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Three kinds of phosphate-containing maleimide(PMI) monomers, namely diethyl (4-(N-maleimido) phenyl) phosphate (4P) diphenyl (4-(N-maleimido) phenyl) phosphate (PP) and diethyl (2,6-dibromo-4-(N-maleimido)phenyl) phosphate (BrP), were synthesized and blended with a phenol-novolac type of epoxy so as to study their potential as reactive flame retardants. Thermal reaction of these blending systems had been discussed. Mechanical and thermal properties of blends had also been analysed. It was expected that with an increase in the PMI content in the blending system, the Michael-addition reaction would take place more and easily. Increasing the PMI contents reduced the storage modulus, the Tg and the tensile strength, however good thermal stability was maintained. The flame retardancy of all the phosphate-containing epoxy systems was promoted significantly by increasing the PMI content. Besides, the PMI with halogen atom may combine the flame retarding mechanism of gas-phase and solid-phase to promote their flame retardancy.

The lamellar morphology of a melt-miscible blend consisting of two crystalline constituents, poly(vinylidene fluoride) (PVDF) and poly(3-hydroxybutyrate) (PHB), has been investigated by small angle X-ray scattering (SAXS). Owing to the proximity of melting points, PVDF and PHB crystallized over essentially the same temperature range, and consequently created a crystalline/crystalline state with the morphology characterized by the spatial arrangement of PVDF and PHB lamellae. Irrespective of the crystallization temperatures (Tc), the SAXS patterns revealed the presences of two lamellar stack (LS) domains, where one contained mainly PVDF lamellae (PVDF LS domain) and the other primarily consisted of PHB lamellae (PHB LS domain). The interlamellar (IL) regions of both LS domains were found to contain mixed amorphous PVDF and PHB. The blends crystallized at higher Tcexhibited smaller SAXS invariants. This observed Tcdependence was connected with the disparity in crystallization kinetics that gave rise to different LS domain sizes at different Tcs.

The semicrystalline morphology of poly(3-hydroxy butyrate) (PHB)/poly(vinyl acetate) (PVAc) blends at four crystallization temperatures (Tc = 70, 90, 110, and 125 °C) was probed by small-angle X-ray scattering (SAXS). Morphological parameters including the crystal thickness (lc) and the amorphous layer thickness (la) were deduced from the interphase distribution function. Blending with PVAc thickened the PHB crystals. The amorphous layers were also swollen upon blending, but la displayed a maximum in its variation with PVAc composition. A zero-angle scattering was observed in the Lorentz-corrected SAXS profiles of PHB/PVAc 60/40 blend crystallized at 110 and 125 °C and 50/50 composition crystallized at 90−125 °C. Such a zero-angle scattering was attributed to the presences of amorphous domains between the lamellar stacks so as to generate gaps in the sequential stacking of lamellae. These amorphous domains were generated by the interfibrillar segregation of PVAc, where PVAc was expelled beyond several layers of lamellae and subsequently resided in the regions between the lamellar stacks. On the basis of the composition variation of la, the observation of zero-angle scattering, and the magnitude of the volume fraction of lamellar stacks, it was concluded that when PVAc composition was ≤20 wt %, the morphology was predominantly characterized by the interlamellar segregation; above this composition, interlamellar and interfibrillar segregation coexisted, and the extent of interfibrillar segregation increased with the increases of PVAc composition and crystallization temperature.

ThiFSGH and ThiI are required for the biosynthesis of the thiazole moiety of thiamin in Escherichia coli. The overproduction, purification, and characterization of ThiFS and the identification of two of the early steps in the biosynthesis of the thiazole moiety of thiamin are described here. ThiS isolated from E. coli thiI+ is post-translationally modified by converting the carboxylic acid group of the carboxyl-terminal glycine into a thiocarboxylate. The thiI gene plays an essential role in the formation of the thiocarboxylate because ThiS isolated from a thiI- strain does not contain this modification. ThiF catalyzes the adenylation by ATP of the carboxyl-terminal glycine of ThiS. This reaction is likely to be involved in the activation of ThiS for sulfur transfer from cysteine or from a cysteine-derived sulfur donor.

Clozapine has been shown to have superior effectiveness compared with classic neuroleptics in treating refractory schizophrenia in Caucasians, but its efficacy and safety in Chinese have not been adequately studied. Forty Chinese schizophrenic patients were recruited in a 12-week, double-blind, comparative trial. Twenty-one patients were randomly assigned to clozapine treatment and 19 to chlorpromazine treatment. The average dose was 543 ± 157 and 1163 ± 228 mg/day for clozapine and chlorpromazine, respectively. The results showed that six clozapine-treated patients (28.6) had more than 20 improvement in Brief Psychiatric Rating Scale score and were classified as responders, whereas none of the chlor-promazine-treated patients was classified as a responder. The degree of improvement in positive symptoms, negative symptoms and Brief Psychiatric Rating Scale scores in the clozapine group was inversely correlated with the severity of negative symptoms at entry into the trial. Two clozapine-treated patients were withdrawn from the study, one because of leukopenia and nausea, and the other because of vomiting and hypotension. Chlorpromazine treatment was prematurely discontinued in two patients, because of jaundice and over sedation in one, and because of severe weight loss in the other (9 kg). The rate of moderate-to-severe sialorrhea was high in clozapine-treated patients (28.6). Two clozapine-treated patients and two chlorpromazine-treated patients showed significant improvement in previously existing tardive dyskinesia and one chlorpromazine-treated patient exhibited aggravation of tardive dyskinesia. The results of this study indicate that clozapine treatment might have advantages over chlorpromazine for Chinese schizophrenic patients who are refractory to typical neuroleptic treatment.