Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 193
Filtrar
1.
Nat Mater ; 21(5): 514-517, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35210586

RESUMO

Ultrafast manipulation of magnetism bears great potential for future information technologies. While demagnetization in ferromagnets is governed by the dissipation of angular momentum1-3, materials with multiple spin sublattices, for example antiferromagnets, can allow direct angular momentum transfer between opposing spins, promising faster functionality. In lanthanides, 4f magnetic exchange is mediated indirectly through the conduction electrons4 (the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction), and the effect of such conditions on direct spin transfer processes is largely unexplored. Here, we investigate ultrafast magnetization dynamics in 4f antiferromagnets and systematically vary the 4f occupation, thereby altering the magnitude of the RKKY coupling energy. By combining time-resolved soft X-ray diffraction with ab initio calculations, we find that the rate of direct transfer between opposing moments is directly determined by this coupling. Given the high sensitivity of RKKY to the conduction electrons, our results offer a useful approach for fine tuning the speed of magnetic devices.

2.
Rhinology ; 61(6): 531-540, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37453138

RESUMO

BACKGROUND: Loss of sense of smell is one of the most burdensome symptoms of chronic rhinosinusitis with nasal polyps (CRSwNP) but its relationship to sinus disease on imaging is unclear. Dupilumab improves sense of smell and radiographic severity of sinus disease in patients with CRSwNP. We investigated the relationship of sinus opacification severity and loci to olfactory impairment and dupilumab efficacy in patients with CRSwNP from the SINUS-24/SINUS-52 (NCT02912468/NCT02898454) studies. METHODS: Sinus opacification was evaluated using the Lund-Mackay computed tomography (LMK-CT) score and sense of smell using patient-reported loss of smell (LoS) score, University of Pennsylvania Smell Identification Test (UPSIT) score and the 22-item Sino-Nasal Outcome Test (SNOT-22) smell/taste item. RESULTS: At baseline, 95% of patients (688/724) had impaired sense of smell and opacification was extensive across all sinuses. Greater olfactory impairment was associated with greater opacification, especially in the ethmoid, sphenoid and frontal sinuses. At Week 24, reductions in LMK-CT total score and ethmoid and sphenoid sinus scores with dupilumab were weakly correlated with improvements in sense of smell assessed by LoS, UPSIT and SNOT-22 smell/taste item. More dupilumab than placebo patients achieved clinically meaningful improvement in LMK-CT total score at Week 24 and Week 52. CONCLUSION: Radiographic disease severity on imaging was associated with smell outcomes in this cohort. Opacification of the ethmoid, sphenoid and frontal sinuses was associated with severe smell loss. These data suggest that dupilumab effects on smell may be partly mediated through reduced sinus inflammation.


Assuntos
Seio Frontal , Pólipos Nasais , Transtornos do Olfato , Rinite , Sinusite , Humanos , Pólipos Nasais/complicações , Pólipos Nasais/tratamento farmacológico , Olfato , Rinite/complicações , Rinite/diagnóstico por imagem , Rinite/tratamento farmacológico , Sinusite/complicações , Sinusite/tratamento farmacológico , Doença Crônica , Transtornos do Olfato/etiologia , Transtornos do Olfato/complicações
3.
Rhinology ; 61(2): 108-117, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36716382

RESUMO

BACKGROUND: The SYNAPSE study (NCT03085797) demonstrated that mepolizumab decreased nasal polyp (NP) size and nasal obstruction in patients with chronic rhinosinusitis with NP (CRSwNP). METHODS: SYNAPSE, a randomized, double-blind study, included patients with recurrent, refractory, severe CRSwNP, eligible for repeated surgery despite receiving standard of care (SoC). Patients received 4-weekly mepolizumab 100 mg or placebo subcutaneously plus SoC for 52 weeks. This post hoc analysis further characterized treatment responses and association with patient characteristics. The proportion of patients meeting any and each of five response criteria indicating improvement in disease-specific quality of life, NP size, nasal obstruction, loss of smell, and overall symptoms at Weeks 24 and 52, were assessed in subgroups: 1) no surgery; 2) neither surgery nor systemic corticosteroids (SCS). RESULTS: Of 407 patients in the intention-to-treat population, 381 and 343 patients had no sinus surgery by Weeks 24 and 52, respectively. More mepolizumab- versus placebo-treated patients without surgery by Weeks 24 and 52 met each response criteria. Of the mepolizumab-treated patients without surgery by Week 24, 109 (55%) responded across >=3 criteria, increasing to 126 (67%) by Week 52. Similar response trends were seen for patients with neither surgery nor SCS by Weeks 24 and 52. At either timepoint, there were no major differences in baseline characteristics between mepolizumab-treated full- (5/5 categories) and non-responders (0/5 categories). CONCLUSIONS: Most patients who completed SYNAPSE required neither surgery nor SCS use and in addition achieved a progressive and sustained clinical response to mepolizumab underscoring the therapeutic benefits of mepolizumab in severe CRSwNP.


