cssi/SciSciGPT-SciSciNet huggingface dataset:
A Fluorescence Quench and Dequench Assay of Fibrinogen Polymerization, Fibrinogenolysis, or Fibrinolysis

We present a kinetic assay based on the use of fluorescein isothiocyanate (FITC)-labeled fibrinogen as a fluoroactive substrate. The multiple FITCs bound to fibrinogen experienced quenching due to their close proximity. The thrombin-induced polymerization of FITC-fibrinogen led to additional fluorescence quenching due to enhanced neighbor-neighbor interactions in protofibrils and protofibril aggregates. The initial rate of quenching was directly dependent on the thrombin concentration at either low or high ionic strength. The final extent of quenching during polymerization with thrombin could be modulated by prevailing ionic strength and thrombin concentration suggesting that the quenching was due to fibril extension as well as aggregation. The full extent of quenching was greatly reduced by addition to the reaction of unlabeled fibrinogen or Gly-Pro-Arg-Pro, as expected for quenching due to neighbor-neighbor interactions. In contrast to polymerization, cleavage of fibrinogen by plasmin released FITC-labeled fragments free of proximity-based quenching that resulted in a large intensity increase as lysis proceeded--a process termed dequenching. The majority of the dequenching signal during fibrinogenolysis occurred during the generation of fragment X which proceeded as a first-order process with respect to fibrinogen-bound plasmin with kcat = 0.479 s-1. The Kd of active plasmin to fibrinogen was calculated to be 0.42 microM. Addition of epsilon-aminocaproic acid (epsilon ACA)-plasmin complex to FITC-fibrinogen produced little dequenching, demonstrating a requirement for binding in order to initiate lysis.(ABSTRACT TRUNCATED AT 250 WORDS)
Balancing Cycle Time and Workstations

Abstract This paper develops a model which simultaneously considers the minimization of cycle time and the number of workstations in an assembly line balancing problem. The model is developed from such known zero-one formulations as the Patterson and Albract [13] and the Thangavelu and Shetty [17] models. The flexibility provided by the model should prove especially valuable in the planning stages of a line balancing operation.
Wind and Temperature Profile Characteristics from Observations on a 1400 ft Tower

Abstract Profiles of mean wind speed obtained from a 1420-ft tower are analyzed on the basis of similarity theory to determine the relationship of profile shape to lapse rate structure. A total of 274 profiles representing four observation times (0600, 1000, 1400, and 1800 CST) are used in the analysis. Thirty minute averages of the wind speed are taken at eleven levels on the tower at these observation times. The wind speed values are normalized by means of the friction velocity as well as a reference height velocity computed at the lowest observation level, and profiles for these wind speeds are grouped according to profile shape characteristics. For each group, an average profile is computed and the vertical variation of mean wind speed is compared to a logarithmic or power law profile form. Results of the study indicate that the mean wind profiles are dependent on the lapse rate structure and can be divided into “non-inversion” (lapse rates greater than isothermal) and “inversion” (lapse rates less th...
Human enteric population ecology and degradation of gut mucins.

In this issue Prizont and Konigsberg (1) clearly demonstrate that three f3-glycosidases present in cecal contents of conventional rats are bacterial in origin and are virtually absent from cecal contents of germfree rats. Furthermore, they demonstrate that the structural features conferring human blood group B antigen specificity in gut mucin glycoproteins of germfree rats are rapidly degraded when incubated with the cell-free fraction of cecal contents from conventional rats. These findings contribute additional evidence that the enteric microflora produces the enzymatic tools necessary for degrading carbohydrates from structural macromolecules in the gut lumen; potential substrates include mucin glycoproteins and the membrane glycoproteins and glycolipids of mucosal epithelium. What significance does this have to us as hosts, physicians, and scientists? In attempting to answer this question we will first look at it from the viewpoint of the indigenous enteric microflora. Mankind harbors a colonic microflora that numbers 1013-10 TM bacteria, a population equalling or exceeding the total number of cells comprising the human body (2). As many as 500 strains are estimated to comprise the popUlation, but a comparatively small number of obligately anaerobic species dominate it (3). Their fecal population densities show little variation from day to day. Indeed, when species in fecal samples were ranked according to abundance, there were greater differences in the rank order among subjects than in the same subject from day to day, suggesting that each of us harbors a stable microbial ecosystem that is quantitatively unique (4). Energy sources are required to maintain stable population densities against rates of bacterial death and fecal losses. Most of the dominant genera of human enteric bacteria ferment carbohydrates as primary energy sources (5, 6). Smith and Bryant (5)
The problem of extending the set of support strategy

This article is the third of a series of articles discussing various open research problems in automated reasoning. The problem proposed for research focuses on redefining or extending the definition of the set of support strategy so that the resulting strategy is as effective at all clause levels as it is at level 1. We include specific test problems for evaluating a proposed solution to this research problem.
Variable Selection to Discriminate between Two Groups: Stepwise Logistic Regression or Stepwise Discriminant Analysis?

Abstract Monte Carlo methods were used to compare the stepwise variable selection procedure in discriminant analysis with the stepwise procedure using logistic regression. In these studies four of the candidate variables were related to group membership and four were not. The data sets were generated from normal, lognormal, and Bernoulli distributions. Several sample sizes, mean vectors, and covariance matrices were used. In most situations there was little difference between stepwise logistic regression and discriminant analysis in the probability of selecting the related variables. In some situations stepwise discriminant analysis gave a greater probability of selecting the related variables.
Structure of the myosin crossbridge lattice in insect flight muscle.

