bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of the effective and macroscopic ageing behavior of viscoelastic composite materials
Authors: El Kouri Mohamed , Bakkali Abderrahmane , Azrar Lahcen
Published: November 2022

In this work, a mathematical modeling is developed to estimate the ageing macroscopic response and effective behavior of viscoelastic composites. The modeling is developed directly in time domain by considering the Volterra tensorial integral product describing the local behavior and governing equations. The ageing dynamic Green’s tensor is introduced in order to solve the partial differential equations for the time dependent displacement and make the transition between local and macroscopic fields. The localization tensor making the scale transition is obtained through using the heterogeneity problem and the Mori-Tanaka mean field approach. Once this step is completed, averaging techniques are used to derive the effective ageing behavior of viscoelastic composites. To compute the macroscopic response and the effective behavior a numerical scheme is used. Numerical results are presented with respect to the shape and volume fraction of inclusions and for different ageing viscoelastic composites.
Numerically based qualitative evaluation of GPR vertical and horizontal resolutions for reinforced concrete structures
Authors: Bachiri Tahar , Hamdaoui Mohammed , Alsharahi Gamil , Bezzazi Mohammed , Faize Ahmed
Published: November 2022

The GPR is widely used for non-destructive evaluation of reinforced concrete structures. High resolution of detection is needed in order to differentiate between multiple targets present in the host medium. This article aims to numerically study the vertical and horizontal resolutions associated to detection of reinforcing bars buried in a structure made from concrete by means of GPR inspection. Use was made of open source software GprMax2D by considering the three work frequencies: 1GHz, 1.6GHz and 2GHz. The method of scanning is assumed to be according to B-scan protocol which was conducted along a profile traced on the surface of the inspected member. In situ measurements were made for a bridge pillar made of reinforced concrete by the MALÅ CX GPR system with a frequency centred on 1.6 GHz. The obtained results show that the GPR is effective in the examination of reinforced concrete structure and most of the steel bars can be detected. After making correction, the horizontal resolution predicted by a conventional formula was verified. However, the real vertical resolution imposes a minimum distance separating steel bars that is higher than that proposed in the literature. This is due to the high conductivity of steel bars that yields strong reflection of the signal at the first reached bars and which impedes significant secondary reflection from targets located below them.
Assessment and synergy analysis of outdoor thermal comfort and thermal infrared remote sensing for urban heat island studies
Authors: Ahsissene Safae , Rhziel Fatima Zahrae , Raissouni Naoufal
Published: November 2022

The aim of this research is to explore the potentialities and limits of the integration of remote sensing biophysical data (land surface temperature) in the outdoor thermal comfort studies. Accordingly, by examining correlations between land surface temperature and air temperature, and using respectively remote sensing satellite data MODIS and different weather stations archives alongside questionnaire surveys. Currently, the parameters of thermal comfort indices are usually calculated using the data from one, or few permanent or portable ground-based weather stations. Due to the lack of adequate distribution of weather stations, those calculations generally do not accurately represent the alteration of thermal comfort, through time and space. Nevertheless, it has been essentially proved that despite strong tendencies between in-situ measured parameters and remotely sensed ones, various elements need to be studied (e.g., location, land surface type, vegetation, and elevation). Finally, preliminary results confirm that the proposed linear approaches are providing considerable and promising performance suitable for future specific situations and studies purposes.
Les tumoroïdes, modèles précliniques en plein essor pour l’oncologie
Authors: Thorel Lucie , Florent Romane , Perréard Marion , Vincent Audrey , Poulain Laurent , Weiswald Louis-Bastien
Published: November 2022

La récente émergence des cultures d’organoïdes tumoraux, ou tumoroïdes, a permis d’enrichir le répertoire des modèles précliniques en oncologie. Très proches de la tumeur dont elles dérivent, ces microtumeurs offrent de nombreuses possibilités en termes de recherche fondamentale, telles que l’étude de la carcinogenèse ou de la chimioré-sistance, de validation préclinique de nouvelles molécules à visée anticancéreuse, ou encore de personnalisation des traitements. Divers développements techniques et l’enrichissement des tumoroïdes par l’addition d’autres types cellulaires sont actuellement en cours pour améliorer la pertinence de ces modèles et exploiter de façon optimale leur remarquable potentiel.
Psoriasis und Adipositas
Authors: Seitz Anna-Theresa , Kunz Manfred , Saalbach Anja , Kalweit Lena , Vogt Lisa , Kohlmann Johannes , Simon Jan C.
Published: November 2022

Die Psoriasis ist eine chronisch-entzündliche Hauterkrankung. Der
Entzündungsprozess betrifft nicht nur die Haut, sondern auch weitere
Gewebe, wie Gelenke, Bänder und die Gefäße. Bei einem
Großteil aller Psoriasis-Patienten bestehen Nebenerkrankungen wie
Diabetes, Übergewicht, Fettstoffwechselstörungen und
erhöhter Blutdruck. Der genaue pathophysiologische Zusammenhang zwischen
Adipositas und Psoriasis ist nicht hinreichend geklärt. Es ist unklar,
ob Psoriasis die Entstehung von Übergewicht begünstigt oder ob
Adipositas die Entstehung einer Psoriasis durch einen chronisch
pro-inflammatorischen Zustand fördert. Neuere Daten zeigen einen
deutlichen Zusammenhang zwischen der Konzentration freier Fettsäuren und
dem Ausprägungsgrad der Psoriasis. Eine Ernährungsumstellung und
eine erhöhte körperliche Aktivität haben
grundsätzlich eine positive Wirkung auf die Schuppenflechte und
können das Ansprechen der verschiedenen Therapien erhöhen.
Ablösung der Lasersondenspitze – eine seltene Komplikation der endoluminalen Therapie
Authors: Rafi-Stenger Leyla , Stücker Markus
Published: November 2022

