不同干燥方式对核桃青皮品质的影响

核桃是我国最重要的干果之一,因此,分析了晒干、阴干、60℃热风、微波以及中短波红外5种不同干燥方式对核桃青皮性质的影响。包括核桃青皮干燥时间、最终含水率、色差以及有效成分(黄酮、总酚、蒽醌)含量的影响。研究发现以晒干所得到的产品品质最优良。但这种方式受天气影响比较明显,在阴天下雨情况下,60℃的热风与中短波红外干燥核桃对青皮的品质也没有较严重的影响。但中短波红外干燥时间是60℃热风干燥时间的1/3,所以,操作效率更高。     

不同干燥方式对芦笋功能成分及体外抗氧化活性的影响

为提高芦笋的耐贮性,本文探究了烫漂预处理和三种干燥方式（热风、冷冻和热风-微波干燥）对芦笋粉中总酚、VC、多糖和黄酮等功能成分含量及其提取物体外抗氧化活性的影响。结果表明,不烫漂冷冻干燥的芦笋粉色泽最好,且VC含量最高。热风-微波干燥的芦笋中总酚、多糖和黄酮的含量均最高,且烫漂的样品总酚、黄酮含量显著高于不烫漂样品,而多糖含量则是不烫漂的更高,其次为冷冻干燥。干燥后芦笋醇提物的ABTS自由基清除率为96%～97%,以冷冻干燥的样品最高,烫漂对其结果无显著影响;而其水提物含量以热风-微波干燥的样品最高,为96.25%,可见,烫漂提高了ABTS自由基清除力。水提物和醇提物的DPPH清除率为烫漂后热风-微波干燥的芦笋粉最高。综上,热风-微波干燥和烫漂有利于芦笋加工过程中总酚、多糖和黄酮的浸出以及抗氧化能力的保持,冷冻干燥有利于芦笋中VC保留。     

运输中温度变化对速冻松茸生理生化的影响

为研究运输中温度变化对速冻松茸品质的影响对运输车中的速冻松茸于8:00开始取样,2 h取一次样,记录实时温度,并测定水分含量、丙二醛含量、多酚氧化酶活性(PPO)和过氧化物酶(POD)活性,采用SPSS分析。结果表明:水分含量与温度显著相关(相关系数R=-0.642),丙二醛(MDA)含量与温度相关性不显著(R=0.455),PPO活性与温度极显著相关(R=0.994*),POD活性与温度微弱相关(R=0.125)。     

基于多元统计分析的干制方式对红枣片香气成分的影响

采用热风干燥、微波干燥、真空干燥3种不同干制方式得到红枣片样品,利用固相微萃取结合气相色谱-质谱联用技术(SPME-GC/MS)分析鉴定红枣片样品的香气成分及含量变化,并对红枣片中主要香气物质进行主成分分析(PCA)和正交偏最小二乘判别分析(OPLS-DA)。结果表明,PCA模型能初步实现对不同干制方式的区分;且OPLS-DA模型能提供不同干制方式处理的红枣片的标志性差异成分,糠醇是微波处理的红枣样品中的特征性成分,(R)-1,2-丙二醇是真空干燥工艺红枣样品的代表性物质,而蘑菇醇及2,4-壬二烯醛只存在于热风工艺处理的样品中。建立的正交偏最小二乘回归模型Q2X值为0.910,Q2Y值为0.987,具有较高的稳定性和预测能力。本试验为探索利用红枣香气成分指标区分干制方式和评价产品香气品质的可能性提供了理论和技术依据。     

叶面喷施铁、锌肥对黄土丘陵区“梨枣”抗氧化性的影响

选择长势均一、生长良好的8年生山地矮化密植"梨枣"为研究对象,设置不同浓度铁、锌微肥处理对"梨枣"叶片进行叶面喷施,分析了"梨枣"中维生素C、总黄酮含量、酶含量的变化以及"梨枣"的不同浓度多酚对羟基自由基、1,1-二苯基-2-三硝基苯肼(DPPH·)及过氧化氢的清除率,以探索铁、锌肥对黄土丘陵区"梨枣"抗氧化性的影响。结果表明:不同处理影响"梨枣"中维生素C含量,并显著提高了总黄酮含量,其中以0.6%FeSO_4+0.3%ZnSO_4(L3)处理的含量最高,达到2.86mg·g-1和3.02mg·g~(-1),分别较CK提高了21.8%和105.4%,且均与CK达到显著差异(P0.05)。不同施肥处理有效降低枣果中抗坏血酸氧化酶及多酚氧化酶的活性。0.6%FeSO_4+0.3%ZnSO_4处理的抗坏血酸氧化酶活性表现最低,为氧化抗坏血酸0.069mg·g~(-1)·min~(-1)FW,较CK降低了75.1%;多酚氧化酶活性以L3处理的多酚氧化酶活性表现最低,为氧化抗坏血酸0.146mg·g~(-1)·min~(-1)FW,较CK降低了42.0%。不同处理"梨枣"的多酚能有效清除羟基自由基、DPPH·以及过氧化氢,其中以L3处理的效果最为显著,抗氧化性效果最优。     

不同干燥法与贮藏温度对玉兰花粉萌发的影响

以5～7a生玉兰为试材,研究了日晒干燥法、阴干干燥法、灯照干燥法、恒温干燥法4种干燥方法和室温、4、0、-20、-40、-80℃6个贮藏温度对玉兰花粉萌发的影响。结果表明:玉兰花粉采用阴干干燥法干燥优于日晒、灯照和恒温干燥法。阴干后的花粉分别在室温、4、0、-20、-40、-80℃贮藏10、20、30和40d,玉兰花粉的离体萌发率均降低。室温下,玉兰花粉的萌发率随贮藏时间的增加降低得最快,贮藏前(0d)玉兰花粉的萌发率为73.3%,至40d萌发率已降为0%。4和0℃条件下,花粉萌发率的降低速度相近。-40和-80℃花粉的贮藏效果最好,保存至40d时,花粉萌发率仍然在50%以上。     

不同干燥方法对牡丹草化学成分及抗氧化活性的影响

以牡丹草为试材,采用晒干、阴干、硅胶干燥等方法进行干燥处理,通过紫外可见分光光度法测定各样品中总皂苷、总黄酮及多糖含量,研究不同干燥处理方法对牡丹草化学成分的影响,并以清除DPPH自由基(DPPH·)、ABTS自由基(ABTS+·)、羟基自由基(·OH)、超氧阴离子(O2·-)等多种抗氧化能力为指标,评价不同干燥方法处理后各牡丹草样品的抗氧化活性,同时结合Pearson相关性分析,探讨各样品抗氧化能力与样品中总皂苷、总黄酮及多糖含量的关系,进一步研究不同干燥处理方法对牡丹草抗氧化活性的影响,以期为牡丹草药材的炮制加工提供参考依据.结果 表明.70℃干燥处理后的牡丹草总黄酮、总皂苷和多糖含量最高,分别为0.0098、0.0088、0.0147 g·g-1,所测定的5种抗氧化指标中,70℃干燥处理后的牡丹草药材对O2·-、ABTS+·清除能力最强,IC50分别为4.981、3.543g·L-1;真空冷冻干燥处理后的牡丹草药材对DPPH·、·OH清除能力最强,其IC50分别为3.358、4.336 g·L-1;70℃干燥处理后的牡丹草药材总还原能力最强.通过Pearson相关性分析结果可知,牡丹草药材中的总皂苷及总黄酮含量与抗氧化能力存在显著相关性(P＜0.05).     

微波预干燥时间对芦笋老茎粉体干燥品质的影响

以芦笋老茎为试材，采用微波预干燥方法，研究了不同微波预干燥时间对芦笋老茎粉体干燥品质的影响，以期为芦笋老茎微波热风联合干燥中微波预干燥时间参数的选择提供参考依据。结果表明：经微波2 min处理芦笋老茎粉体的DPPH自由基清除能力相对较强；微波4 min粉体粗多糖含量、持油力最好，较单一热风分别提高了6.30%和96.43%;微波6 min粉体色泽保持相对最好；微波8 min干燥速率最快，粉体平均粒径最小，且比表面积、持水力、膨胀力最好，较单一热风提高129.00%、28.00%和43.75%。经微波2 min、微波4 min处理的粉体适宜作为功能配料添加到固体饮料等各类食品中；经微波6 min处理的粉体适宜对产品色泽要求较高的功能配料生产；经微波8 min、微波10 min处理的粉体适宜进行规模化配料生产，并广泛应用于胶囊、压片糖果等系列大健康食品的加工。     

UPLC测定不同方式干燥的猴头菌中麦角甾醇的含量

以采摘于黑龙江省海林市的猴头菌为研究对象,分别使用自然干燥、加热干燥、真空加热干燥、真空冷冻干燥和微波干燥等方式将其制备成样品,然后用超高效液相色谱(UPLC)-紫外检测法来测定不同干燥方式的样品中麦角甾醇的含量。采用Waters ACQUITY UPLC BEH C18色谱柱(50 mm×2.1 mm,1.7μm),流动相:乙腈,流速:0.3 mL/min,检测波长282 nm,进样体积4μL,以猴头菌中麦角甾醇的含量为指标,分别对提取溶剂、水浴时间和料液比进行了最佳条件优化。结果表明:最佳的提取溶剂为无水乙醇,水浴时间为30 min,料液比为1∶20(g∶mL),其回归方程Y=9609.4X+4955.6,R2=0.9998,平均加样回收率为100.70%,RSD为0.66%。猴头菌经70℃真空干燥方式处理的麦角甾醇含量最高,而采用1.34 KW微波干燥处理的麦角甾醇含量最低,表明了不同的干燥方式会对猴头菌中的麦角甾醇含量有所影响,因而应当根据不同的药用和医疗途径去选择合适的干燥加工方式。     

贮藏温度对“紫红龙”火龙果SA、JA及酶活性变化的影响

以"紫红龙"火龙果为材料,利用高效液相色谱法(HPLC)检测了不同贮藏温度和时间内"紫红龙"果皮中水杨酸(SA)、茉莉酸(JA)的含量,利用比色法测定了不同处理下过氧化氢(H_2O_2)含量、脂氧合酶(LOX)、苯丙氨酸解氨酶(PAL)和多酚氧化酶(PPO)的酶活性,以期为火龙果资源利用及贮藏保鲜相关研究提供理论依据。通过研究常温(25℃)和低温(5℃)贮藏条件下"紫红龙"火龙果果皮SA、JA含量,H_2O_2积累以及LOX、PAL和PPO酶活性的变化规律,发现低温在一定程度上能够诱导果皮内源SA和JA的积累,降低H_2O_2的含量,提高LOX酶活性;低温处理可延缓"紫红龙"火龙果果实腐烂,延长贮藏时间。     

间歇浸没式生物反应器在辰星草培养苗扩繁中的应用

以茎尖培养得到的辰星草(Limonium hybrid‘MistyBIue’)培养苗(带2叶片)为试材。培养基为MS BA 1．0mg／L 蔗糖30g／L，pH调节为5．8。固体培养和振荡培养使用250mL三角瓶，每瓶100mL培养基。生物反应器培养使用5L气球型反应器，2L培养基。完全浸没式生物反应器培养时，无“载桥”，培养苗在培养基中始终处于浸泡状态；间歇浸没式生物反应器培养时，离反应器底部15cm处架有“载桥”，培养基定时与‘‘载桥”上的苗接触，每     

Effects of cardiac remodeling on atrial arrhythmogenesis in aged rabbit left atrium

AIM: To investigate the effects of myocardial remodeling of aged left atrium (LA) on atrial arrhythmogenesis in rabbits.METHODS: The male New Zealand rabbits were divided into young LA and aged LA groups. By observing the changes of monophasic action potential (MAP) and burst-pacing in LA of the rabbits in vivo, the main cardioelectrophysiological parameters such as resting membrane potential (RMP), action potential amplitude (APA), ma-ximum rise veloctiy of action potential (dv/dt_max), plateau potential and action potential duration at 30%, 50% and 90% (APD₃₀, APD₅₀ and APD₉₀), as well as the inducibility and duration of atrial arrhythmias were recorded. L-type calcium current (I_Ca,L) was analyzed via whole-cell patch-clamp technique in enzymatically dissociated single rabbit LA myocytes. The myocardial collagen content was quantified after Masson staining, and the ultrastructure of the LA cells was observed under scanning electron microscope. The expression of Cav1.2 in LA tissue of the 2 groups was detected by Western blot.RESULTS: Compared with young LA group, dv/dt_max and plateau potential were significantly decreased, APD₃₀ and APD₅₀ were shortened, and APD₉₀ was notably prolongated in aged LA group (P<0.01). The inducibility or duration of atrial arrhythmias was severely increased or prolongated in aged LA group (P<0.01). With voltage clamp model, the density of I_Ca,L in aged LA group was significantly decreased, and current-voltage curve was notably moved upward compared with young LA group. When the clamp potential was +20 mV, the density of I_Ca,L was notably modified from (11.72±1.39) pA/pF in young LA group to (6.08±0.98) pA/pF in aged LA group (P<0.01). Compared with young LA group, the protein level of collagen was significantly increased (P<0.01), and the arrange of atrial myocytes was irregular in LA of rabbits in aged LA group. The atrial myocytes of the LA wall in aged LA group exhibited abnormal ultrastructural alterations, such as karyopyknosis, irregular and swelling mitochondria with the presence of vacuoles, and mild and severe sarcomere degeneration. Compared with those in LA tissues of young rabbits, the expression levels of Cav1.2 in the LA tissues of aged rabbits were severely reduced (P<0.01), and had a significant positive correlation with the reduction of I_Ca,L (r=0.83, P<0.01).CONCLUSION: The pathophysiological characteristics of aged LA are significantly altered, and might contribute to vulnerability and susceptibility of occurrence of atrial fibillation in aged rabbits. The mechanisms might completely attribute to the notable reduction of I_Ca,L, abnormal alterations of ultrastructures and obvious decrease in the expression of Cav1.2 in the aged LA of aged rabbits.     

Changes of transmural repolarization heterogeneity and ion currents in rabbits with left ventricular hypertrophy

AIM: To investigate the changes of transmural repolarization heterogeneity and ion currents in rabbits with left ventricular hypertrophy. METHODS: Ventricular hypertrophy was induced by a partial constriction of the abdominal aorta in rabbits. Myocytes were isolated by a two steps enzymological method. The sub-endocardial (Endo) and sub-epicardium (Epi) tissues were separated from other region (midmyocardium, Mid) with a razor. Whole cell patch clamp technique was used to record the action potential and ion currents. RESULTS: The action potentials duration at 90% repolarization (APD₉₀) of Epi, Mid and Endo were all prolonged significantly in hypertrophy group compared to control group. This prolongation of APD₉₀ was more pronounced in Mid (26.0%±2.7%) than that in Epi (14.0%±1.6%) and Endo (10.0%±1.1%). The transmural repolarization heterogeneity was increased significantly in the hypertrophy group. The I_Ks and I_to density in Epi, Mid and Endo was decreased significantly in hypertrophy group compared to those in control group. This decrease in I_Ks and I_to density was more pronounced in Mid than in Epi and Endo. No significantly difference of I_Ca,L and I_Kr density between hypertrophy group and control group in three layers was observed. The I_K1 density decreased significantly in hypertrophy group compared to control group, but the extent of the decrease had no differences among the three layers. CONCLUSIONS: The transmural repolarization heterogeneity increases significantly in rabbit hypertrophied ventricle. The decrease in transmural heterogeneity of I_to and I_Ks is the main causes.     

Effect of bFGF on expression of endothelial cell integrin β1 subunits

AIM: To study the effect of basic fibroblast growth factor(bFGF) to the expression of integrin β₁ subunit of endothelial cells. METHOD: The expression of integrin β₁ subunit of endothelial cells was determined before and after bFGF treatment with Western Blot and immage analysis method.RESULTS: The mean gray value of immunostain by immage analysis method is 166.11±9.86 in the experimental group and 175.32±5.12 in the control group, suggested that bFGF may upregulate expression of integrin β₁ subunits of endothelial cell. CONCLUSION: bFGF may play an important role in angiogenesis by way of inducing the overexpression of endothelial cell integrin β₁ subunits.     

新书推荐：《分子克隆实验指南》（第三版）

AIM: To study the effect of panax notoginseng sponins (PNS) on L-type Ca²⁺ current in isolated right ventricle myocytes from chronic hypoxic rats. METHODS: Using whole cell patch clamp recording technique,we measured I_Ca-L in isolated right ventricle myocytes which were divided into three group:control group, chronic hy-poxic group and chronic hypoxic group with PNS(100 mg·kg^-1·d^-1). RESULTS: The result showed I_Ca-L of cells from chronic hypoxic group were significantly larger than the other two groups(P＜0.05). CONCLUSION: PNS decreases L-type Ca²⁺ current of the right ventricle myocytes from chronic hypoxic rats.     

SO2 derivatives stimulate inflammation of airway epithelial cells through NLRP3 inflammasome

AIM:To investigate the effect of sulfur dioxide (SO₂) derivatives (sodium sulfite and sodium bisulfate) on NLRP3 inflammasome in airway epithelial cells. METHODS:SO₂ derivatives at different concentrations were applied to bronchial epithelial 16HBE cells for 12 h. The production of reactive oxygen species (ROS) was detected by flow cytometry. The protein levels of NLRP3 and caspase-1 p20 were analyzed by Western blot. The level of interleukin-1β(IL-1β) in the cell culture supernatant was measured by ELISA. The cell viability was measued by MTT assay, and the concentration of SO₂ derivatives used in the following experiments was 2 mmol/L. When the NLRP3 gene in 16HBE cells was silenced by RNA interference technique or N-acetyl cysteine (NAC) was used to pretreat 16HBE cells, the intracellular ROS was detected by flow cytometry, and the protein levels of NLRP3 and caspase-1 p20 and the secretion of IL-1β were determined by Western blot and ELISA, respectively. RESULTS:Compared with the control group, the level of intracellular ROS, the protein levels of NLRP3 and caspase-1 p20, and the secretion of IL-1β in cell supernatant were increased significantly in 2 mmol/L and 4 mmol/L SO₂ derivative groups (P<0.05). Compared with the 2 mmol/L group, the protein levels of NLRP3 and caspase-1 p20 were significantly inhibited in NLRP3 siRNA group (P<0.05). The concentration of IL-1β in the cell culture supernatant was significantly decreased (P<0.05). No significant difference of ROS level was observed. Significantly decreased protein levels of NLRP3 and caspase-1 p20, and the concentration of IL-1β in NAC group were found (P<0.05). CONCLUSION:SO₂ derivatives directly promote the production of IL-1β through NLRP3 inflammasome in bronchial epithelial cells.     

Effect of garlicin on sodium channel current in rat ventricular myocytes

AIM: To observe the effect of garlicin on sodium channel(I_Na) in isolated ventricular myocytes of rats. METHODS: The ventricular myocytes of rats were obtained by enzymatic dissociation and treated with different concentrations of garlicin. The change of I_Na was recorded by the technique of whole-cell patch clamp recording.RESULTS: Garlicin decreased the I_Na of isolated ventricular myocytes in a dose- and voltage-dependent manner. The current density was elevated to peak under the condition that the membrane voltage was -40 mV before treated with garlicin. The current density was decreased by 48% from peak after treated with 500 μmol/L garlicin . No significant change of the active curve with the use of garlicin was observed. The median inactive voltages of the inactive curves before and after garlicin treatment were (-88.61±9.60) mV and (-103.03±8.90) mV (P<0.01), respectively, and the slopes were -7.85±0.88 and -7.55±2.75 (P>0.05), respectively, indicating that garlicin made a shift to the negative direction. CONCLUSION: Garlicin treatment induced the current density-voltage curve of I_Na to shift up and significantly decreased the current density. The inactive curve of sodium channel moved to the left, while the current density was not decreased after treated with garlicin. Garlicin blocks sodium channel in its inactive state in a dose- and voltage-dependent manner.     

Effect of membrane environment at high temperature on voltage-dependence of delayed rectifier K＋ channel in hypothalamus neurons

AIM:To observe the effects of high temperature on voltage - dependence of delayed rectifier K⁺ channel (I_k) in hypothalamus neurons. METHODS: The date recording from cell - attached patches of patch - clamp technique. RESULTS: With temperature raising, shift of voltage dependence may be mediated at different degree, while higher temperature might weaken and depressed. CONCLUSION: Shift of voltage dependence likely contribut- ed to the body fever and heatstroke.     

Effect of bFGF on human kidney fibroblasts

AIM: To study the effect of bFGF on cell proliferation, secretion of type I collagen and expression of integrin β₁ in human kidney fibroblasts(KFB). METHODS: The KFB was cultured and stimulated by bFGF in vitro. The proliferation and collagen I secreting of KFB, the expression of integrin β₁ were measured by MTT, ELISA and flow cytometer, respectively. RESULTS: bFGF(25-50 μg/L) could obviously stimulate the cell proliferation(P< 0.05), promote the secretion of collagen I(P< 0.05) and enhance the expression of integrin β₁(P< 0.05) in human kidney fibroblast. CONCLUSION: bFGF could induce renal interstitial fibrosis by promoting cell proliferation, secretion of collagen I and integrin β₁ expression of KFB.