Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Gland Surg ; 12(9): 1242-1250, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37842533

RESUMO

Background: Thyroid surgery is associated with a number of surgical complications including recurrent laryngeal nerve (RLN) injury and hypoparathyroidism. The existing methods share the same principle-the mobilization of the thyroid from the lateral side. The aim of this study was to evaluate the safety of a novel technique of thyroidectomy-tension-free thyroidectomy (TFT) based on the medial approach to the laryngeal nerves and parathyroid glands (PTGs). Methods: The study was conducted between August 2021 and July 2022 in Saint Petersburg State University Hospital. A total of 261 patients with thyroid diseases were enrolled in the study and operated on using the TFT technique. Results: The operations with the use of TFT technique were completed in all but two cases which required the conversion to the standard lateral approach. Of 259 TFT cases unilateral laryngeal paresis was registered in 6 (2.3%) cases or in 1.7% of the number of RLNs at risk. In all but one case the vocal fold function recovered in less than 6 months of the follow-up. Among 87 patients who underwent total thyroidectomy transient postoperative hypoparathyroidism was found in 10 cases (11.5%), rate of persistent hypoparathyroidism was 0%. One case of postoperative bleeding was recorded (0.4%). Conclusions: The TFT technique demonstrated high safety and several advantages over the traditional method of performing operations on the thyroid gland.

2.
ACS Nano ; 17(16): 15978-15988, 2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37535838

RESUMO

Alloying offers an increasingly important handle in nanomaterials design in addition to the already widely explored size and geometry of nanostructures of interest. As the key trait, the mixing of elements at the atomic level enables nanomaterials with physical or chemical properties that cannot be obtained by a single element alone, and subtle compositional variations can significantly impact these properties. Alongside the great potential of alloying, the experimental scrutiny of its impact on nanomaterial function is a challenge because the parameter space that encompasses nanostructure size, geometry, chemical composition, and structural atomic-level differences among individuals is vast and requires unrealistically large sample sets if statistically relevant and systematic data are to be obtained. To address this challenge, we have developed a microshutter device for spatially highly resolved physical vapor deposition in the lithography-based fabrication of nanostructured surfaces. As we demonstrate, it enables establishing compositional gradients across a surface with single nanostructure resolution in terms of alloy composition, which subsequently can be probed in a single experiment. As a showcase, we have nanofabricated arrays of AuAg, AuPd, and AgPd alloy nanoparticles with compositions systematically controlled at the level of single particle rows, as verified by energy dispersive X-ray and single particle plasmonic nanospectroscopy measurements, which we also compared to finite-difference time-domain simulations. Finally, motivated by their application in state-of-the-art plasmonic hydrogen sensors, we investigated PdAu alloy gradient arrays for their hydrogen sorption properties. We found distinctly composition-dependent kinetics and hysteresis and revealed a composition-dependent contribution of a single nanoparticle response to the ensemble average, which highlights the importance of alloy composition screening in single experiments with single nanoparticle resolution, as offered by the microshutter nanofabrication approach.

3.
Plants (Basel) ; 13(1)2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38202355

RESUMO

A comparative karyotype analysis of four species of yellow-flowered Eranthis sect. Eranthis, i.e., E. bulgarica, E. cilicica, E. hyemalis, and E. longistipitata from different areas, has been carried out for the first time. All the studied specimens had somatic chromosome number 2n = 16 with basic chromosome number x = 8. Karyotypes of the investigated plants included five pairs of metacentric chromosomes and three pairs of submetacentric/subtelocentric chromosomes. The chromosome sets of the investigated species differ mainly in the ratio of submetacentric/subtelocentric chromosomes, their relative lengths, and arm ratios. A new oligonucleotide probe was developed and tested to detect 45S rDNA clusters. Using this probe and an oligonucleotide probe to 5S rDNA, 45S and 5S rDNA clusters were localized for the first time on chromosomes of E. cilicica, E. hyemalis, and E. longistipitata. Major 45S rDNA clusters were identified on satellite chromosomes in all the species; in E. cilicica, minor clusters were also identified in the terminal regions of one metacentric chromosome pair. The number and distribution of 5S rDNA clusters is more specific. In E. cilicica, two major clusters were identified in the pericentromeric region of a pair of metacentric chromosomes. Two major clusters in the pericentromeric region of a pair of submetacentric chromosomes and two major clusters in the interstitial region of a pair of metacentric chromosomes were observed in E. longistipitata. E. hyemalis has many clusters of different sizes, localized mainly in the pericentromeric regions. Summarizing new data on the karyotype structure of E. sect. Eranthis and previously obtained data on E. sect. Shibateranthis allowed conclusions to be formed about the clear interspecific karyological differences of the genus Eranthis.

