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Ischemic stroke is one of the main causes of death and long-term disability worldwide, which seriously affects the quality of life of patients and brings a heavy economic burden to families and society. Epidemiological studies have shown that stroke has become the second leading cause of death and major disabling disease in the world, with the characteristics of high morbidity, high recurrence, and high mortality. Epigenetic mechanism is the molecular process where gene expression and function in each cell are dynamically regulated and interconnected and a biological mechanism that changes genetic performance without changing the DNA sequence, including DNA methylation, histone modifications, and non-coding RNA. However, the research on epigenetics is currently focused on other diseases such as tumors. Recent studies have found that epigenetics has received extensive attention in the past few decades as a key factor involved in the pathophysiological process of ischemic stroke. The present study introduced the mediation of epigenetics in the induction of stroke, summarized the potential drug targets for these mechanisms in the treatment of stroke, and further explored the significance of traditional Chinese medicine(TCM) against cerebral ischemia injury based on TCM classification of stroke.

Cerebral ischemia-reperfusion injury(CIRI) is an important factor hindering the recovery of ischemic stroke patients after blood flow recanalization. Mitochondria, serving as thequot;energy chamberquot; of cells, have multiple important physiological functions, such as supplying energy, metabolizing reactive oxygen species, storing calcium, and mediating programmed cell death. During CIRI, oxidative stress, calcium overload, inflammatory response, and other factors can easily lead to neuronal mitochondrial dyshomeostasis, which is the key pathological link leading to secondary injury. As reported, the mitochondrial quality control(MQC) system, mainly including mitochondrial biosynthesis, kinetics, autophagy, and derived vesicles, is an important endogenous mechanism to maintain mitochondrial homeostasis and plays an important protective role in the damage of mitochondrial structure and function caused by CIRI. This paper reviewed the mechanism of MQC and the research progress on MQC-targeting therapy of CIRI in recent 10 years to provide theoretical references for exploring new strategies for the prevention and treatment of ischemic stroke with traditional Chinese medicine.

To investigate the antidepressant-like effects of Chaihu Shugan Powder (CSP, 柴胡疏肝散) and to explore its underlying mechanisms. Thirty-two Sprague-Dawley rats were randomly divided into control (CON), chronic unpredictable mild stress (CUMS), fluoxetine (FLU), and CSP groups, 8 rats in each group. All of the rats except for those in the control group were subjected to 3 consecutive weeks of CUMS to establish the depression model. The open field test (OFT), forced swimming test (FST), and sucrose preference test were used to assess the anti-anxiety and antidepressant effects of CSP. Terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling was used to determine the apoptosis rate in the hippocampal tissues. The mRNA and protein levels of glucose-regulated protein (GRP) 78, spliced X-box-binding protein (XBP)-1, CCAAT/enhancer-binding protein homologous protein (CHOP), caspase-12, and c-Jun N-terminal kinase (JNK) in the hippocampus of rats were evaluated by real-time PCR and Western blot analysis, respectively. Administration of CSP alleviated anxiety and depression-like behavior in CUMS rats, as revealed by enhanced time and distance in the center of the OFT (P

When ischemia or hemorrhagic stroke occurs, astrocytes are activated by a variety of endogenous regulatory factors to become reactive astrocytes. Subsequently, reactive astrocytes proliferate, differentiate, and migrate around the lesion to form glial scar with the participation of microglia, neuron-glial antigen 2(NG2) glial cells, and extracellular matrix. The role of glial scars at different stages of stroke injury is different. At the middle and late stages of the injury, the secreted chondroitin sulfate proteoglycan and chondroitin sulfate are the main blockers of axon regeneration and nerve function recovery. Targeted regulation of glial scars is an important pathway for neurological rehabilitation after stroke. Chinese medicine has been verified to be effective in stroke rehabilitation in clinical practice, possibly because it has the functions of promoting blood resupply, anti-inflammation, anti-oxidative stress, inhibiting cell proliferation and differentiation, and benign intervention in glial scars. This study reviewed the pathological process and signaling mechanisms of glial scarring after stroke, as well as the intervention of traditional Chinese medicine upon glial scar, aiming to provide theoretical reference and research evidence for developing Chinese medicine against stroke in view of targeting glial scarring.

Background Insomnia is a common but frequently overlooked sleep disorder after stroke, and there are limited effective therapies for insomnia following stroke. Traditional Chinese medicine (TCM), including acupuncture and the Chinese herbal medication (CHM) Suanzaoren decoction (SZRD), has been reported as an alternative option for insomnia relief after stroke in China for thousands of years. Here, this study aims to investigate the efficacy and safety of electroacupuncture (EA) in combination with SZRD in the treatment of insomnia following stroke. Methods A total of 240 patients with post-stroke insomnia will be included and randomized into four groups: the EA group, SZRD group, EA & SZRD group, and sham group. The same acupoints (GV20, GV24, HT7, and SP6) will be used in the EA group, EA & SZRD group, and sham group, and these patients will receive the EA treatment or sham manipulation every other day for 4 consecutive weeks. SZRD treatments will be given to participants in the SZRD group and EA & SZRD group twice a day for 4 consecutive weeks. The primary outcome measures include Pittsburgh Sleep Quality Index scores and polysomnography. Secondary outcome measures include the Insomnia Severity Index, the National Institutes of Health Stroke Scale, the Hospital Anxiety and Depression Scale, brain magnetic resonance imaging, functional magnetic resonance imaging, and nocturnal melatonin concentrations. The primary and secondary outcomes will be assessed at baseline (before treatment), during the 2nd and 4th weeks of the intervention, and at the 8th and 12th weeks of follow-up. Safety assessments will be evaluated at baseline and during the 4th week of the intervention. Discussion This study will contribute to assessing whether the combination of these two therapies is more beneficial for post-stroke insomnia than their independent use, and the results of this clinical trial will improve our understanding of the possible mechanisms underlying the effects of combination therapies. Trial registration Chinese Clinical Trials Register ChiCTR2000031413. Registered on March 30, 2020

The microstructure investigations of a U3Si2 specimen implanted by 84 MeV Xe ions at 450∘C are reported here. In the region that corresponds to the highest irradiation dose, U3Si2 was found to decompose into a Si-enriched nanocrystalline USi matrix phase and a U-enriched amorphous inclusion phase. Density functional theory (DFT) calculations were used to help understand the decomposition mechanism. Xe bubbles of different morphologies were observed in USi nano-grains, on USi grain boundaries, and phase boundaries. Original U3Si2 micro-grains were preserved on both sides of the irradiation damage peak region within the sample, implying a radiation dose threshold for decomposition of approximately 150 dpa at 450∘C. In the preserved U3Si2 region beneath the irradiation damage peak, where significant amount of Xe ions were deposited, a monomodal size distribution of intragranular Xe bubbles with an average size of 2.68 nm formed. In both decomposed and preserved U3Si2, the size of Xe bubbles was found to be lower than 50 nm. Based on this observation, the fission gas behavior of U3Si2 is controllable and free of run-away swelling despite the occurrence of decomposition at this irradiation temperature.

The structural, elastic, electronic, vibrational and thermodynamic properties of uranium aluminides UAlx (x = 2, 3, 4) were studied by density functional theory calculations. The single crystal elastic constants of UAlx were predicted using the stress-strain method, which were further used to calculate the polycrystalline aggregate properties of UAlx, including bulk modulus, shear modulus, Young’s modulus, and Poisson’s ratio, etc. The calculated electronic density of states confirm that UAlx compounds are metallic phases with majority states at the Fermi level contributed by U 5f electrons. The phonon dispersion relations and density of states show that the low frequency acoustic phonon modes of UAlx are dominated by the lattice vibration of uranium atoms while high frequency optical phonon modes are from the vibration of aluminum atoms. Using quasiharmonic approximation, thermodynamic properties of UAlx, including Gibbs free energy, entropy, heat capacity, and linear thermal expansion coefficient, were predicted by including both lattice vibrational and thermal electronic contributions. The thermal electronic energy was found to be crucial for the description of the temperature dependence of the thermodynamic properties. The derived Gibbs energy functions of UAlx are expected to be useful to the thermodynamic modeling of the ternary U-Mo-Al system.

Uranium-molybdenum (U-Mo) particles dispersed in an aluminum matrix is the most promising candidate fuel to convert high-power research and test reactors in Europe from using high-enriched to using low-enriched fuel. However, chemical interaction between the U-Mo and the Al matrix leads to undesirable fuel behavior. Zirconium nitride (ZrN) is used as a diffusion barrier between the U-Mo fuel particles and the Al matrix. To understand the potential microstructural evolution of ZrN during irradiation, a high-energy heavy ion (84 MeV Xe) irradiation experiment was performed on atomic layer deposited (ALD) nanocrystalline ZrN deposited on an Al plate. A fluence of 1.86 × 1017 ions/cm2, or 90.3 dpa was reached during this experiment. Both analytic transmission electron microscopy (TEM) and synchrotron microbeam X-ray diffraction (μXRD) techniques were utilized to investigate the kinetics of radiation-induced grain growth of ZrN at various radiation doses based on the Williamson-Hall analyses. The grain growth kinetics can be described by a power law expression, D n − D 0 n = K ϕ , with n = 5.1. The Al-ZrN interaction products (Al3Zr and AlN) created by radiation-induced ballistic mixing/radiation-enhanced diffusion and their corresponding formation mechanism were determined from electron diffraction and elemental composition analysis. These experimental results were confirmed by first principle thermodynamic density functional theory (DFT) calculations. The results from this ion irradiation study were also compared to in-pile irradiation data from physical vapor deposited (PVD) ZrN samples for a comprehensive evaluation of the interaction between Al and ZrN and its influence on diffusion barrier performance.

