Publications by authors named "Lukach A"

Solifenacin (SFC) is a potent muscarinic antagonist that effectively reduces bladder muscle contraction, thereby alleviating symptoms such as frequency of micturition and urgency. Oxidation of SFC leads to the formation of impurities like Impurity K. Effective analysis and control of this impurity is crucial for ensuring compliance with regulatory standards and safeguarding patient health.

View Article and Find Full Text PDF

Cholesterotic fibrous histiocytoma is a particularly rare variant of dermatofibroma that is distinguished histopathologically by the presence of prominent cholesterol deposits within the lesion. We report the case of a 54-year-old male with poorly controlled hyperlipidemia who presented with a firm violaceous papule on the right shin, diagnosed as a cholesterotic fibrous histiocytoma. We also review and summarize the existing literature on this uncommon entity.

View Article and Find Full Text PDF

Sclerosing perineuromas are rare, benign peripheral nerve sheath tumors classically reported on the fingers and palms of young men. We present the case of a 12-year-old boy with a slow-growing nodule on his right knee. Excision was performed, and pathology was consistent with a sclerosing perineuroma.

View Article and Find Full Text PDF

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder characterized by recurrent nodules, abscesses, and sinus tracts that can be debilitating and significantly impair quality of life. Small studies and case reports have suggested a possible association between HS and inflammatory bowel disease (IBD).

Aims: We performed a case-control study to further characterize IBD patients with HS in terms of smoking status, BMI, sites affected by HS, IBD type and features, and IBD medication history.

View Article and Find Full Text PDF

The Rhythm Experience and Africana Culture Trial (REACT!) is a multi-site randomized controlled intervention study designed to examine the efficacy of using African Dance as a form of moderate-intensity physical activity to improve cognitive function in older African Americans. African Americans are almost two times more likely than Caucasians to experience cognitive impairment in late adulthood. This increased risk may be attributed to lower level and quality of education, lower socioeconomic status, and higher prevalence of vascular diseases, type 2 diabetes, hypertension, and obesity, all of which are recognized as risk factors for dementia.

View Article and Find Full Text PDF

Coassembly of nanoparticles with different size-, shape-, and composition-dependent properties is a promising approach to the design and fabrication of functional materials and devices. This paper reports the results of a detailed investigation of the formation and properties of free-stranding composite films formed by the coassembly of cellulose nanocrystals and shape-isotropic plasmonic gold nanoparticles. The effect of gold nanoparticle size, surface charge, and concentration on the structural and optical properties of the composite films has been studied.

View Article and Find Full Text PDF

We report the structural and optical properties of composite films formed from mixed suspensions of cellulose nanocrystals (CNCs) and fluorescent latex nanoparticles (NPs). We explored the effect of NP concentration, size, surface charge, glass transition temperature and film processing conditions on film structure and properties. The chiral nematic order, typical of CNC films, was preserved in films with up to 50 wt% of negatively-charged latex NPs.

View Article and Find Full Text PDF

The entropically driven coassembly of nanorods (cellulose nanocrystals, CNCs) and nanospheres (dye-labeled spherical latex nanoparticles, NPs) was studied in aqueous suspensions and in solid films. In mixed CNC-latex suspensions, phase separation into an isotropic latex-NP-rich and a chiral nematic CNC-rich phase took place; the latter contained a significant amount of latex NPs. Drying the mixed suspension resulted in CNC-latex films with planar disordered layers of latex NPs, which alternated with chiral nematic CNC-rich regions.

View Article and Find Full Text PDF

We demonstrate the application of polystyrene-functionalized gold nanorods (AuNRs) as a platform for surface enhanced Raman scattering (SERS) quantification of the exogenous cancer biomarker Acetyl Amantadine (AcAm). We utilize the hydrophobicity of the polystyrene attached to the AuNR surface to capture the hydrophobic AcAm from solution, followed by drying and detection using SERS. We achieve a detection limit of 16 ng/mL using this platform.

View Article and Find Full Text PDF

The resemblance between colloidal and molecular polymerization reactions is very useful in fundamental studies of polymerization reactions, as well as in the development of new nanoscale systems with desired properties. Future applications of colloidal polymers will require nanoparticle ensembles with a high degree of complexity that can be realized by hetero-assembly of NPs with different dimensions, shapes, and compositions. A method has been developed to apply strategies from molecular copolymerization to the co-assembly of gold nanorods with different dimensions into random and block copolymer structures (plasmonic copolymers).

View Article and Find Full Text PDF

Plasmonic polymers present an interesting concept that builds on the analogy between molecular polymers and linear chains of strongly interacting metal nanoparticles. Ensemble-averaged optical properties of plasmonic polymers are strongly influenced by their structure. In the present work, we formed plasmonic polymers by using solution-based assembly of gold nanorods (NRs) end-tethered with photoactive macromolecular tethers.

View Article and Find Full Text PDF

2-Substituted indoles (5a,b and 7) and fused indoles (9a-c, 11a,b, and 12) have been obtained by the S(RN)1 mechanism from photostimulated reactions of o-iodoaniline (1) and 1-halo-2-naphthalen-2-ylamines (3a,b) with enolate ions of acyclic (acetophenone (6), 2- (4a) and 4-acetylpyridine (4b)) and cyclic ketones (1- (8a) and 2-indanone (10a), 1- (8b) and 2-tetralone (10b) and 1-benzosuberone (8c)) in DMSO and liquid ammonia as solvents. The carbanions derived from 4a,b, 8a, and 10b are novel nucleophiles that form new C-C bonds by the S(RN)1 mechanism.

View Article and Find Full Text PDF

Several bridgehead halobisnoradamantane derivatives (5, 7, 10, and 17) were synthesized from tricyclic diester 1 in good yields using standard methods. The reactivity through the S(RN)1 mechanism of the above compounds and the known halobisethano derivatives 24 and 25a-c was studied. Iodo derivatives 7, 10, and 25a reacted with diphenylphosphide ions in DMSO under irradiation to give the corresponding substitution and reduction products by the S(RN)1 mechanism, while iodo ketone 17 gave a mixture of the rearranged substitution product 36 and the reduction product 18.

View Article and Find Full Text PDF

Spontaneous deamidation of lactoferrin preparations from women's milk was found during incubation for 28 days under simulated physiological conditions (0.85% NaCl, pH 7.0, 37 degrees C).

View Article and Find Full Text PDF

The reactions of 1,3-dihaloadamantanes with various carbanionic nucleophiles were studied. Potassium enolates of acetophenone (2) and pinacolone (10b) and the anion of nitromethane (10a) reacted with 1,3-diiodoadamantane (1a) in DMSO under photostimulation by a free radical chain process to form a 1-iodo monosubstitution product as an intermediate, which undergoes concerted fragmentation to form derivatives of 7-methylidenebicyclo[3.3.

View Article and Find Full Text PDF

Shifts in thermoregulation of the body leading to increased resistance to diseases were recorded in persons active in winter swimming in sea water. The shifts also involved cardiorespiratory function producing occasional unwanted effects in persons with cardiovascular diseases.

View Article and Find Full Text PDF