LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 111

Search options

  1. Article ; Online: Optimizing image contrast of second phases in metal alloys.

    Georgin, Benjamin M / Viswanathan, Gopal B / Welk, Brian A / Kloenne, Zachary T / Fraser, Hamish L

    Ultramicroscopy

    2021  Volume 228, Page(s) 113346

    Abstract: Novel imaging strategies in the scanning electron microscope aimed at significantly improved image contrast of second phases in metal alloys are described. These include the use of low accelerating voltages, small working distances, and a novel detection ...

    Abstract Novel imaging strategies in the scanning electron microscope aimed at significantly improved image contrast of second phases in metal alloys are described. These include the use of low accelerating voltages, small working distances, and a novel detection system. Contrast is assessed as a function of voltage and optimized imaging conditions which result in much improved image quality are presented. These strategies are applied to two precipitation hardened Ni-base alloys, a cast single crystal and a hot isostatically pressed sample.
    Language English
    Publishing date 2021-06-24
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 1479043-9
    ISSN 1879-2723 ; 0304-3991
    ISSN (online) 1879-2723
    ISSN 0304-3991
    DOI 10.1016/j.ultramic.2021.113346
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Regulation of the ovarian follicular vasculature.

    Fraser, Hamish M

    Reproductive biology and endocrinology : RB&E

    2006  Volume 4, Page(s) 18

    Abstract: Angiogenesis is associated with follicular development and is regulated independently within each follicle potentially making the functioning of its vasculature critically important in determining its fate. This review examines the various ways in which ... ...

    Abstract Angiogenesis is associated with follicular development and is regulated independently within each follicle potentially making the functioning of its vasculature critically important in determining its fate. This review examines the various ways in which follicular angiogenesis may be monitored, describes the follicular localisation and changes in pro- and anti-angiogenic factors that may regulate the process and how antagonists may be used to elucidate their physiological role in vivo. Thus, inhibition of vascular endothelial growth factor (VEGF), VEGF receptor-2, vascular endothelial cell cadherin or interference with the angiopoietin system can inhibit follicular development or prevent ovulation.
    MeSH term(s) Angiogenesis Inducing Agents/blood ; Angiogenesis Inducing Agents/metabolism ; Animals ; Cadherins/physiology ; Callithrix ; Female ; Gene Expression Profiling ; Humans ; Immunohistochemistry ; Mice ; Oligonucleotide Array Sequence Analysis ; Ovarian Follicle/blood supply ; Ovarian Follicle/diagnostic imaging ; Ovarian Follicle/growth & development ; Ovary/blood supply ; Ovary/cytology ; Ultrasonography, Doppler ; Vascular Endothelial Growth Factor A/antagonists & inhibitors ; Vascular Endothelial Growth Factor A/physiology ; Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors ; Vascular Endothelial Growth Factor Receptor-2/physiology
    Chemical Substances Angiogenesis Inducing Agents ; Cadherins ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factor Receptor-2 (EC 2.7.10.1)
    Language English
    Publishing date 2006-04-12
    Publishing country England
    Document type Journal Article ; Review
    ISSN 1477-7827
    ISSN (online) 1477-7827
    DOI 10.1186/1477-7827-4-18
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Comparison of Diagnostic and Triage Accuracy of Ada Health and WebMD Symptom Checkers, ChatGPT, and Physicians for Patients in an Emergency Department: Clinical Data Analysis Study.

    Fraser, Hamish / Crossland, Daven / Bacher, Ian / Ranney, Megan / Madsen, Tracy / Hilliard, Ross

    JMIR mHealth and uHealth

    2023  Volume 11, Page(s) e49995

    Abstract: Background: Diagnosis is a core component of effective health care, but misdiagnosis is common and can put patients at risk. Diagnostic decision support systems can play a role in improving diagnosis by physicians and other health care workers. Symptom ... ...