4.
Langenbecks Arch Surg ; 407(8): 3651-3659, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36251078

RESUMO

BACKGROUND: Parathyroidectomy is the only definitive treatment for primary hyperparathyroidism (PHPT). Precise localization of abnormal glands is a key to a successful surgery. Most patients are expected to be successfully treated with focused parathyroidectomy. However, this approach is associated with a risk of existing multiglandular disease which may lead to the postoperative persistence of PHPT. METHODS: Eight hundred ten patients who underwent an initial surgery for PHPT at SPBU Hospital in 2017-2018 were included in the study. Preoperative imaging results were evaluated. Multivariate logistic regressions were calculated to estimate predictive values of preoperative data for the risk of postoperative persistence and risk of MGD. RESULTS: Multiglandular disease was found to be a leading cause of persistent hyperparathyroidism. An anamnesis of thyroid surgery was found to be a significant risk factor for the persistence of hyperparathyroidism. The rate of persistence did not differ significantly between groups with bilateral neck exploration and focused parathyroidectomy. Age, sex, body mass index as well as negative results of preoperative US, MIBI, and 4D CT were not independently associated with a higher risk of MGD. All preoperative imaging modalities showed from low to moderate sensitivity for the detection of MGD. The frequency of cases of a missed second adenoma did not differ significantly between patients with concordant and discordant preoperative data. There were 7 cases with previously unsuspected second adenomas found solely due to bilateral neck exploration. CONCLUSIONS: None of the combination of preoperative visualization modalities was able to rule out the MGD and reliably identify patients for focused parathyroidectomy. Additional preoperative visualization failed to improve overall results. Bilateral neck exploration appeared to have a slight benefit for the patients with concordant preoperative imaging results.


Assuntos
Adenoma , Hiperparatireoidismo Primário , Humanos , Hiperparatireoidismo Primário/diagnóstico por imagem , Hiperparatireoidismo Primário/cirurgia , Tecnécio Tc 99m Sestamibi , Paratireoidectomia/métodos , Glândulas Paratireoides , Adenoma/cirurgia , Estudos Retrospectivos
5.
Nat Commun ; 12(1): 5427, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521841

RESUMO

Grains constitute the building blocks of polycrystalline materials and their boundaries determine bulk physical properties like electrical conductivity, diffusivity and ductility. However, the structure and evolution of grains in nanostructured materials and the role of grain boundaries in reaction or phase transformation kinetics are poorly understood, despite likely importance in catalysis, batteries and hydrogen energy technology applications. Here we report an investigation of the kinetics of (de)hydriding phase transformations in individual Pd nanoparticles. We find dramatic evolution of single particle grain morphology upon cyclic exposure to hydrogen, which we identify as the reason for the observed rapidly slowing sorption kinetics, and as the origin of the observed kinetic compensation effect. These results shed light on the impact of grain growth on kinetic processes occurring inside nanoparticles, and provide mechanistic insight in the observed kinetic compensation effect.

6.
Parasite ; 28: 52, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34142954

RESUMO

The natural distribution range of Aedes koreicus is Korea, China, Japan, and the Russian Far East. Since 2008, this species has been recorded as an invasive species in some European countries (Belgium, European Russia, Germany, Hungary, Italy, Slovenia, and Switzerland). The invasive mosquito species Ae. koreicus is reported from the Republic of Kazakhstan for the first time. Its morphological identification was confirmed by molecular-genetic analyses of ND4 sequences using specific primers. Aedes koreicus larvae were found in an artificial water reservoir together with the larvae of Culiseta longiareolata and Culex pipiens s.l. Aedes koreicus successfully overwintered in Almaty at low winter temperatures in 2018-2019. This suggests that the Ae. koreicus acclimation capacity is greater than it has been considered until now. We assume that Ae. koreicus will spread over the west and south of the Republic of Kazakhstan and territories of Kyrgyzstan and Uzbekistan Republics bordering the Almaty region.


