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1.
J Phys Chem Lett ; 12(35): 8453-8459, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34448584

RESUMO

We perform a first-principles study and identify two intriguing ferromagnets, hollow-Fe8N (H-Fe8N) and bridge-Fe8N (B-Fe8N) monolayers, by extensive structural searches. Both H-Fe8N and B-Fe8N nanosheets are buckled triangular lattices with a similar motif, but they are distinguishable by the positions of N atoms. The magnetic and electronic properties show that H-Fe8N is a low-spin ferromagnet; in contrast, B-Fe8N is a high-spin ferromagnet, which originates from the 3d orbital splitting of the Fe atom due to the low/high symmetric crystal field. Surprisingly, two stable Fe8N monolayers can be transferred to each other by N atom diffusion from the bridge position to the hollow position with the migration energy barrier of 1.5 eV. The energy barrier is affected by introduced Fe defects and rare earth metal dopants. These findings introduce a new tactic to regulate the 2D Fe-nitride monolayers at the atomic scale.

2.
Medicine (Baltimore) ; 100(2): e24031, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33466148

RESUMO

RATIONALE: Osteonecrosis (ON) is a devastating illness that leads to bone ischemia and potential joint destruction. Systemic lupus erythematosus (SLE) is a chronic, autoimmune disease, with multi-system involvement which is closely associated with occurrence of ON. Multifocal ON, with an estimated morbidity of 3% in SLE patients, is extremely rare in juvenile subjects. PATIENT CONCERNS: A 13.3-year-old female SLE patient was admitted to hospital 20 months following the SLE diagnosis because of a sudden aggravation of sore knees. She suffered from double knee joint pain and her left knee joint showed typical signs of inflammation including redness, swelling, heat, and pain. DIAGNOSES: The SLE patient was diagnosed with multifocal ON of her knee joint based on magnetic resonance imaging findings of bone destruction and osteoproliferation at the bilateral distal femur and proximal tibia. INTERVENTIONS: The patient received high-dose methylprednisolone and intravenous cyclophosphamide pulse therapies for controlling active lupus and nephritis. Oral calcitriol and dipyridamole were administered to alleviate knee pain and inhibit thrombi formation, thereby suppressing ON progress. OUTCOMES: Three weeks following the treatment, the swelling in patient's left knee subsided. Her self-reporting pain score decreased from 9 to 4 and walking time increased from 45minutes to 90minutes per day. Nearly 5 weeks later, the pain in bilateral knee joints disappeared and the patient could walk without difficulties. LESSONS: This patient is the youngest SLE patient who developed multifocal ON based on the reported literature. It suggests that ON can occur in young SLE patients. A combination of internal and external risk factors can promote the development of ON. The balanced approach to the application of corticosteroids and immunosuppressors in the treatment of SLE and prevention of ON is a challenging problem that deserves further exploration.


Assuntos
Lúpus Eritematoso Sistêmico/complicações , Osteonecrose/complicações , Adolescente , Conservadores da Densidade Óssea/uso terapêutico , Calcitriol/uso terapêutico , Ciclofosfamida/uso terapêutico , Dipiridamol/uso terapêutico , Feminino , Humanos , Imunossupressores/uso terapêutico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Lúpus Eritematoso Sistêmico/patologia , Metilprednisolona/uso terapêutico , Osteonecrose/tratamento farmacológico , Osteonecrose/patologia , Inibidores da Agregação Plaquetária/uso terapêutico
3.
J Phys Chem Lett ; 11(22): 9643-9648, 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33125245

RESUMO

Low-dimensional materials with high stabilities and outstanding mechanical properties are essential for next generation microelectromechanical systems (MEMS). The successful synthesis of two-dimensional (2D) tungsten nitride makes it a promising candidate for the MEMS application. Here, we have confirmed the existence of experimentally synthesized W2N3 and predicted three additional new 2D monolayer tungsten nitrides: WN2, WN4, and W3N based on extensively structural searches by CALYPSO method and first-principle calculations. The calculations indicate that the nitrogen-rich WN4 monolayer possesses large in-plane negative Poisson ratios attributed to the 4-fold-coordinated WN4 νx = -0.103 and νy = -0.113, which are tetrahedron combined with the strong coupling between the 2p orbitals of N and 5d orbitals of W. Our findings not only enrich the family of 2D transition metal nitrides with excellent mechanical properties but also open avenues for design and synthesis of other novel 2D layered materials.

4.
Pediatr Radiol ; 48(8): 1108-1112, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29736770

RESUMO

BACKGROUND: Phalangeal microgeodic syndrome is an uncommon benign self-limiting condition that often occurs during cold weather. The etiology and the pathogenesis of the disease remain unclear. OBJECTIVE: To report a series of children with phalangeal microgeodic syndrome. MATERIALS AND METHODS: Twenty children with phalangeal microgeodic syndrome were retrospectively identified at our hospital after 2007. The clinical data, radiologic manifestation and pathologic appearance were analyzed. RESULTS: The average age was 10.3 years (range: 6.5-14.6 years). Twelve patients were boys. Twenty-five phalanges were affected radiographically (23 middle phalanges [92%] and 2 proximal phalanges [8%]). On radiographs, there were multiple small phalangeal lacunae in all cases. Metaphyseal rarefaction was seen in 15 phalanges, and metaphyseal transverse lucent bands were found in 7 phalanges. Epiphyseal rarefaction was seen in three phalanges. On magnetic resonance imaging (MRI), diffuse signal abnormalities of affected phalanges were observed in all cases. Multiple other phalanges and metacarpals also showed marrow edema in three cases. CONCLUSION: Phalangeal microgeodes may represent bone absorption and destruction in response to exaggerated peripheral circulatory impairment following chilblain, and mainly occur in bone growth spurts.


Assuntos
Doenças Ósseas/diagnóstico por imagem , Falanges dos Dedos da Mão/diagnóstico por imagem , Imageamento por Ressonância Magnética , Adolescente , Biópsia , Doenças Ósseas/patologia , Criança , Temperatura Baixa , Edema/diagnóstico por imagem , Edema/patologia , Feminino , Falanges dos Dedos da Mão/patologia , Humanos , Masculino , Estudos Retrospectivos , Síndrome
5.
Appl Microbiol Biotechnol ; 102(4): 1837-1846, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29327068

RESUMO

Escherichia coli (E. coli) is associated with an array of health-threatening contaminations, some of which are related to biofilm states. The pgaABCD-encoded poly-beta-1,6-N-acetyl-D-glucosamine (PGA) polymer plays an important role in biofilm formation. This study was conducted to determine the inhibitory effect of gallic acid (GA) against E. coli biofilm formation. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of GA against planktonic E. coli were 0.5 and 4 mg/mL, and minimal biofilm inhibitory concentration and minimal biofilm eradication concentration values of GA against E. coli in biofilms were 2 and 8 mg/mL, respectively. Quantitative crystal violet staining of biofilms and ESEM images clearly indicate that GA effectively, dose-dependently inhibited biofilm formation. CFU counting and confocal laser scanning microscopy measurements showed that GA significantly reduced viable bacteria in the biofilm. The contents of polysaccharide slime, protein, and DNA in the E. coli biofilm also decreased. qRT-PCR data showed that at the sub-MIC level of GA (0.25 mg/mL) and expression of pgaABC genes was downregulated, while pgaD gene expression was upregulated. The sub-MBC level of GA (2 mg/mL) significantly suppressed the pgaABCD genes. Our results altogether demonstrate that GA inhibited viable bacteria and E. coli biofilm formation, marking a novel approach to the prevention and treatment of biofilm-related infections in the food industry.


Assuntos
Antibacterianos/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Proteínas de Escherichia coli/biossíntese , Escherichia coli/efeitos dos fármacos , Ácido Gálico/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Contagem de Colônia Microbiana , Escherichia coli/fisiologia , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Microscopia Confocal , Reação em Cadeia da Polimerase em Tempo Real , Coloração e Rotulagem/métodos , beta-Glucanas/metabolismo
6.
Biomed Res Int ; 2016: 4720785, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27652262

RESUMO

Background. The objective of this study was to investigate the independent and combined effects of maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) on offspring growth at 0-3 years old. Methods. A total of 826 pairs of nondiabetic mothers and their offspring were recruited in this study. Maternal information was abstracted from medical records and questionnaires. Offspring growth trajectories of weights and BMIs were depicted based on anthropometric measurements. Results. Offspring of mothers who were prepregnancy overweight/obese or obtained excessive GWGs continuously had greater weight and BMI Z-scores throughout the first 3 years of life. Children of prepregnancy overweight/obese mothers with excessive GWGs had a phenotype of higher weight and BMI Z-scores than those prepregnancy overweight/obese ones with nonexcessive GWGs from birth to 18 months. Maternal excessive GWGs increased offspring's risk of overweight/obesity at 12 months (AOR = 1.43, 95% CI: 1.03-2.00) and 24 months (AOR = 1.51, 95% CI: 1.02-2.25). Combination of excessive prepregnancy BMIs and GWGs was significantly associated with offspring's overweight/obesity at 30 months (AOR = 2.98, 95% CI: 1.36-6.53). Conclusions. Maternal prepregnancy overweight/obesity and excessive GWG are both significantly associated with rapid offspring growth from birth to 3 years old. Excessive GWGs strengthen the effects of high maternal prepregnancy BMIs on excessive offspring growth during their early life.


Assuntos
Peso ao Nascer , Índice de Massa Corporal , Desenvolvimento Infantil , Obesidade , Complicações na Gravidez , Adulto , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Gravidez
7.
BMC Pregnancy Childbirth ; 16: 60, 2016 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-27000102

RESUMO

BACKGROUND: Dyslipidemia in pregnancy are associated with gestational diabetes mellitus (GDM), preeclampsia, preterm birth and other adverse outcomes, which has been extensively studied in western countries. However, similar studies have rarely been conducted in Asian countries. Our study was aimed at investigating the associations between maternal dyslipidemia and adverse pregnancy outcomes among Chinese population. METHODS: Data were derived from 934 pairs of non-diabetic mothers and neonates between 2010 and 2011. Serum blood samples were assayed for fasting total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C) concentrations during the first, second and third trimesters. The present study explored the associations between maternal lipid profile and pregnancy complications and perinatal outcomes. The pregnancy complications included GDM, preeclampsia and intrahepatic cholestasis of pregnancy (ICP); the perinatal outcomes included preterm birth, small/large for gestational age (SGA/LGA) infants and macrosomia. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated and adjusted via stepwise logistic regression analysis. Optimal cut-off points were determined by ROC curve analysis. RESULTS: After adjustments for confounders, every unit elevation in third-trimester TG concentration was associated with increased risk for GDM (OR = 1.37, 95% CI: 1.18-1.58), preeclampsia (OR = 1.50, 95% CI: 1.16-1.93), ICP (OR = 1.28, 95% CI: 1.09-1.51), LGA (OR = 1.13, 95% CI: 1.02-1.26), macrosomia (OR = 1.19, 95% CI: 1.02-1.39) and decreased risk for SGA (OR = 0.63, 95% CI: 0.40-0.99); every unit increase in HDL-C concentration was associated with decreased risk for GDM and macrosomia, especially during the second trimester (GDM: OR = 0.10, 95% CI: 0.03-0.31; macrosomia: OR = 0.25, 95% CI: 0.09-0.73). The optimal cut-off points for third-trimester TG predicting GDM, preeclampsia, ICP, LGA and SGA were separately ≥ 3.871, 3.528, 3.177, 3.534 and ≤ 2.530 mmol/L. The optimal cut-off points for third-trimester HDL-C identifying GDM, macrosomia and SGA were respectively ≤ 1.712, 1.817 and ≥ 2.238 mmol/L. CONCLUSIONS: Among Chinese population, maternal high TG in late pregnancy was independently associated with increased risk of GDM, preeclampsia, ICP, LGA, macrosomia and decreased risk of SGA. Relative low maternal HDL-C during pregnancy was significantly associated with increased risk of GDM and macrosomia; whereas relative high HDL-C was a protective factor for both of them.


Assuntos
Lipídeos/sangue , Complicações na Gravidez/sangue , Resultado da Gravidez , Trimestres da Gravidez/sangue , Adulto , Peso ao Nascer , China , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Diabetes Gestacional/sangue , Jejum/sangue , Feminino , Macrossomia Fetal/etiologia , Idade Gestacional , Humanos , Recém-Nascido , Razão de Chances , Pré-Eclâmpsia/sangue , Gravidez , Nascimento Prematuro/etiologia , Curva ROC , Fatores de Risco , Triglicerídeos/sangue , Adulto Jovem
8.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 44(1): 101-7, 2015 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-25851984

RESUMO

Low-density lipoprotein receptor (LDLR) and metabolic syndrome (MS) are closely correlated. Changes in LDLR expression, feedback regulation and degradation, impacts of LDLR deficiency on blood lipid levels, roles of LDLR in islet ß cell dysfunction and cholesterol homeostasis dysregulation, expression of LDLR gene nuclear transcription factors and polymorphism of LDLR gene segments are all involved in the development of specific components of MS. In recent years, a variety of targets and intervention mechanisms in relation to LDLR and MS have been extensively studied. Knowledge about association between LDLR and MS may contribute to the development of strategies for prevention and treatment of MS. This article reviews the update on the association between LDLR and MS.


Assuntos
Lipoproteínas LDL , Síndrome Metabólica , Receptores de LDL , Homeostase , Humanos , Metabolismo dos Lipídeos
9.
Med Sci Monit ; 20: 2097-105, 2014 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-25357084

RESUMO

BACKGROUND: Small- and large-for-gestational-age (SGA, LGA) newborns are associated with metabolic syndrome in their later life. Cord blood C-peptide, insulin, glycosylated hemoglobin (HbA1c), and lipids levels may be altered in SGA and LGA newborns; however, the results are conflicting. Therefore, this study aimed to determine the effect of cord blood markers on SGA and LGA newborns. MATERIAL AND METHODS: This was a prospective cohort study and included 2873 term newborns of non-diabetic women. Among these newborns, 83 (2.9%) were SGA, 2236 (77.8%) were appropriate-for-gestational-age (AGA), and 554 (19.3%) were LGA newborns. Cord blood C-peptide, insulin, HbA1c, triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels were measured. The chi-square, Kruskal-Wallis, and Mann-Whitney tests were used to analyze categorical variables and continuous variables, respectively. Multinomial logistic regression analysis was used to determine the independent effect of these variables on SGA and LGA newborns. RESULTS: Cord serum TG level was significantly higher in the SGA group than in AGA and LGA groups (p<0.05). The LGA group had significantly higher cord serum insulin level than AGA and SGA groups (p<0.05). After adjustment for confounding variables, including maternal age, parity, pre-pregnancy body mass index (BMI), education, annual household income, pregnancy-induced hypertension (PIH), mode of delivery, and newborn sex, high TG and insulin levels remained significantly associated with SGA and LGA newborns, respectively (p<0.05). CONCLUSIONS: High cord serum TG and insulin levels are independently associated with SGA and LGA newborns, respectively.


Assuntos
Peso ao Nascer , Sangue Fetal/metabolismo , Idade Gestacional , Hemoglobina A Glicada/metabolismo , Insulina/sangue , Lipídeos/sangue , Adulto , Feminino , Humanos , Recém-Nascido , Gravidez , Estudos Prospectivos , Adulto Jovem
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