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The relationship between dNA fragmentation and the intensity of morphologically abnormal human spermatozoa

Asian pacific Journal of Reproduction 2024年第1期13卷 22-27页

作者： Mercedes González-Martínez Pascual Sánchez-Martín Carmen López-Fernández stephen d.johnston Jaime Gosálvez Clínica Ginemed Unidad de ReproducciónSevillaSpain department of Biology Universidad Autónoma de MadridCantoblancoMadridSpain School of Environment The University of QueenslandGattonAustralia School of Veterinary Science The University of QueenslandGattonAustralia

Objective:To determine the relationship between teratozoospermia and sperm dNA fragmentation(SdF)in the human ***:This retrospective study included 100 normozoospermic men as a control cohort(abnormal forms>14%),210 patients with a high level of abnormal forms(≤4%)and 65 patients presenting with a moderate level of abnormal forms(>4%to≤14%)based on the World Health Organization *** morphology was assessed using bright field *** dNA fragmentation was assessed using the sperm chromatin dispersion ***-parametric analyses were conducted to examine the relationship between abnormal sperm morphology and sperm dNA fragmentation;receiver operating characteristic(ROC)analyses were conducted to assess sensitivity and specificity of this ***:A correlation analysis revealed that the higher the proportion of abnormal spermatozoa in the ejaculate,the higher the level of SdF(Spearman's Rho=-0.230;Pdifferences in the proportion of SdF were found when all cohorts were compared(Pdifferences were also retained when the different cohorts were compared *** analysis showed a moderate but significant predictive value for SdF to differentiate patients with different levels of ***:Although analysis of a more continuous range of values for teratozoospermia would help further clarify any causal relationship with SdF,there is clearly a synergistic or coincident affiliation between these variables that needs to be acknowledged by the clinician when interpreting the spermiogram.

关键词： Teratozoospermia Sperm morphology Sperm dNA fragmentation Male factor Human reproduction Human fertility

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Cas13d-mediated gene knockdown in CAR T cells:towards off-the-shelf cancer treatment

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Signal Transduction and Targeted Therapy 2024年第5期9卷 1796-1798页

作者： Midori johnston Nadine Urban Can dincer FIT Freiburg Centre for Interactive Materials and Bioinspired Technology University of FreiburgFreiburgGermany IMTEK-department of Microsystems Engineering University of FreiburgFreiburgGermany

In a recent study published in Cell,Tieu et *** RfxCas13d to dynamically enhance performance and longevity of chimeric antigen receptor(CAR)T cells by massively multiplexed gene knockdown and thereby,move the treatmen... 详细信息

关键词： treatment shelf

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未处理或上游法处理后精子的dNA碎片能否预测使用赠卵ICSI后的妊娠？

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Asian Journal of Andrology 2013年第6期15卷 812-818,I0010页

作者： Jaime Gosálvez Pedro Caballero Carmen López-Fernández Leonor Ortega José Andrés Guijarro José Luís FernAndez stephen d johnston Rocio Nufiez-Calonge Faculty of Biology Autonomous University of Madrid Cantoblanco Madrid 28049 Spain CIfnica Tambre Madrid 28002 Spain GINIBIC-Complejo Hospitalario Universitario A CoruRa A Corufna15006 Spain School of Agriculture and Food Science The University of Queensland Gatton 4343 Australia

This study compared the potential of assessing sperm dNA fragmentation （SdF） from neat semen and the subsequent swim-up （SU） procedure to predict pregnancy when conducting ICSI of fertile donor oocytes. Infertile females （n=81） were transferred embryos resulting from intracytoplasmic sperm injection （ICSI） of their partner＇s spermatozoa and proven donor oocytes. This model normalized the impact of female factor in putative sperm dNA repair. Semen was blindly assessed for SdF using Halosperm immediately following ejaculation （NS） and after swim-up at the time of ICSI fertilisation. There was a decrease in SdF values of the ejaculated semen sample following the swim-up protocol （P=0.000）. Interestingly, pregnancy could be equally predicted from SdF values derived from either neat or swim-up semen samples. Receiver operator curves and the derived Youden＇s indices determined SdF cutoff values for NS and SU of 24.8% and 17.5%, respectively. Prediction of pregnancy from NS SdF had a sensitivity of 75% and a specificity of 69%, whereas for SU SdF was 78% and 73%, respectively. While increased levels of SdF negatively impact reproductive outcome, we have shown that a reduction in SdF following sperm selection using ICSI with proven donor oocytes is not mandatory for achieving pregnancy. This suggests that a certain level of dNA damage that is not detectable using current technologies could be impacting on the relative success of assisted reproductive technology （ART） procedures. Consequently, we propose a modification of the so called ＇iceberg model＇ as a possible rationale for understanding the role of SdF in reproductive outcome.

