bluuebunny/crossref_metadata_2025 huggingface dataset:
Aplicación clínica de la técnica percutánea en la tenosinovitis estenosante de los flexores de la mano
Authors: Brotat M. , Pérez C. , Medrano B. , Flórez L. , Ferrero M.Á. , Moreno M.F.
Published: September 2017

Introducción: La tenosinovitis estenosante de los flexores de la mano es una patología que conduce al bloqueo de la polea de flexión proximal del dedo. Aunque el tratamiento inicial es conservador, si éste no es efectivo, está indicado el tratamiento quirúrgico mediante liberación abierta o percutánea.

Material y método: Estudio descriptivo retrospectivo de 116 pacientes intervenidos de dedo en resorte en el HCUV (enero 2005- diciembre 2007), seguimiento medio 36 meses. Análisis de datos con el 91% de los pacientes (105 pacientes) con un total de 182 dedos afectos realizando comparación de ambas técnicas.

Resultados: Edad media varones 53.70 años y la de las mujeres 53.95. El 34% de las manos intervenidas no presentan otras patologías asociadas. Primer dedo más afectado, seguido del tercero y cuarto. Se realizó técnica percutánea en el 42% de los pacientes, abierta en el 53% y ambas en el 5% del total. Destacan los problemas con la cicatriz en la tenolisis abierta. Técnica percutánea permite reincorporación a la vida laboral 8 días antes.

Discusión: La liberación percutánea de la polea AI es una alternativa a la liberación abierta por su bajo coste y por permitir una rápida reincorporación del paciente a su vida laboral. Gracias a estudios experimentales en cadáver, se obtienen referencias topográficas que aportan mayor seguridad, permitiendo ampliar el uso de esta técnica que ha demostrado grandes ventajas en el ámbito socio-económico y laboral.
Artroplastia total de muñeca. Resultados funcionales, complicaciones y factores predictivos de la evolución
Authors: Aragó A. , Moreno B. , López M. , de la Sotilla J.M. , Alcázar L. , Calvo M. Á.
Published: September 2017

Objetivo: El objetivo de este estudio es presentar los resultados a corto plazo de la artroplastia total de muñeca y estudiar los factores que determinan su evolución.

Material y método: Se han revisado retrospectivamente 15 pacientes intervenidos mediante prótesis total de muñeca Tipo Universal2® (KMI, Carlsbad, California). Se han estudiado los factores epidemiológicos, las radiografías, la movilidad y la fuerza prequirúrgica y postquirúrgica. Se han evaluado a los pacientes mediante el cuestionario DASH y la escala visual analógica, EVA. Se han utilizado diversos test estadísticos para el estudio de la predicción de la evolución. Se han descrito las complicaciones y las reintervenciones.

Resultados: Los pacientes han presentado una disminución del dolor estadísticamente significativa. No hemos obtenido diferencias estadísticamente significativas de ninguno de los valores para prever la evolución. Seis de los casos requirieron ser reintervenidos debido a complicaciones como pinzamiento, “impingement” cubital, neuropatía del nervio cubital y luxación del primer compartimento extensor.

Conclusiones: La artroplastia total de muñeca es una alternativa en el tratamiento de la artrosis radiocarpiana avanzada en pacientes que quieren preservar cierta movilidad en la muñeca. Las complicaciones han surgido debido a que se trata de una exigente técnica quirúrgica, y disminuyen con la curva de aprendizaje. No se han encontrado factores predictivos de su evolución.
Tratamiento de la enfermedad de Kienböck juvenil mediante fijación temporal escafo-trapezoidea
Authors: Valtueña A. , Olea A. , Hualde A.
Published: September 2017

No existe un consenso acerca del tratamiento de la enfermedad de Kienböck en el adolescente. Se presenta un caso de un paciente de 14 años que fue tratado de manera satisfactoria con una fijación temporal entre trapezoide y escafoides usando tres agujas de Kirschner que se mantuvieron 6 meses. El seguimiento radiológico mostró recuperación de la intensidad de señal en resonancias magnéticas seriadas. A los dos años de la cirugía el paciente no tiene dolor y ha recuperado un rango articular completo
Sarcoma fibroblástico mixoinflamatorio acral: caso clínico y revisión bibliográfica
Authors: Jiménez A. , Proubasta I. , Arriaga N. , Alegría I.
Published: September 2017

El sarcoma fibroblástico mixoinflamatorio es un tumor maligno de bajo grado de partes blandas, generalmente localizado en extremidades y que afecta a sujetos de mediana edad. Clínicamente, la lesión es infiltrativa, indolora y de curso evolutivo lento. Se presenta un caso que afecta la mano, haciendo una extensa revisión de la bibliografía, con especial atención a su diagnóstico y tratamiento.
Síndrome del canal radial: nueva técnica de liberación endoscópica
Authors: Gonzalez J.
Published: September 2017

El objetivo de este trabajo es presentar una nueva técnica endoscópica para la liberación de la rama motora del nervio radial en el síndrome del canal radial.

El síndrome del canal radial es la neuropatía compresiva de la rama motora del nervio radial que, muy a menudo, requiere la liberación quirúrgica mediante la apertura completa de las estructuras que producen la compresión.

Las vías de abordaje convencionales son amplias, requieren disecciones agresivas y laboriosas. El pequeño tamaño del nervio y su posición profunda entre vientres musculares hace que, fácilmente, pueda ser dañado durante su disección si la visualización no es correcta en todo momento.

Presentamos una nueva técnica que combina el marcaje preoperatorio de la posición del nervio mediante ecografía y liberación mediante técnica endoscópica.

Esta técnica permite un abordaje quirúrgico mucho menor, una mejor visualización del nervio en todo su recorrido y de las estructuras anatómicas durante la disección.

Se presenta una serie de 22 intervenciones en 20 pacientes intervenidos entre 2010 y 2014. En 14 casos los resultados fueron excelentes, 5 buenos y 3 regulares. Las complicaciones fueron en un caso una lesión parcial del nervio durante la cirugía y 4 casos de paresia a la extensión de los dedos que se recuperaron completamente en todos los casos entre las 3 y 6 semanas.
Esomeprazol-induzierter kutaner Lupus erythematodes
Authors: Gliem Nina , Broekaert Sigrid , Seitz Cornelia , Schön Michael , Ellenrieder Volker
Published: September 2017

Protonenpumpeninhibitoren gehören zu den weltweit am häufigsten verwendeten Arzneimitteln. Sie gelten als weitgehend sicher und nebenwirkungsarm. Wir berichten über eine 69-jährige Patientin, bei der 2 Monate nach Einleitung einer Therapie mit Esomeprazol anuläre erythematöse Plaques überwiegend an lichtexponierten Körperstellen auftraten. Anhand des klinischen Bildes, dem histologischen Befund eines Hautbioptats und dem Nachweis von Anti-Ro/SSA-Antikörpern wurde die Diagnose eines subakut kutanen Lupus erythematodes gestellt. Insbesondere der zeitliche Zusammenhang mit dem Beginn der Protonenpumpeninhibitor-Therapie begründete den hochgradigen Verdacht auf eine medikamenteninduzierte Genese. Nach Absetzen von Esomeprazol waren die charakteristischen Hautveränderungen ohne spezifische Therapie nahezu vollständig rückläufig, was die anfängliche Verdachtsdiagnose erhärtete. Beim Auftreten typischer Hautveränderungen in lichtexponierten Arealen im zeitlichen Zusammenhang mit der Einnahme von PPI sollte daher immer auch an die Möglichkeit eines medikamenteninduzierten kutanen Lupus erythematodes gedacht werden. Aufgrund der häufigen Rezidive nach erneuter Exposition sollte eine erneute Therapie mit PPI vermieden werden.
Development of an Incremental Sit-to-Stand Exercise for Aerobic Fitness Evaluation
Authors: Nakamura Keisuke , Nagasawa Yuya , Sawaki Shoji , Yokokawa Yoshiharu , Ohira Masayoshi
Published: September 2017

Incremental sit-to-stand exercise (ISTS) is an incremental exercise test using external signals to control the sit-to-stand rate in a given time frame. This study aimed to investigate the concurrent validity and reproducibility of the ISTS in aerobic fitness evaluation among healthy elderly women. Sixteen elderly women performed the ISTS and cycle ergometer test at 3-day to 2-week intervals, and six of the participants performed the ISTS twice. Peak oxygen uptake (VO2), peak heart rate and completion time on the ISTS and cycle ergometer test were determined. Measured peak VO2 on the cycle ergometer test was significantly related to the peak VO2 (r=0.80, P<0.05) and the completion time (r=0.65, P<0.05) on the ISTS. The intraclass correlation coefficients were 0.96 for peak VO2 values and 0.91 for the completion time values during the two ISTSs. In conclusion, the ISTS is a valid, reproducible and safe test for aerobic fitness evaluation in healthy elderly women.
Glaskörperersatz in der Ablatiochirurgie – warum wir eine ganz neue Tamponadestrategie brauchen!
Authors: Szurman Peter
Published: September 2017

Das wichtigste Konzept zur Behandlung der Netzhautablösung ist die Pars-plana-Vitrektomie in Kombination mit Endotamponaden (Luft, Gase, Silikonöle). Trotz zahlreicher technischer Innovationen und modernsten Tamponadematerialien scheinen die Grundprobleme der Ablatiochirurgie aber nicht gelöst zu sein: Seit Jahrzehnten ist die primäre Erfolgsrate nicht zufriedenstellend, es gibt keine gute Strategie bei Mehrlochsituationen und die Problematik der proliferativen Vitreoretinopathie oder der persistierenden Hypotonie ist nicht gelöst. Insbesondere die Geschichte der Tamponaden ist voller Mythen und Missverständnisse. Trotz immer neuer Materialentwicklungen haben diese bei genauer Betrachtung nur wenig Einfluss auf die Erfolgsrate gehabt. Zunehmend zeigt sich, dass der Wert der Tamponade deutlich überschätzt wird. Der Grund dafür ist ein konzeptuell falscher Ansatz: Denn alle verfügbaren Tamponaden sind hydrophob und üben ihre tamponierenden Eigenschaften über Auftriebsvektor und Oberflächenspannung aus. Dies beschränkt sie auf die hydraulische Tamponadefunktion in nur einer Richtung und erlaubt keine vollständige Füllung des Glaskörperraums. Der hydrophobe Charakter des Tamponadematerials birgt damit grundsätzliche Nachteile, die beispielsweise die PVR-Entwicklung oder erneute Lochbildung eher fördern als hemmen. Deshalb ist eine Neubewertung des Stellenwerts von Tamponaden nötig. Die Lösung könnte ein radikaler Strategiewechsel weg von hydrophoben hin zu hydrophilen Tamponaden mit Hydrogelen sein. Diese bilden die natürliche und recht komplexe Funktion des juvenilen, gesunden Glaskörpers viel besser ab als Gase oder Öle.
Epidemiology of Overuse Injuries in Youth Team Sports: A 3-year Prospective Study
Authors: Leppänen Mari , Pasanen Kati , Kannus Pekka , Vasankari Tommi , Kujala Urho , Heinonen Ari , Parkkari Jari
Published: September 2017

