On the prime graph of <Emphasis Type="Italic">PSL</Emphasis>(2, <Emphasis Type="Italic">p</Emphasis>) where <Emphasis Type="Italic">p</Emphasis> > 3 is a prime number

Let G be a finite group. We define the prime graph Γ(G) as follows. The vertices of Γ(G) are the primes dividing the order of G and two distinct vertices p, q are joined by an edge if there is an element in G of order pq. Recently M. Hagie [5] determined finite groups G satisfying Γ(G) = Γ(S), where S is a sporadic simple group. Let p > 3 be a prime number. In this paper we determine finite groups G such that Γ(G) = Γ(PSL(2, p)). As a consequence of our results we prove that if p > 11 is a prime number and p ≢ 1 (mod 12), then PSL(2, p) is uniquely determined by its prime graph and so these groups are characterizable by their prime graph. The third author was supported in part by a grant from IPM (No. 84200024).     

A characterization of the finite simple group L<Subscript>16</Subscript>(2) by its prime graph

In this paper as the main result we prove that the projective special linear group L ₁₆(2) is uniquely determined by its prime graph. In fact we give a positive answer to an open problem arose in Zavarnitsin (Algebra Logic 43(4), 220–231, 2006) and we obtain a first example of a finite group with connected prime graph which is uniquely determined by its prime graph. This research was in part supported by a grant from IPM (No. 86200023).     

Combined hollow fiber-based liquid-liquid-liquid microextraction and in-situ differential pulse voltammetry to improve selectivity, sensitivity, and interference elimination in electrochemical analysis

In this paper, a combined hollow fiber-based liquid three-phase microextraction and voltammetric method are applied for the first time as a highly selective and sensitive method of electrochemical analysis. Desipramine, used as a model compound was extracted from 8 mL aqueous solution (donor phase, 0.10 mol L⁻¹ NaOH) through a thin phase of propyl benzoate inside the pores of a polypropylene hollow fiber and finally into a 10 μL acidic acceptor solution inside the hollow fiber. Three microelectrodes designed and constructed for the purposes of this study were placed into the two ends of the hollow fiber inside the acceptor solution, and voltammetric analysis was performed in-situ during the extraction. After 15 min, the final stable signal was used for analytical applications. Under the optimized conditions, an enrichment factor of 301 was achieved and the relative standard deviation (R.S.D.) of the method was 6.2% (n = 5). The calibration curve was obtained in the range of 5-5000 nmol L⁻¹ with a reasonable linearity (R² > 0.988) and the limit of detection (LOD) was found to be 0.8 nmol L⁻¹. Finally, the applicability of the proposed method was evaluated by extraction and determination of desipramine in plasma and urine samples without any dilutions.     

Unique solvability of a linear problem with perturbed periodic boundary values

We investigate the problem with perturbed periodic boundary values

Stable intersections of affine cantor sets

We construct open sets of pairs of affine Cantor sets (K, K′) with the simplest possible combinatorics (i. e., defined by two affine increasing maps) which have stable intersection, while the product of lateral thicknesses τ_R(K) • τ_L (K′) is smaller than one. Thus, in a strong form, the converse to the following classic result due to Newhouse is not true: if the product of the thicknesses of two Cantor sets is bigger than one then there are translations of them which have stable intersection. We also describe the topological structure of K—K′ for typical pairs (K, K′) in this open set.     

Inhibition of Survivin Restores the Sensitivity of Breast Cancer Cells to Docetaxel and Vinblastine

Combination therapy is considered a viable strategy to overcome the resistance to chemotherapeutics. Survivin as a member of the inhibitor of apoptosis protein (IAP) family, which is involved in resistance to various drugs. We investigated the role of combination therapy in downregulating survivin and increasing drug’s efficacy in MDA-MB-231 cells. MTT assay and DAPI staining were applied to study the anti-proliferative activity and apoptosis response of the agents. Real-time RT-PCR and Western blot analysis were applied to study survivin mRNA and protein. Our findings showed that combined treatment of cells with docetaxel and vinblastine reduces survivin expression and consequently decreases the IC₅₀ value of docetaxel from 70 to 5 nM (p?p?相似文献   

One‐Pot Synthesis of 5,7,8,9,9a,10‐Hexahydro‐8‐thioxotetrahydropyrido[2,3‐d : 6,5‐d′]dipyrimidine‐2,4,6(1H,3H,5aH)‐triones via a Four‐Component Coupling Reaction of Aldehydes,Amines, Barbituric Acids,and Thiouracil

An efficient one‐pot approach to the synthesis of 5,7,8,9,9a,10‐hexahydro‐8‐thioxopyrido[2,3‐d : 6,5‐d′]dipyrimidine‐2,4,6(1H,3H,5aH)‐triones 5 via a four‐component reaction of an aldehyde 1 , an amine 2 , a barbituric acid 3 , and thiouracil ( 4 ) is reported for the first time. This new multicomponent reaction is accomplished in refluxing EtOH in the presence of tungstophosphoric acid (H₃PW₁₂O₄₀) as a catalyst. A variety of hexahydropyrido[2,3‐d : 6,5‐d′]dipyrimidinetrione derivatives were successfully synthesized in excellent yields with this protocol (Table 2).