Rat Mammary Gland RNA: Incorporation of C14-Formate and Effect of Hormones and 7,12-Dimethylbenz[alanthracene

In female rats, the incorporation of sodium C(14)-formate into mammary gland RNA decreases immediately after a singlefeeding of 20 milligrams of 7,12-dimethylbenz[a] anthracene. In males, there is a gradual increase in the incorporation. In castrated rats, the decrease or increase of C(14)-formate incorporation is dependent on the presence of estrogen or androgen, respectively.     

高速摄影拍摄频率与判读的误差分析

研究分析了点的直接测量和有基准点输入测量两种测量方法的测量误差及其对测量结果的影响 ,介绍了一种高速摄影拍摄频率的合理选择方法     

霉变板栗病原真菌的分离与致病性测定

从霉变板栗样品中分离出10种真菌，根据其菌落特征及繁殖方式，进行了初步分离和致病性测定，结果表明，青霉菌、曲霉菌、毛霉菌、炭疽菌和疫霉菌的致病力都在80%以上，混合菌感染为100%。     

Changes in properties of soil-derived dissolved organic matter induced by biodegradation

Properties of dissolved organic matter (DOM) determine its biodegradation. In turn, biodegradation changes the properties of the remaining DOM, which may be decisive for the formation of stable organic carbon in soil. To gain information on both mechanisms and controlling factors of DOM biodegradation and the properties of biodegraded DOM, we investigated changes in the composition of 13 different DOM samples extracted from maize straw, forest floors, peats, and agricultural soils during a 90-day incubation using UV absorbance, fluorescence emission spectroscopy, FTIR-spectroscopy, ¹H-NMR spectroscopy, pyrolysis-field ionization mass spectroscopy (Py-FIMS), and ¹³C natural abundance before and after incubation. Changes in the DOM properties were related to the extent of biodegradation determined by the release of CO₂. Increasing UV absorption and humification indices deduced from fluorescence emission spectra, and increasing portions of aromatic H indicated relative enrichment of aromatic compounds during biodegradation. This enrichment significantly correlated with the amount of DOC mineralized suggesting that aromatic compounds were relatively stable and slowly mineralized. ¹³C depletion during the incubation of highly degradable DOM solutions indicated an enrichment of lignin-derived aromatic compounds. Py-FI mass spectra indicated increasing contents of phenols and lignin monomers at the expense of lignin dimers and alkylaromatics during incubation. This partial degradation of higher-molecular, lignin-derived DOM compounds was accompanied by relative increases in the proportions of lower-molecular degradation products and microbial metabolites. Carbohydrates, especially when abundant at high initial contents, seem to be the preferred substrate for microorganisms. However, four independent methods suggested also some microbial production of carbohydrates and peptides during DOM degradation. After incubation, the composition of highly degradable DOM samples became similar to relatively stable DOM samples with respect to aromaticity, carbohydrate content, and thermal stability. We conclude that DOM biodegradation seems to result in organic matter properties being a precondition for the formation of stable carbon. These structural changes induced by DOM biodegradation should also result in stronger DOM sorption to the soil matrix additionally affecting DOM stabilization.     

Delphinidin 3-O-(2-O-beta-D-Glucopyranosyl-alpha-l-arabinopyranoside): a novel anthocyanin identified in Beluga black lentils

A major anthocyanin was isolated from the acidified methanolic extract of Beluga black lentils by XAD7 column chromatography and preparative high-performance liquid chromatography. By means of electrospray ionization mass spectrometry and one- and two-dimensional nuclear magnetic resonance spectroscopy, its structure was determined to be delphinidin 3-O-(2-O-beta-D-glucopyranosyl-alpha-l-arabinopyranoside).     

Generation of a cold-adapted PRRSV with a nucleotide substitution in the ORF5 and numerous mutations in the hypervariable region of NSP2

A cold-adapted porcine reproductive and respiratory syndrome virus (CA-VR2332) was generated from the modified live virus strain VR2332. CA-VR2332 showed impaired growth when cultured at 37°C with numerous mutations (^S731^F, ^E819^D, ^G975^E, and ^D1014^N) in the hypervariable region of the NSP2, in which the mutation ^S731^F might play a vital role in viral replication at 30°C. Conserved amino acid sequences of the GP5 protein suggests that CA-VR2332 is a promising candidate for producing an effective vaccine against PRRSV infection. Further studies on replication and immunogenicity in vivo are required to evaluate the properties of CA-VR2332.     

昆明菜区大白菜根肿病防治技术研究初探

 在昆明地区,4～10月份为大白菜根肿病发生流行期,尤以7～10月危害尤烈,11月～翌年3月发病轻。4～10月的温、湿度及土壤偏酸的适生环境,加重了根肿病的发生及危害。大白菜整个生育期均可感病,尤以2叶期最易感染,培育无病壮苗是防病、保苗、保产的关键措施。大白菜品种间对根肿病有抗病性差异的表现,初步认为星星、白菜王等品种较抗病。百菌清、多菌灵、药肥复配剂为防治根肿病的有效药剂,施药方法以播前土壤施药为好。     

棉花花青素能量耗散过程维持光合机构稳定性分析

【目的】研究棉花花青素能量耗散过程维持光合机构稳定性。【方法】选取花青素含量差异较大的棉花为材料,测定花青素含量、光合色素含量、气体交换参数、叶绿素荧光参数、NDH介导的环式电子流活性、ATP合成酶活性、玉米黄质的合成速率等。【结果】随花青素含量升高,吸光能力逐渐增强,而净光合速率逐渐减弱,将面临较多的过剩激发能;NDH介导的环式电子流活性均逐渐增强,并且环式电子调控的ATP合成也逐渐增强;相对于无花青素的棉花,花青素存在的条件下,叶黄素循环的热耗散明显较弱,并且随花青素含量的增多,叶黄素循环的过程逐渐减弱,可能花青素的耗散能力逐渐增强。【结论】花青素能够作为一种光保护机制起到耗散过剩光能有效保护PSI和PSII。