47 research outputs found
Constrained Willmore Surfaces
Constrained Willmore surfaces are conformal immersions of Riemann surfaces
that are critical points of the Willmore energy under compactly
supported infinitesimal conformal variations. Examples include all constant
mean curvature surfaces in space forms. In this paper we investigate more
generally the critical points of arbitrary geometric functionals on the space
of immersions under the constraint that the admissible variations
infinitesimally preserve the conformal structure. Besides constrained Willmore
surfaces we discuss in some detail examples of constrained minimal and volume
critical surfaces, the critical points of the area and enclosed volume
functional under the conformal constraint.Comment: 17 pages, 8 figures; v2: Hopf tori added as an example, minor changes
in presentation, numbering changed; v3: new abstract and appendix, several
changes in presentatio
Radiotherapy after mastectomy for screen-detected ductal carcinoma in situ
Background. A role for radiotherapy after mastectomy for ductal carcinoma in situ (DCIS) is unclear. Using a prospective audit of DCIS detected through the NHS Breast Screening Programme we sought to determine a rationale for the use of postmastectomy radiotherapy for DCIS. Methods. Over a nine year period, from 9,972 patients with screen-detected DCIS and complete surgical, pathology, radiotherapy and follow up data, 2,944 women underwent mastectomy for DCIS of whom 33 (1.12%) received radiotherapy. Results. Use of post mastectomy radiotherapy was significantly associated with a close (<1mm) pathology margin, particularly (Ï2(1) 95.81; p<0.00001), DCIS size (Ï2 (3) 16.96; p<0.001) and the presence of microinvasion (Ï2(1) 3.92; p<0.05). At median follow up 61 months, no woman who received radiotherapy had an ipsilateral further event, and only 1/33 women (3.0%) had a contralateral event. Of the women known not to have had radiotherapy post mastectomy, 45/2,894 (1.6%) had an ipsilateral further event and 83 (2.9%) had a contralateral event. Conclusion: For DCIS treated by mastectomy, a close (<1mm) margin, large tumour size and microinvasion, may merit radiotherapy to reduce ipsilateral recurrence
Systematic Review of Health Organization Guidelines Following the AMSSM 2019 Youth Early Sport Specialization Summit
Context: Youth sport specialization may place young athletes at increased risk for negative impacts to their physical and/or psychological health. In response to these health concerns, several health organizations have created guidelines and position statements to guide parents and practitioners toward best practices for management of the young athlete. Objective: To systematically review and synthesize current organizationsâ recommendations and guidelines regarding youth sport specialization. Data Sources: English-language articles from January 1, 2000, to December 31, 2018, in the NCBI Pubmed, Embase, Cochrane, CINAHL, and SPORTDiscus databases. Study Selection: Articles that reported on recommendations or interventions by health organizations or health representatives of sports organizations. A total of 56 articles were assessed, with 11 meeting inclusion eligibility criteria. Study Design: Systematic review. Level of Evidence: Level 4. Data Extraction: Two investigators independently identified all recommendations within the results that fit within a 15-item framework encompassing 4 domains: Psychological Development/Approach, Physical Development/Load, Facilities and Resources, and Timing and Monitoring of Specialization. Results: Recommendations across organizations were primarily clustered in the Physical Development/Load (43%), Facilities and Resources (48%), and Sport Specialization (55%) domains. In contrast, the Psychological Development/Approach domain had fewer recommendations (20%). The most common recommendations endorsed concepts: âMonitor athlete well-being,â âYouth athletes need access to well-trained, quality coaches,â âMulti-sport participation,â âLimit early organized participation and/or training,â and âParents require awareness of training, coaching, and best practices.â The level of evidence provided to support a given recommendation varied significantly. The level of detail and the consistency of terms used throughout the results were typically low. Recommendations were frequently made without reference to potential outcome measures or specific strategies that could be used for practical implementation in the community. Conclusion: There was broad representation of different aspects of specialization but limited consistency between health organization guidelines. Adopting a framework for recommendations as used in this review could assist organizations in structuring future recommendations that are specific, measurable, and framed in a manner that will promote action in the youth sport community
Viability analysis and apoptosis induction of breast cancer cells in a microfluidic device: effect of cytostatic drugs
Breast cancer is the leading cause of cancer deaths among non-smoking women worldwide. At the moment the treatment regime is such that patients receive different chemotherapeutic and/or hormonal treatments dependent on the hormone receptor status, the menopausal status and age. However, in vitro sensitivity testing of tumor biopsies could rationalize and improve the choice of chemo- and hormone therapy. Lab-on-a-Chip devices, using microfluidic techniques, make detailed cellular analysis possible using fewer cells, enabling working with a patientsâ own cells and performing chemo- and hormone sensitivity testing in an ex vivo setting. This article describes the development of two microfluidic devices made in poly(dimethylsiloxane) (PDMS) to validate the cell culture properties and analyze the chemosensitivity of MCF-7 cells (estrogen receptor positive human breast cancer cells) in response to the drug staurosporine (SSP). In both cases, cell viability was assessed using the life-stain Calcein-AM (CAAM) and the death dye propidium iodide (PI). MCF-7 cells could be statically cultured for up to 7Â days in the microfluidic chip. A 30Â min flow with SSP and a subsequent 24Â h static incubation in the incubator induced apoptosis in MCF-7 cells, as shown by a disappearance of the aggregate-like morphology, a decrease in CAAM staining and an increase in PI staining. This work provides valuable leads to develop a microfluidic chip to test the chemosensitivity of tumor cells in response to therapeutics and in this way improve cancer treatment towards personalized medicine
Atividade de plasmina e plasminogĂȘnio no leite longa vida com alta e baixa contagem de cĂ©lulas somĂĄticas durante o armazenamento
Management of patients with increased risk for familial pancreatic cancer: updated recommendations from the International Cancer of the Pancreas Screening (CAPS) Consortium
Surgical oncolog
Survey of Global Genetic Diversity Within the Drosophila Immune System.
Numerous studies across a wide range of taxa have demonstrated that immune genes are routinely among the most rapidly evolving genes in the genome. This observation, however, does not address what proportion of immune genes undergo strong selection during adaptation to novel environments. Here, we determine the extent of very recent divergence in genes with immune function across five populations of Drosophila melanogaster and find that immune genes do not show an overall trend of recent rapid adaptation. Our population-based approach uses a set of carefully matched control genes to account for the effects of demography and local recombination rate, allowing us to identify whether specific immune functions are putative targets of strong selection. We find evidence that viral-defense genes are rapidly evolving in Drosophila at multiple timescales. Local adaptation to bacteria and fungi is less extreme and primarily occurs through changes in recognition and effector genes rather than large-scale changes to the regulation of the immune response. Surprisingly, genes in the Toll pathway, which show a high rate of adaptive substitution between the D. melanogaster and D. simulans lineages, show little population differentiation. Quantifying the flies for resistance to a generalist Gram-positive bacterial pathogen, we found that this genetic pattern of low population differentiation was recapitulated at the phenotypic level. In sum, our results highlight the complexity of immune evolution and suggest that Drosophila immune genes do not follow a uniform trajectory of strong directional selection as flies encounter new environments