Switching supramolecular polymeric materials with multiple length scales

It was demonstrated that polymeric supramolecular nanostructures with several length scales allow straightforward tailoring of hierarchical order-disorder and order-order transitions and the concurrent switching of functional properties. Poly(4-vinyl pyridine) (P4VP) was stoichiometrically protonated with methane sulfonic acid (MSA) to form P4VP(MSA)1.0, which was then hydrogen-bonded to pentadecylphenol. Microphase separation, re-entrant closed-loop macrophase separation, and high-temperature macrophase separation were observed. When MSA and pentadecylphenol were complexed to the P4VP block of a microphase-separated diblock copolymer poly[styrene-block-(4-vinyl pyridine)], self-organized structures-in-structures were obtained whose hierarchical phase transitions can be controlled systematically. This microstructural control on two different length scales (in the present case, at 48 and 350 angstroms) was then used to introduce temperature-dependent transitions in electrical conductivity.     

Uterine Motility in Sows During Spontaneous Parturition and Induced Parturitions with the PGF Analog Alfbprostol and Oxytocin

Contents: Uterine activity, i.e. myometrial contractions, were recorded in 11 sows prior to and during parturition by using strain gauges placed onto uterine horns about 15 to 20 cm cranial of the bifurcation. Tocographic patterns observed prior to and during spontaneous and alfaprostol induced parturitions were normal. Administration of 20, 10 or 5 I.U. oxytocin 22 hours after alfaprostol quickly initiated abnormal periparturient contraction patterns with 20 and 10 I.U. oxytocin and in one of two animals receiving 5 I. U. These were characterized initially by prolonged tetanic contractions resulting in delayed deliveries, and later by the premature occurrence of patterns seen normally only during the phase of placental expulsions, although not all piglets had been delivered. The importance to use myornetrial activity profiles to evaluate parturition induction methods was stressed .     

Gastrointestinal transit times in normal and reovirus-inoculated turkeys

Brilliant pigment powder was used to measure minimum gastrointestinal transit times (GTT) in control and cloned-reovirus-inoculated turkey poults. Compared with controls, inoculated poults had longer GTT at 120 hr (P less than 0.05) but not at 24 and 72 hr after receiving a single oral dose of cloned reovirus. Reovirus inoculation was associated with failure to eat following a fasting period. Feces passed by reovirus-inoculated turkeys were more fluid and less well formed than normal.     

The efficacy of hyperimmune serum in the treatment of sweating sickness

Natural and experimental cases of sweating sickness were treated using a hyperimmune serum as specific treatment and hyperimmune serum combined with symptomatic and supportive treatment based on the clinicopathological changes observed in cases of sweating sickness. The treatment regimens were found to be highly effective in pigs and sheep as well as in calves, although recovery in the latter species was slower.     

Divergent selection of chickens for antibody response to sheep erythrocytes: kinetics of primary and secondary immunizations

Chicks from lines selectively bred for either high or low antibody response post-primary immunization (PPI) to sheep erythrocytes (SRBC) and their reciprocal crosses were immunized intravenously with 0.1 ml of 0.25% SRBC antigen in Trials 1 and 3 and with 0.1 ml of 0.025%, 0.25%, or 25% SRBC antigen in Trial 2. All initial immunizations were made at 35 days of age, and 0.1 ml of 0.25% SRBC booster dose was given 24 days later. Results showed that (a) population differences appeared by day 4 PPI and persisted through day 24 PPI, (b) regardless of population, peak titers occurred at about the same time for primary and secondary immunizations, (c) dosage of antigen influenced differences among populations in antibody response to primary immunization, and (d) both selected lines had similar responses in 2-mercaptoethanol-sensitive and 2-mercaptoethanol-resistant antibodies to primary but not secondary immunization.