cssi/SciSciGPT-SciSciNet huggingface dataset:
5.9 – Radiocarbon

Willard Libby's invention of the radiocarbon dating method revolutionized the fields of archeology and Quaternary geology because it brought into being a means to correlate events that occurred during the past 3.5 × 104 years on a planet-wide scale. This contribution was recognized with the award of the Nobel prize for chemistry. In addition, radiocarbon measurements have been a boon to the quantification of many processes taking place in the environment, to name a few: the rate of ‘ventilation’ of the deep ocean, the turnover time of humus in soils, the rate of growth of cave deposits, the source of carbon-bearing atmospheric particulates, the rates of gas exchange between the atmosphere and water bodies, the replacement time of carbon atoms in human tissue, and depths of bioturbation in marine sediment. Some of these applications have been greatly aided by the creation of excess 14C atoms as the result of nuclear tests conducted in the atmosphere. Since the 1960s, this so-called bomb radiocarbon has made its way into all of the Earth's active carbon reservoirs. To date, tens of thousands of radiocarbon measurements have been made in laboratories throughout the world.
Chapter 5 – Frequency Analysis: The Fourier Transform

Publisher Summary This chapter consolidates the concept of frequency response of a linear time-invariant system. The frequency representation of signals as well as the frequency response of systems are tools of great significance in signal processing, communications, and control theory. By a limiting process the harmonic representation of periodic signals is extended to the Fourier transform, a frequency-dense representation for non-periodic signals. Basic properties of the Fourier transform and important Fourier pairs are presented in the chapter. The Fourier transform measures the frequency content of a signal and unifies the representation of periodic and aperiodic signals. The connection between the Laplace and the Fourier transforms is highlighted for computational and analytical reasons. There are, however, signals where the Fourier transform cannot be obtained from the Laplace transform; for those cases, properties of the Fourier transform is used. The duality of the direct and inverse transforms is of special interest in computing the Fourier transform. Two significant applications are filtering and communications. The fundamentals of modulation and basic of filtering is introduced in the chapter. The idea of changing the frequency content of a signal via modulation is basic in analog communications. Modulation allows sending signals over the airwaves using antennas of reasonable sizes. The chapter represents sampling, quantization, and coding bridge the continuous-time and the digital signal processing, and those transformations similar to the Laplace and the Fourier transforms will permits processing of discrete–time signals and systems.
Inducing mesenchymal stem cell attachment on non-cell adhesive hydrogels through click chemistry

We introduce an innovative approach to adhere mesenchymal stem cells (MSCs) to a hydrogel scaffold by nucleating adhesion through strain-promoted click chemistry. This method yields a significant increase in cell viability compared to non-functionalized and RGD peptide functionalized hydrogels, providing a promising alternative to traditional biomaterials cell attachment approaches.
Two-Phase Total Synthesis of Taxanes: Tactics and Strategies

This Perspective goes into the fine details of our laboratory's quest to answer a longstanding fundamental question: Could any new approach to terpene synthesis, perhaps one patterned on biosynthesis, enable a divergent synthetic approach to the taxane family of natural products? We targeted Taxol, the flagship taxane, as the upper limit of chemical complexity and employed two-phase terpene synthesis logic as the guiding strategy. The first synthesis target was taxadiene, the lowest oxidized member of the taxane family, followed by three site-selective allylic oxidations at C5, C10, and C13, which led to the two-phase synthesis of taxuyunnanine D. Successful C9 oxidation enabled access to a wider range of taxanes, which was demonstrated by the two-phase synthesis of decinnamoyltaxinine E and taxabaccatin III. The final two sp3 C-H oxidations at C1 and C7 were attained by dioxirane-mediated C-H oxidation and an oxidation relay based on judicious substrate design, culminating in a two-phase synthesis of Taxol. The purpose of this Perspective is to articulate strategies and tactics developed for the two-phase synthesis of taxanes, whose lessons can be potentially extrapolated to medicinal chemistry endeavors in the taxane family, as well as to the synthesis of other terpene families.
Reset: Reclaiming the Internet for Civil Society

Reset: Reclaiming the Internet for Civil Society is a book about society and culture, primarily American society and culture. The author’s premise is that the internet is primarily a marketing tool and that is it designed to create a toxic addiction in our minds. He uses the term “surveillance capitalism” often to depict what he sees as the race for our data and ultimately our minds. He makes a good case for this in his first four chapters. His fifth chapter, Retreat, Reform, Restraint, makes the case that we can resist this marketing of our minds if we can show proper restraint.
Microbial sulfate reduction and organic sulfur formation in sinking marine particles

Climate change is driving an expansion of marine oxygen-deficient zones, which may alter the global cycles of carbon, sulfur, nitrogen, and trace metals. Currently, however, we lack a full mechanistic understanding of how oxygen deficiency affects organic carbon cycling and burial. Here, we show that cryptic microbial sulfate reduction occurs in sinking particles from the eastern tropical North Pacific oxygen-deficient zone and that some microbially produced sulfide reacts rapidly to form organic sulfur that is resistant to acid hydrolysis. Particle-hosted sulfurization could enhance carbon preservation in sediments underlying oxygen-deficient water columns and serve as a stabilizing feedback between expanding anoxic zones and atmospheric carbon dioxide. A similar mechanism may help explain more-extreme instances of organic carbon preservation associated with marine anoxia in Earth history.
Streamlining the Bankruptcy Process

