bluuebunny/crossref_metadata_2025 huggingface dataset:
Corneal endothelial cell loss after trabeculectomy and phacoemulsification in one or two steps: a prospective study
Authors: Soro-Martínez María Isabel , Miralles de Imperial-Ollero Juan Antonio , Pastor-Montoro Miriam , Arcos-Villegas Gabriel , Sobrado-Calvo Paloma , Ruiz-Gómez José María , Miralles de Imperial-Mora-Figueroa Jaime , Villegas-Pérez María Paz
Published: January 2021

Objective

The objective of this study was to analyse the results of the surgical treatment of coexisting cataract and glaucoma and its effects on corneal endothelial cell density (CECD).

Methods

We include two longitudinal prospective studies: one randomised that included 40 eyes with open angle glaucoma that received one- (n = 20) or two-step (n = 20) phacotrabeculectomy and another that included 20 eyes that received phacoemulsification. We assess the impact of surgery on different clinical variables and in particular in CECD using Confoscan 4™ confocal microscopy and semiautomatic counting methods.

Results

Phacoemulsification and phacotrabeculectomy, but not trabeculectomy, increase significantly best-corrected visual acuity and anterior chamber depth and trabeculectomy and one- or two-step phacotrabeculectomy decreased similarly the intraocular pressure. We document percentages of endothelial cell loss of 3.1%, 17.9%, 31.6% and 42.6% after trabeculectomy, phacoemulsification and one- or two-step phacotrabeculectomy, respectively. The coefficient of variation did not increase significantly after surgery but the percentage of hexagonality decreased significantly after phacoemulsification and after two-step phacotrabeculectomy.

Conclusions

Trabeculectomy, phacoemulsification and phacotrabeculectomy are surgical techniques that cause morphological changes and decrease the densities of the corneal endothelial cells. Trabeculectomy produces lesser endothelial cell loss than phacoemulsification, and phacoemulsification lesser cell loss than phacotrabeculectomy. Two-step phacotrabeculectomy (trabeculectomy followed 3 months later by phacoemulsification) causes more cell loss than one-step phacotrabeculectomy, and this could be due to the cumulative effects of two separate surgical traumas or to a negative conditioning lesion effect of the first surgery. For the treatment of coexisting glaucoma and cataract, one-step phacotrabeculectomy is the treatment of choice.
Safety and efficacy of repeated crosslinking assisted by transepithelial double-cycle iontophoresis in keratoconus progression after primary corneal crosslinking
Authors: Wu Huping , Li Lan , Luo Shunrong , Fang Xie , Shang Xumin , Xie Zhiwen , Xiao Xianwen , He Huan , Lin Zhirong , Liu Zuguo
Published: January 2021

Objectives

To evaluate the safety and efficacy of repeated corneal collagen crosslinking assisted by transepithelial double-cycle iontophoresis (DI-CXL) in the management of keratoconus progression after primary CXL.

Methods

A retrospective analysis was conducted in the patients who underwent repeated CXL between 2016 and 2018. These patients were treated with DI-CXL if keratoconus progression was confirmed after primary CXL. Scoring of ocular pain and corneal epithelial damage, visual acuity, corneal tomography, in vivo corneal confocal microscopy (IVCM) was performed before and at 3, 6, 12, and 24 months after DI-CXL.

Results

Overall, 21 eyes of 12 patients (mean age 17.3 ± 1.9 years) were included in this study. Before DI-CXL, an average increase of 4.26 D inKmaxwas detected in these patients with a mean follow-up interval of (23.0 ± 13.7) months. After DI-CXL, corneal epithelial damage rapidly recovered within days. Visual acuity remained unchanged with follow-up of 24 months. When compared to baseline, significant decreases were observed inKmax(at 3 months) and K2 (at 3 and 6 months) after DI-CXL. Corneal thickness of thinnest point significantly decreased at 3 months postoperatively. When compared to baseline, no significant differences were found in any of the refractive or tomographic parameters at 12 and 24 months. IVCM revealed trabecular patterned hyperdense tissues after DI-CXL in the anterior stroma at the depth of 200 μm or more. No corneal infiltration or persistent epithelial defect was recorded after DI-CXL.

Conclusion

DI-CXL is safe and effective as a good alternative in stabilizing keratoconus progression after primary CXL.
Excess protein enabled dog domestication during severe Ice Age winters
Authors: Lahtinen Maria , Clinnick David , Mannermaa Kristiina , Salonen J. Sakari , Viranta Suvi
Published: January 2021

