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BackgroundMo leaching rate is one of the key product properties for high molybdenum radioactive waste vitrification. Furthermore, soluble molybdenum yellow phase is easy to precipitate, resulting in the enhancement of Mo leaching. It was reported that ZnO can promote the network stability and chemical durability in borosilicate glass to some extent. Whereas, if the composition of solidification glass is complex, then whether ZnO can still improve the chemical stability is worth studying. On the other hand, due to the long period of chemical stability test, it is hoped that the Mo leaching rate can be predicted by mathematical simulation to accelerate the research process.PurposeThis study aims to investigate the effect of ZnO in borosilicate glass on Mo leaching rate in simulated high-level radioactive waste (HLW), and establish the prediction model of Mo leaching rate.MethodsFirstly, a series multi-component borosilicate solidification glass samples with simulated high MoO3 (mass ~3%) HLW and designed mass fractions of ZnO content of 1%, 1.5%, 3.5%, 4%, 4.5%, and 5%, respectively, were prepared for experimental test of Mo leaching rate. Then the glass structure gene modeling (GSgM) were employed to accurately simulate the glass properties using a small amount of data to establish the corresponding structural prediction model. Finally, Infrared spectrometer (IR), X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and thermal dilatometer (DIL) were used to test the transformation temperature, heating rate, coefficient of thermal expansion, etc. of the samples, and the model validation was also performed.ResultsExperimental results show that Mo leaching is mainly affected by Si-O-Si rocking vibration around ~530 cm-1 and νSi-O-Si vibration in Q4 at ~1 180 cm-1, furthermore, B2O3, ZrO2 and alkali variation influence the relative concentration of these two structural units, and then affect the Mo leaching. Mo leaching rate is enhanced with mass of ZnO over 3.5% in this complex glass system.ConclusionsModel validation in this study proves that the structure model of Mo leaching rate has good simulation accuracy and statistical reliability, which are further improved after model iteration, hence can be used for the Mo-leaching prediction in the quick-screening of glass composition development.

To study the distribution of surrounding rock plastic zone in roadway under unequal stress in two directions, the south rail lane in 500 m underground 81 mining area of Xutuan Coal Mine is taken as the engineering background. The influencing factors on roadway surrounding plastic zone under unequal stress in two directions, as well as their influencing laws are studied by using the numerical simulation software Abaqus and adopting control variable method. The results show that the plastic zone is strongly affected by ground pressure, lateral pressure coefficient and surrounding rock lithology. The size of plastic zone is somewhat affected by the roadway radius and support, but it is not obvious. And the roadway radius and support have almost no effect on the shape of plastic zone. According to the study, improving the surrounding rock lithology and reducing the principal stress difference are two effective means to control the plastic deformation of roadway surrounding rock.

Based on the special lateral pressure coefficients of 1,the radius of surrounding rock plastic zone obtained by approximate implicit method has a large theoretical error contrasted with the corresponding analytical solution of the mature axisymmetric plane strain theory.In order to improve this shortcoming, from the existing estimation method for surrounding rock plastic zone radius on horizontal axis and based on the formulas of plastic zone under axisymmetric stress field and assumption of the constant total collection degree of line loads,the approximate analytical solution of the surrounding rock plastic zone of unequal stress field on vertical (or horizontal) axis was derived.Then combining with shape of plastic zone determined by approximate implicit method,the plastic zone of surrounding rock under unequal compression in two directions was relatively accurately determined.The proposed method not only eliminates the theoretical error of the approximate implicit method for the lateral pressure coefficient of 1,but also overcomes the theoretical defects of radial stress equal to zero in elastoplastic boundary of surrounding rock by using original estimation method with axisymmetric stress.So proposed method could be considered as a relatively reasonable and accurate estimation method for the plastic zone in roadway surrounding rock under unequal compression in two directions.

Abstract Background Lower limb paralysis occurs in 11% of patients after surgical procedure of thoracic or thoracoabdominal aneurysms and is an unpredictable and distressful complication. The aim of this study was to investigate the effects of tetramethylpyrazine (TMP), an intravenous drug made from traditional Chinese herbs, on the neurologic outcome and hisotpathology after transient spinal cord ischemia in rabbits. Methods Forty-five male New Zealand white rabbits were anesthetized with isoflurane and spinal cord ischemia was induced for 20 min by infrarenal aortic occlusion. Animals were randomly allocated to one of five groups (n = 8 each). Group C received no pharmacologic intervention. Group P received intravenous infusion of 30 mg·kg-1 TMP within 30 min before aortic occlusion. Group T1, Group T2 and Group T3 received intravenous infusion of 15, 30 and 60 mg·kg-1 TMP respectively within 30 min after reperfusion. In the sham group (n = 5), the animals underwent the same procedures as the control group except infrarental aortic unocclusion. Neurologic status was scored by using the Tarlov criteria (in which 4 is normal and 0 is paraplegia) at 4 h, 8 h, 12 h, 24 h, and 48 h after reperfusion. All animals were sacrificed at 48 h after reperfusion and the spinal cords (L5) were removed immediately for histopathologic study. Results All animals in the control group became paraplegic. Neurologic status and histopathology (48 h) in the Groups P, T2 and T3 were significantly better than those in the control group (P < 0.05). There was a strong correlation between the final neurologic scores and the number of normal neurons in the anterior spinal cord (r = 0.776, P < 0.01). Conclusion Tetramethylpyrazine significantly reduces neurologic injury related to spinal cord ischemia and reperfusion after aortic occlusion within a certain range of dose.

Background: The lateral hypothalamus (LHA) is an evolutionarily conserved structure that regulates basic functions of an organism, particularly wakefulness. To clarify the function of LHAGABA neurons and their projections on regulating general anesthesia is crucial for understanding the excitatory and inhibitory effects of anesthetics on the brain. The aim of the present study is to investigate whether LHAGABA neurons play either an inhibitory or a facilitatory role in sevoflurane‐induced anesthetic arousal regulation. Methods: We used fiber photometry and immunofluorescence staining to monitor changes in neuronal activity during sevoflurane anesthesia. Opto‐/chemogenetic modulations were employed to study the effect of neurocircuit modulations during the anesthesia. Anterograde tracing was used to identify a GABAergic projection from the LHA to a periaqueductal gray (PAG) subregion. Results: c‐Fos staining showed that LHAGABA activity was inhibited by induction of sevoflurane anesthesia. Anterograde tracing revealed that LHAGABA neurons project to multiple arousal‐associated brain areas, with the lateral periaqueductal gray (LPAG) being one of the dense projection areas. Optogenetic experiments showed that activation of LHAGABA neurons and their downstream target LPAG reduced the burst suppression ratio (BSR) during continuous sevoflurane anesthesia. Chemogenetic experiments showed that activation of LHAGABA and its projection to LPAG neurons prolonged the anesthetic induction time and promoted wakefulness. Conclusions: In summary, we show that an inhibitory projection from LHAGABA to LPAGGABA neurons promotes arousal from sevoflurane‐induced loss of consciousness, suggesting a complex control of wakefulness through intimate interactions between long‐range connections. [ABSTRACT FROM AUTHOR]

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent psychiatric disorder in children. Although an imbalance of excitatory and inhibitory inputs has been proposed as contributing to this disorder, the mechanisms underlying this highly heterogeneous disease remain largely unknown. Here, we show that N-myc downstream-regulated gene 2 (NDRG2) deficiency is involved in the development of ADHD in both mice and humans. Ndrg2-knockout ([Ndrg2.sup.-/-]) mice exhibited ADHD-like symptoms characterized by attention deficits, hyperactivity, impulsivity, and impaired memory. Furthermore, interstitial glutamate levels and excitatory transmission were markedly increased in the brains of [Ndrg2.sup.-/-] mice due to reduced astroglial glutamate clearance. We developed an NDRG2 peptide that rescued astroglial glutamate clearance and reduced excitatory glutamate transmission in NDRG2-deficient astrocytes. Additionally, NDRG2 peptide treatment rescued ADHD-like hyperactivity in the [Ndrg2.sup.-/-] mice, while routine methylphenidate treatment had no effect on hyperactivity in these animals. Finally, children who were heterozygous for rs1998848, a SNP in NDRG2, had a higher risk of ADHD than children who were homozygous for rs1998848. Our results indicate that NDRG2 deficiency leads to ADHD phenotypes and that impaired astroglial glutamate clearance, a mechanism distinct from the well-established dopamine deficit hypothesis for ADHD, underlies the resultant behavioral abnormalities., Introduction Attention-deficit/hyperactivity disorder (ADHD) is a heterogeneous disorder that affects 1 in 20 children and results in poor lifetime outcomes (1, 2). Males are approximately 3 to 4 times more [...]