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1.
Sci Technol Adv Mater ; 25(1): 2315015, 2024.
Article in English | MEDLINE | ID: mdl-38455384

ABSTRACT

We report investigations of the magnetic textures in periodic multilayers [Pt(1 nm)/(CoFeB(0.8 nm)/Ru(1.4 nm)]10 using polarised neutron reflectometry (PNR) and small-angle neutron scattering (SANS). The multilayers are known to host skyrmions stabilized by Dzyaloshinskii-Moriya interactions induced by broken inversion symmetry and spin-orbit coupling at the asymmetric interfaces. From depth-dependent PNR measurements, we observed well-defined structural features and obtained the layer-resolved magnetization profiles. The in-plane magnetization of the CoFeB layers calculated from fitting of the PNR profiles is found to be in excellent agreement with magnetometry data. Using SANS as a bulk probe of the entire multilayer, we observe long-period magnetic stripe domains and skyrmion ensembles with full orientational disorder at room temperature. No sign of skyrmions is found below 250 K, which we suggest is due to an increase of an effective magnetic anisotropy in the CoFeB layer on cooling that suppresses skyrmion stability. Using polarised SANS at room temperature, we prove the existence of pure Néel-type windings in both stripe domain and skyrmion regimes. No Bloch-type winding admixture, i.e. an indication for hybrid windings, is detected within the measurement sensitivity, in good agreement with expectations according to our micromagnetic modelling of the multilayers. Our findings using neutron techniques provide valuable microscopic insights into the rich magnetic behavior of skyrmion-hosting multilayers, which are essential for the advancement of future skyrmion-based spintronic devices.


The study presents a unique investigation of [Pt/CoFeB/Ru]10 multilayers, revealing suppressed skyrmion phases, intricate magnetic domain structures, and Néel-type domain walls, providing crucial insights for spintronic applications.

2.
Biol Trace Elem Res ; 201(12): 5848-5860, 2023 Dec.
Article in English | MEDLINE | ID: mdl-36964813

ABSTRACT

The use of medicinal plants for self-medication of minor health conditions has become a widespread practice in contemporary society. Few consumes, however, question the contamination of these products with toxic factors resulting from the planet's increasingly polluted environment. This paper presents the levels of five toxic elements (As, Cr, Pb, Cd, and Hg) and nine organochlorine pesticides (hexachlorobenzene (HCB), lindane, heptachor, aldrin, dieldrin, endrin, p,p'DDE, p,p'DDD, and p,p'DDT) in 14 brands of regularly consumed medicinal products in Romania. The toxic elements content was determined using energy-dispersive X-ray fluorescence (EDXRF) technique, and organochlorine pesticide residues (OPCs) were quantified using gas-chromatographic method, equipped with electron capture detector (GC-ECD). The results show that in the case of Cr, Cd, and Hg, the concentrations exceeded the limit values established by World Health Organisation (WHO) for raw herbal material. The higher level of OPCs (such as p,p'DDD, p,p'DDT, aldrin, and dieldrin) was found in the samples of Hypericum perforatum-St. John's wort, Crataegus monogyna-hawthorn, and Epilobium parviflorum-hoary willowherb. The correlations between the content of toxic elements and pesticides were determined by statistical analysis. Hierarchical clustering technique was used to detect natural grouping between the toxic elements and pesticides. For herb samples, four clusters were identified, the strongest correlated cluster consisting of Pb, HCB, Cr, and Hg. A further analysis within this cluster suggested that Cr levels are statistically different from the rest of the elements.


Subject(s)
Mercury , Pesticide Residues , Pesticides , Plants, Medicinal , Pesticide Residues/analysis , Dieldrin/analysis , DDT/analysis , Plants, Medicinal/chemistry , Aldrin/analysis , Hexachlorobenzene/analysis , Cadmium/analysis , Lead/analysis , Pesticides/analysis , Mercury/analysis , Pharmaceutical Preparations/analysis
3.
ACS Appl Mater Interfaces ; 15(1): 566-577, 2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36563339

