| 1. |
|
|
| 2. |
- Danielsson, Christian, et al.
(författare)
-
Exploration of human, rat, and rabbit embryonic cardiomyocytes suggests K-channel block as a common teratogenic mechanism
- 2013
-
Ingår i: Cardiovascular Research. - : Oxford University Press (OUP): Policy B. - 0008-6363 .- 1755-3245. ; 97:1, s. 23-32
-
Tidskriftsartikel (refereegranskat)abstract
- Several drugs blocking the rapidly activating potassium (K-r) channel cause malformations (including cardiac defects) and embryonic death in animal teratology studies. In humans, these drugs have an established risk for acquired long-QT syndrome and arrhythmia. Recently, associations between cardiac defects and spontaneous abortions have been reported for drugs widely used in pregnancy (e.g. antidepressants), with long-QT syndrome risk. To investigate whether a common embryonic adverse-effect mechanism exists in the human, rat, and rabbit embryos, we made a comparative study of embryonic cardiomyocytes from all three species. less thanbrgreater than less thanbrgreater thanPatch-clamp and quantitative-mRNA measurements of K-r and slowly activating K (K-s) channels were performed on human, rat, and rabbit primary cardiomyocytes and cardiac samples from different embryo-foetal stages. The K-r channel was present when the heart started to beat in all species, but was, in contrast to human and rabbit, lost in rats in late organogenesis. The specific K-r-channel blocker E-4031 prolonged the action potential in a species- and development-dependent fashion, consistent with the observed K-r-channel expression pattern and reported sensitive periods of developmental toxicity. E-4031 also increased the QT interval and induced 2:1 atrio-ventricular block in multi-electrode array electrographic recordings of rat embryos. The K-s channel was expressed in human and rat throughout the embryo-foetal period but not in rabbit. less thanbrgreater than less thanbrgreater thanThis first comparison of mRNA expression, potassium currents, and action-potential characteristics, with and without a specific K-r-channel blocker in human, rat, and rabbit embryos provides evidence of K-r-channel inhibition as a common mechanism for embryonic malformations and death.
|
|
| 3. |
- Andersson, Sandra, et al.
(författare)
-
The Transcriptomic and Proteomic Landscapes of Bone Marrow and Secondary Lymphoid Tissues
- 2014
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:12, s. e115911-
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The sequencing of the human genome has opened doors for global gene expression profiling, and the immense amount of data will lay an important ground for future studies of normal and diseased tissues. The Human Protein Atlas project aims to systematically map the human gene and protein expression landscape in a multitude of normal healthy tissues as well as cancers, enabling the characterization of both housekeeping genes and genes that display a tissue-specific expression pattern. This article focuses on identifying and describing genes with an elevated expression in four lymphohematopoietic tissue types (bone marrow, lymph node, spleen and appendix), based on the Human Protein Atlas-strategy that combines high throughput transcriptomics with affinity-based proteomics. Results: An enriched or enhanced expression in one or more of the lymphohematopoietic tissues, compared to other tissue-types, was seen for 693 out of 20,050 genes, and the highest levels of expression were found in bone marrow for neutrophilic and erythrocytic genes. A majority of these genes were found to constitute well-characterized genes with known functions in lymphatic or hematopoietic cells, while others are not previously studied, as exemplified by C19ORF59. Conclusions: In this paper we present a strategy of combining next generation RNA-sequencing with in situ affinity-based proteomics in order to identify and describe new gene targets for further research on lymphatic or hematopoietic cells and tissues. The results constitute lists of genes with enriched or enhanced expression in the four lymphohematopoietic tissues, exemplified also on protein level with immunohistochemical images.
|
|
| 4. |
- Anselm, Jonas, et al.
(författare)
-
Bannlys alla politiska beslut som ger mer klimatutsläpp
- 2014
-
Ingår i: Dagens Nyheter.
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Torftig valdebatt. Dagspolitiken klarar inte att hantera ödesfrågan om klimatet, vilket oroar oss. Vi föreslår därför ett ”utsläppsmoratorium”: inga beslut får tas som ökar utsläppen av växthusgaser. Principen måste kopplas till mål om exempelvis förnybar energi och grön infrastruktur, skriver 23 forskare och debattörer.
|
|
| 5. |
|
|
| 6. |
- Asoodar, Mohsen, et al.
(författare)
-
Accurate Condition Monitoring of Semiconductor Devices in Cascaded H-Bridge Modular Multilevel Converters
- 2023
-
Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 38:3, s. 3870-3884
-
Tidskriftsartikel (refereegranskat)abstract
- This article presents an online condition monitoring (CM) scheme for semiconductors used in modular multilevel converters (MMCs) that comprise cascaded H-bridge submodules. The CM algorithm is based on detecting changes in the ON-state resistance of the semiconductors over time. The proposed method is shown to successfully perform a curve tracing of semiconductors in MMCs while the semiconductor junction remains at a temperature that is readily measurable and undergoes minute changes during the measurement process. The ON-state resistance value is estimated from the measured ON-state voltage drop of the semiconductors and the measured arm current. Measuring the ON-state resistance at known temperatures allows for separating temperature-dependent variations of the ON-state resistance from age-dependent variations of this parameter. Suitable methods for reducing the effect of noise on the curve-traced data are proposed, and a recursive least square estimator is used to extract the optimum ON-state resistance from the traced v(CE) - i
|
|
| 7. |
- Asoodar, Mohsen, et al.
