| 1. |
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| 2. |
- Forrest, ARR, et al.
(författare)
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A promoter-level mammalian expression atlas
- 2014
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 507:7493, s. 462-
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Pfaller, M.A., et al.
(författare)
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Twelve years of fluconazole in clinical practice : Global-trends in species distribution and fluconazole susceptibility of bloodstream isolates of Candida
- 2004
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Ingår i: Clinical Microbiology and Infection. - : Elsevier BV. - 1198-743X .- 1469-0691. ; 10:SUPPL. 1, s. 11-23
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Tidskriftsartikel (refereegranskat)abstract
- We determined the species distribution and in-vitro susceptibility of 6082 bloodstream infection (BSI) isolates of Candida spp. collected from 250 medical centres in 32 nations over a 10-year period from 1992 through 2001. The species included 3401 C. albicans, 984 C. glabrata, 796 C. parapsilosis, 585 C. tropicalis, 153 C. krusei, 67 C. lusitaniae, 48 C. guilliermondii, 10 C. famata, 10 C. kefyr, six C. pelliculosa, five C. rugosa, four C. lipolytica, three C. dubliniensis, three C. inconspicua, two C. sake and one isolate each of C. lambica, C. norvegensis and C. zeylanoides. Minimum inhibitory concentration determinations were made using the National Committee for Clinical Laboratory Standards reference broth microdilution method. Variation in the rank order and frequency of the different species of Candida was observed over time and by geographic area. The proportion of BSI due to C. albicans and C. glabrata increased and C. parapsilosis decreased over time in Canada, the USA and Europe. C. glabrata was an infrequent cause of BSI in Latin America and the Asia-Pacific region. Very little variation in fluconazole susceptibility was observed among isolates of C. albicans, C. tropicalis and C. parapsilosis. These species accounted for 78% of all BSI and remained highly susceptible (91-100% susceptible) to fluconazole from 1992 to 2001 irrespective of geographic origin. The prevalence of fluconazole resistance among C. glabrata isolates was variable both over time and among the various countries and regions. Resistance to fluconazole among C. glabrata isolates was greatest in the USA and varied by US census region (range 0-23%). These observations are generally encouraging relative to the sustained usefulness of fluconazole as a systemically active antifungal agent for the treatment of candida BSI. © 2004 Copyright by the European Society of Clinical Microbiology and Infectious Diseases.
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| 4. |
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| 5. |
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| 6. |
- Blunden, Jessica, et al.
(författare)
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State of the climate in 2013
- 2014
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Ingår i: Bulletin of the American Meteorological Society. - 0003-0007. ; 95
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Tidskriftsartikel (refereegranskat)abstract
- © 2014, American Meteorological Society. All rights reserved. In 2013, the vast majority of the monitored climate variables reported here maintained trends established in recent decades. ENSO was in a neutral state during the entire year, remaining mostly on the cool side of neutral with modest impacts on regional weather patterns around the world. This follows several years dominated by the effects of either La Niña or El Niño events. According to several independent analyses, 2013 was again among the 10 warmest years on record at the global scale, both at the Earth’s surface and through the troposphere. Some regions in the Southern Hemisphere had record or near-record high temperatures for the year. Australia observed its hottest year on record, while Argentina and New Zealand reported their second and third hottest years, respectively. In Antarctica, Amundsen-Scott South Pole Station reported its highest annual temperature since records began in 1957. At the opposite pole, the Arctic observed its seventh warmest year since records began in the early 20th century. At 20-m depth, record high temperatures were measured at some permafrost stations on the North Slope of Alaska and in the Brooks Range. In the Northern Hemisphere extratropics, anomalous meridional atmospheric circulation occurred throughout much of the year, leading to marked regional extremes of both temperature and precipitation. Cold temperature anomalies during winter across Eurasia were followed by warm spring temperature anomalies, which were linked to a new record low Eurasian snow cover extent in May. Minimum sea ice extent in the Arctic was the sixth lowest since satellite observations began in 1979. Including 2013, all seven lowest extents on record have occurred in the past seven years. Antarctica, on the other hand, had above-average sea ice extent throughout 2013, with 116 days of new daily high extent records, including a new daily maximum sea ice area of 19.57 million km2 reached on 1 October. ENSO-neutral conditions in the eastern central Pacific Ocean and a negative Pacific decadal oscillation pattern in the North Pacific had the largest impacts on the global sea surface temperature in 2013. The North Pacific reached a historic high temperature in 2013 and on balance the globally-averaged sea surface temperature was among the 10 highest on record. Overall, the salt content in nearsurface ocean waters increased while in intermediate waters it decreased. Global mean sea level continued to rise during 2013, on pace with a trend of 3.2 mm yr-1 over the past two decades. A portion of this trend (0.5 mm yr-1) has been attributed to natural variability associated with the Pacific decadal oscillation as well as to ongoing contributions from the melting of glaciers and ice sheets and ocean warming. Global tropical cyclone frequency during 2013 was slightly above average with a total of 94 storms, although the North Atlantic Basin had its quietest hurricane season since 1994. In the Western North Pacific Basin, Super Typhoon Haiyan, the deadliest tropical cyclone of 2013, had 1-minute sustained winds estimated to be 170 kt (87.5 m s-1) on 7 November, the highest wind speed ever assigned to a tropical cyclone. High storm surge was also associated with Haiyan as it made landfall over the central Philippines, an area where sea level is currently at historic highs, increasing by 200 mm since 1970. In the atmosphere, carbon dioxide, methane, and nitrous oxide all continued to increase in 2013. As in previous years, each of these major greenhouse gases once again reached historic high concentrations. In the Arctic, carbon dioxide and methane increased at the same rate as the global increase. These increases are likely due to export from lower latitudes rather than a consequence of increases in Arctic sources, such as thawing permafrost. At Mauna Loa, Hawaii, for the first time since measurements began in 1958, the daily average mixing ratio of carbon dioxide exceeded 400 ppm on 9 May. The state of these variables, along with dozens of others, and the 2013 climate conditions of regions around the world are discussed in further detail in this 24th edition of the State of the Climate series.
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| 7. |
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| 8. |
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| 9. |
- Kang, M. S., et al.
