Formation of Chiral Interdigitated Multilayers at the Air-Liquid Interface Through Acid-Base Interactions

Thin interdigitated films composed of a long-chain, water-insoluble chiral acid (p-pentadecylmandelic acid of absolute configuration R) and a water-soluble chiral base (phenylethylamine, R') were constructed at the air-solution interface. The (R, R') structure was characterized to near-atomic resolution by grazing-incidence x-ray diffraction (GIXD). The two diastereomeric systems, (R, R') and (R, S'), demonstrate similar surface pressure-molecular area isotherms, but their structures are completely different on the molecular level, as monitored by GIXD. Complementary data on these two architectures were provided by atomic force microscopy.     

Evaluation of Canine-Derived Fibrin Sealant as a Hemostatic Agent

The purpose of this study was to determine whether canine-derived fibrinogen concentrate applied with bovine thrombin was a safe and effective topical hemostatic agent. A canine liver biopsy model was selected to test this product. Cryoprecipitate was prepared from frozen canine plasma using two freeze/thaw/centrifugation cycles. Six healthy adult dogs (weighing more than 18 kg) were used in the fibrin sealant study, and an additional three dogs were used as controls for the liver biopsy. A 1 × 3 cm liver biopsy specimen was obtained, digital pressure was applied to reduce bleeding, and the fibrinogen concentrate was immediately sprayed on the bleeding surface simultaneously with bovine thrombin (1,000 IU/mL). The mean ± standard error of the mean (SEM) blood pressure at time of biopsy was 98 ± 9 mm Hg, and the rate of hemorrhage from the cut liver edge was 8.0 ± 1.1 mL/min. The total blood loss during fibrin sealant application was 37 ± 9 mL and total time for hemostasis was 5.5± 1.3 minutes. There was no additional hemorrhage after application of the fibrin sealant. In the three control dogs, fibrin sealant was not applied and only digital compression was used to decrease hemorrhage. Before digital compression, the rate of hemorrhage from the cut liver edge was 13.1 ±3.1 mL/min. Bleeding had not stopped after 10 minutes of compression and the mean postcompression rate of hemorrhage was 4.0 ± 2.6 mL/min. Signs of secondary bleeding after fibrin sealant was applied were not evident during the immediate postoperative period or over the next 14 days. The coagulation profile, alanine amino transferase (ALT), alkaline phosphatase (AP), and bile acids were not significantly different on day 14 from preoperative values, suggesting that the liver was only mildly affected. The dogs were euthanatized and gross and histological examinations of the biopsy site were performed on day 14. There were minimal or no adhesions at the biopsy site. In all dogs, the hepatic capsule was less than 1 mm thick and histological signs of secondary bleeding, hepatocellular damage, thrombosis, infection, or inflammation were not observed. In this study, canine-derived fibrin sealant was a safe and effective topical hemostatic agent.     

The need to implement the landscape of fear within rodent pest management strategies

Current reactive pest management methods have serious drawbacks such as the heavy reliance on chemicals, emerging genetic rodenticide resistance and high secondary exposure risks. Rodent control needs to be based on pest species ecology and ethology to facilitate the development of ecologically based rodent management (EBRM). An important aspect of EBRM is a strong understanding of rodent pest species ecology, behaviour and spatiotemporal factors. Gaining insight into the behaviour of pest species is a key aspect of EBRM. The landscape of fear (LOF) is a mapping of the spatial variation in the foraging cost arising from the risk of predation, and reflects the levels of fear a prey species perceives at different locations within its home range. In practice, the LOF maps habitat use as a result of perceived fear, which shows where bait or traps are most likely to be encountered and used by rodents. Several studies have linked perceived predation risk of foraging animals with quitting‐harvest rates or giving‐up densities (GUDs). GUDs have been used to reflect foraging behaviour strategies of predator avoidance, but to our knowledge very few papers have directly used GUDs in relation to pest management strategies. An opportunity for rodent control strategies lies in the integration of the LOF of rodents in EBRM methodologies. Rodent management could be more efficient and effective by concentrating on those areas where rodents perceive the least levels of predation risk. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Arteriovenous Fistulas as an Aid in Blood Collection from Canine Blood Donors

To facilitate blood collection from blood donor dogs, arteriovenous fistulas were established between the common carotid arteries and external jugular veins in five adult dogs. Twelve to 16 mm, side-to-side anastomoses were created using simple interrupted 6–0 polypropylene sutures. Starting 1 month after the surgical procedure, 500 ml of blood was collected from each dog as required. Electrocardiography, thoracic radiography, and cardiac output and rate were used to monitor cardiac changes. Blood flow characteristics, and proliferative and dystrophic cellular changes occurring in the vessels were documented in one dog.
The mean blood collection times were 2 minutes and 45 seconds from the fistula site and 9.0 minutes from the opposite jugular vein. Ventricular hypertrophy and myocardial changes were observed on electrocardiogram in two dogs, and radiographic evidence of pulmonary hypertension was noted in three dogs. Reversed blood flow was documented in the common carotid artery and external jugular vein distal to the arteriovenous fistula. Four dogs were still in use as blood donors 1 to 1 1/2 years after establishment of the fistulas. Clinical signs of congestive heart failure were not observed.     

Effect of body condition score and reuse of progesterone‐releasing intravaginal devices on conception rate following timed artificial insemination in Nelore cows

This study had the aim of investigating the efficiency of timed artificial insemination (TAI) through the progesterone‐releasing intravaginal device (PRID), used in new condition and for the second and third times in Nelore cows. The effects of device reuse and body condition score (BCS) on the conception rate (CR) were evaluated in 1,122 multiparous Nelore cows (mean BCS of 2.7 ± 0.4), which were randomly distributed into three groups that received new (n = 330), once (n = 439) and twice used (n = 353) PRID. Among the 1,122 females that underwent TAI, 573 became pregnant, thus representing an overall CR of 51.06%. Cows with BCS between 2.75 and 4.0 had greater (p < .0001) CR (69.75%) than cows with BSC of 2.0–2.5 (32.98%). It was observed that the CR through using PRID was 60.00%, 51.71% and 41.93% for new, once and twice used PRID, respectively, with difference between all groups (p < .0001). Under tropical conditions, animals with BCS greater than 2.5 had a higher CR, and the CR decreased proportionally with the number of times that the PRID had been used.     

Evaluation of Efficacy and Safety of Zinc Gluconate Associated with Dimethyl Sulphoxide for Sexually Mature Canine Males Chemical Neutering

The aim of this research was to evaluate the efficacy of zinc gluconate associated with dimethyl sulphoxide (DMSO) for chemical neutering in canine males. Fifteen sexually mature male dogs were divided in two groups, named control and treated. An injection was administered to both testicles, at a concentration of 26.2 mg zinc gluconate per ml and 0.5% DMSO in the treated group (11 dogs). The control group was given injections of saline solution (four dogs). Clinical examination and blood collection for a haemogram were done both before and after drug injection. There were 12 spermograms performed to analyse sperm motility, sperm vigour, ejaculate volume, testicle size, pathology and sperm concentrations. Libido was also measured. An ultrasound examination and histopathology were performed at the end of the experiment. Dogs’ libido after chemical injection was reduced by over 50%. The spermogram analysis showed final mean results of 14.54% for sperm motility, 0.72 of sperm vigour and 37 150 per million spermatozoa per millilitre, values considered below the necessary levels at which fertilization can occur. Ultrasound and histopathology analyses of testicles for the treated group revealed more intense injuries when compared with the control group, with compromised testicular parenchyma and a decrease of germ cell number leading to total atrophy, indicating that the treatment reduced the fertilizing potential of male dogs, promoting a possible subfertile status.     

The kondo effect in the unitary limit

We observe a strong Kondo effect in a semiconductor quantum dot when a small magnetic field is applied. The Coulomb blockade for electron tunneling is overcome completely by the Kondo effect, and the conductance reaches the unitary limit value. We compare the experimental Kondo temperature with the theoretical predictions for the spin- 12 Anderson impurity model. Excellent agreement is found throughout the Kondo regime. Phase coherence is preserved when a Kondo quantum dot is included in one of the arms of an Aharonov-Bohm ring structure, and the phase behavior differs from previous results on a non-Kondo dot.