Formation of phenazine from azobenzene over H-ZSM5: Reaction control by a molecular constrained environment

Azobenzene undergoes a unique reaction in the channels of H-ZSM5 zeolite at 593–673 K to give phenazine which is mainly retained within the zeolite. The yield of phenazine is increased by the addition to the reaction carrier gas of oxygen (1% vol.) which probably functions as a hydrogen acceptor. No reaction occurs when low acidity silicalite is used. On H-USY zeolite the yield of phenazine is low and the main product is a black, insoluble material which is probably polymeric. Benzo(c)cinnoline which is a known dehydrocyclization product from azobenzene under strongly acidic reaction conditions is never more than a trace product using H-ZSM5 or H-USY. A reaction scheme is proposed involving homolysis of the N ~ N bond in protonated trans-azobenzene, forming two radicals which, in a H-ZSM5 channel, are constrained in their mutual orientation so as to lead to the formation of phenazine.     

High-gain free electron lasers using induction linear accelerators

High-power free electron lasers (FEL's) can be realized using induction linear accelerators as the source of the electron beam. These accelerators are currently capable of producing intense currents (10²-10⁴A) at moderately high energy (1-50 MeV). Experiments using a 500 A, 3.3 MeV beam have produced 80 MW of radiation at 34.6 GHz and are in good agreement with theoretical analysis. Future experiments include a high-gain, high-efficiency FEL operating at 10.6 μm using a 50 MeV beam.     

Dietary patterns vs. dietary recommendations: Identifying the gaps for complex carbohydrate

Dietary guidelines of the U.S. and Canada recommend that 55% of dietary calories of individuals should come from carbohydrates, especially complex carbohydrates. However, they generally fail to describe how much should come from complex carbohydrates. Undoubtedly, this is because of confusion about the composition of complex carbohydrate foods and incomplete knowledge of the health benefits of all components of grain products. With the intent of shifting dietary food selection to increase carbohydrate consumption above the current 46% of calories, food guides recommend 5 to 12 servings per day from grain products. Current estimated intake for adults is between four to five servings of grain products, of which less than one is from whole grain, in an average 2000‐kcal adult diet. To follow the advice of the U.S. Food Guide Pyramid, which suggests half the bread (grains) group should be whole‐grain products, adult Americans should increase their intake of whole‐grain products four‐ to fivefold and double their intake of total grain products.     

A study of the relationship between temperature and the infectivity of Schistosoma mansoni and Schistosoma haematobium cercariae

An unusual form of left ventricular aneurysm affecting young Negroes has recently been described at the aortic or mitral valve ring; constitutional factors have been postulated. A 4-year-old Negro boy was observed with a left ventricular submitral aneurysm, probably one of the largest and one of the most calcified to be reported. Tuberculous lymphadenitis involving some of the mediastinal lymph nodes was found on postmortem examination; tuberculosis was believed to be a secondary contributing factor. A review of the literature disclosed only 5 other children with calcified left ventricular aneurysms, of which 2 were of the subvalvular type.     

Lactate metabolism in the dog during shock from hemorrhage, cardiac tamponade or endotoxin

Serum IgE concentrations of patients with paragonimiasis were determined by a radioimmunosorbent test. The mean concentration was 3,462.3 IU/ml in a group of 13 cases of paragonimiasis miyazakii in which patients showed clinical symptoms and/or positive immunological diagnostic tests, and 1,026.6 IU/ml in a control group of 13 individuals who had eaten uncooked freshwater crabs, Potamon dehaani, but had been found to be free from the infection. Moreover, the IgE level of the pleural exudates obtained from four patients with paragonimiasis miyazakii on the day of bleeding or within several days after was significantly higher than that of their sera, ranging between 4,200 IU/ml and 10,000 IU/ml. This was true also in a case of paragonimiasis westermani. Sera and pleural exudates of patients with both forms of paragonimiasis were applied to immunosorbent columns of Sepharose 4B beads coupled with saline extracts of Paragonimus miyazakii, P. weetermani, or P. ohirai. IgE eluted from the corresponding column was considered to be specific, being around 5% to 10% of the total IgE.     

Respiratory abnormalities and ventilatory capacity in a Papua New Guinea Island community

Several molecular forms of human glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NADP+ 1-oxidoreductase, EC 1.1.1.49) corresponding to different stages of post-synthetic modifications have been purified from human leukocytes. The various enzyme forms were different in their specific activity, their kinetic properties and their isoelectrofusing pattern. The molecular weight of the subunits of the different forms was not modified. The changes in the electrofocusing pattern were not due to modifications of the N-terminal ends, the oxidation of thiol groups or the non-covalent fixation of an acid molecule upon the enzyme. Carboxypeptidase B cleaved a C-terminal lysine from the different enzyme forms and shifted the isoelectric point of the different enzyme active bands towards the acid pH. The different enzyme forms studied here seemed to result from the action upon 'native glucose-6-phosphate dehydrogenase' of 'modifying factors' especially abundant in some leukemic granulocytes. The modifying factors did not seem to be consumed during the 'modification' of glucose-6-phosphate dehydrogenase. Moreover, the storage for one year of unmodified enzyme resulted in changes in its electrofocusing pattern similar to those quickly induced by the 'modifying factors'. Consequently it appears that the modifying factors are catalysts of the modification of special residues of glucose-6-phosphate dehydrogenase. The hypothesis that this modification involves the deamination of asparagine or glutamine residues is put forward.