spontaneous abortion (sab) is the most common complication of early pregnancy. numerous risk factors are associated with an increased risk of pregnancy loss such as: blighted ovum. the aim of this study was to determine the frequency of balanced chromosomal translocations in couples with a history of recurrent spontaneous abortions and ultrasound diagnosed blighted ovum. sixty eight couples wit...

2-(3-Benzyloxy)prop-1-ynyl)benzaldehyde with PtCl(2) in toluene would form Pt-pyryliums that underwent [3+2] cycloaddition with alkenes to the oxygen-bridged (5H-benzo[7]annulen-5-ylidene)platinum(ii) intermediates with good stereoselectivities. Their tandem rearrangement afforded diverse types of polycycles depending on the electronic nature of the alkenes.

[2.2]Paracyclophanes, incorporating functional groups in the aliphatic bridges, suitable for elimination to give [2.2]paracyclophanedienes, are synthesized through a novel approach. It relies on a double Pummerer rearrangement on dithiacyclophane precursors, followed by ring contraction through a photochemical sulfur extrusion, and it is compatible with aryl moieties possessing very different e...

An unusual [1,5]-Brook rearrangement of the lithium alkoxide of geminal bis(silyl) homoallylic alcohol is described. The unique steric and electronic effects of geminal bis(silane) were found to be crucial for promoting this long-range silyl migration, as well as for facilitating the subsequent γ/Z-selective addition of silyl allyllithium with carbonyl compounds to synthesize diverse configurat...

background: acute lymphoblastic leukemia (all) is the most common form of childhood cancer leading to cancer-related death in children. most infants with all harbor recurring structural chromosomal rearrangements that are important initiating events in leukemogenesis but are insufficient to explain the biology and heterogeneity of the disease. mixed-lineage leukemia-rearrangement (mll-rearrange...

Thermal rearrangement of 7,7-dichloro-[a,c]-dibenzo-[4,1,0]-bicycloheptane (1) to 5,6-dichloro-5Hdibenzo-[a,c]-cycloheptene (2) was studied in the solid phase and in solvents with different polarities. Thefirst-order constants at various temperatures for the rearrangement process were evaluated from theabsorption time data. The activation parameters for this rearrangement were obtained from the...

A facility layout problem is concerned with determining the best position of departments, cells, or machines on the plant. An efficient layout contributes to the overall efficiency of operations. It’s been proved that, when system characteristics change, it can cause a significant increase in material handling cost. Consequently, the efficiency of the current layout decreases or is lost and it ...

We consider adaptive identification algorithms based on hyperstability concepts with polyphase structures. The SPR condition required for convergence of these schemes can be always met by using a sufficiently high polyphase expansion factor M: The degree of persistent excitation required for parameter convergence is obtained. If some a priori knowledge about the system to identify is available,...