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1.
Sci Rep ; 14(1): 1680, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38243038

RESUMO

The magnetic properties of Co(10 Å)/NiO(40 Å)/Fe trilayer epitaxially grown on W(110) substrate were investigated with use of x-ray magnetic linear dichroism (XMLD) and x-ray magnetic circular dichroism (XMCD). We showed that magnetic anisotropy of Fe film that can be controlled by a thickness-driven spin reorientation transition is transferred via interfacial exchange coupling not only to NiO layer but further to ferromagnetic Co overlayer as well. Similarly, a temperature driven spin reorientation of Fe sublayer induces a reorientation of NiO spin orientation and simultaneous switching of the Co magnetization direction. Finally, by element specific XMCD and XMLD magnetic hysteresis loop measurements we proved that external magnetic field driven reorientation of Fe and Co magnetizations as well as NiO Néel vector are strictly correlated and magnetic anisotropy fields of Fe and Co sublayers are identical despite the different crystal structures.

2.
Opt Express ; 31(23): 38891-38909, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-38017981

RESUMO

In this paper, novel optimization methodologies of sub-relativistic guided interaction structures for dielectric laser particle acceleration (DLA) are presented. In particular, we focus on co-propagating geometries based on slot waveguides in continuous wave (CW) operation, where the particle flow and the direction of propagation of the accelerating field are co-linear. Since the velocity of sub-relativistic particles varies along the acceleration path, proper tapering of the waveguide geometry is required to achieve an extended acceleration region, and, thus a large energy gain. The design of an optimal taper ensuring particle-wave synchronicity and maximum energy gain is pursued through a physics-based approach, and these results are compared, for validation, with the outcomes of a downhill simplex method searching algorithm. Additionally, the application of a simplified 2D model of the accelerating slot waveguide is investigated and profitably used to get qualitative results useful for fast structure optimization. Indeed, this approach can hold significant potential for the development of novel accelerating structures, as it enables a thorough and fast exploration of the design space.

3.
J Anesth Analg Crit Care ; 3(1): 42, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37880725

RESUMO

INTRODUCTION: Unintentional dural puncture (UDP) occurs in 0.5-1.5% of labour epidural analgesia cases. To date, little is known about evidence of UDP-related complications. This work aimed to assess the incidence of intrapartum and postpartum complications in parturients who experienced UDP. METHODS: This is a 10-year retrospective observational study on parturients admitted to our centre who presented UDP. Data collection gathered UDP-related complications during labour and postpartum. All women who displayed UDP received medical therapy and bed rest. An epidural blood patch (EBP) was not used in this population. Once asymptomatic, patients were discharged from the hospital. RESULTS: Out of 7718 neuraxial analgesia cases, 97 cases of UDP occurred (1.25%). During labour, complications appeared in a small percentage of analgesia procedures performed, including total spinal anaesthesia (1.0%), extended motor block (3%), hypotension (4.1%), abnormal foetal heart rate (2%), inadequate analgesia (14.4%), and general anaesthesia following neuraxial anaesthesia failure (33.3% of emergency caesarean sections). During the postpartum period, 53.6% of parturients exhibited a postdural puncture headache, 13.4% showed neurological symptoms, and 14.4% required neurological consultation and neuroimaging. No patient developed subdural hematoma or cerebral venous sinus thrombosis; one woman presented posterior reversible encephalopathy syndrome associated with eclampsia. Overall, 82.5% of women experienced an extension of hospital stay. CONCLUSION: Major complications occurred in a small percentage of patients during labour. However, since they represent high-risk maternal and neonatal health events, a dedicated anaesthesiologist and a trained obstetric team are essential. No major neurological complications were registered postpartum, and EBP was not performed. Nevertheless, all patients with UDP were carefully monitored and treated until complete recovery before discharge, leading to an extension of their hospitalization.

