不同海拔下甲醇替代率和主喷正时对RCCI发动机性能的影响

为探究不同海拔条件下甲醇/柴油反应活性控制压燃（reactivity controlled compression ignition, RCCI）发动机的运行特性,该研究基于甲醇/柴油双燃料发动机试验台架,试验研究1 800r/min、100%负荷和3 200r/min、100%负荷下不同甲醇替代率、柴油喷射正时对发动机燃烧与排放性能的影响规律。结果表明：不同海拔条件下随着甲醇替代率的增加,缸压和瞬时放热率峰值逐渐升高,燃烧始点和燃烧中心前移,当量有效燃油消耗率（equivalent brake specific fuel consumption, ESFC）降低,有效热效率升高,NO_x和碳烟排放大幅降低,THC（total hydrocarbons）和CO排放增加。1 800 r/min、100%负荷工况下,甲醇替代率由0增至20%,0、1 000、2 000m海拔下最大缸压平均增加1.72MPa,瞬时放热率峰值平均升高25.08J/(°),ESFC平均降低4.67%,有效热效率平均升高4.90%,NO_x和碳烟排放分别平均降低16.63%和50%,THC和CO排放量分别平均增加142.03、388.18 mg/kg。3 200 r/min下甲醇替代率由0增至7%,不同海拔高度下ESFC平均降低1.76%,有效热效率平均升高1.79%,NO_x和碳烟排放量分别平均降低8.17%和20.70%。海拔高度由0升至2 000m,1 800r/min、20%甲醇替代率与3 200r/min、7%甲醇替代率下,瞬时放热率峰值分别降低4.80和8.08J/(°),燃烧中心分别推迟1.44°和1.43°,有效热效率分别降低0.82%和0.68%,ESFC分别升高2.10%和1.99%,NO_x排放量分别减少10.61%和7.35%,碳烟排放分别增加26.54%和32.12%,THC排放分别升高29.88%和15.45%,CO排放量分别增加22.42%和18.15%。固定甲醇替代率后,随着柴油主喷正时提前,不同海拔条件下缸压和放热率峰值逐渐升高,燃烧中心向上止点靠近,ESFC逐渐降低,有效热效率升高,碳烟排放减少,NO_x、THC和CO排放增加。1 800 r/min、15%甲醇替代率下,主喷正时从-1.5°提前至-7.5°,不同海拔高度下ESFC平均降低8.27%,有效热效率平均升高9.08%,碳烟排放平均减少90.94%。为提升高海拔条件下甲醇/柴油RCCI发动机的热效率和燃油经济性,可以适当增大柴油主喷正时。研究结果可为不同海拔环境下甲醇/柴油RCCI发动机燃烧与污染物排放控制优化提供参考。     

Effect of poly(ADP-ribose) polymerase on the response of guinea pig tracheas induced by peroxynitrite in vitro

AIM and METHODS: to elucidater the effect of poly(ADP-ribose) polymerase(PARP) on tracheal hyperreactivity of guinea - pig induced by peroxynitrite, the responses of guinea pig tracheas to histamine af- ter incubation with peroxynitrite in the absence and presence of 3 - aminobenzamide(3 - AB), a highly selective inhibitor for PARP, were observed in vitro. RESULTS: The exposure of tracheal strips to peroxynitrite led to epithelial damage and hyperreacitivity to histamine, both of which were reversed by 3 - AB(lmmol/L or 5mmol/L), whereas incubation of tracheal strips with 3 - AB(5mmol/L) had no effect on the reponses. CONCLUSION: PARP is involved in the epithelial damage and hyperreactivity of guinea - pig tracheas induced by peroxynitrite. The results suggested that inhibition of excessive activation of PARP may represent a novel strategy for the prevention and therapy of airway hyperreactivity in asthma.     

Role of TLR4-TRPC6 in LPS-induced NF-κB P65 expression and nuclear translocation in airway epithelial 16HBE cells

AIM: To investigate the role of Toll-like receptor 4 (TLR4) and transient receptor potential channel 6 (TRPC6) signaling pathway in lipopolysaccharide (LPS)-induced nuclear factor-κB (NF-κB) P65 expression and nuclear translocation in airway epithelial cells (16HBE) for supplementing the mechanism for airway inflammation. METHODS: After stimulating the 16HBE cells with LPS at 1 mg/L for 0, 0.5, 2, 6, 12 and 24 h, the expression of NF-κB P65 at mRNA and protein levels in the 16HBE cells were determined by RT-PCR and Western blot respectively, and the nuclear translocation of NF-κB P65 was detected by immunocytochemical staining method. The effects of TLR4 inhibitor CLI-095 at 5 μmol/L and TRPC6 agonist Hyp9 at 10 μmol/L on LPS (1 mg/L)-induced NF-κB P65 expression and nuclear translocation in the 16HBE cells were determined by RT-PCR, Western blot and immunocytochemical staining. RESULTS: LPS increased the mRNA and protein expression of NF-κB P65 and nuclear translocation in the 16HBE cells(P<0.05). TLR4 inhibitor CLI-095 reduced the mRNA and protein expression of NF-κB P65 and nuclear translocation induced by LPS, while Hyp9 enhanced the mRNA and protein expression of NF-κB P65 and nuclear translocation induced by LPS in the 16HBE cells(P<0.05). CONCLUSION: LPS induces the expression and nuclear translocation of NF-κB P65 in the 16HBE cells via TLR4-TRPC6 signaling pathway.     

湿法机械处理改善粘胶级竹溶解浆反应性能的研究

为提高溶解浆进行粘胶纤维产品生产的加工性能及减少二硫化碳的排放,采用PFI（papirindustriens forsknings institut）磨打浆和瓦利打浆机打浆这2种湿法机械处理,以改善竹溶解浆的反应性能。以预水解硫酸盐法竹溶解浆为原料,考察PFI磨打浆及瓦利打浆机打浆对溶解浆反应性能及纤维形态的影响,并对同等打浆度条件下的2种湿法机械处理的效果进行比较。PFI磨和瓦利打浆机分别在打浆度为60.5°SR（15 000 r）及36.4°SR（30 min）的优化工艺条件下,Fock反应性能从68.3%分别提高到73.2%和84.0%,粘胶过滤性能由“不通过”到粘胶过滤值分别为3 196.1 s和2 115.6 s。同时,上述2种处理方式均使纤维粗度和长度下降,细小纤维含量、比表面积和总孔隙量增加,且使聚合度损失小。同等打浆度条件下,基于瓦利打浆机对纤维更多的剪切行为,瓦利打浆机打浆对反应性能的提高效果更为显著。     

不同感染量REV对鸡免疫反应和细胞毒性作用的影响

用不同剂量网状内皮增生症病毒（REV）感染肉鸡和SPF鸡后，检测血液中T淋巴细胞对ConA的反应和NK细胞、细胞毒T细胞（CTL）的细胞毒性作用以及NDV抗体生成变化等，观察REV感染对机体非特异性、特异性细胞免疫反应和体液免疫反应的影响。结果表明无论高剂量还是低剂量REV感染均造成体液免疫和非特异性细胞免疫抑制，而且高剂量比低剂量对免疫功能的抑制作用更强，但对NK细胞和细胞毒T细胞的细胞杀伤活性却有升高趋势，在抗肿瘤方面发挥一定的作用。这种结果说明REV感染对机体的免疫抑制是有选择性的，且抑制程度与感染病毒量有关。     

Histamine receptor antagonist prevent and ameliorate airway remodeling and acid-base imbalance in asthma of guinea pig

AIM:To investigate the effect of histamine receptor antagonist on airway remodeling and acid-base imbalance in asthma of guinea pig. METHODS:Guinea pigs were divided into 5 groups: the normal control group, the asthma model group, the continued asthma model group, histamine group and histamine receptor antagonist group. For each group, the content of histamine, Na+, Cl-, PaO2, PaCO2, pH, AB, SB in serum, and thickness of airway mucosa and smooth muscle cell layer were measured and compared with each other. RESULTS:(1) According to the content of histamine in serum and thickness of airway mucosa and smooth muscle, the order was: the histamine group>continued asthma model group>the asthma model group>the normal control group (P<0.01), and the histamine receptor antagonist groupthe continued asthma model group (P<0.01), but for PaCO2, the order was conversed. Airway remodeling, increase in histamine in serum, respiratory acidosis and metabolic acidosis in asthmatic guinea pig were observed. Exogenous histamine accentuated the change, however, histamine receptor antagonist attenuated it. CONCLUSION:Histamine may take part in the airway remodeling of asthma. Histamine receptor antagonist can prevent and ameliorate airway remodeling and acid-base imbalance in asthma of guinea pig.     

鸡新城疫病毒F蛋白部分表位基因的克隆表达及其免疫反应性

为研究NDV-F蛋白抗原表位在动物免疫应答中的作用特点,作者克隆和表达了NDV-F蛋白基因的部分片段,并检测其免疫反应性.首先根据F基因和载体pGEX-4T-1的多克隆位点自行设计了1对引物,以已克隆的NDV(F48E9株)的F基因为模板,通过PCR扩增获得长度为594 bp的片段.接着在电泳和酶切鉴定后将其定向插入pGEX-4T-1,构建重组质粒pGEX-4T-1-F594,并经PCR、双酶切及测序鉴定后,进一步将其转化到大肠杆菌BL21中.最后用IPTG诱导表达,提取物用SDS-PAGE和Western-blotting分析.结果表明,该基因片段表达的融合蛋白大小约为46 000,以包涵体形式存在,并具有良好的免疫反应性.     

Effect of Kechuanning on airway remodeling and protein level of p-ERK1/2 in lung tissues of asthmatic rats induced by virus

AIM:To investigate the effect of Kechuanning on airway remodeling and the protein level of p-ERK1/2 in lung tissues of asthmatic rats induced by virus. METHODS:The asthmatic rat model induced by respiratory syncytial virus was established. The experimental rats were divided into normal group, asthma model group, low dose (0.33 mL/kg), middle dose (3.0 mL/kg) and high dose (10 mL/kg) of Kechuanning groups, and PD98059 (3 mg/kg) group. The airway responsiveness of the rats was measured by animal ventilator. The pathological changes of the lung tissues were observed by HE staining. PAS staining and Masson staining were used to observe goblet epithelial cells metaplasia and airway collagen deposition. The expression of matrix metalloproteinases-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in the lung tissues of the rats was detected by immunohistochemical staining. The protein levels of ERK1/2 and p-ERK1/2 were determined by Western blot. RESULTS:Compared with model group, the airway responsiveness of the rats in middle dose and high dose of Kechuanning groups was significantly decreased (P<0.01), the injury of lung tissues was significantly decreased, the goblet epithelial cells metaplasia and airway collagen deposition were significantly reduced (P<0.01), and the expression of MMP-9 and TIMP-1 in the lung tissues was also significantly decreased (P<0.01). In addition, the protein level of p-ERK1/2 in high dose of Kechuanning group was significantly decreased compared with model group (P<0.01). CONCLUSION:Kechuanning may treat asthma by regulating the expression of p-ERK1/2 in the lung tissues and improving the airway remodeling symptoms of asthmatic rats induced by virus.