    Abstract Background: Diagnosis is a core component of effective health care, but misdiagnosis is common and can put patients at risk. Diagnostic decision support systems can play a role in improving diagnosis by physicians and other health care workers. Symptom checkers (SCs) have been designed to improve diagnosis and triage (ie, which level of care to seek) by patients.
    Objective: The aim of this study was to evaluate the performance of the new large language model ChatGPT (versions 3.5 and 4.0), the widely used WebMD SC, and an SC developed by Ada Health in the diagnosis and triage of patients with urgent or emergent clinical problems compared with the final emergency department (ED) diagnoses and physician reviews.
    Methods: We used previously collected, deidentified, self-report data from 40 patients presenting to an ED for care who used the Ada SC to record their symptoms prior to seeing the ED physician. Deidentified data were entered into ChatGPT versions 3.5 and 4.0 and WebMD by a research assistant blinded to diagnoses and triage. Diagnoses from all 4 systems were compared with the previously abstracted final diagnoses in the ED as well as with diagnoses and triage recommendations from three independent board-certified ED physicians who had blindly reviewed the self-report clinical data from Ada. Diagnostic accuracy was calculated as the proportion of the diagnoses from ChatGPT, Ada SC, WebMD SC, and the independent physicians that matched at least one ED diagnosis (stratified as top 1 or top 3). Triage accuracy was calculated as the number of recommendations from ChatGPT, WebMD, or Ada that agreed with at least 2 of the independent physicians or were rated "unsafe" or "too cautious."
    Results: Overall, 30 and 37 cases had sufficient data for diagnostic and triage analysis, respectively. The rate of top-1 diagnosis matches for Ada, ChatGPT 3.5, ChatGPT 4.0, and WebMD was 9 (30%), 12 (40%), 10 (33%), and 12 (40%), respectively, with a mean rate of 47% for the physicians. The rate of top-3 diagnostic matches for Ada, ChatGPT 3.5, ChatGPT 4.0, and WebMD was 19 (63%), 19 (63%), 15 (50%), and 17 (57%), respectively, with a mean rate of 69% for physicians. The distribution of triage results for Ada was 62% (n=23) agree, 14% unsafe (n=5), and 24% (n=9) too cautious; that for ChatGPT 3.5 was 59% (n=22) agree, 41% (n=15) unsafe, and 0% (n=0) too cautious; that for ChatGPT 4.0 was 76% (n=28) agree, 22% (n=8) unsafe, and 3% (n=1) too cautious; and that for WebMD was 70% (n=26) agree, 19% (n=7) unsafe, and 11% (n=4) too cautious. The unsafe triage rate for ChatGPT 3.5 (41%) was significantly higher (P=.009) than that of Ada (14%).
    Conclusions: ChatGPT 3.5 had high diagnostic accuracy but a high unsafe triage rate. ChatGPT 4.0 had the poorest diagnostic accuracy, but a lower unsafe triage rate and the highest triage agreement with the physicians. The Ada and WebMD SCs performed better overall than ChatGPT. Unsupervised patient use of ChatGPT for diagnosis and triage is not recommended without improvements to triage accuracy and extensive clinical evaluation.
    MeSH term(s) Humans ; Triage/methods ; Emergency Service, Hospital ; Physicians ; Health Personnel ; Self Report
    Language English
    Publishing date 2023-10-03
    Publishing country Canada
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, P.H.S. ; Research Support, Non-U.S. Gov't
    ZDB-ID 2719220-9
    ISSN 2291-5222 ; 2291-5222
    ISSN (online) 2291-5222
    ISSN 2291-5222
    DOI 10.2196/49995
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Digital determinants of health: Editorial.

