| 1. |
- Lock, John G, et al.
(author)
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Reticular adhesions are a distinct class of cell-matrix adhesions that mediate attachment during mitosis
- 2018
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In: Nature Cell Biology. - Stockholm : Karolinska Institutet, Dept of Biosciences and Nutrition. - 1465-7392 .- 1476-4679.
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Journal article (peer-reviewed)abstract
- Adhesion to the extracellular matrix persists during mitosis in most cell types. However, while classical adhesion complexes, such as focal adhesions, do and must disassemble to enable mitotic rounding, the mechanisms of residual mitotic cell-extracellular matrix adhesion remain undefined. Here, we identify 'reticular adhesions', a class of adhesion complex that is mediated by integrin alpha v beta 5, formed during interphase, and preserved at cell-extracellular matrix attachment sites throughout cell division. Consistent with this role, integrin beta 5 depletion perturbs mitosis and disrupts spatial memory transmission between cell generations. Reticular adhesions are morphologically and dynamically distinct from classical focal adhesions. Mass spectrometry defines their unique composition, enriched in phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P-2)-binding proteins but lacking virtually all consensus adhesome components. Indeed, reticular adhesions are promoted by PtdIns(4,5)P-2, and form independently of talin and F-actin. The distinct characteristics of reticular adhesions provide a solution to the problem of maintaining cell-extracellular matrix attachment during mitotic rounding and division.
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| 4. |
- Dara, Pantea, 1994
(author)
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Measurements and simulations of thermoplasmonically induced Marangoni flows
- 2023
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Licentiate thesis (other academic/artistic)abstract
- Particle transport in microfluidic environments is often dominated by slow diffusion near interfaces. However, by inducing localized fluid flow, it is possible to actively transport suspended nano-objects in confined spaces. One promising method for achieving precise and dynamic control over fluid flow on the microscale is to use photothermal effects based on the illumination of plasmonic metal nanoparticles, which exhibit very high optical absorption for light wavelengths near resonance. The particles can thus be used as nanoscale heat sources that locally increase the temperature of the surrounding fluid, resulting in processes such as thermophoresis, convection, and vapor bubble generation. This thesis focuses on the latter effect and the associated bubble nucleation and thermal Marangoni convection processes. Marangoni flows result from the surface tension gradient that establishes on a thermoplasmonically induced vapor bubble at equilibrium. However, in addition to this, strong flow transients appear as a bubble is created and expands. Both phenomena lead to similar flow profiles. Here it is shown that the direction of these flows can be controlled by manipulating the temperature gradient on the surface of the bubble. Specifically, it is demonstrated that the direction of the strong transient flows around a nanobubble can be reverted by breaking the photothermal symmetry using two unequal nearby arrays of plasmonic nanoparticles. Furthermore, we investigate the possibility of remotely controlling the flow direction by turning the incident light polarization. The results are based on vectorial flow measurements using optical force microscopy supported by extensive flow profile simulations.
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| 5. |
- Darabi, H, et al.
(author)
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Fine scale mapping of the 17q22 breast cancer locus using dense SNPs, genotyped within the Collaborative Oncological Gene-Environment Study (COGs)
- 2016
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In: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6, s. 32512-
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Journal article (peer-reviewed)abstract
- Genome-wide association studies have found SNPs at 17q22 to be associated with breast cancer risk. To identify potential causal variants related to breast cancer risk, we performed a high resolution fine-mapping analysis that involved genotyping 517 SNPs using a custom Illumina iSelect array (iCOGS) followed by imputation of genotypes for 3,134 SNPs in more than 89,000 participants of European ancestry from the Breast Cancer Association Consortium (BCAC). We identified 28 highly correlated common variants, in a 53 Kb region spanning two introns of the STXBP4 gene, that are strong candidates for driving breast cancer risk (lead SNP rs2787486 (OR = 0.92; CI 0.90–0.94; P = 8.96 × 10−15)) and are correlated with two previously reported risk-associated variants at this locus, SNPs rs6504950 (OR = 0.94, P = 2.04 × 10−09, r2 = 0.73 with lead SNP) and rs1156287 (OR = 0.93, P = 3.41 × 10−11, r2 = 0.83 with lead SNP). Analyses indicate only one causal SNP in the region and several enhancer elements targeting STXBP4 are located within the 53 kb association signal. Expression studies in breast tumor tissues found SNP rs2787486 to be associated with increased STXBP4 expression, suggesting this may be a target gene of this locus.
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| 6. |
- Fu, Xi, et al.
(author)
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Associations between species-level indoor microbiome, environmental characteristics, and asthma in junior high schools of Terengganu, Malaysia
- 2022
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In: Air quality, atmosphere and health. - : Springer Nature. - 1873-9318 .- 1873-9326. ; 15:6, s. 1043-1055
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Journal article (peer-reviewed)abstract
- Indoor microbiome exposure is important for asthma development, but current studies characterize the microbiome at the genus or above levels due to technical limitations. We aim to profile bacterial and fungal composition and concentration at the species level and assess its potential health effects. Four hundred sixty-three students from 8 junior high schools in Terengganu, Malaysia, were surveyed for asthma symptoms. Full-length PacBio amplicon sequencing and qPCR were conducted to quantify the absolute microbial concentration in the vacuum dust of the selected classroom. In total, 1358 bacterial and 358 fungal species were characterized, and drastic compositional variation was observed among classrooms. Three-level linear regression analyses revealed that taxa richness in Cyanobacteria were negatively associated with asthma (FDR < 0.001). The absolute concentration of Nocardioides exalbidus was protectively associated with asthma, and four bacteria species were positively associated with asthma (FDR < 0.1). Interestingly, all five species were recently isolated and characterized in Asian countries and never reported to associate with asthma. Indoor NO2 and formaldehyde concentration were associated with the overall bacterial community variation and fungal richness, respectively (p < 0.05). No environmental characteristics were directly associated with asthma, but indoor relative humidity, CO2 concentration, and weight of vacuum dust were associated with the asthma-related species (p < 0.05), suggesting a potential indirect health effect on students. This is the first study to characterize indoor microbiome and asthma-associated microorganisms at the species level, representing a region-specific microbiome exposure pattern in a tropical Asian country.
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| 7. |
- Fu, Yifeng, 1984, et al.
(author)
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Application of through silicon via technology for in situ temperature monitoring on thermal interfaces
- 2010
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In: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 1361-6439 .- 0960-1317. ; 20:2, s. id 025027 (5 pp)-
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Journal article (peer-reviewed)abstract
- In this paper, a series of micro-machining processes have been developed to fabricate a test platform with the ability of in situ temperature monitoring on thermal interface behaviour. Through silicon vias (TSVs) with an aspect ratio up to 13 using Cu as a conductor have been applied to connect an array of platinum-based temperature sensors directly deposited on the thermal interfaces to be measured. The sensors are subsequently calibrated by an industry standard resistance temperature detector. Results show that the temperature sensors function normally in a temperature range up to 250 degrees C. This demonstrates the successful deposition of temperature-sensing materials and their good connection to the TSVs. The realization of direct precise temperature measurement on the thermal interface of this test platform enables thermal characterization with a high accuracy.
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| 8. |
- Fu, Y, et al.
(author)
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Capacitance analysis for a metal-insulator-semiconductor structure with an ultra-thin oxide layer
- 2003
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In: Applied Physics A. - : Springer Science Business Media. - 0947-8396 .- 1432-0630. ; 76:1, s. 27-31
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Journal article (peer-reviewed)abstract
- We have studied theoretically the capacitance characteristics of a metal-insulator-semiconductor structure with an ultra-thin oxide layer by self-consistently solving Schrodinger and Poisson equations. It is demonstrated that a diffused interface between Si and SiO2 results in a better agreement between the theoretical prediction of conduction current and experimental I-V data. The calculated steady-state capacitance, obtained both analytically and numerically, increases following the increase of the gate bias when the gate bias is small; it reaches a saturation value at intermediate gate bias. The capacitance decreases with increasing gate bias when the gate bias is rather large due to the depletion of the gate material. Simple analytical expressions for the gate capacitance are derived, based on quantum-mechanical considerations, for future device design. The steady-state capacitance of a metal-insulator-semiconductor structure with an oxide layer of 1.5-2.0 nm by state-of-the-art technology is 20 mF/m(2), while it is 40 mF/m(2) when the practical limit of SiO2 layer thickness, i.e. 10-12 Angstrom, is reached.
