Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nat Mater ; 21(7): 748-753, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35710632

RESUMO

One-dimensional electron systems exhibit fundamentally different properties than higher-dimensional systems. For example, electron-electron interactions in one-dimensional electron systems have been predicted to induce Tomonaga-Luttinger liquid behaviour. Naturally occurring grain boundaries in single-layer transition metal dichalcogenides exhibit one-dimensional conducting channels that have been proposed to host Tomonaga-Luttinger liquids, but charge density wave physics has also been suggested to explain their behaviour. Clear identification of the electronic ground state of this system has been hampered by an inability to electrostatically gate such boundaries and tune their charge carrier concentration. Here we present a scanning tunnelling microscopy and spectroscopy study of gate-tunable mirror twin boundaries in single-layer 1H-MoSe2 devices. Gating enables scanning tunnelling microscopy and spectroscopy for different mirror twin boundary electron densities, thus allowing precise characterization of electron-electron interaction effects. Visualization of the resulting mirror twin boundary electronic structure allows unambiguous identification of collective density wave excitations having two velocities, in quantitative agreement with the spin-charge separation predicted by finite-length Tomonaga-Luttinger liquid theory.

2.
Nature ; 546(7657): 265-269, 2017 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-28445468

RESUMO

The realization of long-range ferromagnetic order in two-dimensional van der Waals crystals, combined with their rich electronic and optical properties, could lead to new magnetic, magnetoelectric and magneto-optic applications. In two-dimensional systems, the long-range magnetic order is strongly suppressed by thermal fluctuations, according to the Mermin-Wagner theorem; however, these thermal fluctuations can be counteracted by magnetic anisotropy. Previous efforts, based on defect and composition engineering, or the proximity effect, introduced magnetic responses only locally or extrinsically. Here we report intrinsic long-range ferromagnetic order in pristine Cr2Ge2Te6 atomic layers, as revealed by scanning magneto-optic Kerr microscopy. In this magnetically soft, two-dimensional van der Waals ferromagnet, we achieve unprecedented control of the transition temperature (between ferromagnetic and paramagnetic states) using very small fields (smaller than 0.3 tesla). This result is in contrast to the insensitivity of the transition temperature to magnetic fields in the three-dimensional regime. We found that the small applied field leads to an effective anisotropy that is much greater than the near-zero magnetocrystalline anisotropy, opening up a large spin-wave excitation gap. We explain the observed phenomenon using renormalized spin-wave theory and conclude that the unusual field dependence of the transition temperature is a hallmark of soft, two-dimensional ferromagnetic van der Waals crystals. Cr2Ge2Te6 is a nearly ideal two-dimensional Heisenberg ferromagnet and so will be useful for studying fundamental spin behaviours, opening the door to exploring new applications such as ultra-compact spintronics.

3.
Zhonghua Bing Li Xue Za Zhi ; 50(4): 369-375, 2021 Apr 08.
Artigo em Zh | MEDLINE | ID: mdl-33831997

RESUMO

Objective: To analyze the expression of mismatch repair (MMR) proteins in colorectal cancers (CRC) and to evaluate the feasibility and potential pitfalls of immunohistochemistry (IHC) analysis for MMR. Methods: The IHC sections for MMR proteins were reviewed in 3 428 cases of resected CRC without neoadjuvant therapy at Tianjin Medical University Cancer Institute and Hospital from July 2014 to October 2018. For the cases with unclear MMR IHC results during the initial review, IHC staining was repeated and microsatellite instability (MSI) analysis was performed. Relationships between the expression of MMR proteins and MSI status as well as the clinicopathological parameters were analyzed. Results: IHC staining for MMR was repeated in 28 (0.8%) cases due to poor quality of original IHC sections. Inconsistent results between the original diagnosis and re-diagnosis were found in 119 (3.5%) cases, mainly resulting from PMS2 and MLH1. Finally, 261 (7.6%) cases of CRC showed mismatch repair deficiency (dMMR), mainly from the deficiency of both MLH1 and PMS2 (43.3%,113/261). In the 14 cases with MSI results, the concordant of MSI and MMR was 13 cases. In the 29 dMMR cases with next generation sequencing (NGS) results, the concordant of MSI-high and dMMR was 93.1%(27/29). The cases with inconsistent results between MSI and MMR showed negative expression of MSH6 or PMS2. Twenty-one CRC showed negative expression of MLH1 and partially positive (or weak positive) expression of PMS2, or negative expression of MSH2 and partially positive (or weak positive) expression of MSH6. Among the 19 cases with MSI results, 16 cases were MSI-high, two cases were MSI-low, and one case was microsatellite stable. Compared with mismatch repair proficiency (pMMR), dMMR was more frequently detected in female patients younger than 50 years old, with family history, at early stage (Ⅰ-Ⅱ) CRC, and in the tumors from right colon,with poor differentiation, or mucinous adenocarcinoma/signet ring cell carcinoma (all P<0.05). Conclusions: At present, IHC staining is a clinically effective and convenient method to detect MMR expression, but the operating process and result assessment remain variable and need to be standardized. MSI analysis can be performed in the difficult-to-evaluate cases for MMR to enhance prognostic evaluation and treatment option.


Assuntos
Neoplasias Colorretais , Reparo de Erro de Pareamento de DNA , Neoplasias Colorretais/genética , Reparo de Erro de Pareamento de DNA/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Endonuclease PMS2 de Reparo de Erro de Pareamento/metabolismo , Proteína 1 Homóloga a MutL/genética , Proteína 1 Homóloga a MutL/metabolismo , Proteína 2 Homóloga a MutS/metabolismo , Estudos Retrospectivos
4.
Neoplasma ; 67(5): 1002-1011, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32453597

RESUMO

Renal cell carcinoma (RCC) is the most common malignant tumor of the kidney. In this study, we investigated the role of miR-346 in RCC cells under hypoxia. OS-RC-2 and 786-O cells were cultured in 1% O2 or normal oxygen. Cell proliferation, migration, and invasion abilities were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, transwell migration, and invasion assays, respectively. Quantitative real-time PCR (qRT-PCR) was performed to detect the expression of miR-346 and N-myc downstream-regulated gene 2 (NDRG2). Then bioinformatics analysis, dual-luciferase reporter assay, and RNA immunoprecipitation were carried out to determine the relationship between miR-346 and NDRG2. The protein expression of NDRG2 was detected by western blot assay. Hypoxia promoted cell proliferation, migration, and invasion in OS-RC-2 and 786-O cells. Meanwhile, we found that miR-346 was upregulated in RCC cells under hypoxia as relative to normoxia. miR-346 deletion could decrease the viability, migration, and invasion abilities of RCC cells under hypoxia. Besides, our data demonstrated that NDRG2 was a target gene of miR-346. The expression of NDRG2 in OS-RC-2 and 786-O cells was lower under hypoxia than under normal oxygen conditions. Moreover, NDRG2 overexpression could inhibit cell proliferation, migration, and invasion in RCC cells under hypoxia. And NDRG2 silencing reversed the inhibitory effects of the miR-346 inhibitor on the viability, migration, and invasion abilities of RCC cells in hypoxia conditions. miR-346 promoted the viability, migration, and invasion of RCC cells under hypoxia by targeting NDRG2.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , MicroRNAs/genética , Proteínas Supressoras de Tumor/genética , Carcinoma de Células Renais/genética , Hipóxia Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Humanos , Neoplasias Renais/genética
5.
Zhonghua Yu Fang Yi Xue Za Zhi ; 53(9): 907-912, 2019 Sep 06.
Artigo em Zh | MEDLINE | ID: mdl-31474072

RESUMO

Objective: To explore the blood lead level and its relationship with behavior in school-age children from rural areas of Chongqing. Methods: A total of 697 students from grades 3 to 6 in the fall semester of 2014 from 14 rural townships in one district of Chongqing was selected by using the random cluster sampling method. Blood were sampled to analyze the lead level. Neurobehavioral tests were performed to determine their personal cognitive and memory ability. Questionnaires and physical examinations were administered to obtain the information of confounding factors. All students were divided into Q1-Q4 groups according to the quartile of their blood lead level. The relationship between the blood lead level and behavior was analyzed by multivariate logistic regression model and restricted spline regression model. Results: The mean age of 697 students was (10.07±1.36) years old, and the median (interquartile range) of their blood lead level was 44.31 (35.42) µg/L. Multivariate logistic regression model showed that after adjusting for age, gender, body mass index and maternal culture level, compared with Q1 group, the OR (95%CI) values of high digit symbol substitution test (DSST) scores and high overall memory quotient (MQ) scores in Q3 group were 1.65 (1.01-2.70) and 2.10 (1.21-3.62), and the OR (95%CI) value of high long term memory (LTM) scores in Q4 group was 0.53 (0.31-0.92). The results of the restricted spline regression model showed that the dose-response curves between the blood lead level and MQ/LTM test scores were both parabolic (P<0.05). Conclusion: The blood lead level of school-age children from rural areas of Chongqing is the same as that from other areas of China, but slightly higher than that from other areas of Chongqing. Children with higher blood lead level have poor long-term memory ability.


Assuntos
Comportamento Infantil , Chumbo , População Rural , Estudantes , Criança , China , Humanos , Chumbo/sangue , População Rural/estatística & dados numéricos , Estudantes/estatística & dados numéricos , Inquéritos e Questionários
6.
Zhonghua Nei Ke Za Zhi ; 57(4): 264-269, 2018 Apr 01.
Artigo em Zh | MEDLINE | ID: mdl-29614584

RESUMO

Objective: To analyze the clinical features of secondary gout in glycogen storage disease type Ⅰa (GSD Ⅰa), so as to improve the awareness of this disease. Methods: The clinical features, laboratory findings, treatments and prognosis of 5 GSD Ⅰa patients with secondary gout who had been admitted to the Peking Union Medical College Hospital during 2006 to 2016 were collected and analyzed. GSD Ⅰa was confirmed by liver biopsy and genotyping. Results: Among the 5 patients (median age: 27 years), 3 were males and 2 were females. The mean age of gout onset was 17 ranging from 10 to 22 years old. The common manifestations of GSD included hepatomegaly since childhood, hypoglycemia, growth retardation, anemia, hyperlactacidemia and hyperlipidemia. All the 5 patients were complicated with gouty tophi and kidney stone. Gouty tophi and kidney stone were identified 3.8 years and 10.2 years after the first occurrence of articular symptoms, respectively. Renal damage occurred in 3 cases. All the patients underwent several therapeutic modalities including lifestyle intervention, allopurinol, and raw corn starch treatment. Conclusions: Determination of the presence of primary disease should be performed actively for young-onset gout with early occurrence of gouty tophi. GSD should be suspected if there exist clinical manifestations like hepatomegaly, recurrent hypoglycemia, growth retardation. Early management of hyperuricemia and gout in GSD patients is important to prevent complications and improve prognosis.


Assuntos
Doença de Depósito de Glicogênio Tipo I/diagnóstico , Gota/complicações , Gota/etiologia , Adolescente , Adulto , Biópsia , Criança , Feminino , Genótipo , Doença de Depósito de Glicogênio Tipo I/complicações , Doença de Depósito de Glicogênio Tipo I/genética , Gota/diagnóstico , Humanos , Hiperuricemia/complicações , Rim , Cálculos Renais/complicações , Masculino , Adulto Jovem
8.
Zhonghua Yu Fang Yi Xue Za Zhi ; 51(6): 539-545, 2017 Jun 06.
Artigo em Zh | MEDLINE | ID: mdl-28592100

RESUMO

Objective: To investigate the association between aflatoxin exposure and primary hepatocellular carcinoma (PHC) development. Methods: From December 2013 to May 2016, we selected 214 patients newly diagnosed with PHC as cases, and 214 patients as controls from three hospitals in Chongqing. Cases were confirmed with PHC diagnosis standard. And cases caused by clear reasons such as drug-induced liver injury, alcoholic liver damage, fatty liver and gallstones etiology, were excluded. Controls were included with no cancer and no digestive system disease, and recruited simultaneously with cases. Cases and controls were frequency-matched (1∶1) by same gender and age (±3 years). Peripheral blood and random urine samples were collected and analyzed for serum HBsAg status by biochemistry analyzer, and serum AFB(1)-ALB adduct and urinary AFB(1)-N(7)-GUA adduct by ELISA. Basic information, living habits and history of disease for patients were obtained by questionnaires. We used wilcoxon rank sum test to compare the median of serum AFB(1)-ALB adduct and urinary AFB(1)-N(7)-GUA adduct in cases and controls. Logistic regression analyses were performed to assess risk factors for PHC, and synergism index (S) of aflatoxin with other factors was estimated by the method of Andersson. Results: There was no significant difference in age between PHC cases (50.74±9.67) years and controls (51.15±9.90) years. Logistic regression showed that the odds ratio of HBV infection for PHC development was 46.3 (95% CI: 23.3-88.0). There was a significant difference in median concentrations of serum AFB(1)-ALB adduct (cases vs controls: 146.23 vs 74.42 ng/g albumin, P<0.001), but no difference in median concentrations of urinary AFB(1)-N(7)-GUA adduct was observed (cases vs controls: 0.17 vs 0.14 ng/mg creatinine, P<0.210). The odd ratios for PHC risk after adjustment were 1.9 (95%CI: 1.1-3.4) for AFB(1)-ALB adduct, and 2.1 (95%CI: 1.0-4.2) for AFB(1)-N(7)-GUA adduct. Moreover, we observed a positive interaction of aflatoxin exposure with HBV, alcohol drinking, and diabetes. The S was 4.7 (95%CI: 2.8-7.9), 3.5 (95%CI: 1.0-12.0), and 12.4 (95%CI: 1.8-84.2), respectively for serum AFB(1)-ALB adduct with each of the three factors mentioned, and was 1.9 (95%CI:1.1-3.1), 2.0 (95%CI: 1.1-3.6), and 2.0 (95%CI: 1.1-3.6), respectively for urinary AFB(1)-N(7)-GUA adduct with each of the three factors mentioned. Conclusion: HBV was still the main risk factor, and AFB(1) exposure was also an independent risk factor for PHC in Chongqing. There was a positive interaction of aflatoxin with HBV, alcohol drinking, and diabetes.


Assuntos
Aflatoxina B1/toxicidade , Carcinoma Hepatocelular/induzido quimicamente , Neoplasias Hepáticas/induzido quimicamente , Aflatoxina B1/sangue , Aflatoxina B1/urina , Aflatoxinas/toxicidade , Consumo de Bebidas Alcoólicas , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Humanos , Modelos Logísticos , Masculino , Fatores de Risco
9.
Phys Rev Lett ; 117(7): 076602, 2016 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-27563981

RESUMO

Despite recent progress in spin-current research, the detection of spin current has mostly remained indirect. By synchronizing a microwave waveform with synchrotron x-ray pulses, we use the ferromagnetic resonance of the Py (Ni_{81}Fe_{19}) layer in a Py/Cu/Cu_{75}Mn_{25}/Cu/Co multilayer to pump a pure ac spin current into the Cu_{75}Mn_{25} and Co layers, and then directly probe the spin current within the Cu_{75}Mn_{25} layer and the spin dynamics of the Co layer by x-ray magnetic circular dichroism. This element-resolved pump-probe measurement unambiguously identifies the ac spin current in the Cu_{75}Mn_{25} layer.

10.
Phys Rev Lett ; 113(14): 147207, 2014 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-25325659

RESUMO

Fe/NiO/Fe/CoO/Ag(001) single crystalline films were grown epitaxially and investigated by x-ray magnetic circular dichroism and x-ray magnetic linear dichroism. The bottom Fe layer magnetization is pinned through exchange coupling to the CoO layer and the top Fe layer magnetization can be rotated by an in-plane external magnetic field. We find that the NiO spins wind up to form a domain wall due to the perpendicular NiO/Fe interfacial coupling as the top layer Fe magnetization rotates from 0° to 90°, but switch wall chirality and unwind the wall as the Fe magnetization rotates from 90° to 180°. This observation shows that Mauri's 180° domain wall does not exist in perpendicularly coupled ferromagnetic-antiferromagnetic systems in the strong coupling regime.

11.
Zhonghua Er Ke Za Zhi ; 62(6): 526-529, 2024 Jun 02.
Artigo em Zh | MEDLINE | ID: mdl-38763873

RESUMO

Objective: To investigate the safety, efficacy and effective dose of empagliflozin in the treatment of glycogen storage disease type Ⅰb (GSD Ⅰb). Method: This was a cross sectional study. A total of 28 children with GSDⅠb who started oral empagliflozin treatment from January 2021 to June 2023 in the WeChat group of patients with glycogen storage disease were selected as the study objects. Clinical data such as general situation, current situation of medication and adverse reactions of the children were collected through questionnaires from June 18 to 30, 2023. The differences of symptoms and laboratory tests before and after empagliflozin treatment were compared by using paired chi-square test and Wilcoxon signed rank sum test. Results: Totally 28 children with GSD Ⅰb were from 12 different provinces, autonomous regions and municipalities in China. There were 14 males and 14 females. Empagliflozin treatment was started at the age of 4.8 (2.4, 10.8) years, the time of treatment was 14.5 (11.3, 21.5) months, the initial dosage was (0.23±0.11) mg/(kg·d), and the maintenance dosage was (0.28±0.12) mg/(kg·d). Empagliflozin showed positive effects on neutropenia, severity of inflammatory bowel disease like symptoms(Z=-3.70, -2.65, both P<0.05), The proportion of recurrent oral ulcers, recurrent bacterial infections and anemia was significantly lower than that before medication (18% (5/28) vs. 46% (13/28), 14% (4/28) vs. 46% (13/28), 21% (6/28) vs. 46% (13/28), χ²=4.05, 5.26, 3.05, all P<0.05). Granulocyte colony-stimulating factor (GCSF) was once used in 5 children with GSD Ⅰb, all of them had completely stopped GCSF after empagliflozin treatment. The most common adverse events during empagliflozin treatment were hypoglycemia (5 children) and urinary infection (3 children). All 28 patients had no serious adverse reactions. Conclusions: Empagliflozin can increase the neutrophil count of children with GSD Ⅰb, and had a favorable effect on symptoms such as recurrent oral ulcers, and recurrent infection. The common adverse events during empagliflozin treatment were hypoglycemia and urinary infection.


Assuntos
Compostos Benzidrílicos , Glucosídeos , Doença de Depósito de Glicogênio Tipo I , Humanos , Compostos Benzidrílicos/uso terapêutico , Compostos Benzidrílicos/administração & dosagem , Glucosídeos/administração & dosagem , Glucosídeos/uso terapêutico , Feminino , Masculino , Criança , Doença de Depósito de Glicogênio Tipo I/tratamento farmacológico , Pré-Escolar , Estudos Transversais , Resultado do Tratamento , Inibidores do Transportador 2 de Sódio-Glicose/administração & dosagem , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , China , Hipoglicemia/tratamento farmacológico
12.
Phys Rev Lett ; 110(17): 177204, 2013 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-23679766

RESUMO

Using spin-polarized low energy electron microscopy, we discovered a new type of domain wall structure in perpendicularly magnetized Fe/Ni bilayers grown epitaxially on Cu(100). Specifically, we observed unexpected Néel-type walls with fixed chirality in the magnetic stripe phase. Furthermore, we find that the chirality of the domain walls is determined by the film growth order with the chirality being right handed in Fe/Ni bilayers and left handed in Ni/Fe bilayers, suggesting that the underlying mechanism is the Dzyaloshinskii-Moriya interaction at the film interfaces. Our observations may open a new route to control chiral spin structures using interfacial engineering in transition metal heterostructures.

13.
Zhonghua Er Ke Za Zhi ; 61(6): 515-519, 2023 Jun 02.
Artigo em Zh | MEDLINE | ID: mdl-37312462

RESUMO

Objective: To analyze the short-time efficacy of empagliflozin in the treatment of glycogen storage disease type Ⅰb (GSD Ⅰb). Methods: In this prospective open-label single-arm study, the data of 4 patients were collected from the pediatric department in Peking Union Medical College Hospital from December 2020 to December 2022. All of them were diagnosed by gene sequencing and had neutropenia. These patients received empagliflozin treatment. Their clinical symptoms such as height and weight increase, abdominal pain, diarrhea, oral ulcer, infection times, and drug applications were recorded at 2 weeks, 1 month, 2 months, 3 months, 6 months, 9 months, 12 months, and 15 months after treatment to assess the therapeutic effect. The liquid chromatography-tandem mass spectrometry method was used to monitor the changes in 1, 5-anhydroglucitol (1, 5AG) concentration in plasma. At the same time, adverse reactions such as hypoglycemia and urinary tract infection were closely followed up and monitored. Results: The 4 patients with GSD Ⅰb were 15, 14, 4 and 14 years old, respectively at the beginning of empagliflozin treatment, and were followed up for 15, 15, 12 and 6 months, respectively. Maintenance dose range of empagliflozin was 0.24-0.39 mg/(kg·d). The frequency of diarrhea and abdominal pain decreased in cases 2, 3, and 4 at 1, 2 and 3 months of treatment, respectively. Their height and weight increased at different degrees.The absolute count of neutrophils increased from 0.84×109, 0.50×109, 0.48×109, 0.48×109/L to 1.48×109, 3.04×109, 1.10×109, 0.73×109/L, respectively. Granulocyte colony-stimulating factor was gradually reduced in 1 patients and stopped in 3 patient. Plasma 1, 5 AG levels in 2 children were significantly decreased after administration of empagliflozin (from 46.3 mg/L to 9.6 mg/L in case 2, and from 56.1 mg/L to 15.0 mg/L in case 3). All 4 patients had no adverse reactions such as hypoglycemia, abnormal liver or kidney function, or urinary system infection. Conclusion: In short-term observation, empagliflozin can improve the symptoms of GSD Ⅰb oral ulcers, abdominal pain, diarrhea, and recurrent infection, also can alleviate neutropenia and decrease 1, 5AG concentration in plasma, with favorable safety.


Assuntos
Doença de Depósito de Glicogênio Tipo I , Hipoglicemia , Neutropenia , Humanos , Criança , Pré-Escolar , Adolescente , Estudos Prospectivos , Doença de Depósito de Glicogênio Tipo I/tratamento farmacológico , Dor Abdominal , Diarreia/tratamento farmacológico
14.
Zhonghua Er Ke Za Zhi ; 59(6): 466-470, 2021 Jun 02.
Artigo em Zh | MEDLINE | ID: mdl-34102819

RESUMO

Objective: To enhance the early recognition of Prader-Willi syndrome by summarizing the clinical characteristics of Prader-Willi syndrome (PWS) during perinatal period. Methods: Through a nationwide cross-sectional study in the Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences,226 children diagnosed as PWS by molecular genetics were recruited from September 2019 to March 2020. Clinical data including fetuses Age, birth weight, fetal movement, fetal position, amniotic fluid, mode of bith, crying, muscle tension, feeding, and cryptorchidism were collected to analyze the clinical characteristics of Chinese PWS patients in the perinatal period, and according to the mode of birty, birth weight and genotypes to perform subgroup analysis. The clinical manifestations of different subtypes were statistically analyzed by t test, χ2 test or Mann-Whitney U test. Results: Among the 226 PWS patients, 120 were males, and 106 were females. Among them, 100 (44.2%) patients were small for gestational age. Decreased fetal movement was the most common manifestation 202 cases (89.4%) during pregnancy, and other manifestations included polyhydramnios 71 cases (31.4%) and abnormal fetal position 58 cases (25.7%). One hundred and eighty-five (81.9%) patients were delivered by cesarean section and the frequency of abnormal fetal position was significantly higher (30.8%(57/185) vs. 2.4%(1/41),χ²=14.161,P<0.01). As for abnormal manifestations after birth included hypotonia 221 cases (97.8%),220 cases (97.3%) showing weak crying, 116 cases among the total 120 males patients (96.7%) wanifested with cryptordnildism and 206 feeding difficulties (91.2%). In terms of genetic subtype, most of them (184/226, 81.4%) had a paternal deletion, while maternal age (35±5 vs. 29±5, t=-6.591, P<0.01) and the frequency of polyhydramnios (47.6% (20/42) vs. 27.7% (51/185), χ²=6.286, P=0.012) were significantly higher in the non-deletion group. Conclusions: The main manifestations of PWS patients during the perinatal period are hypotonia, weak crying, feeding difficulties, decreased fetal movement, cryptorchidism and those patients are more likely to be born by cesarean section. In newborns with these characteristics, pediatricians should be aware of the possibility of PWS. In terms of the relationship between genotypes and phenotypes, polyhydramnios is more frequently observed in the non-deletion group.


Assuntos
Síndrome de Prader-Willi , Cesárea , Criança , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Recém-Nascido , Masculino , Hipotonia Muscular , Síndrome de Prader-Willi/epidemiologia , Síndrome de Prader-Willi/genética , Gravidez
15.
Zhonghua Wei Chang Wai Ke Za Zhi ; 24(5): 440-448, 2021 May 25.
Artigo em Zh | MEDLINE | ID: mdl-34000774

RESUMO

Objective: To analyze the expression of mismatch repair (MMR) protein and the EB virus infection in gastric adenocarcinoma, and to examine the association of MMR expression and EB virus infection with clinicopathological parameters. Methods: A case-control study was performed. Clinicopathological data of patients who was pathologically diagnosed as gastric adenocarcinoma, received radical gastrectomy and had complete clinicopathological data from August 2017 to April 2020 in Tianjin Medical University Cancer Institute and Hospital were retrospectively collected and analyzed. The immunohistochemistry (IHC) of MMR proteins and in situ hybridization (ISH) of Epstein-Barr virus encoded RNA (EBER) were reviewed. The associations of MMR and EBER results with clinicopathological parameters were analyzed. The main observations of the study were MMR and EBER expression, and association of MMR and EBER results with clinicopathological parameters. Results: Eight hundred and eighty-six patients were enrolled, including 98 patients who received preoperative neoadjuvant chemoradiotherapy. Of 886 patients, 613 (69.2%) were males and the median age was 60 (22-83) years; 831 (93.8%) were mismatch repair proficiency (pMMR), and 55 (6.2%) were mismatch repair deficiency (dMMR). In dMMR group, 47 cases (85.5%) had the deficiency of both MLH1 and PMS2, 1 case (1.8%) had the deficiency of both MSH2 and MSH6, 4 cases (7.3%) had the deficiency only in PMS2, 2 cases (3.6%) had the deficiency only in MSH6, and 1 case (1.8%) had the deficiency only in MSH2. The deficiency rates of PMS2, MLH1, MSH6 and MSH2 were 5.8% (51/886), 5.3% (47/886), 0.3% (3/886) and 0.2% (2/886), respectively. Among the 871 cases with EBER results, 4.9% (43/871) were positive EBER. Univariate analysis showed that dMMR was more frequently detected in female patients (χ(2)=10.962, P=0.001), cancer locating in the antrum (χ(2)=9.336,P=0.020), Lauren intestinal type (χ(2)=9.718, P=0.018), stage T3 (χ(2)=25.866, P<0.001) and TNM stage II (χ(2)=15.470, P=0.002). The ratio of dMMR was not significantly associated with age, tumor differentiation, histological type, lymph node metastasis, distant metastasis or Her-2 immunohistochemical score (all P>0.05). Compared with negative EBER, positive EBER was more frequent in male patients (χ(2)=9.701, P=0.002), cancer locating in gastric fundus and corpus (χ(2)=17.964, P<0.001), gastric cancer with lymphoid stroma (χ(2)=744.073, P<0.001) and poorly differentiated cancer (χ(2)=13.739, P=0.010). Positive EBER was not significantly associated with age, depth of invasion, lymph node metastasis, distant metastasis, TNM stage or Her-2 immunohistochemical score (all P>0.05). In addition, all dMMR cases were EBER negative, and all cases of positive EBER were pMMR. Conclusions: The positive EB virus status is mutually exclusive with dMMR, indicating that different molecular subtypes of gastric adenocarcinoma are involved in different molecular pathways in tumorigenesis and progression. The overlapping of dMMR or positive EBER status and positive Her-2 expression is found in some cases of gastric adenocarcinoma. Patients with gastric adenocarcinoma after radical surgery should be tested for MMR status if they are female, the tumor locates in gastric antrum, the TNM staging is stage II or T3, or if the Lauren classification is intestinal type. And if patients are male, the tumor locates in the gastric fundus and corpus, the cancer is lymphoid stroma, or poor differentiated, the expression of EBER should be detected. Results of our study may provide evidence for further decision-making of clinical treatment.


Assuntos
Adenocarcinoma , Infecções por Vírus Epstein-Barr , Neoplasias Gástricas , Estudos de Casos e Controles , Reparo de Erro de Pareamento de DNA , Feminino , Herpesvirus Humano 4 , Humanos , Masculino , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Endonuclease PMS2 de Reparo de Erro de Pareamento/metabolismo , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Proteína 2 Homóloga a MutS/metabolismo , Estudos Retrospectivos
16.
Phys Rev Lett ; 104(21): 217204, 2010 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-20867133

RESUMO

The exchange bias of epitaxially grown CoO/Fe/Ag(001) was investigated using x-ray magnetic circular dichroism and x-ray magnetic linear dichroism (XMLD) techniques. A direct XMLD measurement on the CoO layer during the Fe magnetization reversal shows that the CoO compensated spins are rotatable at thinner thickness and frozen at larger thickness. By a quantitative determination of the rotatable and frozen CoO spins as a function of the CoO film thickness, we find the remarkable result that the exchange bias is well established before frozen spins are detectable in the CoO film. We further show that the rotatable and frozen CoO spins are uniformly distributed in the CoO film.

17.
Eur Rev Med Pharmacol Sci ; 24(19): 10036-10044, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33090409

RESUMO

OBJECTIVE: Glycogen storage disease type Ia (GSDIa) is a glucose metabolic disorder. GSDIa patients are characterized by hypoglycemia, hepatomegaly, hyperlipidemia, and hyperlactacidemia. This retrospective study aimed to review the lipid status, explore lipid treatment targets, and assess preferable lipid-lowering drugs. PATIENTS AND METHODS: Clinical data on GSDIa patients' characteristics were collected. Most patients were followed-up once a year. Diet control and raw cornstarch treatment were used to maintain normal blood glucose and lipid levels. Some patients were given lipid-lowering drugs. We compared the lipid levels before and after each treatment. RESULTS: A total of 163 GSDIa patients were enrolled in this study. After treatment with raw cornstarch, the total triglycerides (TG) level has significantly decreased by 30±50% (8.37±7.23 to 5.39±5.29 mmol/L, p<0.001). There was no change in the total cholesterol (TC) level. Fifteen patients regularly took atorvastatin, and 15 took fibrates for more than one year. The therapeutic effect of atorvastatin was better than fibrates. The TC was positively correlated with TG after treatment, resulting in the following linear equation: TG=1.63×TC-2.86. Using this equation and Chinese children's normal TC level of 5.18 mmol/L, we aimed to maintain the patients at TG < 5.58 mmol/L. CONCLUSIONS: Patients with GSDIa have significant abnormalities in lipid metabolism. Because the complications of hyperlipidemia are caused mainly by TC, thereby, by maintaining it at a normal level, we could set a TG target by the linear equation that allowed a certain degree of hypertriglyceridemia. This study found that the therapeutic effect of atorvastatin was better than fibrates.


Assuntos
Colesterol/sangue , Doença de Depósito de Glicogênio Tipo I/tratamento farmacológico , Hiperlipidemias/tratamento farmacológico , Hipolipemiantes/uso terapêutico , Triglicerídeos/sangue , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Fenofibrato/uso terapêutico , Genfibrozila/uso terapêutico , Glucose-6-Fosfatase/genética , Doença de Depósito de Glicogênio Tipo I/sangue , Doença de Depósito de Glicogênio Tipo I/genética , Humanos , Hiperlipidemias/sangue , Hiperlipidemias/genética , Lactente , Recém-Nascido , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Mutação , Estudos Retrospectivos , Amido/uso terapêutico , Adulto Jovem
18.
Zhonghua Xue Ye Xue Za Zhi ; 41(4): 287-291, 2020 Apr 14.
Artigo em Zh | MEDLINE | ID: mdl-32447931

RESUMO

Objective: To investigate the living status and quality of life (QOL) in type1 Gaucher disease (GD1) patients who underwent long-term enzyme replacement therapy (ERT) and identify possible relevant factors affecting QOL. Methods: Clinical data and SF-36 questionnaires were recorded in 22 adult GD1 patients under regular ERT at Peking Union Medical Colleague Hospital (PUMCH) from January 1995 to June 2017. Results: 13 males and 9 females were included in this study. The current median age, age at diagnosis and initial time of ERT were 41 (24-52) , 6 (1-38) and 26 (6-41) years respectively. Of these patients, 68.2% was living in less-developed regions, 86.4% were under college education, and 77.3% had personal annual income less than ¥30 000 RMB. Though after a median 16 (7-22) years of ERT, the QOL of GD1 patients was still significantly worse (P<0.05) compared with normal Chinese population based on SF-36 questionnaires. History of splenectomy was a negative factor of QOL, mainly in physical health (P<0.05) . Patients could get benefit from early start of ERT in both physical and mental health (P<0.05) . Mental health was not affected by history of splenectomy and related bone diseases. Conclusion: Most adult GD1 patients at PUMCH reside in less-developed regions and have low levels of education and annual income. History of splenectomy and time to start ERT are two important factors affecting QOL. Chinese adult GD1 patients are associated with reduced QOL, even after long-term ERT.


Assuntos
Doença de Gaucher , Adulto , Terapia de Reposição de Enzimas , Feminino , Doença de Gaucher/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Esplenectomia , Inquéritos e Questionários
19.
Sci Adv ; 6(36)2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32917619

RESUMO

Magnetic skyrmions are topological spin textures, which usually exist in noncentrosymmetric materials where the crystal inversion symmetry breaking generates the so-called Dzyaloshinskii-Moriya interaction. This requirement unfortunately excludes many important magnetic material classes, including the recently found two-dimensional van der Waals (vdW) magnetic materials, which offer unprecedented opportunities for spintronic technology. Using photoemission electron microscopy and Lorentz transmission electron microscopy, we investigated and stabilized Néel-type magnetic skyrmion in vdW ferromagnetic Fe3GeTe2 on top of (Co/Pd) n in which the Fe3GeTe2 has a centrosymmetric crystal structure. We demonstrate that the magnetic coupling between the Fe3GeTe2 and the (Co/Pd) n could create skyrmions in Fe3GeTe2 without the need of an external magnetic field. Our results open exciting opportunities in spintronic research and the engineering of topologically protected nanoscale features by expanding the group of skyrmion host materials to include these previously unknown vdW magnets.

20.
Nat Commun ; 10(1): 5603, 2019 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811144

RESUMO

Merons which are topologically equivalent to one-half of skyrmions can exist only in pairs or groups in two-dimensional (2D) ferromagnetic (FM) systems. The recent discovery of meron lattice in chiral magnet Co8Zn9Mn3 raises the immediate challenging question that whether a single meron pair, which is the most fundamental topological structure in any 2D meron systems, can be created and stabilized in a continuous FM film? Utilizing winding number conservation, we develop a new method to create and stabilize a single pair of merons in a continuous Py film by local vortex imprinting from a Co disk. By observing the created meron pair directly within a magnetic field, we determine its topological structure unambiguously and explore the topological effect in its creation and annihilation processes. Our work opens a pathway towards developing and controlling topological structures in general magnetic systems without the restriction of perpendicular anisotropy and Dzyaloshinskii-Moriya interaction.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA