Targeted benefits of prolonged-infusion piperacillin-tazobactam in an in vitro infection model of Pseudomonas aeruginosa.

Given the inconsistent clinical findings, our goal was to characterize the pharmacodynamics (PDs) of prolonged-infusion piperacillin-tazobactam (TZP) in an in vitro pharmacodynamic model of Pseudomonas aeruginosa. Specifically, the study was designed to investigate the influence of MIC on the activity of prolonged-infusion TZP using pharmacokinetics (PKs) consistent with a non-critically ill patient population. There was no benefit with prolonged- compared with standard-infusion TZP against isolates with susceptible MICs of 8 or 16 mg/L. However, prolonged-infusion TZP produced more than two times the final bacterial kill against less susceptible isolates with an intermediate MIC of 32 mg/L. The PDs of TZP were well described by a sigmoid Emax model (r(2) = 0.84) where %ƒT>MIC thresholds of 27 and 75% were associated with bacteriostatic and bactericidal effects, respectively. However, the well-established PD relationship with %ƒT>MIC was not observed with prolonged-infusion TZP. In conclusion, this study characterizes the targeted benefits of prolong-infusion TZP based on pathogen MIC, and supports the assertion that the benefits are selective and most likely observed in patients with less susceptible pathogens or altered PKs.

Derivation of growth mechanism of nano-defects in GaN from TEM data

Transmission electron microscopy (TEM) has been used to describe 'hollow' defects, e.g. nanotubes and pinholes (empty inside) formed in GaN hetero- and homoepitaxial layers. These defects are believed to be formed due to the presence of impurities and dopants. These defects appear to be even more deleterious than dislocations for the application of GaN in devices because their formation interrupts two-dimensional growth of quantum wells, and therefore will influence electrical and optical properties of the material. Experimental observations show that both these defects start from V-shaped indentations delineated by (1011) planes, and their density increases with higher concentrations of impurities or dopants. These 'hollow' defects are often found to be attached to dislocations, but the frequently observed termination of these defects inside the crystal eliminates dislocations as the source of these defects. Theoretical predictions also do not suggest that dislocations would have large-diameter empty cores like these of nanotubes and pinholes.

Reliability of the Advanced Psychodiagnostic Interpretation (API) scoring system for the Bender Gestalt.

This study assesses the interrater reliability of the revised Advanced Psychodiagnostic Interpretation (API) scoring system for the Bender Gestalt Test (BGT). The API scoring system identifies 207 possible distortions in a BGT protocol. Agreement across nine raters exceeded 90% for each of three clinical protocols. Kappa statistics indicated that the API system exhibited good interrater reliability. Further research is necessary in such areas as test-retest reliability and validity to further demonstrate the effectiveness of the procedure.

Test-retest reliability of the Advanced Psychodiagnostic Interpretation (API) scoring system for the Bender Gestalt in chronic schizophrenics.

This study assesses the test-retest reliability of the revised Advanced Psychodiagnostic Interpretation (API) scoring system for the Bender Gestalt Test (BGT). The API system identifies 207 possible distortions in a BGT protocol. Test-retest reliability for 40 schizophrenic patients tested twice with a mean interval of 6.4 years (SD=3.8 years) was good, ranging from .71 to .80. Further reliability and validity studies are needed to further demonstrate the effectiveness of the system.

Formation of fumonisins and other secondary metabolites by Fusarium oxysporum and F. proliferatum: a comparative study.

The principal aim of this study was to estimate the formation of fumonisins (FB(1) and FB(2)), moniliformin (MON), and ergosterol (ERG) by Fusarium oxysporum and Fusarium proliferatum, while the formation of beauvericin (BEA) was estimated by the latter Fusarium species only. Moreover, the effect of temperature on the biosynthesis of mycotoxins was also evaluated. Fumonisins were formed by F. proliferatum, with the highest yield at 18 degrees C (720.0-1976.6 microg g(-1) for FB(1), 74.2-670.8 microg g(-1) for FB(2)) and only by three of four F. oxysporum strains at a very low level (0.02-4.77 microg g(-1) for FB(1), 0.02-2.15 microg g(-1) for FB(2)). The amount of MON formed by F. proliferatum was the highest (p < 0.001) at 32 degrees C (3056.87 microg g(-1)), while MON biosynthesis by F. oxysporum was lower 227.54 microg g(-1) (p < 0.001). BEA was produced by F. proliferatum with the highest level at 25 degrees C (p < 0.001). ERG-recognized as an indicator of fungal biomass development and as a consequence of mycotoxin formation-was found at the highest concentration at a biosynthesis temperature of 25 degrees C for F. proliferatum and F. oxysporum (p < 0.001).

Lingual orthodontics and orthognathic surgery.

Lingual orthodontics is an appealing option for patients requiring orthognathic surgical correction, since these patients are invariably adults or mature teenagers who are no longer at the usual "orthodontic age." Appearance is undoubtedly the most important motivating factor for adults seeking orthodontic treatment, and since the more physically attractive person has the advantage over the not-so-attractive person, it is self-evident that these patients would prefer an appliance that is less visible. Using the Ormco, Creekmore, or Begg lingual appliances in the maxillary arch and a labial appliance in the mandibular arch, the authors have successfully treated a variety of dentofacial deformities with a combined lingual orthodontic and surgical approach. The aim of this article is to establish some guidelines for the treatment of a variety of surgical cases and to highlight what are perceived to be the advantages and disadvantages of these 3 lingual appliances in the treatment of orthognathic cases and of the lingual orthognathic approach in general.

Resistance to nasal airflow related to changes in head posture.

The relationship] between mode of respiration, cranial posture, and craniofacial morphology has been the subject of many articles in recent years. Some authors postulate that mouth breathers extend their heads backward in an effort to increase airway patency. The purpose of the present study was to determine whether artificially induced extended head posture decreases the resistance to nasal airflow. The experimental sample comprised fifteen male students with normal vertical facial proportions and no histories of chronic mouth breathing. In the sample, head posture was assessed by measuring the craniovertical angle by means of an angle finder. Nasal resistance units were calculated from the parameters of nasal airflow and differential pressure across the nasal airway during the complete respiratory cycle using an equation analogous to Ohm's law. Readings were obtained in both the normal and 10-degree extended head posture position, and the results were compared. No association could be found between an extended head posture position and a decreased resistance to nasal airflow.

Screw dislocations in GaN grown by different methods.

A study of screw dislocations in hydride-vapor-phase-epitaxy (HVPE) template and molecular-beam-epitaxy (MBE) overlayers was performed using transmission electron microscopy (TEM) in plan view and in cross section. It was observed that screw dislocations in the HVPE layers were decorated by small voids arranged along the screw axis. However, no voids were observed along screw dislocations in MBE overlayers. This was true both for MBE samples grown under Ga-lean and Ga-rich conditions. Dislocation core structures have been studied in these samples in the plan-view configuration. These experiments were supported by image simulation using the most recent models. A direct reconstruction of the phase and amplitude of the scattered electron wave from a focal series of high-resolution images was applied. It was shown that the core structures of screw dislocations in the studied materials were filled. The filed dislocation cores in an MBE samples were stoichiometric. However, in HVPE materials, single atomic columns show substantial differences in intensities and might indicate the possibility of higher Ga concentration in the core than in the matrix. A much lower intensity of the atomic column at the tip of the void was observed. This might suggest presence of lighter elements, such as oxygen, responsible for their formation.

Atomic structure of defects in GaN:Mg grown with Ga polarity.

The atomic structure of characteristic defects (Mg-rich hexagonal pyramids and truncated pyramids) in GaN:Mg thin films grown with Ga polarity was determined at atomic resolution by reconstruction of the scattered electron wave in a transmission electron microscope. Small cavities within the defects have inside walls covered by GaN of reverse polarity. We propose that lateral overgrowth of the cavities restores matrix polarity on the defect base. From matrix to defect, exchange of Ga and N sublattices leads to a 0.6+/-0.2 A displacement of Ga sublattices. We observe a [1100]/3 shift from matrix AB stacking to BC stacking for the entire pyramid. Electron energy loss spectroscopy detected changes in N edge and presence of oxygen on the defect walls. Our results explain commonly observed decrease of acceptor concentration in heavily doped GaN:Mg.