RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 원문제공처
          펼치기
        • 등재정보
        • 학술지명
          펼치기
        • 주제분류
        • 발행연도
          펼치기
        • 작성언어
        • 저자
          펼치기

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • KCI등재

        Magnetically Controlled Growing Rods: The Experience of Mechanical Failure from a Single Center Consecutive Series of 28 Children with a Minimum Follow-up of 2 Years

        Alastair Beaven,Adrian C. Gardner,David S. Marks,,Jwalant S. Mehta,Matthew Newton-Ede,,Jonathan B. Spilsbury 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.5

        Study Design: Retrospective observational study of a continuous series of 28 children. Purpose: To determine the mechanical failure rate in our cohort of children treated with magnetically controlled growth rods (MCGRs). Overview of Literature: Previous studies report a MCGR mechanical failure rate of 0%–75%. Methods: All patients with MCGR implantation between 2012 and 2015 were examined and followed up for a minimum of 2 years. A retrospective evaluation of contemporaneously documented clinical findings was conducted, and radiographs were retrospectively examined for mechanical failure. The external remote controller (ERC)-specified length achieved in the clinic was compared to the length measured on subsequent radiographs. Results: Fourteen mechanical failures were identified in 28 children (50%) across a total of 52 rods (24 pairs and four single constructs). Mechanical failures were due to: failure to lengthen under general anesthesia (seven children), actuator pin fracture (four), rod fracture (one), foundation screw failure (one), and ran out of rod length (one). Of the 14 mechanical failures, six were treated with final fusion operations (reflecting limited further growth potential), and eight patients were treated with the intention for further lengthening. We therefore consider these eight patients to represent the true incidence of mechanical failure in our cohort (29%). The difference between the ERC length and radiographic length was found to be identical in 11% cases; 35% were overestimates, and 54% were underestimates. The median underestimate was 2.45 mm whereas the median overestimate was 3.1 mm per distraction episode. In total, 95% of all ERC distractions were within ±10 mm of the radiographic length achieved over a median of nine distraction episodes. Conclusions: Our series is the most comprehensive MCGR series published to date, and we present a mechanical failure rate of 29%. Clinicians should be mindful of the discrepancies between ERC length and radiographic measurements of rod length; other modalities may be more helpful in this regard.

      • KCI등재

        Dysregulation of the EphrinB2−EphB4 ratio in pediatric cerebral arteriovenous malformations is associated with endothelial cell in vitro and functions as a novel noninvasive biomarker in patients

        Katie Pricola Fehnel,David L. Penn,Micah Duggins-Warf,Maxwell Gruber,Steven Pineda,Julie Sesen,Alexander Moses-Gardner,Nishali Shah,Jessica Driscoll,David Zurakowski,Darren B. Orbach,Edward R. Smith 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

        We investigated (1) EphrinB2 and EphB4 receptor expression in cerebral AVMs, (2) the impact of an altered EphrinB2: EphB4 ratio on brain endothelial cell function and (3) potential translational applications of these data. The following parameters were compared between AVM endothelial cells (AVMECs) and human brain microvascular endothelial cells (HBMVECs): quantified EphrinB2 and EphB4 expression, angiogenic potential, and responses to manipulation of the EphrinB2:EphB4 ratio via pharmacologic stimulation/inhibition. To investigate the clinical relevance of these in vitro data, Ephrin expression was assessed in AVM tissue (by immunohistochemistry) and urine (by ELISA) from pediatric patients with AVM (n=30), other cerebrovascular disease (n=14) and control patients (n=29), and the data were subjected to univariate and multivariate statistical analyses. Compared to HBMVECs, AVMECs demonstrated increased invasion (p=0.04) and migration (p=0.08), impaired tube formation (p=0.06) and increased EphrinB2:EphB4 ratios. Altering the EphrinB2:EphB4 ratio (by increasing EphrinB2 or blocking EphB4) in HBMVECs increased invasion (p=0.03 and p<0.05, respectively). EphrinB2 expression was increased in AVM tissue, which correlated with increased urinary EphrinB2 levels in AVM patients. Using the optimal urinary cutoff value (EphrinB2>25.7pg/μg), AVMs were detected with high accuracy (80% vs. controls) and were distinguished from other cerebrovascular disease (75% accuracy). Posttreatment urinary EphrinB2 levels normalized in an index patient. In summary, AVMECs have an EphrinB2:EphB4 ratio that is increased compared to that of normal HBMVECs. Changing this ratio in HBMVECs induces AVMEC-like behavior. EphrinB2 is clinically relevant, and its levels are increased in AVM tissue and patient urine. This work suggests that dysregulation of the EphrinB2:EphB4 signaling cascade and increases in EphrinB2 may play a role in AVM development, with potential utility as a diagnostic and therapeutic target.