Freeze fracture and deep-etching of quick-frozen insect flight muscles provides unusually clear views of thick filament projections in rigor and relaxed states. In rigor, these projections form crossbridges that are deployed helically. The tracks of these helices are left-handed, repeat every ∼38 nm, tilt at ∼42° to the muscle axis, and, when viewed on edge, produce the unique “double chevron” pattern of crossbridges that characterizes this muscle type in thin sections (Reedy, 1968) . These helical parameters substantiate Reedy's earlier deduction that rigor crossbridges form two-start helices in this muscle. On the other hand, deep-etchings of insect flight muscles relaxed with Mg-ATP before freezing do not fit with earlier results. Contrary to earlier thin section views and the expectations of X-ray diffraction, thick filaments in such relaxed muscles display no hint of a 14·5 nm axial periodicity; instead, their projections appear to be very disordered. This suggests that when crossbridges are detached, they are free to “wobble” by at least ±7 nm in the axial direction and thus obscure their points of origin from the thick filaments. With the images of detached crossbridges in mind, closer inspection of rigor thick filaments yields no indication of any “extra” projections between the helically deployed ones, i.e. there is no indication of any detached crossbridges in rigor muscles. Thus in this type of muscle, at least, the establishment of a rigor pattern may not involve a “selection” of suitably located myosin heads from a larger population, as is generally thought, but may instead involve a systematic redistribution of the whole population of heads until all of them became crossbridges.
Comparison of Waist to Hip Ratio Sites and Heart Disease Risk Factors in Healthy Premenopausal Women

Abstract LEARNING OUTCOME: To identify the recommended waist to hip ratio measurement method for determination of upper body fat distribution. Upper body fat distribution (UBFD) is associated with an increased risk for cardiovascular disease (CVD). Women with UBFD often have low HDL-cholesterol levels, hypertriglyceridemia, and hypertension. The waist to hip ratio (WHR) is a useful screening tool to determine UBFD and potential CVD risk. A WHR in women of >0.8 is indicative of UBFD. Currently, there is no agreement regarding which anatomical sites most effectively identify UBFD. The purpose of this study was to determine which of four commonly used WHR waist sites correlated best with CVD risk factors in premenopausal women. Forty healthy females (aged 34.3±10.7yrs.) volunteered for this study. Diastolic blood pressure (DBP), fasting lipids [HDL-cholesterol (HDL) and triglycerides (TG)], and percent body fat (%BF) were determined. Four waist sites were measured: WHR 1 - smallest waist; WHR 2 - midway between the lowest rib and anterior superior iliac spine: WHR 3 - umbilicus; and WHR 4 –1/3 the distance between the xiphoid process and the umbilicus. Maximum extension of the buttocks was used for the hip site. The group mean for %BF was 29.5±7%, DBP was 73.7±8.1mmHg, HDL was 70.2±17.7mg/dl, and TG was 106.9±56.1mg/dl. The average WHRs varied with each site used; WHR 1,2,3, and 4 averaged 0.77, 0.82, 0.88, and 0.80, respectively. Pearson product moment correlation coefficients determined that WHR 2 correlated (p 0.8 but no CVD risks. We accepted WHR2 as being the best measure because it had a high TP rate (86%) and a low FP rate (45%). We recommend WHR2 as the best site to identify UBFD and potential risk for CVD.
The model theory of differential fields revisited

The intent of this article is to provide a general and elementary account of the model theory of differential fields, collecting together various results (many without proof) and offering a few algebraic details for the logician reader. The first model-theoretic look at differential fields was taken by Abraham Robinson in the context of model completeness, while later developments have served to illustrate concepts developed by Morley and Shelah.
Unit prices on retail shelf labels: an assessment of information prominence

Abstract Although unit prices have been provided to consumers for nearly 30 years, the format in which this information is presented has been largely ignored. An examination of major grocery retailers found considerable differences in how prominently unit prices are presented to shoppers on shelf labels. Two methodological approaches are then used to examine the prominence of unit prices in a grocery–shopping context. The results of a field study support expectations that, among consumers who are relatively low in price consciousness, the prominence of unit price information has a positive effect on awareness and usage of such information. In a second study, a controlled experiment shows that increasing the prominence of unit price information affects consumers’ shopping behaviors by shifting purchases toward lower unit priced items and ultimately reducing grocery expenditures. Suggestions for future research and implications for retailers and policymakers are discussed.
Applying Ethics to Insider Trading

Insider trading has received a bad name in recent decades. The popular press makes it sound like an evil practice where those who engage in it are totally devoid of ethical principles. Yet not all insider trading is unethical and some studies have concluded that certain kinds of insider trading are actually beneficial to the greater investment community. Some scholars in philosophy, law and economics have disputed whether insider trading should be punished at all while others assert that it should be illegal in all cases. This paper explores the nature of insider trading and analyzes the issues to determine the positive and negative aspects of insider trading, and how policy should be changed. The best hope would be for studies to be made that isolate the individuals or groups who are fraudulently harmed by insider trading. If any such groups exist, then clearly worded legislation could be passed to prevent any fraud from being committed against these individuals and groups, while allowing non-fraudulent transactions to be completed without fear of prosecution. Until it can be clearly determined that someone is fraudulently harmed by insider trading, there should be no law or regulation restricting the practice, since such restrictions violate individual rights and will likely have a negative market reaction.
Abdominal pain radiating to the back

