Publications by authors named "Bartnik A"

A laser-plasma source emitting photons with energies in the water window spectral range has been used to reveal the radiation chemical yields of single-strand breaks in plasmid DNA as a function of OH radical scavenger concentration. Direct and indirect effects were investigated separately using DNA samples with various levels of hydration. We experimentally determined the value of the efficiency factor for strand cleavage in DNA caused by the reaction with OH radicals at 0.

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Objective: Baseline paramagnetic rim lesion (PRL) load predicts disease progression in people with multiple sclerosis (pwMS). Understanding how PRLs relate to other known MS-related factors, and the practical utility of PRLs in clinical trials, is crucial for informing clinical decision-making and guiding development of novel disease-modifying treatments (DMTs).

Methods: This study included 152 pwMS enrolled in a larger prospective, longitudinal cohort study who had 3T MRI scans and clinical assessments at baseline and 5- or 10-year follow-ups.

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Background And Objectives: Recent technological advances have enabled visualizing in vivo a subset of chronic active brain lesions in persons with multiple sclerosis (pwMS), referred to as "paramagnetic rim lesions" (PRLs), with iron-sensitive MRI. PRLs predict future clinical disease progression, making them a promising clinical and translational imaging marker. However, it is unknown how disease progression is modified by PRL evolution (PRL disappearance, new PRL appearance).

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Magnetic resonance imaging of the brain is a useful tool in both the clinic and research settings, aiding in the diagnosis and treatments of neurological disease and expanding our knowledge of the brain. However, there are many challenges inherent in managing and analyzing MRI data, due in large part to the heterogeneity of data acquisition. To address this, we have developed MRIO, the Magnetic Resonance Imaging Acquisition and Analysis Ontology.

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Article Synopsis
  • The study investigates the role of the CHRFAM7A gene in human neuropsychiatric disorders like Alzheimer's, schizophrenia, and anxiety, focusing on its influence on brain structure and function.
  • Researchers conducted a genotype analysis on 46 healthy subjects to compare those who carry the gene's direct allele with those who don’t, assessing neuropsychological performance and conducting MRI scans for structural brain analysis.
  • Findings from cognitive tests and MRI scans were analyzed through age-adjusted statistical methods to identify how CHRFAM7A may affect brain and cognitive functions.
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The increasing use of neuroimaging in clinical research has driven the creation of many large imaging datasets. However, these datasets often rely on inconsistent naming conventions in image file headers to describe acquisition, and time-consuming manual curation is necessary. Therefore, we sought to automate the process of classifying and organizing magnetic resonance imaging (MRI) data according to acquisition types common to the clinical routine, as well as automate the transformation of raw, unstructured images into Brain Imaging Data Structure (BIDS) datasets.

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This paper discusses the results of the micro-Raman analysis performed on paper-like graphene oxide (GO) samples consisting of many functionalised graphene layers and annealed at moderate temperatures (≤500 °C) under vacuum conditions (p ≃ 10 mbar). The analysis of the standalone samples revealed that the obtained material is characterised by a noticeable disorder level but still stays below the commonly accepted threshold of high or total disorder. GO formed in a simple way showed two spectral bands above 1650 cm recorded very rarely or not at all and their origin has been discussed in detail.

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Background: Paramagnetic rim lesions (PRLs) have been linked to higher clinical disease severity and relapse frequency. However, it remains unclear whether PRLs predict future, long-term disease progression.

Objectives: The study aimed to assess whether baseline PRLs were associated with subsequent long-term (10 years) Expanded Disability Status Scale (EDSS) increase and relapse frequency and, if so, whether PRL-associated EDSS increase was mediated by relapse.

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Background: The structural changes associated with cognitive performance in older people with multiple sclerosis (PwMS; age ≥ 50 years old) remain unknown.

Objective: To determine the relationship between whole-brain (WBV), thalamus as the largest deep gray matter nuclei, and cortex-specific volume measurements with both cognitive impairment and numerical performance in older PwMS. The main hypothesis is that cognitive impairment (CI) in older PwMS is explained by cortical thinning in addition to global and thalamic neurodegenerative changes.

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Objective: Magnetic resonance imaging of the brain is a useful tool in both the clinic and research settings, aiding in the diagnosis and treatments of neurological disease and expanding our knowledge of the brain. However, there are many challenges inherent in managing and analyzing MRI data, due in large part to the heterogeneity of data acquisition.

Materials And Methods: To address this, we have developed MRIO, the Magnetic Resonance Imaging Acquisition and Analysis Ontology.

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Pulmonary endarterectomy (PEA) may not achieve full clearance of vascular obstructions in patients with more distal chronic thromboembolic pulmonary hypertension (CTEPH). Balloon pulmonary angioplasty (BPA) may be indicated to treat these residual vascular lesions. We compared whether patients post-PEA (PP) treated by BPA derived similar benefit to those who had inoperable CTEPH (IC), and assessed predictors of BPA response after surgery.