      • A Generic Concept of Marketing : HISTORY OF MARKETING THOUGHT

        SHETH, JAGDISH N.,GARDNER, DAVID M. 충남대학교 경영동우회 1994 經友論集 Vol.25 No.-

        두개의 근복적인 변화들은 마케팅 역사의 Bartel's 고전의 재조사가 초기의 육십개의 사상학파들을 생각해낸 이래로 적어도 여섯개의 새로운 사상학파를 발생시켰다. 이것들은 (a)교화가치의 개념과 경제교환개념의 대체이다. 그리고(b)마케팅 프로그램들과 활동들의 제창자와 같이 소비자와 판매자 사이의 힘의 균형의 출현을 의미한다.

      • SCOPUSKCI등재

        Addition of interleukin-6 to mouse embryo culture increases blastocyst cell number and influences the inner cell mass to trophectoderm ratio

        Kelley, Rebecca L,Gardner, David K The Korean Society for Reproductive Medicine 2017 Clinical and Experimental Reproductive Medicine Vol.44 No.3

        Objective: In vitro culture of preimplantation embryos is improved by grouping embryos together in a drop of media. Individually cultured embryos are deprived of paracrine factors; with this in mind, we investigated whether the addition of a single embryo-secreted factor, interleukin-6 (IL-6), could improve the development of individually cultured embryos. Methods: Mouse embryos were cultured individually in $2{\mu}L$ of G1/G2 media in 5% oxygen and supplemented with a range of doses of recombinant mouse or human IL-6. Results: Mouse IL-6 increased hatching at doses of 0.01 and 10 ng/mL compared to the control (93% and 93% vs. 78%, p< 0.05) and increased the total number of cells at a dose of 0.1 ng/mL compared to the control ($101.95{\pm}3.36$ vs. $91.31{\pm}3.33$, p< 0.05). In contrast, the highest dose of 100 ng/mL reduced the total number of cells ($79.86{\pm}3.29$, p< 0.05). Supplementation with human IL-6 had a different effect, with no change in hatching or total cell numbers, but an increase in the percentage of inner cell mass per embryo at doses of 0.1, 1, and 100 ng/mL compared to the control ($22.9%{\pm}1.1%$, $23.3%{\pm}1.1%$, and $23.1%{\pm}1.1%$ vs. $19.5%{\pm}1.0%$, p< 0.05). Conclusion: These data show that IL-6 improved mouse embryo development when cultured individually in complex media; however, an excess of IL-6 may be detrimental. Additionally, these data indicate that there is some cross-species benefit of human IL-6 for mouse embryos, but possibly through a different mechanism than for mouse IL-6.

      • KCI등재

        Push-out tests and bond strength of rectangular CFST columns

        Xiushu Qu,Zhi-Hua Chen,David A. Nethercot,Leroy Gardner,Marios Theofanous 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.19 No.1

        Push-out tests have been conducted on 18 rectangular concrete-filled steel tubular (CFST) columns with the aim of studying the bond behaviour between the steel tube and the concrete infill. The obtained load-slip response and the distribution of the interface bond stress along the member length and around the cross-section for various load levels, as derived from measured axial strain gradients in the steel tube, are reported. Concrete compressive strength, interface length, cross-sectional dimensions and different interface conditions were varied to assess their effect on the ultimate bond stress. The test results indicate that lubricating the steel-concrete interface always had a significant adverse effect on the interface bond strength. Among the other variables considered, concrete compressive strength and cross-section size were found to have a pronounced effect on the bond strength of non-lubricated specimens for the range of cross-section geometries considered, which is not reflected in the European structural design code for composite structures, EN 1994-1-1 (2004). Finally, based on nonlinear regression of the test data generated in the present study, supplemented by additional data obtained from the literature, an empirical equation has been proposed for predicting the average ultimate bond strength for SHS and RHS filled with normal strength concrete.

