In Vitro Activity of Tebipenem against Various Resistant Subsets of Escherichia coli Causing Urinary Tract Infections in the United States (2018 to 2020).

This study investigated the activity of an oral carbapenem, tebipenem, against various molecularly characterized subsets of Escherichia coli. A total of 15.0% of E. coli isolates (360/2,035 isolates) met the MIC criteria for screening for ß-lactamases. Most of those isolates (74.7% [269/360 isolates]) carried blaCTX-M. The CTX-M distribution varied (50% to 86%) among Census Regions, as did that of plasmid AmpC genes (up to 41% among E. coli isolates from the New England Region). Tebipenem and intravenous carbapenems showed uniform activity against various E. coli subsets.

A magnetic particle time-of-flight (MagPTOF) diagnostic for measurements of shock- and compression-bang time at the NIF (invited).

A magnetic particle time-of-flight (MagPTOF) diagnostic has been designed to measure shock- and compression-bang time using D(3)He-fusion protons and DD-fusion neutrons, respectively, at the National Ignition Facility (NIF). This capability, in combination with shock-burn weighted areal density measurements, will significantly constrain the modeling of the implosion dynamics. This design is an upgrade to the existing particle time-of-flight (pTOF) diagnostic, which records bang times using DD or DT neutrons with an accuracy better than ±70 ps [H. G. Rinderknecht et al., Rev. Sci. Instrum. 83, 10D902 (2012)]. The inclusion of a deflecting magnet will increase D(3)He-proton signal-to-background by a factor of 1000, allowing for the first time simultaneous measurements of shock- and compression-bang times in D(3)He-filled surrogate implosions at the NIF.

A novel particle time of flight diagnostic for measurements of shock- and compression-bang times in D3He and DT implosions at the NIF.

The particle-time-of-flight (pTOF) diagnostic, fielded alongside a wedge range-filter (WRF) proton spectrometer, will provide an absolute timing for the shock-burn weighted ρR measurements that will validate the modeling of implosion dynamics at the National Ignition Facility (NIF). In the first phase of the project, pTOF has recorded accurate bang times in cryogenic DT, DT exploding pusher, and D(3)He implosions using DD or DT neutrons with an accuracy better than ±70 ps. In the second phase of the project, a deflecting magnet will be incorporated into the pTOF design for simultaneous measurements of shock- and compression-bang times in D(3)He-filled surrogate implosions using D(3)He protons and DD-neutrons, respectively.

X-ray bang-time measurements at the National Ignition Facility using a diamond detector.

A chemical vapor deposition polycrystalline photoconductive diamond detector was fielded at NIF to measure the time of peak x-ray emission, or x-ray bang time, of inertial confinement fusion implosions. Imaging the capsule with a pinhole provides contrast against Hohlraum emission, allowing clear identification of the capsule component in the raw scope trace. X-ray bang time was measured to within ±41-46 ps with the internal photoconductive diamond detector.

South pole bang-time diagnostic on the National Ignition Facility (invited).

The south pole bang-time diagnostic views National Ignition Facility (NIF) implosions through the lower Hohlraum laser entrance hole to measure the time of peak x-ray emission (peak compression) in indirect-drive implosions. Five chemical-vapor-deposition diamond photoconductive detectors with different filtrations and sensitivities record the time-varying x rays emitted by the target. Wavelength selecting highly oriented pyrolytic graphite crystal mirror monochromators increase the x-ray signal-to-background ratio by filtering for 11-keV emission. Diagnostic timing and the in situ temporal instrument response function are determined from laser impulse shots on the NIF. After signal deconvolution and background removal, the bang time is determined to 45-ps accuracy. The x-ray "yield" (mJ∕sr∕keV at 11 keV) is determined from the time integral of the corrected peak signal.

High performance imaging streak camera for the National Ignition Facility.

An x-ray streak camera platform has been characterized and implemented for use at the National Ignition Facility. The camera has been modified to meet the experiment requirements of the National Ignition Campaign and to perform reliably in conditions that produce high electromagnetic interference. A train of temporal ultra-violet timing markers has been added to the diagnostic in order to calibrate the temporal axis of the instrument and the detector efficiency of the streak camera was improved by using a CsI photocathode. The performance of the streak camera has been characterized and is summarized in this paper. The detector efficiency and cathode measurements are also presented.

Measuring symmetry of implosions in cryogenic Hohlraums at the NIF using gated x-ray detectors (invited).

Ignition of imploding inertial confinement capsules requires, among other things, controlling the symmetry with high accuracy and fidelity. We have used gated x-ray imaging, with 10 µm and 70 ps resolution, to detect the x-ray emission from the imploded core of symmetry capsules at the National Ignition Facility. The measurements are used to characterize the time dependent symmetry and the x-ray bang time of the implosion from two orthogonal directions. These measurements were one of the primary diagnostics used to tune the parameters of the laser and Hohlraum to vary the symmetry and x-ray bang time of the implosion of cryogenically cooled ignition scale deuterium/helium filled plastic capsules. Here, we will report on the successful measurements performed with up to 1.2 MJ of laser energy in a fully integrated cryogenics gas-filled ignition-scale Hohlraum and capsule illuminated with 192 smoothed laser beams. We will describe the technique, the accuracy of the technique, and the results of the variation in symmetry with tuning parameters, and explain how that set was used to predictably tune the implosion symmetry as the laser energy, the laser cone wavelength separation, and the Hohlraum size were increased to ignition scales. We will also describe how to apply that technique to cryogenically layered tritium-hydrogen-deuterium capsules.

Standard design for National Ignition Facility x-ray streak and framing cameras.

The x-ray streak camera and x-ray framing camera for the National Ignition Facility were redesigned to improve electromagnetic pulse hardening, protect high voltage circuits from pressure transients, and maximize the use of common parts and operational software. Both instruments use the same PC104 based controller, interface, power supply, charge coupled device camera, protective hermetically sealed housing, and mechanical interfaces. Communication is over fiber optics with identical facility hardware for both instruments. Each has three triggers that can be either fiber optic or coax. High voltage protection consists of a vacuum sensor to enable the high voltage and pulsed microchannel plate phosphor voltage. In the streak camera, the high voltage is removed after the sweep. Both rely on the hardened aluminum box and a custom power supply to reduce electromagnetic pulse/electromagnetic interference (EMP/EMI) getting into the electronics. In addition, the streak camera has an EMP/EMI shield enclosing the front of the streak tube.

Radiation hardening of gated x-ray imagers for the National Ignition Facility (invited).

The National Ignition Facility will soon be producing x-ray flux and neutron yields higher than any produced in laser driven implosion experiments in the past. Even a non-igniting capsule will require x-ray imaging of near burning plasmas at 10(17) neutrons, requiring x-ray recording systems to work in more hostile conditions than we have encountered in past laser facilities. We will present modeling, experimental data and design concepts for x-ray imaging with electronic recording systems for this environment (ARIANE). A novel instrument, active readout in a nuclear environment, is described which uses the time-of-flight difference between the gated x-ray signal and the neutron which induces a background signal to increase the yield at which gated cameras can be used.

Novel Use of a Pyrenomycetous Mycoparasite for Management of Fusarium Wilt of Watermelon.

Fusarium wilt of watermelon, caused by Fusarium oxysporum f. sp. niveum, is a destructive disease that limits watermelon production in many areas of the world. The discovery of several pyrenomycetous ascomycetes occurring naturally in association with different formae speciales of F. oxysporum identified these fungi as potential biological control organisms for watermelon wilt. One such mycoparasitic isolate, identified as Sphaerodes retispora var. retispora, was chosen for biological control and ecological trials in the greenhouse. Four different methods to inoculate the mycoparasite were evaluated, three of which utilized the parasite encapsulated into sodium alginate pellets. The other method employed root-dipping plants with mycoparasite ascospore suspensions. Ecological factors also were investigated, including the ability of S. retispora var. retispora to colonize watermelon roots, and its ability to survive in soil over time and reduce propagules of F. oxysporum f. sp. niveum. In the biological control studies, the use of the mycoparasite significantly reduced plant mortality and increased dry weights of watermelon plants after being challenged with F. oxysporum f. sp. niveum, compared with pathogen-inoculated controls. It appears that the incorporation of the parasite into alginate pellets in the planting mix at seeding may be the most practical method for future field evaluations of transplant-grown vegetable crops. In the ecological studies, the mycoparasite was recovered from infested soil after 9 months, but was only isolated from watermelon roots when applied in the presence of F. oxysporum. S. retispora var. retispora had no effect on F. oxysporum f. sp. niveum propagules after being applied to soils in the greenhouse.

Clinical implications for affected parents and siblings of probands with long-QT syndrome.

BACKGROUND: Whenever a proband is identified with long-QT syndrome (LQTS), his or her parents and siblings should be evaluated regarding the possibility of carrying the disorder. In the majority of cases, one of the proband's parents and one or more siblings are affected. The aim of this study was (1) to determine whether the clinical severity of LQTS in the proband is useful in identifying first-degree family members at high risk for cardiac events, and (2) to evaluate the clinical course of affected parents and siblings of LQTS probands. METHODS AND RESULTS: The clinical and ECG characteristics of 211 LQTS probands and 791 first-degree relatives (422 parents and 369 siblings) were studied to determine if the clinical profile of the proband is useful in determining the clinical severity of LQTS in affected parents and siblings. Affected female parents of an LQTS proband had a greater cumulative risk for a first cardiac event than affected male parents. The probability of a parent or sibling having a first cardiac event was not significantly influenced by the severity of the proband's clinical symptoms. Female sex and QT(c) duration were risk factors for cardiac events among affected parents, and QT(c) was the only risk factor for cardiac events in affected siblings. CONCLUSIONS: The severity profile of LQTS in a proband was not found to be useful in identifying the clinical severity of LQTS in affected first-degree relatives of the proband.

First Report of Powdery Mildew on Greenhouse Tomatoes Caused by Oidium neolycopersici in Florida.

In December 1999, typical signs of powdery mildew-dense white mycelium in irregular patterns often covering almost the entire upper surface of leaves-were observed in production greenhouses on tomato cv. Tradiro. Microscopic observations revealed mycelium with lobed appressoria and large, approximately cylindrical conidia that measured 38 to 45 × 16 to18 µm. Short germ tubes were at one end of the conidium and ended in a lobed appressorium. Conidiophores were straight with cylindrical foot-cells (≈40 to 42 µm), followed by two short cells (14 to18 µm). Based on these characteristics the fungus was identified as 0idium neolycopersici Kiss et al. (2) (formerly O. lycopersicum Braun [1]). Disease-free tomato cv. FL47 plants were inoculated at the fourth true-leaf stage with conidia by transferring fungal colonies collected from plants in production greenhouses with a single-edged razor blade to the adaxial surface of the test plants (six plants and three leaves per plant). Plants were grown in the greenhouse at 20 to 25°C. Powdery mildew, exhibiting the same morphological features, was observed 12 days later on inoculated tomato leaves. Powdery mildew on tomatoes in Suwannee Valley area greenhouses in Florida was quite common and severe in 1999 to 2000. Secondary cycles of the disease were observed, resulting in disease incidence up to 50 to 60% in some greenhouses, requiring repeated applications of sulfur for its management. This disease is expected to become a significant problem in greenhouse tomatoes, requiring regular disease control measures. This powdery mildew has not yet been observed in field-grown tomatoes in Florida. The pathogen has been reported in Connecticut on tomatoes grown under greenhouse and field conditions (3). To our knowledge, this is the first report of O. neolycopersici on greenhouse-grown tomatoes in Florida. References: (1) U. Braun. The Powdery Mildews (Erysiphales) of Europe. Gustav Fisher Verlag, New York, 1995. (2) L. Kiss et al. Mycol. Res. 105:684, 2001. (3) J. A. LaMondia et al. Plant Dis. 83:341, 1999.

Quaternary ammonium block of mutant Na+ channels lacking inactivation: features of a transition-intermediate mechanism.

1. The quaternary ammonium (QA) lidocaine derivative QX-314 (2-(triethylamino)-N-(2,6-dimethylphenyl)-acetamide) induces internal pore blockade of single cardiac Na+ channels enzymatically modified (papain) to eliminate fast inactivation. The mechanism involves dual, interacting blocking modes (rapid and discrete) with binding domains deep in the pore from the cytoplasmic mouth, and where the rapid blocked configuration serves as a transition-intermediate for the development of discrete block. The primary goals of this study were to test for this mechanism in a recombinant Na+ channel genetically engineered to selectively lack fast inactivation, and if present, to explore the underlying structural features. 2. Fast inactivation was removed in rat skeletal muscle mu1 Na+ channels (RSkM1) with an IFM-QQQ mutation in the cytoplasmic III-IV interdomain (QQQ). QQQ was expressed in Xenopus oocytes and single-channel activity was studied in cell-free, inside-out membrane patches. Application of QX-314 (QX, 0-4 mM) to the cytoplasmic membrane surface caused two distinct modalities of single-channel blockade: reduction of unitary current and interruptions of current lasting tens of milliseconds. These are consistent with rapid and discrete pore block, respectively. The voltage and concentration dependence of block indicates that the modes interact and have binding sites that share a deep location in the pore, at approximately 65 % of the membrane electric field in from the cytoplasmic mouth. 3. Mutation of phenylalanine (F1579) in domain IV-S6, critical in local anaesthetic block, to alanine in QQQ (QQQ-F1579A) disabled discrete block but notably failed to alter rapid block, single-channel gating and slope conductance. 4. Amplitude distribution analysis was applied to long bursts (> 50 ms) of QQQ-F1579A activity to investigate the kinetics of rapid block. Computed rapid blocking and unblocking rate constants are 42 000 +/- 18 000 m-1 ms-1 and 82 +/- 22 ms-1, respectively (n = 3, -20 mV). 5. The results support a general transition-intermediate mechanism that governs internal QX and local anaesthetic pore block of voltage-gated Na+ channels and provide insight into underlying structural features.

Mold allergy is a risk factor for persistent cold-like symptoms in children.

In winter, children with mold allergy may develop persistent cold-like symptoms (PCLS) that often defy conventional therapy. To investigate the cause of PCLS, we enrolled 44 children (25 with PCLS and 19 controls) in a 2-year study to compare their clinical symptoms and the mold count in their homes. Children with PCLS had a higher percent of eosinophils in nasal smears as compared with those without PCLS (32% vs 26%). On a scale of 0 to 3, the PCLS group had higher symptom scores (P < 0.001 for all symptoms): bloodshot eyes (2.92 vs 0.79), mouth breathing (2.04 vs 0.68), rhinorrhea (2.48 vs 0.89), nasal voice (2.68 vs 1.00), postnasal drip (2.64 vs 0.47), and headache (2.72 vs 0.53) than the non-PCLS group. The clinical scores also correlated significantly with the mold count in the home (the r value ranged from 0.6716 to 0.7450). We conclude that management of children with PCLS should include decreasing humidity and enforcing environmental control to eradicate mold from inside the homes.

Patient satisfaction and the LoFric catheter for clean intermittent catheterization.

A pilot study was initiated to determine patient satisfaction with the use of a newly available pre-lubricated, hydrophilic, disposable LoFric* catheter for clean intermittent catheterization. The study population consisted of 16 new patients and 25 experienced with clean intermittent catheterization. Patients were asked questions regarding convenience, ease of handling, comfort and general opinion of the catheters. Four new and 8 experienced patients dropped out of the study. Of the new patients who completed the study 75% found clean intermittent catheterization less troublesome than expected and all wish to continue using the catheter. Of the experienced patients 81% had a more favorable general opinion of the disposable than of the previous catheter, 81% found the disposable catheter to be more convenient and 88% thought it was easier to handle. It appears that most people will be satisfied with the disposable catheter and will prefer it as an alternative to a plastic catheter with lubrication applied by the patient.

Fungi Associated with Females and Cysts of Heterodera glycines in a Florida Soybean Field.

Fungal colonization was determined for females and cysts of Heterodera glycines on soybean roots or in rhizosphere soil from a Florida soybean field. A total of 1,620 females and cysts were examined in 1991, and 1,303 were examined in 1992. More than 35 species of fungi were isolated from females and cysts. The frequency of fungi colonizing white and yellow females was low, but a high frequency of fungi was encountered in brown cysts, which increased with time of exposure of the cysts to the soil. No single fungal species predominated in the nematode females or cysts in this field. Rarely was a female or cyst colonized by more than one fungus. The common fungi isolated from the females and cysts were Neocosmospora vasinfecta, Fusarium solani, Fusarium oxysporum, Dictyochaeta coffeae, Dictyochaeta heteroderae, Pyrenochaeta terrestris, Exophiala pisciphila, Gliocladium catenulatum, Stagonospora heteroderae, and a black yeast-like fungus. The communities of common fungal species isolated from cysts in several regions in the southeastern United States appear to be similar.

Formaldehyde exposure in a gross anatomy laboratory.

A gross anatomy laboratory for medical students was evaluated for formaldehyde levels throughout its eight-week term. Results indicated that exposures for students and instructors were below the 3-ppm permissible exposure limit (assuming a maximum of five hours of daily exposure) established by the Occupational Safety and Health Administration. However, about one third of the eight-hour time-weighted-average exposures were greater than 1 ppm under the same assumptions. Exposure levels for students and instructors did not differ. Exposures tended to decrease over the term unless internal cadaver cavities were being dissected. These exposures are significant in light of the recent implication of formaldehyde as an animal carcinogen and the trend to reduce permissible levels to 1 ppm or lower.