2,729 research outputs found
Porous Biomimetic Microlens Arrays as Multifunctional Optical Structures
Microlenses are important optical components that image, detect and couple light. Most synthetic microlenses, however, have fixed position and shape once they are fabricated. Therefore, the attainable range of their tunability and complexity is rather limited. In comparison, biological world provides a multitude of varied, new paradigms for the development of adaptive optical networks. This review discusses a few inspirational examples of biological lenses and their synthetic analogs. We focus on the fabrication and characterization of biomimetic microlens arrays with integrated pores, whose appearance and function are similar to a highly efficient optical element formed by brittlestars. The complex microlens design can be created by three-beam interference lithography. These synthetic microlenses have strong focusing ability, and the structure can be, therefore, used as an adjustable lithographic mask, and a tunable optical device coupled with the microfluidic system. The replacement of rigid microlenses with soft hydrogels provides means for changing the lens geometry and refractive index continuously in response to external stimuli, resulting in intelligent, multifunctional, tunable optics
SPG20 protein spartin is recruited to midbodies by ESCRT-III protein Ist1 and participates in cytokinesis.
Hereditary spastic paraplegias (HSPs, SPG1-46) are inherited neurological disorders characterized by lower extremity spastic weakness. Loss-of-function SPG20 gene mutations cause an autosomal recessive HSP known as Troyer syndrome. The SPG20 protein spartin localizes to lipid droplets and endosomes, and it interacts with tail interacting protein 47 (TIP47) as well as the ubiquitin E3 ligases atrophin-1-interacting protein (AIP)4 and AIP5. Spartin harbors a domain contained within microtubule-interacting and trafficking molecules (MIT) at its N-terminus, and most proteins with MIT domains interact with specific ESCRT-III proteins. Using yeast two-hybrid and in vitro surface plasmon resonance assays, we demonstrate that the spartin MIT domain binds with micromolar affinity to the endosomal sorting complex required for transport (ESCRT)-III protein increased sodium tolerance (Ist)1 but not to ESCRT-III proteins charged multivesicular body proteins 1-7. Spartin colocalizes with Ist1 at the midbody, and depletion of Ist1 in cells by small interfering RNA significantly decreases the number of cells where spartin is present at midbodies. Depletion of spartin does not affect Ist1 localization to midbodies but markedly impairs cytokinesis. A structure-based amino acid substitution in the spartin MIT domain (F24D) blocks the spartin-Ist1 interaction. Spartin F24D does not localize to the midbody and acts in a dominant-negative manner to impair cytokinesis. These data suggest that Ist1 interaction is important for spartin recruitment to the midbody and that spartin participates in cytokinesis
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SOCIAL WORKERS\u27 PERCEPTION ON THE NEEDS AND SERVICES FOR FOSTER CHILDREN WITH SPECIAL NEEDS
Foster children are already at a disadvantage given that they tend to live in a home without their parents. Social workers have direct interactions working with children with special needs, and through interviews with the workers, we aimed to understand whether or not the services available are able to meet foster children’s special needs. The research on special needs children in foster care is quite limited. The purpose of the study was to identify social workers’ perceptions of the needs of special needs foster children and their access to services.
This study used qualitative interviews with open-ended questions to gather qualitative data from ten social worker participants. The researchers employed thematic analysis techniques to analyze the qualitative data. The themes that emerged from analyzing the data were social workers’ challenges in providing services to special needs foster children, social workers’ access to services, and the need for institutional support to effectively manage service delivery for special needs foster children. This study found that social workers face challenges in obtaining training for parents and social workers, navigating complex funding processes, managing inconsistent desires between parents and court officials, and dealing with the limited number of capable foster homes. The social workers interviewed identified different tactics that could be implemented in order to improve services for the special needs foster children through changes and improvements within the department. Understanding large-scale policy and practice issues, such as organizational change or resource management, can lead county agency social workers to advocate for the challenges of special needs children in child welfare
Addition of a Preoperative Educational Video for Enhanced Recovery After Breast Cancer Surgery
Introduction: Patients undergoing breast cancer surgery at an urban teaching hospital lacked uniform and comprehensive preoperative education regarding Enhanced Recovery After Surgery (ERAS). A retrospective chart review was conducted comparing one year of data prior to ERAS incorporation to one year after implementation to assess the impact on breast cancer surgery patient outcomes. Methods: In collaboration with stakeholders, an animated video was created to educate patients regarding the ERAS pathway and set perioperative expectations. A valid, reliable survey measuring the patient’s surgical care experience was adapted and distributed along with the video to breast cancer patients undergoing surgery as a result of their diagnosis. Results: 100% (n=15) of survey participants responded either “yes, definitely” or “yes, somewhat” that the video explained what to expect during the recovery period. 93% of survey participants (n=14) responded that they felt more calm and relaxed after this video intervention, either definitely or somewhat, with one participant responding “no.” Fisher’s exact test demonstrated no statistically significant associations between age or level of education regarding the two primary outcomes. There was a statistically significant association found between having more office visits before surgery and the video “yes, definitely” versus “yes somewhat” explaining what to expect during the recovery period (p=0.043). Conclusions: This quality improvement project successfully provided effective patient education regarding ERAS for breast cancer surgery patients through a video modality that set perioperative expectations and helped the patient feel more calm and relaxed
Testing 2D temperature models in Bayesian retrievals of atmospheric properties from hot Jupiter phase curves
Spectroscopic phase curves of transiting hot Jupiters are spectral
measurements at multiple orbital phases, giving a set of disc-averaged spectra
that probe multiple hemispheres. By fitting model phase curves to observations,
we can constrain the atmospheric properties of hot Jupiters such as molecular
abundance, aerosol distribution and thermal structure, which offer insights
into their dynamics, chemistry, and formation. In this work, we propose a novel
2D temperature scheme consisting of a dayside and a nightside to retrieve
information from near-infrared phase curves, and apply the scheme to phase
curves of WASP-43b observed by HST/WFC3 and Spitzer/IRAC. In our scheme,
temperature is constant on isobars on the nightside and varies with
cos(longitude/) on isobars on the dayside, where and
are free parameters. We fit all orbital phases simultaneously using
the radiative transfer package NEMESISPY coupled to a Bayesian inference code.