关键词： assisted reproductive technology egg donation male factor sperm dNA fragmentation

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Inter-center variation in the efficiency of sperm dNA damage reduction following density gradient centrifugation

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Natural Science 2013年第7期5卷 15-20页

作者： Carmen López-Fernández stephen d.johnston Altea Gosálbez Jose Luís Fernández Juan G.Alvarez Jaime Gosálvez department of Biology Genetics UnitUniversity Autónoma of MadridMadridSpain School of Agriculture and Food Science The University of QueenslandGattonAustralia Laboratorio de Genética Molecular y Radiobiología Centro Oncológico de GaliciaA CorunaSpain Centro ANdROGEN A CorunaSpain

This was a prospective multicenter study aiming at comparing the efficiency of sperm selection by density gradient centrifugation (dGC) in reducing sperm dNA fragmentation (SdF) in different ART centers. The study was designed using 290 semen samples collected from 10 different ART centers performing artificial insemination, in vitro fertilization and blind assessment of SdF at the University facilities. The results showed that while there was a significant reduction in the SdF levels in sperm isolated from the gradient centrifuged pellet (dGC) compared to neat semen samples (NSS), there was also significant inter-center variability in the efficiency to reduce SdF values by dGC (78.5% to 29.2%). Surprisingly, for some patients, the level of SdF actually increased following sperm selection. The main conclusions derived from this study were that 1) isolation of sperm from the gradient pellet by dGC must be performed using validated, optimized protocols;2) routine comparison of SdF values in NSS semen and in processed sperm after dGC or swim-up must be recommended as part of the internal quality control (QC) of ART laboratories to test the efficacy of sperm processing;and 3) SdF values in processed spermatozoa should be obtained to compare with the pregnancy rate when insemination or fertilization is about to be performed, otherwise, attempts to predict pregnancy outcome from SdF could be biased or are essentially meaningless.

关键词： Assisted Reproductive Technology Fertility Sperm dNA Fragmentation Male Factor Semen Processing

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Use of Solid State Carbothermic Reduction in Production of Transition Metals and Their Carbides

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Journal of Iron and Steel Research(International) 2000年第2期7卷 14-22页

作者： YANG Yin-dong SOMMERVILLE I d johnston R F McLEAN A University of Toronto LaTrobe University

The use of solid state carbothermic reduction as a precursor to the smelting of transition metal ores was examined . The advantages of the introduction of a prereduction stage include enabling the more efficient use of fines and the achievement of higher energy efficiencies. A solid state reduction using carbon as the reductant offers a simpler alternative for their treatment. Subsequent treatment of the reduced material could include intensive bath smelting to produce ferroalloys or, in some case, solid state separation of the transition metal carbide where this has commercial significance.

关键词： solid state carbothermic reduction transition metals carbide

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development of Mathematical Model of Slag Flow Field and Temperature Field in ESR System

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Journal of Iron and Steel Research(International) 2000年第2期7卷 27-31页

作者： YANG Yin-dong SOMMERVILLE I d johnston R F McLEAN A University of Toronto LaTrobe University

The heat transfer phenomena and driving forces of slag bath flow in ESR process were analyzed, and the mathematical models in ESR system were reviewed and evaluated. The electromagnetic force is the main driving force for the flow formation in the ESR slag pool, and the temperature difference in the pool creates a convective flow in the system. The shape of the electrode tip has an effect on electromagnetic field distribution in slag pool, thus affects the flow pattern. Finally an improved mathematical model of slag pool flow was proposed.

关键词： ESR electromagnetic force buoyancy force flow field temperature field mathematical model

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Effects of Reduced Nocturnal Temperature on Performance and Behavior of Nursery Pigs

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Journal of Integrative Agriculture 2012年第9期11卷 1509-1516页

作者： Lee J johnston West Central Research and Outreach Center University of MinnesotaMorris MN 56267 USA

Previous studies suggested that pigs prefer lower environmental temperatures during nighttime compared to daytime. So reducing nocturnal temperature in nursery barns may not jeopardize performance or welfare of pigs, but can save energy for heating the barn. A study was conducted to investigate growth performance and behavioral response of nursery pigs to reduced nocturnal temperature. This study was conducted in four replicates, each utilizing 270 newly weaned pigs and lasting for 5 wk. Temperature setpoint in the control room （CON） was started at 30℃ and decreased by 2℃ per week. In the treatment room （RNT）, temperature setpoint was maintained same as in CON between 7：00 h and 19：00 h, and reduced by 8~C between 19：00 h and 7：00 h starting from d 5. Growth performance （15 pens/room, 9 pigs/pen, BW=（6.3±0.61） kg） was monitored for 5 wk, and behaviors in 6 pens in each room were video-recorded for 24 h 3 d after being exposed to the experimental temperature. Instantaneous scan sampling was performed to determine time budgets for standing, sitting, eating, drinking, belly nosing, three postures of lying, and huddling. Two focal pigs were continuously viewed to record duration and occurrence of eating and drinking. Reduced nocturnal temperature did not affect the growth performance of the pigs, time spent standing, sitting, total lying and eating or duration and frequencies of eating and drinking （all P〉0.10）. However, RNT increased time spent lying sternal （83 vs. 72%, P〈0.001） and number of pigs that were huddling （70 vs. 50% of lying pigs, P〈0.001）, and decreased time spent lying laterally （0.8 vs. 4.6%, P〈0.001）, lying half laterally （5.3 vs. 11.0%, P〈0.001）, and belly nosing （0.9 vs. 1.7%, P=0.01） during nighttime. These results indicate that nursery pigs adopted the posture of lying sternal and huddled together to reduce heat loss from their body surface to maintain thermal balance and growth performance in RNT. Such mild reduction in nocturnal temperature in th

