The development of hybrid inorganic–organic films with well-controlled properties is important for many applications. Molecular layer deposition (MLD) allows the deposition of these hybrid films ...using sequential, self-limiting reactions, similar to atomic layer deposition (ALD). In this paper, we use first principles density functional theory (DFT) to investigate the growth mechanism of titanium-containing hybrid organic–inorganic MLD films, known as “titanicones”. We investigate in detail the chemistry between the most common Ti precursors, namely titanium tetrachloride (TiCl
4
) and tetrakis(dimethylamido)titanium (Ti(DMA)
4
), and ethylene glycol (EG) and glycerol (GL) as the organic precursors. We analyse the impact of the substrate on the initial MLD reactions in titanicone film growth using three different surface models: anatase TiO
2
, rutile TiO
2
and Al
2
O
3
. Calculated energetics show that while TiCl
4
is reactive towards the anatase and rutile TiO
2
surfaces, it is not reactive towards the Al
2
O
3
surface. Ti(DMA)
4
is reactive towards all surfaces. This is attributed to the stronger Ti–Cl bonds in TiCl
4
compared to Ti–N bonds in Ti(DMA)
4
. Ti(DMA)
4
also shows high reactivity to the organics compared to TiCl
4
. Double reactions of EG and GL with the TiCl
3
species from TiCl
4
and TiDMA species from Ti(DMA)
4
are also explored to better understand the origin of the different thicknesses of EG–titanicone and GL–titanicone films observed in experimental work. We find that EG and GL coupled with TiCl
4
can orient in a flat lying configuration on anatase while on rutile, the preferred orientation is upright. When combined with Ti(DMA)
4
, EG and GL prefer the flat lying configuration on all surfaces. This work shows that the choice of the surface and the metallic precursor has a major impact on the behaviour of organic species. DFT findings provide motivation to develop a low temperature rutile TiO
2
/titanicone film suggesting that the desired film growth could be achieved.
Stereotactic radiotherapy (SRT) involves the precise delivery of highly conformal, dose-intense radiation to well-demarcated tumors. Special equipment and expertise are needed, and a unique ...biological mechanism distinguishes SRT from other forms of external beam radiotherapy. Families find the convenient schedules and minimal acute toxicity of SRT appealing. Common indications in veterinary oncology include nasal, brain, and bone tumors. Many other solid tumors can also be treated, including spinal, oral, lung, heart-base, liver, adrenal, and prostatic malignancies. Accessibility of SRT is improving, and new data are constantly emerging to define parameters for appropriate case selection, radiation dose prescription, and long-term follow-up.
Real-time monitoring of physiological changes of tumor tissue during radiation therapy (RT) could improve therapeutic efficacy and predict therapeutic outcomes. Cherenkov radiation is a normal ...byproduct of radiation deposited in tissue. Previous studies in rat tumors have confirmed a correlation between Cherenkov emission spectra and optical measurements of blood-oxygen saturation based on the tissue absorption coefficients. The purpose of this study is to determine if it is feasible to image Cherenkov emissions during radiation therapy in larger human-sized tumors of pet dogs with cancer. We also wished to validate the prior work in rats, to determine if Cherenkov emissions have the potential to act an indicator of blood-oxygen saturation or water-content changes in the tumor tissue-both of which have been correlated with patient prognosis.
A DoseOptics camera, built to image the low-intensity emission of Cherenkov radiation, was used to measure Cherenkov intensities in a cohort of cancer-bearing pet dogs during clinical irradiation. Tumor type and location varied, as did the radiation fractionation scheme and beam arrangement, each planned according to institutional standard-of-care. Unmodulated radiation was delivered using multiple 6 MV X-ray beams from a clinical linear accelerator. Each dog was treated with a minimum of 16 Gy total, in ≥3 fractions. Each fraction was split into at least three subfractions per gantry angle. During each subfraction, Cherenkov emissions were imaged.
We documented significant intra-subfraction differences between the Cherenkov intensities for normal tissue, whole-tumor tissue, tissue at the edge of the tumor and tissue at the center of the tumor (p<0.05). Additionally, intra-subfraction changes suggest that Cherenkov emissions may have captured fluctuating absorption properties within the tumor.
