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result(s) for
"Sokolowski, Piotr"
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Static Analysis of Wooden Beams Strengthened with FRCM-PBO Composite in Bending
by
Kossakowski, Paweł Grzegorz
,
Sokołowski, Piotr Kazimierz
in
Analysis
,
Bending
,
Bending stresses
2023
The article presents an analysis of the static work of bent solid-wood beams reinforced with FRCM–PBO (fiber-reinforced cementitious matrix–p-phenylene benzobis oxazole) composite. In order to ensure better adhesion of the FRCM–PBO composite to the wooden beam, a layer of mineral resin and quartz sand was applied between the composite and the wooden beam. Ten wooden pine beams with dimensions of 80 × 80 × 1600 mm were used for the tests. Five wooden beams, unreinforced, were used as referenced elements and another five were reinforced with FRCM–PBO composite. The tested samples were subjected to a four-point bending test in which the static scheme of a simply supported beam subjected to two symmetrical concentrated forces was used. The main purpose of the experiment was to estimate the load capacity, the flexural modulus and the maximum bending stress. The time needed to destroy the element and the deflection were also measured. The tests were carried out based on the PN-EN 408: 2010 + A1 standard. The material used for the study was also characterized. The methodology and assumptions adopted in the study were presented. The tests confirmed a significant increase in destructive force by 141.46%, maximum bending stress by 118.9%, modulus of elasticity by 18.32%, time needed to destroy the sample by 106.56% and deflection by 115.58% compared to the reference beams. The unusual method of wood reinforcement presented in the article can be considered as innovative, characterized not only by a significant load capacity margin exceeding 141%, but also by simplicity of application.
Journal Article
Experimental Test of Reinforced Timber of FRCM-PBO with Pull-Off Adhesion Method
by
Bąk-Patyna, Paulina
,
Bysiec, Dominika
,
Maleska, Tomasz
in
Adhesion
,
Adhesive strength
,
Beams (structural)
2022
The article describes the results of pull-off adhesion strength of the FRCM-PBO (Fiber Reinforced Cementitious Matrix-p-Phenylene benzobis oxazole) composite adhered to the epoxy resin layer which is the connector with the timber beam. In addition, this paper shows the results of the tests of resistance to pull-off the epoxy resin layer from the pine beam. The tests were carried out based on the Polish Standard PN-EN 1542. The Pearson linear correlation analysis was also carried out in order to determine the correlation between the obtained results and the destructive forces. The factors that occurred during the test that may affect its results, such as the method of applying the bursting force, surface preparation of the tested elements and the types of substrate destruction, were also characterized. The experimental data show that in all the tested samples, non-initial adhesive destruction between the adhesive layer and the disc was observed.
Journal Article
Safety and efficacy of MD1003 (high-dose biotin) in patients with progressive multiple sclerosis (SPI2): a randomised, double-blind, placebo-controlled, phase 3 trial
2020
There is an unmet need to develop therapeutic interventions directed at the neurodegeneration that underlies progression in multiple sclerosis. High-dose, pharmaceutical-grade biotin (MD1003) might enhance neuronal and oligodendrocyte energetics, resulting in improved cell function, repair, or survival. The MS-SPI randomised, double-blind, placebo-controlled study found that MD1003 improved disability outcomes over 12 months in patients with progressive multiple sclerosis. The SPI2 study was designed to assess the safety and efficacy of MD1003 in progressive forms of multiple sclerosis in a larger, more representative patient cohort.
SPI2 was a randomised, double-blind, parallel-group, placebo-controlled trial done at 90 academic and community multiple sclerosis clinics across 13 countries. Patients were aged 18–65 years, had a diagnosis of primary or secondary progressive multiple sclerosis fulfilling the revised International Panel criteria and Lublin criteria, a Kurtzke pyramidal functional subscore of at least 2 (defined as minimal disability), an expanded disability status scale (EDSS) score of 3·5–6·5, a timed 25-foot walk (TW25) of less than 40 s, evidence of clinical disability progression, and no relapses in the 2 years before enrolment. Concomitant disease-modifying therapies were allowed. Patients were randomly assigned (1:1) by an independent statistician using an interactive web response system, with stratification by study site and disease history, to receive MD1003 (oral biotin 100 mg three times daily) or placebo. Participants, investigators, and assessors were masked to treatment assignment. The primary endpoint was a composite of the proportion of participants with confirmed improvement in EDSS or TW25 at month 12, confirmed at month 15, versus baseline. The primary endpoint was assessed in the intention-to-treat analysis set, after all participants completed the month 15 visit. Safety analyses included all participants who received at least one dose of MD1003. This trial is registered with ClinicalTrials.gov (NCT02936037) and the EudraCT database (2016-000700-29).
From Feb 22, 2017, to June 8, 2018, 642 participants were randomly assigned MD1003 (n=326) or placebo (n=316). The double-blind, placebo-controlled phase of the study ended when the primary endpoint for the last-entered participant was assessed on Nov 15, 2019. The mean time in the placebo-controlled phase was 20·1 months (SD 5·3; range 15–27). For the primary outcome, 39 (12%) of 326 patients in the MD1003 group compared with 29 (9%) of 316 in the placebo group improved at month 12, with confirmation at month 15 (odds ratio 1·35 [95% CI 0·81–2·26]). Treatment-emergent adverse events occurred in 277 (84%) of 331 participants in the MD1003 group and in 264 (85%) of 311 in the placebo group. 87 (26%) of 331 participants in the MD1003 group and 82 (26%) of 311 participants in the placebo group had at least one serious treatment-emergent adverse event. One (<1%) person died in the MD1003 group and there were no deaths in the placebo group. Despite use of mitigation strategies, MD1003 led to inaccurate laboratory results for tests using biotinylated antibodies.
This study showed that MD1003 did not significantly improve disability or walking speed in patients with progressive multiple sclerosis and thus, in addition to the potential of MD1003 for deleterious health consequences from interference of laboratory tests, MD1003 cannot be recommended for treatment of progressive multiple sclerosis.
MedDay Pharmaceuticals.
Journal Article
Adrenal steroids in adrenomyeloneuropathy
2005
Adrenoleukodystrophy (ALD) and its adult variant adrenomyeloneuropathy (AMN) are X-linked diseases associated with a deficiency in the peroxisomal degradation of saturated very long chain fatty acids (VLCFA) resulting in an accumulation of VLCFA in the central and peripheral myelin, the adrenal cortex and the testis. Adrenal insufficiency with clinical hypocortisolism occurs in approximately two thirds of the patients with AMN.We studied the circulating adrenal hormones17α-hydroxyprogesterone (17α-OHP), androstenedione and dehydroepiandrosterone sulphate (DHEAS) in 63 male AMN patients (age 17-65 years) and the DHEAS serum levels in 95 healthy male controls (age 30-65 years). 34 of the patients presented with the phenotype of only spinal cord and peripheral nerve disability without hypocortisolism, 29 of the patients presented with the phenotype of either additional hypocortisolism or Addison's syndrome only. Normal 17α-OHP concentrations were found in all patients with no significant difference between patients without and with hypocortisolism (6.07±0.61 nmol/l and 4.76±0.37 nmol/l). Androstenedione concentration was significantly (p<0.01) lower in patients with hypocortisolism (2.99±0.65 pmol/l versus 5.71±0.68 pmol/l). As serum levels of DHEAS are agedependent we divided the two groups into two subgroups each (subgroup one: age 17-40 years, subgroup two: age 41-65 years). The DHEAS concentration of patients without and with hypocortisolism was significantly (p<0.01) lower in both subgroups (1. 4.35±0.84 µmol/l, n=15, 2. 15±0.28 µmol/l, n=19; 1. 1.90±0.57 µmol/, n=21, 2. 0.96±0.29 µmol/l, n=8) compared to controls (1. 9.0±0.96 µmol/l; 2. 5.21±0.25 µmol/l). In conclusion, androstenedione and DHEAS serum concentrations are subnormal in all AMN patients and may therefore serve as sensitive markers of the adrenal function in adrenomyeloneuropathy.
Journal Article
Adrenal steroids in adrenomyeloneuropathy. Dehydroepiandrosterone sulfate, androstenedione and 17alpha-hydroxyprogesterone
by
Wichers-Rother, Maria
,
Sokolowski, Piotr
,
Grigull, Andreas
in
17-alpha-Hydroxyprogesterone - blood
,
Adrenoleukodystrophy - blood
,
Adrenoleukodystrophy - drug therapy
2005
Adrenoleukodystrophy (ALD) and its adult variant adrenomyeloneuropathy (AMN) are X-linked diseases associated with a deficiency in the peroxisomal degradation of saturated very long chain fatty acids (VLCFA) resulting in an accumulation of VLCFA in the central and peripheral myelin, the adrenal cortex and the testis. Adrenal insufficiency with clinical hypocortisolism occurs in approximately two thirds of the patients with AMN. We studied the circulating adrenal hormones 17alpha-hydroxyprogesterone (17alpha-OHP), androstenedione and dehydroepiandrosterone sulphate (DHEAS) in 63 male AMN patients (age 17-65 years) and the DHEAS serum levels in 95 healthy male controls (age 30-65 years). 34 of the patients presented with the phenotype of only spinal cord and peripheral nerve disability without hypocortisolism, 29 of the patients presented with the phenotype of either additional hypocortisolism or Addison's syndrome only. Normal 17alpha-OHP concentrations were found in all patients with no significant difference between patients without and with hypocortisolism (6.07 +/- 0.61 nmol/l and 4.76 +/- 0.37 nmol/l). Androstenedione concentration was significantly (p < 0.01) lower in patients with hypocortisolism (2.99 +/- 0.65 pmol/l versus 5.71 +/- 0.68 pmol/l). As serum levels of DHEAS are agedependent we divided the two groups into two subgroups each (subgroup one: age 17-40 years, subgroup two: age 41-65 years). The DHEAS concentration of patients without and with hypocortisolism was significantly (p < 0.01) lower in both subgroups (1. 4.35 +/- 0.84 micromol/l, n = 15, 2. 15 +/- 0.28 micromol/l, n = 19; 1. 1.90 +/- 0.57 micromol/, n = 21, 2. 0.96 +/- 0.29 micromol/l, n = 8) compared to controls (1. 9.0 +/- 0.96 micromol/l; 2. 5.21 +/- 0.25 micromol/l). In conclusion, androstenedione and DHEAS serum concentrations are subnormal in all AMN patients and may therefore serve as sensitive markers of the adrenal function in adrenomyeloneuropathy.
Journal Article
Adrenal steroids in adrenomyeloneuropathy : Dehydroepiandrosterone sulfate, androstenedione and 17a-hydroxyprogesterone
by
GRIGULL, Andreas
,
KOHLER, Wolfgang
,
STOFFEL-WAGNER, Birgit
in
Anesthesia
,
Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy
,
Biological and medical sciences
2005
Journal Article
The cystathionine beta-synthase variant c.844_845ins68 protects against CNS demyelination in X-linked adrenoleukodystrophy
by
Kemp, Stephan
,
Sokolowski, Piotr
,
Klockgether, Thomas
in
Adrenoleukodystrophy - enzymology
,
Adrenoleukodystrophy - genetics
,
ALMN
2006
The clinical course of X‐linked adrenoleukodystrophy (X‐ALD) is of unexplained heterogeneity. Major X‐ALD phenotypes are the progressive childhood cerebral form (CCALD) with early confluent cerebral demyelination and the adult‐onset adrenomyeloneuropathy (AMN). Adult AMN may present with demyelinated foci of the CNS (adrenoleukomyeloneuropathy, ALMN) or without (“pure” AMN). Activated methionine is essential for CNS myelination, and methionine metabolism is important for glutathione synthesis, which may influence neurodegeneration. Cystathionine beta‐synthase (CBS) is a key enzyme of methionine metabolism. The CBS variant c.844_845ins68 (p.‐) may influence the availability of activated methionine as well as of glutathione. In this study, we analyzed this variant in genomic DNA samples of 86 X‐ALD patients. We observed the allele carrying the insertion in 12 of 49 patients without CNS demyelination (“pure” AMN), but in none of the 37 patients with CNS demyelination (CCALD or ALMN; χ2=10.531; p=0.001). We conclude that the insertion allele of CBS c.844_845ins68 protected X‐ALD patients against CNS demyelination in our study sample. These data suggest that the individual conditions in methionine metabolism may be a disease modifier of X‐ALD. Since methionine metabolism can easily be influenced by vitamin and amino acid substitution, this observation could be a basis of novel treatment strategies in this yet untreatable disease. © 2006 Wiley‐Liss, Inc.
