醚化、交联对玉米淀粉功能性质的影响

本文研究了醚化和交联反应对玉米淀粉物理性质和结构的影响。实验结果表明:醚化明显地改善了淀粉糊的透明度和低温稳定性,降低了糊化温度;醚化淀粉再经交联后,可改善淀粉糊的粘度稳定性。醚化及交联反应主要在淀粉的非结晶区进行,反应并未破坏淀粉颗粒。醚化影响直链淀粉的构象并在颗粒表面形成空穴,交联则使淀粉颗粒在蒸煮后仍保持完整并抑制了直链淀粉的渗出。     

Women with unexplained recurrent pregnancy loss do not have evidence of an underlying prothrombotic state: Experience with calibrated automated thrombography and rotational thromboelastometry

Introduction

Where unexplained recurrent pregnancy loss (RPL) is attributed to an underlying maternal prothrombotic state, empirical prophylactic anticoagulation may be recommended.

Materials and Methods

In the present study we used calibrated automated thrombography and rotational thromboelastometry to determine the procoagulant potential of these women as a rationale for anticoagulation. Fifty women with ≥ three consecutive unexplained losses prior to 14 weeks’ gestation or one loss after this time were compared with forty-one parous women with no miscarriages. Exclusion criteria included antiphospholipid syndrome, inherited thrombophilia and prior venous thromboembolism. Thrombin generation in platelet poor plasma and whole blood thromboelastometry was performed outside pregnancy to determine the presence or not of an underlying prothrombotic state.

Results

Peak thrombin and endogenous thrombin potential were not significantly increased in subjects relative to controls. The use of low tissue factor (1 pM) to better reflect physiological conditions and assay modification to better assess the protein C pathway (5 pM in the presence of thrombomodulin) provided no additional discrimination. Consistent results were shown with thromboelastometry; mean parameters were equivalent between subjects and controls.

Conclusions

These data demonstrate that global coagulation assays provide no evidence of an underlying hypercoagulable state in women with unexplained RPL; this is in keeping with the results of recent randomised controlled trials and strengthens the evidence base against use of anticoagulants in this setting.     

玉米花粉的破壁处理及营养学研究

我国有极其丰富的玉米花粉资源，至今未被充分利用，为了合理地开发这一营养宝库，我们对玉米花粉进行了破壁工艺研究，并对破壁与未破壁的玉米花粉进行了全面营养成分分析、营养评价等实验研究。结果表明采用急变温差与机械法相结合的破壁方法，工艺简单，高倍镜及电镜检测证明，破壁率达９１％，而且破壁后的花粉含有更丰富的游离氨基酸、维生素、微量元素等。营养评价证明破壁花粉的蛋白质功效比值（ＰＥＲ）、表现消化率（ＡＤ）、和蛋白质净利用率（ＮＰＵ）均显著优于未破壁花粉。本研究为科学地开发利用我国的玉米花粉资源提供了依据。     

玉米须多糖提取方法的比较研究

目的:比较玉米须多糖的酶、超声辅助提取及这两种方法联合提取这三种方法的优劣。方法:采用正交试验,优化玉米须多糖的酶及超声提取方案,并研究这两种方案的结合效果。结果:三种提取工艺中联合提取多糖得率最高,酶辅助提取次之,超声提取最低。结论:联合提取是一条高效的提取路线。     

玉米中四种黄曲霉毒素的关系

目的了解我国玉米中黄曲霉毒素B1（AFB1）、黄曲霉毒素B2（AFB2）、黄曲霉毒素G1（AFG1）和黄曲霉毒素G1（AFG1）污染的关系。方法用统计方法分析玉米中任意两种毒素污染率、污染浓度的相关性;计算AFB1与总黄曲霉毒素（AFs）的数量关系,分析AFB1在AFs中的构成1结果AFB1检出率最高,AFB1没有单独污染,均伴随AFB1。任两种毒素浓度呈正相关（P=0．000）,AFB1、AFB1、AFG1与AFG1的相关系数均大于0．951任两种毒素检出率有相关性（P=0．000）,AFB1和AFBz相关性最强1随AFB1浓度区间增高,AFB1检出率增高,AFG1和AFG1检出率先升高后降低;AFB1与AFs浓度比升高,AFs高于4μg／kg时,浓度比超过0．51结论AFB1和AFBz污染密切相关,AFBz伴随AFB1,二者污染率和浓度呈正向变化。当AFB1浓度较高时,对AFG1和AFG1呈现抑制作用1按照AFs限量是AFB1的两倍,当玉米中AFs限量在4μg／kg以上时,同时制定AFB1和AFs限量,与仅制定AFB1限量相比,不增加管理效力。     

Potential application of a multifunctional biosurfactant extract obtained from corn as stabilizing agent of vitamin C in cosmetic formulations

Vitamin C is an essential nutrient for human health, which can be found in the epidermis, playing an important role in the collagen production and protection of the skin. However, humans cannot produce this vitamin, being necessary to include it in health care products. Moreover, vitamin C is easily degradable making quite difficult to keep it as L-ascorbic acid form during long time. Thus, cosmetic and pharmaceutical industries include dehydrated vitamin C in its formulations to prevent its degradation. Therefore, it must be rehydrated before use, leading to a tedious process.The aim of this work was to study the addition of a multifunctional biosurfactant extract (BS), obtained from corn wet-milling industry, to an aqueous solution of L-ascorbic acid (AA) in order to improve the stability of this vitamin.A Box-Behnken factorial design was established in order to predict the degradation of vitamin C, using as independent variables: the concentration of vitamin C, the concentration of BS and the storage time. This study allowed to obtain a theoretical equation that predicts the degradation of vitamin C in presence and absence of BS, which was quantified by high performance liquid chromatography (HPLC).The experimental results showed that the presence of BS can inhibit the degradation of vitamin C in water up to 58% after 14 days in comparison with the same assays in absence of biosurfactant. This work opens the door to the use of this BS as stabilizing agent of formulations containing unstable active principles like vitamin C.     

90Sr-90Y敷贴联合鸡眼膏治疗鸡眼的疗效观察

目的 评价⁹⁰Sr-⁹⁰Y敷贴联合鸡眼膏治疗鸡眼的临床疗效及安全性。方法 选取2019年9月—2020年12月在天门市第一人民医院治疗鸡眼的85例患者,基于随机数字表将患者随机分为A、B、C3组。A组28例,行单纯⁹⁰Sr-⁹⁰Y 敷贴治疗;B组27例,行⁹⁰Sr-⁹⁰Y 敷贴 + 间断鸡眼膏联合治疗;C组30例,行⁹⁰Sr-⁹⁰Y 敷贴 + 连续鸡眼膏联合治疗。比较3组患者治疗效果、痊愈时间、复发率及不良反应发生率。结果 3组患者治愈率分别为78.57%（21/28）、81.48%（22/27）及83.33%（25/30）,差异无统计学意义（P > 0.05）;总有效率分别为92.86%（26/28）、92.59%（25/27）、96.67%（29/30）,差异无统计学意义（P > 0.05）;治愈时间分别为（5.67 ±1.80）周、（2.82 ±1.11）周、（2.24 ±1.05）周,B、C两组的治愈时间明显短于A组（P < 0.05）;复发率分别为9.52%（2/21）、4.55%（1/22）、4.00%（1/25）,差异无统计学意义（P > 0.05）;不良反应发生率分别为3.57%（1/28）、11.11%（3/27）、26.67%（8/30）,C组不良反应发生率高于A组（P < 0.05）。结论 ⁹⁰Sr-⁹⁰Y敷贴+间断鸡眼膏联合治疗鸡眼的疗效好、复发率低,且治愈时间短、不良反应少,值得临床推广。     

高原鼢鼠对草场的危害及防治阈值的探讨

本文通过高原鼢鼠对草场形成危害的途径及造成牧草损失的测算,根据投入与产出的价值,建立高原鼢鼠防治的经济阈值模型(Economic threshold mould),进而求得海北高寒草甸上高原鼢鼠的防治阈限为x=4.18。确定地下害鼠经济阈值的方法具有普遍性,本防治阈值模式适用于高寒草甸草场,为我们对该害鼠的综合治理提供了依据。     

Regulation of caloric intake in yellow mice (C57BL/6J-Ay/alpha).

The ability of yellow and normal black mice to reduce food intake when given surplus calories was studied to elucidate the mechanisms responsible for hyperphagia in yellow mice. When given sugar solutions to drink, immature (6–7 weeks old) yellow mice increased total caloric intake more than did lean control mice. Older (11–14 weeks) yellow mice were similar to control mice. The oldest yellow mice tested (25–33 weeks) increased total caloric intake less than lean control mice, when given sugar solutions. In contrast, yellow mice of all ages increased total caloric intake more than lean mice when given corn oil. Yellow mice had similar or lower preference for sugar and oil calories than did black mice.     

Ethanol-conditioned flavor preferences compared with sugar- and fat-conditioned preferences in rats

Rats can learn to prefer flavors paired with ethanol and various nutrients. The present study examined the relative strengths of flavor preferences conditioned by 5% ethanol and isocaloric solutions of 7.18% sucrose, 7.18% fructose, or 3.26% corn oil. In three experiments, nondeprived rats were trained with different flavored solutions (conditioned stimuli, CS) paired with intragastric (IG) infusions: a CS+E flavor paired with ethanol infusion, a second CS+ paired with a nutrient infusion, and a CS- paired with water infusion. In two-bottle tests, rats strongly preferred a sucrose-paired CS+S over the CS- and over the CS+E. The preference for the CS+E over CS- was weaker. These effects occurred when the rats drank substantially more CS+S than CS+E in training and when training intakes were matched. Similar results were obtained when the nutrient infusion was fructose or corn oil, except that preferences for the CS+F or CS+O over the CS+E were less pronounced than with CS+S. Consistent with the IG results, rats trained to drink flavored sucrose and ethanol solutions preferred the CS+S to CS+E in a flavored water test. These results confirm prior reports of ethanol-conditioned preferences but show that ethanol is less effective than other nutrients at isocaloric concentrations. The marked individual differences in ethanol-conditioned preferences may be related to the impact of the sugar or fat infusions on the reward evaluation of the ethanol-paired flavor.