(författare)
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Preclinical in vivo longitudinal assessment of KG207-M as a disease-modifying Alzheimer's disease therapeutic
- 2022
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 0271-678X .- 1559-7016. ; 42:5, s. 788-801
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Tidskriftsartikel (refereegranskat)abstract
- In vivo biomarker abnormalities provide measures to monitor therapeutic interventions targeting amyloid-beta pathology as well as its effects on downstream processes associated with Alzheimer's disease pathophysiology. Here, we applied an in vivo longitudinal study design combined with imaging and cerebrospinal fluid biomarkers, mirroring those used in human clinical trials to assess the efficacy of a novel brain-penetrating anti-amyloid fusion protein treatment in the McGill-R-Thy1-APP transgenic rat model. The bi-functional fusion protein consisted of a blood-brain barrier crossing single domain antibody (FC5) fused to an amyloid-beta oligomer-binding peptide (ABP) via Fc fragment of mouse IgG (FC5-mFc2a-ABP). A five-week treatment with FC5-mFc2a-ABP (loading dose of 30 mg/Kg/iv followed by 15 mg/Kg/week/iv for four weeks) substantially reduced brain amyloid-beta levels as measured by positron emission tomography and increased the cerebrospinal fluid amyloid-beta(42/40) ratio. In addition, the 5-week treatment rectified the cerebrospinal fluid neurofilament light chain concentrations, resting-state functional connectivity, and hippocampal atrophy measured using magnetic resonance imaging. Finally, FC5-mFc2a-ABP (referred to as KG207-M) treatment did not induce amyloid-related imaging abnormalities such as microhemorrhage. Together, this study demonstrates the translational values of the designed preclinical studies for the assessment of novel therapies based on the clinical biomarkers providing tangible metrics for designing early-stage clinical trials.
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| 10. |
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| 11. |
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| 12. |
- Oleskevych, Anna I, et al.
(författare)
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Enhanced diffusion caused by surface reactions in thin films of Sn–Cu–Mn
- 2014
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 550, s. 723-731
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes an investigation of low-temperature diffusion in thin films of Sn/Cu, Cu/Mn and Sn/Cu/Mn. The combination of Rutherford backscattering spectroscopy, grazing incidence X-ray diffraction and Auger electron spectroscopy has been used to provide information about the concentration distribution of components and the depth of the various phases and interfaces. The results show that processes that occur on a free surface of thin films can stimulate diffusion of elements in the bulk. It is shown that the element with higher affinity to oxygen tends to move to the surface in order to oxidize and that this oxidation process provides a driving force for further diffusion. Introduction of a third layer to a bilayer system may lead to changes in the surface topography caused by the reactive diffusion between upper layers and it causes the development of fast, ‘short-circuit’ diffusion paths and so increases the diffusion of elements from the bottom to the top. Reactive diffusion between Sn and Cu in the top layers leads to significant changes at the surface with features of the size of 10 to 20 nmappearing. These changes provide shortcuts for the diffusion of Mn atoms from the bottom layer to the free surface. As a consequence of these processes, the sequence of layers of different elements in thin-film structures alters diffusionand results in different sample properties.
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| 13. |
- Qazi, S. Junaid S., et al.
(författare)
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Alignment of Dispersions of Plate-Like Colloidal Particles of Ni(OH)(2) Induced by Elongational Flow
- 2011
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 115:13, s. 3271-3280
-
Tidskriftsartikel (refereegranskat)abstract
- Small-angle neutron scattering, SANS, has been used to study the alignment of a sterically stabilized colloidal dispersion of nickel hydroxide induced by elongational flow. Two different concentrations, 20 and 23 wt %, of well-defined hexagonal platelets have been studied. Significant anisotropy in the scattering patterns has been observed for the higher concentration dispersion that increases with increasing elongational strain rate. The effect of pipe flow (shear flow) on the orientational ordering at the inlets is also described. Near the outlets there is also a shear stress and this tends to increase the alignment. The orientational distribution of the particles under flow is described in terms of an order parameter calculated with respect to an individual director for each scattering pattern. The experimental measurements are supported by comparison with computer simulations which help to explain the effects of local velocity on the alignment induced by elongational flow. A slight decrease in the observed alignment was found after continuous flow for approximately 30 min and possible reasons are discussed.
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| 14. |
- Qazi, S. Junaid S., et al.
(författare)
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Alignment of Plate-Like Particles in a Colloidal Dispersion under Flow in a Uniform Pipe Studied by High-Energy X-ray Diffraction
- 2010
-
Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 26:24, s. 18701-18709
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Tidskriftsartikel (refereegranskat)abstract
- High-energy angle-dispersive X-ray diffraction has been used to study the alignment of colloidal suspension of kaolinite particles in water as they flow along a pipe. X-rays with energies above 25 keV have a major advantage, as they can penetrate through thick samples and walls of containers and permit investigation of samples under realistic flow conditions. As an example of the method, flow through a circular cross-section pipe with an internal diameter of 5 mm has been studied: this is typical of industrial applications. The angular distribution of intensities of peaks in the diffraction pattern as a function of the location of the pipe in the X-ray beam provides information about the alignment of particles under flow. Order parameters have been calculated to describe the alignment and direction of orientation. It is observed that the particles align in the direction of flow with their flat faces parallel to the flow. The experimental results are compared with the calculations of the local strain rate that help to explain the onset of alignment of the particles.
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| 15. |
- Qazi, S. Junaid S., et al.
(författare)
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Dispersions of plate-like colloidal particles : Cubatic order?
- 2010
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 348:1, s. 80-84
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Tidskriftsartikel (refereegranskat)abstract
- Experimental evidence for the existence of 'cubatic' order in a colloidal dispersion of plate-like particles is presented. In a 'cubatic' phase, disk-like particles self-assemble with domains of a few parallel plates and the director tends to be orthogonal in adjacent domains. This phase has been predicted previously by computer simulation. The domains are approximately equiaxial and are predicted to exist only within a limited range of aspect ratios and volume fractions. This locally ordered structure cannot be identified readily using scattering techniques, since the patterns are expected to be similar to those of isotropic liquid phases. For this reason, we have used a real-space technique of cryo-transmission electron microscopy that directly probes such locally ordered structures to study dispersions of nickel hydroxide particles. Polydispersity of particle size is expected to require some local tilting in order to include larger particles in a dense structure and this is discussed with respect to the concentration range for which cubatic order is observed. This new structure offers the possibility of novel materials that could be prepared by self-assembly and have applications in a wide range of fields.
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| 16. |
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| 17. |
- Qazi, S. Junaid S.
