Solvent-free Synthesis of Dihydrofuran-fused [60]Fullerene Derivatives by High-speed Vibration Milling

Solvent-free organic reactions have been attracting great interest of chemists due to the elimination of the usage of harmful organic solvents,low costs,and simplicity in the procedure1.Solvent-free mechanochemical reactions of fullerenes were explored and are significant for the reactions of fullerenes because the low solubility of fullerenes in common organic solvents requires large quantity of organic solvents and some novel fullerene reactions could only occur in the solid-state reaction2.…     

A Novel Asymmetric ent-Kauranoid Dimer from Isodon enanderianus

ＩｎｔｒｏｄｕｃｔｉｏｎＩｓｏｄｏｎｅｎａｎｄｅｒｉａｎｕｓ (Ｈａｎｄ . Ｍａｚｚ .)Ｈ .Ｗ .Ｌｉ(Ｌａｂｉａｔａｅ) ,ｗｉｄｅｌｙｄｉｓｔｒｉｂｕｔｅｄｉｎｔｈｅｓｏｕｔｈｅｒｎｐａｒｔｓｏｆＹｕｎｎａｎＰｒｏｖｉｎｃｅ ,ｈａｓｂｅｅｎｕｓｅｄｉｎＣｈｉｎｅｓｅｔｒａｄｉｔｉｏｎａｌｆｏｌｋｍｅｄｉｃｉｎｅａｓａｎｔｉ ｉｎｆｌａｍｍａｔｏｒｙａｎｄｄｅｔｏｘｉｆｉｅｄａｇｅｎｔ.1Ｐｒｅｖｉｏｕｓｐｈｙｔｏｃｈｅｍｉｃａｌｉｎｖｅｓｔｉｇａｔｉｏｎｈａｓｓｈｏｗｎｔｈｅｐｒｅｓ ｅｎｃｅｏｆａｓｅｒ…     

On a characterization of the normal distribution by means of identically distributed linear forms

Let X₁, X₂,…, be independent, identically distributed random variables. Suppose that the linear forms L₁ = Σ_j=1^∞a_jX_j and L₂ = Σ_j=1^∞b_jX_j exist with probability one and are identically distributed; necessary and sufficient conditions assuring that X₁ is normally distributed are presented. The result is an extension of a theorem of Linnik (Ukrainian Math. J.5 (1953), 207–243, 247–290) concerning the case that the linear forms L₁ and L₂ have a finite number of nonvanishing components. This proof only makes use of elementary properties of characteristic functions and of meromorphic functions.     

On copowers of an ordered skew field

It is shown that the double of an ordered skew fieldE over a subfieldK, which is its own bicentralizer, can again be ordered, and a corresponding result for groups is deduced.     

MNDO study of reaction paths: Diboration of acetylene

The reaction of B₂H₄ with acetylene has been studied by the MNDO method. It is shown that the reaction is exothermic and proceeds in two steps. The first step is the formation of a three-center -complex and this is the rate-determining step of the reaction. The second step is the rearrangement of the -complex to the product and this step requires a very small amount of activation energy. The activation barrier for the diboration reaction is 12.8 kcal/mol.The proposed mechanism is significantly different from those proposed earlier and explains all experimental data relating to this reaction.     

Thermodynamic Insight into the Origin of a Calix[n]arene-[60]fullerene Interaction and its Application to a Porphyrin-[60]fullerene Energy Transfer System

The calixarene-fullerene interaction,which causes only a slight change in the absorptionspectra, has been substantiated by calorimetricmeasurements: the H° values arecomparable with those obtained from the associationconstants estimated by a spectroscopic method. Furthermore, we determined the association constantbetween homooxacalix[3]arene and [60]fullerenederivatives with a porphyrin moiety by fluorescencespectra.     

Peptides-XXXXVI: Studies in the synthesis of an analogue of hen egg white lysozyme

The previously synthesised (1–37), (38–75), (76–93), (94–104), (105–117) and (118–129) fragments of the analogue were combined making extensive use of the DCCI/HONSu method. The final coupling involved the (1–75) and (76–129) sub-fragments. Aggregation of the latter fragment caused problems in purification by routine gel filtration methods employing Enzacryl K2 or Sephadex LH60. The fully protected (1–129) product was partially purified by washing, then deprotectcd and purified by gel filtration and ion exchange chromatography. Satisfactory removal of the acetamidomethyl group used for cysteine protection could not be achieved.     

An extremal problem related to probability

Summary We consider a walk from a stateA ₁ to a stateA _n+1 in which the probability of remaining atA _i isp _i , and the probability of progressing fromA _i toA _i+1 is 1 –p _i . The probabilityW _nk of reachingA _n+1 fromA ₁ in exactlyn + k steps can then be expressed as a polynomial of degreen + k in then variablesp ₁,,p _n . We determine the maximum value ofW _nk and the (unique) choice (p ₁,,p _n ) for which this extremum occurs.Dedicated to Professor Otto Haupt with best wishes on his 100th birthday     

Regressions and monotone chains II: The poset of integer intervals

A regressive function (also called a regression or contractive mapping) on a partial order P is a function mapping P to itself such that (x)x. A monotone k-chain for is a k-chain on which is order-preserving; i.e., a chain x ₁<...ksuch that (x ₁)...(x_k). Let P _nbe the poset of integer intervals {i, i+1, ..., m} contained in {1, 2, ..., n}, ordered by inclusion. Let f(k) be the least value of n such that every regression on P _nhas a monotone k+1-chain, let t(x,j) be defined by t(x, 0)=1 and t(x,j)=x ^t(x,j–1). Then f(k) exists for all k (originally proved by D. White), and t(2,k) < f(K) <t( + _k, k) , where _k 0 as k. Alternatively, the largest k such that every regression on P _nis guaranteed to have a monotone k-chain lies between lg^*(n) and lg^*(n)–2, inclusive, where lg^*(n) is the number of appliations of logarithm base 2 required to reduce n to a negative number. Analogous results hold for choice functions, which are regressions in which every element is mapped to a minimal element.