cssi/SciSciGPT-SciSciNet huggingface dataset:
RISM theory of polymer liquids: Analytical results for continuum models of melts and alloys☆

Abstract Exact and approximate analytical solutions to the polymer RISM integral equation theory for melts and alloys are derived for long, flexible Gaussian chains. Comparisons of predictions for the isothermal compressibility and site-site intermolecular pair correlation function with exact numerical results reveals that the simplifications invoked to achieve analytic solutions are surprisingly accurate. A detailed study of the effective chi-parameter and critical temperature of binary isotopic blends of linear chains and copolymers of various microstructures is presented. In three dimensions, novel non-mean field predictions for the scaling of the critical temperature with degree of polymerization and copolymer architecture are found, and a rich dependence of the corresponding prefactor on system-specific features is determined. The breakdown of Flory-Huggins theory is due to a relatively long range, but weak, concentration fluctuation process which is a consequence of the combined influences of chain connectivity, intermolecular excluded volume and dispersion-like interactions. Physical analogies with critical phenomena ideas are developed, and comparisons are made of the theoretical predictions with recent small-angle neutron scattering observations.
Interaction of lanthanide shift reagents with organophosphorus substrates

Abstract The interaction of lanthanide (β-diketonate) 3 shift reagents (LSR) with a variety of tricoordinate and tetracoordinate organophosphorus substrates has been examined. In each case, sizable proton and 31P induced shifts were observed. A pseudocontact shift mechanism accounts for the majority of the observed proton induced shifts. However, significant contact shift contributions are required in order to account for the direction and magnitude of several of the observed 31P induced shifts. Several of the commercially available LSRs are not suitable for use in obtaining induced 31 P shifts due to broadening of the signal into the baseline. In terms of both the magnitude of the induced proton and 31p shifts and line broadening, Yb(fod) 3 and Pr(fod) 3 appear to be the best general shift reagents for organophosphorus substrates.
Alteration of polyurea hard domain morphology by diethanol amine (DEOA) in molded flexible polyurethane foams

Abstract In this study, the morphology of polyurea hard domains in flexible polyurethane molded foams was investigated to evaluate the influence of diethanol amine (DEOA), a commercially utilized cross-linking agent. Tapping Mode AFM was utilized to reveal that DEOA dramatically alters the morphology of the solid state. Without DEOA, the solid state phase separation leads to the formation of lamellae-like polyurea domains ca. 50–100 nm long by 5 nm wide, and these lamellae frequently aggregate to form larger precipitates ca. 30–50 nm in diameter. These larger aggregations appear to be evenly distributed in the material. However, when DEOA is added to the formulation, the hard domains become smaller and more geometrically isotropic, ca. 5 nm in diameter. Furthermore, in the DEOA containing material, the hard domains do not appear to form the larger 50 nm aggregates but instead remain distributed at ca. 10 nm apart. The addition of DEOA thus reduced the observed level of hard domain interconnectivity, an effect which is suggested to explain in part the corresponding reduction in modulus (i.e. stiffness) that is commonly observed when DEOA is added to such foam formulations. The morphological alterations observed using AFM were also found to correlate well with the DEOA induced changes in the small angle X-ray scattering profiles of these samples.
Anomalous composition-dependent dynamics of nanoconfined water in the interlayer of disordered calcium-silicates.

With shear interest in nanoporous materials, the ultraconfining interlayer spacing of calcium–silicate–hydrate (C–S–H) provides an excellent medium to study reactivity, structure, and dynamic properties of water. In this paper, we present how substrate composition affects chemo-physical properties of water in ultraconfined hydrophilic media. This is achieved by performing molecular dynamics simulation on a set of 150 realistic models with different compositions of calcium and silicon contents. It is demonstrated that the substrate chemistry directly affects the structural properties of water molecules. The motion of confined water shows a multi-stage dynamics which is characteristic of supercooled liquids and glassy phases. Inhomogeneity in that dynamics is used to differentiate between mobile and immobile water molecules. Furthermore, it is shown that the mobility of water molecules is composition-dependent. Similar to the pressure-driven self-diffusivity anomaly observed in bulk water, we report the first study on composition-driven diffusion anomaly, the self diffusivity increases with increasing confined water density in C–S–H. Such anomalous behavior is explained by the decrease in the typical activation energy required for a water molecule to escape its dynamical cage.
REPORT ON A PATIENT SUCCESSFULLY TREATED BY ESTROGEN ADMINISTRATION

RECURRING ULCERATIVE STOMATITIS With Coexistent genital ulcers has been recognized in women as a disease entity since 1895 (1). This syndrome has received many names, and various the’ ories as to its etiology have been proposed. Three of these are: first, that it is an acute infectious disease; second, that it is a tuberculid, and third, that it is due to some type of ovarian dysfunction. Wein and Perlstein reviewed the literature in 1932, (1) and reported their observations on a patient with this disorder. They concluded that an ovarian dysfunction was the primary cause, and that it was not an infectious disease. Ziserman in 1935 (2) and Whitlow in 1936 (3) reached similar conclusions. Ziserman (2) was the first to attempt a therapeutic approach based on an endocrine etiology. In his patient he observed evidence of ovarian dysfunction, and by the use of gonadotropic endocrine substances he obtained a good therapeutic result. Prinz and Greenbaum (4) state that ovarian substances have been shown to be of v...
Evaluation of incident management strategies with a simulation program developed using ARENA

ABSTRACT This paper presents an incident management simulation model for evaluating the performance of incident managementstrategies currently used and considered for future use. Five incident types are considered. Their severity degrees are assumed to be related with the incident characteristics, such as number of vehicles involved, number of injuries, and fatalities, etc. The relationship between severity degree and the incident properties is derived from previous data given inOzbay et al.'. The same data source is used to estimate probabilistic durations, such as incident occurrence rates, clearancetimes. Detection and verification time, dispatch time and clearance time can all be reduced through effective incident management strategies. The study presented in this paper focuses on the reduction of dispatch time by using various deployment strategies of ERT (Emergency Response Team). Thus, ARENA simulation development package that employsSiman simulation language is used to model and examine the effects of each incident management strategies.Keywords: Incident, Management, Simulation, Response, ARENA, Siman
Effect of Cross Groove on Flow Boiling in a Microgap

Flow boiling performance of a microgap channel has been investigated experimentally. Experimental studies were carried out on a bottom surface heated single microgap channel having 5×0.372 mm cross sectional area using DI water as coolant. Four rectangular grooves were cut along the flow direction and surface morphology of the microgrooves was modified by depositing ZnO nanoparticles from a nanofluid using electrophoresis deposition technique. Flow boiling experiments were conducted for different mass flux. The results from the microgap channel having no cross grooves have been used as the baseline data. Cross grooves have been found effective in reducing boiling incipience temperature and enhancing heat transfer coefficient. Up to 50% enhancement in two-phase heat transfer coefficient was observed for the cross groove. Nanoparticles deposition reduces boiling incipient temperature but does not show any significant effect on two-phase heat transfer coefficient.Copyright © 2012 by ASME
Applying Scenario Planning Across Multiple Levels of Analysis

Planning for an uncertain future is problematic yet necessary for organizations to remain viable. Scenario planning helps organizations to increase their capacity to learn and adapt as the future u...
Dimensions of Religion, Depression Symptomatology, and Substance Use Among Rural African American Cocaine Users

Research has shown a relationship between depression, substance use, and religiosity but, few have investigated this relationship in a community sample of African Americans who use drugs. This study examined the relationship between dimensions of religion (positive and negative religious coping; private and public religious participation; religious preference; and God-, clergy-, and congregation-based religious support), depression symptomatology, and substance use among 223 African American cocaine users. After controlling for gender, employment, and age, greater congregation-based support and greater clergy-based support were associated with fewer reported depressive symptoms. In addition, greater congregation-based support was associated with less alcohol use.
A Requirement for Bid for Induction of Apoptosis by Photodynamic Therapy with a Lysosome‐ but Not a Mitochondrion‐targeted Photosensitizer

Photodynamic therapy (PDT) with lysosome-targeted photosensitizers induces the intrinsic pathway of apoptosis via the cleavage and activation of the BH3-only protein Bid by proteolytic enzymes released from photodisrupted lysosomes. To investigate the role of Bid in apoptosis induction and the role of damaged lysosomes on cell killing by lysosome-targeted PDT, we compared the responses of wild type and Bid-knock-out murine embryonic fibroblasts toward a mitochondrion/endoplasmic reticulum-binding photosensitizer, Pc 4, and a lysosome-targeted sensitizer, Pc 181. Whereas apoptosis and overall cell killing were induced equally well by Pc 4-PDT in both cell lines, Bid -/- cells were relatively resistant to induction of apoptosis and to overall killing following PDT with Pc 181, particularly at low PDT doses. Thus, Bid is critical for the induction of apoptosis caused by PDT with the lysosome-specific sensitizers, but dispensable for PDT targeted to other membranes.
You can teach an old dog new tricks. How AIDS trials are pioneering new strategies.

Clinical trials of a new treatment are undertaken in three phases. Phase I trials are designed to test the safety of the new treatment, phase II to test its efficacy, and phase III to compare it wi...
Coronary flow velocity during coronary angioplasty in regions of myocardial infarction

In patients undergoing angioplasty for angina after myocardial infarction, patterns of post-stenotic coronary blood flow velocity depend not only on satisfactory dilation of the flow-limiting lesion, but also on the vasoregulatory capacity of infarcted myocardium. The case examples demonstrate both normal and persistently abnormal flow velocity patterns following successful coronary angioplasty for post-infarction ischemia. Recognition of collateral flow patterns, easily available using the Doppler angioplasty guidewire, may provide valuable information predicting the viability of post-infarcted myocardium and the resolution of abnormal distal coronary flow patterns.
Rotational spectrum, structure and modeling of an isomer of the HCCH–OCS dimer

Abstract A second T-shaped isomer of the HCCH–OCS dimer has been observed by Fourier-transform microwave spectroscopy. This isomer has the OCS monomer interacting with the triple bond of the acetylene monomer through the sulfur atom, with a calculated center of mass separation, R CM , of 4.622(2) A. The effects of nuclear spin statistics on the relative intensities of the transitions confirm the C 2v symmetry of the complex. The dipole moment, μ a =0.9516(8) D, indicates an induced moment of 0.24 D. The geometry is consistent with results from a semi-empirical model and ab initio calculations which suggest that this isomer is higher in energy than the near-parallel HCCH–OCS isomer.
Polarized light microscopy and spectroscopy of individual single-walled carbon nanotubes

Polarized light microscopy (PLM) is used to image individual single-walled carbon nanotubes (SWNTs) suspended in air across a slit opening. The imaging contrast relies on the strong optical anisotropy typical of SWNTs. We combine PLM with a tunable light source to enable hyperspectral excitation spectroscopy and nanotube chirality assignment. Comparison with fluorescence microscopy and spectroscopy confirms the assignment made with PLM. This represents a versatile new approach to imaging SWNTs and related structures. Open image in new window
Analysis of cyclitols in cycad plant tissues

Abstract Cyclitols (and sugar alcohols) in extracts of plant tissues may be analyzed by gas chromatography as trimethylsilyl ethers after removal of reducing sugars by treatment with barium hydroxide followed by deionization. A known amount of one of the components already present may be used as an internal standard. The method was applied to various samples of cycad plant tissue and some common forage crops. Neither the content of pinitol nor its ratio to myoinositol appears likely to be implicated in cycad toxicity.
North East Consortium for Health Information (NECHI) Explores DynaMed and Up-To-Date as Viable Research Tools and Point-of-Care Resources for the Purpose of Facilitating Informed Purchasing by Library and Hospital Administrators

Hospital librarians scrutinize databases on a regular basis. The most important feature of a database is that it delivers needed information to any health care professional for use in patient care. The delivery mode needs to be understandable and easily accessible. Between 2009 and 2011, the North East Consortium for Health Information (NECHI) found itself needing to make decisions about point-of-care databases, the two prominent ones being Up-To-Date and DynaMed. Consortium members were concerned that there was heavy reliance on Up-To-Date information without further inquiry into other sources. A comparison developed that looked at institutional level decisions, input from end users, types of information supplied, and financial considerations. It was concluded by NECHI librarians that the target audience needed to be administrators of libraries and library services and that financial consideration had to be one of the factors, but not the only factor.
Water use and acute diarrhoeal illness in children in a United States metropolitan area

SUMMARY We examined the association between water exposures and acute diarrhoeal illness (ADI) in children under non-outbreak conditions in a major US metropolitan area. We used a nested case-control study of children seen in an urban/suburban emergency department. Cases were those seen for a complaint of diarrhoea, while controls were age-matched children with a non-gastrointestinal complaint. Parents of subjects completed a validated water-use survey. Stratum-specific adjusted odds ratios (aOR) were calculated for the three main water effects : water source [surface vs. ground (well)], drinking-water type (tap vs. bottled), and use of water filters. Of 2472 subjects, 45% drank mostly or only bottled water. Well-water use was associated with increased odds of ADI compared to surface water [aOR 1 . 38, 95 % confidence interval (CI) 1 . 01–1 . 87]. Use of bottled water did not affect the odds of ADI in well-water users, but increased the odds of ADI for surface-water users (aOR 1 . 27, 95 % CI 1 . 02–1 . 57). We conclude that well-water use and bottled-water use are associated with increased odds of ADI in children.
Giant multipole resonances

Abstract The positions and the transition strengths of the giant multipole resonances of the spherical nuclei ( 16 O, 40 Ca, 90 Zr and 208 Pb) are calculated with large configuration spaces in the random phase approximation based on the Hartree-Fock ground states of a newly developed Skyrme interaction. Positions of many giant resonances are reproduced within 5 % of the experimental values. Most of the energy-weighted sum rules calculated from the double commutators are exhausted to within 13 % by the contribution from the RPA response function.
Task-dependent costs in processing two simultaneous auditory stimuli

A listener presented with two speech signals must at times sacrifice the processing of one signal in order to understand the other. This study was designed to distinguish costs related to interference from a second signal (selective attention) from costs related to performing two tasks simultaneously (divided attention). Listeners presented with two processed speech-in-noise stimuli, one to each ear, either (1)identified keywords in both or (2)identified keywords in one anddetected the presence of speech in the other. Listeners either knew which ear to report in advance (single task) or were cued afterward (partial-report dual task). When the dual task required two identification judgments, performance suffered relative to the single-task condition (as measured by percent correct judgments). Two different tasks (identification for one stimulus and detection for the other) resulted in much smaller reductions in performance when the cue came afterward. We concluded that the degree to which listeners can simultaneously process dichotic speech stimuli seems to depend not only on the amount of interference between the two stimuli, but also on whether there is competition for limited processing resources. We suggest several specific hypotheses as to the structural mechanisms that could constitute these limited resources.
Papain-induced allergic reactions.

Summary Papain is a proteolytic enzyme with elastolytic activity, which produces emphysemalike lesions when introduced into the airways of animals. It is encountered by humans in numerous occupations, medications and domestic products. Sensitization to papain in two subjects in different occupations was confirmed with skin tests with chemical-grade papain and radioallergosorbent tests (RAST), with a papain which had been chemically inactivated by selective active site blockade. Skin tests and RAST were negative in non-symptomatic co-workers. Withdrawal from occupational exposure to papain resulted in an improvement in symptoms. In a survey of 330 subjects at the time they were receiving routine allergy skin tests, seven reacted to papain. Sensitization was confirmed by the RAST. Serum IgG antibodies to papain were detected among sensitized individuals and also in five out of 266 sera obtained from a clinical hospital laboratory. The findings illustrate immune responses to papain in humans in the form of atopic sensitization and serum IgG antibodies. Moreover, recurrent respiratory symptoms in the presenting persons served to illustrate that they and their co-workers were repeatedly exposed to air-borne papain. In view of the potential danger from the proteolytic effects of papain, these observations illustrate the need for further investigations of the effects of human exposure to air-borne papain.
Use of magnetic resonance imaging and positron emission tomography in the assessment of synovial volume and glucose metabolism in patients with rheumatoid arthritis

Objective. To measure the anatomic and physiologic changes in the synovium of patients with active rheumatoid arthritis (RA) before and after the initiation of treatment with low-dose systemic glucocorticoids and methotrexate (MTX). Methods. Two patients with RA with active synovitis involving the carpus were evaluated by imaging parameters at baseline and again after 14 weeks (of treatment with low-dose prednisone and MTX). Standard clinical parameters, laboratory measurements, and contrast-enhanced magnetic resonance imaging (MRI) (synovial volume estimate) and positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (18-FDG) (synovial metabolism estimate) were performed. Results. Compared with baseline, standard clinical parameters (i.e., joint count, joint index, morning stiffness, global assessments of arthritis activity, and erythrocyte sedimentation rate) improved dramatically in both patients after treatment with low-dose prednisone and MTX. In concert with this trend, the synovial volume of the affected wrist was reduced by 60%, and 76% and the metabolism of 18-FDG was reduced by 66% and 69% in the 2 patients. Conclusion. These preliminary observations indicate that a volumetric estimate of inflamed synovium (using contrast-enhanced MRI) and quantification of synovial deoxyglucose metabolism (using PET) are technically feasible and, in the 2 reported cases, correlate well with standard outcome measures. These imaging modalities may provide new objective parameters to determine RA disease activity and effectiveness of antirheumatic medications; however, the potential clinical utility of these measures remains to be defined.
The Match Between Family Needs and Services for High-Risk Neglecting Families

ABSTRACT Child neglect is characterized by a complexity of family problems and needs. Whether families' needs are actually matched to the appropriate services is a critical area for study, although little empirical work exists. In this study, we examine the match between needs and services for a sample of high-risk neglecting families, using cluster analysis to identify clusters of services and previously identified need clusters. We examine need–service match from two perspectives: 1) how well services are allocated to family need, and 2) how well family needs are covered by available services. Some service clusters are well allocated to corresponding needs, such as intensive drug court and family preservation services to substance-abusing families; however, other service patterns are much less coherent. With regard to how well needs are covered by available services, although approximately one-third of substance-abusing families receive the intensive drug court intervention, another one-third receive th...
Case report: Three patients with substantial serum levels of 3-epi-25(OH)D including one with 3-epi-25(OH)D2 while on high-dose ergocalciferol.

Context: We report the presence of substantial concentrations of 3-epi-25(OH)D3 in two patients and a third patient with 3-epi-25(OH)D2. Patients: The first patient, a 66-year-old female receiving cholecalciferol 4000 IU daily was originally found to have 53 ng/mL of 25(OH)D3 and almost an equal amount of 3-epi-25(OH)D3. Subsequently, the patient had four additional samples, each of which has similar levels of both 25(OH)D3 and 3-epi-25(OH)D3. The second patient, a 7-year-old male receiving cholecalciferol 1000 IU daily, had a 25(OH)D3 concentration of 37 ng/mL and 3-epi-25(OH)D3 of approximately 10 ng/mL. The third and most intriguing patient, a 55-year-old female was receiving ergocalciferol 50 000 IU twice weekly for approximately 3 months, at which time her serum 25(OH)D2 was 64 ng/mL and her 3-epi-25(OH)D2 was approximately 32 ng/mL. This patient's physician changed her vitamin D therapy to cholecalciferol 1000 IU daily, discontinuing ergocalciferol, and a second specimen was collected 5 months later...
The state of politics in Africa: The corporatist factor

In the past decade, studies of thestate in Africa have either suggested its pervasiveness in both political and economic life or have concentrated on its nonrepresentative (i.e., undemocratic) nature and its dependence on foreign capital for its survival. This study adopts a different reasoning. It suggests that thestate in African countries should be viewed as grappling with problems of managing society within the context of underdevelopment, a task that is increasingly becoming more difficult given the recurring economic crises on the continent. Politics ofcorporatist organization thus become an attractive option for the state to express its authority and attempt to legitimize its existence.
Interconnect-Centric Computing

Summary form only given. As we enter the many-core era, the interconnection networks of a computer system, rather than the processor or memory modules, will dominate its performance. Several recent developments in interconnection network architecture including global adaptive routing, high-radix routers, and technology-matched topologies offer large improvements in the performance and efficiency of this critical component. The implementation of a portion of several interconnection networks on multi-core chips also raises new opportunities and challenges for network design. This talk explores the role of interconnection networks in modern computer systems, recent developments in network architecture and design, and the challenges of on-chip interconnection networks. Examples will be drawn from several systems including the Cray BlackWidow
Reply to Boonstra: The Nature of Periodic Input to the Muscle.

reply: In response to our recent paper (Neto and Christou 2010), Dr. Boonstra raised primarily two arguments in his letter. The first argument indicates that periodic input to the muscle may be evident not only at lower frequencies of muscle activity (sub-60 Hz) but also as the modulation of higher frequencies (e.g., modulation of 100–200 Hz). The secondary argument suggests that rectification of the EMG may be an appropriate method to capture such high frequency modulation. Although we agree with the first argument that the modulation of motor units may be derived from higher frequencies, the following questions remain with respect to his secondary argument:
Attitude and the perception of faces

Abstract To assess the effects of affective orientation on the judgment of facial attriutes, 165 subjects were asked to make judgments of the attributes of each of two faces. For each face, subjects were either given no information about the person in the photo, or were given biographical information connoting either a favorable or unfavorable personality. It was predicted that when subjects make judgments along dimensions that were evaluatively loaded (e.g., smilling vs frowning mouth), manipulated attitude would influence these judgments. For the seven dimensions rated by the subjects, four dimensions showed the predicted effect. The other three dimensions, which did not show the effect, were the only ones that showed a significant effect due to the face itself. It was concluded that for dimensions that are not highly structured by the characteristics of the face, attitude can significantly influence judgments of facial attributes.
Coding and sampling for compressive x-ray diffraction tomography

Coded apertures and energy resolving detectors may be used to improve the sampling efficiency of x-ray tomography and increase the physical diversity of x-ray phenomena measured. Coding and decompressive inference enable increased molecular specificity, reduced exposure and scan times. We outline a specific coded aperture x-ray coherent scatter imaging architecture that demonstrates the potential of such schemes. Based on this geometry, we develop a physical model using both a semi-analytic and Monte Carlo-based framework, devise an experimental realization of the system, describe a reconstruction algorithm for estimating the object from raw data, and propose a classification scheme for identifying the material composition of the object at each location
Intratracheal pulmonary ventilation improves gas exchange during laparoscopy in a pediatric lung injury model

Abstract Background/Purpose This study was aimed at determining whether intraoperative intratracheal pulmonary ventilation (ITPV) could prevent/treat respiratory complications of laparoscopy in a model of pediatric pulmonary insufficiency. Methods Severe lung injury was induced in 0- to 2-month-old lambs (n = 5) by endotracheal saline lavage. Animals then underwent establishment of CO 2 pneumoperitoneum. Intraperitoneal pressures were progressively raised from 0 to 15 mm Hg, at intervals of 5 mm Hg. At each interval, blood gas and hemodynamic data were recorded, 20 minutes after initiation of both conventional ventilation and pure ITPV. All ventilatory parameters were constant and identical on both modes of ventilation. Results On conventional ventilation, severe respiratory acidosis and hypoxemia ensued at intraperitoneal pressures of 5 mm Hg and 10 mm Hg or more, respectively. Compared with conventional ventilation, ITPV led to statistically significant decreases in Pco 2 at intraperitoneal pressures of 5 mm Hg (43.2 ± 5.2 vs 56.1 ± 6.6 mm Hg) and 10 mm Hg (45.1 ± 3.2 vs 61 ± 6.3 mm Hg) and to significant increases in Po 2 at 10 mm Hg (92 ± 10.2 vs 61 ± 8.1 mm Hg), resolving the acidosis and hypoxemia at those pressure levels. Conclusions Compared with conventional ventilation, ITPV improves both CO 2 removal and oxygenation during CO 2 pneumoperitoneum in a pediatric lung injury model. Intratracheal pulmonary ventilation may be a safer intraoperative mode of ventilation for neonates and children with respiratory failure who require laparoscopy.
632 LIVER BIOPSY IS SAFELY PERFORMED IN AN AMBULATORY DAY HOSPITAL SETTING

So-called “outpatient” percutaneous liver biopsy is advocated for low risk adults. We assessed feasibility of pediatric liver biopsy in a short-stay program designed to reduce patient anxiety about hospitalization and minimize hospitalization costs. 27 of 86 pediatric liver biopsies were performed without overnight hospitalization. Criteria for “one-day” liver biopsy were (a) no other acute or chronic need for admission, (b) pro time 105, (c) no anticipated bleeding problem. Outpatients NOT considered for “one-day” biopsy were on hemodialysis (6) required platelets, plasma or DDAVP pre-biopsy (4) or lived more than one hour from the hospital. Sedation, usually IM DPT, was the same as for regularly hospitalized patients. Vital signs were closely monitored for six hours after the procedure, then patients went home with a parent to maintain bed rest for 24 hours. Results: 9/27 liver biopsies were performed in conjunction with other procedures, usually endoscopy and mucosal biopsies. No complications occurred in this group. One infant, after receiving an excessive dose of demerol, was monitored for 12 hours before discharge. One patient remained overnight at parent request Conclusions: In suitably selected pediatric patients, percutaneous liver biopsy can be accomplished without overnight hospitalization. There were no unrecognized complications requiring readmission. The hospital cost was halved and family lifestyle minimally disturbed.
Are golden parachutes an optimal contracting response or evidence of managerial entrenchment?: Evidence from successful takeovers

Two models that attempt to explain the adoption of golden parachutes are examined. The first model views golden parachutes as an optimal contracting response to a takeover, the other perceives them as an outgrowth of severe managerial entrenchment that results in contracts for the benefit of managers. Using a sample of 169 successful acquisitions of NYSE targets from 1981 through 1989, I document that targets that have adopted golden parachutes experience significantly higher excess returns around the announcement of a takeover than targets without these contracts. I find similar increased excess returns for the bidder/target portfolios. In addition, bidder excess return is independent of the existence of golden parachutes in targets. Additional results suggest that golden parachutes do not reduce managerial resistance to takeovers. The results are consistent with the managerial entrenchment hypothesis and inconsistent with the optimal contracting hypothesis. Sensitivity tests confirm these results.
Rational addiction, lagged demands and the efficiency of excise taxes: Revisions of standard theory*

The interdependence of consumption over time unsettles many firmly held conclusions that concern the impact of government policies. Becker and Murphy's (1988) analysis of the complimentarity of consumption of a given good over time suggests that people will not always adjust marginally to changes in the parameters of consumption, one of which is surely the presence, absence, or prospects of excise taxation. Lee and Kreutzer's (1982) analysis of the lagged demand curve indicates that any threat to the stability of future property rights — through the imposition of excise taxes or anything else — can have what would be considered, viewed from the accepted paradigm, perverse consumption behavior. Excise taxes in many essential regards represent threats to current and future property rights. As a consequence, for goods whose consumption is interdependent over time, or addictive, excise taxes can retard consumption in both current and future time periods by more than might be thought from the perspective of the standard analytical models. Such a conclusion undermines conventional wisdom, which holds that excise taxes are often designed and applied to products with inelastic demands simply to minimize economic distortions.
Hemoglobin conformation couples erythrocyte S-nitrosothiol content to O2 gradients

Abstract It is proposed that the bond between nitric oxide (NO) and the Hb thiol Cys-β93 (SNOHb) is favored when hemoglobin (Hb) is in the relaxed (R, oxygenated) conformation, and that deoxygenation to tense (T) state destabilizes the SNOHb bond, allowing transfer of NO from Hb to form other (vasoactive) S-nitrosothiols (SNOs). However, it has not previously been possible to measure SNOHb without extensive Hb preparation, altering its allostery and SNO distribution. Here, we have validated an assay for SNOHb that uses carbon monoxide (CO) and cuprous chloride (CuCl)-saturated Cys. This assay is specific for SNOs and sensitive to 2–5 pmol. Uniquely, it measures the total SNO content of unmodified erythrocytes (RBCs) (SNORBC), preserving Hb allostery. In room air, the ratio of SNORBC to Hb in intact RBCs is stable over time, but there is a logarithmic loss of SNORBC with oxyHb desaturation (slope, 0.043). This decay is accelerated by extraerythrocytic thiol (slope, 0.089; P < 0.001). SNORBC stability is uncoupled from O2 tension when Hb is locked in the R state by CO pretreatment. Also, SNORBC is increased ≈20-fold in human septic shock (P = 0.002) and the O2-dependent vasoactivity of RBCs is affected profoundly by SNO content in a murine lung bioassay. These data demonstrate that SNO content and O2 saturation are tightly coupled in intact RBCs and that this coupling is likely to be of pathophysiological significance. sepsis nitric oxide vascular physiology
Surface properties of fluorinated oxetane polyol modified polyurethane block copolymers

Abstract This article describes the surface properties of fluorinated oxetane polyol (F-Polyol) containing linear segmented polyurethane elastomers. A series of polyurethane elastomers derived from a soft segment based on 2300 g/mol polyhexamethylene carbonate, and a hard segment composed of 4,4′-methylene diphenyl diisocyanate chain extended with 1,4-butanediol were modified with a 3285 g/mol F-Polyol via either melt or solution reaction in dimethyl acetamide. X-ray photoelectron spectroscopy confirmed that the surfaces of the modified polyurethanes exhibit notable fluorine enrichment within the uppermost 5 nm, depending on the bulk composition and the polymerization method. Field emission scanning electron microscopy and tapping mode atomic force microscopy experiments demonstrated that relatively large micro-scale domain structures were exclusively found in the melt-polymerized polyurethanes. This was attributed to incompatibility of the F-Polyol with the other reactive constituents during the melt polymerization. Friction experiments revealed that the friction coefficient of the fluorinated polyurethanes decreased by about 2-fold as the surface fluorine concentration increased from 0 to about 20 at.%. Furthermore, the melt-polymerized polyurethanes underwent a stick-slip motion, whereas the more homogeneous solution-polymerized polyurethanes experienced a conventional stable sliding. These friction behaviors are discussed in terms of the surface topography and morphology.
Generation of superoxide anion impairs histamine-induced increases in macromolecular efflux

The first goal of this study was to determine the effect of generation of superoxide anion using pyrogallol on histamine-induced increases in macromolecular efflux. We used intravital microscopy and fluorescein isothiocyanate-dextran (FITC-dextran; MW 70K) to examine macromolecular extravazation from postcapillary venules in the hamster cheek pouch in response to histamine before and following topical application of vehicle or pyrogallol. Extravazation of macromolecules was quantitated by counting venular leaky sites. Histamine elicited reproducible increases in venular leaky sites before and during infusion of vehicle. In contrast, topical application of pyrogallol (0.5 mM) abolished histamine-induced increases in formation of venular leaky sites. Our second goal was to examine whether pyrogallol-induced inhibition of venular leaky site formation could be reversed by superoxide dismutase. Application of superoxide dismutase (300 U/ml) to the cheek pouch in the presence of pyrogallol restored histamine-induced increases in venular leaky sites. Thus, the generation of superoxide anion alters histamine-induced increases in macromolecular efflux. These results support the concept that disease states that produce oxidative stress may impair agonist-induced increases in microvascular permeability via inactivation of nitric oxide.
Eliminating Structural Error in Real-Time Adjustable Four-Bar Path Generators Using Iterative Learning Control

Fundamental concepts of Iterative Learning Control (ILC) are applied to path generating problems in mechanisms. As an illustration to such class of problems, an adjustable four-bar linkage is used. The coupler point of a four-bar traces a coupler curve that will in general deviate from the desired coupler path. Except at the precision points, the coupler curve will exhibit some structural error, which is the deviation from the specified curve. The structural error will repeat itself every cycle at exactly the same points over the range of interest. Since ILC is a methodology that was developed to handle similar repetitive errors in control systems, it is believed that it will be well served to apply it to this class of problems. Results show that ILC can be simple to implement, and it is found to be very well suited for such path generation problems.Copyright © 2004 by ASME
Alterations in the dopaminergic receptor system after chronic administration of cocaine

Several studies suggest that one of the most important factors contributing to cocaine dependence is an alteration in the actions of the neurotransmitter dopamine in the central nervous system. In order to understand some of the neuroreceptor consequences of cocaine administration, groups of rats were injected with cocaine (2 daily doses of 15 mg/kg) for 1 to 21 days. Binding of [3H]cocaine, [3H]SCH23390, [3H]raclopride, and [3H]BTCP in striatal and cortical tissue from the treated animals was compared to controls. [3H]Cocaine binding was increased by the drug in the striatum and cortex at days 14 and 21, respectively. The binding of [3H]SCH23390 to D1 dopamine receptors was significantly increased at day 3 of cocaine exposure. In striatal membranes, [3H]BTCP binding to dopamine uptake sites was significantly increased after day 7, whereas binding in cortical membranes was increased from day 1. [3H]Raclopride binding to D2 dopamine receptors remained unchanged throughout the study in both cortical and striatal tissues. These results indicate that repeated exposure to cocaine produces an upregulation (possible supersensitivity) in cortical D1, cocaine, and DA-uptake sites which occurs in a time-dependent manner. These increases are coupled with an upregulation in striatal D1, cocaine, and DA-uptake sites, without simultaneous changes in D2 receptors. Thus, cocaine's effects are not uniformly distributed across all brain regions, but rather are focused within areas of the dopamine system. © 1993 Wiley-Liss, Inc.
Abstracting Symbolic Execution with String Analysis

Forward symbolic execution is a technique for program analysis that explores the execution paths of a program by maintaining a symbolic representation of the program state. Traditionally, applications of this technique have focused on symbolically representing only primitive data types, while more recent extensions have expanded to reference types. We demonstrate the ability to symbolically execute a commonly used library class, specifically a string, at an abstract level. By abstracting away the implementation details of strings using finite-state automata, symbolic execution can scale to more complex programs. This technique can be applied to programs which generate complicated strings, such as SQL database queries.
Sodium Acetate Coated Tenofovir-Loaded Chitosan Nanoparticles for Improved Physico-Chemical Properties

It is hypothesized that sodium acetate (SA) can be used for in situ coating of drug loaded chitosan NPs for improved physico-chemical properties. Tenofovir (TFV) is used as a model drug. Uncoated chitosan NPs are prepared by ionic gelation. SA is generated in situ from half neutralization of acetic acid with sodium hydroxide, and coats chitosan NPs during freeze-drying. The NPs' physico-chemical properties [e.g., particle mean diameters (PMD) zeta potential (ζ), EE%, drug release profile, morphology] are characterized by dynamic light scattering, spectrophotometry, Korsmeyer-Peppas model, transmission electron microscopy (TEM), respectively. Melting point (MP), non-aqueous titration, Fourier transform infrared (FTIR) analysis, and powder X-ray diffractometry (XRD) pattern evaluate the SA coated chitosan NPs. The NPs' cytotoxicity on macrophages Raw 264.7 is assessed by neutral red, resazurin, nitrite oxide (NO) and cytokines assays. Collectively, FTIR, ζ, XRD, MP, and TEM data confirm that SA coats chitosan NPs. The PMD range is 136–348 nm (uncoated) and 171–379 nm (coated NPs). The ζ values range is +24.3–28.5 mV (uncoated) and 0.1–3.1 mV (coated NPs). The EE% ranges from 5.5 to 11.7% (uncoated NPs) and increased up to 86.3-92.7%(8-17-fold) after coating. The SA also prevents NPs aggregation during the freeze-drying and aqueous dispersion. The core-shell NPs exhibited a sustain release of TFV following anomalous transport mechanism (R2 ~ 0.99). The coated NPs are non-cytotoxic (cell viability ~100%) and without any proinflammatory response. This SA coating chitosan NPs mechanism may be useful for (i) efficient encapsulation, (ii) stabilizing colloidal dispersions, (iii) controlling the release and solubility of bioactive agents.
NONSTATIONARY RELATIONAL CONTRACTS WITH ADVERSE SELECTION