Prospective studies on overuse injuries and their impact on athletic training among youth team sports are scarce. The purpose of this study was to investigate the incidence, severity and player related risk factors of overuse injuries among young (12–20 years) basketball and floorball players. A total of 387 players participated in a 3-year prospective study. Each player completed a baseline questionnaire regarding their background information. Overuse injuries that prevented players to fully or partly participate in their regular training were collected. In all, 204 overuse injuries were registered (injury incidence 1.51 injuries/1 000 h of exposure; 95% CI 1.35–1.78). Most of the injuries involved the knee (35%) and lower back (21%), and were classified as severe (44%). Injury incidence was 1.51 (95% CI 1.2–1.82) and 1.61 (95% CI 1.32–1.91) in basketball and floorball, respectively. Incidence was significantly higher among female compared with male players (incidence rate ratio 1.58; 95% CI 1.20–2.09). Previous injury and playing at adult level were the strongest factors associated with occurrence of an overuse injury. In conclusion, overuse injuries of the knee and low back are relatively common in youth basketball and floorball. Effective prevention strategies as well as training load monitoring is needed in youth team sports.
Tuberkulose
Authors: Blaas Stefan
Published: September 2017

Was ist neu?

Epidemiologie Bedingt durch die Zunahme der Migration ist es 2015 in Deutschland zu einem deutlichen Anstieg von Tuberkulosefällen gekommen. Die resistente Tuberkulose nimmt weltweit zu.

Neue Leitlinie Die Leitlinie zur Behandlung der Tuberkulose bei Erwachsenen wurde im Sommer 2017 aktualisiert. Für Kinder wird eine eigene Leitlinie für 2017 erwartet.

Fremdsprachige Patienteninformationen finden sich z. B. unter http://www.explaintb.org.

Resistente Tuberkulose Zur Behandlung der multiresistenten Tuberkulose (MDR-TB) gibt es neue WHO-Empfehlungen. Darin wird unter bestimmten Voraussetzungen ein verkürztes Therapieregime vorgeschlagen. Dieses wird für Deutschland aufgrund der hierzulande zu erwartenden Resistenzen nicht empfohlen.
Long-term quality of life after peroral endoscopic myotomy remains compromised in patients with achalasia type III
Authors: Hernández Mondragón Oscar , González Martinez Marina , Blancas Valencia Juan , Hernandez Reyes Maria , Solórzano Pineda Omar , Blanco Velasco Gerardo
Published: September 2017

Background and study aims Peroral endoscopic myotomy (POEM) is an excellent endoscopic treatment for achalasia. Clinical and manometric parameters are used for evaluation and follow-up. However, clinical success does not guarantee high quality of life (QoL) scores, generating doubts about their direct relationship. We aimed to evaluate QoL scores before and after POEM at medium and long term, to evaluate differences between achalasia subtypes and find which factors related to low QoL scores.

Patients and methods Achalasia-confirmed patients undergoing POEM between February 2012 and November 2016. and completing at least 1 year of follow-up, were included. Assessment before and at 1, 6, 12, 24, 36 and 48 months after POEM employed manometry, barium series, Eckardt score, and the AE-18 health-related QoL scale. Demographic, clinical, and procedure characteristics were documented, with comparisons between subgroups. Multiple logistic regression analysis was done.

Results 65 of 88 patients were included (38 women, 27 men; median age 47 years, interquartile range [IQR] 20 – 81), and 50 (76.9 %) completed 4 years of follow-up. Eckardt score improved (median, preprocedure 10 vs. post-procedure 2; P = 0.002) and this persisted. There was initial improvement in median integrated relaxation pressure (IRP) (29.4 mmHg [16 – 55] vs. 10.3 mmHg [3 – 18]; P = 0.000) and median QoL scores (40 vs. 68 at 1 month; P = 0.002); however IRP increased and QoL scores decreased. Men with confirmed type III achalasia had low QoL scores.

Conclusions All patients had significant clinical improvement after POEM, with medium- to long-term persistence. Though quality of life and IRP initially improved, they deteriorated in the long term. Male sex and type III achalasia seem to be associated with low QoL scores.
Effects of Cobalamin (Vitamin B12) on Gentamicin Induced Nephrotoxicity in Rat
Authors: Hajihashemi Saeed , Hamidizad Zeinab , Rahbari Ali , Ghanbari Fatemeh , Motealeghi Zohre
Published: September 2017

Background The main side effect of gentamicin is nephrotoxicity. The effect of cobalamin (Cob) was investigated on gentamicin nephrotoxicity in rats.

Methods Renal injury induced by i.p. injection of gentamicin (100 mg/kg) for 8 consecutive days. Cobalamin (6 mg/kg/day, i.p) treatment was done for 8 consecutive days as co-treatment and post-treatment protocol.

Results Cobalamin significantly increased creatinine clearance levels and renal blood flow which were reduced by gentamicin. Also, cobalamin significantly improved serum electrolytes (sodium and potassium) levels which were disturbed by gentamicin. Cobalamin significantly compensated deficits in the antioxidant defense mechanisms, suppressed lipid per oxidation and ameliorated renal tissue damage mediated by gentamicin.