Thermophysical properties of interaction layer (IL) formed in U-Mo/Al dispersion fuel are important for the evaluation of its impact on the fuel performance. Binary and ternary phases observed in the IL, however, are not well studied yet. Recently we predicted the thermophysical properties of the binary U-Al compounds in U-Al system using density functional theory (DFT) calculations. In this paper, we investigated the structural, elastic, electronic, vibrational and thermodynamic properties of the ternary U-Mo-Al compounds formed in IL, including (U0.75,Mo0.25)Al3, U6Mo4Al43 and UMo2Al20, using DFT calculations. The polycrystalline aggregate properties of these compounds were obtained from the predicted single crystal elastic constants. The calculated electronic density of states confirm that all of the compounds exhibit typical metallic behavior with the majority states at the Fermi level dominated by U 5f electrons. Using quasi-harmonic approximation, we predicted the thermodynamic properties of these compounds by including both electronic and lattice contributions. We also investigated the effect of density on the thermodynamic properties of (U0.75,Mo0.25)Al3 phase. The current results are expected to be helpful to the modeling of the fuel performance of U-Mo/Al dispersion fuel and the thermodynamic modeling of the ternary U-Mo-Al system.

Due to its superior thermophysical properties, ZrN thin film has been studied as a diffusion barrier for a variety of applications. However, cracks and delamination of ZrN coating takes place because of its brittleness. To identify new diffusion barrier materials with improved fracture toughness, we systematically studied the mechanical properties, surface energies and fracture toughness of IVB, VB and VIB transition metal mononitrides using first-principles calculations. TiN and HfN show slightly better toughness than ZrN. To improve the toughness of ZrN, we investigated the fracture toughness of ZrN alloyed with 25% IVB, VB and VIB transition metal nitrides. TiN, HfN and TaN was found to be able to increase the fracture toughness of ZrN through alloying. Meanwhile, we predicted the interfacial fracture toughness of ZrN/TiN and ZrN/HfN interfaces to evaluate the fracture toughness of ZrN/TiN and ZrN/HfN multilayer structures. Both ZrN/TiN and ZrN/HfN films exhibit higher interfacial fracture toughness than that of ZrN single film. Therefore, alloying and multilayer structures are promising approaches to enhance the toughness of brittle ZrN film.

Electroacupuncture is known as an effective adjuvant therapy in ischemic cerebrovascular disease. However, its underlying mechanisms remain unclear. Studies suggest that autophagy, which is essential for cell survival and cell death, is involved in cerebral ischemia reperfusion injury and might be modulate by electroacupuncture therapy in key ways. This paper aims to provide novel insights into a therapeutic target of electroacupuncture against cerebral ischemia/reperfusion injury from the perspective of autophagy. Here we review recent studies on electroacupuncture regulation of autophagy-related markers such as UNC-51-like kinase-1 complex, Beclin1, microtubule-associated protein-1 light chain 3, p62, and autophagosomes for treating cerebral ischemia/reperfusion injury. The results of these studies show that electroacupuncture may affect the initiation of autophagy, vesicle nucleation, expansion and maturation of autophagosomes, as well as fusion and degradation of autophagolysosomes. Moreover, studies indicate that electroacupuncture probably modulates autophagy by activating the mammalian target of the rapamycin signaling pathway. This review thus indicates that autophagy is a therapeutic target of electroacupuncture treatment against ischemic cerebrovascular diseases.

We demonstrate an unconventional near-infrared photodetector fabricated from a ZnO chip with a metallic subwavelength grating structure as a contact and optical window, which harvests hot electrons generated by plasmonic resonances introduced by incident light. The grating structure has a strong selection of the polarization of incident light, meaning that the detector is naturally polarization-sensitive. In our device, the polarization extinction ratio is as high as 64:1, much higher than that relying on crystal orientations. Since the photoresponse is introduced by plasmonic resonance, a narrow photoresponse spectrum with a linewidth of 32.1 nm at 1.201 μm is obtained. By simply changing the grating period, the spectral position can be tailored freely within the near-infrared region, i.e., wavelength-selective. Such a spectral response is not likely to be realized with conventional semiconductor photodetectors, which depend on the band edge absorption. We propose a modified Fowler's model, which well explains the line shape of photoresponse spectra of such devices.

Cerebral ischemia/reperfusion (CIR) injury occurs when blood flow is restored in the brain, causing secondary damage to the ischemic tissues. Previous studies have shown that electroacupuncture (EA) treatment contributes to brain protection against CIR injury through modulating autophagy. Studies indicated that SIRT1-FOXO1 plays a crucial role in regulating autophagy. Here we investigated the mechanisms underlying the neuroprotective effect of EA and its role in modulating autophagy via the SIRT1-FOXO1 signaling pathway in rats with CIR injury. EA pretreatment at “Baihui”, “Quchi” and “Zusanli” acupoints (2/15Hz, 1mA, 30 min/day) was performed for 5 days before the rats were subjected to middle cerebral artery occlusion, and the results indicated that EA pretreatment substantially reduced the Longa score and infarct volume, increased the dendritic spine density and lessened autophagosomes in the peri-ischemic cortex of rats. Additionally, EA pretreatment also reduced the ratio of LC3-II/LC3-I, the levels of Ac-FOXO1 and Atg7, and the interaction of Ac-FOXO1 and Atg7, but increased the levels of p62, SIRT1, and FOXO1. The above effects were abrogated by the SIRT1 inhibitor EX527. Thus, we presume that EA pretreatment elicits a neuroprotective effect against CIR injury, potentially by suppressing autophagy via activating the SIRT1-FOXO1 signaling pathway.

In nuclear industry, damages caused to in-core structural materials by high-energy neutrons have been studied for years. Recently, the possibility of storing energy through the creation of defects in crystalline materials via heavy particle bombardment was investigated. To evaluate the potential of the Wigner effect as energy-storing process, a graphite-moderated Molten Salt Reactor was adopted as a test case. Neutronics simulations performed with OpenMC Monte Carlo code allowed estimating the amount of energy released during fission events, the fraction that is deposited in graphite, and the fraction that has the potential to cause radiation damages. Molecular dynamics simulations were then performed to study the evolution of cascades triggered by high-energy neutrons. As a major outcome, a more accurate estimate of the radiation damage with respect to the traditional approaches was obtained, and the fraction of the deposited neutron energy that can be stored through long-lived defects was quantified.

To evaluate the effect of Buyang Huanwu Decoction (补阳还五汤, BYHWD) on glial scar after intracerebral hemorrhage (ICH) and investigate the underlying mechanism. Collagenase type VII (0.5 U) was injected stereotaxically into right globus pallidus to induce ICH model. One hundred and twenty Sprague-Dawley rats were randomly divided into 3 groups according to a random number table, including normal group (n=40), ICH model group (n=40) and BYHWD group (n=40), respectively. After ICH, the rats in the BYHWD group were intragastrically administered with BYHWD (4.36 g/kg) once a day for 21 days, while the rats in ICH group were administered with equal volume of distilled water for 21 days, respectively. Double immunolabeling was performed for proliferating cell nuclear antigen (PCNA)+/glial fibrillary acidic protein (GFAP)+ nuclei. The expression of GFAP and leukemia inhibitory factor (LIF) was evaluated by immunohistochemistry and quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR). The astrocytes with hypertrophied morphology around the hematoma was observed on day 3 after ICH. The number of GFAP positive cells and GFAP mRNA levels increased notably on day 3 and reached the peak on day 14 post-ICH (P

We have developed a mesoscale model to calculate the degradation of the effective thermal conductivity in irradiated U-Mo alloys caused by the fission-induced gas bubbles and recrystallization. The phase-field approach is employed to generate the grain microstructures of U-7Mo fuels with intra- and inter-granular gas bubbles. Based on the phase-field microstructures, the thermal conductivities of U-7Mo as a function of the fission density can be predicted by the developed mesoscale model. The predicted values of effective thermal conductivities are consistent with available experimental data although the grain structure and the distribution of gas bubbles were generated from the phase-field simulations that may not exactly correspond to experimental microstructures. Results show that the effective thermal conductivity decreases rapidly with recrystallization compared to the one prior to recrystallization, which can be attributed to the sudden increase of grain boundary densities and corresponding intergranular gas bubbles at high fission densities. Smaller grain size fuel structure has a lower thermal conductivity at the same fission density due to the increased grain boundary density. The current study can provide a better understanding of the fission-induced degradation mechanism of the thermal conductivity in U-Mo fuels.

We investigate the lattice and electronic thermal conductivities of uranium aluminide compounds, i.e., UAl2, UAl3 and UAl4, by density functional theory calculations. The lattice and electronic contributions to the total thermal conductivity of uranium aluminides are compared, and the contributions of phonons with different mean free times and modes to the lattice thermal conductivity of UAl3 are analyzed from the calculated cumulative and spectral thermal conductivities. The effect of Mo addition and U vacancy on the thermal conductivities of UAl3 and UAl4 is studied by considering the elastic phonon scattering due to mass difference. Both Mo addition and U vacancy are found to significantly reduce the thermal conductivities of ideal UAl3 and UAl4 even with very low concentrations. The currently predicted thermal conductivities of uranium aluminide compounds are expected to be useful to the evaluation of the effective thermal conductivity of the interaction layer formed in U-Mo/Al dispersion fuel.

The evolution of fission gas bubbles in irradiated materials plays a critical role in the microstructural processes that leads to dimensional changes of U-Mo alloy fuels, e.g., fuel swelling. Although the intergranular bubbles-induced fuel swelling has been long-discussed for U-Mo fuel, there are very few computational studies of the formation of intragranular gas bubbles and its impact on fuel swelling. To this end, we develop a three-dimensional phase-field model to investigate the evolution of intragranular gas bubbles in U-Mo fuel. Fission induced defect formation and annihilation processes, such as vacancy-interstitial recombination, fission gas atom resolution, and interactions with dislocations and grain boundaries are incorporated in the model. Simulations show that the intragranular gas bubbles can be stabilized to certain sizes due to the balance between the generation and annihilation of defects. The intragranular gas bubbles induced fuel swelling is predicted to be comparable to experimental measurements. The effects of the irradiation and fuel fabrication conditions (i.e., fission rate, fuel grain size, and mechanical work induced deformation) on the bubble evolution and the resultant swelling are investigated. The current simulations provide a better understanding of intragranular gas bubble-induced swelling and a solid foundation for the future study of the nucleation and growth of intergranular gas bubbles and recrystallization in U-Mo fuel.

U-Mo alloys are promising fuels for future high-performance research reactors with low enriched uranium. Surface properties, such as surface energy, are important inputs for mesoscale simulations (e.g., phase field method) of fission gas bubble behaviors in irradiated nuclear fuels. The lack of surface energies of U-Mo alloys prevents an accurate modeling of the morphology of gas bubbles and gas bubble-induced fuel swelling. To this end, we study the surface properties of U-Mo system, including bcc Mo, α-U, γ-U, and γ U-Mo alloys. All surfaces up to a maximum Miller index of three and two are calculated for cubic Mo and γ-U and non-cubic α-U, respectively. The equilibrium crystal shapes of bcc Mo, α-U and γ-U are constructed using the calculated surface energies. The dominant surface orientations and the area fraction of each facet are determined from the constructed equilibrium crystal shape. The disordered γ U-Mo alloys are simulated using the Special Quasirandom Structure method. The (1 1 0) and (1 0 0) surface energies of γ U-7Mo and U-10Mo alloys are predicted to lie between those of γ-U and bcc Mo, following a linear combination of the two constituents’ surface energies. To better compare with future measurements of surface energies, the area fraction weighted surface energies of α-U, γ-U and γ U-7Mo and U-10Mo alloys are also predicted.

Fission gas behavior of U3Si2 under various loss-of-coolant accident (LOCA) conditions in light water reactors (LWRs) was simulated using rate theory. A rate theory model for U3Si2 that covers both steady-state operation and power transients was developed for the GRASS-SST code based on existing research reactor/ion irradiation experimental data and theoretical predictions of density functional theory (DFT) calculations. The steady-state and LOCA condition parameters were either directly provided or inspired by BISON simulations. Due to the absence of in-pile experiment data for U3Si2’s fuel performance under LWR conditions at this stage of accident tolerant fuel (ATF) development, a variety of LOCA scenarios were taken into consideration to comprehensively and conservatively evaluate the fission gas behavior of U3Si2 during a LOCA.

In this work, an innovative energy storage concept based on the purposeful creation of defects in crystalline material by neutron irradiation is presented. Lattice defects are generated when heavy particles collide with the atoms in a crystal structure, i.e., if the incoming particles have enough energy, recoil atoms are displaced from their initial lattice sites. Most of the displaced atoms will eventually combine with nearby vacancies, but some of them will come to rest in non-ideal locations. The energy held by displaced atoms is called Wigner energy. Lattice defects can migrate and form clusters, and the Wigner energy can be released from these groupings if sufficient activation energy is provided. In the nuclear industry, this effect is well-known since it represented an issue for graphite-moderated reactors. This work presents the conceptual design of an engineering system that exploits this physical process to store the energy of neutrons in advanced reactor concepts. In the first part of the paper, the theoretical performance of an energy storage system based on the Wigner effect is described. Given the lattice properties and the compatibility with the harsh reactor environment, graphite was selected as the candidate material for the irradiation targets. Both experimental data and molecular dynamics simulations confirmed that this system can achieve performance comparable with state-of-the-art batteries in terms of stored energy density. In the second part of the paper, the engineering challenges of this innovative technology and the proposed solutions are described. After defining the optimal irradiation conditions, the different steps of the operation of the proposed energy system (from energy storing to energy harvesting) were defined. Finally, the integration of this concept with advanced reactor designs, i.e., a Sodium-cooled Fast Reactor and a Molten Salt-cooled Reactor, was investigated and the corresponding performance was evaluated.

Rate theory simulations of fission gas behavior in U 3 Si 2 are reported for light water reactor (LWR) steady-state operation scenarios. A model of U 3 Si 2 was developed and implemented into the GRASS-SST code based on available research reactor post-irradiation examination (PIE) data, and density functional theory (DFT) calculations of key material properties. The reliability of the model was examined by performing sensitivity analysis of the key parameters. Simplified peripheral models were also introduced to capture the fuel-cladding interaction. The simulations identified three regimes of U 3 Si 2 swelling behavior between 390 K and 1190 K. Under typical steady-state LWR operating conditions where U 3 Si 2 temperature is expected to be below 1000 K, intragranular bubbles are dominant and fission gas is retained in those bubbles. The consequent gaseous swelling is low and associated degradation in the fuel thermal conductivity is also limited. Those predictions of U 3 Si 2 performance during steady-state operations in LWRs suggest that this fuel material is an appropriate LWR candidate fuel material. Fission gas behavior models established based on this work are being coupled to the thermo-mechanical simulation of the fuel behavior using the BISON fuel performance multi-dimensional finite element code.

We have developed a mesoscale phase-field model for studying the effect of recrystallization on gas-bubble-driven swelling in irradiated U-Mo alloy fuel. The model can simulate the microstructural evolution of the intergranular gas bubbles on the grain boundaries as well as the recrystallization process. Our simulation results show that the intergranular gas-bubble-induced fuel swelling exhibits two stages: slow swelling kinetics before recrystallization and rapid swelling kinetics with recrystallization. We observe that the recrystallization can significantly expedite the formation and growth of gas bubbles at high fission densities. The reason is that the recrystallization process increases the nucleation probability of gas bubbles and reduces the diffusion time of fission gases from grain interior to grain boundaries by increasing the grain boundary area and decreasing the diffusion distance. The simulated gas bubble shape, size distribution, and density on the grain boundaries are consistent with experimental measurements. We investigate the effect of the recrystallization on the gas-bubble-driven fuel swelling in U-Mo through varying the initial grain size and grain aspect ratio. We conclude that the initial microstructure of fuel can be used to effectively control the recrystallization and therefore reduce the swelling in U-Mo fuel.

To assess the efficacy and safety of the combination of total glucoside of peony (TGP) and methotrexate (MTX) for the treatment of rheumatoid arthritis (RA). Randomized controlled trial (RCT) data on the traditional Chinese active component TGP combined with MTX vs. MTX alone for the treatment of RA was collected by searching the Pubmed, Embase, Cochrane Library, CNKI, VIP Journals database, and Wanfang database up to February 2017. Study selection, data extraction, data synthesis, and data analyses were performed according to the Cochrane standards. A total of eight RCTs involving 522 participants were included in this meta-analysis. Compared with MTX alone, the use of TGP combined with MTX exhibited better therapeutic effects for the treatment of RA (P = 0.004). In addition, TGP combined with MTX caused a more significant decrease in erythrocyte sedimentation rate (ESR) (P

To evaluate the effectiveness of ZrN as a diffusion barrier against fission gases, we investigate the incorporation and migration of fission gas atoms, with a focus on Xe, in ZrN by first-principles calculations. The formations of point defects in ZrN, including vacancies, interstitials, divacancies, Frenkel pairs, and Schottky defects, are first studied. Among all the defects, the Schottky defect with two vacancies as first nearest neighbor is predicted to be the most favorable incorporation site for fission gas Xe in ZrN. The migration of Xe gas atom in ZrN is investigated through two diffusion mechanisms, i.e., interstitial and vacancy-assisted diffusions. The migration barrier of Xe gas atom through the intrinsic interstitials in ZrN is considerably lower than that through vacancies. Therefore, at low temperatures fission gas Xe atoms diffuse mainly through interstitials in single crystal ZrN, whereas at high temperatures Xe may diffuse in ZrN assisted by vacancies.

Objective To evaluate the clinical efficacy of acupuncture in treatment of postpartum depression. Methods Pubmed database and Embase database were retrieved online in English, and China National Knowledge Internet (CNKI), China Biology Medicine disc (CBM), VIP database and Wanfang Data were retrieved in Chinese. Literature in recent 10 years relating to clinical randomized controlled trials of acupuncture in treatment of postpartum depression were collected, and Meta analysis was performed by adopting RevMan5.3. Results Fourteen articles were included in the study in total; it was shown from HAMD result that after combination, WMD=−1.27, 95%CI (−2.55, 0.01); according to Z-test, Z=1.95, P=0.05, and the difference in efficacy between treatment group and control group was statistically significant. It was shown from EPDS result that after combination, WMD=−0.53, 95%CI (−0.92, −0.03); according to Z-test, Z=2.08, P Conclusion Acupuncture treatment for postpartum depression is effective, but more clinical randomized controlled trials with high quality and large sample size are still needed to verify the result.

In schistosomiasis, egg deposition in the liver contributes to the formation of hepatic granuloma and fibrosis, which are the most serious clinical pathological features. It has been proposed that activation of the nuclear factor kappa B (NF-κB) signaling pathways is closely associated with the development of hepatic granuloma and fibrosis. Genistein has been shown to inhibit the activity of NF-κB signaling pathways, which might be a potential agent to protect against Schistosoma japonicum egg-induced liver granuloma and fibrosis. In this study, liver granuloma and fibrosis were induced by infecting BALB/c mice with 18 ± 3 cercariae of S. japonicum. At the beginning of egg granuloma formation (early phase genistein treatment from 4 to 6 weeks after infection) or after the formation of liver fibrosis (late phase genistein treatment from 6 to 10 weeks after infection), the infected mice were injected with genistein (25, 50 mg/kg). The results revealed that genistein treatment significantly decreased the extent of hepatic granuloma and fibrosis in infected mice. The activity of NF-κB signaling declined sharply after the treatment with genistein, as evidenced by the inhibition of NF-κB-p65, phospho-NF-κB-p65, and phospo-IκB-α expressions, as well as the expression of IκB-α and the messenger RNA (mRNA) expression of inflammatory cytokines (MCP1, TNFα, IL1β, IL4, IL10) mediated by NF-κB signaling pathways in the early phase of the infection. Moreover, western blot and immunohistochemistry assays demonstrated that the contents of α-smooth muscle actin (α-SMA) and transforming growth factor-β were dramatically reduced in liver tissue under the treatment of genistein in the late phase of the infection. At the same time, the mRNA expression of MCP1, TNFα, and IL10 was inhibited markedly. These results provided evidence that genistein reduces S. japonicum egg-induced liver granuloma and fibrosis, at least partly due to decreased NF-κB signaling, and subsequently decreased MCP1, TNFα, and IL10 expressions. This implies that genistein can be a potential natural agent against schistosomiasis.

To investigate the effect of electroacupuncture (EA) preconditioning on autophagy in cerebral cortex tissues of rats with cerebral ischemia-reperfusion injury (CIRI), so as to explore its mechanisms underlying improvement of CIRI.Thirty-three male Sprague-Dawley rats were randomly divided into sham operation, model and EA groups (Compared with the sham operation group, the neurological deficit score and infarct volume were significantly increased (EA pretreatment is effective in improving CIRI in rats, which may be realized through suppressing autophagy in the ischemic cerebral cortex tissue.

Molten mixtures of lithium chloride and metallic lithium (LiCl-Li) play an essential role in the electrolytic reduction of various metal oxides. These mixtures possess unique high temperature physical and chemical properties that have been investigated for decades. However, due to their extreme chemical reactivity, no study to date has been capable of definitively proving the basic physical nature of Li dissolution in molten LiCl. In this study, the evolution of the structure of molten LiCl-Li is probed as metallic Li is electrochemically introduced into the melt in situ, using synchrotron radiation experiments based on high energy wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS). The time-resolved scattering results indicate the formation of transient Cl- ion cages surrounding low-density voids with a periodicity of ∼8.3 A, which suggests the formation of metastable Li nanocluster. The structure of the LiCl-Li nanoclusters in the solution is modeled using ab initio molecular dynamics (AIMD) simulations. The simulation results are in agreement with the X-ray diffraction measurement and suggest the nanoclusters are predominantly Li8, along with smaller clusters.

Polyamines (putrescine, spermidine, and spermine) are essential polycations that play important roles in various physiological and pathophysiological processes in mammalian cells. The study was to investigate their role in cardioprotection against ischemia/reperfusion (I/R) injury and the underlying mechanism. Isolated hearts from male Sprague-Dawley rats were Langendorff-perfused and cardiac I/R was achieved by 30 min of global ischemia followed by 120 min of reperfusion. Different concentrations of polyamines (0.1, 1, 10, and 15 μmol/L of putrescine, spermidine, and spermine), cyclosporin A (0.2 μmol/L), or atractyloside (20 μmol/L) were given 10 min before the onset of reperfusion. The hemodynamics were monitored; the lactate dehydrogenase (LDH) levels in the coronary effluent were measured spectrophotometrically; infarct size was determined by the 2,3,5-triphenyltetrazolium chloride staining method; and mitochondrial permeability transition pore (MPTP) opening was determined spectrophotometrically by the Ca

Excessive autophagy is one of the crucial factors of cerebral ischemia-reperfusion injury (CIRI), which has been demonstrated to be one of the targets for acupuncture treatment of ischemic stroke. In the present paper, we make a review about the development of acupuncture intervention induced improvement of CIRI (such as reducing the infarction area, improving learning-memory ability and motor function) by regulating autophagy in animal studies. Outcomes showed that acupuncture intervention can function in 1) inhibiting CIRI-induced increase of the number of lysosomes and autophagic lysosomes, and relieving structural injury of mitochondria, and reducing the number of autophagosome in the central region of the ischemic cerebral cortex tissue; 2) down-regulating the expression of microtubule-associated protein Ⅱ light chain 3 (LC3Ⅱ) and the ratio of LC3-Ⅱ/LC3-Ⅰ in the ischemic cerebral region, and 3) regulating the expression of Beclin 1 (autophagy-related gene), promoting the expression of P62 (autophagy-related adaptor protein). In addition, acupuncture can also regulate phosphoinositide 3 kinase (PI3K)- protein kinase B (AKT)- mammalian target of rapamycin complex 1(mTOR) signaling at different time-points (down-regulation at the early stage and up-regulation at the later stage), and activating AMP-activated protein kinase (AMPK)-mTOR- UNC51-like kinase-1 signaling to relieve cerebral ischemic injury. These results reveal some mechanisms of acupuncture therapy underlying improvement of CIRI and provide experimental basis for clinical application of acupuncture therapy in the treatment of ischemic stroke.

To explore the effect of electrical stimulation at auricular points (EAS) combined with sound masking on the expression of cAMP-response element binding protein (CREB), brain-derived neurotrophic factor (BDNF) and tyrosine receptor kinase B (TrkB) in the auditory cortex of tinnitus rats.A total of 27 adult male SD rats were randomly divided into a control group, a model group and an EAS group. The rats in the model group and the EAS group were intervened with intraperitoneal injection of sodium salicylate to induce tinnitus model, while the rats in the control group were intervened with injection of 0.9% NaCl solution. After the model was successfully established, the rats in the EAS group were treated with electrical stimulation at "Shenmen" (TF① Compared with the control group, the GPIAS values in 12 kHz, 16 kHz, 20 kHz and 28 kHz were significantly decreased in the model group (allEAS could improve the GPIAS values of high-frequency background sound in tinnitus rats, which may be related with the upregulation of the BDNF/TrkB/CREB signaling pathway in the auditory cortex, leading to the reversion of the maladaptive plasticity.

To investigate the antidepressant-like effects of Chaihu Shugan Powder (CSP, ) and to explore its underlying mechanisms.Thirty-two Sprague-Dawley rats were randomly divided into control (CON), chronic unpredictable mild stress (CUMS), fluoxetine (FLU), and CSP groups, 8 rats in each group. All of the rats except for those in the control group were subjected to 3 consecutive weeks of CUMS to establish the depression model. The open field test (OFT), forced swimming test (FST), and sucrose preference test were used to assess the anti-anxiety and antidepressant effects of CSP. Terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling was used to determine the apoptosis rate in the hippocampal tissues. The mRNA and protein levels of glucose-regulated protein (GRP) 78, spliced X-box-binding protein (XBP)-1, CCAAT/enhancer-binding protein homologous protein (CHOP), caspase-12, and c-Jun N-terminal kinase (JNK) in the hippocampus of rats were evaluated by real-time PCR and Western blot analysis, respectively.Administration of CSP alleviated anxiety and depression-like behavior in CUMS rats, as revealed by enhanced time and distance in the center of the OFT (P0.05), an increased preference for sucrose, and longer swimming time and shorter immobility time during the FST (all P0.05). In addition, CSP treatment significantly reduced the rate of apoptosis in rat hippocampal neurons (P0.05). The mRNA and protein expression levels of GRP78, spliced XBP-1, and CHOP were down-regulated along with the expression of caspase-12 and cleaved caspase-12 proteins (all P0.05), whereas total and phosphorylated JNK1 protein levels did not differ significantly between control and CSP-treated rats.CSP can improve depression-like behavior in rats exposed to CUMS, possibly by suppressing CHOP and caspase-12 mediated apoptosis in the rat hippocampus.

A monolithic fuel design based on a U-Mo alloy has been selected as the fuel type for conversion of the U. S. High-Performance Research Reactors. A critical phenomenon of interest regarding U-Mo monolithic fuel is the large amount of swelling that takes place during operation, particularly at high fission densities. The accurate prediction of fuel evolution under irradiation requires implementation of correct thermodynamic and kinetic properties into mesoscale and engineering fuel performance modeling codes. One such property where there exists incomplete data is the diffusion of relevant species under irradiation. Fuel performance swelling predictions rely on an accurate representation of diffusion in order to determine the rate of fission gas swelling and the local microstructural evolution. In this work, we present molecular dynamics simulations of the radiation driven diffusion of U, Mo, and Xe in U-Mo nuclear fuels. Diffusion coefficients for each species are determined over a range of temperatures and compositions. Updated diffusion coefficients are presented that are applicable under irradiation and incorporate both intrinsic and radiation driven diffusion.

A mesoscale model is developed by integrating the rate theory and phase-field models and is used to study the fission-induced recrystallization in U-7Mo alloy. The rate theory model is used to predict the dislocation density and the recrystallization nuclei density due to irradiation. The predicted fission rate and temperature dependences of the dislocation density are in good agreement with experimental measurements. This information is used as input for the multiphase phase-field model to investigate the fission-induced recrystallization kinetics. The simulated recrystallization volume fraction and bubble-induced swelling agree well with experimental data. The effects of the fission rate, initial grain size, and grain morphology on the recrystallization kinetics are discussed based on an analysis of recrystallization growth rate using the modified Avrami equation. We conclude that the initial microstructure of the U-Mo fuels, especially the grain size, can be used to effectively control the rate of fission-induced recrystallization and therefore swelling.

Zirconium nitride (ZrN) exhibits exceptional mechanical, chemical, and electrical properties, which make it attractive for a wide range of technological applications, including wear-resistant coatings, protection from corrosion, cutting/shaping tools, and nuclear breeder reactors. Despite its broad usability, an atomic scale understanding of the superior performance of ZrN, and its response to external stimuli, for example, temperature, applied strain, and so on, is not well understood. This is mainly due to the lack of interatomic potential models that accurately describe the interactions between Zr and N atoms. To address this challenge, we develop a modified embedded atom method (MEAM) interatomic potential for the Zr–N binary system by training against formation enthalpies, lattice parameters, elastic properties, and surface energies of ZrN (and, in some cases, also Zr3N4) obtained from density functional theory (DFT) calculations. The best set of MEAM parameters are determined by employing a multiobj...