(författare)
-
Online Health Monitoring of DC-Link Capacitors in Modular Multilevel Converters for FACTS and HVDC Applications
- 2021
-
Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 36:12, s. 13489-13503
-
Tidskriftsartikel (refereegranskat)abstract
- This article presents an online health monitoring scheme for dc capacitors in modular multilevel converters (MMCs). The health monitoring algorithm is based on detecting changes in the dc capacitance value over time. The proposed algorithm only utilizes measurements that are typically available in flexible alternating current transmission systems and high-voltage direct current applications. Hence, in the proposed estimation method, no additional sensors are used. The estimation scheme considers the presence of noise in voltage and current measurements, and utilizes a recursive least square estimator in conjunction with a special low-pass filter to minimize the estimation errors. Simulation results of a hardware replica, as well as experimental results on a low-power MMC prototype show that the proposed scheme can identify the dc-link capacitance value with a maximum error of 1%.
|
|
| 8. |
- Asoodar, Mohsen, et al.
(författare)
-
Temperature Considerations for Online Health Monitoring of DC-Link Capacitors in Modular Multilevel Converters
- 2021
-
Ingår i: 2021 23rd European Conference on Power Electronics and Applications, EPE 2021 ECCE Europe. - : Institute of Electrical and Electronics Engineers Inc..
-
Konferensbidrag (refereegranskat)abstract
- In this paper, the effect of temperature on online heath monitoring of dc capacitors in modular multilevel converters (MMCs) is studied. The submodule capacitance value is considered as the main indicator of health. Both self heating and ambient temperature are considered as sources of temperature variation. The study is conducted on a single phase MMC with full-bridge submodules. However, a similar analysis can be used for half-bridge MMCs and multiphase MMCs as well. The thermal behaviour of the capacitors is explained analytically and simulated using a simplified Cauer model. The effect of temperature on the estimated capacitance values is shown, and a method for reducing this effect is proposed. The results are verified using simulations in MATLAB/Simulink.
|
|
| 9. |
- Bornefalk, Hans, et al.
(författare)
-
Design considerations to overcome cross talk in a photon counting silicon strip detector for computed tomography
- 2010
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 621:1-3, s. 371-378
-
Tidskriftsartikel (refereegranskat)abstract
- This article presents a Monte Carlo simulation of the detector energy response in the presence of pileup in a segmented silicon microstrip detector designed for high flux spectral computed tomography with sub-millimeter pixel size. Currents induced on the collection electrode of a pixel segment are explicitly modeled and signals emanating from events in neighboring pixels are superimposed together with electronic noise before the entire pulse train is processed by a model of the readout electronics to obtain the detector energy response function. The article shows how the lower threshold and the time constant of the electronic filters need to be set in order to minimize the detrimental influence of cross talk from neighboring pixel segments, an issue that is aggravated by the sub-millimeter pixel size and the proposed segmented detector design. (C) 2010 Elsevier B.V. All rights reserved.
|
|
| 10. |
- Bornefalk, Hans, et al.
(författare)
-
Effect of Temperature Variation on the Energy Response of a Photon Counting Silicon CT Detector
- 2013
-
Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 60:2, s. 1442-1449
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of temperature variation on pulse height determination accuracy is determined for a photon counting multibin silicon detector developed for spectral CT. Theoretical predictions of the temperature coefficient of the gain and offset are similar to values derived from synchrotron radiation measurements in a temperature controlled environment. By means of statistical modeling, we conclude that temperature changes affect all channels equally and with separate effects on gain and threshold offset. The combined effect of a 1 degrees C temperature increase is to decrease the detected energy by 0.1 keV for events depositing 30 keV. For the electronic noise, no statistically significant temperature effect was discernible in the data set, although theory predicts a weak dependence. The method is applicable to all x-ray detectors operating in pulse mode.
|
|
| 11. |
- Bornefalk, Hans, et al.
(författare)
-
Image quality in photon counting-mode detector systems
- 2013
-
Patent (populärvet., debatt m.m.)abstract
- The current invention applies to photon counting silicon x-ray detectors with energy discriminating capabilities and applications in x-ray imaging systems. The overall image quality produced by such a system is improved by the presented novel methods for optimally using the energy information in Compton events and making selective use of counts induced from charges collected in neighboring pixels. The pile-up problem during high-flux imaging regimes is reduced by a novel method for signal reset, which improves the count efficiency by reducing the risk of losing event due to signal pile-up in the read out electronics chain.
|
|
| 12. |
- Bornefalk, Hans, et al.