关键词： reduced nocturnal temperature behavior growth performance pigs

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Active stabilization of terahertz waveforms radiated from a two-color air plasma

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Photonics Research 2022年第1期10卷 96-103页

作者： YONGHAO MI KYLE johnston VALENTINA SHUMAKOVA SφREN H.MφLLER KAMALESH JANA CHUNMEI ZHANG ANdRé STAUdTE SHAWN SEdERBERG PAUL B.CORKUM Joint Attosecond Science Laboratory University of Ottawa and National Research Council CanadaOntario K1N 6X1Canada School of Engineering Science Simon Fraser UniversityBurnabyBritish Columbia V5A 1S6Canada

Intense laser fields focused into ambient air can be used to generate high-bandwidth current densities in the form of plasma channels and *** with bichromatic fields enables us to adjust the amplitude and sign of these currents using the relative phase between the two light ***-color filamentation in gas targets provides a route to scaling the energy of terahertz pulses to microjoule levels by driving the plasma channel with a high-energy laser ***,the structure of plasma channels is highly susceptible to drifts in both the relative phase and other laser parameters,making control over the waveform of the radiated terahertz fields *** establish a clear link between the phase dependence of plasma currents and terahertz radiation by comparing in situ detection of current densities and far-field detection of terahertz electric *** show that the current measurement can be used as a feedback parameter for stabilizing the terahertz *** approach provides a route to energetic terahertz pulses with exceptional waveform stability.

关键词： stabilization terahertz Active

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diabetes is associated with increased risk of hepatocellular carcinoma in non-alcoholic steatohepatitis with cirrhosis-implications for surveillance and future pharmacotherapy

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Hepatobiliary Surgery and Nutrition 2020年第2期9卷 230-234页

作者： Michael P.johnston Janisha Patel Christopher d.Byrne department of Hepatology University Hospital Southampton NHS Foundation TrustSouthamptonUK Human development and Health Faculty of MedicineUniversity of SouthamptonSouthamptonUK National Institute for Health Research Southampton Biomedical Research Centre University of Southampton and University Hospital Southampton NHS Foundation TrustSouthamptonUK

Hepatocellular carcinoma(HCC)is the most common liver-related complication seen in patients with non-alcoholic fatty liver disease(NAFLd)and non-alcoholic steatohepatitis(NASH)(1).NASH is strongly associated with type 2 diabetes mellitus(T2dM)but it has also been apparent for a number of years that T2dM is associated with an increased risk of HCC independent of the presence of NASH(2).A 2006 meta-analysis of retrospective cohort studies and case-control studies demonstrated an association between T2dM and an increased risk of HCC(3).International guidelines advocate surveillance for HCC in patients with NASH who have progressed to cirrhosis(4).An important clinical question is whether T2dM confers an increased risk of HCC once patients with NASH have progressed to *** a recent study by Yang and colleagues(5),the authors reported strong evidence that T2dM is an independent risk factor for HCC in patients with NASH-related *** and colleagues performed a retrospective analysis of a prospectively registered research dataset of patients with NASH-related cirrhosis.

关键词： T2dM cirrhosis patients

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Stability of dirac Equation in Four-dimensional Gravity

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Chinese Physics Letters 2017年第6期34卷 10-13页

作者： F. Safari H. Jafari J. Sadeghi S. J. johnston d. Baleanu department of Mathematics University of Mazandaran Babolsar Iran Physics department University of Mazandaran Babolsar 4716-95447 Iran department of Mathematical Sciences University of South Africa UNISA 0003 South Africa department of Mathematics Faculty of Art and Science Cankaya University Balgat 06530 Turkey Institute of Space Sciences Magurele-Bueharest Romania

We introduce the dirac equation in four-dimensional gravity which is a generally covariant form. We choose the suitable variable and solve the corresponding equation. To solve such equation and to obtain the corresponding bispinor, we employ the factorization method which introduces the associated Laguerre polynomial. The asso- ciated Laguerre polynomials help us to write the dirac equation of four-dimensional gravity in the form of the shape invariance equation. Thus we write the shape invariance condition with respect to the secondary quantum number. Finally, we obtain the spinor wave function and achieve the corresponding stability of condition for the four-dimensional gravity system.

关键词： Stability of dirac Equation in Four-dimensional Gravity

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