Hintergrund In der Vergangenheit bestand die chirurgische
Therapie der Stammvarikose in Crossektomie, Stripping und falls notwendig in minichirurgischer
Phlebektomie. In den letzten 10 Jahren haben endoluminale Techniken und hier speziell
Lasertechniken an Bedeutung gewonnen. Komplikationen nach endoluminalen Laserprozeduren sind
selten beschrieben.

Methode Wir berichten erstmalig in einem Fallbericht über die
intraoperative Ablösung der Lasersondenspitze bei endoluminaler Therapie einer Vena saphena
magna Stammvarikose. Ein unmittelbarer sicherer Nachweis der abgelösten Sondenspitze mittels
Duplexsonografie war aufgrund der infiltrierten TLA Lösung nicht möglich. Eine CT-Diagnostik
blieb ergebnislos.

Ergebnisse Am Tag nach der Operation ließ sich die abgelöste
Sondenspitze problemlos mittels Ultraschall nachweisen. Um eine Embolisation der abgesprengten
Glaspartikel sicher zu vermeiden, entschlossen wir uns zu einem offenen chirurgischen Vorgehen
mit Resektion der Sondenspitze und Durchführung einer korrekten Crossektomie.

Schlussfolgerung Mit zeitlicher Verzögerung (Stunden) ist eine
Ortung der abgelösten Sondenspitze mittels Ultraschall sicher möglich. Chirurgische
Intervention, aber auch passives Zuwarten, sind zu diskutieren.
Fallvorstellung: Migränerezidiv nach
Covid-19-Infektion
Authors: Schmittdiel Marieluise
Published: November 2022

Durch eine Covid-19-Infektion wird eine chronische, über 40 Jahre
bestehende Migräne, die zuvor mit Pulsatilla gut unter Kontrolle
gebracht werden konnte, reaktiviert und spricht nicht mehr auf die bisherige,
gut wirkende Arznei an. Auf den ersten Blick leidet die Patientin unter den
gleichen Migränebeschwerden. Im Zuge der erneuten Fallaufnahme zeigt
sich jedoch ein kleiner Unterschied – eine zusätzliche neue
Kopfschmerzqualität. Die Fallanalyse, die mit dem Symptomenlexikon (SL)
durchgeführt wurde, zeigt deutlich, dass Pulsatilla diese neue
Symptomatik nicht mehr abdeckt, sondern dass eine neue Arznei angezeigt ist, mit
der das Migränerezidiv erfolgreich therapiert werden kann.
Effect Produced by a Cyclooctyne Derivative on Both Infarct Area and Left Ventricular Pressure via Calcium Channel Activation
Authors: Lauro Figueroa-Valverde , Marcela Rosas-Nexticapa , Maria López-Ramos , Francisco Díaz-Cedillo , Magdalena Alvarez-Ramirez , Virginia Mateu-Armad Maria , Montserrat Melgarejo-Gutierrez
Published: November 2022

Background There are reports which indicate that some cyclooctyne derivatives may exert changes in cardiovascular system; however, its molecular mechanism is not very clear.

Objective The aim of this study was to evaluate the biological activity of four cyclooctyne derivatives (compounds 1 to 4) produced on infarct area and left ventricular pressure.

Methods Biological activity produced by cyclooctyne derivatives on infarct area was determinate using an ischemia/reperfusion injury model. In addition, to characterize the molecular mechanism of this effect, the following strategies were carried out as follows; i) biological activity produced by cyclooctyne derivative (compound 4) on either perfusion pressure or left ventricular pressure was evaluated using an isolated rat heart; ii) theoretical interaction of cyclooctyne derivative with calcium channel (1t0j protein surface) using a docking model.

Results The results showed that cyclooctyne derivative (compound 4) decrease infarct area of in a dose-dependent manner compared with compound 1 to 3. Besides, this cyclooctyne derivative increase both perfusion pressure and left ventricular pressure which was inhibited by nifedipine. Other theoretical data suggests that cyclooctyne derivative could interact with some aminoacid residues (Met83, Ile85, Ser86, Leu108, Glu114) involved in 1t0j protein surface.

Conclusions All these data indicate that cyclooctyne derivative increase left ventricular pressure via calcium channel activation and this phenomenon could be translated as a decrease of infarct area.
The Addition of Dydrogesterone after Frozen Embryo Transfer in Hormonal Substituted Cycles with Low Progesterone Levels
Authors: Metello Jose , Tomas Claudia , Ferreira Pedro , Santos-Ribeiro Samuel
Published: November 2022

Objective To determine whether a rescue strategy using dydrogesterone (DYD) could improve the outcomes of frozen embryo transfer cycles (FET) with low progesterone (P4) levels on the day of a blastocyst transfer.