Dr. Teena Kohli: Today’s case is that of a 79-year-old woman who presented to the Emergency Department (ED) via ambulance with a chief complaint of abdominal, back and bilateral leg pain. The patient was in her usual state of health until the evening prior to presentation when she fell in her apartment. After the fall she remained on her couch unable to move her legs. She started to develop abdominal pain, back pain and leg pain. The pain progressively worsened overnight and when she arrived in the ED at 10:00 a.m. the next morning, the pain was severe. She also complained of lack of sensation to both of the lower extremities. The patient had a history of heart disease, diabetes, hypertension, hypercholesterolemia and depression. Dr. Ryan Friedberg: Before Dr. Kohli describes her physical findings, are there any questions regarding the initial history? Dr. Richard Wolfe: Can you describe her cardiac history in more detail? Dr. Kohli: The patient had hypertension and coronary artery disease with a history of myocardial infarction and an ejection fraction of 20%. She underwent a two-vessel coronary artery bypass graft in 1999. She was not known to have any dysrhythmias, did not use tobacco, and was living alone independently. Her medications included lisinopril, gatifloxacin, paroxetine, furosemide, metoprolol, glyburide, atorvastatin, aspirin and doxepin. On physical examination, the vital signs were: temperature 36.4°C (97.5°F), pulse 74 beats/min, blood pressure 130/90 mm Hg, respirations 20 breaths/min, and oxygen saturation 98% on room air. The patient was in moderate distress, sitting up in bed, moaning loudly. She was awake, alert and oriented. The head and neck examination revealed no head trauma, the pupils were equal, round, reactive to light, and the extra-ocular muscles were intact. There was no jugular venous distention. The chest was clear to auscultation bilaterally with no wheezes, rhonchi or rales. The heart had a regular rate and rhythm without any murmurs, gallops or rubs. The abdomen was distended and diffusely tender with guarding, but no rebound tenderness. The back was diffusely tender in the lumbosacral region. The lower extremities were mottled in appearance and cool to the touch. Both legs were plegic and insensate from the groin to the toes. There were no palpable or dopplerable femoral, popliteal or pedal pulses. Are there any questions about the physical examination? Dr. Carlo Rosen: On abdominal examination, did you feel any pulsatile masses? Was a bedside ultrasound examination performed? Dr. Kohli: No pulsatile masses were appreciated on abdominal examination. The tenderness was diffuse throughout the entire abdomen with no specific area that was worse. She described the pain as severe, cramping, aching pain. Before I give the results of the bedside ultrasound, would anyone like to comment on the differ-
Hypertension: is it time to reconsider blood pressure guidelines?

The KDIGO recommendation for blood pressure management in patients with chronic kidney disease and proteinuria is based partly on underpowered subgroup and post hoc analyses. New observational data, however, demonstrate that lower blood pressure goals may be harmful in this group of patients.
Melanoma of the gallbladder: a review of cases seen at Duke University Medical Center.

BACKGROUND Both primary and metastatic melanoma of the gallbladder are rare. In cases involving isolated tumors of the gallbladder, there continues to be controversy regarding the establishment of primary status. Despite appropriate therapy, the diagnosis of either condition portends a poor prognosis, with few patients surviving more than 2 years. METHODS A review of all patients seen at Duke University Medical Center since 1970 generated 1 case of primary and 19 cases of secondary melanoma of the gallbladder. These were analyzed with respect to presentation, clinical and pathologic diagnosis, treatment, and prognosis. RESULTS The sole patient with a primary lesion presented with acute cholecystitis. Ultrasound demonstrated a mass in the lumen of the gallbladder. Cholecystectomy revealed melanoma, and the patient eventually died of disseminated disease 13.5 months later. Survival was poor for patients who presented with metastases to the gallbladder in the setting of widespread disease, with 0% survival at 1 year (n = 11). Those with isolated, resectable lesions fared better overall, with 100% survival (n = 6) at 1 year. One patient remains alive and free of disease 13.8 years later, which, to our knowledge, represents the longest documented survival for a patient with melanoma that has metastasized to the gallbladder. CONCLUSIONS Surgery remains the mainstay of therapy for patients with gallbladder melanoma and appears to improve patient outcome in the setting of resectable disease. Hopefully, further investigations will lead to standardized protocols for the treatment of these lesions. Cancer 1999;85:32–9. © 1999 American Cancer Society.
C-Jun induces mammary epithelial cellular invasion and breast cancer stem cell expansion

The molecular mechanisms governing breast tumor cellular self-renewal contribute to breast cancer progression and therapeutic resistance. The ErbB2 oncogene is overexpressed in approximately 30% of human breast cancers. c-Jun, the first cellular proto-oncogene, is overexpressed in human breast cancer. However, the role of endogenous c-Jun in mammary tumor progression is unknown. Herein, transgenic mice expressing the mammary gland-targeted ErbB2 oncogene were crossed with c-jun(f/f) transgenic mice to determine the role of endogenous c-Jun in mammary tumor invasion and stem cell function. The excision of c-jun by Cre recombinase reduced cellular migration, invasion, and mammosphere formation of ErbB2-induced mammary tumors. Proteomic analysis identified a subset of secreted proteins (stem cell factor (SCF) and CCL5) induced by ErbB2 expression that were dependent upon endogenous c-Jun expression. SCF and CCL5 were identified as transcriptionally induced by c-Jun. CCL5 rescued the c-Jun-deficient breast tumor cellular invasion phenotype. SCF rescued the c-Jun-deficient mammosphere production. Endogenous c-Jun thus contributes to ErbB2-induced mammary tumor cell invasion and self-renewal.
Value of Pavement Smoothness

Smoothness, the absence of bumps and dips in the riding surface of a pavement, improves the quality of the ride and is believed to prolong the life of the pavement. Research addressed the effect of Virginia's special provision for smoothness on contract prices for hot-mix asphalt. The research also examined the financial value of the resulting product (presumably smoother pavements). The analysis included maintenance cost savings for the owner-agency, as well as any reduction in delay and operating costs for the motoring public. A detailed statistical analysis found no statistically definitive effect on bid price as a result of the use of a special provision for rideability. A similar analysis on a more focused data set, however, did document a lifetime reduction in the international roughness index of almost 9 in./mi. This reduction in roughness (increase in smoothness) implies an increase in pavement service life, which translates into reduced annual maintenance costs. The lifetime decrease in roughness...
Exploitation of specific properties of trifluoroethanol for extraction and separation of membrane proteins

Hydrophobic proteins are difficult to analyze by two-dimensional electrophoresis (2-DE) because of their intrinsic tendency to self-aggregate during the first dimension (isoelectric focusing, IEF) or the equilibration steps. This aggregation renders their redissolution for the second dimension uncertain and results in the reduction of the number and intensity of protein spots, and in undesirable vertical and horizontal streaks across gels. Trifluoroethanol (TFE) is traditionally used at high concentration to solubilize peptides and proteins for NMR studies. Depending upon its concentration, TFE strongly affects the three-dimensional structure of proteins. We report here a phase separation system based on TFE/CHCl(3), which is able to extract a number of intrinsic membrane proteins. The addition of TFE in the in-gel sample rehydration buffer to improve membrane protein IEF separation is also presented. The procedure using urea, thiourea, and sulfobetaine as chaotropic agents was modified by the addition of TFE and removing of sulfobetaine at an optimized concentration in the solubilization medium used for the first dimension. When using membrane fractions isolated from Escherichia coli, the intensity and the number of spots detected from 2-DE gels that used TFE in the solubilization medium were significantly increased. The majority of the proteins identified using peptide mass fingerprinting and tandem mass spectrometry (MS/MS) were intrinsic membrane proteins, proteins of beta barrel structure or transmembrane proteins.
A geometric approach to a class of equilibrium existence theorems

In this paper we propose a general mathematical approach to existence problems in economics based on the geometry of vector bundles and the methods of intersection theory. The existence problem is formulated as: Does an approximate vector bundle admit a non-zero continuous section? The motivation and major application comes from incomplete market theory, where the appropriate vector bundle has, as one of the components of its base space, a Grassmanian manifold. Several general existence results are offered. One infinite dimensional generalization is included.
Gender, Emotion, and the Family

Do women express their feelings more than men? Popular stereotypes say they do, but in this text, Leslie Brody breaks with conventional widsom. Her work integrates biological and socio-cultural developments to explore the nature and extent of gender differences in emotional expression, as well as the endlessly complex questions of how such differences come about. Nurture, far more than nature, it is argued, emerges as the stronger force in fashioning gender differences in emotional expression. Brody shows that whether and how men and women express their feelings varies widely form situation to situation and from culture to culture, and depends on a number of particular characteristics including age, ethnicity, cultural background, power, and status. Especially pertinent is the organization of the family, in which boys and girls elicit and absorb different emotional strategies. Brody also examines the importance of gender roles, whether in the family, the peer group, or the culture at large, as men and women use various patterns of emotional expression to adapt to power and status imbalances.
Preliminary Evaluation of Potential Impacts of Non-Petroleum Oils on the Aquatic Environment

ABSTRACT Non-petroleum oils—specifically crude and refined corn and safflower oils, and refined sunflower and soybean oils—have been shown to form stable emulsions, with the amount of emulsion bein...
Effects of Mg composition on open circuit voltage of Cu2O-MgxZn1 xO heterojunction solar cells

