Unenhanced helical CT of ureterolithiasis: value of the tissue rim sign

OBJECTIVE: The tissue rim sign-a rim or halo of soft-tissue attenuation seen around the circumference of an intraureteral calculus on unenhanced axial CT-has been described as useful in differentiating ureteral calculi from extraurinary abdominal or pelvic calcifications. The purpose of this study was to determine the prevalence of the tissue rim sign in patients with ureterolithiasis and extraurinary calcifications and to determine the relationship between the tissue rim sign, the size of a calculus, and the degree of urinary obstruction. MATERIALS AND METHODS: Unenhanced helical CT studies followed by excretory urography were obtained in 59 patients with suspected acute ureterolithiasis. Each calcification along the expected course of the ureter seen on axial CT scans was categorized as a ureteral calculus or as an extraurinary calcification. Each categorization was based on CT, urographic, and clinical findings and the presence or absence of a tissue rim sign. When the outer wall of the ureter could not be seen because there was no clear fat plane at the level of the calcification on CT, the sign was categorized as "indeterminate." The size of the calculus was measured on CT, and the degree of urinary obstruction was estimated on the basis of the urograms. RESULTS: Thirty-two patients each had a single ureteral calculus. Of these patients, CT revealed a positive tissue rim sign in 16 patients (50%), was negative in five patients (16%), and was indeterminate in 11 patients (34%). In addition, we saw 57 extraurinary calcifications in 18 patients (11 patients with ureteral calculi and seven patients without ureteral calculi). None of the 57 extraurinary calcifications was associated with a positive tissue rim sign. The tissue rim sign was negative in 39 (68%) of the 57 extraurinary calcifications and indeterminate in the remaining 18 (32%). Ureteral calculi with a negative tissue rim sign were larger than ureteral calculi with a positive tissue rim sign (p < .01). A high degree of obstruction was present in four of five patients with ureteral calculi for which CT showed a negative tissue rim sign. Conversely, six of 16 patients in whom CT revealed a positive tissue rim sign also had a high degree of obstruction. Therefore, no clear relationship was found between the degree of obstruction and the presence of a positive tissue rim sign. CONCLUSION: A positive tissue rim sign is specific for the diagnosis of ureterolithiasis. However, a negative tissue rim sign does not preclude such a diagnosis. The presence or absence of this tissue rim sign correlates with the size of a calculus but not with the degree of urinary obstruction. When CT reveals an indeterminate tissue rim sign, careful inspection for other CT findings, such as ipsilateral ureteral dilatation, perinephric edema, dilatation of the intrarenal collecting system, and renal swelling, is necessary.     

High-yield expression, purification, and characterization of active, soluble Bacteroides fragilis metallo-beta-lactamase, CcrA

Two new areas of anchor development are biodegradable anchors and "mini" anchors. The group of biodegradable anchors tested include the Bio-Anchor, LactoSorb, Biofix, Bio-Statak, Mini Screw suture anchor, DePuy 4.5 molded, DePuy 4.5 machined, DePuy 3.5 machined, TAG Wedge 4, TAG Rod 2, TAG Wedge 3, TAG Wedge 2, and Stealth. "Mini anchors" have drill holes or minor diameters of < 2.2 mm. Those tested include the Mini Revo and Bio-Anchor, miniHarpoon, mini Mitek and Fast in 3, Statak 1.5 and 2.5, SB 2 and PeBA 3, Corkscrew 5, Corkscrew 3.5, and Fastak A2, Ogden 2.5, TAG Wedge 2, ROC 1.9, and Questus 2.5. Additional anchors tested that fit neither category include the Anspach, Questus 3.5 and 5.0, SB 3 and PeBA-C, Ogden 3.5, Fast in 4, Ultrafix, and the ROC 3.5, ROC 2.8, ROC 2.3, and ROC XS. An anchor comparison, using an established protocol in fresh porcine femurs, recorded failure strength, failure mode, eyelet size, minor and major diameters, and drill hole sizes. Except for the Bio-Anchor and TAG Wedge 2, biodegradable anchors tend to be larger to compensate for their lower strength relative to metal. Biodegradable screw anchors' predominant failure mode was eyelet cutout, whereas biodegradable nonscrew anchors failed to predominantly by anchor pullout. From an initial mechanical perspective, these biodegradable anchors perform acceptably. Both biodegradable and "mini" anchors include screw and nonscrew designs. As expected, screw designs perform well and generally fail at higher loads than nonscrew anchors. Although biodegradable anchors, as a group, are not as strong as metal anchors, they are stronger than the sutures for which they are designed. The move to smaller ("mini") and biodegradable anchors is supported by these data. Whether an anchor fails at twice the suture breaking strength or 10 times the suture breaking strength should make no difference.     