Dogs (Canis familiaris) are the first animals to be domesticated by humans and the only ones domesticated by mobile hunter-gatherers. Wolves and humans were both persistent, pack hunters of large prey. They were species competing over resources in partially overlapping ecological niches and capable of killing each other. How could humans possibly have domesticated a competitive species? Here we present a new hypothesis based on food/resource partitioning between humans and incipient domesticated wolves/dogs. Humans are not fully adapted to a carnivorous diet; human consumption of meat is limited by the liver’s capacity to metabolize protein. Contrary to humans, wolves can thrive on lean meat for months. We present here data showing that all the Pleistocene archeological sites with dog or incipient dog remains are from areas that were analogous to subarctic and arctic environments. Our calculations show that during harsh winters, when game is lean and devoid of fat, Late Pleistocene hunters-gatherers in Eurasia would have a surplus of animal derived protein that could have been shared with incipient dogs. Our partitioning theory explains how competition may have been ameliorated during the initial phase of dog domestication. Following this initial period, incipient dogs would have become docile, being utilized in a multitude of ways such as hunting companions, beasts of burden and guards as well as going through many similar evolutionary changes as humans.
Publisher Correction: Age and sex affect deep learning prediction of cardiometabolic risk factors from retinal images
Authors: Gerrits Nele , Elen Bart , Van Craenendonck Toon , Triantafyllidou Danai , Petropoulos Ioannis N. , Malik Rayaz A. , De Boever Patrick
Published: January 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Author Correction: Successful breeding predicts divorce in plovers
Authors: Halimubieke Naerhulan , Kupán Krisztina , Valdebenito José O. , Kubelka Vojtěch , Carmona-Isunza María Cristina , Burgas Daniel , Catlin Daniel , St Clair James J. H. , Cohen Jonathan , Figuerola Jordi , Yasué Maï , Johnson Matthew , Mencarelli Mauro , Cruz-López Medardo , Stantial Michelle , Weston Michael A. , Lloyd Penn , Que Pinjia , Montalvo Tomás , Bansal Udita , McDonald Grant C. , Liu Yang , Kosztolányi András , Székely Tamás
Published: January 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
A new method for measuring pen pressure in forensic handwriting analysis – a proof of concept study
Authors: Negrini Neto O. , Sarkis J. E. S. , Siqueira A. N. , Ribeiro L. A. S. , Freitas A. Z.
Published: January 2021

This work describes a new method for the analysis of handwritten documents through a system composed of a pre-selector optical analyser equipped with light sources of different wavelengths combined with an optical coherence tomography instrument.
Preparation of menthol-based hydrophobic deep eutectic solvents for the extraction of triphenylmethane dyes: quantitative properties and extraction mechanism
Authors: Fan Taotao , Yan Zongcheng , Yang Chanyuan , Qiu Shunguo , Peng Xiong , Zhang Jianwei , Hu Lihua , Chen Li
Published: January 2021

A series of natural, environmentally friendly and low-cost menthol-based hydrophobic deep eutectic solvents (DES) were synthesized to extract triphenylmethane (TPM) dyes.
Bone targeting nano-aggregates prepared from self-assembled polyaspartamide graft copolymers for pH sensitive DOX delivery
Authors: Lim Cheol won , Kim Dukjoon
Published: January 2021

In this study, PSI-based nano-aggregates with biocompatibility and biodegradability were synthesized as drug carriers for targeted bone metastasis treatment.
Cationic polymer synergizing with chemotherapeutics and re-purposing antibiotics against cancer cells
Authors: Zheng Yiran , Kng Jessica , Yang Chuan , Hedrick James L. , Yang Yi Yan
Published: January 2021

A quaternary ammonium-functionalized cationic polymer synergizes with existing chemotherapeutics and re-purposes antibiotics to increase therapeutic efficacy, mitigate toxicity and circumvent drug resistance via its membrane disruption mechanism.
A lipid droplet targeted fluorescent probe for high-efficiency image-guided photodynamic therapy of renal cell carcinoma
Authors: Tan Ping , Zhuang Weihua , Li Shufen , Zhang Jiapeng , Xu Hang , Yang Lu , Liao Yanbiao , Chen Mao , Wei Qiang
Published: January 2021

A lipid droplets (LDs) specific fluorescent probe TTIE is prepared for LDs specific image-guided photodynamic therapy (PDT), which can light up the LDs in human clear cell renal cell carcinoma cells and tissues, and kill tumor cells via PDT process.
Template syntheses of diverse haloargentates with reversible photochromism behaviors and efficient photocatalytic properties
Authors: Xue Zhen-Zhen , Wang A-Ni , Wei Qi , Wei Li , Han Song-De , Pan Jie
Published: January 2021

A series of haloargentates have been prepared exhibiting a reversible photochromic phenomenon and efficient photocatalytic properties.
Unusual temperature dependence of the fluorescence decay in heterostructured stilbene
Authors: Karpicz Renata , Ostapenko Nina , Ostapenko Yura , Polupan Yaroslava , Lazarev Igor , Galunov Nikolai , Macernis Mindaugas , Abramavicius Darius , Valkunas Leonas
Published: January 2021

The fluorescence decay kinetics of solid stilbene demonstrate elongation of the excitation lifetime with a temperature increase. This unusual dependence can be explained by fluorescence from a thermalized exciton distribution in aggregated stilbene clusters.
Bioaccessibility of potentially toxic elements in mine residue particles
Authors: Jesús Eulises Corona-Sánchez , González-Chávez Ma. del Carmen A. , Carrillo-González Rogelio , García-Cué José Luis , Fernández-Reynoso Demetrio S. , Noerpel Matthew , Scheckel Kirk G.
Published: January 2021

Inhalable and gastric PTE bioaccessibility from mine residues may be a high risk for people in mining towns.
Pd-Catalysed carbonylative Suzuki–Miyaura cross-couplings using Fe(CO)5under mild conditions: generation of a highly active, recyclable and scalable ‘Pd–Fe’ nanocatalyst
Authors: Zhu Zhuangli , Wang Zhenhua , Jian Yajun , Sun Huaming , Zhang Guofang , Lynam Jason M. , McElroy C. Robert , Burden Thomas J. , Inight Rebecca L. , Fairlamb Ian J. S. , Zhang Weiqiang , Gao Ziwei
Published: January 2021

Fe(CO)5delivers COin situfor carbonylative-Suzuki–Miyaura cross-coupling, leading to concomitant formation of catalytically competent Pd–Fe nanoparticles.
Pressure effects on underwater laser-induced breakdown spectroscopy: an interpretation with self-absorption
Authors: Zhang Yongquan , Tian Ye , Lu Yuan , Guo Lin , Li Ying , Guo Jinjia , Zheng Ronger
Published: January 2021

