Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
Nano Lett ; 24(26): 7919-7926, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38836594

RESUMO

Schottky diode, capable of ultrahigh frequency operation, plays a critical role in modern communication systems. To develop cost-effective and widely applicable high-speed diodes, researchers have delved into thin-film semiconductors. However, a performance gap persists between thin-film diodes and conventional bulk semiconductor-based ones. Featuring high mobility and low permittivity, indium-tin-oxide has emerged to bridge this gap. Nevertheless, due to its high carrier concentration, indium-tin-oxide has predominantly been utilized as electrode rather than semiconductor. In this study, a remarkable quantum confinement induced dedoping phenomenon was discovered during the aggressive indium-tin-oxide thickness downscaling. By leveraging such a feature to change indium-tin-oxide from metal-like into semiconductor-like, in conjunction with a novel heterogeneous lateral design facilitated by an innovative digital etch, we demonstrated an indium-tin-oxide Schottky diode with a cutoff frequency reaching terahertz band. By pushing the boundaries of thin-film Schottky diodes, our research offers a potential enabler for future fifth-generation/sixth-generation networks, empowering diverse applications.

2.
BMC Med ; 21(1): 388, 2023 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-37814306

RESUMO

BACKGROUND: Dipeptidyl peptidase-4 inhibitors (DPP-4i) have become firmly established in treatment algorithms and national guidelines for improving glycemic control in type 2 diabetes mellitus (T2DM).To report the findings from a multicenter, randomized, double-blind, placebo-controlled phase 3 clinical trial, which was designed to assess the efficacy and safety of a novel DPP-4 inhibitor fotagliptin in treatment-naive patients with T2DM. METHODS: Patients with T2DM were randomized to receive fotagliptin (n = 230), alogliptin (n = 113) or placebo (n = 115) at a 2:1:1 ratio for 24 weeks of double-blind treatment period, followed by an open-label treatment period, making up a total of 52 weeks. The primary efficacy endpoint was to determine the superiority of fotagliptin over placebo in the change of HbA1c from baseline to Week 24. All serious or significant adverse events were recorded. RESULTS: After 24 weeks, mean decreases in HbA1c from baseline were -0.70% for fotagliptin, -0.72% for alogliptin and -0.26% for placebo. Estimated mean treatment differences in HbA1c were -0.44% (95% confidence interval [CI]: -0.62% to -0.27%) for fotagliptin versus placebo, and -0.46% (95% CI: -0.67% to -0.26%) for alogliptin versus placebo, and 0.02% (95%CI: -0.16% to 0.19%; upper limit of 95%CI < margin of 0.4%) for fotagliptin versus alogliptin. So fotagliptin was non-inferior to alogliptin. Compared with subjects with placebo (15.5%), significantly more patients with fotagliptin (37.0%) and alogliptin (35.5%) achieved HbA1c < 7.0% after 24 weeks of treatment. During the whole 52 weeks of treatment, the overall incidence of hypoglycemia was low for both of the fotagliptin and alogliptin groups (1.0% each). No drug-related serious adverse events were observed in any treatment group. CONCLUSIONS: In summary, the study demonstrated improvement in glycemic control and a favorable safety profile for fotagliptin in treatment-naive patients with T2DM. TRIAL REGISTRATION: ClinicalTrail.gov NCT05782192.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores da Dipeptidil Peptidase IV , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hemoglobinas Glicadas , Glicemia , Hipoglicemiantes/efeitos adversos , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Método Duplo-Cego , Resultado do Tratamento
3.
J Cell Mol Med ; 23(2): 1059-1071, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30461198

RESUMO

Fibroblast growth factor 21 (FGF21) is important in glucose, lipid homeostasis and insulin sensitivity. However, it remains unknown whether FGF21 is involved in insulin expression and secretion that are dysregulated in type 2 diabetes mellitus (T2DM). In this study, we found that FGF21 was down-regulated in pancreatic islets of db/db mice, a mouse model of T2DM, along with decreased insulin expression, suggesting the possible involvement of FGF21 in maintaining insulin homeostasis and islet ß-cell function. Importantly, FGF21 knockout exacerbated palmitate-induced islet ß-cell failure and suppression of glucose-stimulated insulin secretion (GSIS). Pancreatic FGF21 overexpression significantly increased insulin expression, enhanced GSIS, improved islet morphology and reduced ß-cell apoptosis in db/db mice. Mechanistically, FGF21 promoted expression of insulin gene transcription factors and soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, the major regulators of insulin secretion, as well as activating phosphatidylinositol 3-kinase (PI3K)/Akt signaling in islets of db/db mice. In addition, pharmaceutical inhibition of PI3K/Akt signaling effectively suppressed FGF21-induced expression of insulin gene transcription factors and SNARE proteins, suggesting an essential role of PI3K/Akt signaling in FGF21-induced insulin expression and secretion. Taken together, our results demonstrate a protective role of pancreatic FGF21 in T2DM mice through inducing PI3K/Akt signaling-dependent insulin expression and secretion.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Insulina/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia , Animais , Apoptose/fisiologia , Glucose/metabolismo , Resistência à Insulina/fisiologia , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pâncreas/metabolismo
4.
Am J Emerg Med ; 37(2): 379.e1-379.e3, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30424987

RESUMO

CONTEXT: Thyrotoxic periodic paralysis (TPP) is a relatively common complication seen in Asian hyperthyroid patients. However, it is a rare occurrence to find a TPP case comprised of acute hypercapnic respiratory failure in patients with painless thyroiditis. PATIENT: A 29-year-old Chinese man presented with flaccid paralysis of all four limbs and he was brought to emergency room. Severe hypokalemia was found on admission. Although treatment had been initiated with potassium chloride supplementation, he went on to develop acute hypercapnic respiratory failure likely due to muscle fatigue. The patient was intubated for mechanical ventilatory support. Once his serum potassium levels were normalized, he was able to be weaned off ventilator support. Thyroid function tests showed elevated free thyroxine concentration and low thyroid-stimulating hormone concentration. He underwent a thyroid uptake scan with 131I which revealed decreased uptake rate of thyroid area. Based on the patient's clinical presentation and associated findings, we diagnosed him with TPP due to painless thyroiditis. We have reviewed TPP cases caused by painless thyroiditis and TPP cases associated with acute hypercapnic respiratory failure. CONCLUSION: It is important to note that potentially fatal complications such as acute hypercapnic respiratory failure might occur in acute attacks of TPP even in cases of TPP due to painless thyroiditis.


Assuntos
Hipercapnia/complicações , Paralisia Periódica Hipopotassêmica/complicações , Insuficiência Respiratória/complicações , Tireoidite/complicações , Adulto , Povo Asiático , Humanos , Hipercapnia/diagnóstico , Hipercapnia/etnologia , Hipopotassemia/etnologia , Hipopotassemia/etiologia , Paralisia Periódica Hipopotassêmica/diagnóstico , Paralisia Periódica Hipopotassêmica/etnologia , Masculino , Paraplegia/etnologia , Paraplegia/etiologia , Insuficiência Respiratória/diagnóstico , Insuficiência Respiratória/etnologia , Tireoidite/diagnóstico , Tireoidite/etnologia
5.
Gynecol Endocrinol ; 35(9): 752-755, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30905204

RESUMO

Silver-Russell syndrome (SRS) is a heterogeneous disorder characterized by severe intrauterine and postnatal growth retardation and typical dysmorphic features including body asymmetry, relative macrocephaly, protruding forehead, and feeding difficulties. Previous descriptions of SRS focus on the management of specific issues in children. Herein, we present clinical and metabolic characteristics of an adult woman with SRS accompanied by gestational diabetes mellitus (GDM). Given the rare circumstances presented in our case, the emerging questions concerning the management of metabolic issues and fertility potential in adult SRS patient deserve more attention. Further, long-term follow up is essential to gain future insights into the natural history and optimal management in adulthood.


Assuntos
Diabetes Gestacional , Nascido Vivo , Síndrome de Silver-Russell , Adulto , Povo Asiático , Diabetes Gestacional/diagnóstico , Diabetes Gestacional/genética , Diabetes Gestacional/terapia , Feminino , Humanos , Recém-Nascido , Gravidez , Complicações na Gravidez/diagnóstico , Complicações na Gravidez/genética , Complicações na Gravidez/terapia , Resultado da Gravidez , Síndrome de Silver-Russell/complicações , Síndrome de Silver-Russell/diagnóstico , Síndrome de Silver-Russell/genética , Síndrome de Silver-Russell/terapia , Nascimento a Termo
6.
J Neurosci ; 36(4): 1242-53, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-26818512

RESUMO

A characteristic phenotype of congenital generalized lipodystrophy 2 (CGL2) that is caused by loss-of-function of seipin gene is mental retardation. Here, we show that seipin deficiency in hippocampal CA1 pyramidal cells caused the reduction of peroxisome proliferator-activated receptor gamma (PPARγ). Twelve-week-old systemic seipin knock-out mice and neuronal seipin knock-out (seipin-nKO) mice, but not adipose seipin knock-out mice, exhibited spatial cognitive deficits as assessed by the Morris water maze and Y-maze, which were ameliorated by the treatment with the PPARγ agonist rosiglitazone (rosi). In addition, seipin-nKO mice showed the synaptic dysfunction and the impairment of NMDA receptor-dependent LTP in hippocampal CA1 regions. The density of AMPA-induced current (IAMPA) in CA1 pyramidal cells and GluR1/GluR2 expression were significantly reduced in seipin-nKO mice, whereas the NMDA-induced current (INMDA) and NR1/NR2 expression were not altered. Rosi treatment in seipin-nKO mice could correct the decrease in expression and activity of AMPA receptor (AMPAR) and was accompanied by recovered synaptic function and LTP induction. Furthermore, hippocampal ERK2 and CREB phosphorylation in seipin-nKO mice were reduced and this could be rescued by rosi treatment. Rosi treatment in seipin-nKO mice elevated BDNF concentration. The MEK inhibitor U0126 blocked rosi-restored AMPAR expression and LTP induction in seipin-nKO mice, but the Trk family inhibitor K252a did not. These findings indicate that the neuronal seipin deficiency selectively suppresses AMPAR expression through reducing ERK-CREB activities, leading to the impairment of LTP and spatial memory, which can be rescued by PPARγ activation. SIGNIFICANCE STATEMENT: Congenital generalized lipodystrophy 2 (CGL2), caused by loss-of-function mutation of seipin gene, is characterized by mental retardation. By the generation of systemic or neuronal seipin knock-out mice, the present study provides in vivo evidence that neuronal seipin deficiency causes deficits in spatial memory and hippocampal LTP induction. Neuronal seipin deficiency selectively suppresses AMPA receptor expression, ERK-CREB phosphorylation with the decline of PPARγ. The PPARγ agonist rosiglitazone can ameliorate spatial cognitive deficits and rescue the LTP induction in seipin knock-out mice by restoring AMPA receptor expression and ERK-CREB activities.


Assuntos
Transtornos Cognitivos/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas Heterotriméricas de Ligação ao GTP/deficiência , PPAR gama/metabolismo , Receptores de AMPA/metabolismo , Tiazolidinedionas/uso terapêutico , Animais , Proteína de Ligação a CREB/metabolismo , Transtornos Cognitivos/genética , Modelos Animais de Doenças , Subunidades gama da Proteína de Ligação ao GTP , Proteínas Heterotriméricas de Ligação ao GTP/genética , Hipocampo/efeitos dos fármacos , Técnicas In Vitro , Potenciação de Longa Duração/efeitos dos fármacos , Potenciação de Longa Duração/genética , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Knockout , Técnicas de Patch-Clamp , Rosiglitazona , Comportamento Espacial/efeitos dos fármacos , Natação/psicologia
7.
Endocr Pract ; 23(5): 576-582, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28225307

RESUMO

OBJECTIVE: 17α-hydroxylase/17, 20-lyase deficiency (17OHD) is caused by mutations in the cytochrome P450 17A1 (CYP17A1) gene. To better understand 17OHD, a rare disease, we described the clinical features and performed CYP17A1 gene analysis in 8 affected Chinese patients. METHODS: Patients with complete (7/8) or partial (1/8) 17OHD were derived from 6 families. The diagnosis was established according to their clinical, biochemical, hormonal, and radiological characteristics. Long-term follow-up of some patients was also designed. RESULTS: Patients with 17OHD suffered from varying degrees of hypokalemia and hypertension. Symptoms in female patients with partial 17OHD manifested as secondary amenorrhea, recurrent ovarian cysts, elevated estradiol level, and lower follicle-stimulating hormone and luteinizing hormone levels; primary amenorrhea was typical in patients with complete 17OHD. Adrenal masses and decreased bone mineral density (BMD) were discovered in 2 patients, respectively. During long-term follow-up, 4 patients developed low BMD, while 3 individuals underwent respiratory infections and recurrent urinary tract infections. CYP17A1 gene analysis revealed 7 different kinds of mutation, including 1 novel mutation, L266V. CONCLUSION: The clinical characteristics of partial 17OHD were different from those of complete 17OHD. Low BMD and infections were common in patients with 17OHD on long-term steroid treatment. Seven mutations were identified in the CYP17A1 gene, and 1 was novel. ABBREVIATIONS: ACTH = adrenocorticotropic hormone BMD = bone mineral density CAH = congenital adrenal hyperplasia CT = computed tomography DEXA = dual-energy X-ray absorptiometry DEX = dexamethasone 17OHD = 17α-hydroxylase/17, 20-lyase deficiency.


Assuntos
Hiperplasia Suprarrenal Congênita/diagnóstico , Hiperplasia Suprarrenal Congênita/genética , Esteroide 17-alfa-Hidroxilase/genética , Transtornos 46, XX do Desenvolvimento Sexual/genética , Transtornos 46, XX do Desenvolvimento Sexual/patologia , Adolescente , Hiperplasia Suprarrenal Congênita/patologia , Hormônio Adrenocorticotrópico/sangue , Adulto , Amenorreia/genética , Amenorreia/patologia , China , Análise Mutacional de DNA , Feminino , Hormônio Foliculoestimulante/sangue , Disgenesia Gonadal 46 XY/genética , Disgenesia Gonadal 46 XY/patologia , Humanos , Adulto Jovem
8.
Proc Natl Acad Sci U S A ; 111(19): 7054-9, 2014 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-24778225

RESUMO

Obesity impairs male fertility, providing evidence for a link between adipose tissue and reproductive function; however, potential consequences of adipose tissue paucity on fertility remain unknown. Lack of s.c. fat is a hallmark of Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2), which is caused by mutations in BSCL2-encoding seipin. Mice with a targeted deletion of murine seipin model BSCL2 with severe lipodystrophy, insulin resistance, and fatty liver but also exhibit male sterility. Here, we report teratozoospermia syndrome in a lipodystrophic patient with compound BSCL2 mutations, with sperm defects resembling the defects of infertile seipin null mutant mice. Analysis of conditional mouse mutants revealed that adipocyte-specific loss of seipin causes progressive lipodystrophy without affecting fertility, whereas loss of seipin in germ cells results in complete male infertility and teratozoospermia. Spermatids of the human patient and mice devoid of seipin in germ cells are morphologically abnormal with large ectopic lipid droplets and aggregate in dysfunctional clusters. Elevated levels of phosphatidic acid accompanied with an altered ratio of polyunsaturated to monounsaturated and saturated fatty acids in mutant mouse testes indicate impaired phospholipid homeostasis during spermiogenesis. We conclude that testicular but not adipose tissue-derived seipin is essential for male fertility by modulating testicular phospholipid homeostasis.


Assuntos
Astenozoospermia/genética , Subunidades gama da Proteína de Ligação ao GTP/genética , Proteínas Heterotriméricas de Ligação ao GTP/genética , Infertilidade Masculina/genética , Lipodistrofia Generalizada Congênita/genética , Espermatozoides/metabolismo , Animais , Astenozoospermia/metabolismo , Astenozoospermia/patologia , Sequência de Bases , Epididimo/citologia , Epididimo/metabolismo , Estradiol/sangue , Feminino , Subunidades gama da Proteína de Ligação ao GTP/deficiência , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Proteínas Heterotriméricas de Ligação ao GTP/deficiência , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Humanos , Infertilidade Masculina/metabolismo , Infertilidade Masculina/patologia , Células Intersticiais do Testículo/citologia , Células Intersticiais do Testículo/metabolismo , Metabolismo dos Lipídeos/fisiologia , Lipodistrofia Generalizada Congênita/metabolismo , Lipodistrofia Generalizada Congênita/patologia , Hormônio Luteinizante/sangue , Masculino , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Linhagem , Gravidez , Túbulos Seminíferos/citologia , Túbulos Seminíferos/metabolismo , Espermatozoides/patologia , Testosterona/sangue
9.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 33(5): 666-9, 2016 Oct.
Artigo em Zh | MEDLINE | ID: mdl-27577218

RESUMO

OBJECTIVE: To detect potential mutation in a pedigree affected with congenital nephrogenic diabetes insipidus (NDI). METHODS: Clinical data of a male patient affected with NDI was collected. Genomic DNA was extracted from peripheral blood samples from the patient and five family members. The whole coding region of the arginine vasopressin receptor 2 (AVPR2) gene was amplified by PCR and directly sequenced. RESULTS: The patient presented polyuria and polydipsia postnatally. Computerized tomography revealed bilateral hydronephrosis and hydroureter. The patient was responsive to hydrochlorothiazide but not to desmopressin. DNA analysis identified a hemizygous missence mutation c.295 T>C in exon 2 of the AVPR2 gene in the proband. His mother and grandmother were both heterozygous for the same mutation. CONCLUSION: The congenital NDI in the patient was probably due to mutation of the AVPR2 gene.


Assuntos
Diabetes Insípido Nefrogênico/genética , Predisposição Genética para Doença/genética , Mutação , Receptores de Vasopressinas/genética , Adolescente , Sequência de Bases , Análise Mutacional de DNA , Diabetes Insípido Nefrogênico/congênito , Éxons/genética , Saúde da Família , Feminino , Humanos , Masculino , Linhagem
10.
Eur J Ophthalmol ; : 11206721241258637, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862403

RESUMO

PURPOSE: To quantify the presence of early structural alterations in the outer retinal layer and choroid among healthy subjects and diabetic patients with no or mild diabetic retinopathy, and to establish the correlation between the measured structural parameters and retinal sensitivity. METHODS: In total, 31 eyes from subjects with type 2 diabetes and 29 eyes from healthy subjects were enrolled. Optical coherence tomography was used to measure outer retina layers and choroid, while microperimetry was used to characterize the changes of visual function in a 6-mm diameter area at macula. Quantitative analysis of structural and functional changes was performed between groups and the structure-function correlations were determined. RESULTS: The thickness of myoid and ellipsoid zone, choroid and the mean retinal sensitivity were significantly smaller in diabetic group than that in controls (all P values < 0.05). Besides, thinner choroid and outer retina was associated with the decreased retinal sensitivity,especially in diabetic patients (r = 0.377, P = 0.048; r = 0.401, P = 0.034; respectively). Final multiple regression models showed the outer retinal thickness (ORT) (P = 0.033), choroidal thickness (P = 0.003) and the interaction between ORT and choroidal thickness (P = 0.001) were significant predictors to retinal sensitivity. CONCLUSIONS: Thinning of choroid and outer retina were significantly correlated with reduced retinal sensitivity, which indicate outer retina and choroid might be potential imaging markers for evaluation of visual function related to neural impairment in type 2 diabetic patients without or in the early stage of diabetic retinopathy.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA