桂黄降脂颗粒质量标准研究

目的:建立桂黄降脂颗粒的质量标准。方法:采用薄层色谱法对桂黄降脂颗粒中山楂、丹参进行定性鉴别;采用HPLC法对山楂中的槲皮素和丹参中的丹参素钠进行含量测定。结果:薄层色谱斑点清晰、分离度效果较好、且阴性无干扰;槲皮素在11.2~33.6μg范围内呈良好的线性关系,r=0.9995(n=5),样品平均回收率为98.00%,RSD 1.33%;丹参素钠在0.0166~0.332 mg·mL-1范围内呈良好的线性关系,r=0.9998(n=5),样品平均回收率为97.87%,RSD 1.35%。结论:该方法准确可靠、专属性强、重现性好,可以作为控制桂黄降脂颗粒质量的有效方法。     

高效液相色谱法测定超滤后血浆中的谷氨酰胺

用高效液相色谱法测定超滤后血浆中的谷氨酰胺, 平均回收率为96.75%, 在130～1300μmol/L范围内呈线性关系(r=0.9906), 健康人正常值男性为(694.97±102.31)μmol/L, 女性为(623.79±99.27)μmol/L, 男女间值有显著差别(P＜0.05)该分析方法简单、迅速, 可用于外科肠道内营养的监测和对肠粘膜结构与功能的研究.     

雅鲁藏布江中上游白草主要分布区植物群落特征

沿环境梯度揭示植物群落特征及其环境影响因子的研究是生态学研究的重点内容之一。雅鲁藏布江作为世界海拔最高的河流之一,目前尚未开展流域内白草(Pennisetum centrasiaticum)主要分布区植物群落研究。从雅鲁藏布江上游源头区仲巴县帕羊镇至中游米林县派镇白草主要分布区设置26个样地对植物群落特征进行调查。研究结果表明:(1)雅鲁藏布江中上游白草主要分布区有119个植物物种,属35科96属,主要有禾本科、菊科和豆科。各样点优势种有白草、砂生槐(Sophora moorcroftiana)、藏沙蒿(Artemisia wellbyi)、白莲蒿(Artemisia sacrorum)、固沙草(Orinus thoroldii),白草群落物种丰富度最大的是江孜县(S=37),最小的是桑日县(S=12),白草重要值最大的是拉孜县(67.52%),最小的是桑日县(11.88%);(2)26个样点的平均地下生物量为3374.23 g/m²,各白草主要分布区群落在0-10 cm、10-20 cm和20-30 cm土层的地下生物量占比分别为60.38%,26.36%和13.26%;(3)相关分析结果表明,白草高度与海拔(r=-0.60),白草高度与土壤pH(r=-0.53),白草生物量与土壤pH(r=-0.55)呈极显著负相关(P<0.01);(4)RDA分析表明:轴1和轴2共解释全部方差的40.60%,在环境-群落的解释中起主导作用。(5)通过聚类分析,将雅鲁藏布江中上游白草主要分布区划分为梯度Ⅰ(平均3008.67 m)、梯度Ⅱ(平均3824.75 m)和梯度Ⅲ(平均4419.29 m),禾本科功能群在不同海拔梯度均有最大的高度、盖度和重要值,4个功能群(禾本科、豆科、菊科和杂类草)的高度随海拔上升而下降,群落物种丰富度和群落地下生物量占比随海拔上升而增加。上述结果表明白草是雅鲁藏布江中上游广泛分布的乡土草种,其群落特征多样,与环境因子有较强的相关性。     

云南芒果种质基因组大小测定与变异分析

为了解云南芒果(Mangifera indica L.)种质资源的基因组的变异情况, 采用流式细胞术对35 份云南芒果种质资源的基因组大小进行了测定和变异分析。结果表明, 云南芒果种质资源的基因组大小存在一定差异, 基因组的平均C值是0.445110 pg, 0.4353177×10⁹ bp, 最小的是采自景洪的半栽培种YSM-44 (0.434567 pg, 0.4250060×10⁹ bp), 最大的是采自红河的野生种YSM-25 (0.458679 pg, 0.4485881×10⁹ bp)。基因组C值变异程度最大的是野生种(CV=1.65%), 其次为半野生种(CV=1.26%)、半栽培种(CV=1.21%)和栽培种(CV=0.11%)。与芒果具有相近基因组大小的多为苔藓植物, 与"C值悖论"观点相一致。因此, 应用流式细胞术能准确、快捷地测定芒果基因组大小, 而且云南野生、半野生及半栽培芒果种质资源遗传变异类型丰富, 有较大的挖掘利用潜力。     

痹康颗粒的质量标准研究

目的:建立痹康颗粒的质量标准.方法:采用薄层色谱法对痹康颗粒中当归、丁香进行定性研究,并采用高效液相色谱法对方中补骨脂素、异补骨脂素进行含量测定研究.色谱柱:Agilent XDB-C18柱(4.6mm 150mm,5μm);流动相:甲醇-水(45:55);检测波长:246nm;流速:1.0ml/分钟;柱温:25℃.结果:薄层色谱斑点清晰,阴性无干扰;补骨脂素在浓度范围8.64～43.20mg/ml内呈良好的线性关系,r=0.9998,平均加样回收率为97.33%,RSD=1.08%(n=6);异补骨脂素在浓度范围8.92～44.60mg/ml内呈良好的线性关系,r=0.9997,平均加样回收率为98.38%,RSD=0.92%(n=6).结论:该方法简便、准确、可靠,可以作为痹康颗粒的质量控制方法.     

广东地区外来种五爪金龙的传粉生物学研究

五爪金龙(Ipomoea cairica)是一种匍匐或攀援生长的入侵杂草。2006–2007年作者在广东地区开展了对该入侵种的传粉生物学研究。五爪金龙在广东全年均可开花, 花序为聚伞花序, 花冠为紫色或蓝紫色喇叭状。开花时间在早晨4: 30–5: 20之间, 下午17: 40闭合, 持续大约12 h。每朵花平均分泌花蜜量为5.82 ± 2.47 μL (n = 10), 花蜜平均含糖量为41.03 ± 6.52%, 氨基酸含量为0.042 mg/mL。开花过程中花粉活性和柱头可受性均保持较高水平(>90%)。花粉/胚珠比率(P/O)为4,778.18 ± 264.58 (n = 10)。木蜂(Xylocopa sp.)是其有效的传粉昆虫, 蝇类和蝶类为随机访问者。开花过程中柱头与花药相接触, 有利于自花授粉。然而, 繁育系统的研究表明五爪金龙是自交不亲和植物, 其种子仅能通过异花授粉获得。     

林分特征和土壤养分对林下草本物种多样性的影响

林下草本植物是森林生态系统的重要组成部分,对维持森林群落演替和发展具有重要的生态功能。该研究以青海省互助北山林场青海云杉纯林(Ⅰ)、红桦纯林(Ⅱ)、青杨纯林(Ⅲ)、阔叶混交林(Ⅳ)和针阔叶混交林(Ⅴ)5种典型林分为研究对象,采用典型取样法在各林分选择4个20 m×20 m的样地,对样地内所有树木进行每木检尺,每个样地设置5个1 m×1 m的草本小样方,调查记录林下草本植物,并分层钻取5个小样方的土样进行分析;采用灰色关联法分析林下草本多样性与林分特征、土壤养分特征之间的关系,以明确影响林下草本物种多样性的主导因子,为该区人工林地的改造与经营提供理论依据。结果表明：(1)5种林分林下共发现草本植物86种,分属 30科 74属,其中林分Ⅴ的植物科、属、种数量均最多(25科42属49种),林分Ⅰ均最少(17科26属27种);林分Ⅰ、Ⅲ、Ⅳ中草本层均以野草莓的重要值最大(分别为 44.42%、20.29%、23.05%),林分Ⅱ、Ⅴ分别以山尖子、野草莓、黑麦草为优势种,其重要值分别为 20.97%、13.95%、13.68%和8.34%、16.83%、27.82%。(2)5种林分的林下草本物种丰富度(S)、Shannon Wiener多样性指数(D)、Simpson多样性指数(H)均差异显著(P<0.05),而Pielou均匀度指数(J)差异不显著,但S、D、H、J均表现为阔叶纯林(Ⅱ和Ⅲ)、混交林(Ⅳ和Ⅴ)高于针叶纯林(Ⅰ)。(3)不同林分间的林分密度 (SD)、平均胸径(DBH)、平均树高(H)、平均冠幅(CW)均无显著差异,但平均胸径、平均树高、平均冠幅在整体上表现为针阔混交林>阔叶混交林>阔叶纯林>针叶纯林。(4)土壤碱解氮(AN)、速效磷(AP)、速效钾(AK)、有机质(SOC)含量及酸碱度(pH)均表现为混交林和阔叶纯林高于针叶纯林,且土壤AN、AP、AK、SOC含量均随土层深度增加而降低,土壤pH值随土层深度增加而增加。(5)研究认为,森林生态系统中林下草本物种多样性对林分特征和土壤养分特征均有显著响应,林分平均胸径是影响草本多样性最主要的林分因子,碱解氮是最主要的土壤养分特征。因此,在未来林分改造中,积极改善人工林建设模式,优化林分特征,提升土壤肥力,以提高林下草本植物的多样性,维持林分的稳定和可持续发展。     

紫元益消丸的质量标准研究

目的:建立紫元益消丸的质量控制方法.方法:采用薄层色谱法鉴定蜈蚣,紫河车,鸡内金和蟾酥各味药材;高效液相色谱法测定蟾酥中华蟾酥毒基和脂蟾毒配基的含量.结果:紫元益消丸中的蟾酥、蜈蚣、紫河车、鸡内金的薄层色谱具有鉴别特征,斑点清晰;华蟾酥毒基在0.09-0.46 μg· mL-1范围内线性关系良好(r=0.9943),平均回收率95.57％,RSD为2.27％(n=5);脂蟾毒配基在0.16-1.01 μg·mL-1范围内线性关系良好(r=0.9984),平均回收率94.53％,RSD为2.06％(n=5).结论:鉴别方法专属性强、灵敏度高;定量方法简便快速、结果准确且重复性好,可用于紫元益消丸的质量控制.     

化龙山七筋姑种内二倍体与四倍体表型分化分析

七筋姑(Clintonia udensis Trautv. et Mey.)属百合科(Liliaceae)七筋姑属(Clintonia Raf.),多年生草本,具有二倍体(2n=14)和四倍体(4n=28)两种倍性。在陕西化龙山地区,二倍体主要分布在南坡海拔2 450 m处,四倍体主要生长在北坡海拔1 900 m左右,成为研究种内多倍体分化的理想材料。该研究从七筋姑营养和繁殖系统出发,研究其不同倍性的表型分化,揭示不同倍性的生态适应特征,为阐明七筋姑种内多倍体的演化提供线索。研究表明：(1)在根、茎、叶、花、果实、种子的11个性状中,二倍体的果实体积性状最为稳定(CV=0.02),叶长性状遗传多样性最高(CV=0.85);四倍体中果实体积性状也最为稳定(CV=0.06),而花数量性状多样性最高(CV=0.42)。(2)四倍体的果实体积平均值明显高于二倍体,但种子数量平均值显著少于二倍体,果实体积和种子体积性状在不同倍性间的分化占比最高(V_st=0.69)。(3)四倍体营养器官表型性状的遗传变异丰富度低于二倍体,其平均变异系数(CV=0.16)小于二倍体的变异系数(CV=0.44);在繁殖系统表型性状中,四倍体的遗传变异丰富度高于二倍体,平均变异系数(CV=0.30)大于二倍体(CV=0.26)。(4)显著性分析表明,二倍体与四倍体表型性状差异显著(P<0.05),而繁殖系统性状在不同倍性间无显著差异(P>0.05);PCA分析同样显示二倍体与四倍体间存在明显差异。四倍体显著的表型差异是对低海拔环境长期适应的结果。     

河南董寨再引入朱鹮种群的巢址分布特征

为了解再引入朱鹮(Nipponia nippon)种群的分布与扩张情况,本研究对董寨再引入朱鹮野外种群的繁殖巢址进行了调查研究。在2014到2022年间,共调查统计了84个野化放飞朱鹮及其后代的繁殖巢址,使用圆形分布法分析了巢址与放飞点的相对方位和集中程度,并根据全部巢址的空间分布,使用固定核空间方法计算得到巢区(95%巢址所在区域)与核心巢区(50%巢址所在区域)的分布范围和面积。将巢址图层、土地覆盖图层以及数字高程模型叠加,观察朱鹮巢址选择的生境偏好,并使用单样本t检验判断了巢址平均海拔与巢区海拔间的差异。结果显示,繁殖巢址与放飞点平均距离(平均值 ± 标准差)(12.82 ± 14.11)km(n = 84),平均方位角(平均值 ± 标准差)为(138.99 ± 82.44)°(瑞利检验：Z = 10.60,P < 0.01)。核心巢区与巢区面积分别为74.43 km2和549.66 km2。巢址平均海拔(平均值 ± 标准差)(103 ± 43)m,显著低于巢区内平均海拔(t =﹣5.48,df = 83,P < 0.01)。巢址的分布主要位于水稻田和森林的交界区域。逐年繁殖区域分布图显示,繁殖区域基本朝向西北-东南方向扩张,与圆形分布分析结果一致。本研究描述了董寨再引入朱鹮种群繁殖巢址的分布特征与扩张趋势,可以为野外朱鹮潜在繁殖地和栖息地的保护提供参考,优化保护工作中的人力物力资源配置。     

Physiological response of eight Mediterranean maquis species to low air temperatures during winter

We analyzed the physiological response of the Mediterranean evergreen species (Arbutus unedo L., Cistus incanus L., Erica arborea L., Erica multiflora L., Phillyrea latifolia L., Pistacia lentiscus L., Quercus ilex L., and Rosmarinus officinalis L.) to winter low air temperatures. In occasion of two cold events, in February 2005 (T _min = 1.8 °C), and January 2006 (T _min = 3.1 °C and minimum T _air = −0.40 °C during the nights preceding the measurements), R. officinalis, C. incanus, and E. multiflora had the highest net photosynthetic rate (P _N) decrease (73 %, mean value) with respect to the winter P _N maximum, followed by A. unedo (62 %), P. latifolia and P. lentiscus (54 %, mean value), E. arborea (49 %), and Q. ilex (44 %). Among the considered species, Q. ilex was able to maintain P _N near the maximum for 150 min during the day, A. unedo, P. lentiscus, E. arborea, P. latifolia, E. multiflora, and R. officinalis for 60 min, and C. incanus for 30 min. The calculated mean winter daily P _N ranged from 7.9±0.6 (Q. ilex) to 2.8±0.5 (R. officinalis) μmol(CO₂) m⁻² s⁻¹. During the study period, chlorophyll (Chl) content decreased by 36 % on an average in the two cold events, and the carotenoid (Car) to Chl ratio increased by 133 % in Q. ilex, having the highest value in January 2006. Principal component analysis underlined the highest cold resistance of Q. ilex by high P _N and high Car/Chl ratio. On the contrary, R. officinalis and C. incanus had the lowest cold resistance by the highest P _N decrease and the lowest Car/Chl (C. incanus). Thus, winter stress could be an additional limitation to Mediterranean evergreen species production, and the capacity of the species to maintain P _N near 90–100 % during winter is determinant for biomass accumulation.     

Asymmetrical (ADMA) and symmetrical dimethylarginine (SDMA) as potential risk factors for cardiovascular and renal outcome in chronic kidney disease – possible candidates for paradoxical epidemiology?

Summary. Background: Asymmetrical dimethylarginine (ADMA) is an inhibitor of nitric-oxide synthase. It has been linked to atherosclerotic risk in the general population as well as in end-stage renal disease patients (ESRD), whereas symmetrical dimethylarginine (SDMA) is thought to be biological inactive. Prospective data concerning the role of both dimethylarginines are rare in patients with chronic kidney disease. Methods: 200 patients with chronic kidney disease (mean age 57.6 ± 13.0 years, 69 female, 131 male); 82 with chronic renal failure (CRF), 81 on maintenance haemodialysis (HD) and 37 renal transplant recipients (RTR) were prospectively followed for 24 months. ADMA and SDMA were measured by HPLC. The relation of plasma levels of ADMA and SDMA together with conventional risk factors for the cardiovascular and renal outcome was investigated with Cox proportional hazards model. Results: Mean serum levels of SDMA were significantly increased in all groups compared to the control group (P ≤ 0.0005), ADMA was increased only in HD and RTR (P ≤ 0.004). Forty-seven cardiovascular events (CVE) occurred during follow-up, 35 patients died, and 39 patients reached ESRD. Multivariate analysis showed diabetes (RR 3.072, P = 0.01), ESRD (RR 11.915, P < 0.0005), elevated CRP levels (RR 3.916, P < 0.0005) and surprisingly a lower ADMA level (RR 0.271, P = 0.008) as independent risk factors for CVE. Serum creatinine (RR 11.378, P = 0.001), haemoglobin (RR 0.710, P = 0.038 for an increment of 1 mmol/l), and SDMA levels (RR 1.633, P = 0.006, per 1 μmol/l increment) were predictors for the progression to ESRD. Conclusions: Data from a heterogeneous group of patients with chronic kidney disease provide evidence that conventional risk factors seem to play a more important role than elevated serum levels of ADMA or SDMA for cardiovascular events. Increasing serum SDMA concentration seems to play an additive role for the renal outcome besides serum creatinine and haemoglobin levels. Whether ADMA might possibly be a candidate for the phenomenon of “paradoxical epidemiology” in chronic kidney disease needs further investigation.     

HPLC法同时测定鸡矢藤中熊果酸和齐墩果酸的含量

目的:建立高效液相色谱法同时测定鸡矢藤中熊果酸和齐墩果酸的含量。方法:色谱柱为DiamonsilTM C18(250×4.6 mm,5滋m),流动相为甲醇-0.05mol.L-1磷酸溶液(93∶7)为流动相,检测波长210 nm,进样量10滋L。结果:熊果酸在21.28滋g.mL-1～212.8滋g.mL-1范围内线性关系良好(r=0.9997),平均回收率为97.79%(RSD=1.30%);齐墩果酸在24.02滋g.mL-1～240.2滋g.mL-1范围内线性关系良好(r=0.9996),平均回收率为98.36%(RSD=1.11%)。结论:该方法简便、灵敏、准确,可用于鸡矢藤药材的质量评价。     

蛇伤药酒的质量控制

目的　建立蛇伤药酒的质量控制方法。　方法　用薄层色谱法对蛇伤药酒制剂中黄连、黄柏、大黄进行定性鉴别 ;用紫外分光光度法测定黄连、黄柏中有效成分小檗碱的含量。测定波长为 ( 2 64± 1 ) nm。　结果　定性鉴别色谱特征明显 ,易于区别 ;盐酸小檗碱的含量测定线性范围在 1 .42～ 7.1 0 μg,r=0 .9996,平均回收率为 99.1 4% ,RSD为 1 .3 4%。　结论　该方法可有效的控制蛇伤药酒的质量。     

利用LightCycler研究食管鳞状细胞癌与MTHFR C677T多态性的关系

亚甲基四氢叶酸还原酶(MTHFR)在叶酸代谢中起重要作用.MTHFR基因第677位核苷酸的多态性（C→T）能影响其酶活性并与肿瘤易感性有关.为比较中国北方人群MTHFR C677T多态性与食管鳞状细胞癌（ESCC）易感性之间的关系, 通过高速实时聚合酶链反应（real-time PCR）和解链曲线（melting curve）方法分析了189名ESCC患者和141名健康对照的MTHFR C677T多态性位点的基因型.结果显示,健康对照组的MTHFR C/C（纯合野生）、C/T和T/T（纯合突变）基因型的频率分别为17.7%、38.3%和44.0%.ESCC患者的T/T基因型频率（42.3%）与健康对照组无显著差异（χ²=0.089, P＞0.05）,其C/T基因型频率（49.2%）仅略高于对照组（χ²＝3.890, P＜0.05）,而患者组的C/C基因型频率(8.5%)显著低于健康对照组(17.7%) (χ²=6.37, P=0.012).与C/T和T/T基因型相比,C/C基因型可显著降低ESCC的发病风险(相对风险度的比值比（OR）=0.43, 95%可信区间（CI）=0.22～0.84),在吸烟者和有上消化道肿瘤家族史的患者中这一倾向更加明显.研究提示,在中国北方人群中, MTHFR C677T纯合野生基因型对ESCC的发病起保护作用.     

Fish arsenic may influence human blood arsenic,selenium, and T4:T3 ratio

The effects of an arsenic-rich fish diet and selenium (Se) supplementation on blood arsenic (As), Se, and thyroid hormones were studied in 32 women divided into four equal groups. Groups 1 and 4 received 400 μg Se-methionine daily, group 2 received 400 μg selenite daily, and group 3 received placebo tablets for 15 wk. In addition, groups 1–3 increased their fish intake, eating at least three fish dinners weekly. Mean blood Se concentrations (initially 1.68 ± 0.24 μmol/L) increased twofold in the Se-methionine groups (p < 0.0001) and by 32% in the selenite group (p < 0.01). Group means of blood As concentrations increased by 63% (p < 0.01), 50% (p < 0.01), 106% (p < 0.01), and 29% (p < 0.05) in the four groups, respectively. Analyzed As intake from duplicate portions of consumed fish correlated with final blood As concentrations (r=0.85, p < 0.001, n=32). In the group not receiving Se, there was a positive correlation between final blood As concentrations and plasma T4 : T3 ratio (r=0.80, p < 0.02, n=8). Initially, blood As concentrations correlated negatively with both T3 and T4 in plasma, but this correlation disappeared upon Se supplementation. The results demonstrate that increased intake of fish may influence blood As concentrations and that circulating thyroid hormones may be influenced by Se-As interactions.     

Chemical composition and antimicrobial activity of <Emphasis Type="Italic">Thymus pannonicus</Emphasis> All. (<Emphasis Type="Italic">Lamiaceae</Emphasis>) essential oil

This paper presents the results of a study on chemical composition and antimicrobial activity of Thymus pannonicus All. (Lamiaceae) essential oil from Vojvodina province (north of Serbia). The investigated oil was hydrodistilled from a flowering plant and analysed by GC and GC-MS. Fifty-three constituents were identified (>97% of total oil), with geranial (41.42%, w/w) and neral (29.61%, w/w) as the most prominent. The antimicrobial activity of the oil was evaluated using agar disc diffusion and broth microdilution method against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, two strains of Klebsiella pneumoniae and two strains of Candida albicans. The essential oil exhibited antimicrobial activity to varying degrees against all tested strains. The maximum activity of T. Pannonicus oil was observed against E. coli, S. aureus and both tested strains of C. Albicans (MIC = 50 μ/ml, each). Moderate activity was observed against P. aeruginosa and one of the tested strains of K. Pneumoniae (MIC = 200 μ/ml), while E. faecalis and the other strain of K. Pneumoniae expressed a higher degree of resistance (MIC > 200 μ/ml). This study confirms that essential oil of T. pannonicus possesses remarkable in vitro antimicrobial activity against several medicinally important pathogens. This is attributable to lemon-scented citral, a mixture of geranial and neral, which has well-documented antimicrobial activity against a range of bacteria and fungi.     

薄层扫描法测定产妇定胶囊中盐酸水苏碱的含量

为建立一种控制产妇定胶囊质量的方法,本文采用薄层扫描法测定处方中君药益母草中所含的主要有效成分盐酸水苏碱的含量.结果表明盐酸水苏碱在3.090～30.900μg范围内线性关系良好,平均回收率为99.06%,RSD=2.57%(n=5).该方法灵敏、准确,分辨率高,可用于产妇定胶囊的质量控制.     

退耕还林背景下黄土高原蒸散量时空演变特征及归因

受气候变化和人类活动影响,近几十年黄土高原地表环境和水碳通量发生显著变化,对区域水资源和生态系统格局产生深刻影响。基于植被界面过程(VIP)遥感蒸散发模型,对退耕还林(草)工程实施以来黄土高原蒸散量(ET)时空变化格局进行模拟研究,揭示了近20年黄土高原水碳通量时空演变特征及其原因。结果表明:(1) 2000-2019年黄土高原ET总体呈显著上升趋势(P < 0.05),倾向率为3.77 mm/a,其中黄河中游黄土丘陵沟壑区ET增长最为显著,而陕西关中平原东部、宁夏银川平原南部等农业区则呈显著下降趋势,倾向率为-5.68 mm/a;(2) 气候变量和归一化植被指数(NDVI)对ET显著上升区的区域平均贡献分别为14.7%和78.6%(其中人类活动贡献为70.5%),而对ET显著下降区的区域平均贡献分别为-58.4%和-31.5%(其中人类活动贡献为-31.6%),表明人类活动和气候变化分别主导了ET显著上升区和ET显著下降区的蒸散变化;(3) 在气候变化主导区域,气温和降水量分别为能量受限区和水分受限区ET增加的主导气象因子,而气溶胶浓度升高导致的日照时数和地表风速下降对作物碳同化和蒸腾具有显著的抑制作用,成为农业区ET下降的主导气象因子。     

苦玄参药材中苦玄参苷ⅠA和ⅠB的含量分析

采用HPLC法对不同产地的苦玄参药材主成分苦玄参苷ⅠA和ⅠB的含量进行分析,发现苦玄参苷ⅠB含量高于苦玄参苷ⅠA;色谱条件:Waters C18(4.6mmi.d.×250mm,5μm)色谱柱,流动相∶乙睛∶水=36?64(体积比),流速为0.8mL/min,检测波长为264nm。苦玄参苷ⅠA、ⅠB分别在0.05～0.50mg/mL和0.072～0.720mg/mL与峰面积有良好的线性关系。苦玄参苷ⅠA的线性回归方程Y=13658X-92.72(r=0.9993),平均回收率为100.58%(n=5),相对标准偏差(RSD)为1.86%;苦玄参苷ⅠB的线性回归方程Y=5258.9X-41.01(r=0.9994),平均回收率为101.15%(n=5),相对标准偏差(RSD)为1.31%。该研究为制定苦玄参药材质量检测标准提供了简便、快速、准确的方法。