舒血宁注射液联合胞磷胆碱钠对脑梗死患者神经功能及血清IGF-1、vWF、HIF-1α水平的影响

目的:研究舒血宁注射液联合胞磷胆碱钠对脑梗死患者神经功能及血清胰岛素样生长因子(IGF-1)、血浆血管性病友因子(v WF)、缺氧诱导因子-1α(HIF-1α)水平的影响。方法:收集2014年3月至2016年3月我院收治的120例脑梗死患者,按抽签法分为对照组和实验组,每组各60例。两组均采用基础治疗,对照组在此基础上采用胞磷胆碱钠治疗,每次2粒,每天3次;实验组在对照组的基础上采用舒血宁注射液治疗,每次5 m L,加入0.9%生理盐水250 m L中混合后进行静脉滴注,每天1次。两组治疗疗程均为2周。对比两组治疗前后神经功能缺损评分(NIHSS)、日常生活能力(ADL),血清IGF-1、v WF、HIF-α水平的变化,不良反应的发生情况及治疗疗效。结果:治疗后,实验组总有效率显著高于对照组[91.66%(55/60) vs. 71.66%(43/60)](P0.05),NIHSS评分显著低于对照组[(7.01±1.23)分vs.(10.52±1.98)分](P0.05),ADL评分显著高于对照组[(68.16±5.62)分vs.(56.20±5.13)分](P0.05);血清IGF-1水平显著高于对照组[(174.29±27.35)IU/mL vs.(152.08±25.29)IU/mL](P0.05),血清v WF、HIF-α水平显著低于对照组[(5.63±1.21)mg/L vs.(11.92±1.35)mg/L,(14.21±3.11)μmol/L vs.(20.16±3.89)μmol/L](P0.05);两组不良反应的发生率比较无显著差异(P0.05)。结论:舒血宁注射液联合胞磷胆碱钠治疗脑梗死的临床疗效显著优于单用胞磷胆碱钠治疗,其可有效改善患者的神经功能,恢复脑组织功能,可能与其效减轻炎症反应及抑制氧化应激反应有关。     

鲑鱼降钙素联合糖皮质激素吸入治疗COPD合并骨质疏松的疗效及对血清PINP、β-CTX、MMP-9水平的影响

目的:研究鲑鱼降钙素联合糖皮质激素吸入治疗慢性阻塞性肺疾病(Chronic obstructive pulmonary disease COPD)合并骨质疏松的疗效及对血清Ⅰ型前胶原氨基端肽(Amino terminal peptide of procollagen type I PINP)、β-胶原降解产物(β-Cterminal telopeptide of typeⅠcollagenβ-CTX)、基质金属蛋白酶(matrixmetalloproteinase-9 MMP-9)水平的影响。方法:选取2017年3月至2018年4月我院收治的97例COPD合并骨质疏松患者,按照随机数表法分为观察组(47例)和对照组(50例),两组均采用常规治疗,对照组在此基础上采用糖皮质激素吸入治疗,观察组在对照组的基础上采用鲑鱼降钙素治疗。观察和比较两组患者的疗效,治疗前后肺功能指标(一秒钟用力呼气量(forced expiratory volume in one second FEV1)、第一秒用力呼气容积占用力肺活量百分比(Forced expiratory volume in the first second is the percentage of forced vital capacity FEV1/FVC)、血清PINP、β-CTX、MMP-9水平、腰椎骨密度、股骨颈股密度的变化。结果:治疗后,观察组总有效率显著高于对照组[91.48%(43/47) vs. 70.00%(35/50)](P0.05);FEV1、PO2、FEV1/FVC水平均显著高于对照组[(85.20±13.72)%vs.(70.62±11.37)%,(76.30±8.64)mmhg vs.(62.49±7.13)mmhg,(68.08±11.34)%vs.(60.84±9.75)%](P0.05);PINP、β-CTX、MMP-9水平均显著低于对照组[(17.02±3.67)mg/L vs.(14.86±3.13)mg/L,(93.20±8.01)ng/L vs.(117.39±11.42)ng/L,(47.24±3.75)ng/mL vs.(60.26±4.67)ng/mL](P0.05);腰椎骨密度、股骨颈股密度水平均显著高于对照组[(1.12±0.25)g/cm~2vs.(0.89±0.23)g/cm2,(1.14±0.23)g/cm~2vs.(0.90±0.21)g/cm~2](P0.05)。结论:鲑鱼降钙素联合糖皮质激素吸入治疗COPD合并骨质疏松的疗效显著优于单用糖皮质激素吸入治疗,其能够更有效改善患者肺功能,调节血钙,提高骨密度,缓解骨痛,可能与其降低血清PINP、β-CTX、MMP-9的水平有关。     

白芍总苷对糜烂型口腔扁平苔藓外周血TNF-α，IFN-γ及IL-10水平的影响

目的:研究白芍总苷对糜烂型口腔扁平苔藓外周血肿瘤坏死因子(TNF-α)、γ-干扰素(IFN-γ)及白细胞介素-10(IL-10)水平的影响。方法:选取2014年7月至2015年7月我院接诊的糜烂型口腔扁平苔藓患者80例作为本次研究对象。对照组患者采用低浓度他克莫司治疗,观察组采用白芍总苷治疗,观察两组患者治疗前后血清TNF-α、IFN-γ及IL-10水平的变化、糜烂面积、疼痛评分及近期治疗疗效。结果:治疗后,观察组血清TNF-α、IL-10水平显著低于对照组,血清IFN-γ水平明显高于对照组[(2.16±0.61)μg/m L vs(3.04±0.80)μg/m L、(258.93±5.72)ng/L vs(273.41±6.03)ng/L、(319.27±53.46)ng/L vs(290.95±51.03)ng/L(P0.05),糜烂面积、疼痛评分均显著低于对照组[(0.10±0.03)cm2 vs(0.51±0.10)cm~2、(1.01±0.30)分vs(3.20±0.78)分](P0.05),近期治疗疗效优于对照组95.00%(38/40)vs75.00%(30/40)(P0.05)。结论:白芍总苷治疗糜烂型口腔扁平苔藓的效果显著,可能与其调节血清TNF-α、IFN-γ及IL-10的水平有关。     

微创踝关节融合术治疗老年创伤性踝关节炎中的临床效果及对患者氧化损伤与骨代谢的影响

目的:研究微创踝关节融合术治疗老年创伤性踝关节炎中的临床效果及对患者氧化损伤与骨代谢的影响。方法:收集2014年3月至2015年3月我院收治的94例老年创伤性踝关节炎患者,按随机数表法分为实验组和对照组,每组各45例。两组患者在手术前均进行常规检查,对照组采用常规开放式踝关节融合术,实验组采用微创踝关节融合术。对比两组治疗后血清氧化损伤指标肌红蛋白(MYO)、缺血修饰白蛋白(IMA)、总抗氧化能力(TAC)、丙二醛(MDA)水平,骨代谢指标碱性磷酸酶(ALP)、酸性磷酸酶(ACP)、甲状旁腺素(PTH)、骨钙素(BGP)、降钙素(CT)水平,视觉疼痛模拟评分(VAS)、美国矫形外科足踝协会(AOFAS)评分及不良反应的发生情况。结果:治疗后,实验组血清MYO、IMA、MDA水平显著低于对照组[(20.48±2.59)ng/mL vs.(27.07±2.97)ng/m L,(65.68±8.20)U/L vs.(74.27±9.01)U/L,(5.01±1.03)nmol/L vs.(9.64±2.17)nmol/L](P0.05),血清TAC水平显著高于对照组[(11.40±2.50)kU/L vs.(7.36±1.03)kU/L](P0.05);血清ALP、BGP、CT水平均显著高于对照组[(103.28±12.47)U/L vs.(90.53±10.02)U/L,(11.08±1.42)ng/L vs.(8.01±1.23)ng/L,(61.39±5.87)ng/L vs.(50.28±4.92)ng/L](P0.05),ACP、PTH水平均显著低于对照组[(5.21±0.60)U/L vs.(8.03±0.92)U/L,(42.95±5.38)ng/L vs.(60.49±6.92)ng/L](P0.05);VAS评分显著低于对照组[(1.06±0.23)分vs.(3.79±0.67)分](P0.05),AOFAS评分显著高于对照组[(73.02±6.28)分vs.(65.58±5.13)分](P0.05);不良反应总发生率显著低于对照组[6.66%(3/45) vs. 20.41%(10/49)](P0.05)。结论:微创踝关节融合术可调节老年创伤性踝关节炎患者的骨代谢,增强骨密度,减少术后不良反应,有利于改善患者预后。     

骨化三醇联合腹膜透析疗法治疗慢性肾功能衰竭的临床疗效及对患者血清ProGRP、Cysc、Chemerin水平的影响

目的:探讨骨化三醇联合腹膜透析疗法治疗慢性肾功能衰竭的临床疗效及对患者血清Pro-Gastrin-Releasing Peptide (ProGRP)、CystatinC(Cysc)、Chemerin水平的影响。方法:选取我院2017年2月至2018年1月收治的98例慢性肾功能衰竭患者,按照随机数表法将其分为观察组(n=51)和对照组(n=47)。对照组采用腹膜透析疗法治疗,观察组采用骨化三醇联合腹膜透析疗法治疗。观察和比较两组治疗前后肾功能指标尿素氮(blood urea nitrogen,BUN)、血清肌酐(Serum creatinine Cr)、24小时尿蛋白(24 h urinary protein,24 h UP),生化指标白蛋白(albumin,Alb)、血红蛋白(hemoglobin,Hb)及红细胞(red blood cell,RBC),胃泌素释放肽前体(ProGRP)、血清胱抑素(Cys C)、趋化素(Chemerin)水平的变化,6个月、1年生存率及不良反应的发生情况。结果:治疗后,观察组BUN、SCr、24hUP水平均显著低于对照组[(13.95±3.06)mmol/L vs.(21.10±3.85)mmol/L,(260.12±40.32)μmol/L vs.(354.93±51.06)μmol/L,(1.75±0.45)g/24 h vs.(2.67±0.80)g/24 h](P0.05);Alb水平显著低于对照组[(27.85±3.58)g/L vs.(33.06±4.27)g/L](P0.05);Hb、RBC显著高于对照组[(91.72±13.46)g/L vs.(82.36±10.15)g/L,(379.47±92.08)×1012/L vs.(315.70±73.24)×1012/L](P0.05);ProGRP、Chemerin水平显著低于对照组[(49.23±4.72)pg/mL vs.(63.87±7.30)pg/mL,(37.02±6.15)μg/L vs.(30.63±4.81)μg/L](P0.05);Cysc水平显著高于对照组[(80.75±16.08)mL/min vs.(98.81±18.07)mL/min](P0.05);6个月、1年生存率均显著高于对照组[96.08%(49/51) vs. 91.49%(43/47),90.20%(46/51) vs. 74.47%(35/47)](P0.05);不良反应总发生率显著低于对照组[17.65%(9/51) vs. 44.68%(21/47)](P0.05)。结论:骨化三醇联合腹膜透析疗法治疗慢性肾功能衰竭的临床效果显著优于单用,其可有效减轻患者的临床症状,纠正电解质紊乱,改善肾功能和预后,可能与降低血清ProGRP、Chemerin水平及提高血清Cysc水平有关。     

腺苷蛋氨酸联合白蛋白治疗新生儿黄疸的临床疗效及对血清γ-谷氨酰转移酶、胰岛素样生长因子水平的影响

目的:探讨腺苷蛋氨酸联合白蛋白治疗新生儿黄疸的临床疗效及对患儿血清γ-谷氨酰转移酶、胰岛素样生长因子水平的影响。方法:选取2017年3月至2019年3月我院收治的203例新生儿黄疸患儿,按照随机数表法分为观察组(n=105)和对照组(n=98)。对照组采用白蛋白治疗,观察组采用腺苷蛋氨酸联合白蛋白治疗。观察及对比两组治疗疗效,黄疸消退时间及黄疸指数水平,治疗前后胆红素各项指标、γ-谷氨酰转移酶、胰岛素样生长因子、转铁蛋白水平的变化。结果:治疗后,观察组总有效率显著高于对照组[92.38%(97/105) vs. 80.61%(79/98)](P0.05);黄疸消退时间及黄疸指数水平均显著低于对照组[(4.15±0.82) d vs.(5.31±0.92) d,(56.02±7.36)μmol/L vs.(82.86±9.32)μmol/L](P0.05);间接胆红素、结合胆红素、总胆红素水平均显著低于对照组[(108.75±6.21) d vs.(146.03±7.32) d,(7.49±0.85)μmol/L vs.(9.57±1.02)μmol/L,(117.80±6.52)μmol/L vs.(151.09±8.34)μmol/L](P0.05);γ-谷氨酰转移酶、胰岛素样生长因子均显著低于对照组[(56.01±6.45) U/L vs.(89.56±10.73) U/L,(19.30±2.17) ng/L vs 26.78±3.67) ng/L](P0.05);而转铁蛋白水平均显著高于对照组[(1.96±0.27)g/L vs.(1.60±0.24)g/L](P0.05)。结论:腺苷蛋氨酸联合白蛋白治疗新生儿黄疸的临床疗效显著优于单用白蛋白治疗,其可有效改善患儿的黄疸临床症状,降低血清胆红素、γ-谷氨酰转移酶、胰岛素样生长因子水平。     

丁苯酚联合尼莫地平对急性脑出血患者神经功能及血清MMP-9、NF-κB水平的影响

目的:探讨丁苯酚联合尼莫地平对急性脑出血患者及神经功能及血清基质金属蛋白酶9(MMP-9)和核转录因子kappa B(NF-κB)水平的影响。方法:选择90例急性脑出血患者作为研究对象并将其随机分为两组,每组各45例。两组患者均给予口服尼莫地平片治疗,观察组在对照组基础上加以口服丁苯酚软胶囊,疗程均为30天。比较两组患者的临床疗效以及治疗前后血清MMP-9、NF-κB水平和神经功能的变化。结果:观察组患者的临床总有效率显著高于对照组[42(93.99%)vs 37(82.22%)](P0.05)。治疗后,观察组的血清MMP-9、NF-κB水平均明显低于对照组[121.51±14.76 vs 137.09±14.71;0.14±0.04vs0.24±0.05](P0.05),日常生活质量评分(ADL)明显高于对照组[37.09±5.91 vs 33.54±6.74](P0.05),神经功能缺损评分(NIHSS)明显低于对照组[15.31±7.61 vs18.54±5.21](P0.05),认知功能评分(MMSE)明显高于对照组[27.54±4.21vs23.72±5.75](P0.05)。结论:丁苯酚联合尼莫地平治疗急性脑出血患者的临床疗效优于口服尼莫地平片单药治疗,可有效改善患者的神经和认知功能,可能与其显著降低血清MMP-9、NF-κB水平有关。     

脑血疏口服液联合依达拉奉对高血压脑出血的治疗效果及对血清IL-6，IL-1β，MMP-9的影响

目的:研究脑血疏口服液联合依达拉奉对高血压脑出血的治疗效果及对血清白介素-6(IL-6)、IL-1β、基质金属蛋白酶-9(MMP-9)的影响。方法:选取2014年10月至2016年9月我院收治的102例高血压脑出血患者,根据入院顺序分为观察组和对照组,51例每组。对照组使用常规治疗,观察组在此基础上采取脑血疏口服液联合依达拉奉完成治疗。比较两组患者临床疗效,神经功能评分、血肿周围水肿量、血肿量,血清IL-6、IL-1β、MMP-9水平。结果:治疗后,观察组临床总有效率显著高于对照组[94.12%(48/51)比78.43%(40/51)](P0.05);神经功能评分、血肿量、周围水肿量显著低于对照组[(11.04±1.21)分、(8.65±0.54)m L、(5.87±0.54)m L比(19.87±1.76)分、(13.56±1.23)m L、(9.65±0.92)m L](P0.05);血清IL-6、IL-1β、MMP-9水平低于对照组[(8.98±0.87)ng/m L、(12.34±1.21)ng/L、(74.21±8.42)ng/L比(11.21±1.02)ng/m L、(23.87±2.37)ng/L、(92.17±9.86)ng/L](P0.05)。两组患者不良反应的发生率比较差异无统计学意义(P0.05)。结论:脑血疏口服液联合依达拉奉治疗高血压脑出血的临床疗效明显优于常规治疗,可能与其有效降低患者血清IL-6、IL-1β、MMP-9水平有关。     

参苓白术散联合复方谷氨酰胺肠溶胶囊对肠易激综合征患者的肠黏膜屏障功能及5-HT、IFN-γ、IL-8水平的影响

目的:探讨参苓白术散联合复方谷氨酰胺肠溶胶囊对肠易激综合征患者的肠黏膜屏障功能及5-羟色胺(5-HT)、γ-干扰素(IFN-γ)、白细胞介素8(IL-8)水平的影响。方法:选取2017年3月至2018年1月的89例肠易激综合征患者。按照随机数表法分为观察组(n=46)和对照组(n=43),对照组采用复方谷氨酰胺肠溶胶囊治疗,观察组采用参苓白术散联合复方谷氨酰胺肠溶胶囊治疗。观察两组治疗疗效,肠黏膜屏障功能(DAO、D-乳酸、细菌内毒素),血清5-HT、IFN-γ、IL-8水平,不良反应发生率。结果:治疗后,观察组总有效率显著高于对照组[93.47%vs 72.09%](P0.05);中医症状积分显著低于对照组[(2.81±0.42)分vs(5.79±0.74)分](P0.05);DAO、D-乳酸、细菌内毒素水平均显著低于对照组[(10.02±1.50)U/L vs(11.85±1.98)U/L,(7.18±1.37)mg/L vs (8.56±1.53)mg/L,(0.60±0.08)pg/mL vs (0.75±0.12)pg/mL](P 0.05);血清5-HT、IFN-γ、IL-8水平均显著低于对照组[(351.08±20.93)pg/mL vs(364.12±29.71)pg/mL,(26.95±5.02)pg/mL vs(31.28±6.10)pg/mL,(2.97±0.51)ng/L vs(4.03±0.62)ng/L](P0.05);不良反应总发生率显著低于对照组[6.52%(3/46)vs20.93%(9/43)](P0.05)。结论:参苓白术散联合复方谷氨酰胺肠溶胶囊治疗肠易激综合征患者的临床疗效显著,可改善临床症状,改善肠黏膜屏障功能,及5-HT、IFN-γ、IL-8水平,减轻炎症反应,安全可靠。     

氯沙坦联合环磷腺苷葡胺对肺心病患者心肺及免疫功能的影响

目的:探讨氯沙坦联合环磷腺苷葡胺对肺心病患者心肺功能和免疫功能的影响。方法:选择2010年9月至2015年9月我院接诊的94例肺心病患者并按随机数表法分为观察组和对照组,每组各47例。对照组给予常规肺心病治疗,观察组在对照组的基础上给予氯沙坦联合环磷腺苷葡胺进行治疗。比较两组治疗前后CO、LVEF、SV、FEV1及FEV1/FV、Ig G、Ig A、补体C3、血清白细胞介素-2(interleukin-2,IL-2)、可溶性白细胞介素2受体(soluble interleukin-2 receptor,s IL-2R)、8-异前列腺素(8-ISO prostaglandin,8-iso-PG)水平的变化以及治疗后的临床疗效。结果:治疗后,观察组CO、LVEF、SV、FEV1及FEV1/FVC水平均显著高于对照组[(5.21±0.27)vs(4.15±0.46),(63.42±6.17)vs(52.37±5.76),(74.68±9.24)vs(64.56±11.73),(1.75±0.27)vs(1.32±0.31),(75.68±10.62)vs(65.49±10.05)](P0.05),血清补体C3高于对照组[(1.34±0.12)g/L vs(1.16±0.10)g/L](P0.05);血清s IL-2R、8-iso-PG水平显著低于对照组[(371.46±161.06)U/ml vs(435.75±152.43)U/ml,(23.58±11.72)ng/L vs(31.08±11.39)ng/L](均P0.05);观察组总有效率高于对照组[(95.74)%vs(78.72)%](P0.05)。结论:氯沙坦联合环磷腺苷葡胺可有效提高肺心病患者心、肺及免疫功能。     

壳聚糖酶的克隆表达与壳寡糖的制备分析

目的:克隆壳聚糖酶基因于大肠杆菌中实现高表达,制备壳寡糖。方法:以枯草芽孢杆菌总DNA为模板扩增壳聚糖酶基因(CSN),克隆至载体pET23a(+)上,转化菌株BL21(DE3)。重组子经0.5 mmol/L IPTG诱导后,SDS-PAGE和质谱检测与鉴定重组酶。酶纯化后水解壳聚糖,薄层色谱分析其水解产物。结果:质谱证明壳聚糖酶(31.5kDa)成功表达,表达量占菌体总蛋白的45%左右。纯化后重组酶浓度为900 mg/L,纯度95%、回收率85%,酶活力为10 000 U/mg。壳聚糖降解产物为壳二糖至壳四糖。结论:原核表达载体pET23a(+)-CSN构建正确,壳聚糖酶表达量与活性高,适用于水解壳聚糖制备壳寡糖。     

国内外蝗害治理技术现状与展望

本文首先概述了国内外蝗虫发生与为害的态势,总结了现阶段我国蝗虫发生与为害的主要特点:即农田飞蝗暴发频繁而且严重,草原土蝗的发生时常造成严重的经济损失,而且侵入城市干扰市民生活,我国与周边国家之间蝗虫过境迁移频繁,使用化学农药污染环境和农产品;分析了国内外蝗虫防治对策与技术的发展现状,重点介绍了应急防治和可持续治理对策、...     

Coiled-coil nanomechanics and uncoiling and unfolding of the superhelix and alpha-helices of myosin

The nanomechanical properties of the coiled-coils of myosin are fundamentally important in understanding muscle assembly and contraction. Force spectra of single molecules of double-headed myosin, single-headed myosin, and coiled-coil tail fragments were acquired with an atomic force microscope and displayed characteristic triphasic force-distance responses to stretch: a rise phase (R) and a plateau phase (P) and an exponential phase (E). The R and P phases arise mainly from the stretching of the coiled-coils, with the hinge region being the main contributor to the rise phase at low force. Only the E phase was analyzable by the worm-like chain model of polymer elasticity. Restrained molecular mechanics simulations on an existing x-ray structure of scallop S2 yielded force spectra with either two or three phases, depending on the mode of stretch. It revealed that coiled-coil chains separate completely near the end of the P phase and the stretching of the unfolded chains gives rise to the E phase. Extensive conformational searching yielded a P phase force near 40 pN that agreed well with the experimental value. We suggest that the flexible and elastic S2 region, particularly the hinge region, may undergo force-induced unfolding and extend reversibly during actomyosin powerstroke.     

Kinetics and thermodynamics of peroxidase- and laccase-catalyzed oxidation of N-substituted phenothiazines and phenoxazines

N -substituted phenothiazines (PTs) and phenoxazines (POs) catalyzed by fungal Coprinus cinereus peroxidase and Polyporus pinsitus laccase were investigated at pH 4–10. In the case of peroxidase, an apparent bimolecular rate constant (expressed as k _cat/K _m) varied from 1 ×10⁷M⁻¹s⁻¹to 2.6×10⁸M⁻¹s⁻¹ at pH 7.0. The constants for PO oxidation were higher in comparison to PT. pH dependence revealed two or three ionizable groups with pK _a values of 4.9–5.7 and 7.7–9.7 that significantly affected the activity of peroxidase. Single-turnover experiments showed that the limiting step of PT oxidation was reduction of compound II and second-order rate constants were obtained which were consistent with the constants at steady-state conditions. Laccase-catalyzed PT and PO oxidation rates were lower; apparent bimolecular rate constants varied from 1.8×10⁵M⁻¹s⁻¹ to 2.0×10⁷M⁻¹s⁻¹ at pH 5.3. PO constants were higher in comparison to PT, as was the case with peroxidase. The dependence of the apparent bimolecular constants of compound II or copper type 1 reduction, in the case of peroxidase or laccase, respectively, was analyzed in the framework of the Marcus outer-sphere electron-transfer theory. Peroxidase-catalyzed reactions with PT, as well as PO, fitted the same hyperbolic dependence with a maximal oxidation rate of 1.6×10⁸M⁻¹s⁻¹ and a reorganization energy of 0.30 eV. The respective parameters for laccase were 5.0×10⁷M⁻¹s⁻¹ and 0.29 eV. Received: 20 September 1999 / Accepted: 24 February 2000     

白术同源四倍体的诱导和鉴定及其与二倍体过氧化物酶的比较

以白术（Atractylodes macrooephala Koidz.）二倍体组培苗为材料,对其四倍体诱导方法进行研究,共获得45个白术同源四倍体株系,为优良株系的选育提供了材料。此外,还分析比较了其中8个白术四倍体株系与二倍体的过氧化物酶同工酶（POD）的酶谱差异,发现四倍体各株系过氧化物酶同工酶谱比二倍体的均多了Rf0.310的谱带,且总过氧化物酶比活力也发生了很大改变,对探讨白术四倍体优良株系的生理生化机理具有一定的参考价值。     

放牧对牧草光合作用、呼吸作用和氮、碳吸收与转运的影响

研究放牧对草地植物生理活动的影响,对于揭示草地放牧演替的生理机制有重要意义.大量研究表明,家畜放牧对牧草光合作用、呼吸作用以及C和N吸收与转运的影响,可以分为生理伤害和生理恢复2个阶段.放牧通过改变草地冠层结构影响牧草光合作用,净光合作用速率短期内迅速下降,随着叶面积指数增加又逐渐上升,呼吸作用有相似的变化趋势.牧草放牧后再生长所需的C和N最初主要来自根系和留茬中的贮藏物质,此后随着牧草生长恢复逐渐由同化作用供给,C代谢与土壤N水平负相关.放牧后牧草生理活动变化与牧草遗传特性、种间竞争、家畜放牧特征、非生物环境等因素密切相关.     

Synthesis of hapten and conjugates of coumestrol and development of immunoassay

3-O-Carboxymethylcoumestrol was prepared as the hapten for immunoassay by a partial alkylation of coumestrol with ethyl chloroacetate in acetone alkalized with potassium carbonate. 3-O-Ethoxycarbonylmethylcoumestrol was separated by column chromatography and finally was hydrolyzed with formic acid. 1H and 13C NMR data (APT, COSY, HMQC, and HMBC) revealed that the reaction was regioselective, as 3-O-ethoxycarboxymethylcoumestrol was the only monosubstituted derivative. The hapten was then conjugated to bovine serum albumin and used for immunization of rabbits. A radioimmunoassay (RIA) system was established based on the polyclonal antiserum and a 125I-labeled hapten-tyrosine methyl ester conjugate as the radioligand. Parameters of the RIA: sensitivity: 12 pg per tube, 50% intercept: 140 pg per tube, working range: 20-4000 pg per tube. The cross-reactivity of a panel isoflavonoid and lignan phytoestrogens was either negligible (e.g. formononetin 0.07%; biochanin A 0.06%) or not detectable at all. The major immunoreactive peak in HPLC fractions from an alfalfa extract had the same retention time as coumestrol standard and represented 94.8% of the signal. The remaining 5.2% of immunoreactivity was distributed between five minor peaks. We conclude that after the validation for particular matrices, the method will be a useful tool for analysis of coumestrol, especially in low volume and low concentration samples.