saracatinib, an inhibitor currently undergoing clinical evaluation, sensitized chemoresistant cells to cisplatin. Collectively, our findings identify CD55 as a unique signaling node that drives self-renewal and therapeutic resistance through a bifurcating signaling axis and provides an opportunity to target both signaling pathways in endometrioid tumors.