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LiYF_(4):Yb/LiYF_(4) and LiYF_(4):Yb,Er/LiYF_(4) core/shell nanocrystals with luminescence decay times similar to YLF laser crystals and the upconversion quantum yield of the Yb,Er doped nanocrystals

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Nano Research 2021年第3期14卷 797-806页

作者： Frederike Carl leonie birk Bettina Grauel Monica Pons Christian Würth Ute Resch-Genger Markus Haase Institute of Chemistry of New Materials Department Biology/ChemistryUniversity OsnabrueckBarbarastr.749076OsnabrueckGermany Division 1.2 Biophotonics Federal Institute for Materials Research and Testing(BAM)Richard-Willstaetter-Str.1112489BerlinGermany

We developed a procedure to prepare luminescent LiYF_(4):Yb/LiYF_(4) and LiYF_(4):Yb,Er/LiYF_(4) core/shell nanocrystals with a size of approximately 40 nm revealing luminescence decay times of the dopant ions that approach those of high-quality laser crystals of LiYF_(4):Yb(Yb:YLF)and LiYF_(4):Yb,Er(Yb,Er:YLF)with identical doping *** the luminescence decay times of Yb^(3+)and Er^(3+)are known to be very sensitive to the presence of quenchers,the long decay times of the core/shell nanocrystals indicate a very low number of defects in the core particles and at the core/shell *** improvement in the performance was achieved by introducing two important modifications in the commonly used oleic acid based ***,the shell was prepared via a newly developed method characterized by a very low nucleation rate for particles of pure LiYF_(4) shell ***,anhydrous acetates were used as precursors and additional drying steps were applied to reduce the incorporation of OH−in the crystal lattice,known to quench the emission of Yb^(3+)*** power density(P)-dependent absolute measurements of the upconversion luminescence quantum yield(ΦUC)of LiYF_(4):Yb,Er/LiYF_(4) core/shell particles reveal a maximum value of 1.25%at P of 180 W·cm^(−2).Although lower than the values reported for NaYF4:18%Yb,2%Er core/shell nanocrystals with comparable sizes,theseΦUC values are the highest reported so far for LiYF_(4):18%Yb,2%Er/LiYF_(4) nanocrystals without additional *** improvements may nevertheless be possible by optimizing the dopant concentrations in the LiYF_(4) nanocrystals.

关键词： nanocrystal decay time luminescence LiYF_(4) quantum yield upconversion

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Contribution and Relevance of Transfontanellar Ultrasound in Newborns in Ouagadougou: Multicentre Study on 1000 Cases

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Open Journal of Radiology 2024年第2期14卷 64-73页

作者： Ouedraogo Pakisba Ali Ouedraogo Nina-Astrid Somé Milckisédek Judickael Dabire Stive Arnauld Tankoano Ida Aida Napon Aischa Madina Nikiema Zakari Diallo Ousseini Lougue Sorgho leonie Claudine Cisse Rabiou Department of Medical Imaging Ouahigouya Regional University Hospital Centre Ouahigouya University Ouahigouya Burkina Faso Department of Diagnostic and Interventional Radiology Bogodogo University Hospital Ouagadougou Burkina Faso Department of Medical Imaging Souro Sanon University Hospital Bobo Dioulasso Burkina Faso Medical Imaging Service Yalgado Oudraogo University Hospital Ouagadougou Burkina Faso Department of Medical Imaging Charles de Gaulle Pediatric University Hospital Ouagadougou Burkina Faso Radiodiagnostic and Medical Imaging Laboratory Health Sciences Training and Research Unit Joseph Ki-Zerbo University Ouagadougou Burkina Faso

