cssi/SciSciGPT-SciSciNet huggingface dataset:
Treatment of multidrug-resistant tuberculosis

Recent outbreaks of multi-drug-resistant tuberculosis (MDR-TB) have resulted in significant morbidity and mortality in patients with AIDS. The poor outcomes are attributable to delayed diagnoses, slow reporting of antimycobacterial susceptibility results, inadequate treatment regimens and profound immunosuppression. There are no prospective clinical trials which have evaluated the optimal treatment of MDR-TB. A retrospective study has shown that in immunocompetent patients with secondary MDR-TB, only 56% responded to prolonged courses of multiple drug regimens, and 22% died of TB. In patients with AIDS, even fewer patients respond, with median survivals of 2-4 months. In general, better responses have been associated with in vitro susceptibility of patients' isolates. If possible, patients with MDR-TB should receive at least three drugs to which their isolates are susceptible for at least 24 months; these regimens are likely to include ethambutol, pyrazinamide, a quinolone, and an aminoglycoside. Selected patients benefit from surgical intervention combined with aggressive chemotherapy. MDR-TB is best prevented by directly observed therapy of patients with susceptible organisms and rigorous infection control practices in areas of high incidence of MDR-TB. Effective treatment regimens for MDR-TB await the development of novel compounds which have better in vitro activity against MDR-TB than currently available drugs.
The electron gas: inclusion of antiparallel spin correlations

Abstract An electron gas with a uniform neutralizing background is the canonical model for the study of the properties of an interacting many-body system. Most treatments of this problem treat inadequately the correlations between anti-parallel spins which are expected to influence strongly certain properties of the system. Using a new variational formulation, we show how to handle the non-linearities introduced into the many-body equations by such correlations; the compressibility is lowered and the paramagnetic susceptibility enhanced.
Role of biliary scintiscan in predicting the need for cholangiography.

Background: Currently used predictors for bile duct calculi in patients undergoing cholecystectomy have low specificity resulting in unnecessary cholangiograms being performed. The role of biliary scintiscan in predicting the presence of bile duct calculi was assessed. Methods: Seventy-five patients with symptomatic gallstone disease were studied prospectively regarding the value of a history of jaundice or acute pancreatitis, raised serum bilirubin and serum alkaline phosphatase levels, and visualization of stones or presence of dilated bile ducts on ultrasonography (standard criteria) in detecting bile duct calculi. Results of biliary scintiscan were evaluated against a combination of standard criteria. The ‘gold standard’ for evaluation was endoscopic or peroperative cholangiography. Results: Biliary scintiscan had a higher sensitivity and specificity (93 and 94 per cent) than a combination of the above standard and modified predictors for biliary calculi (89 and 71 per cent). A combination of ultrasonography and selective use of scintiscan, in the absence of bile duct dilatation only, had higher values (96 and 98 per cent). Conclusion: A combination of ultrasonography and biliary scintiscan can accurately predict bile duct calculi and could be used as a guide for selective cholangiography. © 2000 British Journal of Surgery Society Ltd
Aging mice show a decreasing correlation of gene expression within genetic modules.

In this work we present a method for the differential analysis of gene co-expression networks and apply this method to look for large-scale transcriptional changes in aging. We derived synonymous gene co-expression networks from AGEMAP expression data for 16-month-old and 24-month-old mice. We identified a number of functional gene groups that change co-expression with age. Among these changing groups we found a trend towards declining correlation with age. In particular, we identified a modular (as opposed to uniform) decline in general correlation with age. We identified potential transcriptional mechanisms that may aid in modular correlation decline. We found that computationally identified targets of the NF-ΚB transcription factor decrease expression correlation with age. Finally, we found that genes that are prone to declining co-expression tend to be co-located on the chromosome. Our results conclude that there is a modular decline in co-expression with age in mice. They also indicate that factors relating to both chromosome domains and specific transcription factors may contribute to the decline.
Animal model for investigating the anxiogenic effects of self-administered cocaine.

Male albino rats were trained to traverse a straight alley for a reward of five intravenous injections of cocaine (0.75 mg/kg/injection in a volume of 0.1 ml/injection delivered over 4 s). Animals were tested one trial per day with the following dependent measures assessed on each trial: start latency, running time, the number of retreats, and the location within the alley where each retreat occurred. While start latencies remained short and stable, running times tended to increase over days. This effect was apparently related to a concomitant increase in the number of retreats occurring in the alley (r=0.896). Retreats tended to occur in very close proximity to the goal box, suggesting that animals working for IV cocaine come to exhibit a from of conflict behavior (i.e., retreats) putatively stemming from the drug's well documented rewarding and anxiogenic properties. Consistent with this hypothesis was the demonstration that diazepam (0.5, 1.0, 2.0 mg/kg IP) pretreatment dose-dependently reduced the incidence of retreat behaviors in the alley. In addition, the rewarding efficacy of the cocaine dosing parameters was subsequently confirmed in the runway subjects by conditioned place preference. The present paradigm, therefore, provides a useful method for investigating the anxiogenic effects of self-administered cocaine in laboratory animals.
Improving developer activity metrics with issue tracking annotations

