Actively Controllable Solid-Phase Microextraction in a Hierarchically Organized Block Copolymer-Nanopore Electrode Array Sensor for Charge-Selective Detection of Bacterial Metabolites.

Pseudomonas aeruginosa produces a number of phenazine metabolites, including pyocyanin (PYO), phenazine-1-carboxamide (PCN), and phenazine-1-carboxylic acid (PCA). Among these, PYO has been most widely studied as a biomarker of P. aeruginosa infection. However, despite its broad-spectrum antibiotic properties and its role as a precursor in the biosynthetic route leading to other secondary phenazines, PCA has attracted less attention, partially due to its relatively low concentration and interference from other highly abundant phenazines. This challenge is addressed here by constructing a hierarchically organized nanostructure consisting of a pH-responsive block copolymer (BCP) membrane with nanopore electrode arrays (NEAs) filled with gold nanoparticles (AuNPs) to separate and detect PCA in bacterial environments. The BCP@NEA strategy is designed such that adjusting the pH of the bacterial medium to 4.5, which is above the pKa of PCA but below the pKa of PYO and PCN, ensures that PCA is negatively charged and can be selectively transported across the BCP membrane. At pH 4.5, only PCA is transported into the AuNP-filled NEAs, while PYO and PCN are blocked. Structural characterization illustrates the rigorous spatial segregation of the AuNPs in the NEA nanopore volume, allowing PCA secreted from P. aeruginosa to be quantitatively determined as a function of incubation time using square-wave voltammetry and surface-enhanced Raman spectroscopy. The strategy proposed in this study can be extended by changing the nature of the hydrophilic block and subsequently applied to detect other redox-active metabolites at a low concentration in complex biological samples and, thus, help understand metabolism in microbial communities.

Dual diagnosis discourse in Victoria Australia: the responsiveness of mental health services.

OBJECTIVE: In recent decades, psychiatric services have been challenged to be more responsive to patients' coexisting problems, in particular those concerning substance use. In Australia this has been referred to as a "No Wrong Door" approach. This paper explores the meanings of this move for the acute mental health sector, including attitudes toward a No Wrong Door approach to people with a dual diagnosis of mental illness and substance use disorder. METHODS: This qualitative study involved a review of the research literatures, analysis of policy documents, and interviews with 19 key informants in a case study of the State of Victoria, Australia. RESULTS: The analysis resulted in two broad themes surrounding the implications of dual diagnosis discourse for the mental health sector. The first involves progress regarding the concept of No Wrong Door with subthemes including interprofessional cultural conflicts, intersectoral professional status issues, terminology, problem definition, perspectives on serious mental illness, the role of the client, and pharmacological treatment. The second overarching theme focuses upon informants' thoughts on future directions for the sector and highlights divided opinion on the implications of dual diagnosis discourse for the mental health service and social care systems. CONCLUSIONS: While the perspectives on system change and multiple issues such as resource concerns and cultural clashes are presented here, the informants in this study also gave clear guidance for the future of dual diagnosis work in the mental health sector (e.g., focusing on orienting services toward consumer strengths and recovery), along with recommendations for future research. This paper contributes to the small body of qualitative research on the history and course of efforts to develop appropriate practice in mental health services with regard to patients who have substance use problems and other mental health disorders.

Factors that enable and hinder the implementation of projects in the alcohol and other drug field.

OBJECTIVE: Few studies systematically explore elements of successful project implementation across a range of alcohol and other drug (AOD) activities. This paper provides an evidence base to inform project implementation in the AOD field. APPROACH: We accessed records for 127 completed projects funded by the Alcohol, Education and Rehabilitation Foundation from 2002 to 2008. An adapted realist synthesis methodology enabled us to develop categories of enablers and barriers to successful project implementation, and to identify factors statistically associated with successful project implementation, defined as meeting all funding objectives. Thematic analysis of eight case study projects allowed detailed exploration of findings. RESULTS: Nine enabler and 10 barrier categories were identified. Those most frequently reported as both barriers and enablers concerned partnerships with external agencies and communities, staffing and project design. CONCLUSION: Achieving supportive relationships with partner agencies and communities, employing skilled staff and implementing consumer or participant input mechanisms were statistically associated with successful project implementation. IMPLICATIONS: The framework described here will support development of evidence-based project funding guidelines and project performance indicators. The study provides evidence that investing project hours and resources to develop robust relationships with project partners and communities, implementing mechanisms for consumer or participant input and attracting skilled staff are legitimate and important activities, not just in themselves but because they potentially influence achievement of project funding objectives.

Quantitative evaluation of equine deep digital flexor tendon morphology using magnetic resonance imaging.

Injury of the distal aspect of the deep digital flexor tendon (DDFT) is a recognized cause of lameness, but diagnosis is difficult. This study aimed to improve understanding of DDFT morphology and pathology using retrospective evaluation of magnetic resonance (MR) images. We hypothesized that: (1) The distal aspect of the DDFT in normal horses would have a repeatable proximal/distal pattern and symmetry between limbs and between lobes; (2) DDFT dimensions would be related to bodyweight, navicular bone dimensions and hoof size; (3) this symmetry and pattern would be lost in DDFT injury; and (4) DDFT size would increase with injury. MR images of 64 live horse limbs, 26 with no identified DDFT lesion and 38 with identified DDFT abnormalities, and 19 normal cadaver limbs were analyzed. Using standardized transverse images, measurements of DDFT cross-sectional area, medial-lateral (ML) width and dorsal-palmar depth were obtained at six preselected sites. A uniform distal to proximal shape pattern was identified in all horses. The flattened crescent shape at the insertion changed to a deeper bilobed shape more proximally, with the mid-navicular area having the greatest cross-sectional area. Strong ML (P < 0.0006) and left/right symmetry (P < 0.02) were observed. In addition, there was a strong association between DDFT cross-sectional area and horse weight (P = 0.005) and between DDFT and navicular bone ML width (P = 0.004). Symmetry between sides or between lobes was lost at sites with a unilateral lesion and correlation between horse weight and DDFT cross-sectional area was lost in the presence of lesions. DDFTs with core lesions had a consistent increase in cross-sectional area overall, but other lesion types had no significant increase in size. The shape and symmetry seen in normal tendons could be related to the mechanical demands placed upon individual lobes. The limited increase in cross-sectional area with injury may be explained by the restrictive structures of the hoof, possibly explaining the ongoing pain seen in such lesions.