| 1. |
- Andersson, Ove, et al.
(author)
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Pressure-induced collapse of ice clathrate and hexagonal ice mixtures formed by freezing
- 2009
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In: Journal of Chemical Physics. - : American Institute of Physics Publishing LLC. - 0021-9606 .- 1089-7690. ; 131, s. 114503-114513
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Journal article (peer-reviewed)abstract
- We report thermal conductivity κ measurements of the pressure-induced collapse of two mixtures of ice and tetrahydrofuran (THF) clathrate hydrate formed by freezing aqueous solutions, THF·23 H2O and THF·20 H2O, one containing twice as much excess water than the other. On pressurizing, κ of the solid mixture first decreases at the onset pressure of 0.8 GPa, as occurs for collapse of pure ice, reaches a local minimum at a pressure of 1.0 GPa, and then increases as occurs for the collapse of the pure clathrate THF·17 H2O. This shows that in the apparently homogeneous mixture, the ice and the clathrate collapse as if the two were in a mechanically mixed state. The manner in which the clathrate aggregate can arrange in the solid indicates that ice occupies the interstitial space in the tightly packed aggregates and H2O molecules belonging to the lattice of one form hydrogen bond with that of the other, a feature that is preserved in their collapsed states. On decompression, the original clathrate is partially recovered in the THF·20 H2O mixture, but the collapsed ice does not transform to the low density amorph. We surmise that on irreversible transformation to the original clathrate, the aggregates expand. Any pressure thus exerted on the small domains of the collapsed ice with a hydrogen bonded interface with the clathrate aggregates could prevent it from transforming to the low density amorph. Measurements of κ are useful in investigating structural collapse of crystals when dilatometry is unable to do so, as κ seems to be more sensitive to pressure-induced changes than the volume.
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| 2. |
- Andersson, Ove, et al.
(author)
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Tricritical Lifshitz point in the temperature-pressure-composition diagram for (PbySn1-y)2 P2(SexS1-x)6 ferroelectrics
- 2009
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In: Physical Review B Condensed Matter. - : American Physical Society. - 0163-1829 .- 1095-3795. ; 80, s. 174107-
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Journal article (peer-reviewed)abstract
- The heat capacity of Sn2P2S6 ferroelectric crystals has been measured under quasihydrostatic pressures up to 0.7 GPa. The analysis of the heat-capacity and literature data for the birefringence shows that the tricritical point of Sn2P2S6 is in the 0.20–0.25 GPa range. Moreover, in the approximation of a linear change in the free-energy expansion coefficients, with respect to concentration and pressure, thermodynamic trajectories have been constructed for (PbySn1−y)2 P2(SexS1−x)6 solid solutions. We have thereby identified the region of the T-p-y-x diagram for (PbySn1−y)2 P2(SexS1−x)6 showing the tricritical Lifshitz point.
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| 3. |
- Andrén, Ove, et al.
(author)
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Incidence and mortality of incidental prostate cancer : a Swedish register-based study
- 2009
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In: British Journal of Cancer. - London : Nature publishing group. - 0007-0920 .- 1532-1827. ; 100:1, s. 170-173
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Journal article (peer-reviewed)abstract
- In a national register-based study of incidence trends and mortality of incidental prostate cancer in Sweden, we found that a significant proportion (26.6%) of affected men diagnosed died of their disease, which challenges earlier descriptions of incidental prostate cancer as a non-lethal disease.
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| 4. |
- Castelain, Mickaël, et al.
(author)
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Characterization of the Biomechanical Properties of T4 Pili Expressed by Streptococcus pneumoniae – A Comparison between Helix-like and Open Coil-like Pili
- 2009
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In: ChemPhysChem. - : Wiley. - 1439-4235 .- 1439-7641. ; 10:9-10, s. 1533-1540
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Journal article (peer-reviewed)abstract
- Bacterial adhesion organelles, known as fimbria or pili, are expressed by Gram–positive as well as Gram–negative bacteria families. These appendages play a key role in the first steps of the invasion and infection processes, and they therefore provide bacteria with pathogenic abilities. To improve the knowledge of pili-mediated bacterial adhesion to host cells and how these pili behave under the presence of an external force, we first characterize, using force measuring optical tweezers, open coil-like T4 pili expressed by Gram–positive Streptococcus pneumoniae with respect to their biomechanicalproperties. It is shown that their elongation behavior can be well described by the worm-like chain model and that they possess a large degree of flexibility. Their properties are then compared with those of helix-like pili expressed by Gram–negative uropathogenic Escherichia coli (UPEC), which have different pili architecture. The differences suggest that these two types of pili have distinctly dissimilar mechanisms to adhere and sustain external forces. Helix-like pili expressed by UPEC bacteria adhere to host cells by single adhesins located at the distal end of the pili while their helix-like structures act as shock absorbers to dampen the irregularly shear forces induced by urine flow and to increase the cooperativity of the pili ensemble. Open coil-like pili expressed by S. pneumoniae adhere to cells by a multitude of adhesins distributed along the pili. It is hypothesized that these two types of pili represent different strategies of adhering to host cells in the presence of external forces. When exposed to significant forces, bacteria expressing helix-like pili remain attached bydistributing the external force among a multitude of pili, whereas bacteria expressing open coil-like pili sustain large forces primarily by their multitude of binding adhesins.