Here we demonstrate that it is possible to obtain Cherenkov emissions from canine cancers within a fraction of radiotherapy. The entire optical spectrum was obtained which includes the window for imaging changes in water and hemoglobin saturation. This lends credence to the goal of using this method during radiotherapy in human patients and client-owned pets.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Student success in basic medical science courses is typically determined by their individual performance on examinations of various types. Previous research both within and outside medical education ...has shown that the use of educational assessment activities can increase learning as demonstrated by performance on subsequent examinations, a phenomenon known as the testing effect. Activities primarily designed and used for assessment and evaluation purposes can also be used as teaching opportunities. We developed a method for measuring and evaluating student accomplishment in a preclinical basic science course that incorporates both individual and collaborative efforts, encourages and rewards active participation, does not compromise the reliability of the assessment outcome and is perceived by the students as helpful and valuable. The approach involved a two-part assessment activity composed of an individual examination and a small group examination with each component differentially weighted in determining an overall examination score. We found that the method was successful in encouraging collaborative efforts during the group component and provided valid measures of student grasp of the subject matter. We describe the development and implementation of the method, provide data derived from its use in a preclinical basic science course and discuss factors to be addressed when utilizing this approach to ensure fairness and reliability of the outcome. We include brief summary comments from students regarding their impressions of the value of this method.
ABSTRACT Although canine pituitary masses (PM) are increasingly treated with stereotactic radiotherapy (SRT), historical literature supports superior outcomes with conventional full‐course ...fractionated radiation therapy (FRT). A multi‐institutional retrospective study was performed, including dogs with PM treated from 2016 to 2022 with SRT (total dose 30 or 35 Gy in 5 daily fractions) or FRT (total dose 50–54 Gy in 19–20 daily fractions). The influence of potential prognostic/predictive factors was assessed, including pituitary: brain height, pituitary: brain volume, sex, age and endocrine status (functional F vs. nonfunctional NF PM). Forty‐four dogs with PM were included (26 F, 14 NF, 4 unknown). All patients completed protocols as scheduled (SRT = 27, FRT = 17) and two dogs had suspected Grade 1 acute neurotoxicity. During the first 6 months after RT, 5/27 (19%) dogs treated with SRT (4 F, 1 NF) and 3/17 (18%) dogs treated with FRT (all F) died or were euthanised because of progressive neurologic signs. The overall median survival time was 608 days (95% CI, 375–840 days). Young age at the time of treatment was significant for survival ( p = 0.0288); the overall median survival time was 753 days for dogs <9 years of age (95% CI, 614–892 days) and 445 days for dogs ≥9 years of age (95% CI, 183–707 days). Survival time was not associated with treatment type or any other factor assessed herein. A prospective study using standardised protocols would further validate the results of the present study and potentially elucidate the predictors of early death.
Planetary radar observations have provided invaluable information on the solar system through both ground-based and space-based observations. In this overview article, we summarize how radar ...observations have contributed in planetary science, how the radar technology as a remote-sensing method for planetary exploration and the methods to interpret the radar data have advanced in the eight decades of increasing use, where the field stands in the early 2020s, and what are the future prospects of the ground-based facilities conducting planetary radar observations and the planned spacecraft missions equipped with radar instruments. The focus of the paper is on radar as a remote-sensing technique using radar instruments in spacecraft orbiting planetary objects and in Earth-based radio telescopes, whereas ground-penetrating radar systems on landers are mentioned only briefly. The key scientific developments are focused on the search for water ice in the subsurface of the Moon, which could be an invaluable in situ resource for crewed missions, dynamical and physical characterization of near-Earth asteroids, which is also crucial for effective planetary defense, and a better understanding of planetary geology.
