cssi/SciSciGPT-SciSciNet huggingface dataset:
How to avoid problems in redo coronary artery bypass.

Background Redo cardiac surgery still carries higher mortality and increased morbidity as compared with primary coronary revascularizations. Various steps can be taken to decrease the incidences of adverse outcomes. From our experience, we have accumulated safe steps to be taken during the surgical procedure to reach a positive outcome. Methods We reviewed our own experience of redo coronary artery bypass surgery (CABG) at two institutions during the last 4 years. Though the surgeons were the same at both institutions, because of institutional variability of patient referrals, operative equipment, anesthesia management, and preoperative care, we kept the data separate. Five surgeons performed CABG with almost similar myocardial preservation techniques; however, the surgical skill varied slightly depending on the seniority and clinical experience. We performed 433 redo coronary artery revascularizations at one institution and 201 in the second institution. Fifteen percent of these patients also had additional procedures, such as valve repair, valve replacement, or aneurysm resection. In this patient group, 160 patients underwent either urgent or emergent CABG. Urgent surgery was defined as patient revascularization during the same admission as cardiac catheterization, and emergency surgery was defined as a patient undergoing surgery on the same day as the catheterization, especially when hemodynamic instability was present. The total mortality was 7%, while the elective redo CABG mortality was 3%. The length of stay ranged from 8.5 to 12.6 days. The morbidity included perioperative stroke in 18 patients and nonfatal perioperative myocardial infarction (MI) in 19 patients. Major factors contributing to the mortality were stroke, perioperative bleeding and exploration, renal failure, respiratory failure, and malnutrition. Conclusion We outlined the precautions and safe surgical approaches to be undertaken during redo CABG for a successful outcome.
Sodium, chloride and water exchange in selected developmental stages of the horseshoe crab, Limulus polyphemus (Linnaeus)

Exchange coefficients for 3H2O, 22Na+, and 36Cl− were determined in eggs, embryonic membrane-enclosed trilobite (globe) stage, and trilobites of the horseshoe crab, Limulus polyphemus (Linnaeus), reared in 10, 15, 25, or 35%. S at 25°C. For eggs, H2O and Cl− exchange coefficients showed slight but statistically insignificant decreases at salinity extremes, while those for Na+ showed no consistent salinity effect. At all salinities tested, approximate halftimes for H2O, Cl−, and Na+ exchange were 7.5, 80, and 50 min, respectively. The globe membranes were so permeable that halftimes for water exchange were <6 min under all conditions. The membranes were also very permeable to Na+ and Cl−, with halftimes of ≈ 10 min. No salinity effect was observed. Exchange coefficients for the trilobites indicate that this stage was less permeable to water than the eggs or globes, but the inorganic ions were exchanged more rapidly than they were in the egg stage. Halftimes for H2O exchange were ≈ 14 min in all salinities. Halftimes of Na+ exchange were ≈ 10 min, with no significant salinity effect. In the trilobite stage, there appeared to be a salinity effect on Cl− exchange. In 10 and 15%., halftimes were about 30 min, while in the two higher salinities, halftimes were 15 min. These data indicate that the eggs conserve ions, perhaps as a means of tolerating steep gradients of salinity change or consistent low salinity levels. The embryonic membranes probably play no role in ionic adaptation. No developmental stage was observed to reduce its apparent H2O permeability at salinity extremes.
The influence of lift frequency, lift duration and work experience on discomfort reporting

Discomfort surveys are commonly used to assess risk in the workplace and prioritize jobs for interventions before an injury or illness occurs. However, discomfort is a subjective measure and the relationship of discomfort to work-related factors is poorly understood. The objective of this study was to understand how reports of discomfort relate to work-related risk factors for the low back. A total of 12 novice and 12 experienced manual materials handlers performed repetitive, asymmetric lifts at different load levels and at six different lift frequencies throughout an 8-h exposure period. Discomfort was recorded hourly throughout the day. Analyses were performed to determine which experimental factors influenced reporting of discomfort and if discomfort trends matched spine loading trends. Novice lifters reported significantly higher discomfort levels than experienced subjects. They also reported increases in discomfort as moment exposure increased and as the exposure time increased. Novices lifting at 8 Nm load moment level reported increased discomfort from 0.07 to 0.63 by the end of the day, at 36 Nm they reported an increase from 0.04 to 0.40 and at 85 Nm they reported an increase from 0.37 to 3.06. Experienced subjects, on the other hand, reported low levels of discomfort regardless of moment exposure, lift frequency or exposure duration. The reported discomforts were generally unrelated to the biomechanical loading on the spine. Discomfort reporting appears to be more a reflection of experience than of work risk factor exposure. Experienced subjects may have more efficient motor patterns, which reduce spinal load and thus discomfort. Novice subjects seemed to have a lower threshold of discomfort. Caution is needed when using discomfort reporting as a means to identify jobs in need of interventions, in that biomechanical loading may not be accurately represented. Discomfort should only be used as a supplement to objective measures, such as spinal loading, to assess the risk of low back disorders.
Engineered herpes simplex virus vectors for antitumor therapy and vaccine delivery

Genetically modified herpes simplex viruses (HSVs) have been exploited for both antitumor therapy and vaccine delivery. These mutant viruses retain their ability to replicate and lyse permissive cells, including many tumor types, and are referred to as oncolytic HSVs. In addition, deletion of nonessential genes permits the introduction of foreign genes to augment the antitumor effect by either immune stimulation, targeting for select tumors, or expression of tumor or vaccine antigens. This article reviews the development of oncolytic HSVs as an anticancer therapy, as well as the application of HSV-1 vectors for delivery of targeted antigens or as vaccine adjuvants. The impact of these novel vectors with respect to enhanced antitumor activity and development of antitumor vaccination strategies is discussed.
Efficacy of bacterial removal from instrumented root canals in vitro related to instrumentation technique and size

Abstract Objective. This in vitro investigation assessed the efficacy of removing radioactively labeled bacteria from infected canals with 2 engine-driven rotary nickel titanium instrumentation techniques differing in sequence and apical enlargement size. Study Design. A standard quantity of 3 H-thymidine-labeled Enterococcus faecalis (3.70 × 10 4 cpm, 2.0 × 10 7 colony-forming units) was used to inoculate the mesiobuccal canals of 50 extracted mandibular molars. The teeth were incubated for 5 days to allow infection of the surrounding dentin from the canals. Five of the teeth were used as controls to determine the number of cycles of irrigation and drying necessary to reduce the 3 H counts recovered from the canals to baseline levels. After this process, the unbound bacteria in the root canals of the remaining 45 teeth then were washed out with buffer until baseline levels of radioactivity were obtained. The mesiobuccal root of 1 of these 45 teeth was removed, decalcified, and digested, and the total radioactivity released from the root dentin was measured. Of the remaining 44 teeth, 22 then were instrumented with GT and Profile (Dentsply/Tulsa Dental Co, Tulsa, Okla) instruments to apical size #35 (group 1) and 22 teeth with Pow-R instruments (Moyco/Union Broach, York, Pa) to apical size #50 (group 2), in the presence of a standard quantity of phosphate-buffered saline solution placed in the canal. After instrumentation, the medium from each canal was collected with paper points and its radioactivity was counted with liquid scintillation spectrometry. Results. The mean 3 H level recovered with instrumentation of canals in group 1 was 75 cpm (± 29, standard deviation) and in group 2 was 123 cpm (± 50, standard deviation). A 2-tailed Mann-Whitney test indicated that the radioactivity of samples from group 2 was significantly higher than that of samples from group 1. Conclusion. The results suggested that instrumentation to an apical size of #50, as performed with the Pow-R instruments, was more effective in debriding infected root canals than instrumentation to an apical size of #35, as performed with the GT and Profile instruments. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;94:366-71)
Nonlinear Detection And Estimation Of Images Degraded By Film-Grain Noise

Taking into account the chemical and optical degrading factors as well as the granularity noise results in a subjectively reasonable mathematical model for the formation and recording of photographic images. This model represents highly nonlinear observations, making the subsequent restoration difficult. When images are scanned with very small apertures on a microdensitometer, the noise is so severe that conventional estimators do not perform well. In these cases detection schemes suited to individual degraded pictures are much more effective. When the noise is not so severe, an adaptive minimum mean square error filter can be applied. This filter explicitly includes the nonlinear image formation effects and does not require the assumption of stationary image statistics.© (1976) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Sizing Single Cantilever Beam Specimens for Characterizing Facesheet/Core Peel Debonding in Sandwich Structure

This technical publication details part of an effort focused on the development of a standardized facesheet/core peel debonding test procedure. The purpose of the test is to characterize facesheet/core peel in sandwich structure, accomplished through the measurement of the critical strain energy release rate associated with the debonding process. Following an examination of previously developed tests and a recent evaluation of a selection of these methods, a single cantilever beam (SCB) specimen was identified as being a promising candidate for establishing such a standardized test procedure. The objective of the work described here was to begin development of a protocol for conducting a SCB test that will render the procedure suitable for standardization. To this end, a sizing methodology was developed to ensure appropriate SCB specimen dimensions are selected for a given sandwich system. Application of this method to actual sandwich systems yielded SCB specimen dimensions that would be practical for use. This study resulted in the development of a practical SCB specimen sizing method, which should be well-suited for incorporation into a standardized testing protocol.
Caspase-Dependent Cdk Activity Is a Requisite Effector of Apoptotic Death Events

The caspase-dependent activation of cyclin-dependent kinases (Cdks) in varied cell types in response to disparate suicidal stimuli has prompted our examination of the role of Cdks in cell death. We have tested the functional role of Cdk activity in cell death genetically, with the expression of dominant negative Cdk mutants (DN-Cdks) and Cdk inhibitory genes. Here we demonstrate that Cdk2 activity is necessary for death-associated chromatin condensation and other manifestations of apoptotic death, including cell shrinkage and the loss of adhesion to substrate. Susceptibility to the induction of the cell death pathway, including the activation of the caspase cascade, is unimpaired in cells in which Cdk2 activity is inhibited. The direct visualization of active caspase activity in these cells confirms that death-associated Cdk2 acts downstream of the caspase cascade. Cdk inhibition also does not prevent the loss of mitochondrial membrane potential and membrane phospholipid asymmetry, which may be direct consequences of caspase activity, and dissociates these events from apoptotic condensation. Our data suggest that caspase activity is necessary, but not sufficient, for the full physiological cell death program and that a requisite function of the proteolytic caspase cascade is the activation of effector Cdks.
Mechanism for the Pseudoelastic Behavior of FCC Shape Memory Nanowires

Pseudoelasticity and shape memory have been recently discovered in single-crystalline FCC nanowires of Cu, Ni, Au and Ag. The deformation mechanism responsible for this novel behavior is surface-stress-driven reorientations of the FCC lattice structure. A mechanism-based continuum model has been developed for the lattice reorientation process during loading through the propagation of a single twin boundary. Here, this model is extended to the nucleation, propagation and annihilation of multiple twin boundaries associated with the reverse reorientation process during unloading. The extended model captures the major characteristics of the loading and unloading behavior and highlights the dominating effect of the evolution of twin boundary structure on the pseudoelasticity.
Effects of Glucocorticoids on Expression of the fos Protooncogene in AtT-20 Cells

Glucocorticoid regulation of expression of the protooncogene fos has been examined in AtT-20 cells at both the RNA and protein levels. When cells were incubated continuously in the presence of dexamethasone, an early (30 min) rise in the expression of fos mRNA was observed, which declined by 1 h, but rose again after 2 h of hormone treatment. Six hours after hormone treatment, fos mRNA levels had returned to control levels in spite of the continued presence of dexamethasone. Serum treatment resulted in a sustained increase in fos mRNA levels; however, the glucocorticoid and serum effects were additive. Dexamethasone and/or serum both increased the steady state levels of fos protein. Glucocorticoid treatment of AtT-20 cells results in complex changes in fos expression, but does not affect their viability or growth rate; these results suggest that fos may play a role in mediation or modulation of glucocorticoid effects other than growth.
Analysis of covariance for the removal of temporal effects in experiments with serial treatments

This research demonstrates the value of analysis of covariance for removing temporal effects from data collected through a retail experiment in which treatments are applied sequentially in a single store with rest periods interposed between treatments. Time series factors which were significant at the 0.05 level in a stepwise, dummy variable, multiple regression analysis became covariates in the analysis of variance models for both the treatment week data and the rest week data of each experimental product. For three of the four experimental products, the regression analysis revealed time series factors which may have affected the experimental treatments. For two of the experimental products, time series factors adversely affected the traditional ANOVA models. However, the application of analysis of covariance successfully removed the effects of these factors from the ANOVA models.
Ustekinumab for the treatment of psoriatic arthritis

Ustekinumab is a fully human monoclonal antibody directed against the p40 subunit shared by interleukin 12 and interleukin 23, two naturally occurring protein regulators that play an important role in immune-mediated inflammatory diseases, including psoriatic arthritis (PsA). In September of 2009, the US FDA approved ustekinumab for the treatment of adult patients with moderate to severe plaque psoriasis. Beginning in November of 2009, Janssen Biotech (formerly Centocor Biotech), the developer of ustekinumab, initiated clinical trials to investigate the efficacy of ustekinumab in the treatment of other inflammatory disorders, including PsA. Phase II and Phase III studies showed both a good safety profile and significant efficacy for ustekinumab in the treatment of PsA, leading to the drug's approval in both Europe and the USA. In an immunotherapy market currently dominated by anti-TNF-α drugs for the treatment of PsA, ustekinumab offers an alternative option for patients with PsA, including those unresponsive to methotrexate and the TNF-α inhibitory agents currently approved for this potentially debilitating disease.
Cell-specific nanoplatform-enabled photodynamic therapy for cardiac cells

Over the last decades, various cardiac ablation technologies and procedures have been developed for patients with drug-resistant cardiac arrhythmias. It is now widely accepted that in selected patient populations, catheter ablation is an advantageous alternative to lifelong pharmacologic treatment.1-3 Ablation consists of delivering physical energy locally to specific myocardial regions to abolish arrhythmogenic tissue. Regardless of the energy employed, be it radiofrequency energy, cryoenergy, laser, or ultrasound, ablation techniques are limited by the non-specific nature of the resultant cellular damage. Myocytes perpetuating the arrhythmia experience similar damage to that of bystander cells, such as fibroblasts, adipocytes or neurons. This can result in complications such as atrioesophageal fistula, pulmonary veins stenosis, or coronary artery injury.4-8 In addition, the lack of cellular discrimination increases the required energy for ablation and can prolong procedure times.
Hazardous air pollutant and ozone precursor emissions from a low-NOx natural gas-fired industrial burner

Due to heightened environmental concerns, urban areas throughout the world are switching to natural gas for fueling continuous stationary combustion systems. As natural gas systems shift to lean, premixed operation to reduce NOx formation and maintain high combustion efficiency, hazardous air pollutant and ozone precursor emissions—specifically, volatile organic compounds (VOCs)—may potentially increase. The regulation of stationary source VOC pollutants under the 1990 Clean Air Act Amendments may pose unforeseen challenges in the design and operation of advanced gas-fired combustion systems. The present paper investigates the relationship between VOC emissions and excess air, fuel-air mixing, and NOx and CO emission levels for a scaled, generic, low-NOx, natural gas-fired burner. The stack samples were analyzed for C2−C10 aliphatic hydrocarbons, aromatic hydrocarbons, and aldehydes. Most VOCs were emitted in low concentrations (
How robotic products become social products: an ethnographic study of cleaning in the home

Robots that work with people foster social relationships between people and systems. The home is an interesting place to study the adoption and use of these systems. The home provides challenges from both technical and interaction perspectives. In addition, the home is a seat for many specialized human behaviors and needs, and has a long history of what is collected and used to functionally, aesthetically, and symbolically fit the home. To understand the social impact of robotic technologies, this paper presents an ethnographic study of consumer robots in the home. Six families' experience of floor cleaning after receiving a new vacuum (a Roomba robotic vacuum or the Flair, a handheld upright) was studied. While the Flair had little impact, the Roomba changed people, cleaning activities, and other product use. In addition, people described the Roomba in aesthetic and social terms. The results of this study, while initial, generate implications for how robots should be designed for the home.
X-ray observations of 2l-nl' transitions and configuration-interaction effects from Kr, Mo, Nb and Zr in near neon-like charge states from tokamak plasmas

X-ray spectra of 2l-3l' transitions in the elements krypton (Z = 36), zirconium (Z = 40), niobium (Z = 41) and molybdenum (Z = 42) from charge states around neon-like have been observed from Alcator C and Alcator C-Mod plasmas. Accurate wavelengths (±0.5 mA) have been determined with reference to neighbouring aluminium, silicon, sulfur, chlorine and argon lines with relatively well known wavelengths. Line identifications have been made by comparison to ab initio atomic structure calculations, using a fully relativistic, parametric potential code. Calculated wavelengths and oscillator strengths are presented for 2l-3l' transitions in neon-like ions and neighbouring Na-, Mg-, F- and O-like satellites. Electric quadrupole transitions in neon-like ions of the form 2s-3d and 2p-3p are found to be relatively bright, and their measured intensities agree well with the results of collisional-radiative modelling. The 2p-3s magnetic quadrupole transition is also relatively intense in the absence of collisional de-excitation at tokamak densities (1013-1015 cm-3). For krypton, transitions with upper levels up to n = 9 have been observed, and the measured wavelengths and intensities have been compared with calculations. For some neon-like transitions with nearly degenerate upper levels, there can be substantial configuration interaction which alters the line intensities.
The personality characteristics of the rigid learner

Abstract The present research investigated the personality dimensions concomitant with learner's cognitive rigidity. The results showed a highly reliable multiple relationship between rigidity scores and dimensions of IPAT's 16PF. Specifically, the personality dimensions of tenseness, compulsivity, group dependency, absent mindedness, sensitivity, and emotional stability explained 36% of the variability in subjects' increasing levels of cognitive rigidity. The results were interpreted as showing a pervasive use of stereotype behavior as a coping strategy in dealing with a greater amount of anxiety concomitant with cognitive rigidity.
Experimental investigations of inorganic membrane reactors: A distributed feed approach for partial oxidation reactions

An inorganic membrane reactor (MBR) is investigated for the oxidative dehydrogenation of ethane to ethylene. A tube and shell configuration is used where ethane is fed at the top of an annular packed catalyst bed and air permeates radially outward into the reaction zone along the length of the permeable reactor wall (porous α-alumina membrane). Using a magnesium oxide catalyst doped with lithium and samarium oxide, the effects of the overall ethane to oxygen feed ratio, temperature, and residence time are evaluated. The results are compared to a tubular reactor (PFR) operated with the same catalyst and conditions. The MBR outperforms the PFR in both ethylene yield and selectivity at low feed ratios. At 873 K, an ethane to oxygen feed ratio of 0.5, and a residence time of 4 s, per pass ethylene yields of 50.5 and 8.1% are produced in the MBR and PFR, respectively. The corresponding ethylene selectivities are 53 and 8.4%. As the feed ratio increases, the performance of the MBR and PFR merges. In addition, periodic counter-propagating blue flames are observed in the tubular reactor for some experiments with feed ratios between 0.25 and 1.0. No flames are observed in the MBR.
Fault orientations in extensional and conjugate strike-slip environments and their implications

Seismically active conjugate strike-slip faults in California and Japan typically have mutually orthogonal right- and left-lateral fault planes. Normal- fault dips at earthquake nucleation depths are concentrated between 40° and 50°. The observed orientations and their strong clustering are surprising, because conventional faulting theory suggests fault initiation with conjugate 60° and 120° intersecting planes and 60° normal-fault dip or fault reactivation with a broad range of permitted orientations. The observations place new constraints on the mechanics of fault initiation, rotation, and evolutionary development. We speculate that the data could be explained by fault rotation into the observed orientations and deactivation for greater rotation or by formation of localized shear zones beneath the brittle-ductile transition in Earth9s crust. Initiation as weak frictional faults seems unlikely.
Effects of calcium and Bay K-8644 on calcium currents in adrenal medullary chromaffin cells.

The kinetic and steady-state characteristics of calcium currents in cultured bovine adrenal chromaffin cells were analyzed by the patch-clamp technique. Whole cell inward Ca2+ currents, recorded in the presence of either 5.2 or 2.6mm Ca2+ exhibited a single, noninactivating component. To analyze the effects of Ca2+ and Bay K-8644 on the kinetics of the Ca2+ currents, we used a modified version of the Hodgkin-Huxley empirical model. At physiological [Ca2+] (2.5mm) the midpoint of the steady-state Ca2+-channel activation curve lay at −6.9 mV. Increasing the [Ca2+] to 5.2mm shifted the midpoint by −4.3 mV along the voltage axis. At the midpoint, changes in potential of 7.8 mV (for 5.2mm Ca2+) and 9.2 mV (for 2.5mm Ca2+) induced ane-fold change in the activation of the current. Increasing [Ca2+]0 from 2.5 to 5.2mm induced a marked increase in the rate constant for turning on the Ca2+ permeability. Conductances were estimated from the slope of the linear part of the currentvoltage relationships as 8.7 and 4.2 nS in the presence of 5.2 and 2.5mm Ca2+, respectively. Incubation of the cells in the presence of Bay K-8644 at increasing concentrations from 0.001 to 0.1 μm increased the slope conductance from 4.2 to 9.6 nS. Further increases in the concentration of Bay K-8644 from 1 to 100 μm induced a marked reduction in the conductance to 1.1 nS. In the presence of Bay K-8644 (0.1 μm) the midpoint of the activation curve was shifted by 6.1 mV towards more negative potentials, i.e., from −6.9 to −13 mV. At the midpoint potential of −13 mV, a change in potential of 6.9 mV caused ane-fold change in Ca2+ permeability. The kinetic analysis showed that Bay K-8644 significantly reduced the size of the rate constant for turning off the Ca2+ permeability.
Permeability characterization of dual scale fibrous porous media

Abstract The proper characterization of fabrics used in liquid composite molding (LCM) is integral to accurately model the flow through these porous preforms. The dual-scale nature of many fabrics has brought about a need for a methodology, which characterizes not only the bulk permeability of the preform, but the micro-scale permeability of the fiber tows. These two permeability values can then be used in LCM simulations that can separately track the bulk flow front progression and the saturation of the fiber tows in preforms that exhibit dual-scale porosity. A three dimensional simulation called liquid injection molding simulation (LIMS) has been developed at the University of Delaware that can predict the impregnation of the fiber preform with resin in closed molding processes such as resin transfer molding (RTM) and vacuum assisted resin transfer molding (VARTM). To address the dual-scale porosity, standard 2D or 3D mesh elements are combined with 1D elements, which are attached at each node and represent the fiber tows. This implementation allows for the interactions between the bulk and micro flow, and can predict the saturation of the fiber tows, along with the movement of the bulk resin flow front. However, it does require two permeability inputs: one for the elements representing the bulk preform and another for the 1D elements representing the fiber tows. A methodology is proposed to determine the bulk permeability and a parameter that is closely associated with the micro permeability of the tows for dual-scale fabrics. This is accomplished by comparing the inlet pressure profiles of one-dimensional constant flow rate injection RTM experiments with a simulation of flow in a dual-scale fabric. The methodology is validated and characterizations for four different fabrics are performed to demonstrate the versatility and limitation of the methodology.
Photogeneration of self-localized polarons in YBa2Cu3O7-δ and La2CuO4

Photoinduced infrared absorption measurements of YBa2Cu3O7-δ (δ = 0.75) and La2CuO4 are reported. We have observed photoinduced infrared active vibrational modes and associated phonon bleachings which indicate the formation of a localized structural distortion in the Cu-O plane around the photogenerated carriers. In both materials, an associated electronic transition indicates that this structural distortion causes the formation of a self-localized electronic state in the energy gap. The photoinduced distortion and the associated self-localized gap state demonstrate that the photoexcitations are relatively long-lived polarons (or bipolarons). The dynamic mass associated with the distortion is smaller in YBa2Cu3O7-δ than in La2CuO4 (smaller dynamic mass implies a longer range distortion). Since these features are not observed in the isostructural compound, La2NiO4, we conclude that polaron (or bipolaron) formation plays an important role in the high temperature superconductivity.
Reliability modeling for appliances using the Proportional Hazard Model

The Proportional Hazard Model (PHM) is very flexible to incorporate categorical and continuous variables to the survival analysis. The model can be used to assess the risk of a set of covariates with immediate application for repeated events with multiple failure modes in many electromechanical appliances. The major advantage of not requiring a parametric equation is subjected to some challenges for a direct estimation of the survival curve, as the model is developed in terms of the hazard function. Hazards models can be easily used when operating conditions or consumer usage pattern are to be assessed, such as the experiment used in this research.
Built-in electric fields in InAs/GaAs quantum dots: Geometry dependence and effects on the electronic structure

Built-in electrostatic fields in zincblende quantum dots originate mainly from-(1) the fundamental crystal atomicity and the interfaces between two dissimilar materials, (2) the atomistic strain relaxation, and (3) the piezoelectric polarization. In this paper, using the atomistic NEMO 3-D simulator, we study the origin and nature of various internal fields in InAs/GaAs quantum dots having three different geometries, namely, box, dome, and pyramid. We then calculate and delineate the impact of the internal fields on the one-particle electronic states in terms of shift in the conduction band energy states, anisotropy and twofold degeneracy in the P level, and formation of mixed excited bound states. A list of models and approaches used in this study is as follows: (1) Valence force field (VFF) with strain-dependent Keating potentials for atomistic strain relaxation; (2) 20-band nearest-neighbor sp3 d5 s∗ tight-binding model for the calculation of single-particle energy states; and (3) For piezoelectricity, for the first time within the framework of sp3 d5 s∗ tight-binding theory, four different recently-proposed polarization models (linear and non-linear) have been considered in this study. In contrast to recent studies of similar quantum dots, our calculations yield a non-vanishing net piezoelectric contribution to the built-in electrostatic field. We also demonstrate the importance of full three-dimensional (3-D) atomistic material representation and the need for using realistically-extended substrate and cap layers (systems containing millions of atoms) in the numerical modeling of these reduced-dimensional quantum dots.
Is bone mineral density predictive of fracture risk reduction

Bone mineral density (BMD) measurement is a widely available noninvasive means of identifying individuals with osteoporosis and, possibly, those at high risk for fracture. This nonsystematic review examines the relationship between BMD increase and fracture risk reduction in clinical trials evaluating osteoporosis therapy. The trials examined here are predominantly in postmenopausal women. BMD increase correlates poorly with fracture risk reduction in clinical trials of osteoporosis therapy conducted in postmenopausal women. Although BMD may increase with therapy, the increase is not measurable until later, and the overall increase is too small to account for the timing and magnitude of fracture risk reduction. BMD is only one of many contributors to bone strength and fracture risk reduction. Bone strength is derived from bone quantity, which consists of density and size, and bone quality, which, in turn, consists of structure (micro- and macroarchitecture), material properties, and turnover. Data are beginning to accrue suggesting that changes in bone turnover markers may be an accurate predictor of fracture risk reduction. Future research will elucidate the link between changes in bone turnover markers and bone architecture as a measure of osteoporosis treatment efficacy. Until then, physicians will continue to rely on fracture risk reduction data from well-designed clinical trials when judging the efficacy of different treatments for osteoporosis.
How managers control employees' time

This article presents a study which explored the underlying factors that influence the number of hours employees put into their workday. The increased number of hours on the job is often linked to a shift from an industrial era to a knowledge era. The manner in which managers control their subordinates work hours is chronicled, employing three general methods. These methods include imposing demands, monitoring, and modeling behavior. Each method is examined for its effectiveness and frequency of use.
FORMATION OF OIL-IN-GLYCEROL/WATER EMULSIONS

ABSTRACT 011-in-glycerol/water emulsions at various ratios of water to glycerol in the external phase were prepared with Tween 80 and either light mineral oil or soybean oil. A minimum in the droplet size was observed at about 15% w/w water in the external phase of the emulsions. At the same water concentration, a clouding of the surfactant occurs at room temperature and the surface and interfacial tensions are minimal. It appears, therefore, that the minimum droplet size of the emulsions is related to the clouding phenomenon, as a result of changes in the properties of the solvent and the surfactant.
Drug delivery by red blood cells: vascular carriers designed by mother nature

Importance of the field: Vascular delivery of several classes of therapeutic agents may benefit from carriage by red blood cells (RBC), for example, drugs that require delivery into phagocytic cells and those that must act within the vascular lumen. The fact that several protocols of infusion of RBC-encapsulated drugs are now being explored in patients illustrates a high biomedical importance for the field.Areas covered by this review: Two strategies for RBC drug delivery are discussed: encapsulation into isolated RBC ex vivo followed by infusion in compatible recipients and coupling therapeutics to the surface of RBC. Studies of pharmacokinetics and effects in animal models and in human studies of diverse therapeutic enzymes, antibiotics and other drugs encapsulated in RBC are described and critically analyzed. Coupling to RBC surface of compounds regulating immune response and complement, affinity ligands, polyethylene glycol alleviating immune response to donor RBC and fibrinolytic plasminogen activato...
The outcome of total elbow arthroplasty in juvenile idiopathic arthritis (juvenile rheumatoid arthritis) patients

Background Elbow prosthetic replacement in patients with juvenile idiopathic arthritis (JIA) can be complicated and technically challenging. Thus, we sought to evaluate the clinical benefit and the prosthetic longevity of primary semiconstrained linked total elbow arthroplasty (TEA) performed to treat these patients. Methods Between 1983 and 2005, 29 elbows in 24 patients (20 women and 4 men) had been replaced because of JIA. The mean age was 37 years (range, 24-68 years). Because of underlying deformity, the implant contour was modified for 9 elbows (31%) and a customized implant was inserted in 5 elbows (17%). The mean follow-up duration was 10.5 years (range, 4.6-20.1 years). Results During the follow-up period, 8 elbows underwent reoperation, including 6 (21%) that underwent implant revision. At most recent follow-up, 22 elbows (76%) subjectively had a satisfactory overall functional result. The mean Mayo Elbow Performance Score was 78 points (range, 50-100 points), with 18 elbows graded as having an excellent or good result. Compared with preoperative range of motion, the mean extension-flexion arc improved from 65° ± 44° to 89° ± 35° ( P = .01), mean flexion improved from 113° ± 23° to 126° ± 26° ( P = .02), and mean extension improved from 48° ± 25° to 37° ± 26° ( P = .08). By use of the Kaplan-Meier survivorship method, the rate of TEA survival from any revision was 96.4% (95% confidence interval, 89.8%-100%) and 79.9% (95% confidence interval, 65.1%-97.5%) at 5 years and 10 years, respectively. Conclusion Primary TEA for JIA patients is technically challenging and frequently requires implant modification or custom designs. These patients might have high complication and revision rates. However, most benefit from the intervention for a long term.
Hypotensive effects of 5-HT1A receptor activation: ventral medullary sites and mechanisms of action in the rat

Serotonin-1A (5-HT1A) binding sites were previously localized in several regions of the ventral medulla associated with neural regulation of the cardiovascular system. Some of these binding sites were associated with serotonergic neurons of the ventral medulla. The purpose of these studies was to assess and characterize hypotensive responses to a 5-HT1A agonist, (8-hydroxy-dipropylaminotetraline, 8-OH-DPAT), administered to the ventral medulla of the rat, to correlate the responsive ventral medullary sites with the distribution of 3H-8-OH-DPAT binding sites, and to assess the role of serotonergic systems in mediating the hypotensive responses. Ventral medullary application of 8-OH-DPAT caused dose-related reductions in mean arterial pressure and heart rate which were mediated by the autonomic nervous system. The hypotensive response to 8-OH-DPAT was attenuated by pretreatment with the 5-HT1A antagonists, spiperone or NAN-190. Microinjections of 8-OH-DPAT into ventral medullary structures revealed that 8-OH-DPAT responsive sites included the raphe pallidus, the parapyramidal region, and the rostral ventrolateral medulla. The role of serotonergic terminals in mediating the responses of 8-OH-DPAT was evaluated in animals pretreated with the serotonin nerve toxin, 5,7-dihydroxytryptamine (5,7-DHT). Cardiovascular responses to ventral medullary application of 8-OH-DPAT were unaffected by the selective depletion of serotonin. Thus, whereas the hypotensive responses elicited by 8-OH-DPAT in the raphe pallidus and parapyramidal region may involve serotonergic neurons, other non-serotonergic sites (e.g. the rostral ventrolateral medulla) can mediate the hypotensive actions of 8-OH-DPAT.
Stages of tail regeneration in the adult newt, Notophthalmus viridescens

Five distinguishable stages of tail regeneration in the adult newt have been established. The stages are based on external morphological changes and internal histological characteristics rather than chronological age of the regenerate.
A simple phenomenological approach to the phase-dependent conductivity of a superconducting weak link

Abstract Dependence of the pair density on pair velocity and consequently on the phase difference for a metallic weak link implies a phase-dependent conductivity which is calculated using a simple phenomenological approach.
Air conditioner failure investigation-intergranular cracking in a pure copper condenser tube

A failure of a 7 1/2-year-old commercial rooftop air conditioning system was investigated. The systematic failure analysis procedure and eventual discovery of a leak in a pure copper condenser coil are discussed. Severe denting of several tubes, including the tube that leaked, was discovered in the area of the steel tube sheet. A metallurgical examination, including scanning electron microscopy, revealed intergranular cracking, a process that is common among some copper alloys suffering from stress-corrosion cracking but is rarely observed in pure copper. Research of available literature is presented, and the conditions under which pure copper may exhibit intergranular cracking are discussed. Also presented are vibration measurements of the air conditioner taken during operation, which rule out operating loads as the cause of the tube denting and eventual cracking. The cause of the denting remains unknown. However, the denting probably occurred during manufacturing, and the high stresses associated with the dents, in the presence of corrosion, resulted in intergranular cracking and eventual leaking.
The structural biochemistry of Zucchini implicates it as a nuclease in piRNA biogenesis