    Fraser, Hamish S / Marcelo, Alvin / Kalla, Mahima / Kalua, Khumbo / Celi, Leo A / Ziegler, Jennifer

    PLOS digital health

    2023  Volume 2, Issue 11, Page(s) e0000373

    Language English
    Publishing date 2023-11-28
    Publishing country United States
    Document type Editorial
    ISSN 2767-3170
    ISSN (online) 2767-3170
    DOI 10.1371/journal.pdig.0000373
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Regulation of the ovarian follicular vasculature

    Fraser Hamish M

    Reproductive Biology and Endocrinology, Vol 4, Iss 1, p

    2006  Volume 18

    Abstract: Abstract Angiogenesis is associated with follicular development and is regulated independently within each follicle potentially making the functioning of its vasculature critically important in determining its fate. This review examines the various ways ... ...

    Abstract Abstract Angiogenesis is associated with follicular development and is regulated independently within each follicle potentially making the functioning of its vasculature critically important in determining its fate. This review examines the various ways in which follicular angiogenesis may be monitored, describes the follicular localisation and changes in pro- and anti-angiogenic factors that may regulate the process and how antagonists may be used to elucidate their physiological role in vivo. Thus, inhibition of vascular endothelial growth factor (VEGF), VEGF receptor-2, vascular endothelial cell cadherin or interference with the angiopoietin system can inhibit follicular development or prevent ovulation.
    Keywords Physiology ; QP1-981 ; Science ; Q ; DOAJ:Physiology ; DOAJ:Biology ; DOAJ:Biology and Life Sciences
    Language English
    Publishing date 2006-04-01T00:00:00Z
    Publisher BioMed Central
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  6. Article ; Online: Clinicians perceptions of a telemedicine system: a mixed method study of Makassar City, Indonesia.

    Indria, Dea / Alajlani, Mohannad / Fraser, Hamish S F

    BMC medical informatics and decision making

    2020  Volume 20, Issue 1, Page(s) 233

    Abstract: Background: This case study in Makassar City, Indonesia aims to investigate the clinicians' perceptions, including both satisfaction and barriers in using telemedicine in a large, established program which supported 3974 consultations in 2017.: ... ...

    Abstract Background: This case study in Makassar City, Indonesia aims to investigate the clinicians' perceptions, including both satisfaction and barriers in using telemedicine in a large, established program which supported 3974 consultations in 2017.
    Methods: A mixed methodology was used in this research utilizing a questionnaire with 12 questions, and semi-structured interviews. A purposeful sample of clinicians using the telemedicine system at the 39 primary care clinics in Makassar City were surveyed. A total of 100 clinicians participated in this study. All of them completed the questionnaires (76.9% response rate) and 15 of them were interviewed.
    Results: The result showed that 78% of the clinicians were satisfied with the telemedicine system. In free text responses 69% said that telemedicine allowed quicker diagnosis and treatment, 47% said poor internet connectivity was a significant obstacle in using the system, and 40% suggested improvement to the infrastructure including internet connection and electricity.
    Conclusion: Overall, the clinicians were satisfied with the system, with the main benefit of rendering the diagnosis faster and easier for patients. However, poor internet connectivity was indicated as the main barrier. Most of the clinicians suggested improving the infrastructure especially the internet network.
    MeSH term(s) Ambulatory Care Facilities ; Humans ; Indonesia ; Surveys and Questionnaires ; Telemedicine
    Keywords covid19
    Language English
    Publishing date 2020-09-17
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2046490-3
    ISSN 1472-6947 ; 1472-6947
    ISSN (online) 1472-6947
    ISSN 1472-6947
    DOI 10.1186/s12911-020-01234-7
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article: SRB Reproduction, Fertility and Development Award Lecture 2008. Regulation and manipulation of angiogenesis in the ovary and endometrium.

    Fraser, Hamish M / Duncan, W Colin

    Reproduction, fertility, and development

    2009  Volume 21, Issue 3, Page(s) 377–392

    Abstract: The marked cyclical physiological angiogenesis in the developing follicle, corpus luteum and endometrium implies a critical role in health and disease. Our approach to understanding its regulation has been to localise and quantify the temporal changes in ...

