A Study of the Micellar Formation of N-Alkyl Betaine Ethyl Ester Chlorides Based on the Physicochemical Properties of Their Aqueous Solutions.

In this study, a series of four surface-active compounds-N-alkyl betaine ethyl ester chlorides, CnBetC2Cl-were synthesized and characterized in aqueous solutions. As with other alkyl betaines, these amphiphiles can be practically used, for example, as co-surfactants and/or solubility enhancers acting according to hydrotropic or micellar mechanisms, depending on the alkyl chain length in the amine. We focused on the representatives of the medium alkyl chain length (C6-C12) to find the dependence between the alkyl chain length in N-alkyl betaine ethyl ester chlorides and the surface, volumetric, acoustic, and viscometric properties of their solutions. Ethyl esters, the derivatives of amino acids, were chosen to increase functionality and take advantage of possible hydrolysis in solutions at higher pH, which is also a key parameter in biodegradability. The micellization parameters were calculated based on the physicochemical characteristics. We focused our interest on the ester with a dodecyl substituent since we can compare and discuss its properties with some other C12 representatives that are available in literature. Surprisingly, its micellization characteristic is almost temperature-independent in the investigated temperature range, t = (15-45) °C. Particularly interesting are the results of dynamic light scattering (DLS), which show that the changes in physicochemical parameters of the C12 homolog around the CMC are caused by the two types of micelles of different sizes present in solutions.

Spectrally Tunable Neural Network-Assisted Segmentation of Microneurosurgical Anatomy.

BACKGROUND: Distinct tissue types are differentiated based on the surgeon's knowledge and subjective visible information, typically assisted with white-light intraoperative imaging systems. Narrow-band imaging (NBI) assists in tissue identification and enables automated classifiers, but many anatomical details moderate computational predictions and cause bias. In particular, tissues' light-source-dependent optical characteristics, anatomical location, and potentially hazardous microstructural changes such as peeling have been overlooked in previous literature. METHODS: Narrow-band images of five (n = 5) facial nerves (FNs) and internal carotid arteries (ICAs) were captured from freshly frozen temporal bones. The FNs were split into intracranial and intratemporal samples, and ICAs' adventitia was peeled from the distal end. Three-dimensional (3D) spectral data were captured by a custom-built liquid crystal tunable filter (LCTF) spectral imaging (SI) system. We investigated the normal variance between the samples and utilized descriptive and machine learning analysis on the image stack hypercubes. RESULTS: Reflectance between intact and peeled arteries in lower-wavelength domains between 400 and 576 nm was significantly different (p < 0.05). Proximal FN could be differentiated from distal FN in a higher range, 490-720 nm (p < 0.001). ICA with intact tunica differed from proximal FN nearly thorough the VIS range, 412-592 nm (p < 0.001) and 664-720 nm (p < 0.05) as did its distal counterpart, 422-720 nm (p < 0.001). The availed U-Net algorithm classified 90.93% of the pixels correctly in comparison to tissue margins delineated by a specialist. CONCLUSION: Selective NBI represents a promising method for assisting tissue identification and computational segmentation of surgical microanatomy. Further multidisciplinary research is required for its clinical applications and intraoperative integration.

A Study of Catalytic Oxidation of a Library of C2 to C4 Alcohols in the Presence of Nanogold.

The classical stoichiometric oxidation of alcohols is an important tool in contemporary organic chemistry. However, it still requires huge modifications in order to comply with the principles of green chemistry. The use of toxic chemicals, hazardous organic solvents, and the large amounts of toxic wastes that result from the reactions are a few examples of the problems that must be solved. Nanogold alone or conjugated with palladium were supported on different carriers (SiO2, C) and investigated in order to evaluate their catalytic potential for environmentally friendly alcohol oxidation under solvent-free and base-free conditions in the presence H2O2 as a clean oxidant. We tested different levels of Au loading (0.1⁻1.2% wt.) and different active catalytic site forms (monometallic Au or bimetallic Au⁻Pd sites). This provided new insights on how the structure of the Au-dispersions affected their catalytic performance. Importantly, the examination of the catalytic performance of the resulting catalysts was oriented toward a broad scope of alcohols, including those that are the most resistant to oxidation-the primary aliphatic alcohols. Surprisingly, the studies proved that Au/SiO2 at a level of Au loading as low as 0.1% wt. appeared to be efficient and prospective catalytic system for the green oxidation of alcohol. Most importantly, the results revealed that 0.1% Au/SiO2 might be the catalyst of choice with a wide scope of utility in the green oxidation of various structurally different alcohols as well as the non-activated aliphatic ones.

Electrolytic copper as cheap and effective catalyst for one-pot triazole synthesis.

Electrolytic copper is a well-known form of pure, oxygen free copper that is used for industrial applications. In this work, the catalytic potential of this relatively cheap material was studied. The addition of less than 0.015 mol equivalent of copper powder effectively catalysed the one-pot synthesis of triazoles from a diverse range of organic halides and alkynes. Quantitative conversions in aqueous solvents can be achieved within minutes. The heterogenous nature of the catalyst afforded a low level of copper contamination in the products, thus meeting the rigorous criteria of the pharmaceutical industry.

Catalytic Gas-Phase Glycerol Processing over SiO2-, Cu-, Ni- and Fe- Supported Au Nanoparticles.