(författare)
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Flow of Colloidal Mesophases
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation presents new work and results in the flow of complex fluids and experimental methodologies for their investigation. Plate-like colloidal particles of kaolinite and nickel hydroxide are studied. A study of lamellar fragments and their mixture with the nickel hydroxide particles is also presented. The lamellar fragments are self-assembled structures of surfactant molecules that approximate disks. Particles are seen to align with their large faces parallel to the flow direction under shear and elongational strains. Order parameters have been calculated to quantify the extent of preferential alignment and direction of orientation. The experimental data are supported by comparisons with finite-element fluid mechanics calculations that provide estimates of the flow patterns and the strain rates. Elongational strain rates in the range of 5 − 20 s−1 are required to induce a high degree of alignment with the various sizes of the particles whereas about two to three order of magnitude higher shear strain rates are required. The combination of both elongational and shear strain is an effective means to provide a uniform alignment. Comparison of the Peclet numbers calculated for both the shear and elongational flow are presented and this explains that alignment occurs when the energy per particle of the strain is larger than the thermal energy. Mixtures have shown complex behavior: significant changes in the structure are observed that are not seen to the same extent in samples at rest. X-ray diffraction and small-angle neutron scattering techniques are used to characterize the samples and determine the structure in flowing systems. Laboratory X-ray diffraction can be used to characterize dispersed samples. The combination of dynamic light scattering and X-ray diffraction was used to estimate the thickness of the stabilizing layers of the polymer on the colloidal particles. Scattering of synchrotron radiation and neutrons are powerful complementary techniques to provide information about flow and the potential to apply them to systems that are beyond the scope of simple simulations has been demonstrated.
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| 18. |
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| 19. |
- Qazi, S. Junaid S., et al.
(författare)
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Impact of Ni(OH)(2) Platelike Particles on Lamellar Surfactant Mesophases and the Orientation of Their Mixtures under Elongational Flow
- 2011
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 115:35, s. 10413-10424
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Tidskriftsartikel (refereegranskat)abstract
- This article describes the behavior under elongational flow of mixtures of lamellar fragments and platelike colloidal particles. Mixtures of a dialkyl chain cationic surfactant, DHTAC (15 wt %), and the nonionic surfactant Brij 97 (0.5 wt %) form dispersions of lamellar phase fragments, and these were studied in the presence of smaller platelike colloidal particles of Ni(OH)(2) stabilized with sodium polyacrylate. Small-angle neutron scattering was used to follow the changes in the lamellar phase fragments in the mixture under elongational flow. The addition of a small fraction of the Ni(OH)(2) dispersion resulted in significantly increased viscosity and reduced the structure and size of the lamellar fragments, and this effect was further enhanced because of the flow induced alignment. The behavior of the mixture under elongational flow is described, and the induced orientation is discussed in terms of order parameters at the different positions using spatially resolved small-angle scattering. The effect of flow rate on the orientational alignment in the mixture is also described.
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| 20. |
- Qazi, S. Junaid S., et al.
(författare)
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Orientation of a Dispersion of Kaolinite Flowing in a Jet
- 2012
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 28:8, s. 3704-3713
-
Tidskriftsartikel (refereegranskat)abstract
- Orientational alignment in a dilute dispersion of kaolinite particles has been investigated in a flow pattern that combines both shear and elongational stress, namely flow at a jet created by a 2 mm diameter nozzle inserted in a 6 mm diameter pipe. Spatially-resolved X-ray diffraction with synchrotron radiation permits detailed maps of the alignment to be deduced and compared with fluid mechanics calculations of the flow. The angular distribution of diffracted intensity from a given position in the pipe provides information about the orientation distribution of the particles. This is quantified and presented in terms of order parameters. The cone-shaped nozzle provides a jet of liquid giving a high degree of alignment of the particles that is uniform along lines across the conical section and constant in the small straight-sided region at the exit of the nozzle. The vortex motion that arises from the flow with a modest Reynolds number could be determined as well as the tendency for some particles to align with their large faces perpendicular to the overall flow direction at the flat surface of the nozzle outlet.
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| 21. |
- Qazi, S. Junaid S., et al.
(författare)
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Self-Assembled Structures of Disc-Like Colloidal Particles
- 2011
-
Ingår i: Trends in colloid andinterface science XXIV. - Berlin, Heidelberg : Springer. - 9783642190377 ; , s. 61-65
-
Konferensbidrag (refereegranskat)abstract
- Self-assembly is an important phenomenon that leads to formation of interesting and novel structures in colloidal dispersions. We present experimental evidence for the existence of a ‘cubatic’ phase in a colloidal dispersion of disc-like particles of nickel hydroxide colloidal dispersions. In this structure, disc-like particles self-assemble as domains of a few parallel discs and the orientation tends to be orthogonal in adjacent domains. This phase has been predicted previously by computer simulations. The domains are approximately equiaxial and are predicted to exist only within a limited range of aspect ratios and volume fractions. We have used the real space technique of cryo-transmission electron microscopy in our studies as this locally ordered structure could not be identified readily using scattering techniques, since the patterns are expected to be similar to those of isotropic liquid phases.
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| 22. |
- Qazi, S. Junaid S., et al.
(författare)
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Use of wide-angle X-ray diffraction to measure shape and size of dispersed colloidal particles
- 2009
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 338:1, s. 105-110
-
Tidskriftsartikel (refereegranskat)abstract
- Laboratory X-ray diffraction is used to investigate the size and shape of dispersed plate-like and spherical colloidal particles. Analysis of the wide-angle diffraction data provides information about the size and shape of crystals from the width of the Bragg peaks according to the Debye-Scherrer formula. The measurements, data analysis, and evaluation are discussed. It is shown that X-ray diffraction with conventional laboratory equipment on dispersed particles is feasible as a tool to determine both particle size and shape. Data for two samples - gold colloids and nickel (II) hydroxide particles are presented. The advantages and limitations of the method are discussed. X-ray diffraction measurements that are made in combination with dynamic light scattering can be used to estimate the thickness of stabilizing layers of polymers. (C) 2009 Elsevier Inc. All rights reserved.
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| 23. |
- Tynkova, A., et al.
(författare)
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Interdiffusion in Au(120 nm)/Ni(70 nm) thin films at the low-temperature annealing in the different atmospheres
- 2013
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 87, s. 69-74
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Tidskriftsartikel (refereegranskat)abstract
- The development of the interdiffusion processes and the surface morphology changes in thin films of Au(120 nm)/Ni(70 nm) during annealing at 200 degrees C for 20 min in vacuum with different residual atmosphere pressures of 10(-3) and 10(-6) Pa and in an environment of hydrogen at a pressure of 5 x 10(2) Pa have been studied. Secondary ion mass spectrometry, Auger electron spectroscopy, X-ray diffraction, optical microscopy, atomic force microscopy and scanning electron microscopy were used. Surface microdefects that form in the films are related to the local oxidation of nickel and to the stress that arises due to interdiffusion. Defect formation and reactions at the surface are found to be controlling factors in the transport of nickel to the surface and in the observed morphology.