TITLE: Premier signalement de l'espèce de moustique envahissante Aedes koreicus (Diptera, Culicidae) en République du Kazakhstan. ABSTRACT: L'aire de répartition naturelle d'Aedes koreicus est la Corée, la Chine, le Japon et l'Extrême-Orient russe. Depuis 2008, cette espèce a été signalée comme espèce envahissante dans certains pays européens (Belgique, Russie européenne, Allemagne, Hongrie, Italie, Slovénie et Suisse). L'espèce de moustique envahissante Ae. koreicus est signalée ici pour la première fois en République du Kazakhstan. Son identification morphologique a été confirmée par des analyses de génétique moléculaire de la séquence ND4 à l'aide d'amorces spécifiques. Des larves d'Aedes koreicus ont été trouvées dans un réservoir d'eau artificiel avec des larves de Culiseta longiareolata et Culex pipiens s.l. Aedes koreicus a hiverné avec succès à Almaty à de basses températures hivernales en 2018-2019. Cela suggère que la capacité d'acclimatation d'Ae. koreicus est supérieure à ce qui avait été envisagé jusqu'à présent. Nous supposons qu'Ae. koreicus s'étendra sur l'ouest et le sud de la République du Kazakhstan et les territoires du Kirghizistan et des républiques d'Ouzbékistan bordant la région d'Almaty.


Assuntos
Aedes , Culicidae , Aedes/genética , Animais , China , Europa (Continente) , Alemanha , Hungria , Espécies Introduzidas , Itália , Japão , Cazaquistão , República da Coreia , Federação Russa , Eslovênia
7.
Insects ; 11(1)2020 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-31963900

RESUMO

In this study, cytogenetic analysis of the metaphase chromosomes from imaginal discs of Aedes (Diptera: Culicidae) mosquitoes-Aedes communis, Ae. punctor, Ae. intrudens, and Ae. rossicus-was performed. The patterns of C-banding and DAPI staining of the heteroсhromatin and the length of the chromosomes demonstrate species specificity. In particular, the Ae. punctor chromosomes are the shortest compared with Ae. communis, Ae. intrudens, and Ae. rossicus, and they also carry additional C and DAPI bands in intercalary regions. The Ae. intrudens chromosomes are the longest, they have pericentromeric C bands, and they almost lack any DAPI bands near the centromere of chromosome 3 versus Ae. communis, which has the largest pericentromeric DAPI blocks in all three chromosome pairs. Ae. rossicus also possesses DAPI bands in the centromeric regions of all chromosomes, but their staining is weaker compared with those of Ae. communis. Therefore, the analysis of karyotypes is a tool for species-level identification of these mosquitoes.

8.
Nanoscale ; 11(44): 21207-21217, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31663581

RESUMO

Three-layer core-shell-nanoparticle nanoarchitectures exhibit properties not achievable by single-element nanostructures alone and have great potential to enable rationally designed functionality. However, nanofabrication strategies for crafting core-shell-nanoparticle structure arrays on surfaces are widely lacking, despite the potential of basically unlimited material combinations. Here we present a nanofabrication approach that overcomes this limitation. Using it, we produce a library of nanoarchitectures composed of a metal core and an oxide/nitride shell that is decorated with few-nanometer-sized particles with widely different material combinations. This is enabled by resolving a long-standing challenge in this field, namely the ability to grow a shell layer around a nanofabricated core without prior removal of the lithographically patterned mask, and the possibility to subsequently grow smaller metal nanoparticles locally on the shell only in close proximity of the core. Focusing on the application of such nanoarchitectures in plasmonics, we show experimentally and by Finite-Difference Time-Domain (FDTD) simulations that these structures exhibit significant optical absorption enhancement in small metal nanoparticles grown on the few nanometer thin dielectric shell layer around a plasmonic core, and derive design rules to maximize the effect by the tailored combination of the core and shell materials. We predict that these structures will find application in plasmon-mediated catalysis and nanoplasmonic sensing and spectroscopy.