4.
J Phys Condens Matter ; 35(49)2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37582382

RESUMO

L3M2,3M2,3Auger transition is measured near the L3resonance of ferromagnetic Fe films on W(110). The kinetic energies of the Auger peaks display the typical Raman behaviour for photon energies well below the absorption threshold, where the Auger energy follows the changes in the photon energy. Classical Auger behaviour with constant kinetic energy sets in at about 1.5 eV below the L3resonance independently from the number of Fe layers down to the monolayer thickness. Strong x-ray circular magnetic dichroism is observed at the L3edge in the entire L3M2,3M2,3Auger spectrum. Different Auger features originating from the final state with two 3p core holes show slight variations in the dichroic signal, which is attributed to the exchange interaction between the core holes and the valence band. Finally, XMCD-PEEM magnetic domain imaging using Auger electrons is demonstrated with a high level of contrast and lateral resolution approaching that of imaging with secondary photoelectrons.

5.
Sci Rep ; 13(1): 4824, 2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-36964276

RESUMO

We report on the magnetic properties of antiferromagnetic NiO(001) thin films in epitaxially grown NiO/MgO(dMgO)/Cr/MgO(001) system for different thicknesses of MgO, dMgO. Results of X-ray Magnetic Linear Dichroism show that together with an increase of dMgO, rotation of NiO spins from in-plane towards out-of-plane direction occurs. Furthermore, we investigated how the proximity of Fe modifies the magnetic state of NiO in Fe/NiO/MgO(dMgO)/Cr/MgO(001). We proved the existence of a multidomain state in NiO as a result of competition between the ferromagnet/antiferromagnet exchange coupling and strain exerted on the NiO by the MgO buffer layer.

6.
J Small Anim Pract ; 63(12): 897-903, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36000486

RESUMO

OBJECTIVES: To describe ultrasound-guided microwave ablation as a minimally invasive treatment option for primary or metastatic hepatocellular carcinomas. METHODS: Four client-owned dogs underwent percutaneous ultrasound-guided microwave ablation of three primary and one metastatic hepatocellular carcinoma, diagnosed on cytology/histopathology. In each case, multiple ultrasound-guided thermal lesions were created in a 10 to 40 minutes ablation at 30 to 35 W. Real-time monitoring was performed using 10 MHz diagnostic ultrasound transducers. The procedures were performed without complication and CT scans or abdominal ultrasounds were repeated immediately after. Patients were discharged on oral analgesia on the same day or 24 hours later. RESULTS: Hepatocellular carcinomas were successfully ablated, which in some cases resulted in an improvement in clinical signs and laboratory values. The patients were followed up for a time ranging between 39 and 649 days and no evidence of disease progression was found. Three out of four patients are still alive at the time of writing. CLINICAL SIGNIFICANCE: In these four patients, minimally invasive ultrasound-guided microwave ablation was feasible and resulted in no immediate complications. Regular imaging follow-up is recommended after the procedure and further studies on microwave ablation are warranted to establish its effectiveness in dogs with hepatocellular carcinomas.


Assuntos
Carcinoma Hepatocelular , Doenças do Cão , Neoplasias Hepáticas , Micro-Ondas , Animais , Cães , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/cirurgia , Carcinoma Hepatocelular/veterinária , Ablação por Cateter/veterinária , Ablação por Cateter/métodos , Doenças do Cão/diagnóstico por imagem , Doenças do Cão/cirurgia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/veterinária , Micro-Ondas/uso terapêutico , Resultado do Tratamento , Ultrassonografia de Intervenção/veterinária
8.
Ultrasound Obstet Gynecol ; 60(3): 381-389, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35247287

RESUMO

OBJECTIVE: To evaluate the performance of third-trimester ultrasound for the diagnosis of clinically significant placenta accreta spectrum disorder (PAS) in women with low-lying placenta or placenta previa. METHODS: This was a prospective multicenter study of pregnant women aged ≥ 18 years who were diagnosed with low-lying placenta (< 20 mm from the internal cervical os) or placenta previa (covering the internal cervical os) on ultrasound at ≥ 26 + 0 weeks' gestation, between October 2014 and January 2019. Ultrasound suspicion of PAS was raised in the presence of at least one of these signs on grayscale ultrasound: (1) obliteration of the hypoechogenic space between the uterus and the placenta; (2) interruption of the hyperechogenic interface between the uterine serosa and the bladder wall; (3) abnormal placental lacunae. Histopathological examinations were performed according to a predefined protocol, with pathologists blinded to the ultrasound findings. To assess the ability of ultrasound to detect clinically significant PAS, a composite outcome comprising the need for active management at delivery and histopathological confirmation of PAS was considered the reference standard. PAS was considered to be clinically significant if, in addition to histological confirmation, at least one of these procedures was carried out after delivery: use of hemostatic intrauterine balloon, compressive uterine suture, peripartum hysterectomy, uterine/hypogastric artery ligation or uterine artery embolization. The diagnostic performance of each ultrasound sign for clinically significant PAS was evaluated in all women and in the subgroup who had at least one previous Cesarean section and anterior placenta. Post-test probability was assessed using Fagan nomograms. RESULTS: A total of 568 women underwent transabdominal and transvaginal ultrasound examinations during the study period. Of these, 95 delivered in local hospitals, and placental pathology according to the study protocol was therefore not available. Among the 473 women for whom placental pathology was available, clinically significant PAS was diagnosed in 99 (21%), comprising 36 cases of placenta accreta, 19 of placenta increta and 44 of placenta percreta. The median gestational age at the time of ultrasound assessment was 31.4 (interquartile range, 28.6-34.4) weeks. A normal hypoechogenic space between the uterus and the placenta reduced the post-test probability of clinically significant PAS from 21% to 5% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 9% in the subgroup with previous Cesarean section and anterior placenta. The absence of placental lacunae reduced the post-test probability of clinically significant PAS from 21% to 9% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 36% in the subgroup with previous Cesarean section and anterior placenta. When abnormal placental lacunae were seen on ultrasound, the post-test probability of clinically significant PAS increased from 21% to 59% in the whole cohort and from 62% to 78% in the subgroup with previous Cesarean section and anterior placenta. An interrupted hyperechogenic interface between the uterine serosa and bladder wall increased the post-test probability for clinically significant PAS from 21% to 85% in women with low-lying placenta or placenta previa and from 62% to 88% in the subgroup with previous Cesarean section and anterior placenta. When all three sonographic markers were present, the post-test probability for clinically significant PAS increased from 21% to 89% in the whole cohort and from 62% to 92% in the subgroup with previous Cesarean section and anterior placenta. CONCLUSIONS: Grayscale ultrasound has good diagnostic performance to identify pregnancies at low risk of PAS in a high-risk population of women with low-lying placenta or placenta previa. Ultrasound may be safely used to guide management decisions and concentrate resources on patients with higher risk of clinically significant PAS. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Placenta Acreta , Placenta Prévia , Cesárea , Feminino , Humanos , Placenta/diagnóstico por imagem , Placenta/patologia , Placenta Acreta/diagnóstico por imagem , Placenta Acreta/patologia , Placenta Prévia/diagnóstico por imagem , Placenta Prévia/patologia , Gravidez , Terceiro Trimestre da Gravidez , Diagnóstico Pré-Natal , Estudos Prospectivos , Estudos Retrospectivos , Ultrassonografia Pré-Natal/métodos
9.
J Small Anim Pract ; 63(1): 78-81, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34109622

RESUMO

An intracranial metallic foreign body (sewing needle) was diagnosed in an 11-month-old Cavalier King Charles Spaniel. Clinical evaluation showed drooling and chewing, but an otherwise normal neurological examination. Skull radiographs showed a metallic foreign body extending from the pharynx into the skull. A CT scan confirmed the presence of a foreign body crossing the right foramen lacerum into the brain. The needle was removed surgically with the aid of fluoroscopy. No complications were noted, except for transient right Horner's syndrome, most likely due to partial damage of the sympathetic postganglionic fibres that lie in the region of the tympanic bulla following surgery. The owner reported the dog being healthy 3 months after surgery.


Assuntos
Doenças do Cão , Corpos Estranhos , Animais , Encéfalo , Doenças do Cão/diagnóstico por imagem , Doenças do Cão/cirurgia , Cães , Fluoroscopia , Corpos Estranhos/diagnóstico por imagem , Corpos Estranhos/cirurgia , Corpos Estranhos/veterinária , Agulhas/veterinária , Tomografia Computadorizada por Raios X/veterinária
10.
Opt Express ; 29(7): 11132, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33820231

RESUMO

Figure 1(b) in [V. F. Gili et al, Opt. Express24, 15965 (2016)10.1364/OE.24.015965] is corrupted and is corrected in this erratum.

11.
Ultrasound Obstet Gynecol ; 57(2): 298-304, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32851714

RESUMO

OBJECTIVE: To assess whether repeat cervical-length (CL) measurement in women discharged from hospital after their first episode of threatened preterm labor can predict their risk of spontaneous preterm birth. METHODS: This was a secondary analysis of a randomized controlled trial of maintenance tocolysis, in which CL was measured on transvaginal ultrasound at the time of hospital discharge and after 2, 4, 8 and 12 weeks, in women who remained undelivered after their first episode of threatened preterm labor. After univariate analysis, multivariate logistic regression analysis was used to assess whether CL < 10 mm at the time of hospital discharge or at any follow-up evaluation could predict spontaneous delivery prior to 37 weeks of gestation. RESULTS: Of 226 women discharged after a diagnosis of threatened preterm labor, 57 (25.2%) delivered spontaneously prior to 37 weeks' gestation. The risk of spontaneous preterm birth was higher among women with CL < 10 mm at hospital discharge compared to those with CL ≥ 10 mm (adjusted odds ratio (aOR), 3.3; 95% CI, 1.2-9.2). Moreover, spontaneous preterm delivery was more common when CL < 10 mm was detected up to 2 weeks (aOR, 2.9; 95% CI, 1.1-7.3) or up to 4 weeks (aOR, 7.3; 95% CI, 2.3-22.8) post discharge, as compared with when CL was persistently ≥ 10 mm. The association was not significant when considering CL measurements at 8 weeks, and there was insufficient information to assess the effect of measurements obtained at 12 weeks. CONCLUSIONS: Women who remain undelivered after their first episode of threatened preterm labor continue to be at high risk of spontaneous preterm birth if their CL is below 10 mm at the time of hospital discharge or at any follow-up visit up to 4 weeks later. CL measurement could be included in the antenatal care of these women in order to stratify their risk of preterm birth, rationalize resource utilization and help clinicians improve pregnancy outcome. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Medida do Comprimento Cervical , Trabalho de Parto Prematuro , Nascimento Prematuro , Diagnóstico Pré-Natal , Adulto , Feminino , Idade Gestacional , Humanos , Alta do Paciente , Valor Preditivo dos Testes , Gravidez , Terceiro Trimestre da Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Análise de Regressão
12.
Ig Sanita Pubbl ; 76(4): 241-255, 2020.
Artigo em Italiano | MEDLINE | ID: mdl-33161421

RESUMO

The last few weeks of pregnancy are critical to a baby's health because important organs, including the brain and lungs, are not completely developed until the end of pregnancy. The adverse events during labor and childbirth can have very serious physical, psychological and financial consequences for the child, the family, health professionals and the whole community. These events can be reduced through interventions aimed at improving the safety and quality of care, based on evidence-based knowledge, guidelines and practices that must be widely and effectively applied. This work reports the experience of the Lombardy Region on improvement actions in the obstetric and gynecological procedures for the reduction of adverse events and sentinel events through the monitoring and management of the RCGS trigger tool.


Assuntos
Procedimentos Cirúrgicos em Ginecologia/normas , Segurança do Paciente , Garantia da Qualidade dos Cuidados de Saúde/normas , Melhoria de Qualidade , Qualidade da Assistência à Saúde , Criança , Parto Obstétrico , Feminino , Humanos , Ciência da Implementação , Lactente , Guias de Prática Clínica como Assunto , Gravidez
13.
Nanoscale ; 12(37): 19477, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32959041

RESUMO

Correction for 'Fine tuning of ferromagnet/antiferromagnet interface magnetic anisotropy for field-free switching of antiferromagnetic spins' by M. Slezak et al., Nanoscale, 2020, DOI: 10.1039/d0nr04193a.

14.
Nanoscale ; 12(35): 18091-18095, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32856646

RESUMO

We show that in a uniform thickness NiO(111)/Fe(110) epitaxial bilayer system, at given temperature near 300 K, two magnetic states with orthogonal spin orientations can be stabilized in antiferromagnetic NiO. Field-free, reversible switching between these two antiferromagnetic states is demonstrated. The observed phenomena arise from the unique combination of precisely tuned interface magnetic anisotropy, thermal hysteresis of spin reorientation transition and interfacial ferromagnet/antiferromagnet exchange coupling. The possibility of field-free switching between two magnetic states in an antiferromagnet is fundamentally interesting and can lead to new ideas in heat assisted magnetic recording technology.

15.
Ultramicroscopy ; 216: 113035, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32544784

RESUMO

X-ray photoemission electron microscopy, one of the most successful imaging tools at synchrotrons, is known to have limitations related to the application of external fields and to the short electron mean free path. In order to overcome such issues, we adapt an existing XPEEM instrument to simultaneously perform coherent x-ray scattering measurements in reflectivity mode, thus adding a complementary method to XPEEM. Photon-in photon-out x-ray scattering provides the sensitivity to buried interfaces as well as the possibility to work under external fields, which is challenging when using charged particles for imaging. XPEEM, in turn, greatly alleviates the difficulties associated with the reconstruction methods used in coherent diffraction imaging. The combination of the two methods is demonstrated for an artifical spin-ice lattice showing both chemical and magnetic contrast.

19.
Phys Rev Lett ; 123(21): 217201, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31809154

RESUMO

While the usual approach to tailor the behavior of condensed matter and nanosized systems is the choice of material or finite-size or interfacial effects, topology alone may be the key. In the context of the motion of magnetic domain walls (DWs), known to suffer from dynamic instabilities with low mobilities, we report unprecedented velocities >600 m/s for DWs driven by spin-transfer torques in cylindrical nanowires made of a standard ferromagnetic material. The reason is the robust stabilization of a DW type with a specific topology by the Œrsted field associated with the current. This opens the route to the realization of predicted new physics, such as the strong coupling of DWs with spin waves above >600 m/s.

20.
J Phys Condens Matter ; 31(44): 445804, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31392970

RESUMO

We report a combined study of imaging the antiferromagnetic (AFM) spin structure and measuring the spin Hall magnetoresistance (SMR) in epitaxial thin films of the insulating non-collinear antiferromagnet SmFeO3. X-ray magnetic linear dichroism photoemission electron microscopy measurements reveal that the AFM spins of the SmFeO3(1 1 0) align in the plane of the film. Angularly dependent magnetoresistance measurements show that SmFeO3/Ta bilayers exhibit a positive SMR, in contrast to the negative SMR expected in previously studied collinear AFMs. The SMR amplitude increases linearly with increasing external magnetic field at higher magnetic fields, suggesting that field-induced canting of the AFM spins plays an important role. In contrast, around the coercive field, no detectable SMR signal is observed, indicating that the SMR of the AFM and canting magnetization components cancel out. Below 50 K, the SMR amplitude increases sizably by a factor of two as compared to room temperature, which likely correlates with the long-range ordering of the Sm ions. Our results show that the SMR is a sensitive technique for non-equilibrium spin systems of non-collinear AFMs.

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