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1.
Neurol Sci ; 44(4): 1375-1381, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36456878

RESUMEN

BACKGROUND: Fabry disease is an inherited metabolic disorder with various symptoms. Neurological manifestations are small fiber neuropathy, cerebral white matter lesions (WML), megadolicho basilar artery, and stroke. The relevance of the D313Y variant in the galactosidase alpha gene is controversially discussed. OBJECTIVES: We aimed at elucidating the implications of this differential diagnosis of multiple sclerosis (MS), focussing on the analysis of WML over time and correlations with other markers. METHODS: We reviewed retrospectively the clinical, laboratory, and magnetic resonance imaging data of 21 carriers of the D313Y variant at a single German outpatient clinic for MS between 2004 and 2021. RESULTS: In our cohort (15 females, 6 males), mean age at diagnosis was 44.1 ± 16.3 years, and mean follow-up duration was 3.1 ± 3.9 years. WML were rated on both, the Fazekas scale and the age-related white matter changes rating scale, and were of variable interindividual extent. Follow-up imaging showed virtually no progress. WML did not correlate with the severity of clinical findings or lysoGb3 levels. Symptomatic carriers of the variant are characterized by an almost complete lack of internal organ manifestations and laboratory findings, usually associated with Fabry disease. CONCLUSION: WML in carriers of the D313Y variant do not seem to be suitable for assessing or predicting the (para-) clinical status. Concerning MS patients, the variant and its clinical signs can be a differential diagnosis, but also a co-factor. Imaging and cerebrospinal fluid findings facilitate the distinction between both entities.


Asunto(s)
Enfermedad de Fabry , Esclerosis Múltiple , Sustancia Blanca , Masculino , Femenino , Humanos , alfa-Galactosidasa/genética , Enfermedad de Fabry/diagnóstico por imagen , Enfermedad de Fabry/genética , Enfermedad de Fabry/complicaciones , Sustancia Blanca/patología , Estudios Retrospectivos , Estudios de Seguimiento , Esclerosis Múltiple/complicaciones , Imagen por Resonancia Magnética , Encéfalo/patología
2.
Chemistry ; 28(7): e202104135, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34967480

RESUMEN

A phosphinine-borane adduct of a Me3 Si-functionalized phosphinine and the Lewis acid B(C6 F5 )3 has been synthesized and characterized crystallographically for the first time. The reaction strongly depends on the nature of the substituents in the α-position of the phosphorus heterocycle. In contrast, the reaction of B2 H6 with various substituted phosphinines leads to an equilibrium between the starting materials and the phosphinine-borane adducts that is determined by the Lewis basicity of the phosphinine. The novel phosphinine borane adduct (6-B(C6 F5 )3 ) shows rapid and facile insertion and [4+2] cycloaddition reactivity towards phenylacetylene. A hitherto unknown dihydro-1-phosphabarrelene is formed with styrene. The reaction with an ester provides a new, facile and selective route to 1-R-phosphininium salts. These salts then undergo a [4+2] cycloaddition in the presence of Me3 Si-C≡CH and styrene to cleanly form unprecedented derivatives of 1-R-phosphabarrelenium salts.

3.
Chemistry ; 27(15): 4964-4970, 2021 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-33443300

RESUMEN

Dibenzo[a,e]pentalene (DBP) is a non-alternant conjugated hydrocarbon with antiaromatic character and ambipolar electrochemical behavior. Upon both reduction and oxidation, it becomes aromatic. We herein study the chemical oxidation and reduction of a planar DBP derivative and a bent DBP-phane. The molecular structures of its planar dication, cation radical and anion radical in the solid state demonstrate the gained aromaticity through bond length equalization, which is supported by nucleus independent chemical shift-calculations. EPR spectra on the cation radical confirm the spin delocalization over the DBP framework. A similar delocalization was not possible in the reduced bent DBP-phane, which stabilized itself by proton abstraction from a solvent molecule upon reduction. This is the first report on structures of a DBP cation radical and dication in the solid state and of a reduced bent DBP derivative. Our study provides valuable insight into the charged species of DBP for its application as semiconductor.

4.
Chemistry ; 27(50): 12788-12795, 2021 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-34251712

RESUMEN

The synthesis and isolation of a phosphinine selenide was achieved for the first time by reacting red selenium with 2,6-bis(trimethylsilyl)phosphinine. The rather large coupling constant of 1 JP,Se =883 Hz is in line with a P-Se bond of high s-character. The σ-electron donating Me3 Si-substituents significantly increase the energy of the phosphorus lone pair and hence its basicity, making the heterocycle considerably more basic and nucleophilic than the unsubstituted phosphinine C5 H5 P, as confirmed by the calculated gas phase basicities. NBO calculations further reveal that the lone pairs of the selenium atom are stabilized through donor-acceptor interactions with antibonding orbitals of the aromatic ring. The novel phosphinine selenide shows a distinct reactivity towards hexafluoro-2-butyne, Au(I)Cl as well as i PrOH. Our results pave the way for new perspectives in the chemistry of phosphorus in low coordination.

5.
Chemistry ; 24(63): 16851-16856, 2018 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-30156349

RESUMEN

The introduction of a triphenylborate group at the 4-position of 2,6-dimesitylpyridine afforded a sterically demanding anionic pyridine. The charge introduced through the borate group drastically increases its basicity and measurement of its pKa value (18.46) revealed a significantly higher value than that of 4-dimethylaminopyridine (17.95). THF ring-opening was observed upon treating its lithium salt with TMSCl, which demonstrates its high nucleophilicity. The mesityl groups at the 2,6-positions are oriented orthogonal to the pyridine ring and do not block the nitrogen atom of the pyridine. The reaction of the protonated pyridine with Li[BH4 ] yielded the corresponding Lewis acid/base adduct, which shows that the title compound can be used as a monodentate ligand in coordination chemistry. The crystal structures of all the compounds presented in this work are reported.

6.
Mol Genet Metab ; 122(1-2): 113-120, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28851512

RESUMEN

Gaucher disease (GD), an autosomal recessive lipid storage disorder, arises from mutations in the GBA1 (ß-glucocerebrosidase) gene, resulting in glucosylceramide accumulation in tissue macrophages. Lyso-Gb1 (glucosylsphingosine, lyso-GL1), a downstream metabolic product of glucosylceramide, has been identified as a promising biomarker for the diagnosis and monitoring of patients with GD. This retrospective, exploratory analysis of data from phase 3 clinical trials of velaglucerase alfa in patients with type 1 GD evaluated the potential of lyso-Gb1 as a specific and sensitive biomarker for GD. A total of 22 treatment-naïve patients and 21 patients previously treated with imiglucerase (switch patients) were included in the analysis. Overall, demographics between the two groups were similar. Mean lyso-Gb1 concentrations were reduced by 302.2ng/mL from baseline to week 209 in treatment-naïve patients and by 57.3ng/mL from baseline to week 161 in switch patients, corresponding to relative reductions of 82.7% and 52.0%, respectively. In both the treatment-naïve and switch groups, baseline mean lyso-Gb1 was higher for patients with at least one N370S mutation (363.9ng/mL and 90.7ng/mL, respectively) than for patients with non-N370S mutations (184.6ng/mL and 28.3ng/mL, respectively). Moderate correlations between decreasing lyso-Gb1 levels and increasing platelet counts, and with decreasing spleen volumes, were observed at some time points in the treatment-naïve group but not in the switch group. These findings support the utility of lyso-Gb1 as a sensitive and reliable biomarker for GD, and suggest that quantitation of this biomarker could serve as an indicator of disease burden and response to treatment.


Asunto(s)
Biomarcadores/sangre , Enfermedad de Gaucher/sangre , Enfermedad de Gaucher/tratamiento farmacológico , Glucosilceramidasa/uso terapéutico , Glucolípidos/sangre , Esfingolípidos/sangre , Adolescente , Adulto , Niño , Terapia de Reemplazo Enzimático , Femenino , Enfermedad de Gaucher/genética , Enfermedad de Gaucher/fisiopatología , Glucosilceramidasa/administración & dosificación , Glucosilceramidasa/genética , Glucosilceramidas/sangre , Glucosilceramidas/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Mutación/efectos de los fármacos , Recuento de Plaquetas , Estudios Retrospectivos , Bazo , Estadística como Asunto , Adulto Joven
7.
Chemistry ; 23(45): 10763-10767, 2017 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-28643874

RESUMEN

Herein a convenient one-pot route to a sterically demanding superbasic pyridine is presented. Functionalization of the 2- and 6-positions with the strongly σ-donating boryl-groups shifts the calculated gas phase basicity of the pyridine nitrogen atom to 1012 kJ mol-1 , which outperforms the "proton sponge" 1,8-bis(dimethylamino)naphthalene (996 kJ mol-1 ). The diazaboryl groups are oriented orthogonally to the pyridine ring and do not block the N-position, which resembles the geometry of commonly used N-heterocyclic carbenes. This allows the substituted pyridine to be used as a neutral N-donor ligand in coordination chemistry that is demonstrated herein with the Lewis adducts of haloboranes. Contrary to NHCs, which can form extraordinarily stable adducts, the pyridine ligand is intended to act as a weaker-coordinating alternative and could allow for alternative ligand chemistry.

