Publications by authors named "Jurczyk J"

Mental preparation for sports competition in karate is significant, as it is deeply embedded in the philosophical and ethical values that underpin this combat method. In practice, the mental preparation of karateka varies depending on the type of competition, for example preparation for kata (forms) and kumite (fights). Thus, this perspective offers a concise account of the authors' viewpoint on the leading mental skills required of kata competitors.

View Article and Find Full Text PDF

We recently reported a chiral phosphoric acid (CPA) catalyzed enantioselective photomediated ring contraction of piperidines and other saturated heterocycles. By extruding a single heteroatom from a ring, this transformation builds desirable C(sp)-C(sp) bonds in the ring contracted products; however, the origins of enantioselectivity remain poorly understood. In this work, enantioselectivity of the ring contraction has been explored across an expanded structurally diverse substrate scope, revealing a wide range of enantioselectivities (0-99%) using two distinct CPA catalysts.

View Article and Find Full Text PDF

Selective enhancement of synaptic GABA signaling mediated by GABA-A receptors has been previously reported to promote functional recovery after ischemic stroke, while tonic GABA signaling has been detrimental. To identify agents that enhance synaptic signaling, we synthesized GABA-A ligands based on three chemotypes with affinity values p= 6.44-8.

View Article and Find Full Text PDF

Under mild blue-light irradiation, α-acylated saturated heterocycles undergo a photomediated one-atom ring contraction that extrudes a heteroatom from the cyclic core. However, for nitrogenous heterocycles, this powerful skeletal edit has been limited to substrates bearing electron-withdrawing substituents on nitrogen. Moreover, the mechanism and wavelength-dependent efficiency of this transformation have remained unclear.

View Article and Find Full Text PDF

Residential building material stock constitutes a significant part of the built environment, providing crucial shelter and habitat services. The hypothesis concerning stock mass and composition has garnered considerable attention over the past decade. While previous research has mainly focused on the spatial analysis of building masses, it often neglected the component-level stock analysis or where heavy labor cost for onsite survey is required.

View Article and Find Full Text PDF

Brain ischemia is one of the leading causes of death and long-term disability worldwide. Cessation of the blood supply to the brain directly stimulates many pathological events, including glutamate overload and neuroinflammation. Glial cell activation occurs shortly after ischemia onset, resulting in the release of proinflammatory cytokines and exacerbation of the detrimental effects of neuroinflammation.

View Article and Find Full Text PDF

Gas-assisted focused electron-beam-induced deposition is a versatile tool for the direct writing of complex-shaped nanostructures with unprecedented shape fidelity and resolution. While the technique is well-established for various materials, the direct electron beam writing of silver is still in its infancy. Here, we examine and compare five different silver carboxylates, three perfluorinated: [Ag(µ-OCCF)], [Ag(µ-OCCF)], and [Ag(µ-OCCF)], and two containing branched substituents: [Ag(µ-OCCMeEt)] and [Ag(µ-OCBu)], as potential precursors for focused electron-beam-induced deposition.

View Article and Find Full Text PDF

Brain ischemia is one of the leading causes of death and long-term disability in the world. Interruption of the blood supply to the brain is a direct stimulus for many pathological events. The massive vesicular release of glutamate (Glu) after ischemia onset induces excitotoxicity, which is a potent stress on neurons.

View Article and Find Full Text PDF

Recent developments in nanoprinting using focused electron beams have created a need to develop analysis methods for the products of electron-induced fragmentation of different metalorganic compounds. The original approach used here is termed focused-electron-beam-induced mass spectrometry (FEBiMS). FEBiMS enables the investigation of the fragmentation of electron-sensitive materials during irradiation within the typical primary electron beam energy range of a scanning electron microscope (0.

View Article and Find Full Text PDF

Medicinal chemistry continues to be impacted by new synthetic methods. Particularly sought after, especially at the drug discovery stage, is the ability to enact the desired chemical transformations in a concise and chemospecific fashion. To this end, the field of organic synthesis has become captivated by the idea of 'molecular editing'-to rapidly build onto, change or prune molecules one atom at a time using transformations that are mild and selective enough to be employed at the late stages of a synthetic sequence.

View Article and Find Full Text PDF

The effect of the g.4290 C>G substitution in the FADS2 gene and g.285 C>T in the FABP4 gene on carcass quality, meat quality, and fatty acid profile of the pectoralis superficialis muscle of 238 male broiler chickens reared up to 45 days of age was analyzed.

View Article and Find Full Text PDF

A proper reference gene (RG) is required to reliably measure mRNA levels in biological samples via quantitative reverse transcription PCR (RT-qPCR). Various experimental paradigms require specific and stable RGs. In studies using rodent models of brain ischaemia, a variety of genes, such as β-actin (Actb), hypoxanthine phosphoribosyltransferase 1 (Hprt1), peptidyl-propyl isomerase A (Ppia) and glyceraldehyde-3-phosphate dehydrogenase (Gapdh), are used as RGs.