piRNAs act to protect the genome from the damaging effect of unrestrained expression of mobile elements; here it is suggested that the phosphodiesterase Zucchini may be the nuclease that generates the 5′ ends of primary piRNAs. Small RNAs that are processed by the PIWI protein (piRNAs) act to protect the genome from the damaging effects of unrestrained expression of mobile and repetitive elements. Primary piRNAs are made by cleavage of longer piRNA cluster transcripts, but the nuclease responsible for their biogenesis was unknown. Two papers from the laboratories of Greg Hannon and Osamu Nureki now implicate the phosphodiesterase Zucchini/PLD6 as the nuclease that generates the 5′ ends of primary piRNAs. PIWI-family proteins and their associated small RNAs (piRNAs) act in an evolutionarily conserved innate immune mechanism to provide essential protection for germ-cell genomes against the activity of mobile genetic elements1. piRNA populations comprise a molecular definition of transposons, which permits them to distinguish transposons from host genes and selectively silence them. piRNAs can be generated in two distinct ways, forming either primary or secondary piRNAs. Primary piRNAs come from discrete genomic loci, termed piRNA clusters, and seem to be derived from long, single-stranded precursors2. The biogenesis of primary piRNAs involves at least two nucleolytic steps. An unknown enzyme cleaves piRNA cluster transcripts to generate monophosphorylated piRNA 5′ ends. piRNA 3′ ends are probably formed by exonucleolytic trimming, after a piRNA precursor is loaded into its PIWI partner1,3. Secondary piRNAs arise during the adaptive ‘ping-pong’ cycle, with their 5′ termini being formed by the activity of PIWIs themselves2,4. A number of proteins have been implicated genetically in primary piRNA biogenesis. One of these, Drosophila melanogaster Zucchini, is a member of the phospholipase-D family of phosphodiesterases, which includes both phospholipases and nucleases5,6,7. Here we produced a dimeric, soluble fragment of the mouse Zucchini homologue (mZuc; also known as PLD6) and show that it possesses single-strand-specific nuclease activity. A crystal structure of mZuc at 1.75 A resolution indicates greater architectural similarity to phospholipase-D family nucleases than to phospholipases. Together, our data suggest that the Zucchini proteins act in primary piRNA biogenesis as nucleases, perhaps generating the 5′ ends of primary piRNAs.
Early overuse and disuse of the affected forelimb after moderately severe intraluminal suture occlusion of the middle cerebral artery in rats

We have previously shown that early forced overuse of the affected forelimb worsens outcome following moderately severe transient focal cortical ischemic stroke in rats using a distal middle cerebral artery occlusion (MCAo) model. This effect may be site-dependent, because we have also found that early forced use of the affected limb after unilateral 6-OHDA induced degeneration of ascending nigrostriatal dopamine neurons markedly enhanced functional outcome and is neuroprotective. The present study examines the effects of early overuse and disuse following a moderately severe proximal MCAo model, by means of intraluminal suture occlusion. Ischemia was produced in male Long-Evans rats with 60 min of occlusion, or sham surgery was performed. Early overuse or disuse of the affected forelimb was forced by immobilizing either the ipsilateral or contralateral forelimb, respectively, in a plaster cast or the animal was left uncasted. Casts were removed on day 10 and sensorimotor testing was performed weekly during days 17-38. Animals were sacrificed on day 45 and brains were fixed for later cresyl violet staining. The MCAo+contralateral cast group performed worse than all other groups on tests of forelimb sensorimotor function. All MCAo groups regardless of cast condition had significant atrophy of the ischemic striatum, but there was no significant atrophy of the ischemic cortex in any group. Forced disuse, but not overuse, of the affected forelimb immediately following proximal ischemia using the intraluminal suture model has detrimental effects on functional outcome, without exaggerating anatomical damage. The effects of disuse and overuse during the first 10 days after stroke differ depending on cortical or subcortical involvement.
Assessing energy efficiency and energy conservation potential among commercial buildings: A statistical approach

Abstract Energy conservation in the commercial sector is impeded by the lack of simple yet reliable measures of building energy efficiency. A simple Energy Utilization Index is preferable, but it lacks reliability if it remains unadjusted for significant sources of variation. Linear regression analysis represents a straightforward method for introducing necessary sophistication, but care must be exercised in model specification and sample selection. A model incorporating climate, occupancy patterns, HVAC design, and building type explains 42% of the EUI variance in a sample of Texas school and university buildings.
Design of IIR pulseshaping filters

A method for the design of analog pulse-shaping filters is extended for the design of digital IIR (infinite-impulse response) pulse-shaping filters. In the method of K. Huber (1987), the Lagrange multiplier is used to solve the analog pulse-shaping-filter design problem. The author uses the same technique to solve the digital IIR pulse-shaping-filter design problem. >
The Clinical Manifestations and Treatment of Sexually Transmitted Diseases in Human Immunodeficiency Virus-Positive Men

Sexually transmitted diseases (STDs) occur commonly in sexually active human immunodeficiency virus (HIV)-positive men. STDs may have atypical presentations, can cause significant morbidity in persons with HIV infection, and may increase the risk of HIV transmission. Thus, the appropriate diagnosis and treatment of STDs in this population are extremely important. The clinical manifestations and treatment of several common STDs in HIV-positive men are reviewed. Further research is needed to define effective management and screening strategies for STDs in men with HIV infection.