In this study, we investigated different metal pairings of Au nanoparticles (NPs) as potential catalysts for glycerol dehydration for the first time. All of the systems preferred the formation of hydroxyacetone (HYNE). Although the bimetallics that were tested, i.e., Au NPs supported on Ni, Fe and Cu appeared to be more active than the Au/SiO2 system, only Cu supported Au NPs gave high conversion (ca. 63%) and selectivity (ca. 70%) to HYNE.

Ni-Supported Pd Nanoparticles with Ca Promoter: A New Catalyst for Low-Temperature Ammonia Cracking.

In this paper we report a new nanometallic, self-activating catalyst, namely, Ni-supported Pd nanoparticles (PdNPs/Ni) for low temperature ammonia cracking, which was prepared using a novel approach involving the transfer of nanoparticles from the intermediate carrier, i.e. nano-spherical SiO2, to the target carrier technical grade Ni (t-Ni) or high purity Ni (p-Ni) grains. The method that was developed allows a uniform nanoparticle size distribution (4,4±0.8 nm) to be obtained. Unexpectedly, the t-Ni-supported Pd NPs, which seemed to have a surface Ca impurity, appeared to be more active than the Ca-free (p-Ni) system. A comparison of the novel PdNPs/Ni catalyst with these reported in the literature clearly indicates the much better hydrogen productivity of the new system, which seems to be a highly efficient, flexible and durable catalyst for gas-phase heterogeneous ammonia cracking in which the TOF reaches a value of 2615 mmolH2/gPd min (10,570 molNH3/molPd(NP) h) at 600°C under a flow of 12 dm3/h (t-Ni).

Synthesis of New Styrylquinoline Cellular Dyes, Fluorescent Properties, Cellular Localization and Cytotoxic Behavior.

New styrylquinoline derivatives with their photophysical constants are described. The synthesis was achieved via Sonogashira coupling using the newly developed heterogeneous nano-Pd/Cu catalyst system, which provides an efficient synthesis of high purity products. The compounds were tested in preliminary fluorescent microscopy studies to in order to identify their preferable cellular localization, which appeared to be in the lipid cellular organelles. The spectroscopic properties of the compounds were measured and theoretical TD-DFT calculations were performed. A biological analysis of the quinolines that were tested consisted of cytotoxicity assays against normal human fibroblasts and colon adenocarcinoma cells. All of the compounds that were studied appeared to be safe and indifferent to cells in a high concentration range. The presented results suggest that the quinoline compounds that were investigated in this study may be valuable structures for development as fluorescent dyes that could have biological applications.

Immunohistochemical pattern of protein P21, cyclin D1 and cyclin E in endometrial hyperplasia.

PURPOSE: In our research we investigated immunohistochemical expression of cell cycle proteins protein p21, cyclin D1 and cyclin E in physiological endometrium (n = 15), hyperplastic endometrium (n = 61), and post hormone replacement therapy endometrium (n = 24). MATERIAL AND METHODS: We performed immunohistochemical analysis of selected cell cycle proteins in 100 specimens of human endometrium. RESULTS: The average immunoexpression index scores in glandular endometrial cells (GES) and stromal endometrial cells (SEC) were respectively: for p21- GES: 11.8 +/- 17.19%; SEC: 9.31 +/- 17.15%; for cyclin D1- GES: 9.25 +/- 18.41%; SEC: 3.22 +/- 11.46%; for cyclin E: GES: 26.42 +/- 27.47%; SEC: 4.61 +/- 7.90%. Statistical analysis disclosed more intense p21 glandular immunoreactivity among women with endometrial hyperplasia in comparison to other subpopulations. In the case of assessment of cyclin D1 immunoreactivity, there was no statistical correlation between analysed parameters. The average cyclin E immunoreactivity in endometrial glandular cells was significantly higher (p = 0.003) in women with endometrial hyperplasia and correlated with age. CONCLUSIONS: Intensive immunoreactivity of cyclin E in glandular cells is typical for endometrial hyperplasia and can be treated as an objective indicator of this pathological process during histopathological diagnostic procedures. Immunoreactivity index of p21 and cyclin D1 is independent of the morphological pattern of human endometrium, patients' age and gynaecological history of patients.

Evaluation of retinoblastoma protein expression in endometrial hyperplasia.

UNLABELLED: In our study we investigated immunohistochemical expression of retinoblastoma protein (pRb) in physiological endometrium (n = 15), hyperplastic endometrium (n = 61) and post-hormone replacement therapy (HRT) endometrium (n = 24). METHODS: We performed an immunohistochemical analysis of pRb expression in 100 specimens of human endometrium. RESULTS: The average pRb immunoexpression index score in glandular endometrial cells and stromal endometrial cells were 57,699 and 21,191 respectively. The less intense pRb immunostaining for the glandular cells was displayed in women over 49 years old. The most intense staining effect of glandular cells was observed among patients with physiological endometrium, no older than 49 years of life. There was no statistically significant correlation between the obtained pRb immunoexpression and clinical data of the examined patients. CONCLUSIONS: We conclude that immunohistochemistry is not sensitive and specific enough to reveal pRb alterations resulting in endometrium pathologies. Alternatively, pathological rearrangements of endometrium may be independent from the accuracy of the pRb control over restriction point in cell-cycle pathway.