(författare)
-
Simulation study of an energy sensitive photon counting silicon strip detector for computed tomography : identifying strengths and weaknesses and developing work-arounds
- 2010
-
Ingår i: MEDICAL IMAGING 2010. - : SPIE. - 9780819480231
-
Konferensbidrag (refereegranskat)abstract
- We model the effect of signal pile-up on the energy resolution of a photon counting silicon detector designed for high flux spectral CT with sub-millimeter pixel size. Various design parameters, such as bias voltage, lower threshold level for discarding of electronic noise and the entire electronic read out chain are modeled and realistic parameter settings are determined. We explicitly model the currents induced on the collection electrodes of a pixel and superimpose signals emanating from events in neighboring pixels, either due to charge sharing or signals induced during charge collection. Electronic noise is added to the pulse train before feeding it through a model of the read out electronics where the pulse height spectrum is saved to yield the detector energy response function. The main result of this study is that a lower threshold of 5 keV and a rather long time constant of the shaping filter (tau(0) = 30 ns) are needed to discard induced pulses from events in neighboring pixels. These induction currents occur even if no charge is being deposited in the analyzed pixel from the event in the neighboring pixel. There is also only a limited gain in energy resolution by increasing the bias voltage to 1000 V from 600 V. We show that with these settings the resulting energy resolution, as measured by the FWHM/E of the photo peak, is 5% at 70 keV.
|
|
| 13. |
- Carlson, Karin, et al.
(författare)
-
Language policy for a bilingual faculty
- 2005
-
Ingår i: Bi- and multilingual universities, Helsinki, Finland, Sept 1-3, 2005.
-
Konferensbidrag (refereegranskat)abstract
- The Faculty of Science and Technology of Uppsala University is for all practical purposes a bilingual institution, using both Swedish and English in education and research. Extensive use of English in teaching, and also in intrauniversity communication, permits recruitment of nonSwedishspeaking students, researchers and professors, and also prepares our students forinternational careers. However, the introduction of English has been somewhat haphazard, not taking into account possible negative effects on communication in Swedish, nor on students'learning.In order to improve students' and professors' language skills, and achieve a good balance between Swedish and English, the faculty board appointed a language committee in 2003 whose task was to propose a language policy for the faculty. A first part, stating as a main goal that all communication from and within the faculty should have the highest quality possible, has been adopted by the board. A second part including language planning with respect to status, corpus, and acquisition for both Swedish and English to accomplish this goal was sent to the board of the faculty in May, 2005. Implementation of this policy will affect all faculty activities, especially education. Suggestedannual reports on language status will raise our present minimal knowledge about possible domain losses and allow for relevant countermeasures.
|
|
| 14. |
- Danielsson, Christer
(författare)
-
Analysis of Synchronous machine dynamics using a novel equivalent circuit model
- 2009
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis investigates simulation of synchronous machines using a novel Magnetic Equivalent Circuit (MEC) model. The proposed model offers sufficient detail richness for design calculations, while still keeping the simulation time acceptably short. Different modeling methods and circuit alternatives are considered. The selected approach is a combination of several previous methods added with some new features. A detailed description of the new model is given. The flux derivative is chosen as the magnetic flow variable which enables a description with standard circuit elements. The model is implemented in dq-coordinates to reduce complexity and simulation time. A new method to reflect winding harmonics is introduced. Extensive measurements have been made to estimate the traditional dq-model parameters. These in combination with analytical calculations are used to determine the parameters for the new MEC model. The model is implemented using the Dymola simulation program. The results are evaluated by comparison with measurements and FEM simulations. Three different operation cases are investigated; synchronous operation, asynchronous start and inverter fed operation. The agreement with measurements and FEM simulations varies, but it is believed that it can be improved by more work on the parameter determination. The overall conclusion is that the MEC method is a useful approach for detailed simulation of synchronous machines. It enables proper modeling of magnetic saturation, and promises sufficiently detailed results to enable accurate loss calculations. However, the experience is that the complexity of the circuits should be kept at a reasonable low level. It is believed that the practical problems with model structure, parameter determination and the simulation itself will otherwise be difficult to master.
|
|
| 15. |
- Danielsson, Christer, et al.
(författare)
-
Experimental determination of the parameters for a salient rotor synchronous machine with and without pole screens
- 2008
-
Ingår i: ICEM. - 9781424417353
-
Konferensbidrag (refereegranskat)abstract
- This paper investigates simulation models for salient pole solid rotor synchronous machines through experimental model identification. Two different methods are used, the classical Stand-still frequency response test method and the more recent Prediction error method. The results are compared and analyzed. It is shown that a third order model is required to describe the machine dynamics accurately. Further, the impact of extra copper pole screen is investigated, and it is concluded that these could have a beneficial effect with inverter supply.
|
|
| 16. |
- Danielsson, Erik, et al.
(författare)
-
A 4H-SiC BJT with an epitaxially regrown extrinsic base layer
- 2005
-
Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 483, s. 905-908
-
Tidskriftsartikel (refereegranskat)abstract
- 4H-SiC BJTs were fabricated using epitaxial regrowth instead of ion implantation to form a highly doped extrinsic base layer necessary for a good base ohmic contact. A remaining p(+) regrowth spacer at the edge of the base-emitter junction is proposed to explain a low current gain of 6 for the BJTs. A breakdown voltage of 1000 V was obtained for devices with Al implanted JTE.
|
|
| 17. |
- Danielsson, Mats, Professor, et al.
(författare)
-
Edge-on photon-counting detector
- 2021
-
Patent (populärvet., debatt m.m.)abstract
- An edge-on photon-counting detector includes at least one detector module having a respective edge facing incident X-rays. The at least one detector module includes a semiconductor substrate. The edge-on photon-counting detector also includes a plurality of active integrated pixels arranged in the semiconductor substrate.
|
|
| 18. |
|
|
| 19. |
- Danielsson, Ninni, et al.
(författare)
-
Introducing Users to Privacy and Identity Management in the Context of Usability Testing
- 2005
-
Konferensbidrag (refereegranskat)abstract
- In today's information society, privacy-enhanced identity management can help users to control their personal spheres when makinguse of e-services. However, privacy is a difficult concept to visualise, and comprehensible and intuitive user interfaces are needed to make such systems usable and informative for normal users. Typically, usability tests are used as a means to achieve this. This paper describes how the concept of identity management was introduced to the test subjects before a series of tests on prototypes and mock-ups of user interfaces were conducted. One reason why this was necessary was to provide the test subjects with enough context information to be able to perform the tests. Both oral and written introductions have been used, as well as introductory films. This paper discusses how these introductions have evolved during the usability testing process, and it further elaborates on which kinds of introductions are most suitable for which kind of usability test.
|
|
| 20. |
- Danielsson, Patrik, et al.
(författare)
-
The prevalence of chronic obstructive pulmonary disease in Uppsala, Sweden - the Burden of Obstructive Lung Disease (BOLD) study : cross-sectional population-based study
- 2012
-
Ingår i: Clinical Respiratory Journal. - 1752-6981 .- 1752-699X. ; 6:2, s. 120-127
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: To estimate chronic obstructive pulmonary disease (COPD) prevalence in Uppsala and the impact of risk factors on disease prevalence using the standardised methods of the Burden of Obstructive Lung Disease (BOLD) study initiative. Methods: Randomly selected participants, aged 40 years or more (n = 548) responded to a questionnaire regarding smoking habits, respiratory symptoms, medical history, and exposure to airway irritants. Spirometry, with a post-bronchodilator test, was performed and COPD defined as post-bronchodilatory forced expiratory volume in 1 s (FEV(1) )/forced vital capacity (FVC) < 0.70 or FEV(1) /FVC < lower limit of normality (LLN). Circulatory inflammatory markers were measured. Results: COPD prevalence was 16.2%, which was the fourth lowest prevalence of COPD, compared with 12 other BOLD centres. Main risk factors for COPD were increasing age [odds ratio (OR) = 2.08 per 10 years] and smoking (OR = 1.33 per 10 pack years). Higher education was protective (OR = 0.70 per 5 years). Previous tuberculosis was an almost significant risk factor for COPD (P = 0.08). Subjects with COPD reported more respiratory symptoms but only 29% had previous doctor diagnosed COPD, asthma, chronic bronchitis or emphysema. Participants with COPD had higher levels of C-reactive protein (P = 0.01), but no difference was observed in interleukin 6 (IL-6) levels. Using LLN instead of the fixed FEV(1) /FVC ratio reduced the prevalence of COPD to 10%. Conclusion: COPD prevalence in Uppsala was similar to other BOLD centres in high-income countries. Apart from known COPD risk factors (age, smoking, lower educational level), a history of tuberculosis may be associated with COPD even in high-income countries. COPD remains under-diagnosed, as only 29% of subjects with COPD had a previously diagnosed lung disorder.
|
|
| 21. |
|
|
| 22. |
- Danielsson, Örjan, et al.
(författare)
-
Reducing stress in silicon carbide epitaxial layers
- 2003
-
Ingår i: Journal of Crystal Growth. - : Elsevier. - 0022-0248 .- 1873-5002. ; 252:1-3, s. 289-296
-
Tidskriftsartikel (refereegranskat)abstract
- A susceptor for the epitaxial growth of silicon carbide, with an up-lifted substrate holder, is investigated and compared to other susceptor designs both experimentally and by the use of computational fluid dynamics simulations. It is shown that the wafer bending due to temperature gradients is diminished in a hot-wall reactor compared to growth in a cold-wall reactor. The substrate backside growth is diminished using the up-lifted substrate holder, limiting the substrate bending due to the backside growth. Thereby the stress built into the epitaxial layers during growth is significantly reduced. Simulations indicate a lower effective C/Si ratio over the wafer, and a lower preferable growth temperature, as compared to the original susceptor design. In addition a slightly higher growth rate is achieved
|
|
| 23. |
- Eriksson, Christer, et al.
(författare)
-
Variant size- and glycoforms of the scavenger receptor cysteine-rich protein gp-340 with differential bacterial aggregation
- 2007
-
Ingår i: Glycoconjugate Journal. - : Springer Science and Business Media LLC. - 1573-4986 .- 0282-0080. ; 24:2-3, s. 131-142
-
Tidskriftsartikel (refereegranskat)abstract
- Glycoprotein gp-340 aggregates bacteria in saliva as part of innate defence at mucosal surfaces. We have detected size- and glycoforms of gp-340 between human saliva samples (n=7) and lung gp-340 from a proteinosis patient using antibodies and lectins in Western blots and ELISA measurements. Western blots of saliva samples, and of gp-340 purified, from the seven donors using a gp-340 specific antibody distinguished four gp-340 size variants, designated I to IV (n=2,2,2 and 1). While saliva gp-340 variants I to III had single bands of increasing sizes, variant IV and lung gp-340 had double bands. Purified I to IV proteins all revealed a N-terminal sequence TGGWIP upon Edman degradation. Moreover, purified gp-340 from the seven donors and lung gp-340 shared N-glycans, sialylated Gal beta 1-3GalNAc and (poly)lactosamine structures. However, the larger size gp-340 grouping II/III (n=4) and smaller size grouping I/IV correlated with a secretor, Se(+), and a non secretor, Se(-), dependent glycoform of gp-340, respectively (p=0.03). The Se(+) glycoforms contained ABH, Le(b), Le(y) and polylactosamine structures, while the Se(-) glycoforms lacked ABH antigens but expressed Lea, Lex and lactosamine structures. By contrast, lung gp- 340 completely lacked ABH, Le(a/b), Le(x/y) or sLe(x) structures. Gp-340 and secretor typing of saliva from additional donors (n=29) showed gp-340 glycoforms I to IV for 6, 16, 4 and 0 donors, respectively, and 3 non-typeable donors, and verified that gp-340 glycoforms I and II/III correlate with Se(-) and Se(+) phenotypes, respectively (p < 0.0001). The glycoforms of saliva and lung gp-340 mediated differential aggregation of Le(b)-(Helicobacter pylori), sialylpolylactosamine(Streptococcus suis) or sialic acid- (Streptococcus mutans) binding bacteria. In conclusion, variant size- and glycoforms of gp-340 are expressed by different individuals and may modulate the biological properties of gp-340 pertinent to health and disease.
|
|
| 24. |
- Gong, H., et al.
(författare)
-
Admittance-Dissipativity Analysis and Shaping of Dual-Sequence Current Control for VSCs
- 2022
-
Ingår i: IEEE Journal of Emerging and Selected Topics in Power Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 2168-6777 .- 2168-6785. ; 10:1, s. 324-335
-
Tidskriftsartikel (refereegranskat)abstract
- This paper analyzes the admittance-dissipativity of dual-sequence current control for grid-connected voltage-source converters (VSCs). The output admittance model of dual-sequence current control is first developed in the stationary reference frame by using complex vectors. Impacts of digital filters used within current control and voltage-feedforward (VFF) control loops, and of the delay compensation at the fundamental frequency, are then evaluated. It is found that the cascaded use of sequence-decomposition filter (SDF) and the low-pass filter (LPF) in the VFF control loop adds a non-dissipative region in the output admittance, and the fundamental-frequency delay-compensation further worsens the dissipativity. An analytical design method for the LPF is then developed to mitigate the non-dissipative region, which lowers the instability risks and improves the stability robustness of dual-sequence current control under different grid conditions. Lastly, simulations and experimental results corroborate theoretical analyses.
|
|
| 25. |
- Grinnemo, Karl-Henrik, et al.
(författare)
-
Costimulation blockade induces tolerance to HESC transplanted to the testis and induces regulatory T-cells to HESC transplanted into the heart
- 2008
-
Ingår i: Stem Cells. - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099. ; 26:7, s. 1850-1857
-
Tidskriftsartikel (refereegranskat)abstract
- In order to study the ability of costimulation blockade to induce tolerance to human embryonic stem cells (HESC), severe combined immunodeficient (SCID), and immunocompetent C57BL/6 mice treated with costimulation blockade received intratesticular and intramyocardial HESC transplants. All SCID mice with intratesticular HESC transplants developed teratoma. When SCID mice were transplanted intramyocardially, only two of five mice developed teratoma-like tumors. C57BL/6 mice transplanted intratesticularly and treated with costimulation blockade all developed teratoma and were surrounded by CD4(+)CD25(+)Foxp3(+) T-cells, while isotype control treated recipients rejected their grafts. Most C57BL/6 mice transplanted intramyocardially and treated with costimulation blockade demonstrated lymphocytic infiltrates 1 month after transplantation, whereas one maintained its graft. Isolation of regulatory T-cells from intramyocardial transplanted recipients treated with costimulation blockade demonstrated specificity toward undifferentiated HESC and down-regulated naive T-cell activation toward HESC. These results demonstrate that costimulation blockade is sufficiently robust to induce tolerance to HESC in the immune-privileged environment of the testis. HESC specific regulatory T-cells developed to HESC transplanted to the heart and the success of transplantation was similar to that seen in SCID mice.
|
|
| 26. |
|
|
| 27. |
- Jauhiainen, Alexandra, 1981, et al.
(författare)
-
Distinct cytoplasmic and nuclear functions of the stress induced protein DDIT3/CHOP/GADD153
- 2012
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:4
-
Tidskriftsartikel (refereegranskat)abstract
- DDIT3, also known as GADD153 or CHOP, encodes a basic leucine zipper transcription factor of the dimer forming C/EBP family. DDIT3 is known as a key regulator of cellular stress response, but its target genes and functions are not well characterized. Here, we applied a genome wide microarray based expression analysis to identify DDIT3 target genes and functions. By analyzing cells carrying tamoxifen inducible DDIT3 expression constructs we show distinct gene expression profiles for cells with cytoplasmic and nuclear localized DDIT3. Of 175 target genes identified only 3 were regulated by DDIT3 in both cellular localizations. More than two thirds of the genes were downregulated, supporting a role for DDIT3 as a dominant negative factor that could act by either cytoplasmic or nuclear sequestration of dimer forming transcription factor partners. Functional annotation of target genes showed cell migration, proliferation and apoptosis/survival as the most affected categories. Cytoplasmic DDIT3 affected more migration associated genes, while nuclear DDIT3 regulated more cell cycle controlling genes. Cell culture experiments confirmed that cytoplasmic DDIT3 inhibited migration, while nuclear DDIT3 caused a G1 cell cycle arrest. Promoters of target genes showed no common sequence motifs, reflecting that DDIT3 forms heterodimers with several alternative transcription factors that bind to different motifs. We conclude that expression of cytoplasmic DDIT3 regulated 94 genes. Nuclear translocation of DDIT3 regulated 81 additional genes linked to functions already affected by cytoplasmic DDIT3. Characterization of DDIT3 regulated functions helps understanding its role in stress response and involvement in cancer and degenerative disorders.
|
|
| 28. |
|
|
| 29. |
|
|
| 30. |
- Lakens, Daniel, et al.
(författare)
-
Justify your alpha
- 2018
-
Ingår i: Nature Human Behaviour. - : Nature Publishing Group. - 2397-3374. ; 2:3, s. 168-171
-
Tidskriftsartikel (refereegranskat)abstract
- In response to recommendations to redefine statistical significance to P ≤ 0.005, we propose that researchers should transparently report and justify all choices they make when designing a study, including the alpha level.
|
|
| 31. |
- Liegnell, Rasmus, et al.
(författare)
-
Elevated plasma lactate levels via exogenous lactate infusion do not alter resistance exercise-induced signaling or protein synthesis in human skeletal muscle.
- 2020
-
Ingår i: American Journal of Physiology. Endocrinology and Metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 319, s. E792-E804
-
Tidskriftsartikel (refereegranskat)abstract
- Lactate has been implicated as a potential signaling molecule. In myotubes, lactate incubation increases mTORC1- and ERK-signaling and induces hypertrophy, indicating that lactate could be a mediator of muscle adaptations to resistance exercise. However, the potential signaling properties of lactate, at rest or with exercise, have not been explored in human tissue. In a cross-over design study, 8 men and 8 women performed one-legged resistance exercise while receiving venous infusion of saline or sodium lactate. Blood was sampled repeatedly, and muscle biopsies were collected at rest and at 0, 90,180 min and 24 h after exercise. The primary outcomes examined were intracellular signaling, fractional protein synthesis rate (FSR), and blood/muscle levels of lactate and pH. Post-exercise blood lactate concentrations were 130% higher in the Lactate trial (3.0 vs 7.0 mmol×l-1, p<0.001) whereas muscle levels were only marginally higher (27 vs 32 mmol×kg-1 d.w., p=0.003) compared to the Saline-trial. Post-exercise blood pH was higher in the Lactate-trial (7.34 vs 7.44, p<0.001), with no differences in intramuscular pH. Exercise increased the phosphorylation of mTORS2448 (~40%), S6K1T389 (~3-fold), and p44T202/T204 (~80%) during recovery, without any differences between trials. FSR over the 24-h recovery period did not differ between the Saline (0.067 %/h) and Lactate (0.062 %/h) trials. This study does not support the hypothesis that blood lactate levels can modulate anabolic signaling in contracted human muscle. Further in vivo research investigating the impact of exercised versus rested muscle and the role of intramuscular lactate is needed to elucidate its potential signaling properties.
|
|
| 32. |
|
|
| 33. |
- Ramberg, Christina, 1962-, et al.
(författare)
-
Preliminära skiljedomar
- 2013
-
Ingår i: Juridisk Tidskrift. - 1100-7761. ; :2, s. 452-455
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 34. |
|
|
| 35. |
- Sundberg, Christel, et al.
(författare)
-
Increasing the dose efficiency in silicon photon-counting detectors utilizing dual shapers
- 2018
-
Ingår i: Medical Imaging 2018. - : SPIE - International Society for Optical Engineering. - 9781510616363
-
Konferensbidrag (refereegranskat)abstract
- Silicon photon-counting spectral detectors are candidates for the next generation of medical CT. For silicon detectors, a low noise floor is necessary to obtain good detection efficiency. A low noise floor can be obtained by having a slow shaping filter in the ASIC, but this leads to a long dead-time, thus decreasing the count-rate performance. In this work, we evaluate the benefit of utilizing two sub-channels with different shaping times. It is shown by simulation that utilizing a dual shaper can increase the dose efficiency for equal count-rate capability by up to 17%.
|
|
| 36. |
- Svensson, Christer, 1941-, et al.