8.
Cerebrovasc Dis ; 43(3-4): 152-160, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28088807

RESUMEN

BACKGROUND: Although 20-30% of all strokes occur in the posterior circulation, few studies have explored the characteristics of patients with strokes in the posterior compared to the anterior circulation so far. Especially data on young patients is missing. METHODS: In this secondary analysis of data of the prospective multi-centre European sifap1 study that investigated stroke and transient ischemic attack (TIA) patients aged 18-55 years, we compared vascular risk factors, stroke aetiology, presence of white matter hyperintensities (WMH) and cerebral microbleeds (CMB) between patients with ischaemic posterior circulation stroke (PCS) and those having suffered from anterior circulation stroke (ACS) based on cerebral MRI. RESULTS: We diagnosed PCS in 612 patients (29.1%, 407 men, 205 women) and ACS in 1,489 patients (70.9%). Their age (median 46 vs. 47 years, p = 0.205) and stroke severity (modified Rankin Scale: both 2, p = 0.375, Barthel Index 90 vs. 85, p = 0.412) were similar. PCS was found to be more frequent among the male gender (66.5 vs. 60.1% with ACS, p = 0.003). Vertebral artery (VA) dissection was more often the cause of PCS (16.8%) than was carotid artery dissection of ACS (7.9%, p < 0.001). Likewise, small vessel disease (Trial of Org 10172 in Acute Stroke Treatment [TOAST] = 3, PCS: 14.7%, ACS: 11.8%) and stroke of other determined aetiology (TOAST = 4, PCS: 24.5%, ACS: 16.0%) were more frequent in those with PCS. Furthermore, patent foramen ovale (PFO; PCS: 31.1%, ACS: 25.4%, p = 0.029) was more often detected in patients with PCS. In contrast, large-artery atherosclerosis (TOAST = 1, PCS: 15.4%, ACS: 22.2%) and cardio-embolic stroke (TOAST = 2, PCS: 15.6%, ACS: 18.0%) were less frequent in those with PCS (p < 0.001) as were preceding cerebrovascular events (10.1 vs. 14.1%, p = 0.014), TIA (4.8 vs. 7.7%, p = 0.016) and smoking (53.2 vs. 61.0%, p = 0.001). The presence, extent, and location of WMH and CMB did not differ between the 2 groups. CONCLUSIONS: Our data suggested a different pattern of aetiology and risk factors in young patients with PCS compared to those with ACS. These findings especially call for a higher awareness of VA dissection and potentially for more weight of a PFO as a risk factor in young patients with PCS. Clinical trial registration-URL: http://www.clinicaltrials.gov; NCT00414583.


Asunto(s)
Enfermedad de Fabry/epidemiología , Infarto de la Arteria Cerebral Anterior/epidemiología , Infarto de la Arteria Cerebral Posterior/epidemiología , Ataque Isquémico Transitorio/epidemiología , Adolescente , Adulto , Factores de Edad , Evaluación de la Discapacidad , Europa (Continente)/epidemiología , Enfermedad de Fabry/diagnóstico , Femenino , Humanos , Infarto de la Arteria Cerebral Anterior/diagnóstico , Infarto de la Arteria Cerebral Posterior/diagnóstico , Ataque Isquémico Transitorio/diagnóstico , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Adulto Joven
9.
Int J Mol Sci ; 18(10)2017 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-29053611

RESUMEN

Glucosylceramide and glucosylsphingosine are the two major storage products in Gaucher disease (GD), an inherited metabolic disorder caused by a deficiency of the lysosomal enzyme glucocerebrosidase. The build-up of glucosylceramide in the endoplasmic reticulum and prominent accumulation in cell lysosomes of tissue macrophages results in decreased blood cell and platelet counts, and skeletal abnormalities. The pathological role of the deacylated form of glucosylceramide, glucosylsphingosine (lyso-Gb1), a recently identified sensitive and specific biomarker for GD, is not well investigated. We established a long-term infusion model in C57BL/6JRj mice to examine the effect of lyso-Gb1 on representative hallmark parameters of GD. Mice received lyso-Gb1 at a dosage of 10 mg·kg-1 per day as a continuous subcutaneous administration, and were routinely checked for blood lyso-Gb1 levels using liquid chromatography-multiple reaction monitoring mass spectrometry (LC/MRM-MS) measurements at four-weekly intervals throughout treatment. The C57BL/6JRj mice showed a stable increase of lyso-Gb1 up to->500-fold greater than the normal reflecting concentrations seen in moderately to severely affected patients. Furthermore, lyso-Gb1 accumulated in peripheral tissues. The mice developed hematological symptoms such as reduced hemoglobin and hematocrit, increased spleen weights and a slight inflammatory tissue response after eight weeks of treatment. The above findings indicate a measurable visceral and hematological response in treated mice that suggests a role for lyso-Gb1 in the development of peripheral signs of GD.


Asunto(s)
Enfermedad de Gaucher/inducido químicamente , Enfermedad de Gaucher/patología , Psicosina/análogos & derivados , Vísceras/química , Animales , Cromatografía Liquida , Modelos Animales de Enfermedad , Enfermedad de Gaucher/sangre , Hematócrito , Hemoglobinas/análisis , Humanos , Hígado/química , Hígado/efectos de los fármacos , Espectrometría de Masas , Ratones , Ratones Endogámicos C57BL , Tamaño de los Órganos , Psicosina/efectos adversos , Psicosina/sangre , Bazo/química , Bazo/efectos de los fármacos , Vísceras/efectos de los fármacos
10.
Chemistry ; 21(2): 893-9, 2015 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-25363673

RESUMEN

The addition of BCl3 to the carbene-transfer reagent NHC→SiCl4 (NHC=1,3-dimethylimidazolidin-2-ylidene) gave the tetra- and pentacoordinate trichlorosilicon(IV) cations [(NHC)SiCl3 ](+) and [(NHC)2 SiCl3 ](+) with tetrachloroborate as counterion. This is in contrast to previous reactions, in which NHC→SiCl4 served as a transfer reagent for the NHC ligand. The addition of BF3 ⋅OEt2 , on the other hand, gave NHC→BF3 as the product of NHC transfer. In addition, the highly Lewis acidic bis(pentafluoroethyl)silane (C2 F5 )2 SiCl2 was treated with NHC→SiCl4 . In acetonitrile, the cationic silicon(IV) complexes [(NHC)SiCl3 ](+) and [(NHC)2 SiCl3 ](+) were detected with [(C2 F5 )SiCl3 ](-) as counterion. A similar result was already reported for the reaction of NHC→SiCl4 with (C2 F5 )2 SiH2 , which gave [(NHC)2 SiCl2 H][(C2 F5 )SiCl3 ]. If the reaction medium was changed to dichloromethane, the products of carbene transfer, NHC→Si(C2 F5 )2 Cl2 and NHC→Si(C2 F5 )2 ClH, respectively, were obtained instead. The formation of the latter species is a result of chloride/hydride metathesis. These compounds may serve as valuable precursors for electron-poor silylenes. Furthermore, the reactivity of NHC→SiCl4 towards phosphines is discussed. The carbene complex NHC→PCl3 shows similar reactivity to NHC→SiCl4 , and may even serve as a carbene-transfer reagent as well.

11.
Cerebrovasc Dis ; 40(3-4): 129-35, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26227782

RESUMEN

BACKGROUND: The prospective, multinational European 'Stroke in Young Fabry Patients' (sifap1) study collected 4,467 patients with acute ischemic cerebrovascular events aged 18-55 years. Initially, aetiologic subtyping was performed using the TOAST classification; however, recently the phenotypic ASCO classification was presented and might be more useful to identify stroke aetiologies in young patients with a wide set of different causes. ASCO is a classification system divided in four etiologic categories (Atherosclerosis, Small vessel disease (SVD), Cardiac embolism, Other cause) with different grades of severity (1-3) and aims to characterise patients in a more comprehensive way. METHODS: We determined the ASCO score for each patient, according to prospectively collected data using the study protocol. The distribution of aetiologies was analysed with regard to concomitant causes, cryptogenic stroke and different age groups. RESULTS: A potentially causal aetiology (grade 1) was detected in 29.3% of 4,467 patients. Merging grades 1 and 2, a suspected aetiology was found in 54.1%. In 8.6% of patients concomitant aetiologies were identified. Most common causes were cervical arterial dissection and persistent foramen ovale, but there was also a high prevalence of large artery atherosclerosis and SVD especially in older patients of this collective. About 50% of patients had more than one finding with a lower grade of evidence (grade 3). In 14% final classification of strictly cryptogenic stroke was made. CONCLUSIONS: This is the largest study to date, using the ASCO characterisation of ischemic stroke aetiologies. ASCO classification provides first evidence that many young patients presenting with acute stroke have concomitant stroke aetiologies associated with a substantial atherosclerosis risk profile. ASCO could be integrated in clinical routine and registry data banks, as well as large clinical trials to improve stroke documentation.


Asunto(s)
Isquemia Encefálica/etiología , Ataque Isquémico Transitorio/etiología , Accidente Cerebrovascular/etiología , Adolescente , Adulto , Aterosclerosis/complicaciones , Isquemia Encefálica/diagnóstico , Femenino , Humanos , Ataque Isquémico Transitorio/diagnóstico , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Factores de Riesgo , Accidente Cerebrovascular/diagnóstico , Adulto Joven
12.
Angew Chem Int Ed Engl ; 53(48): 13269-72, 2014 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-25256121

RESUMEN

Chlorosilicates represent important intermediates in S(N)2 reactions of chlorosilanes. They can be stabilized by the introduction of electron-withdrawing substituents. Salts of various (pentafluoroethyl)chlorosilicates have been isolated and structurally characterized.


Asunto(s)
Silicatos/química , Silicatos/síntesis química , Estructura Molecular
13.
Stroke ; 44(2): 340-9, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23306324

RESUMEN

BACKGROUND AND PURPOSE: Strokes have especially devastating implications if they occur early in life; however, only limited information exists on the characteristics of acute cerebrovascular disease in young adults. Although risk factors and manifestation of atherosclerosis are commonly associated with stroke in the elderly, recent data suggests different causes for stroke in the young. We initiated the prospective, multinational European study Stroke in Young Fabry Patients (sifap) to characterize a cohort of young stroke patients. METHODS: Overall, 5023 patients aged 18 to 55 years with the diagnosis of ischemic stroke (3396), hemorrhagic stroke (271), transient ischemic attack (1071) were enrolled in 15 European countries and 47 centers between April 2007 and January 2010 undergoing a detailed, standardized, clinical, laboratory, and radiological protocol. RESULTS: Median age in the overall cohort was 46 years. Definite Fabry disease was diagnosed in 0.5% (95% confidence interval, 0.4%-0.8%; n=27) of all patients; and probable Fabry disease in additional 18 patients. Males dominated the study population (2962/59%) whereas females outnumbered men (65.3%) among the youngest patients (18-24 years). About 80.5% of the patients had a first stroke. Silent infarcts on magnetic resonance imaging were seen in 20% of patients with a first-ever stroke, and in 11.4% of patients with transient ischemic attack and no history of a previous cerebrovascular event. The most common causes of ischemic stroke were large artery atherosclerosis (18.6%) and dissection (9.9%). CONCLUSIONS: Definite Fabry disease occurs in 0.5% and probable Fabry disease in further 0.4% of young stroke patients. Silent infarcts, white matter intensities, and classical risk factors were highly prevalent, emphasizing the need for new early preventive strategies. Clinical Trial Registration Information- URL: http://www.clinicaltrials.gov.Unique identifier: NCT00414583.