High costs and a tendency to allow nonviable firms to reorganize represent two major problems with the present Chapter 11 bankruptcy resolution process. I propose a new system that differs from the old in two important respects. First, an automatic mechanism would award each claimant class consideration in line with priority. Second, effective control of the bankrupt firm would be quickly transferred to its rightful owners (i.e., the creditors), who would elect a new board of directors in the third or fourth month of the bankruptcy proceeding.
Feasibility of unilateral hemilaminectomy utilizing a Williams retractor for the resection of intradural-extramedullary spinal neoplasms.

Abstract Background While open approaches have historically been used in the surgical treatment of intradural-extramedullary spine tumors, minimally-invasive surgical (MIS) techniques are frequently applied to minimize post-operative complications associated with open surgery. Tubular retractor systems in particular have been employed in combination with the unilateral hemilaminectomy (UHL) approach. Here we describe the use of a Williams retractor as a safe and effective minimally-invasive alternative to tubular retractor systems with similar post-operative outcomes. Methods We retrospectively reviewed a cohort of eight patients who underwent unilateral hemilaminectomy using a Williams retractor for the minimally-invasive resection of intradural-extramedullary neoplasms at a large tertiary academic center from 2017 to 2019. Patient demographics, pathologic specimens, radiographic studies, and intraoperative parameters were collected and analyzed. Results In our series, gross total resection was achieved in all cases. Average operative time was 158 ± 40 minutes, the mean estimated blood loss (EBL) was 44.4 ± 30.4 mL, and mean length of stay was three days. All patients reported symptomatic improvement at follow-up as reported by Visual Analog Scale scores. Conclusion A Williams retractor yields similar outcomes with respect to post-operative pain, operative time, and EBL as it maintains the advantages of the UHL approach in the resection of intradural-extramedullary spine tumors while enhancing feasibility and providing significant cost savings.
A Generalization of Mertens' Theorem

Mertens' proved an interesting and useful theorem about the partial product of the Riemann zeta function at s = 1. Namely.
Chapter 34 Towards gene therapy of neurodegenerative disease

Publisher Summary While the molecular genetic causes of neurodegenerative diseases are becoming increasingly better understood, the translations of these insights into new therapies have lagged significantly. Gene therapy has been touted as having great promise for narrowing the disparity between molecular pathogenesis and therapeutics in that the logic underlying the replacement of a bad with a good gene is compelling. However, this seemingly straightforward notion breaks down when applied to genetic diseases other than those of a recessive nature. Indeed, more refined analysis of genes causing neurodegenerative disease indicate that unlike recessive loss of function disorders these mutant gene products produce a dominant gain of toxic function. This is particularly well illustrated in familial ALS (FALS) where mutations in SOD result in the acquistion of modified enzymatic properties that are believed to lead to motor neuron injury and cell death. Similar toxic gain of function mechanisms are also postulated for Huntington's, Alzheimer's and a subset of Parkinson's disease patients. Another feature shared by the neurodegenerative diseases that involve gain of function mutations is that selective neuronal populations are most susceptible to this toxic action. These pathogenetic characteristics of the neurodegenerative diseases, the dominant nature of these mutations and selective neuronal vulnerability, and additionally their progressive natural histories define the challenge confronting the development of gene therapies. Stated otherwise, plausible gene therapies must target to vulnerable populations the expression of gene(s), which neutralize or mitigate the action of toxic mutant proteins for the duration of the disease. Although this chapter examines these issues in the context of development of neuroprotective gene therapy for Parkinson's disease (PD), several of the central issues discussed will have relevance to other neurodegenerative diseases. Non-neuroprotective gene therapy strategies have been described that represent an alternative and complementary approach.
An Object-Oriented Class Library for Scalable Parallel Heuristic Search

In this report, we describe the design and implementation of a Parallel Heuristic Search Class Library, with emphasis on the use of object-oriented programming techniques for distributed applications. Another key consideration is the scalability of the library. We present the rationale behind major design decisions as well as the adoption of particular programming conventions. Along with an outline of the general framework of the library, we discuss implementation details of individual library classes. To demonstrate the applicability of the class library, it was used to port two existing parallel applications to an object-oriented platform. Different software metrics regarding the porting projects are used for evaluating library usability.
Characterization of lymphocyte-activating factor (LAF) produced by a macrophage cell line, P388D1. II. Biochemical characterization of LAF induced by activated T cells and LPS.

