Variation in composition of two bumble bee species across communities affects nectar robbing but maintains pollinator visitation rate to an alpine plant,Salvia przewalskii

1. In many flowering plants, bumble bees may forage as both pollinators and nectar robbers. This mixed foraging behaviour may be influenced by community context and consequently, potentially affect pollination of the focal plant. 2. Salvia przewalskii is both pollinated and robbed exclusively by bumble bees. In the present study area, it was legitimately visited by two species of bumble bees with different tongue length, Bombus friseanus and Bombus religiosus, but it was only robbed by Bombus friseanus, the shorter‐tongued bumble bee. The intensity of nectar robbing and pollinator visitation rate to the plant were investigated across 26 communities in the Hengduan Mountains in East Himalaya during a 2‐year project. For each of these communities, the floral diversity, and the population size and floral resource of S. przewalskii were quantified. The abundances of the two bumble bee species were also recorded. 3. Both nectar robbing and pollinator visitation rate were influenced by floral diversity. However, pollinator visitation rate was not affected by nectar robbing. The results revealed that relative abundance of the two bumble bee species significantly influenced the incidence of nectar robbing but not the pollinator visitation rate. Increased abundance of B. religiosus, the legitimate visitors, exacerbated nectar robbing, possibly by causing B. friseanus to shift to robbing; however, pollinator visitation remained at a relatively high level. 4. The results may help to explain the persistence of both nectar robbing and pollination, and suggest that, in comparison to pollination, nectar robbing is a more unstable event in a community.     

绿咖啡豆中低咖啡因绿原酸的提取分离研究

建立高效液相色谱—双波长同时检测咖啡豆提取物中绿原酸和咖啡因含量的方法。咖啡因和绿原酸在0.2～1.0 mg·mL-1范围内，峰面积与浓度呈现良好的线性关系。咖啡因：Y＝44077X＋227.78，R＝0.9997，RSD＝0.78%；绿原酸：Y＝34896X＋289.96，R＝0.9995, RSD＝0.93%。以绿原酸含量为指标，在单因素试验基础上建立正交试验，确定从绿咖啡豆中提取绿原酸的最佳条件为乙醇浓度20%，液料比6∶1，提取时间60 min，提取温度70 ℃。以咖啡因和绿原酸含量为指标，通过萃取试验，确定最佳脱咖啡因萃取剂为环己烷-三氯甲烷-丙酮混合溶剂，萃取工艺为1.5倍体积萃取剂萃取3次，产物中咖啡因含量由(3.52±0.08)%下降至(0.47±0.11)%。     

A new oviraptorid (Dinosauria: Theropoda) from the Upper Cretaceous of Bayan Mandahu,Inner Mongolia

Abstract: A new oviraptorid is described on the basis of a partial forelimb collected from the Upper Cretaceous redbeds of Bayan Mandahu, Inner Mongolia. Machairasaurus leptonychus, gen. et sp. nov. is diagnosed by slender, weakly curved manual unguals, reduced flexor tubercles, penultimate phalanges that are subequal in length to the preceding phalanges, and short, robust manual digits. Machairasaurus is found to be a member of the Ingeniinae, along with Ingenia yanshini, Heyuannia huangi, Conchoraptor gracilis, and Nemegtomaia barsboldi. Machairasaurus exhibits unusual proportions of the manus, suggesting that the manus was not primarily used to grasp prey. Instead, Machairasaurus and other oviraptorids are likely to have fed largely on plant material. The recognition of a previously unknown oviraptorid at Bayan Mandahu provides further evidence that the Bayan Mandahu dinosaur assemblage is distinct from that found at the Djadokhta Formation exposures at Bayn Dzak, Tugriken Shireh, and Ukhaa Tolgod. Given that these localities are separated by just a few hundred kilometres and represent similar palaeoenvironments, marked differences in the fauna suggest that the Bayan Mandahu Formation of Inner Mongolia is not coeval with the known Djadokhta localities in Mongolia.     

朝鲜蓟提取物颗粒剂的制备工艺研究

以单因素试验为基础，采用正交实验设计优化制备朝鲜蓟(Cynara scolymus)提取物颗粒剂的最佳工艺条件。以原料与辅料配比、原料药比例、乙醇浓度及干燥温度为考察因素，以颗粒合格率、溶化时间作为评价指标，采用L₉(3⁴)正交试验分别对颗粒合格率、溶化时间进行直观分析及方差分析。结果表明，最佳成型工艺为乳糖:糊精=3:1，乙醇浓度60%，原料药比例7.0%，干燥温度50 ℃。按此方案进行验证实验，颗粒性状良好，颗粒合格率为91.45%，含水量4.90%，减失重量不超过2.0%，溶解时间85.67 s，均符合2020年中国药典有关规定。通过正交试验优选的颗粒剂制备工艺稳定、简便易行，为朝鲜蓟提取物的剂型开发及工业化生产颗粒剂提供理论依据。     

椿根皮的化学成分及抑菌活性研究

为探寻椿根皮抑菌的物质基础，该研究采用硅胶、Sephadex LH-20等方法对椿根皮甲醇提取物进行分离和纯化，通过理化性质和波谱数据分析单体化合物的结构，并以卡那霉素为对照组采用流式细胞法测试化合物的抑菌活性。结果表明：从椿根皮中得到22个化合物，分别鉴定为pleuchiol (1)、withastramonolide (2)、7-ketositosterol (3)、白桦酯醇(4)、桦木酸甲酯(5)、1, 2, 4-trimethoxybenzene (6)、顺丁烯二酸二甲酯(7)、sonderianol (8)、dibutyl phthalate (9)、pinoresinol (10)、对羟基苯甲酸乙酯(11)、avenalumic acid methyl ester (12)、5,3′-dihydroxy-3,7,4′-trimethoxy-flavone (13)、spathulenol (14)、2-甲基-5-丙基酮-7-羟基色原酮(15)、 7,4′-dihydroxyflavone (16)、annphenone (17)、3-羟基-4-甲氧基苯甲酸(18)、5,3′...