Vilnius University Institutional Repository
Not a member yet
51864 research outputs found
Sort by
Electronic g-tensors of dangling bonds in hydroxylated and aminated nanodiamonds: a computational study /
No full textThe calculations of electronic g-tensors, one of the most important parameters in electron paramagnetic resonance spectroscopy, are carried out for dangling bonds (DBs) introduced into hydroxylated and aminated diamond nanoparticles, or nanodiamonds (NDs), of different shapes and sizes. Regarding the shapes of NDs, octahedral, cubic, and tetrahedral model systems are used, while the impact of the change in size is inspected by increasing octahedral ND from C35 to C84. The results for single DBs reveal that tetrahedral NDs exhibit the widest variation range of the isotropic g-shift values for both surface functionalization schemes, whereas the isotropic g-shifts of octahedral and cubic NDs tend to strongly overlap. On the other hand, if one treats NDs as an ensemble of nanoparticles constituting a sample, the isotropic g-shifts arithmetically averaged over all available DBs show that tetrahedral ND with hydroxylated surface possesses a significantly higher value than the rest of the considered systems. However, applying the Boltzmann distribution results in a substantially lower value for cubic ND. In contrast, aminated NDs do not demonstrate average values that stand out from the others, irrespective of the analysis method employed. Overall, in addition to the comprehensive magnetic properties, the obtained data also provide interesting details on the formation of DBs in hydroxylated and aminated NDs
Development of a sensitive quantum dot-linked immunoassay for the multiplex detection of biochemical markers in a microvolumeric format /
No full textSinglet fission in heterogeneous lycopene aggregates /
No full textWe have prepared lycopene aggregates with low scattering in an acetone–water suspension. The aggregates exhibit highly distorted absorption, extending from the UV up to 568 nm, as a result of strong excitonic interactions. We have investigated the structural organization of these aggregates by resonance Raman and TEM, revealing that the lycopene aggregates are not homogeneous, containing at least four different aggregate species. Transient absorption measurements upon excitation at 355, 515, and 570 nm, to sub-select these different species, reveal significant differences in dynamics between each of the aggregate types. The strong excitonic interactions produce extremely distorted transient electronic signatures, which do not allow an unequivocal identification of the excited states at times shorter than 60 ps. However, these experiments demonstrate that all the lycopene aggregated species form long-living triplets via singlet fission
Pancreatic 3D organoids and microfluidic systems-applicability and utilization in surgery: a literature review /
No full textBackground: Pancreatic organoids are a rapidly advancing field of research with new discoveries being made every day. A literature review was performed to answer the question of how relevant 3D pancreatic organoids are for surgery. Materials and Methods: We started our investigation by identifying articles in PubMed within the last 5 years using the keywords ((“pancreatic organoid”, OR “organ-on-a-chip”, OR “pancreatic chip” OR “3D culture methods”) AND pancreatic surgery). Only English articles were included in this literature review. This literature review was performed in a non-systematic way; articles were chosen without a predetermined protocol of inclusion and were based on the aim of the review. Results and Conclusions: There are many promising innovations in the field of 3D cultures. Drug sensitivity testing in particular holds great potential for surgical application. For locally advanced PDAC, EUS-FNB obtained cancer tissue can be cultured as organoids, and after 4 weeks, neoadjuvant treatment could be adjusted for each patient individually. Utilizing this approach could increase the number of R0 resections and possibly cure the disease. Furthermore, microfluidic devices, as a platform for pancreatic islet pre-transplant evaluation or cultivation of beta cells derived from HiPSC in vitro, promise broad application of islet transplantation to T1DM patients in the near future
Keratokonuso gydymo intrarageniniais žiedais ir ragenos sutvirtinimo operacijos efektyvumo palyginimas /
No full textOverweight, obesity, and cardiovascular disease in heterozygous familial hypercholesterolaemia: the EAS FH Studies Collaboration registry /
No full textBACKGROUND AND AIMS: Overweight and obesity are modifiable risk factors for atherosclerotic cardiovascular disease (ASCVD) in the general population, but their prevalence in individuals with heterozygous familial hypercholesterolaemia (HeFH) and whether they confer additional risk of ASCVD independent of LDL cholesterol (LDL-C) remains unclear.
METHODS: Cross-sectional analysis was conducted in 35 540 patients with HeFH across 50 countries, in the EAS FH Studies Collaboration registry. Prevalence of World Health Organization-defined body mass index categories was investigated in adults (n = 29 265) and children/adolescents (n = 6275); and their association with prevalent ASCVD.
RESULTS: Globally, 52% of adults and 27% of children with HeFH were overweight or obese, with the highest prevalence noted in Northern Africa/Western Asia. A higher overweight/obesity prevalence was found in non-high-income vs. high-income countries. Median age at familial hypercholesterolaemia diagnosis in adults with obesity was 9 years older than in normal weight adults. Obesity was associated with a more atherogenic lipid profile independent of lipid-lowering medication. Prevalence of coronary artery disease increased progressively across body mass index categories in both children and adults. Compared with normal weight, obesity was associated with higher odds of coronary artery disease in children (odds ratio 9.28, 95% confidence interval 1.77-48.77, adjusted for age, sex, lipids, and lipid-lowering medication) and coronary artery disease and stroke in adults (odds ratio 2.35, 95% confidence interval 2.10-2.63 and odds ratio 1.65, 95% confidence interval 1.27-2.14, respectively), but less consistently with peripheral artery disease. Adjusting for diabetes, hypertension and smoking modestly attenuated the associations.
CONCLUSIONS: Overweight and obesity are common in patients with HeFH and contribute to ASCVD risk from childhood, independent of LDL-C and lipid-lowering medication. Sustained body weight management is needed to reduce the risk of ASCVD in HeFH
Mesenchymal stromal cells for steroid-refractory biopsy-proven grade III-IV acute Graft-versus-Host Disease with predominant gastrointestinal involvement /
No full textIntroduction: Steroid-refractory acute Graft-versus-Host Disease (SR-aGVHD) is a potentially fatal complication occurring in approximately 60-70% of severe grade III-IV GVHD cases, with a higher incidence in patients with gastrointestinal (GI) involvement. GI aGVHD is associated with poor prognosis, with a 2-year overall survival (OS) rate of only 25% in patients with stage 3-4 GI involvement. Mesenchymal stromal cells (MSC) have emerged as a promising therapeutic option due to their favorable efficacy and safety profile. However, data on bone marrow (BM)-derived MSC use in biopsy-proven grade III-IV SR-aGVHD with GI involvement, particularly in stage 3-4 cases, remain limited. Methods: This prospective, observational, single-arm, single-center study assessed the efficacy and safety of BM-derived MSC for treating adult patients with biopsy-proven grade III-IV SR-aGVHD with predominant GI involvement. Early (1st-2nd) passage BM-derived MSC were administered weekly at a target dose of 1x106 MSC/kg in two regimens: up to three (MSC3) and six doses (MSC6). Results: Fifty-seven adult patients with biopsy-proven III-IV grade SR-aGVHD (93% with GI involvement) received MSC treatment. The overall response rate (ORR) was 39% and 42% on Days 14 and 28, respectively, with no significant differences between the two MSC groups (Day 28 ORR 38% for MSC3 and 44% for MSC6). In patients with stage 3-4 GI involvement, the ORR was 26% and 36% at the corresponding time points with comparable efficacy between the two MSC groups (Day 28 ORR 31% for MSC3 and 38% for MSC6). Day 14 and Day 28 responders had significantly higher OS compared to non-responders (52% vs. 7%, p=0.000; 54% vs. 5%, p=0.000), with a comparable OS benefit observed in patients with stage 3-4 GI involvement (45% vs. 8%, p=0.005; 42% vs. 6%, p=0.005), respectively. MSC treatment had a favorable safety profile. The one, 5 and 10-year OS rates were 27%, 24%, and 24%, respectively. Conclusions: The grade III-IV SR-aGVHD patients, including cases with biopsy-proven severe GI involvement, had significantly better clinical outcomes if responses to MSC treatment were observed on Days 14 and 28. Intensified MSC administration schedule has failed to improve the clinical outcomes. MSC studies focusing on aGVHD prevention and (or) first-line treatment in combination with other agents should be considered
