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1.
Front Pediatr ; 11: 1161329, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37384308

RESUMO

Objective: To provide a reference for the prevention and control of myopia by analyzing and discussing the findings of an epidemiological survey of the prevalence of myopia among children and adolescents in Fuzhou City from 2019 to 2021. Methods: Participants for this cross-sectional study were drawn from Gulou District and Minqing County in Fuzhou City using cluster random sampling to account for differences in population density, economic development, and other environmental variables. Results: Myopia was more prevalent in 2020 than in 2019, but by 2021 it had dropped to about the same level as in 2019. Myopia was more prevalent among girls than boys during the course of the study period, with a three-year prevalence of 44.72% for boys and 52.16% for girls. Mild myopia accounted for 24.14% of all cases, followed by moderate myopia at 19.62%, and severe myopia at 4.58%. Students in urban regions had a prevalence of myopia equivalent to that of students in the suburbs, and this prevalence rose with age. Conclusion: Myopia was quite prevalent among children and adolescents in Fuzhou City, and was shown to be steadily rising as students progressed through the school system. This suggests that all levels of government, educational institutions, medical facilities, and concerned parents in Fujian Province should focus on the issue of myopia and collaborate to reduce the risk factors for the development of myopia in school-aged participants.

2.
Neural Plast ; 2023: 2382980, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37124873

RESUMO

Objective: Many stroke victims have severe swallowing problems. Previous neuroimaging studies have found that several brain regions scattered in the frontal, temporal, and parietal lobes, such as Brodmann's areas (BA) 6, 21, and 40, are associated with swallowing function. This study sought to investigate changes in swallowing function and resting-state functional magnetic resonance imaging (rs-fMRI) in stroke patients with dysphagia following action observation treatment. It also sought to detect changes in brain regions associated with swallowing in stroke patients. Methods: In this study, 12 healthy controls (HCs) and 12 stroke patients were recruited. Stroke patients were given 4 weeks of action observation therapy. In order to assess the differences in mfALFF values between patients before treatment and HCs, the fractional amplitude of low-frequency fluctuations (fALFF) in three frequency bands (conventional frequency band, slow-4, and slow-5) were calculated for fMRI data. The significant brain regions were selected as regions of interest (ROIs) for subsequent analysis. The mfALFF values were extracted from ROIs of the three groups (patients before and after treatment and HCs) and compared to assess the therapeutic efficacy. Results: In the conventional band, stroke patients before treatment had higher mfALFF in the inferior temporal gyrus and lower mfALFF in the calcarine fissure and surrounding cortex and thalamus compared to HCs. In the slow-4 band, there was no significant difference in related brain regions between stroke patients before treatment and HCs. In the slow-5 band, stroke patients before treatment had higher mfALFF in inferior cerebellum, inferior temporal gyrus, middle frontal gyrus, and lower mfALFF in calcarine fissure and surrounding cortex compared to HCs. We also assessed changes in aberrant brain activity that occurred both before and after action observation therapy. The mfALFF between stroke patients after therapy was closed to HCs in comparison to the patients before treatment. Conclusion: Action observation therapy can affect the excitability of certain brain regions. The changes in brain function brought about by this treatment may help to further understand the potential mechanism of network remodeling of swallowing function.


Assuntos
Transtornos de Deglutição , Acidente Vascular Cerebral , Humanos , Deglutição , Transtornos de Deglutição/diagnóstico por imagem , Transtornos de Deglutição/etiologia , Imageamento por Ressonância Magnética/métodos , Córtex Motor , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia
3.
J Ovarian Res ; 16(1): 54, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36932420

RESUMO

This meta-analysis was conducted to summarize the effects of n-3 polyunsaturated fatty acid (n-3 PUFA) on metabolic status including insulin metabolism and lipid metabolism in women with polycystic ovary syndrome (PCOS) by randomized controlled trials (RCTs). Four mainstream databases including PubMed, Cochrane Library, Embase and Web of Science were searched from their inception to October 2021. The registration number of this study was CRD42021285233. The quality assessment was performed referring the Cochrane Risk of Bias Tool. Mean differences (MD) and 95% confidence intervals (CIs) were generated for continuous variables by meta-analysis. Subgroup analyses were performed based on study duration (≤ 8 weeks or > 8 weeks), the source of n-3 PUFA (marine derived or plant origins) and dosage of n-3 PUFA (≤ 1000 mg/d or > 1000 mg/d). Eventually, 11 RCTs reporting 816 patients were enrolled. Compared with control group, n-3 PUFA treatment decreased waist circumference (MD = -2.76, 95% CI: -3.82 to -1.69; p < 0.00001), fasting plasma glucose (MD = -3.91, 95% CI: -5.69 to -2.13; p < 0.0001), fasting insulin (MD = -2.45, 95% CI: -3.19 to -1.71; p < 0.00001), homeostatic model assessment of insulin resistance (MD = -0.45, 95% CI: -0.80 to -0.11; p = 0.01), triglyceride (MD = -9.33, 95% CI: -10.56 to -8.10; p < 0.00001), total cholesterol (MD = -12.32, 95% CI: -19.15 to -5.50; p = 0.0004), low-density lipoprotein cholesterol (MD = -10.53, 95% CI: -19.31 to -1.75; p = 0.02), and increase quantitative insulin sensitivity check index (MD = 0.01, 95% CI: 0.01 to 0.02; p < 0.00001), Adiponectin (MD = 1.46, 95% CI: 1.12 to 1.80; p < 0.00001) in PCOS patients. However, n-3 PUFA failed to change body weight, body mass index, high-density lipoprotein cholesterol, very low-density lipoprotein cholesterol and hs-CRP in the overall analysis. Further subgroup analyses showed that supplements of n-3 PUFA for more than 8 weeks is more conducive to improve the metabolic status in insulin resistance and lipid profiles. The meta-analysis demonstrates that n-3 PUFA may be an effective intervention for alleviating metabolic status in PCOS. Hence, we recommend PCOS patients replenish n-3 PUFA with duration > 8 weeks regardless of the source and the dosage to retard the pathogenesis of PCOS related metabolic diseases.


Assuntos
Ácidos Graxos Ômega-3 , Resistência à Insulina , Síndrome do Ovário Policístico , Feminino , Humanos , Síndrome do Ovário Policístico/tratamento farmacológico , Síndrome do Ovário Policístico/metabolismo , Ácidos Graxos Ômega-3/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Insulina , Colesterol , Lipoproteínas LDL
4.
Environ Sci Pollut Res Int ; 29(58): 87645-87667, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35821316

RESUMO

People are increasingly paying much attention to battery technology, especially the zinc-nickel battery and the lithium battery, for solving energy shortages and environmental contamination. Meanwhile, the drastic change in the external outside environment has brought a huge challenge to manage the battery industry chain. Therefore, in the uncertain external environment, the study of supply chain competition between lithium battery and new nickel battery manufacturers is the focus of this paper. We build a cooperative game model under the demand disturbance and a non-cooperative game under the background of product promotion. The results show that (i) the price set by the manufacturer increases with technical improvement when consumers are more sensitive to the technical level. (ii) The optimal price of all manufacturers will drop as the CETRC (carbon emission technology renewal coefficient) increases. (iii) The price of zinc-nickel batteries will be higher than that of lithium battery as the market promotion rate is in the middle range. In the model, the supply chain determines different optimal prices according to the different ranges of the demand disturbance.


Assuntos
Carbono , Lítio , Humanos , Níquel , Políticas , Zinco , Comércio
5.
Environ Sci Pollut Res Int ; 29(54): 82324-82335, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35751722

RESUMO

With the present situation of development in green technology as the background, combined with technology marketing models in other areas, this paper builds three technology marketing models, based on the Stackelberg game between the technology suppliers and distributors. Namely, the three models are direct official marketing, agency relationship cooperation, and agency sale relationship cooperation. Dynamic system model is built on relationship cooperation. By comparing with and analyzing the model solution results, and observing the effect of various parameters in terms of numerical simulation on enterprise decision variables, profits, and the optimal mode policy selection, we find that the level of price discount will decide whether the technology supplier selects the agency sales model, while the level of the profit distribution factor decides whether the technology supplier takes direct official sale. Meanwhile, excessive price adjustment speed will disturb the market stability and interfere with enterprise decision-making.


Assuntos
Carbono , Marketing , Comércio , Tecnologia , Simulação por Computador
6.
Environ Sci Pollut Res Int ; 29(3): 4519-4539, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34410600

RESUMO

Nowadays, with more and more WEEE (waste electrical and electronic equipment) being abandoned, WEEE recycling activities are increasingly popular. In this paper, we build a closed-loop supply chain model and focus on the recycling behaviors of the members in this supply chain, which contains two manufacturers, the retailer, and the consumer. In the reverse chain, we set up dual channels and design two recycling methods: sell-back method and trade-in method. We use classical backward induction to run the model. And then we analyze the stability of the system and the impacts of some essential parameters by numerical simulation. The speed of the manufacture's decision adjustment has a significant effect on the stability of the model. Manufacturers should adopt a stable rather than radical price adjustment strategy in order to achieve stable profit growth in the whole supply chain and avoid a chaotic price war. Manufacturers should increase innovation investment in recycling technology to reduce the cost of remanufacturing products and improve the initiative in market competition. In the end, we adopt the parameter control method and the decision-making method to control chaos, and they both have a good control effect.


Assuntos
Resíduo Eletrônico , Gerenciamento de Resíduos , Resíduo Eletrônico/análise , Eletrônica , Reutilização de Equipamento , Reciclagem
7.
Aging (Albany NY) ; 13(5): 7084-7095, 2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33638949

RESUMO

Polycystic ovarian syndrome (PCOS) is one of the most common reproductive endocrine disorders which are involved in complicated and unknown pathogenic mechanisms. Paeoniflorin (PAE) plays a significant anti-fibrotic role according to previous studies. The aim of the present study was to investigate the effect of PAE on ovarian fibrosis and its underlying mechanism in PCOS development. An animal model of PCOS was established by subcutaneous injection of 60mg/kg/d dehydroepiandrosterone (DHEA) for 35 consecutive days. Rats in PAE-L, PAE-M and PAE-H groups were administrated by gavage with PAE (20, 40, 80 mg/kg/d) for 4 weeks. Our results indicated that DHEA-induced PCOS rats showed similar phenotypes with PCOS patients. PAE could significantly block the DHEA-induced decline of ovary weight and organ coefficient, shorten the prolonged diestrus period, and regulate the irregular estrous cycle of PCOS rats. Moreover, PAE regulated reproductive hormone levels and improved ovarian fibrosis induced by DHEA. PAE treatment could also reduce the expression levels of TGF-ß1 and Smad3, and increase the expression levels of Smad7 and MMP2. In conclusion, PAE significantly attenuated the ovarian fibrosis in PCOS, which could be mediated by TGF-ß1/Smads signaling pathway. Herein, PAE can be used for the treatment of ovarian fibrosis in PCOS progression.


Assuntos
Glucosídeos/uso terapêutico , Monoterpenos/uso terapêutico , Síndrome do Ovário Policístico/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Desidroepiandrosterona/farmacologia , Modelos Animais de Doenças , Ciclo Estral/efeitos dos fármacos , Feminino , Ovário/efeitos dos fármacos , Ovário/metabolismo , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/metabolismo , Ratos , Ratos Sprague-Dawley
9.
Int J Nurs Sci ; 7(2): 170-178, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32685613

RESUMO

OBJECTIVE: To investigate the effects of mirror neuron theory-based visual feedback therapy (VFT) on restoration of upper limb function of stroke patients and motor-related cortical function using functional magnetic resonance imaging (fMRI). METHODS: Hemiplegic stroke patients were randomly divided into two groups: a VFT group and a control (CTL) group. Sixteen patients in the VFT group received conventional rehabilitation (CR) and VFT for 8 weeks, while 15 patients in the CTL group received only CR. The Barthel Index (BI) was used to assess the activities of daily living at baseline and the 8th week of the recovery training period. The Fugl-Meyer assessment (FMA) scale, somatosensory evoked potential (SEP), and fMRI were used to evaluate the recovery effect of the training therapies. The latencies and amplitudes of N9 and N20 were measured. Before recovery training, fMRI was performed for all patients in the VFT and CTL groups. In addition, 17 patients (9 in the VFT group and 8 in the CTL group) underwent fMRI for follow-up 2 months after treatment. Qualitative data were analyzed using the χ 2 test. The independent sample t-test was used to compare normally distributed data among different groups, the paired sample t-test was used to compare data between groups, and the non-parametric test was used to comparing data without normal distribution among groups. RESULTS: There were no significant differences between the VFT and CTL group in all indexes. However, after 8 weeks of recovery training, these indexes were all significantly improved (P < 0.05). As compared with the CTL group, the FMA scores, BI, and N9/N20 latencies and amplitudes of SEP in the VFT group were significantly improved (P < 0.05). Two months after recovery training, fMRI showed that the degree of activation of the bilateral central anterior gyrus, parietal lobe, and auxiliary motor areas was significantly higher in the VFT group than the CTL group (P < 0.05). CONCLUSIONS: VFT based on mirror neuron theory is an effective approach to improve upper extremity motor function and daily activity performance of stroke patients. The therapeutic mechanism promotes motor relearning by activating the mirror neuron system and motor cortex. SEP amplitudes increased only for patients who participated in visual feedback. VFT promotes sensory-motor plasticity and behavioral changes in both the motor and sensory domains.

10.
Polymers (Basel) ; 10(9)2018 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-30960968

RESUMO

The development of antitumor drugs has attracted cancer researchers and the identification of novel antitumor lead compounds is certainly of great interest. The fermentation broth of Bacillus sp. N11-8, which was isolated from the Antarctic waters, showed cytotoxicity towards different cells. A cytotoxic polypeptide, PBN11-8, was purified from the fermentation broth of Bacillus sp. N11-8 using ultrafiltration, ammonium sulfate precipitation, anion exchange liquid chromatography and high performance liquid chromatography (HPLC). Cloning and sequence analysis showed that PBN11-8 polypeptide (MW: ~19 kDa by the electrospray-ionization (ESI)) displayed high similarity with peptidase M84 from Bacillus pumilus. PBN11-8 possessed moderate cytotoxicity towards several cancer cell lines with IC50 values of 1.56, 1.80, 1.57, and 1.73 µg/mL against human hepatocellular carcinoma cell line BEL-7402, human renal clear cell adenocarcinoma cell line 786-0, human hepatocellular carcinoma cell line HepG2, and human pancreatic cancer cell line Panc-28, respectively. Moreover, the polypeptide displayed weak cytotoxicity towards normal cell line renal tubular epithelial cell line HK2 and human normal liver cell line L02 cells. Wound healing migration and Transwell experiments demonstrate that PBN11-8 could inhibit the migration and invasion of BEL-7402. Further investigation revealed that PBN11-8 suppresses focal adhesion kinase (FAK)-mediated adhesion, migration, and invasion by disturbing FAK/extracellular regulated protein kinases (ERK) signaling and matrix metalloproteinase-2(MMP-2) and matrix metalloproteinase-9 (MMP-9) in BEL-7402 cells. Thus, PBN11-8 represents a potential novel anti-cancer lead compound.

11.
Medicine (Baltimore) ; 96(42): e8080, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29049194

RESUMO

BACKGROUND: The aim of this study was to explore the effects of action observation therapy on motor function of upper extremity, activities of daily living, and motion evoked potential in cerebral infarction patients. METHOD: Cerebral infarction survivors were randomly assigned to an experimental group (28 patients) or a control group (25 patients). The conventional rehabilitation treatments were applied in both groups, but the experimental group received an additional action observation therapy for 8 weeks (6 times per week, 20 minutes per time). Fugl-Meyer assessment (FMA), Wolf Motor Function Test (WMFT), Modified Barthel Index (MBI), and motor evoked potential (MEP) were used to evaluate the upper limb movement function and daily life activity. RESULTS: There were no significant differences between experiment and control group in the indexes, including FMA, WMFT, and MBI scores, before the intervention. However, after 8 weeks treatments, these indexes were improved significantly. MEP latency and center-motion conduction time (CMCT) decreased from 23.82 ±â€Š2.16 and 11.15 ±â€Š1.68 to 22.69 ±â€Š2.11 and 10.12 ±â€Š1.46 ms. MEP amplitude increased from 0.61 ±â€Š0.22 to 1.25 ±â€Š0.38 mV. A remarkable relationship between the evaluations indexes of MEP and FMA was found. CONCLUSIONS: Combination of motion observation and traditional upper limb rehabilitation treatment technology can significantly elevate the movement function of cerebral infarction patients in subacute seizure phase with upper limb dysfunction, which expanded the application range of motion observation therapy and provided an effective therapy strategy for upper extremities hemiplegia in stroke patients.


Assuntos
Infarto Cerebral/reabilitação , Terapia por Exercício/métodos , Recuperação de Função Fisiológica , Reabilitação do Acidente Vascular Cerebral/métodos , Extremidade Superior/fisiopatologia , Atividades Cotidianas , Idoso , Infarto Cerebral/fisiopatologia , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Movimento , Observação/métodos , Amplitude de Movimento Articular , Resultado do Tratamento
12.
ACS Appl Mater Interfaces ; 9(3): 2642-2649, 2017 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-28025891

RESUMO

Intrinsic spatial inhomogeneity or phase separation in cuprates, manganites, etc., related to electronic and/or magnetic properties, has attracted much attention due to its significance in fundamental physics and applications. Here we use scanning Kerr microscopy and scanning electron microscopy with polarization analysis with in situ electric fields to reveal the existence of intrinsic spatial inhomogeneity of the magnetic response to an electric field on a mesoscale with the coexistence of looplike (nonvolatile) and butterfly-like (volatile) behaviors in Co40Fe40B20/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 ferromagnetic/ferroelectric (FM/FE) multiferroic heterostructures. Both the experimental results and micromagnetic simulations suggest that these two behaviors come from the 109° and the 71°/180° FE domain switching, respectively, which have a spatial distribution. This FE domain-switching-controlled magnetism is significant for understanding the nature of FM/FE coupling on the mesoscale and provides a path for designing magnetoelectric devices through domain engineering.

13.
Sci Rep ; 6: 19965, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26817516

RESUMO

We report ferroelectricity and self-polarization in the (001) oriented ultrathin relaxor ferroelectric PMN-PT films grown on Nb-SrTiO3, SrRuO3 and La0.7Sr0.3MnO3, respectively. Resistance-voltage measurements and AC impedance analysis suggest that at high temperatures Schottky depletion width in a 4 nm thick PMN-PT film deposited on Nb-SrTiO3 is smaller than the film thickness. We propose that Schottky interfacial dipoles make the dipoles of the nanometer-sized polar nanoregions (PNRs) in PMN-PT films grown on Nb-SrTiO3 point downward at high temperatures and lead to the self-polarization at room temperature with the assistance of in-plane compressive strain. This work sheds light on the understanding of epitaxial strain effects on relaxor ferroelectric films and self-polarization mechanism.

15.
Sci Rep ; 4: 3727, 2014 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-24430913

RESUMO

We report a giant electric-field control of magnetization (M) as well as magnetic anisotropy in a Co40Fe40B20(CoFeB)/Pb(Mg1/3Nb2/3)0.7Ti0.3O3(PMN-PT) structure at room temperature, in which a maximum relative magnetization change (ΔM/M) up to 83% with a 90° rotation of the easy axis under electric fields were observed by different magnetic measurement systems with in-situ electric fields. The mechanism for this giant magnetoelectric (ME) coupling can be understood as the combination of the ultra-high value of anisotropic in-plane piezoelectric coefficients of (011)-cut PMN-PT due to ferroelectric polarization reorientation and the perfect soft ferromagnetism without magnetocrystalline anisotropy of CoFeB film. Besides the giant electric-field control of magnetization and magnetic anisotropy, this work has also demonstrated the feasibility of reversible and deterministic magnetization reversal controlled by pulsed electric fields with the assistance of a weak magnetic field, which is important for realizing strain-mediated magnetoelectric random access memories.

16.
Zhonghua Er Ke Za Zhi ; 49(11): 843-7, 2011 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-22336308

RESUMO

OBJECTIVE: To explore the relationship between children's motor coordination and their physical growth to provide clues for clarifying the causal relationship between them and to effectively enhance the children's physical growth. METHOD: Ten kindergartens were selected randomly from district of Hongkou, Putuo and Pudong in Shanghai, and 1099 children were included in the analysis. The children's motor coordination was assessed using Developmental Coordination Disorder Questionnaire (DCDQ). The relationship between the children's motor coordination and their physical growth were analyzed by Structural Equation Model (SEM). The above relationship by different gender, age and BMI (overweight or not) were analyzed with multi-group SEM. RESULTS: Of 1099 subjects, 561 were boys (51%), and 538 were girls (49%). Of the total subjects, 354 (32.2%) were children aged 3-years old, 441 (40.1%) were children aged 4-years, 276 (25.2%) were children aged 5-years, and 28 were children (2.5%) aged 6-years old. The result of SEM showed that the children's gross motor, fine motor and general motor ability was correlated positively with children's physical growth (P < 0.001), their standardized estimation of structural coefficient were 0.40, 0.36, 0.37 respectively. The result of multi-group SEM showed that there was no significant difference in the SEM between different gender and ages. The fine motor ability was positively correlated with child physical growth (P < 0.001). There was no inter-group difference in the structural model (each P > 0.05). However, there was difference in the structural model between overweight and normal group, of them, only the structural coefficient of gross motor and physical growth were different between the two groups (t = 1.697, P < 0.05). CONCLUSION: There is a relationship between children's motor coordination and physical growth. The degree of association between the gross moter and physical growth in overweight children were different from the normal children. Further study on the factors influencing the children's physical growth is needed.


Assuntos
Desenvolvimento Infantil , Destreza Motora , Pré-Escolar , China , Feminino , Humanos , Masculino , Inquéritos e Questionários
17.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 18(4): 1055-8, 2010 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-20723328

RESUMO

This study was aimed to investigate the relation of human leukocyte antigen-A, B, DRB1 genes with the susceptibility of population to leukemia in Anhui province of China. The HLA genotypes were analyzed by PCR-SSP in 140 patients with chronic myelocytic leukemia (CML), 84 patients with acute lymphoblastic leukemia (ALL), 90 patients with acute nonlymphocytic leukemia (ANLL) and 916 healthy unrelated donors of hematopoietic stem cell as normal control admitted to Anhui provincial hospital. The gene frequencies of HLA-A, B, DRB1 between patients and normal controls were compared, chi² test was used for statistical analysis. The results showed that as compared with normal controls, the gene frequencies of A2, A11, B58 and DR9 in CML patients all obviously increased, and gene frequency of DR7 decreased; the gene frequencies of All and B13 in ALL patients were significantly higher than that in normal controls; the gene frequencies of A24, B58 and DR9 in ANLL patients were significantly higher than that in normal controls. It is concluded that HLA-A2, A11, B58 and DR9 are predisposing genes of CML patients, DR7 is an antagonistic gene, HLA-A11 and B13 are predisposing genes of ALL patients, HLA-A24, B58 and DR9 are predisposing genes of ANLL patients.


Assuntos
Antígenos HLA-A/genética , Antígenos HLA-B/genética , Antígenos HLA-DR/genética , Leucemia/genética , Alelos , Estudos de Casos e Controles , China/epidemiologia , Frequência do Gene , Genótipo , Cadeias HLA-DRB1 , Haplótipos , Humanos , Leucemia/epidemiologia
18.
J Zhejiang Univ Sci B ; 9(3): 261-4, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18357629

RESUMO

To investigate the Fe2+ effects on root tips in rice plant, experiments were carried out using border cells in vitro. The border cells were pre-planted in aeroponic culture and detached from root tips. Most border cells have a long elliptical shape. The number and the viability of border cells in situ reached the maxima of 1600 and 97.5%, respectively, at 20-25 mm root length. This mortality was more pronounced at the first 1-12 h exposure to 250 mg/L Fe2+ than at the last 12-36 h. After 36 h, the cell viability exposed to 250 mg/L Fe2+ decreased to nought, whereas it was 46.5% at 0 mg/L Fe2+. Increased Fe2+ dosage stimulated the death of detached border cells from rice cultivars. After 4 h Fe2+ treatment, the cell viabilities were > or =80% at 0 and 50 mg/L Fe2+ treatment and were <62% at 150, 250 and 350 mg/L Fe2+ treatment; The viability of border cells decreased by 10% when the Fe2+ concentration increased by 100 mg/L. After 24 h Fe2+ treatment, the viabilities of border cells at all the Fe2+ levels were <65%; The viability of border cells decreased by 20% when the Fe2+ concentration increased by 100 mg/L. The decreased viabilities of border cells indicated that Fe2+ dosage and treatment time would cause deadly effect on the border cells. The increased cell death could protect the root tips from toxic harm. Therefore, it may protect root from the damage caused by harmful iron toxicity.


Assuntos
Ferro/toxicidade , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Oryza/citologia , Raízes de Plantas/crescimento & desenvolvimento , Plântula/citologia
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