Assuntos
Obstrução Nasal , Pólipos Nasais , Rinite , Humanos , Obstrução Nasal/tratamento farmacológico , Qualidade de Vida , Anticorpos Monoclonais Humanizados/uso terapêutico , Doença Crônica , Corticosteroides/uso terapêutico , Pólipos Nasais/complicações , Pólipos Nasais/tratamento farmacológico , Rinite/complicações , Rinite/tratamento farmacológico
4.
Rhinology ; 61(1): 85-89, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36507741

RESUMO

Chronic rhinosinusitis (CRS) is known to affect around 5 % of the total population, with major impact on the quality of life of those severely affected (1). Despite a substantial burden on individuals, society and health economies, CRS often remains underdiagnosed, under-estimated and under-treated (2). International guidelines like the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) (3) and the International Consensus statement on Allergy and Rhinology: Rhinosinusitis 2021 (ICAR) (4) offer physicians insight into the recommended treatment options for CRS, with an overview of effective strategies and guidance of diagnosis and care throughout the disease journey of CRS.


Assuntos
Hipersensibilidade , Pólipos Nasais , Rinite , Sinusite , Humanos , Rinite/diagnóstico , Rinite/terapia , Rinite/epidemiologia , Qualidade de Vida , Sinusite/diagnóstico , Sinusite/terapia , Sinusite/epidemiologia , Doença Crônica , Pólipos Nasais/diagnóstico , Pólipos Nasais/terapia
5.
Cryo Letters ; 44(1): 37-46, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36629840

RESUMO

BACKGROUND: Successful cryopreservation of bovine oocytes is very important for research and commercial applications. However, the survival and development rate of vitrified-thawed (VT) oocytes are lower than those of non-vitrified-thawed (non-VT) oocytes. OBJECTIVE: To investigate the effect of adding hydroxypropyl cellulose (HPC) to the vitrification solution for bovine oocytes. MATERIALS AND METHODS: For vitrification, bovine metaphase II oocytes were pretreated with a solution containing 10% ethylene glycol supplemented with 0, 10, 50, or 100 ug/mL HPC for 5 min, exposed to a solution containing 30% ethylene glycol supplemented with 0, 10, 50, or 100 ug/mL HPC for 30 s, and then directly plunged into liquid nitrogen. RESULTS: The survival rate of oocytes was significantly higher in the 50 HPC group than in the 0, 10, and 100 HPC groups. The reactive oxygen species level was lower in the non-VT and 50 HPC groups than in the other groups. The mRNA levels of proapoptotic genes (Bax) were lower in the non-VT, 0, and 50 HPC groups than in the other groups. The mRNA levels of antiapoptotic genes (BCl2) were higher in the non-VT than in the other groups. The development rates of embryos (day 8) obtained via parthenogenetic activation (PA) were determined in the non-VT, 0 HPC, and 50 HPC groups. The cleavage rate was significantly higher in the non-VT group. CONCLUSION: Supplementation of vitrification solution with HPC improves the survival of VT bovine oocytes and the development capacity of embryos derived from these oocytes via PA. doi.org/10.54680/fr23110110212.


Assuntos
Criopreservação , Vitrificação , Animais , Bovinos , Criopreservação/veterinária , Oócitos/fisiologia , Crioprotetores/farmacologia , Suplementos Nutricionais , Etilenoglicóis/farmacologia
6.
Rhinology ; 59(3): 301-311, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33847325

RESUMO

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease with a high symptom burden and poor quality of life. Treatment options include recurrent surgeries and/or frequent systemic corticosteroids (SCS). Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4 and interleukin-13, key drivers of type 2-mediated inflammation. We report results of pooled analyses from 2 randomised, double-blind, placebo-controlled phase 3 studies (SINUS 24 [NCT02912468]; SINUS-52 [NCT02898454]) to evaluate dupilumab effect versus placebo in adults with CRSwNP with/without SCS use and sinonasal surgery. METHODOLOGY: SINUS-24 patients were randomised 1:1 to subcutaneous dupilumab 300 mg (n=143) or placebo (n=133) every 2 weeks (q2w) for 24 weeks. SINUS-52 patients were randomised 1:1:1 to 52 weeks of subcutaneous dupilumab 300 mg q2w (n=150), 24 weeks q2w followed by 28 weeks of dupilumab 300 mg every 4 weeks (n=145) or 52 weeks of placebo q2w (n=153). RESULTS: Dupilumab reduced the number of patients undergoing sinonasal surgery (82.6%), the need for in-study SCS use (73.9%), and SCS courses (75.3%). Significant improvements were observed with dupilumab vs placebo regardless of prior sinonasal surgery or SCS use in nasal polyp, nasal congestion, Lund-MacKay, and Sinonasal Outcome Test (22-items) scores, and the University of Pennsylvania Smell Identification Test. CONCLUSIONS: Dupilumab demonstrated significant improvements in disease signs and symptoms and reduced the need for sino-nasal surgery and SCS use versus placebo in patients with severe CRSwNP, regardless of SCS use in the previous 2 years, or prior sinonasal surgery.


Assuntos
Pólipos Nasais , Rinite , Corticosteroides , Adulto , Anticorpos Monoclonais Humanizados , Doença Crônica , Método Duplo-Cego , Humanos , Interleucina-13 , Pólipos Nasais/tratamento farmacológico , Pólipos Nasais/cirurgia , Qualidade de Vida , Rinite/complicações , Rinite/tratamento farmacológico , Rinite/cirurgia , Resultado do Tratamento
7.
Int Nurs Rev ; 67(4): 512-518, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33006174

RESUMO

AIMS: This study investigated how patient safety is currently taught in pre-registration nursing programmes across South Korea and explored nurse educators' perspectives on curriculum change. BACKGROUND: Pre-graduate education plays a critical role in preparing nurses with the requisite patient safety competencies. However, little is known about how patient safety education is addressed in South Korean nursing schools or the perspectives of nurse educators regarding patient safety education and a need for change. METHODS: This descriptive study used data collected during a 2019 accreditation workshop provided by the Korean Accreditation Board of Nursing Education. A paper-and-pencil survey was completed by 80 nurse educators working in 16 regions throughout Korea. RESULTS: A little consistency was found in approaches to teaching patient safety. Patient safety topics are addressed throughout various nursing courses, and patient safety education is limited in hours of instruction and breadth of content. A majority of respondents indicated that additional supports are needed, including a national standardized curriculum for patient safety education. CONCLUSION: A new approach to teaching patient safety is needed in Korean pre-registration nursing education. Overall, patient safety education is limited and provided through a fragmented approach with little attention to systems, workplace design or human issues that are necessary for developing the critical reasoning and skills to support patient safety. IMPLICATIONS FOR NURSING POLICY: The accrediting and regulatory bodies in South Korea should work together to develop and implement explicit standards of patient safety education and patient safety competencies for nursing students. Development of a standardized national curriculum is essential for providing a consistent, systematic and comprehensive approach to patient safety education in nursing programmes.


Assuntos
Bacharelado em Enfermagem , Educação em Enfermagem , Estudantes de Enfermagem , Currículo , Docentes de Enfermagem , Humanos , Segurança do Paciente , República da Coreia
9.
Int Endod J ; 52(10): 1479-1488, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31062874

RESUMO

AIM: To explore the involvement of TLR5 in pulp inflammation and to examine the effects of TLR5 activation with its ligand, FlaB protein, on pro-inflammatory gene expression. METHODOLOGY: TLR5 expression in dental pulp tissues and human dental pulp cells (hDPCs) were determined by immunohistochemistry, immunocytochemistry, Western blots and RT-PCR analyses. To examine the role of TLR5, hDPCs were treated with recombinant FlaB protein (500 ng mL-1 ) to activate the receptor or with a small interfering RNA against TLR5 (si-TLR5) to downregulate the receptor. After exposure to FlaB, the expression of inflammation-related proteins was screened using a protein array kit. Western blots or qRT-PCR analyses were performed to identify changes in the expression of uPA (urokinase plasminogen activator), TIMPs (tissue inhibitor of metalloproteinases), and IL-6 and to determine their signalling pathways. Statistical analysis was performed using one-way analysis of variance (anova) with Tukey post hoc test; P < 0.05 was considered statistically significant. RESULT: TLR5 expression was identified in pulp tissues and hDPCs. In the protein array analysis, treatment with FlaB significantly increased uPA expression (P < 0.01) and significantly decreased TIMP1/4 (P < 0.05). FlaB treatment also significantly increased expression of the inflammatory marker IL-6 (P < 0.01). FlaB treatment increased phosphorylation of the NF-κB p65 subunit, JNK, p38 and ERK. Chemical inhibitors of NF-κB (Bay11-7082), p38 (SB202190) or ERK (U0126) decreased the FlaB induction of uPA expression. Downregulation of TLR5 expression by siRNA decreased the FlaB induction of uPA protein and p65 phosphorylation. CONCLUSION: TLR5 activation with FlaB treatment induced the expression of uPA via the NF-κB and MAPK signalling pathways. Flagellin-bearing oral bacteria may cause pulp inflammation through TLR5. The findings provide new clues to control pulpal diseases by targeting TLR5 signalling pathways.


Assuntos
NF-kappa B , Ativador de Plasminogênio Tipo Uroquinase , Polpa Dentária , Humanos , Mediadores da Inflamação , Plasminogênio , Receptor 5 Toll-Like
10.
Br J Dermatol ; 179(3): 689-701, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29485733

RESUMO

BACKGROUND: Adiponectin is an adipocyte-derived cytokine that circulates as a full-length protein and a fragment containing the globular domain of adiponectin (gAd). A recent study has reported the antimelanogenic effects of full-length adiponectin. OBJECTIVES: To examine the involvement of gAd in melanogenesis and its mechanisms of action. METHODS: The effects of gAd on melanogenesis and its mechanisms of action were investigated in human epidermal melanocytes and reconstructed epidermis, including melanin content, cellular tyrosinase activity, cyclic adenosine monophosphate (cAMP) production and protein kinase A (PKA) activity, expression and phosphorylation of signalling molecules. RESULTS: Exogenous gAd increased melanin content, and the mRNA levels of microphthalmia-associated transcription factor (MITF) and its downstream genes TRP1, but not TRP2, were increased by gAd. However, cAMP production and PKA activity were not affected by gAd. Moreover, attempts to elucidate the underlying mechanism behind the gAd-mediated effect revealed that gAd could regulate melanogenesis by upregulating MITF through phosphorylation of the cAMP response element-binding protein (CREB). In addition, upregulation of MITF was mediated by activation of adenosine monophosphate-activated protein kinase (AMPK)-p38 mitogen-activated protein kinase (MAPK) signalling. Taken together, these findings indicate that promotion of melanogenesis by gAd occurs through increased expression of MITF, which is mediated by activation of the AMPK-p38 MAPK-CREB pathway. CONCLUSIONS: These findings suggest that gAd contributes to epidermal homeostasis via its effect on melanocyte biology, and products of adipose tissue could affect epidermal biology.


Assuntos
Adiponectina/metabolismo , Tecido Adiposo/metabolismo , Melaninas/biossíntese , Melanócitos/metabolismo , Pigmentação da Pele/fisiologia , Linhagem Celular , Ensaios Enzimáticos , Células Epidérmicas/metabolismo , Epiderme/metabolismo , Humanos , Fator de Transcrição Associado à Microftalmia/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Domínios Proteicos/fisiologia , Transdução de Sinais/fisiologia , Regulação para Cima
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA