Novel Role of Calcium-Sensitive Receptors in Chronic Hypoxia-Induced Proliferation of Pulmonary Vein Smooth Muscle Cells

Objective:Vascular remodeling due to chronic hypoxia(CH)occurs not only in the pulmonary arteries but also in the pulmonary veins.Pulmonary vascular remodeling arises from the proliferation of pulmonary vascular myocytes.However,the mechanism by which CH induces the proliferation of pulmonary vein smooth muscle cells(PVSMCs)is unknown.This study aimed to investigate the mechanism by which CH affects the proliferation of PVSMCs.Methods:PVSMCs were isolated from rat distal pulmonary veins and exposed to CH(4%O2,60h),and the expression of the calcium-sensitive receptor(CaSR)was detected by Western blotting and immunofluorescence.MTT assay was used to detect the proliferation viability of the cells,and the changes in the intracellular calcium concentration were detected by laser confocal scanning technique.Results:CaSR expression was present in rat distal PVSMCs,and CaSR protein expression was upregulated under hypoxia.The positive regulator spermine not only enhanced CH-induced CaSR upregulation but also enhanced CH-induced increase in cell viability and calcium ion concentration.The negative CaSR regulator NPS2143 not only attenuated CH-induced CaSR upregulation but also inhibited CH-induced cell viability and calcium ion concentration.Conclusion:CaSR-mediated hyperproliferation is a novel pathogenic mechanism for the development of proliferation in distal PVSMCs under CH conditions.

Effects of chloramphenicol preconditioning on oxidative respiratory function of cerebral mitochondria in rats exposed to acute hypoxia

Objective: To investigate the roles of chloramphenicol (CAP) preconditioning in the oxidative respiratory function of cerebral mitochondria in rats exposed to acute hypoxia during acute hypoxia by observing the changes of mitochondrial oxidative respiratory function and cytochrome C oxidase (COX) activity. Methods: Adult male Wistar rats were randomly divided into 4 groups: control (C), medication (M), hypoxia (H), and medication plus hypoxia (MH). Rats in groups M and MH were administered by peritoneal injection of CAP (50 mg/kg) every 12 h for 7 d before decapitation, but those in groups H and MH were exposed to a hypobaric chamber simulating 5 000 m high altitude for 24 h. The rat cerebral cortex was removed and mitochondria were isolated by centrifugation. Mitochondrial respiratory function and COX activity were measured by Clark oxygen electrode. Results: Compared with Group C, Group H showed significantly elevated state 4 respiration (ST 4), decreased state 3 respiration (ST 3), and respiratory control rate (RCR) in mitochondrial respiration during acute hypoxic exposure. ST 3 in Group MH was significantly lower than that in Group C, but was not significantly different from that in Groups H and M, while ST 4 in Group MH was significantly lower than that in groups C and H. RCR in Group MH was higher than that in Group H, but lower than that in Group C. COX activity in Group H was significantly lower than that in Group C. In Group MH, COX activity increased and was higher than that in Group H, but was still lower than that in Group C. Conclusion: Acute hypoxic exposure could lead to mitochondrial respiratory dysfunction, suggesting that CAP preconditioning might be beneficial to the recovery of rat respiratory function. The change of COX activity is consistent with that of mitochondrial respiratory function during acute hypoxic exposure and CAP-administration, indicating that COX plays an important role in oxidative phosphorylation function of mitochondria from cerebral cortex of hypoxic rats.

Inhibitory effects of ketamine and L--NAME on expression of c-fos and NOS in hypothalamic paraventricular nucleus after acute hypothermia and hypoxia in rats

Objective: To determine whether NMDA receptor activation mediates the expression of c--fos and NOS and study the relationship between the expression of c--fos and NOS in the hypothalamic paraventricularnucleus (PVN) following acute hypothermia and hypoxia. Methods: Fos immunohistochemistry, NADPH--d histochemistry and Fos/NADH--d double labeling were used. Results: Acute hypothermia and hypoxia induced the overexpression of on fos and NOS in PVN in rats. Pretreatment with ketamine, a NMDA receptor antagonist, resulted in partial inhibition of the expression of c--fos and NOS and that with blocker of NOS resulted in significant inhibition of the expression of c--fos. Conclusion: The activation of NMDA receptor is involved in the expression of c- fos and NOS in PVN in the rats subjected to acute hypothermia and hypoxia.Meanwhile, hypothalamic endogenous NO participates in adaptive reaction to hypothermia and hypoxia,which might be related to the modulation of c- fos expression.

Effects of Rhynchophylline on L type Calcium Channels in Isolated Rat Cortical Neurons During Acute Hypoxia

Aim: To study the effects of rhynchophylline (Rhy) on the L type calcium channels in freshly dissociated cortical neurons of Wistar rats during acute hypoxia. Methods: Cell attached configuration of patch clamp technique. L type calcium channel was activated by stepping from 40 mV to 0 mV. Results: The results showed that the L type calcium channels of cortical neurons were activated by acute hypoxia. The mean open time of the channel was increased, the mean close time decreased and the open state probability raised during acute hypoxia. Rhy (15 and 30μmol·L -1 ) in concentration dependent manner blocked activity of the channels. The drug shortened the mean open time of the channels from 8 87 ms to 3 03 ms and 2 23 ms ( P 【0 001), prolonged the mean close time from 9 23 ms to 38 84 ms and 54 43 ms ( P 【0 001), and decreased the open state probability from 0 142 to 0 031 and 0 025 ( P 【0 001) under the hypoxia condition, respectively. The effects of Rhy were similar to but weaker than those of verapamil (15 μmol·L -1 ). Conclusion: The study confirmed that Rhy has the blockade effects on L type calcium channels in cortical neurons of rats during hypoxia, by which it protects the brain from hypoxic injury.

Silicon/flake graphite/carbon anode materials prepared with different dispersants by spray-drying method for lithium ion batteries

Silicon/flake graphite/carbon （Si/FG/C） composites were synthesized with different dispersants via spray drying and subsequent pyrolysis, and effects of dispersants on the characteristics of the composites were investigated. The structure and properties of the composites were determined by X-ray diffractometry （XRD）, scanning electron microscopy （SEM） and electrochemical measurements. The results show that samples have silicon/flake graphite/amorphous carbon composite structure, good spherical appearances, and better electrochemical performance than pure nano-Si and FG/C composites. Compared with the Si/FG/C composite using washing powder as dispersant, the Si/FG/C composite using sodium dodecyl benzene sulfonate （SDBS） as dispersant has better electrochemical performance with a reversible capacity of 602.68 mA·h/g, and a capacity retention ratio of 91.58 % after 20 cycles.

Varian2100 C\D加速器ION2联锁分析及处理

电离室作为监测调控射束位置和测量辐射强度的核心部件 ,需要外加一定的电场 ,在比较恒定的温度下 ,才能可靠稳定地工作。ION2 (ION1)联锁提示电离室极化电压工作状态异常 ,它可以由电源本身故障引起 ,也可以由电离室故障而引起。根据具体情况分析处理 ,使电离室工作在正常的状态下 。

C/Sn复合薄膜的磁控溅射制备及其作为锂离子电池负极材料的电化学性能

采用磁控溅射的方法在铜箔上制备了C/Sn复合薄膜并将其作为锂离子电池负极材料,研究了C/Sn复合薄膜中Sn质量分数对其电化学性能的影响。研究发现,随着复合薄膜中Sn质量分数的增加,其首圈放电比容量增加,在一定范围内增加Sn质量分数,首圈库仑效率增加,但当Sn质量分数过多时其库仑效率降低。Sn质量分数分别为89.20%、91.61%、93.85%、95.81%的四种复合薄膜,在电流密度为500 mA/g时的首圈放电比容量分别为1195.4、1372.97、1574.86、1642.30 mA·h/g,首圈库仑效率分别为86.84%、87.88%、94.06%、80.66%。循环200圈后,四种复合薄膜的比容量衰减率分别为0.70%、6.13%、11.32%、18.88%。研究结果表明,当复合薄膜中Sn质量分数为89.20%时,其具有最优的倍率性能和循环稳定性能,随着复合薄膜中Sn质量分数的增加,其倍率性能及循环稳定性变差。

Cytoprotective role of heme oxygenase-1 and heme degradation derived end products in liver injury