ABSTRACT

Magnetotactic bacteria Magnetospirillum magneticum AMB-1 have been cultured using three different media: magnetic spirillum growth medium with Wolfe's mineral solution (MSGM + W), magnetic spirillum growth medium without Wolfe's mineral solution (MSGM - W), and flask standard medium (FSM). The influence of the culture medium on the structural, morphological, and magnetic characteristics of the magnetosome chains biosynthesized by these bacteria has been investigated by using transmission electron microscopy, X-ray absorption spectroscopy, and X-ray magnetic circular dichroism. All bacteria exhibit similar average size for magnetosomes, 40-45 nm, but FSM bacteria present slightly longer subchains. In MSGM + W bacteria, Co2+ ions present in the medium substitute Fe2+ ions in octahedral positions with a total Co doping around 4-5%. In addition, the magnetic response of these bacteria has been thoroughly studied as functions of both the temperature and the applied magnetic field. While MSGM - W and FSM bacteria exhibit similar magnetic behavior, in the case of MSGM + W, the incorporation of the Co ions affects the magnetic response, in particular suppressing the Verwey (∼105 K) and low temperature (∼40 K) transitions and increasing the coercivity and remanence. Moreover, simulations based on a Stoner-Wolhfarth model have allowed us to reproduce the experimentally obtained magnetization versus magnetic field loops, revealing clear changes in different anisotropy contributions for these bacteria depending on the employed culture medium. Finally, we have related how these magnetic changes affect their heating efficiency by using AC magnetometric measurements. The obtained AC hysteresis loops, measured with an AC magnetic field amplitude of up to 90 mT and a frequency, f, of 149 kHz, reveal the influence of the culture medium on the heating properties of these bacteria: below 35 mT, MSGM - W bacteria are the best heating mediators, but above 60 mT, FSM and MSGM + W bacteria give the best heating results, reaching a maximum heating efficiency or specific absorption rate (SAR) of SAR/f ≈ 12 W g-1 kHz-1.


Subject(s)
Hyperthermia, Induced , Magnetosomes , Magnetospirillum , Magnetospirillum/chemistry , Magnetospirillum/metabolism , Magnetosomes/chemistry , Magnetic Phenomena
4.
Cancers (Basel) ; 14(12)2022 Jun 08.
Article in English | MEDLINE | ID: mdl-35740506

ABSTRACT

Individual response to sunitinib in metastatic renal cell carcinoma (mRCC) patients is highly variable. Earlier, sunitinib outcome was related to single nucleotide polymorphisms (SNPs) in CYP3A5 and ABCB1. Our aim is to provide novel insights into biological mechanisms underlying sunitinib action. We included mRCC patients from the European EuroTARGET consortium (n = 550) and the RIKEN cohort in Japan (n = 204) which were analysed separately and in a meta-analysis of genome-wide association studies (GWAS). SNPs were tested for association with progression-free survival (PFS) and overall survival (OS) using Cox regression. Summary statistics were combined using a fixed effect meta-analysis. SNP rs28520013 in PDLIM3 and the correlated SNPs rs2205096 and rs111356738 both in DSCAM, showed genome-wide significance (p < 5 × 10−8) with PFS and OS in the meta-analysis. The variant T-allele of rs28520013 associated with an inferior PFS of 5.1 months compared to 12.5 months in non-carriers (p = 4.02 × 10−10, HR = 7.26). T-allele carriers of rs28520013 showed an inferior OS of 6.9 months versus 30.2 months in non-carriers (p = 1.62 × 10−8, HR = 5.96). In this GWAS we identified novel genetic variants in PDLIM3 and DSCAM that impact PFS and OS in mRCC patients receiving sunitinib. The underlying link between the identified genes and the molecular mechanisms of sunitinib action needs to be elucidated.

5.
ACS Nano ; 16(5): 7398-7408, 2022 05 24.
Article in English | MEDLINE | ID: mdl-35472296

ABSTRACT

Over the past few years, the use of nanomagnets in biomedical applications has increased. Among others, magnetic nanostructures can be used as diagnostic and therapeutic agents in cardiovascular diseases, to locally destroy cancer cells, to deliver drugs at specific positions, and to guide (and track) stem cells to damaged body locations in regenerative medicine and tissue engineering. All these applications rely on the magnetic properties of the nanomagnets which are mostly determined by their magnetic anisotropy. Despite its importance, the magnetic anisotropy of the individual magnetic nanostructures is unknown. Currently available magnetic sensitive microscopic methods are either limited in spatial resolution or in magnetic field strength or, more relevant, do not allow one to measure magnetic signals of nanomagnets embedded in biological systems. Hence, the use of nanomagnets in biomedical applications must rely on mean values obtained after averaging samples containing thousands of dissimilar entities. Here we present a hybrid experimental/theoretical method capable of working out the magnetic anisotropy constant and the magnetic easy axis of individual magnetic nanostructures embedded in biological systems. The method combines scanning transmission X-ray microscopy using an axi-asymmetric magnetic field with theoretical simulations based on the Stoner-Wohlfarth model. The validity of the method is demonstrated by determining the magnetic anisotropy constant and magnetic easy axis direction of 15 intracellular magnetite nanoparticles (50 nm in size) biosynthesized inside a magnetotactic bacterium.


Subject(s)
Magnetite Nanoparticles , Microscopy , Anisotropy , Microscopy/methods , X-Rays , Magnetics
6.
Clin Cancer Res ; 24(10): 2350-2356, 2018 05 15.
Article in English | MEDLINE | ID: mdl-29490989

ABSTRACT

Purpose: The survival of patients with clear cell metastatic renal cell carcinoma (cc-mRCC) has improved substantially since the introduction of tyrosine kinase inhibitors (TKI). With the fact that TKIs interact with immune responses, we investigated whether polymorphisms of genes involved in immune checkpoints are related to the clinical outcome of cc-mRCC patients treated with sunitinib as first TKI.Experimental Design: Twenty-seven single-nucleotide polymorphisms (SNP) in CD274 (PD-L1), PDCD1 (PD-1), and CTLA-4 were tested for a possible association with progression-free survival (PFS) and overall survival (OS) in a discovery cohort of 550 sunitinib-treated cc-mRCC patients. SNPs with a significant association (P < 0.05) were tested in an independent validation cohort of 138 sunitinib-treated cc-mRCC patients. Finally, data of the discovery and validation cohort were pooled for meta-analysis.Results:CTLA-4 rs231775 and CD274 rs7866740 showed significant associations with OS in the discovery cohort after correction for age, gender, and Heng prognostic risk group [HR, 0.84; 95% confidence interval (CI), 0.72-0.98; P = 0.028, and HR, 0.73; 95% CI, 0.54-0.99; P = 0.047, respectively]. In the validation cohort, the associations of both SNPs with OS did not meet the significance threshold of P < 0.05. After meta-analysis, CTLA-4 rs231775 showed a significant association with OS (HR, 0.83; 95% CI, 0.72-0.95; P = 0.008). Patients with the GG genotype had longer OS (35.1 months) compared with patients with an AG (30.3 months) or AA genotype (24.3 months). No significant associations with PFS were found.Conclusions: The G-allele of rs231775 in the CTLA-4 gene is associated with an improved OS in sunitinib-treated cc-mRCC patients and could potentially be used as a prognostic biomarker. Clin Cancer Res; 24(10); 2350-6. ©2018 AACR.


Subject(s)
CTLA-4 Antigen/genetics , Carcinoma, Renal Cell/genetics , Carcinoma, Renal Cell/mortality , Polymorphism, Single Nucleotide , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , Biomarkers, Tumor , Carcinoma, Renal Cell/drug therapy , Carcinoma, Renal Cell/pathology , Female , Humans , Male , Middle Aged , Prognosis , Proportional Hazards Models , Protein Kinase Inhibitors/therapeutic use , Sunitinib/therapeutic use , Survival Analysis , Treatment Outcome
7.
Urol Oncol ; 35(8): 529.e9-529.e16, 2017 08.
Article in English | MEDLINE | ID: mdl-28385611

ABSTRACT

OBJECTIVE: For patients with metastatic renal cell cancer (mRCC), treatment choice is mainly based on clinical parameters. With many treatments available and the limited response to treatment and associated toxicities, there is much interest in identifying better biomarkers for personalized treatment. EuroTARGET aims to identify and characterize host- and tumor-related biomarkers for prediction of response to tyrosine kinase inhibitor therapy in mRCC. Here, we describe the EuroTARGET mRCC patient cohort. METHODS AND MATERIALS: EuroTARGET is a European collaborative project designed as an observational study for which patients with mRCC were recruited prospectively in 62 centers. In addition, 462 patients with mRCC from previous studies were included. Detailed clinical information (baseline and follow-up) from all patients was entered in web-based case record forms. Blood was collected for germline DNA and pharmacokinetic/pharmacodynamic analyses and, where available, fresh-frozen tumor material was collected to perform tumor DNA, RNA, kinome, and methylome analyses. RESULTS: In total, 1,210 patients with mRCC were included. Of these, 920 received a tyrosine kinase inhibitor as first-line targeted treatment (sunitinib [N = 713, 78%], sorafenib [N = 41, 4%], or pazopanib [N = 166, 18%]) and had at least 6 months of outcome assessment (median follow-up 15.3 months [interquartile range: 8.5-30.2 months]). Germline DNA samples were available from 824 of these patients, fresh-frozen tumor material from 142 patients, fresh-frozen normal kidney tissue from 95 patients, and tissue microarrays created from formalin-fixed paraffin-embedded tumor material from 247 patients. Of the 920 patients, germline DNA variant chip data were successfully generated for 811 patients (Illumina HumanOmniExpress BeadChip). For 80 patients, next-generation exome sequencing of germline and tumor DNA was performed, tumor RNA sequencing was performed for 124 patients, kinome activity measured and processed for 121 patients (PamChip), and methylome data (Illumina Infinium HumanMethylation450 BeadChip) were created for 116 RCC tissues (and 23 normal kidney tissues). For 73 out of the 920 patients, all platform data types were generated. In addition, 40 patients were included in a pharmacokinetic/pharmacodynamic phase IV substudy. CONCLUSIONS: Analysis of EuroTARGET cohort data will contribute to personalization of therapy for patients with mRCC. The extensive clinical data and multiplatform EuroTARGET data will be freely available.


Subject(s)
Biomarkers, Tumor/analysis , Carcinoma, Renal Cell/drug therapy , Kidney Neoplasms/drug therapy , Molecular Targeted Therapy/methods , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , Carcinoma, Renal Cell/genetics , Cohort Studies , Female , Humans , Indazoles , Indoles/therapeutic use , Kidney Neoplasms/genetics , Male , Middle Aged , Niacinamide/analogs & derivatives , Niacinamide/therapeutic use , Phenylurea Compounds/therapeutic use , Prospective Studies , Protein Kinase Inhibitors/therapeutic use , Pyrimidines/therapeutic use , Pyrroles/therapeutic use , Sorafenib , Sulfonamides/therapeutic use , Sunitinib , Young Adult
8.
Lipids ; 43(9): 829-41, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18615262

ABSTRACT

Black Sea molluscs and gastropods are the most studied organisms from the Romanian littoral zone. In particular, those from the Mytilidae species are of great interest because biochemical investigations have shown that they can be sources of biological active substances which can have different applications (e.g. food additives). We report here the extraction of lipids from two different species of molluscs (Mytilus galloprovincialis L., Mediterranean mussel) and gastropods (Rapana venosa, hard-shell clam). The extracts were evaluated in terms of antioxidant and composition properties and their healing properties were tested on skin burns in Wistar rats. Our studies proved that the two lipid extracts contained a relatively complex distribution of compounds, in terms of characteristic indices, polyunsaturated fatty acids (PUFA) and vitamins E and D. The presence of such compounds rendered the extracts very efficient in healing induced skin burns in Wistar rats. The histological analysis showed a reduction in the time of healing (12-13 and 13-15 days for the Mytilus galloprovincialis (L.) Rapana venosa extracts, respectively) compared to 20-22 for untreated animals, based on results from tissues and blood samples. Our investigations have been proved to be promising in terms of future potential applications of the extracts as skin-care products, cosmetics and/or pharmaceutical preparations owing to their dermorestitutive properties.


Subject(s)
Burns/drug therapy , Fatty Acids, Unsaturated/therapeutic use , Lipids/chemistry , Lipids/therapeutic use , Mytilus/chemistry , Animals , Burns/pathology , Chemical Phenomena , Chemistry, Physical , Gas Chromatography-Mass Spectrometry , Gastropoda/chemistry , Male , Rats , Rats, Wistar , Skin/blood supply , Skin/pathology , Spectrophotometry, Infrared , Spectrophotometry, Ultraviolet , Spectrum Analysis , Wound Healing/drug effects
9.
Arch Ital Urol Androl ; 74(2): 57-8, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12161936

ABSTRACT

OBJECTIVE: Our aim was to perform a comparative study between IVP (Intra Venous Pyelography) and Doppler US (Ultras Sound) in assessing the normal renal function. The US assessment of the normal renal function consisted in the evaluation of ureteral flux. MATERIALS AND METHODS: The group of patients consisted in 79 patients with small size urinary stones (5-12 mm). Among them, 58 patients had pelvic stones and 21 patients had ureteral stones. The ultrasound system used in our study was a B&K Medical Panther 2002 equipped with a 3.5 MHz transducer. RESULTS: The sensibility in detecting ureteral flux in patients with pelvic stones and normal IVP was 100%. The sensibility in detecting uretheral flux in ureteral stones with IVP aspect of hydronephrosis was 65%. CONCLUSIONS: In cases of normal aspect of IVP the presence of uretheral flux assessed by ultrasound could substitute the IVP in the preoperative evaluation for ESWL treatment. In cases of hydronephrotic aspect of IVP, the concordance between results based on IVP and those based on Doppler US in good enough for proposing the Doppler US evaluation of renal function in obstructive stones as a new diagnostic imaging modality. Doppler US could be the method of choice for renal function pre ESWL evaluation mainly for patients with known intolerance to contrast media.


Subject(s)
Lithotripsy , Ultrasonography, Doppler , Unnecessary Procedures , Urinary Calculi/diagnostic imaging , Urography , Contrast Media/administration & dosage , Diagnostic Tests, Routine , Humans , Hydronephrosis/diagnostic imaging , Hydronephrosis/etiology , Injections, Intravenous , Kidney Pelvis/diagnostic imaging , Lithotripsy/instrumentation , Preoperative Care , Sensitivity and Specificity , Ureter/diagnostic imaging , Urinary Calculi/therapy
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