Chemical dehydrofluorination and electrical conductivity of poly(vinylidene fluoride) films

The dehydrofluorination of poly(vinylidene fluoride) (PVDF) powder and films was studied using several kinds of base solution. Especially the reactivity of 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) in ethanol, KOH in 2-propanol and aqueous NaOH solution with tetrabutylammonium bromide was investigated by the change in infrared (IR) and ultraviolet-visible (UV-VI) absorptions of PVDF films. The elimination reactions by DBU or KOH were considered to be accompanied by substitution reaction. The electrical conductivity of dehydrofluorinated PVDF films increased markedly by doping with iodine, and the activation energies of conduction were found to be between 0.4 and 0.5 eV. When a drawn PVDF film was dehydrofluorinated and doped with iodine, anisotropy in conductivity was observed.     

Anesthesia case of the month. Dystocia, cesarean section and acupuncture resuscitation of newborn kittens

OBJECTIVE: To assess the results of laparoscopic splenectomy as a treatment for immune thrombocytopenic purpura (ITP). MATERIAL AND METHODS: We conducted a retrospective study of all patients who underwent laparoscopic splenectomy for ITP at our institution between August 1992 and May 1997. RESULTS: Of 27 patients who underwent attempted laparoscopic splenectomy for ITP at our institution during the study period, 26 had completion of the procedure without conversion to an open splenectomy. The median postoperative hospital stay was 1.5 days, and no postoperative deaths occurred. In one patient, pancreatitis developed postoperatively. In four patients, splenectomy failed--two initially and two subsequently--and reinstitution of medical therapy was necessary. The other patients have remained free of medication, and 19 patients have platelet counts greater than 100 x 10(9)/L. The 3-year actuarial success rate was 81.5%. Response to corticosteroid therapy preoperatively may be an indicator of success of splenectomy. CONCLUSION: Laparoscopic splenectomy is safe and allows prompt recovery. Long-term response rates are similar to those achieved with open splenectomy.     

Novel antitumor 2-cyanoaziridine-1-carboxamides

A set of 20 2-cyanoaziridine-1-carboxamides was synthesized from 2-cyanoaziridine and appropriate isocyanates. These compounds were active against a variety of solid and hematological tumor cells in culture, including strains resistant to doxorubicin and mitoxantrone. Their potencies in these assays correlated with the lipophilicity of substituents. The N-phenyl derivative was more potent and equally effective to imexon, a cyclized 2-cyanoaziridine-1-carboxamide of clinical interest, against cloned fresh human tumors.     

The role of state policies and programs in buffering the effects of poverty on children's immunization receipt

OBJECTIVES: This study assessed the influence of public policies on the immunization status of 2-year old children in the United States. METHODS: Up-to-dateness for the primary immunization series was assessed in a national sample of 8100 children from the 1988 National Maternal and Infant Health Survey and its 1991 Longitudinal Follow-Up. RESULTS: Documented immunization rates of this sample were 33% for poor children and 44% for others. More widespread Medicated coverage was associated with greater likelihood of up-to-dateness among poor children. Up-to-dateness was more likely for poor children with public rather than private sources of routine pediatric care, but all children living in states where most immunizations were delivered in the public sector were less likely to be up to date. Poor children in state with partial vaccine replacement programs were less likely to be up to date than those in free-market purchase states. CONCLUSIONS: While state policies can enhance immunization delivery for poor children, heavy reliance on public sector immunization does not ensure timely receipt of vaccines. Public- and private-sector collaboration is necessary to protect children from vaccine-preventable diseases.     

Efficient power regeneration and drive of an induction motor by means of optimal torque derived by the variational method

When the motor speed is reduced by using a regenerative brake, the mechanical energy of rotation is converted to electrical energy. When the regenerative torque is large, the corresponding current increases so that the copper loss also becomes large. On the other hand, the damping effect of rotation increases with time when the regenerative torque is small. In order to use this limited energy effectively, the optimal regenerative torque should be ascertained in order to maximize the regeneration of electrical energy. This paper proposes a methodology, based on the variational method, for the design of regenerative torque for an induction motor in order to maximize the regenerative electric energy. Similarly, the optimal torque for acceleration is derived in order to minimize the driving energy. Finally, an efficient motor drive system with the proposed optimal torque and a power storage system stabilizing the DC link voltage will be proposed. The effectiveness of the proposed methods is illustrated by simulations and experiments. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(1): 41–50, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.21010