Conclusion The results of the current study indicated that cobalamin effectively protected the kidney tissue against gentamicin induced acute nephrotoxicity in rats. The antioxidant and anti-inflammatory activities can be supposed the main factors responsible for the nephroprotective effect of cobalamin.
Influence of High-Dose Folic Acid on Methotrexate Efficacies and Safety in Japanese Rheumatoid Arthritis Patients
Authors: Kameyama Shun , Kase Yuko , Kurihara Saori , Yoshida Fumiko , Noda Masamitu , Iiduka Toshimi , Horiguchi Masami , Sugiyama Kentaro , Hirano Toshihiko
Published: September 2017

Backgrounds Folic acid dose at ≦5 mg/week has been recommended for rheumatoid arthritis (RA) patients to decrease risk of methotrexate adverse effects. However, higher doses of folic acid is used in some cases. We examined the influence of high-dose folic acid on methotrexate efficacies and safety in Japanese RA patients.

Methods 502 RA patients of four hospitals prescribed methotrexate and folic acid were included. These patients were divided into two subgroups according to the threshold of folic acid dose by 5 mg/week. Basic patient characteristics, methotrexate doses, and the efficacies or adverse effects of methotrexate were retrospectively compared between the two patient subgroups.

Results The frequency of folic acid use at doses higher than 5 mg/week was significantly different between the four hospitals (P<0.001). The prevalence of methotrexate adverse effects was not significantly different between the patients taking folic acid less and more than 5 mg/week. However, in the lower dose methotrexate subgroup (≦8 mg/week), the prevalence of patients exhibiting abnormal serum ALT concentrations in the patients using higher (>5 mg/week) dose of folic acid was significantly higher than that in the lower (≦5 mg/week) folic acid-treated subgroup (P=0.029). Folic acid dose between patients taking methotrexate less and more than 8 mg/week was not significantly different.

Major conclusion Folic acid dose was dependent on the hospitals, while efficacies and hepatotoxicity of methotrexate was not basically different between patients taking less and more than 5 mg/week of folic acid.
Taguchi Experimental Design for Optimization of Recombinant Human Growth Hormone Production in CHO Cell Lines and Comparing its Biological Activity with Prokaryotic Growth Hormone
Authors: Aghili Zahra , Zarkesh-Esfahani Sayyed
Published: September 2017

Growth hormone deficiency results in growth retardation in children and the GH deficiency syndrome in adults and they need to receive recombinant-GH in order to rectify the GH deficiency symptoms. Mammalian cells have become the favorite system for production of recombinant proteins for clinical application compared to prokaryotic systems because of their capability for appropriate protein folding, assembly, post-translational modification and proper signal. However, production level in mammalian cells is generally low compared to prokaryotic hosts. Taguchi has established orthogonal arrays to describe a large number of experimental situations mainly to reduce experimental errors and to enhance the efficiency and reproducibility of laboratory experiments.

In the present study, rhGH was produced in CHO cells and production of rhGH was assessed using Dot blotting, western blotting and Elisa assay. For optimization of rhGH production in CHO cells using Taguchi method An M16 orthogonal experimental design was used to investigate four different culture components. The biological activity of rhGH was assessed using LHRE-TK-Luciferase reporter gene system in HEK-293 and compared to the biological activity of prokaryotic rhGH.

A maximal productivity of rhGH was reached in the conditions of 1%DMSO, 1%glycerol, 25 µM ZnSO4 and 0 mM NaBu. Our findings indicate that control of culture conditions such as the addition of chemical components helps to develop an efficient large-scale and industrial process for the production of rhGH in CHO cells. Results of bioassay indicated that rhGH produced by CHO cells is able to induce GH-mediated intracellular cell signaling and showed higher bioactivity when compared to prokaryotic GH at the same concentrations.
Micro-Raman scattering and dielectric investigations of phase transitions behavior in the PbHf0.7Sn0.3O3 single crystal
Authors: Jankowska-Sumara Irena , Ko Jae-Hyeon , Podgórna Maria , Oh Soo Han , Majchrowski Andrzej
Published: September 2017

Raman light scattering was used to detect the sequence of transitions in a PbHf1-xSnxO3 (PHS) single crystal with x = 0.30 in a temperature range of 77–873 K. Changes of Raman spectra were observed in the vicinity of structural phase transitions: between the antiferroelectric (AFE1)–antiferroelectric (AFE2)—intermediate—paraelectric phases. Light scattering and dielectric investigations were used to find out the nature and sequence of the phase transition, as well as the large dielectric permittivity values measured at the phase transition, by searching for the soft-phonon-mode behavior. The experimentally recorded spectra were analyzed in terms of the damped-harmonic oscillator model for the phonon bands. It is demonstrated that the structural phase transformations in PHS can be considered as the result of softening of many modes, not only the ferroelectric one. It was also proved that locally broken symmetry effects are present at temperatures far above the Curie temperature and are connected with the softening of two optic modes of different nature.
Torsional frequency mixing and sensing in optomechanical resonators
Authors: Huang J. G. , Cai H. , Gu Y. D. , Chin L. K. , Wu J. H. , Chen T. N. , Yang Z. C. , Hao Y. L. , Liu A. Q.
Published: September 2017

In this letter, a torsional optomechanical resonator for torque sensing and torsional mechanical frequency mixing is experimentally demonstrated. The torsional mechanical resonator is embedded into a split optical racetrack resonator, which provides high sensitivity in measuring torsional mechanical motion. Using this high sensitivity, torsional mechanical frequency mixing is observed without regenerative mechanical motion. The displacement noise floor of the torsional mechanical resonator is 50 fm/Hz0.5, which demonstrates a resonant torque sensitivity of 3.58 × 10−21 N m/Hz0.5. This demonstration will benefit potential applications for on-chip RF signal modulation using optical mechanical resonators.
Anab initiostudy of hydroxylated graphane
Authors: Buonocore Francesco , Capasso Andrea , Lisi Nicola
Published: September 2017