(författare)
-
X-ray detector system based on photon counting
- 2018
-
Patent (populärvet., debatt m.m.)abstract
- Disclosed is an x-ray detector system including a multitude of detector elements, each connected to a respective photon counting channel for providing at least one photon count output, and a read-out unit connected to the photon counting channels for outputting the photon count outputs. Each one of at least a subset of the photon counting channels includes at least two photon counting sub-channels, each photon counting sub-channel providing at least one photon count output and having a shaping filter, wherein the shaping filters of the photon counting sub-channels are configured with different shaping times, and wherein the photon counting sub-channels, having shaping filters with different shaping times, are adapted for counting photons of different energy levels. Furthermore, the read-out unit is configured to select, for each photon counting channel, photon count outputs from the photon counting sub-channels.
|
|
| 37. |
|
|
| 38. |
- Söderlind, Eskil, et al.
(författare)
-
Recombining germline-derived CDR sequences for creating diverse single-framework antibody libraries
- 2000
-
Ingår i: Nature Biotechnology. - : Springer Science and Business Media LLC. - 1087-0156 .- 1546-1696. ; 18:8, s. 852-856
-
Tidskriftsartikel (refereegranskat)abstract
- We constructed a single-chain Fv antibody library that permits human complementarity-determining region (CDR) gene fragments of any germline to be incorporated combinatorially into the appropriate positions of the variable-region frameworks VH-DP47 and VL-DPL3. A library of 2 x 109 independent transformants was screened against haptens, peptides, carbohydrates, and proteins, and the selected antibody fragments exhibited dissociation constants in the subnanomolar range. The antibody genes in this library were built on a single master framework into which diverse CDRs were allowed to recombine. These CDRs were sampled from in vivo-processed gene sequences, thus potentially optimizing the levels of correctly folded and functional molecules, and resulting in a molecule exhibiting a lower computed immunogenicity compared to naive immunoglobulins. Using the modularized assembly process to incorporate foreign sequences into an immunoglobulin scaffold, it is possible to vary as many as six CDRs at the same time, creating genetic and funcfional variation in antibody molecules.
|
|
| 39. |
- Xu, Cheng, et al.
(författare)
-
Energy resolution of a segmented silicon strip detector for photon-counting spectral CT
- 2013
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 715, s. 11-17
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated the energy resolution of a segmented silicon strip detector for photon-counting spectral computed tomography (CT). The detector response to different monochromatic photon energies and various photon fluxes was characterized at the Elettra synchrotron. An RMS energy resolution of 1.50 keV has been demonstrated for 22 keV photons at zero flux, and it deteriorated as a function of input count rate at a rate of 5.1 eV mm(2)/Mcps. The charge sharing effect has been evaluated. The results show that around 11.1% of the interacting photons experience charge sharing for 22 keV photons and 15.3% for 30 keV.
|
|
| 40. |
- Xu, Cheng, et al.
(författare)
-
Evaluation of a Second-Generation Ultra-Fast Energy-Resolved ASIC for Photon-Counting Spectral CT
- 2013
-
Ingår i: IEEE Transactions on Nuclear Science. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9499 .- 1558-1578. ; 60:1, s. 437-445
-
Tidskriftsartikel (refereegranskat)abstract
- A second-generation ultra-fast energy-resolved application specific integrated circuit (ASIC) has been developed for photon-counting spectral computed tomography (CT). The energy resolution, threshold dispersion and gain of the ASIC were characterized with synchrotron radiation at Diamond Light Source. The standard deviation of threshold offsets at zero keV is 0.89 keV. An RMS energy resolution of 1.09 keV has been demonstrated for 15 keV photon energy at a count rate of 40 kcps, and it deteriorates at a rate of 0.29 keV/Mcps with the increase of output cout rate. The count rate performance of the ASIC has also been evaluated with 120 kV polychromatic x-rays produced by a tungsten anode tube and the results are presented.
|
|
| 41. |
- Xu, Cheng, et al.
(författare)
-
Evaluation of an ultra-fast photon-counting energy-resolved ASIC for spectral CT
- 2012
-
Ingår i: Progress in Biomedical Optics and Imaging - Proceedings of SPIE. - : SPIE - International Society for Optical Engineering. - 9780819489623 ; , s. 83130Y-
-
Konferensbidrag (refereegranskat)abstract
- We have developed an ultra-fast photon-counting energy-resolved application specific integrated circuit (ASIC) for spectral computed tomography (CT). A comprehensive characterization has been carried out to investigate the performance of the ASIC in terms of energy resolution under different photon flux rates and the count rate linearity in photon-counting mode. An energy resolution of 4.7 % has been achieved for 59.5 keV low flux photons. The count rate performance of the ASIC was measured with 120 kVp polychromatic x-rays. The results indicate that the count rate linearity can be kept for a flux rate up to 150 Mphotons s -1 mm -2 with retained energy information, and this value is increased to be 250 Mphotons s -1 mm -2 in photon-counting mode.
|
|
| 42. |
- Xu, Cheng, et al.
(författare)
-
Performance characterization of a silicon strip detector for spectral computed tomography utilizing a laser testing system
- 2011
-
Ingår i: MEDICAL IMAGING 2011. - : SPIE. - 9780819485038 - 0819485039
-
Konferensbidrag (refereegranskat)abstract
- A new silicon strip detector with sub-millimeter pixel size operated in single photon-counting mode has been developed for use in spectral computed tomography (CT). An ultra fast application specific integrated circuit (ASIC) specially designed for fast photon-counting application is used to process the pulses and sort them into eight energy bins. This report characterizes the ASIC and detector in terms of thermal noise (0.77 keV RMS), energy resolution when electron-hole pairs are generated in the detector diode (1.5 keV RMS) and Poissonian count rate with retained count rate linearity and energy resolution (200 Mcps.mm(-2)). The performance of the photon-counting detector has been tested using a picosecond pulsed laser system to inject energy into the detector, simulating x-ray interactions. The laser testing results indicate a good energy-discriminating capability of the detector, assigning the pulses to higher and higher energy bins as the intensity of the laser pulses are increased.
|
|
| 43. |
- Xu, Cheng, et al.
