Optical anisotropy induced by ion bombardment of Ag(001)

Grazing incidence ion bombardment results in the formation of nanoripples that induce an anisotropic optical reflection The evolution of the reflectance anisotropy has been monitored in situ with reflectance anisotropy spectroscopy. The Rayleigh-Rice theory (RRT) has been used to analyze the optical spectra quantitatively and provides the evolution of the average ripple period and root-mean-squared surface roughness. After an incipient phase, both the increase in the periodicity and the roughness vary roughly with the square root of the sputter time. Additional high-resolution low-energy electron diffraction (HR-LEED) measurements have been performed to characterize details of the average structure created by ion bombardment

Characterization of nanometre-scale patterns on CU(001) and AG(001) by means of optical spectroscopy and high-resolution electron diffraction

The creation of nanometre-scale patterns by self organization is of great interest, because of its potential to homogeneously cover large areas in a fast and cheap way. To be able to use this technique in an industrial environment, it is of great importance that one understands the underlying fundamental mechanisms. Often this is achieved by (ex-situ) analysis of the patterned surfaces after the self-organization process. However, to fully understand the pattern formation process, an in-situ probe is needed. For this purpose we have set up and applied an optical in-situ technique (Reflectance Anisotropy Spectroscopy; RAS) to measure the difference in reflection along two perpendicular azimuth directions. We developed a model to analyze the results in detail and obtain the parameters that describe the main properties of the evolving anisotropic surface patterns, such as periodicity and amplitude.\ud \ud The applicability of our model is demonstrated in different situations. We show that the azimuth-direction plays an important role in determining the final morphology of the surface in addition to parameters like the substrate temperature, the ions’ polar angle of incidence and the ion energy. RAS is shown to be a viable in-situ monitor of the emerging average periodicity and amplitude of ripples formed during ion erosion at a polar angle of incidence of 70 degrees, For periodicities below 200nm, analysis with the Rayleigh-Rice (RRT) assuming a one-dimensional Gaussian periodicity distribution is sufficient to describe the optical data. The creation of more two-dimensional features, obtained at a polar angle of incidence of 61.5 degrees, can be monitored and analyzed in a similar way by extending our model in 2 dimensions. Again a Gaussian distribution fits the data best. Even ripples with a periodicity below 200nm, obtained at a polar of incidence of 80 degrees, can be monitored with RAS, but the periodicity and amplitude are strongly coupled in this case. Finally, RAS can also be used to obtain morphological information during growth of ultrathin films

Thyroid hormone uptake in cultured rat anterior pituitary cells: effects of energy status and bilirubin

Transport of thyroxine (T(4)) into the liver is inhibited in fasting and by bilirubin, a compound often accumulating in the serum of critically ill patients. We tested the effects of chronic and acute energy deprivation, bilirubin and its precursor biliverdin on the 15-min uptake of [(125)I]tri-iodothyronine ([(125)I]T(3)) and [(125)I]T(4) and on TSH release in rat anterior pituitary cells maintained in primary culture for 3 days. When cells were cultured and incubated in medium without glucose and glutamine to induce chronic energy deprivation, the ATP content was reduced by 45% (P<0. 05) and [(125)I]T(3) uptake by 13% (NS), but TSH release was unaltered. Preincubation (30 min) and incubation (15 min) with 10 microM oligomycin reduced ATP content by 51% (P<0.05) and 53% (P<0. 05) under energy-rich and energy-poor culture conditions respectively; [(125)I]T(3) uptake was reduced by 66% (P<0.05) and 64% (P<0.05). Neither bilirubin nor biliverdin (both 1-200 microM) affected uptake of [(125)I]T(3) or [(125)I]T(4). Bilirubin (1-50 microM) did not alter basal or TRH-induced TSH release. In conclusion, the absence of inhibitory effects of chronic energy deprivation and bilirubin on thyroid hormone uptake by pituitary cells supports the view that the transport is regulated differently than that in the liver

Effects of interleukin-1 beta on thyrotropin secretion and thyroid hormone uptake in cultured rat anterior pituitary cells