Methods Retrospective cohort study including FET cycles performed between July 2019 and October 2020 following an artificial endometrial preparation cycle using estradiol valerate and micronized vaginal P4 (400 mg twice daily). Whenever the serum P4 value was below 10 ng/mL on the morning of the planned transfer, DYD 10 mg three times a day was added as supplementation. The primary endpoint was ongoing pregnancy beyond 10 weeks. The sample was subdivided into two groups according to serum P4 on the day of FET: low (< 10 ng/mL, with DYD supplementation) or normal (above 10 ng/mL). We performed linear or logistic generalized estimating equations (GEE), as appropriate.

Results We analyzed 304 FET cycles from 241 couples, 11.8% (n = 36) of which had serum P4 below 10 ng/mL on the FET day. Baseline clinical data of patients was comparable between the study groups.

Overall, 191 cycles (62.8%) had a biochemical pregnancy, of which 131 (44,1%) were ongoing pregnancies, with a 29,8% miscarriage rate. We found no statistically significant differences in the hCG positive (63 vs 64%) or ongoing pregnancy rates (50 vs 43,3%) between those FETs with low or normal serum P4 values, even after multivariable logistic regression modelling.

Conclusion Our results indicate that DYD 10 mg three times a day administered in women who perform FET with P4 serum levels < 10 ng/mL, allows this group to have pregnancy rates beyond 12 weeks at least as good as those with serum levels above 10 ng/mL.
Working Memory for Faces among Individuals with Congenital Deafness
Authors: Heled Eyal , Ohayon Maayon
Published: November 2022

Abstract Background Studies examining face processing among individuals with congenital deafness show inconsistent results that are often accounted for by sign language skill. However, working memory for faces as an aspect of face processing has not yet been
examined in congenital deafness. Purpose To explore working memory for faces among individuals with congenital deafness who are skilled in sign language. Research Design A quasi-experimental study of individuals with congenital deafness and a control group.
Study Sample Sixteen individuals with congenital deafness who are skilled in sign language and 18 participants with intact hearing, matched for age, and education. Intervention The participants performed two conditions of the N-back test in ascending difficulty
(i.e., 1-back and 2-back). Data Collection and Analysis Levene's and Shapiro‐Wilk tests were used to assess group homoscedasticity and normality, respectively. A two-way repeated measures analysis of variance was applied to compare the groups in response time and accuracy
of the N-back test, as well as Pearson correlation between response time and accuracy, and sign language skill duration. Results The congenital deafness group performed better than controls, as was found in the response time but not in the accuracy variables. However, an interaction
effect showed that this pattern was significant for the 1-back but not for the 2-back condition in the response time but not the accuracy. Further, there was a marginal effect in response time but a significant one in accuracy showing the 2-back was performed worse than the 1-back. No significant
correlation was found between response time and accuracy, and sign language skill duration. Conclusion Face processing advantage associated with congenital deafness is dependent on cognitive load, but sign language duration does not affect this trend. In addition, response
time and accuracy are not equally sensitive to performance differences in the N-back test.
Legal Pregnancy Interruption due to Sexual Violence in a Public Hospital in the South of Brazil
Authors: Trapani Vitoria Finger , Feuerschuette Otto Henrique May , Júnior Alberto Trapani
Published: November 2022

Objective To analyze the cases of all women who attend to a service of legal termination of pregnancy in cases of sexual violence in a public reference hospital and to identify the factors related to its execution.

Methods Cross-sectional observational study with information from medical records from January 2014 to December 2020. A total of 178 cases were included, with an evaluation of the data referring to the women who attended due to sexual violence, characteristics of sexual violence, hospital care, techniques used, and complications. The analysis was presented in relative and absolute frequencies, medians, means, and standard deviation. Factors related to the completion of the procedure were assessed using binary logistic regression.

Results Termination of pregnancy was performed in 83.2% of the cases; in 75.7% of the cases, the technique used was the association of transvaginal misoprostol and intrauterine manual aspiration. There were no deaths, and the rate of complications was 1.4%. Gestational age at the time the patient's sought assistance was the determining factor for the protocol not being completed. Pregnancies up to 12 weeks were associated with a lower chance of the interruption not occurring (odds ratio [OR]: 0.41; 95% confidence interval [CI]: 0.12–0.88), while cases with gestational age > 20 weeks were associated with a greater chance of the interruption not happening (OR: 29.93; 95%CI: 3.91–271.50).

Conclusion The service studied was effective, with gestational age being the significant factor for resolution.
Pregestational Diabetes and Congenital Heart Defects
Authors: Maduro Catarina , Castro Luís Ferreira de , Moleiro Maria Lúcia , Guedes-Martins Luís
Published: November 2022

Studies have consistently shown a significant increase in the risk of congenital heart defects in the offspring of diabetic mothers compared with those of nondiabetic pregnancies. Evidence points that all types of pregestational diabetes have the capacity of generating cardiac malformations in a more accentuated manner than in gestational diabetes, and there seems to be an increased risk for all congenital heart defects phenotypes in the presence of maternal diabetes. Currently, the application of some therapies is under study in an attempt to reduce the risks inherent to diabetic pregnancies; however, it has not yet been possible to fully prove their effectiveness. The present review aims to better understand the mechanisms that govern the association between pregestational diabetes and congenital heart defects and how maternal diabetes interferes with fetal cardiac development, as there is still a long way to go in the investigation of this complex process.
Nutritional Status of Iodine in a Group of Pregnant Women from the State of Minas Gerais Correlated with Neonatal Thyroid Function
Authors: Scherr Natália Campos Gonçalves , Nogueira Anelise Impelizieri , Rajão Kamilla Maria Araújo Brandão , Leite Henrique Vitor
Published: November 2022

Objective To evaluate the iodine sufficiency of pregnant women assisted in a University Hospital of Minas Gerais, and to correlate the urinary concentrations of maternal iodine with the fetal thyroid hormone levels at birth.

Methods Urinary iodine concentrations from 30 pregnant women with a singleton pregnancy and gestational age lower than 20 weeks were analyzed. Occasional samples of the mothers' urine were collected for the urinary iodine concentration dosage, and these were correlated with the newborns' thyroid-stimulating hormone (TSH) levels.

Results The median iodine urinary concentration of this study's pregnant women population was 216.73 mcg/l, which is proper for the group, following the World Health Organization (WHO). No cases of neonatal hypothyroidism were reported in the study, which corroborates the iodine sufficiency in this population sample.

Conclusion This study shows that despite the increased demand for iodine from pregnant women and the Brazilian Health Regulatory Agency (ANVISA) recommendation of 2013 for reduction of salt iodization levels, the population of pregnant women attended in the prenatal ambulatory of normal risk from the Federal University of Minas Gerais is considered sufficient in iodine. As a higher sample is necessary for the confirmation of these findings, it is too early to recommend the universal supplementation of iodine for Brazilian pregnant women, and more studies must be carried out, considering that iodine supplementation for pregnant women in an area of iodine sufficiency is associated to the risks of the fetus's excessive exposure to iodine.
Efficacy of Hormonal and Nonhormonal Approaches to Vaginal Atrophy and Sexual Dysfunctions in Postmenopausal Women: A Systematic Review
Authors: Sarmento Ayane Cristine Alves , Costa Ana Paula Ferreira , Lírio Juliana , Eleutério Jr José , Baptista Pedro Vieira , Gonçalves Ana Katherine
Published: November 2022

Objective To evaluate the efficacy of the hormonal and nonhormonal approaches to symptoms of sexual dysfunction and vaginal atrophy in postmenopausal women.

Data Sources We conducted a search on the PubMed, Embase, Scopus, Web of Science, SciELO, the Cochrane Central Register of Controlled Trials (CENTRAL), and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases, as well as on clinical trial databases. We analyzed studies published between 1996 and May 30, 2020. No language restrictions were applied.

Selection of Studies We selected randomized clinical trials that evaluated the treatment of sexual dysfunction in postmenopausal women.

Data Collection Three authors (ACAS, APFC, and JL) reviewed each article based on its title and abstract. Relevant data were subsequently taken from the full-text article. Any discrepancies during the review were resolved by consensus between all the listed authors.

Data Synthesis A total of 55 studies were included in the systematic review. The approaches tested to treat sexual dysfunction were as follows: lubricants and moisturizers (18 studies); phytoestrogens (14 studies); dehydroepiandrosterone (DHEA; 8 studies); ospemifene (5 studies); vaginal testosterone (4 studies); pelvic ﬂoor muscle exercises (2 studies); oxytocin (2 studies); vaginal CO2 laser (2 studies); lidocaine (1 study); and vitamin E vaginal suppository (1 study).

Conclusion We identified literature that lacks coherence in terms of the proposed treatments and selected outcome measures. Despite the great diversity in treatment modalities and outcome measures, the present systematic review can shed light on potential targets for the treatment, which is deemed necessary for sexual dysfunction, assuming that most randomized trials were evaluated with a low risk of bias according to the Cochrane Collaboration risk of bias tool. The present review is registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42018100488).
Idee für mehr Nachhaltigkeit: Mieten oder Leasen statt kaufen
Authors: Banedj-Schafii Mandana
Published: November 2022

Nachhaltigkeit ist mittlerweile auch im Krankenhaus angekommen. Mieten bzw. Leasen kann in Kombination mit einem Rundum-Sorglos-Paket definierter Medizinprodukte eine mögliche Zukunftsalternative zum Kauf bieten. Der Beitrag fokussiert Chancen und Risiken derartiger Betreibermodelle.
Gutachten zum Klimaschutz: Wege zum klimaneutralen Krankenhaus
Authors: Hohnstein Aileen
Published: November 2022

Der Gesundheitssektor trägt selbst wesentlich zur Klimakrise bei. Im Auftrag der Krankenhausgesellschaft Nordrhein-Westfalen haben Wissenschaftlerinnen und Wissenschaftler zwei Gutachten erstellt, die Handlungsempfehlungen für Krankenhäuser sowie Finanzierungsmöglichkeiten dafür skizzieren.
Kolumne: Der Markt muss für Innovationen offenbleiben
Authors: Fellner Dieter
Published: November 2022

Die Marktmacht großer Klinik-Einkaufsgemeinschaften hat Preisanpassungen für innovative Medizintechnik-Produkte in den vergangenen Jahren nahezu unmöglich gemacht. Doch in diesem Jahr verhandeln Medizintechnik-Hersteller mit dem Rücken zur Wand. Der deutsche Markt muss für Innovationen offenbleiben.
Risikomanagement: Supply-Chain-Risk-Management in der Krankenhauslogistik
Authors: Kriegel Johannes
Published: November 2022