(författare)
-
Preliminary evaluation of a silicon strip detector for photon-counting spectral CT
- 2012
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 677, s. 45-51
-
Tidskriftsartikel (refereegranskat)abstract
- An edge-on silicon strip detector designed for photon-counting spectral computed tomography (CT) is presented. Progress on the development of an application specific integrated circuit (ASIC) to process the pulses and sort them into energy bins is reported upon. The ASIC and detector are evaluated in terms of electronic noise, energy resolution, count rate linearity under high-frequency periodic pulses, threshold variation and gain. The high-frequency periodic pulses are injected both by means of an external pulse generator and a pulsed laser illuminating the silicon diode. The pulsed laser system has similar to 100 ps pulse width and thus generates near instantaneous pulses in the diode, thus mimicking real X-ray conversions. The evaluation shows a low thermal noise level of 0.77 key RMS, an energy resolution of 1.5 keV RMS when electron-hole pairs are generated in the detector diode by the laser injection. The test results furthermore indicate a good energy-discriminating capability of the detector with the thresholds spread out, assigning the external pulses to higher and higher energy bins as the pulse intensity is increased.
|
|
| 44. |
- Zhang, Hongyang, et al.
(författare)
-
Loop-at-a-Time Stability Analysis for Grid-Connected Voltage-Source Converters
- 2021
-
Ingår i: IEEE Journal of Emerging and Selected Topics in Power Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 2168-6777 .- 2168-6785. ; 9:5, s. 5807-5821
-
Tidskriftsartikel (refereegranskat)abstract
- The instability phenomena caused by converter–grid interactions can be prevented by designing controllers with adequate stability margins. Yet, the multiple-input–multiple-output (MIMO) dynamics of grid-connected voltage-source converters (VSCs) complicate the stability analysis for the controller design. To tackle this challenge, this article presents a loop-at-a-time stability analysis for grid-connected VSCs, which not only shows close correlations with the generalized Nyquist criterion for MIMO systems but also enables to quantify the stability margins of individual closed loops. Moreover, the interactions between the closed loops can be analyzed. Test cases with numerical sensitivity analysis, simulations, and field measurements of a converter validate the theory.
|
|
| 45. |
- Zhou, K., et al.
(författare)
-
An overlooked subset of Cx3cr1(wt/wt) microglia in the Cx3cr1(CreER-Eyfp/wt) mouse has a repopulation advantage over Cx3cr1(CreER-Eyfp/wt) microglia following microglial depletion
- 2022
-
Ingår i: Journal of Neuroinflammation. - : Springer Science and Business Media LLC. - 1742-2094. ; 19:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background Fluorescent reporter labeling and promoter-driven Cre-recombinant technologies have facilitated cellular investigations of physiological and pathological processes, including the widespread use of the Cx3cr1(CreER-Eyfp/wt) mouse strain for studies of microglia. Methods Immunohistochemistry, Flow Cytometry, RNA sequencing and whole-genome sequencing were used to identify the subpopulation of microglia in Cx3cr1(CreER-Eyfp/wt) mouse brains. Genetically mediated microglia depletion using Cx3cr1(CreER-Eyfp/wt)Rosa26(DTA/wt) mice and CSF1 receptor inhibitor PLX3397 were used to deplete microglia. Primary microglia proliferation and migration assay were used for in vitro studies. Results We unexpectedly identified a subpopulation of microglia devoid of genetic modification, exhibiting higher Cx3cr1 and CX3CR1 expression than Cx3cr1(CreER-Eyfp/wt)Cre(+)Eyfp(+) microglia in Cx3cr1(CreER-Eyfp/wt) mouse brains, thus termed Cx3cr1(high)Cre(-)Eyfp(-) microglia. This subpopulation constituted less than 1% of all microglia under homeostatic conditions, but after Cre-driven DTA-mediated microglial depletion, Cx3cr1(high)Cre(-)Eyfp(-) microglia escaped depletion and proliferated extensively, eventually occupying one-third of the total microglial pool. We further demonstrated that the Cx3cr1(high)Cre(-)Eyfp(-) microglia had lost their genetic heterozygosity and become homozygous for wild-type Cx3cr1. Therefore, Cx3cr1(high)Cre(-)Eyfp(-) microglia are Cx3cr1(wt/wt)Cre(-)Eyfp(-). Finally, we demonstrated that CX3CL1-CX3CR1 signaling regulates microglial repopulation both in vivo and in vitro. Conclusions Our results raise a cautionary note regarding the use of Cx3cr1(CreER-Eyfp/wt) mouse strains, particularly when interpreting the results of fate mapping, and microglial depletion and repopulation studies.
|
|
