A study of crystalline biomaterials for articular cartilage bioengineering

This study examines the suitability of marine origin coral species, Porites lutea (POR) and the hydrozoan Millepora dichotoma (MIL), for use as novel three dimensional growth matrices in the field of articular cartilage tissue engineering. Therefore, mesenchymal stem cells (MSCs) and chondrocytes were grown on the skeletal material obtained from each of these two organisms to investigate their potential use as three dimensional scaffolding for cartilage tissue growth. Chondrogenic induction of MSCs was achieved by addition of transforming growth factor-β1 (TGF-β1) and insulin growth factor-I (IGF-I). Cell adherence, proliferation, differentiation and tissue development were investigated through six weeks of culture. Cartilage tissue growth and chondrocytic phenotype maintenance of each cell type were examined by cell morphology, histochemical analyses, expression of collagen type II and quantitative measures of glycosaminoglycan (GAG) content. The MSCs and the chondrocytes were shown good adherence to the scaffolds and maintenance of the chondrocytic phenotype in the initial stages of culture. However after two weeks of culture on MIL and three weeks on POR these cultures began to exhibit signs of further differentiation and phenotypic loss. The shown results indicated that POR was a better substrate for chondrocytes phenotype maintenance than MIL. We believe that surface modification of POR combined with mechanical stimuli will provide a suitable environment for chondrogenic phenotype maintenance. Further investigation of POR and other novel coralline biomatrices is indicated and warranted in the field of cartilage tissue engineering applications.     

Customized Electronic Coupling in Self‐Assembled Donor–Acceptor Nanostructures

Charge transfer processes between donor–acceptor complexes and metallic electrodes are at the heart of novel organic optoelectronic devices such as solar cells. Here, a combined approach of surface‐sensitive microscopy, synchrotron radiation spectroscopy, and state‐of‐the‐art ab initio calculations is used to demonstrate the delicate balance that exists between intermolecular and molecule–substrate interactions, hybridization, and charge transfer in model donor–acceptor assemblies at metal‐organic interfaces. It is shown that charge transfer and chemical properties of interfaces based on single component layers cannot be naively extrapolated to binary donor–acceptor assemblies. In particular, studying the self‐assembly of supramolecular nanostructures on Cu(111), composed of fluorinated copper‐phthalocyanines (F₁₆CuPc) and diindenoperylene (DIP), it is found that, in reference to the associated single component layers, the donor (DIP) decouples electronically from the metal surface, while the acceptor (F₁₆CuPc) suffers strong hybridization with the substrate.     

Readability level of Health Insurance Portability and Accountability Act notices of privacy practices used by psychologists in clinical practice.

Obtaining informed consent from a client to participate in psychotherapy includes providing an understanding of what treatment or evaluation is going to take place with the psychologist, as well as what the psychologist may or may not do with the client's records. Psychologists have an obligation to communicate clearly with their clients regarding informed consent. In this investigation, 1 Health Insurance Portability and Accountability Act Notice of Privacy Practices was solicited from a practicing psychologist in each state plus the District of Columbia. The authors then analyzed these forms using 2 measures of readability. A large majority (82%) of these forms were written at the ceiling reading level (12th grade), and almost the entire sample (94%) fell into the difficult range of reading ease. On the basis of the data obtained in this investigation, it is recommended that psychologists move to improve the readability of these documents and should do so to improve clinical practice, reduce liability, and follow ethical standards. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Advanced rail clamp networks for ESD protection

A new, area efficient, boosted and distributed active MOSFET rail clamp network for I/O pad ESD protection is presented. In addition, a compact new rail clamp trigger circuit with high resistance to false triggering is introduced.     

Are emotionally charged lures immune to false memory?

Using the Deese–Roediger–McDennott task and E. Tulving's (1985) remember–know judgments for recognition memory, the authors explored whether emotional words can show the false memory effect. Participants studied lists containing nonemotional, orthographic associates (e.g., cape, tape, ripe; part, perk, dark) of either emotional (e.g., rape) or nonemotional (e.g., park) critical lures. This setup produced significant false "remembering" of emotional lures, even though initially no emotional words appeared at study. When 3 emotional nonlure words appeared at study, emotional-lure false recognition more than doubled. However, when these 3 study words also appeared on the recognition test, false memory for the emotional lures was reduced. Across experiments, participants misremembered nonemotional lures more often than they did emotional lures, but they were more likely to rate emotional lures as "remembered," once they had been recognized as "old." The authors discuss findings in light of J. J. Freyd and D. H. Gleaves, (1996) criticisms of this task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developing a space-filling mixture experiment design when the components are subject to linear and nonlinear constraints

This article presents a case study of developing a space-filling design (SFD) for a constrained mixture experiment when the experimental region is specified by single-component constraints (SCCs), linear multiple-component constraints (LMCCs), and nonlinear multiple-component constraints (NMCCs). Traditional methods and software for designing constrained mixture experiments with SCCs and LMCCs (using either optimal design or SFD approaches) are not directly applicable because of the NMCCs. A SFD algorithm in the JMP^® software was modified to accommodate the NMCCs; the modification is described in this article. The case study involves high-level waste (HLW) glass that is subject to the formation of nepheline crystals as the glass cools. This can significantly reduce the durability of HLW glass (which is undesirable). The goal of the study was to develop a SFD for the HLW glass compositional region where nepheline may form, and generate data for modeling nepheline formation as a function of HLW glass composition. The HLW glass composition region was specified in terms of eight components with SCCs, two LMCCs, and two NMCCs. The NMCCs were based on a nonlinear logistic regression model for a binary nepheline response that was developed from previous data. This article discusses the HLW glass example, the constraints specifying the experimental composition region, and how an existing algorithm for generating SFDs was modified to accommodate the NMCCs. The methodology discussed in this article can be applied to any example in which the experimental region is specified by one or more nonlinear constraints in addition to linear constraints on mixture components and/or non-mixture variables.     

Semiconductor microlenses fabricated by one-step focused ion beamdirect writing

We fabricated a refractive semiconductor micro-lenses using a focused ion beam (FIB) direct writing technique. The simple one-step FIB process produced high-quality micro-lenses of silicon, the most popular and low cost semiconductor material used in optoelectronics. A spherical Si microlens with a nominal lens diameter of 48 μm exhibited a radius curvature and focal length of 100 and 40 μm, respectively. The maximum derivation between the measured and designed profiles is less than λ/100. The surface roughness, RMS, measured by use of atomic force microscope in 1× 1 μm² square area, is 1.1 nm. This microlens fabrication method could be readily applicable due to the simplicity in processing and the high-quality results     

Inferring migration flows from the migration propensities of infants: Mexico and Indonesia

The need for methods of indirectly estimating migration flows is particularly important in developing countries, where migration data are often incomplete and inaccurate. This paper focuses on the use of an indirect internal migration estimation method applied to Mexican and Indonesian census data. It shows that the mobility propensities of infants can be used to infer the corresponding propensities of all other age groups. However, the promise of this method is reduced in instances of inadequate data, and great care must be taken to identify outlying values in the data and to correct obviously erroneous patterns. Future work increasingly will be directed to this issue.     

The duties of patients: a distant mirror

We studied nine patients with cerebral ptosis and gaze deviation following an acute stroke. The brains of all nine showed an extensive lesion in the fronto-parieto-temporal regions. In five the stroke was left hemispheric. The assumption is that cerebral ptosis may have a bihemispheric representation and results from damage to the connections rather than to a specific area.