Laser-induced breakdown spectroscopy (LIBS) has been successfully applied for in situ detection in the sea, and the water pressure is found to be the main influence on the LIBS signal compared to temperature or salinity.
Direct multi-element analysis of natural toothbrush by electrothermal vaporization into inductively coupled plasma optical emission spectrometry
Authors: Althobiti Randa A. , Beauchemin Diane
Published: January 2021

Direct analysis of ground natural toothbrush by ETV-ICPOES is accurate, precise and much faster than total digestion and ICPOES analysis.
Probing blood plasma samples for the detection of diabetes using SERS aided by PCA and LDA multivariate data analyses
Authors: Das Sumit Kumar , Bhattacharya Tara Shankar , Ghosh Manash , Chowdhury Joydeep
Published: January 2021

Fabrication of a SERS-active substrate using Langmuir–Blodgett and self-assembly techniques for the detection of diabetes from blood plasma samples.
Terephthalaldehyde as a good crosslinking agent in crosslinked chitosan hydrogel for the selective removal of anionic dyes
Authors: Garg Madhvi , Bhullar Navneet , Bajaj Bharat , Sud Dhiraj
Published: January 2021

This work reports the selectivity and good adsorption performance for the removal of anionic dyes using an ultrasonic-synthesized terephthalaldehyde crosslinked chitosan hydrogel.
A low temperature organic synthesis of monodispersed NiRu nanocrystals for CO2 methanation
Authors: Liu Yang , Liang Xin , Zhang Jie , Yun Jimmy , Yang Zuobo
Published: January 2021

Monodisperse NiRu NPs synthesized by a tuning hot-inject method was loaded on Al2O3 as a building bulk for CO2 methanation.
The controlled synthesis of g-C3N4/Cd-doped ZnO nanocomposites as potential photocatalysts for the disinfection and degradation of organic pollutants under visible light irradiation
Authors: Sher Mudassar , Javed Mohsin , Shahid Sammia , Iqbal Shahid , Qamar Muhammad Azam , Bahadur Ali , Qayyum Muhammad Abdul
Published: January 2021

The controlled design of novel Z-scheme g-C3N4/Cd-ZnO heterojunction via chemical co-precipitation technique. 60% g-C3N4 hybridized with 7% Cd-doped ZnO (g-C3N4/Cd-ZnO) NCs have been proved to be optimum visible-light-driven (VLD) photocatalysts.
An aqueous phase TEMPO mediated electrooxidation of 2-thiophenemethanol using MnO2–Pi dispersed nanocarbon spheres on a carbon fiber paper electrode
Authors: Mathew Agnus T. , S Supriya , K. B. Akshaya , Varghese Anitha , Hegde Gurumurthy
Published: January 2021

An environmentally benign and economic method was developed for the electrocatalytic oxidation of 2-thiophenemethanol in an aqueous acidic medium.
Additive-free photo-mediated oxidative cyclization of pyridinium acylhydrazones to 1,3,4-oxadiazoles: solid-state conversion in a microporous organic polymer and supramolecular energy-level engineering
Authors: Kim Kyung-su , Chung You Kyoung , Kim Hyunwoo , Ha Chae Yeon , Huh Joonsuk , Song Changsik
Published: January 2021

We discovered the efficient catalyst-free, photo-mediated oxidative cyclization reaction of bis-p-pyridinium benzoyl hydrazone (BH1) to 2-pyridinium-5-phenyl-1,3,4-oxadiazoles.
Optimizing the hydrophobicity of GDL to improve the fuel cell performance
Authors: Zhou Ke , Li Tianya , Han Yufen , Wang Jihao , Chen Jia , Wang Kejian
Published: January 2021

The gas diffusion layer (GDL) is an important component in the proton exchange membrane fuel cell (PEMFC), and the main function of GDL is to transfer water and gas.
Effects of physicochemical properties of polyacrylamide (PAA) and (polydimethylsiloxane) PDMS on cardiac cell behavior
Authors: Daliri Karim , Pfannkuche Kurt , Garipcan Bora
Published: January 2021

In vitrocell culture is commonly applied in laboratories around the world.
Steering droplets on substrates using moving steps in wettability
Authors: Grawitter Josua , Stark Holger
Published: January 2021

We use the boundary element method (BEM) and the Cox–Voinov law to study the motion of droplets on a substrate with a moving wettability profile. Under the right conditions, droplets surf.
Quantifying the energy loss for a perovskite solar cell passivated with acetamidine halide
Authors: Yuan Ligang , Luo Huiming , Wang Jiarong , Xu Zonghao , Li Jiong , Jiang Qingsong , Yan Keyou
Published: January 2021

We quantified non-radiative recombination loss and charge transfer loss for acetamidine halide passivated perovskite solar cells.
Two-dimensional building blocks for photocatalytic ammonia production
Authors: Ran Jingrun , Xia Bingquan , Zhang Yanzhao , Qiao Shi-Zhang
Published: January 2021

This perspective summarizes the design and synthesis of two-dimensional building block based photocatalysts for light-induced NH3 production. The structure–performance relationship and mechanism of photocatalysts are highlighted.
Fork-shaped paper SERS sensors coated with raspberry-like bimetallic nanospheres for the detection of the boosted mixture: experimental design and applications
Authors: Xu Yuanyuan , Gao Xingguo , Yang Cheng , Man Baoyuan , Leng Jiancai
Published: January 2021

Raspberry-like bimetal Au@AgNPs nanostructures with multiple hotspots on an arrow-shaped paper strip to sensitively detect the complex samples.
Stable deep blue emission with unity quantum yield in organic–inorganic halide perovskite 2D nanosheets doped with cerium and terbium at high concentrations
Authors: Parveen Sumaiya , Prasanna Ponnappa Kechanda , Chakraborty Sudip , Giri P. K.
Published: January 2021

Cerium and terbium doping at high concentrations in organic–inorganic halide perovskite 2D nanosheets enables a stable deep blue emission with unity quantum yield.
An effective strategy to obtain near-infrared emission from shoulder to shoulder-type binuclear platinum(ii) complexes based on fused pyrene core bridged isoquinoline ligands
Authors: Zhang Kai , Wang Tianyu , Wu Tingwen , Ding Zhenming , Zhang Qiang , Zhu Weiguo , Liu Yu
Published: January 2021

Emission is efficiently tuned from deep-red to near-infrared and maximum EQEs from 8.84% to 6.06% are obtained for Pt(ii) complexes via inserting a second metal platinum(ii) ion.
Angiotensin-converting enzyme 2 and COVID-19 in cardiorenal diseases
Authors: Sharma Ravindra K. , Li Jing , Krishnan Suraj , Richards Elaine M. , Raizada Mohan K. , Mohandas Rajesh
Published: January 2021

The rapid spread of the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has brought into focus the key role of angiotensin-converting enzyme 2 (ACE2), which serves as a cell surface receptor required for the virus to enter cells. SARS-CoV-2 can decrease cell surface ACE2 directly by internalization of ACE2 bound to the virus and indirectly by increased ADAM17 (a disintegrin and metalloproteinase 17)-mediated shedding of ACE2. ACE2 is widely expressed in the heart, lungs, vasculature, kidney and the gastrointestinal (GI) tract, where it counteracts the deleterious effects of angiotensin II (AngII) by catalyzing the conversion of AngII into the vasodilator peptide angiotensin-(1-7) (Ang-(1-7)). The down-regulation of ACE2 by SARS-CoV-2 can be detrimental to the cardiovascular system and kidneys. Further, decreased ACE2 can cause gut dysbiosis, inflammation and potentially worsen the systemic inflammatory response and coagulopathy associated with SARS-CoV-2. This review aims to elucidate the crucial role of ACE2 both as a regulator of the renin–angiotensin system and a receptor for SARS-CoV-2 as well as the implications for Coronavirus disease 19 and its associated cardiovascular and renal complications.
Unsupervised automated retinal vessel segmentation based on Radon line detector and morphological reconstruction
Authors: Tavakoli Meysam , Mehdizadeh Alireza , Pourreza Shahri Reza , Dehmeshki Jamshid
Published: January 2021

Retinal blood vessel segmentation and analysis is critical for the computer‐aided diagnosis of different diseases such as diabetic retinopathy. This study presents an automated unsupervised method for segmenting the retinal vasculature based on hybrid methods. The algorithm initially applies a preprocessing step using morphological operators to enhance the vessel tree structure against a non‐uniform image background. The main processing applies the Radon transform to overlapping windows, followed by vessel validation, vessel refinement and vessel reconstruction to achieve the final segmentation. The method was tested on three publicly available datasets and a local database comprising a total of 188 images. Segmentation performance was evaluated using three measures: accuracy, receiver operating characteristic (ROC) analysis, and the structural similarity index. ROC analysis resulted in area under curve values of 97.39%, 97.01%, and 97.12%, for the DRIVE, STARE, and CHASE‐DB1, respectively. Also, the results of accuracy were 0.9688, 0.9646, and 0.9475 for the same datasets. Finally, the average values of structural similarity index were computed for all four datasets, with average values of 0.9650 (DRIVE), 0.9641 (STARE), and 0.9625 (CHASE‐DB1). These results compare with the best published results to date, exceeding their performance for several of the datasets; similar performance is found using accuracy.
Investigation on soil resistivity of two‐layer soil structures using finite element analysis method
Authors: Illias Hazlee Azil , Su Chuang Sheng , Bakar Ab Halim Abu
Published: January 2021

Effective grounding is the most important aspect in every electrical installation because it can ensure efficient equipment operation in the event of electrical faults. Measurement data of soil resistivity is used to assess the suitability of the soil for grounding purpose and also to evaluate the structures of the soil. However, the limitation of soil resistivity measurement is various investigations on two‐layer soil structures cannot be performed due to the variation of natural soil structures is limited. Therefore, in this work, modelling of soil resistivity of two‐layer soil structures was proposed using finite element analysis method to estimate the depth of upper layer of non‐homogeneous soil based on the measurement results from Wenner and Schlumberger methods. Also, using the proposed method, the effect of soil resistivity of each layer on the overall two‐layer soil resistivity was investigated. To validate the results obtained from the proposed method, comparison between the FEA results and measured field data was made. It was found that the average error between both results is <3%. From the model that has been developed, the soil properties can be varied, which enhances the information that can be obtained from two‐layer soil structures.
Determination of biological joint reaction forces from in-vivo experiments using a hybrid combination of biomechanical and mechanical engineering software
Authors: Becker Joanne , Mermoz Emmanuel , Linares Jean-Marc
Published: January 2021

In biomechanical field, several studies used OpenSim software to compute the joint reaction forces from kinematics and ground reaction forces measurements. The bio-inspired joints design and their manufacturing need the usage of mechanical modeling and simulation software tools. This paper proposes a new hybrid methodology to determine biological joint reaction forces from in vivo measurements using both biomechanical and mechanical engineering softwares. The methodology has been applied to the horse forelimb joints. The computed joint reaction forces results would be compared to the results obtained with OpenSim in a previous study. This new hybrid model used a combination of measurements (bone geometry, kinematics, ground reaction forces…) and also OpenSim results (muscular and ligament forces). The comparison between the two models showed values with an average difference of 8% at trotting and 16% at jumping. These differences can be associated with the differences between the modelling strategies. Despite these differences, the mechanical modeling method allows the computation of advanced simulations to handle contact conditions in joints. In future, the proposed mechanical engineering methodology could open the door to define a biological digital twin of a quadruped limb including the real geometry modelling of the joint.
Analysis of E-Consumer Behaviour – Selected Findings from an Analysis of Czech E-Shops and their Customers during the Global Pandemic
Authors: Pollak Frantisek , Konecny Michal
Published: January 2021

The study presented in this contribution deals with the issue of using modern methods of data collection for the purposes of analysing consumer behaviour. Professional literature as well as business practice offer us an enormous number of approaches, traditional or innovative, with which it is possible to obtain and then evaluate data in order to understand specific patterns of consumer behaviour. Following on from our previous research in the field, we have applied a method of collecting and evaluating customers e-data in real time. As a source of data, we used the virtual social network Facebook. As a sample we selected customers of the five largest e-shops operated in the Czech Republic. On a sample of more than one and a half million users we monitored the B2C communication of e-shops and subsequently the C2B Facebook interaction of their customers during the lockdown caused by the COVID-19 pandemic. In the observed period we analysed hundreds of thousands of interactions and then outlined basic trends and specific characteristics of consumer behaviour suitable for further research. The selected findings resulting from the implemented analyses contribute to the creation of a knowledge base of a qualitative nature, which can help to define research goals in the future process of examining the effects of the pandemic on various aspects of business.
Blended-Learning-Konzepte in der Intensivmedizin am Beispiel des ERIC-Trainings
Authors: Paul Nicolas , Dähnert Enrico , Grunow Julius J. , Landgraf Philipp , Schröder Torsten , Weiss Björn , Spies Claudia D. ,   und das ERIC-Konsortium
Published: January 2021

Zusamenfassung

Die Implementierung der wachsenden medizinischen Evidenz und neuer Innovationen in dem dynamischen Umfeld der Intensivmedizin stellt hohe Anforderungen an die berufsbegleitende Weiterbildung des Personals. Die neue Versorgungsform Enhanced Recovery after Intensive Care (ERIC) kombiniert daher ein modernes Blended-Learning-Konzept mit einer telemedizinischen Versorgung im Rahmen einer komplexen Intervention zur Verbesserung der Behandlungsqualität.
Entwicklung der Ergebnisse des zweiten und dritten Abschnitts der
Ärztlichen Prüfung („M2“ Und
„M3“) In Deutschland
Authors: Palmowski Andriko
Published: January 2021

Ziel der Studie Analyse der Entwicklung der Ergebnisse des Zweiten
(klinisch-schriftlichen, „M2“) und Dritten
(klinisch-mündlichen; „M3“) Abschnitts der
Ärztlichen Prüfung in Deutschland.

Methodik Es wurden öffentlich verfügbare Daten des
Zweiten und Dritten Abschnitts der Ärztlichen Prüfung
analysiert (Jahre 2014–2020). Meta-Regressions-Modelle
(mixed-effects) schätzten Zusammenhänge zwischen
Prüfungsergebnissen und dem Zeitpunkt der Prüfung ein.

Ergebnisse Im untersuchten Zeitraum nahmen insgesamt 63 811
bzw. 32 852 Teilnehmer an den untersuchten M2- bzw.
M3-Prüfungen teil. Der Prozentsatz durchschnittlich richtig
beantworteter Fragen aller M2-Examina lag bei 77,7% (Minimum:
73%; Maximum: 82,7%). Es zeigte sich über die Zeit
eine große Variation in den Ergebnissen: Der Anteil von Teilnehmern
mit „sehr gutem“ Ergebnis variierte zwischen 0,1%
(Frühjahr 2020) und 17% (Herbst 2015) und der Anteil von
Teilnehmern mit „gutem“ Ergebnis zwischen 21%
(Frühjahr 2020) und 52% (Herbst 2015). Insgesamt zeigte sich
bei Analyse der M2-Examina ein negativer Trend. Über die Zeit sanken
bspw. der Prozentsatz richtig beantworteter Fragen (Steigung
β=-0,82%; p < 0,01) und der Anteil von
Teilnehmern mit „sehr gutem“ (β=-1,17;
p=0,04) und „gutem“ (β=-2,58;
p=0,02) Ergebnis. In den Modellen konnte mit dem Zeitpunkt der
Prüfung zwischen 20 und 34% der Heterogenität
zwischen den Prüfungen erklärt werden. In den M3-Examina
zeigte sich nur eine sehr geringe Variation über die Zeit,
außerdem waren keine Trends zu erkennen
(p=0,08–0,60).

Schlussfolgerung Die Ergebnisse der M2-Examina variierten über
die letzten Jahre stark, außerdem zeigte sich ein deutlicher Trend
hin zu durchschnittlich schlechteren Ergebnissen. Die Ergebnisse der
M3-Examina blieben hingegen bei geringer Variation auf konstantem Niveau.
Mögliche Ursachen dieser Entwicklungen – etwa schlechter
werdende schriftliche Fähigkeiten der Studierenden oder ein
höherer Anforderungsgrad in den M2-Examina – sollten
untersucht werden. Die große Variation der durchschnittlichen
Ergebnisse stellt die Reliabilität und Vergleichbarkeit der
M2-Examina in Frage.
Lungenultraschall in der Neonatologie zur Diagnostik eines Pneumothorax (Teil 1): Eine Evidenzanalyse – Zeit für einen neuen Goldstandard
Authors: Sandig Jan , Bührer Christoph , Czernik Christoph
Published: January 2021

Der Lungenultraschall ist eine in der Notfallmedizin gut erforschte Untersuchungsmethode. Der Pneumothoraxausschluss mithilfe des Lungenultraschalls ist in den letzten Jahren auch bei Neugeborenen intensiv erforscht worden. Es wurden standardisierte Untersuchungsalgorithmen und unstrittige pathognomonische Untersuchungsbefunde veröffentlicht. Im Vergleich zum etablierten diagnostischen Standardverfahren, der Röntgenthoraxaufnahme, bietet der Lungenultraschall eine Reihe von Vorteilen, wobei der Verzicht auf ionisierende Strahlung und die rasche Diagnosestellung bei exzellenter Sensitivität und vergleichbarer Spezifität herausstechen. Der Lungenultraschall leistet somit einen Beitrag zur Verbesserung der Versorgungsqualität in der neonatologischen Intensivmedizin. Wir sehen daher die Nutzung des Lungenultraschalls als neues Standardverfahren in der Pneumothoraxdiagnostik beim Neugeborenen an.
Use of Non-vitamin K Antagonist Oral Anticoagulants for Stroke Prevention across the Stroke Spectrum: Progress and Prospects
Authors: Camm A. John , Atar Dan
Published: January 2021

Multiple randomized controlled trials and many real-world evidence studies have consistently shown that non-vitamin K antagonist oral anticoagulants (NOACs) are preferable to vitamin K antagonists for thromboembolic stroke prevention in the majority of patients with atrial fibrillation (AF). However, their role in the management of patients with AF and comorbidities, as well as in other patient populations with a high risk of stroke, such as patients with prior embolic stroke of undetermined source (ESUS) and those with atherosclerosis, is less clear. There is now increasing evidence suggesting that NOACs have a beneficial effect in the prevention of stroke in patients with AF and comorbidities, such as renal impairment and diabetes. In addition, while studies investigating the efficacy and safety of NOACs for the prevention of secondary stroke in patients with a history of ESUS demonstrated neutral results, subanalyses suggested potential benefits in certain subgroups of patients with ESUS. One NOAC, rivaroxaban, has also recently been found to be effective in reducing the risk of stroke in patients with chronic cardiovascular disease including coronary artery disease and peripheral artery disease, further broadening the patient groups that may benefit from NOACs. In this article, we will review recent evidence for the use of NOACs across the stroke spectrum in detail, and discuss the progress and future prospects in the different stroke areas.
Variable Presentation and Reduced Penetrance in Autosomal Dominant Acute Necrotizing Encephalopathy Related to RANBP2 Variant
Authors: Carvalho Daniel R. , Speck-Martins Carlos E. , Martins Bernardo J. A. F. , Izumi Ana Paula , La Rocque-Ferreira Alessandra
Published: January 2021

Acute necrotizing encephalopathy (ANE) is clinically characterized by fever, acute alteration of consciousness, seizures, and rapid progression to coma within days of onset of a viral illness occurring in healthy children without evidence of central nervous system infection. Brain magnetic resonance imaging (MRI) shows multiple symmetrical lesions affecting primarily the thalami but also brain stem, putamina, periventricular white matter, and cerebellum. Most cases of ANE are sporadic and nonrecurrent. However, a missense variant in RANBP2 has been identified in some families with recurrent ANE (OMIM # 608033), also named autosomal dominant ANE (ADANE). Clinical manifestation, clinical course, and brain MRI imaging findings of six affected members of two distinct families with ADANE were described. Sequencing revealed heterozygous c.1754C > T variant in RANBP2 (p.Thr585Met) in affected and asymptomatic family members. Only few ADANE families have been reported and it is the first description in South America. Differential diagnosis of Leigh disease and acute disseminated encephalomyelitis is discussed. Our report reinforces incomplete penetrance of ADANE and intrafamilial phenotypic variability of outcome.
Turbulent kinetic energy in 2D isothermal interchange-dominated scrape-off layer E × B drift turbulence: Governing equation and relation to particle transport
Authors: Coosemans R. , Dekeyser W. , Baelmans M.
Published: January 2021

This paper studies the turbulent kinetic energy (k⊥) in 2D isothermal electrostatic interchange-dominated E × B drift turbulence in the scrape-off layer and its relation to particle transport. An evolution equation for the former is analytically derived from the underlying turbulence equations. Evaluating this equation shows that the dominant source for the turbulent kinetic energy is due to interchange drive, while the parallel current loss to the sheath constitutes the main sink. Perpendicular transport of the turbulent kinetic energy seems to play a minor role in the balance equation. Reynolds stress energy transfer also seems to be negligible, presumably because no significant shear flow develops under the given assumptions of isothermal sheath-limited conditions in the open field line region. The interchange source of the turbulence is analytically related to the average turbulent E × B energy flux, while a regression analysis of TOKAM2D data suggests a model that is linear in the turbulent kinetic energy for the sheath loss. A similar regression analysis yields a diffusive model for the average radial particle flux, in which the anomalous diffusion coefficient scales with the square root of the turbulent kinetic energy. Combining these three components, a closed set of equations for the mean-field particle transport is obtained, in which the source of the turbulence depends on mean flow gradients and k⊥ through the particle flux, while the turbulence is saturated by parallel losses to the sheath. Implementation of this new model in a 1D mean-field code shows good agreement with the original TOKAM2D data over a range of model parameters.
Multiparameter quantum metrology with postselection measurements
Authors: Ho Le Bin , Kondo Yasushi
Published: January 2021

We analyze simultaneous quantum estimations of multiple parameters with postselection measurements in terms of a trade-off relation. The system, or a sensor, is characterized by a set of parameters, interacts with a measurement apparatus (MA), and then is postselected onto a set of orthonormal final states. Measurements of the MA yield an estimation of the parameters. We first derive classical and quantum Cramér–Rao lower bounds and then discuss their archivable condition and the trade-offs in the postselection measurements, in general, including the case when a sensor is in a mixed state. Its whole information can, in principle, be obtained via the MA, which is not possible without postselection. We then apply the framework to simultaneous measurements of phase and its fluctuation as an example.
Stability diagrams of two optically mutual-injected quantum cascade lasers
Authors: Li Y. , Yang N. , Chu W. , Duan S. , Xie Y. , Sun J. , Ren T.
Published: January 2021

The dynamic properties and stability of optically mutual-injected arrays composed of terahertz quantum cascade lasers (THz QCLs) were investigated and compared with those of diode laser (DL) arrays. The influences of the coupling strength and frequency detuning on the working states of the arrays were analyzed using numerical simulations of the time evolutions of the electric fields and their corresponding Fourier-transform spectra. It was found that when the frequency detuning between individual lasers was zero, the QCL arrays could always maintain phase-locked operation. In contrast, the DLs were only able to function in a stable state with weak coupling strengths. With increasing coupling strength, periodic, quasi-periodic, multi-periodic, and aperiodic oscillations appeared. When the frequency detuning of the array lasers was nonzero, the QCL array could not be phase-locked at low coupling strengths, and it only entered the phase-locked region if the coupling strength was increased. However, the DL array could only work stably at low coupling strengths and quickly entered the aperiodic oscillation region as the coupling strength was increased. When we fixed the coupling strength and changed the frequency detuning, with large frequency detunings, both the QCL and DL arrays exhibited periodic oscillations. However, the QCLs were phase-locked at low frequency detunings, while the DLs exhibited periodic and multi-periodic oscillations across a broader frequency range. The results indicate that QCL arrays are more stable than DL arrays across a wide range of coupling strengths and frequency detuning parameters.
Reliability and Maintainability Investigation of Generator in Steam Turbine Power Plant using RAMD analysis
Authors: Gupta Nivedita , Kumar Ashish , Saini Monika
Published: January 2021

Generator is key unit of steam turbine power plant which is used to convert mechanical energy into electrical energy. This energy is further used for completing the requirement generated by various sectors of country. Generator is one of the most important component of steam turbine power plant configured with seven subsystems in series configuration. So, it is necessary to ensure its smooth functioning which is attain by the proper functioning of its subcomponents. It is important to increase operational availability of subsystem. Hence, present study is proposed to investigate various reliability measures of generator used in STP through RAMD approach at component level. For this purpose, mathematical models using Markovian birth death process have been developed for all subsystems of generator. These models are very helpful in reliability, maintainability, and availability analysis of generators. RAMD analysis will play significant role in this direction. This will help to find critical component of system so that proper maintenance strategies can be proposed. It is assumed that all failure and repair rates associated with each component followed exponential distribution and adequate repair facility always remains available with system. Various system performance measures like reliability function, maintainability function, dependability function and steady state availability for different components as well as system have been evaluated. The numerical results have been derived to highlight the importance of study.
Fingerprint Based Authentication Architecture for Accessing Multiple Cloud Computing Services using Single User Credential in IOT Environments
Authors: Alemu Biniyam , Kumar Rajesh , Sinwar Deepak , Raghuwanshi Ghanshyam
Published: January 2021

Cloud computing technology provides access to the pool of configurable resources including storage space, application, services and on demand network. Involvement of Cloud with the organization minimizes organization efforts toward fulfilling its customer’s needs. One of the major advantages of cloud computing is the Single Sign On (SSO) technique that allows the user to access multiple application services using a single user credential. In cloud computing, there are many issues, and challenges to be discussed. However, prevention from security attacks is much more difficult in preserving privacy of user agents. This paper has proposed SSO-based bio-metric authentication architecture for cloud computing services to overcome the security and privacy attacks. Bio-metric authentication is effective for resources controlled by end devices at the time of accessing the cloud services since these devices are computationally inefficient for user information processing during authentication. Accordingly, security attack in the cloud computing gets minimized using the proposed architecture. The proposed architecture also includes a novel approach in which there exist one to one relationship between user agent and the service provider. In this user agents can use their fingerprint while requesting for registration and accessing different cloud application services at cloud. Based on comparative study with several existing architectures, the highlights of the proposed architecture have been presented.
Structuring Learning Analytics through Visual Media and Online Classrooms on Social Cognition during COVID-19 Pandemic
Authors: Latheef Afeefa , Liyakath Ali Mohdhoom Fathima , Bhardwaj Aradhana Balodi , Shukla Vinod Kumar
Published: January 2021

Media as the core source of information and knowledge disperse in the society, its effect on the learning, understanding and analysing about the society in the human minds and cognition is certainly impacted. In focal to the visual media such as advertisement, movies, video etc., it enunciates and indicates a high level of learning process and social learning. Media has a huge impact on the different aspects of cognition in the population, especially on the age category of teenagers and young adults. With the current situation of covid 19, there has been a paradigm shift within the educational sector, forcing visual media as the key source of education and learning, with many countries utilizing remote learning or digital learning to cope with the current educational crisis. This study therefore aims to investigate and understand the impact of the visual media and different video learning platforms in improvement of the social cognition and learning among student. Questionnaire survey method was employed as a tool to collect data from the sample of 250 students between the age group of 16 – 25 and a sample of 155 teachers with the experience of 1 -10 + years in the field of education across UAE and India. The result indicates that the student population showcase a keen interest and participation on the information and knowledge dispersed through screens such as movies and presentation rather than the content published such as newspaper and books. It helps students foster self-awareness, cultural value, cognitive skills and moral wellbeing with the help of visual media.
Hybrid Learning Model for Metal Artifact Reduction
Authors: Bedi Pradeep , Goyal S B , Yadav Dileep Kumar , Kumar Sunil , Sharma Monika
Published: January 2021

In today’s healthcare, the human brain imaging is done for finding the tumors and other disorders of the brain. The Magnetic Resonance Imaging (MRI) plays a significant role throughout the complete clinical procedure starting from diagnostics and treatment planning to surgical processes and follow up studies. The MRI of brain allows the clinical expert for the earliest detection and treatment of brain abnormality or any neurological diseases, which is the most treatable stage that gives patients the greatest chance of survival. An artifact is a feature appearing in an image which is not present in the original imaged object. The types of artifacts are herringbone artifact, zipper artifact, motion artifact, aliasing artifact, chemical shift artifact, magnetic susceptibility artifact, central point artifact, Gibbs ringing artifact and intensity inhomogeneity artifact. After segmentation, the features are extracted using Gray level co-occurrence matrix (GLCM) and an CNN, Deep belief network, Proposed hybrid model (Based on CNN and Deep belief network (DBN)) and Morphological Technique with Segmentation Techniques is implemented to classify the brain MRI images as either normal (without tumor) or abnormal (with tumor). Proposed hybrid model for metal artifact reduction and represent though the experiment our proposed model very effective to existing one. Results in Accuracy (in %) Before artifact removal(92.12%), After artifact removal (95.77%)
Machine Learning Based Predictive Model for Coronavirus Pandemic
Authors: Singh Supreet , Sharma Lavanya , Kumar Birender
Published: January 2021

Technological advancements have a rapid effect on each domain of day today life, whether it is medical domain or any other domain. Artificial intelligence has shown promising outcomes in emergency department through its decision making by investigating the data. COVID-19 has affected many countries across the globe in a matter of no time. Citizens all over the world are susceptible to its consequences in future.Covid-19 being a contagious disease needs a program that will make it easier for the tracking, the spread and preventing the future cases. Proposed algorithm that can predict on-going Covid-19 positive cases in India. For experimental analysis machine learning algorithm has been coded to make future predictions.
Survey on Internet of Things and its Application in Agriculture
Authors: Mishra Kanderp Narayan , Kumar Shishir , Patel Nileshkumar R.
Published: January 2021

The Internet of Things (IoT) is empowering the field of agriculture. The IoT application helps the farmer and makes him aware about all the latest information which is related to agriculture. In this study, authors have found that the implementation of IoT is very important in the field of agriculture that makes farming smarter. IoT applications make farmers smarter with the latest information about the crop and weather. By using the IoT application the farmer can prepare a plan for next season’s crop. With the help of IoT based agriculture application the farmers already know the information about the weather, soil, wind speed and direction, relative humidity, and temperature. The farmers know about the disease of crops and then consult the expert and get an appropriate solution to the disease. The experts may advise the farmer how farmers can protect the crop from the disease. The IoT agriculture application helps to increase the production of crops and reduce the loss of crops from the disease. The IoT based agriculture application is like a friend of a farmer because the IoT based agriculture applications are helping the farmer at every moment of agriculture activities. India has set a food grain production target of 298.3 million tonnes for the current fiscal year 2020-21 which is 2.5% higher compared to previous fiscal year’s targets. Agriculture sector contribution to Indian economy is 17%. To empower Indian farmers and in turn to empower Indian economy, IoT based agriculture applications are essential for the farmers.
Segmenting e-Commerce Customer through Data Mining Techniques
Authors: Punhani Ritu , Arora V.P.S , Sai Sabitha A. , Shukla Vinod Kumar
Published: January 2021

Business-to-business e-commerce is in much attention nowadays, mainly due to its growing use. In today’s world, it has become imperative for companies to segment their customers and thereby take required measures to survive against other companies. Since there exist a lot, each company must fulfil the demands of their users or they might lose them to other alternatives that exist. This report aims to analyse the customer data from two years: 2018 and 2019 of the company: Autofurnish.com and thereby recommend methods to increase customer influx and give suggestions on what mistakes should not be repeated by the company in future for better performance and sales. To analyse the database, RapidMiner tool has been used. RapidMiner is an open source predictive analytic software that gives support regarding data mining. It lets the user to build models based on their needs and gives solutions quickly. For this analysis, K- means algorithm clustering will be used. Clustering is dividing groups based on similarities and K means is one of the very commonly used methods to do so. In the software, data has been imported having information about customers which is then analysed to prove different results draw a contrast between two years as told before keeping customer segmentation in mind based on various attributes given in the dataset. Relationships between the features are identified as assess to company’s performance.