Unstimulated P388D 1 cells, as well as P388D 1 cells stimulated with PHA-activated guinea pig T lymphocytes or LPS, produced a lymphocyte activating factor (LAF). In order to have a chemical basis for comparing this LAF with the LAF produced by normal macrophages, we have analyzed several biochemical characteristics of the P388D 1 -derived LAF. Sephadex G-75 chromatography of concentrated LAF-containing supernatants from cultures of unstimulated and T cell stimulated P388D 1 cells demonstrated that the cell line LAF had a m.w. of approximately 16,000. On DEAE cellulose, the T cell-induced LAF fractionated into at least three major peaks and one minor peak. By using hydroxylapatite chromatography, two of the major peaks of LAF activity were separated from residual contaminating Lowry positive material. LPS-stimulated P388D 1 also produced LAF with a m.w. of 16,000. However, the LPS-induced LAF appeared to lack one of the DEAE peaks of LAF activity observed with the T cell-derived LAF. In contrast to LPS, T cells may induce the synthesis and/or release of an additional LAF component or enzymatically modify one or more of the LAF species that are produced in response to both stimulants. Based on the results of chemical characterization studies, the P388D 1 -derived LAF appears to be similar in size and charge to the lymphocyte activating factor produced by normal macrophages.
Λ-Neutron Scattering Lengths

Radiative capture of the K− on the deuteron is examined as a reaction for the measurement of the Λ-neutron scattering lengths. It is shown that a measurement of the deviation of the vector deuteron polarization asymmetry from −1 provides a direct determination of the difference of the singlet and triplet scattering lengths.
LiBeB Nucleosynthesis and Clues to the Chemical Evolution of the Universe

Theories of LiBeB nucleosynthesis are reviewed in the context of experimental nuclear reaction cross section data. These fragile elements disintegrate readily in the hot dense conditions present in the Big Bang and stellar evolution. Thus, their synthesis must occur in a cold, dilute cosmological environment. Reactions of H and He ions with CNO nuclei during the passage of galactic cosmic rays through the interstellar medium can account for most of the LiBeB abundances. The isotope 7Li requires production in the Big Bang and other sources. Because Be and B formation requires the existence of CNO formed during stellar evolution, their presence in old halo stars serves as a signal for nucleosynthesis. Measurements of cross sections for LiBeB production can now be combined with highly sensitive new measurements of the elemental abundances of these elements to gain new insights into the chemical evolution of the universe.
Long-Acting Anticoagulant Rodenticide (Superwarfarin) Poisoning: A Review of Its Historical Development, Epidemiology, and Clinical Management

Long-acting anticoagulant rodenticides (LAARs) inhibit vitamin K epoxide reductase (VKOR). Related bleeding may present a diagnostic challenge and require administration of blood component therapy, hemostatic agents, and vitamin K. This article intends to provide the reader a comprehensive understanding of LAAR poisoning. An exhaustive literature search of PubMed, Science Direct, US National Library of Medicine Toxicology Data Network, and Google Scholar yielded 174 reported cases of LAAR poisoning from which clinical data were extracted and reviewed. In addition, 25 years of epidemiologic data from the American Association of Poison Control Centers was reviewed. In the United States, on average, there were 10413 exposures reported with 2750 patients treated annually. For 25 years, there were 315951 exposures reported with nearly 90% among children and more than 100000 patients treated in a health care facility. Fortunately, only 2% of all exposures result in morbidity or mortality. Inhalational, transcutaneous, and oral routes of exposure have been documented. Most exposures are unintentional. The most frequently reported bleeding sites are mucocutaneous, with hematuria being the most common feature. Deaths were most commonly associated with intracranial hemorrhage. Long-acting anticoagulant rodenticide-induced paradoxical thrombosis and thrombotic complications accompanying hemostatic therapy have also been observed. Most patients present with coagulation assay values beyond measurable limits. Long-acting anticoagulant rodenticides have an extremely high affinity for VKOR compared with warfarin, characterized by rebound coagulopathy and bleeding after initial treatment and the need for high-dose, long-term therapy with vitamin K1. Treatment of acute hemorrhagic symptoms often required intravenous vitamin K1 in excess of 50 to 100 mg; chronic maintenance with 100 mg PO vitamin K1 daily was the most frequently used dose required to suppress coagulopathy. Treatment courses averaged 168 days. Adjunctive hemostatic therapy with recombinant factor VIIa and prothrombin complex concentrate has been reported, and phenobarbital has been used to expedite LAAR metabolism.
Validity and Usability of a Professional Association’s Web-Based Knowledge Translation Portal: American Physical Therapy Association’s PTNow.org

PTNow.org is an evidence-based, on-line portal created by a professional membership association to promote use of evidence in practice and to help decrease unwarranted variation in practice. The site contains synthesis documents designed to promote efficient clinical reasoning. These documents were written and peer-reviewed by teams of content experts and master clinicians. The purpose of this paper is to report on the content and construct validity as well as usability of the site. Physical therapist participants used clinical summaries (available in 3 formats--as a full summary with hyperlinks, “quick takes” with hyperlinks, and a portable two-page version) on the PTNow.org site to answer knowledge acquisition and clinical reasoning questions related to four patient scenarios. They also responded to questions about ease of use related to website navigation and about format and completeness of information using a 1–5 Likert scale. Responses were coded to reflect how participants used the site and then were summarized descriptively. Preferences for clinical summary format were analyzed using an analysis of variance (ANOVA) and a Dunnett T3 post hoc analysis. Seventeen participants completed the study. Clinical relevance and completeness ratings by experienced clinicians, which were used as the measure of content validity, ranged from 3.1 to 4.6 on a 5 point scale. Construct validity based on the information on the PTNow.org site was supported for knowledge acquisition questions 66 % of the time and for clinical reasoning questions 40 % of the time. Usability ratings for the full clinical summary were 4.6 (1.2); for the quick takes, 3.5 (.98); and for the portable clinical summary, 4.0 (.45). Participants preferred the full clinical summary over the other two formats (F = 5.908, P = 0.007). One hundred percent of the participants stated that they would recommend the PTNow site to their colleagues. Prelimary evidence supported both content validity and construct validity of knowledge acquisition, and partially supported construct validity of clinical reasoning for the clinical summaries on the PTNow.org site. Usability was supported, with users preferring the full clinical summary over the other two formats. Iterative design is ongoing.
Revolutionary Geometries of Mobile Hydrokinetic Turbines for Wind Energy Applications

An abundant source of renewable energy is feasible by harnessing the kinetic energy of moving water using hydrokinetic turbines. The knowledge of wind turbine design, turbomachinery and fluid dynamic principles of incompressible flow can be applied to design traditional and novel geometries of mobile hydrokinetic turbines. A preliminary design is created using the Blade Element Momentum Theory (BEMT) which includes the Prandtl’s correction for tip losses and model corrections. The axial and angular induction factors are calculated iteratively taking into account the coefficient of lift and drag at a certain angle of attack for specific airfoils. Although BEMT does not account for the tip vortices and radial flow induced by the rotation, it provides a good initial geometry. The blade geometry can then be parametrically modified using an in-house 3-D blade geometry generator (3DBGB), and can be analyzed further using a 3-D CFD analysis system. Different configurations such as unshrouded single row, unshrouded counter rotating and shrouded nozzle-rotor-OGV can be explored based on a suitable power requirement. The shrouded design uses a traditional axial turbomachinery approach using 1-D meanline and axisymmetric design-analysis tools (T-AXI suite). Novel geometries with solidity varying spanwise can also be explored to take advantage of the flow across the turbine. A design and analysis system for hydrokinetic turbines is demonstrated. The system is linked to an optimizer to obtain blade shapes with maximum efficiency. A counter rotating design is explored and an optimum design with increased efficiency is obtained. A comparative study of the axial gap between the rotors in a counter rotating system is also presented to show its effect on the power coefficient. The turbine blade designs presented will revolutionize wind energy harness technology.Copyright © 2015 by ASME
TPN-Induced Sympathetic Activation Is Related to Diet, Bacterial Translocation, and an Intravenous Line HELTON WS, ROCKWELL M, GARCIA RM, ET AL: Arch Surg 130:209-214, 1995

Total parenteral nutrition (TPN) has been associated with impaired immune response, breakdown in gut mucosal integrity, and the development of hepatic toxicity. Diet alone, however, may not account for increases in bacterial translocation (BT) and mucosal permeability.1,2 There is increasing recognition of the role of neural innervation of visceral organs such as the gut and the potential mediating effects of parenteral nutrition. Catecholamines, including epinephrine and norepinephrine, may be further inhibitory to immune function.3Male Sprague-Dawley rats were randomized to one of four groups: sham operation and food feeding (C); IV line, saline, and food feeding (S); IV TPN (T); or IV line and oral TPN (O). Urine was collected for catecholamine determination. On day 7, animals were killed, and mesenteric lymph nodes were cultured to assess BT.Food-fed animals (C) gained significantly more weight than either groups T or O despite isocaloric feeds. Animals with IV lines (S, T, and O) manifest BT at a rat...
Clone and patch size in chimeric mouse skin

Abstract The analysis of means and variances in the proportion of activities of many small samples of normal chimeric tissue can lead to estimates of the extent of variegation of that tissue. The clone and patch size can be applied to developmental problems such as an estimation of the number of cells responsible for the formation of chemically induced tumors. The clone size of normal chimeric mouse epidermis was estimated to be 600 cells. The patch size was estimated to be 15,000 cells. Chemically induced skin tumors were estimated to have arisen from no more than 8 cells.
Error analysis of parameters determined with statistical models of overlap from nonhomogeneous separations

Abstract The origin of uncertainties in the number of peaks in analytical separations predicted by statistical models of overlap is reviewed. An expression for the variance of the number of peaks in separations containing nonhomogeneous Poisson distributions of single-component peaks is then derived. This expression is confirmed by simple computer simulations of nonhomogeneous Poisson point processes. The expression is used to calculate the uncertainty in the estimate of the number of single-component peaks in, and saturations of, 48 gas chromatograms of lime oil. An expression derived by Martin and coworkers for the probability density function of single-component peaks also is modified by an estimate of the number of single-component peaks to reduce the function's breadth and to improve the statistical parameters calculated from the function.
Noninvasive prognostication of polyomavirus BK virus-associated nephropathy.

BACKGROUND BK virus-associated nephropathy (BKVN) is associated with an increased risk of graft failure. METHODS Levels of mRNAs encoding proteins implicated in inflammation and fibrosis were measured in urine collected at the time of biopsy diagnosis of BKVN in 29 kidney graft recipients and analyzed for prognosticating graft failure using logistic regression. RESULTS Ten of 29 BKVN patients had graft failure within 36 months of BKVN diagnosis and the remaining 19 patients did not. Serum creatinine level, BKVN biopsy stage, and urinary cell levels of mRNA for plasminogen activator inhibitor (PAI)-1, vimentin, tissue inhibitor of metalloproteinase-1, fibronectin, granzyme B, or perforin were associated with graft failure. A combination of PAI-1 mRNA level, BKVN biopsy stage, and creatinine level (P = 0.0015, by logistic regression) and a combination of PAI-1 mRNA and creatinine levels (P = 0.001) were the best-fitting models for prognosticating graft failure, and PAI-1 mRNA level was the only independent predictor (odds ratio, 2.8; 95% confidence interval [CI], 1.1-6.8; P = 0.03) by multivariable analysis. The area under the curve for the combination of PAI-1 mRNA, biopsy, and creatinine was 0.92 (95% CI, 0.80-1.0; P < 0.001) by receiver operating characteristic curve analysis, and the area under the curve was 0.92 (95% CI, 0.80-1.0; P < 0.001) for the combination of PAI-1 mRNA and creatinine. Graft outcome was correctly predicted in 27 of 29 BKVN patients by either model. CONCLUSION Urinary cell level of PAI-1 mRNA, measured at the time of BKVN diagnosis, is an independent prognosticator of graft failure and a prediction model of serum creatinine and PAI-1 mRNA is as accurate as the model that includes the biopsy result.
Role of melanin in mechanical properties of Glycera jaws.

Abstract The remarkable mechanical prowess of the jaws of the bloodworm Glycera dibranchiata appears to be a consequence of a robust cross-linked network of organic molecules, notably melanin and proteins, as well as small amounts of unmineralized Cu and a Cu-based mineral. The present study focuses on the role of melanin. Mechanical properties of untreated jaws and the constituent melanin are probed through nanoindentation, both in air and underwater. Complementary information is obtained from density and porosity measurements and attempts at Cu removal from the jaws using EDTA, an effective metal chelator in most biological systems. In near-tip regions of the jaws, mechanical properties attain the highest values and diminish only slightly when wet (by 15–25%), in contrast to the behavior of other organic biomaterials. The melanin constituent contributes significantly to the mechanical integrity of the jaw; its hardness and elastic modulus are about half those of untreated jaws. Although melanin may be the dominant shape-determining component of the structure, it remains to be shown whether jaw assembly is mediated by protein deposition on a melanin scaffold or, conversely, by melanin deposition on a protein scaffold. The inability of EDTA to chelate Cu from the jaws and the relatively high density of the jaws and the melanin support the notion of a highly cross-linked molecular structure. Finally, based on the metric H3/E2 (H being hardness and E the Young’s modulus), the results suggest that the abrasion resistance of the jaws is superior to all engineering polymers and competitive with the hardest metallic alloys.
Thinking of having a higher predictive power for your first-stage model in propensity score analysis? Think again

The predictive power of the first-stage propensity score (PS) model is commonly reported in clinical publications via c-statistics for logistic regressions. A c-statistic greater than 0.80 was recommended in a recent publication. However, we argue that a cut-off like this may not be the best determinant of the first stage PS model, and it is a misconception that the higher predictive power always implies a better PS model. A better way to assess the PS model is to study the relationships between variables of observed confounders, treatment assignment, and outcomes, while the c-statistic can help check the model adequacy. We recommend researchers not blindly craving for high predictive powers with large c-statistics when building the first-stage PS models.
Efficacy of oral iron in patients with restless legs syndrome and a low-normal ferritin: A randomized, double-blind, placebo-controlled study.

Abstract Background and Purpose Restless Legs Syndrome (RLS) is a primary disorder of sensation that affects sleep and has been associated with iron deficiency. The purpose of this study was to determine if symptomatic RLS patients with low-normal serum ferritin levels benefit from oral iron replacement. Patients and Methods This was a randomized, placebo-controlled, double-blinded study. Eligible patients were randomized to oral iron therapy vs. appearance-matched placebo and followed over a 12 week period. Results Baseline International Restless Leg Scale (IRLS) scores for the treatment (24.8 ± 5.72) and placebo (23.0 ± 5.03) groups were similar. Baseline ferritin levels for the treatment (40.6 ± 15.3 ng/ml) and placebo (36.7 ± 20.8 ng/ml) groups were also similar. After 12 weeks, IRLS scores decreased more in the treatment arm (10.3 ± 7.40) than in the placebo arm (1.14 ± 5.64), ( p = 0.01). Ferritin levels increased more in the treatment arm (25.1 ± 20.3 ng/ml) than in the placebo arm (7.5 ± 13.7 ng/ml), ( p = 0.04). We observed a nonsignificant trend toward improved quality of life in the treated patients, ( p = 0.07). Conclusions This is the first double-blinded, placebo-controlled study to demonstrate statistically significant improvement in RLS symptoms using oral iron therapy in patients with low-normal ferritin. The findings from this study suggest that additional larger randomized placebo-controlled trials of iron as treatment for patients with low-normal ferritin are warranted.
Design, synthesis, and characterization of a novel hexa-azacyclophane and interactions with d(CGCA3T3GCG)2, ctDNA and T4DNA

Abstract A novel polyazacyclophane hexa-amine (1) has been designed, synthesized and characterized by X-ray crystallography, 1H NMR and fluorescence spectroscopy. 1 has the structural shape and disposition of charges complementary to the major groove of B-DNA. Acid dissociation constants for the protonated 1 were pKa1(D) = 4.8 and pKa2(D) = 8.5. Equilibrium constants for the binding of 1 to ctDNA and T4 DNA were 1.2 × 105 and 1.8 × 106, respectively.
Fear of death and human destructiveness.

We are in possession of the technical knowledge required to provide for the material needs of all of humanity without systematic plunder and extermination of others, yet, systematic plunder and genocidal extermination continue to thrive. Understanding the psychological underpinnings of human violence, in hope of ameliorating or at least attenuating human cruelty and destruction, should thus be one of the most important priorities of the natural and social sciences. For almost two decades we have been developing, testing, and refining a theoretical account of human behavior that we believe offers some important insights about human violence. In this chapter, we present the intellectual roots and core propositions of this theory, review the large body of evidence supporting it, and discuss the implications of these ideas for understanding and ameliorating the viciousness that has characterized so much of our species’ history to date.
Microfabrication-Compatible Nanoporous Gold Foams as Biomaterials for Drug Delivery

There is an unmet need for multi-functional devices that can monitor and modulate biological activity in order to effectively study biological phenomena and systematically develop therapeutics. Even though miniaturization technology has significantly enhanced the capabilities of such devices, increasing demands for multi-functionality within a small device footprint require innovations on the materials front, where nanostructured materials offer unique opportunities.[1–6] Nanoporous gold (np-Au), produced by a self-assembly process involving selective dissolution of silver from a gold-silver alloy,[7] is one such material that has great potential for biomedical applications with its large effective surface area, ease of surface functionalization, and electrical conductivity. However, it has mainly received attention for its catalytic performance[8] and fundamental scientific investigations,[9, 10] while its biomedical applications remain largely unexplored. We have previously shown this material’s utility for a biomedical application, where np-Au was used as a multiple electrode array coating, exhibiting increased sensitivity in detecting electrical activity from organotypic hippocampus slices.[11] A desirable attribute for functional biomedical coatings is drug delivery capability to modulate tissue response in situ. Np-Au with its controllable open-pore structure is an ideal material for this purpose. The objective of this paper is to illustrate that: (i) np-Au is permissive to culturing adherent cells; and (ii) the porous network can be used for releasing biologically-relevant molecules for controlling cell behavior, which is demonstrated by the delivery of a drug that suppresses cell proliferation. Taken together with np-Au’s performance in monitoring electrophysiological activity, the current findings promise an “all-in-one” functional coating that enables biosensing, drug delivery, and biocompatibility.
Migration and proliferation of diploid human fibroblasts following "wounding" of confluent monolayers.

Six diploid human fibroblast strains were grown in confluent monolayers. Holes were scraped in these monolayers and the number of cells proliferating into these “wounds” with time were determined. The migration and mitotic aspects of the proliferation of fibroblasts into these wounds were analyzed separately. Small amounts of undialysed or dialysed serum were essential for cell division but not migration. Saline extracts of skin could not substitute for serum in the medium. Neither zinc nor cupric ion at tolerable concentrations (10−5M) increased the rate of cell proliferation. Normal human fibroblasts did not immediately start to divide from confluency into the “wound” space. Their generation time was about 32–39 hours. Fibroblasts from patients with cystic fibrosis began to divide almost immediately into the “wounded” area. Their generation time was about 48 to 56 hours.
A photo-curing study of a pigmented UV-curable alkyd

Abstract The photo-curing of a pigmented UV-curable tung oil alkyd system (UVTA) was investigated. The UV-curable alkyd was a Diels–Alder Adduct of trimethylolpropane trimethacrylate with a tung oil-based alkyd. A mixture of yellow iron oxide, red iron oxide, titanium dioxide and lamp black pigments were chosen to obtain an observed yellow color. The pigment mixture, UV-curable alkyd and a reactive diluent were formulated together and photo-cured via a free radical mechanism. The through and surface cure was assessed by thumb twist, blocking resistance and MEK single rub. The through cure and surface cure assessment showed that optimum cure was achieved using UV-A as a source with two photoinitiators: phenylbis(2,4,6-trimethylbenzoyl-phosphine oxide) at 2 wt% and 1-hydroxy-cyclohexyl-phenyl-ketone at 4 wt%. The effect of reactive diluent was also investigated. Ten different reactive diluents were used. After curing, pencil hardness, conical mandrel, impact resistance, cross cut adhesion and gloss were measured. In addition, dynamic mechanical thermal analysis (DMTA) was used to evaluate selected systems. The coatings tests showed that the use of long chain linear structure diluents, such as isodecyl methacrylate, provided UV-curable paint films with better impact resistance, flexibility, and adhesion over other reactive diluents.
Cross polarization, radio frequency field homogeneity, and circuit balancing in high field solid state NMR probes.

Abstract Homogeneous radio frequency (RF) fields are important for sensitivity and efficiency of magnetization transfer in solid state NMR experiments. If the fields are inhomogeneous the cross polarization (CP) experiment transfers magnetization in only a thin slice of sample rather than throughout the entire volume. Asymmetric patterns have been observed in plots of the CP signal versus RF field mismatch for an 800 MHz solid-state NMR probe where each channel is resonated in a single-ended mode. A simple model of CP shows these patterns can be reproduced if the RF fields for the two nuclei are centered at different places in the coil. Experimental measurements using B1 field imaging, nutation arrays on extremely short NMR samples, and de-tuning experiments involving disks of copper incrementally moved through the coil support this model of spatially offset RF fields. We have found that resonating the high frequency channel in a double-ended or “balanced” mode can alleviate this field offset problem, and have implemented this in a three-channel solid state NMR probe of our own design.
An XML transaction processing benchmark

XML database functionality has been emerging in "XML-only" databases as well as in the major relational database products. Yet, there is no industry standard XML database benchmark to evaluate alternative implementations. The research community has proposed several benchmarks which are all useful in their respective scope, such as evaluating XQuery processors. However, they do not aim to evaluate a database system in its entirety and do not represent all relevant characteristics of a real-world XML application. Often they only define read-only single-user tests on a single XML document. We have developed an application-oriented and domain-specific benchmark called "Transaction Processing over XML" (TPoX). It exercises all aspects of XML databases, including storage, indexing, logging, transaction processing, and concurrency control. Based on our analysis of real XML applications, TPoX simulates a financial multi-user workload with XML data conforming to the FIXML standard. In this paper we describe TPoX and present early performance results. We also make its implementation publicly available.
Rubber toughening of an amorphous polyamide by functionalized SEBS copolymers: Morphology and Izod impact behavior

Abstract Rubber toughening of an amorphous polyamide (Zytel 330) using combinations of triblock copolymers of the type SEBS and a maleic anhydride functionalized version, SEBS-g-MA, was investigated and the results compared with those of nylon 6 and nylon 66. The effects of rubber content and the type of extruder on the morphology, Izod impact behavior and the ductile–brittle transition temperature were explored. The shape and sizes of the rubber particles in blends with this amorphous polyamide were found to be more similar to those in nylon 6 than in nylon 66 blends. The twin screw extruder produced smaller particles with a more narrow distribution of sizes than the single screw extruder. Higher rubber contents generally yielded tougher blends; there is a critical rubber particle size above which the ternary blends are brittle at 20 wt% total rubber. The ductile-to-brittle temperature was found to decrease with increased rubber content and decreased rubber particle size. In general, the trends for this amorphous polyamide are rather similar to those reported earlier for semi-crystalline nylon 6 and nylon 66.
On an analytical solution for the damped Hertzian spring

Contact models including an elastic and a dissipative force are widely used to model inelastic granular collisions. Whilst there exists an analytical solution for the linear spring-dashpot (LSD) model, for the more practically important non-linear models often only the asymptotic behaviour is known. In this letter, we demonstrate that if the Hertzian contact model is complemented by a damping force proportional to 1/4-power of the normal deformation, it is possible to map its behaviour onto the LSD model and hence obtain simple analytical relationships between the model parameters and the characteristics of the granular collision. In practice, this allows the prediction of parameters for discrete element models of powder flow and compaction by using experimental observables such as restitution coefficient and collision time as input data.
In situ stress measurements during the electrochemical adsorption/desorption of self-assembled monolayers

Abstract This paper examines the surface stress associated with the electrochemical desorption of 4-mercaptobenzoic acid (4-MBA) from (1 1 1) textured Au in aqueous 0.1 mol L−1 KOH. Self-assembled monolayers of varying coverage were adsorbed onto the Au electrode surface from a 0.1 mol L−1 aqueous KOH solution containing 1 mmol L−1 4-MBA. Adsorption follows Langmuir kinetics and fully formed monolayers, corresponding to 0.29 coverage with respect to the Au surface, are formed in about 120 min. XP spectra confirm the formation of the Au–S bond while FTIR spectra indicate that the 4-MBA is orientated with the carboxylate pointed away from the surface. The one-electron reductive desorption of 4-MBA occurs at a potential of −0.9 to −1.0 V vs. SSE, depending on coverage, and causes a surface stress change in the tensile direction, indicating that 4-MBA adsorption induces a compressive surface stress to the Au. At short immersion times and low monolayer coverage, the surface stress increases with coverage as the stress response is primarily governed by the Au–S bond density. SAM desorption following longer immersion times produces large stress changes with little corresponding change in SAM coverage. We attribute the additional compressive stress to stabilization of the Au–S bonding regions and the coulombic repulsion between neighboring molecules, both associated with ordering of the 4-MBA on the Au surface.
Noncysteinyl coordination to the [4Fe-4S]2+ cluster of the DNA repair adenine glycosylase MutY introduced via site-directed mutagenesis. Structural characterization of an unusual histidinyl-coordinated cluster

The Escherichia coli DNA repair enzyme MutY plays an important role in the recognition and repair of 7,8-dihydro-8-oxo-2'-deoxyguanosine-2'-deoxyadenosine (OG*A) mismatches in DNA. MutY prevents DNA mutations caused by the misincorporation of A opposite OG by catalyzing the deglycosylation of the aberrant adenine. MutY is representative of a unique subfamily of DNA repair enzymes that also contain a [4Fe-4S]2+ cluster, which has been implicated in substrate recognition. Previously, we have used site-directed mutagenesis to individually replace the cysteine ligands to the [4Fe-4S]2+ cluster of E. coli MutY with serine, histidine, or alanine. These experiments suggested that histidine coordination to the iron-sulfur cluster may be accommodated in MutY at position 199. Purification and enzymatic analysis of C199H and C199S forms indicated that these forms behave nearly identical to the WT enzyme. Furthermore, introduction of the C199H mutation in a truncated form of MutY (C199HT) allowed for crystallization and structural characterization of the modified [4Fe-4S] cluster coordination. The C199HT structure showed that histidine coordinated to the iron cluster although comparison to the structure of the WT truncated enzyme indicated that the occupancy of iron at the modified position had been reduced to 60%. Electron paramagnetic resonance (EPR) spectroscopy on samples of C199HT indicates that a significant percentage (15-30%) of iron clusters were of the [3Fe-4S]1+ form. Oxidation of the C199HT enzyme with ferricyanide increases the amount of the 3Fe cluster by approximately 2-fold. Detailed kinetic analysis on samples containing a mixture of [3Fe-4S]1+ and [4Fe-4S]2+ forms indicated that the reactivity of the [3Fe-4S]1+ C199HT enzyme does not differ significantly from that of the WT truncated enzyme. The relative resistance of the [4Fe-4S]2+ cluster toward oxidation, as well as the retention of activity of the [3Fe-4S]1+ form, may be an important aspect of the role of MutY in repair of DNA damage resulting from oxidative stress.
Seasonal Variation in the Diet of Ring-Tailed Coatis (Nasua nasua) in Iguazu, Argentina

There is widespread evidence that feeding ecology can lead to differences in mammalian social systems. To understand how diet and ecology affect the social behavior of ring-tailed coatis (Nasua nasua), detailed measures of feeding behavior were recorded from 2 well-studied groups over a 2-year period. The proportion of fruit and invertebrates in the diet of ring-tailed coatis in Iguazu, Argentina, was very similar to that in diets of white-nosed coatis (N. narica) and ring-tailed coatis studied at field sites in Brazil. Consumption of vertebrates in Iguazu was exceptionally rare. The proportion of time spent foraging for invertebrates and fruit generally matched seasonal changes in the abundance these foods in the environment. During the winter, when invertebrate and fruit availability was low, coatis spent a large amount of time feeding on 2 exotic fruit species. The presence of exotic fruits provided coatis with food during the lean winter season and may have influenced the high reproduction and survivorship found in this population. Coatis spent about 44% of their fruit-foraging time exploiting pindo palm (Syagrus romanzoffianum) fruits and it appeared that this fruit species played a major role in shaping the ranging and feeding behavior of coati groups. The time spent foraging at fruit trees and the total number of fruits eaten varied depending on the species of tree. Coati groups spent an average of 2.5–12.5 min feeding on different species of fruit trees, and coati groups ate an average of 2.6–269.8 fruits per tree species. The quick depletion of fruit trees and high density of foraging individuals, especially when feeding on pindo, plays an important role in shaping the social system of coatis.
Ab Initio Study of the Hydrogen Exchange Reaction at Group 3 and 4 Metals in Comparison to That at Alkali Metals

Computations are reported at several theoretical levels for the exchange reaction of group 3 and 4 metal hydrides with hydrogen. At the CISD+Q level weak complexes are formed with an association energy of 0.1−3.0 kcal mol-1. The transition states for the exchange with group 3 transition metals have C2v symmetry and an energy of 8−10 kcal mol-1 relative to the reactants. This barrier is lower than that for exchange of alkali-metal hydrides with hydrogen (15.7−21.7 kcal mol-1) and much lower than for exchange of group 4 transition-metal hydrides (31.5−45.9 kcal mol-1). The transition states of alkali-metal hydrides approximate ion pairs of the alkali-metal cations with H3- ion, whereas the transition-metal cases involve bonding interactions with empty d orbitals.
War surgeon of the twentieth century.

In this historical note, written 50 years after the Allied Forces were victorious over the powers of darkness in Europe, we pay tribute to the war surgeons who cared for the wounded on the battle fields of the Eastern Front during World War II. This generation of surgeons has almost disappeared from history without a trace. Their pictures do not decorate departmental lecture halls, and the burial place of many of them remains unknown. As no book chapters or journal articles are readily available to describe their deeds, we tell the story of one, Karl Schein. His portrait as a war surgeon reflects the life of many like him who were killed, perished, or vanished in the chaos of the wars of this century without a reference to remind us of their legacy.
The growth of fundraising: Framing the impact of research and literature on education and training

The proliferation of research and literature has had an impact on available training opportunities for fundraising professionals.