I develop a model of nonstationary relational contracts in order to study internal wage dynamics. Workers are heterogeneous, and each worker’s ability is both private information and fixed for all time. Learning therefore occurs within employment relationships. The inferences, however, are confounded by moral hazard. Incentive provision is restricted by an inability to commit to long-term contracts. Relational contracts, which must be self-enforcing, must therefore be used. The wage dynamics in the optimal contract, which are pinned down by the tension between incentive provision and contractual enforcement, are intimately related to the learning effect.
A meta-analysis of clinical trials comparing the serotonin (5HT)-2 receptor antagonists trazodone and nefazodone with selective serotonin reuptake inhibitors for the treatment of major depressive disorder.

Abstract Objective To compare response rates among patients with major depressive disorder (MDD) treated with either a serotonin-2 (5HT2-) receptor antagonist or a selective serotonin reuptake inhibitor (SSRI). Methods Medline and PubMed were searched for double-blind, randomized clinical trials comparing either trazodone or nefazodone with an SSRI for the treatment of MDD. Data from 9 reports involving a total 988 patients were identified and combined using a random-effects model. Results Patients randomized to treatment with a 5HT2 antagonist were as likely to experience clinical response as patients randomized to treatment with an SSRI (RR=1.002, 95% CI: 0.85–1.17, P =0.978). Pooled response rates for trazodone/nefazodone and the SSRIs were 61.1% and 61.7%, respectively. There was also no difference in overall discontinuation rates ( P =0.334), discontinuation due to adverse events ( P =0.676), or discontinuation due to inefficacy ( P =0.289) between the two groups. Conclusions These results suggest that the 5HT2-receptor antagonists trazodone and nefazodone and the SSRIs do not differ with respect to their overall efficacy and tolerability in the treatment of MDD. Although the sample size was relatively large and conveyed sufficient statistical power to test for differences in the overall sample, depression is a heterogeneous condition and differences may exist between treatments in particular subgroups of patients.
Rolling Friction on a Wheeled Laboratory Cart.

A simple model is developed that predicts the coefficient of rolling friction for an undriven laboratory cart on a track that is approximately independent of the mass loaded onto the cart and of the angle of inclination of the track. The model includes both deformation of the wheels/track and frictional torque at the axles/bearings. The concept of rolling friction is contrasted with the static or kinetic friction that in general is also present, such as for a cylinder or ball rolling along a horizontal or inclined surface.
Anticoagulation Monitoring Part 1: Warfarin and Parenteral Direct Thrombin Inhibitors

OBJECTIVE:To review the availability, mechanisms, limitations, and clinical application of point-of-care (POC) devices used in the management of warfarin and parenteral direct thrombin inhibitors.DATA SOURCES:Scientific articles were identified through a MEDLINE search (1966–August 2004), manufacturer Web sites, additional references listed in articles and Web sites, and abstracts from scientific meetings.STUDY SELECTION AND DATA EXTRACTION:English-language literature from clinical trials was reviewed to evaluate the accuracy, reliability, and clinical application of POC monitoring devices.DATA SYNTHESIS:The prothrombin time expressed as the international normalized ratio (PT—INR) is a well-established test for monitoring warfarin anticoagulation. Multiple devices are available for POC testing. Because there is no universally accepted standard, the performance of each device is typically tested against a standard test performed in a reference laboratory. Performance of currently available devices, as meas...
Complex decision-making in stroke: preoperative mechanical thrombectomy of septic embolus for emergency cardiac valve surgery

Stroke is a common and devastating embolic manifestation of infective endocarditis. We report a case of cardioembolic stroke in a patient with enterococcal endocarditis, with National Institutes of Health Stroke Scale score of 3. A middle-aged patient with bacterial endocarditis exhibited mild intermittent left hemiparesis and dysarthria in the setting of severe aortic insufficiency requiring urgent aortic valve replacement. Cerebrovascular imaging revealed a partially occlusive thrombus in the M1 segment of the right middle cerebral artery, which became symptomatic during relative hypotension. Given the expected hypotension during the urgently needed aortic valve replacement, there was a significant risk of infarction of most of the right hemisphere. Thus, mechanical thrombectomy was performed immediately prior to thoracotomy, and the patient awoke neurologically intact. This case demonstrates avoidance of a large stroke due to a subocclusive thrombus and anticipated intraoperative hypotension with preoperative mechanical thrombectomy.