Graphene-based derivatives with covalent functionalization and well-defined stoichiometry are highly desirable in view of their application as functional surfaces. Here, we have evaluated by ab initio calculations the energy of formation and the phase diagram of hydroxylated graphane structures, i.e., fully functionalized graphene derivatives coordinated with –H and –OH groups. We compared these structures to different hydrogenated and non-hydrogenated graphene oxide derivatives, with high level of epoxide and hydroxyl groups functionalization. Based on our calculations, stable phases of hydroxylated graphane with low and high contents of hydrogen are demonstrated for high oxygen and hydrogen partial pressure, respectively. Stable phases of graphene oxide with a mixed carbon hybridization are also found. Notably, the synthesis of hydroxylated graphane has been recently reported in the literature.
Heat transport and coupling modes in Rayleigh–Bénard convection occurring between two layers with largely different viscosities
Authors: Yoshida Masaki , Iwamori Hikaru , Hamano Yozo , Suetsugu Daisuke
Published: September 2017

A high-resolution numerical simulation model in two-dimensional cylindrical geometry was used to discuss the heat transport and coupling modes in two-layer Rayleigh-Bénard convection with a high Rayleigh number (up to the order of 109), an infinite Prandtl number, and large viscosity contrasts (up to 10−3) between an outer, highly viscous layer (HVL) and an inner, low-viscosity layer (LVL). In addition to mechanical and thermal interaction across the HVL-LVL interface, which has been investigated by Yoshida and Hamano [“Numerical studies on the dynamics of two-layer Rayleigh-Bénard convection with an infinite Prandtl number and large viscosity contrasts,” Phys. Fluids 28(11), 116601 (2016)], the spatiotemporal analysis in this study provides new insights into (1) heat transport over the entire system between the bottom of the LVL and the top of the HVL, in particular that associated with thermal plumes, and (2) the convection regime and coupling mode of the two layers, including the transition mechanism between the mechanical coupling mode at relatively low viscosity contrasts and the thermal coupling mode at higher viscosity contrasts. Although flow in the LVL is highly time-dependent, it shares the spatially opposite/same flow pattern synchronized to the nearly stationary upwelling and downwelling plumes in the HVL, corresponding to the mechanical/thermal coupling mode. In the transitional regime between the mechanical and thermal coupling modes, the LVL exhibits periodical switching between the two phases (i.e., the mechanical and thermal coupling phases) with a stagnant period. A detailed inspection revealed that the switching was initiated by the instability in the uppermost boundary layer of the LVL. These results suggest that convection in the highly viscous mantle of the Earth controls that of the extremely low-viscosity outer core in a top-down manner under the thermal coupling mode, which may support a scenario of top-down hemispherical dynamics proposed by the recent geochemical study.
Photobleaching of randomly rotating fluorescently decorated particles
Authors: Taneja Swadhin , Rutenberg Andrew D.
Published: September 2017

Randomly rotating particles that have been isotropically labeled with rigidly linked fluorophores will undergo non-isotropic (patchy) photobleaching under illumination due to the dipole coupling of fluorophores with light. For a rotational diffusion rate D of the particle and a photobleaching time scale τ of the fluorophores, the dynamics of this process are characterized by the dimensionless combination Dτ. We find significant interparticle fluctuations at intermediate Dτ. These fluctuations vanish at both large and small Dτ or at small or large elapsed times t. Associated with these fluctuations between particles, we also observe transient non-monotonicities of the brightness of individual particles. These non-monotonicities can be as much as 20% of the original brightness. We show that these novel photobleach-fluctuations dominate over variability of single-fluorophore orientation when there are at least 103 fluorophores on individual particles.
Atomistic modeling of the Ge composition dependence of solid phase epitaxial regrowth in SiGe alloys
Authors: Prieto-Depedro M. , Payet A. , Sklénard B. , Martin-Bragado I.
Published: September 2017

The solid phase epitaxial regrowth (SPER) of SiGe alloys has been studied using atomistic simulation techniques. Molecular Dynamics (MD) simulations reproduce the recrystallization process of amorphous structures created in two different ways: introducing atoms at random positions according to the crystalline density and carefully relaxing the structure; and using a bond switching algorithm by means of ab initio. Activation energies are confronted, and the first method is validated as an efficient way to generate amorphous-crystalline structures suitable to study SPER processes. The MD extracted results show that the SPER rate does not vary monotonically with the Ge composition; instead, activation energies reveal a non-linear behaviour with the addition of Ge, due to the two-part behaviour of the SPER rate: SPER rate itself and a hypothesized extra strain due to the bond length difference. Since SPER is a thermally activated process, nudged elastic band calculations are carried out in order to extend the previous assumption. The energy barrier for an atom to attach to the crystalline phase is computed. The extracted values confirm the presence of the mentioned strain contribution required for an atom to recrystallize when it is not as the same type of the bulk.
Extended screened exchange functional derived from transcorrelated density functional theory
Authors: Umezawa Naoto
Published: September 2017

We propose a new formulation of the correlation energy functional derived from the transcorrelated method in use in density functional theory (TC-DFT). An effective Hamiltonian, HTC, is introduced by a similarity transformation of a many-body Hamiltonian, H, with respect to a complex function F: HTC=1FHF. It is proved that an expectation value of HTC for a normalized single Slater determinant, Dn, corresponds to the total energy: E[n] = ⟨Ψn|H|Ψn⟩/⟨Ψn|Ψn⟩ = ⟨Dn|HTC|Dn⟩ under the two assumptions: (1) The electron density nr associated with a trial wave function Ψn = DnF is v-representable and (2) Ψn and Dn give rise to the same electron density nr. This formulation, therefore, provides an alternative expression of the total energy that is useful for the development of novel correlation energy functionals. By substituting a specific function for F, we successfully derived a model correlation energy functional, which resembles the functional form of the screened exchange method. The proposed functional, named the extended screened exchange (ESX) functional, is described within two-body integrals and is parametrized for a numerically exact correlation energy of the homogeneous electron gas. The ESX functional does not contain any ingredients of (semi-)local functionals and thus is totally free from self-interactions. The computational cost for solving the self-consistent-field equation is comparable to that of the Hartree-Fock method. We apply the ESX functional to electronic structure calculations for a solid silicon, H− ion, and small atoms. The results demonstrate that the TC-DFT formulation is promising for the systematic improvement of the correlation energy functional.
Molybdenum disulfide and water interaction parameters
Authors: Heiranian Mohammad , Wu Yanbin , Aluru Narayana R.
Published: September 2017

Understanding the interaction between water and molybdenum disulfide (MoS2) is of crucial importance to investigate the physics of various applications involving MoS2 and water interfaces. An accurate force field is required to describe water and MoS2 interactions. In this work, water–MoS2 force field parameters are derived using the high-accuracy random phase approximation (RPA) method and validated by comparing to experiments. The parameters obtained from the RPA method result in water–MoS2 interface properties (solid-liquid work of adhesion) in good comparison to the experimental measurements. An accurate description of MoS2-water interaction will facilitate the study of MoS2 in applications such as DNA sequencing, sea water desalination, and power generation.
Re-examination of the Cs2 ground singlet X1Σg+ and triplet a3Σu+ states
Authors: Sovkov Vladimir B. , Xie Feng , Lyyra A. Marjatta , Ahmed Ergin H. , Ma Jie , Jia Suotang
Published: September 2017

This paper clarifies the disagreement in the depth of the potential energy curve of the cesium dimer singlet ground state which has lasted for nearly a decade. We point out that the origin of this disagreement must be a technical misprint in the values of the three binding energies reported by Danzl et al. [Science 321, 1062 (2008)], while the X1Σg+ state potential reported by Coxon and Hajigeorgiou [J. Chem. Phys. 132, 094105 (2010)], based on experimental data by Amiot and Dulieu [J. Chem. Phys. 117, 5155 (2002)], is quite correct. We have recalculated the potential energy function of the triplet ground state a3Σu+ by using the available experimental data spanning both the attractive and the repulsive branches so that the potential energy function complies asymptotically with the singlet ground state X1Σg+ potential energy function by Coxon and Hajigeorgiou. This is important for the simulation of the near dissociation properties such as Feshbach resonances, which are typically observed in modern experiments with ultracold atoms and molecules.
Envelope solitons in three-component degenerate relativistic quantum plasmas
Authors: Islam S. , Sultana S. , Mamun A. A.
Published: September 2017

The criteria for the formation of envelope solitons and their basic features in a three-component degenerate relativistic quantum plasma (DRQP) system (containing relativistically degenerate electrons, non-degenerate inertial light nuclei, and stationary heavy nuclei) are theoretically investigated. The nonlinear Schrödinger equation is derived by employing the multi-scale perturbation technique. The envelope solitons are found to be associated with the modified ion-acoustic waves in which the inertia (restoring force) is provided by the mass density of light nuclei (degenerate pressure of cold electrons). The basic features of these envelope solitons, which are found to formed in such a DRQP system, and their modulational instability criteria (on the basis of the plasma parameters associated with the degenerate pressure of electrons, number densities of degenerate electrons, inertial light nuclei, and stationary heavy nuclei) are identified. The numerical simulations are also performed to confirm the stability of the envelope solitons predicted here by analytical analysis.
Quality controls for wind measurement of a 1290-MHz boundary layer profiler under strong wind conditions
Authors: Liu Zhao , Zheng Chaorong , Wu Yue
Published: September 2017

Wind profilers have been widely adopted to observe the wind field information in the atmosphere for different purposes. But accuracy of its observation has limitations due to various noises or disturbances and hence need to be further improved. In this paper, the data measured under strong wind conditions, using a 1290-MHz boundary layer profiler (BLP), are quality controlled via a composite quality control (QC) procedure proposed by the authors. Then, through the comparison with the data measured by radiosonde flights (balloon observations), the critical thresholds in the composite QC procedure, including consensus average threshold T1 and vertical shear threshold T3, are systematically discussed. And the performance of the BLP operated under precipitation is also evaluated. It is found that to ensure the high accuracy and high data collectable rate, the optimal range of subsets is determined to be 4 m/s. Although the number of data rejected by the combined algorithm of vertical shear examination and small median test is quite limited, it is proved that the algorithm is quite useful to recognize the outlier with a large discrepancy. And the optimal wind shear threshold T3 can be recommended as 5 ms−1/100m. During patchy precipitation, the quality of data measured by the four oblique beams (using the DBS measuring technique) can still be ensured. After the BLP data are quality controlled by the composite QC procedure, the output can show good agreement with the balloon observation.
Evolution and prevention of meltback etching: Case study of semipolar GaN growth on patterned silicon substrates
Authors: Khoury Michel , Tottereau Olivier , Feuillet Guy , Vennéguès Philippe , Zúñiga-Pérez Jesus
Published: September 2017

