cssi/SciSciGPT-SciSciNet huggingface dataset:
An endothelial and astrocyte co-culture model of the blood–brain barrier utilizing an ultra-thin, nanofabricated silicon nitride membrane

The endothelial cells comprising brain capillaries have extremely tight intercellular junctions which form an essentially impermeable barrier to passive transport of water soluble molecules between the blood and brain. Several in vitro models of the blood–brain barrier (BBB) have been studied, most utilizing commercially available polymer membranes affixed to plastic inserts. There is mounting evidence that direct contact between endothelial cells and astrocytes, another cell type found to have intimate interaction with the brain side of BBB capillaries, is at least partially responsible for the development of the tight intercellular junctions between BBB endothelial cells. However, the membranes commonly used for BBB in vitro models are lacking certain attributes that would permit a high degree of direct contact between astrocytes and endothelial cells cultured on opposing sides. This work is based on the hypothesis that co-culturing endothelial and astrocyte cells on opposite sides of an ultra-thin, highly porous membrane will allow for increased direct interaction between the two cell types and therefore result in a better model of the BBB. We used standard nanofabrication techniques to make membranes from low-stress silicon nitride that are at least an order of magnitude thinner and at least two times more porous than commercial membrane inserts. An experimental survey of pore sizes for the silicon nitride membranes suggested pores ∼400 nm in diameter are adequate for restricting astrocyte cell bodies to the seeded side while allowing astrocyte processes to pass through the pores and interact with endothelial cells on the opposite side. The inclusion of a spun-on, cross-linked collagen membrane allowed for astrocyte attachment and culture on the membranes for over two weeks. Astrocytes and endothelial cells displayed markers specific to their cell types when grown on the silicon nitride membranes. The transendothelial electrical resistances, a measure of barrier tightness, of endothelial and astrocyte co-cultures on the silicon nitride membranes were comparable to the commercial membranes, but neither system showed synergy between the two cell types in forming a tighter barrier. This lack of synergy may have been due to the loss of ability of commercially available primary bovine brain microvascular endothelial cells to respond to astrocyte differentiating signals.
Manifestation of Aortic Root Abscess From Acute Bacterial Endocarditis

71-YEAR-OLD man with a history of coronary artery disease, moderate aortic stenosis, and arterial hypertension was scheduled for aortic valve replacement and possible aortic root replacement. One month before admission, he was treated for methicillin-sensitive Staphylococcus aureus endocarditis. A transthoracic echocardiogram revealed a lesion on the mitral valve that was suspected to be a vegetation associated with mild mitral regurgitation. The patient began a course of intravenous oxacillin as an outpatient. Two weeks later, the patient was admitted to the hospital with signs of worsening acute congestive heart failure. At that time, a transesophageal echocardiogram (TEE) was reported to show a mobile density on the mitral valve, a flail posterior mitral leaflet, and severe mitral regurgitation. A small fluid collection was noted in the posterolateral wall of the aortic root. After optimization, the patient was brought to the operating room for mitral valve and aortic valve replacement surgery. An intraoperative 2D TEE showed a high-velocity turbulent jet of blood flow that was directed posteriorly from the aortic valve and was present during both systole and diastole (Fig 1 and Video 1 [supplementary videos are available online]). Additionally, there was no prolapsing or flail segment of the posterior mitral leaflet. A 3-dimensional echocardiographic rendering was performed. What is the diagnosis?
Excitation Spectra and Quantum Efficiency of GaP Containing Zn and O

We have investigated the quantum efficiency for the production of red luminescence in $p$-type GaP doped with deep oxygen donors and shallow zinc acceptors. We find the luminescence can be efficiently excited by energy transfer from bound excitons, $E\ensuremath{\approx}2.317$ eV, as well as by absorption of quanta of energy in the characteristic (phonon-assisted) absorption region $h\ensuremath{\nu}\ensuremath{\approx}2.2$ eV, and in the pair-creation region well above the band edge. The high efficiency of the exciton-induced radiation is interpreted as a resonant transfer of energy to an exciton which is weakly bound (\ensuremath{\sim}10 meV) to an O-Zn complex and which decays to the ground (red-emitting) exciton state. The temperature dependence of the efficiency for the different excitation processes is presented and discussed and the loss in efficiency above \ensuremath{\sim}70\ifmmode^\circ\else\textdegree\fi{}K is interpreted in terms of an Auger process involving free holes.
Fertility-sparing treatment in younger women with adenocarcinoma in situ of the cervix

Abstract Objective For women who have completed childbearing, the treatment of choice for adenocarcinoma in situ (ACIS) of the cervix is hysterectomy. In women who desire future fertility, however, conservative therapy is an acceptable alternative. In this study we compare the outcomes for young women who underwent loop conization or were treated with cold knife conization. Methods We performed a retrospective analysis in 112 patients with ACIS, age 30 or younger, treated with cold knife conization or loop conization between 1998 and 2010. Decision to perform office loop conization was based on the size of the cervix and the colposcopic lesion. Main outcomes were negative margins after the procedure and recurrence of ACIS. Results Fifty-eight patients (52%) were treated with cold knife conization and 54 (48%) underwent loop conization. The odds ratio for cold knife conization to achieve negative cone margins compared with loop conization was 1.4 (95% CI 0.6–3.5). We observed no difference in residual or recurrent ACIS between patients treated with loop conization versus cold knife conization. Conclusions In select young patients who desire future fertility, loop conization and cold knife conization have equivalent rates of negative margins and negative follow-up. For optimal results, patients must have a lesion which can be removed in one pass of a loop, confirmed by expert colposcopy. Loop excision should be considered the treatment of choice in this specific group of patients.
Attraction of Blacklight Traps Baited with Virgin Female Tobacco Hornworm Moths

From 1 to 30 live virgin female moths of the tobacco hornworm, Mallduca sexta (Johannson), were placed with blacklight insect traps. For each additional virgin female, up to 10, placed with the light trap, the male catch increased by a factor equal to the male catch of the trap without virgin females. Vertical positioning of virgin females at the trap site did not influence male catches in the trap.
Lysosomal metal, redox and proton cycles influencing the CysHis cathepsin reaction

In the 1930's pioneers discovered that maximal autolysis in tissue homogenates requires metal chelator, sulfhydryl reducing agent and acid pH. However, metals, reducing equivalents and protons (MR&P) have been overlooked as combined catalytic controls. Three categories of lysosomal machinery drive three distinguishable cycles importing and exporting MR&P. Zn2+ preemptively inhibits CysHis catalysis under otherwise optimal protonation and reduction. Protein-bound cell Zn2+ concentration is 200–2000 times the non-sequestered inhibitory concentration. Following autophagy, lysosomal proteolysis liberates much inhibitory Zn2+. The vacuolar proton pump is the driving force for Zn2+ export, as well as protonation of the peptidolytic mechanism. Other machinery of lysosomal cycles includes proton-driven Zn2+ exporters (e.g. SLC11A1), Zn2+ channels (e.g. TRPML-1), lysosomal thiol reductase, etc. The CysHis dyad is a sensor of the vacuolar environment of MR&P, an integrator of these simultaneous variables, and a catalytic responder. Rate-determination can shift between autophagic substrate acquisition (swallowing) and substrate degradation (digesting). Zn2+ recycling from degraded proteins to new proteins is a fourth cycle that might pace lysosomal function under some conditions. Heritable insufficient or excess functions of CysHis cathepsins are associated with dysfunctional inflammation and immunity/auto-immunity, including diabetic pathogenesis.
Design of experiments: designing simulation experiments

Simulation models are useful for examining the performance of alternative system configurations and/or alternative operating procedures for a system. This tutorial provides some techniques for planning a set of simulation model runs, in order to gain insight on system behavior. There is an emphasis on graphical methods.
The Radioactive Decay of Calcium 47

Spectrometric studies have been made of the beta and gamma radiations from calcium 47 (5.35 day) and its radioactive daughter scandium 47 (3.4 day). Using conversion and photoelectrons and the scintillation spectrometer, gamma rays of energy 149.5, 234, 495, 800, and 1303 kev are found in scandium following beta emission from the calcium. The beta spectrum is complex with energies of 0.46 and 1.4 Mev.Scandium 47 decays with a single allowed beta transition with upper energy limit of 0.64\ifmmode\pm\else\textpm\fi{}0.03 Mev and a single gamma ray of 159.5 kev. A satisfactory level scheme is proposed for the decay and checked in some of its details by coincidence observations.
The occurrence of higher fatty acids in corn pollen

The methyl esters of the fatty acids of corn pollen were prepared and fractionated through a Stedman column. Palmitic, stearic, oleic, linoleic, and linolenic acids were identified by the melting points of thep-bromophenacyl esters of the saturated acids and the hydroxy and bromine addition compounds of the unsaturated acids.
Direct and maternal effects on birth and weaning weight in sheep

Abstract Weights at birth (BW) and weaning (120W) of Rambouillet, Targhee and Columbia lambs adjusted for sex, age of dam, year and type of birth and rearing, were used to study genetic relationships between direct and maternal effects. Data were analyzed to estimate variances among and within paternal and maternal half-sibs, variances among full-sibs and cousins and the covariances offspring-dam and offspring-sire. Heritability estimates for BW and 120W were 0.33 and 0.34 (paternal half-sib), 0.38 and 0.20 (regression offspring-dam), and 0.17 and 0.08 (regression offspring-sire), respectively. Observed variances and covariances were equated to their theoretical expectations for additive and dominance direct and maternal effects using five different statistical models. Each model was applied to a data set grouping animals with specific relationships. For BW heritability estimates of direct effects ranged between 0.20 and 0.34, for maternal effects they ranged between 0.30 and 0.65 depending on the model applied. Corresponding estimates for 120W ranged between 0.13 and 0.21, and between 0.02 and 0.47. Estimated genetic correlations between additive direct and additive maternal effects for BW ranged between −0.18 and −0.74 and for 120W ranged between 0.55 and −0.88 depending on the model applied. These results indicate that additive direct and additive maternal effects for BW and 120W were important, and that generally a negative genetic correlation between additive direct and maternal effects was observed. Therefore, the portion of the selection differential realized in a maternally influenced trait, is expected to be low.
Evolutionary Analysis and Lateral Gene Transfer of Two-Component Regulatory Systems Associated with Heavy-Metal Tolerance in Bacteria

Microorganisms have adapted intricate signal transduction mechanisms to coordinate tolerance to toxic levels of metals, including two-component regulatory systems (TCRS). In particular, both cop and czc operons are regulated by TCRS; the cop operon plays a key role in bacterial tolerance to copper, whereas the czc operon is involved in the efflux of cadmium, zinc, and cobalt from the cell. Although the molecular physiology of heavy metal tolerance genes has been extensively studied, their evolutionary relationships are not well-understood. Phylogenetic relationships among heavy-metal efflux proteins and their corresponding two-component regulatory proteins revealed orthologous and paralogous relationships from species divergences and ancient gene duplications. The presence of heavy metal tolerance genes on bacterial plasmids suggests these genes may be prone to spread through horizontal gene transfer. Phylogenetic inferences revealed nine potential examples of lateral gene transfer associated with metal efflux proteins and two examples for regulatory proteins. Notably, four of the examples suggest lateral transfer across major evolutionary domains. In most cases, differences in GC content in metal tolerance genes and their corresponding host genomes confirmed lateral gene transfer events. Three-dimensional protein structures predicted for the response regulators encoded by cop and czc operons showed a high degree of structural similarity with other known proteins involved in TCRS signal transduction, which suggests common evolutionary origins of functional phenotypes and similar mechanisms of action for these response regulators.
Functional and partially-functional skewed-load tests

Functional broadside tests were defined to address overtesting that may occur with unrestricted scan-based tests. However, the fault coverage achievable by functional broadside tests is lower than the fault coverage achievable by unrestricted scan-based tests. It was observed that skewed-load tests can improve the fault coverage achievable by unrestricted broadside tests. Motivated by these observations, we define functional (and partially-functional) skewed-load tests to improve the fault coverage of functional broadside tests while attempting to curb overtesting. We present experimental results to demonstrate the ability of functional skewed-load tests to improve the fault coverage without exceeding the maximum switching activity of functional broadside tests (which is one indication of potential overtesting).
Brief psychiatric treatment and symptom improvement in university students.

Abstract A total of 242 university students seen in an outpatient mental health clinic were evaluated for symptom changes during treatment using both a self-report inventory and chart notations. Specific clusters of major presenting and major improving symptoms, based on combined frequency and severity measures, were obtained for each of the largest diagnostic groups. Self-rated improvement on major symptoms ranged from 81.8 to 88.4% for patients with anxiety neurosis, depressive neurosis, and adjustment reaction, while personality disorder patients reported 54.5% improvement. Chart-based overall improvement rates were uniformly lower (36.4 to 77.3%) than corresponding self-report figures for each diagnostic group. The extent to which chart-rated overall improvement correlated with self-rated improvement on specific symptoms was analyzed.
The search for determinants of chronic depression: a review of six factors

While strides have been made in the classification, assessment and identification of chronic depression, there remains a limited understanding of the factors underlying chronicity. This review focuses on six putative determinants of chronic depression: developmental factors, personality and personality disorders, psychosocial stressors, comorbid disorders, biological factors and cognitive factors. The strongest support was found for the role of developmental factors in the chronicity of depression. Some support was found for the role of chronic stressors and certain personality features such as stress reactivity. Few other factors found support. The determinants of chronic depression do not differ qualitatively from acute depression. Rather, the development of chronic depression may involve increased levels of childhood adversity, protracted environmental stress and heightened stress reactivity. However, it is difficult to determine to what extent these putative determinants might reflect retrospective bias in data collection, or even parental reaction to children with subthreshold depressive traits. Detailed etiological models await further research attention to understudied areas and improved research designs. Suggestions for future research include greater specification of criteria for chronicity, use of more appropriate comparison groups and longer term prospective follow-up studies.
24,25,28-trihydroxyvitamin D2 and 24,25,26-trihydroxyvitamin D2: novel metabolites of vitamin D2.

Understanding of the inactivation pathways of 25-hydroxyvitamin D{sub 2} and 24-hydroxyvitamin D{sub 2}, the two physiologically significant monohydroxylated metabolites of vitamin D{sub 2}, is of importance, especially during hypervitaminosis D{sub 2}. At present, little information is available regarding the inactivation pathway of 25-hydroxyvitamin D{sub 2} except its further metabolism into 24,25-dihydroxyvitamin D{sub 2}. In our present study, the authors investigated the metabolic fate of 25-hydroxyvitamin D{sub 2} in the isolated perfused rat kidney and demonstrated its conversion not only into 24,25-dihydroxyvitamin D{sub 2} but also into two other new metabolites, namely, 24,25,28-trihydroxyvitamin D{sub 2} and 24,25,26-trihydroxyvitamin D{sub 2}. The structure identification of the new metabolites was established by the techniques of ultraviolet absorption spectrophotometry and mass spectrometry and by the characteristic nature of each new metabolite's susceptibility to sodium metaperiodate oxidation. In order to demonstrate the physiological significance of the two new trihydroxy metabolites of vitamin D{sub 2}, induced hypervitaminosis D{sub 2} in a rat using (3{alpha}-{sup 3}H)vitamin D{sub 2} and analyzed its plasma for the various (3{alpha}-{sup 3}H)vitamin D{sub 2} metabolites on two different high-pressure liquid chromatography systems. The results indicate that both 24,25,26-trihydroxyvitamin D{sub 2} and 24,25,26-trihydroxyvitamin D{sub 2} circulate in the vitamin D{sub 2} intoxicated rat inmore » significant amounts along with other previously identified monohydroxy and dihydroxy metabolites of vitamin D{sub 2}, namely, 24-hydroxyvitamin D{sub 2}, 25-hydroxyvitamin D{sub 2}, and 24,25-dihydroxyvitamin D{sub 2}.« less
Behavioral Thermoregulation of Brook and Rainbow Trout: Comparison of Summer Habitat Use in an Adirondack River, New York

Abstract The body temperatures of 15 hatchery-origin and two wild brook trout Salvelinus fontinalis and 11 hatchery-origin rainbow trout Oncorhynchus mykiss were monitored with internally implanted, temperature-sensitive radio transmitters from June through September 1997 in a fifth-order Adirondack river (New York). The fish were released into a 12-km reach that during summer had maximum temperatures near those that are lethal for salmonids. Body temperatures were compared between species and with river temperatures. In 1997, the maximum river temperature was 26.4°C, and the highest average daily temperature was 25.0°C. The brook trout were usually cooler than the main river flow because they used two of five tributary confluences or groundwater discharge areas in two pools within the main river. The temperatures of the brook trout from June through September were an average of 2.3°C cooler than the main flow of the river and differed significantly (P = 0.002) from those of the rainbow trout, which were ...
THE QUANTAL NATURE OF CALCIUM RELEASE TO CAFFEINE IN SINGLE SMOOTH MUSCLE CELLS RESULTS FROM ACTIVATION OF THE SARCOPLASMIC RETICULUM CA2+-ATPASE

Abstract Calcium release from intracellular stores occurs in a graded manner in response to increasing concentrations of either inositol 1,4,5-trisphosphate or caffeine. To investigate the mechanism responsible for this quantal release phenomenon, [Ca] changes inside intracellular stores in isolated single smooth muscle cells were monitored with mag-fura 2. Following permeabilization with saponin or α-toxin the dye, loaded via its acetoxymethyl ester, was predominantly trapped in the sarcoplasmic reticulum (SR). Low caffeine concentrations in the absence of ATP induced only partial Ca release; however, after inhibiting the calcium pump with thapsigargin the same stimulus released twice as much Ca. When the SR Ca-ATPase was rendered non-functional by depleting its “ATP pool,” submaximal caffeine doses almost fully emptied the stores of Ca. We conclude that quantal release of Ca in response to caffeine in these smooth muscle cells is largely due to the activity of the SR Ca-ATPase, which appears to return a portion of the released Ca back to the SR, even in the absence of ATP. Apparently the SR Ca-ATPase is fueled by ATP, which is either compartmentalized or bound to the SR.
Data-based hybrid reduced order modeling for vortex-induced nonlinear fluid–structure interaction at low Reynolds numbers

Abstract Fluid–structure interaction (FSI) phenomena are of significant importance in several engineering fields. Recently developed active flow control devices regulate the FSI in order to control the dynamic response of the structure that is involved. As a first step to use active control, computationally efficient reduced-order models are required. The reduced-order models must be able to predict the nonlinear structural dynamic response given an incoming flow condition. This paper presents a computationally efficient method for the construction of a hybrid reduced-order model for FSI problems based on data obtained through high-fidelity numerical simulations. The model splits the force and the structural dynamic response into two separate blocks and uses model reduction techniques to account for the flow field information. The current model is tested on a vibrating rigid cylinder submerged in a flow at low Reynolds number regime.
Extended system matrices-Transfer functions and system equivalence

We introduce an extension of the usual notion of an input/output map and for linear constant-parameter systems an extended transfer function, that has a (matrix) polynomial- or more generally a differential/difference operator inverse, containing as a submatrix Rosenbrock's system matrix. A new class of system equivalence - "maximally strict system equivalence" (m.s.s.e.) is introduced as a necessary and sufficient condition for two minimal systems to have the same transfer function. We give an outline of the extension of these results to non-minimal systems, where results are only known for state-space systems in this generality. In the conclusion we discuss the relation of the extended system matrix to other deterministic and stochastic problems.
Use of cost-effectiveness analysis in planning cancer chemoprophylaxis trials

Abstract We present a conceptual framework for the use of cost-effectiveness analysis in planning cancer chemoprophylaxis trials and evaluating such choices as sample size, study design, diagnostic evaluation, and duration of follow-up. The approach is illustrated by cost-effectiveness calculations for a trial of synthetic retinoids as cancer prophylaxis agents. Our work emphasizes the need for studies large enough to have a reasonable power of detecting 10%–20% reductions in mortality. Conversely, we note that rare but serious idiosyncratic side effects such as those seen in the “swineflu” vaccination program are likely to escape detection even in trials involving tens of thousands of subjects.
Bifurcations of subharmonics

Abstract We consider a piecewise linear second order ordinary differential equation which is topologically equivalent to the sine-Gordon equation. The system is subjected to a time harmonic disturbance and the behavior of the periodic solutions is examined. It is shown that subharmonic motions with period n times that of the disturbance appear via saddle-node bifurcations for all n = 1, 2, 3,…. These motions then undergo period-doubling or pitchfork bifurcations as parameters are varied beyond the saddle-node bifurcation values. The limit n → ∞ is considered and is compared with a Melnikov calculation for the system. Due to the piecewise linear nature of the system no approximations are necessary and thus the results are valid for “nonsmall” parameter values. Furthermore, this provides an answer to the uniformity question in the study of stability of subharmonics.
Competitive tree-structured dictionaries

In this note we describe a general technique for making treestructured dynamic dictionaries adapt to be competitive with the most efficient implementation, by using potential energy parameters and a simple partial rebuilding scheme. Introduction. On-line algorithms deal with optimizing the performance of operation sequences (e.g., see [4, 9]). Such algorithms are desired to be -competitive [4], for some parameter , where is an upper bound on the ratio of the costs of the solution defined by the on-line algorithm and an oracle’s algorithm. In this paper we are interested in dictionary data structures that are competitive in this same sense. Our Results. We present a simple adaptive tree-based dictionary structure that is balanced and competitive. Our approach is based on a potential energy parameter stored at each node in the tree. As updates and queries are performed, the potential energy of tree nodes are increased or decreased. Whenever the potential energy of a node reaches a threshold level, we rebuild the subtree rooted at that node. We show that, in spite of its conceptual simplicity, such a scheme is constant-ratio competitive with a static oracle using a priori knowledge of the operation distribution. Related Prior Work. Besides general work for on-line algorithms (e.g., see [4, 9]) and data structures that use partial rebuilding [7], there has been some prior work on methods for adapting data structures to the way in which they are being used. Most previous data structure competitive analyses have been directed at simple linked-lists structures, with “move-to-front” heuristics applied [9]. Work on other adaptive data structures includes splay trees [10], which perform a sophisticated move-to-root heuristic, but perform many rotations with each access. There is also the randomized binary search tree of Seidel and Aragon [8], which performs random structural changes with each access and can adapt in an expected, probabilistic sense based on data structure usage. Energy-Balanced Binary Search Trees. A dictionary holds pairs of ordered keys and elements, subject to update and query operations. A common way of implementing the dictionary ADT is to use a binary search tree, which maintains balance by local rotation operations. Typically, such rotations are fast, but if the tree has auxiliary structures, rotations are often slow. Standard binary search trees, such as AVL trees [1], red-black trees [3], scapegoat trees [2], or weight-balanced trees [6], maintain balance, but do not adapt themselves based on the distribution of accesses and updates. Splay trees [10], on the other hand, adapt (in an asymptotic sense), but perform a large number of rotations with each access. Finally, randomized binary search trees [8], have good expected behavior but offer no worst-case guarantees on per-
Parameterization of Trade-Cumulus Cloud Amounts

Abstract A scheme for parameterizing the fractional cloud coverage of trade cumuli is developed which gives the cloud cover in terms of the cloud-layer relative humidity and the liquid water content of the convective elements. This parameterization gives good agreement with cloud observations obtained during the Atlantic Trade-Wind Experiment, 1969. The scheme was incorporated into a simple one-dimensional model of the thermodynamic structure of the trade-wind boundary layer in order to evaluate the dependence of cloud cover on sea surface temperature, surface wind speed, and radiative processes. For steady-state conditions over relatively cold water (∼16°C), the cloud cover decreases as sea surface temperature increases while over warmer water (∼24°C) there is a slight increase in cloud cover as the sea surface temperature increases. When used in a downstream mode, the model structure obtained by moving from cold to warm water can be used to evaluate the effect of advection. Over cold water, the advectiv...
Host control of tumor growth

A humoral factor (molecular weight less than 60,000) that was present in the ascitic fluid of mice bearing intraperitoneal tumors and in pleural effusions from human cancer patients was found to promote the growth of a murine tumor and to suppress cell-mediated tumor immunity. However, the hosts that had recovered from the immunosuppressive state produced a serum factor that could neutralize the immunosuppressive effect.
Quantitative analysis of gene expression by reverse transcription polymerase chain reaction and capillary electrophoresis with laser-induced fluorescence detection

There has been a dramatic expansion of DNA sequence information compiled over the past several years for a variety of eukaryotic and prokaryotic genomes. Accompanying this increase in knowledge of genomic structure and organization has been a growing interest in studying the function of individual genes including regulation of their expression. A number of methods such as Northern blotting, ribonuclease protection assay, and hybridization arrays have been developed to analyze gene expression at the transcriptional (mRNA) level. Although quantitative estimates of mRNA transcripts can be obtained from each of these methods, oftentimes they lack sufficient sensitivity or the methodology is too costly or too labor-intensive to be applied to the analysis of a large number of samples. The most sensitive method for analyzing gene expression at the mRNA level involves the combination of reverse transcription and polymerase chain reaction (RT-PCR). However, in order to provide accurate quantitative estimates of gene expression, a rapid and efficient method is required for separation and detection of the double-stranded DNA (dsDNA) products of RT-PCR. Recent advances in capillary electrophoresis with laser-induced fluorescence detection (CE/LIF) have made this method suitable for the automated analysis of large numbers of RT-PCR samples. An overview of the application of CE/LIF to quantitative analysis of gene expression by RT-PCR is presented along with selected protocols and examples. Both relative-quantitative (RQ) and quantitative-competitive (QC) approaches to RT-PCR are discussed in conjunction with the use of CE/LIF for rapid and accurate quantitative analysis of PCR products.
Possible medullary κ hyperalgesic mechanism. I: A new potential role for endogenous opioid peptides in pain perception

Abstract The κ-agonist, ethylketazocine, produces hyperalgesia in the acutely decerebrated dog as indicated by a shortening of the skin twitch reflex latency whereas fentanyl is inactive. Naloxone produces analgesia and antagonizes the hyperalgesic effect of ethylketazocine. Spinal cord transection decreases the latency of the skin twitch reflex and allowed the analgesic effect of fentanyl and ethylketazocine on this nociceptive reflex to become manifest. These observations indicate that there is a non-opioid analgesic and a κ hyperalgesic mechanism present in the pontine-medullary region of the dog brainstem. It suggests that the hyperalgesic mechanism is mediated by an endogenous κ-opioid peptide and that the analgesic effect of naloxone is in part related to antagonism of the activity of this hyperalgesia producing opioid peptide.
The inference of the magnetic field vector in prominences

Prominences owe their existence to the presence of magnetic fields in the solar corona. The magnetic field determines their geometry and is crucial to their stability, energetics, and dynamics. This review summarizes techniques for measurement of the magnetic field vector in prominences. New techniques for inversions of full Stokes spectro-polarimetry, incorporating both the Zeeman and Hanle mechanisms for generation and modification of polarization, are now at the forefront. Also reviewed are measurements of the magnetic fields in the photosphere below prominences, and how they may be used to infer the field geometry in and surrounding the prominence itself.
Relationship between ATPase activity, Ca2+, and force in α-toxin- and β-escin-treated smooth muscle

On a rendu le muscle lisse permeable avec de 1-α-toxine et de la β-escine. On a determine l'activite d'ATPase en utilisant un systeme de regeneration phosphoenolpyruvate-pyruvate kinase pour l'ATP, en observant les variations de fluorescence du NADH; le Ca 2+ a ete mesure en utilisant la fluorescence du fura 2. Les faisceaux de cellules traites a l'a-toxine et a la β-escine ont eu une plus forte activite d'ATPase, qui a ete reduite de 80% lorsqu'on les a exposes a 1% de Triton X-100. Cette activite sensible au Triton a augmente d'approximativement 20% lorsqu'on a ajoute du GTP ou du GTPγS dans les solutions, et elle a ete d'une amplitude beaucoup plus grande que l'ATPase activee par le Ca 2+ , associee a la contraction. Cette forte activite ATPasique membranaire produira un gradient d'ATP dans le faisceau de cellules et un gradient d'ADP a l'exterieur de celui-ci. Ainsi la modulation de cette ATPase par les mecanismes de la relation G-proteine-recepteur pourrait alterer la force a une concentration constante de Ca 2+ , en modifiant le rapport ADP/ATP dans les cellules. Les mesures du rapport de fluorescence 340/380 du fura 2 dans les faisceaux traites a l'α-toxine apres des variations subites de Ca 2+ extracellulaire ont montre que les cellules n'etaient pas permeables a l'EGTA Ca. Des experiences similaires dans les cellules traitees a la β-escine ont montre que les cellules etaient beaucoup plus permeables a l'EGTA Ca. Ces experiences montrent qu'une attention particuliere doit etre portee aux fibres traitees a l'α-toxine et a la β-escine pour s'assurer que le Ca 2+ , l'ADP et l'ATP intracellulaires demeurent constants
Rapid development of left main disease after coronary artery bypass grafting for failed angioplasty: a rare cause of postoperative angina.

We report a case of failed coronary angioplasty requiring urgent coronary artery bypass graft surgery. The return of angina pectoris early after surgery led to repeat catheterization, demonstrating a rapidly progressive stenosis of the left main coronary artery. This was treated successfully with coronary angioplasty. In patients with recurrent angina early after bypass surgery in whom angioplasty preceded surgery, acceleration of left main disease should be considered. © 1993 Wiley-Liss, Inc.
Achievement of chaotic synchronization trajectories of master–slave manipulators with feedback control strategy

This paper addresses a master–slave synchronization strategy for complex dynamic systems based on feedback control. This strategy is applied to 3-DOF planar manipulators in order to obtain synchronization in such complicated as chaotic motions of end-effectors. A chaotic curve is selected from Duffing equation as the trajectory of master end-effector and a piecewise approximation method is proposed to accurately represent this chaotic trajectory of end-effectors. The dynamical equations of master–slave manipulators with synchronization controller are derived, and the Lyapunov stability theory is used to determine the stability of this controlled synchronization system. In numerical experiments, the synchronous motions of end-effectors as well as three joint angles and torques of master–slave manipulators are studied under the control of the proposed synchronization strategy. It is found that the positive gain matrix affects the implementation of synchronization control strategy. This synchronization control strategy proves the synchronization’s feasibility and controllability for complicated motions generated by master–slave manipulators.
Urokinase-dependent adhesion loss and shape change after cyclic adenosine monophosphate elevation in cultured rat mesangial cells.

Mesangial cells in culture change shape and become less adhesive in response to cAMP elevation (e.g., treatment with isoproterenol plus isobutylmethylxanthine (IM). Inhibitors of serine proteases inhibit cellular shape change in response to IM. To further examine the role of cell surface proteases in shape change, adhesion plaque proteins (i.e., preparations of ventral membranes and extracellular matrix) were separated in SDS-polyacrylamide gels containing gelatin with and without plasminogen. Four discrete zones of lysis were evident in plasminogen gels (indicative of activation of plasminogen) from control adhesion plaques: one inconspicuous zone with a Mr approximately 150 kD, another at approximately 115 kD, and a doublet at approximately 35-32 kD. Another diffuse zone of lysis centered around Mr approximately 70 kD and contained a defined band of approximately 56 kD. Adhesion plaques contained most of the plasminogen activators (PA). 5 min after IM treatment, the Mr approximately 150- and approximately 115-kD PA were increased in activity. Vasopressin (VP), which prevented shape change and adhesion loss when added along with IM, inhibited the increase in these PA. Preincubation with monoclonal or polyclonal antibodies to urokinase-type plasminogen activator (uPA) totally inhibited the IM-inducible shape change and adhesion loss. Activation of plasminogen throughout the gels revealed multiple protease resistant bands that markedly increased with IM treatment (maximal at 45 min). These may represent focal control mechanisms. uPA thus may mediate focal proteolysis, which results in shape change and decreased adhesion.
Modulation of lateral perforant path excitatory responses by metabotropic glutamate 8 (mGlu8) receptors

The contribution of metabotropic glutamate 8 (mGlu8) receptors to modulation of medial and lateral perforant path (MPP and LPP) inputs to the dentate gyrus was investigated using electrophysiological recording of field excitatory postsynaptic potentials (fEPSPs) from hippocampal slices taken from wild-type and mGlu8 receptor knockout animals. Application of the selective group III mGlu receptor agonist, L-AP4 (1-100 microM), reduced fEPSPs evoked by LPP, but not MPP stimulation in wild-type slices in a concentration-dependent manner (EC(50) = 4.7 microM). The selective mGlu8 receptor agonist, DCPG (1-30 microM) also suppressed LPP fEPSPs with an EC(50) value of 3.1 microM. The L-AP4-induced reduction in LPP fEPSPs could be blocked by the group III antagonist, MSOP (100 microM) in wild-type slices and was eliminated in mGlu8 receptor-deficient slices. Additional experiments showed that MPP fEPSPs were suppressed by the group II agonist, LY379268 (0.01-3 microM) in control slices (EC(50) = 153.1 nM); an effect that was not altered in mGlu8 receptor knockout slices (EC(50) = 153.8 nM). In addition, LY379268 had little effect on fEPSPs evoked by LPP stimulation in mGlu8 receptor-deficient slices. In conjunction with recent receptor localization studies, these results suggest that the mGlu8 receptors serve as autoreceptors on LPP afferents to the dentate gyrus.
Glass corrosion A record of the past? A predictor of the future?

Abstract The principles of chemical corrosion of glasses are reviewed. The influence of temperature, glass composition, glass homogeneity and corrosion media are related to observed corrosion rates. A comparison of the durability of man-made and natural glasses is offered and the corrosion rates of tektites and obsidians are discussed. Natural glasses are not likely to advance our present understanding of corrosion theory.
Formulation and testing of a climatonomic simulation of the microclimate of the dry valleys and of the little America v station in Antarctica

A climatonomy model to synthesize monthly-mean energy fluxes and temperatures for a snow-covered and snow-free surface in the Antarctic is described. The system is composed of two submodels based on simple, bulk parameterization of physical processes. The first describes the scattering and absorption of global radiation by the atmosphere, while the second partitions the surface fluxes at the ground and predicts their time-series values over the annual cycle.
Holographic generation of bubble gratings at liquid—glass interfaces and the dynamics of bubbles on surfaces

Abstract Intense diffraction from a periodic array of microscopic bubbles is reported. The bubbles are generated by 100 ps, 1.06 μm pulses from a Nd:YAG laser which are crossed at a liquid—dielectric interface. The time dependence of the diffraction yields information on surface bubble expansion, contraction, and migration. The mechanism for the production of the bubble gratings is described.
Absence of minor groove monovalent cations in the crosslinked dodecamer C-G-C-G-A-A-T-T-C-G-C-G.

The structure of a crosslinked B -DNA dodecamer of sequence C-G-C-G-A-A-T-T-C-G-C-G has been solved to a resolution of 1.43 A. The dithiobis-propane crosslink, -CH2-CH2-CH2-S-S-CH2-CH2-CH2-, bridges N7 atoms of adenine bases 6 and 18 in the two central base-pairs within the major groove. The crosslink is sufficiently long that no bending is induced in the helix, which is essentially isostructural with the native unlinked dodecamer at 1.9 A. A constellation of solvent peaks tentatively fitted as a spermine molecule in that earlier analysis is now seen at higher resolution to be a well-defined octahedral magnesium hexahydrate complex in the major groove. One end of the duplex curves around that complex to produce a roll-bend near base-pairs 3-5, and an overall bend in helix axis, as has long been noted. Two other magnesium complexes connect the helices and help to knit the crystal lattice together. No evidence exists for partial sodium or potassium ion substitution for solvent water molecules within the minor groove spine of hydration, as had been suggested previously: not coordination geometry and environment, nor B values, nor calculated valence values, nor difference map analyses. Indeed, the very numbers that have been claimed in support of partial substitution by sodium or potassium ions are reproduced with the present crystals, which by chemical analysis contains only one trace sodium ion per 160 bp, and one potassium ion per 41 bp. In contrast, our crystals contain one Mg2+ per base-pair, meaning that phosphate group charge neutrality is accomplished by divalent cations, not monovalent ions. Three of these magnesium cations per duplex are localized and visible in the X-ray analysis, and nine are disordered and invisible. Hence although binding of monovalent cations within the minor groove of A -tracts on occasion may be a consequence of groove narrowing, it cannot be the cause of that narrowing. Cations, contrary to what has been claimed, are not in charge.
Molecular imaging in Prostate cancer

Prostate cancer (PCa) is the most common non-cutaneous malignancy in men. New ways to diagnose this cancer in its early stages are needed. Unique genetic and biochemical changes in the cell pave the way for tumors to grow and metastasize. Novel imaging approaches attempt to detect pathological processes in cancer cells at the molecular level. This has led to the establishment and development of the field of molecular imaging. Positron emission tomography (PET), magnetic resonance spectroscopic imaging (MRSI), magnetic resonance imaging (MRI), and radiolabeled antibodies are a few of the modalities that can detect abnormal tumor metabolic processes in the clinical setting. Other imaging techniques are still in their early phase of development but hold promise for the future, including bioluminescence imaging (BLI), measurement of tumor oxygenation, and measurement of uptake of iodine by tumors. These techniques are non-invasive and can spare the patient undue morbidity, while potentially providing early diagnosis, accurate follow-up and, finally, valuable prognostic information.
Transcriptional control of cancer metastasis

Transcriptional regulation is an essential component of tumor progression and metastasis. During cancer progression, dysregulation of oncogenic or tumor-suppressive transcription factors (TFs), as well as master cell fate regulators and tumor microenvironment-induced factors, collectively influence multiple steps of the metastasis cascade, including local invasion, dissemination, and eventual colonization of the tumor to distant organs. Furthermore, epigenetic alterations in tumor cells, including DNA methylation, as well as activation or suppression of histone deacetylases (HDACs), histone acetyltransferases (HATs), and other chromatin-modifying enzymes, can further distort the transcriptional network to influence metastasis. We focus here on recent research advances in transcriptional control of metastasis and highlight the therapeutic potential of targeting such transcriptional regulatory networks.
Keys to modeling LNG spills on water.

Although no LNG ship has experienced a loss of containment in over 40 years of shipping, it is important for risk management planning to understand the predicted consequences of a spill. A key parameter in assessing the impact of an LNG spill is the pool size. LNG spills onto water generally result in larger pools than land spills because they are unconfined. Modeling of LNG spills onto water is much more difficult than for land spills because the phenomena are more complex and the experimental basis is more limited. The most prevalent practice in predicting pool sizes is to treat the release as instantaneous or constant-rate, and to calculate the pool size using an empirical evaporation or burn rate. The evaporation or burn rate is particularly difficult to estimate for LNG spills on water, because the available data are so limited, scattered, and difficult to extrapolate to the large releases of interest. A more effective modeling of possible spills of LNG onto water calculates, rather than estimating, the evaporation or burn rate. The keys to this approach are to: * Use rigorous multicomponent physical properties. * Use a time-varying analysis of spill and evaporation. * Use a material and energy balance approach. * Estimate the heat transfer from water to LNG in a way that reflects the turbulence. These keys are explained and demonstrated by predictions of a model that incorporates these features. The major challenges are describing the effects of the LNG-water turbulence and the heat transfer from the pool fire to the underlying LNG pool. The model includes a fundamentally based framework for these terms, and the current formulation is based on some of the largest tests to-date. The heat transfer coefficient between the water and LNG is obtained by applying a "turbulence factor" to the value from correlations for quiescent film and transition boiling. The turbulence factor is based on two of the largest unignited tests on water to-date. The heat transfer from the fire to the pool is based on the burning rate for the largest pool fire test on land to-date. Language: en