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Ultrafast-optical-pump - structural-probe measurements, including ultrafast electron and x-ray scattering, provide direct experimental access to the fundamental timescales of atomic motion, and are thus foundational techniques for studying matter out of equilibrium. High-performance detectors are needed in scattering experiments to obtain maximum scientific value from every probe particle. We deploy a hybrid pixel array direct electron detector to perform ultrafast electron diffraction experiments on a WSe/MoSe 2D heterobilayer, resolving the weak features of diffuse scattering and moiré superlattice structure without saturating the zero order peak.

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Little is known about how the brain's functional organization changes over time with respect to structural damage. Using multiple sclerosis as a model of structural damage, we assessed how much functional connectivity (FC) changed within and between preselected resting-state networks (RSNs) in 122 subjects (72 with multiple sclerosis and 50 healthy controls). We acquired the structural, diffusion, and functional MRI to compute functional connectomes and structural disconnectivity profiles.

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The development of the broad-bandwidth photon sources emitting in the soft X-ray range has attracted great attention for a long time due to the possible applications in high-resolution spectroscopy, nano-metrology, and material sciences. A high photon flux accompanied by a broad, smooth spectrum is favored for the applications such as near-edge X-ray absorption fine structure (NEXAFS), extended X-ray absorption fine structure (EXAFS), or XUV/X-ray coherence tomography (XCT). So far, either large-scale facilities or technologically challenging systems providing only limited photon flux in a single shot dominate the suitable sources.

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Chronic thromboembolic pulmonary hypertension occurs in a proportion of patients with prior acute pulmonary embolism and is characterised by breathlessness, persistently raised pulmonary pressures and right heart failure. Surgical pulmonary endarterectomy (PEA) offers significant prognostic and symptomatic benefits for patients with proximal disease distribution. For those with inoperable disease, management options include balloon pulmonary angioplasty (BPA) and medical therapy.

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Despite a range of covalent protein modifications, few techniques exist for quantification of protein bioconjugation in cells. Here, we describe a novel method for quantifying protein bioconjugation through covalent bond formation with HaloTag. This approach utilizes unnatural amino acid (UAA) mutagenesis to selectively install a small and bioorthogonally reactive handle onto the surface of a protein.

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Acute myeloid leukaemia (AML) creates an immunosuppressive environment to conventional T cells through Arginase 2 (ARG2)-induced arginine depletion. We identify that AML blasts release the acute phase protein serum amyloid A (SAA), which acts in an autocrine manner to upregulate ARG2 expression and activity, and promote AML blast viability. Following in vitro cross-talk invariant natural killer T (iNKT) cells become activated, upregulate mitochondrial capacity, and release IFN-γ.

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We report the design and performance of a time-resolved electron diffraction apparatus capable of producing intense bunches with simultaneously single digit micrometer probe size, long coherence length, and 200 fs rms time resolution. We measure the 5d (peak) beam brightness at the sample location in micro-diffraction mode to be . To generate high brightness electron bunches, the system employs high efficiency, low emittance semiconductor photocathodes driven with a wavelength near the photoemission threshold at a repetition rate up to 250 kHz.

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A near 1-keV photons from the Xe/He plasma produced by the interaction of laser beam with a double stream gas puff target were employed for studies of L absorption edges of period 4 transitional metals with atomic number Z from 26 to 30. The dual-channel, compact NEXAFS system was employed for the acquisition of the absorption spectra. L absorption edges of the samples were identified in transmission mode using broadband emission from the Xe/He plasma to show the applicability of such source and measurement system to the NEXAFS studies of the transition metals, including magnetic materials.

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Polyetheretherketone (PEEK), due to its excellent mechanical and physico-chemical parameters, is an attractive substitute for hard tissues in orthopedic applications. However, PEEK is hydrophobic and lacks surface-active functional groups promoting cell adhesion. Therefore, the PEEK surface must be modified in order to improve its cytocompatibility.

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Understanding cancer cell adhesion could help to diminish tumor progression and metastasis. Adhesion mechanisms are currently the main therapeutic target of TNBC-resistant cells. This work shows the distribution and size of adhesive complexes determined with a common fluorescence microscopy technique and soft X-ray contact microscopy (SXCM).

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Characterization of Xe emission in the spectral range between 1 and 1.5 keV is presented in the case when the laser-plasma is generated by nanosecond laser pulse irradiation of a double stream Xe/He gas-puff target. Gas target density was estimated using extreme ultraviolet (EUV) radiography.

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This video tutorial demonstrates the insertion of a temporary biventricular assist device as a bridge to a heart transplant in a patient with end-stage heart failure with decompensation and increasing pulmonary pressure . This technique utilizes cardiopulmonary bypass to maintain hemodynamic stability throughout the procedure. Transesophageal echocardiography is used to guide the correct positioning of the ventricular cannulae.

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