急速降温对砀山酥梨采后生理和保鲜效果的影响

研究了采后急速降温和缓慢降温对冷藏和模拟货架期砀山酥梨果实呼吸强度、乙烯释放量、虎皮病指数、果心褐变指数以及果皮色泽和果实内在品质(硬度、可溶性固形物和可滴定酸)等指标的影响。结果表明,砀山酥梨果实贮藏210d,20℃模拟货架期,与缓慢降温处理相比,急速降温处理既能明显降低果实虎皮病和果心褐变的发病程度,又能降低果实腐烂率和果柄干枯褐变程度,而且还保持了果实较高的可溶性固形物。急速降温处理还能降低模拟货架期果实呼吸强度和乙烯释放量,从而延缓果实的衰老,但对贮藏及货架期可滴定酸含量和果皮颜色的亮度(L值)影响不大。急速降温不会加重砀山酥梨果实虎皮病和果心褐变的发生,在实际应用中可将砀山酥梨果实的缓慢降温贮藏改为急速降温贮藏,如果长期(210d左右)贮藏,建议货架期低于9d。     

高渗CO_2和PE保鲜袋对冷藏及货架期‘砀山酥梨’果实品质的影响

【目的】明确冷藏‘砀山酥梨’适宜的保鲜膜包装。【方法】研究不同保鲜膜包装的‘砀山酥梨’果实在(0±0.5)℃低温条件下冷藏150 d和210 d,常温20℃条件下放置24 h和货架9 d时果实呼吸强度、乙醇质量分数、虎皮病和果心褐变以及贮藏品质的变化规律。【结果】果实贮藏210 d+20℃货架9 d时,CK(裸果)果实呼吸强度和乙醇质量分数高,可溶性固形物(SSC)和硬度低,果皮颜色暗、黄,虎皮严重,风味异常,由于失水导致果皮皱缩,果柄干枯、褐变严重,商品价值降低;与CK相比,PVC薄膜袋虽能抑制果皮转黄,保持果实的硬度和果柄的新鲜程度,降低货架期果实的呼吸强度,但由于冷藏期间PVC袋内CO2体积分数高(2.30%~2.70%),O2体积分数低(17.0%~17.9%),导致果实中乙醇积累,造成货架期虎皮病和果心褐变严重,引起风味劣变;PE薄膜袋扎口包装的果实风味基本正常,贮藏效果稍好于PVC包装;PE薄膜袋掩口和高渗出CO2保鲜袋能保持贮藏和货架期果实较高的硬度和可溶性固形物(SSC)以及较低的乙醇质量分数,而且果实风味和外观颜色正常,无虎皮,果心褐变轻微。【结论】‘砀山酥梨’不宜裸果贮藏。相对于PVC和PE薄膜袋扎口包装来说,PE薄膜袋掩口和高渗出CO2保鲜袋对‘砀山酥梨’长期贮藏、保持货架期果实品质和抑制褐变具有良好的效果。     

澳洲青苹苹果虎皮病关键预警基因的筛选

【目的】筛选澳洲青苹苹果果实贮藏过程中虎皮病发生前的关键表达基因，为澳洲青苹苹果虎皮病发生预警研究提供理论依据。【方法】以澳洲青苹苹果果实为试材，于商业采收期采收并于低温（0±0.5℃）下长期贮藏，监测果实色泽和乙烯释放量，同时统计冷库贮藏期及冷藏后货架期的虎皮病发病情况，并采用实时荧光定量PCR技术检测与澳洲青苹苹果虎皮病发生相关基因的表达水平。【结果】澳洲青苹苹果低温贮藏50 d时，果实在冷库中未发病，置于货架期2 d时，果实出现轻微的虎皮病症状；低温贮藏70 d时，果实在冷库中开始发病。基于前人研究及转录组数据，鉴定到MdACO、MdAFS、MdCAT1、MdCAT2、MdPAL1、MdPAL2、MdC3H、MdPPO、MdPOD1、MdPOD2与澳洲青苹苹果虎皮病相关；通过实时荧光定量PCR技术进一步分析，确定MdAFS、MdC3H和MdCAT1的表达量在虎皮病发生前10 d，即贮藏第40天急剧上升，随后呈现下降的趋势，可作为虎皮病发生的预警基因。【结论】MdAFS、MdC3H和MdCAT1可作为澳洲青苹苹果贮藏期虎皮病发生的关键预警基因。     

采收期对“红香酥”梨果实采后生理和品质的影响

以北京地区的"红香酥"梨为试材,研究了3个采收期果实在20℃常温贮藏过程中呼吸强度、乙烯释放量、组织膜透性、果皮色泽、果肉硬度、可溶性固形物、可滴定酸、维生素C含量以及果实腐烂等指标的变化规律。结果表明,随着采收期推迟,果实呼吸强度和乙烯释放量的峰值出现的时间提前;采收越晚,果肉和果心的相对电导率越高。9月1日(盛花期后138d)采收的果实,果肉硬度、可滴定酸和维生素C含量保持较高,但单果质量低,果面着色差,果皮的膜透性强;9月19日(盛花期后156d)采收的果实,可溶性固形物和固酸比高,果皮颜色亮(L值高)、着色好,但贮藏后期,果实维生素C含量下降明显,腐烂率较高,贮藏时间短。9月10日(盛花期后147d)采收的果实(种子颜色3/4左右变褐、可溶性固形物为11.04%、果肉硬度6.36kg/cm2),能保持果实相对较高的硬度、维生素C含量和固酸比,口感较好,贮藏30d时,果实腐烂率相对较低,贮藏效果最好,商品性最高,可以作为红香酥梨在北京及周边地区长期贮藏最适宜的采收期。     

温州蜜柑宫川耐浮皮芽变系果实浮皮特性和耐贮性研究

【目的】探究宫川温州蜜柑（Citrus unshiu Marc.‘Miyagawa wase’）耐浮皮芽变系的果实品质、浮皮特性和耐贮性能,为耐浮皮柑橘新品种的选育和推广提供参考。【方法】连续多年测定比较耐浮皮芽变系及其对照母树宫川的果实主要品质性状包括单果质量、果形指数、色泽、硬度、可溶性固形物含量、可滴定酸含量、维生素C(Vc)含量和浮皮指数;观察测定宫川及其芽变系果皮特征和厚度,利用石蜡切片和透射电镜比较两者果皮细胞和亚细胞结构差异;通过常温贮藏试验,比较两者果实贮藏性能。【结果】芽变系成熟果实平均单果质量102.90 g,果形指数0.78,色调角h0值68.19,硬度0.96 kg·cm-2,可溶性固形物含量（w,后同）13.88%,可滴定酸含量0.62%,Vc含量29.87 mg·100 g-1,其中硬度、可溶性固形物和Vc含量均显著高于宫川,浮皮指数显著低于宫川;芽变系果实果皮厚度显著低于宫川,白皮层细胞排列相对整齐且细胞结构较为完整,宫川白皮层细胞表现质壁分离,细胞器降解,趋于衰老;常温贮藏过程中,芽变系果实硬度、可溶性固形物含量、可滴定酸含量等指标均高于同时期宫川,浮皮...     

不同贮藏温度对‘红香酥’梨果实品质和相关生理指标的影响

以山西省运城市盐湖区的‘红香酥’梨果实为试材,研究了-1.5、-0.5、0.5、1.5、3.0℃5个低温环境下‘红香酥’梨贮藏120、180、240 d以及对应的20℃货架7 d的果实外观品质和内在品质、呼吸强度和乙烯释放量等相关生理指标的变化规律,以确定‘红香酥’梨最适贮藏温度和最佳贮藏期。结果表明:L值和h°可较好地反映‘红香酥’梨果实贮藏期间果皮颜色的变化情况,贮藏后期(贮藏180～240d),1.5℃和3.0℃贮藏果实的果皮颜色亮(L值高)、黄(h°低、a值负值绝对值低)、果皮油腻化、果实腐烂严重;-1.5℃贮藏虽能较好地维持果皮绿色和抑制果实腐烂,但贮藏后期果心出现严重褐变,而且果实硬度和可溶性固形物含量较低;-0.5℃和0.5℃贮藏能长期维持‘红香酥’梨较高的果实硬度和可溶性固形物含量,明显抑制果皮转黄和果心褐变,保持果实较好的食用品质和商品价值,还能更好地抑制果实呼吸强度和乙烯释放量、降低果实乙醇的积累和减轻细胞膜的损伤程度。建议‘红香酥’梨中短期(120d以内)贮藏温度以1.5～3.0℃为宜,不宜太高;中长期贮藏(120～240 d)可采用-0.5～1.5℃,不宜太低。     

1-甲基环丙烯处理对“金红”苹果采后生理和常温贮藏品质的影响

以"金红"苹果果实为试材,采用1.0μL·L~(-1)浓度的1-甲基环丙烯(1-MCP)处理果实,研究了常温(20±1)℃条件下,1-MCP处理对"金红"苹果果实采后生理和贮藏品质的影响。结果表明:与对照(CK,1-MCP处理浓度为0)相比,1.0μL·L~(-1) 1-MCP处理可有效抑制"金红"苹果常温贮藏期间果实呼吸强度和乙烯释放量,推迟或抑制果实呼吸高峰和乙烯释放高峰的出现,显著(P≤0.05)降低果实的乙醇和乙醛含量,减轻细胞膜的透性,降低果实腐烂率。并且1-MCP能有效抑制果皮返糖发亮和底色转黄,保持果皮红黄鲜艳度,明显抑制果实硬度、维生素C和可滴定酸含量的下降,较好维持贮藏中后期果实的SSC。采用1-MCP处理可以将"金红"苹果常温贮藏期从9～12 d延长到30 d,仍能保持较好的外观和内在品质。     

1-MCP处理对新高梨冷藏后常温货架寿命的影响

以新高梨为试材,果实经1-MCP(1-甲基环丙烯)处理再冷藏一定时间后,研究常温货架期间1-MCP对果实贮藏效果的影响.结果表明:1-MCP能明显抑制果实呼吸强度、乙烯释放量的升高,推迟呼吸高峰和乙烯高峰出现的时间;抑制了果实丙二醛(MDA)和果皮相对膜透性的升高;延缓了果实硬度、可滴定酸含量的下降,阻碍了可溶性固形物的上升,使果实的货架期明显延长,延缓了果心褐变,但却加速了果实的果皮褐变.     

1-MCP对苹果采后生理的影响

以金冠、乔纳金、红富士和津轻苹果果实为试材,在常温(20±1℃)条件下,研究了不同浓度的1-MCP(1-甲基环丙烯)对果实呼吸强度、硬度、可滴定酸、叶绿素、淀粉指数和可溶性固形物含量的影响。结果表明,与对照相比,1-MCP可以明显降低果实的呼吸强度,延迟果实呼吸高峰的出现,从而抑制果实的后熟与衰老。1-MCP处理明显地减缓了果实硬度和酸度的下降,减少了叶绿素降解和淀粉的分解和转化。在贮藏期间,1-MCP处理增加了乔纳金和红富士果实苦痘病的发生。果实硬度、可滴定酸和果皮叶绿素的变化有极显著的相关性,与果实品质变化密切相关。     

低温贮藏对‘金红’苹果能量代谢和品质的影响

为探究不同贮藏温度对‘金红’苹果果实能量代谢和生理品质的影响,将‘金红’苹果分别放置在–2、0、2、4 ℃条件下贮藏,定期测定果实能量相关物质三磷酸腺苷（ATP）、二磷酸腺苷（ADP）、磷酸腺苷（AMP）含量和能荷（EC）变化以及H+-ATPase、Ca2+-ATPase、琥珀酸脱氢酶（SDH）、细胞色素氧化酶（CCO）、超氧化物歧化酶（SOD）等相关酶活性,同时测定果实呼吸速率、乙烯释放速率、果实硬度、维生素C、可滴定酸、可溶性固形物含量等生理品质指标,并调查果实组织褐变情况。结果表明：整个贮藏及货架期,–2 ℃下的果实ATP、ADP和AXP（AXP = ATP + ADP + AMP）含量、EC以及能量相关代谢酶活性（H+-ATPase、SDH、CCO）、SOD、乙烯释放速率始终保持最低,维生素C含量后期下降迅速;4 ℃下的果实硬度、可溶性固形物含量和可滴定酸含量降幅较大;–2 ℃下的果实褐变指数最高（果皮和果肉均出现了严重褐变）,0 ℃下的果实果皮和果肉也有轻微褐变,2 ℃和4 ℃果实无褐变。贮藏30、45、90 d以及贮藏90 d + 货架3 d和90 d + 货架5 d期间,2 ℃贮藏的果实保持较高的能量水平,果实品质和风味保持较好,0 ℃果实次之。研究结果表明,‘金红’苹果组织褐变与能量亏缺有密切关系,能量亏缺越多,褐变越严重,适宜的低温能维持果实较高的能量水平,同时抑制果实褐变,维持果实较好的贮藏品质,延缓果实衰老。     

Effects of radiation from 188Re on smooth muscle cell proliferation

AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β^-particles emission from ¹⁸⁸Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by ¹⁸⁸Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [³H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of ¹⁸⁸Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from ¹⁸⁸ Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G₀/G₁ arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation.     

Effect of L-Arg on plasma content of endothelin and expression of c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy

AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P＜0.01). The ET content in plasma also decreased significantly by L-Arg(P＜0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration.     

Compositional and Functional Properties of Saskatoon Berry and Blueberry

Abstract

Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared.     

多效唑对猕猴桃离体试管苗生长及内源激素的影响

多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。     

Proteomic analysis between pathological scars and normal skin

AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars.     

Cryopreservation of shoot apices of hawthorn in vitro cultures originating from East Asia

The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species.     

Coupling past management practice and historic landscape change on John F. Kennedy Space Center,Florida

Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere.     

Metallothionein inhibits homocysteine-induced proliferation of rat vascular smooth muscle cells

AIM:To investigate the effect of metallothionein(MT) on proliferation of rat vascular smooth muscle cells (VSMCs) stimulated by homocysteine and its mechanism. METHODS:VSMCs proliferation was measured by [³-H]-TdR incorporation, mitogen-activated protein kinase(MAPK)activity were determined by immunoprecipitation method, the intracellular contents of MT and malondialdehyde (MDA)were assayed by -hemoglobin saturation method and TBA reaction, respectively, and lactate dehydrogenase (LDH) leakage was measured by NADH oxidation. RESULTS:Hcy(10^-6-10^-4 mmol/L) stimulated [³-H]-TdR incorporation by the VSMCs in a concentration-dependent manner. Compared with control, [³-H]-TdR incorporation in VSMCs treated with 0.1 mmol/L Hcy was increased by 4.2 fold (P＜0.01). Meanwhile, Hcy enhanced MAPK activity, MDA formation and LDH release (P＜0.01)in a concentration-dependent manner. Treatment of VSMCs with MT alone did not change above parameters, compared with control. However, MT (10^-6-10^-4 mol/L)attenuated significantly Hcy-stimulated proliferation of VSMCs (P＜0.01)in a concentration-dependent manner. And MT inhibited obviously Hcy-induced activation of MAPK activity, MDA formation and LDH release. Preincubation of VSMCs with 0.5 mmol/L ZnCl₂ for 6 h induced an increase cellular MT content by 5.7-fold (P＜0.01). The MT-overexpressed VSMCs resisted Hcy-stimulating action on MAPK activity, MDA formation and LDH leakage (P＜0.01). CONCLUSION:These results show that MT has an inhibitory effect on Hcy-induced VSMCs proliferation, and that MT could inhibit Hcy-stimulated MAPK activity and lipid peroxidation.     

XBP-01 accelerated apoptosis induced by oxidized low density lipoprotein in vascular smooth muscle cells

AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis.     

The effect of exposure on landscape scale soil surface temperatures and species distribution models

Species distribution models (SDMs) often use elevation as a surrogate for temperature or utilise elevation sensitive interpolations from weather stations. These methods may be unsuitable at the landscape scale, especially where there are sparse weather stations, dramatic variations in exposure or low elevational ranges. The goal of this study was to determine whether radiation, moisture or a novel estimate of exposure could improve temperature estimates and SDMs for vegetation on the Illawarra Escarpment, near Sydney, Australia. Forty temperature sensors were placed on the soil surface of an approximately 12,000 ha study site between November 2004 and August 2006. Linear regression was used to determine the relationship with environmental factors. Elevation was correlated more with moderate temperatures (winter maximums, summer minimums, spring and autumn averages) than extreme temperatures (summer maximums, winter minimums). The correlation (r ²) between temperature and environmental factors was improved by up to 0.38 by incorporating exposure, moisture and radiation in the regressions. Summer maximums and winter minimums were predominately determined by exposure to the NW and coastal influences respectively, while exposure to the NE and SW was important during other seasons. These directions correspond with the winds that are most influential in the study area. The improved temperature estimates were used in Generalised Additive Models for 37 plant species. The deviance explained by most models was increased relative to elevation, especially for moist rainforest species. It was concluded that improving the accuracy of seasonal temperature estimates could improve our ability to explain the patchy distribution of many species. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.