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| 24. |
- Ainalem, Marie-Louise, et al.
(författare)
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On the Ability of PAMAM Dendrimers and Dendrimer/DNA Aggregates To Penetrate POPC Model Biomembranes
- 2010
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 114:21, s. 7229-7244
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Tidskriftsartikel (refereegranskat)abstract
- Poly(amido amine) (PAMAM) dendrimers have previously been shown, as cationic condensing agents of DNA, to have high potential for nonviral gene delivery. This study addresses two key issues for gene delivery: the interaction of the biomembrane with (i) the condensing agent (the cationic PAMAM dendrimer) and (ii) the corresponding dendrimer/DNA aggregate. Using in situ null ellipsometry and neutron reflection, parallel experiments were carried out involving dendrimers or generations 2 (G2), 4 (G4), and 6 (G6). The study demonstrates that free dendrimers of all three generations were able to traverse supported palmitoyloleoylphosphatidylcholine (POPC) bilayers deposited on silica surfaces. The model biomembranes were elevated front the solid surfaces upon dendrimer penetration, which offers a promising new way to generate more realistic model biomembranes where the contact with the supporting surface is reduced and where aqueous cavities are present beneath the bilayer. The largest dendrimer (GO) induced partial bilayer destruction directly upon penetration, whereas the smaller dendrimers (G2 and G4) leave the bilayer intact, so we propose that lower generation dendrimers have greater potential as transfection mediators. In addition to the experimental observations, coarse-grained simulations on the interaction between generation 3 (03) dendrimers and POPC bilayers were performed in the absence and presence of a bilayer-supporting negatively charged surface that emulates the support. The simulations demonstrate that G3 is transported across free-standing POPC bilayers by direct penetration and not by endocytosis. The penetrability was, however, reduced in the presence of a surface, indicating that the membrane transport observed experimentally was not driven solely by the surface. The experimental reflection techniques were also applied to dendrimer/DNA aggregates of charge ratio = 0.5, and while G2/DNA and G4/DNA aggregates interact with POPC bilayers. G6/DNA displays no such interaction. These results indicate that, in contrast to free dendrimer molecules, dendrimer/DNA aggregates of low charge ratios are not able to traverse a membrane by direct penetration.
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| 25. |
- Asim, M, et al.
(författare)
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Synthetic lethality between androgen receptor signalling and the PARP pathway in prostate cancer
- 2017
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8:1, s. 374-
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Tidskriftsartikel (refereegranskat)abstract
- Emerging data demonstrate homologous recombination (HR) defects in castration-resistant prostate cancers, rendering these tumours sensitive to PARP inhibition. Here we demonstrate a direct requirement for the androgen receptor (AR) to maintain HR gene expression and HR activity in prostate cancer. We show that PARP-mediated repair pathways are upregulated in prostate cancer following androgen-deprivation therapy (ADT). Furthermore, upregulation of PARP activity is essential for the survival of prostate cancer cells and we demonstrate a synthetic lethality between ADT and PARP inhibition in vivo. Our data suggest that ADT can functionally impair HR prior to the development of castration resistance and that, this potentially could be exploited therapeutically using PARP inhibitors in combination with androgen-deprivation therapy upfront in advanced or high-risk prostate cancer.
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| 26. |
- Barfeld, Stefan J, et al.
(författare)
-
Myc-dependent purine biosynthesis affects nucleolar stress and therapy response in prostate cancer.
- 2015
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 6:14, s. 12587-12602
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Tidskriftsartikel (refereegranskat)abstract
- The androgen receptor is a key transcription factor contributing to the development of all stages of prostate cancer (PCa). In addition, other transcription factors have been associated with poor prognosis in PCa, amongst which c-Myc (MYC) is a well-established oncogene in many other cancers. We have previously reported that the AR promotes glycolysis and anabolic metabolism; many of these metabolic pathways are also MYC-regulated in other cancers. In this study, we report that in PCa cells de novo purine biosynthesis and the subsequent conversion to XMP is tightly regulated by MYC and independent of AR activity. We characterized two enzymes, PAICS and IMPDH2, within the pathway as PCa biomarkers in tissue samples and report increased efficacy of established anti-androgens in combination with a clinically approved IMPDH inhibitor, mycophenolic acid (MPA). Treatment with MPA led to a significant reduction in cellular guanosine triphosphate (GTP) levels accompanied by nucleolar stress and p53 stabilization. In conclusion, targeting purine biosynthesis provides an opportunity to perturb PCa metabolism and enhance tumour suppressive stress responses.
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| 27. |
- Barfeld, Stefan J, et al.
(författare)
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Myc-dependent purine biosynthesis affects nucleolar stress and therapy response in prostate cancer
- 2015
-
Ingår i: Oncotarget. - 1949-2553. ; 6:14, s. 12587-12602
-
Tidskriftsartikel (refereegranskat)abstract
- The androgen receptor is a key transcription factor contributing to the development of all stages of prostate cancer (PCa). In addition, other transcription factors have been associated with poor prognosis in PCa, amongst which c-Myc (MYC) is a well-established oncogene in many other cancers. We have previously reported that the AR promotes glycolysis and anabolic metabolism; many of these metabolic pathways are also MYC-regulated in other cancers. In this study, we report that in PCa cells de novo purine biosynthesis and the subsequent conversion to XMP is tightly regulated by MYC and independent of AR activity. We characterized two enzymes, PAICS and IMPDH2, within the pathway as PCa biomarkers in tissue samples and report increased efficacy of established anti-androgens in combination with a clinically approved IMPDH inhibitor, mycophenolic acid (MPA). Treatment with MPA led to a significant reduction in cellular guanosine triphosphate (GTP) levels accompanied by nucleolar stress and p53 stabilization. In conclusion, targeting purine biosynthesis provides an opportunity to perturb PCa metabolism and enhance tumour suppressive stress responses.
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| 28. |
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| 29. |
- Berts, Ida, 1984-, et al.
(författare)
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Controlling adsorption of albumin with hyaluronan on silica surfaces and sulfonated latex particles
- 2017
-
Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 504, s. 315-324
-
Tidskriftsartikel (refereegranskat)abstract
- Polysaccharides are known to modify binding of proteins at interfaces and this paper describes studies of these interactions and how they are modified by pH. Specifically, the adsorption of human serum albumin on to polystyrene latex and to silica is described, focusing on how this is affected by hyaluronan. Experiments were designed to test how such binding might be modified under relevant physiological conditions. Changes in adsorption of albumin alone and the co-adsorption of albumin and hyaluronan are driven by electrostatic interactions. Multilayer binding is found to be regulated by the pH of the solution and the molecular mass and concentration of hyaluronan. Highest adsorption was observed at pH below 4.8 and for low molecular mass hyaluronan (<= 150 kDa) at concentrations above 2 mg ml(-1). On silica with grafted hyaluronan, albumin absorption is reversed by changes in solvent pH due to their strong electrostatic attraction. Albumin physisorbed on silica surfaces is also rinsed away with dilute hyaluronan solution at pH 4.8. The results demonstrate that the protein adsorption can be controlled both by changes of pH and by interaction with other biological macromolecules.
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| 30. |
- Braadland, Peder Rustoen, et al.
(författare)
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Low beta(2)-adrenergic receptor level may promote development of castration resistant prostate cancer and altered steroid metabolism
- 2016
-
Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:2, s. 1878-1894
-
Tidskriftsartikel (refereegranskat)abstract
- The underlying mechanisms responsible for the development of castration-resistant prostate cancer (CRPC) in patients who have undergone androgen deprivation therapy are not fully understood. This is the first study to address whether beta(2)-adrenergic receptor (ADRB2)- mediated signaling may affect CRPC progression in vivo. By immunohistochemical analyses, we observed that low levels of ADRB2 is associated with a more rapid development of CRPC in a Norwegian patient cohort. To elucidate mechanisms by which ADRB2 may affect CRPC development, we stably transfected LNCaP cells with shRNAs to mimic low and high expression of ADRB2. Two UDP-glucuronosyltransferases, UGT2B15 and UGT2B17, involved in phase II metabolism of androgens, were strongly downregulated in two LNCaP shADRB2 cell lines. The low-ADRB2 LNCaP cell lines displayed lowered glucuronidation activities towards androgens than high-ADRB2 cells. Furthermore, increased levels of testosterone and enhanced androgen responsiveness were observed in LNCaP cells expressing low level of ADRB2. Interestingly, these cells grew faster than high-ADRB2 LNCaP cells, and sustained their low glucuronidation activity in castrated NOD/SCID mice. ADRB2 immunohistochemical staining intensity correlated with UGT2B15 staining intensity in independent TMA studies and with UGT2B17 in one TMA study. Similar to ADRB2, we show that low levels of UGT2B15 are associated with a more rapid CRPC progression. We propose a novel mechanism by which ADRB2 may affect the development of CRPC through downregulation of UGT2B15 and UGT2B17.
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| 31. |
- Gustafsson, Emil, et al.
(författare)
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Understanding interactions of plasticisers with a phospholipid monolayer
- 2024
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Ingår i: Soft Matter. - : Royal Society of Chemistry. - 1744-683X .- 1744-6848. ; 20:13, s. 2892-2899
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Tidskriftsartikel (refereegranskat)abstract
- The use of DEHP (diethylhexyl phthalate) is now banned for most applications in Europe; the exception is for blood bags, where its toxicity is overshadowed by its ability to extend the storage life of red blood cells. Another plasticiser, BTHC (butanoyl trihexyl citrate), is used in paediatric blood bags but does not stabilise blood cells as effectively. Interactions between plasticisers and lipids are investigated with a phospholipid, DMPC, to understand the increased stability of blood cells in the presence of DEHP as well as bioaccumulation and identify differences with BTHC. Mixed monolayers of DMPC and DEHP or BTHC were studied on Langmuir troughs where surface pressure/area isotherms can be measured. Neutron reflection measurements were made to determine the composition and structure of these mixed layers. A large amount of plasticiser can be incorporated into a DMPC monolayer but once an upper limit is reached, plasticiser is selectively removed from the interface at high surface pressures. The upper limit is found to occur between 40–60 mol% for DEHP and 20–40 mol% for BTHC. The areas per molecule are also different with DEHP being in the range of 50–100 Å2 and BTHC being 65–120 Å2. Results indicate that BTHC does not fit as well as DEHP in DMPC monolayers which could help explain the differences observed with regards to the stability of blood cells.
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| 32. |
- Hellsing, Maja S., 1975-
(författare)
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Adsorption and Ordering of Surface Active Molecules and Particles at Solid Interfaces and in the Bulk
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Factors that influence the process of adsorption and order of dilute and concentrated systems of molecules and particles are explored in this thesis. The results are based largely on neutron scattering techniques. Study of the adsorption from dilute solutions of a common surfactant, AOT (sodium bis (2-ethylhexyl) sulfosuccinate), at a solid/liquid interface showed that AOT molecules adsorbed to the interface in a bilayer structure, with the hydrocarbon tails at maximum packing density even at very low concentrations. At higher AOT concentrations, a stack of fluctuating layers each separated by large amounts of water next to the dense bilayer was seen. The driving force for adsorption is dominated by self-assembly of AOT. It was found that an oriented lamellar phase wets the interface below the bulk concentration for formation of this phase.Proteins can be viewed as polymeric surfactants. The adsorption of proteins from seeds of the Moringa oleifera tree to a silicon oxide surface was studied to elucidate the mechanism of the protein as a flocculent in water treatment processes. The protein was found to adsorb at the interface as dense layers with a thickness suggestive of co-adsorption rather than single isolated molecules. The strong adsorption and tendency to associate in solution suggest mechanisms for flocculating particulate impurities in water.As with surfactants, dispersions of colloidal particles can assemble in regular structures by self-assembly. Polystyrene latex particles were studied and could form large three-dimensional crystals of about 1×1 cm2 in a 2 mm path cell. The diffraction pattern indicated a close packed structure with the 110 axis perpendicular to the container wall. The crystal was well-aligned and oriented by the direction of flow. At the solid interface large two-dimensional domains of about 20 cm2 of highly oriented particles were formed. The particle-particle separation at the surface and in the bulk was determined by the charge repulsion of the particles.
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| 33. |
- Hellsing, Maja S., et al.
(författare)
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Crystalline order of polymer nanoparticles over large areas at solid/liquid interfaces
- 2012
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 100:22, s. 221601-
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Tidskriftsartikel (refereegranskat)abstract
- We report on the formation of large two-dimensional domains (about 20 cm2) of oriented and ordered structures of polystyrene particles dispersed in water at a solid/liquid interface. Gentle flow of the dispersed sample into the holder at a shear strain rate of about 0.1 s−1 caused particles at the air/latex meniscus to self-assemble in a regular structure on both solid silica or alumina surfaces. Scattering experiments show that the particle separation at the surface was the same as in the bulk and determined by repulsion arising from the charges on the particles. Close-packed planes formed parallel to the interface.
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| 34. |
- Hellsing, Maja S., et al.
(författare)
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Effect of Concentration and Addition of Ions on the Adsorption of Aerosol-OT to Sapphire
- 2010
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 26:18, s. 14567-14573
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Tidskriftsartikel (refereegranskat)abstract
- Aerosol-OT (sodium bis 2-ethylhexyl sulfosuccinate or NaAOT) adsorbs to hydrophilic sapphire solid surfaces The structure of the formed bilayer has been determined over the concentration range 0 2-7 4mM NaAOT It was found that the hydrocarbon tails pack at maximum packing limit at very low concentrations, and that the thickness of the bilayer was concentration-independent The adsorption was found to increase with concentration, with the surfactant molecules packing closer laterally The area per molecule was found to change from 138 +/- 25 to 51 +/- 4 angstrom(2) over the concentration range studied, with the thickness of the layer being constant at 33 2 A Addition of small amounts of salt was found to increase the surface excess, with the bilayer being thinner with a slightly larger area per molecule Addition of different salts of the same valency was found to have a very similiar effect, as had the addition of NaOH and HCl Hence, the effects of adding acid or base should be considered an effect of ionic strength rather than an effect of pH Adsorption of NaAOT to the sapphire surface that carries an opposite charge to the anionic surfactant is similar in many respects to the adsorption reported previously for hydrophilic and hydrophobic silica surfaces This suggests that the adsorption of NaAOT to a sui face is driven primarily by NaAOT self-assembly rather than effects of electrostatic at to the interface
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| 35. |
- Hellsing, Maja S., et al.
(författare)
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Scattering from Dilute and Lamellar Phase Solutions of Aerosol-OT Simultaneous Probe of Surface Structures and Bulk
- 2011
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Ingår i: Trends in colloid andinterface science XXIV. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783642190377 ; , s. 139-142
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Konferensbidrag (refereegranskat)abstract
- The benefits of simultaneous studies of adsorbed layers and bulk structures are shown for solutions of the surfactant Aerosol-OT. Above the critical micelle concentration, Aerosol-OT forms an aligned lamellar phase at the sapphire/solution interface which is in equilibrium with a bulk phase that consists of coexisting micellar solution and dispersed lamellar phase. Measurements of the aligned surface layers and the bulk scattering from a 2% wt solution by grazing incidence and small-angle neutron scattering show that the bulk consist of lamellar structures with the same d-spacing as seen at the surface but without the surface induced alignment. The surface lamellar structure corresponds to a 10% volume fraction for a 2% wt bulk which implies that there must be coexistence of regions of different concentration. Scattering patterns measured in grazing incidence geometry clearly show the relative contributions from small-angle scattering and specular reflectivity.
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| 36. |
- Hellsing, Maja S., et al.
(författare)
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Structure of a large colloidal crystal : controlling orientation and three-dimensional order
- 2012
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 2:18, s. 7091-7098
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Tidskriftsartikel (refereegranskat)abstract
- The three-dimensional crystal structure of charge stabilised polystyrene latex in deionised water was investigated by small-angle neutron diffraction. Crystallisation with a grain size of approximately 1 x 1 cm(2) was observed when the sample was flowed gently in to a 2 mm path cell. Bragg scattering peaks arising from the structure were observed under rotation about three perpendicular axes of the sample. The diffraction patterns indicate clearly that there is a cubic close packed structure with a 110 axis perpendicular to the cell wall. Rotations in small steps show large changes and indicate that the crystal is well oriented and has three-dimensional order. The crystal orientation was controlled by the meniscus and direction of flow when filling the cell.
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| 37. |
- Hellsing, Maja S., et al.
(författare)
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Structure of flocs of latex particles formed by addition of protein from Moringa seeds
- 2014
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Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - : Elsevier BV. - 0927-7757 .- 1873-4359. ; 460, s. 460-467
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Tidskriftsartikel (refereegranskat)abstract
- Proteins extracted from the seeds of Moringa trees are effective flocculents for particles dispersed in water and are attractive as a natural and sustainable product for use in water purification. Studies with a model system consisting of polystyrene latex particles have shown that the protein adsorbs to the surface and causes flocculation as unusually dense aggregates. Small-angle neutron scattering that exploits contrast matching of deuterated latex particles dispersed in D2O to highlight bound protein has shown that the adsorbed amount reaches about 3 mg m(-2). The particles form very compact flocs that are characterized by fractal dimensions that approach the theoretical maximum of 3. Ultra small-angle neutron scattering allows these flocs to be characterized for a range of particle and protein concentrations. Proteins from two species of Moringa trees were investigated. The protein from Moringa stenopetala seeds gave rise to slightly lower fractal dimensions compared to Moringa oleifera, but still much larger than values observed for conventional ionic or polymeric flocculents that are in the range 1.75-2.3. Compact flocs are desirable for efficient separation of impurities and dewatering of sludge as well as other applications. A trend of increasing fractal dimension with particle concentration was observed when M. stenopetala seed protein was used and this resembles the behaviour predicted in Brownian dynamics simulation of flocculation. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.
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| 38. |
- Kasper, S, et al.
(författare)
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Selective activation of the probasin androgen-responsive region by steroid hormones
- 1999
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Ingår i: Journal of molecular endocrinology. - : Bioscientifica. - 0952-5041 .- 1479-6813. ; 22:3, s. 313-325
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Tidskriftsartikel (refereegranskat)abstract
- Glucocorticoid and androgen receptors have been shown to function through the same palindromic glucocorticoid response element (GRE) and yet have differential effects on gene transcription. In this study, we examined the functional and structural relationship of the androgen and glucocorticoid receptors with the androgen responsive region (ARR) of the probasin (PB) gene containing two androgen receptor binding sites, ARBS-1 and ARBS-2. Transfection studies indicated that one copy of each cis-acting DNA element was essential for maximal androgen-induced chloramphenicol acetyltransferase (CAT) activity and that androgen selectivity was maintained when multiple copies of the minimal wild type (wt) androgen responsive region containing both ARBS-1 and ARBS-2 (-244 to -96) were subcloned in front of the thymidine kinase promoter. Furthermore, replacing the androgen response region with 1, 2 or 3 copies of either ARBS-1 or ARBS-2 restored less than 4% of the biological activity seen with the wt PB ARR. Multiple copies of either ARBS-1 or ARBS-2 did not result in glucocorticoid-induced CAT gene activity. By comparison, 1 or 2 copies of the tyrosine aminotransferase (TAT) GRE, as well as the mouse mammary tumour virus GRE, were strong inducers of CAT activity in response to both androgen and glucocorticoid treatment. In addition, band shift assays demonstrated that although the synthetic glucocorticoid receptor, GR-DNA binding domain (GR-DBD), and the synthetic androgen receptor, AR2, could interact with the TAT GRE (dissociation constants Kd of 63.9 and 14.1 respectively), only AR2 but not GR-DBD binding could be detected on ARBS-1 and ARBS-2. Our findings provide further evidence that androgen-induced regulation of gene transcription can occur through androgen-specific DNA binding sites that are distinct from the common GRE.
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| 39. |
- Kwaambwa, Habauka M., et al.
(författare)
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Interaction of Moringa oleifera seed protein with a mineral surface and the influence of surfactants
- 2015
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 448, s. 339-346
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Tidskriftsartikel (refereegranskat)abstract
- The paper describes the adsorption of purified protein from seeds of Moringa olelfera to a sapphire interface and the effects of addition of the anionic surfactant sodium dodecylsulfate (SOS) and the cationic surfactant hexadecyltrimethylammonium bromide (CTAB). Neutron reflection was used to determine the structure and composition of interfacial layers adsorbed at the solid/solution interface. The maximum surface excess of protein was found to be about 5.3 mg m(-2). The protein does not desorb from the solid/liquid interface when rinsed with water. Addition of SDS increases the reflectivity indicating co-adsorption. It was observed that CTAB is able to remove the protein from the interface. The distinct differences to the behavior observed previously for the protein at the silica/water interface are identified. The adsorption of the protein to alumina in addition to other surfaces has shown why it is an effective flocculating agent for the range of impurities found in water supplies. The ability to tailor different surface layers in combination with various surfactants also offers the potential for adsorbed protein to be used in separation technologies.
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| 40. |
- Kwaambwa, Habauka M., et al.
(författare)
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Salt induced polystyrene latex flocs investigated by neutron scattering
- 2017
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Ingår i: Journal of Colloid and Interface Science. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0021-9797 .- 1095-7103. ; 505, s. 9-13
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Tidskriftsartikel (refereegranskat)abstract
- Studies with a model system consisting of polystyrene latex particles showed that the protein from seeds of Moringa trees adsorbs to the surface and causes flocculation as unusually dense aggregates. In this study, electrolytes sodium chloride (NaCI), ferric chloride (FeCl3) and aluminium sulfate (Al-2(SO4)(3)) have been used to aggregate model polystyrene particles. The study augments previous work using neutron scattering on the flocculation of polystyrene latex with protein from seeds of Moringa trees that had indicated higher floc dimension, df, values as the concentration of particles increased. The measurements were made using ultra small-angle neutron scattering. Generally the fractal dimension, and thus the floc density, increased with particle concentration and salt concentration. Flocculation was apparent at much lower concentrations of FeCl3 and Al-2(SO4)(3) than of NaCI. The values of df were found not to simply scale with ionic strength for the three electrolytes studied with FeCl3 being the most effective flocculating agent.
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| 41. |
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| 42. |
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| 43. |
- Moulin, M., et al.
(författare)
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Towards a molecular understanding of the water purification properties of Moringa seed proteins
- 2019
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 554, s. 296-304
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Tidskriftsartikel (refereegranskat)abstract
- Seed extracts from Moringa oleifera are of wide interest for use in water purification where they can play an important role in flocculation; they also have potential as anti-microbial agents. Previous work has focused on the crude protein extract. Here we describe the detailed biophysical characterization of individual proteins from these seeds. The results provide new insights relating to the active compounds involved. One fraction, designated Mo-CBP3, has been characterized at a molecular level using a range of biochemical and biophysical techniques including liquid chromatography, X-ray diffraction, mass spectrometry, and neutron reflection. The interfacial behavior is of particular interest in considering water purification applications and interactions with both charged (e.g. silica) and uncharged (alumina) surfaces were studied. The reflection studies show that, in marked contrast to the crude extract, only a single layer of the purified Mo-CBP3 binds to a silica interface and that there is no binding to an alumina interface. These observations are consistent with the crystallographic structure of Mo-CBP3-4, which is one of the main isoforms of the Mo-CBP3 fraction. The results are put in context of previous studies of the properties of the crude extract. This work shows possible routes to development of separation processes that would be based on the specific properties of individual proteins.
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| 44. |
- North, R. L., et al.
(författare)
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The state of Lake Simcoe (Ontario, Canada) : the effects of multiple stressors on phosphorus and oxygen dynamics
- 2013
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Ingår i: Inland Waters. - 2044-2041 .- 2044-205X. ; 3:1, s. 51-74
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Tidskriftsartikel (refereegranskat)abstract
- Lake Simcoe, the largest lake in southern Ontario outside of the Laurentian Great Lakes, is affected by numerous stressors including eutrophication resulting from total phosphorus (TP) loading, climate change, and invasions of exotic species. We synthesized the long-term responses of Lake Simcoe to these stressors by assessing trends in water quality and biological composition over multiple trophic levels. Evidence for climate change included increasing thermal stability of the lake and changes in subfossil diatom communities over time. Although the deep water dissolved oxygen (O-2) minimum has increased significantly since TP load reductions, it is still below estimated historical values and the Lake Simcoe Protection Plan end-of-summer target level of 7 mg O-2 L-1. Low deep water O-2 concentrations corresponded with a decline in coldwater fish abundance. Since 1980, some nutrient concentrations have decreased (spring TP) while others have increased (silica), but many show no obvious changes (ice-free TP, nitrate, ammonium). Increases in water clarity, combined with declines in chlorophyll a and phytoplankton biovolumes in Cook's Bay, were temporally consistent with declines in TP loading and the lake-wide establishment of dreissenid mussels as a major component of the Lake Simcoe ecosystem. Using an investigative tool, we identified 2 periods when abrupt shifts potentially occurred in multiple parameters: 1986 and 1995-1997. Additional ecosystem level changes such as declines in zooplankton, declines in offshore benthic invertebrate abundance, and increased nearshore invertebrate abundance likely reflect the effects of invasive species. The interaction of these multiple stressors have significantly altered the Lake Simcoe ecosystem.