Abstract Mg x Zn 1− x O (0≤ x ≤0.13) films grown by metal-organic chemical vapor deposition (MOCVD) were chosen as the n-type semiconductor layer forming a heterojunction with electrodeposited p-type cuprous oxide (Cu 2 O) for photovoltaic applications in this study. We investigated the effects of Mg contents ( x ) on the performance of Ag–Cu 2 O–Mg x Zn 1− x O–fluorine-doped tin oxide (FTO)-glass heterojunction solar cells, where Ag and FTO are used as top and bottom electrodes, respectively. An enhancement of the open-circuit voltage ( V OC ) with the increase of x , from 251 mV at x =0 to 570 mV at x =10%, was observed. In order to understand how V OC increases with Mg%, the band alignment between Cu 2 O and Mg x Zn 1− x O was demonstrated using X-ray photoelectron spectroscopy (XPS) measurements. The result indicates that the conduction band of Mg x Zn 1− x O moves closer to the vacuum level with increasing of x , leading to a decrease of the conduction band offset between Mg x Zn 1− x O and Cu 2 O and hence an enhancement of theoretical V OC . Another improvement with the increase of Mg% was realized on the shunt resistance ( R sh ) of devices. With the improved V OC and R sh , a relatively high solar power conversion efficiency ( η AM1.5 =0.71%) was obtained on the Mg x Zn 1− x O ( x =10%) based solar cell.
Coordinate frame free Dubins vehicle circumnavigation

A Dubins vehicle circumnavigation controller is derived based on an analysis of state space dynamics resulting from a state transformation. The controller is designed and analyzed in the state space with two continuous and one discrete variables. We showed that the property of our control strategy can be studied based on 2D phase portraits, including the case when the vehicle turning rate is bounded. As a part of our analysis, we found conditions that need to be satisfied for the controller to work and that can be used for gain scheduling and application of the control to a larger range bound. The results are illustrated by 2D phase portraits and simulations describing the control implementation, which is based only on range measurements.
ORDINATION AND CARDINATION IN COUNTING AND PIAGET'S NUMBER CONCEPT TASK

Brainerd ( 2 ) has described how counting can be utilized to generate instances of ordination and cardination. Thus he observed that, if children were aware of the positional meanings of number names (ordinal) before their numerousness meanings (cardinal), this could be regarded as an instance of the ordination-cardination sequence. To assess this sequence by means of counting, the responses of 94 children, aged 5:6 to 7 : l (years:months), to Questions 3 (subject is to find and mark a house with 7 windows from among four choices-numerousness) and 17 (subject is requested to mark the 7th bird in a row of IO-rdinal position) of the Metropolitan Readiness Tests, Form A , Test 5 Numbers ( 3 ) were examined. Correct responses for both questions were glven by 70 subjects. Of the remaining 24 subjects, 22 responded correctly only to Question 3 and the other two subjects only to Question 17. In this instance of the generation of ordination and cardination by means of counting, the trend of the results indicate that, when ordination and cardination are not in concert, a cardination response is more likely to be observed. This same group of subjects was also evaluated with Piaget's (1, pp. 260-261) number-concept task. Eight subjects manifested a comprehension of one-to-one correspondence between the items of two rows after an alteration of the perceptual correspondence between the items. These subjects maintained the quantitative and/or cardinal equivalence of the rows. The remaining 86 subjects always judged the row that was greater in length to have more items than its corresponding row. Such length bound responses are a manifestation of the inability of the subjects to quantify by means of the correspondence operation. According to Piaget (5, p. 976) responses like this, in which subjects emphasize length, are founded on ordinal quantification. In the light of this these responses can rightly be regarded as ordination responses. In sum it appears that cardination in counting is attained before either ordination in counting or the cardination of the correspondence operation. A Piagetian (4, p. 138) explanation of the above results would be that even though 92 subjects were able to generate cardinal numbers by counting, the results of their counting were not genuine cardinal numbers if in the second instance they are unable to maintain a quantitative or cardinal equivalence of two rows of items after an alteration of the perceptual correspondence between the row items.
Integrating Contemplative Tools into Biomedical Science Education and Research Training Programs

Academic preparation of science researchers and/or human or veterinary medicine clinicians through the science, technology, engineering, and mathematics (STEM) curriculum has usually focused on the students (1) acquiring increased disciplinary expertise, (2) learning needed methodologies and protocols, and (3) expanding their capacity for intense, persistent focus. Such educational training is effective until roadblocks or problems arise via this highly-learned approach. Then, the health science trainee may have few tools available for effective problem solving. Training to achieve flexibility, adaptability, and broadened perspectives using contemplative practices has been rare among biomedical education programs. To address this gap, a Cornell University-based program involving formal biomedical science coursework, and health science workshops has been developed to offer science students, researchers and health professionals a broader array of personal, contemplation-based, problem-solving tools. This STEM educational initiative includes first-person exercises designed to broaden perceptional awareness, decrease emotional drama, and mobilize whole-body strategies for creative problem solving. Self-calibration and journaling are used for students to evaluate the personal utility of each exercise. The educational goals are to increase student self-awareness and self-regulation and to provide trainees with value-added tools for career-long problem solving. Basic elements of this educational initiative are discussed using the framework of the Tree of Contemplative Practices.
A Directional Interstitial Antenna for Microwave Tissue Ablation: Theoretical and Experimental Investigation

Microwave ablation (MWA) is a minimally invasive thermal therapy modality increasingly employed for the treatment of tumors and benign disease. For successful treatment, complete thermal coverage of the tumor and margin of surrounding healthy tissue must be achieved. Currently available interstitial antennas for MWA have cylindrically symmetric radiation patterns. Thus, when treating targets in proximity to critical structures, caution must be taken to prevent unintended thermal damage. A novel coaxial antenna design for MWA with an asymmetrical cylindrical heating pattern is presented in this paper. This radiation pattern is achieved by employing a hemicylindrical reflector positioned at a critical distance from a conventional coaxial monopole antenna. Finite-element method simulations were employed to optimize the geometric dimensions of the antenna with the objective of minimizing the antenna reflection coefficient at the 2.45-GHz operating frequency, and maximizing volume of the ablation zone. Prototype antennas were fabricated and experimentally evaluated. Simulations indicated an optimal S 11 of –32 dB at 2.45 GHz in close agreement with experimental measurements of –29 dB. Ex vivo experiments were performed to validate simulations and observe effects to the antennas’ heating pattern with the varying input power and geometry of the reflector. Ablation zones up to 20 mm radially were observed in the forward direction, with minimal heating (less than 4 mm) behind the reflector.
Instability of a two-layer thin liquid film with surfactants : Dewetting waves

Dewetting dynamics of a liquid film composed of two superposed ultra-thin layers of immiscible liquids resting on a solid substrate is investigated in the case when surfactants are present at the liquid-liquid interface. Two cases are considered: insoluble surfactant and surfactant soluble in the lower liquid. The dependence of Hamaker constants on the surfactant concentration is taken into account. A system of three strongly nonlinear evolution equations describing large (comparable to the layer thicknesses), long-wave perturbations of the liquid-liquid and liquid-gas interfaces, as well as the surfactant concentration, is derived for each case in the lubrication approximation. The linear stability analysis shows that in the presence of surfactants, oscillatory dewetting instability can occur. Numerical simulations of this system of nonlinear evolution equations are performed. It is found that in the case of oscillatory instabilities, the system exhibits either standing or traveling "dewetting waves." The weakly nonlinear analysis explains this phenomenon.
Segmentation and tracking of partial planar templates

We present an algorithm that can segment and track partial planar templates, from a sequence of images taken from a moving camera. By “partial planar template”, we mean that the template is the projection of a surface patch that is only partially planar; some of the points may correspond to other surfaces. The algorithm segments each image template to identify the pixels that belong to the dominant plane, and determines the three dimensional structure of that plane. We show that our algorithm can track such patches over a larger visual angle, compared to algorithms that assume that patches arise from a single planar surface. The new tracking algorithm is expected to improve the accuracy of visual simultaneous localization and mapping, especially in outdoor natural scenes where planar features are rare.
Atrophic gastritis in pernicious anemia: Diagnosis by double-contrast radiography

A retrospective study was performed to determine whether the areae gastricae pattern in the stomach or other radiologic features could be used on double-contrast upper gastrointestinal examinations to accurately diagnose atrophic gastritis in pernicious anemia. The double-contrast studies from 21 patients with pernicious anemia and 55 age-matched controls were interspersed and reviewed blindly to assess gastric size, mucosal folds, and the areae gastricae pattern in the stomach. The best set of criteria for differentiating the pernicious anemia group from the controls included a fundal diameter of 8 cm or less, absent mucosal folds in the fundus or body, and small (i.e., 1–2 mm in size) or absent areae gastricae. This combination of findings was present in 81% of patients with pernicious anemia but it also was present in 11% of the controls, so that atrophic gastritis in pernicious anemia could not be reliably diagnosed on radiologic criteria. Nevertheless, patients with pernicious anemia invariably had small or absent areae gastricae in the stomach, so that the presence of prominent areae gastricae, particularly in the fundus, may be a useful criterion for excluding this disease.
Coexistence of hydrogen and carbon solutes in the palladium lattice

Carbon atoms can penetrate into the palladium lattice, forming interstitial solid solutions up to PdC0.15.No β-PdH is detected on exposure of this phase to H2. However, a continuous series of ternary PdCxHy (0 <x < 0.15, 0 < y < 0.65) can be obtained for samples containing lesser amounts of carbon. The quantity of hydrogen accommodated in such systems depends only on the carbon concentration, and not on the phase homogeneity.
Solid state coordination chemistry of the copper(I)–cyano–organodiimine system. Two- and three-dimensional copper cyanide phases incorporating linear dipodal ligands

A series of composite inorganic–organic materials from the copper/cyanide/organoimine system have been isolated and structurally characterized. The structural consequences of introducing sterically demanding substituents and of expanding the donor to donor distance in linear dipodal organodiimine ligands has been addressed, exploiting the bridging bidentate ligands pyrazine (pyr), 2-methylpyrazine (mpyr), 2-ethylpyrazine (etpyr), 2,3-dimethylpyrazine (2,3-dmp), 2,5-dimethylpyrazine (2,5-dmp), 2,6-dimethylpyrazine (2,6-dmp), quinoxaline (qox), phenazine (phenz), 4,4′-bipyridine (4,4′-bpy) and trans-4,4′-bipyridylethylene (dpe). Hydrothermal reactions of CuCN and KCN with the appropriate ligand yielded two general subclasses of materials: two-dimensional networks and three-dimensional frameworks. The 2-D phases include [Cu3(CN)3(pyr)] (1), [Cu2(CN)2(etpyr)] (2), [Cu2(CN)2(tmp)] (3), [Cu2(CN)2(qox)] (4), [Cu2(CN)2(phenz)] (5) and [Cu7(CN)7(4,4′-bpy)2] (6). The 3-D materials are represented by [Cu3(CN)3(pyr)2] (7), [Cu2(CN)2(mpyr)] (8), [Cu2(CN)2(2,3-dmp)] (9), [Cu2(CN)2(2,5-dmp)] (10), [Cu2(CN)2(2,6-dmp)] (11), [Cu2(CN)2(4,4′-bpy)](12) and [Cu2(CN)2(dpe)] (13). The materials characteristically exhibit {Cu(CN)}n chains and/or {Cux(CN)x} rings as structural motifs. The detailed connectivity between such substructures is influenced by the identity of the organodiimine ligand and the associated steric demands and spatial extension. The syntheses and structural characterization by X-ray diffraction of 1–13 are discussed in relation to the supramolecular chemistry of other copper cyanide solid state materials.
Regulation of Krüppel-like Factor 4 by the Anaphase Promoting Complex Pathway Is Involved in TGF-β Signaling

Kruppel-like factor 4 (KLF4), a zinc finger-containing transcriptional factor, regulates a variety of biological processes, including cell proliferation, differentiation, apoptosis, and stem cell reprogramming. Post-translational modifications of KLF4, including phosphorylation, acetylation, and sumoylation, regulate its transcriptional activity. Most recent studies also demonstrate that KLF4 is targeted for ubiquitin-dependent proteolysis during cell cycle progression. However, the underlying mechanism remains largely unknown. In this study, we demonstrated that KLF4 is profoundly degraded in response to TGF-β signaling. We have identified the Cdh1-anaphase promoting complex as a putative E3 ligase that governs TGF-β-induced KLF4 degradation. The TGF-β-induced KLF4 degradation is mediated by the destruction box on the KLF4. Either depletion of Cdh1 by RNA interference or stabilization of KLF4 by disruption of its destruction box significantly attenuates TGF-β-induced ubiquitylation and degradation. In addition, depletion of Cdh1 or stabilization of KLF4 antagonizes TGF-β-induced activation of transcription. Determining the role of KLF4 proteolysis in response to TGF-β signaling has opened a new perspective to understand the TGF-β signaling pathway.
Essays of a Peripheral Mind: Wyatt Earp, T. rex, and Other Dinosaurs

Essays of a Peripheral Mind: Wyatt Earp, T. rex, and Other Dinosaurs DOI:10.2458/azu_rangelands_v31i5_havsatd2
Differential Expression of Sugarcane Polyubiquitin Genes and Isolation of Promoters from two Highly-Expressed Members of the Gene Family

Summary To identify potential strong constitutive promoters, accumulation of polyubiquitin mRNA in sugarcane ( Saccharum hybrid) was studied using gene-specific probes from five sugarcane polyubiquitin cDNA clones. Based on comparisons of 3′ untranslated regions, these cDNAs can be grouped into four sub-groups within the sugarcane polyubiquitin gene family. RNA gel blot experiments indicated that these sub-groups differ substantially in constitutive expression levels and response to heat shock. Reverse northern experiments confirmed the relative magnitudes of constitutive expression in young leaves. One sub-group, homologous to cDNAs scubi241 and scubi511, was found to have the highest level of constitutive expression and to be little affected by heat shock. Genomic clones belonging to this sub-group were isolated; two of these clones, ubi4 and ubi9, were found to differ in the number of protein coding repeats but were highly similar in overall structure and in the sequence of DNA flanking the transcribed region. Both genes contain a single large intron located immediately upstream of the translation start codon. Transient expression experiments showed that the cloned promoters are sufficient to drive high levels of GUS expression in sugarcane suspension cells and in tobacco leaves.
A sequentialization of the Patterson classifier [Correction]

The expression for Pn-1 above equation (10) on page 1988 of the above-named letter is corrected.
Evidence of increased dopamine receptor signaling in food-restricted rats.

It is well established that chronic food restriction enhances sensitivity to the rewarding and motor-activating effects of abused drugs. However, neuroadaptations underlying these behavioral effects have not been characterized. The purpose of the present study was to explore the possibility that food restriction produces increased dopamine (DA) receptor function that is evident in behavior, signal transduction, and immediate early gene expression. In the first two experiments, rats received intracerebroventricular (i.c.v.) injections of the D1 DA receptor agonist SKF-82958, and the D2/3 DA receptor agonist quinpirole. Both agonists produced greater motor-activating effects in food-restricted than ad libitum-fed rats. In addition, Fos-immunostaining induced by SKF-82958 in caudate-putamen (CPu) and nucleus accumbens (Nac) was greater in food-restricted than ad libitum-fed rats, as was staining induced by quinpirole in globus pallidus and ventral pallidum. In the next two experiments, neuronal membranes prepared from CPu and Nac were exposed to SKF-82958 and quinpirole. Despite the documented involvement of cyclic AMP (cAMP) signaling in D1 DA receptor-mediated c-fos induction, stimulation of adenylyl cyclase (AC) activity by SKF-82958 in CPu and Nac did not differ between groups. Food restriction did, however, decrease AC stimulation by the direct enzyme stimulant, forskolin, but not NaF or MnCl(2), suggesting a shift in AC expression to a less catalytically efficient isoform. Finally, food restriction increased quinpirole-stimulated [(35)S]guanosine triphosphate-gammaS binding in CPu, suggesting that increased functional coupling between D2 DA receptors and G(i) may account for the augmented behavioral and pallidal c-Fos responses to quinpirole. Results of this study support the hypothesis that food restriction leads to neuroadaptations at the level of postsynaptic D1 and D2 receptor-bearing cells which, in turn, mediate augmented behavioral and transcriptional responses to DA. The signaling pathways mediating these augmented responses remain to be fully elucidated.
Synthesis and reactivity of a tethered diene cyclopentadiene, (C5Me4H)SiMe2(CH2CH=CHCH=CH2), and its alkali metal salts

Abstract (C 5 Me 4 H)SiMe 2 Cl reacts with (THF)KCH 2 CHCHCHCH 2 to form (C 5 Me 4 H)SiMe 2 (CH 2 CHCHCHCH 2 ) ( 1 ). Compound 1 reacts with KH and n -BuLi to make M(C 5 Me 4 )SiMe 2 (CH 2 CHCHCHCH 2 ), M=K, 2 ; Li, 3 , respectively. Carbon–silicon cleavage occurs when 1 reacts with K to form (C 5 Me 4 H)K, which crystallizes from dimethoxyethane as [(C 5 Me 4 H)K(DME)] x . This potassium salt has an extended structure which generates bent metallocene (C 5 Me 4 H) 2 K(DME) sub-structures which have 133.9° ring centroidKring centroid angles. Compound 1 reacts with TiCl 4 to make (C 5 Me 4 H)TiCl 3 ( 5 ), which has a piano stool structure.
Intracellular Calcium Concentration and Growth Hormone Secretion in Individual Somatotropes: Effects of Growth Hormone-Releasing Factor and Somatostatin

The cytosolic free calcium concentration and cumulative GH release were measured simultaneously in normal pituitary cells. This was made possible by a novel combination of fluorescence microscopy using the calcium indicator fura-2 and a reverse hemolytic plaque assay. GRF (10 nM) rapidly increased the intracellular free calcium concentration ([ Ca2+]i) from a basal level of 234 +/- 17 nM (mean +/- SE) to a peak value of 480 +/- 61 nM 1 min after stimulation. This GRF-induced calcium rise was totally abolished in calcium-free medium or in the presence of calcium channel blockers cobalt chloride (2 mM) and verapamil (100 microM). When somatostatin (SRIF; 1 nM) was added after basal recordings, cytosolic calcium decreased to 96 +/- 23 nM in identified somatotropes. [Ca2+]i returned to baseline upon the removal of SRIF inhibition. This rebound was higher when a sequential treatment of SRIF followed by GRF was applied. Exposing cells to a combination of GRF (10 nM) plus SRIF (1 nM) resulted in a decrease in [Ca2+]i identical to that caused by SRIF treatment alone. Despite the 10-fold excess of GRF, SRIF not only inhibited hormone secretion, but also totally overcame the GRF-induced rise of [Ca2+]i. In summary, stimulation by GRF increases cytosolic calcium in normal somatotropes. This increase is proposed to be due to the influx of calcium through membrane ion channels. In contrast, SRIF decreases [Ca2+]i. This might explain the cAMP-independent effects of this peptide. The effect of SRIF dominates over that of GRF with respect to both changes in [Ca2+]i and hormone release. Changes in the GH secretory rate are, therefore, accompanied by parallel changes in [Ca2+]i, both of which are primarily regulated by SRIF.
MBE growth of two-dimensional electron system with extremely low disorder

We report on the growth of modulation-doped GaAs/AlxGa1-xAs heterostructures with extremely low disorder. The structures have mobilities (μ) on the order of 1×106 cm2/V ·s (at 4.2 K) for areal densities (ns) as low as 4×1010 cm-2. In growing these structures we employed the atomic plane doping technique and ultrathick ( > 1000 A) spacer layers with graded composition. These structures have the highest “figure-of-merit” for mobility (μ/n3/2s) ever reported.
Refinement of F-Actin Model against Fiber Diffraction Data by Long-Range Normal Modes

The atomic model of F-actin was refined against fiber diffraction data using long-range normal modes as adjustable parameters to account for the collective long-range filamentous deformations. To determine the effect of long-range deformations on the refinement, each of the four domains of G-actin was treated as a rigid body. It was found that among all modes, the bending modes make the most significant contributions to the improvement of the refinement. Inclusion of only 7–9 bending modes as adjustable parameters yielded a lowest R-factor of 6.3%. These results demonstrate that employing normal modes as refinement parameters has the advantage of using a small number of adjustable parameters to achieve a good fitting efficiency. Such a refinement procedure may therefore prevent the refinement from overfitting the structural model. More importantly, the results of this study demonstrate that, for any fiber diffraction data, a substantial amount of refinement error is due to long-range deformations, especially the bending, of the filaments. The effects of these intrinsic deformations cannot be easily compensated for by adjusting local structural parameters, and must be properly accounted for in the refinement to achieve improved fit of refined models with experimental diffraction data.
The reduced cell multipole method for Coulomb interactions in periodic systems with million-atom unit cells

Abstract Standard methods for calculating Coulomb interactions of periodic systems use Ewald-type formulations or minimum image approximations, neither of which is practical for large (million-atom) systems. We describe the reduced cell multipole method which is 38 times faster than the Ewald method for a 4816-atom (unit cell) system. The method scales linearly with the number of atoms in the cell, making simulations of million-atom systems practical, as demonstrated in a series of applications on a laboratory workstation.