Patients'' and relatives'' opinion and knowledge about electroconvulsive therapy: implications for nursing

This study examines sources of motivation to seek treatment. Participants were 105 male alcoholics and their non-alcoholic female partners who participated in a study of three different approaches to the conjoint treatment of alcoholism. Participants' sources of motivation were coded from responses to questions at the initial clinical screening interview. Sources of motivation were classified as "internal" or "external." More participants had internal sources of motivation (74%) than external sources. Participants with internal sources of motivation scored higher on the Michigan Alcoholism Screening Test than participants with external sources of motivation, but did not differ on other measures of pretreatment severity of alcohol problems. About half of the participants (53%) cited their partner as a primary source of motivation to seek treatment. Other sources of motivation cited were: increasing problems with alcohol, mental health problems, and physical health problems. There was greater variability among internal sources of motivation than among external sources of motivation. Participants' partners but not the male participants themselves, experienced an increase in marital satisfaction from pre- to within-treatment when the participant was motivated to come to treatment by his partner.     

The synergy of low lung function and low body mass index predicting all-cause mortality among older Japanese-American men

OBJECTIVE: To assess the joint characteristics of low standardized weight and compromised pulmonary function in predicting all-cause mortality. DESIGN: A population-based, prospective cohort study. SETTING: Oahu Island, Hawaii. PARTICIPANTS: Surviving Japanese-American men of the Honolulu Heart Program cohort, 71 to 93 years of age (N = 3059). MEASUREMENTS: Body mass index (BMI-weight in kilograms/square of height in meters) and 1-second forced expiratory volume (FEV1) as a percentage of age- and height-predicted FEV1 from the 1991 to 1993 examination of the cohort. Mortality data derived from the ongoing tracking of deaths of the cohort. Relations of selected risk factors among joint levels of BMI (< or = 21, > 21 to < 25, > or = 25 kg/m2) and percent predicted FEV1 (< or = 70%, > 70%) were determined. The impact of these covariates on relations between joint BMI/percent predicted FEV1 levels and subsequent all-cause mortality was assessed. RESULTS: The highest age-adjusted mortality rate (91.9 deaths per 1000 person-years) was noted among men characterized by the joint conditions of percent predicted FEV1 < or = 70% and BMI < or = 21 kg/m2. This rate was 4.0 times the mortality rate of a "healthy" reference group characterized by percent predicted FEV1 > 70% and 21 < BMI < 25 kg/m2. This rate ratio is attenuated to 3.2 upon statistical control for measures of current and past smoking behavior. Among the three strata of BMI, statistical interaction is reflected in a heterogeneity of mortality rate differences (49.7, 21.8, -9.6 deaths/person-year, respectively) and rate ratios (2.18, 1.98, .66, respectively) comparing men with percent predicted FEV1 < or = 70% to > 70%. CONCLUSION: Joint loss of pulmonary function and relative weight is predictive of subsequent all-cause mortality in excess of additive or multiplicative effects of each condition separately. Smoking behavior may contribute to this observation.     

An Examination of Determinants of Software Testing and Project Management Effort

Software estimation research has primarily focused on software effort involved in direct software development. As more and more organizations buy instead of building software, more effort is spent on software testing and project management. In this empirical study, the effect of program duration, computer platform, and software development tool (SDT) on program testing effort and project management effort is studied. The study results point to program duration and software tool as significant determinants of testing and management effort. Computer platform, however, does not have an effect on testing and management effort. Furthermore, the mean testing effort for third generation (3G) development environment was significantly higher than the mean testing effort for fourth generation (4G) environments that used IDE. In addition, the management effort for 4G environment projects without the use of IDE was lower than nonprogramming report generation projects.     

Ionic conductivity and diffusion coefficient of barium-chloride-based polymer electrolyte with poly(vinyl alcohol)–poly(4-styrenesulphonic acid) polymer complex

A composite polymer electrolyte comprising poly(vinyl alcohol)–poly(4-styrenesulphonic acid) with barium chloride dihydrate (\(\hbox {BaCl}_{2}{\cdot } 2\hbox {H}_{2}\hbox {O}\)) salt complex has been synthesized following the usual solution casting. The ionic conductivity of polymer electrolyte was analysed by impedance spectroscopy. The highest room temperature (at 30\({^{\circ }}\)C) conductivity evaluated was 9.38 \(\times \) 10\(^{-6}\) S cm\(^{-1}\) for 20 wt% loading of \(\hbox {BaCl}_{2}\) in the polymer electrolyte. This has been referred to as the optimum conducting composition. The temperature-dependent ionic conductivity of the polymer electrolyte exhibits the Arrhenius relationship, which represents the hopping of ions in polymer composites. Cation and anion diffusion coefficients are evaluated using the Trukhan model. The transference number and enhanced conductivity imply that the charge transportation is due to ions. Therefore this polymer electrolyte can be further studied for the development of electrochemical device applications.     

Biological evaluation of ultrananocrystalline and nanocrystalline diamond coatings

Nanostructured biomaterials have been investigated for achieving desirable tissue-material interactions in medical implants. Ultrananocrystalline diamond (UNCD) and nanocrystalline diamond (NCD) coatings are the two most studied classes of synthetic diamond coatings; these materials are grown using chemical vapor deposition and are classified based on their nanostructure, grain size, and sp³ content. UNCD and NCD are mechanically robust, chemically inert, biocompatible, and wear resistant, making them ideal implant coatings. UNCD and NCD have been recently investigated for ophthalmic, cardiovascular, dental, and orthopaedic device applications. The aim of this study was (a) to evaluate the in vitro biocompatibility of UNCD and NCD coatings and (b) to determine if variations in surface topography and sp³ content affect cellular response. Diamond coatings with various nanoscale topographies (grain sizes 5–400?nm) were deposited on silicon substrates using microwave plasma chemical vapor deposition. Scanning electron microscopy and atomic force microscopy revealed uniform coatings with different scales of surface topography; Raman spectroscopy confirmed the presence of carbon bonding typical of diamond coatings. Cell viability, proliferation, and morphology responses of human bone marrow-derived mesenchymal stem cells (hBMSCs) to UNCD and NCD surfaces were evaluated. The hBMSCs on UNCD and NCD coatings exhibited similar cell viability, proliferation, and morphology as those on the control material, tissue culture polystyrene. No significant differences in cellular response were observed on UNCD and NCD coatings with different nanoscale topographies. Our data shows that both UNCD and NCD coatings demonstrate in vitro biocompatibility irrespective of surface topography.     

Under canopy light detection and ranging‐based autonomous navigation

This paper describes a light detection and ranging (LiDAR)‐based autonomous navigation system for an ultralightweight ground robot in agricultural fields. The system is designed for reliable navigation under cluttered canopies using only a 2D Hokuyo UTM‐30LX LiDAR sensor as the single source for perception. Its purpose is to ensure that the robot can navigate through rows of crops without damaging the plants in narrow row‐based and high‐leaf‐cover semistructured crop plantations, such as corn (Zea mays) and sorghum ( Sorghum bicolor). The key contribution of our work is a LiDAR‐based navigation algorithm capable of rejecting outlying measurements in the point cloud due to plants in adjacent rows, low‐hanging leaf cover or weeds. The algorithm addresses this challenge using a set of heuristics that are designed to filter out outlying measurements in a computationally efficient manner, and linear least squares are applied to estimate within‐row distance using the filtered data. Moreover, a crucial step is the estimate validation, which is achieved through a heuristic that grades and validates the fitted row‐lines based on current and previous information. The proposed LiDAR‐based perception subsystem has been extensively tested in production/breeding corn and sorghum fields. In such variety of highly cluttered real field environments, the robot logged more than 6 km of autonomous run in straight rows. These results demonstrate highly promising advances to LiDAR‐based navigation in realistic field environments for small under‐canopy robots.     

Influence of flame-generated ions on the simultaneous charging and coagulation of nanoparticles during combustion

Flames generate a large amount of chemically and thermally ionized species, which are involved in the growth dynamics of particles formed in flames. However, existing models predicting particle formation and growth do not consider particle charging, which may lead to bias in the calculated size distribution of particles. In this study, Fuchs' charging theory was coupled with a monodisperse particle growth model to study the simultaneous charging and coagulation of nanoparticles during combustion. In order to quantify the charging characteristics of nanoparticles, a high-resolution DMA was used to measure the mobilities of ions generated from a premixed flat flame operated at various conditions. The effect of temperature on ion–particle and particle–particle combination coefficients was further examined. The proposed model showed that the influence of charging on particle growth dynamics was more prominent when the ion concentration was comparable to or higher than the particle concentrations, a condition that may be encountered in flame synthesis and solid fuel-burning. Simulated results also showed that unipolar ion environments strongly suppressed the coagulation of particles. In the end, a simplified analysis of the relative importance of particle charging and coagulation was proposed by comparing the characteristic time scales of these two mechanisms.

© 2017 American Association for Aerosol Research