Role of imine isomerization in the stereocontrol of the Staudinger reaction between ketenes and imines.

Computational-experimental analysis has allowed determining that the stereochemistry of the Staudinger reaction between ketenes and imines is strongly associated with the nature of the imine, which affects the two steps of the reaction. The first step, namely the nucleophilic attack of the sp-hybridized nitrogen atom of the imine on the sp-hybridized carbon atom of the ketene, is affected by the energetically accessible isomerization patterns of the imine. The second step consists of a conrotatory electrocyclization of the zwitterionic intermediate formed in the previous step.

Trends in total hip arthroplasty.

This article discusses developments in total hip arthroplasty related to the use of highly cross-linked polyethylene (HXLPE) liner material as the new standard of care for acetabular cup articulation surfaces. The pathologic implications of metal-on-metal hip prostheses in asymptomatic patients also are discussed.

A Versatile Method for the Protection of Carbonyl Compounds by Camphor Sulfonic Acid.

Background: Carbonyl groups are important functional groups and they play a key role in organic chemistry. This group needs to be protected in multistep synthesis against various reagents for a counter-reaction. The effort towards developing an efficient methodology for the protection of car-bonyl functional group is always a demanding reaction.

Seasonal detection of atrazine and atzA in man-made waterways receiving agricultural runoff in a subtropical, semi-arid environment (Hidalgo County, Texas, USA).

Atrazine is a widely-used herbicide that can impact non-target organisms in the environment but can be biologically degraded by several types of microorganisms. In this study, the gene atzA, which encodes for the initial step in bacterially-mediated atrazine degradation, was used as an indicator of atrazine pollution in agricultural canals located in Hidalgo County, Texas, USA. The concentration of atrazine and atzA were monitored once per month for 12 months during 2010-2011.

Cry-like genes, in an uncommon gene configuration, produce a crystal that localizes within the exosporium when expressed in an acrystalliferous strain of Bacillus thuringiensis.

Cry proteins are pesticidal toxins produced by the bacterium Bacillus thuringiensis (Bt), which aggregate in sporulating cells to form a crystal. Except in a relatively few cases, these crystals are located outside the exosporium that surrounds the spore. Bt2-56 is a strain of Bt that has the relatively uncommon characteristic of locating its Cry protein-containing crystal within the exosporium, and in association with a long, multifiber filament.

Anti-cancer Parasporin Toxins are Associated with Different Environments: Discovery of Two Novel Parasporin 5-like Genes.

Cry toxins are primarily a family of insecticidal toxins produced by the bacterium Bacillus thuringiensis (Bt). However, some Cry toxins, called parasporins (PSs), are non-insecticidal and have been shown to differentially kill human cancer cells. Based on amino acid homology, there are currently six different classes of parasporins (PS1-6).

An expeditious green route toward 2-aryl-4-phenyl-1H-imidazoles.

Background: Azaheterocycles are an important class of compounds because of their highly potent medicinal activities, and the imidazole subcategory is of special interest in regard to drug discovery research.

Findings: An expeditious synthetic protocol of 2-aryl-4-phenyl-1H-imidazoles has been accomplished by reacting phenylglyoxal monohydrate, ammonium acetate, and aldehyde under sonication. Following this green approach a series of 2-aryl-4-phenyl-1H-imidazoles has been synthesized using diversely substituted aldehydes.

Isolation and Characterization of the Lytic Cold-Active Bacteriophage MYSP06 from the Mingyong Glacier in China.

As unique ecological systems, glaciers are characterized by low temperatures and low nutrient levels, which allow them to be considered as “living fossils” for the purpose of researching the evolution of life and the environmental evolution of the earth. Glaciers are also natural microbial “reservoirs”. In this work, a lytic cold-active bacteriophage designated MYSP06 was isolated from Janthinobacterium sp.

Experimental test of host specificity in a behaviour-modifying trematode.

Host behavioural modification by parasites is a common and well-documented phenomenon. However, knowledge on the complexity and specificity of the underlying mechanisms is limited, and host specificity among manipulating parasites has rarely been experimentally verified. We tested the hypothesis that the ability to infect and manipulate host behaviour is restricted to phylogenetically closely related hosts.

Motor neurons in the escape response circuit of white shrimp (Litopenaeus setiferus).

Many decapod crustaceans perform escape tailflips with a neural circuit involving giant interneurons, a specialized fast flexor motor giant (MoG) neuron, populations of larger, less specialized fast flexor motor neurons, and fast extensor motor neurons. These escape-related neurons are well described in crayfish (Reptantia), but not in more basal decapod groups. To clarify the evolution of the escape circuit, I examined the fast flexor and fast extensor motor neurons of white shrimp (Litopenaeus setiferus; Dendrobranchiata) using backfilling.

Diagnosis and treatment of cuff tear arthropathy.

Rotator cuff tears account for a significant majority of shoulder pain presentations. Without diagnosis and management, advanced cuff tears may progress to cuff tear arthropathy, a degenerative arthritis condition of the shoulder. This article discusses the causes and management of cuff tear arthropathy, including definitive treatment with reverse shoulder arthroplasty.

The Use of Polystyrene Beads to Prepare Arrayed Samples of Bacillus thuringiensis for Microscopic Examination.

A common activity in the global search for useful Cry toxins is the microscopic screening of bacterial colonies for the presence of Bacillus thuringiensis. High-throughput screens require that aliquots from large numbers of colonies be arrayed on a microscopic slide. However, precisely placing a small amount of bacteria on a slide, and at a density that is useful for microscopic examination, is both difficult to achieve and time consuming.

Challenges From and Beyond Symptomatology: Stereotype Threat in Young Adults With ADHD.

Objective: Stereotype threat-faced when one confronts a personally relevant stereotype in a domain-relevant context-can significantly jeopardize individual performance in test-taking situations. Research has overlooked the potential for mental health labels to serve as bases for stereotype threat in such situations. This study examines whether ADHD, a disorder frequently serving as a basis for standardized testing accommodation, may trigger stereotype threat in testing situations.

Identification of Chemical Compounds That Inhibit the Function of Glutamyl-tRNA Synthetase from Pseudomonas aeruginosa.

Pseudomonas aeruginosa glutamyl-tRNA synthetase (GluRS) was overexpressed in Escherichia coli. Sequence analysis indicated that P. aeruginosa GluRS is a discriminating GluRS and, similar to other GluRS proteins, requires the presence of tRNA(Glu) to produce a glutamyl-AMP intermediate.

Unusual Benign Tumors of the Breast.

The purpose of this article is to describe the imaging characteristics of a variety of benign breast tumors that may be encountered in daily practice, in order to formulate an appropriate differential diagnosis and to establish concordance between the imaging and the pathologic findings, and to assist the clinician with appropriate management.

Occupational Deprivation or Occupational Adaptation of Mexican Americans on Renal Dialysis.

The aim of this study was to explore the occupational changes and perceptions experienced by Mexican Americans with end-stage renal disease (ESRD) and their families living with dialysis. In-depth interviews were conducted with 17 Mexican Americans with ESRD and 17 family members. The participants with ESRD described altered or lost activity patterns, capacities and freedoms.

Anti-apoptotic and Beneficial Metabolic Activities of Resveratrol in Type II Gaucher Disease.

Gaucher disease (GD) is one of the most common lysosomal storage disorders and is caused by an inherited deficiency in glucocerebrosidase. Resveratrol is a phytoalexin that has many beneficial activities, including anti-oxidant, anti-apoptotic, and neuroprotective effects. The aim of this study was to determine if resveratrol has a therapeutic effect on primary fibroblast cells derived from a patient with type II GD.

Skin Barrier Recovery is not Associated with Self-Perceived Stress.

The primary aim of the current study was to examine the association between self-perceived stress and skin-barrier recovery. From an initial sample of 410 students, 19 high-stress and 12 low-stress Hispanic women completed a behavioural survey and were assessed for recovery of skin barrier following a tape-stripping procedure. No association was found between self-perceived stress and skin barrier recovery at either the 30-min or 3.

Relation of peer effects and school climate to substance use among Asian American adolescents.

Using a nationally representative, longitudinal sample of Asian American late adolescents/young adults (ages 18-26), this article investigates the link between peer effects, school climate, on the one hand, and substance use, which includes tobacco, alcohol, and other illicit mood altering substance. The sample (N = 1585) is drawn from the National Longitudinal Study of Adolescent Health (Waves I and III). The study is set to empirically test premises of generational, social capital and stage-environment fit theories.

Recognizing and managing infections in total joint arthroplasty.

Periprosthetic joint infections are a devastating complication of joint arthroplasty procedures, affecting 1% to 4% of patients. With the increasing demand for joint replacement, the clinical and financial burden of periprosthetic joint infections is challenging. This article reviews the diagnosis and treatment of periprosthetic joint infections.

Pathogenesis and management of diabetic foot ulcers.

Diabetic foot ulcers are a devastating component of diabetes progression and are caused by loss of glycemic control, peripheral neuropathy, peripheral vascular disease, and immunosuppression. An estimated 15% of patients with diabetes have diabetic foot ulcers. This article describes the pathogenesis, diagnosis, clinical management, and advances in wound treatment for diabetic foot ulcers.

Enantioselective palladium(0)-catalyzed Nazarov-type cyclization.

A Pd(0)-catalyzed asymmetric Nazarov-type cyclization is described. The optimized ligand for the reaction incorporates a weakly coordinating pyridine ring into a TADDOL-derived phosphoramidite (TADDOL=α,α,α,α-tetraaryl-1,3-dioxolane-4,5-dimethanol). The reaction leads to the formation of cyclopentenones as single diastereoisomers that incorporate two contiguous asymmetric centers, one tertiary and one an all-carbon-atom quaternary stereocenter, in high yield and optical purity.

Can crayfish take the heat? Procambarus clarkii show nociceptive behaviour to high temperature stimuli, but not low temperature or chemical stimuli.

Nociceptors are sensory neurons that are tuned to tissue damage. In many species, nociceptors are often stimulated by noxious extreme temperatures and by chemical agonists that do not damage tissue (e.g.

CE: The potential effects of sleep loss on a nurse's health.

While much has been written about the effects of extended work hours on quality of nursing care, nurse burnout, and job attrition, the potential adverse effects of acute and chronic sleep loss on the overall health and well-being of nurses has received little attention. The author describes the acute and chronic effects of sleep loss on nurses, strategies nurses can use to increase the quantity and quality of their sleep, and institutional policies that can promote adequate rest and recuperation between work shifts for nursing staff.