Meltback etching, a deteriorating chemical reaction occurring between gallium and silicon under typical metal organic chemical vapor deposition growth conditions, is a common problem that often limits the development of GaN on silicon substrates, in particular, patterned substrates, and therefore must be circumvented. To further understand this reaction, energy dispersive X-ray spectroscopy was performed in cross-section, and a proposed 2-dimensional model on how meltback etching evolves throughout the growth process is discussed, which indicated an inter-diffusion reaction occurring primarily between gallium and silicon where gallium from GaN diffuses into the silicon substrate while silicon from the substrate diffuses out and incorporates into the GaN crystal. Moreover, we demonstrate an anisotropic behavior of the gallium penetrating the silicon substrate, which has shown to be delimited by the Si {111} planes. Finally, an approach to prevent meltback etching by changing the fractions of nitrogen and hydrogen in the carrier gas is presented and discussed.
On a mechanism of high-temperature superconductivity: Spin-electron acoustic wave as a mechanism for the Cooper pair formation
Authors: Andreev Pavel A. , Polyakov P. A. , Kuz'menkov L. S.
Published: September 2017

We have found the mechanism of the electron Cooper pair formation via the electron interaction by means of the spin-electron acoustic waves. This mechanism takes place in metals with rather high spin polarization, such as ferromagnetic, ferrimagnetic, and antiferromagnetic materials. The spin-electron acoustic wave mechanism leads to transition temperatures 100 times higher than the transition temperature allowed by the electron-phonon interaction. Therefore, spin-electron acoustic waves give the explanation for the high-temperature superconductivity. We find that the transition temperature has strong dependence on the electron concentration and the spin polarization of the electrons.
Distributed feedback lasing in a metallic cavity
Authors: Zhai Tianrui , Tong Fei , Cao Fengzhao , Niu Lianze , Li Songtao , Wang Meng , Zhang Xinping
Published: September 2017

Distributed feedback (DFB) lasing is observed in a metallic cavity, which consists of a gold grating and a polymer membrane. The gold grating is prepared by evaporating a 25 nm thin film of gold on the photoresist grating fabricated by interference lithography. A 150 nm thick polymer membrane is directly attached on the gold grating, forming a suspended membrane supported by the grating ridge. The assembly method decreases the metallic contact area, which makes the mode more photonic and thereby reduces the ohmic loss of the metal. Low threshold DFB lasing can be achieved when the sample is optically pumped. The fabrication technique provides a facile way to realize plasmonic DFB polymer lasers.
Ephemeral parasitism on blooming diatoms in a temperate estuary
Authors: Guinder Valeria A. , Carcedo M. Cecilia , Buzzi Natalia , Molinero Juan Carlos , Abbate Celeste López , Melisa Fernández Severini , Florencia Biancalana , Kühn Stefanie
Published: September 2017

Parasites of phytoplankton influence phytoplankton bloom dynamics and may severely affect the type of food available for higher trophic levels. The incidence of parasitic infections generally is expected to increase across ecosystems worldwide under the scenario of global change. Herein we report on a massive parasite infection on two dominant diatoms of the austral winter bloom, namely Thalassiosira pacifica and Chaetoceros diadema, recorded during an extreme precipitation period in the Bahía Blanca Estuary, Argentina. The parasite infection was concomitant with a marked drop in water salinity and affected more than 40% of host cells. Although the parasite on C. diadema was not identified, the parasite on T. pacifica was most likely Pirsonia sp., a nanoflagellate with high host specificity. After the intense rainy period and the parasitic infection, the phytoplankton biomass dropped (by more than 80%) and the community structure shifted to one with smaller species (i.e. Thalassiosira curviseriata, T. hibernalis and T. minima). We discuss the implications that these modifications may have on the food web dynamics and the potential relationship between precipitation-driven modifications in water properties and the emergence of parasitism in coastal eutrophic environments.
Combined effects of predation risk and food quality on freshwater detritivore insects
Authors: Bordalo Maria D. , Vieira Hugo C. , Rodrigues Andreia C. M. , Rosa Rita , Soares Amadeu M. V. M. , Pestana João L. T.
Published: September 2017

Because both predation risk and resource quality have a pivotal role in ecological communities, their combined effects were assessed in stream detritivores. Bioassays were conducted using a simplified trophic chain, coupling effects of predation risk and basal resources with different nutritious qualities, namely, a predator planarian Dugesia subtentaculata, a caddisfly shredder Sericostoma vittatum, a dipteran collector Chironomus riparius, native alder Alnus glutinosa and invasive eucalypt Eucalyptus globulus. We investigated whether individual performance of C. riparius larvae is affected under predation risk and whether the response can be mediated by resource quality. We also assessed whether shredder–collector interactions are altered under these conditions. Predation risk and food quality influenced leaf decomposition and C. riparius growth independently. Chironomus riparius fed preferentially on alders, resulting in increased growth rate. Litter processing decreased under planarian presence, in both leaf types, impairing the growth of C. riparius larvae, this effect being exacerbated with eucalypts. Chironomus riparius growth was also reduced in the presence of the caddisfly, suggesting competition between these species, irrespective of planarian presence, but dependent on leaf type. The present study highlighted the importance of assessing predator influence along detritus-based processing chains, because predation risk may result in sublethal costs, with potential cascading effects.
The reverse precautionary principle: science, the environment and the salmon aquaculture industry in Macquarie Harbour, Tasmania, Australia
Authors: Kirkpatrick Jamie B. , Kriwoken Lorne K. , Styger Jennifer
Published: September 2017

