cssi/SciSciGPT-SciSciNet huggingface dataset:
The role of the Fontan procedure in the surgical treatment of congenital heart malformations with double-outlet right ventricle

Abstract The Fontan procedure in one of its many modifications is applicable to the surgical treatment of those patients with double-outlet right ventricle who are not amenable to bi-ventricular correction. Included in this group are patients with significant hypoplasia of one of the ventricles, patients with distant (non-committed) ventricular septal defect, patients with significant straddling of the atrioventricular valves, patients with abnormal atrioventricular connections (such as absence of one of the valves), or common atrioventricular valve connection. The presence of complex associated lesions such as those seen in the heterotaxia syndromes may, by virtue of the surgical risk of attempts at bi-ventricular repair, make the Fontan approach a suitable option for these patients. The presence of a subaortic conus and the potential for subaortic obstruction, a frequent findings in patients with double outlet right ventricle, plays an important role in the preparation and conduct of the Fontan operation. Copyright © 2000 by W.B. Saunders Company
An intelligent agent for multimedia

This paper presents an approach to building an intelligent agent for personalized multimedia information filtering. A so-called "intelligent personal agent" adapts to the needs of users by interacting with them in various manners. We go beyond the keyword boundary and propose the notion of a "multimedia profile" which acts as an interface in providing a suitable and easy representation of user interests. A group of "interest profiles" are maintained in the multimedia profile. A "picture board" in the profile provides image selections to compose an interest profile. Audio and video sections in the profile can also be used for the same purpose. The personal agents of different users can possess specialized skills other than filtering the newspaper, like creating "documentaries" and offering them to other users or their agents.
Characterization of monomeric and dimeric forms of recombinant Sml1p-histag protein by electrospray mass spectrometry.

Abstract Sml1p is small protein that binds to and inhibits the activity of ribonucleotide reductase (RNR) 3 , a protein enzyme complex that controls the balance and level of the cellular deoxynucleotide diphosphate pools that are critical for DNA synthesis and repair. In this respect, Sml1p is a checkpoint protein whose function is to regulate the activity of the large subunit of RNR (Rnr1p). Sml1p is thought to be regulated by the MEC1/RAD53 cell cycle checkpoint pathway. Neither the structure of Sml1p nor its complex to Rnr1p is well known. In this report, we describe how a recombinant Sml1p-histag protein (in both monomeric and dimeric forms) can be characterized with electrospray mass spectrometry. Mass spectrometry can play a vital role in the study of the Sml1p-Rnr1p complex by: ( 1 ) confirming the identities and purities of recombinant proteins such as Sm1lp-histag (with mass accuracy and resolution far superior to SDS–PAGE) and ( 2 ) verifying the presence or absence of PTM, chemical modifications, or metal–ion binding to the protein species, which may alter the function and binding of the protein partners.
Polyurethane analog of the polyester, polyethylene terephthalate

Polyethylene piperazine-1,4-dicarboxylate, a polyurethane which structurally resembles the polyester, polyethylene terephthalate, was prepared by interfacial polymerization, and the properties of the two polymers, as well as the alternating copolymer of the two structures, are compared. Information on the molecular weight and molecular weight distribution of the polyurethane is presented, and a mechanism for the thermal decomposition observed is proposed. A series of copolymers of polyethylene piperazine-1,4-dicarboxylate with high melting polyamides was prepared by reacting piperazine with mixtures of ethylene bischloroformate with adipoyl, terephthaloyl, and bibenzoyl chlorides and data on crystalline melting points, solubility, and water absorption are given. It is concluded that the adipamide and terephthalamide copolymers with the polyethylene piperazine-1,4-dicarboxylate exhibited isomorphism.
Maternal influence on the decision to adopt Norplant.

Purpose: To examine maternal influence and related variables on adolescents' decision to adopt Norplant. Methods: A prospective study of 121 adolescent females who received Norplant through a hospital-based outpatient adolescent gynecology service. Each patient completed self-report questionnaires about her decision process, sexual behaviors and standardized measures of depression and anxiety at their insertion appointment or first-follow-up appointment. Results: Almost 40% of the sample reported that their mother significantly influenced their decision to use Norplant and 61% of all patients stated that they had informed their mother of their choice of this contraceptive method. Through logistic regression, six variables were found to be significantly associated with mother as the most important decision source. These included: obtaining information about Norplant from a parent, maintaining the same sexual partner, past pill use, and not knowing other adolescents who boast about using the Norplant system. Conclusion: These data suggest that when parental consent is not required, adolescent females disclose sensitive information regarding choice-making to their mothers when they decided to adopt Norplant.
Epidemiology of prostatitis

Background Prostatitis describes a combination of infectious diseases (acute and chronic bacterial prostatitis), chronic pelvic pain syndrome, and asymptomatic inflammation.
Short haul aviation: Will energy limit its future?

Abstract The paper examines transportation's particular dependence on petroleum products and the relative efficiency of air as compared to other modes in short haul markets. Policy alternatives are examined and their impacts on the overall transportation and air systems predicted. It concludes that any of the policy options will result in a curtailment in the short haul air system we know today. Whether the long haul air system will also suffer and whether short haul markets will receive adequate service by other modes will depend on which policy option is chosen.
Invited paper: Future of global optimization in optical design

Global Optimization (GO) is an area of applied mathemetics that has been active for many years. A large variety of GO algorithms have been constructed in an effort to find a solution to the general GO problem. Some of these have proved to be successful on certain classes of problems. However no general deterministic algorithm exists that can locate the global optimum for every multidimensional problem. Traditionally in the lens design discipline the search for an optimum solution in the design space has been done by optimization methods. The conventional design methods are in principle local search methods and do not pmvide any global information on the design space. As the available computer power increases GO tools can be used also in optical design. A two phase search algorithm based on global optimization techniques is described. In a first phase using a coarse sampling approach the program finds the favorable regions that correspond to potentially promising configurations. In a second phase conventional optimization routines are used to find the best solutions in eh region. Then an optimum solution is determined according to the application at hand. The pro algorithm is analyzed and compared to more conventional design approaches. A further refmement of the algorithm excludes from the systematic search some unfavorable configuration regions through the use of a simple expert system. Search times are further reduced through parallel-processing methods. We believe this approach to lens design represents new initiative towards the determination of the optimum solution in any lens design problem. 1.
Extent and sources of geographic variation in Medicare end-stage renal disease expenditures.

Abstract Geographic variations in practices and expenditures have been widely documented, leading to concerns that care in some regions is clinically suboptimal and/or economically inefficient. Our objectives are to determine the extent and sources of geographic variation in Medicare expenditures per patient with end-stage renal disease (ESRD) per year. The study population included all patients with ESRD with Medicare as primary payer during 1997 (n = 284,670). Medicare expenditures were summarized at the hospital referral region (HRR) level. Using regression analysis, we estimated the relationship between expenditures and demographics, case mix, dialysis provider characteristics, distribution of patients across renal replacement therapy modalities, standardized hospitalization ratios, and healthcare wages. Spending per patient-year varied threefold across HRRs, ranging from $17,791 to $59,025 (mean, $38,966 ± $6,774 [SD]). The regression equation explained 80% of this variation. Although several demographic and case-mix indicators that have been related to spending at the individual level were statistically significant predictors of spending at the HRR level, they did not show enough geographic variation to explain a large fraction of spending variation. Rather, patient distributions across renal replacement modalities, hospitalization patterns, and healthcare wages were the most powerful predictors of spending. Compared with Medicare generally, both the mean and SD of ESRD expenditures were approximately seven times larger. The substantial geographic variability in expenditures for patients with ESRD indicates the potential for improving efficiency and quality of care. Interventions designed to increase transplantation rates, ensure access to peritoneal dialysis, and reduce hospitalization appear most promising. © 2001 by the National Kidney Foundation, Inc.
Multiplex pure rotational coherent anti-stokes Raman spectroscopy in a molecular beam

Pure rotational coherent anti-Stokes Raman spectroscopy using a single broad-band dye laser was applied to study the rotational energy distribution of molecules in a pulsed supersonic beam. The multiplex BOXCARS configuration allows the accurate determination of rotational constants and rotational temperatures, and offers many advantages over other methods. The technique was applied to calibrate the cooling effect of a pulsed molecular beam of nitrogen and to study the rotational energy distributions of infrared multiphoton-excited ethylene.
Natural resources and the marshallian effects of input-reducing technological changes

Abstract Input-reducing technologies are often cited as potential solutions to the pressure for over-harvesting natural resources. The underlying implicit assumption that technological change reducing the Hicksian input demand also reduces the Marshallian input demand neglects the impacts of input-reducing technological changes on Marshallian supplies. This reasearch shows that Marshallian supply effects generally offset the impacts of technological change on Hicksian input demands, and, if the offset is large enough, Marshallian input demands could even increase. As an example, I statistically determine the extent increased technological efficiency in lumber production reduced the demand for sawlogs in the Pacific Northwest. The statistical results indicate that input-reducing technological changes did not reduce the overall Marshallian demand for sawlogs. Resource conservation policies which rely solely on the implementation of input-reducing technologies may be ineffective or even counterproductive.
The War Proneness of Alliances

In the theoretical literature, alliances have been hypothesized to lead to war as well as away from war. This study statistically examines the relationship between the size of alliances and the war...
Increased Rheb-TOR signaling enhances sensitivity of the whole organism to oxidative stress

The accumulation of free radical damage to an organism over its lifespan can cause premature aging and disease including cancer, atherosclerosis and neurodegenerative disorders. The well-conserved Rheb-Target-of-rapamycin (TOR)-S6-kinase (S6K) signaling pathway regulates several cellular processes and has been shown to influence lifespan and diseases such as cancer and neurodegenerative disorders. Using adult Drosophila, we describe for the first time in metazoans that TOR activity can influence the stress response. We find that mildly increasing systemic Rheb-TOR-S6K signaling sensitizes the whole organism to oxidative stress and promotes senescence of locomotor activity with age. Furthermore, we find that S6K is required for increased Rheb-TOR signaling to sensitize the whole organism to oxidative stress and promote the senescence of locomotor activity. Interestingly, we also find that increasing Rheb-TOR signaling in muscle can increase the sensitivity of adults to oxidative stress. These data imply that pathological situations that increase TOR activity might perturb the ability of the whole organism to cope with stress causing disease progression and aging.
Depression in epilepsy : a complex relation with unexpected consequences

Purpose of review The recent significant increase in research on depressive disorders in epilepsy has led to a greater recognition of its negative impact on multiple aspects of these patients' lives. Thus, a review of this topic could not be timelier. Recent findings A population-based study suggests that a lifetime history of depressive disorders is relatively frequent in epilepsy patients. Contrary to long-held beliefs, the relation between these two disorders is bidirectional and a history of depression can often be identified before the first seizure has ever happened. Such a relation is the expression of common pathogenic mechanisms operant in both conditions, among which decreased binding of serotonin-1A receptors appears to be pivotal. Furthermore, a lifetime history of depression preceding the onset of epilepsy appears to be predictive of worse seizure control with pharmacotherapy and epilepsy surgery. Summary These data are likely to change the way the relation between depression and epilepsy is conceptualized, to enhance the early recognition and treatment of this disorder and to generate further research on the impact of depressive disorders on seizure response to pharmacologic and surgical treatments.
Pressure broadening of rotational bands. I - A statistical theory

Absorption of electromagnetic waves by rotational transitions of molecules is formulated for the case in which the wave frequency is displaced from resonance by an amount large compared to the reciprocal duration of a typical binary collision, and also large compared to the differences between frequencies of the strong resonances of the gas. In this far-wing limit, Fano's relaxation operator is reduced to a scalar parameter which depends on the frequency displacement. This relaxation parameter is not symmetric with respect to reflection about resonance, but becomes symmetric when multiplied by the factor exp (h/2pi) (omega sub d)/2kT where omega sub d is the frequency displacement. The theory applies to dipolar molecules of any shape, in collisions with either dipolar or quadrupolar molecules.
Repression of cointegration ability of insertion element IS1 by transcriptional readthrough from flanking regions

We describe a repression mechanism in which read-through messages transcribed from a gene into an IS1 sequence inhibit its ability to mediate plasmid cointegration. This mechanism was derived from the demonstration that removal of the promoter region of the chloramphenicol resistance gene in transposon Tn9, or introduction of a strong transcription terminator of phage T7 downstream of the chloramphenicol resistance gene, increases the cointegration ability of the downstream IS1 sequence when in a particular orientation. The cointegration ability of an IS1 sequence downstream of the chloramphenicol resistance gene but in an orientation opposite that of the above-mentioned IS1 sequence also can be repressed. Analysis of transcripts synthesized in vitro showed that the transcripts of the chloramphenicol resistance gene were read through into the IS1 sequence located downstream of the gene in either orientation. Repression of this type may be one mechanism that controls the rate of transposition of the IS1 element, which apparently does not encode a structural gene for repressor.
Multiple) Channel acquisition and contention handling mechanisms for dynamic spectrum access in a distributed system of cognitive radio networks

In dynamic spectrum access, cognitive radio networks compete with one another to acquire under-utilized and idle channels for data transmission. Each network strives to acquire as many channels as possible to satisfy its maximum channel requirement. The main goal of a network is to maximize its utility and at the same time minimize the amount of contention it experiences with other secondary networks. In this paper we focus on the study of channel acquisition and contention handling mechanisms that a system of networks can adopt to maximize utility and minimize contention. A system of networks becomes stable if all networks have acquired enough number of channels to satisfy their channel requirements without any contention between them. It is obvious that a network's utility depends on the stability of the system and how fast the stability is attained. The mechanisms proposed in this paper ensure fast convergence of the system by minimizing the contention experienced until a state of equilibrium is finally attained. Simulation experiments were conducted taking into consideration the unpredictable behavior of the primary users who are the licensed owners of the spectrum bands.
A Condition Based Maintenance Model with Exponential Failures and Fixed Inspection Intervals

This paper discusses a condition based maintenance model with exponential failures, and fixed inspection intervals. A condition of the equipment, such as vibration, is monitored at equidistant time intervals. If the variable indicating the condition is above a threshold an instantaneous maintenance action is performed and the monitored condition takes on its initial value. The equipment can fail only once within an inspection interval. The probability of failure is exponential and the failure rate is dependent on the condition. The cost to be minimized is the long-run average cost of maintenance actions and failures. We study the optimal solution to this problem obtained via dynamic programming and compare it to an approximate steady state solution based on renewal theory.
In vivo study on the short-term effect of radiofrequency energy on chondromalacic patellar cartilage and its correlation with calcified cartilage pathology in an equine model.

Chondromalacia can cause joint pain and synovial effusion with the potential for developing into osteoarthritis. Thermal chondroplasty using radiofrequency energy (RFE) has been reported to be superior to mechanical debridement for treating chondromalacia. We compared short-term changes in biomechanical properties of articular cartilage after treatment with monopolar (mRFE) or bipolar RFE (bRFE) or mechanical debridement (MD) on experimentally created grade II chondromalacia patellae. Chondromalacia patellae was created arthroscopically in both patellae of 15 ponies. Ten months after surgery, each patella was randomly assigned to one of four experimental groups: sham operated, untreated control; MD; bRFE; and mRFE. Animals were euthanized 6 months after treatment and fresh osteochondral sections were collected from the treated area, the border of the chondromalacic and nonchondromalacic area, and from two untreated areas for analysis of mechanical properties. The same areas were harvested from an additional six untreated ponies. The aggregate modulus (HA), Poisson's ratio (νs), and permeability (k) were determined for each area under creep indentation, and cartilage thickness was measured with a needle probe. The relation between zone of calcified cartilage (ZCC) and mechanical properties of hyaline cartilage (HC) was assessed histomorphometrically. Treated areas of all four groups had inferior mechanical properties compared at the same location. The treated and border areas had significantly lower HA values than the untreated areas. Permeability values showed significant differences between bRFE and other treated groups. Chondromalacic areas showed thinning of cartilage compared to nonchondromalacic areas. Biomechanical properties of the injured cartilage were inferior to nonchondromalacic cartilage regardless of the treatment type. mRFE had the highest stiffness value compared to other treatments and significantly higher values than MD. A significant correlation was observed between the mechanical properties of HC and ZCC thickness. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Viscosities of fatty acids and methylated fatty acids saturated with supercritical carbon dioxide

The viscosities of several types of lipids saturated with supercritical carbon dioxide (SC-CO2) were measured with a high-pressure capillary viscometer. Oleic acid and linoleic acid were evaluated from 85 to 350 bar at 40 and 60°C. The more SC-CO2-soluble methylated derivatives of these fatty acids were evaluated from 90 to 170 bar at 40 and 60°C. The complex mixture of anhydrous milk fat (AMF) was evaluated from 100–310 bar at 40°C. The viscosities of the methylated fatty acids saturated with SC-CO2 decreased between 5 and 10 times when the pressure increased from 1 to 80 bar, followed by a further decrease by a factor of 2 to 3 when the pressure was increased from 80 to 180 bar. The viscosities of the fatty acids and AMF saturated with SC-CO2 had viscosity reduction similar to the methylated fatty acids between 1 and 80 bar, but they decreased much less between 80 and 350 bar. At constant pressure, the viscosity of the fatty acids and AMF decreased with increasing temperature, whereas the viscosity of the methylated fatty acids increased with increasing temperature. The lipid/SC-CO2 mixtures were Newtonian, and their viscosities were best interpreted by using the mass concentration of dissolved SC-CO2 in the lipids and the pure component viscosities.
The North American Menopause Society recommendations for clinical care of midlife women.

In celebration of the 25th anniversary of The North American Menopause Society (NAMS), the Society has compiled a set of key points and clinical recommendations for the care of midlife women. NAMS has always been a premier source of information about menopause for both healthcare providers and midli
Organ transplantation in rodents: Novel applications of long-established methods

Rodent models of solid organ transplantation have been used for many decades. Standardized operative techniques resulting in highly reproducible survival rates have been developed for several organs. This allowed scientists to investigate many clinically relevant problems, test new drugs and establish novel treatment regimens. Recently, many studies used these models to explore novel issues such as graft modification by pharmaceutical, surgical or genetic engineering methods, post-transplant regeneration, leukocyte trafficking or interactions between the innate and allo-specific arms of the immune response. The results from these studies clearly facilitate a more complex and comprehensive understanding of existing problem. The long-established methods of rodent organ transplantation, combined with the newest achievements in surgical techniques, biotechnology and imaging, will remain indispensable tools of transplantation biology.
Semi-nondestructive genetic sampling from live eusocial wasps, Polistes dominulu and Polistes fuscatu

We present a method of extracting DNA from medium-sized paper wasps without sacrificing the animal. From the distal half of a single leg, enough DNA is extracted for 125 PCR reactions. This DNA - collected from Polistes dominulus and P. fuscatus– amplifies as well as DNA extracted from larger amounts of tissue taken from sacrificed animals, and the resulting microsatellite regions amplify faithfully. Although the nest tenure of P. dominulus workers with leg-cuts was shorter than control animals, test animals appeared to behave normally. This DNA extraction method is well suited for studies that combine behavioral observations and genetic analysis on animals likely to disappear during the observation period. Collecting genetic data without destroying colonies will enable researchers to examine behavior in eusocial insects without damaging the future population size or altering the population genetic structure.
Susceptibility of myelin proteins to a neutral endoproteinase: the degradation of myelin basic protein (MBP) and P2 protein by purified bovine brain multicatalytic proteinase complex (MPC).

Multicatalytic proteinase complex (MPC) was isolated from bovine brain and the susceptibility of myelin basic protein (MBP) and P2 protein of bovine central and peripheral nervous system was examined. SDS-polyacrylamide electrophoretic analysis of purified MPC revealed protein bands of molecular weight ranging from 22–35 kDa. The enzyme is activated by SDS at a concentration less than 0.01%. Upon incubation with MPC, purified MBP and P2 proteins were degraded into smaller fragments. There was a 57% and 100% loss of MBP at 2 and 6 hours of incubation. The P2 protein which is not susceptible to any endogenous non-lysosomal enzyme thus far studied was digested into small peptide fragments only in the presence of SDS (0.01%) and not in its absence. These results indicate that MPC which is active at physiological conditions may have a role in the turnover of myelin proteins and in demyelinating diseases.
An extended local connectionist manifesto: Embracing relational and procedural knowledge

Page has performed an important service by dispelling several myths and misconceptions concerning the localist approach. The localist position and computational model presented in the target article, however, are overly restrictive and do not address the representation of complex conceptual items such as events, situations, actions, and plans. Working toward the representation of such items leads to a more sophisticated and articulated view of the localist approach.
Dephosphorylation of cardiac myofibril C-protein by protein phosphatase 1 and protein phosphatase 2A.

Abstract C-protein purified from chicken cardiac myofibrils was phosphorylated with the catalytic subunit of cAMP-dependent protein kinase to nearly 3 mol [ 32 P]phosphate/mol C protein. Digestion of 32 P-labeled C-protein with trypsin revealed that the radioactivity was nearly equally distributed in three tryptic peptides which were separated by reversed-phase HPLC. Fragmentation of 32 P-labeled C-protein with CNBr showed that the isotope was incorporated at different ratios in three CNBr fragments which were separated on polyacrylamide gels in the presence of sodium dodecyl sulfate. Phosphorylation was present in both serine and threonine residues. Incubation of 32 P-labeled C-protein with the catalytic subunit of protein phosphatase 1 or 2A rapidly removed 30–40% of the [ 32 P]phosphate. The major site(s) dephosphorylated by either one of the phosphatases was a phosphothreonine residue(s) apparently located on the same tryptic peptide and on the same CNBr fragment. CNBr fragmentation also revealed a minor phosphorylation site which was dephosphorylated by either of the phosphatases. Increasing the incubation period or the phosphatase concentration did not result in any further dephosphorylation of C-protein by phosphatase 1, but phosphatase 2A at high concentrations could completely dephosphorylate C-protein. These results demonstrate that C-protein phosphorylated with cAMP-dependent protein kinase can be dephosphorylated by protein phosphatases 1 and 2A. It is suggested that the enzyme responsible for dephosphorylation of C-protein in vivo is phosphatase 2A.
Utilizing Local Phase Information to Remove Rain from Video

In the context of extracting information from video, bad weather conditions like rain can have a detrimental effect. In this paper, a novel framework to detect and remove rain streaks from video is proposed. The first part of the proposed framework for rain removal is a technique to detect rain streaks based on phase congruency features. The variation of features from frame to frame is used to estimate the candidate rain pixels in a frame. In order to reduce the number of false candidates due to global motion, frames are registered using phase correlation. The second part of the proposed framework is a novel reconstruction technique that utilizes information from three different sources, which are intensities of the rain affected pixel, spatial neighbors, and temporal neighbors. An optimal estimate for the actual intensity of the rain affected pixel is made based on the minimization of registration error between frames. An optical flow technique using local phase information is adopted for registration. This part of the proposed framework for removing rain is modeled such that the presence of local motion will not distort the features in the reconstructed video. The proposed framework is evaluated quantitatively and qualitatively on a variety of videos with varying complexities. The effectiveness of the algorithm is quantitatively verified by computing a no-reference image quality measure on individual frames of the reconstructed video. From a variety of experiments that are performed on output videos, it is shown that the proposed technique performs better than state-of-the-art techniques.
Decomposition of alkyl-substituted urea molecules at a hydroxide-bridged dinickel center.

The interactions between N-methylurea, N,N‘-dimethylurea, N,N-dimethylurea, tetramethylurea, and thiourea and the hydroxide-bridged dinickel complex [Ni2(μ-OH)(μ-H2O)(bdptz)(H2O)2](OTs)3 were investigated. Structural characterization of [Ni2(μ-OH)(μ-H2O)(bdptz)(Me-urea)(CH3CN)](ClO4)3 (1) and [Ni2(μ-OH)(μ-H2O)(bdptz)(thiourea)(CH3CN)](ClO4)3 (2) provided insight into the interactions of the substrates with the dinickel center. In 1, the methylurea molecule coordinates to the dinickel complex through its carbonyl oxygen atom. Complex 2 has a similar geometry, with the thiourea molecule bound to a nickel ion through its sulfur atom. When the urea substrates are heated in the presence of the hydroxide-bridged dinickel complex, N-methylurea and N,N-dimethylurea react to form methylammonium cyanate and dimethylammonium cyanate, respectively. After long reaction times, thiourea reacts similarly, producing ammonium thiocyanate. The other substrates are unreactive. These results indicate that the dinickel complex...
Myocardial metabolic imaging in the acute care setting

There are more than 5 million annual emergency department (ED) visits in the United States alone for evaluation of chest pain and other related symptoms. Accurately distinguishing patients with a true acute coronary syndrome (ACS) from those with noncardiac chest pain is paramount not only for proper triage and initiation of appropriate therapy but also in streamlining cost by avoiding unnecessary hospitalization and diagnostic testing in patients without cardiac conditions. Although patients with typical symptoms and electrocardiographic (ECG) changes are identified readily, they represent a small minority of ED encounters. In fact, the number of patients with acute myocardial infarction (AMI) with ST-segment elevation is diminishing in relation to the emerging larger number of patients with AMI with non–ST-segment elevation and unstable angina who may not have characteristic ECG changes or an early rise in cardiac enzyme levels, if at all.
A variable-angled suction nerve root retractor for lumbar spine surgery.

A simple, variable-angled suction nerve root retractor is described for use primarily in lumbar disc surgery.
Diffusion and reaction in high-occupancy zeolite catalysis—II. Experimental results

The equilibrium sorption and uptake diffusion of C6C8 alkylbenzenes in HZSM-5-catalysts are studied between 23 and 128°C, using a high-sensitivity vacuum electrobalance. At room temperature, sorption of benzene, toluene and p-xylene exhibits hysteresis, indicating a phase change. At high temperatures ( > 68°C), sorption is reversible up to 0.1 of saturation pressure. The uptake diffusivity (Du) increases by a factor of 30 with occupancy up to ∼ 4 molecules/unit cell. The counterdiffusion rate of the binary benzene—toluene system, on the other hand, decreases sharply with occupancy. The occupancy dependence of Du for the single-component sorption, and the counterdiffusion behavior of the benzene—toluene system are in qualitative agreement with the predictions of the stochastic theory of Part I.
Experimental cyanine red, a new stain for nucleic acids and acid mucopolysaccharides.

A new cationic dye, experimental cyanine red (du Pont), with an absorption maximum of 536 mμ and a pH of 2.9 in 0.5% aqueous solution, is shown to be suitable for staining nucleic acids and tissue materials presumed to contain acid mucopolysaccharides. Mammalian tissues fixed in 10% neutral buffered formalin or Bouin's fluid are dehydrated, embedded in paraffin, sectioned, mounted, deparaffinized, passed through ethanols to water, and stained for 3-30 min in 0.5% experimental cyanine red in water. Differentiation and dehydration in 3 changes (about 1 min each) of n-butanol is followed by clearing in xylene and mounting in resin.
Identification of high- and low-affinity NGF receptors during development of the chicken central nervous system.

Abstract In order to study regulation of the nerve growth factor (NGF) receptor during embryogenesis in chick brain, we have used affinity crosslinking of tissues with 125 I-NGF. NGF interacts with high- and low-affinity receptors; high-affinity receptors are required for the majority of NGF's actions. Most measurements of receptor levels do not distinguish between high- and low-affinity forms of the receptor. We have used the lipophilic crosslinking agent HSAB to identify the high-affinity, functional receptor during development of the chicken central nervous system. A peak of expression during Embryonic Days 5–10 was detected in all regions of the chicken central nervous system, but, shortly after birth, only the cerebellar region displays significant levels of NGF receptor protein. The time course of expression confirms the dramatic regulation of the NGF receptor gene during defined embryonic periods. The detection of high-affinity NGF receptors in brain and neural retina provides strong evidence that NGF is involved in essential ontogenetic events in the development of the chicken central nervous system.
Testing of child-resistant containers.

(1978). Testing of Child-Resistant Containers. Clinical Toxicology: Vol. 12, No. 3, pp. 357-365.
Measurement of Ultraviolet Exposure in Epidemiological Studies of Skin and Skin Cancers

As our understanding of the role of UV in causing skin cancer continues to expand, researchers and clinicians must continue to remain up to date on the various means by which UV exposure can be quantified. The purpose of this article was to review the current methods used to measure lifetime exposure to UV and to summarize the strengths and weaknesses of each of these approaches. Thus we include here a review of research articles that deal with questionnaire reliability and physical examination. We also review more technologically advanced techniques used to measure chronic UV exposure; these include microtopography, histology, gene studies and spectroscopy. Both the utility of using a specific measurement technique and the accuracy of particular techniques are explored. Finally, we touch upon the results of articles that link UV exposure to skin cancer and what this means for the future of UV-induced skin cancer research.
Dextromethorphan reduces neocortical ischemic neuronal damage in vivo.

The dextrorotatory morphinan dextromethorphan (DM), a clinically tested antagonist of the (NMDA) receptor-channel complex, was tested in an in vivo model of acute transient focal cerebral ischemia. Rabbits were randomly assigned to pretreatment with a 20 mg/kg i.v. bolus followed by 10 mg/kg/h of 0.4% DM in normal saline (NS), or with an equivalent volume of NS alone. They then underwent 1 h occlusion of the left internal carotid artery and anterior cerebral artery followed by 4 h of reperfusion. DM-treated animals showed a significant decrease in the percentage of severe neocortical ischemic neuronal damage (10.5%), as compared to NS-treated animals (49.6%).
Fluidized-Bed Fluoride Volatility Processing of Irradiated UO2 Fuels

In five laboratory-scale experiments in which irradiated UO2 reactor fuel was processed in a fluidized bed, high removals of uranium and plutonium were achieved by oxidizing with O2, fluorinating w...
Water intake and plasma renin activity of rats after intravenous infusions of rat renin.

Abstract Rats infused intravenously with homologous renin (0.1–16 U) for 40 min exhibited a linear relation between administered dose and water intake. At the lower doses, observed plasma renin activities also were proportional to water consumption but the intakes were not very large. These results are consistent with other recent findings that raised doubts about the normal role of angiotensin as a dipsogen. At the higher doses, plasma renin activities and angiotensin I levels were reduced compared to the lower doses of renin suggesting that plasma renin substrate had been severely depleted. The explanation for the sustained increases in water intake remains to be determined.
Reply to 'Is ALS caused by an altered oxidative activity of mutant superoxide dismutase?'

Although the molecular mechanisms whereby mutant SOD1 causes selective motor neuron death remain unclear, a prevalent hypothesis1, 2 is that the toxic property of mutant SOD1 might be related to mutation-induced conformational changes in SOD1 that result in aberrant oxidative activities, which are catalyzed by the copper atom that is bound in the active site of mutant SOD1. The realization that the copper chaperone for SOD1 (CCS) is necessary for efficient copper incorporation into SOD1 in yeast12 and in mammals8 encouraged us to directly test this copper theory in vivo by deleting the CCS in multiple lines of mutant SOD1 mice. The absence of CCS results in a significant reduction in the level of copper-loaded mutant SOD1, but it has no effect on the onset, progression or pathology of motor neuron disease in mutant SOD1 mice7. These results demonstrate that aberrant, Cu-dependent activity of mutant SOD1 does not participate in the pathogenesis of familial ALS (FALS).
Malaligned dynamic anterior cervical plate: a biomechanical analysis of effectiveness.

Study design Biomechanical evaluation. Objective To evaluate the kinematic and load-sharing differences of dynamic anterior cervical plates when placed in-line at 0° and off-axis at 20°. Summary of background data The use of dynamic anterior cervical plating systems has recently gained popularity due to the theoretical benefit of improved load sharing with graft subsidence. Occasionally, due to anatomical restraints, the anterior cervical plate may be placed off-axis in the coronal plane. This may potentially decrease the dynamization capability of the plate, leading to less load sharing and potentially decreased fusion rates. The purpose of this study was to comprehensively evaluate the kinematic and load-sharing differences of a dynamic plate placed in-line versus off-axis in the coronal plane. Methods Thirteen fresh-frozen human cadaveric cervical spines (C2-T1) were used. Nondestructive range-of-motion testing was performed with a pneumatically controlled spine simulator in flexion/extension, lateral bending, and axial rotation using the OptoTrak motion measurement system. A C5 corpectomy was performed, and a custom interbody spacer with an integrated load cell collected load-sharing data under axial compression at varying loads. A dynamic anterior cervical plate was placed in-line at 0° and then off-axis at 20°. Testing conditions ensued using a full-length spacer, followed by simulated subsidence by removing 10% of the height of the original spacer. Results There were no kinematic differences noted in the in-line model versus the off-axis model. After simulated subsidence, the small decreases in stiffness and increases in motion were similar whether the plate was placed in-line or off-axis in all 3 planes of motion. There were also no significant differences in the load-sharing characteristics of the in-line plate versus the off-axis plate in either the full-length model or the subsided interbody model. Conclusion This study suggests that off-axis dynamic plate positioning does not significantly impact construct kinematics or graft load sharing. As such, we do not recommend removal or repositioning of an off-axis placed dynamic plate because the kinematic and load-sharing biomechanical properties are similar. Level of evidence N/A.
Meeting Sex Partners Through the Internet, Risky Sexual Behavior, and HIV Testing Among Sexually Transmitted Infections Clinic Patients

The Internet has now become a popular venue to meet sex partners. People who use the Internet to meet sex partners may be at a higher risk for contracting HIV and STIs. This study examined the association between meeting sex partners from the Internet, and HIV testing, STI history, and risky sexual behavior. Data were obtained from the Virginia Department of Health STD Surveillance Network. Logistic regression models were used to obtain crude and adjusted odds ratios, and 95 % confidence intervals for the associations between meeting sex partners through the Internet and ever tested for HIV, HIV testing in the past 12 months, STI history, and risky sexual behavior. Logistic regression was also used to determine if gender and men who have sex with men interaction terms significantly improved the model. Women who met a sex partner from the Internet were more likely to have had an HIV test in the past 12 months than women who did not meet a partner in this way. On the other hand, men who met a sex partner through the Internet were more likely to have ever had an HIV test than other men, but this was only seen for heterosexual men. All populations who met a sex partner from the Internet were more likely to take part in risky sexual behavior. HIV prevention strategies should emphasize annual testing for all populations.
Dynamics of the Bacterial Flagellar Motor: The Effects of Stator Compliance, Back Steps, Temperature, and Rotational Asymmetry

The rotation of a bacterial flagellar motor (BFM) is driven by multiple stators tethered to the cell wall. Here, we extend a recently proposed power-stroke model to study the BFM dynamics under different biophysical conditions. Our model explains several key experimental observations and reveals their underlying mechanisms. 1), The observed independence of the speed at low load on the number of stators is explained by a force-dependent stepping mechanism that is independent of the strength of the stator tethering spring. Conversely, without force-dependent stepping, an unrealistically weak stator spring is required. 2), Our model with back-stepping naturally explains the observed absence of a barrier to backward rotation. Using the same set of parameters, it also explains BFM behaviors in the high-speed negative-torque regime. 3), From the measured temperature dependence of the maximum speed, our model shows that stator-stepping is a thermally activated process with an energy barrier. 4), The recently observed asymmetry in the torque-speed curve between counterclockwise- and clockwise-rotating BFMs can be quantitatively explained by the asymmetry in the stator-rotor interaction potentials, i.e., a quasilinear form for the counterclockwise motor and a quadratic form for the clockwise motor.
Effect of copper, herbicides, and a mixed effluent on chemoattraction of tetrahymena pyriformis

The inhibitory effect of copper, 2,4-D, Roundup, and an industrial effluent on chemoattraction responses of the ciliate Tetrahymena pyriformis was examined using a microcapillary technique. Each toxicant was tested with four replicates on three separate occasions. All toxicants inhibited chemoattraction at sublethal concentrations; although at lower concentrations of the herbicides, complete recovery to control levels was observed with longer exposures. Results indicate that sublethal concentrations of certain chemical pollutants may interfere with the ciliate's motility or chemosensory abilities. This may ultimately affect the ecosystem by inhibiting their ability to maintain their population levels and roles in the environment.
Sulfated mucopolysaccharide synthesis during the development of Rana pipiens.

Abstract Sulfated mucopolysaccharide (MPS) synthesis during the development of Rana pipiens was studied autoradiographically and biochemically following injection of embryos with 35 S-sulfate. 35 S-sulfate incorporation can be detected in unfertilized and fertilized eggs. The sulfate-incorporating material accumulates along the periphery of yolk platelets of eggs. During cleavage, the 35 S-sulfate-incorporating material accumulates on cell surfaces as well as along the periphery of yolk platelets. Biochemical analysis utilizing the enzymes chondroitinase ABC and AC and nitrous acid degradation indicates that the MPS synthesized during cleavage is approximately 82% heparin and/or heparan sulfate and 18% chondroitin 4-sulfate. During gastrulation, a greatly enhanced incorporation of 35 S-sulfate is observed in the invaginating chordamesoderm and lateroventral mesoderm, and by the end of gastrulation enhanced incorporation can be detected in neural tissue. During this period, chondroitin 6-sulfate synthesis is initiated. Incorporation of 35 S-sulfate is observed in all tissues of the embryo from the beginning of neurulation through hatching. This ubiquitous incorporation is accompanied by an increase in the relative amount of chondroitin 6-sulfate synthesized. During the period following hatching, incorporation is suppressed in some tissues and enhanced in others so that by the late feeding tadpole stage a very high incorporation is observed only in cartilaginous tissue. These results indicate that sulfated MPS synthesis occurs in all stages of development of Rana pipiens , but that significant changes in the rate of synthesis occur in various cell types during gastrulation and after hatching. The ubiquity of sulfated MPS synthesis during the critical early stages of development and the changes in the pattern of synthesis in various cell types suggest that these molecules are involved in a number of embryonic processes.