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Povzetek: Radiochemotherapy is the main treatment for patients with squamous cell carcinoma of the anal canal. Anaemia is reported to have adverse effect on survival in cancer patients. The aim of the study was to evaluate the influence of anaemia on radiochemotherapy treatment outcome in patients with squamous cell carcinoma of the anal canal. Patients and methods. One hundred consecutive patients with histologically confirmed squamous cell carcinoma of the anal canal were treated radically with 3-dimensional conformal or intensity-modulated radiation therapy followed by brachytherapy or external beam radiotherapy boost and with concurrent mitomycin C and 5-fluorouracil. The influence on survival of pre-treatment, mean on-treatment and end-of-treatment haemoglobin (Hb) concentrations was studied. Results. The 5-year locoregional control, disease free survival, disease specific survival and overall survival rates for all patients were 72%, 71%, 77% and 62%, respectively. In univariate analysis, patients with pre-treatment and end-oftreatment Hb > 120 g/L survived statistically significantly better compared to patients with Hb % 120 g/L. Patients with mean on-treatment Hb > 120 g/L only had statistically significant better locoregional control and overall survival than patients with Hb % 120 g/L. In multivariate analysis, independent prognostic factors were pre-treatment Hb (> 120 g/L vs. % 120 g/L) for overall survival (hazard ratio [HR] = 0.419, 95% confidence interval [CI] = 0.190%0.927, p = 0.032) and stage (I & II vs. III) for disease specific (HR = 3.523, 95% CI = 1.375%9.026, p = 0.009) and overall survival (HR = 2.230, 95% CI = 1.167%4.264, p = 0.015). Conclusions. The pre-treatment, mean on-treatment and end-of-treatment Hb concentration > 120 g/L carried better prognosis for patients for with squamous cell carcinoma of the anal canal treated with radiochemotherapy. The pre-treatment Hb > 120 g/L was an independent prognostic factor for overall survival of patients with anal canal cancer.
Ključne besede: anaemia, anal canal squamous cell carcinoma, radiochemotherapy
Objavljeno v DiRROS: 30.04.2024; Ogledov: 14; Prenosov: 4
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Povzetek: Teeth exemplify architectures comprising an interplay of inorganic and organic constituents, resulting in sophisticated natural composites. Rodents (Rodentia) showcase extraordinary adaptations, with their continuously growing incisors surpassing human teeth in functional and structural optimizations. In this study, employing state-of-the-art direct atomic-scale imaging and nanoscale spectroscopies, we present compelling evidence that the release of material from ameloblasts and the subsequent formation of iron-rich enamel and surface layers in the constantly growing incisors of rodents are complex orchestrated processes, intricately regulated and independent of environmental factors. The synergistic fusion of three-dimensional tomography and imaging techniques of etched rodent́s enamel unveils a direct correlation between the presence of pockets infused with ferrihydrite-like material and the acid resistant properties exhibited by the iron-rich enamel, fortifying it as an efficient protective shield. Moreover, observations using optical microscopy shed light on the role of iron-rich enamel as a microstructural element that acts as a path for color transmission, although the native color remains indistinguishable from that of regular enamel, challenging the prevailing paradigms. The redefinition of “pigmented enamel” to encompass ferrihydrite-like infusion in rodent incisors reshapes our perception of incisor microstructure and color generation. The functional significance of acid-resistant iron-rich enamel and the understanding of the underlying coloration mechanism in rodent incisors have far-reaching implications for human health, development of potentially groundbreaking dental materials, and restorative dentistry. These findings enable the creation of an entirely different class of dental biomaterials with enhanced properties, inspired by the ingenious designs found in nature.
Ključne besede: teeth microstructure, ameloblasts, ferritin, Fe-rich enamel, tomography, rodent
Objavljeno v DiRROS: 26.04.2024; Ogledov: 36; Prenosov: 9
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Povzetek: Beyond growth parameters and drought tolerance, comparatively little is known about the functioning of different beech (Fagus sylvatica L.) provenances. We investigated properties of leaves, stem secondary xylem, and ectomycorrhiza (ECM), and explored their interdependencies to identify the best performing beech provenance in optimal growth conditions. The study was conducted on 23-year-old trees in a provenance trial. The investigated provenances originated from Atlantic (Belgium—BE), Alpine (Italy—IT, Slovenia—SI), and continental climates (the Czech Republic—CZ). A significant effect of provenance was observed for stem vessel diameters and conductive area, as well as for foliar %C, δ13C, δ15N, and δ18O. δ13C as a proxy of intrinsic water use efficiency (iWUE) showed that the highest iWUE was achieved in BE provenance. Individuals with a better iWUE had wider growth rings regardless of provenance. Better iWUE was associated with lower specific leaf area (SLA). ECM community composition and diversity indices did not differ significantly among the provenances. Specific ECM taxa were associated with individuals with high SLA, δ13C, δ15N, and δ18O. In optimal growth conditions with no stress events, BE is a promising provenance due to an efficient water conducting system with high vessel diameters and conductive area, and high iWUE, while Alpine provenances showed an adaptation of their water conducting system to freezing conditions at their original locations. Integrating findings from different compartments improves our understanding of functioning of different beech provenances.
Ključne besede: Fagus sylvatica, provenance trial, stable isotopes, specific leaf area, xylem vessels, ectomycorrhizal fungi
Objavljeno v DiRROS: 19.04.2024; Ogledov: 68; Prenosov: 33
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Ključne besede: scientific research, health, lifestyle
Objavljeno v DiRROS: 16.04.2024; Ogledov: 77; Prenosov: 39
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Povzetek: Let $f$ be a noncommutative polynomial of degree $m\ge 1$ over an algebraically closed field $F$ of characteristic $0$. If $n\ge m-1$ and $\alpha_1,\alpha_2,\alpha_3$ are nonzero elements from $F$ such that $\alpha_1+\alpha_2+\alpha_3=0$, then every trace zero $n\times n$ matrix over $F$ can be written as $\alpha_1 A_1+\alpha_2A_2+\alpha_3A_3$ for some $A_i$ in the image of $f$ in $M_n(F)$.
Ključne besede: Waring problem, noncommutatative polynomials, matrix algebras
Objavljeno v DiRROS: 10.04.2024; Ogledov: 65; Prenosov: 28
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