Cooperative and Noncooperative Assembly of Oligopyrenotides Resolved by Atomic Force Microscopy

The supramolecular assembly of amphiphilic oligopyrenotide building blocks (covalently linked heptapyrene, Py7) is studied by atomic force microscopy (AFM) in combination with optical spectroscopy. The assembly process is triggered in a controlled manner by increasing the ionic strength of the aqueous oligomer solution. Cooperative noncovalent interactions between individual oligomeric units lead to the formation of DNA-like supramolecular polymers. We also show that the terminal attachment of a single cytidine nucleotide to the heptapyrenotide (Py7-C) changes the association process from a cooperative (nucleation−elongation) to a noncooperative (isodesmic) regime, suggesting a structure misfit between the cytidine and the pyrene units. We also demonstrate that AFM enables the identification and characterization of minute concentrations of the supramolecular products, which was not accessible by conventional optical spectroscopy.

Correlation of Pullout Force of Kirschner (K-) Wire to Other Factors Indicative of Bone Quality

More than 250,000 hip fractures occur annually in the United States and the most common fracture location is the femoral neck, the weakest region of the femur. Hip fixation surgery is conducted to repair hip fractures by using a Kirschner (K-) wire as a temporary guide for permanent bone screws. Variation has been observed in the force required to extract the K-wire from the femoral head during surgery. It is hypothesized that a relationship exists between the K-wire pullout force and the bone quality at the site of extraction. Currently, bone mineral density (BMD) is used as a predictor for bone quality and strength. However, BMD characterizes the entire skeletal system and does not account for localized bone quality and factors such as lifestyle, nutrition, and drug use. A patient’s BMD may not accurately describe the quality of bone at the site of fracture. This study aims to investigate a correlation between the force required to extract a K-wire from femoral head specimens and the quality of bone. A procedure to measure K-wire pullout force was developed and tested with pig femoral head specimens. The procedure was implemented on 8 human osteoarthritic femoral head specimens and the average pullout force for each ranged from 563.32 ± 240.38 N to 1041.01 ± 346.84 N. The data exhibited significant variation within and between each specimen and no statistically significant relationships were determined between pullout force and patient age, weight, height, BMI, inorganic to organic matter ratio, and BMD. A new testing fixture was designed and manufactured to merge the clinical and research environments by enabling the physician to extract the K-wire from each bone specimen himself. The new device allows the physician to gather tactile feedback on the relative ease of extraction while load history is recorded similar to the previous procedure for data acquisition. Future work will include testing human bones with the new device to further investigate correlations for predicting bone quality.

Investigation of Aerosol Properties Using Environmental Atomic Force Microscopy

Atmospheric aerosols affect both global and regional climate by altering the radiative balance of the atmosphere and acting as cloud condensation nuclei. Despite an increased focus on the research of atmospheric aerosols due to concerns about global climate change, current methods to observe the morphology of aerosols and to measure their hygroscopic properties are limited in various ways by experimental procedure. The primary objectives of this thesis were to use atomic force microscopy to determine the morphology of atmospherically relevant aerosols and to investigate theutility of environmental atomic force microscopy for imaging aerosols as they respond to changes in relative humidity. Traditional aerosol generation and collection techniques were used in conjunction with atomic force microscopy to image commonorganic and inorganic aerosols. In addition, environmental AFM was used to image aerosols at a variety of relative humidity values. The results of this research demonstrated the utility of atomic force microscopy for measuring the morphology of aerosols. In addition, the utility of environmental AFM for measuring the hygroscopic properties of aerosols was demonstrated. Further research in this area will lead to an increased understanding of the role oforganic and inorganic aerosols in the atmosphere, allowing for the effects of anthropogenic aerosol emissions to be quantified and for more accurate climate models to be developed.

Summary of the Report of the Ad Hoc Task Force on Psychopharmacology of the American Psychological Association

The American Psychological Association Board of Directors established an ad hoc task force on psychopharmacology to explore the desirability and feasibility of psychopharmacology prescription privileges for psychologists. In this context, the Task Force's charges were to determine the competence criteria necessary for training psychologists to provide service to patients receiving medications and to develop and evaluate the necessary curricular models. This article summarizes the Task Force's major recommendations and provides specific information regarding its training recommendations . It is hoped that this article will encourage broad discussion of psychology's most appropriate integration of psychopharmacology knowledge and its applications into its training programs and professional activities.

European guidelines on management of restless legs syndrome: report of a joint task force by the European Federation of Neurological Societies, the European Neurological Society and the European Sleep Research Society

Since the publication of the first European Federation of Neurological Societies (EFNS) guidelines in 2005 on the management of restless legs syndrome (RLS; also known as Willis-Ekbom disease), there have been major therapeutic advances in the field. Furthermore, the management of RLS is now a part of routine neurological practice in Europe. New drugs have also become available, and further randomized controlled trials have been undertaken. These guidelines were undertaken by the EFNS in collaboration with the European Neurological Society and the European Sleep Research Society.

Becoming a member of the work force: perceptions of adults with Asperger Syndrome

Research has shown that comparatively few adults with Asperger Syndrome (AS) participate in the competitive work force. The purpose of this study was to gain in-depth knowledge about contextual factors, which contribute to successful labor market participation in some adults with AS.

Immediate and delayed transplantation of mesenchymal stem cells improve muscle force after skeletal muscle injury in rats

Mesenchymal stem cell (MSC) therapy is a promising approach for regaining muscle function after trauma. Prior to clinical application, the ideal time of transplantation has to be determined. We investigated the effects of immediate and delayed transplantation. Sprague-Dawley rats received a crush trauma to the left soleus muscle. Treatment groups were transplanted locally with 2 × 10(6) autologous MSCs, either immediately or 7 days after trauma. Saline was used as sham therapy. Contraction force tests and histological analyses were performed 4 weeks after injury. GFP-labelled MSCs were followed after transplantation. The traumatized soleus muscles of the sham group displayed a reduction of twitch forces to 36 ± 17% and of tetanic forces to 29 ± 11% of the non-injured right control side, respectively. Delayed MSC transplantation resulted in a significant improvement of contraction maxima in both stimulation modes (twitch, p = 0.011; tetany, p = 0.014). Immediate transplantation showed a significant increase in twitch forces to 59 ± 17% (p = 0.043). There was no significant difference in contraction forces between muscles treated by immediate and delayed cell transplantation. We were able to identify MSCs in the interstitium of the injured muscles up to 4 weeks after transplantation. Despite the fundamental differences of the local environment, which MSCs encounter after transplantation, similar results could be obtained with respect to functional muscle regeneration. We believe that transplanted MSCs residing in the interstitial compartment evolve their regenerative capabilities through paracrine pathways. Our data suggest a large time window of the therapeutical measures.