Objectives: To demonstrate the contribution and relevance of ETFs through the study of 1000 examination reports carried out in the medical imaging departments of the OUAGADOUGOU CHU. Material and method: Analytical descriptive study with retrospective collection, extended from 1st January 2020 to 1st January 2022. Results: Of the 1000 transfontanellar ultrasound reports, the mean age of patients was 7.61 +/ 7.5 days, with extremes of zero and 28 days. Sex was specified in 989 cases. Males accounted for 54.49% and females for 45.51%. 555 transfontanellar ultrasound were performed in 2020. 441 in 2021 and 4 in 2022. 61.9% of transfontanellar ultrasound were performed at the Bogodogo University Hospital, 205 at Charles de Gaulle and 176 at Tengandogo. Indications for transfontanellar ultrasound were dominated by neonatal distress (65.8%), followed by convulsions (10.2%) and prematurity (9.1%). Transfontanellar ultrasound was normal in 570 cases (57%) and abnormal in 430 cases (43%). Abnormalities were dominated by haemorrhage and ischaemic lesions in 66.28% (285) and 21.63% (93) of cases respectively. In the group of normal transfontanellar ultrasound, neonatal distress represented 59.65% of indications and prematurity 10.7% of indications. As for abnormal transfontanellar ultrasound, neonatal suffering accounted for 73.95% of indications and convulsions for 12.56%. The average age ofpatients with an abnormal transfontanellar ultrasound was 8.74 days +/ 7.89 days. The indication for investigations was relevant in 42.2% of cases and irrelevant in 57.8%;of the transfontanellar ultrasound with relevant indications, 0.71 were normal and 99.29 abnormal;of the transfontanellar ultrasound with irrelevant indications, the transfontanellar ultrasound was normal in 98.1% and abnormal in 1.9%. Conclusion: Transfontanellar ultrasound is an important part of ultrasound in current practice. Haemorrhage, anoxic-ischaemic lesions and hydrocephalus are the most frequent pathologies fou

关键词： Transfontanellar Ultrasound Neonatal Distress Relevance

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External quality control and training of semen analysis in the Netherlands:starting point for further reduction of outcome variability

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Asian Journal of Andrology 2022年第1期24卷 15-20页

作者： Louise Lemmens leonie van den Hoven Netty J van Vrouwerff Didi DM Braat Willianne LDM Nelen Marian A Spath Alex MM Wetzels Fertility Laboratory Department of Obstetrics and GynaecologyRadboud University Medical CenterPO Box 91016500 HB NijmegenThe Netherlands Department of Clinical Chemistry Sint Antonius HospitalPO Box 25003430 EM NieuwegeinThe Netherlands Department of Obstetrics and Gynaecology Radboud University Medical CenterPO Box 91016500 HB NijmegenThe Netherlands

Semen analysis is characterized by high levels of intra-and inter-laboratory variability,due to a low level of standardization,high subjectivity of the assessments,and problems with automated *** improve consistency of laboratory results,quality control and training of technicians are important *** goals of this study are to evaluate the results of an external quality control(EQC)program and standardized training by ESHRE Basic Semen Analysis Courses(BSAC)on the variability in manual assessments of semen *** performed retrospective analyses of(1)the interlaboratory variability in the Dutch EQC program and(2)the interobserver variability in BSACs for concentration,motility,and morphology *** data showed that the interlaboratory coefficient of variation(CV)for concentration assessment decreased(range from 24.0%–97.5%to 12.7%–20.9%)but not for morphology and motility *** variability was lower if improved Neubauer hemocytometers were *** assessment showed highest CVs(up to 375.0%),with many outliers in the period of 2007–*** BSAC,a significant reduction of interobserver variability could be established for all parameters(P<0.05).The absence of an effect in the EQC program for motility and morphology might be explained by respectively the facts that motility assessment was introduced relatively late in the EQC program(since 2013)and that criteria for morphology assessment changed in *** results might have been influenced by the pretraining level of participants and the influence of external *** EQC and training show positive effects on reducing *** willingness by laboratories to change their methods toward standards may lead to further improvements.

关键词： external quality control semen analysis standardized training

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Same or different?Abstract relational concept use in juvenile bamboo sharks and Malawi cichlids

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Current Zoology 2021年第3期67卷 279-292页

作者： Theodora Fuss leonie John Vera Schluessel Institute of Zoology Rheinische Friedrich-Wilhelms-University BonnMeckenheimer Allee 169Bonn53115Germany

Sorting objects and events into categories and concepts is an important cognitive prerequisite that spares an individual the learning of every object or situation encountered in its daily ***,specific items are classified in general groups that allow fast responses to novel *** present study assessed whether bamboo sharks Chiloscyllium griseum and Malawi cichlids Pseudotropheus zebra can distinguish sets of stimuli(each stimulus consisting of two abstract,geometric objects)that meet two conceptual preconditions,i.e.,(1)"sameness"versus"difference"and(2)a certain spatial arrangement of both *** two alternative forced choice experiments,individuals were first trained to choose two different,vertically arranged objects from two different but horizontally arranged *** discriminations were followed by extensive transfer test *** tests using stimuli consisting of(a)black and gray circles and(b)squares with novel geometric patterns provided conflicting information with respect to the learnt rule"choose two different,vertically arranged objects",thereby investigating(1)the individuals'ability to transfer previously gained knowledge to novel stimuli and(2)the abstract relational concept(s)or rule(s)applied to categorize these novel *** results suggest that the level of processing and usage of both abstract concepts differed considerably between bamboo sharks and Malawi *** sharks seemed to combine both concepts-although not with equal but hierarchical prominence-pointing to advanced cognitive ***,Malawi cichlids had difficulties in discriminating between symbols and failed to apply the acquired training knowledge on new sets of geometric and,in particular,gray-level transfer stimuli.

关键词： visual concept learning spatial arrangement relational abstract concept Malawi cichlid bamboo shark

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Assortative mating and self-fertilization differ in their contributions to reinforcement, cascade speciation, and diversification

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Current Zoology 2016年第2期62卷 169-181页

作者： Dean M. CASTILLO Amanda K. GIBSON leonie C. MOYLE Department of Biology 1001 East Third Street Indiana University Bloomington IN 47405 USA

Cascade speciation and reinforcement can evolve rapidly when traits are pleiotropic and act as both signal/cue in nonrandom mating. Here, we examine the contribution of two key traits-assortative mating and self-fertilization-to reinforcement and (by extension) cascade speciation. First, using a population genetic model of reinforcement we find that both assortative mating and self-fertilization can make independent contributions to increased reproductive isolation, consistent with reinforcement. Self-fertilization primarily evolves due to its 2-fold transmission advantage when inbreeding depression () is lower ( < 0.45) but evolves as a function of the cost of hybridization under higher inbreeding depression (0.45 < < 0.48). When both traits can evolve simultaneously, increased self-fertilization often prohibits the evolution of assortative mating. We infer that, under specific conditions, mating system transitions are more likely to lead to increased reproductive isolation and initiate cascade speciation, than assortative mating. Based on the results of our simulations, we hypothesized that transitions to self-fertilization could contribute to clade-wide diversification if reinforcement or cascade speciation is common. We tested this hypothesis with comparative data from two different groups. Consistent with our hypothesis, there was a trend towards uniparental reproduction being associated with increased diversification rate in the Nematode phylum. For the plant genus , however, self-fertilization was associated with reduced diversification. Reinforcement driving speciation via transitions to self-fertilization might be short lived or unsustainable across macroevolutionary scales in some systems (some plants), but not others (such as nematodes), potentially due to differences in susceptibility to inbreeding depression and/or the ability to transition between reproductive modes.

关键词：随机交配多元化施肥形态选型级联生殖隔离近交衰退

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Parkinson’s disease and translational research

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Translational Neurodegeneration 2020年第4期9卷 547-557页

作者： Elisabeth Dinter Theodora Saridaki leonie Diederichs Heinz Reichmann Bjorn H.Falkenburger Department of Neurology Technische Universitat DresdenDresdenGermany Deutsches Zentrum fur Neurodegenerative Erkrankungen DresdenGermany Department of Neurology RWTH University AachenAachenGermany

Parkinson's disease(PD)is diagnosed when patients exhibit bradykinesia with tremor and/or rigidity,and when these symptoms respond to dopaminergic *** in the last years there was a greater recognition of additional aspects of the disease including non-motor symptoms and prodromal states with associated pathology in various regions of the nervous *** this review we discuss current concepts of two major alterations found during the course of the disease:cytoplasmic aggregates of the protein a-synuclein and the degeneration of dopaminergic *** provide an overview of new approaches in this field based on current concepts and latest *** many areas,translational research on PD has advanced the understanding of the disease but there is still a need for more effective therapeutic options based on the insights into the basic biological phenomena.

关键词： α-Synuclein Pre-formed fibrils Protein aggregates Aggresome Dopamine deficiency Medium spiny neurons Autophagy

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The Calcineurin B-Like Ca2＋ Sensors CBL1 and CBL9 Function in Pollen Germination and Pollen Tube Growth in Arabidopsis

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Molecular Plant 2013年第4期6卷 1149-1162页

作者： Anette Maihs leonie Steinhorst Jian-Pu Han Li-Ke Shen Yi Wang Jorg Kudla Institut for Biologie und Biotechnologie der Pflanzen Universitat MOnster Schlossplatz 4 48149 MOnster Germany State Key Laboratory of Plant Physiology and Biochemistry College of Biological Sciences National Plant Gene Research Center (Beijing) China Agricultural University Beijing 100193 China

Ca2＋ has been established as an important second messenger regulating pollen germination and tube growth. However, to date, only a few signaling components have been identified to decode and relay Ca2＋ signals in growing pollen tubes. Here, we report a function for the calcineurin B-like （CBL） Ca2＋ sensor proteins CBL1 and CBL9 from Arabidopsis in pollen germination and tube growth. Both proteins are expressed in mature pollen and pollen tubes and impair pollen tube growth and morphology if transiently overexpressed in tobacco pollen. The induction of these phenotypes requires efficient plasma membrane targeting of CBL1 and is independent of Ca2＋ binding to the fourth EF-hand of CBL1. Overexpression of CBL1 or its closest homolog CBL9 in Arabidopsis renders pollen germination and tube growth hypersensitive towards high external K＋ concentrations while disruption of CBL1 and CBL9 reduces pollen tube growth under low K~ conditions. Together, our data identify a crucial function for CBL1 and CBL9 in pollen germination and tube growth and suggest a model in which both proteins act at the plasma membrane through regulation of K＋ homeostasis.

关键词： calcium CBL pollen tube growth potassium

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Epidemiological, Clinical and Virological Profiles of Influenza Infection in the Democratic Republic of the Congo, from 2009 to 2018

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Open Journal of Epidemiology 2022年第3期12卷 329-342页

作者： Saleh Muhemedi Paul Lusamba Edith Nkwembe Leopold Lubula leonie Manya Pélagie Babakazo Antoinette Tshefu Kinshasa School of Public Health University of Kinshasa Kinshasa The Democratic Republic of Congo National Institute for Biomedical Research Ministry of Health Hygiene and Prevention Kinshasa The Democratic Republic of Congo Directorate of Epidemiological Surveillance Ministry of Health Hygiene and Prevention Kinshasa The Democratic Republic of Congo

Background: To better understand the epidemiological characteristic of influenza infection, the Democratic Republic of Congo set up the sentinel influenza surveillance system in 2007 with eleven health facilities. Oral and nasopharyngeal specimens were sampled from outpatients with influenza-like illness (ILI) and inpatients with severe acute respiratory illness (SARI) using case definitions. Those specimens were shipped to the Influenza National Laboratory for testing with the real-time reverse-transcription polymerase chain reaction. This study aimed to describe ILI and SARI patients’ epidemiological, clinical, and virological profiles. Material and Method: We conducted a cross-sectional study based on a documentary review of suspected notified influenza cases from January 2009 to December 2018. As variables, we exploited sex, age, symptoms, sentinel site of provenance, patient category, viral type and subtype identified, and period of health facility visit. Results: Of 18,461 notified cases, 1795 (9.7%) were positive for the Influenza virus, among them;53.1% of patients under five years old;68% of type A virus, 31.5% of type B;21% of SARI positive vs. 79% for ILI positive cases. The majority of cases occurred during the rainy season. Conclusion: The results of this study contribute to a better understanding of the influenza infection in the Democratic Republic of Congo.

关键词： Sentinel Surveillance Influenza DRC

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Treatment of sepsis: What is the antibiotic choice in bacteremia due to carbapenem resistant Enterobacteriaceae?

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World Journal of Clinical Cases 2017年第8期5卷 324-332页

作者： Fatema Alhashem Nicolette leonie Tiren-Verbeet Emine Alp Mehmet Doganay Department of Pediatrics King Hamad University Hospital Bone marrow Transplantation Department Erciyes University Hospital Department of Infectious Diseases Faculty of MedicineErciyes University

Sepsis is one of the major challenges of today. Although gram-positive bacteria related infections are more prevalent in hospital setting, the highest mortality rate is associated with gram-negative microorganisms especially Enterobacteriaceae. Enterobacteriaceae, including Escherichia coli, Klebsiella spp., Proteus spp., Enterobacter spp. and Serratia spp. Resistance to β-lactams in Enterobacteriaceae is primarily attributed to the production of B-lactamase enzymes with subsequent antibiotic hydrolysis and to a lesser extent by alteration of efflux pump or porins expression. Carbapenem resistant Enterobacteriaceae(CRE) and Acinetobacter baumannii are the most notorious pathogens due to the high incidence of morbidity and mortality especially in the immunocompromised patients in the intensive care unit. The most appropriate antimicrobial therapy to treat CRE is still controversial. Combination therapy is preferred over monotherapy due to its broad-spectrum coverage of micro-organisms, due to its synergetic effect and to prevent development of further resistance. Current suggested therapies for CRE resistance as well as promising antibiotics that are currently under investigation for winning the war against the emerging CRE resistance are reviewed and discussed.

关键词： Carbapenem resistant Enterobacteriaceae Sepsis Bacteraemia Bacteremia Treatment Antibiotics

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法语发音快速入门

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2023年

主讲人： leonie

想要学习法语，就必须要从最基础的知识开始入门，尤其是语言部分，更是需要被重视起来。但是很多人都觉得语音比较难，没有好的方法。今天我们就为大家整理了法语语音3大入门学习方法，希望能够对大家有所帮助。

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