9.
ACS Nano ; 13(5): 6090-6100, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31091069

RESUMO

The ongoing quest to develop single-particle methods for the in situ study of heterogeneous catalysts is driven by the fact that heterogeneity in terms of size, shape, grain structure, and composition is a general feature among nanoparticles in an ensemble. This heterogeneity hampers the generation of a deeper understanding for how these parameters affect catalytic properties. Here we present a solution that in a single benchtop experimental setup combines single-particle plasmonic nanospectroscopy with mass spectrometry for gas phase catalysis under reaction conditions at high temperature. We measure changes in the surface state of polycrystalline platinum model catalyst particles in the 70 nm size range and the corresponding bistable kinetics during the carbon monoxide oxidation reaction via the peak shift of the dark-field scattering spectrum of a closely adjacent plasmonic nanoantenna sensor and compare these changes with the total reaction rate measured by the mass spectrometer from an ensemble of nominally identical particles. We find that the reaction kinetics of simultaneously measured individual Pt model catalysts are dictated by the grain structure and that the superposition of the individual nanoparticle response can account for the significant broadening observed in the corresponding nanoparticle ensemble data. In a wider perspective our work enables in situ plasmonic nanospectroscopy in controlled gas environments at high temperature to investigate the role of the surface state on transition metal catalysts during reaction and of processes such as alloying or surface segregation in situ at the single-nanoparticle level for model catalysts in the few tens to hundreds of nanometer size range.

10.
J Vector Ecol ; 43(2): 245-251, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30408286

RESUMO

Karyotypes of Aedes (Culicidae) mosquitoes (Ae. excrucians, Ae. behningi, and Ae. euedes) have been analyzed using the metaphase chromosomes of imaginal discs. Lacto-aceto-orcein, C-banding, and DAPI staining have detected species-specific features in the morphology and lengths of these chromosomes in the examined species. Species-specific features of chromosome 1 in the location of heterochromatin blocks have been shown. Thus, the metaphase chromosomes in the imaginal discs of Ae. excrucians, Ae. behningi, and Ae. euedes are a characteristic for species identification of mosquito species.


Assuntos
Aedes/genética , Cromossomos de Insetos/genética , Malária/transmissão , Mosquitos Vetores/genética , Plasmodium/fisiologia , Aedes/parasitologia , Aedes/fisiologia , Animais , Cariótipo , Cariotipagem , Metáfase , Mosquitos Vetores/parasitologia , Mosquitos Vetores/fisiologia , Especificidade da Espécie
11.
Nat Commun ; 8(1): 1084, 2017 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-29057929

RESUMO

Grain boundaries separate crystallites in solids and influence material properties, as widely documented for bulk materials. In nanomaterials, however, investigations of grain boundaries are very challenging and just beginning. Here, we report the systematic mapping of the role of grain boundaries in the hydrogenation phase transformation in individual Pd nanoparticles. Employing multichannel single-particle plasmonic nanospectroscopy, we observe large variation in particle-specific hydride-formation pressure, which is absent in hydride decomposition. Transmission Kikuchi diffraction suggests direct correlation between length and type of grain boundaries and hydride-formation pressure. This correlation is consistent with tensile lattice strain induced by hydrogen localized near grain boundaries as the dominant factor controlling the phase transition during hydrogen absorption. In contrast, such correlation is absent for hydride decomposition, suggesting a different phase-transition pathway. In a wider context, our experimental setup represents a powerful platform to unravel microstructure-function correlations at the individual-nanoparticle level.

12.
Am J Trop Med Hyg ; 93(3): 619-22, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26149867

RESUMO

Herein, we report the results of study of Anopheles species in Primorsk and Khabarovsk regions of Russia. Three species of the Anopheles hyrcanus group: An. kleini, An. pullus, and An. lesteri were identified by molecular taxonomic diagnostics for the first time in Russia. Surprisingly, An. sinensis, which earlier was considered the only species of Anopheles in Russian Far East, was not observed. We analyzed nucleotide variation in the 610-bp fragment of the 5' end of the cytochrome c oxidase subunit I (COI) region. All species possessed a distinctive set of COI sequences. A maximum likelihood phylogenetic tree was constructed for members of the hyrcanus group. The examined Anopheles hyrcanus group members could be divided into two major subgroups: subgroup 1 (An. hyrcanus and An. pullus) and subgroup 2 (An. sinensis, An. kleini, and An. lesteri), which were found to be monophyletic.


Assuntos
Anopheles/genética , Animais , Sequência de Bases , Dados de Sequência Molecular , Filogenia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA