Recent experiments on epitaxial growth of metals on graphene have shown a strong dependence of island densities on coverage. These investigations cannot be explained by the standard mean-field nucleation theories. To understand them, we extend to higher coverage the former theory of rate equations developed for the initial state of nucleation, in a system where adsorbate interaction is included. We account for that, in the case of high coverage, the repulsive interaction influences both the attachment of monomers to clusters and the mobility of atoms. In our work we analyze the modification of the dependence of the island density on coverage, temperature and F/D ratio. In some regimes our theory results in the experimentally observed substantial growth of island density with coverage for a high deposited amount and a weak dependence on deposition rate F. We also find out the local maxima in temperature dependence of island density, as a consequence of long-range repulsive interactions.

• MeSH
• chemické modely MeSH
• grafit chemie   metabolismus   MeSH
• kovy chemie   metabolismus   MeSH
• makromolekulární látky chemie   metabolismus   MeSH
• počítačová simulace MeSH
• povrchové napětí MeSH
• termodynamika MeSH
• velikost částic MeSH
• změna skupenství MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• grafit MeSH
• kovy MeSH
• makromolekulární látky MeSH

We studied the response of gypsy moth (Lymantria dispar (Linnaeus) (Lepidoptera: Lymantriidae)) to the content of manganese in food in the laboratory breeding of caterpillars. The food of the caterpillars {Betula pendula Roth (Fagales: Betulaceae) leaves} was contaminated by dipping in the solution of MnCl2 · 4H2O with manganese concentrations of 0, 0.5, 5 and 10 mg ml(-1), by which differentiated manganese contents (307; 632; 4,087 and 8,124 mg kg(-1)) were reached. Parameters recorded during the rearing were as follows: effect of manganese on food consumption, mortality and length of the development of caterpillars, pupation and hatching of imagoes. At the same time, manganese concentrations were determined in the offered and unconsumed food, excrements, and exuviae of the caterpillars, pupal cases and imagoes by using the AAS method. As compared with the control, high manganese contents in the food of gypsy moth caterpillars affected the process of development particularly by increased mortality of the first instar caterpillars (8 % mortality for caterpillars with no Mn contamination (T0) and 62 % mortality for subjects with the highest contamination by manganese (T3)), by prolonged development of the first-third instar (18.7 days (T0) and 27.8 days (T3)) and by increased food consumption of the first-third instar {0.185 g of leaf dry matter (T0) and 0.483 g of leaf dry matter (T3)}. The main defence strategy of the caterpillars to prevent contamination by the increased manganese content in food is the translocation of manganese into frass and exuviae castoff in the process of ecdysis. In the process of development, the content of manganese was reduced by excretion in imagoes to 0.5 % of the intake level even at its maximum inputs in food.

• MeSH
• chov MeSH
• kukla účinky léků   růst a vývoj   MeSH
• larva účinky léků   růst a vývoj   MeSH
• listy rostlin chemie   MeSH
• mangan toxicita   MeSH
• můry účinky léků   růst a vývoj   MeSH
• potraviny * MeSH
• stravovací zvyklosti účinky léků   MeSH
• tělesná hmotnost účinky léků   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• mangan MeSH

• MeSH
• dítě MeSH
• lidé MeSH
• postižení * MeSH
• rekreace * MeSH
• ubytovací zařízení * MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH

Transformation of ten colchicinoids by isolated rat liver microsomes resulted in the mixture of C-2, C-3, and C-10 O-demethylated metabolites. Colchicinoids administered i.p. to rats (2.5 mumol/kg) increased serum and liver activities of alkaline phosphatase and decreased liver microsomal demethylase activity as well as cytochrome P-450 content. The changes of acid phosphatase level were less pronounced. The aspartate and alanine aminotransferase activities were significantly increased only in colchicine treated rats. No relations between enzyme activity changes and colchicinoid hydrophobicities quantified by partition coefficients (log P) were found. However, the enzyme activity changes were related to the type of substitution at C-3, C-7, and C-10 of colchicinoids. Particularly, O-demethylation at C-3 resulted into the fall of alkaline phosphatase response. On the other hand, the microsomal demethylation and cytochrome P-450 content were related to the modification of the nitrogen substituent at C-7.

• MeSH
• biotransformace MeSH
• fosfotransferasy metabolismus   MeSH
• jaterní mikrozomy účinky léků   metabolismus   MeSH
• kolchicin analogy a deriváty   metabolismus   farmakologie   MeSH
• krysa rodu Rattus MeSH
• oxygenasy metabolismus   MeSH
• potkani Wistar MeSH
• techniky in vitro MeSH
• transaminasy metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fosfotransferasy MeSH
• kolchicin MeSH
• oxygenasy MeSH
• transaminasy MeSH

Polyesteramides based on epsilon-caprolactam and epsilon-caprolactone differing in the content of ester-amide structural units were subjected to biodegradation - composting in a big compost pile under controlled conditions (controlled composting) and in small composters at a steady temperature of 60 degrees C (isothermal composting). Both types of composting resulted in degradation of the polyesteramides depending on copolymer composition, isothermal composting being more robust. The contribution of abiotic hydrolysis to the degradation of polyesteramides was studied at 60 degrees C in buffer solutions with pH 5.4, 7.4 and 8.4. The prevailing effect of abiotic hydrolysis over biological one was shown at 60 degrees C. Ester bonds in polyestramide chains were preferentially cleaved; therefore, the scope of degradation increased with the content of ester units in the copolymer.

• MeSH
• biodegradace MeSH
• houby metabolismus   MeSH
• hydrolýza MeSH
• kaprolaktam chemická syntéza   chemie   metabolismus   MeSH
• kapronáty chemická syntéza   chemie   metabolismus   MeSH
• laktony chemická syntéza   chemie   metabolismus   MeSH
• polymery chemická syntéza   chemie   metabolismus   MeSH
• půda analýza   MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• caprolactone MeSH Prohlížeč
• kaprolaktam MeSH
• kapronáty MeSH
• laktony MeSH
• polymery MeSH
• půda MeSH

Two types of copolymers--poly(ester-amide)s--by the anionic copolymerization of epsilon-caprolactam and epsilon-caprolactone, and aromatic-aliphatic copolyesters based on glycolyzed polyethylene terephthalate from used beverage bottles and epsilon-caprolactone were prepared. Biodegradation tests of these copolymers were performed by two methods, viz. composting under controlled conditions and treatment with ligninolytic fungi. Both methods resulted in degradation of the copolymers, composting being more robust. Out of fungal strains tested Inonotus hispidus degraded aromatic-aliphatic copolyesters most intensively.

• MeSH
• Basidiomycota metabolismus   MeSH
• biodegradace MeSH
• kaprolaktam metabolismus   MeSH
• kapronáty metabolismus   MeSH
• laktony metabolismus   MeSH
• lignin metabolismus   MeSH
• mikroskopie elektronová rastrovací MeSH
• nylony metabolismus   MeSH
• půda * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• caprolactone MeSH Prohlížeč
• kaprolaktam MeSH
• kapronáty MeSH
• laktony MeSH
• lignin MeSH
• nylony MeSH
• půda * MeSH

Chest X-ray (CXR) is considered to be the most widely used modality for detecting and monitoring various thoracic findings, including lung carcinoma and other pulmonary lesions. However, X-ray imaging shows particular limitations when detecting primary and secondary tumors and is prone to reading errors due to limited resolution and disagreement between radiologists. To address these issues, we developed a deep-learning-based automatic detection algorithm (DLAD) to automatically detect and localize suspicious lesions on CXRs. Five radiologists were invited to retrospectively evaluate 300 CXR images from a specialized oncology center, and the performance of individual radiologists was subsequently compared with that of DLAD. The proposed DLAD achieved significantly higher sensitivity (0.910 (0.854-0.966)) than that of all assessed radiologists (RAD 10.290 (0.201-0.379), p < 0.001, RAD 20.450 (0.352-0.548), p < 0.001, RAD 30.670 (0.578-0.762), p < 0.001, RAD 40.810 (0.733-0.887), p = 0.025, RAD 50.700 (0.610-0.790), p < 0.001). The DLAD specificity (0.775 (0.717-0.833)) was significantly lower than for all assessed radiologists (RAD 11.000 (0.984-1.000), p < 0.001, RAD 20.970 (0.946-1.000), p < 0.001, RAD 30.980 (0.961-1.000), p < 0.001, RAD 40.975 (0.953-0.997), p < 0.001, RAD 50.995 (0.985-1.000), p < 0.001). The study results demonstrate that the proposed DLAD could be utilized as a decision-support system to reduce radiologists' false negative rate.

• Klíčová slova
• YOLO, computer-aided diagnosis, convolutional neural network, deep learning, lung cancer, object detection, pulmonary lesion,
• Publikační typ
• časopisecké články MeSH

We extend a standard theory of second-layer nucleation in the regime of low temperature, where the diffusion is the limiting process. The theory takes into consideration the fluctuations of the adatoms and the distribution of stable clusters on a surface, and yields an expression for the nucleation rate and time evolution of the density of stable clusters. When diffusion is slow, the fluctuations of the monomer distribution play an important role and results differ qualitatively and quantitatively from those obtained using the standard rate-equation approach to nucleation. We argue that in this case the standard theory fails because slow diffusion delays nucleation and the nucleation rate depends on the fluctuations of interatomic distances. It is shown that the final density of stable clusters depends on the fluctuations of the monomer and stable clusters distribution and can be even independent of the deposition rate, as was experimentally observed at low temperatures.

• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

We present a theoretical investigation of the influence of domain boundaries on the Ge/Si(111)-5 × 5 phase using both large-scale DFT simulations and an analytical model. It is shown that different boundary types modify the atomic and electronic structure of the adjoining 5 × 5 domains in very different ways. A simple theoretical model, that describes the energy interaction J between the boundaries and the 5 × 5 phase, is presented and the interaction energy decay J(x) ≈ x(-n) for different domain boundaries is estimated. Additionally, the influence of the boundaries on the atomic and electronic structure of adatoms in the parental 5 × 5 phase is analyzed and it is argued that the presence of domain boundaries may strongly affect not only the physical but also the chemical properties of the Ge/Si(111)-5 × 5 phase.

• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH