32 research outputs found

    Autologous cord blood mononuclear cell infusion for the prevention of bronchopulmonary dysplasia in very preterm monozygotic twins: A study protocol for a randomized, placebo-controlled, double-blinded multicenter trial

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    BackgroundPreterm-associated complications remain the main cause of neonatal death. Survivors face the challenges of short- and long-term complications. Among all complications, bronchopulmonary dysplasia (BPD) remains the first important cause of neonatal mortality and morbidity. Current treatment does not address this main preterm complication. Cord blood is regarded as a convenient source of stem cells. The paracrine bioactive factors of stem cells contribute to tissue repair and immune modulation. Our clinical studies and those of others have shown that cord blood cell infusion is both safe and possibly effective in the prevention and treatment of BPD. The therapeutic use of cord blood has emerged as a promising therapy. However, the genetic heterogeneity between control and intervention groups may reduce the comparability especially among small sample trials. The purpose of this study protocol is to investigate the effects of autologous cord blood mononuclear cell (ACBMNC) infusion on the prevention of BPD in very preterm monozygotic twins of less than 32 gestation weeks.MethodsIn this prospective, randomized, placebo-controlled, double-blinded multicenter clinical trial, 60 pairs of monozygotic twin preterm neonates of less than 32 weeks admitted to the Neonatal Intensive Care Unit are randomly assigned to receive intravenous ACBMNC infusion (targeted at 5 × 107 cells/kg) or placebo (normal saline) within 24 h after birth in a 1:1 ratio. The primary outcome will be survival without BPD at 36 weeks of postmenstrual age. The secondary outcomes will include the mortality rate, BPD severity, other common preterm complication rates, respiratory support duration, length and cost of hospitalization, and long-term respiratory and neurodevelopmental outcomes during a 2-year follow-up. Furthermore, we will perform single-cell RNA sequencing for cord blood cells and blood cells 3–10 days after intervention and detect whether reactive oxygen species and inflammatory cytokines are present.ConclusionThis will be the first randomized, placebo-controlled, double-blinded trial to evaluate the efficacy of ACBMNC infusion to prevent BPD in monozygotic twin premature infants and investigate the underlying protective mechanisms. The results of this trial will provide valuable clinical evidence for translational application of cord blood cell therapy in very preterm infants.Trial registration: ClinicalTrials.gov, NCT05087498, registered 10/09/2021, https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S000BAD7&selectaction=Edit&uid=U0002PLA&ts=2&cx=qvyylv

    Effects of the Insemination of Hydrogen Peroxide-Treated Epididymal Mouse Spermatozoa on γH2AX Repair and Embryo Development

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    BACKGROUND: Cryopreservation of human semen for assisted reproduction is complicated by cryodamage to spermatozoa caused by excessive reactive oxygen species (ROS) generation. METHODS AND FINDINGS: We used exogenous ROS (H(2)O(2)) to simulate cryopreservation and examined DNA damage repair in embryos fertilized with sperm with H(2)O(2)-induced DNA damage. Sperm samples were collected from epididymis of adult male KM mice and treated with capacitation medium (containing 0, 0.1, 0.5 and 1 mM H(2)O(2)) or cryopreservation. The model of DNA-damaged sperm was based on sperm motility, viability and the expression of γH2AX, the DNA damage-repair marker. We examined fertility rate, development, cell cleavage, and γH2AX level in embryos fertilized with DNA-damaged sperm. Cryopreservation and 1-mM H(2)O(2) treatment produced similar DNA damage. Most of the one- and two-cell embryos fertilized with DNA-damaged sperm showed a delay in cleavage before the blastocyst stage. Immunocytochemistry revealed γH2AX in the one- and four-cell embryos. CONCLUSIONS: γH2AX may be involved in repair of preimplantation embryos fertilized with oxygen-stressed spermatozoa

    Experimental Investigation into the Oxidative Characteristics of Tahe Heavy Crude Oil

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    The thermal method of in-situ combustion (ISC) was proposed to produce Tahe heavy oil; therefore, the oxidative characteristics of this oil are critical, especially its coking behaviors, which are closely related to the combustion process. In this work, a series of thermogravimetric and differential scanning calorimetry (TG-DSC) tests with isothermal and non-isothermal models were conducted to determine the oxidative characteristics of Tahe heavy oil. Moreover, the morphology of the produced cokes was observed with a scanning electron microscope (SEM). The results showed that the heavy oil was partially coked due to high-pressure oxidation, and these cokes were significantly more active than the heavy oil, leading to noticeable heat release at low temperatures. Higher-temperature oxidation involved compounds in the coking and thus required more time to initiate the reactions. A significant reduction of the elements (S, H, N) was observed in higher-pressure oxidation, and the porous morphology of the coke was created. Increasing the oxidation pressure led to higher-porosity cokes and subsequently enhanced the reaction of oil and air. The particle structures generated by oxidation reactions on the surface of oxidized coke can be consumed by the combustion process

    Parental attachment and depressive symptoms in Chinese adolescents: The mediation effect of emotion regulation

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    Objective We examined if the links between adolescents' parental attachment and depressive symptoms are mediated by emotion regulation (cognitive reappraisal and expressive suppression), and identified which mediator has a stronger mediation effect. Method The Inventory of Parent and Peer Attachment, Emotion Regulation Questionnaire, and the “Center for Epidemiological Studies‐Depression Scale” were distributed to 1955 Chinese adolescents (about 50% boys; 49% in senior high school; aged 10–20-years, M = 14.85 ± 2.86-years) from seven provinces. Descriptive statistics, correlation analyses, regression analyses, and mediation analyses were conducted to test the hypotheses. Results The results showed that cognitive reappraisal and expressive suppression partially mediated the associations between paternal and maternal attachment and depressive symptoms after controlling for grade and sex. Further, the indirect effects of parental attachment through cognitive reappraisal were stronger than those through expressive suppression. Conclusions These findings suggest that adolescents with secure parental attachment (vs. insecure) have a lower risk of developing depressive symptoms and that increasing use of cognitive reappraisal and decreasing use of expressive suppression may help adolescents reduce their depressive symptoms

    Characteristics of Viscoelastic-Surfactant-Induced Wettability Alteration in Porous Media

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    Wettability alteration is one of the most important mechanisms of surfactant flooding. In this work, the combined Amott/USBM (United States Bureau of Mines) method was applied to study the average wettability alteration of initially neutral cores after viscoelastic-surfactant (VES) filtration. The effects of static aging, dynamic aging, VES concentration, filtration flow rate, and pore radius on the alteration of a core’s average wettability were studied. The wettability-alteration trends measured by Amott and USBM were consistent, demonstrating that the overall hydrophilicity of the core was enhanced after VES filtration. The wettability alterations of the core brought about by dynamic aging were more significant than by static aging. The viscoelastic properties of the VES played an important role in altering the wettability. In addition, the ability of the VES to affect the core’s wettability was significantly enhanced when the VES concentration was increased, which was beneficial in increasing VES adsorption on the pore-wall surface, thus altering the overall wettability of the core. Increasing filtration flow rates can destroy those high-viscosity VES aggregates via the higher shear rate. A higher retention of VES makes the core more hydrophilic. The difference in the wettability of cores with different pore radius after VES filtration was not significant. The alteration of average wettability caused by VES in porous media provides a new vision for studying the EOR mechanism of VES

    miR-155-5p Implicates in the Pathogenesis of Renal Fibrosis via Targeting SOCS1 and SOCS6

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    Renal fibrosis is associated with the reduction in the functional renal parenchyma and in most cases progresses to end-stage kidney failure, a devastating condition that requires lifelong dialysis or kidney transplantation. However, due to the extreme complexity in the pathogenesis of renal fibrosis and our limited knowledge, therapeutic options for renal fibrosis in the clinical setting are still scarce and often ineffective. Hence, further studies on the molecular mechanisms underlying renal fibrosis are compellingly needed. Multiple miRNAs have demonstrated to participate in kidney diseases in a TGF-β dependent or independent manner, but there is very little known about miR-155-5p on renal fibrosis. In the present study, we firstly explored the expression level and functions of miR-155-5p in the setting of renal fibrosis. Our research revealed that miR-155-5p is highly expressed in kidney tissues from patients and unilateral ureteral obstruction (UUO) rat models, and miR-155-5p knockdown significantly blocks renal fibrosis both in vivo and in vitro. In mechanism, our data demonstrate that miR-155-5p promotes renal fibrosis by increasing the phosphorylated activation of STAT3 via targeting SOCS1/6. Altogether, our findings highlight a miR-155-5p/SOCS/STAT3 axis in the pathogenesis of renal fibrosis, which may provide promising therapeutic targets for clinical prevention of this disease

    Development of sEMG Sensing Techniques for Hand Prostheses

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    In order to make prosthetic hands acting like human hands as much as possible and improve the biomimetics and intelligence, it is necessary to add multi-sensor perception system on electric prosthetic hand system. In this paper, the theory of sEMG and its signal analysis technology are introduced. SEMG sensing techniques for hand prostheses are surveyed. These sensing techniques include tactile and slip sensing, proximity sensing, cold and hot sensing, and multi-sensing fusion. Meanwhile these prosthetic hands sensors and sEMG sensing techniques are compared. Some further researches and developing trend of sEMG sensing techniques for hand prostheses are indicated

    Oxidative Stress Delays Prometaphase/Metaphase of the First Cleavage in Mouse Zygotes via the MAD2L1-Mediated Spindle Assembly Checkpoint

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    In zygotes, DNA damage delays the first cleavage to enable repair. Our previous study found that 0.03 mM hydrogen peroxide (H2O2) was the minimum concentration required for induction of oxidative DNA damage in mouse zygotes and that this represented the most similar situation to the clinical phenomenon. In this study, we quantified the cleavage rates of cells in blastocysts at different developmental stages, followed by immunofluorescence to detect activation of γ-H2A histone family member X (a marker of DNA damage) in zygotes to confirm that oxidative DNA damage was induced in H2O2-treated zygotes. Monitoring H3S10P (phosphorylation of Ser10 on histone H3; a prometaphase/metaphase marker) levels at different hour postinsemination revealed that treatment of zygotes with 0.03 mM H2O2 resulted in a prometaphase/metaphase delay. Furthermore, immunofluorescence staining for mitotic arrest deficient 2-like 1 and the protein kinase TTK, components of the spindle assembly checkpoint (SAC), suggested that this delay possibly involved SAC activation. These studies of the relationships between oxidative stress and SAC can promote the success rate of in vitro fertilization
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