Asunto(s)
Enfermedad de Fabry/diagnóstico , Enfermedad de Fabry/epidemiología , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/epidemiología , Enfermedad Aguda , Adolescente , Adulto , Factores de Edad , Trastornos Cerebrovasculares/diagnóstico , Trastornos Cerebrovasculares/epidemiología , Trastornos Cerebrovasculares/genética , Estudios de Cohortes , Europa (Continente)/epidemiología , Enfermedad de Fabry/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Accidente Cerebrovascular/genética , Adulto Joven
14.
J Neural Transm (Vienna) ; 120(10): 1433-40, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23748977

RESUMEN

Headache as symptom of stroke is linked to gender, history of migraine, younger age, cerebellar stroke, and low blood pressure. These associations have been controversial, large scale studies are missing. We used the stroke in young fabry patients study to examine the association of demographic, clinical and imaging factors with the occurrence of headache in 4,431 young ischaemic stroke patients (18-55 years; mean: 44.7 years) with an ischemic cerebrovascular event (CVE) (ischemic stroke-IS 75.9%, TIA 24.1%). Headache in males occurred more frequently in bilateral localisation (right/left/bilateral: 27.5, 24.6, 39.2%, p < 0.01), but not in females (40.3, 34.7, 39.6%). Headache occurrence was more often associated in both genders with IS or TIA in the posterior cerebral territory (male: 33.2%, p < 0.05; female: 51.0%, p < 0.01) and vertebrobasilar arteries (male: 44.8%, p < 0.001; female: 51.2%, p < 0.001). The larger the size of the most prominent lesion the more likely patients were complaining headache during the IS (≤1 cm vs. >half lobe: 19.5 vs. 28.4% in male, p < 0.001; 28.9 vs. 39.1% in female, p < 0.01). Binary logistic regression analyses revealed lower age (p < 0.001), female sex (p < 0.001), larger size of the largest lesion (p < 0.001), and localization in the vertebrobasilar territory (p < 0.001) as predictors for headache during CVE. Headache at stroke onset is more common during IS in females, younger patients, with greater size of the acute lesion, and affected in posterior cerebral artery or vertebrobasilar system. Headache is a leading symptom in specific combination of stroke factors. These factors should be taken into account when patients report headache during IS or TIA.


Asunto(s)
Cefalea/epidemiología , Cefalea/etiología , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/patología , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Adulto Joven
15.
Inorg Chem ; 52(10): 5651-3, 2013 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-23621423

RESUMEN

(Difluoroorganyl)dimethylamines, RCF2NMe2 (R = H, Ph, tBu), can be used as carbene precursors for phosphorus trifluoride in an oxidative addition reaction. By this method, complexes of sterically nondemanding asymmetric and acyclic carbenes were obtained that are otherwise not accessible.


Asunto(s)
Aminas/química , Fluoruros/química , Metano/análogos & derivados , Fósforo/química , Cristalografía por Rayos X , Ligandos , Metano/química , Modelos Moleculares , Estructura Molecular , Oxidación-Reducción
16.
Nat Commun ; 14(1): 5424, 2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37696785

RESUMEN

Magnetic skyrmions, topologically-stabilized spin textures that emerge in magnetic systems, have garnered considerable interest due to a variety of electromagnetic responses that are governed by the topology. The topology that creates a microscopic gyrotropic force also causes detrimental effects, such as the skyrmion Hall effect, which is a well-studied phenomenon highlighting the influence of topology on the deterministic dynamics and drift motion. Furthermore, the gyrotropic force is anticipated to have a substantial impact on stochastic diffusive motion; however, the predicted repercussions have yet to be demonstrated, even qualitatively. Here we demonstrate enhanced thermally-activated diffusive motion of skyrmions in a specifically designed synthetic antiferromagnet. Suppressing the effective gyrotropic force by tuning the angular momentum compensation leads to a more than 10 times enhanced diffusion coefficient compared to that of ferromagnetic skyrmions. Consequently, our findings not only demonstrate the gyro-force dependence of the diffusion coefficient but also enable ultimately energy-efficient unconventional stochastic computing.

17.
Diagnostics (Basel) ; 13(17)2023 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-37685353

RESUMEN

Gaucher disease (GD) is a rare autosomal recessive disorder arising from bi-allelic variants in the GBA1 gene, encoding glucocerebrosidase. Deficiency of this enzyme leads to progressive accumulation of the sphingolipid glucosylsphingosine (lyso-Gb1). The international, multicenter, observational "Lyso-Gb1 as a Long-term Prognostic Biomarker in Gaucher Disease"-LYSO-PROOF study succeeded in enrolling a cohort of 160 treatment-naïve GD patients from diverse geographic regions and evaluated the potential of lyso-Gb1 as a specific biomarker for GD. Using genotypes based on established classifications for clinical presentation, patients were stratified into type 1 GD (n = 114) and further subdivided into mild (n = 66) and severe type 1 GD (n = 48). Due to having previously unreported genotypes, 46 patients could not be classified. Though lyso-Gb1 values at enrollment were widely distributed, they displayed a moderate and statistically highly significant correlation with disease severity measured by the GD-DS3 scoring system in all GD patients (r = 0.602, p < 0.0001). These findings support the utility of lyso-Gb1 as a sensitive biomarker for GD and indicate that it could help to predict the clinical course of patients with undescribed genotypes to improve personalized care in the future.

18.
Eur J Hum Genet ; 31(10): 1108-1116, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37433892

RESUMEN

Niemann-Pick type C1 disease (NPC1 [OMIM 257220]) is a rare and severe autosomal recessive disorder, characterized by a multitude of neurovisceral clinical manifestations and a fatal outcome with no effective treatment to date. Aiming to gain insights into the genetic aspects of the disease, clinical, genetic, and biomarker PPCS data from 602 patients referred from 47 countries and diagnosed with NPC1 in our laboratory were analyzed. Patients' clinical data were dissected using Human Phenotype Ontology (HPO) terms, and genotype-phenotype analysis was performed. The median age at diagnosis was 10.6 years (range 0-64.5 years), with 287 unique pathogenic/likely pathogenic (P/LP) variants identified, expanding NPC1 allelic heterogeneity. Importantly, 73 P/LP variants were previously unpublished. The most frequent variants detected were: c.3019C > G, p.(P1007A), c.3104C > T, p.(A1035V), and c.2861C > T, p.(S954L). Loss of function (LoF) variants were significantly associated with earlier age at diagnosis, highly increased biomarker levels, and a visceral phenotype (abnormal abdomen and liver morphology). On the other hand, the variants p.(P1007A) and p.(S954L) were significantly associated with later age at diagnosis (p < 0.001) and mildly elevated biomarker levels (p ≤ 0.002), consistent with the juvenile/adult form of NPC1. In addition, p.(I1061T), p.(S954L), and p.(A1035V) were associated with abnormality of eye movements (vertical supranuclear gaze palsy, p ≤ 0.05). We describe the largest and most heterogenous cohort of NPC1 patients published to date. Our results suggest that besides its utility in variant classification, the biomarker PPCS might serve to indicate disease severity/progression. In addition, we establish new genotype-phenotype relationships for "frequent" NPC1 variants.


Asunto(s)
Fenotipo , Adulto , Humanos , Recién Nacido , Lactante , Preescolar , Niño , Adolescente , Adulto Joven , Persona de Mediana Edad
19.
Inorg Chem ; 51(2): 763-5, 2012 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-22216889

RESUMEN

Carbene complexes of Ge(IV)- and Sn(IV)-fluorides have been synthesized by oxidative addition of 2,2-difluoro-1,3-dimethylimidazolidine and bis(dimethylamino)difluoromethane to GeCl(2)•dioxane and SnF(2). Chloride analogs of the Ge(IV) complexes were also isolated. All compounds were characterized in the solid state by single-crystal X-ray diffraction.


Asunto(s)
Metano/análogos & derivados , Compuestos Organometálicos/química , Compuestos de Estaño/química , Fenómenos Químicos , Cristalografía por Rayos X , Fluoruros/química , Germanio/química , Espectroscopía de Resonancia Magnética , Metano/química , Estructura Molecular , Compuestos Organometálicos/síntesis química , Compuestos de Estaño/síntesis química , Difracción de Rayos X
20.
Sci Rep ; 12(1): 11877, 2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35831478

RESUMEN

The interfacial Dzyaloshinskii-Moriya Interaction (iDMI) is an antisymmetric exchange interaction that is induced by the broken inversion symmetry at the interface of, e.g., a ferromagnet/heavy metal. Thus, the presence of iDMI is not expected in symmetrical multilayer stacks of such structures. Here, we use thermal annealing to induce the iDMI in a [Py/Pt]×10 symmetrical multilayer stack. Brillouin light scattering spectroscopy is used to directly evidence the iDMI induction in the annealed sample. Structural characterizations highlight the modified crystallinity as well as a higher surface roughness of the sample after annealing. First principles electronic structure calculations demonstrate a monotonic increase of the iDMI with the interfacial disorder due to the interdiffusion of atoms, depicting the possible origin of the induced iDMI. The presented method can be used to tune the iDMI strength in symmetric multilayers, which are the integral part of racetrack memories, magnonic devices as well as spin-orbitronic elements.

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