We first validate the performance of our retrieval scheme with synthetic phase
curves generated from a GCM, and find our 2D scheme can accurately retrieve the
latitudinally-averaged thermal structure and constrain the abundance of HO
and CH. We then apply our 2D scheme to the observed phase curves of
WASP-43b and find: (1) the dayside temperature-pressure profiles do not vary
strongly with longitude and are non-inverted; (2) the retrieved nightside
temperatures are extremely low, suggesting significant nightside cloud
coverage; (3) the HO volume mixing ratio is constrained to
--, and we retrieve an upper bound for
CH at 10.Comment: 23 pages, 20 figures, 3 tables, accepted for publication in MNRA
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Inhibition of yes-associated protein suppresses brain metastasis of human lung adenocarcinoma in a murine model.
Yes-associated protein (YAP) is a main mediator of the Hippo pathway and promotes cancer development and progression in human lung cancer. We sought to determine whether inhibition of YAP suppresses metastasis of human lung adenocarcinoma in a murine model. We found that metastatic NSCLC cell lines H2030-BrM3(K-rasG12C mutation) and PC9-BrM3 (EGFRΔexon19 mutation) had a significantly decreased p-YAP(S127)/YAP ratio compared to parental H2030 (K-rasG12C mutation) and PC9 (EGFRΔexon19 mutation) cells (P < .05). H2030-BrM3 cells had significantly increased YAP mRNA and expression of Hippo downstream genes CTGF and CYR61 compared to parental H2030 cells (P < .05). Inhibition of YAP by short hairpin RNA (shRNA) and small interfering RNA (siRNA) significantly decreased mRNA expression in downstream genes CTGF and CYR61 in H2030-BrM3 cells (P < .05). In addition, inhibiting YAP by YAP shRNA significantly decreased migration and invasion abilities of H2030-BrM3 cells (P < .05). We are first to show that mice inoculated with YAP shRNA-transfected H2030-BrM3 cells had significantly decreased metastatic tumour burden and survived longer than control mice (P < .05). Collectively, our results suggest that YAP plays an important role in promoting lung adenocarcinoma brain metastasis and that direct inhibition of YAP by shRNA suppresses H2030-BrM3 cell brain metastasis in a murine model
Gene trapping identifies transiently induced survival genes during programmed cell death
BACKGROUND: The existence of a constitutively expressed machinery for death in individual cells has led to the notion that survival factors repress this machinery and, if such factors are unavailable, cells die by default. In many cells, however, mRNA and protein synthesis inhibitors induce apoptosis, suggesting that in some cases transcriptional activity might actually impede cell death. To identify transcriptional mechanisms that interfere with cell death and survival, we combined gene trap mutagenesis with site-specific recombination (Cre/loxP system) to isolate genes from cells undergoing apoptosis by growth factor deprivation. RESULTS: From an integration library consisting of approximately 2 × 10(6) unique proviral integrations obtained by infecting the interleukin-3 (IL-3)-dependent hematopoietic cell line - FLOXIL3 - with U3Cre gene trap virus, we have isolated 125 individual clones that converted to factor independence upon IL-3 withdrawal. Of 102 cellular sequences adjacent to U3Cre integration sites, 17% belonged to known genes, 11% matched single expressed sequence tags (ESTs) or full cDNAs with unknown function and 72% had no match within the public databases. Most of the known genes recovered in this analysis encoded proteins with survival functions. CONCLUSIONS: We have shown that hematopoietic cells undergoing apoptosis after withdrawal of IL-3 activate survival genes that impede cell death. This results in reduced apoptosis and improved survival of cells treated with a transient apoptotic stimulus. Thus, apoptosis in hematopoietic cells is the end result of a conflict between death and survival signals, rather than a simple death by default
PPAR gamma/mTOR signalling: striking the right balance in cartilage homeostasis
This is an Open Access article distributed in accordance with the terms of the Creative
Commons Attribution (CC BY 4.0) license, which
permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See: http://creativecommons.org/licenses/by/4.0http://dx.doi.org/10.1136/annrheumdis-2014-20574
Synthesis of photoacid crosslinkable hydrogels for the fabrication of soft, biomimetic microlens arrays
Soft, biomimetic microlens arrays were fabricated by interference lithography from the copolymers of poly(2-hydroxyethyl methacrylate), whose hydroxyl groups were crosslinked by photoacids and external crosslinkers
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