Hydrogen bond catalyzed direct reductive amination of ketones.

[reaction: see text] A novel, biomimetic concept for the direct reductive amination of ketones is described that relies on selective imine activation by hydrogen bond formation. The mild, acid- and metal-free process requires only catalytic amounts of thiourea as hydrogen bond donor and utilizes the Hantzsch ester for transfer hydrogenation. The method allows the efficient synthesis of structurally diverse amines.

Effect on enamel microhardness of two consumer-available bleaching solutions when compared with a dentist-prescribed, home-applied bleaching solution and a control.

Background: There exists limited data in the literature regarding the efficacy and safety of consumer-available, paint-on bleaching solutions.

Purpose: The purpose of this in vitro study was to evaluate the effect of two consumer-available, paint-on bleaching products on enamel microhardness against a control and a dentist-prescribed, home-applied (DPHA) bleaching product.

Materials And Methods: Eighty enamel slabs were obtained from extracted human teeth and randomly divided into four treatment groups: (1) control; (2) Opalescence (Ultradent Products, Inc.

One year outcomes for heroin dependence: findings from the Australian Treatment Outcome Study (ATOS).

Aim: To determine 1 year outcomes for drug use, criminality, psychopathology and injection-related health problems in those entering treatment for heroin dependence in Australia.

Design: Longitudinal prospective cohort study.

Participants: Seven hundred and forty five individuals entering treatment (methadone/buprenorphine maintenance therapy; detoxification; residential rehabilitation) and 80 heroin users not seeking treatment.

The characteristics of heroin users entering treatment: findings from the Australian treatment outcome study (ATOS).

The current study aimed to describe the characteristics (demographics, drug use, mental and physical health) of entrants to treatment for heroin dependence in three treatment modalities; and to compare these characteristics with heroin users not in or seeking treatment. Participants were 825 current heroin users recruited from Sydney, Adelaide and Melbourne: 277 entering methadone/buprenorphine maintenance treatment (MT), 288 entering detoxification (DTX), 180 entering drug-free residential rehabilitation (RR) and 80 not in treatment (NT). Treatment entrants were generally long-term heroin users with previous treatment experience.

Tailor-made olefinic medium-chain-length poly[(R)-3-hydroxyalkanoates] by Pseudomonas putida GPo1: batch versus chemostat production.

Functionalized medium-chain-length polyhydroxyalkanoates (mclPHAs) have gained much interest in research on biopolymers because of their ease of chemical modification. Tailored olefinic mclPHA production from mixtures of octanoic acid and 10-undecenoic acid was investigated in batch and dual (C,N) nutrient limited chemostat cultures of Pseudomonas putida GPo1 (ATCC 29347). In a batch culture, where P.

The relationship between take-away methadone policies and methadone diversion.

The development of policies in relation to unsupervised doses of methadone (take-away doses) should be based upon the best available evidence. There are both risks and benefits associated with take-away doses. This study aimed to explore the relationship between take-away policies and one measure of harm: methadone injection rates.

Critical appraisal. To bevel or not in anterior composites.

Composites are widely used for the functional and esthetic restorations of anterior teeth. The placement of a cavosurface margin bevel on the enamel margins of anterior composite preparations traditionally has been recommended to enhance retention and for esthetic reasons, as bevels result in a gradual transition between the restoration and the tooth. However, advances in adhesive and composite technology, as well as careful composite selection and application techniques, have made it possible to place adequate anterior composites without a bevel.

Paying research participants: a study of current practices in Australia.

Objective: To examine current research payment practices and to inform development of clearer guidelines for researchers and ethics committees.

Design: Exploratory email based questionnaire study of current research participant reimbursement practices. A diverse sample of organisations and individuals were targeted.

Dynamic factor analysis of groundwater quality trends in an agricultural area adjacent to Everglades National Park.

The extensive eastern boundary of Everglades National Park (ENP) in south Florida (USA) is subject to one of the most expensive and ambitious environmental restoration projects in history. Understanding and predicting the water quality interactions between the shallow aquifer and surface water is a key component in meeting current environmental regulations and fine-tuning ENP wetland restoration while still maintaining flood protection for the adjacent developed areas. Dynamic factor analysis (DFA), a recent technique for the study of multivariate non-stationary time-series, was applied to study fluctuations in groundwater quality in the area.

Direct resin-based composites: current recommendations for optimal clinical results.

Composite resins are increasingly used for the restoration of anterior and posterior teeth. Although adhesives and composites have become easier to use than earlier generations of these materials, the use of composite resins is still technique-sensitive. This article reviews the current recommendations for the use of direct composite resins and summarizes the technique for both anterior and posterior restorations.

Shear bond strength of self-etching bonding systems in combination with various composites used for repairing aged composites.

Purpose: Repair of worn, broken or discolored composite restorations can be accomplished using new composite material and dentin bonding systems. The purpose of this study was to investigate the effectiveness of self-etching adhesive systems for composite re-bonding procedures onto different composite substrates that had been aged for 6 years prior to testing.

Materials And Methods: Two hundred cylinders (4 mm x 5 mm) of composite were fabricated using 4 hybrid composites [AeliteFil (Bisco), Prodigy (SDS Kerr), TPH (Dentsply Caulk), and Z100 (3M ESPE)] following manufacturers' directions and stored for 6 years in 1% NaCl solution.

[Medical publications within private libraries of the European enlightenment. About the medically learned German novelist Johann Gottwerth Müller (1743-1828) and his stock of medical books].

The German novelist J. G. Müller is one of the popular writers of the late 18th century.

Contribution of the tetrodotoxin-resistant voltage-gated sodium channel NaV1.9 to sensory transmission and nociceptive behavior.

The transmission of pain signals after injury or inflammation depends in part on increased excitability of primary sensory neurons. Nociceptive neurons express multiple subtypes of voltage-gated sodium channels (NaV1s), each of which possesses unique features that may influence primary afferent excitability. Here, we examined the contribution of NaV1.

Clinical strategies for success in proximoincisal composite restorations. Part II: Composite application technique.

Unlabelled: Reproducing the form, function, and optical characteristics of natural dental structures with direct composites in large and moderately large proximoincisal (Class IV) restorations represents a great challenge for clinicians in general. Understanding color is fundamental to achieving success when restoring these defects, as was discussed in Part I of this two-part article (Volume, 16, Number 6). The proper restoration of the functional lingual contour is also a challenge that cannot be overcome without close attention to the restorative technique.

Old Masters' lead white pigments: investigations of paintings from the 16th to the 17th century using high precision lead isotope abundance ratios.

White lead (2PbCO(3).Pb(OH)(2)), a common component in 17c. artists' painting materials, was singled out to investigate the potential of lead isotope abundance ratios in the field of authentication and origin assignment.

Factors associated with 12 months continuous heroin abstinence: findings from the Australian Treatment Outcome Study (ATOS).

Aims: To determine the role of treatment and client characteristics associated with the achievement of continuous heroin abstinence.

Design: Longitudinal cohort study.

Setting: Sydney and Adelaide, Australia.