32 research outputs found

    Dexmedetomidine Ameliorates the Neurotoxicity of Sevoflurane on the Immature Brain Through the BMP/SMAD Signaling Pathway

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    Numerous studies have demonstrated that general anesthetics might damage the nervous system, thus, the effect of general anesthetics on the developing brain has attracted much attention. Dexmedetomidine (Dex) exhibits a certain neuroprotective effect, but the mechanism is obscure. In our study, pregnant rats on gestational day 20 (G20) were exposed to 3% sevoflurane for 2 h or 4 h, and the neuronal apoptosis in hippocampal CA1 region of the offspring rats was detected by quantification of TUNEL positive cells and cleaved-caspase3 (cl-caspase3). Different doses of Dex were intraperitoneally injected before sevoflurane anesthesia; then, the expression of apoptotic-related proteins including BCL-2, BAX and cl-caspase3 as well as amyloid precursor protein (APP, a marker of axonal injury), p-CRMP-2 and CRMP-2 were measured at postnatal days 0, 1and 3 (P0, P1, and P3, respectively). As an antagonist of the bone morphgenetic proteins (BMP) receptor, DMH1 was co-administered with sevoflurane plus Dex to investigate whether BMP/SMAD is associated with the neuroprotective effects of Dex. The results showed that prenatal sevoflurane anesthesia for 4 h activated apoptosis transiently, as manifested by the caspase3 activity peaked on P1 and disappeared on P3. In addition, the expressions of APP and p-CRMP-2/CRMP-2 in postnatal rat hippocampus were significantly increased, which revealed that prenatal sevoflurane anesthesia caused axonal injury of offspring. The long-term learning and memory ability of offspring rats was also impaired after prenatal sevoflurane anesthesia. These damaging effects of sevoflurane could be mitigated by Dex and DMH1 reversed the neuroprotective effect of Dex. Our results indicated that prenatal exposure to 3% sevoflurane for 4 h increased apoptosis and axonal injury, even caused long-term learning and memory dysfunction in the offspring rats. Dex dose-dependently reduced sevoflurane- anesthesia-induced the neurotoxicity by activating the BMP/SMAD signaling pathway

    Acetaldehyde dehydrogenase 2 (ALDH2) deficiency exacerbates pressure overload-induced cardiac dysfunction by inhibiting Beclin-1 dependent autophagy pathway

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    AbstractMitochondrial aldehyde dehydrogenase 2 (ALDH2) was demonstrated to play cardioprotective roles in cardiovascular diseases. Nonetheless, little is known about the roles and mechanisms of ALDH2 in pressure overload-induced cardiac damages. In this study, we revealed that ALDH2 deficiency overtly exacerbated transverse aortic constriction (TAC)-induced cardiac dysfunction. Cardiomyocyte enlargement was observed in both WT and ALDH2−/− mice in HE-stained myocardial tissue samples at 8weeks post TAC surgery. Mitochondrial morphology and structure were also significantly damaged post TAC surgery and the changes were aggravated in ALDH2−/− TAC hearts. ALDH2 deficiency also depressed myocardial autophagy in hearts at 8weeks post TAC surgery with a potential mechanism of repressing the expression of Beclin-1 and promoting the interaction between Bcl-2 and Beclin-1. These data indicate that ALDH2 deficiency exacerbates the pressure overload induced cardiac dysfunction partly by inhibiting Beclin-1 dependent autophagy pathway.This article is part of a Special Issue entitled: Autophagy and protein quality control in cardiometabolic diseases

    Novel Magnetic-Sensing Modalities with Nitrogen-Vacancy Centers in Diamond

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    In modern-day quantum metrology, quantum sensors are widely employed to detect weak magnetic fields or nanoscale signals. Quantum devices, exploiting quantum coherence, are inevitably connected to physical constants and can achieve accuracy, repeatability, and precision approaching fundamental limits. As a result, these sensors have shown utility in a wide range of research domains spanning both science and technology. A rapidly emerging quantum sensing platform employs atomic-scale defects in crystals. In particular, magnetometry using nitrogen-vacancy (NV) color centers in diamond has garnered increasing interest. NV systems possess a combination of remarkable properties, optical addressability, long coherence times, and biocompatibility. Sensors based on NV centers excel in spatial resolution and magnetic sensitivity. These diamond-based sensors promise comparable combination of high spatial resolution and magnetic sensitivity without cryogenic operation. The above properties of NV magnetometers promise increasingly integrated quantum measurement technology, as a result, they have been extensively developed with various protocols and find use in numerous applications spanning materials characterization, nuclear magnetic resonance (NMR), condensed matter physics, paleomagnetism, neuroscience and living systems biology, and industrial vector magnetometry. In this chapter, NV centers are explored for magnetic sensing in a number of contexts. In general, we introduce novel regimes for magnetic-field probes with NV ensembles. Specifically, NV centers are developed for sensitive magnetometers for applications where microwaves (MWs) are prohibitively invasive and operations need to be carried out under zero ambient magnetic field. The primary goal of our discussion is to improve the utility of these NV center-based magnetometers

    Evaluation of Mixed-Mode Ventilation Thermal Performance and Energy Saving Potential from Retrofitting a Beijing Office Building

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    Mixed-mode cooling can effectively reduce the energy consumption of building cooling while satisfying the thermal comfort of occupancy and indoor air quality requirements. This paper predicted the thermal performance and energy-saving potential of an existing Beijing office building (in continental climates) operated in a mixed-mode from April to October. For the natural ventilation mode, the results predicted by simulation were validated with the results of experiments conducted in October 2021 and April 2022. Occupancy thermal comfort of the mixed-mode building was predicted using Predicted Mean Vote (PMV) and adaptive comfort models. The predictions demonstrated acceptable satisfactory thermal comfort for the occupancy. The results showed that the mixed-mode building’s annual cooling energy use is reduced by around 45% compared to the air-conditioned building. In addition, the building’s indoor temperature and velocity distributions were predicted using a Computational Fluid Dynamics (CFD) simulation. The validation showed a satisfactory agreement between CFD simulation and measurement data. It is found from CFD results that cross-ventilation can provide thermal comfort for the occupancy while improving fresh air requirements. The suggested that operational strategies of mixed-mode cooling can be used in office buildings in continental climates. Retrofitting the existing office building can bring a significant amount of energy saving

    Analyzing the influence of square Maxwell coil’s assembly errors on the uniformity of magnetic field gradient

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    A Maxwell coil is a gradient magnetic field source with high uniformity, and it is widely used in the experiment of magnetic effect in space gravitational wave detection, magnetic resonance molecular imaging, and other precision magnetic measurement experiments. In this paper, taking the square Maxwell coil as a research object, the influences of four kinds of assembly errors on the uniformity of magnetic field gradient (UOMFG) are systematically analyzed and the results are verified by simulation using the finite element method. We obtained variation rules of UOMFG changing with the four assembly errors and summarized three useful conclusions. These rules and conclusions are instructive in the design, processing, and assembly of the square Maxwell coil and are beneficial for the optimal utilization of the working area in the precision magnetic measurement experiments

    Intergenerational transmission of parental child-rearing gender-role attitudes and its influence on gender roles in single-parent families

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    Abstract Background The development of children’s gender roles in single-parent families is worthy of attention. It may be affected by family members’ gender roles and parental child-rearing gender-role attitudes (PCGA). PCGA will form a consistent or inconsistent intergenerational relationship between parents and children. Objective This study examined the intergenerational similarities in gender roles and PCGA. Also, the intergenerational transmission of parental child-rearing gender-role attitudes (ITPCGA) in single-parent families, and the impact of various family factors on children’s gender roles were comprehensively considered. Method Participants were 550 single-parent parent-adolescent dyads. The Gender-role Scale and the Parental Child-rearing Gender-role Attitude Scale were used to evaluate participants’ gender-role and PCGA. Chi-square tests and logistic regression analyses were used to examine the intergenerational similarities in gender roles and PCGA, and the influencing family factors of ITPCGA and children’s gender roles. Results The intergenerational similarities of gender role types and PCGA types existed. Both parents’ gender roles and family gender pairs affected ITPCGA, father-daughter families and parents’ undifferentiated and sex-typed gender roles significantly predicted undesirable ITPCGA. Family gender pair, parent’s gender roles and ITPCGA types affected children’s gender roles. Undesirable ITPCGA significantly predicted children’s undifferentiated gender roles; father-daughter families and mother-son families, parents’ undifferentiated and sex-typed gender roles significantly predicted children’s sex-typed gender roles, and mother-son families and parents’ reversed gender roles significantly predicted children’s reversed gender role. Conclusions This study highlights the effects of single-parent family gender pairs and parents’ gender roles on ITPCGA, which influences the development of children’s gender roles

    A New Approach to Calculate the Shielding Factor of Magnetic Shields Comprising Nonlinear Ferromagnetic Materials under Arbitrary Disturbances

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    To enable the realization of ultra-low magnetic fields for scientific and technological research, magnetic shielding is required to create a space with low residual magnetic field and high shielding factors. The shielding factors of magnetic shields are due to nonlinear material properties, the geometry and structure of the shields, and the external magnetic fields. Magnetic shielding is used in environments full of random realistic disturbances, resulting in an arbitrary and random external magnetic field, and in this case, the shielding effect is hard to define simply by the shielding factors. A new method to simulate and predict a dynamic internal space magnetic field wave is proposed based on the Finite Element method (FEM) combined with the Jiles-Atherton (JA) model. By simulating the hysteresis behavior of the magnetic shields and establishing a dynamic model, the new method can simulate dynamic magnetic field changes inside magnetic shields as long as the external disturbances are known. The shielding factors under an AC external field with a sine wave and certain frequencies are calculated to validate the feasibility of the new method. A real-time wave of internal magnetic flux density under an AC triangular wave external field is simulated directly with the new method versus a method that splits the triangular wave into several sine waves by a Fourier transform, divides the shielding factors, and then adds the quotients together. Moreover, real-time internal waves under some arbitrary fields are measured. Experimental internal magnetic flux density waves of a 4-layer magnetically shielded room (MSR) at the Harbin Institute of Technology (HIT) fit the simulated results well, taking experimental errors into account
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