| 1. |
- Lindgren, Johan, et al.
(författare)
-
Soft-tissue evidence for homeothermy and crypsis in a Jurassic ichthyosaur
- 2018
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 564:7736
-
Tidskriftsartikel (refereegranskat)abstract
- Ichthyosaurs are extinct marine reptiles that display a notable external similarity to modern toothed whales. Here we show that this resemblance is more than skin deep. We apply a multidisciplinary experimental approach to characterize the cellular and molecular composition of integumental tissues in an exceptionally preserved specimen of the Early Jurassic ichthyosaur Stenopterygius. Our analyses recovered still-flexible remnants of the original scaleless skin, which comprises morphologically distinct epidermal and dermal layers. These are underlain by insulating blubber that would have augmented streamlining, buoyancy and homeothermy. Additionally, we identify endogenous proteinaceous and lipid constituents, together with keratinocytes and branched melanophores that contain eumelanin pigment. Distributional variation of melanophores across the body suggests countershading, possibly enhanced by physiological adjustments of colour to enable photoprotection, concealment and/or thermoregulation. Convergence of ichthyosaurs with extant marine amniotes thus extends to the ultrastructural and molecular levels, reflecting the omnipresent constraints of their shared adaptation to pelagic life.
|
|
| 2. |
- Arvidsson, Anna, 1973, et al.
(författare)
-
Early interactions between leukocytes and three different potentially bioactive titanium surface modifications
- 2011
-
Ingår i: Journal of Biomedical Materials Research. Part B - Applied biomaterials. - : Wiley. - 1552-4973 .- 1552-4981. ; 97:2, s. 364-72
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to compare the early interactions between leukocytes and three different surface modifications, suggested as bioactive. Blasted titanium discs were modified by alkali and heat treatment, sodium fluoride treatment, or hydroxyapatite coating. A number of these discs were also immersed in simulated body fluid (SBF) for a week, a treatment which yielded high levels of calcium and phosphate on each surface type. The specimens were exposed for human venous blood for 32 minutes and the respiratory burst response was measured in terms of reactive oxygen species with a luminometer, and coverage of viable cells with a fluorescence microscope after staining steps. The topography, morphology, and chemistry of the surfaces were evaluated with optical interferometry and scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX). A high respiratory burst response was found for HA coated titanium in comparison with the other surface groups (p < 0.0005). The SBF immersion resulted in an increased respiratory burst response (p < 0.0005) and removed statistically significant differences between the surface groups. Thus, the results in the present study indicate that different titanium surface modifications influence the early inflammatory response differently, and that calcium phosphate compounds increase the inflammatory response.
|
|
| 3. |
- Beziat, Vivien, et al.
(författare)
-
NK cell responses to cytomegalovirus infection lead to stable imprints in the human KIR repertoire and involve activating KIRs
- 2013
-
Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 121:14, s. 2678-2688
-
Tidskriftsartikel (refereegranskat)abstract
- Human natural killer (NK) cells are functionally regulated by killer cell immunoglobulin-like receptors (KIRs) and their interactions with HLA class I molecules. As KIR expression in a given NK cell is genetically hard-wired, we hypothesized that KIR repertoire perturbations reflect expansions of unique NK-cell subsets and may be used to trace adaptation of the NK-cell compartment to virus infections. By determining the human KIR-ome at a single-cell level in more than 200 donors, we were able to analyze the magnitude of NK cell adaptation to virus infections in healthy individuals. Strikingly, infection with human cytomegalovirus (CMV), but not with other common herpesviruses, induced expansion and differentiation of KIR-expressing NK cells, visible as stable imprints in the repertoire. Education by inhibitory KIRs promoted the clonal-like expansion of NK cells, causing a bias for self-specific inhibitory KIRs. Furthermore, our data revealed a unique contribution of activating KIRs (KIR2DS4, KIR2DS2, or KIR3DS1), in addition to NKG2C, in the expansion of human NK cells. These results provide new insight into the diversity of KIR repertoire and its adaptation to virus infection, suggesting a role for both activating and inhibitory KIRs in immunity to CMV infection.
|
|
| 4. |
- Johansson, Jakob, et al.
(författare)
-
On the function of lead (Pb) in machining brass alloys
- 2022
-
Ingår i: International Journal of Advanced Manufacturing Technology. - : Springer Science and Business Media LLC. - 0268-3768 .- 1433-3015. ; 120:11-12, s. 7263-7275
-
Tidskriftsartikel (refereegranskat)abstract
- Lead has traditionally been added to brass alloys to achieve high machinability, but the exact mechanisms at work are still debated. Lead-free brass alternatives could be developed if these mechanisms were better understood. Accordingly, machinability characteristics were investigated for two brass alloys with similar mechanical properties and phase composition, but with very different machining characteristics because one has 3 wt.% lead (CuZn38Pb3) while the other has only 0.1 wt.% (CuZn42). The effect of the lead was investigated using infrared temperature measurement, electron microscopy, secondary ion mass spectroscopy, quick-stop methods, and high-speed filming. Neither melting of lead nor its deposition on the tool rake surface takes place during machining thus confirming its limited lubrication and tribological effects. Instead, the main role of lead is to promote discontinuous chip formation. Lead deforms to flake-like shapes that act as crack initiation points when the workpiece material passes through the primary deformation zone. This effect prevents the development of stable tool–chip contact, thus lowering cutting forces, friction, and process temperature.
|
|
| 5. |
|
|
| 6. |
- Nygård, Per, et al.
(författare)
-
Damage Mechanisms in Paper
- 2006
-
Ingår i: 2006 Progress in Paper Physics.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
| 7. |
- Abrahamsson, Per-Anders, et al.
(författare)
-
Factors Predicting the Off-treatment Duration in Patients with Prostate Cancer Receiving Degarelix as Intermittent Androgen Deprivation Therapy
- 2017
-
Ingår i: European Urology Focus. - : Elsevier BV. - 2405-4569. ; 3:4-5, s. 470-479
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Intermittent androgen deprivation therapy (IAD) is commonly used in prostate cancer because of the benefits of the off-treatment period (OTP). The off-treatment time for patients depends on cancer progression, often measured as a rise in prostate-specific antigen (PSA). Objective: To evaluate if certain factors can predict OTP duration following 7-mo degarelix therapy. Design, setting, and participants: This multivariable analysis included 191 prostate cancer patients with baseline PSA 4–50 ng/ml or PSA doubling time <24 mo entering the first OTP with PSA ≤4 ng/ml and testosterone <0.5 ng/ml. OTP continued until disease progression, measured as PSA >4 ng/ml. Despite a study-defined OTP maximum of 24 mo, a 50% failure rate was not observed within certain strata. A Weibull distribution was used to estimate median time to PSA >4 ng/ml adjusted for the following variables: age; baseline (or end of induction period [EOI]) PSA; baseline testosterone; cancer stage/previous curative treatment; and Gleason score. According to the results and the utility of these factors in clinical practice, the model was reduced in a stepwise manner. Time to testosterone recovery (testosterone >0.5 and >2.2 ng/ml) was estimated in a similar manner. Results: The full five-factor model showed that baseline PSA (p < 0.0001), age (p = 0.004), prostate cancer stage/previous therapy (p = 0.023), and baseline testosterone (p = 0.039) influenced OTP. A reduced two-factor model (baseline PSA, age) showed that only baseline PSA influenced OTP (p < 0.0001), and patients with baseline PSA ≤4 ng/ml had the longest OTP. In addition, EOI PSA (p < 0.0001) and age (p = 0.050) significantly influenced OTP. The times to testosterone >0.5 and >2.2 ng/ml were longer for older patients and those with lower baseline testosterone levels. Conclusion: Patients with lower baseline and EOI PSA, and older patients can stay off therapy longer and therefore may benefit more from degarelix IAD. These factors may help in proposing an algorithm to predict the OTP and optimise visit frequency. Patient summary: We describe extended analysis results for a trial in which patients with prostate cancer received intermittent androgen deprivation treatment. Prostate-specific antigen levels at baseline and at the end of the induction period, as well as older age, predicted the duration of the off-treatment period. Testosterone recovery was slower in older patients and in patients who had lower pretreatment testosterone levels. These factors may help in deciding whether to choose continuous or intermittent treatment as a strategy. Trial registration: Clinicaltrials.gov NCT00801242 Age and prostate-specific antigen levels before and at the end of active treatment seem to predict off-treatment duration for degarelix as intermittent androgen deprivation treatment (ADT). This information could be valuable in proposing an algorithm to predict the off-treatment period, optimise visit schedules, and set the restart sate for ADT.
|
|
| 8. |
- Agarwal, Nisha Rani, 1987, et al.
(författare)
-
Investigation of psoriasis skin tissue by label-free multi-modal imaging: a case study on a phototherapy-treated patient
- 2019
-
Ingår i: Psoriasis: Targets and Therapy. - 2230-326X. ; 9, s. 43-57
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Psoriasis is a systemic inflammatory disease characterized by epidermal proliferation in the skin. Altered lipid metabolism is considered to be a central factor in the psoriatic etiopathogenesis. Thus, it is necessary to visualize chemical specificity of the samples for better medical diagnosis and treatment. Here, we investigate its role in the development of psoriatic lesions, before and after ultraviolet phototherapy, in a case study. Methods: The distribution and morphology of different lipids and fibrous proteins in psoriatic (lesional) tissues were visualized by two complementary label-free imaging techniques: 1) non-linear microscopy (NLM), providing images of lipids/proteins throughout the skin layers at submicrometer resolution; and 2) mass spectrometry imaging (MSI), offering high chemical specificity and hence the detection of different lipid species in the epidermal and dermal regions. A conventional method of histological evaluation was performed on the tissues, with no direct comparison with NLM and MSI. Results: Psoriatic tissues had a higher lipid content, mainly in cholesterol, in both the epidermal and dermal regions, compared to healthy tissues. Moreover, the collagen and elastin fibers in the psoriatic tissues had a tendency to assemble as larger bundles, while healthy tissues showed smaller fibers more homogeneously spread. Although phototherapy significantly reduced the cholesterol content, it also increased the amounts of collagen in both lesional and non-lesional tissues. Conclusion: This study introduces NLM and MSI as two complementary techniques which are chemical specific and can be used to assess and visualize the distribution of lipids, collagen, and elastin in a non-invasive and label-free manner.
|
|
| 9. |
- Amombo Noa, Francoise Mystere, 1988, et al.
(författare)
-
Metal-Organic Frameworks with Hexakis(4-carboxyphenyl)benzene: Extensions to Reticular Chemistry and Introducing Foldable Nets
- 2020
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 142:20, s. 9471-9481
-
Tidskriftsartikel (refereegranskat)abstract
- Nine metal-organic frameworks have been prepared with the hexagon-shaped linker 1,2,3,4,5,6-hexakis(4-carboxyphenyl)-benzene (H(6)cpb) by solvothermal reactions in dimethylformamide (dmf) or dimethylacetamide (dmac) with acetic acid or formic acid as modulators: [Bi-2(cpb)(acetato)(2)(dmf)(2)]center dot 2dmf CTH-6 forms a rtl-net; 2(H2NMe2)[Cu-2(cpb)] CTH-7 forms a kgd-net; [Fe-4(cpb)-(acetato)(2)(dmf)(4)] CTH-8 and [Co-4(cpb)(acetato)(2)(dmf)(4)] CTH-9 are isostructural and form yav-nets; 2(HNEt3)[Fe-2(cpb)] CTH-10 and the two polymorphs of 2(H2NMe2)[Zn-2(cpb)]center dot 1.5dmac, Zn-MOF-888 and CTH-11, show kgd-nets; [Cu-2(cpb)-(acetato)(2)(dmf)(2)]center dot 2dmf, CTH-12, forms a mixed coordination and hydrogen-bonded sql-net; and 2(H2NMe2)[Zn-2(cpb)] CTH-13, a similarly mixed yav-net. Surface area values (Brunauer-Emmett-Teller, BET) range from 34 m(2) g(-1) for CTH-12 to 303 m(2) g(-1) for CTH-9 for samples activated at 120 degrees C in dynamic vacuum. All compounds show normal (10-fold higher) molar CO2 versus N-2 uptake at 298 K, except the 19-fold CO2 uptake for CTH-12 containing Cu(II) dinuclear paddle-wheels. We also show how perfect hexagons and triangles can combine to a new 3D topology laf, a model of which gave us the idea of foldable network topologies, as the laf-net can fold into a 2D form while retaining the local geometry around each vertex. Other foldable nets identified are cds, cds-a, ths, sqc163, clh, jem, and tfc covering the basic polygons and their combinations. The impact of this concept on "breathing" MOFs is discussed. I-2 sorption, both from gas phase and from MeOH solution, into CTH-7 were studied by time of flight secondary ion mass spectrometry (ToF-SIMS) on dried crystals. I-2 was shown to have penetrated the crystals, as layers were consecutively peeled off by the ion beam. We suggest ToF-SIMS to be a method for studying sorption depth profiles of MOFs.
|
|
| 10. |
- Angerer, Tina B., 1987, et al.
(författare)
-
Improved Molecular Imaging in Rodent Brain with Time-of-Flight-Secondary Ion Mass Spectrometry Using Gas Cluster Ion Beams and Reactive Vapor Exposure
- 2015
-
Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 87:8, s. 4305-4313
-
Tidskriftsartikel (refereegranskat)abstract
- Imaging mass spectrometry has shown to be a valuable method in medical research and can be performed using different instrumentation and sample preparation methods, each one with specific advantages and drawbacks. Time-of-flight-secondary ion mass spectrometry (TOF-SIMS) has the advantage of high spatial resolution imaging but is often restricted to low mass molecular signals and can be very sensitive to sample preparation artifacts. In this report we demonstrate the advantages of using gas cluster ion beams (GCIBs) in combination with trifluoracetic acid (TFA) vapor exposure for the imaging of lipids in mouse brain sections. There is an optimum exposure to TFA that is beneficial for increasing high mass signal as well as producing signal from previously unobserved species in the mass spectrum. Cholesterol enrichment and crystallization on the sample surface is removed by TFA exposure uncovering a wider range of lipid species in the white matter regions of the tissue, greatly expanding the chemical coverage and the potential application of TOF-SIMS imaging in neurological studies. Ar-4000(+) (40 keV) in combination with TFA treatment facilitates high resolution, high mass imaging closing the gap between TOF-SIMS and matrix-assisted laser desorption ionization (MALDI).
|
|