The effects of interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF alpha) on basal and TRH-induced TSH release, and the effects of IL-1 beta on the uptake of [125I]T3 and [125I]T4 and on nuclear binding of [125I]T3 were examined. Furthermore, the release of other anterior pituitary hormones in the presence of IL-1 beta was measured. Anterior pituitary cells from male Wistar rats were cultured for 3 days in medium containing 10% FCS. Incubation were performed at 37 C in medium with 0.5% BSA for measurement of [125I]T3 uptake and with 0.1% BSA for measurement of [125I]T4 uptake. Exposure to IL-1 beta (1 pM-1 nM) or TNF alpha (100 pM) for 2-4 h resulted in a significant decline in TSH release, which was almost 50% (P < 0.05) for 1 nM IL-1 beta and 24% (P < 0.05) for 100 pM TNF alpha. Measurement of other anterior pituitary hormones (FSH, LH, PRL, and ACTH) in the same incubation medium showed that IL-1 beta did not alter their release. When the effects of IL-1 beta (1 pM-1 nM) and TNF alpha (100 pM) on TRH-induced TSH release were measured in short term experiments, the inhibitory effects had disappeared. The addition of 1-100 nM octreotide, a somatostatin analog, resulted in a decrease in TRH-induced TSH release up to 33% of the control value (P < 0.05). Exposure to dexamethasone (1 nM to 1 microM) affected basal and TRH-induced TSH release similar to the effect of IL-1 beta. The 15-min uptake of [125I]T3 and [125I]T4, expressed as femtomoles per pM free hormone, was not affected by the presence of IL-1 beta (1-100 pM). When IL-1 beta (100 pM) was present during 3 days of culture, TSH release was reduced to 88 +/- 2% of the control value (P < 0.05). This effect was not associated with an altered [125I]T3 uptake (15 min to 4 h) or with any change in nuclear T3 binding. We conclude that 1) IL-1 beta decreases TSH release by a direct action on the pituitary; 2) this effect is not due to elevated thyroid hormone uptake or increase T3 nuclear occupancy; 3) IL-1 beta does not affect TRH-induced TSH release or the release of other anterior pituitary hormones; and 4) TNF alpha affects basal and TRH-induced TSH release in the same way as IL-1 beta

Evaluation of Ac-Lys(0)(IRDye800CW)Tyr(3)-octreotate as a novel tracer for SSTR2-targeted molecular fluorescence guided surgery in meningioma

PURPOSE: Meningioma recurrence rates can be reduced by optimizing surgical resection with the use of intraoperative molecular fluorescence guided surgery (MFGS). We evaluated the potential of the fluorescent tracer 800CW-TATE for MFGS using in vitro and in vivo models. It targets somatostatin receptor subtype 2 (SSTR(2)), which is overexpressed in all meningiomas. METHODS: Binding affinity of 800CW-TATE was evaluated using [(177)Lu] Lu-DOTA-Tyr(3)-octreotate displacement assays. Tumor uptake was determined by injecting 800CW-TATE in (SSTR(2)-positive) NCI-H69 or (SSTR(2)-negative) CH-157MN xenograft bearing mice and FMT2500 imaging. SSTR(2)-specific binding was measured by comparing tumor uptake in NCI-H69 and CH-157MN xenografts, blocking experiments and non-targeted IRDye800CW-carboxylate binding. Tracer distribution was analyzed ex vivo, and the tumor-to-background ratio (TBR) was calculated. SSTR(2) expression was determined by immunohistochemistry (IHC). Lastly, 800CW-TATE was incubated on frozen and fresh meningioma specimens and analyzed by microscopy. RESULTS: 800CW-TATE binding affinity assays showed an IC(50) value of 72 nM. NCI-H69 xenografted mice showed a TBR of 21.1. 800CW-TATE detection was reduced after co-administration of non-fluorescent DOTA-Tyr(3)-octreotate or administration of IRDye800CW. CH-157MN had no tumor specific tracer staining due to absence of SSTR(2) expression, thereby serving as a negative control. The tracer bound specifically to SSTR(2)-positive meningioma tissues representing all WHO grades. CONCLUSION: 800CW-TATE demonstrated sufficient binding affinity, specific SSTR(2)-mediated tumor uptake, a favorable biodistribution, and high TBR. These features make this tracer very promising for use in MFGS and could potentially aid in safer and a more complete meningioma resection, especially in high-grade meningiomas or those at complex anatomical localizations. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11060-021-03739-1

Heritability and Phenotypic Variation of Canine Hip Dysplasia Radiographic Traits in a Cohort of Australian German Shepherd Dogs

