536 research outputs found
Monitoring alkylphenols in water using the polar organic chemical integrative sampler (POCIS): determining sampling rates via the extraction of PES membranes and Oasis beads
Polar organic chemical integrative samplers (POCIS) have previously been used to monitor alkylphenol (AP) contamination in water and produced water. However, only the sorbent receiving phase of the POCIS (Oasis beads) is traditionally analyzed, thus limiting the use of POCIS for monitoring a range of APs with varying hydrophobicity. Here a “pharmaceutical” POCIS was calibrated in the laboratory using a static renewal setup for APs (from 2-ethylphenol to 4-n-nonylphenol) with varying hydrophobicity (log Kow between 2.47 and 5.76). The POCIS sampler was calibrated over its 28 day integrative regime and sampling rates (Rs) were determined. Uptake was shown to be a function of AP hydrophobicity where compounds with log Kow < 4 were preferentially accumulated in Oasis beads, and compounds with log Kow > 5 were preferentially accumulated in the PES membranes. A lag phase (over a 24 h period) before uptake in to the PES membranes occurred was evident. This work demonstrates that the analysis of both POCIS phases is vital in order to correctly determine environmentally relevant concentrations owing to the fact that for APs with log Kow ≤ 4 uptake, to the PES membranes and the Oasis beads, involves different processes compared to APs with log Kow ≥ 4. The extraction of both the POCIS matrices is thus recommended in order to assess the concentration of hydrophobic APs (log Kow ≥ 4), as well as hydrophilic APs, most effectively. © 2017 Elsevier Lt
Socioeconomic disparities in early language development in two Norwegian samples
Socioeconomic disparities in early language are widespread and have long-lasting effects. The aim of this study is to investigate when social gaps in language problems arise and how they change across the first years of schooling. We address this question in two large longitudinal Norwegian datasets: the Behavior Outlook Norwegian Developmental Study (BONDS) and the Norwegian Mother, Father and Child Cohort Study (MoBa). Despite some slight differences across the two samples, we found that children from higher social backgrounds are less likely to have language difficulties starting from age 18 months and up to age 8 (grade 2). Moreover, while early language problems are strongly predictive of later language, maternal education makes an additional contribution to explaining language difficulties at the beginning of school life. Social inequality in language development arises early, even in a country like Norway, with low unemployment and one of the most egalitarian societies in Europe.info:eu-repo/semantics/acceptedVersio
Strømundersøkelse og sedimentkvalitet i dypbassenget vest for Malmøykalven, Indre Oslofjord
Strømmålinger nært bunnen (70m) i det anoksiske dypbassenget vest for Malmøykalven i perioden desember 1998-februar 1999 viste maksimale strømhastigheter på <3 cm/s. Slike strømhastigheter vil ikke føre til oppvirvling av sedimenter av siltig/leirig materiale. De havnesedimentene som planlegges dumpet er tildels grovere enn sedimentene på Malmøykalven, slik at sjansene for oppvirvling er enda mindre. Dessuten skal massene tildekkes av rene masser og kornstørrelsen på dekkmassene må avpasses strømforholdene for å hindre at dekkmassene eroderes under perioder med dypvannsutskiftning. Målinger av oksygen i vannmassen i desember viste anoksisk vann fra 40 m og ned til bunnen. Målinger av sedimentenes innhold av miljøgifter (Hg, Cd, Pb, PAH, PCB,TBT og olje) på fem lokaliteter i bassenget viste moderat forurensning, med unntak av PAH og olje som viste høye konsentrasjoner. Sedimentene er tydelig påvirket av dumping av overskuddsmasser i dette bassenget de senere årene. På grunnlag av vurdering av oksygen, strøm og sedimentkvalitet er dette bassenget egnet som deponeringssted for forurensede muddermasser. Det forutsetter imidlertid at massene dekkes til med uforurenset dekkmasse slik at sedimentets miljøstandard heves i forhold til dagens. Det forutsettes også at uavklarte spørsmål vedrørende miljøpåvirkninger knyttet til selve deponeringen og dekkmassens beskaffenhet avklares.Oslo havnevese
Varietal differences in protein polymer built-up of wheat at different temperature and nitrogen regimes during grain filling
Both radionuclide imaging and near-infrared fluorescent (NIRF) imaging have a high sensitivity to detect tumors in vivo. The combination of these modalities using dual-labeled antibodies may allow both preoperative and intraoperative tumor localization and may be used in image-guided surgery to ensure complete resection of tumor tissue. Here, we evaluated the potential of dual-modality imaging of prostate cancer with the monoclonal antibody D2B, directed against an extracellular domain of prostate-specific membrane antigen (PSMA). For these studies, D2B was labeled both with (111)In and with the NIRF dye IRDye800CW.D2B was conjugated with N-hydroxysuccinimide-IRDye800CW and p-isothiocyanatobenzyl-diethylenetriaminepentaacetic acid (ITC-DTPA) and subsequently radiolabeled with (111)In. For biodistribution and NIRF imaging, (111)In-DTPA-D2B-IRDye800CW (2 μg, 0.55 MBq/mouse) was injected intravenously into BALB/c nude mice with subcutaneous PSMA-expressing LNCaP tumors (right flank) and PSMA-negative PC3 tumors (left flank). The biodistribution was determined at 1, 2, 3, and 7 d after injection. In addition, micro-SPECT/CT and NIRF imaging with (111)In-DTPA-D2B-IRDye800CW (3 μg, 8.5 MBq/mouse) was performed on mice with intraperitoneally growing LS174T-PSMA tumors.(111)In-DTPA-D2B-IRDye800CW specifically accumulated in subcutaneous PSMA-positive LNCaP tumors (45.8 ± 8.0 percentage injected dose per gram at 168 h after injection), whereas uptake in subcutaneous PSMA-negative PC3 tumors was significantly lower (6.6 ± 1.3 percentage injected dose per gram at 168 h after injection). Intraperitoneal LS174T-PSMA tumors could be visualized specifically with both micro-SPECT/CT and NIRF imaging at 2 d after injection, and the feasibility of image-guided resection of intraperitoneal tumors was demonstrated in this model.Dual-labeled (111)In-DTPA-D2B-IRDye800CW enables specific and sensitive detection of prostate cancer lesions in vivo with micro-SPECT/CT and NIRF imaging. In addition to preoperative micro-SPECT/CT imaging to detect tumors, NIRF imaging enables image-guided surgical resection. These preclinical findings warrant clinical studies with (111)In-DTPA-D2B-IRDye800CW to improve tumor detection and resection in prostate cancer patients
