蜂王浆的营养保健功能

从第三代保健品功能因子的要求出发，试图从功能因子的角度综述蜂王浆的众多营养保健功能蜂王浆的营养保健功能众多，主要是延缓衰老、抗癌、增强机体免疫力、调节血液、美容等作用．     

离体繁殖石刁柏Asparagus officinalis的培养基改良试验

本试验表明,石刁柏(芦笋)的离体繁殖与培养基中激素的种类和用量有密切关系.若在培养基中添加一定量的榔子汁,人参.蜂皇精.效果很好.采用此方法.既提高繁殖效率,又降低成本.方法简便可靠,但应注意掌握离体繁殖的其他条件.     

纯天然蜂王浆口服液的研究

纯天然蜂王浆口服液是王浆蜜的第２代产品，由优质蜂王浆和优质蜂蜜精制而成。其特点是不含任何化学添加剂，完全保持纯天然状态。在室内常温下经过２年多保存期试验表明，该品存放１年，不分层，不发苦，不长霉，不结晶，各项指标完全达到设计要求，符合质量标准。     

Calcineurin sets the bandwidth for discrimination of signals during thymocyte development

At critical times in development, cells are able to convert graded signals into discrete developmental outcomes; however, the mechanisms involved are poorly understood. During thymocyte development, cell fate is determined by signals originating from the alphabeta T-cell receptor. Low-affinity/avidity interactions between the T-cell receptor and peptide-MHC complexes direct differentiation to the single-positive stage (positive selection), whereas high-affinity/avidity interactions induce death by apoptosis (negative selection). Here we show that mice deficient in both calcineurin and nuclear factor of activated T cells (NFAT)c2/c3 lack a population of preselection thymocytes with enhanced ability to activate the mitogen-activated protein kinase (Raf-MEK-ERK) pathway, and fail to undergo positive selection. This defect can be partially rescued with constitutively active Raf, indicating that calcineurin controls MAPK signalling. Analysis of mice deficient in both Bim (which is required for negative selection) and calcineurin revealed that calcineurin-induced ERK (extracellular signal-regulated kinase) sensitization is required for differentiation in response to 'weak' positive selecting signals but not in response to 'strong' negative selecting signals (which normally induce apoptosis). These results indicate that early calcineurin/NFAT signalling produces a developmental period of ERK hypersensitivity, allowing very weak signals to induce positive selection. This mechanism might be generally useful in the discrimination of graded signals that induce different cell fates.     

Parasitic Cape honeybee workers, Apis mellifera capensis, evade policing.

Relocation of the Cape honeybee, Apis mellifera capensis, by bee-keepers from southern to northern South Africa in 1990 has caused widespread death of managed African honeybee, A. m. scutellata, colonies. Apis mellifera capensis worker bees are able to lay diploid, female eggs without mating by means of automictic thelytoky (meiosis followed by fusion of two meiotic products to restore egg diploidy), whereas workers of other honeybee subspecies are able to lay only haploid, male eggs. The A. m. capensis workers, which are parasitizing and killing A. m. scutellata colonies in northern South Africa, are the asexual offspring of a single, original worker in which the small amount of genetic variation observed is due to crossing over during meiosis (P. Kryger, personal communication). Here we elucidate two principal mechanisms underlying this parasitism. Parasitic A. m. capensis workers activate their ovaries in host colonies that have a queen present (queenright colonies), and they lay eggs that evade being killed by other workers (worker policing)-the normal fate of worker-laid eggs in colonies with a queen. This unique parasitism by workers is an instance in which a society is unable to control the selfish actions of its members.     

论玛丽·斯图亚特的联姻外交

对中世纪欧洲王室联姻的典型--苏格兰女王玛丽·斯图亚特一生中的三次婚姻进行了描述和分析,指出王室联姻作为一种外交手段得到了最为广泛的应用.玛丽·斯图亚特一生中的三次婚姻都是在尽力与欧洲大陆强国法国或西班牙建立姻亲同盟,企图借助联姻来增强苏格兰的实力以抗衡英格兰.她的联姻对联姻双方以及16世纪下半期的欧洲国际关系都产生了重大影响.     

Entomology: Asian honeybees parasitize the future dead

The queen of a honeybee colony has a reproductive monopoly because her workers' ovaries are normally inactive and any eggs that they do lay are eaten by their fellow workers. But if a colony becomes queenless, the workers start to lay eggs, stop policing and rear a last batch of males before the colony finally dies out. Here we show that workers of the Asian dwarf red honeybee Apis florea from other colonies exploit this interval as an opportunity to move in and lay their own eggs while no policing is in force. Such parasitism of queenless colonies does not occur in the western honeybee A. mellifera and may be facilitated by the accessibility of A. florea nests, which are built out in the open.     

论玛丽·斯图亚特的联姻外交

对中世纪欧洲王室联姻的典型——苏格兰女王玛丽·斯图亚特一生中的三次婚姻进行了描述和分析,指出王室联姻作为一种外交手段得到了最为广泛的应用。玛丽·斯图亚特一生中的三次婚姻都是在尽力与欧洲大陆强国法国或西班牙建立姻亲同盟,企图借助联姻来增强苏格兰的实力以抗衡英格兰。她的联姻对联姻双方以及16世纪下半期的欧洲国际关系都产生了重大影响。     

虎纹捕鸟蛛卵巢发育的组织学

根据卵巢的组织学和形态特征分析,虎纹捕鸟蛛的卵巢为若干由生殖上皮向卵巢腔内突起的卵巢小体构成.在卵细胞发育过程中,一直有滋养细胞形成的托柄向其供应养分.卵巢发育可分为5个时期：形成期、生长期、成熟期、排卵期和恢复期.在生殖季节里可多次产卵,为多次产卵类型.卵巢的大小重量与蛛体重量成正相关,而成熟的蜘蛛性腺指数仅随卵细胞的发育而变化,不随蛛体大小改变.     

黑玉米果冻加工工艺及主要营养成分测定

以黑玉米为原料,通过单因素试验和正交试验,对影响黑玉米果冻品质的主要因素进行了分析,以确定黑玉米果冻的最佳加工工艺及配方.结果显示:最佳配方各成分的添加量为黑玉米汁16%、蔗糖9.5%、柠檬酸0.2%、复配胶1.2%,按此配方制得的黑玉米果冻的组织状态、色泽、风味和口感都较为理想.经测定,黑玉米果冻中蛋白质的体积质量为...     

基于微卫星标记的西方蜜蜂抗螨蜂种群体遗传多态性分析

为了分析西方蜜蜂抗螨蜂种的群体遗传多态性情况,采用18对微卫星(SSR)引物对抗螨蜂种子一代和子二代,并与同场饲养不抗螨的本地意蜂和浙大蜜浆高产蜂种进行比对,共计22个群体进行遗传多样性检测.结果表明:遗传一致度在0.2时,抗螨蜂种子代发生一定的分化,其他两个品系基本一致.抗螨蜂种子代之间的亲缘关系较近(遗传距离在0.043 9以内),与本地意蜂和浙大蜜浆高产蜂种各自相互分开.从而对抗螨蜂种的选育和保护具有重要的指导意义.     

Molecular cloning, expression and regional distribution of rat ciliary neurotrophic factor

Ciliary neurotrophic factor (CNTF) was originally characterized as a survival factor for chick ciliary neurons in vitro. More recently, it was shown to promote the survival of a variety of other neuronal cell types and to affect the differentiation of E7 chick sympathetic neurons by inhibiting their proliferation and by inducing the expression of vasoactive intestinal peptide immunoreactivity (VIP-IR). In cultures of dissociated sympathetic neurons from newborn rats, CNTF induces cholinergic differentiation as shown by increased levels of choline acetyltransferase (ChAT). This increase is paralleled by a reduction of tyrosine hydroxylase (TH) activity. Moreover, CNTF promotes the differentiation of bipotential 02A progenitor cells to type-2-astrocytes in vitro. To help establish which, if any, of these functions CNTF exerts in vivo, it is necessary to determine its primary structure, cellular expression, developmental regulation and localization. The complementary DNA-deduced amino-acid sequence and subsequent expression of cDNA clones covering the entire coding region in HeLa-cells indicate that CNTF is a cytosolic protein. This, together with its regional distribution and its developmental expression, show that CNTF is not a target-derived neurotrophic factor. CNTF thus seems to exhibit neurotrophic and differentiation properties only after becoming available either by cellular lesion or by an unknown release mechanism.     

