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1.
Mol Cell Proteomics ; 22(7): 100580, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37211046

RESUMO

Current proteomic technologies focus on the quantification of protein levels, while little effort is dedicated to the development of system approaches to simultaneously monitor proteome variability and abundance. Protein variants may display different immunogenic epitopes detectable by monoclonal antibodies. Epitope variability results from alternative splicing, posttranslational modifications, processing, degradation, and complex formation and possesses dynamically changing availability of interacting surface structures that frequently serve as reachable epitopes and often carry different functions. Thus, it is highly likely that the presence of some of the accessible epitopes correlates with function under physiological and pathological conditions. To enable the exploration of the impact of protein variation on the immunogenic epitome first, here, we present a robust and analytically validated PEP technology for characterizing immunogenic epitopes of the plasma. To this end, we prepared mAb libraries directed against the normalized human plasma proteome as a complex natural immunogen. Antibody producing hybridomas were selected and cloned. Monoclonal antibodies react with single epitopes, thus profiling with the libraries is expected to profile many epitopes which we define by the mimotopes, as we present here. Screening blood plasma samples from control subjects (n = 558) and cancer patients (n = 598) for merely 69 native epitopes displayed by 20 abundant plasma proteins resulted in distinct cancer-specific epitope panels that showed high accuracy (AUC 0.826-0.966) and specificity for lung, breast, and colon cancer. Deeper profiling (≈290 epitopes of approximately 100 proteins) showed unexpected granularity of the epitope-level expression data and detected neutral and lung cancer-associated epitopes of individual proteins. Biomarker epitope panels selected from a pool of 21 epitopes of 12 proteins were validated in independent clinical cohorts. The results demonstrate the value of PEP as a rich and thus far unexplored source of protein biomarkers with diagnostic potential.


Assuntos
Biomarcadores Tumorais , Neoplasias , Humanos , Proteoma , Proteômica/métodos , Epitopos , Anticorpos Monoclonais/química
2.
Nano Lett ; 23(15): 6785-6791, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37524333

RESUMO

The hallmark of spintronics has been the ability of spin-orbit interactions to convert a charge current into a spin current and vice versa, mainly in the bulk of heavy metal thin films. Here, we demonstrate how a light metal interface profoundly affects both the nature of spin-orbit torques and its efficiency in terms of damping-like (HDL) and field-like (HFL) effective fields in ultrathin Co films. We measure unexpectedly HFL/HDL ratios much larger than 1 by inserting a nanometer-thin Al metallic layer in Pt|Co|Al|Pt as compared to a similar stacking, including Cu as a reference. From our modeling, these results evidence the existence of large Rashba interaction at the Co|Al interface generating a giant HFL, which is not expected from a metallic interface. The occurrence of such enhanced torques from an interfacial origin is further validated by demonstrating current-induced magnetization reversal showing a significant decrease of the critical current for switching.

3.
Eur Radiol ; 2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37921926

RESUMO

OBJECTIVES: The introduction of low-dose CT (LDCT) altered the landscape of lung cancer (LC) screening and contributed to the reduction of mortality rates worldwide. Here we report the final results of HUNCHEST-II, the largest population-based LDCT screening program in Hungary, including the screening and diagnostic outcomes, and the characteristics of the LC cases. METHODS: A total of 4215 high-risk individuals aged between 50 and 75 years with a smoking history of at least 25 pack-years were assigned to undergo LDCT screening. Screening outcomes were determined based on the volume, growth, and volume doubling time of pulmonary nodules or masses. The clinical stage distribution of screen-detected cancers was compared with two independent practice-based databases consisting of unscreened LC patients. RESULTS: The percentage of negative and indeterminate tests at baseline were 74.2% and 21.7%, respectively, whereas the prevalence of positive LDCT results was 4.1%. Overall, 76 LC patients were diagnosed throughout the screening rounds (1.8% of total participants), out of which 62 (1.5%) patients were already identified in the first screening round. The overall positive predictive value of a positive test was 58%. Most screen-detected malignancies were stage I LCs (60.7%), and only 16.4% of all cases could be classified as stage IV disease. The percentage of early-stage malignancies was significantly higher among HUNCHEST-II screen-detected individuals than among the LC patients in the National Koranyi Institute of Pulmonology's archive or the Hungarian Cancer Registry (p < 0.001). CONCLUSIONS: HUNCHEST-II demonstrates that LDCT screening for LC facilitates early diagnosis, thus arguing in favor of introducing systematic LC screening in Hungary. CLINICAL RELEVANCE STATEMENT: HUNCHEST-II is the so-far largest population-based low-dose CT screening program in Hungary. A positive test's overall positive predictive value was 58%, and most screen-detected malignancies were early-stage lesions. These results pave the way for expansive systematic screening in the region. KEY POINTS: • Conducted in 18 medical facilities, HUNCHEST-II is the so far largest population-based low-dose CT screening program in Hungary. • The vast majority of screen-detected malignancies were early-stage lung cancers, and the overall positive predictive value of a positive test was 58%. • HUNCHEST-II facilitates early diagnosis, thus arguing in favor of introducing systematic lung cancer screening in Hungary.

