1. |
- Hansson, B. A. M., et al.
(author)
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Characterisation of a liquid-xenon jet laser-plasma extreme-ultraviolet source
- 2004
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In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 75:6, s. 2122-2129
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Journal article (peer-reviewed)abstract
- A liquid-xenon-jet laser-plasma source for extreme-ultraviolet (EUV) and soft-x-ray generation has been characterized. Being a source candidate for EUV lithography (EUVL), we especially focus on parameters important for the integration of the source in EUVL systems. The deep-ultraviolet (DUV) out-of-band radiation (=120–400 nm) was quantified, to within a factor of two, using a flying-circus tool together with a transmission-grating spectrograph resulting in a total DUV conversion efficiency (CE) of ~0.33%/2sr. The size and the shape of the xenon plasma was investigated using an in-band-only EUV microscope, based on a spherical Mo/Si multilayer mirror and a charge-coupled device detector. Scalability of the source size from 20–270 µm full width at half maximum was shown. The maximum repetition-rate sustainable by the liquid-xenon-jet target was simulated by a double-pulse experiment indicating feasibility of >17 kHz operation. The xenon-ion energy distribution from the plasma was determined in a time-of-flight experiment with a Faraday-cup detector showing the presence of multi-kilo-electron-volt ions. Sputtering of silicon witness plates exposed to the plasma was observed, while a xenon background of >1 mbar was shown to eliminate the sputtering. It is concluded that the source has potential to meet the requirements of future EUVL systems.
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2. |
- Lumpkin, A. H., et al.
(author)
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Evidence for microbunching "sidebands" in a saturated free-electron laser using coherent optical transition radiation
- 2002
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In: Physical Review Letters. - 1079-7114. ; 88:23, s. 4-4
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Journal article (peer-reviewed)abstract
- We report the first measurements of z -dependent coherent optical transition radiation (COTR) due to electron-beam microbunching at high gains (>10(4) ) including saturation of a self-amplified spontaneous emission free-electron laser (FEL). In these experiments the fundamental wavelength was near 530 nm, and the COTR spectra exhibit the transition from simple spectra to complex spectra (5% spectral width) after saturation. The COTR intensity growth and angular distribution data are reported as well as the evidence for transverse spectral dependencies and an "effective" core of the beam being involved in microbunching.
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3. |
- Albert, J., et al.
(author)
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Risk of HIV transmission from patients on antiretroviral therapy: A position statement from the Public Health Agency of Sweden and the Swedish Reference Group for Antiviral Therapy
- 2014
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In: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 46:10, s. 673-677
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Journal article (peer-reviewed)abstract
- The modern medical treatment of HIV with antiretroviral therapy (ART) has drastically reduced the morbidity and mortality in patients infected with this virus. ART has also been shown to reduce the transmission risk from individual patients as well as the spread of the infection at the population level. This position statement from the Public Health Agency of Sweden and the Swedish Reference Group for Antiviral Therapy is based on a workshop organized in the fall of 2012. It summarizes the latest research and knowledge on the risk of HIV transmission from patients on ART, with a focus on the risk of sexual transmission. The risk of transmission via shared injection equipment among intravenous drug users is also examined, as is the risk of mother-to-child transmission. Based on current knowledge, the risk of transmission through vaginal or anal intercourse involving the use of a condom has been judged to be minimal, provided that the person infected with HIV fulfils the criteria for effective ART. This probably also applies to unprotected intercourse, provided that no other sexually transmitted infections are present, although it is not currently possible to fully support this conclusion with direct scientific evidence. ART is judged to markedly reduce the risk of blood-borne transmission between people who share injection equipment. Finally, the risk of transmission from mother to child is very low, provided that ART is started well in advance of delivery.
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4. |
- Berglund, Magnus M.