Amino acid functionalized perylene bisimides (PBIs) form self‐assembled structures in solution, the nature of which depends on the local environment. Using a high‐throughput photocatalysis setup, ...five PBIs are studied for the hydrogen evolution reaction (HER) under a range of conditions (pH and hole scavenger concentration) across 350 experiments to explore the relationship between supramolecular structure and photocatalytic activity. Using small angle X‐ray scattering (SAXS), NMR spectroscopy and ultraviolet‐visible (UV‐vis) absorption spectroscopy, it is shown that photocatalytic activity is determined by the nature of the self‐assembled aggregate that is formed, demonstrating the potential of self‐assembly to tune activity. There is a clear correlation between the presence of charged flexible cylindrical aggregates and the occurrence of photocatalytic H2 production, with UV–vis spectroscopy indicating that the most active structure type has a distinctive form of π‐aggregation which is proposed to enable efficient charge separation across multiple PBI units.
Self‐assembly is an exciting but underexplored field in photocatalysis. The design of molecular chromophores is common, but less attention is paid to how these building blocks assemble. Using high‐throughput testing and detailed characterization, it is shown how a single set of starting molecules can give rise to profoundly different levels of photocatalytic activity depending on their supramolecular structure.
RORgammat is an isoform of RORC, preferentially expressed in Th17 cells, that functions as a critical regulator of type 3 immunity. As murine Th17-driven inflammatory disease models were greatly ...diminished in RORC knock-out mice, this receptor was prioritised as an attractive therapeutic target for the treatment of several autoimmune diseases. Human genetic studies indicate a significant contributory role for RORC in several human disease conditions. Furthermore, genome-wide association studies (GWAS) report a significant association between inflammatory bowel disease (IBD) and the RORC regulatory variant rs4845604. To investigate if the rs4845604 variant may affect CD4.sup.+ T cell differentiation events, naïve CD4.sup.+ T cells were isolated from eighteen healthy subjects homozygous for the rs4845604 minor (A) or major (G) allele). Isolated cells from each subject were differentiated into distinct T cell lineages by culturing in either T cell maintenance medium or Th17 driving medium conditions for six days in the presence of an RORC inverse agonist (to prevent constitutive receptor activity) or an inactive diastereomer (control). Our proof of concept study indicated that genotype had no significant effect on the mean number of naïve CD4 T cells isolated, nor the frequency of Th1-like and Th17-like cells following six days of culture in any of the four culture conditions. Analysis of the derived RNA-seq count data identified genotype-driven transcriptional effects in each of the four culture conditions. Subsequent pathway enrichment analysis of these profiles reported perturbation of metabolic signalling networks, with the potential to affect the cellular detoxification response. This investigation reveals that rs4845604 genotype is associated with transcriptional effects in CD4.sup.+ T cells that may perturb immune and metabolic pathways. Most significantly, the rs4845604 GG, IBD risk associated, genotype may be associated with a differential detoxification response. This observation justifies further investigation in a larger cohort of both healthy and IBD-affected individuals.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
High-resolution radar images reveal near-Earth asteroid (66391) 1999 KW4 to be a binary system. The ~1.5-kilometer-diameter primary (Alpha) is an unconsolidated gravitational aggregate with a spin ...period ~2.8 hours, bulk density ~2 grams per cubic centimeter, porosity ~50%, and an oblate shape dominated by an equatorial ridge at the object's potential-energy minimum. The ~0.5-kilometer secondary (Beta) is elongated and probably is denser than Alpha. Its average orbit about Alpha is circular with a radius ~2.5 kilometers and period ~17.4 hours, and its average rotation is synchronous with the long axis pointed toward Alpha, but librational departures from that orientation are evident. Exotic physical and dynamical properties may be common among near-Earth binaries.
Income Status and Life Satisfaction FitzRoy, Felix R.; Nolan, Michael A.
Journal of happiness studies,
01/2022, Letnik:
23, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The importance of both income rank and relative income, as indicators of status, has long been recognised in the literature on life satisfaction and happiness. Recently, several authors have made ...explicit comparisons of the relative importance of these two measures of income status, and concluded that rank dominates to the extent that reference income becomes insignificant in regressions including both these explanatory variables, and that even absolute or household income, otherwise always positively related to happiness, may lose statistical significance. Here we test this hypothesis with a large UK panel (British Household Panel Survey and Understanding Society) for 1996–2017, split by age and retirement status, and find, contrary to previous results, that rank, household income and reference income are all usually important explanatory variables, but with significant differences between subgroups. This finding holds when rank is in its often-used relative form, and also with absolute rank.
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