Aufgrund der systemrelevanten Bedeutung der Krankenhauslogistik ist es erforderlich, ein spezifisches Supply-Chain-Risikomanagement für die Krankenhauslogistik zu etablieren. Mittels einer Risikoidentifizierung gilt es, konkrete Zielsetzung zu definieren, mögliche Störungsanfälligkeiten zu verringern sowie die Verlässlichkeit der Ressourcenbereitstellung am jeweiligen Point-of-Care zu gewährleisten.
Aktuelle Rechtsprechung: Das „dritte Pandemie-Jahr“ in der vergaberechtlichen Rechtsprechung
Authors: Kühn Matthias
Published: November 2022

Auch im dritten Jahr nach Ausbruch von COVID-19 hat pandemiebedingtes Vorgehen von Vergabestellen wieder zu vergaberechtlichen Gerichtsentscheidungen geführt, deren Kenntnis für Klinikeinkäufer von Bedeutung sein kann.
Prozesssteuerung im Klinikbetrieb: Reinigungsoptimierung durch digitales Qualitätsmanagement
Authors: Tegeler Sven
Published: November 2022

Der Klinikbetrieb muss zunehmend wirtschaftlich und flexibel organisiert werden. Das betrifft nicht nur Leistungen medizinischer Art, sondern auch solche außerhalb der Kernprozesse. Um reibungslose Abläufe zu gewährleisten, setzen Klinikbetreiber vermehrt auf ein digitales Auftragsmanagement.
Variation in shell morphology and life-history traits of
Authors: Collado Gonzalo A. , Muñoz Ingrid , Acuña-Rodríguez Ian S. , Valladares Moisés A.
Published: November 2022

Context The New Zealand mudsnail, Potamopyrgus antipodarum, has invaded numerous countries around the world, including Chile. Aim We aimed to determine variation in shell morphology and fecundity in 12 populations scattered in six hydrological basins in this country. Methods Populations were compared using shell morphometry, principal-component analysis (PCA), and brood size. Independent linear mixed models (LMM) were applied to study spatially correlated data. Results The morphometric analysis showed significant differences in shell variables, whereas the PCA showed a high degree of overlap of specimens as well as separation of populations in the morphometric space. Brood size differed significantly among populations, ranging from 0 to 63 offspring. Altitude and shell length had an effect on brood size, whereas shell length showed variation among basins. Latitude did not have a direct effect on any of the two variables. Conclusions Potamopyrgus antipodarum exhibits great morphological and life-history trait variation, which could be favouring its rapid expansion in Chile. The lack of genetic variation of this species, previously reported in the country, suggests that differences found in our study are likely to be due to environmental variation. Implications Further studies should be addressed to assess the origin of the variance.
Enhanced performance of flexible LED by low-temperature annealing
Authors: Tang Xiansheng , Zhang Wei , Ma Ziguang , Han Lili , Gong Weihua , Wang Zhaowei , Wang Jinyu , Zhou Junge , Jia Haiqiang , Du Chunhua
Published: November 2022

The ohmic contact of n-GaAs having surface treatment was achieved at 300°C. It shows that surface treatment makes the GaAs easier to form an ohmic contact with Ni/Au/Ge/Ni/Au multilayer. Low-temperature annealing was applied to flexible AlGaInP/GaInP multi-quantum well red LED @630 nm wavelength, whose substrate is replaced by an electroplated Cu thin film from the thick GaAs substrate. The measured current–voltage properties exhibit a much-reduced turn-on voltage, which decreased from 3.75 to 1.5 V. The light output power current measurement shows that the output power reduction, only 2%, in flexible LEDs is insignificant. This work provides a way to improve the performance of flexible optoelectronic devices.
Effect of sintering process on the properties of transparent Al2O3
Authors: Zhang Luping , Liu Quan , Yu Dazhao , Lu Mi , Lin Jianping
Published: November 2022

Transparent Al2O3 is the most widely used transparent ceramic. The main factors affecting the transparency of Al2O3 are porosity and impurities. It was found that increasing the sintering temperature or extending the holding time can increase the grain size and reduce the porosity. Holding at 1800°C for more than 1 h is critical for grain growth and elimination of porosity. The increase in light transmittance mainly depends on the decrease in porosity, and the increase in grain size also helps. The increase in bending strength is inversely proportional to the increase in grain size. In a comprehensive comparison, the sample held at 1800°C for 2 h can achieve 87% light transmittance based on the bending strength of 322 MPa.
Investigation of dynamics of laser-produced carbon plasma during the laser irradiation using collective Thomson scattering
Authors: Pan Yiming , Tomita Kentaro , Yamagata Yukihiko , Sunahara Atsushi , Nishihara Katsunobu
Published: November 2022

Plasma temperature, density, and flow velocity are the critical physical properties of laser produced plasma (LPP) to reveal the ablation dynamics, energy transport, and hydrodynamic evolution. In the time window during and just after laser irradiation, experimental data are very scarce so that many theoretical models remain untested. Here we report a clear evolution history of LPP expansion dynamics within 0–14 ns after the laser peak and in a region very close to the target (0.13–0.6 mm). A table-top Nd:YAG laser (intensity 6 × 109 W cm−2, pulse 7 ns) was used to generate the LPP from a planar graphite target, whose width was arranged to be smaller than the laser spot diameter to produce a one-dimensional planar expansion plasma near the target. The electron density (

n
e

), temperature (

T
e

), and drift velocity (

V
d

) in the LPPs were measured using the ion feature of collective Thomson scattering, providing a space- and time-resolved 2D profile of the LPP. The experimental observations made it possible for the expansion dynamics to be compared directly with the LPP expansion models. The results suggest that during the laser pulse, the LPP is approximately isothermal and expands predominantly one-dimensionally in the target normal direction, in which the LPP drift velocity is found to increase linearly with distance. The linear extrapolation of the velocity indicates that the LPP has a considerable velocity at the initial target surface; this velocity is approximately the speed of sound derived from the observed

T
e

. The experimental results were found to be in moderate agreement with the 1D self-similar isothermal expansion model. The ratio of the internal to kinetic energy in the observed area was ∼0.6, as predicted by the isothermal expansion model. The experimental findings were compared with the results of the 2D hybrid code STAR, and good agreement was obtained.
Tuning defect-related optical bands by channeling implants in semiconductors
Authors: Azarov Alexander , Galeckas Augustinas , Ling Francis Chi-Chung , Kuznetsov Andrej
Published: November 2022

Ion implantation is an excellent method to introduce defects into semiconductors, extending their functionalities in a controllable way. Herein, we investigated an option to use crystallographically aligned implants as an additional route to control the balance between optically active defects, selecting ZnO as a test material. The optical data were correlated with the structural analysis confirming the formation of different dominating crystalline defects in samples implanted along and off [0001] direction. Specifically, we demonstrated that different proportions in the contents of the extended and point defects in the initial as-implanted states of these samples, lead to prominent variations in the defect-related luminescence upon annealing. As such, we conclude that channeling implants may have an added value in the functionalization of defects in semiconductors, e.g. to tune specific spectral contents in the defect-related emission bands.
Silica-based mesoporous ion-imprinted fluorescent sensors for the detection of Pb2+ in aqueous environments
Authors: Xu Qingming , Lv Jie , Wu Tongfei , Hu Bo , Li Yunhui , Zeng Fanming , Zhu Jianwei
Published: November 2022

In this work, an environment-friendly core–shell material based on CDs@SiO2 as the core and mesoporous ion-imprinted layer as the shell was reported. As a highly sensitive and accurate fluorescent sensor for the detection of Pb2+ in environmental water, the composition combined ion imprinting technology with quantum dots to selectively quench the fluorescence of CDs by metal coordination in the presence of Pb2+, and the visual change of gradually weakening blue color could be observed by the naked eye for visual detection. The mesoporous structure significantly improved the detection recognition rate of CDs@SiO2@MIIPs.The molecularly imprinted sensor presented a favorable linear relationship over a Pb2+ concentration range from 10 nmol l−1 to 100 nmol l−1 and a detection limit of 2.16 nmol l−1 for Pb2+. The imprinting factor of the CDs@SiO2@MIIPs was 5.13. The sensor has a fast detection rate, is highly selective in the identification of Pb2+, and can be reused up to 10 times. The applicability of the method was evaluated by the determination of Pb2+ in spiked environmental water samples with satisfactory results.
Electric current-assisted manipulation of liquid metals using a stylus at micro-and nano-scales
Authors: Shastri Vijayendra , Majumder Sukanya , Ashok Anuj , Roy Kaustav , Pratap Rudra , Kumar Praveen
Published: November 2022

A novel methodology, based on wetting and electromigration, for transporting liquid metal, over long distances, at micro-and nano-scale using a stylus is reported. The mechanism is analogous to a dropper that uses ‘suction and release’ actions to ‘collect and dispense’ liquid. In our methodology, a stylus coated with a thin metal film acts like the dropper that collects liquid metal from a reservoir upon application of an electric current, holds the liquid metal via wetting while carrying the liquid metal over large distances away from the reservoir and drops it on the target location by reversing the direction of electric current. Essentially, the working principle of the technique relies on the directionality of electromigration force and adhesive force due to wetting. The working of the technique is demonstrated by using an Au-coated Si micropillar as the stylus, liquid Ga as the liquid metal to be transported, and a Kleindiek-based position micro-manipulator to traverse the stylus from the liquid reservoir to the target location. For demonstrating the potential applications, the technique is utilized for closing a micro-gap by dispensing a minuscule amount of liquid Ga and conformally coating the desired segment of the patterned thin films with liquid Ga. This study confirms the promising potential of the developed technique for reversible, controlled manipulation of liquid metal at small length scales.
Joint estimation of interaction position and energy deposition in semiconductor SPECT imaging sensors using fully connected neural network
Authors: Yang Can , Zannoni Elena Maria , Meng Ling-Jian
Published: November 2022

Objective. Pixelated semiconductor detectors such as CdTe and CZT sensors suffer spatial resolution and spectral performance degradation induced by charge-sharing effects. It is critical to enhance the detector property through recovering the energy-deposition and position estimation. Approach. In this work, we proposed a fully-connected-neural-network-based charge-sharing reconstruction algorithm to correct the charge-loss and estimate the sub-pixel position for every multi-pixel charge-sharing event. Main results. Evident energy resolution improvement can be observed by comparing the spectrum produced by a simple charge-sharing addition method and the proposed energy correction methods. We also demonstrate that sub-pixel resolution can be achieved in projections obtained with a small pinhole collimator and an innovative micro-ring collimator. Significance. These achievements are crucial for multiple-tracer SPECT imaging applications, and for other semiconductor detector-based imaging modalities.
Fabrication of multi-filament(Ba,A)Fe2As2 (A: Na, K) HIP round wires and a small superconducting coil
Authors: Pyon Sunseng , Ito Takamasa , Sakagami Ryosuke , Tamegai Tsuyoshi , Awaji Satoshi , Kito Hijiri , Ishida Shigeyuki , Eisaki Hiroshi , Yoshida Yoshiyuki , Kajitani Hideki
Published: November 2022

We report the fabrication and systematic characterizations of multi-filament (Ba,A)Fe2As2 (A: Na, K) round wires processed under high pressure. The evaluated transport and magnetic critical current density show clear core-number dependence. This trend originates from degradation of the superconducting core during the wire-drawing process, degradation of the concentric texturing of the core, and the enhanced sausaging effect of the core (revealed by x-ray tomography) as the number of cores increases. Details of the characterizations and suggestions for the improvement of the fabrication process are discussed. We constructed a superconducting magnet using seven-filament (Ba,K)Fe2As2 hot-isostatic pressed round wires. The generated magnetic field and critical current (I
c) of the coils at 4.2 K are 1.0 kOe and 18 A, respectively. Measurements of the I
c of short segments picked up from the coil show that there is enough room for improvements.
Vector beams encoded by diverse orthogonal polarization states and their generation based on metasurfaces
Authors: Yue Zhiyuan , Lu Peiyao , Xu Jilian , Li Zhong , Teng Shuyun
Published: November 2022

Vector beams with spatially varying polarization states have wide application prospects. Convenient and feasible generation of compact vector beams become important for the applications in integrated optics and optical communication. Based on the superposition of orthogonal polarization vortex beams and the metasurface design, this paper studies systematically vector beams with hybrid states of polarization in diverse orthogonal polarization encoding. The spatial polarization of vector beam can be controlled through choosing the polarization types and adjusting the contributions of two orthogonal polarized beams. The generated vector beams based on metasurfaces verify the output of diversity polarization states in the transverse plane. The high polarization sensitivity of vector beam is beneficial to the polarization multiplexing and the utilization of optical metasurface realizes the polarization manipulation in nanometer scale. This work lays the foundation for the construction of complex vector beams and it is helpful for expanding the applications of vector beams.
Dark conduction mechanisms of PTQBDT based heterojunction diode
Authors: Gullu H H , Yıldız D E , Hacioglu S O , Cirpan A , Toppare L
Published: November 2022

Al:LiF/PTQBT:PCBM/PEDOT:PSS/ITO/glass organic-based diode is fabricated with different weight ratios in PTQBT:PCBM active layer. The diodes D1, D2 and D3 are prepared using the precursor solution for spin coating process as 1:2, 1:3 and 1:4, respectively. Under dark, main diode parameters are extracted by conventional thermionic emission theory using the results ofI−Vmeasurements. Parasitic resistance contribution, non-ideal barrier height formation and high values of ideality factor indicate possible effects of space charge limited current flow mechanism on forward biasedI−Vcharacteristics. At saturated voltage region, series resistances are calculated and the results are evaluated according to Cheung’s method. The possible voltage sharing between interface layer and depletion region are also investigated by analysis of density of interface states. In addition, field effect is found in a major role on the reverse current flow and the mechanism is evaluated according to Schottky-Richardson model.
Comparative studies of terahertz-based optical properties in transmission/reflection modes of GaSe: S and measurement of its scattering losses due to surface roughness for efficient terahertz generation
Authors: Ghorui Chandan , Kidavu Arjun V , Kumar P Naveen , Das S , Chaudhary A K , Andreev Yu M
Published: November 2022

The paper reports the efficient terahertz generation using nonlinear optical rectification process and comparative studies of optical, dielectric, and surface scattering properties of 1.0 mm thin GaSe: S crystal in transmission/reflection modes. We employed 800 nm wavelength of 140 fs and 50 fs pulse durations obtained from Ti: Sapphire oscillator and amplifier systems at 80 MHz and 1 kHz repetition rates, respectively, and evaluated the THz generation potential and optical properties such as refractive index, absorption coefficients, relative permittivity in transmission mode. In the next step, the crystal was subjected to a commercial THz system of 0.3 picosecond pulses at 100 MHz repetition rate in reflection geometry and once again recorded the similar parameters and compared with the transmission mode data. In addition, these data were used to measure the scattering losses from the surface of the crystal in terms of surface roughness, optical impedance, and Fresnel’s reflection coefficients. The maximum generated THz power was of the order of 4.5 μW with conversion efficiency (η) ∼ 2.2 × 10−3%. The measured THz efficiency was found equivalent to 20 mm thick GaSe crystal used in the difference frequency mixing technique. Finally, we have measured the Rayleigh roughness factor (g) of the crystal surface at different THz frequencies. When g < 1 (for small roughness) the Fresnel reflection loss factor becomes 0.75 at 1.4 THz frequency range which helps to enhance the generated signal.
Dissecting kinetically coupled quintessence: phenomenology and observational tests
Authors: Teixeira Elsa M. , Barros Bruno J. , Ferreira Vasco M.C. , Frusciante Noemi
Published: November 2022

We investigate an interacting dark energy model which allows for the kinetic term of the scalar field to couple to dark matter via a power-law interaction. The model is characterised by scaling solutions at early times, which are of high interest to alleviate the coincidence problem, followed by a period of accelerated expansion. We discuss the phenomenology of the background evolution and of the linear scalar perturbations and we identify measurable signatures of the coupling in the dark sector on the cosmic microwave background, the lensing potential auto-correlation and the matter power spectra. We also perform a parameter estimation analysis using data of cosmic microwave background temperature, polarisation and lensing, baryonic acoustic oscillations and supernovae. We find that the strength of the coupling between the dark sectors, regulated by the parameter α, is constrained to be of order 10-4. A model selection analysis does not reveal a statistical preference between ΛCDM and the Kinetic model.
Highly efficient exchange of orbital angular momentum of light via electron spin coherence
Authors: Alkawak Omar A , Faisal Raheem Al-Behadili , Yasin Yaser , Ibrahim Wessim Salahaddin , Ruhaima Ali Abdul Kadhim , Hassan Ward Zahraa , Hadrawi Salema K , Kong H
Published: November 2022

In this letter we analysed the efficient exchange of orbital angular momentum (OAM) of light in a double V-type semiconductor quantum well via electron spin coherence. We found that due to the four-wave mixing (FWM) mechanism the OAM state of the vortex light can transfer from applied lights to a new generated signal beam when the efficiency of the FWM processes is enough high. We also shown that the absorption spectrum of the new generated light depends on the OAM number and azimuthal angle of the optical vortex light. We realized that for some specific parametric conditions the absorption spectrum of the generated light becomes negative which corresponds to the lasing without inversion.
Numerical simulation and experiment on morphology control of grooves processed by a picosecond laser on TC11 titanium alloy
Authors: Hua Xijun , Wang Changguo , Xu Sheng , Xie Xuan
Published: November 2022

The chief aim of this paper is to control groove morphology precisely. In this paper, a 2D temperature field model for ultrafast picosecond laser grooving was set up on the foundation of the two-temperature model coupled with the phase change model. Then, a series of simulations were executed to investigate the influence of laser parameters such as laser power, scanning speed and repetition rate on ultrafast picosecond laser grooving. Finally, a number of experiments were performed to verify the model. The results suggest that the laser power has an obvious influence on the groove width and depth because the heat-affected zone area and single-pulse laser energy increase when the laser power varies from 2 W to 5 W. Obvious impacts of scanning speed on the groove depth and quality are observed in the present simulation due to the variation of overlap between sequential pulses and pulse numbers. The groove width and quality depend on the repetition rate. This is because the increase in the repetition rate has a certain contribution to increasing the temperature of heat residue and pulse number. This research contributes to present theoretical guidance on laser grooving.
Accuracy and precision of navigated transcranial magnetic stimulation
Authors: Nieminen Aino E , Nieminen Jaakko O , Stenroos Matti , Novikov Pavel , Nazarova Maria , Vaalto Selja , Nikulin Vadim , Ilmoniemi Risto J
Published: November 2022

Objective. Transcranial magnetic stimulation (TMS) induces an electric field (E-field) in the cortex. To facilitate stimulation targeting, image-guided neuronavigation systems have been introduced. Such systems track the placement of the coil with respect to the head and visualize the estimated cortical stimulation location on an anatomical brain image in real time. The accuracy and precision of the neuronavigation is affected by multiple factors. Our aim was to analyze how different factors in TMS neuronavigation affect the accuracy and precision of the coil–head coregistration and the estimated E-field. Approach. By performing simulations, we estimated navigation errors due to distortions in magnetic resonance images (MRIs), head-to-MRI registration (landmark- and surface-based registrations), localization and movement of the head tracker, and localization of the coil tracker. We analyzed the effect of these errors on coil and head coregistration and on the induced E-field as determined with simplistic and realistic head models. Main results. Average total coregistration accuracies were in the range of 2.2–3.6 mm and 1°; precision values were about half of the accuracy values. The coregistration errors were mainly due to head-to-MRI registration with average accuracies 1.5–1.9 mm/0.2–0.4° and precisions 0.5–0.8 mm/0.1–0.2° better with surface-based registration. The other major source of error was the movement of the head tracker with average accuracy of 1.5 mm and precision of 1.1 mm. When assessed within an E-field method, the average accuracies of the peak E-field location, orientation, and magnitude ranged between 1.5 and 5.0 mm, 0.9 and 4.8°, and 4.4 and 8.5% across the E-field models studied. The largest errors were obtained with the landmark-based registration. When computing another accuracy measure with the most realistic E-field model as a reference, the accuracies tended to improve from about 10 mm/15°/25% to about 2 mm/2°/5% when increasing realism of the E-field model. Significance. The results of this comprehensive analysis help TMS operators to recognize the main sources of error in TMS navigation and that the coregistration errors and their effect in the E-field estimation depend on the methods applied. To ensure reliable TMS navigation, we recommend surface-based head-to-MRI registration and realistic models for E-field computations.