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| 9. |
- Fu, Yuanqing, et al.
(author)
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Circulating vitamin C concentration and risk of cancers : a Mendelian randomization study
- 2021
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In: BMC Medicine. - : BioMed Central (BMC). - 1741-7015. ; 19
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Journal article (peer-reviewed)abstract
- Background: Circulating vitamin C concentrations have been associated with several cancers in observational studies, but little is known about the causal direction of the associations. This study aims to explore the potential causal relationship between circulating vitamin C and risk of five most common cancers in Europe.Methods: We used summary-level data for genetic variants associated with plasma vitamin C in a large vitamin C genome-wide association study (GWAS) meta-analysis on 52,018 Europeans, and the corresponding associations with lung, breast, prostate, colon, and rectal cancer from GWAS consortia including up to 870,984 participants of European ancestry. We performed two-sample, bi-directional Mendelian randomization (MR) analyses using inverse-variance-weighted method as the primary approach, while using 6 additional methods (e.g., MR-Egger, weighted median-based, and mode-based methods) as sensitivity analysis to detect and adjust for pleiotropy. We also conducted a meta-analysis of prospective cohort studies and randomized controlled trials to examine the association of vitamin C intakes with cancer outcomes.Results: The MR analysis showed no evidence of a causal association of circulating vitamin C concentration with any examined cancer. Although the odds ratio (OR) per one standard deviation increase in genetically predicted circulating vitamin C concentration was 1.34 (95% confidence interval 1.14 to 1.57) for breast cancer in the UK Biobank, this association could not be replicated in the Breast Cancer Association Consortium with an OR of 1.05 (0.94 to 1.17). Smoking initiation, as a positive control for our reverse MR analysis, showed a negative association with circulating vitamin C concentration. However, there was no strong evidence of a causal association of any examined cancer with circulating vitamin C. Sensitivity analysis using 6 different analytical approaches yielded similar results. Moreover, our MR results were consistent with the null findings from the meta-analysis exploring prospective associations of dietary or supplemental vitamin C intakes with cancer risk, except that higher dietary vitamin C intake, but not vitamin C supplement, was associated with a lower risk of lung cancer (risk ratio: 0.84, 95% confidence interval 0.71 to 0.99).Conclusions: These findings provide no evidence to support that physiological-level circulating vitamin C has a large effect on risk of the five most common cancers in European populations, but we cannot rule out very small effect sizes.
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| 10. |
- Fu, Yu, et al.
(author)
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Conceptual Design of an Extended Reality Exercise Game for the Elderly
- 2022
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In: Applied Sciences. - : MDPI. - 2076-3417. ; 12:13
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Journal article (peer-reviewed)abstract
- Facing the increasingly serious ageing problem, IT technology is being applied more and more to alleviate the increasing health demands of the elderly. Virtual reality (VR) games, in particular, have been shown to benefit the physical and mental health of the elderly. However, almost all consumer-level VR games address the general user, not considering the characteristics of the elderly, such as their particular needs regarding cognitive aspects and safety. In addition, the existing VR rowing games’ research typically focuses on athlete training or is based on a rowing machine. Extending on previous research, this paper proposes a conceptual design of a VR rowing game, VRrowing to provide a home exercise game for the elderly which benefits both physical and mental health. This research first analysed the relevant literature and existing VR exercise games for the elderly to find characteristics and their particular needs. Then, following design principles (in exercise games, human–computer interaction, and user interfaces (UIs)) for the elderly, this study proposed a conceptual design of VRrowing through the MDA framework (standing for mechanics, dynamics, and aesthetics). The results cover the system architecture, activities and tasks, patterns and roles, mechanics and structures, and UI examples. Based on comprehensive consideration of the results from relevant research and fostering strengths and circumventing weaknesses, VRrowing was designed as a sports game, aimed at the elderly according to their characteristics and needs, which fills the void of home VR rowing games for seniors’ exercise. This research has reference value for scientific research or development personnel in VR game applications and evaluations, especially for such games targeting the elderly. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
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