| 31. |
- Romani, E. C., et al.
(författare)
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Gold nanoparticles on the surface of soda-lime glass : morphological, linear and nonlinear optical characterization
- 2012
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Ingår i: Optics Express. - 1094-4087. ; 20:5, s. 5429-5439
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Tidskriftsartikel (refereegranskat)abstract
- Materials presenting high optical nonlinearity, such as materials containing metal nanoparticles (NPs), can be used in various applications in photonics. This motivated the research presented in this paper, where morphological, linear and nonlinear optical characteristics of gold NPs on the surface of bulk soda-lime glass substrates were investigated as a function of nanoparticle height. The NPs were obtained by annealing gold (Au) thin films previously deposited on the substrates. Pixel intensity histogram fitting on Atomic Force Microscopy (AFM) images was performed to obtain the thickness of the deposited film. Image analysis was employed to obtain the statistical distribution of the average height of the NPs. In addition, absorbance spectra of the samples before and after annealing were measured. Finally, the nonlinear refractive index (n(2))and the nonlinear absorption index (alpha 2) at 800 nm were obtained before and after annealing by using the thermally managed eclipse Z-scan (TM-EZ) technique with a Ti: Sapphire laser (150 fs pulses). Results show that both n2 and alpha 2 at this wavelength change signs after the annealing and that the samples presented a high nonlinear refractive index.
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| 32. |
- Severson, Tesa M, et al.
(författare)
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BRCA1-like signature in triple negative breast cancer: Molecular and clinical characterization reveals subgroups with therapeutic potential.
- 2015
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Ingår i: Molecular Oncology. - : Wiley. - 1574-7891. ; 9:8, s. 1528-1538
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Tidskriftsartikel (refereegranskat)abstract
- Triple negative (TN) breast cancers make up some 15% of all breast cancers. Approximately 10-15% are mutant for the tumor suppressor, BRCA1. BRCA1 is required for homologous recombination-mediated DNA repair and deficiency results in genomic instability. BRCA1-mutated tumors have a specific pattern of genomic copy number aberrations that can be used to classify tumors as BRCA1-like or non-BRCA1-like. BRCA1 mutation, promoter methylation, BRCA1-like status and genome-wide expression data was determined for 112 TN breast cancer samples with long-term follow-up. Mutation status for 21 known DNA repair genes and PIK3CA was assessed. Gene expression and mutation frequency in BRCA1-like and non-BRCA1-like tumors were compared. Multivariate survival analysis was performed using the Cox proportional hazards model. BRCA1 germline mutation was identified in 10% of patients and 15% of tumors were BRCA1 promoter methylated. Fifty-five percent of tumors classified as BRCA1-like. The functions of genes significantly up-regulated in BRCA1-like tumors included cell cycle and DNA recombination and repair. TP53 was found to be frequently mutated in BRCA1-like (P < 0.05), while PIK3CA was frequently mutated in non-BRCA1-like tumors (P < 0.05). A significant association with worse prognosis was evident for patients with BRCA1-like tumors (adjusted HR = 3.32, 95% CI = 1.30-8.48, P = 0.01). TN tumors can be further divided into two major subgroups, BRCA1-like and non-BRCA1-like with different mutation and expression patterns and prognoses. Based on these molecular patterns, subgroups may be more sensitive to specific targeted agents such as PI3K or PARP inhibitors.
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| 33. |
- Smid, Marcel, et al.
(författare)
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The circular RNome of primary breast cancer
- 2019
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 29:3, s. 356-366
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Tidskriftsartikel (refereegranskat)abstract
- Circular RNAs (circRNAs) are a class of RNAs that is under increasing scrutiny, although their functional roles are debated. We analyzed RNA-seq data of 348 primary breast cancers and developed a method to identify circRNAs that does not rely on unmapped reads or known splice junctions. We identified 95,843 circRNAs, of which 20,441 were found recurrently. Of the circRNAs that match exon boundaries of the same gene, 668 showed a poor or even negative (R <0.2) correlation with the expression level of the linear gene. In silico analysis showed only a minority (8.5%) of circRNAs could be explained by known splicing events. Both these observations suggest that specific regulatory processes for circRNAs exist. We confirmed the presence of circRNAs of CNOT2, CREBBP, and RERE in an independent pool of primary breast cancers. We identified circRNA profiles associated with subgroups of breast cancers and with biological and clinical features, such as amount of tumor lymphocytic infiltrate and proliferation index. siRNA-mediated knockdown of circCNOT2 was shown to significantly reduce viability of the breast cancer cell lines MCF-7 and BT-474, further underlining the biological relevance of circRNAs. Furthermore, we found that circular, and not linear, CNOT2 levels are predictive for progression-free survival time to aromatase inhibitor (AI) therapy in advanced breast cancer patients, and found that circCNOT2 is detectable in cell-free RNA from plasma. We showed that circRNAs are abundantly present, show characteristics of being specifically regulated, are associated with clinical and biological properties, and thus are relevant in breast cancer.
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| 34. |
- Xie, Shao-Hua, et al.
(författare)
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Association between levels of sex hormones and risk of esophageal adenocarcinoma and Barrett’s esophagus
- 2019
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Ingår i: Clinical Gastroenterology and Hepatology. - Stockholm : Karolinska Institutet, Dept of Molecular Medicine and Surgery. - 1542-3565. ; 18:12, s. 2701-
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Esophageal adenocarcinoma (EAC) occurs most frequently in men. We performed a Mendelian randomization analysis to investigate whether genetic factors that regulate levels of sex hormones associated with risk of EAC or Barrett’s esophagus (BE). Methods: We conducted a Mendelian randomization analysis using data from patients with EAC (n=2488) or BE (n=3247) and control participants (n=2127), included in international consortia of genome-wide association studies in Australia, Europe, and North America. Genetic risk scores or single nucleotide variants were used as instrumental variables for 9 specific sex hormones. Logistic regression provided odds ratios (ORs) with 95% CIs. Results: Higher genetically predicted levels of follicle stimulating hormones were associated with increased risks of EAC and/or BE in men (OR, 1.14 per allele increase; 95% CI, 1.01- 1.27) and in women (OR, 1.28; 95% CI, 1.03-1.59). Higher predicted levels of luteinizing hormone were associated with a decreased risk of EAC in men (OR, 0.92 per standard deviation increase; 95% CI, 0.87-0.99) and in women (OR, 0.93; 95% CI, 0.79-1.09), and decreased risks of BE (OR, 0.88; 95% CI, 0.77-0.99) and EAC and/or BE (OR, 0.89; 95% CI, 0.79-1.00) in women. We found no clear associations for other hormones studied, including sex hormone-binding globulin, dehydroepiandrosterone sulphate, testosterone, dihydrotestosterone, estradiol, progesterone, or free androgen index. Conclusions: In a Mendelian randomization analysis of data from patients with EAC or BE, we found an association between genetically predicted levels of follicle stimulating and luteinizing hormones and risk of BE and EAC.
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| 35. |
- Aalto, Susanne, 1964, et al.
(författare)
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High-resolution HNC 3-2 SMA observations of Arp 220
- 2009
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 493:2, s. 481-487
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Tidskriftsartikel (refereegranskat)abstract
- Aims. We study the properties of the nuclear molecular gas of the ultra luminous merger Arp 220 and effects of the nuclear source on gas excitation and chemistry. Specifically, our aim is to investigate the spatial location of the luminous HNC 3-2 line emission and address the underlying cause of its unusual brightness.Methods. We present high resolution observations of HNC J=3-2 with the submillimeter array (SMA).Results. We find luminous HNC 3-2 line emission in the western part of Arp 220, centred on the western nucleus, while the eastern side of the merger shows relatively faint emission. A bright (36 K at $0\hbox{$.\!\!^{\prime\prime}$ }4$ resolution), narrow (60 ${\rm km~s}^$) emission feature emerges from the western nucleus, superposed on a broader spectral component. A possible explanation is weak maser emission through line-of-sight amplification of the background continuum source. There is also a more extended HNC 3-2 emission feature north and south of the nucleus. This feature resembles the bipolar OH maser morphology around the western nucleus. Substantial HNC abundances are required to explain the bright line emission from this warm environment - even when the high gas column density towards the western nucleus is taken into account. We discuss this briefly in the context of an X-ray affected chemistry and radiative excitation.Conclusions. The luminous and possibly amplified HNC emission of the western nucleus of the Arp 220 merger reflects the unusual, and perhaps transient environment of the starburst/AGN activity there. The faint HNC line emission towards Arp 220-east reveals a real difference in physical conditions between the two merger nuclei.
