118 research outputs found
Multicenter data acquisition made easy
<p>Abstract</p> <p>Background</p> <p>The process for data collection in multicenter trials may be troublesome and expensive. We report our experience with the spreadsheet function in Googledocs for this purpose.</p> <p>Methods</p> <p>In Googledocs the data manager creates a form similar to the paper case record form, which will function as a decentral data entry module. When the forms are submitted, they are presented in a spreadsheet in Googledocs, which can be exported to different standard spreadsheet formats.</p> <p>Results</p> <p>For a multicenter randomized clinical trial with five different participating hospitals we created a decentral data entry module using the spreadsheet function in Googledocs. The study comprised 332 patients (clinicaltrials.gov identifier: NCT00815698) with five visits per patient. One person at each study site entered data from the original paper based case report forms which were kept at the study sites as originals. We did not experience any technical problems using the system.</p> <p>Conclusions</p> <p>The system allowed for decentral data entry, and it was easy to use, safe, and free of charge. The spreadsheet function in Googledocs may potentially replace current expensive solutions for data acquisition in multicenter trials.</p> <p>Trial registration</p> <p>clinicaltrials.gov NCT00815698</p
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Barriers to HIV testing as reported by individuals newly diagnosed with HIV infection in Sweden
Despite the availability of free and anonymous HIV testing almost 60% of Swedish patients are diagnosed late. Identifying predictors of different types of barriers could inform policy makers and health care of interventions to increase testing where needed. This cross-sectional study aimed to describe and analyze barriers to HIV testing as reported by Swedish patients newly diagnosed with HIV infection. N = 285 patients completed the 18-item Barriers to HIV Testing Scale - Karolinska Version. Descriptive analysis and logistic regressions were performed to assess the prevalence of barriers and to identify predictors for the different investigated barriers. Barriers to testing were reported by 60%. Approximately 67% of patients originating from Sweden, 50% from Sub-Saharan Africa and 75% from Eastern European/East Asian countries reported barriers. Patients who were younger and patients who self-initiated HIV testing, had greater odds of reporting a barrier than older individuals and those who were offered a test through screening or by a healthcare professional. To counteract barriers that still exist on an individual level, healthcare-initiated HIV testing could be offered more broadly and information about risks for transmission and effectiveness of HIV treatment still needs to be disseminated among both people born in Sweden and different migrant groups
Investigating the Electromechanical Behavior of Unconventionally Ferroelectric Hf0.5Zr0.5O2-Based Capacitors Through Operando Nanobeam X-Ray Diffraction
Understanding various aspects of ferroelectricity in hafnia-based nanomaterials is of vital importance for the development of future nonvolatile memory and logic devices. Here, the unconventional and weak electromechanical response of epitaxial La0.67Sr0.33MnO3/Hf0.5Zr0.5O2/La0.67Sr0.33MnO3 ferroelectric capacitors is investigated, via the sensitivity offered by nanobeam X-ray diffraction experiments during application of electrical bias. It is shown that the pristine rhombohedral phase exhibits a linear piezoelectric effect with piezoelectric coefficient (|d33|) ≈ 0.5–0.8 pmV−1. It is found that the piezoelectric response is suppressed above the coercive voltage. For higher voltages, and with the onset of DC conductivity throughout the capacitor, a second-order effect is observed. The work sheds light into the electromechanical response of rhombohedral Hf0.5Zr0.5O2 and suggests its (un)correlation with ferroelectric switching
Inducing ferroelastic domains in single crystal CsPbBr3 perovskite nanowires using atomic force microscopy
Ferroelectric and ferroelastic domains have been predicted to enhance metal halide perovskite MHP solar cell performance. While the formation of such domains can be modified by temperature, pressure, or strain, established methods lack spatial control at the level of single domains. Here, we induce the formation of ferroelastic domains in CsPbBr3 nanowires at room temperature using an atomic force microscope AFM tip and visualize the domains using nanofocused x ray diffraction with a 60 nm beam. Regions scanned with a low AFM tip force show orthorhombic 004 reflections along the nanowire axis, while regions exposed to higher forces exhibit 220 reflections. The applied stress locally changes the crystal structure, leading to lattice tilts that define ferroelastic domains, which spread spatially and terminate at 112 type domain walls. The ability to induce individual ferroelastic domains within MHPs using AFM gives new possibilities for device design and fundamental experimental studie
Scalable In Situ Hybridization on Tissue Arrays for Validation of Novel Cancer and Tissue-Specific Biomarkers
Tissue localization of gene expression is increasingly important for accurate interpretation of large scale datasets from expression and mutational analyses. To this end, we have (1) developed a robust and scalable procedure for generation of mRNA hybridization probes, providing >95% first-pass success rate in probe generation to any human target gene and (2) adopted an automated staining procedure for analyses of formalin-fixed paraffin-embedded tissues and tissue microarrays. The in situ mRNA and protein expression patterns for genes with known as well as unknown tissue expression patterns were analyzed in normal and malignant tissues to assess procedure specificity and whether in situ hybridization can be used for validating novel antibodies. We demonstrate concordance between in situ transcript and protein expression patterns of the well-known pathology biomarkers KRT17, CHGA, MKI67, PECAM1 and VIL1, and provide independent validation for novel antibodies to the biomarkers BRD1, EZH2, JUP and SATB2. The present study provides a foundation for comprehensive in situ gene set or transcriptome analyses of human normal and tumor tissues
Simulating Linear Sweep Voltammetry from First-Principles: Application to Electrochemical Oxidation of Water on Pt(111) and Pt<sub>3</sub>Ni(111)
Några reflexioner, beträffande elementarundervisningen i mathematik, i anledning af den i Bihang till paedagogisk tidskrift intagna berättelsen om Rektorsmötet 1868
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