| 181. |
- Jonsson, Ulf G., 1950-, et al.
(författare)
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Investigations Of The Low And High Frequency Response Of 3ω-Sensors Used In Dynamic Heat Capacity Measurements
- 1998
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Ingår i: Measurement science and technology. - London : Institute of Physics. - 0957-0233 .- 1361-6501. ; 9:11, s. 1873-1885
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Tidskriftsartikel (refereegranskat)abstract
- The 3ω-method is used to study time dependent processes through measurements of dynamic heat capacity. The 3ω-sensor is a thin (∼ 0.1 μm) metal strip which is evaporated onto a substrate. The sample is probed by periodic diffusive thermal waves of frequency 2ω emitted from the strip. The heater temperature T0 measured at frequency 3ω yields the dynamic heat capacity. The validity of a one-dimensional heat flow model, assuming an infinitely thin heater, is here studied using a finite element modelling (FEM) technique as well as experiments. To obtain results within 1% of the theory, FEM shows that the ratio between the heater width and the heat wave penetration depth (=√D/ω, where D is the thermal diffusivity) must be greater than 30, which sets a low-frequency limit for the model. At high frequencies, the finite thickness of the heater causes a deviation from the model. For a thickness of 0.1 μm, the deviation is <1% at 200 Hz, reaching 5% at 5 kHz. A small 3ω-component intrinsic to the electronics together with a thermal resistance between heater and sample can explain deviations from T0 ∝ ω-υ, at high frequencies, where υ = 0.5 is predicted by the model but experiments generally show smaller values.
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| 182. |
- Jonsson, Ulf G, et al.
(författare)
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Investigations of the temperature gradients affecting the temperature scale of a 3ω-heat capacity spectrometer
- 2000
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Ingår i: Thermochimica Acta. - : Elsevier. - 0040-6031 .- 1872-762X. ; 347:1-2, s. 45-51
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Tidskriftsartikel (refereegranskat)abstract
- The temperature gradients affecting the temperature scale of a dynamic heat capacity spectrometer based on the 3ω-method are investigated using the SmecticA-Nematic (SmA/N) transition in the liquid crystal octyloxycyanobiphenyl (80CB). The heater (sample) temperature was obtained from a thermocouple by superimposing the temperature increase of the heater, where the increase was calculated from the heater power. The calibration using the SmA/N transition yields a linear relation between the temperature rise of the heater ΔTh and the heater power P:ΔTh = 55.2 P. An estimation of the maximum temperature gradient in the 80CB sample shows that the correction of the sample temperature due to the gradient is small compared to ΔTh (<-0.01 K for ω=3.98.2π rads-1 and -0.14 K for ω=0.01. 2π rads-1). For high heating powers there is a significant temperature gradient in the heater, which causes a broadening of the SmA/N peakwidth from 0.5 K for P=7.7 mW to 2 K for P=29.4 mW.
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| 183. |
- Julin, B., et al.
(författare)
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Dietary cadmium exposure and prostate cancer incidence : a population-based prospective cohort study
- 2012
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Ingår i: British Journal of Cancer. - London, United Kingdom : Nature Publishing Group. - 0007-0920 .- 1532-1827. ; 21:5, s. 895-900
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Tidskriftsartikel (refereegranskat)abstract
- Background: Experimental data convincingly propose the toxic metal cadmium as a prostate carcinogen. Cadmium is widely dispersed into the environment and, consequently, food is contaminated.Methods: A population-based cohort of 41 089 Swedish men aged 45-79 years was followed prospectively from 1998 through 2009 to assess the association between food frequency questionnaire-based estimates of dietary cadmium exposure (at baseline, 1998) and incidence of prostate cancer (3085 cases, of which 894 were localised and 794 advanced) and through 2008 for prostate cancer mortality (326 fatal cases).Results: Mean dietary cadmium exposure was 19 μg per day±s.d. 3.7. Multivariable-adjusted dietary cadmium exposure was positively associated with overall prostate cancer, comparing extreme tertiles; rate ratio (RR) 1.13 (95% confidence interval (CI): 1.03-1.24). For subtypes of prostate cancer, the RR was 1.29 (95% CI: 1.08-1.53) for localised, 1.05 (95% CI: 0.87-1.25) for advanced, and 1.14 (95% CI: 0.86-1.51) for fatal cases. No statistically significant difference was observed in the multivariable-adjusted risk estimates between tumour subtypes (P(heterogeneity)=0.27). For localised prostate cancer, RR was 1.55 (1.16-2.08) among men with a small waist circumference and RR 1.45 (1.15, 1.83) among ever smokers.Conclusion: Our findings provide support that dietary cadmium exposure may have a role in prostate cancer development.
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| 184. |
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| 185. |
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| 186. |
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| 187. |
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| 188. |
- Karyotaki, Eirini, et al.
(författare)
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Internet-Based Cognitive Behavioral Therapy for Depression : A Systematic Review and Individual Patient Data Network Meta-analysis
- 2021
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Ingår i: JAMA psychiatry. - : American Medical Association. - 2168-6238 .- 2168-622X. ; 78:4, s. 361-371
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Forskningsöversikt (refereegranskat)abstract
- IMPORTANCE: Personalized treatment choices would increase the effectiveness of internet-based cognitive behavioral therapy (iCBT) for depression to the extent that patients differ in interventions that better suit them.OBJECTIVE: To provide personalized estimates of short-term and long-term relative efficacy of guided and unguided iCBT for depression using patient-level information.DATA SOURCES: We searched PubMed, Embase, PsycInfo, and Cochrane Library to identify randomized clinical trials (RCTs) published up to January 1, 2019.STUDY SELECTION: Eligible RCTs were those comparing guided or unguided iCBT against each other or against any control intervention in individuals with depression. Available individual patient data (IPD) was collected from all eligible studies. Depression symptom severity was assessed after treatment, 6 months, and 12 months after randomization.DATA EXTRACTION AND SYNTHESIS: We conducted a systematic review and IPD network meta-analysis and estimated relative treatment effect sizes across different patient characteristics through IPD network meta-regression.MAIN OUTCOMES AND MEASURES: Patient Health Questionnaire-9 (PHQ-9) scores.RESULTS: Of 42 eligible RCTs, 39 studies comprising 9751 participants with depression contributed IPD to the IPD network meta-analysis, of which 8107 IPD were synthesized. Overall, both guided and unguided iCBT were associated with more effectiveness as measured by PHQ-9 scores than control treatments over the short term and the long term. Guided iCBT was associated with more effectiveness than unguided iCBT (mean difference [MD] in posttreatment PHQ-9 scores, -0.8; 95% CI, -1.4 to -0.2), but we found no evidence of a difference at 6 or 12 months following randomization. Baseline depression was found to be the most important modifier of the relative association for efficacy of guided vs unguided iCBT. Differences between unguided and guided iCBT in people with baseline symptoms of subthreshold depression (PHQ-9 scores 5-9) were small, while guided iCBT was associated with overall better outcomes in patients with baseline PHQ-9 greater than 9.CONCLUSIONS AND RELEVANCE: In this network meta-analysis with IPD, guided iCBT was associated with more effectiveness than unguided iCBT for individuals with depression, benefits were more substantial in individuals with moderate to severe depression. Unguided iCBT was associated with similar effectiveness among individuals with symptoms of mild/subthreshold depression. Personalized treatment selection is entirely possible and necessary to ensure the best allocation of treatment resources for depression.
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| 189. |
- Kasperzyk, Julie L., et al.
(författare)
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One-carbon metabolism-related nutrients and prostate cancer survival
- 2009
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 90:3, s. 561-569
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Tidskriftsartikel (refereegranskat)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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