矩阵的加号逆理论在参数估计中的应用

本文从矩阵的加号逆理论出发,根据求矛盾线性方程组最佳逼近解的方法,建立起一种新的参数估计方法,同时给出了显著性检验方法,这种方法更简单更精确．     

肿瘤坏死因子－α（TNF－α）及白细胞介素1β（IL1－β）对胶质增生的影响及机理

本文利用小鼠大脑机械损伤模型及体外培养的胶质细胞,采用同位素渗入法观察了细胞介素及其抗体对胶质细胞增生的影响。结果表明：体外培养时ＴＮＦ－α在浓度为１０～２００ｕ／ｍｌ培养液时均能促进胶质细胞增生（Ｐ＜０．０５）,ＩＬ１－β在浓度为５～２００ｕ／ｍｌ培养液时能促进胶质细胞增生,ＴＮＦ－α＋ＩＬ１－β其促进胶质细胞增生作用更强烈,ＴＮＦ－α抗体能完全阻断ＴＮＦ－α的促增生作用,部分阻断ＴＮＦ－α＋ＩＬ１－β的促增生作用。在体实验时,ＩＬ１－β及ＴＮＦ－α的作用与离体时相似,ＩＬ１－β及ＴＮＦ－α亦能促进胶质细胞增生,二者共同作用时促细胞增生作用更强。以上结果提示,外源性ＴＮＦ－α及ＩＬ１－β能促进中枢神经损伤后胶质细胞增生且具有协同作用。     

一种具有纤溶活性的枯草杆菌蛋白激酶的研究──Ⅰ高产酶菌株的筛选与鉴定

本文主要阐述了一种具有纤溶活性的枯草杆菌（Ｂａｃｉｌｌｕｓｓｕｂｔｉｌｉｓ）蛋白激酶产生菌株的筛选与鉴定的研究结果。作者从初筛的１２株Ｂａｃｉｌｌｕｓｓｕｂｌｉｌｉｓ菌中,通过对固体发酵和液体发酵所产生的枯草杆菌蛋白激酶,用琼脂糖－纤维蛋白平板法测其活性,经比较不同菌株的活性,筛选出两株高产酶菌株：Ｂ．ｓｕｂｔｉｌｉｓＨＷ—１２和Ｂ．ｓｕｂｔｉｌｉｓＨＷ—３。同时对菌体和菌落形态特点、生理生化反应进行了鉴定,认为Ｂ．ＳｕｂｔｉｌｉｓＨＷ－１２菌株可用来做为发酵生产该酶的菌种。     

人胸腺素α原cDNA的克隆及在大肠杆菌中的表达

采用基因工程方法制取人胸腺素α原获得成功。用２０ｕｇ／ｍｌ植物血球凝集素（ＰＨＡ）和５００Ｕ／ｍｌ重组人白细胞介素２（ＩＬ－２）联合刺激人胎儿胸腺细胞,从中提取总ＲＮＡ,经反转录ＰＣＲ获得了人胸腺素α原ｃＤＮＡ;将之克隆入ｐＵＣ１９中,序列测定表明与已报道序列一致,进一步将之亚克隆入原核表达载体ｐＢＶ２２０,转化大肠杆菌ＤＨ５ａ．观察到在不改变氨基酸编码的前提下,增加胸腺素ａ原上游引物中Ａ、Ｔ含量,可以明显提高胸腺素α原的表达量,同时,不同培养基对它的表达也有影响。胸腺素α原在大肠杆菌中以可溶形式表达,不需复性。初步活性测定显示,它可明显刺激人外周血淋巴细胞Ｅ－玫瑰花结形成率。重组人胸腺素α原在大肠杆菌中表达,为其临床应用及基础研究奠定了基础。     

A NEW SPECIES OF GENUS HABROPHLEBIODES ULMER (EPHEMEROPTERA: LEPTOPHLEBIIDAE)

Abstract  The present paper deals with a new species Habrophlebiodes zijinensis sp. nov. collected in Nanjing, Jiangsu Povince, China.     

A gene encoding a truncated large subunit of Rubisco is transcribed and salt-inducible in rice

Using the rice salt-tolerant mutant 20 as material, a cDNA library was constructed and two salt-inducible clones, SIR5.5 and SIR8.1, were isolated by differential screening. Homology analysis revealed that the two clones together constituted a chimeric rbcL which encoded a truncated large subunit of Rubisco with 337 amino-acids, plus 64 amino-acids of unknown origin. The expressions of both the normal and the chimeric locus appeared to be developmentally regulated and salt-inducible in shoots of the salt-tolerant mutant 20 and its original variety 77–170. In roots, their expressions were salt-inducible in the salt-tolerant mutant 20 whereas no, or only premature, forms were present in the salt-treated original variety 77–170. Higher concentrations of salt reduced the expressions of both normal rbcL and the chimeric locus. ABA showed no effect on their expression.     

Isolation,characterization and application of a species-specific repeated sequence from Haynaldia villosa

A species-specific repeated sequence, pHvNAU62, was cloned from Haynaldia villosa, a wheat relative of great importance. It strongly hybridized to H. villosa, but not to wheat. In situ hybridization localized this sequence to six of seven H. villosa chromosome pairs in telomeric or sub-telomeric regions. Southern hybridization to whea-H. villosa addition lines showed that chromosomes 1V through 6V gave strong signals in ladders while chromosome 7V escaped detection. In addition to H. villosa, several Triticeae species were identified for a high abundance of the pHvNAU62 repeated sequence, among which Thinopyrum bassarabicum and Leymus racemosus produced the strongest signals. Sequence analysis indicated that the cloned fragment was 292 bp long, being AT rich (61%), and showed 67% homology of pSc7235, a rye repeated sequence. Isochizomer analysis suggested that the present repeated sequence was heavily methylated at the cytosine of the CpG dimer in the genome of H. villosa.It was also demonstrated that pHvNAU62 is useful in tagging the introduced 6VS chromosome arm, which confers a resistance gene to wheat powdery mildew, in the segregating generations.     

Chemical speciation of arsenic in urine of patients with blackfoot disease

Blackfoot disease is a peripheral vascular disease resulting in gangrene of the lower extremities. Although extensive epidemiological study has implicated high arsenic content in artesian well water of the endemic area bears some important connection with the disease, the etiology of the disease is still not clarified. In this study, attention is paid to chemical speciation of arsenic in order to find out whether the concentrations of arsenic species in urine of Blackfoot disease patients are different from those of controls. Experimental results indicate that the total arsenic, inorganic arsenic, monomethylarsonic acid, and other forms of arsenic in the urine of patients are significantly higher than those of the contols. The possible connection of those arsenic species with the etiology of the disease is discussed.     

RFLP tagging of a salt tolerance gene in rice

A salt tolerant rice mutant (M-20) was obtained through selection in vitro. Its tolerance was stably inherited over eight generations and most traints between M-20 and its sensitive original 77–170 (Oryza sativa) were very similar. By deriving an F₂ population of M-20 × 77–170 and splitting every F₂ individual into two parts, with one part planted in normal conditions and another part in saline conditions, the inheritance of salt tolerance in rice was studied. Under normal conditions, there was no apparent segregation among F₂ individuals. Under saline conditions, however, the segregation of traits was obvious. According to our standards, the ratio of salt sensitive:moderately-tolerant:tolerant plants was 25:42:18, in accordance with a 1:2:1 ratio. It suggested that the improvement of salt tolerance in our materials was induced by the mutation of a major tolerant gene which showed incomplete dominance. By use of 130 RFLP probes distributed throughout the rice genome, the gene was tagged by a single copy DNA probe, RG4, which was located on chromosome 7. The genetic distance between the salt tolerant gene and RG4 was 7.0 ± 2.9 cM. Based on the split method, a method which could be currently used to evaluate the damage of salt stress in rice was proposed.     

Synthesis and antiplatelet, antiinflammatory, and antiallergic activities of 2-substituted 3-chloro-1,4-naphthoquinone derivatives

A series of 2-substituted 3-chloro-1,4-naphthoquinones was synthesized, and the antiplatelet, antiinflammatory, and antiallergic activities of these compounds were evaluated. The structure-activity relationships in this series were also examined. Most of the 2-alkyl/arylcarboxamido derivatives of 3-chloro-1,4-naphthoquinone showed potent activities with similar trends in each of the activities evaluated.