Synthese von substituierten benzotriazolen zur stabilisierung aromatischer polyamide gegen UV-licht

2-(2′-Hydroxyphenyl)-benzotriazoles, containing a carbonamide group in 5- or 5′-position, were synthesized to stabilize polyamides. The influence of the ortho-positioned hydroxy group for the stabilizing effect of these substances was examined by methylating it. The synthesized benzotriazoles were characterized, especially with regard to their UV-absorption-spectra. The photolytic resistance of poly-(m-phenyleneisophthalamide), containing these stabilizers, for example 2-(2′-hydroxy-5′-tert-butylphenyl)-benzotriazol-5-carbonic acid anilide, was examined by measuring the viscosity.     

Analog CMOS integrated circuit design: research and undergraduateteaching

The authors describe the use of software that was developed as part of a research program in analog CMOS integrated circuit design for an undergraduate course on analog VLSI design. The software includes some unusual uses of readily available, inexpensive, and easy-to-use programs available for microcomputers such as Macintosh or IBM-PC clones. Although initially intended to help with the design of CMOS operational amplifiers, the IC design method used is very general; other possible applications are described. The flexibility of these programs also allows them to be used with other CAD (computer-aided design) software, including circuit simulators and programs for schematic entry and layout. The software tools allow undergraduate students to complete analog CMOS integrated circuit designs using advanced CAD techniques but without being overwhelmed or losing touch with the underlying circuit design principles. Details of the programs and their use are presented together with the resulting analog IC designs fabricated using MOSIS (MOS Implementation Service)     

Replacement of carcinogenic alkylating agent ethylene oxide in the synthesis of (Z)-3-dodecen-1-YL (E)-2-butenoate,sex pheromone of sweet-potato weevil,Cylas formicarius elegantulus (summers) andCylas formicarius formicarius (F.)

An alternative synthesis of (Z)-3-dodecen-1-y1 (E)-2-butenoate without use of carcinogenic ethylene oxide and HMPA is described. By coupling of the tetrahydropyranyl (THP) ether of 3-butyn-1-ol with 1-bromooctane with sodamide in liquid ammonia, 12-(2-tetrahydropyranyloxy)-9-dodecyne was obtained; subsequent hydrolysis and semihydrogenation afforded (Z)-3-dodecen-1-ol. The alcohol was then reacted with crotonyl chloride to give the desired crotonate with a total yield of 29.8%. Males of sweet-potato weevil,Cylas formicarius were strongly attracted to the synthetic sex pheromone. The attraction from the dispenser of polyethylene tube was better than the attraction from the dispenser of rubber septum in the field.     

Introgression Between Cultivars and Wild Populations of Momordica charantia L. (Cucurbitaceae) in Taiwan

The landrace strains of Momordica charantia are widely cultivated vegetables throughout the tropics and subtropics, but not in Taiwan, a continental island in Southeast Asia, until a few hundred years ago. In contrast, the related wild populations with smaller fruit sizes are native to Taiwan. Because of the introduction of cultivars for agricultural purposes, these two accessions currently exhibit a sympatric or parapatric distribution in Taiwan. In this study, the cultivars and wild samples from Taiwan, India, and Korea were collected for testing of their hybridization and evolutionary patterns. The cpDNA marker showed a clear distinction between accessions of cultivars and wild populations of Taiwan and a long divergence time. In contrast, an analysis of eight selectively neutral nuclear microsatellite loci did not reveal a difference between the genetic structures of these two accessions. A relatively short divergence time and frequent but asymmetric gene flows were estimated based on the isolation-with-migration model. Historical and current introgression from cultivars to wild populations of Taiwan was also inferred using MIGRATE-n and BayesAss analyses. Our results showed that these two accessions shared abundant common ancestral polymorphisms, and the timing of the divergence and colonization of the Taiwanese wild populations is consistent with the geohistory of the Taiwan Strait land bridge of the Last Glacial Maximum (LGM). Long-term and recurrent introgression between accessions indicated the asymmetric capacity to receive foreign genes from other accessions. The modern introduction of cultivars of M. charantia during the colonization of Taiwan by the Han Chinese ethnic group enhanced the rate of gene replacement in the native populations and resulted in the loss of native genes.     

Multiple sebaceous adenomas and internal malignant disease: a case report with chromosomal analysis

A case of multiple sebaceous adenomas associated with internal malignant disease is further documented. Thirteen similar cases reported in the literature are also reviewed. We support the thesis that this association represents a unique syndrome. It can be seen in both sexes and usually is manifested during the fifth and sixth decades. A family history of malignant disease was revealed among seven of the nine cases mentioned. Of the other skin lesions, keratoacanthoma is also frequently seen. The internal malignant tumors most commonly afflict the gastrointestinal tract, especially the large intestine. With proper treatment the internal tumors appear to be of a low degree of malignancy. However, these patients have a propensity to develop muliple visceral tumors and require periodic follow-up. Some patients develop skin tumors prior to the discovery of internal malignant disease, an event that offers some prognostic value. Chromosomal study of the cultured blood lymphocytes by the Giemsa banding technique failed to reveal any abnormality.     

Investigation of hole transport layer in relation to the properties of organic solar cells

Organic solar cells based on a blend of copper phthalocyanine and bulk fullerene are fabricated with a double hole transport layer system. The double hole transport layer was composed of poly3,4-ethylenedioxythiophene:polystyrenesulfonate, and copper phthalocyanine and inserted between the anode and active layer. The double hole transport layer system utilizes advantages of both layer. The poly3,4-ethylenedioxythiophene:polystyrenesulfonate layer modifies the surface morphology of the ITO anode and the copper phthalocyanine layer enhances hole transport. In order to enhance the conductivity of the modification layer, the optimal amount of glycerol is doped into poly3,4-ethylenedioxythiophene:polystyrenesulfonate. Furthermore, the photovoltaic characteristics are further improved. Insertion of the double hole transport layer with a 4 nm-thick copper phthalocyanine layer resulted in open circuit voltage, short current, and power conversion efficiency as high as 0.46 V, 8.8 mA/cm2 and 1.37%, respectively.     

Zur ermittlung von Langperioden durch Röntgenkleinwinkelstreuung von Copolyestern

A computer method for slit-hight corrections is described, in which the experimental X-ray small angle scattering curve is represented by a cubic spline function. This method is applied on the theoretical scattering-curve of spherical particles with homogeneous electron-density and on scattering-curves of polyhexamethyleneadipate and an aliphatic polyesteramide. For the polyester and the polyesteramide long periods of 150 Å and 118 Å, respectively, were found. By means of this and other physical results considerations of the structure of these materials are given.     

Overexpression of bcl-2 or bcl-XL fails to inhibit apoptosis mediated by a novel retinoid

Overexpression of bcl-2 or bcl-XL has been found to inhibit the induction of apoptosis in malignant cells by a large number of agents including a wide variety of chemotherapeutic drugs. CD437 ?6-[3-(1-adamantyl)-4 hydroxyphenyl]-2-naphthalene carboxylic acid? is a novel retinoid that induces apoptosis in a number of malignant cells through a unique mechanism of action. The addition of 1 microM CD437 to HL-60/NEO cells resulted in capase 3 (CPP32) activation and poly(ADP-ribose) polymerase (PARP) cleavage in 3 h whereas in bcl-2- or bcl-XL-overexpressing HL-60 cells CD437 induced CPP32 activation and PARP cleavage in 6 h. Although 50 and 300 nM CD437 were required to induce PARP cleavage in HL-60/NEO and HL-60/bcl-2, HL-60/bcl-XL cells, respectively, maximal apoptosis in both cell lines was achieved utilizing 300 nM CD437. All three cell lines, however, share identical dose-response curves in terms of their growth inhibition, suggesting that CD437-mediated inhibition of growth and induction of apoptosis represent two distinct and separable processes. In addition, CD437 induces GI arrest as well as p21WAFI/CIPI mRNA expression in these cells despite the overexpression of bcl-2 or bcl-XL. CD437 induced mitochondrial instability as indicated by cytochrome c leakage into the cytoplasm in all three cell lines. CD437 also induced growth inhibition and apoptosis of an apoptosis-resistant variant of the HL-60 cell line (HCW-2), which switched expression from bcl-2 to bcl-XL. CD437-mediated apoptosis is not accompanied by downregulation of bcl-2 or bcl-XL or upregulation of bax. The reason for the inability of bcl-2 or bcl-XL overexpression to inhibit CD437-mediated apoptosis is unclear. The ability of CD437 to initiate apoptosis in a spectrum of malignant cells without interference from bcl-2 or bcl-XL overexpression suggests that CD437 may possess significant therapeutic potential in the treatment of malignancy.     

Effects of lactose and glucose on production of itaconic acid and lovastatin by Aspergillus terreus ATCC 20542

Fermentation products of Aspergillus terreus ATCC 20542 (a parent strain for lovastatin production) were collected, and the coexistence of itaconic acid (IA) with lovastatin was confirmed in this study. Using a lactose-based medium (LBM), lovastatin production was 873 mg/l on day 10, but IA production was only 22-28 mg/l during the cultures. When lactose in LBM was simply replaced with glucose, IA production was markedly enhanced by 20-fold (491 mg/l on day 5), which showed a growth-associated pattern. The findings indicated that the carbon source used (glucose or lactose) controlled the biosynthetic pathway. The net yield of lovastatin production when using lactose was calculated to be 25.1 mg/g (5.1-fold) in comparison with when using glucose in the cultures. Furthermore, lovastatin production was further increased by 9.2% when IA (0.5 g/l) was added to LBM. When IA was added at 5 g/l, the fermentation broth turned dark-brown, and lovastatin production was reduced by 18.0%. Hence, these two metabolites (IA and lovastatin) produced by the fungus might be related.