cssi/SciSciGPT-SciSciNet huggingface dataset:
Fourier transform infrared spectroscopic studies of the adsorption of benzene on alumina and alumina supported platinum

Abstract Fourier transform infrared spectroscopy has been used to study the adsorbed state of benzene (C6H6 and C6D6) on γ-alumina and alumina-supported Pt catalysts at 300 K. Benzene physisorbs on the alumina support with an infrared spectrum similar to that of liquid benzene. However, small increases in the energy of combination bands involving out-of-plane hydrogen vibrations and the formation of perturbed hydroxyl groups on the alumina surface indicate that the adsorption of benzene in this case is the result of the interaction of the π-electrons with the OH groups on alumina. This had been observed previously for benzene physisorbed on silica. On Pt/Al2O3, benzene chemisorbs on the Pt metal and physisorbs on the Al2O3 support. The observation of E1u and B2u vibrations of chemisorbed benzene on Pt (i.e., 3050, 1398, 1274, 1147, and 1042 cm−1 for C6H6 and 2260, 1268, and 1230 cm−1 for C6D6 indicates that chemisorbed benzene is distorted to C3v symmetry. The distortion is such that the chemisorbed benzene has alternating long and short C-C bonds. Thus, benzene approaches the classical Kekule structure (i.e. cyclohexatriene) upon adsorption on Pt. The resultant loss in energy of resonance allows benzene to be readily hydrogenated on Pt/Al2O3. The deconvolution of the broad C-H stretching vibration shows it to be composed of four bands. This is interpreted as caused by benzene molecules adsorbed on several crystalline sites of the polycrystalline Pt/Al2O3 catalyst.
Endovascular Therapy for Malperfusion in Acute Type B Aortic Dissection

Presentation with acute type B aortic dissection (B-AD) in the setting of malperfusion is associated with a high risk for major morbidity due to end-organ ischemia. This presentation has traditionally been considered an indication for operation where the entry tear is resected, and branch vessel perfusion is subsequently restored either as a result of the aortic repair or by direct revascularization of the peripheral arterial bed. There are two predominant mechanisms by which malperfusion can occur, and these have previously been defined by our group. 1,2 In static obstruction, the dissection flap entersthebranchvessellumenwithoutanadequatereentrytear (or a diminutive reentry tear) within the course of that artery. The compromised true lumen of that artery then becomes the sole source of inflow into that end organ. In contrast, in dynamic obstruction, the mobile aortic dissection flap intermittently covers the orifice of the branch vessel during the cardiac cycle, thus impeding arterial inflow into the end organ. Treatment is directed at restoring the integrity of the arterial true lumen in static obstruction and of the aortic true lumen in dynamic obstruction. Finally, end-organ perfusion may be compromised by a combination of both mechanisms, as well as by miscellaneous causes including thrombosis or embolism of branches supplied by either lumen. Whereasmalperfusionhastraditionallybeenanindication to proceed with early operative repair of the aorta, endovascular approaches have emerged as an alternative to allow restoration of end-organ perfusion. Two types are discussed in this report, and each has a different focus. The traditional endovascular approach has relied on a percutaneous method of creating a fenestration in the dissection flap to equalize
Effects of a Cognitive Restructuring Program on Inmate Institutional Behavior

Although research suggests that cognitive restructuring programs reduce recidivism, little is known about the effects of such programs on institutional behavior. This study compared randomly selected inmates who participated in other self-help programs and randomly selected inmates who participated in the first phase of a cognitive restructuring program with inmates who had been in the second phase for at least 6 months. The total sample size was 123. Findings suggest that participation in the first phase appears to reduce refusals to obey a direct order, whereas participation in the second phase appears to reduce assaults.
Purification of enzymes by heparin-sepharose affinity chromatography

Abstract Heparin selectively interacts with many enzymes and brings about significant changes in their activities. Due to its polyanionic nature, heparin also binds to many cationic proteins. Both these interactions may be used as a basis for the purification of proteins by heparin-Sepharose affinity chromatography. Recently heparin-Sepharose has been extensively used for the purification of enzymes, coagulation proteins, steroid receptors and protein synthesis factors.
Experience with a new spectra holmium laser probe

The initial enthusiasm related to laser angioplasty witnessed just a few years ago has waned considerably owing to the failure of thermal laser technology to meet clinical expectations. While the initial procedural success rate for the hot-tip probe was acceptable (about 79% in most series), mid- and long-term studies have shown a disappointing recurrence rate. These follow-up data have dictated a new course for the development of laser technology in the vascular system. We evaluated a new delivery system using holmium:YAG laser energy for its ability to recanalize obstructive peripheral atherosclerotic lesions in over 200 patients. The 2.5 mm Spectra Holmium laser probe delivered 2100 nm laser energy at 1000-1200 mJ/pulse at 10 Hz to achieve a maximum energy density of 4000 mJ/mm2. Maximum temperature was 85 degC. Among all lesions, 54% could not be crossed with a wire. Of these, 77% were recanalized by the probe by the probe. Average lasing time for occlusions: 44.8 seconds, and 71.6 seconds for stenoses. Residual stenosis after lasing: 68% in occlusions and 59% in stenoses. Laser success in all lesions was 76%. The Spectra Holmium probe was successful in opening occlusions but had little effect on stenoses due to the small probe size and limited laser aperture. There were no complications related to the laser, and no thermal effect was noted on direct angioscopic observation. More effective multifiber catheters are needed for greater tissue ablation.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A Pre-Columbian Technique for Electrochemical Replacement Plating of Gold and Silver on Copper Objects

Pre-Columbian smiths working in northern Peru gilded and silvered copper objects by electrochemical replacement techniques that deposited films of 0.5–2 μm onto copper sheet. Platings that seem to be identical have been produced in the laboratory using gold dissolved in aqueous solutions of NaCl + KNO3 + KAl(SO4)2 · 12H2O.
Pricing As Creative Marketing

An Assistant Professor at the Universi ty of Chicago, Thomas Nagle is current ly writ ing The Strategy and Tactics of Pricing (Prentice-Hall, fo r thcoming) . The author wou ld like to thank Harry Davis, Universi ty of Chicago, and J o h n Heinke, Universi ty of Santa Clara, for helpful discussions. Pricing is often treated as a technical problem to be solved by applying rules or procedures, not as a creative marketing challenge to be met with new insight into buyers' motivations. But pricing, no less than any other aspect of the marketing mix, can be made more effective by the design of creative strategies that reflect differences among buyers.
The synthesis of bicyclo[2.2.2]octan-2-ones by sequential michael reactions

Abstract The reaction of cross-conjugated dienolate anions derived from substituted cyclohexenones with methyl acrylate and vinyl ketones has been studied. Bicyclo[2.2.2]octan-2-ones are formed by a sequential Michael mechanism; however, the reactions of vinyl ketones must be conducted under amine-free conditions. Unexpecedly, the conjugate base from 2,3-dimethylcyclohex-2-enone gives only a single Michael adduct with vinyl ketones, and if forced to react further undergoes an intramolecular aldol condensation. An alternative Diels-Alder approach to the bicyclo[2.2.2]octanone products is shown to be effective.
Aeromechanical behavior of selected Douglas-fir

Abstract The aeromechanical behavior of three Douglas-fir is described, using wind shear force as the input variable and tree deflection as the output variable. Variance spectra maxima of wind-produced tree deflection were always higher in frequency than the incident shear force. A compliance transfer relation developed from these variables indicated a marked tendency for vibrations to build up as turbulent energy in the wind increased. This analytical form is proposed as a method for examining the involvement of mechanical and aerodynamic factors coupling the tree to the wind.
Elective delivery of infants with macrosomia in diabetic women: Reduced shoulder dystocia versus increased cesarean deliveries

OBJECTIVE: We sought to test the hypothesis that elective delivery of infants diagnosed with macrosomia by ultrasonographic studies in diabetic women will significantly reduce the rate of shoulder dystocia without significantly increasing cesarean section rate. STUDY DESIGN: In a prospective study diabetic women with ultrasonographic estimated fetal weight ≥4250 gm underwent elective cesarean section; women with estimated fetal weight ≥90th percentile but <4250 gm underwent induction of labor. Maternal and neonatal outcomes were analyzed and compared for the periods before and after initiation of the protocol. RESULTS: A total of 2604 diabetic patients were included in this study. The rate of shoulder dystocia was significantly lower after instituting the protocol (2.4% vs 1.1%, odds ratio 2.2). The cesarean section rate increased significantly between the two periods (21.7% vs 25.1%, p < 0.04). Ultrasonography correctly identified the presence or absence of macrosomia in 87% of patients. Only 10.6% of diabetic patients at term required intervention under the protocol (6.8% labor induction, 3.8% elective cesarean section). The rate of shoulder dystocia was 7.4% in macrosomic infants delivered vaginally. CONCLUSION: An ultrasonographically estimated weight threshold as an indication for elective delivery in diabetic women reduces the rate of shoulder dystocia without a clinically meaningful increase in cesarean section rate. This practice, in conjunction with an intensified management approach to diabetes, improves the outcome of these high-risk women and their infants. (Am J Obstet Gynecol 1998;178:922-5.)
Dipolar Defect Model for Fatigue in Ferroelectric Perovskites

A microscopic model for polarization fatigue in ferroelectric perovskites based on dipolar defects formed by the combination of oxygen vacancies and impurity metal ions is presented. The binding energy of an oxygen vacancy to a Pt impurity in $\mathrm{PbTiO}{}_{3}$ is calculated to be $\ensuremath{\sim}2.9\mathrm{eV}$. The complex is strongly polar, is stabilized by electron capture, and pins the polarization of the surrounding lattice.
Interactive finite element analysis of fracture processes: An integrated approach

Abstract A fracture analysis program has been developed which incorporates the concepts of finite element analysis, fracture mechanics, computer graphics, finite element postprocessing, automatic mesh generation, and data base design. The program FRANC (FRacture ANalysis Code) is a tool which allows a practicing engineer or a researcher to perform an incremental fracture analysis at his desk. The program draws on a substantial experience base and this paper describes the philosophy of the program and the integration of its parts. Also, a number of example problems will be presented which show some results of incremental fracture analyses.
Recognition of handwritten digits using template and model matching

Abstract A pipeline strategy for handwritten numeral recognition that combines a two-stage template-based technique and a model-based technique is described. The template matcher combines multiple information sources. The second stage of the template matcher was trained on rejects from the first stage. The template matcher classifies 70–80% of the digits with reliability rates over 99%. It also generates class membership hypotheses for the remaining digits which constrain the model-based system. Recognition rates of 94.03–96.39% and error rates of 0.54%–1.05% are obtained on test data consisting of over 13,000 well-segmented digits from ZIP codes in the USPS mail.
Versicolorin synthesis by Aspergillus parasiticus: Regulation by temperature and zinc

Abstract A mutant strain of Aspergillus parasiticus (ATCC 36537) was grown in shaken liquid culture at 23 or 37°C. The polyketide secondary metabolite versicolorin A was produced at the lower but not the higher temperature. Temperature upshift (23 → 37°C) arrested versicolorin synthesis; temperature downshift (37 → 23°C) allowed versicolorin synthesis to occur after a 6-h lag. Versicolorin synthesis after temperature downshift was blocked by addition of cycloheximide or actinomycin D at the time of temperature shift. Zn 2+ is known to be required for versicolorin synthesis, and Zn 2+ uptake must occur before temperature downshift. We suggest that a transcriptional event required for versicolorin synthesis occurs only in the presence of Zn 2+ and at temperatures below 37°C.
Clinical and Hematologic Effects of Cross Circulation in Baboons

Potential clinical and hematologic complications were studied in 18 baboons subjected to cross circulation for periods of five to 31 days. Cross circulation was a safe procedure during the first four days. After that time, anaphylactoid reactions potentially fatal for one or both partners, thrombocytopenia, leukopenia, hemolytic anemia, and in one case, marrow depression were seen. These reactions were ameliorated but not entirely controlled by administration of methotrexate. When cross circulation was discontinued after five to 31 days, eight of nine baboons showed prompt clinical and hematologic recovery without late sequelae.
Identification of novel microRNA-like molecules generated from herpesvirus and host tRNA transcripts

We applied deep sequencing technology to small RNA fractions from cells lytically infected with murine gammaherpesvirus 68 (γHV68) in order to define in detail small RNAs generated from a cluster of tRNA-related polycistronic structures located at the left end of the viral genome. We detected 10 new candidate microRNAs (miRNAs), six of which were confirmed by Northern blot analysis, leaving four as provisional. In addition, we determined that previously identified and annotated viral miRNA molecules were not necessarily represented as the most abundant sequence originating from a transcript. Based on these new small RNAs and previously reported γHV68 miRNAs, we were able to further describe and annotate the distinctive γHV68 tRNA-miRNA structures. We used this deep sequencing data and computational analysis to identify similar structures in the mouse genome and validated that these host structures also give rise to small RNAs. This reveals a possible convergent usage of tRNA/polymerase III (pol III) transcripts to generate small RNAs from both mammalian and viral genomes.
Symptoms of post-traumatic stress in children with cancer and their parents: effects of informant and time from diagnosis.

Background Post-traumatic stress disorder (PTSD) has been put forth as a model for understanding the adjustment of children with cancer and their parents, but findings in the literature regarding the prevalence of post-traumatic stress symptoms (PTSS) have been mixed. This study examined PTSS levels in both patients and parents as a function of time elapsed from diagnosis, and by use of parent versus child reports for assessing patient PTSS. Procedure Four groups of patients (total N = 162) differing in time elapsed since diagnosis were assessed with standardized measures of PTSS. Patients reported on their own symptoms, while parents reported on their symptoms as well as symptoms in their child. Results Significant differences between groups were observed on all patient PTSS measures. Recently diagnosed patients obtained higher PTSS scores than survivors more than 5 years from diagnosis. Likewise, parents of recently diagnosed patients self-reported significantly higher levels of PTSS than parents of long-term survivors. Parent–child correlations were high and no differences were observed between parent and patient report of patient PTSS. Comparison with historical control data suggests that levels of PTSS in patients are very low. Conclusion Concordance between parent and child reports of child PTSS suggests that data may be obtained with reasonable confidence from either if only one informant is available. Higher levels of PTSS in patients who are recently diagnosed (and their parents) in comparison to long-term survivors, suggest that the symptoms reported reflect primarily a concurrent response to ongoing acute stressors, rather than a post-traumatic re-experiencing of past traumas. This, in combination with the low levels of patient PTSS raise questions regarding the utility of PTSD as a model for understanding patient and parent adjustment to childhood cancer. © 2005 Wiley-Liss, Inc.
Effect of nitrate concentration on hydroponially grown primocane‐fruiting red raspberries

Abstract Primocane‐fruiting red raspberry plants (Rubus idaeus L.) ‘Redwing’ were grown in six hydroponic solutions containing nitrogen (N) levels of 2.5, 5, 10, 15, 20, and 25 meq N per liter. Plant growth rates and final cane heights were similar in all treatments except for reduced growth in the 2.5 meq per liter treatment. Greatest leaf, stem, and root dry weight accumulation was found in the 10 meq per liter treatment. The greatest numbers of nodes, flowers, and inflorescences per cane were found in the 5, 20, and 10 meq per liter treatments, respectively. Solution N levels had no effect on time of flowering.
Binary nonlinear joint transform correlator performance with different thresholding methods under unknown illumination conditions

The correlation performance of binary joint transform correlators with unknown input-image light illumination is investigated for different thresholding methods used in the Fourier plane. It is shown that a binary joint transform correlator that uses a spatial frequency dependent threshold function for binarization of the joint power spectrum is invariant to uniform input-image illumination. Computer simulations and optical experimental results are provided.
Inhaled anesthetic agents

Purpose. The pharmacology, bioavailability and pharmacokinetics, indications, clinical efficacy, adverse effects and toxicities, and dosage and administration of the inhaled anesthetics are reviewed. Summary. The inhaled anesthetics include desflurane, enflurane, halothane, isoflurane, and sevoflurane and are thought to enhance inhibitory postsynaptic channel activity and inhibit excitatory synaptic activity. The mechanism of action of inhaled anesthetics has not been completely defined. A number of factors can influence the pharmacokinetics of inhaled anesthetics, including solubility in blood, cardiac output, tissue equilibration, extent of tissue perfusion, metabolism, and age. All of the available inhaled anesthetics are effective for inducing or maintaining anesthesia or both. Most clinical trials of inhaled anesthetics have evaluated differences in induction and emergence from anesthesia by comparing (1) times to loss of reflex, extubation, and response to verbal commands; orientation to time and place; and ability to sit up without assistance, (2) need for post-surgical analgesia, and (3) time to discharge as measures of efficacy. Adverse effects and toxicities of the inhaled anesthetics include nephrotoxicity, hepatotoxicity, cardiac ar-rhythmias, neurotoxicity, postoperative nausea and vomiting, respiratory depression and irritation, malignant hyperthermia, and postanesthesia agitation. Safety issues surrounding these gases include occupational exposure and intraoperative fires within the delivery systems used with inhaled anesthetics. Drugs used for anesthesia during surgery can account for 5–13% of a hospital’s drug budget. Conclusion. The inhaled anesthetics have been shown to be both safe and effective in inducing and maintaining anesthesia. These agents differ in potency, adverse-effect profile, and cost. Newer anesthetic gases, such as sevoflurane and desflurane, appear to have more favorable physico-chemical properties. These factors, as well as patient characteristics and duration and type of procedure, must be considered when selecting an inhaled anesthetic.
Identification of an orthogonal peptide binding motif for biarsenical multiuse affinity probes.

Biarsenical multiuse affinity probes (MAPs) complexed with ethanedithiol (EDT) permit the selective cellular labeling of proteins engineered with tetracysteine motifs, but are limited by the availability of a single binding motif (i.e., CCPGCC or PG tag) that prevents the differential labeling of coexpressed proteins. To overcome this problem, we have used a high-throughput peptide screen to identify an alternate binding motif (i.e., CCKACC or KA tag), which has a similar brightness to the classical sequence upon MAP binding, but displays altered rates and affinities of association that permit the differential labeling of these peptide sequences by the red probe 4,5-bis(1,3,2-dithiarsolan-2-yl)-resorufin (ReAsH-EDT2) or its green cognate 4‘,5‘-bis(1,3,2-dithoarsolan-2-yl)fluorescein (FLAsH-EDT2). The utility of this labeling strategy was demonstrated following the expression of PG- and KA-tagged subunits of RNA polymerase in E. coli. Specific labeling of two subunits of RNA polymerase in cellular lysates ...
Endothelial nitric oxide synthase affects both early and late collateral arterial adaptation and blood flow recovery after induction of hind limb ischemia in mice

Objective The goals of this study were to determine if endothelial nitric oxide synthase (eNOS) affects both early and late collateral arterial adaptation and blood flow recovery after severe limb ischemia in a mouse model and to determine if eNOS-derived NO is necessary for recruitment of chemokine (C-X-C motif) receptor 4 (CXCR4) + vascular endothelial growth factor receptor-1 (VEGFR1) + hemangiocytes to the site of ischemia. Methods Two studies were completed. In the first, hind limb ischemia was induced by unilateral femoral artery excision in three groups: C57Bl6 (wild-type), eNOS −/− , and C57Bl/6 mice treated with N G -nitro-l-arginine methyl ester (L-NAME) from 1 day before excision through day 3 after excision (early L-NAME group). These groups were studied on day 3 after induction of ischemia. In the second study, hind limb ischemia was induced in C57Bl/6 mice (wild-type) and C57Bl/6 mice treated with L-NAME from days 3 through 28 after induction of ischemia. These groups were studied day 28 after ischemia induction. Dependent variables included hind limb perfusion, collateral artery diameter, and the number and location of hemangiocytes within the ischemic hind limb. Results In the first study, toe gangrene developed in the eNOS −/− and early L-NAME treatment groups by day 2. These groups demonstrated less blood flow recovery and smaller collateral artery diameter than the wild-type group. Hemangiocytes were present within the adventitia of collateral arteries in the wild-type group but were only sparsely present, in a random pattern, in the eNOS −/− and early L-NAME treatment groups. In the second study, the late L-NAME group showed less blood flow recovery and smaller collateral artery diameter on day 28 of ischemia than the wild-type group. Hemangiocytes were present in a pericapillary distribution in the wild-type group, but were present only sparsely in the late L-NAME treatment group. Conclusion Early (day 3) and late (day 28) adaptive responses to hind limb ischemia both require eNOS–derived NO. NO is necessary for normal hemangiocyte recruitment to the ischemic tissue.
Glycemic control is impaired in the evening in prediabetes through multiple diurnal rhythms.

Abstract Aims Recent studies suggest that circadian rhythms regulate glucose metabolism, weight loss, and even drug efficacy. Moreover, molecules targeted at the circadian clock show promise in treating metabolic disease. Therefore, this study set out to better characterize interactions among diurnal rhythms in prediabetes. Methods Ten subjects with prediabetes completed oral glucose tolerance tests at 0700h and 1900h on the same day. Lipids and hormones were also measured. Results Two-hour and three-hour glucose tolerances were worse in the evening by 40±52mg/dl (p=0.02) and 62±46mg/dl (p=0.001), respectively. These impairments were explained by lower insulin sensitivity (OGIS; 5.14±1.02 vs. 4.74±0.77mg/kg/min; p=0.03) and 2-hour AUC insulin levels (87.4±37.6 vs. 69.8±40.2mU∙hr/l; p=0.02) in the evening. Intriguingly, more insulin resistant subjects had weaker rhythms in insulin sensitivity (r=−0.66; p=0.04) but enhanced rhythms in insulin (r=−0.67; p=0.03) and cortisol (r=−0.78; p=0.008) levels. Importantly, the rhythms in cortisol primarily but also insulin sensitivity drove the declines in evening glucose tolerance (r=0.86; p=0.002). Conclusions Glycemic control is dramatically impaired in the evening in people with prediabetes, particularly when the cortisol rhythm is weak, but is unrelated to the rhythm in insulin levels. Therefore, food intake at dinnertime may need to be curbed in prediabetes.
132 Differential Regulation of Osteopontin and Matrix Metalloproteinases During Diabetic Wound Healing

Delayed wound healing is a common complication of diabetes resulting in significant clinical morbidity. The diabetic wound exhibits impaired cellular infiltration and consequently inadequate granulation tissue formation. Additionally, altered patterns of apoptosis. In this study, we have evaluated the differential gene expression pattern in transgenic diabetic female mice, 5–6 weeks old, in a full thickness cutaneous punch wound model. We assessed the role of matrix metalloproteinases (MMPs) and differential gene expression pattern at 4th, 7th and 11th day post wounding. Supernatants obtained from diabetic wound tissue homogenates were subjected to zymogram analysis. The data showed that MMPs were expressed at higher level by 4th day post wounding, whereas expression of MMPs were down regulated towards the 11th day post wounding suggesting their role during early phase of wound healing. The pathway specific gene array data demonstrated differential regulation of several growth factors, transcription factors and other related genes such as fibroblast growth factors and their receptors, ID3 and restin respectively. The cytokine/extracellular matrix protein osteopontin (OPN), an important component of cellular immunity and inflammation also showed higher expression after 4 days post wounding. The expression of OPN remained at higher level after 11 days post wounding in diabetic mice, whereas the expression were down regulated to basal level in normal wounded animal suggesting that the expression of OPN was concomitant with the extent of healing. Other adhesion molecules such as integrin αV and PECAM-1 were also differentially regulated. Though a single gene may not be solely responsible for any defect or impairment in healing as it is a very tightly controlled and regulated process, however, a detailed study of these gene(s) may shed some light to the delayed healing in diabetic mice. Acknowledgements: (These studies are supported by NIH Grant G174KT.)
The Electric Welsbach Lamp

This lamp is to serve as a source of radiation from the visible into the far infrared. The heating unit consists of sheets of ashed Welsbach mantle heated by the glow or arc discharge formed between terminals connected to the secondary of a high potential transformer. When operated in air, a small, pointed gas flame is allowed to play on the mantle, thus steadying the electrical discharge and increasing the temperature. From 0.7 to 15μ, gas plus electricity are used, whereas, from 15μ, to 150μ, gas alone is employed. When the lamp is operated in a partial vacuum, variations in spectral distribution are effected largely by working at different pressures. At pressures around 10 cm the emission is similar to that of the gas Welsbach in the region of longer wave-lengths, while at pressures near 30 cm the emission rivals that of a Nernst lamp in the near infrared (0.7 to 15μ).
Toxicity determined in vitro by morphological alterations and neutral red absorption

A method is described which combines the use of a visual morphological cytotoxicity assay with a quantitative neutral red (NR) spectrophotometric test, for the assessment of the effect of toxic agents on 3T3 cells in culture. These sensitive and reproducible assays lend themselves to a screening procedure of potential toxicants which can help reduce the use of animals for toxicity testing.
Formation of δ1-Acetoxytryptophan-62 in the Oxidation of Tryptophan-62 of Hen Egg-White Lysozyme by N-Bromosuccinimide in Acetate Buffer

The reaction of equimolar amounts of N-bromosuccinimide and hen egg-white lysozyme in acetate buffer, under the conditions of Hayashi et al. (Hayashi, K., Imoto, T., Funatsu, G., and Funatsu, M. (1965), J. Biochem. (Tokyo) 58, 227), yields a protein mixture that has a time-dependent 13C-NMR spectrum. The initial natural-abundance 13C-NMR spectrum indicates the presence of about equal amounts of [oxindolealanine-62]lysozyme and [delta1-acetoxytryptophan-62]lysozyme. The latter converts to [oxindolealanine-62]lysozyme with a half-life of about 2 days at 25 degrees C and pH 3.9. Two observations indicate that the source of the acetyl group of delta1-acetoxytryptophan-62 is the acetate buffer. First, the spectrum of a lysozyme sample treated with N-bromosuccinimide in the presence of [1-13C]acetate yields a very strong acetyl ester carbonyl resonance. The time dependence of the intensity of this resonance yields a half-life of 44 h for [delta1-acetoxytryptophan-62]lysozyme. Second, the initial natural-abundance 13C-NMR spectrum of a lysozyme sample treated with N-bromosuccinimide in the absence of acetate indicates essentially complete conversion of tryptophan-62 into oxindolealanine.
Particular solutions to the problem of vertical flow of water and air through porous media near a water table.

Abstract Particular solutions to the problem of vertical flow of water and air through homogeneous porous media are derived and the regularity properties of the solutions are presented. It is found that under certain conditions a singularity occurs in the solutions at the water table, though it is not certain whether or not a singularity always occurs. Effects of air flow on water flow are discussed.
Translating ultraviolet autofluorescence microscopy toward clinical endomicroscopy

The potential of autofluorescence microscopy under ultraviolet excitation is investigated as a method to visualize superficial epithelial microstructures and their modification with progression of disease. This method does not require the use of contrast agents, sectioning methods, or tissue preparation. Imaging of esophagus tissue is the focus of this study and deals with three main issues: a) What is the origin of the signal; b) How the gradual microstructure modification associated with various stages of esophageal disease is visualized; c) What are the designing parameters for in vivo implementation.
Circumferential wall thickness measurements of the human left ventricle: Reference data for thallium-201 single-photon emission computed tomography

New heart imaging methods, including echocardiography, single-photon emission computed tomography (SPECT) and nuclear magnetic resonance, involve measurements of left ventricular (LV) wall thickness in cross sections perpendicular to the LV long axis. To provide a reference base, LV myocardial wall thicknesses were measured in human autopsy specimens. Short-axis views were chosen at the base of the heart, at the level of the papillary muscles and at a level close to the apex. At the 3 levels, LV wall thicknesses were measured for each of 36 circumferential sectors. The measurements revealed a nonuniformity of LV myocardial wall thickness, related to the papillary muscles, the anterior and posterior junctions with the right ventricle and the thinness of the ventricular septum. These findings help to explain the structured appearance of SPECT 201-thallium short-axis views.
Wars for Oil: Moby-Dick, Orientalism, and Cold War Criticism

Beginning with Edward Said's reflections on the media fall-out post 9/11, the ideological representations of which he likens to the mythi- cal drama enacted in Moby-Dick, the article goes on to revisit the consen- sus achieved in Cold-War criticism of the novel in light of our awareness of the cultural construction of recent events. Specifically, the article ques- tions the dichotomizing of the novel in terms of East and West and the crit- ical casting of Fedallah and Ahab as scapegoats for collective guilt, draw- ing on the work of ReneGirard on the subject. In this way, it confirms the analogical justness of Said's evocation of Moby-Dick in relation to America's ''collective imagination'' of its relationship to the Near East and argues the book's power to re-orient and subvert that very representation by revealing both its mythical core and the collective acts of violence it seeks to conceal or sanction.
Decertifying the principalship: The politics of administrator preparation in Florida

Although some factors seem to be moving to allow greater decertification of the school principal profession, other factors, moving in the opposite direction, call for greater oversight by government. Four factors—perceived shortage of principals, accountability and the changing role of principals, growing influence of the state over school administration, and new conceptualization of good public management—have created a set of challenges to certification that have propelled a renewed analysis of certification and licensure. This article focuses on alternative certification and licensure of principals—looking at the historical factors leading up to the introduction of alternative licensure for principals—the challenges to alternative licensure programs, and provides a case study of one district’s and one state’s (Florida) current experimentation.
Human Platelet Dense Granules Contain Polyphosphate and Are Similar to Acidocalcisomes of Bacteria and Unicellular Eukaryotes

Inorganic polyphosphate (polyP) has been identified and measured in human platelets. Millimolar levels (in terms of Pi residues) of short chain polyP were found. The presence of polyP of ∼70–75 phosphate units was identified by 31P NMR and by urea-polyacrylamide gel electrophoresis of platelet extracts. An analysis of human platelet dense granules, purified using metrizamide gradient centrifugation, indicated that polyP was preferentially located in these organelles. This was confirmed by visualization of polyP in the dense granules using 4′,6-diamidino-2-phenylindole and by its release together with pyrophosphate and serotonin upon thrombin stimulation of intact platelets. Dense granules were also shown to contain large amounts of calcium and potassium and both bafilomycin A1-sensitive ATPase and pyrophosphatase activities. In agreement with these results, when human platelets were loaded with the fluorescent calcium indicator Fura-2 acetoxymethyl ester to measure their intracellular Ca2+ concentration ([Ca2+]i), they were shown to possess a significant amount of Ca2+ stored in an acidic compartment. This was indicated by the following: 1) the increase in [Ca2+]i induced by nigericin, monensin, or the weak base, NH4Cl, in the nominal absence of extracellular Ca2 and 2) the effect of ionomycin, which could not take Ca2+ out of acidic organelles and was more effective after alkalinization of this compartment by the previous addition of nigericin, monensin, or NH4Cl. All of these characteristics of the platelet dense granules, together with their known acidity and high density (both by weight and by electron microscopy), are similar to those of acidocalcisomes (volutin granules, polyP bodies) of bacteria and unicellular eukaryotes. The results suggest that acidocalcisomes have been conserved during evolution from bacteria to humans.
Performance-Based Design of Deep Foundation Systems in Load and Resistance Factor Design Framework

Performance-based design methods are increasingly being used for the design and analysis of structures. For performance-based design of deep foundation systems, limiting tolerable movements are one of the design criteria that can be used in lieu of the usual ultimate load capacity. The limiting tolerable movement is often selected to correspond to a movement that will cause damage to a structure but will not produce a collapsible failure of the structure. Performance-based design principles can be extended to include the axial design of deep foundation systems under strength and service loading conditions. In this extended approach, limiting tolerable settlements can be selected to correspond to a movement that will either cause excessive stresses in the structure or render a structure functionally inoperable because of serviceability limits. A performance-based design approach for axial design of deep foundations under the strength and serviceability limit states was developed. The design approach is int...
Transfer of Sulfur from IscS to IscU during Fe/S Cluster Assembly

The cysteine desulfurase enzymes NifS and IscS provide sulfur for the biosynthesis of Fe/S proteins. NifU and IscU have been proposed to serve as template or scaffold proteins in the initial Fe/S cluster assembly events, but the mechanism of sulfur transfer from NifS or IscS to NifU or IscU has not been elucidated. We have employed [35S]cysteine radiotracer studies to monitor sulfur transfer between IscS and IscU from Escherichia coli and have used direct binding measurements to investigate interactions between the proteins. IscS catalyzed transfer of 35S from [35S]cysteine to IscU in the absence of additional thiol reagents, suggesting that transfer can occur directly and without involvement of an intermediate carrier. Surface plasmon resonance studies and isothermal titration calorimetry measurements further revealed that IscU binds to IscS with high affinity (Kd ~2 µM) in support of a direct transfer mechanism. Transfer was inhibited by treatment of IscU with iodoacetamide, and 35S was released by reducing reagents, suggesting that transfer of persulfide sulfur occurs to cysteinyl groups of IscU. A deletion mutant of IscS lacking C-terminal residues 376-413 (IscSDelta 376-413) displayed cysteine desulfurase activity similar to the full-length protein but exhibited lower binding affinity for IscU, decreased ability to transfer 35S to IscU, and reduced activity in assays of Fe/S cluster assembly on IscU. The findings with IscSDelta 376-413 provide additional support for a mechanism of sulfur transfer involving a direct interaction between IscS and IscU and suggest that the C-terminal region of IscS may be important for binding IscU.
Embedded non-interactive CAPTCHA for Fischer Random Chess

Cheating in chess can take many forms and has existed almost as long as the game itself. The advent of computers has introduced a new form of cheating into the game. Thanks to the computational power of modern-day computers, a player can use a program to calculate thousands of moves for him or her, and determine the best possible scenario for each move and counter-move. These programs are often referred to as “bots,” and can even play the game without any user interaction. In this paper, we describe a methodology aimed at preventing bots from participating in online chess games. The proposed approach is based on the integration of a CAPTCHA protocol into a game scenario, and the subsequent inability of bots to accurately track the game states. Preliminary experimental results provide favorable feedback for further development of the proposed algorithm.
Finite-difference time domain method for light scattering by small ice crystals in three-dimensional space

The finite-difference time domain (FDTD) method for the solution of light scattering by nonspherical particles has been developed for small ice crystals of hexagonal shapes including solid and hollow columns, plates, and bullet rosettes commonly occurring in cirrus clouds. To account for absorption, we have introduced the effective permittivity and conductivity to circumvent the required complex calculations in the direct discretization of the basic Maxwell equations. In the construction of the finite-difference scheme for the time-marching iteration for the near field the mean values of dielectric constants are defined and evaluated by the Maxwell–Garnett rule. In computing the scattered field in the radiation zone (far field) and the absorption cross section, we have applied a new algorithm involving the integration of the electric field over the volume inside the scatterer on the basis of electromagnetic principles. This algorithm removes the high-angular-resolution requirement in integrating the scattered energy for the computation of the scattering cross section. The applicability and the accuracy of the FDTD technique in three-dimensional space are validated by comparison with Mie scattering results for a number of size parameters and wavelengths. We demonstrate that neither the conventional geometric optics method nor the Mie theory can be used to approximate the scattering, absorption, and polarization features for hexagonal ice crystals with size parameters from approximately 5 to 20.
Síndrome de apnea del sueño: soluciones a corto plazo y riesgo cerebrovascular a largo plazo

Introduccion y desarrollo. Durante el sueno, el control de la respiracion pasa de ser un acto semivoluntario a convertirse en una actividad de autorregulacion de maxima prioridad biologica. Los trastornos respiratorios del sueno se centran en el sindrome de apnea obstructiva generalmente asociado a roncopatia. La prevalencia de la apnea del sueno (apnea-hipopnea) en la poblacion general se ha fijado entre el 2% en mujeres y el 4% en hombres. La apnea del sueno eleva la presion arterial, aumenta el riesgo de enfermedad cardiovascular y cerebrovascular, causa somnolencia excesiva y disminuye la calidad de vida de los pacientes que la sufren. Conclusiones. La polisomnografia permite el diagnostico de apnea del sueno y da paso al tratamiento con aparatos de presion positiva de la via aerea (CPAP), que es el metodo mas eficaz y generalizado de tratamiento. Existe evidencia creciente de que el tratamiento sostenido de la apnea del sueno disminuye el riesgo de complicaciones vasculares, ademas de mejorar la calidad de vida y disminuir la somnolencia diurna.
Mathematical Analysis of Bleeding Time Data in Patients with Platelet Disorders and von Willebrand's Disease.

In a previous study the volume of blood obtained from bleeding time incisions was measured every 30 s from normal subjects (n = 15), patients with thrombasthenia (TSA, n=4), idiopathic thrombocytopenic purpura (ITP, n=4), von Willebrand's disease (vWD, n=3), Bernard-Soulier syndrome (BSS, n = 2), and δ and αδ-storage pool deficiencies (SPD, n=4 and 5, respectively) and the experimental results analyzed by empirical curve-fitting of the data. In the present investigation, a mathematical model based on blood flow physiology was developed to describe the rate of blood loss over time from these same patients as a function of two parameters, α, which describes the magnitude of vessel contraction following transection, and β, the rate of vessel dilation to its nominal diameter. For the normal controls a third parameter, δ, was used to describe the rate of vessel closure due to the formation of a hemostatic plug. Optimal values for these parameters for the normal subjects and each patient group were determined b...
Disproportionation reactions between alkyl and fluoroalkyl radicals. VI, Difluoromethyl and n-propyl radicals

Cross-disproportionation to combination ratios for CF 2 H and n-C 3 H 7 radicals have been determined (the hydrogen acceptor radical is given first) to be Δ(n-C 3 H 7 ,CF 2 H)=0.30±0.01 and Δ(CF 2 H,n-C 3 H 7 )=0.057±0.006
Palladium-Catalyzed Acetylene Cyclotrimerization: From Ultrahigh Vacuum to High-Pressure Catalysis

The surface reactions involved in the palladium-catalyzed formation of benzene from acetylene are discussed as an example of the way in which such strategies can be used to understand catalytic reaction pathways in detail. This provides an ideal system for surface science/catalysis studies since benzene is formed both in ultrahigh vacuum in temperature-programmed desorption and under high-pressure, catalytic conditions. It is found that benzene is synthesized on clean Pd(111) by an initial fast reaction between two adsorbed acetylene molecules to yield a tilted C4H4 metallocyclic intermediate. This reacts with a third acetylene to form benzene, and the hexagonal (111) surface of palladium acts as a template for the reaction. Under catalytic conditions, however, it is found that the surface is covered by a relatively unreactive vinylidene layer. Organometallic studies show that acetylene and vinylidene can react to form a C4H4 intermediate analogous to that found to form from acetylene on a palladium surface. This suggests an alternative possible reaction pathway under catalytic conditions in which acetylene and vinylidene react to eventually form benzene. This proposal is confirmed using NMR analysis of a 13C-labeled vinylidene-covered surface. This pathway also successfully rationalizes the observed change in activity as a function of reaction time found using supported palladium catalysts and the observed first-order reaction kinetics.
Post-prison Community Reentry and African American Males: Implications for Family Therapy and Health

African American males make up a large proportion of the US male prison population. Fortunately for the African American community and society at large, many of these men will be released back into their communities and go on to become productive citizens. Scant literature exists relative to reentry programs that exist for this population. In this chapter, the authors discuss some of the issues related to prison incarceration, its effects on African American males and community reentry. Family therapy from an Afrocentric perspective is presented as an intervention designed to strengthen family cohesion once these men are re-united with their families. Further, implications for the health of former African American male inmates, their families, and the African American community are discussed. Recommendations for encouraging African American males to seek mental health and family therapy services upon release from prison are given.
Pediatric hypertension 2001

During the past decade, there has been a surge of interest in childhood and adolescent hypertension. The current review summarizes work published during the past year in the following areas: prenatal and early postnatal causes of hypertension; new information on the genetics of childhood hypertension; the relation of obesity, insulin resistance, and diabetes to hypertension; the use of ambulatory blood pressure monitoring to evaluate childhood hypertension; and advances in drug therapy for children with hypertension. The information obtained during the past year has improved our understanding of the pathogenesis, diagnosis, and treatment of childhood hypertension.
Effect of cortisone on histamine liberation induced by Tween in the dog.

Conclusions(1) The injection of Tween 20 in the dog is followed by the appearance of histamine in the plasma, as demonstrated by paper chromatography. (2) Cortisone does not prevent the hypotensive...