4.
Inorg Chem ; 62(40): 16354-16361, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37739403

RESUMO

This work investigates the effect of copper substitution on the magnetic properties of SmCo5 thin films synthesized by molecular beam epitaxy. A series of thin films with varying concentrations of Cu were grown under otherwise identical conditions to disentangle structural and compositional effects on the magnetic behavior. The combined experimental and theoretical studies show that Cu substitution at the Co3g sites not only stabilizes the formation of the SmCo5 structure but also enhances magnetic anisotropy and coercivity. Density functional theory calculations indicate that Sm(Co4Cu3g)5 possesses a higher single-ion anisotropy as compared to pure SmCo5. In addition, X-ray magnetic circular dichroism reveals that Cu substitution causes an increasing decoupling of the Sm 4f and Co 3d moments. Scanning transmission electron microscopy confirms predominantly SmCo5 phase formation and reveals nanoscale inhomogeneities in the Cu and Co distribution. Our study based on thin film model systems and advanced characterization as well as modeling reveals novel aspects of the complex interplay of intrinsic and extrinsic contributions to magnetic hysteresis in rare-earth-based magnets, i.e., the combination of increased intrinsic anisotropy due to Cu substitution and the extrinsic effect of inhomogeneous elemental distribution of Cu and Co.

5.
Phys Rev Lett ; 129(5): 057201, 2022 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-35960587

RESUMO

We report a magnetic transition region in La_{0.7}Sr_{0.3}MnO_{3} with gradually changing magnitude of magnetization, but no rotation, stable at all temperatures below T_{C}. Spatially resolved magnetization, composition and Mn valence data reveal that the magnetic transition region is induced by a subtle Mn composition change, leading to charge transfer at the interface due to carrier diffusion and drift. The electrostatic shaping of the magnetic transition region is mediated by the Mn valence, which affects both magnetization by Mn^{3+}-Mn^{4+} double exchange interaction and free carrier concentration.


Assuntos
Magnetismo , Eletricidade Estática , Temperatura
6.
Nano Lett ; 21(3): 1205-1212, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33492966

RESUMO

The control of domain walls is central to nearly all magnetic technologies, particularly for information storage and spintronics. Creative attempts to increase storage density need to overcome volatility due to thermal fluctuations of nanoscopic domains and heating limitations. Topological defects, such as solitons, skyrmions, and merons, may be much less susceptible to fluctuations, owing to topological constraints, while also being controllable with low current densities. Here, we present the first evidence for soliton/soliton and soliton/antisoliton domain walls in the hexagonal chiral magnet Mn1/3NbS2 that respond asymmetrically to magnetic fields and exhibit pair-annihilation. This is important because it suggests the possibility of controlling the occurrence of soliton pairs and the use of small fields or small currents to control nanoscopic magnetic domains. Specifically, our data suggest that either soliton/soliton or soliton/antisoliton pairs can be stabilized by tuning the balance between intrinsic exchange interactions and long-range magnetostatics in restricted geometries.

7.
Nano Lett ; 21(19): 8135-8142, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34529916

RESUMO

Iron and its alloys have made modern civilization possible, with metallic meteorites providing one of the human's earliest sources of usable iron as well as providing a window into our solar system's billion-year history. Here highest-resolution tools reveal the existence of a previously hidden FeNi nanophase within the extremely slowly cooled metallic meteorite NWA 6259. This new nanophase exists alongside Ni-poor and Ni-rich nanoprecipitates within a matrix of tetrataenite, the uniaxial, chemically ordered form of FeNi. The ferromagnetic nature of the nanoprecipitates combined with the antiferromagnetic character of the FeNi nanophases gives rise to a complex magnetic state that evolves dramatically with temperature. These observations extend and possibly alter our understanding of celestial metallurgy, provide new knowledge concerning the archetypal Fe-Ni phase diagram and supply new information for the development of new types of sustainable, technologically critical high-energy magnets.


Assuntos
Meteoroides , Ligas , Humanos , Ferro , Imãs , Transição de Fase
8.
Nano Lett ; 20(5): 3642-3650, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32250635

RESUMO

Arrays of interacting 2D nanomagnets display unprecedented electromagnetic properties via collective effects, demonstrated in artificial spin ices and magnonic crystals. Progress toward 3D magnetic metamaterials is hampered by two challenges: fabricating 3D structures near intrinsic magnetic length scales (sub-100 nm) and visualizing their magnetic configurations. Here, we fabricate and measure nanoscale magnetic gyroids, periodic chiral networks comprising nanowire-like struts forming three-connected vertices. Via block copolymer templating, we produce Ni75Fe25 single-gyroid and double-gyroid (an inversion pair of single-gyroids) nanostructures with a 42 nm unit cell and 11 nm diameter struts, comparable to the exchange length in Ni-Fe. We visualize their magnetization distributions via off-axis electron holography with nanometer spatial resolution and interpret the patterns using finite-element micromagnetic simulations. Our results suggest an intricate, frustrated remanent state which is ferromagnetic but without a unique equilibrium configuration, opening new possibilities for collective phenomena in magnetism, including 3D magnonic crystals and unconventional computing.

9.
Acta Vet Hung ; 69(2): 189-193, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34292872

RESUMO

The case of an 8-year-old, sexually active but infertile Przewalski's stallion (Equus ferus przewalskii) was studied. Besides the infertility, the stallion also showed permanent problems with its body condition, being obviously weaker than all the other group members. The horse was kept in a separate place for two years with 12 mares in its harem group (six mares had foals earlier); however, none of the mares covered got pregnant. Andrological and cytogenetic investigations revealed underdeveloped testes, arrested spermatogenesis, azoospermia, and XY/XXY/X0 mosaicism. We classify the case as a mosaic Klinefelter syndrome, the first reported case in Przewalski's horse.


Assuntos
Doenças dos Cavalos , Infertilidade , Animais , Análise Citogenética/veterinária , Feminino , Doenças dos Cavalos/genética , Cavalos , Infertilidade/veterinária , Masculino
10.
J Chem Phys ; 152(11): 114202, 2020 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-32199423

RESUMO

Investigating the local micromagnetic structure of ferromagnetic nanowires (NWs) at the nanoscale is essential to study the structure-property relationships and can facilitate the design of nanostructures for technology applications. Herein, we synthesized high-quality iron and cobalt NWs and investigated the magnetic properties of these NWs using off-axis electron holography. The Fe NWs are about 100 nm in width and a few micrometers in length with a preferential growth direction of [100], while the Co NWs have a higher aspect-ratio with preferential crystal growth along the [110] direction. It is noted that compact passivation surface layers of oxides protect these NWs from further oxidation, even after nearly two years of exposure to ambient conditions; furthermore, these NWs display homogeneous ferromagnetism along their axial direction revealing the domination of shape anisotropy on magnetic behavior. Importantly, the average value of magnetic induction strengths of Fe NWs (2.07 {±} 0.10 T) and Co NWs (1.83 {±} 0.15 T) is measured to be very close to the respective theoretical value, and it shows that the surface oxide layers do not affect the magnetic moments in NWs. Our results provide a useful synthesis approach for the fabrication of single-crystalline, defect-free metal NWs and give insight into the micromagnetic properties in ferromagnetic NWs based on the transmission electron microscopy measurements.

11.
Phys Rev Lett ; 120(16): 167204, 2018 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-29756913

RESUMO

Whereas theoretical investigations have revealed the significant influence of magnetic surface and edge states on Skyrmonic spin texture in chiral magnets, experimental studies of such chiral states remain elusive. Here, we study chiral edge states in an FeGe nanostripe experimentally using off-axis electron holography. Our results reveal the magnetic-field-driven formation of chiral edge states and their penetration lengths at 95 and 240 K. We determine values of saturation magnetization M_{S} by analyzing the projected in-plane magnetization distributions of helices and Skyrmions. Values of M_{S} inferred for Skyrmions are lower by a few percent than those for helices. We attribute this difference to the presence of chiral surface states, which are predicted theoretically in a three-dimensional Skyrmion model. Our experiments provide direct quantitative measurements of magnetic chiral boundary states and highlight the applicability of state-of-the-art electron holography for the study of complex spin textures in nanostructures.

12.
Chemistry ; 24(58): 15589-15595, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-29959855

RESUMO

For the last decades, the chemical reduction of Au3+ to Au0 has been widely employed to produce various gold nanostructures. In comparison with the fast reduction, the slow reduction is systematically investigated in this research to provide more insights to reveal intermediary process and further disclose the underlying mechanism for growing gold nanostructures by using a series of simple ligands with aldehyde groups as weak reducing agents. The different binding energies of ligands to Aun+ (n=3, 1 and 0) exhibit variable binding affinities in starting, intermediate, and final gold species. For example, formic acid has much stronger binding affinity to Au+ than Au3+ , and thus Au+ intermediate is able to be stabilized/captured during slow reduction of Au3+ . Upon the disproportionation of Au+ to Au0 and Au3+ , formic acid has much stronger binding affinity to the newly formed Au0 than other ligands for the controlled formation of gold nanostructures. Meanwhile, the adsorption of ligands causes substantially decreased surface energies on different gold planes. There are much higher energies on {110} planes compared to the other two {111} and {100} planes with certain ratios in these energies, leading to morphological growth of gold nanosheets. In this paper, we experimentally demonstrate anisotropic growth of gold nanosheets by using various ligands with weak reducing and appropriate coordination capabilities, and further provide insights to understand their morphological growth mechanism behind. This synthetic strategy is successfully extended to prepare silver, palladium, and platinum nanoplates.

14.
Nano Lett ; 17(3): 1395-1401, 2017 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-28125235

RESUMO

We use in situ Lorentz microscopy and off-axis electron holography to investigate the formation and characteristics of skyrmion lattice defects and their relationship to the underlying crystallographic structure of a B20 FeGe thin film. We obtain experimental measurements of spin configurations at grain boundaries, which reveal inversions of crystallographic and magnetic chirality across adjacent grains, resulting in the formation of interface spin stripes at the grain boundaries. In the absence of material defects, we observe that skyrmions lattices possess dislocations and domain boundaries, in analogy to atomic crystals. Moreover, the distorted skyrmions can flexibly change their size and shape to accommodate local geometry, especially at sites of dislocations in the skyrmion lattice. Our findings provide a detailed understanding of the elasticity of topologically protected skyrmions and their correlation with underlying material defects.

15.
Nano Lett ; 17(8): 4846-4852, 2017 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-28707893

RESUMO

We conducted a comprehensive investigation of dislocations in Al0.46Ga0.54N. Using aberration-corrected scanning transmission electron microscopy and energy dispersive X-ray spectroscopy, the atomic structure and atom distribution at the dislocation core have been examined. We report that the core configuration of dislocations in AlGaN is consistent with that of other materials in the III-Nitride system. However, we observed that the dissociation of mixed-type dislocations is impeded by alloying GaN with AlN, which is confirmed by our experimental observation of Ga and Al atom segregation in the tensile and compressive parts of the dislocations, respectively. Investigation of the optical properties of the dislocations shows that the atom segregation at dislocations has no significant effect on the intensity recorded by cathodoluminescence in the vicinity of the dislocations. These results are in contrast with the case of dislocations in In0.09Ga0.91N where segregation of In and Ga atoms also occurs but results in carrier localization limiting non-radiative recombination at the dislocation. This study therefore sheds light on why InGaN-based devices are generally more resilient to dislocations than their AlGaN-based counterparts.

16.
Glycobiology ; 27(7): 635-645, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28419225

RESUMO

Here, we introduce a novel scFv antibody, G2-D11, specific for two adjacent Tn-antigens (GalNAc-Ser/Thr) binding equally to three dimeric forms of the epitope, Ser-Thr, Thr-Thr and Thr-Ser. Compared to other anti-Tn reagents, the binding of G2-D11 is minimally influenced by the peptide structure, which indicates a high degree of carbohydrate epitope dominance and a low influence from the protein backbone. With a high affinity (KDapp = 1.3 × 10-8 M) and no cross-reactivity to either sialyl-Tn epitope or blood group A antigens, scFv G2-D11 is an excellent candidate for a well-defined anti-Tn-antigen reagent. Detailed immunohistochemical evaluation of tissue sections from a cohort of 80 patients with gastric carcinoma showed in all cases positive tumor cells. The observed staining was localized to the cytoplasm and in some cases to the membrane, whereas the surrounding tissue was completely negative demonstrating the usefulness of the novel Tn-antigen binding antibody.


Assuntos
Antígenos Glicosídicos Associados a Tumores/imunologia , Carcinoma/metabolismo , Epitopos/química , Anticorpos de Cadeia Única/imunologia , Neoplasias Gástricas/metabolismo , Antígenos Glicosídicos Associados a Tumores/química , Carcinoma/patologia , Linhagem Celular Tumoral , Mapeamento de Epitopos , Epitopos/imunologia , Humanos , Anticorpos de Cadeia Única/química , Neoplasias Gástricas/patologia
17.
Phys Rev Lett ; 119(19): 197205, 2017 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-29219505

RESUMO

A target Skyrmion is a flux-closed spin texture that has twofold degeneracy and is promising as a binary state in next generation universal memories. Although its formation in nanopatterned chiral magnets has been predicted, its observation has remained challenging. Here, we use off-axis electron holography to record images of target Skyrmions in a 160-nm-diameter nanodisk of the chiral magnet FeGe. We compare experimental measurements with numerical simulations, demonstrate switching between two stable degenerate target Skyrmion ground states that have opposite polarities and rotation senses, and discuss the observed switching mechanism.

18.
Microsc Microanal ; 23(4): 782-793, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28625222

RESUMO

This paper reports on the substantial improvement of specimen quality by use of a low voltage (0.05 to ~1 keV), small diameter (~1 µm), argon ion beam following initial preparation using conventional broad-beam ion milling or focused ion beam. The specimens show significant reductions in the amorphous layer thickness and implanted artifacts. The targeted ion milling controls the specimen thickness according to the needs of advanced aberration-corrected and/or analytical transmission electron microscopy applications.

19.
Acta Vet Hung ; 65(4): 500-504, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29256284

RESUMO

The Polled Intersex Syndrome (PIS) is responsible for the absence of horns in homozygous and heterozygous goats causing a female-to-male sex reversal in the homozygous polled genotypic female (XX) goats. A simple and efficient non-invasive method was elaborated to detect the genotypic sex from hair and faecal samples using a pair of primers to amplify the X- and Y-linked alleles of the amelogenin gene. The PCR products were easily distinguishable using agarose gel electrophoresis: we detected an X-specific single band in samples originating from healthy phenotypic females and double (X- and Y-) bands in samples from males. The new PCR method is applicable for diagnosing the sex of PIS-affected animals already as newborn kids, in contrast with the phenotypic findings appearing only after puberty, and thus it may replace the cumbersome chromosome investigations.


Assuntos
Amelogenina/metabolismo , Transtornos do Desenvolvimento Sexual/veterinária , Doenças das Cabras/genética , Cromossomo X/genética , Cromossomo Y/genética , Amelogenina/genética , Animais , DNA/química , DNA/genética , Transtornos do Desenvolvimento Sexual/diagnóstico , Transtornos do Desenvolvimento Sexual/genética , Fezes/química , Feminino , Regulação da Expressão Gênica , Genótipo , Doenças das Cabras/diagnóstico , Cabras , Cabelo/química , Masculino
20.
Orv Hetil ; 158(39): 1523-1527, 2017 Oct.
Artigo em Húngaro | MEDLINE | ID: mdl-28942662

RESUMO

Measles, caused by the Morbilli virus, is a highly (about 95 %) contagious disease affecting primarily children, but without proper immunisation, adults can also be infected. The leading symptoms of the disease are high fever that presents after an incubation period of 9-10 days and the red rash that begins several days after the fever starts. Beyond specific generalized symptoms, measles may have ocular symptoms. The most commonly occurring conjunctivitis, the so-called "red eye symptom", is not characteristic only for measles infection, however, by taking the generalized symptoms it can suggest the diagnosis at the beginning of the disease. Conjunctivitis of varying severity is noticed in the half of the cases without using ophthalmological instrumentation. Using ophthalmological instrumentation, the mild forms of conjunctivitis can be diagnosed, by meticulous ophthalmological examination, further eye diseases can be discovered. The viral conjunctivitis can progress to keratitis and bacterial superinfection can occur. If the infection presents in childhood it can affect the posterior segment. The fight against measles is very effective in Hungary since the vaccination has been introduced, and the lack of vaccination is also the primary cause of the risk to the disease. In the diagnosis, symptomatic treatment of the disease and the curbing of possible mass infections, the practicing physician (general practitioner) has a key role. The correct care of the infected patient in Hungary is provided by a methodological letter, professional information and legal guides. Orv Hetil. 2017; 158(39): 1523-1527.


Assuntos
Conjuntivite/diagnóstico , Conjuntivite/etiologia , Sarampo/diagnóstico , Sarampo/terapia , Adulto , Antibacterianos/uso terapêutico , Criança , Humanos , Hungria , Sarampo/complicações , Oftalmologia
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