Understanding and measuring how groups of developers collaborate on software projects can provide valuable insight into software quality and the software development process. Current practices of measuring developer collaboration (e.g. with social network analysis) usually employ metrics based on version control change log data to determine who is working on which part of the system. Version control change logs, however, do not tell the whole story. Information about the collaborative problem-solving process is also documented in the issue tracking systems that record solutions to failures, feature requests, or other development tasks. To enrich the data gained from version control change logs, we propose two annotations to be used in issue tracking systems: solution originator and solution approver. We examined the online discussions of 602 issues from the OpenMRS healthcare web application, annotating which developers were the originators of the solution to the issue, or were the approvers of the solution. We used these annotations to augment the version control change logs and found 47 more contributors to the OpenMRS project than the original 40 found in the version control change logs. Applying social network analysis to the data, we found that central developers in a developer network have a high likelihood of being approvers. These results indicate that using our two issue tracking annotations identify project collaborators that version control change logs miss. However, in the absence of our annotations, developer network centrality can be used as an estimate of the project's solution approvers. This improvement in developer activity metrics provides a valuable connection between what we can measure in the project development artifacts and the team's problem-solving process.
The Actions of Discontent: Tea Party and Property Rights Activists Pushing Back Against Regional Planning

Problem, research strategy, and findings: The Tea Party's effects on local and regional planning efforts, given the movement's fierce support of property rights and equally fierce opposition to sustainability goals in regional planning efforts, have received little study. I wanted to understand how Tea Party and fellow property rights advocates became involved in regional planning efforts in the San Francisco Bay Area and Atlanta, GA, and how planners perceived and dealt with their objections and tactics. Interactions between the two groups were marked by philosophical differences over the role of government and the necessity and value of regional planning. However, these actors were also deeply divided on plan content and the authenticity of the public outreach process. Tea Party and property rights activists were not the only ones with substantive and procedural concerns about regional planning efforts; tactical -coalitions of unexpected allies emerged, aligning on plan viability, finance methods and fu...
Implementation of a handheld electronic point-of-care billing system improved efficiency in the critical care unit.

Coding and billing are time consuming and important considerations for critical care practitioners. A 1-year prospective, observational study incorporated the use of a personal digital assistant and MDeverywhere software (Hauppauge, New York) for patient coding and billing. Twelve months of data were examined before electronic implementation (pre-elec) and compared with a 12-month period after implementation (post-elec) by using an unpaired t test or z test with P < .05 considered significant. The total number of charges was 2479 pre-elec and 2243 post-elec. The days from date of service to billing for services significantly decreased from 37.8 pre-elec to 12.4 post-elec (P < .001); days in accounts receivable significantly decreased from 92.0 to 73.0 (P < .001). The net collection rate increased from 44.7% pre-elec to 49.3% post-elec (P < .001). Duplicate charges significantly decreased from 5.0% pre-elec to 1.4% post-elec ( P < .001). The return on investment was 1.97-fold (197%). The initiation of pers...
The biological inactivity of glucose 6-phosphite, inorganic phosphites and other phosphites.

Abstract d -Glucose 6-phosphite has been synthesized by reaction of 1,2,3,4-tetra- O -acetyl-β- d -glucopyranose with PCl 3 followed by hydrolysis and deacetylation. d -Glucose 6-phosphite served neither as a substrate nor as an inhibitor of catalysis by hexokinase, glucose-6-phosphatase, glucose 6-phosphate dehydrogenase, or of fermentation by a yeast extract. Ethyl hydrogen phosphite, isopropyl hydrogen phosphite, and butyl hydrogen phosphite did not interact with intestinal phosphatase, and presumably cannot be hydrolyzed by this enzyme. Inorganic orthophosphite at 0.05 M inhibited intestinal phosphatase by 32%, but 0.01 M was without effect. Inorganic phosphite at 0.20 M inhibited 3-phosphoglyceraldehyde dehydrogenase slightly but nonspecifically; sodium sulfate at a comparable ionic strength produced a similar inhibition. At 0.067 M , phosphite had no influence on the capacity of washed yeast cells to ferment glucose, and at 0.02 M phosphites did not impair the respiration of an animal cell tissue culture. Phosphites showed a negligible or low order of toxicity for the rat. The inertness of other phosphites and other phosphite esters in biological reactions of phosphite or phosphate esters likely results from the differences in electrostatic charge distribution rather than of spatial arrangement of the phosphites and phosphates.
The Life Cycle of Trypanosoma Brucei in the Rat and in Rat Plasma.

It is well known that Trypanosoma brucei does not appear in the peripheral circulation until about forty-eight hours after inoculation. The actual history of the organism during this period has not yet been established for Trypanosoma brucei; and in other trypanosomes, in spite of numerous investigations, it has not been fully elucidated (cf. Minchin,l and Carini2). It has been impossible to study the uninterrupted life history of the trypanosome in the mammalian host. The method of cultivating Trypanosoma lewisi outside the mammalian host was first discovered by Novy and McNeal in 1903.3 McNeal4 states that Trypanosoma brucei changes its form in the culture medium into round bodies which are not capable of causing infection in the rat. Laveran and Mesnil5 show four stages of this transformation of trypanosomes into round bodies in a medium of serum and horse blood. These authors term these forms "mis en boule" and believe that they are capable of starting a new infection and that they are comparable, when submitted to unfavorable conditions, to the 'latent bodies' found by More and Breinl6 in Trypanosoma gambiense and later in Trypanosoma equiperdum and Trypanosoma lewisi.7 These mammalian trypanosomes showed, according to these authors, cyclical changes in the number of trypanosomes in the host and the periodic appearance of the 'latent bodies.' Thus there are periods in which many trypanosomes are in the peripheral blood and periods in which few or none can be discovered. These round forms have never been seen in the mammalian
Immunocytochemical detection of serotonin content in raphe neurons of newborn and young adult rabbits before and after acute hypoxia

The present immunocytochemical study demonstrates serotonin (5-HT) depletion in the dorsal raphe nucleus (DRN) of 3- and 21-day-old rabbits following exposure to mild (10% ambient partial pressure of oxygen) and severe hypoxia (5% ambient oxygen). Under the mild hypoxic condition, 5-HT immunoreactivity in cells and fibers of the DRN was decreased in 3-day-old as well as 21-day-old rabbits, as indicated by decreased intensity of the staining compared to age-matched controls. Although this decrease was more pronounced in the younger animals, recovery from mild hypoxia was seen in both age groups. Hypoxic effects were more striking in 3-day-old animals under the severe hypoxic condition, indicating a greater depletion of 5-HT than in the mildly hypoxic condition. However, little additional effect on the older age group was seen. Further, a decreased ability of the 3-day-old rabbits to recover following severe hypoxia suggests that protracted effects on the developing serotonergic system occur following severe hypoxia during the neonatal period. This was demonstrated by the long-lasting decrease in the number of stained cells and fibers of the DRN 4-hr after return to normal conditions (21% O2). We conclude that newborns have a decreased rate of 5-HT synthesis and/or metabolic turnover that results in rapid depletion of intracellular stores and protracted time to recover from a hypoxic challenge. Similar effects could occur in human fetuses, newborns or infants following birth trauma, apnea or other events associated with severe hypoxia.
Working with multiproblem families: an intervention model for community health nurses.

Abstract We propose a model for working with multiproblem families that is based on provider-client conceptual frameworks. The model includes primary areas of conflict in client-provider relationships (values, control, and information), and suggestions for effective intervention strategies. It delineates ways to empower families and to assist nurses in achieving greater professional satisfaction.
Alcohol intoxication inhibits pulmonary S100A8 and S100A9 expression in rats challenged with intratracheal lipopolysaccharide.

Background: Alcohol is known to inhibit the recruitment of polymorphonuclear leukocytes (PMNs) into tissue sites including the lung. During infection and inflammation, recruited neutrophils (PMNs) release S100 proteins that function to promote the recruitment of additional phagocytes. Methods and Results: This study investigated the effects of alcohol intoxication on S100 protein production in the lung in response to lipopolysaccharide (LPS). Animals were administered alcohol (5.5 g/kg) or saline 30 minutes before intratracheal challenge with LPS (100 μg/rat). Alcohol suppressed PMN recruitment into the lung following intratracheal LPS, which was associated with an inhibition of increase in S100A8 levels in both the bronchoalveolar lavage (BAL) fluid and lysates of cells recovered by BAL at 90 minutes and 4 hours post-LPS challenge. S100A8 and S100A9 mRNA expression in cells recovered by BAL was significantly up-regulated at both 90 minutes and 4 hours after the LPS challenge, and alcohol also suppressed this response. In addition, intratracheal LPS caused a transient increase in S100A8 mRNA expression in circulating leukocytes at 90 minutes after the challenge. Similarly, this LPS-induced up-regulation of S100A8 mRNA expression was inhibited in rats intoxicated with alcohol. Conclusion: These data show that alcohol inhibits the S100 protein response in the lung, which may serve as a mechanism underlying alcohol-induced suppression of PMN recruitment into the terminal airways during pulmonary infection.
Acupuncture Treatment for Depression During Pregnancy: Conceptual Framework and Two Case Reports:

Severe depression is common during pregnancy. It is associated with more negative pregnancy outcome and is a risk factor for postpartum depression. Treatment options available for depressed women during pregnancy are limited. Preliminary data suggest acupuncture as an effective treatment for depression. This article presents a systematic and standardized approach to acupuncture treatment, and its implementation is demonstrated using two case reports selected from a larger pool of participants in an ongoing study testingthe efficacy of acupuncture in treating depression during pregnancy. Baseline characteristics and outcome are presented from the integrated perspective of Western psychiatry and Chinese medicine.
When It Comes to Decisions, Myeloid Progenitors Crave Positive Feedback

Positive feedback is a ubiquitous feature of networks that establish and maintain cellular decisions. In this issue of Cell, Laslo et al. (2006) demonstrate how a feedback loop comprised of two mutual repressors regulates the differentiation of myeloid progenitors into either macrophages or neutrophils.
Mediastinoscopy in patients with lung cancer and negative endobronchial ultrasound guided needle aspiration.

Background Endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) has been proposed as a safe, less-invasive alternative to mediastinoscopy to stage mediastinal lymph nodes in patients with lung cancer. We evaluated the negative predictive value of EBUS-TBNA in lung cancer patients suspected of having N2 nodal metastases. Methods This study is a single-institution retrospective review of cases with suspected or confirmed lung cancer undergoing mediastinoscopy after a negative EBUS-TBNA between June 2006 and February 2008. Results A total of 494 patients underwent EBUS-TBNA during the study period. Twenty-nine patients with suspected or confirmed lung cancer had a negative EBUS-TBNA and underwent subsequent mediastinoscopy. Mediastinoscopy was performed for findings suspicious of N2 disease based on noninvasive imaging. Mediastinoscopy found metastatic nodes in eight of 29 patients (28%) for a patient-specific negative predictive value of EBUS-TBNA of 72% (95% CI, 56% to 89%). Mediastinal lymph node dissection found four further patients with positive N2 nodes (19%). The EBUS-TBNA and mediastinoscopy sampled the same lymph node station on 36 occasions in the 29 patients. The average lymph node size was 10 mm. Mediastinoscopy was positive in 5 of 36 stations, for a nodal-specific negative predictive value of EBUS-TBNA of 86% (95% CI, 75% to 97%). Conclusions Endobronchial ultrasound with transbronchial needle aspiration can effectively sample mediastinal lymph node stations in patients with lung cancer. However, in this early experience, 28% of patients with high clinical suspicion of nodal disease had N2 mediastinal nodal metastases confirmed by mediastinoscopy despite negative EBUS-TBNA.
New concepts of transferred and potential transferred forces in structures

Abstract New concepts of transferred force and potential transferred force from the loaded surface to the support surface for a structure are introduced. The basic ideas of these new types of forces are explained using a general continuum model for the structure. Numerical procedures to calculate these forces are presented. Several example problems are solved, and a procedure to depict transferred and potential transferred forces as “force transfer” diagrams, is developed. These forces and transfer diagrams show relative importance of various parts of the structure that can be useful in redesign or optimum design of the structure.
Another visual illusion involving orientation

The orientation of a grating may be misperceived when that grating appears superimposed within one-dimensional visual noise of a different orientation. An adjustment procedure was employed to measure the size of this tilt illusion and its dependence on noise orientation. The illusion is maximum when the noise and test differ by 20 to 40 deg, depending on the spatial frequency of the test grating. Noise composed of spatial frequencies several octaves removed from the test spatial frequency can still cause illusory tilt, although the degree of tilt under these conditions depends on test spatial frequency. This orientation illusion, like the tilt aftereffect, simultaneous tilt illusion and angle expansion illusion, may reflect inhibitory interactions between orientation selective neurons in human vision.
Sphingolipids of developing human central nervous tissue: changes in composition of sphingosine bases.

—Developmental changes in composition of sphingosine bases of cerebrosides, sulphatides and sphingomyelins were investigated in samples from brain stem or corpus callosum from premature infants and patients aged 14 months, 39 and 59 years who died of non-neurological causes. Since insufficient material was obtainable from the premature brains, sulphatides were studied only in older cases. Individual sphingolipids were isolated by combinations of column chromatography and TLC, and were examined for purity by analytical TLC. Sphingosine bases were released by acid-catalysed methanolysis, and analysed as aldehydes by GLC. Effectiveness and limitations of methods used for analyses of sphingosine bases were evaluated. In contrast to adult sphingolipids in which approximately 95 per cent of the sphingosine bases was 18: sphingosine, as much as 10 per cent of the total was 18: dihydrosphingosine in immature sphingolipids. A compound tentatively identified as 20: sphingosine was present in foetal, infant and adult sphingomyelin at 5, 3 and 1 per cent of the total, respectively. Composition of sphingosine bases of non-ganglioside sphingolipids in human brain varies with age, presumably in a complex manner.
Altered posttranslational processing of glycoproteins in cerulein-induced pancreatitis.

Abstract Acute pancreatitis is an auto-digestive disease resulting in inflammation. At the cellular level, acute pancreatitis disrupts posttranslational protein processing and traffic in the secretory pathway, and zymogens become activated in the acinar cell. To better understand the disruption of the secretory pathway in pancreatitis, pulse-chase [ 35 S]met/cys analysis was used to study the effects of supramaximal cerulein stimulation on posttranslational modification in the secretory pathway of the major sulfated glycoprotein of the mouse pancreas, pro-Muclin, and the lysosomal membrane protein LAMP1. Maximal cerulein or high concentration bombesin stimulation had little effect on glycoprotein processing. By contrast, supramaximal cerulein stimulation strongly inhibited pro-Muclin processing as measured by the failure of Muclin to attain its normal mature size of 300 kDa and to become highly sulfated and decreased proteolytic cleavage of pro-Muclin to produce apactin. Digestion of immunoprecipitated [ 35 S]met/cys-labeled Muclin and LAMP1 with endoglycosidase H demonstrated that the supramaximal cerulein-induced block in processing occurred before the medial Golgi compartment. With supramaximal cerulein stimulation, vacuoles formed which contained Muclin, amylase, and LAMP1. Earlier autoradiographic studies showed that newly synthesized proteins end up in pancreatitis-associated vacuoles, so it is likely that glycoproteins with incomplete posttranslational processing are also present in vacuoles. Because glycoproteins are believed to protect the membranes of lysosomes and zymogen granules, when they are not correctly processed, their defensive mechanisms may be impaired, and this could contribute to vacuole fragility in pancreatitis.
Non-random association between electromorphs and inversion chromosomes in finite populations

With the aim of knowing the probable magnitude of non-random association between inversion chromosomes and electromorphs, both deterministic and stochastic studies are conducted on the evolutionary change of non-random association, which is defined as the difference in the frequency of a given allele between inversion and non-inversion chromosomes. In these studies inversion chromosomes are assumed to be subject to selection but electromorphs are selectively neutral, and recombination is allowed to occur between inversion and non-inversion chromosomes with a low frequency. The deterministic study has shown that in a variety of selective schemes for inversion chromosomes the non-random association decays at a rate equal to the recombination value in every generation. Thus, if the recombination value is of the order of 10−5 ˜ 10−4, it would take a long time for the non-random association to disappear. Furthermore, the stochastic study has indicated that random genetic drift generates non-random association of inversions and electromorphs in finite populations and the standard error of non-random association often becomes larger than the mean. In addition to these problems the time required for the electromorph frequencies in the inversion and noninversion chromosomes to become equal in a finite population and the probability that the population of inversion chromosomes remains monomorphic for the allele which existed in the initial inversion introduced are studied. Considering all these quantities, it is concluded that data on the non-random association between electromorphs and inversions are not very informative for the study of the maintenance of protein polymorphism. It is also indicated that in the study of association between electromorphs and inversion chromosomes non-random association or Yule's coefficient of association has a better property than the usual linkage disequilibrium measure or correlation coefficient. Implications of this study on some experimental observations are discussed.
Analysis of the linear stability of compressible boundary layers using the PSE

The application of linearized parabolic stability equations (PSE) to compressible flow is considered. The effect of mean-flow nonparallelism is found to be weak on 2D waves and strong on 3D waves. Results for a single choice of free-stream parameters that corresponds to the atmospheric conditions at 15,000 m above sea level are presented.
Primary responses of rainbow trout to dietary phosphorus concentrations

A series of experiments was conducted to research sensitive indicators for phosphorus status of fish using post-juvenile rainbow trout. Fish were fed up to 24 days with semipurified diets that varied in phosphorus content. Concentrations of glucose-6-phosphate, ATP, creatine phosphate, glucose, total lipids and total cholesterol in blood or skeletal muscle were relatively unchanged by the 24 days of dietary phosphorus restriction. Inorganic phosphorus and ATP levels in the blood, however, correlated significantly and positively. Inorganic phosphorus levels in plasma and urine were significantly lower in fish fed phosphorus-deficient diets than phosphorus-supplemented diets. Urinary phosphorus excretion peaked 6–10 h after feeding fish with diets containing potassium phosphate. Fish receiving either commercial feeds or experimental diets containing phosphorus as fish bone excreted trace amounts of phosphorus in the urine. Faecal content of phosphorus significantly increased when the diet containing potassium phosphate was supplemented with calcium carbonate. Urinary phosphorus concentration was found to be a rapid and sensitive indicator for dietary intake of phosphorus and probably phosphorus status of the fish, and had an advantage over conventional response variables in estimating dietary phosphorus requirement especially with large commercial-size fish.
Level playing fields, tilted playing fields and US competitiveness

Abstract Primary copper is used to exemplify the problems involved in measuring or even properly identifying the specific issues determining fair or unfair trade advantage. Resources, labour and capital, as well as transport, infrastructure and processing, are discussed in terms of contributions to normal competitive advantage, level trade. Non-market aspects including taxes, subsidies and environmental issues as well as statist versus capitalist organizations of business, exchange rates and interventions in the cost of capital are shown to contribute to anti-competitive advantage, tilting the playing field. Aggregation of net advantage is non-trivial even for a comparatively simple commodity.
Eutrophication and salinization of urban and rural kettle lakes in Kalamazoo and Barry Counties, Michigan, USA

Abstract Salinization and eutrophication caused by runoff of road salt and nutrients was assessed in three kettle lakes, two (Woods and Asylum Lakes) located in urban Kalamazoo, MI, and one (Brewster Lake) in rural Hastings, MI. Profiles of dissolved O 2 , conductivity, pH, and temperature were measured in situ , at half meter intervals. Water samples were collected at discrete depth intervals of 1 m and analyzed for Fe(II), Mn(II), ammonium, alkalinity, Cl − , Na, Mg, K and Ca. Results of this study indicate that all three lakes are eutrophic with anoxic bottom waters. Conductivity was much greater, and Cl − levels were more than 100 times greater, in the two urban lakes compared to the rural lake, demonstrating the significant impact of road salt deicers on urban lake water chemistry.
Comparison of the French and U.S. National 3H (Tritiated H2O) Standards by 4πβ Liquid Scintillation Spectrometry

Abstract Radioactivity standards of tritiated water (3H2O)—disseminated by the Laboratoire Primaire des Rayonnements Ionisants (LPRI) and the National Institute of Standards and Technology (NIST), the national radionuclidic metrology and standardization laboratories of France and U.S.A., respectively— have been intercompared by liquid scintillation (LS) spectrometry. The ratio of the certified massic activities for the two standards was compared to that obtained from direct measurements on matched sets of LS cocktails prepared from the standards. Seven experimental trials (involving a total of 21 counting sources for each standard) were performed for the comparison. The trials were performed under a wide range of experimental conditions, including use of two different LS spectrometers and three series of LS cocktail compositions (with systematically varied 3H detection efficiencies). The results exhibited an apparent mean disagreement between standards of
A proposed model for accelerated-stress life-test data exhibiting two failure modes

Accelerated-stress life-testing involves testing of a material or system at a series of stresses higher than that which is normally seen in service. An estimate of the service life is then obtained by extrapolating the failure time vs stress relationship to use stress. A common problem with this methodology is that a change in failure mechanism may occur if stresses become too high. When this occurs, the data above and below the failure mode transition point are generally treated separately. This paper discusses a model that allows for a change in failure mechanism and characterizes the transition by a probability density function over stress. Advantages of the model are: it allows representation of all test data by a single equation; it allows probability statements to be made about the probability of failure of either failure mode; it allows optimal experiments to be designed; and it allows data in the area of the failure mode transition to contribute to the precision of the estimated service life.
Fragmentation energetics for angiotensin II and its analogs from time- and energy-resolved surface-induced dissociation studies

Abstract Surface-induced dissociation (SID) of four model peptides: DRVYIHPF, RVYIHPF, RVYIHAF, and RVYIHDF was studied using a novel Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) specially configured for SID experiments. The energetics and dynamics of peptide fragmentation were deduced by modeling the time- and energy-resolved survival curves for each precursor ion using an RRKM based approach developed in our laboratory. Accurate dissociation parameters can be obtained from these experiments because collision-energy-resolved SID data are very sensitive to both the energetics and dynamics of dissociation. We found that transition from selective to non-selective fragmentation as ion kinetic energy is increased is associated with a substantial (ca. 0.5 eV) increase in the dissociation energy and a 3–4 orders of magnitude increase in the pre-exponential factor. Dissociation thresholds for angiotensin analogs derived from the experimental data are as follows: 1.62 eV for RVYIHAF and RVYIHPF, 1.14 eV for RVYIHDF and 1.13 eV for DRVYIHPF. Pre-exponential factors of 8.2×10 11 , 7.2×10 12 , 3.1×10 8 , and 5.0×10 7 s −1 were obtained for RVYIHPF, RVYIHAF, RVYIHDF, and DRVYIHPF, respectively. Contribution from shattering to the total decomposition of the precursor ion increases for kinetically hindered fragmentation. The largest contribution is observed for a peptide ion that has the largest negative reaction entropy—DRVYIHPF.
Human Erythrocyte Lactate Dehydrogenase: Four Genetically Determined Variants

Four variants of human erythrocyte lactate dehydrogenase (LDH) are described. One of these is similar to the one previously described by Boyer and is interpreted as a variant of LDH-B. The other three are thought to represent variants of LDH-A. Studies of families indicate that LDH-A and LDH-B are under separate genetic control and are inherited as autosomal co-dominants. Evidence is presented that the LDH-A locus is not closely linked to the loci for the ABH and Duffy blood group systems.
Effects of haptic cues on visual recognition memory in fullterm and preterm infants

This study investigated the effects of haptic exploration on visual recognition memory in fullterm and preterm infants, 6 and 12 months of age. Infants were given tasks in which they only viewed an object during familiarization or in which they touched and manipulated it as well. Visual recognition memory was assessed by the paired comparison technique. The results show that contrary to theoretical expectation, manipulation of objects did not enhance visual knowledge about shape. Instead, manipulation actually interfered with performance. Prematures showed developmental lags both in the ability to process exclusively visual information and in the ability to deal with haptic and visual cues simultaneously. These findings imply that there are cognitive differences between high-risk and low-risk infants which can be detected within the first year of life.
Linear Behavior of Carbon Nanotube Diameters with Growth Temperature

High crystalline quality single- and multiwalled carbon nanotubes (CNTs) grow using thermal chemical vapor deposition (CVD) at temperatures ranging from 530 to 630 °C. Using identical Ni catalyst layers and a constant CO reduction annealing process at 600 °C, the number of walls in the resulting CNTs increases linearly from one to eight over this growth temperature range. The highest temperature used in the growth process appears to control the resulting inner core diameter, which is ∼1 nm for all CNTs grown ≤ 610 °C, near the CO reduction anneal used for all the samples. The corresponding CNT outer diameters also increase linearly from 1 to 5 nm up to 610 °C. Using growth temperatures measurably higher than that of the reduction anneal results in both larger inner and outer diameters, inferring that the Ni catalyst islands grow with increasing temperature. These results suggest that independent control of the number of walls and the inner core diameter in CNTs is possible.
Systematic trends in the LIII-edge absorption spectra of the rare-earth based systems

Abstract We have investigated the L III -edge absorption spectra of the metallic systems, RA1 2 (R = lanthanide except Pm, Ho, and Tm), and the insulating systems, RF 3 (R = lanthanide except Pm). From analysis of the data, we have found that the “white lines” (WLs) are wider for the metallic systems as compared to that for the insulating systems. We interpret this result in terms of stronger hybridization in the RA1 2 systems, as expected from the smaller R-R distances in RA1 2 , relative to that in the insulating RF 3 systems. We discuss the EuA1 2 and YbA1 2 systems in the context of mixed-valence phenomena. The EuA1 2 spectrum indicates the system to be weakly mixed valent, whereas the broad WLs encountered in the RA1 2 series mask the bimodal character of the YbA1 2 spectrum.
X-ray properties of galactic black holes

The best evidence for black holes comes from dynamical studies of a few X-ray binary systems that contain massive (M>3M0) compact stars. Unfortunately, the evidence is not decisive; in particular, this argument for black holes depends on the presumption that general relativity is the correct theory of strong gravity. If we hope to advance our position further, we must attempt to make clean quantitative measurements of relativistic effects that occur in the near vicinity of neutron stars and black holes. It appears unlikely that peculiar temporal or broadband spectral phenomena (e.g., ms flickering, steep spectra, etc.) can be used to test general relativity to prove that black holes exist; these phenomena are too confused by erratic magnetohydrodynamic effects. Two potential tests of general relativity are discussed: (1) The discovery of a 4.1 keV line from a neutron star suggests that strong-field spectroscopic tests of the equivalence principle and general relativity may be possible in the 1990s. (2) The polarization features of black-hole disk radiation can be affected strongly by general-relativistic effects; it may be possible to determine the metric of a black hole by measuring the change in polarization direction with energy. Our working hypothesis is that black holes exist and are described by general relativity; we are obliged to show that this hunch is correct.
Quantitative analysis of castration resistant prostate cancer progression through phosphoproteome signaling

Although recent progress has been made in treating castration resistant prostate cancer, the interplay of signaling pathways which enable castration resistant growth is incompletely understood. A data driven, multivariate approach, was used in this study to predict prostate cancer cell survival based on the phosphorylation levels of key proteins in PC3, LNCaP, and MDA-PCa-2b cell lines in response to EGF, IGF1, IL6, TNFα, dihydrotestosterone, and docetaxel treatment. The prostate cancer cell lines were treated with ligands or inhibitors, cell lyates were collected, and the amount of phosphoprotein quantified using 384 well ELISA assays. In separate experiments, relative cell viability was determined using an MTT assay. Normalized data was imported into Matlab where regression analysis was performed. Based on a linear model developed using partial least squares regression, p-Erk1/2 was found to correlate with castration resistant survival along with p-RPS6, and this model was determined to have a leave-one-out cross validated R2 value of 0.61. The effect of androgen on the phosphoproteome was examined, and increases in PI3K related phosphoproteins (p-Akt, p-RPS6, and p-GSK3) were observed which accounted for the majority of the significant increase in androgen-mediated cell survival. Simultaneous inhibition of the PI3K pathway and treatment with androgen resulted in a non-significant increase in survival. Given the strong effect of PI3K related signaling in enabling castration resistant survival, the specific effect of mTor versus complete inhibition was examined using targeted inhibitors. It was determine that mTor inhibition accounts for 52% of the effect of complete PI3K inhibition on cell survival. The differences in signaling between the cell lines were explored it was observed that MDA-PCa-2b exhibited far less activation of p-Erk in response to varying treatments, explaining one of the reasons for the lack of castration resistance. In this work, regression analysis to the phosphoproteome was used to illustrate the sources of castration resistance between the cell lines including reduced p-Erk signaling in MDA-PCa-2b and variations in p-JNK across the cell lines, as well as studying the signaling pathways which androgen acts through, and determining the response to treatment with targeted inhibitors.
Endometrial carcinoma: A new method of classification of therapeutic and prognostic significance

Abstract A retrospective study has been performed on 120 patients with Stage I carcinoma of the endometrium searching for a prognostic index based on histological evaluation of cell type, grade of differentiation, and depth of myometrial invasion measured from the serosal surface in millimeters. A program of therapy is outlined as well as a method of treating the pathological specimen so that this prognostic index can be systematically applied to all patients with this disease. From this study, patients who have disease with 5 mm of the serosal surface of the uterus are believed to be candidates for more extensive methods of treatment than generally applied to Stage I disease of the uterus.
Large thigh abscess after placement of synthetic transobturator sling

Purpose: To report a unique complication associated with transobturator slings. Materials and methods: The evaluation and treatment of a unique infectious complication of transobturator slings is reviewed. Results: A large thigh abscess associated with a transobturator sling was diagnosed and treated. Conclusion: New techniques of sling placement may be associated with unique infectious complications. Slings passing through the obturator foramen and thigh can lead to a significant abscess within the adductor muscles of the thigh.
Scleritis, Pericarditis, and Aortic Insufficiency in a Patient with Rheumatoid Arthritis

A 55-year-old black man developed anterior nodular scleritis in his left eye in November 1981. He had no symptoms of systemic disease, and initial laboratory tests revealed only a positive rheumatoid factor. Fourteen months later he presented with pericarditis and aortic insufficiency requiring aortic valve replacement. Examination of excised valvular and pericardial tissue showed changes compatible with rheumatoid disease. Shortly after the surgery he developed florid rheumatoid arthritis. The clinical course of this patient illustrates how scleritis can be the initial sign of severe systemic disease.
Comparative study of kallikrein-like serine proteinases from rat submandibular glands.

Abstract The present investigation describes the comparative properties, particularly the substrate specificity of three kallikrein-like serine proteinases (I, II and III) purified from rat submandibular gland extract (Bedi, G.S., Prep. Biochem. 22, 67–81. 1992). The physico-chemical and immunological properties of three proteinases were compared by Western blot analysis, immunodiffusion, immuno-electrophoresis, amino terminal sequence analysis, molecular weight determination and isoelectric focusing. Detailed substrate specificity of these proteinases was determined using chromogenic substrates, synthetic peptides and native proteins. The chromogenic substrate tosyl-gly-pro-arg-pNA was hydrolyzed preferentially by Proteinase I. The replacement of pro at the P2 position with bulky hydrophobic residues phe and leu completely abolished the hydrolysis by Proteinase I. The hydrolysis of the chromogenic substrates by Proteinase II was also affected by the amino acid residue present at the P2 position in the or...
Human chorionic gonadotrophin: comparative studies of ovarian uptake in mammals.

l. The localization of radiolabeled human chorionic gonadotrophin (~2SI-HCG) was studied in a number of commonly used mammalian animal models. 2. The ovary proved to be the target organ for ~25I-HCG in all animals studied. 3. The optimum time for the localization of HCG in the ovary varied in all the mammals extending from 1.5 to 4 hr. 4. HCG is apparently used in the target cell for only a brief period and is excreted rapidly as indicated by renal uptake levels. 5. All other female organs and tissues failed to display any affinity for HCG. 6. The affinity of 125I-HCG for the various mammalian ovaries studied occurred in the following sequence: rat > mouse > guinea pig > hamster > monkey.
Ischemic mitral valve regurgitation in patients with depressed ventricular function: cardiac geometrical and myocardial perfusion evaluation with magnetic resonance imaging

Objective: To investigate geometrical and functional changes involving the left ventricle (LV) and mitral valve (MV) apparatus in patients with depressed LV ejection fraction (LVEF) and ischemic MV regurgitation (IMVR). Methods: A series of patients with three vessels coronary artery disease (CAD) and depressed LVEF underwent cardiac magnetic resonance imaging to investigate MV/LV geometry and function, and myocardial perfusion/vitality. Geometrical data were indexed by anterior MV leaflet length. Two groups were identified: CAD without IMVR (group CAD), and with IMVR (group IMV). Results: Eleven patients were enrolled in the CAD group and 13 in the IMV group. IMVR volume was significantly higher in the IMV group (24.0 12.0 vs 4.5 5.2; p < 0.0001). LVEF% was comparable (IMV 34.6 13.0 vs CAD 31.5 13.0; p = ns). Indexed MV/LV geometrical variables were comparable in the two groups. Perfusion/vitality study showed inferior myocardial necrosis occurred more often in the IMV group (p = 0.01). At Pearson test, MV regurgitation occurrence correlated with inferior myocardial necrosis (r = 0.5; p = 0.006), nonindexed systolic/diastolic annular inter-commissural diameters (r = 0.4; p = 0.04) and MV annular areas (r = 0.4; p = 0.04). Papillary muscles distance (PMD) and LV volumes inversely correlated with LVEF% (r = 0.6; p < 0.05 and r = 0.8; p < 0.001). At multivariable analysis, no independent determinantsforIMVRwereidentifiedandLVvolumeswere thesoledeterminants forLVEF%(p < 0.05).Conclusion:In patientswith depressed LVEF%,IMV cannot be explained by LV geometrical modifications alone. AlthoughPMD, LV volumes, and LVEF% are correlated, they have no direct impact in the development of IMVR. In contrast, inferior myocardial necrosis and increased inter-commissural MV diameters may lead to deformity of MV complex and subsequent IMV. # 2008 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.
Ppb standoff detection of nitric oxide in air

We demonstrate standoff detection of NO in air with ppb resolution. The weakly ionized plasma produced by picosecond UV laser pulses via REMPI is detected remotely by a microwave scattering technique.
A Mathematical Description for the Stress-Strain Behavior of Annealed 2 1/4 Cr-1 Mo Steel

We have conducted a detailed series of tensile tests on one heat of annealed 2/sup 1///sub 4/ Cr-1 Mo steel over the range 25 to 593/sup 0/C (75 to 1100/sup 0/F) and at nominal strain rates of 0.4, 0.04, 0.004, and 0.0004/min. To determine an empirical relationship to represent the flow behavior, we fitted the true-stress true-strain data from these tests to several proposed models. The models fit were those proposed by Holloman, Ludwik, Ludwigson, and Voce. From a comparison of the standard error of estimate, the Voce equation was concluded to be the best mathematical description of the data under most test conditions and the best single representation over the wide range of test conditions.