DETECTION OF DNA-PSORALEN PHOTOADDUCTS in situ

Abstract— An immunological method, with the use of specific immune serum, has been developed for detection of 8-methoxypsoralen (8-MOP) photoadducts to DNA, formed in situ in cell nuclei, after combined treatment with 8MOP and UV-A irradiation (Zarçbska et al. , 1978). Lymphocytes fixed on slides or in suspension, and cryostat sections of different mammalian tissues, served as antigenic substrate, after treatment with 8-MOP and UV-A in vitro. Specific fluorescence in these substrates was detected in the nuclei after treatment with 30 ˜ 140 kJ/m² UV-A in the presence of 0.1-0.3 μg/cm² 8-MOP. PHA-stimulated-lymphocytes appeared to be the most sensitive substrate.
However, hairless mice treated with high doses of UV-A in vivo , 70 ˜ 360 kJ/m² did not reveal a specific fluorescence of epidermal nuclei, unless a high local concentration of 8-MOP was attained.
The apparent discrepancy in the level of photoadduct detection between the in vitro and in vivo treated specimens was explained by the low number of DNA-8-MOP-photoadducts formed in vivo under these experimental conditions. The relevance of these findings to the role of DNA-8-MOP-photoadducts formed during PUVA photochemotherapy is discussed.     

ON QUOTIENTS OF BRAID GROUPS

ABSTRACT.

Let G be the group ?[t, t ^?1] x ?. By studying the action of the braid group B_n on the set Gⁿ , we obtain representations of B_n into a wreath product of the symmetric group and the general linear group over ?[t, t ^?1]. This in particular recovers the Burau representation of the braid group. Furthermore, some quotients of the braid group are obtained by using the representations found.     

Assembly of metal-organic frameworks from large organic and inorganic secondary building units: new examples and simplifying principles for complex structures

The secondary building unit (SBU) has been identified as a useful tool in the analysis of complex metal-organic frameworks (MOFs). We illustrate its applicability to rationalizing MOF crystal structures by analysis of nine new MOFs which have been characterized by single-crystal X-ray diffraction. Tetrahedral SBUs in Zn(ADC)(2).(HTEA)(2) (MOF-31), Cd(ATC).[Cd(H(2)O)(6)](H2O)(5) (MOF-32), and Zn(2)(ATB)(H2O).(H2O)(3)(DMF)(3) (MOF-33) are linked into diamond networks, while those of Ni(2)(ATC)(H(2)O)(4).(H2O)(4) (MOF-34) have the structure of the Al network in SrAl(2). Frameworks constructed from less symmetric tetrahedral SBUs have the Ga network of CaGa(2)O(4) as illustrated by Zn(2)(ATC).(C(2)H(5)OH)(2)(H2O)(2) (MOF-35) structure. Squares and tetrahedral SBUs in Zn(2)(MTB)(H2O)(2).(DMF)(6)(H2O)(5) (MOF-36) are linked into the PtS network, which is the simplest structure type known for the assembly of these shapes. The octahedral SBUs found in Zn(2)(NDC)(3).[(HTEA)(DEF)(ClBz)](2) (MOF-37) form the most common structure for linking octahedral shapes, namely, the boron network in CaB(6). New structure types for linking triangular and trigonal prismatic SBUs are found in Zn(3)O(BTC)(2).(HTEA)(2) (MOF-38) and Zn(3)O(HBTB)(2)(H2O).(DMF)(0.5)(H2O)(3) (MOF-39). The synthesis, crystal structure, and structure analysis using the SBU approach are presented for each MOF.     

A Response-Driven Adaptive Design Based on the Klein Urn

The Klein design is a response-driven random rule to allocate experimental subjects between two treatments. It aims to allocate more subjects to the treatment that is performing better, and therefore it is useful when ethical issues are of prime interest. It behaves asymptotically as the drop-the-loser rule, which is known to have a high degree of compromise between ethics and inferential properties. Besides, the Klein design has a powerful stochastic structure, which permits to obtain exact values, for each sample size n, for its main operating characteristics, such as variability of allocations, expected failure rate and power, selection bias or accidental bias. These properties of the Klein design are thoroughly studied and we obtain exact and asymptotic results.