Measuring attitude toward theistic faith : assessing the Astley-Francis Scale among Christian, Muslim and secular youth in England
Empirical research within the social scientific study of religion in general and within the psychology of religion in particular remains very conscious of the complex nature of its subject matter. Empirical research in this field needs to take cognisance of the many forms in which religion is expressed (say, Buddhism, Christianity, Hinduism, Islam, Judaism, and Sikhism) and the many facets within the forms (say, beliefs, behaviours and affiliation). Working in the 1970s, Francis (1978a; 1978b) advanced the view that the attitudinal dimension of religion offered a particularly fruitful basis for coordinating empirical enquiry into the correlates, antecedents and consequences of religiosity across the life span
Water bottle flipping physics
The water bottle flipping challenge consists of spinning a bottle, partially filled with water, and making it land upright. It is quite a striking phenomenon, since at first sight, it appears rather improbable that a tall rotating bottle could make such a stable landing. Here, we analyze the physics behind the water bottle flip, based on experiments and an analytical model that can be used in the classroom. Our measurements show that the angular velocity of the bottle decreases dramatically, enabling a nearly vertical descent and a successful landing. The reduced rotation is due to an increase in the moment of inertia, caused by the in-flight redistribution of the water mass along the bottle. Experimental and analytical results are compared quantitatively, and we demonstrate how to optimize the chances for a successful landing.</p
Optimized labeling of NOTA-conjugated octreotide with F-18
We recently reported a facile method based on the chelation of [18F]aluminum fluoride (Al18F) by NOTA (1,4,7-triazacyclononane-1,4,7-triacetic acid). Here, we present a further optimization of the 18F labeling of NOTA-octreotide (IMP466). Octreotide was conjugated with the NOTA chelate and was labeled with 18F in a two-step, one-pot method. The labeling procedure was optimized with regard to the labeling buffer, ionic strength, peptide concentration, and temperature. Radiochemical yield, specific activity, in vitro stability, and receptor affinity were determined. Biodistribution of 18F-IMP466 was studied in AR42J tumor-bearing mice. In addition, microPET/CT images were acquired. IMP466 was labeled with Al18F in a single step with 97% yield in the presence of 80% (v/v) acetonitrile or ethanol. The labeled product was purified by HPLC to remove unlabeled peptide and unbound Al18F. The radiolabeling, including purification, was performed for 45 min. Specific activities of 48,000 GBq/mmol could be obtained. 18F-IMP466 showed a high tumor uptake and excellent tumor-to-blood ratios at 2 h post-injection. In addition, the low bone uptake indicated that the Al18F–NOTA complex was stable in vivo. PET/CT scans revealed excellent tumor delineation and specific accumulation in the tumor. Uptake in receptor-negative organs was low. NOTA-octreotide could be labeled with 18F in quantitative yields using a rapid two-step, one-pot, method. The compound was stable in vivo and showed rapid accretion in SSTR2-receptor-expressing AR42J tumors in nude mice. This method can be used to label other NOTA-conjugated compounds such as RGD peptides, GRPR-binding peptides, and Affibody molecules with 18F
Emergent non-Hermitian models
The Hatano-Nelson and the non-Hermitian Su-Schrieffer-Heeger models are paradigmatic examples of non-Hermitian systems that host nontrivial boundary phenomena. In this work, we use recently developed graph-theoretical tools to design systems whose isospectral reduction, akin to an effective Hamiltonian, has the form of either of these two models. In the reduced version, the couplings and onsite potentials become energy dependent. We show that this leads to interesting phenomena such as an energy-dependent non-Hermitian skin effect, where eigenstates can simultaneously localize on either ends of the systems, with different localization lengths. Moreover, we predict the existence of various topological edge states, pinned at nonzero energies, with different exponential envelopes, depending on their energy. Overall, our work sheds light on the nature of topological phases and the non-Hermitian skin effect in one-dimensional systems
Development of an analogue optical link for the front-end read-out of the ATLAS electromagnetic calorimeter
We have developed an analogue optical data transmission system intended to meet the read-out requirements of the ATLAS liquid argon electromagnetic calorimeter. Eight-way demonstrators have been built and tested. The link uses arrays of VCSEL diodes as the optical emitters, coupled to a 70 m long fibre ribbon to simulate the distance between the detector and the control room. The receiver is based around a custom-designed PIN photodiode array. We describe here the final results of laboratory tests on a demonstrator, laying stress on the VCSEL-to-fibre coupling issues, and the overall performance of the full link. A 9-bit dynamic range is achieved, with a 5on-linearity
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