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| 45. |
- Nouhi, Shirin, et al.
(författare)
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Grazing-Incidence Small Angle Neutron Scattering from Structures below an Interface
- 2017
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Ingår i: Journal of applied crystallography. - 0021-8898 .- 1600-5767. ; 50:4, s. 1066-1074
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Tidskriftsartikel (refereegranskat)abstract
- Changes of scattering are observed as the grazing angle of incidence of an incoming beam increases and probes different depths in samples. A model has been developed to describe the observed intensity in grazing incidence small angle neutron scattering (GISANS) experiments. This includes the significant effects of instrument resolution, the sample transmission, which depends on both absorption and scattering, as well as the sample structure. The calculations are tested with self-organised structures of two colloidal samples with different size particles that were measured on two different instruments. The model allows calculations for various instruments with defined resolution and can be used to design future improved experiments. The possibilities and limits of GISANS for different studies are discussed using the model calculations.
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| 46. |
- Nouhi, Shirin, et al.
(författare)
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Sticking particles to solid surfaces using Moringa oleifera proteins as a glue
- 2018
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Ingår i: Colloids and Surfaces B: Biointerfaces. - : Elsevier BV. - 0927-7765 .- 1873-4367. ; 168, s. 68-75
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Tidskriftsartikel (refereegranskat)abstract
- Experimental studies have been made to test the idea that seed proteins from Moringa oleifera which are novel, natural flocculating agents for many particles could be used to promote adhesion at planar interfaces and hence provide routes to useful nanostructures. The proteins bind irreversibly to silica interfaces. Surfaces that had been exposed to protein solutions and rinsed were then exposed to dispersions of sulfonated polystyrene latex. Atomic force microscopy was used to count particle density and identified that the sticking probability was close to 1. Measurements with a quartz crystal microbalance confirmed the adhesion and indicated that repeated exposures to solutions of Moringa seed protein and particles increased the coverage. Neutron reflectivity and scattering experiments indicate that particles bind as a monolayer. The various results show that the 2S albumin seed protein can be used to fix particles at interfaces and suggest routes for future developments in making active filters or improved interfaces for photonic devices.
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| 47. |
- Nouhi, Shirin, 1987-
(författare)
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Structure formation at solid/liquid interfaces : Understanding self-assembly and environmental challenges
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The work described in the present dissertation has explored the structure of particles and molecules at solid/liquid interfaces, aiming to understand the physics of self-organizing systems and use this knowledge to address some environmental issues. Surface-sensitive neutron scattering techniques, such as reflectometry and grazing incidence small angle scattering, have been used as the primary tool to investigate structures in proximity to an interface. Some of the challenges in the interpretation of neutron scattering data are discussed, and new methods for analyzing the signal have been proposed.It was shown that charged stabilized colloidal particles can self-assemble and form large areas (20 cm2) of crystalline structures, close to a smooth solid surface extending to depths of several micrometers, while orienting themselves into smaller crystallites in the bulk of the suspension. The adsorption of proteins from the seeds of different species of Moringa trees on alumina, silica and polystyrene surfaces was studied, as a means for using proteins from different sources and with different properties, for the water clarification step in the purification process. The seed proteins also showed to enable locking the structure of colloidal particles at the solid/liquid interface, acting as a molecular glue.Perfluorinated surfactants (PFASs), widely used in industrial, pharmaceutical and food packing products, have been identified as emerging pollutants, raising a global concern for the environment and wildlife. The present study has shown how PFASs molecules of different fluorocarbon chain length and with different functional groups, create defects in model membranes by partitioning and removing phospholipids from the bilayer, making the bilayer thin and less dense.The effect of interface roughness was studied on the lamellar structure of a non-ionic surfactant. Concentrated solutions of the surfactant have been shown to form well-ordered and well-aligned structures at a smooth interface, which could be modified further by simply heating the sample. However it was found that even small roughness, of the same order as the bilayer thickness, can distort the structure to a depth of several micrometers from the interface. Heating the sample could improve the alignment but not as much as that formed at a smooth surface.
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| 48. |
- Olsson, Anders, et al.
(författare)
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A holder to rotate sample cells to avoid sedimentation in small-angle neutron scattering and ultra small-angle neutron scattering experiments
- 2013
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Ingår i: Measurement science and technology. - : IOP Publishing. - 0957-0233 .- 1361-6501. ; 24:10, s. 105901-
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Tidskriftsartikel (refereegranskat)abstract
- Sedimentation, or creaming, of samples can significantly alter the amount of material in the beam during small-angle scattering experiments. Simple rotating mounts that ameliorate this effect are described and the design criteria are carefully discussed. A modular design permits simple adaptation to various instruments and different sample cells. Temperature control in the range 10 degrees C below ambient to about +40 degrees C has been implemented using air flow and a Peltier device. Example ultra small-angle neutron scattering data are shown that exploit the simplicity of the mounts and the capability to position several samples close together on a translation stage.
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| 49. |
- Olsson, Anders, et al.
(författare)
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New possibilities using additive manufacturing with materials that are difficult to process and with complex structures
- 2017
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Ingår i: Physica Scripta. - : IOP PUBLISHING LTD. - 0031-8949 .- 1402-4896. ; 92:5
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Tidskriftsartikel (refereegranskat)abstract
- Additive manufacturing (or 3D printing) opens the possibility of creating new designs and manufacturing objects with new materials rapidly and economically. Particularly for use with polymers and polymer composites, simple printers can make high quality products, and these can be produced easily in offices, schools and in workshops and laboratories. This technology has opened a route for many to test ideas or to make custom devices. It is possible to easily manufacture complex geometries that would be difficult or even impossible to create with traditional methods. Naturally this technology has attracted attention in many fields that include the production of medical devices and prostheses, mechanical engineering as well as basic sciences. Materials that are highly problematic to machine can be used. We illustrate process developments with an account of the production of printer parts to cope with polymer fillers that are hard and abrasive; new nozzles with ruby inserts designed for such materials are durable and can be used to print boron carbide composites. As with other materials, complex parts can be printed using boron carbide composites with fine structures, such as screw threads and labels to identify materials. General ideas about design for this new era of manufacturing customised parts are presented.
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| 50. |
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