Journal Article
Continuous Flow-Mode Synthesis of Aromatic Amines in a 3D-Printed Fixed Bed Reactor Loaded with Amino Sugar-Stabilized Re Apparent Nanoparticles
by
Niyirora, Patrick
,
Cyganowski, Piotr
,
Jamróz, Piotr
in
Aromatic amines
,
Catalysts
,
Fixed bed reactors
2025
In industrial processes, catalysts—materials that speed up chemical reactions without being consumed—are essential. The goal of this research was to create two new rhenium-based nanocomposite catalysts that can effectively and sustainably reduce nitroaromatic compounds to aromatic amines in continuous-flow systems. Nitroaromatic hydrocarbons (NACs), widely used in manufacturing pharmaceuticals, insecticides, and herbicides, often contaminate soil and water, posing significant environmental and health risks. However, their reduction to aromatic amines enables potential industrial reuse. In this study, we synthesized two nanocomposite catalysts based on a copolymer functionalized with N-methyl-D-glucamine, embedded with rhenium (Re)-based apparent nanoparticles, and used them to reduce the NACs in continuous-flow mode to their aromatic amines using newly designed and stereolithographic (SLA) 3D-printed reactors. Advanced characterization techniques were employed to evaluate their structure, morphology, and catalytical performance. Catalyst 1, prepared from a self-modified Purolite D4869 resin and characterized by higher Re loading, exhibited superior conversion rates in batch mode (k1 up to 1.406 s−1). In contrast, Catalyst 2, based on a commercial NMDG-functionalized Dowex resin with a mesoporous structure, demonstrated remarkable stability and catalytic capacity under continuous flow (up to 1.383 mmolNAC mLcat−1). Overall, Catalyst 1 was found to be better suited for rapid batch reactions, whereas Catalyst 2 was found to be more appropriate for long-term flow applications, offering a sustainable route for the efficient conversion of nitroaromatic compounds into valuable aromatic amines. The reactors enabled the efficient conversion of NACs into aromatic amines while enhancing process sustainability and efficiency.
Journal Article
Plasma synthesis of rhenium nanoparticles as an efficient alternative to platinum nanoparticles for nitroaromatic compound hydrogenations
by
Goleniewska, Aleksandra
,
Cyganowski, Piotr
,
Arabasz, Sebastian
in
639/301/357/354
,
639/638/549/884
,
639/638/77/884
2025
Rhenium nanoparticles are an attractive alternative to noble metal-based approaches, which show a limited applicability. The catalytic potential and environmental impact of rhenium nanoparticles (ReNPs) were assessed in conjunction with those of platinum nanoparticles (PtNPs). Both of these nanomaterials were synthesized via low-cost pulse-modulated radiofrequency atmospheric pressure glow discharge (pm-rf-APGD). In this context, pm-rf-APGD was used for the first time to synthesize Re-based nanomaterials. The obtained nanoparticles were used as nanocatalysts for hydrogenation of nitroaromatic compounds. Subsequent characterization revealed high efficacy of rhenium nanoparticles in catalysing the reduction of nitroaromatic compounds, which reached up to 100% conversion yields at a rate constant
k
1
of 5.5 × 10
− 2
min
− 1
. Although the
k
1
values obtained for rhenium nanoparticles were lower than those recorded for platinum nanoparticles, this research highlights the economic aspects and explores the possible optimization of catalytic systems. Some putatively disadvantageous environmental impact of rhenium nanoparticles and platinum nanoparticles was demonstrated by the exposure of
Raphanus sativus
var.
oleiferus
L. seeds to either rhenium nanoparticles or platinum nanoparticles that resulted in development of the shorter sprouts. Despite this negative environmental impact, the outcomes of this study highlight the potential of rhenium nanoparticles for chemical transformation and emphasize the importance of further insights into the economic and environmental aspects of their application and mitigation strategies.
Journal Article