The activation of heme oxygenase-1(HO-1) appears to be an endogenous defensive mechanism used by cells to reduce inflammation and tissue damage in a number of injury models. HO-1, a stress-responsive enzyme that catabolizes heme into carbon monoxide(CO), biliverdin and iron, has previously been shown to protect grafts from ischemia/reperfusion and rejection.In addition, the products of the HO-catalyzed reaction, particularly CO and biliverdin/bilirubin, have been shown to exert protective effects in the liver against a number of stimuli, as in chronic hepatitis C and in transplanted liver grafts. Furthermore, the induction of HO-1 expression can protect the liver against damage caused by a number of chemical compounds. More specifically, the CO derived from HO-1-mediated heme catabolism has been shown to be involved in the regulation of inflammation; furthermore, administration of low concentrations of exogenous CO has a protective effect against inflammation. Both murine and human HO-1 deficiencies have systemic manifestations associated with iron metabolism, such as hepatic overload(with signs of a chronic hepatitis) and iron deficiency anemia(with paradoxical increased levels of ferritin).Hypoxia induces HO-1 expression in multiple rodent,bovine and monkey cell lines, but interestingly, hypoxia represses expression of the human HO-1 gene in a variety of human cell types(endothelial cells, epithelial cells, T cells). These data suggest that HO-1 and CO are promising novel therapeutic molecules for patients with inflammatory diseases. In this review, we present what is currently known regarding the role of HO-1 in liver injuries and in particular, we focus on the implications of targeted induction of HO-1 as a potential therapeutic strategy to protect the liver against chemically induced injury.

乳腺癌组织内VEGF-C、HIF-1α表达与血管生成的相关性研究

目的:探讨乳腺癌患者组织内血管内皮生长因子-C(VEGF-C)、缺氧诱导因子-1α(HIF-1α)表达与血管生成的关系。方法:选取2022年1月—2023年12月泰安市中心医院收治的198例乳腺癌女性患者,并选取同期经病理学检查为乳腺纤维瘤患者50例为对照。采用免疫组化S-P法检测乳腺癌和乳腺纤维瘤组织中VEGF-C、HIF-1α表达及微血管密度(MVD)数,分析VEGF-C、HIF-1α表达与临床病理特征及MVD的关系。结果:乳腺癌患者乳腺组织中VEGF-C、HIF-1α阳性表达率及MVD数均高于乳腺纤维瘤患者,差异有统计学意义(P<0.05)。VEGF-C阳性与阴性表达者年龄、肿瘤直径、组织学分级、ER表达、PR表达等临床病理特征比较,差异无统计学意义(P>0.05);VEGF-C阳性表达者有淋巴结转移、TNM分期为Ⅲ~Ⅳ期、分子分型(Luminal B、HER-2阳性、基底细胞)的患者占比及MVD均高于VEGF-C阴性表达者,差异有统计学意义(P<0.05)。HIF-1α阳性与阴性表达者年龄、肿瘤直径、ER表达、PR表达、分子分型等临床病理特征比较,差异无统计学意义(P>0.05);HIF-1α阳性表达者组织学分级为Ⅱ级、Ⅲ级、有淋巴结转移、TNM分期为Ⅲ~Ⅳ期的患者占比及MVD均高于HIF-1α阴性表达者,差异有统计学意义(P<0.05)。结论:乳腺癌患者组织内VEGF-C、HIF-1α阳性表达率明显升高,并且还与肿瘤血管生成存在显著相关性。

Atorvastatin Attenuates Myocardial Hypertrophy Induced by Chronic Intermittent Hypoxia In Vitro Partly through miR-31/PKCε Pathway

Atorvastatin is proven to ameliorate cardiac hypertrophy induced by chronic intermittent hypoxia （CIH）. However, little is known about the mechanism by which atorvastatin modulates CIH-induced cardiac hypertrophy, and whether specific hypertrophyrelated microRNAs are involved in the modulation. MiR-31 plays key roles in the development of cardiac hypertrophy induced by ischemia/hypoxia. This study examined whether miR-31 was involved in the protective role of atorvastatin against CIH-induced myocardial hypertrophy. H9c2 cells were subjected to 8-h intermittent hypoxia per day in the presence or absence of atorvastatin for 5 days. The size of cardiomyocytes, and the expression of caspase 3 and miR-31 were determined by Western blotting and RT-PCR, respectively. MiR-31 mimic or Ro 31-8220, a specific inhibitor of protein kinase C epsilon （PKCε）, was used to determine the role of miR-31 in the anti-hypertrophic effect of atorvastatin on cardiomyocytes. PKCε in the cardiomyocytes with miR-31 upregulation or downregulation was detected using RT-PCR and Western blotting. The results showed that CIH induced obvious enlargement of cardiomyocytes, which was paralleled with increased atrial natriuretic peptide （ANP）, brain natriuretic peptide （BNP）, and slow/beta cardiac myosin heavy-chain （MYHT） mRNA levels. All these changes were reversed by the treatment with atorvastatin. Meanwhile, miR-31 was increased by CIH in vitro. Of note, the atorvastatin pretreatment significantly increased the mRNA and protein expression of PKCε and decreased that of miR-31. Moreover, overexpression of miR-31 abolished the anti-hypertrophic effect of atorvastatin on cardiomyocytes. Upregulation and downregulation of miR-31 respectively decreased and increased the mRNA and protein expression of PKCε. These results suggest that atorvastatin provides the cardioprotective effects against CIH probably via up-regulating PKCε and down-regulating miR-31.

NiCo-LDH/Ti3C2 MXene hybrid materials for lithium ion battery with high-rate capability and long cycle life

Nickel/cobalt-layered double hydroxides(Ni Co-LDH) have been attracted increasing interest in the applications of anode materials for lithium ion battery(LIB), but the low cycle stability and rate performance are still limited its practice applications. To achieve high performance LIB, the surface-confined strategy has been applied to design and fabricate a new anode material of NiCo-LDH nanosheet anchored on the surface of Ti3C2 MXene(Ni Co-LDH/Ti3C2). The ultra-thin, bended and wrinkled α-phase crystal with an interlayer spacing of 8.1 ? can arrange on the conductive substrates Ti3C2 MXene directly, resulting in high electrolyte diffusion ability and low internal resistance. Furthermore, chemical bond interactions between the highly conductive Ti3C2 MXene and Ni Co-LDH nanosheets can greatly increase the ion and electron transport and reduce the volume expansion of NiCo-LDH during Li ion intercalation. As expected,the discharge capacity of 562 m Ah g-1 at 5.0 A g-1 for 800 cycles without degradation can be achieved,rate capability and cycle performance are better than that of NiCo-LDH(~100 mAh g-1). Furthermore, the density function theory(DFT) calculations were performed to demonstrate that Ni Co-LDH/Ti3C2 system can be used as a highly desirable and promising anode material for lithium ion battery.

Underlying mechanism of protection from hypoxic injury seen with n-butanol extract of Potentilla anserine L. in hippocampal neurons

The alcohol and n-butanol extract of Potentilla anserine L. significantly protects myocardium from acute ischemic injury. However, its effects on rat hippocampal neurons and the mechanism of protection remain unclear. In this study, primary cultured hippocampal neurons from neonatal rats were incubated in 95% N2 and 5% CO2 for 4 hours. Results indicated that hypoxic injury decreased the viability of neurons, increased the expression levels of caspase-9 and caspase-3 mRNA, as well as cytochrome c, Caspase-9, and Caspase-3 protein. Pretreatment with 0.25, 0.062 5, 0.015 6 mg/mL n-butanol extract of Potentilla anserine L. led to a significant increase in cell viability. Expression levels of caspase-9 and caspase-3 mRNA, as well as cytochrome c, Caspase-9, and Caspase-3 protein, were attenuated. The neuroprotective effect of n-butanol extract of Potentilla anserine L. was equivalent to tanshinone IIA. Our data suggest that the n-butanol extract of Potentilla anserine L. could protect primary hippocampal neurons from hypoxic injury by deactivating mitochondrial cell death.

Mechanical analysis of C/C composite grids in ion optical system

The ion thruster is an engine with high specific impulse for satellites and spacecrafts,which uses electric energy to boost the spacecraft.The ion optical system,also known as gate assemblies which consist of acceleration and screen grids,is the key component of the ion thruster.In this paper,the static mechanical properties of the C/C composite grids are evaluated based on the structural design.Representative volume element (RVE) is adopted to simplify the braded composite structure as a continuum material.The dynamical behavior of the 100 mm ion thruster optics in the launch environment (1000g shock-load) is numerically modeled and simulated with the half-sine pulse method.The impact response of the C/C and molybdenum gate assemblies on the stress distribution and deformation is investigated.The simulated results indicate that the magnitudes of the normal displacement of the composite grids subject to the uniformly distributed load are on the same level as molybdenum grids although the normal stiffness of the composite grids is much smaller.When subject to impact loading,the stress distribution in the C/C composite grids is similar to molybdenum grids while the stress magnitude is much smaller.This finding shows that the C/C gate assemblies outperform molybdenum grids and meet the requirement of long lifetime service in space travel.

Effects of low ambient temperatures and dietary vitamin C supplementation on pulmonary vascular remodeling and hypoxic gene expression of 21-d-old broilers

The objective of this study was to evaluate the effects of low ambient temperature （LAT） and dietary vitamin C （VC） sup- plementation on pulmonary vascular remodeling （PVR） and the relative expression of hypoxia inducible factor-la （HIF-la）, vascular endothelial growth factor （VEGF） and its receptor 2 （VEGFR-2） mRNA of lungs in 21-d-old broilers. 400 1-d-old male Cobb broilers were assigned randomly to 4 treatments as follows for 21 d： 1 ） LAT and a basal diet; 2） LAT and a basal diet supplemented with 1 000 mg kg-1 VC （LAT＋VC）; 3） normal ambient temperature （NAT） and a basal diet; 4） NAT and a basal diet supplemented with 1 000 mg kg-1 VC （NAT＋VC）. Each treatment was composed of 10 replicates of 10 birds per replicate. Samples of lung were collected after the broilers were killed at d 21. LAT increased the ratio of vessel wall area to vessel total area （WA/TA, %） and mean media thickness in pulmonary arterioles （mMTPA, %） （P〈0.05）. Dietary VC supplementation decreased mMTPA （P〈0.05）, but had no effect on the WA/TA. LAT increased （P〈0.05） the relative mRNA expression of HIF-la, VEGF and VEGFR-2, while adding VC to the diet could decrease （P〈0.05） their relative mRNA expression. A significant positive correlation existed between the level of VEGF mRNA expression and the value of WA/WT （P〈0.05） or mMTPA （P〈0.05）. These results suggested LAT resulted in pulmonary vascular remodeling, and the increase of HIF-la, VEGF and VEGFR-2 mRNA expression, and dietary VC supplementation can alleviate pulmonary vascular remodeling in broiler by affecting these gene expression.

FORMATION OF HEXAGONAL Co_(2—3)C IN Co BY CARBON ION IMPLANTATION

Co thin films were subjected to 50 keV carbon ion implantation.At the dose of 2.5× 10^(17)/cm^2,a hexagonal Co-carbide phase was observed for the first time.The lattice con- stants from electron diffraction are a=0.2685 nm and c=0.4335 nm.The phase does not dis- appear until the dose of 9×10^(17)/cm^2.Auger spectra showed that the stoichiometry was Co_(2-3)C.The behavior of the ferromagnetic carbides along the descending sequence of Ni-Fe-Co by Fermi energy of solids was interpreted.Furthermore,based on the kinetic con- dition of phase transformation and the band theory of solids,a possible explanation about the difference of the results of ion-metallurgy and thermal metallurgy was proposed.

Chloride Ion Critical Content in Reinforced Concrete

Chloride ion critical content was studied under soaking and cycle of dry and wet conditions, with three electrochemical nondestructive measuring techniques, i e, half-cell potential, A C impedance, and time potential. The experimental results show that chloride ion critical content is primarily determined by the water cement ratio, while for the same concrete mixture the chloride ion critical content in soaking conditions is larger than that in a cycle of dry and wet conditions.

硅碳负极的失效机理与FEC的改善作用

采用含和不含氟代碳酸乙烯酯(FEC)的电解液,研究了一种硅碳材料作为锂离子电池负极的充放电行为,对充放电循环前后的硅碳电极进行了组成和形貌的谱学表征,并通过计算比较了电解液主要成分的还原活性。结果表明:不含FEC的电解液,硅碳负极首次充放电库伦效率低、容量衰减快,这是因为硅碳表面不能形成稳定的SEI,嵌锂后体积膨胀使SEI开裂,电解液持续分解。相反,含FEC的电解液,因FEC比电解液其他组分更容易在硅碳负极上还原,生成含氟的聚合物,形成稳定的SEI,抑制电解液还原分解,并缓冲硅碳负极的体积膨胀,从而显著提高库伦效率和循环稳定性。添加5%的FEC,硅碳负极首次充放电库伦效率从83%提高到86%;添加10%的FEC,0.2 C充放电循环50次后,硅碳负极的容量保持率从28%提高到75%。

Tribological Properties of DLC Film Prepared by C^+ Ion Beam-assisted Deposition (IBAD)

C ^＋ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon （ DLC ） film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nanoindentation , the DLC film has been recognized as hydrogenated DLC film and its tribologicul properties have been evaluated. The bull-on-disc testing results show that the hardness and the tribologicul properties of the DLC film produced by C^ ＋ ion beam- assisted deposition are improved significantly. DLC film produced by C ^＋ ion beam- assisted deposition is positive to have a prosperous tribologicul application in the near future.

Hydrogen cold plasma for synthesizing Pd/C catalysts: the effect of support-metal ion interaction

It has been found that cold plasma is a facile and environmentally benign method for synthesizing supported metal catalysts, and great efforts have been devoted to enlarging its applications. However, little work has been done to disclose the influence mechanism, which is significant for controllable synthesis. In this work, hydrogen cold plasma was adopted to synthesize a palladium catalyst supported on activated carbon （Pd/C-P） using HzPdC14 as a Pd precursor followed by calcination in hydrogen gas to remove the chlorine ions. The Pd/C-P catalyst was found to be made of larger Pd nanoparticles showing a decreased migration to the support outer surface than that prepared by the conventional thermal hydrogen reduction method （Pd/C-C）. Meanwhile, the pore diameter of the activated carbon support is small （,-~4 nm）. Therefore, Pd/C-P exhibits lower CO oxidation activity than Pd/C-C. It was proposed that the strong interaction between the activated carbon and PdC142-, and the enhanced metal-support interaction caused by hydrogen cold plasma reduction made it difficult for Pd nanoparticles to migrate to the support outer surface. The larger-sized Pd nanoparticles for Pd/C-P may be due to the Coulomb interaction resulting in the disturbance of the metal-support interaction. This work has important guiding significance for the controllable synthesis of supported metal catalysts by hydrogen cold plasma.

Thermal stability of LiPF_6/EC+DMC+EMC electrolyte for lithium ion batteries

The thermal stability of lithium-ion battery electrolyte could substantially affect the safety of lithium-ion battery. In order to disclose the thermal stability of 1.0 mol·L-1 LiPF6/ethylene carbonate (EC)+dimethyl carbonate (DMC)+ethylmethyl carbonate (EMC) electrolyte, a micro calorimeter C80 micro calorimeter was used in this paper. The electrolyte samples were heated in argon atmosphere, and the heat flow and pressure performances were detected. It is found that LiPF6 influences the thermal behavior remarkably, with more heat generation and lower onset temperature. LiPF6/EC shows an exothermic peak at 212 ℃ with a heat of reaction -355.4 J·g-1. DMC based LiPF6 solution shows two endothermic peak temperatures at 68.5 and 187 ℃ in argon filled vessel at elevated temperature. EMC based LiPF6 solution shows two endothermic peak temperatures at 191 and 258 ℃ in argon filled vessel. 1.0 mol·L-1 LiPF6/EC+DMC+ EMC electrolyte shows an endothermic and exothermic process one after the other at elevated temperature. By comparing with the thermal behavior of single solvent based LiPF6 solution, it can be speculated that LiPF6 may react with EC, DMC and EMC separately in 1.0 mol·L-1 LiPF6/EC+DMC+EMC electrolyte, but the exothermic peak is lower than that of 1.0 mol·L-1 LiPF6/EC solution. Furthermore, The 1.0 mol·L-1 LiPF6/EC+DMC+EMC electrolyte decomposition reaction order was calculated based on the pressure data, its value is n=1.83, and the pressure rate constants kp=6.49×10-2 kPa·-0.83·min-1.