Follicular growth,differentiation and atresia

Only limited numbers of primordial follicles in mammalian ovary grow and differentiate to reach the stage of dominate follicles and ovulate. 99% of the follicles in the ovary undergo atresia at various stages of development.Regulation of follicular growth, development and atresia is a complex process and involves interactions between endocrine factors and intraovarian regulators. This review summarized: i ) FSH may not be a survival factor in regulating slow-growing preantral follicles. Some locally produced growth factors, activin and orphan receptors might play a more important role at this stage, ii ) Estrogen, activin/inhibin and follistatin coordinate with FSH to regulate and control follicle differentiation, iii) There are two types of follicular atresia induced by apoptosis which originates from GC or oocyte, respectively. Early translation of tPA mRNA into tPA protein in oocyte may be associated with oocytea apoptosis.     

板栗空篷的蛋白质和氨基酸含量变化的研究

本文研究了空篷栗、正常栗的总苞和子房、子叶发育过程中蛋白质和氨基酸含量的变化。结果表明：空篷栗在幼胚发育期、子叶发育期，其总苞和子房中的蛋白质含量均低于正常栗；空篷栗在传粉受精后，子房中的氨基酸含量均低于正常栗；子房、子叶中的１８种氨基酸含量均高于总苞。总苞发育过程中，丙氨酸和异亮氨酸的含量空篷栗低于正常栗；子房、子叶发育过程中，色氨酸、异亮氨酸、苏氨酸、甘氨酸、丝氨酸和赖氨酸的含量空篷栗低于正常栗。这表明，在幼胚发育、子叶发育期，空篷栗得不到足够的物质供应，影响物质的定向运输和积累，导致了空篷栗的产生。文中还讨论了谷氨酸、天门冬氨酸、色氨酸、脯氨酸的含量变化与子房、子叶发育的关系。     

Structural basis of steroid hormone perception by the receptor kinase BRI1

Polyhydroxylated steroids are regulators of body shape and size in higher organisms. In metazoans, intracellular receptors recognize these molecules. Plants, however, perceive steroids at membranes, using the membrane-integral receptor kinase BRASSINOSTEROID INSENSITIVE 1 (BRI1). Here we report the structure of the Arabidopsis thaliana BRI1 ligand-binding domain, determined by X-ray diffraction at 2.5?? resolution. We find a superhelix of 25 twisted leucine-rich repeats (LRRs), an architecture that is strikingly different from the assembly of LRRs in animal Toll-like receptors. A 70-amino-acid island domain between LRRs 21 and 22 folds back into the interior of the superhelix to create a surface pocket for binding the plant hormone brassinolide. Known loss- and gain-of-function mutations map closely to the hormone-binding site. We propose that steroid binding to BRI1 generates a docking platform for a co-receptor that is required for receptor activation. Our findings provide insight into the activation mechanism of this highly expanded family of plant receptors that have essential roles in hormone, developmental and innate immunity signalling.     

Wnt-11 activation of a non-canonical Wnt signalling pathway is required for cardiogenesis

Formation of the vertebrate heart requires a complex interplay of several temporally regulated signalling cascades. In Xenopus laevis, cardiac specification occurs during gastrulation and requires signals from the dorsal lip and underlying endoderm. Among known Xenopus Wnt genes, only Wnt-11 shows a spatiotemporal pattern of expression that correlates with cardiac specification, which indicates that Wnt-11 may be involved in heart development. Here we show, through loss- and gain-of-function experiments, that XWnt-11 is required for heart formation in Xenopus embryos and is sufficient to induce a contractile phenotype in embryonic explants. Treating the mouse embryonic carcinoma stem cell line P19 with murine Wnt-11 conditioned medium triggers cardiogenesis, which indicates that the function of Wnt-11 in heart development has been conserved in higher vertebrates. XWnt-11 mediates this effect by non-canonical Wnt signalling, which is independent of beta-catenin and involves protein kinase C and Jun amino-terminal kinase. Our results indicate that the cardiac developmental program requires non-canonical Wnt signal transduction.