(author)
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Cloning and structure-activity relationship studies of neuropeptide Y family receptors belonging to the Y1 subfamily
- 1999
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Doctoral thesis (other academic/artistic)abstract
- Neuropeptide Y (NPY), peptide YY (PYY), and the pancreatic polypeptide (PP) belong to afamily of structurally related 36-amino-acid peptides. NPY acts as a neurotransmitter both inthe central and the peripheral nervous system and influences many functions includingfeeding, reproduction, and blood pressure while PYY and PP mainly act as hormones in thegut.NPY, PYY, and PP bind to a family of G-protein coupled receptors. This thesis describesthe cloning of five NPY-family receptors, three of which are new subtypes, using degenerateprimers and homology screenings. The rapidly evolving PP-preferring receptor Y4 fromhuman (h) and guinea pig (gp) were found to be more closely related to each other than eitherwas to the rat receptor. The gpY1 receptor is highly conserved with 91-92% identity to Y1from other orders of mammals. Two highly homologous zebrafish (z) receptors, zYb and zYc(75% identical), were cloned. These receptors form together with mammalian Y1, Y4, and y6and a third zebrafish receptor, zYa, a subfamily of receptors with 50% identity betweensubtypes.Structure-activity relationships of the gpY1, zYa, zYb, and zYc as well as rY4, rY4, andgpY4 receptors were investigated using peptide analogues with deletions or replacements ofvarious parts of the NPY molecule. The gpY1 receptor has previously been reported to displaydeviant pharmacological properties. However, the binding properties of the cloned gpY1expressed in CHO cells conforms to other cloned mammalian Y1 receptors. Receptors zYband zYc display properties similar to Y1 with a gradual loss of affinity with progressive N-terminal truncation of the NPY molecule. In contrast, NPY and truncated analogues likeNPY13-36 as well as loop-deleted peptides like [Ahx5-24]NPY bind to the zYa receptor withsimilar affinity as NPY. Despite the Y1-like binding profile and amino acid sequences of zYband zYc, neither of these bound the Y1-selective antagonists BIBP3226 and SR120819A.The different ligand-binding profiles of Y1-subfamily receptors together with the highdegree of sequence homology between the subtypes will be very useful in future modeling ofthese receptors. This will promote the development of new drugs, agonists and antagonists,directed against primarily the Y1 receptor but may also have relevance for drugs directedagainst the Y2 and Y5 receptors.
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5. |
- Ellmark, Peter, et al.
(author)
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Phenotypic protein profiling of different B cell sub-populations using antibody CD-microarrays
- 2008
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In: Cancer Letters. - : Elsevier BV. - 0304-3835 .- 1872-7980. ; 265:1, s. 98-106
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Journal article (peer-reviewed)abstract
- Antibody microarrays enable extensive protein expression profiling, and provide a valuable complement to DNA microarray-based gene expression profiling. In this study, we used DotScan (TM) antibody microarrays that contain antibodies against 82 different cell surface antigens, to determine phenotypic protein expression profiles for human B cell sub-populations. We then demonstrated that the B cell protein profile can be used to delineate the relationship between normal B cells and malignant counterparts. Principle component analysis showed that the lymphomas did not cluster with the normal memory B cells or germinal centre B cells, but they did cluster with germinal centre founder cells and naive B cells.
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6. |
- Eriksen, J., et al.
(author)
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Contagiousness in treated HIV-1 infection
- 2021
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In: Infectious Diseases. - : Informa UK Limited. - 2374-4235 .- 2374-4243. ; 53:1, s. 1-8
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Research review (peer-reviewed)abstract
- Background Effective antiretroviral treatment of HIV-1, defined as continuously undetectable virus in blood, has substantial effects on the infectiousness and spread of HIV. Aim This paper outlines the assessment of the Swedish Reference Group for Antiviral Therapy (RAV) and Public Health Agency of Sweden regarding contagiousness of HIV-infected persons on antiretroviral therapy (ART). Results and Conclusion:The expert group concludes that there is no risk of transmission of HIV during vaginal or anal intercourse if the HIV-infected person fulfils the criteria for effective ART. Summary:The effective antiretroviral therapy (ART) for HIV-1 infection has dramatically reduced the morbidity and mortality among people who live with HIV. ART also has a noticeable effect on the infectiousness and on the spread of the disease in society. Knowledge about this has grown gradually. For ART to be regarded effective, the level of the HIV RNA in the plasma should be repeatedly and continuously undetectable and the patient should be assessed as continually having high adherence to treatment. Based on available knowledge the Swedish Reference Group for Antiviral Therapy (RAV) and the Public Health Agency of Sweden make the following assessment: There is no risk of HIV transmission during vaginal or anal intercourse if the HIV positive person fulfils the criteria for effective treatment. This includes intercourse where a condom is not used. However, there are a number of other reasons for recommending the use of condoms, primarily to protect against the transmission of other STIs (sexually transmitted infections) and hepatitis, as well as unwanted pregnancy. The occurrence of other STIs does not affect the risk of HIV transmission in persons on effective ART. It is plausible that the risk for transmission of HIV infection between people who inject drugs and share injection equipment is reduced if the individual with HIV is on effective ART, but there are no studies that directly show this. The risk of transmission from mother to child during pregnancy, labour and delivery is very low if the mother's treatment is initiated well before delivery and if the treatment aim of undetectable virus levels is attained. This is dependent on healthcare services being aware of the mother's HIV infection at an early stage. In most contacts with health and medical care, including dental care, the risk of transmission is not significant if the patient is on effective treatment, but the risk may remain, although considerably reduced, in more advanced interventions such as surgery. When an incident with risk of transmission occurs, the patient must always inform those potentially exposed about his or her HIV infection.
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7. |
- Faresjö, Rebecca, et al.
(author)
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Single domain antibody conjugated to Aβ-binding scFv penetrates BBB via TfR to interact with Aβ
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Other publication (other academic/artistic)abstract
- Background: Camelid antibody fragments are interesting for use as radioligands for Positron Emission Tomography (PET), in central nervous system imaging, due to their fast clearance from blood. This study evaluated single variable domain of heavy chain (VHH) antibodies derived from llama, targeting the mouse and human transferrin receptor (TfR) for mediating increased brain uptake. In experiments, VHHs were combined with either a human Fc or with the single chain fragment of the amyloid beta (Aβ) antibody 3D6 (scFv3D6) to investigate intrabrain targeting.Methods: One novel and one previously disclosed species cross-reactive VHH towards murine TfR (mTfR) and human TfR (hTfR), as well as two VHHs with selective reactivity to mTfR and hTfR, respectively, were compared. The TfR binders were evaluated as recombinant fusion protein (FP) constructs fused with either a human Fc-fragment (FPFc) or with the Aβ-binding fragment scFv3D6 (FPscFv) at either C- or N-terminal positions of scFv3D6. The above FPs were radiolabeled with iodine-125 (125I) and biodistribution was studied ex vivo at 2 h, 6 h and 24 h after injection in wild-type (WT) mice and AD mouse model AppNL-G-F. Brain, blood, plasma and organ concentrations of the 125I-FPs were measured in a γ-counter. Autoradiography, nuclear track emulsion, and immunohistofluorescence imaging were used to study the brain distribution of the FPs. Results: The constructs based on Fc fusions (FPFc) with binding affinity to mTfR displayed significantly higher brain uptake (around 1-3% ID/gbrain) in comparison with FPFc specific to only hTfR (control; 0.2% ID/gbrain). The VHHs reactive to mTfR fused to a scFv (FPscFv) showed an increased brain uptake 2 h after injection compared to control (FPscFv reactive to hTfR only). FPscFv with VHH linked to the N-terminus of scFv3D6 showed more efficient brain delivery than those fused with the C-terminal of scFv3D6. There was a 17-fold higher brain uptake in AppNL-G-F than WT mice for one of the cross-species reactive FPscFv (FPscFv1B) at 24 h post-injection, and 2.5-fold higher at 6 h, in ex vivo studies. FPscFv1B also showed consistently higher relative brain parenchymal localization compared to the other FPs, whether as Fc- or scFv fusion. Conclusion: We showed that the novel cross-reactive VHHs tested herein displayed enhanced brain delivery in mice and that these could be successfully fused with an Aβ-binding scFv-fragment, maintaining high brain and preferential parenchymal delivery with increased retention to Aβ in brain. In summary, a FPscFv construct with affinity towards both Aβ and mTfR showed differentiated and favorable distribution in AD-mice compared to WT already after 6 h (measured ex vivo); a relevant time point for clinical brain PET.
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8. |
- Hansson, Björn, et al.
(author)
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Stabilization of liquified-inert-gas jets for laser-plasma generation
- 2004
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In: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 95:8, s. 4432-4437
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Journal article (peer-reviewed)abstract
- We investigate the hydrodynamic properties of liquified-inert-gas jets in a vacuum with a special emphasis on their stability. Such jets have applications as targets for laser-plasma generation of soft-x-ray and extreme-ultraviolet (EUV) radiation. An important example is the liquid-xenon-jet laser-plasma source, one of the source candidates for EUV lithography. A simple hydrodynamic model in not sufficient to explain experimental observations of jet stability. Evaporation-induced cooling explains observed in-flight freezing of the jet and may be a key factor influencing jet stability. It is shown how the jet stability, and, thus, the stability of the laser-plasma x-ray and EUV emission, are improved by applying localized heating to the tip of the jet-generating nozzle.
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9. |
- Hoppe, Magnus, 1963-, et al.
(author)
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Intended Involvement – How Public Organizations Struggle to Become Co-producers of New Public Values
- 2024
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In: Scandinavian Journal of Public Administration. - : University of Gothenburg School of Public Administration. - 2001-7405 .- 2001-7413. ; 28:1, s. 78-98
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Journal article (peer-reviewed)abstract
- The paper is guided by the question of how public organizations can adapt to include citizens as co-producers of public values. To answer it, eleven researchers and civil servants, all involved in the transformation of a collaborative platform encompassing a university and four different public organizations, formed a collaborative and boundary-spanning author. Building on personal expertise and situated organizational experiences we conclude that public organizations do not adapt except for specific confined areas where they can still control and command outcomes important to them. Hence, public organizations struggle to become co-producers of new public values. From the process, we also conclude that academics and civil servants together writing an academic article cannot be viewed as a fertile common ground for equal collaboration and co-production. Nevertheless, it might still work as an interesting boundary-spanning activity for arriving at shared understandings and important insights on for instance why organizational moves from intended to actual involvement appear difficult.
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10. |
- Lagerström, Malin C., et al.
(author)
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High affinity agonistic metal ion binding sites within the melanocortin 4 receptor illustrate conformational change of transmembrane region 3
- 2003
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In: Journal of Biological Chemistry. - : American Society for Biochemistry and Molecular Biology. - 0021-9258 .- 1083-351X. ; 278:51, s. 51521-51526
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Journal article (peer-reviewed)abstract
- We created a molecular model of the human melanocortin 4 receptor (MC4R) and introduced a series of His residues into the receptor protein to form metal ion binding sites. We were able to insert micromolar affinity binding sites for zinc between transmembrane region (TM) 2 and TM3 where the metal ion alone was able to activate this peptide binding G-protein-coupled receptor. The exact conformation of the metal ion interactions allowed us to predict the orientation of the helices, and remodeling of the receptor protein indicated that Glu100 and Ile104 in TM2 and Asp122 and Ile125 in TM3 are directed toward a putative area of activation of the receptor. The molecular model suggests that a rotation of TM3 may be important for activation of the MC4R. Previous models of G-protein-coupled receptors have suggested that unlocking of a stabilizing interaction between the DRY motif, in the cytosolic part of TM3, and TM6 is important for the activation process. We suggest that this unlocking process may be facilitated through creation of a new interaction between TM3 and TM2 in the MC4R.
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