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| 5. |
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| 6. |
- Fall, Katja, 1971-, et al.
(author)
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Immediate risk for cardiovascular events and suicide following a prostate cancer diagnosis : prospective cohort study
- 2009
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In: PLoS Medicine. - San Francisco, Calif. : Public Library of Science. - 1549-1277 .- 1549-1676. ; 6:12, s. e1000197-
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Journal article (peer-reviewed)abstract
- BACKGROUND: Stressful life events have been shown to be associated with altered risk of various health consequences. The aim of the present study was to investigate whether the emotional stress evoked by a prostate cancer diagnosis increases the immediate risks of cardiovascular events and suicide.METHODS AND FINDINGS: We conducted a prospective cohort study by following all men in Sweden who were 30 y or older (n = 4,305,358) for a diagnosis of prostate cancer (n = 168,584) and their subsequent occurrence of cardiovascular events and suicide between January 1, 1961 and December 31, 2004. We used Poisson regression models to calculate relative risks (RRs) and 95% confidence intervals (CIs) of cardiovascular events and suicide among men who had prostate cancer diagnosed within 1 y to men without any cancer diagnosis. The risks of cardiovascular events and suicide were elevated during the first year after prostate cancer diagnosis, particularly during the first week. Before 1987, the RR of fatal cardiovascular events was 11.2 (95% CI 10.4-12.1) during the first week and 1.9 (95% CI 1.9-2.0) during the first year after diagnosis. From 1987, the RR for cardiovascular events, nonfatal and fatal combined, was 2.8 (95% CI 2.5-3.2) during the first week and 1.3 (95% CI 1.3-1.3) during the first year after diagnosis. While the RR of cardiovascular events declined, the RR of suicide was stable over the entire study period: 8.4 (95% CI 1.9-22.7) during the first week and 2.6 (95% CI 2.1-3.0) during the first year after diagnosis. Men 54 y or younger at cancer diagnosis demonstrated the highest RRs of both cardiovascular events and suicide. A limitation of the present study is the lack of tumor stage data, which precluded possibilities of investigating the potential impact of the disease severity on the relationship between a recent diagnosis of prostate cancer and the risks of cardiovascular events and suicide. In addition, we cannot exclude residual confounding as a possible explanation.CONCLUSIONS: Men newly diagnosed with prostate cancer are at increased risks for cardiovascular events and suicide. Future studies with detailed disease characteristic data are warranted.
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| 7. |
- Fiorentino, M., et al.
(author)
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Immunohistochemical Expression of BRCA1 in Prostate Cancer
- 2009
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In: Laboratory Investigation. - : Nature Publishing Group. - 0023-6837 .- 1530-0307. ; 22, s. 169A-169A
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Journal article (other academic/artistic)abstract
- Background: BRCA1 is a multifunctional protein involved in DNA repair, gene transcription and the regulation of cell-cycle check-points. While germline mutations of BRCA1 are rare in prostate cancer and seem to play a limited role in tumor susceptibility, BRCA1 expression has not been investigated to date.Design: We analyzed the immunohistochemical expression of BRCA1 in paraffin embedded samples from 524 men with prostate cancer belonging to the Physicians’ Health Study and the Swedish Watchful Waiting cohorts of prostate cancer patients. High density tissue micro-arrays (TMA) including at least three tumor cores for each case were utilized for the immunohistochemical staining with the monoclonal MS110 antibody specific for the N-terminus of the 220 kDa BRCA1 protein. Cases were scored as negative or positive for BRCA1 immunostaining. The Ki67 proliferation index was also assessed on the same TMAs and evaluated by quantitative image analysis.Results: A positive nuclear immunostaining for BRCA1 was revealed in 62 of 524 (11.9%) patients while normal prostate control cores were all negative. BRCA1 positive tumors were associated with 4 times greater proliferation rate compared to BRCA1 negative tumors (p ∼ 0.0003). In addition, we found a linear trend such that tumors with greater number of TMA cores expressing BRCA1 had stronger extent of proliferation. Men with BRCA1 positive tumors had a slightly higher Gleason’s score (mean 7.5) compared to those negative for BRCA1 (mean 7) No significant correlation was found between BRCA1 staining and cancer-specific death.Conclusions: BRCA1 protein is expressed in a small subset of prostate cancers characterized by high proliferation index but not in normal prostate tissue. Expression of BRCA1 might be acquired in selected tumors to prevent DNA damage in actively replicating cells. A different role independent of germline mutations might be disclosed for BRCA1 as cell cycle regulator in prostate cancer.
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| 8. |
- Kasperzyk, Julie L., et al.
(author)
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One-carbon metabolism-related nutrients and prostate cancer survival
- 2009
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In: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 90:3, s. 561-569
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Journal article (peer-reviewed)abstract
- BACKGROUND: Folate and other one-carbon metabolism nutrients may influence prostate cancer pathogenesis. Prior studies of these nutrients in relation to prostate cancer incidence have been inconclusive, and none have explored prostate cancer survival. OBJECTIVE: The objective was to assess whether dietary intakes of folate, riboflavin, vitamin B-6, vitamin B-12, and methionine measured around the time of prostate cancer diagnosis are associated with prostate cancer survival. DESIGN: This population-based prospective study comprised 525 men from Orebro, Sweden, who received a diagnosis of incident prostate cancer between 1989 and 1994 and completed a self-administered food-frequency questionnaire. Record linkages to the Swedish Death Registry enabled all cases to be followed for up to 20 y after diagnosis, and the cause of death was assigned via medical record review. Cox proportional hazards regression was used to calculate multivariable hazard ratios (HRs) and 95% CIs. During a median of 6.4 y of follow-up, 218 men (42%) died of prostate cancer and 257 (49%) of other causes. RESULTS: A comparison of the highest with the lowest quartile showed that vitamin B-6 intake was inversely associated with prostate cancer-specific death (HR: 0.71; 95% CI: 0.46, 1.10; P for trend = 0.08), especially in men with a diagnosis of localized-stage disease (HR; 0.05; 95% CI: 0.01, 0.26; P for trend = 0.0003). However, vitamin B-6 intake was not associated with improved prostate cancer survival among advanced-stage cases (HR: 1.04; 95% CI: 0.64, 1.72; P for trend = 0.87). Folate, riboflavin, vitamin B-12, and methionine intakes were not associated with prostate cancer survival. CONCLUSION: A high vitamin B-6 intake may improve prostate cancer survival among men with a diagnosis of localized-stage disease.
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| 9. |
- Malkiewicz, Katarzyna, et al.
(author)
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Human experts' judgment of chemicals reactivity for identification of hazardous chemicals
- 2009
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In: Toxicology Letters. - : Elsevier BV. - 0378-4274 .- 1879-3169. ; 189, s. S243-S243
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Journal article (other academic/artistic)abstract
- The development of non-testing approaches for the identification of chemicals with the potential to cause environmental hazards, have gained increased attention. In this study the hypothesis that experts’ judgement of chemical reactivity could be used for this purpose has been tested. The judgments of chemical reactivity for 200 organic chemicals, based on their molecular structure were performed by four senior organic and environmental chemists. Potentials for reactivity (namely: oxidative/reductive reactivity, hydrolysis, direct photolysis, reactivity towards radicals) were scored on the 1– scale. Both the experts’ individual judgment, and a compromised judgment after joint discussion for clarification of cases with divergent opinions, was analysed. Furthermore we searched for relations between the expert judgement data and: (a) the chemical characteristics representedby 40 chemical descriptors using partial least squares regression (PLS), and (b) experimental and in silico data for different toxicological and physico-chemical end-points. The results of on-going analyses indicate that for the majority of the chemicals, the individual judgments differed significantly between experts but after discussion among the experts for clarification, the judgments becamemuch more concurrent. The relation between averaged experts’ predicted photolytic degradation potential and chemical characteristic based on a PLS model (with three significant components explaining 76% of the variation) was found. We have also found that in the group of the chemicals with the higher score of the experts judged oxidative reactivity there was higher percentage of biodegradable chemicals when compar
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| 10. |
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