      • THE EVOLUTION OF STAR FORMATION HISTORIES OF QUIESCENT GALAXIES

        Pacifici, Camilla,Kassin, Susan A.,Weiner, Benjamin J.,Holden, Bradford,Gardner, Jonathan P.,Faber, Sandra M.,Ferguson, Henry C.,Koo, David C.,Primack, Joel R.,Bell, Eric F.,Dekel, Avishai,Gawiser, Er American Astronomical Society 2016 The Astrophysical Journal Vol.832 No.1

        <P>Although there has been much progress in understanding how galaxies evolve, we still do not understand how and when they stop forming stars and become quiescent. We address this by applying our galaxy spectral energy distribution models, which incorporate physically motivated star formation histories (SFHs) from cosmological simulations, to a sample of quiescent galaxies at 0.2 < z < 2.1. A total of 845 quiescent galaxies with multi-band photometry spanning rest-frame ultraviolet through near-infrared wavelengths are selected from the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS) data set. We compute median SFHs of these galaxies in bins of stellar mass and redshift. At all redshifts and stellar masses, the median SFHs rise, reach a peak, and then decline to reach quiescence. At high redshift, we find that the rise and decline are fast, as expected, because the universe is young. At low redshift, the duration of these phases depends strongly on stellar mass. Low-mass galaxies (log(M*/M-circle dot) similar to 9.5) grow on average slowly, take a long time to reach their peak of star formation (greater than or similar to 4 Gyr), and then the declining phase is fast (less than or similar to 2 Gyr). Conversely, high-mass galaxies (log(M*/M-circle dot) similar to 11) grow on average fast (less than or similar to 2 Gyr), and, after reaching their peak, decrease the star formation slowly (greater than or similar to 3). These findings are consistent with galaxy stellar mass being a driving factor in determining how evolved galaxies are, with high-mass galaxies being the most evolved at any time (i.e., downsizing). The different durations we observe in the declining phases also suggest that low- and high-mass galaxies experience different quenching mechanisms, which operate on different timescales.</P>

      • KCI등재

        Male Oxidative Stress Infertility (MOSI): Proposed Terminology and Clinical Practice Guidelines for Management of Idiopathic Male Infertility

        Ashok Agarwal,Neel Parekh,Manesh Kumar Panner Selvam,Ralf Henkel,Rupin Shah,Sheryl T. Homa,Ranjith Ramasamy,Edmund Ko,Kelton Tremellen,Sandro Esteves,Ahmad Majzoub,Juan G. Alvarez,David K. Gardner,Cha 대한남성과학회 2019 The World Journal of Men's Health Vol.37 No.3

        Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in the etiology of male infertility, with 30% to 80% of infertile men having elevated seminal reactive oxygen species levels. OS can negatively affect fertility via a number of pathways, including interference with capacitation and possible damage to sperm membrane and DNA, which may impair the sperm’s potential to fertilize an egg and develop into a healthy embryo. Adequate evaluation of male reproductive potential should therefore include an assessment of sperm OS. We propose the term Male Oxidative Stress Infertility, or MOSI, as a novel descriptor for infertile men with abnormal semen characteristics and OS, including many patients who were previously classified as having idiopathic male infertility. Oxidation-reduction potential (ORP) can be a useful clinical biomarker for the classification of MOSI, as it takes into account the levels of both oxidants and reductants (antioxidants). Current treatment protocols for OS, including the use of antioxidants, are not evidence-based and have the potential for complications and increased healthcare-related expenditures. Utilizing an easy, reproducible, and cost-effective test to measure ORP may provide a more targeted, reliable approach for administering antioxidant therapy while minimizing the risk of antioxidant overdose. With the increasing awareness and understanding of MOSI as a distinct male infertility diagnosis, future research endeavors can facilitate the development of evidence-based treatments that target its underlying cause.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