Canine Hip Dysplasia (CHD) is a common, painful and debilitating orthopaedic disorder of dogs with a partly genetic, multifactorial aetiology. Worldwide, potential breeding dogs are evaluated for CHD using radiographically based screening schemes such as the nine ordinally-scored British Veterinary Association Hip Traits (BVAHTs). The effectiveness of selective breeding based on screening results requires that a significant proportion of the phenotypic variation is caused by the presence of favourable alleles segregating in the population. This proportion, heritability, was measured in a cohort of 13,124 Australian German Shepherd Dogs born between 1976 and 2005, displaying phenotypic variation for BVAHTs, using ordinal, linear and binary mixed models fitted by a Restricted Maximum Likelihood method. Heritability estimates for the nine BVAHTs ranged from 0.14–0.24 (ordinal models), 0.14–0.25 (linear models) and 0.12–0.40 (binary models). Heritability for the summed BVAHT phenotype was 0.30±0.02. The presence of heritable variation demonstrates that selection based on BVAHTs has the potential to improve BVAHT scores in the population. Assuming a genetic correlation between BVAHT scores and CHD-related pain and dysfunction, the welfare of Australian German Shepherds can be improved by continuing to consider BVAHT scores in the selection of breeding dogs, but that as heritability values are only moderate in magnitude the accuracy, and effectiveness, of selection could be improved by the use of Estimated Breeding Values in preference to solely phenotype based selection of breeding animals

Glycomic analysis of life stages of the human parasite Schistosoma mansoni reveals developmental expression profiles of functional and antigenic glycan motifs

Contains fulltext : 155377.pdf (publisher's version ) (Open Access)Glycans present on glycoproteins and glycolipids of the major human parasite Schistosoma mansoni induce innate as well as adaptive immune responses in the host. To be able to study the molecular characteristics of schistosome infections it is therefore required to determine the expression profiles of glycans and antigenic glycan-motifs during a range of critical stages of the complex schistosome lifecycle. We performed a longitudinal profiling study covering schistosome glycosylation throughout worm- and egg-development using a mass spectrometry-based glycomics approach. Our study revealed that during worm development N-glycans with Galbeta1-4(Fucalpha1-3)GlcNAc (LeX) and core-xylose motifs were rapidly lost after cercariae to schistosomula transformation, whereas GalNAcbeta1-4GlcNAc (LDN)-motifs gradually became abundant and predominated in adult worms. LeX-motifs were present on glycolipids up to 2 weeks of schistosomula development, whereas glycolipids with mono- and multifucosylated LDN-motifs remained present up to the adult worm stage. In contrast, expression of complex O-glycans diminished to undetectable levels within days after transformation. During egg development, a rich diversity of N-glycans with fucosylated motifs was expressed, but with alpha3-core fucose and a high degree of multifucosylated antennae only in mature eggs and miracidia. N-glycan antennae were exclusively LDN-based in miracidia. O-glycans in the mature eggs were also diverse and contained LeX- and multifucosylated LDN, but none of these were associated with miracidia in which we detected only the Galbeta1-3(Galbeta1-6)GalNAc core glycan. Immature eggs also exhibited short O-glycan core structures only, suggesting that complex fucosylated O-glycans of schistosome eggs are derived primarily from glycoproteins produced by the subshell envelope in the developed egg. Lipid glycans with multifucosylated GlcNAc repeats were present throughout egg development, but with the longer highly fucosylated stretches enriched in mature eggs and miracidia. This global analysis of the developing schistosome's glycome provides new insights into how stage-specifically expressed glycans may contribute to different aspects of schistosome-host interactions

Future time perspective in depression

This investigation sets out to establish ex­perimentally whether depressed patients are limited in their perspective of the future. Eighty-five subjects are used, in three groups - depressives, paranoid schizophrenic controls, and non-psychiatric controls. The results indicate that depressives name fewer prospects in their future than non-depressed subjects, as postulated. Contrary to expectation, however, paranoid schizophrenics are found to be as orientated towards the present as depressives. No comment can be made regarding the degree of organization in the future time perspective of subjects, because of a methodological error in the test involved

Anomalous anisotropy in athermal Bradley-Harper roughening of Cu(001)

Ion bombardment induced surface structures on Cu(001) have been studied under conditions obeying the previously “coined athermal Bradley-Harper (BH) region.” Off-normal ion impact along the ⟨110⟩ and the ⟨100⟩ azimuth at 200 K gives rise to different high-resolution low-energy electron-diffraction patterns. Unanticipated and marked deviations from the inherent fourfold symmetry are obtained already at a polar angle of incidence as low as 10°. Experiments with 800 eV Ar+ ions (flux 6×10 12  ions cm−2 s−1 and fluence 4.3×10 16  ions cm−2) clearly show BH behavior for bombardment along [100] in contract to bombardment along [110]. This observation is attributed to the higher probability for surface penetration of ions when incident along ⟨100⟩ . This remarkable finding is further corroborated by measurement at various energies between 0.2 and 2 keV along [100]