Independently addressable VCSEL arrays on 3-μm pitch

We present an exceedingly dense linear vertical-cavity surface-emitting laser (VCSEL) array with independently addressable elements on a staggered 3-μm pitch. Our devices utilize an all-epitaxial structure and operate at a wavelength of 813 mm with threshold currents below 400 μA. The high-packing density is enabled by combining transparent contact technology with a planar laterally oxidized device architecture. The array exhibits low interelement thermal crosstalk and has electrical resistances of 3 MΩ between adjacent array elements     

The impact of true partnership between a university Level I trauma center and a community Level II trauma center on patient transfer practices

OBJECTIVE: To examine the effect of a clinical and administrative partnership with an academic urban Level I trauma center on the patient transfer practices at a suburban/rural Level II center. METHODS: Data for 2 years before affiliation (PRE) abstracted from inpatient charts and the trauma registry were compared with that for 2 years after (POST). The following data were collected: number of, reason for, and destination and demographics of transfers. Chi(2) test and t test analyses were used; p < 0.05 defined significance; data are mean +/- SEM. RESULTS: Transfer rate increased from 4% PRE to 6.9% (p = 0.001) POST with no significant difference in age, Glasgow Coma Scale score, Injury Severity Score, or Revised Trauma Score. Repatriation occurred in 12.8% POST (none PRE). The current Level I facility accepted 1.8% of all transfers PRE and 36.4% POST (p = 0.0001). PRE/POST rates by reason are as follows: pediatric, 14.6%/9.0% (p = 0.04); intensive care unit, 0.4%/1.7% (p = 0.13); complex orthopedic, 100%/0% (p = 0.005); vascular, 50%/0% (p = 0.008); spinal cord injury, 100%/100%; and ophthalmologic, 0%/100% (p = 0.005). CONCLUSIONS: In this experience of Level I/II partnership (1) transfer patterns were altered, (2) select patient cohort transfers decreased (pediatric, complex orthopedic, vascular), whereas others increased (aortic work-up), and (3) repatriation rates were low.     

The synthesis and thymidylate synthase inhibitory activity of L-gamma-L-linked dipeptide and L-gamma-amide analogues of 2-desamino-2-methyl-N10-propargyl-5,8-dideazafolic acid (ICI 198583)

Sixteen gamma-linked dipeptide and four L-Glu-gamma-amide analogues of 2-desamino-2-methyl-N10-propargyl-5,8-dideazafolic acid (ICI 198583) have been synthesized and evaluated as inhibitors of thymidylate synthase (TS). Z-blocked L-Glu-gamma-L-linked dipeptides and L-Glu-gamma-amides were prepared by condensing alpha-tert-butyl-N-(benzyloxycarbonyl)-L-glutamic acid with the appropriate tert-butyl-protected L-amino acid or amine. The Z group was removed by catalytic hydrogenolysis, and the resulting dipeptides or L-Glu-gamma-amides were condensed with the appropriate pteroic acid analogue trifluoroacetate salt using diethyl cyanophosphoridate as coupling reagent. Deprotection with trifluoroacetic acid in the final step gave the desired quinazoline gamma-linked dipeptides and L-Glu-gamma-amides as their trifluoroacetate salts. Nearly all the dipeptide analogues were potent inhibitors of TS, the best being ICI 198583-gamma-L-2-aminoadipate (IC50 = 2 nM). Several of these dipeptides were found to be susceptible to enzymatic hydrolysis in mice. The quinazoline monocarboxylate L-Glu-gamma-amides, lacking an alpha'-carboxyl group, are less active against TS and L1210 cell growth but are also not susceptible to enzymatic hydrolysis in mice.     

Rustmicin, a potent antifungal agent, inhibits sphingolipid synthesis at inositol phosphoceramide synthase

Rustmicin is a 14-membered macrolide previously identified as an inhibitor of plant pathogenic fungi by a mechanism that was not defined. We discovered that rustmicin inhibits inositol phosphoceramide synthase, resulting in the accumulation of ceramide and the loss of all of the complex sphingolipids. Rustmicin has potent fungicidal activity against clinically important human pathogens that is correlated with its sphingolipid inhibition. It is especially potent against Cryptococcus neoformans, where it inhibits growth and sphingolipid synthesis at concentrations <1 ng/ml and inhibits the enzyme with an IC50 of 70 pM. This inhibition of the membrane-bound enzyme is reversible; moreover, rustmicin is nearly equipotent against the solubilized enzyme. Rustmicin was efficacious in a mouse model for cryptococcosis, but it was less active than predicted from its in vitro potency against this pathogen. Stability and drug efflux were identified as two factors limiting rustmicin's activity. In the presence of serum, rustmicin rapidly epimerizes at the C-2 position and is converted to a gamma-lactone, a product that is devoid of activity. Rustmicin was also found to be a remarkably good substrate for the Saccharomyces cerevisiae multidrug efflux pump encoded by PDR5.     

Cytotoxicity of tocopherols and their quinones in drug-sensitive and multidrug-resistant leukemia cells

Eighty-two patients with traumatic anterior shoulder instability were treated with an arthroscopic transglenoid multiple suture technique (Caspari's method) and followed-up for more than 2 years. A retrospective analysis of the clinical outcome was performed to determine the factors related to poor results. The mean age at operation was 21 years (range, 13 to 50 years) and the mean follow-up period was 40 months (range, 24 to 70 months). According to the status of the ligament-labrum complex and the glenoid bone defect, the Bankart lesions were classified into five types arthroscopically. There were 21 shoulders of type 1, 33 shoulders of type 2, 22 shoulders of type 3, and 6 shoulders of type 5. Twenty-four of the patients played contact sports before the operation. The clinical outcome was assessed by Rowe's criteria (1978). To analyze the factors related to a poor outcome, a multivariate analysis was done to assess the influence of 12 clinical factors (age at operation, age at first dislocation, sex, dominant side, disease duration, number of dislocations, sporting activity before operation, inferior joint laxity, thickness of the ligament-labrum complex, type of Bankart lesion, number of sutures, and method of suture fixation). Fifty-five of 82 patients had an excellent outcome, 14 had a good result, and 13 had a poor result. According to postoperative instability, redislocation was seen in 13 patients (16%), resubluxation in 2 patients (2%), with a recurrence rate of 18%. The mean limitation of external rotation at 90 degrees abduction was 6.0 degrees (range, 0 degrees to 30 degrees), and there was a 10 degrees loss of external rotation in 10 patients. The factors significantly related to recurrence were a type 3 Bankart lesion, playing contact sports preoperatively, a thin ligament-labrum complex, and repair with less than four sutures. In conclusion, a 18% rate of recurrence is not acceptable. To obtain a better clinical outcome, very careful selection of patients for this technique is necessary. Our analysis of the factors related to a poor outcome may help to decide what the proper indications are for this technique.     

Rhinal cortex ablations fail to disrupt reinforcer devaluation effects in rhesus monkeys (Macaca mulatta).

Studies have shown that excitotoxic lesions of the amygdala attenuate reinforcer devaluation effects in monkeys and rats. Because the rhinal (i.e., entorhinal and perirhinal) cortex has prominent reciprocal connections with the amygdala and has been suggested to store knowledge about objects, it is possible that it too composes part of the critical circuitry subserving learning about objects and their associated reinforcement value. To test this possibility, rhesus monkeys with rhinal cortex removals as well as unoperated controls were tested using a reinforcer devaluation procedure. Monkeys with rhinal cortex removals and controls, unlike those with amygdala lesions, tended to avoid displacing objects overlying a devalued food. These results indicate that the rhinal cortex is not a critical part of the neural circuitry mediating the effects of reinforcer devaluation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relative stability of a minimal CTG repeat expansion in a large kindred with myotonic dystrophy

The genetic basis for myotonic dystrophy (DM) is a CTG trinucleotide repeat expansion. The number of CTG repeats commonly increases in affected individuals of successive generations, in association with anticipation. We identified a large DM family in which multiple members had minimal CTG repeat expansions, and in which the number of CTG repeats remained in the minimally expanded range through at least three, and possibly four, generations. This relative stability of minimal CTG repeat expansions may help to maintain the DM mutation in the population.     

Langmuir-blodgett films of stilbazole complexes of iridium(I) and rhodium(I)

Complexes of 4-alkoxystilbazoles with iridium and rhodium form stable Langmuir layers at the air-water interface even when the alkoxy chain is relatively short (C₅–C₁₂). The surface pressure-area isotherms indicate that condensed molecular monolayers are obtained. The area per molecule of each compound in its monolayer form is typically 0.60 nm², which agrees well with the cross-sectional area of the [Ir(CO)₂CI] or [Rh(CO)₂CI] head group predicated using molecular models. This suggests that the molecules are oriented with the metal moiety close to the water surface and their alkoxystilbazole ‘rod’ protruding from the plane of the water surface. Such floating monolayers have been transferred on to solid substrates such as glass, aluminium (AI₂O₃/AI/Glass) and silicon (SiO₂/Si) at relatively high speed (10 mm min ^?1) to form Y-type LB assemblies. The UV–Visible absorption properties of these materials in solution and LB film form have been studied. LB films of these complexes yield bathochromically shifted spectra relative to the LB film spectrum of the uncomplexed stilbazole. Additionally, these spectra are often broader and hypsochromically shifted relative to their corresponding solution spectra as a result of the close molecular packing within the LB film and the associated dipole–dipole interactions. The electrically polar nature of the molecules described in this paper suggest that they may be suitable candidates for new pyroelectric materials. Thus the pyroelectric coefficient (the rate of change of electric polarisation with respect to temperature) has been measured for a polar multilayer LB film containing an iridium complex. A pyroelectric coefficient of 3.5 μCm^?2K^?1 (at 30 °C) has been measured, which is one of the highest reported valued for an LB film. Additionally, a low dielectric loss of around 0.01 has been found over the frequency range 50 Hz–1 kHz, indicating that such LB films may be usfeul materials for pyroelectric sensors.     

Althesin infusion for cardiac catheterisation

A trial of a continuous intravenous infusion of Althesin is described for sedation during cardiac catheterisation, both for children and adults. The conditions produced for the procedure were very satisfactory. The advantages and problems of its use are discussed. The technique justifies further trials.