    Abstract The marked cyclical physiological angiogenesis in the developing follicle, corpus luteum and endometrium implies a critical role in health and disease. Our approach to understanding its regulation has been to localise and quantify the temporal changes in putative angiogenic factors, and their receptors, in human and non-human primate tissue and to use antagonists to dissect their role by specific inhibition at defined periods during the ovulatory cycle in non-human primates in vivo. The course of angiogenesis throughout the cycle and the cellular and molecular effects of inhibitory treatments have been investigated in the marmoset ovary and uterus, whereas consequences on pituitary-ovarian function have been monitored in macaques. Inhibition of vascular endothelial growth factor (VEGF) at the time of follicle recruitment or selection prevents endothelial cell proliferation, leading to inhibition of follicular development. VEGF inhibition during the early luteal phase prevents angiogenesis and restricts development of the luteal microvasculature. Inhibition of angiogenesis at all stages of the cycle leads to profound suppression of ovarian function. Even during the 'post-angiogenic' period of the luteal phase, inhibition of VEGF precipitates a suppression of progesterone secretion, pointing to additional roles for VEGF in the ovary. In the endometrium, oestrogen drives endometrial angiogenesis through VEGF. Thus, oestrogen can restore angiogenesis after ovariectomy, but not in the presence of VEGF inhibitors. These investigations enhance our understanding of the regulation of angiogenesis in the ovary and uterus and inform studies on conditions with abnormal vascularisation, such as polycystic ovary syndrome, endometriosis, uterine fibroids and menstrual dysfunction.
    MeSH term(s) Animals ; Awards and Prizes ; Corpus Luteum/blood supply ; Endometrium/blood supply ; Estrogens/physiology ; Female ; Follicular Phase ; Homeostasis/physiology ; Humans ; Luteal Phase ; Macaca ; Neovascularization, Physiologic ; Ovarian Follicle/blood supply ; Ovary/blood supply ; Ovary/physiology ; Ovulation ; Pituitary Gland/physiology ; Progesterone/metabolism ; Vascular Endothelial Growth Factor A/antagonists & inhibitors ; Vascular Endothelial Growth Factor A/physiology
    Chemical Substances Estrogens ; Vascular Endothelial Growth Factor A ; Progesterone (4G7DS2Q64Y)
    Language English
    Publishing date 2009-03-05
    Publishing country Australia
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 1019913-5
    ISSN 1448-5990 ; 1031-3613
    ISSN (online) 1448-5990
    ISSN 1031-3613
    DOI 10.1071/rd08272
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Performance of models to predict hepatocellular carcinoma risk among UK patients with cirrhosis and cured HCV infection.

    Innes, Hamish / Jepsen, Peter / McDonald, Scott / Dillon, John / Hamill, Victoria / Yeung, Alan / Benselin, Jennifer / Went, April / Fraser, Andrew / Bathgate, Andrew / Ansari, M Azim / Barclay, Stephen T / Goldberg, David / Hayes, Peter C / Johnson, Philip / Barnes, Eleanor / Irving, William / Hutchinson, Sharon / Guha, Indra Neil

    JHEP reports : innovation in hepatology

    2021  Volume 3, Issue 6, Page(s) 100384

    Abstract: Background & aims: Hepatocellular carcinoma (HCC) prediction models can inform clinical decisions about HCC screening provided their predictions are robust. We conducted an external validation of 6 HCC prediction models for UK patients with cirrhosis ... ...