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| 36. |
- Aleklett, Kristin, et al.
(författare)
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Build your own soil : exploring microfluidics to create microbial habitat structures
- 2018
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Ingår i: ISME Journal. - : Springer Science and Business Media LLC. - 1751-7362 .- 1751-7370. ; 12:2, s. 312-319
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Forskningsöversikt (refereegranskat)abstract
- Soil is likely the most complex ecosystem on earth. Despite the global importance and extraordinary diversity of soils, they have been notoriously challenging to study. We show how pioneering microfluidic techniques provide new ways of studying soil microbial ecology by allowing simulation and manipulation of chemical conditions and physical structures at the microscale in soil model habitats.The ISME Journal advance online publication, 14 November 2017; doi:10.1038/ismej.2017.184.
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| 37. |
- Caldas, Kenny A. Q., et al.
(författare)
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Autonomous Driving of Trucks in Off-Road Environment
- 2023
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Ingår i: JOURNAL OF CONTROL AUTOMATION AND ELECTRICAL SYSTEMS. - : Springer. - 2195-3880. ; 34:6, s. 1179-1193
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Tidskriftsartikel (refereegranskat)abstract
- Off-road driving operations can be a challenging environment for human conductors as they are subject to accidents, repetitive and tedious tasks, strong vibrations, which may affect their health in the long term. Therefore, they can benefit from a successful implementation of autonomous vehicle technology, improving safety, reducing labor costs and fuel consumption, and increasing operational efficiency. The main contribution of this paper is the experimental validation of a path tracking control strategy, composed of longitudinal and lateral controllers, on an off-road scenario with a fully loaded heavy-duty truck. The longitudinal control strategy relies on a nonlinear model predictive controller, which considers the path geometry and simplified vehicle dynamics to compute a smooth and comfortable input velocity, without violating the imposed constraints. The lateral controller is based on a robust linear quadratic regulator, which considers a vehicle model subject to parametric uncertainties to minimize its lateral displacement and heading error, as well as ensure stability. Experiments were carried out using a fully loaded vehicle on unpaved roads in an open-pit mine. The truck followed the reference path within the imposed constraints, showing robustness and driving smoothness.
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| 38. |
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| 39. |
- Capella, Gabriel, et al.
(författare)
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DNA repair polymorphisms and the risk of stomach adenocarcinoma and severe chronic gastritis in the EPIC-EURGAST study
- 2008
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 1464-3685 .- 0300-5771. ; 37:6, s. 1316-1325
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Tidskriftsartikel (refereegranskat)abstract
- Background The contribution of genetic variation in DNA repair genes to gastric cancer (GC) risk remains essentially unknown. The aim of this study was to explore the relative contribution of DNA repair gene polymorphisms to GC risk and severe chronic atrophic gastritis (SCAG). Method A nested case control study within the EPIC cohort was performed including 246 gastric adenocarcinomas and 1175 matched controls. Controls with SCAG (n 91), as defined by low pepsinogen A (PGA) levels, and controls with no SCAG (n 1061) were also compared. Twelve polymorphisms at DNA repair genes (MSH2, MLH1, XRCC1, OGG1 and ERCC2) and TP53 gene were analysed. Antibodies against Helicobacter pylori were measured. Results No association was observed for any of these polymorphisms with stomach cancer risk. However, ERCC2 K751Q polymorphism was associated with an increased risk for non-cardial neoplasm [odds ratio (OR) 1.78; 95 confidence interval (CI) 1.023.12], being ERCC2 K751Q and D312N polymorphisms associated with the diffuse type. ERCC2 D312N (OR 2.0; 95 CI 1.093.65) and K751Q alleles (OR 1.82; 95 CI 1.013.30) and XRCC1 R399Q (OR 1.69; 95 CI 1.022.79) allele were associated with an increased risk for SCAG. Conclusion Our study supports a role of ERCC2 in non-cardial GC but not in cardial cancer. A concordant result was observed for subjects with low PGA levels. XRCC1 allele was associated also with SCAG. This is the first prospective study suggesting that individual variation in DNA repair may be relevant for gastric carcinogenesis, a finding that will require further confirmation validation in larger independent studies.
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| 40. |
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