Science is frequently used by opposing sides in environment–development debates. Scientific input from an environmental perspective can be inhibited if those in favour of development control research funding. We test whether such a situation can result in outcomes desired by neither of the protagonists, and seek to identify how negative outcomes can be avoided, using the example of fish farming in Macquarie Harbour, Tasmania. A marked decline in dissolved oxygen (DO) at 19–21m depth in Macquarie Harbour, Tasmania, occurred between 2009 and 2011. DO continues to be low. DO change was associated with changes in the benthic biota, with effects extending from fish farms into the Tasmanian Wilderness World Heritage Area and threatening a Tasmanian endemic fish. The reverse precautionary response of industry and government was to undertake further research because the causes of the changes were not fully understood. We present simple graphs and analyses that suggest that the only substantial predictor of benthic DO reduction is fish production from marine farms, with variability in discharge, catchment rainfall, wind speed, sea surface temperatures and sea level pressure having no effect. Adaptive management of fish farming in Macquarie Harbour seems to require an estuary-wide approach rather than the current attention to the effects of single pens. The broader implications of the case study are that the science related to the environmental impacts of an industry needs to be undertaken by scientists in secure positions funded independently of industry and government.
Fluxes of greenhouse gases from incubated soils using different lid-closure times
Authors: Minh Dang Duy , Macdonald Ben , Warneke Sören , White Ian
Published: September 2017

Different sampling times for greenhouse gas measurements have been proposed in many incubation studies. Little is known about effects of closure time on denitrification and nitrification rates from incubation experiments. The objectives of this study were to analyse greenhouse gas (carbon dioxide, methane and nitrous oxide) production from different soils with different times of lid closure and to assess effects of different activation times (defined as additional pre-incubation periods before incubation experiments) on gas emissions from soils. Forty grams of air-dried soil samples (depth 0–10 cm) were incubated in 125-mL jars at 25°C with the addition of glucose and nitrate. The first experiment measured greenhouse gas fluxes at different lid-closure times (40, 80, 120 and 1440 min). The second experiment assessed the effects of different durations of soil activation (0.7, 1.3, 2 and 24 h) on gas emissions. Both were conducted with a completely randomised design, with three replicates per treatment. Our findings showed closure time <1 h or >2 h may cause an underestimate of greenhouse gas emissions. Lengthening activation times resulted in different emission rates consistent with soil characteristics. To measure gas fluxes based on linear regression would require four or five sampling points and sampling at a 20-min interval over a maximum period of 80 min for estimating gas fluxes from soil. Because pre-incubation time is critical and a driving factor in the measurement of soil-induced gas emissions, a standardised procedure to quantify gas fluxes is needed for application to other soils.
CD1d-Restricted pathways in hepatocytes control local natural killer T cell homeostasis and hepatic inflammation
Authors: Zeissig Sebastian , Peuker Kenneth , Iyer Shankar , Gensollen Thomas , Dougan Stephanie K. , Olszak Torsten , Kaser Arthur , Blumberg Richard S.
Published: September 2017

Significance

Invariant natural killer T (iNKT) cells recognize lipid antigens in the context of CD1d and have potent effects on immunity. Control of iNKT cells is critical to prevent inflammation, but the mechanisms that maintain homeostasis of iNKT cells in peripheral tissues are incompletely understood. Here we demonstrate that hepatocytes promote the apoptosis of local, liver-resident iNKT cells in a manner dependent on CD1d. In the absence of hepatocyte CD1d or microsomal triglyceride transfer protein, a protein responsible for lipid transfer onto CD1d, hepatic iNKT cell numbers are increased, which is associated with susceptibility to iNKT cell-dependent hepatitis. This work thus reveals a pathway of peripheral induction of immune tolerance, which limits susceptibility to iNKT cell-dependent inflammation in the liver.
Waiting can be an optimal conservation strategy, even in a crisis discipline
Authors: Iacona Gwenllian D. , Possingham Hugh P. , Bode Michael
Published: September 2017

Significance

Every year, more species are driven to extinction by the combined pressures of habitat destruction, invasive species, and climate change. These ongoing losses have created a “crisis culture” in conservation, where project funds are spent as soon as they are received. We challenge this orthodoxy and demonstrate how strategic delays can improve efficiency. Waiting can allow agencies to leverage additional benefits from their funds, through investment, capacity building, or monitoring and research. With the right amount of delay, limited conservation resources can protect more species. Surprisingly, they can even do so in less time. Our results suggest that, in addition to their current focus on where to target resources, conservation managers should carefully choose when to spend these funds.
Arresting dissolution by interfacial rheology design
Authors: Beltramo Peter J. , Gupta Manish , Alicke Alexandra , Liascukiene Irma , Gunes Deniz Z. , Baroud Charles N. , Vermant Jan
Published: September 2017

Significance

The challenge of creating foams and emulsions with well-controlled size distribution and properties is encountered in many structured materials, such as food formulations and consumer care products. These products, like ice cream for example, must remain stable over long shelf lifetimes while their microstructure dictates product performance and consumer satisfaction. Despite the common use of particles to stabilize bubbles and emulsions, the cause of such stabilization is unknown. Here, we provide the link between the particles’ ability to impart a resistance, or “armor,” against bubble dissolution and their interfacial rheological properties. We propose a design strategy based on controlling interfacial particle interactions to arrest dissolution of small bubbles to create foam and emulsion materials with stable microstructures and controllable textures.