View Article and Find Full Text PDF

Due to excellent electric conductivity and chemical inertness, Au can be used in new microdevices for energy applications, microelectronics, and biomedical solutions. However, the chemical analysis of Au-containing systems using time-of-flight secondary ion mass spectrometry (TOF-SIMS) can be difficult because of the negative ionization of Au, as most metals form positive ions, and therefore cannot be detected from the same analytical volume. In this work, we present the potential of fluorine gas coinjection for altering the polarity, from the negative to positive, of Au secondary ions generated under Ga beam bombardment.

View Article and Find Full Text PDF

Saturated heterocycles are found in numerous therapeutics and bioactive natural products and are abundant in many medicinal and agrochemical compound libraries. To access new chemical space and function, many methods for functionalization on the periphery of these structures have been developed. Comparatively fewer methods are known for restructuring their core framework.

View Article and Find Full Text PDF

Ischemic stroke is the third leading cause of death in the world, which accounts for almost 12% of the total deaths worldwide. Despite decades of research, the available and effective pharmacotherapy is limited. Some evidence underlines the beneficial properties of hydrogen sulfide (HS) donors, such as NaSH, in an animal model of brain ischemia and in in vitro research; however, these data are ambiguous.

View Article and Find Full Text PDF

A study of TiAlSiC ( = 0 to = 1) MAX-phase alloys is reported. The materials were obtained from mixtures of TiAlC and TiSiC powders with hot pressing sintering technique. They were characterised with X-ray diffraction, heat capacity, electrical resistivity, and magnetoresistance measurements.

View Article and Find Full Text PDF

High-resolution metallic nanostructures can be fabricated with multistep processes, such as electron beam lithography or ice lithography. The gas-assisted direct-write technique known as focused electron beam induced deposition (FEBID) is more versatile than the other candidates. However, it suffers from low throughput.

View Article and Find Full Text PDF

Saturated cyclic amines (aza-cycles) are ubiquitous structural motifs found in pharmaceuticals, agrochemicals, and bioactive natural products. Given their importance, methods that directly functionalize aza-cycles are in high demand. Herein, we disclose a fundamentally different approach to functionalizing cyclic amines which relies on C─C cleavage and attendant cross-coupling.

View Article and Find Full Text PDF

The construction of complex aza-cycles is of interest to drug discovery due to the prevalence of nitrogen-containing heterocycles in pharmaceutical agents. Herein we report an intramolecular C-H amination approach to afford value-added and complexity-enriched bridged bicyclic amines. Guided by density functional theory and nuclear magnetic resonance investigations, we determined the unique roles of light and heat activation in the bicyclization mechanism.

View Article and Find Full Text PDF
Article Synopsis
  • - The rearrangement of carbon-carbon (C-C) single bonds in carbocyclic compounds allows for the creation of uniquely modified structures, making it easier to synthesize complex molecules.
  • - Transition-metal-mediated C-C bond cleavage offers new methods for modifying these structures, providing selectivity advantages over traditional rearrangement techniques.
  • - The document details a successful total synthesis of phomactin terpenoids, showcasing the use of selective C-C bond cleavage in creating complex molecules and discussing challenges and strategies involved in this process.
View Article and Find Full Text PDF

Herein we report the synthesis of substituted indolizidines and related N-fused bicycles from simple saturated cyclic amines through sequential C-H and C-C bond functionalizations. Inspired by the Norrish-Yang Type II reaction, C-H functionalization of azacycles is achieved by forming α-hydroxy-β-lactams from precursor α-ketoamide derivatives under mild, visible light conditions. Selective cleavage of the distal C(sp)-C(sp) bond in α-hydroxy-β-lactams using a Rh-complex leads to α-acyl intermediates which undergo sequential Rh-catalyzed decarbonylation, 1,4-addition to an electrophile, and aldol cyclization, to afford N-fused bicycles including indolizidines.

View Article and Find Full Text PDF

Objective: The aim of the study was to evaluate the safety and tolerance of influenza vaccines for the northern and southern hemispheres in Polish elite athletes participating in the Rio 2016 Olympics.

Design: Prospective, observational, cohort study.

Setting: Institutional level.

View Article and Find Full Text PDF

Focused electron beam-induced deposition using the heteroleptic complex (η-CH)Ru(CO)Br as a precursor resulted in deposition of material with Ru content of 23 at. %. Transmission electron microscopy images indicated a nanogranular structure of pure Ru nanocrystals, embedded into a matrix containing carbon, oxygen, and bromine.

View Article and Find Full Text PDF

Carboxylates constitute an extremely promising class of precursor compounds for the electron beam induced deposition of silver. In this work both silver 2,2-dimethylbutyrate and silver pentafluoropropionate were investigated with respect to their dwell-time-dependent deposition behavior and growth characteristics. While silver 2,2-dimethylbutyrate showed a strong depletion in the center of the impinging electron beam profile hindering any vertical growth, silver pentafluoropropionate indicated a pronounced dependency of the deposit height on the dwell time.

View Article and Find Full Text PDF

Focused electron beam induced deposition (FEBID) is a flexible direct-write method to obtain defined structures with a high lateral resolution. In order to use this technique in application fields such as plasmonics, suitable precursors which allow the deposition of desired materials have to be identified. Well known for its plasmonic properties, silver represents an interesting candidate for FEBID.

View Article and Find Full Text PDF