94 research outputs found

    Research on Influences of Transient High IOP during LASIK on Retinal Functions and Ultrastructure

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    Objectives. To study the influences of transient high intraocular pressure(IOP) during LASIK on retinal functions and ultrastructure. Methods. Thirty-two New Zealand white rabbits were randomly divided into normal control, experimental control, negative suction 20 s and negative suction 3 min groups. The experimental control group was treated only by laser. Rabbit eyes received suction for different periods of time (20 s, 3 min) by negative pressure generator in different groups. The changes of neuro-optic and retinal ultrastructure were observed under electron and light microscopes; retinal neurofunctional changes were observed with flash-visual evoked potential (F-VEP) and flash-electroreinogram (F-ERG). Results. There was no obvious change in optic nerve, retina, ERG a-wave and b-wave in normal control and experimental control groups. There were slight changes in tissues of optic nerve and retina at various times of suction 20 s compared with control group, and a sharp change in suction 3 min group within 14d after operation, but these changes recovered at 28d . Amplitude of ERG b-wave observed at different time will decrease with suction periods prolonged. It can recover to normal level with the prolonged recovery periods. Amplitude and incubation period of ERG a-wave and VEP-P did not change significantly after different duration of suction. Conclusions. The transient high IOP during LASIK might have influence on retinal function and ultrastructure, but these changes were reversible

    A palavra e as condições da educação escolar

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    Estudos recentes sobre gestão e resultados escolares apontam a presença do, assim chamado, efeito-professor como um fator associado ao desempenho dos alunos. Desenvolve-se neste texto a premissa de que esses estudos acabam, paradoxalmente, demonstrando a pertinência da reflexão psicanalítica, que aponta para o estatuto da palavra mestre no interior de uma tradição filial professoral como condição necessária à educação escolar

    The role of inflammatory biomarkers in the development and progression of pre-eclampsia: a systematic review and meta-analysis

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    BackgroundPre-eclampsia (PE) is a pregnancy complication associated with maternal and fetal morbidity and mortality. Among the potential pathogenesis discussed, inflammation is considered an essential initiator of PE. Previous studies have compared the levels of various inflammatory biomarkers that indicate the existence of PE; however, the relative levels of pro-inflammatory and anti-inflammatory biomarkers and their dynamic changes during PE progression remain unclear. This knowledge is essential to explain the occurrence and progression of the disease.ObjectiveWe aimed to identify the relationship between inflammatory status and PE using inflammatory biomarkers as indicators. We also discussed the underlying mechanism by which inflammatory imbalance contributes to PE by comparing the relative levels of pro-inflammatory and anti-inflammatory biomarkers. Furthermore, we identified additional risk factors for PE.MethodsWe reviewed PubMed, Embase, and the Cochrane Library for articles published until 15th September 2022. Original articles that investigated inflammatory biomarkers in PE and normal pregnancy were included. We selected healthy pregnant women as controls. The inflammatory biomarkers in the case and control groups were expressed as standardized mean differences and 95% confidence intervals using a random-effects model. Study quality was assessed using the Newcastle-Ottawa Scale. Publication bias was assessed using Egger’s test.ResultsThirteen articles that investigated 2,549 participants were included in this meta-analysis. Patients with PE had significantly higher levels of C-reactive protein (CRP), interleukin (IL)-4, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF) than the controls. CRP and pro-inflammatory cytokine levels were higher than those of anti-inflammatory cytokines. Patients with gestational age > 34 weeks had significantly higher IL-6 and TNF levels. Patients with higher systolic blood pressure had significantly higher IL-8, IL-10, and CRP levels.ConclusionInflammatory imbalance is an independent risk factor for PE development. Impairment of the anti-inflammatory system is a crucial initiating factor for PE development. Failed autoregulation, manifested as prolonged exposure to pro-inflammatory cytokines, leads to PE progression. Higher levels of inflammatory biomarkers suggest more severe symptoms, and pregnant women after 34 weeks of gestation are more susceptible to PE

    Polar auxin transport modulates early leaf flattening

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    The flattened leaf form is an important adaptation for efficient photosynthesis, and the developmental process of flattened leaves has been intensively studied. Classic microsurgery studies in potato and tomato suggest that the shoot apical meristem (SAM) communicates with the leaf primordia to promote leaf blade formation. More recently, it was found that polar auxin transport (PAT) could mediate this communication. However, it is unclear how the expression of leaf patterning genes is tailored by PAT routes originating from SAM. By combining experimental observations and computer model simulations, we show that microsurgical incisions and local inhibition of PAT in tomato interfere with auxin transport toward the leaf margins, reducing auxin response levels and altering the leaf blade shape. Importantly, oval auxin responses result in the bipolar expression of SlLAM1 that determines leaf blade formation. Furthermore, wounding caused by incisions promotes degradation of SlREV, a known regulator of leaf polarity. Additionally, computer simulations suggest that local auxin biosynthesis in early leaf primordia could remove necessity for external auxin supply originating from SAM, potentially explaining differences between species. Together, our findings establish how PAT near emerging leaf primordia determines spatial auxin patterning and refines SlLAM1 expression in the leaf margins to guide leaf flattening.Peer reviewe

    Paleoclimatic changes during the penultimate interglacial period archived by multiple proxies of Xiashu Loess in the Chaohu Lake Basin, East China

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    The interglacial periods of the Pleistocene (MIS 5) and Holocene have been widely studied as analogs, whereas the records of the penultimate interglacial complex (MIS 7) are relatively sparse. In this study, based on a multitude of proxies, such as magnetic susceptibility, geochemical elements and their ratios, and grain size spanning MIS 7 of Xiashu Loess, the paleoclimatic changes that are synchronous with the five episodes during MIS 7 are reconstructed in the Chaohu Lake Basin, East China. It is proposed that the paleoclimate change in the Chaohu Lake Basin during MIS 7, on orbital time scale, might be controlled by low-latitude insolation; on millennium scales, might be directly driven by the global ice volume variations

    The Establishment and Numerical Calculation of a Heat Transfer Model of a Graphene Heating Energy Storage Floor

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    A new type of graphene electric heating solid wood composite floor and its heat transfer model were designed to enable users to have a higher-quality and safe living experience. A heat transfer mathematical model was developed. The structural entity of the composite graphene heating floor was drawn using Solidworks software. The floor structure was abstracted as a two-dimensional model using MATLAB software to obtain the temperature rise curves and corresponding time of each group. Then, six groups of the best data were selected from the experimental data to simulate the heat storage capacity of graphene floors. The optimal group of the model was verified via experiments. According to the simulation, the comprehensive performance was optimal when the overall thickness of the floor was 18 mm, the thickness of the floor surface was 4 mm, and the thickness of the heat-accumulating layer was 2 mm. The experimental results showed a maximum difference between the measured and calculated data of only 3.2%, which shows the scientific validity, accuracy, and advancement of the model. The composite graphene electric heating energy storage floor designed in this study can be regarded as safe, reliable, environmentally friendly, and healthy

    Mast cells mobilize myeloid-derived suppressor cells and Treg cells in tumor microenvironment via IL-17 pathway in murine hepatocarcinoma model.

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    Tumor immunosuppression is commonly braided with chronic inflammation during tumor development. However, the relationship between immunosuppression and inflammation in tumor microenvironment is still unclear. We have demonstrated that mast cells are accumulated and exacerbate the inflammation and immunosuppression in tumor microenvironment via SCF/c-kit signaling pathway. Here, we further elucidate the underlying mechanism, which involves both myeloid-derived suppressor cells (MDSCs) and regulatory T (Treg) cells. Our data showed that mast cells mobilized the infiltration of MDSCs to tumor and induced the production of IL-17 by MDSCs; MDSCs-derived IL-17 indirectly attracted Treg cells, enhanced their suppressor function, and induced the IL-9 production by Treg cells; in turn, IL-9 strengthened the survival and protumor effect of mast cells in tumor microenvironment. Our findings disclose a closed loop among mast cells, MDSCs and Treg cells in tumor microenvironment, which provides a new insight into the paralleled developments of inflammation and immunosuppression in tumor microenvironment. Based on these findings, we propose that targeting tumor inflammation might be a potential strategy to reverse the immunosuppression of tumor microenvironment, thus facilitating cancer immunotherapy

    Effectiveness of Myocardial Contrast Echocardiography Quantitative Analysis during Adenosine Stress versus Visual Analysis before Percutaneous Therapy in Acute Coronary Pain: A Coronary Artery TIMI Grading Comparing Study

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    The study aim was to compare two different stress echocardiography interpretation techniques based on the correlation with thrombosis in myocardial infarction (TIMI ) flow grading from acute coronary syndrome (ACS) patients. Forty-one patients with suspected ACS were studied before diagnostic coronary angiography with myocardial contrast echocardiography (MCE) at rest and at stress. The correlation of visual interpretation of MCE and TIMI flow grade was significant. The quantitative analysis (myocardial perfusion parameters: A, β, and A×β) and TIMI flow grade were significant. MCE visual interpretation and TIMI flow grade had a high degree of agreement, on diagnosing myocardial perfusion abnormality. If one considers TIMI flow grade <3 as abnormal, MCE visual interpretation at rest had 73.1% accuracy with 58.2% sensitivity and 84.2% specificity and at stress had 80.4% accuracy with 76.6% sensitivity and 83.3% specificity. The MCE quantitative analysis has better accuracy with 100% of agreement with different level of TIMI flow grading. MCE quantitative analysis at stress has showed a direct correlation with TIMI flow grade, more significant than the visual interpretation technique. Further studies could measure the clinical relevance of this more objective approach to managing acute coronary syndrome patient before percutaneous coronary intervention (PCI)

    Methylglyoxal Impairs Insulin Secretion of Pancreatic β-Cells through Increased Production of ROS and Mitochondrial Dysfunction Mediated by Upregulation of UCP2 and MAPKs

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    Methylglyoxal (MG) is a highly reactive glucose metabolic intermediate and a major precursor of advanced glycation end products. MG level is elevated in hyperglycemic disorders such as diabetes mellitus. Substantial evidence has shown that MG is involved in the pathogenesis of diabetes and diabetic complications. We investigated the impact of MG on insulin secretion by MIN6 and INS-1 cells and the potential mechanisms of this effect. Our study demonstrates that MG impaired insulin secretion by MIN6 or ISN-1 cells in a dose-dependent manner. It increased reactive oxygen species (ROS) production and apoptosis rate in MIN6 or ISN-1 cells and inhibited mitochondrial membrane potential (MMP) and ATP production. Furthermore, the expression of UCP2, JNK, and P38 as well as the phosphorylation JNK and P38 was increased by MG. These effects of MG were attenuated by MG scavenger N-acetyl cysteine. Collectively, these data indicate that MG impairs insulin secretion of pancreatic β-cells through increasing ROS production. High levels of ROS can damage β-cells directly via JNK/P38 upregulation and through activation of UCP2 resulting in reduced MMP and ATP production, leading to β-cell dysfunction and impairment of insulin production
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