    Abstract Background & aims: Hepatocellular carcinoma (HCC) prediction models can inform clinical decisions about HCC screening provided their predictions are robust. We conducted an external validation of 6 HCC prediction models for UK patients with cirrhosis and a HCV virological cure.
    Methods: Patients with cirrhosis and cured HCV were identified from the Scotland HCV clinical database (N = 2,139) and the STratified medicine to Optimise Treatment of Hepatitis C Virus (STOP-HCV) study (N = 606). We calculated patient values for 4 competing non-genetic HCC prediction models, plus 2 genetic models (for the STOP-HCV cohort only). Follow-up began at the date of sustained virological response (SVR) achievement. HCC diagnoses were identified through linkage to nation-wide cancer, hospitalisation, and mortality registries. We compared discrimination and calibration measures between prediction models.
    Results: Mean follow-up was 3.4-3.9 years, with 118 (Scotland) and 40 (STOP-HCV) incident HCCs observed. The age-male sex-ALBI-platelet count score (aMAP) model showed the best discrimination; for example, the Concordance index (C-index) in the Scottish cohort was 0.77 (95% CI 0.73-0.81). However, for all models, discrimination varied by cohort (being better for the Scottish cohort) and by age (being better for younger patients). In addition, genetic models performed better in patients with HCV genotype 3. The observed 3-year HCC risk was 3.3% (95% CI 2.6-4.2) and 5.1% (3.5-7.0%) in the Scottish and STOP-HCV cohorts, respectively. These were most closely matched by aMAP, in which the mean predicted 3-year risk was 3.6% and 5.0% in the Scottish and STOP-HCV cohorts, respectively.
    Conclusions: aMAP was the best-performing model in terms of both discrimination and calibration and, therefore, should be used as a benchmark for rival models to surpass. This study underlines the opportunity for 'real-world' risk stratification in patients with cirrhosis and cured HCV. However, auxiliary research is needed to help translate an HCC risk prediction into an HCC-screening decision.
    Lay summary: Patients with cirrhosis and cured HCV are at high risk of developing liver cancer, although the risk varies substantially from one patient to the next. Risk calculator tools can alert clinicians to patients at high risk and thereby influence decision-making. In this study, we tested the performance of 6 risk calculators in more than 2,500 patients with cirrhosis and cured HCV. We show that some risk calculators are considerably better than others. Overall, we found that the 'aMAP' calculator worked the best, but more work is needed to convert predictions into clinical decisions.
    Language English
    Publishing date 2021-10-07
    Publishing country Netherlands
    Document type Journal Article
    ISSN 2589-5559
    ISSN (online) 2589-5559
    DOI 10.1016/j.jhepr.2021.100384
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article: Oestrogen and progesterone receptors in the marmoset endometrium: changes during the ovulatory cycle, early pregnancy and after inhibition of vascular endothelial growth factor, GnRH or ovariectomy.

    Silvestri, Audrey / Fraser, Hamish M

    Reproduction (Cambridge, England)

    2007  Volume 134, Issue 2, Page(s) 341–353

    Abstract: Marmosets are widely used, but detailed studies on localisation of endometrial oestrogen receptors alpha and beta (ER alpha and ER beta ), and the progesterone receptor (PR) are lacking. These receptors were localised and semi-quantitatively analysed ... ...

    Abstract Marmosets are widely used, but detailed studies on localisation of endometrial oestrogen receptors alpha and beta (ER alpha and ER beta ), and the progesterone receptor (PR) are lacking. These receptors were localised and semi-quantitatively analysed throughout the ovulatory cycle, weeks 2, 3 and 4 of pregnancy and after treatment with GnRH antagonist, vascular endothelial growth factor (VEGF) Trap or ovariectomy. The PR in epithelial cells increased markedly between the mid- and late proliferative phases before declining in the mid-secretory phase and pregnancy. PR in stromal cells was present throughout the cycle and levels were maintained in pregnancy. ER alpha was present at the mid-proliferative phase and increased in glands at the late proliferative and early secretory phases, before declining at the late secretory phase and week 4 of pregnancy. Stromal ER alpha showed a similar trend, but decreased earlier, by the mid-secretory phase. ER beta was highly expressed in epithelial cells throughout the cycle and in pregnancy. In stroma, increases in ER beta expression were observed at the late proliferative phase with the staining index decreasing by half as the secretory phase progressed and in pregnancy. GnRH antagonist, VEGF Trap or ovariectomy caused significant reductions in PR and ER beta expression, but not in ER alpha when compared with the late proliferative phase of the normal cycle. Endothelial cells expressed ER beta , but not ER alpha or PR. It is concluded that the steroid receptor profile in the marmoset endometrium is generally similar to the human and should provide a useful model for studies on hormonal manipulation of the endometrium.
    MeSH term(s) Animals ; Callithrix/metabolism ; Endometrium/chemistry ; Endometrium/drug effects ; Endometrium/metabolism ; Estradiol/blood ; Estrogen Receptor alpha/analysis ; Estrogen Receptor beta/analysis ; Female ; Gonadotropin-Releasing Hormone/antagonists & inhibitors ; Immunohistochemistry ; Menstrual Cycle/metabolism ; Oligopeptides/pharmacology ; Ovariectomy ; Pregnancy ; Pregnancy, Animal/metabolism ; Progesterone/blood ; Receptors, Estrogen/analysis ; Receptors, Growth Factor ; Receptors, Progesterone/analysis ; Recombinant Fusion Proteins/pharmacology ; Vascular Endothelial Growth Factor A/antagonists & inhibitors
    Chemical Substances Estrogen Receptor alpha ; Estrogen Receptor beta ; Oligopeptides ; Receptors, Estrogen ; Receptors, Growth Factor ; Receptors, Progesterone ; Recombinant Fusion Proteins ; VEGF Trap R1R2 protein ; Vascular Endothelial Growth Factor A ; Gonadotropin-Releasing Hormone (33515-09-2) ; Progesterone (4G7DS2Q64Y) ; Estradiol (4TI98Z838E) ; antarelix (D19V7048JK)
    Language English
    Publishing date 2007-07-27
    Publishing country England
    Document type Journal Article
    ZDB-ID 2034501-X
    ISSN 1741-7899 ; 1470-1626 ; 1476-3990
    ISSN (online) 1741-7899
    ISSN 1470-1626 ; 1476-3990
    DOI 10.1530/REP-06-0266
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Control of Metal-Organic Framework Crystallization by Metastable Intermediate Pre-equilibrium Species.

    Yeung, Hamish H-M / Sapnik, Adam F / Massingberd-Mundy, Felicity / Gaultois, Michael W / Wu, Yue / Fraser, Duncan A X / Henke, Sebastian / Pallach, Roman / Heidenreich, Niclas / Magdysyuk, Oxana V / Vo, Nghia T / Goodwin, Andrew L

    Angewandte Chemie (International ed. in English)

    2018  Volume 58, Issue 2, Page(s) 566–571

    Abstract: There is an increasing amount of interest in metal-organic frameworks (MOFs) for a variety of applications, from gas sensing and separations to electronics and catalysis. However, the mechanisms by which they crystallize remain poorly understood. Herein, ...

    Abstract There is an increasing amount of interest in metal-organic frameworks (MOFs) for a variety of applications, from gas sensing and separations to electronics and catalysis. However, the mechanisms by which they crystallize remain poorly understood. Herein, an important new insight into MOF formation is reported. It is shown that, prior to network assembly, crystallization intermediates in the canonical ZIF-8 system exist in a dynamic pre-equilibrium, which depends on the reactant concentrations and the progress of reaction. Concentration can, therefore, be used as a synthetic handle to directly control particle size, with potential implications for industrial scale-up and gas sorption applications. These findings enable the rationalization of apparent contradictions between previous studies of ZIF-8 and opens up new opportunities for the control of crystallization in network solids more generally.
    Language English
    Publishing date 2018-12-07
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2011836-3
    ISSN 1521-3773 ; 1433-7851
    ISSN (online) 1521-3773
    ISSN 1433-7851
    DOI 10.1002/anie.201810039
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top