生物统计基础知识(Ⅰ)

为了适应现代生物学研究中试验设计和数据处理的需要,我们组织了《生物统计基础知识》专题讲座,拟分四期刊载:一.平均数和标准差、二.两个样本平均数的比较、三.回归分析、四.方差分析。读后有何意见和要求可写信给我刊。     

生物统计基础知识(Ⅳ)

第Ⅱ讲介绍了两组样本平均数比较时进行显著性检验的方法。如果相互比较的不是两个组,而是三个,四个或更多个组的时候,就需要把前面所用的方法加以推广。适用于比较多组平均数之间差异的检验方法称之为方差分析。所谓方差是指离均差的平方和(简称平方和)与自由度之商。分析时主要是把平方和与自由度按不同的变异起因分解为若干个部分。从而构成来自不同起因的方差,利用它来检验各组平均数之间差异的显著性。     

生物统计基础知识(Ⅲ)

每一自然现象的变化都和它周围其它的现象互相联系着和互相影响着。因此反映这些现象变化规律的各种变量也是互相联系的,互相影响的。从而它们之间就存在着一定的关系。人们通过各种实践发现变量之间的关系大致可分成两种类型。一种类型是我们所熟知的函数关系。其特点是变量之间的关系是完全确定的。例如,对一定数量的饲料M来说,每头牛平均所     

《科研中的统计方法》(生物统计杂志)介绍

《科研中的统计方法》(生物统计杂志)系国内唯一公开发行的一份专业生物统计杂志,每年出两期,安徽省科协主办,安徽医学院编辑发行(该院财务科负责业务联系).该刊发表我国在生物统计研究和应用的学术论文,另辟“问题讨论”、“意见”等栏,活跃学术讨论气氛并普及统计知识,因而它是生物学、医学、农学等     

A Mn(II)–Mn(II) center in human prolidase

Human prolidase, the enzyme responsible for the hydrolysis of the Xaa-Pro/Hyp peptide bonds, is a key player in the recycling of imino acids during the final stage of protein catabolism and extracellular matrix remodeling. Its metal active site composition corresponding to the maximal catalytic activity is still unknown, although prolidase function is of increasing interest due to the link with carcinogenesis and mutations in prolidase gene cause a severe connective tissue disorder. Here, using EPR and ICP-MS on human recombinant prolidase produced in Escherichia coli (hRecProl), the Mn(II) ion organized in a dinuclear Mn(II)–Mn(II) center was identified as the protein cofactor. Furthermore, thermal denaturation, CD/fluorescence spectroscopy and limited proteolysis revealed that the Mn(II) is required for the proper protein folding and that a protein conformational modification is needed in the transition from apo- to Mn(II)loaded-enzyme. The collected data provided a better knowledge of the human holo-prolidase and, although limited to the recombinant enzyme, the exact identity and organization of the metal cofactor as well as the conformational change required for activity were proven.     

进化论系列讲座(二十一)从生物统计到群体遗传

生物统计学派的不屈 前文提到,孟德尔之所以能够发现两大遗传定律,一个重要的原因是他运用了统计学等数学手段来分析生物学上的杂交问题.从这个意义上来说,他也是一位出色的生物统计学家、甚至是先驱之一.只是在他发表《植物杂交试验》那篇论文的时候,生物统计学的系统方法还没有建立起来.     

Complexes of Co(II), Ni(II), Cu(II) and Zn(II) with 3′AMP and 2′AMP

Derivatives of Co(II), Ni(II), Cu(II) and Zn(II) with 3′AMP and 2′AMP were synthesized and characterized by IR UV-Vis and fluorescence spectroscopy. There seems to be bonding of the metal ion to the base in all cases. The activation test, using the complexes as allosteric labels, was carried out with rabbit muscle glycogen phosphorylase b, but the enzyme was not activated, confirming that the phosphate group must necessarily be bonded to position 5′ of the ribose in order to activate this enzyme.     

简明生物统计方法 第二讲 计数资料的统计推断方法(上)

一、用样本百分率估计总体百分率用样本百分率(β)估计总体百分率(p),一般常用区间估计法,即根据β求出p的95％(或99％)的置信区间。 (一)样本比较大(n>50),且p不太靠近0或1(可由β窥测)时,样本百分率趋近于正态分布,可用下列公式求置信区间的上、下限(这是最常见的方法,但样本较小或者p较偏向0或1时准确性差):     

Binuclear metal complexes. 59. Synthesis and magnetism of dicopper(II) and copper(II)-nickel(II) complexes with N,N′-ethylenedisalicylamidatocuprate(II)

The complexes [Cu(samen)Cu(L)] and [Cu(samen)Ni(L)₂] (Lbpy, phen) have been synthesized by the reaction of sodium N,N′-ethylenedisalicylamidatocuprate(II) pentahydrate (Na₂- [Cu(samen)]·5H₂O), a divalent metal ion, and 2,2′- dipyridyl or 1,10-phenanthroline. Cryomagnetic data for the CuCu complexes did not fit the Bleaney- Bowers equation; but the data did fit a modified Bleaney-Bowers equation

with a large negative J and a significant negative θ, suggesting that a considerable magnetic interaction operates between essentially planar [Cu(samen)Cu(L)] molecules. The magnetisms of the CuNi complexes were well interpreted in terms of the susceptibility equation based on the Heisenberg model. An antiferromagnetic spin-exchange interaction (J= −13∼−14 cm⁻¹) was suggested between the metal ions.     

Free metal ion depletion by “good's” buffers: II. N-(2-acetamido)-2-aminoethanesulfonic acid (ACESH): Complexes with Calcium(II), Magnesium(II), Manganese(II), Cobalt(II), Zinc(II), Nickel(II), and Cooper(II)

Potentiometric, visible, and infrared studies of the complexation of N-(2-acetamido)-2-aminoethanesulfonic acid (ACESH) by Ca(II), Mg(II), Mn(II), Co(II), Zn(II), Ni(II), and Cu(II) are reported. Ca(II), Mg(II), and Mn(II) were found not to complex with ACES^?, while Co(II), Zn(II), Ni(II), and Cu(II) were found to form 2:1, ACES^? to M²⁺, complexes, and [Cu(ACES)₂] was found to undergo stepwise deprotonation of the amide groups to form [Cu(H_?1ACES)₂^2?]. Formation (affinity) constants for the various metal complexes are reported, and the probable structures of the various metal chelates in solution are discussed.     

基础内分泌学讲座(II)

动物机体的协调统一受神经、内分泌双重调节。神经系统除直接调节机体活动外,还可通过内分泌系统协调机体的功能。内分泌腺体所分泌的激素又可反馈影响神经系统而对上述调节作出加强或抑制性修正。长期情绪紊乱可引起疾病,主要通过两条途径:其一,神经冲动经各级神经原传递刺激躯体和内脏器官;其二,     

Synthesis, Characterization and Antitumor Studies of Mn(II), Ni(II), Cu(II) and Zn(II) Complexes of N-Nicotinoyl-N′-o-Hydroxythiobenzhydrazide

A new ligand N-Nicotinoyl-N-o-hydroxythiobenzhydrazide (H₂Notbh) forms complexes [Mn(Notbh)(H₂O)], [M(Notbh)] [M=Ni(II) Cu(II) and Zn(II)] which were characterized by various physico-chemical techniques. All the metal complexes were observed to inhibit the growth of tumor in vitro, whereas, ligand did not. In vivo administration of these complexes resulted in prolongation of survival of tumor bearing mice. Tumor bearing mice administered with metal complexes showed reversal of tumor growth associated induction of apoptosis in lymphocytes. The paper discusses the possible mechanisms and therapeutic implication of the H₂Notbh and its metal complexes in tumor regression and tumor growth associated immunosuppression.     

Synthesis and characterization of β-diketiminate germanium(II) and tin(II) bromides

The equimolar reaction of a β-diketiminate lithium salt LLi(OEt₂) [L = HC(CMeNAr)₂; Ar = 2,6-iPr₂C₆H₃] with either GeBr₂ or SnBr₂ in diethyl ether affords the synthetically useful monomeric β-diketiminate-element halides LGeBr (1) and LSnBr (2), respectively. Both are soluble in hydrocarbon solvents, stable in inert atmosphere, and have been characterized by elemental analysis, NMR spectroscopy, and single-crystal X-ray diffraction analysis.     

简明生物统计方法 第三讲 计量资料的统计推断方法(下)

(三)多个样本平均数的差异显著性测验方法三个以上样本平均数的比较,亦即三种以上处理的实验结果(包括对照组与实验组)的比较,其实验分组方法有“完全随机分组“与“随