cssi/SciSciGPT-SciSciNet huggingface dataset:
Palladium-Catalyzed Enyne Cycloisomerization Reaction in an Asymmetric Approach to the Picrotoxane Sesquiterpenes. 2. Second-Generation Total Syntheses of Corianin, Picrotoxinin, Picrotin, and Methyl Picrotoxate

An alternative, more efficient synthesis of the picrotoxane core by palladium-catalyzed cycloisomerization of an enyne requires the design of a new catalyst system based upon 1,3-bis(dibenzophospholyl)propane and 2-(diphenylphosphino)benzoic acid as ligands. Thus, unlike thermal processes which leave little opportunity to address failed reactions, the transition-metal-catalyzed reaction provides opportunities for catalyst modification to overcome limitations. In this way, a seven-step synthesis of the picrotoxane core from carvone emerges. The formation of the bislactone depends critically on the ring substitution pattern. A myriad of selective transannular cyclizations occur as a function of this substitution pattern. The bislactone serves as a pivotal intermediate to picrotoxinin, picrotin, and corianin. During the course of the manipulation of the oxidation pattern to create the correct bislactone, an intermediate generated also provides access to methyl picrotoxate. An improved sequence from the bisla...
Chronic electrical stimulation homeostatically decreases spontaneous activity, but paradoxically increases evoked network activity.

Neural dynamics generated within cortical networks play a fundamental role in brain function. However, the learning rules that allow recurrent networks to generate functional dynamic regimes, and the degree to which these regimes are themselves plastic, are not known. In this study we examined plasticity of network dynamics in cortical organotypic slices in response to chronic changes in activity. Studies have typically manipulated network activity pharmacologically; we used chronic electrical stimulation to increase activity in in vitro cortical circuits in a more physiological manner. Slices were stimulated with “implanted” electrodes for 4 days. Chronic electrical stimulation or treatment with bicuculline decreased spontaneous activity as predicted by homeostatic learning rules. Paradoxically, however, whereas bicuculline decreased evoked network activity, chronic stimulation actually increased the likelihood that evoked stimulation elicited polysynaptic activity, despite a decrease in evoked monosynaptic strength. Furthermore, there was an inverse correlation between spontaneous and evoked activity, suggesting a homeostatic tradeoff between spontaneous and evoked activity. Within-slice experiments revealed that cells close to the stimulated electrode exhibited more evoked polysynaptic activity and less spontaneous activity than cells close to a control electrode. Collectively, our results establish that chronic stimulation changes the dynamic regimes of networks. In vitro studies of homeostatic plasticity typically lack any external input, and thus neurons must rely on “spontaneous” activity to reach homeostatic “set points.” However, in the presence of external input we propose that homeostatic learning rules seem to shift networks from spontaneous to evoked regimes.
Time resolved spectroscopy of valence-alternation-pair luminescence in a-As2S3

Abstract The total light decay (TLD) and time-resolved spectra of the photoluminescence (PL) of a-As2S3 are reported. The time-resolved spectra disagree with those published by other workers. The current results are consistent with a model in which the PL centers are valence-alternation pairs which are bound at the glass transition temperature. The fit of the model to the data yields a value of ∼2.4 A for the decay length of the wavefunction for an electron and/or hole bound at the charged defect.
Essential fatty acid deficient hairless mouse: a model of chronic epidermal hyperproliferation.

SUMMARY Epidermal DNA synthesis has been shown to be increased approximately three-fold in hairless mice that were fed a diet deficient in essential fatty acids (EFA deficient) for 65 days, compared with animals fed a standard diet. Autoradiographic labelling indices showed a 330% increase in the EFA deficient mice over controls. The animals developed evidence of a diffuse thickening, scaling and loss of elasticity of the skin after 40 days on the EFA deficient diet. Histologically, the epidermis of the EFA deficient animals showed acanthosis, hypergranulosis, hyperkeratosis and increased intracellular epidermal spaces. Increased mitotic indices were found with Feulgen staining. This is further evidence that deficiencies of essential fatty acids are associated with disturbance of normal epidermal cell proliferation and control of keratinization. A single application of topical 0·1%. betamethasone valerate to EFA deficient mice reduced the epidermal DNA synthesis to that of normal diet mice. Ten percent linoleic acid topically over 2weeks also returned epidermal DNA synthesis to normal levels.
Treatment of Bacterial Osteomyelitis and Staphylococcus aureus Endocarditis and Single-Dose Therapy for Uncomplicated Neisseria gonorrhoeae Infections: An Overview

Cefonicid is a new second-generation cephalosporin that has broad-spectrum antibacterial activity, achieves high peak serum concentrations, and has a long half-life. The high serum concentration and long half-life of cefonicid make it feasible to administer the drug once daily either intravenously or intramuscularly. For the treatment of bacterial osteomyelitis, a specific antibacterial agent is administered for four to eight weeks. Ideally, the optimal antibiotic should have good activity against organisms commonly implicated in bone infections, be easy to administer, be stable in inflammatory conditions, achieve good concentrations in bone, and have minimal toxicity. For treatment of Staphylococcus aureus endocarditis, the same criterion of minimal toxicity should be met for the agent used; in addition, it should have excellent antistaphylococcal activity in vivo and in vitro, be stable to p-lactamase, and exhibit good bactericidal activity at trough serum levels. In uncomplicated Neisseria gonorrhoeae infections, the ideal antibiotic should be one that could be administered in a single dose in a small volume and would not be painful on intramuscular injection. The antibiotic should be nontoxic; stable to N. gonorrhoeae p-lactamase; and reliably able to eradicate urethral, endocervical, rectal, and pharyngeal infections. Cefonicid may fulfill some of these criteria.
Spermatophores of thalassoid gastropods (Paludomidae) in Lake Tanganyika, East Africa, with a survey of their occurrence in Cerithioidea: functional and phylogenetic implications

. With few exceptions, spermatozoa-encapsulating packages in molluscs are known mostly from cephalopods and pulmonate gastropods. Among non-stylommatophoran gastropods, the marine Cerithioidea are second only to the Neritimorpha in the number of species that posess a spermatophore, but they have only rarely been found in freshwater taxa of this superfamily. We describe and compare here the sperm packages of 11 paludomid cerithioideans as part of an ongoing study on the evolution and systematics of the thalassoid (i.e., “marine-like”) endemic species flock from Lake Tanganyika. Stereomicroscopic and SEM examination revealed unexpected complexity in shape and structure of spermatophores within paludomids. In addition, we present a survey of other Cerithioidea, which revealed that spermatophores are in general structurally simple and confirmed their presence in 12 marine species (five families) and 15 limnic species (four families), including those of 10 thalassoid species for which spermatophores are described herein. Based on histological sections of the male genital tract, we hypothesize that spermatophores are formed anteriorly, wholly or in part, by the so-called spermatophore-forming organ, and which is considered a synapomorphy of the Paludomidae. In addition, we briefly discuss functional aspects inferred from morphological study of the spermatophore-forming organ, with possible implications for spermatozoan transfer and fertilization. Finally, we place the features of the spermatophores and the spermatophore-forming organ in a phylogenetic framework of cerithioidean and paludomid systematics, which suggests that the spermatophore-forming organ is a synapomorphy of Paludomidae, that a bifurcate spermatophore structure is plesiomorphic, and that the evolution of structurally complex, spiny spermatophores has occurred independently in disparate lineages within the thalassoid species flock.
Urocanicacidurea associated with Hepatic Coma

WHILE studying the urinary chromatographic pattern of a patient in hepatic coma the presence of an abnormal spot R F 0.14 and 0.54 in propanol/ammonia, 7 : 3, and butanol/acetic acid/water, 4 : 1 : 5, respectively, was noted after spraying paper chromatograms with diazotized p-sulphanilic acid. This colour reaction suggested that it might be an imidazole derivative, yet chromatography excluded the possibility of it being histamine, histidine or 1-methylimidazole-4-acetic acid (Table 1). As the presence of this unknown compound could not be related to the diet, or therapy, of the patient and appeared to be associated with the disease, an attempt was made to isolate it.
Electron microscopic analysis of adrenalectomy-induced hippocampal granule cell degeneration in the rat: Apoptosis in the adult central nervous system

As described in the preceding paper, adrenalectomy triggers hippocampal granule cell degeneration that begins within days after adrenalectomy, continues for months, and is the only apparent cell death anywhere within the brain. At the light microscopic level, granule cell degeneration is characterized by coalescing of nuclear chromatin into numerous spherical bodies. Since the morphology at the light microscopic level resembled the nuclear morphology characteristic of "apoptosis" rather than "necrosis," we undertook this ultrastructural study to determine if adrenalectomy induces the morphological features characteristic of apoptosis. Electron microscopy revealed coalescing of nuclear chromatin, compaction of cytoplasm, and the budding-off of cytoplasmic bodies that were engulfed by glia. Mitochondria, the Golgi apparatus, and rough endoplasmic reticulum appeared relatively normal early in the process of granule cell degeneration when nuclear changes were prominent. Presynaptic terminals innervating degenerating granule cells appeared normal. Electron-dense degeneration of granule cell axon terminals in association with normal postsynaptic elements of CA3 pyramidal cells highlighted the extraordinary selectivity of adrenalectomy-induced granule cell death. Ten weeks after adrenalectomy, astrocytes were filled with abnormally abundant glial fibrils and neuronal debris. This "apoptotic" morphology produced by adrenalectomy was clearly distinct from the "necrotic" granule cell morphology produced by intrahippocampal injection of the neurotoxin volkensin. These results indicate that, in a manner possibly analogous to castration-induced prostate cell death, loss of adrenal hormone triggers a process in dentate granule cells that causes the morphological changes characteristic of "apoptosis." Thus, adrenal steroids may be obligatory growth factors for dentate granule cells and their loss may initiate a selective process in the mature brain that is unique or that may normally occur only in the developing brain.
Deposition of organic-inorganic composite thin films by Li3PO4 sputtering and C2H4 plasma polymerization

Abstract Organic-inorganic composite macromolecular thin films have been grown by combined r.f.-magnetron sputtering of lithium orthophosphate (Li 3 PO 4 ) and plasma polymerization of ethylene (C 2 H 4 ). Of the process gases used, Ar, N 2 , Ar/N 2 , and Ar/O 2 , only the Ar/O 2 mixture provided suitable control over the co-deposition process. The structure and electrical properties of the smooth, pinhole-free films were investigated by X-ray photoelectron spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Rutherford back-scattering spectroscopy, X-ray diffraction, and a.c.-impedance measurement. The inorganic component of the composite films was found to exist both as a separate phase and as a part of the polymeric backbone. The ionic conductivity was found to decrease with the organic content of the film.
Determination of equilibrium constants and maximum binding capacities in complexIn vitro systems: I. The mammillary system

It is shown that in a system containingn types of mutually noninteracting binding sites, the association constants are then roots of annth order polynomial while the maximum binding capacities can be evaluated by solving a set ofn simultaneous linear equations. Thenth order polynomial and the system ofn linear equations are defined in terms of 2n intermediate coefficients, the coefficients being themselves evaluated by substituting 2n sets of appropriate experimental data into an auxiliary system of 2n linear equations. The existence and uniqueness of the solutions are established.
Prenatal screening for toxoplasmosis

Abstract Objective: To evaluate the merits of screening for toxoplasmosis in all pregnant women. Methods: We used decision analysis to compare three strategies for the antepartum management of congenital toxoplasmosis: 1) no testing for congenital toxoplasmosis; 2) current practice, which is to perform targeted screening in cases of incidental abnormalities noted on ultrasound; and 3) universal serologic screening of pregnant women followed by amniocentesis to diagnose fetal infection in cases of maternal seroconversion. For each of the three strategies, we considered the two available treatment options: intrauterine antiparasitic treatment or pregnancy termination. Results: Universal screening reduced the total number of cases of congenital toxoplasmosis compared with no testing or targeted screening. However, compared with no testing, universal screening with medical treatment resulted in 18.5 additional pregnancy losses for each case of toxoplasmosis avoided. If infected pregnancies underwent termination, universal screening resulted in 12.1 additional pregnancy losses for each case avoided. Conclusion: Maternal screening reduces the number of cases of disease, but at a substantial clinical cost. The rarity of the disease and limitations in diagnosis and therapy limit the effectiveness of screening strategies. The risks associated with amniocentesis are particularly important. Universal maternal screening for congenital toxoplasmosis should not be performed.
A Crystallographic Study of the Role of Sequence Context in Thymine Glycol Bypass by a Replicative DNA Polymerase Serendipitously Sheds Light on the Exonuclease Complex

Thymine glycol (Tg) is the most common oxidation product of thymine and is known to be a strong block for replicative DNA polymerases. A previously solved structure of the bacteriophage RB69 DNA polymerase (RB69 gp43) in complex with Tg in the sequence context 5’-G-Tg-G shed light on how Tg blocks primer elongation: The protruding methyl group of the oxidized thymine displaces the adjacent 5’-G which can no longer serve as a template for primer elongation. [Aller, P., Rould, M.A., Hogg, M, Wallace, S.S., & Doublie S. (2007) PNAS 104, 814–818] Several studies showed that in the 5’-C-Tg-Purine sequence context Tg is more likely to be bypassed by Klenow fragment, a family A DNA polymerase. We set out to investigate the role of sequence context on Tg bypass in a B family polymerase and solved the crystal structures of the bacteriophage RB69 DNA polymerase in complex with Tg containing DNA in the three remaining sequence contexts: 5’-N-Tg-G with N=A, T, or C. A combination of several factors influence Tg bypass, including the associated exonuclease activity, the nature of the 3’and 5’ bases surrounding Tg and the cis/trans interconversion of Tg. We also visualized for the first time the structure of a well-ordered exonuclease complex, allowing us to identify and confirm the role of key residues (Phe123, Met256, and Tyr257) in strand separation and the stabilization of the primer strand in the exonuclease site.
What type of economist are you: r‐strategist or K‐strategist?

This paper proposes a simple model to classify economists according to their preferences towards quality and/or quantity of their publications. When more emphasis is placed on quantity they are defined as r‐strategists. When they put more effort in the quality of their papers targeting top journals, they are defined as K‐strategists. It is shown that prestigious departments tend to select K‐strategists. By analyzing which strategy maximizes the influence of an economist in the profession, the paper shows that neither r‐, nor K‐strategists are the winners. The paper conjectures that the economists more likely to be successful in the profession follow the Samuelson‐strategy, which is characterized by a balance between quality and quantity.
Ultrasound, densitometry, and extraskeletal appendicular fracture risk factors: a cross-sectional report on the Saunders County Bone Quality Study.

The Saunders County Bone Quality Study was designed to determine the feasibility of ultrasonic bone measurement, at the patella, as a predictor of low-trauma fractures in a runal population-based study. At the first visit of this 4-year longitudinal study, anthropometric and clinical measurements and medical, surgical, and fracture histories were obtained for the 1428 participants (899 women and 529 men). Explored risk factors for low-trauma fractures included age, sex, calcium intake, alcohol and caffeine ingestion, tobacco use, body mass and grip strength, age of menopause, estrogen replacement therapy, propensity to fall, distal radius and ulna bone mineral content, and bone density. Forward multivariate logistic regression analysis showed that lower ultrasound values are more consistently associated with reported low-trauma appendicular fractures than the commonly reported forearm absorptiometry measures of radius mineral content and density. When ultrasound, age, and the extra skeletal risk factors were included in an additional multivariate model, only age and ultrasound were significantly associated with appendicular fracture history in women (P=0.0003), whereas only ultrasound was associated in the men (P=0.001). We conclude that ultrasound is a better measure of association with reported low-trauma fractures than the commonly reported forearm SPA measures. Even after adjustment for many of the extra skeletal risk factors, low AVU is highly associated with low-trauma fracture status for both women and men.
Damping amplification in highly extensible hysteretic cables

Abstract The effective damping of resonant transverse vibrations in highly extensible synthetic cables, which exhibit hysteretic behavior in the stress–strain relation, increases by an order of magnitude for certain parametric values. We show that the cause of the phenomenon is the formation of complex hybrid modes, resulting in unusual dynamic behaviour, such as non-monotonic dependence on hysteretic damping and large sensitivity to parametric changes. We explore in detail the properties of the resonant response and provide a unified topological description of the solution.
On the problem of detailed balance and model lineshapes in collision-induced rotovibrational bands: H2-H2 and H2-He

When account is taken of the vibrational dependence of the potential function, the usual condition of detailed balance taken with respect to the vibrational-rotational frequencies does not apply, and model spectral functions satisfying this condition are inaccurate. A model correlation function is derived that deals with the case of vibration-dependent potentials. The parameters of the model are computed from relations involving the spectral moments. This model is shown to give spectral shapes, for a number of examples involving the fundamental and first overtone bands of H2-He and H2-H2 at room temperature and 1000 K, in excellent agreement with spectra calculated quantum mechanically from first principles. The model is useful for predicting the collision-induced vibrational spectra for these and other systems for which the vibration-dependent induced dipole and potential are known.
Mitigation of asteroid impact threats

Although large asteroids and comets have impacted the Earth in the past, we do not want large ones to impact us in the future. Can we prevent this from happening? A considerable amount of work continues to be done in detecting asteroids that may pass near the Earth, but solving the engineering problem of how to actually conduct a mission to deflect an asteroid is still in its infancy. Of the many ways considered to deflect an asteroid, the methods currently in favor fall into three categories: (1) kinetic impactor, (2) nuclear standoff explosion, and (3) gravitational tractor. Other techniques such as landing machinery on the asteroid and shooting off material (mass driver), or parking a giant minor near the asteroid and focusing the sunlight on it to ablate material, are not strongly in favor at this time.
Dietary guidelines for sustainability

A broad-range perspective on the content and implications of nutrition education is presented. The perspective stresses the importance of recognizing effects of food choices on the food supply, global resources (agricultural, economic, natural) and the long-term stability of the food system, as well as on individual nutrition and health. The term "sustainable diets" is proposed to describe recommendations for food choices that support life and health within natural system limits into the foreseeable future. General suggestions are provided to help nutritionists incorporate the sustainability concept into their teachings about food choices. The following "Dietary Guidelines for Americans" are discussed as a framework for addressing issues of sustainability in dietary guidance: 1) Eat a variety of foods, 2) Maintain ideal weight, 3) Avoid too much fat, saturated fat, and cholesterol, 4) Eat foods with adequate starch and fiber, 5) Avoid too much sugar, 6) Avoid too much sodium, 7) Drink alcoholic beverages only in moderation. Learning to view foods as more than just sources of nutrients may guide consumers toward sustainable food choices. A shift to sustainable d0617iets would be an important first step in widespread adoption of a sustainable agriculture policy that promotes the conservation of natural resources and regional self-reliance in food production and consumption.(
How to Think about the Problem of Free Will

In this essay I present what is, I contend, the free-will problem properly thought through, or at least presented in a form in which it is possible to think about it without being constantly led astray by bad terminology and confused ideas. Bad terminology and confused ideas are not uncommon in current discussions of the problem. The worst such pieces of terminology are “libertarian free will” and “compatibilist free will.” The essay consists partly of a defense of the thesis that the use of these phrases by writers on the problem of free will can only generate conceptual confusion and partly of a formulation of the problem that does not make use of them. I contend that this formulation is neutral with respect to the historically important positions on free will (e.g., compatibilism and incompatibilism).
An air-pollution dispersion model for long-range policy analysis

Abstract This paper presents the development of the smeared concentration approximation (SCA) method, which allows air-pollution dispersion to be included in multidisciplinary studies for long-term policy analysis without the direct use of large, complex air-pollution models. The framework of the SCA method is discussed, with its focus on urban-area analysis and its central assumption that a single, spatially averaged exposure for an urban area is a sufficient indicator of air-pollution exposure for long-term policy option analysis. SCA dispersion-parameters (i.e. the model) are presented for calculating a spatially averaged ground-level exposure for each of three emission classes. The SCA dispersion-parameters are presented in the form of an SCA dispersion-kit, to take meteorology into account. Initial validation of the SCA dispersion-parameters is given, and three examples are presented of air-pollution policy analysis based on case studies. These examples show the two major ways in which the SCA method is designed to be used: for regional policy analysis, and for single urban area policy analysis.
Radial Chromatography for the Separation of Nitroaniline Isomers

Separation techniques are usually presented in the undergraduate organic laboratory to teach students how to purify and isolate compounds. Often the concept of liquid chromatography is introduced by having students create “silica gel columns” to separate components of a reaction mixture. Although useful, column chromatography can be a laborious technique for students to perform. The separation efficiency can be compromised if students do not prepare the column correctly, and the time required to separate substances can extend beyond a typical laboratory period. Herein, the use of radial chromatography (centrifugal thin-layer chromatography) as an alternative to the traditional column chromatography technique utilized in many teaching laboratories is discussed. Radial chromatography can be used to introduce the principles that underlie liquid chromatography, with the added benefit of providing a relatively fast and highly efficient separation. An experiment for the efficient separation of a mixture contain...
A Microwave-Assisted Friedel–Crafts Acylation of Toluene with Anhydrides

A microwave-assisted Friedel–Crafts acylation, an electrophilic substitution reaction in which toluene was converted to four different products using acetic, benzoic, propionic, and valeric anhydrides (which were provided as unknowns) in the presence of aluminum chloride, was investigated and carried out as an inquiry-based teaching laboratory experiment for second-semester organic chemistry. The reaction took 15 min to complete and provided a single regioisomer in 60–76% yield after a simple workup. Students used 1H NMR, 13C NMR, DEPT, and IR spectroscopic data to identify their product.
Approximate dynamic programming for an inventory problem: Empirical comparison

This study investigates the application of learning-based and simulation-based Approximate Dynamic Programming (ADP) approaches to an inventory problem under the Generalized Autoregressive Conditional Heteroscedasticity (GARCH) model. Specifically, we explore the robustness of a learning-based ADP method, Sarsa, with a GARCH(1,1) demand model, and provide empirical comparison between Sarsa and two simulation-based ADP methods: Rollout and Hindsight Optimization (HO). Our findings assuage a concern regarding the effect of GARCH(1,1) latent state variables on learning-based ADP and provide practical strategies to design an appropriate ADP method for inventory problems. In addition, we expose a relationship between ADP parameters and conservative behavior. Our empirical results are based on a variety of problem settings, including demand correlations, demand variances, and cost structures.
Improving Diversity, Inclusion, and Representation in Radiology and Radiation Oncology Part 2: Challenges and Recommendations

The ACR Commission for Women and General Diversity is committed to identifying barriers to a diverse physician workforce in radiology and radiation oncology (RRO), and to offering policy recommendations to overcome these barriers. Part 2 of a 2-part position article from the commission addresses issues regarding diversity and inclusion in the context of career choices and professional advancement. Barriers to improving diversity and representation in RRO are reviewed. Discussion focuses on the development and implementation of concrete strategies designed to eliminate the current subspecialty disparity and highlights the need for the ACR to introduce programs and incentives with targeted and achievable goals with measurable outcomes. Recommendations are made aimed at fostering an environment of inclusion and diversity, so as to secure a successful future for all members of the RRO workforce. The future of radiology will be enhanced by increasing diversity and representation in the professional workforce, which will allow us to better address the varied needs of increasingly diverse patient populations, and to mitigate disparities in healthcare access, delivery, and outcomes. By leveraging diverse backgrounds, experiences, and skills of those in RRO, we will create new, effective ways to not only educate our trainees, medical colleagues, and patients but also improve delivery of health care and our service to society.
Acoustic radiation force on a heated sphere including effects of heat transfer and acoustic streaming

A previous theoretical result on the subject of the acoustic radiation force on a heated sphere (Lee and Wang, 1984) is reexamined. For a more complete understanding, effects of heat transfer and acoustic streaming are taken into consideration. Essentially, it was found that, at high sound-pressure levels in a steady situation, the force is not affected significantly by the temperature profile, consistent with the result of an experimental work (Leung and Wang, 1985). This resolves the earlier apparent contradiction between the theory and the experiment. If excessive hot air is accumulated around the sphere, which can happen in transient situations, the force can be weakened or reversed in sign. A heat transfer model due to acoustic streaming was also found.
Web-based collaboration: a key tool for the management of corporate information

In recent years many organisations have had to cope with fewer available management and technical staff. Gan [1999] identified a 25% fall in UK University applications for Built Environment Courses between 1994 and 1997. Construction projects have increasingly applied leading Information Technologies for design, planning, document control and process management which helps offset these issues. The reduction in skilled staff has also created an increasingly virtual team nature to projects, with Extranet tools now being employed on a regular basis. However, once projects are complete, few organisations address the need to capture project results for future work. This paper introduces the issues being addressed by an infrastructure client for the management of asset documentation throughout its lifecycle despite having fewer available staff. This includes the capture of legacy information and provision to capital projects, the management of new project data and the return of validated as-built documentation for whole-life asset management.
Recurrent obstructive jaundice caused by fibrolamellar hepatocellular carcinoma

A 24-year-old man with hepatocellular carcinoma presented with recurrent obstructive jaundice caused by bile duct invasion and distal migration of necrotic tumor fragments. After resection of an isolated left lobe tumor, he was well for 2 years until he again presented with obstructive jaundice caused by necrotic tumor and clot in the common bile duct. Analysis of his tumor revealed the fibrolamellar histologic variant of hepatocellular carcinoma. This case is unique in that the hepatocellular carcinoma was of the fibrolamellar variant and presented both intially and when recurrent 2 years later with obstructive jaundice caused by invasion of the common bile duct.
Innovation policy: not just a jumbo shrimp

Policies that predict and direct innovative research might seem to be a practical impossibility, says David H. Guston, but social sciences point to a solution. With US policy on nano-technology as the main source of examples, David Guston's Commentary outlines a vision of an ideal government innovation policy, in a contribution to our Innovations series. A key problem is the inherent dilemma that policy arrives too late to affect the past, but too early to understand the future. Guston's solution is 'anticipatory governance', a concept outlined on http://www.nanohub.org/resources/3270/0 . This approach, he says, retains an element of revolutionary thinking, yet steers policy towards goals that are prudently and democratically arrived at.
Heightened emotional contagion in mild cognitive impairment and Alzheimer’s disease is associated with temporal lobe degeneration

Emotional changes are common in mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Intrinsic connectivity imaging studies suggest that default mode network degradation in AD is accompanied by the release of an emotion-relevant salience network. We investigated whether emotional contagion, an evolutionarily conserved affect-sharing mechanism, is higher in MCI and AD secondary to biological alterations in neural networks that support emotion. We measured emotional contagion in 237 participants (111 healthy controls, 62 patients with MCI, and 64 patients with AD) with the Interpersonal Reactivity Index Personal Distress subscale. Depressive symptoms were evaluated with the Geriatric Depression Scale. Participants underwent structural MRI, and voxel-based morphometry was used to relate whole-brain maps to emotional contagion. Analyses of covariance found significantly higher emotional contagion at each stage of disease progression [controls < MCI (P < 0.01) and MCI < AD (P < 0.001)]. Depressive symptoms were also higher in patients compared with controls [controls < MCI (P < 0.01) and controls < AD (P < 0.0001)]. Higher emotional contagion (but not depressive symptoms) was associated with smaller volume in right inferior, middle, and superior temporal gyri (PFWE < 0.05); right temporal pole, anterior hippocampus, parahippocampal gyrus; and left middle temporal gyrus (all P < 0.001, uncorrected). These findings suggest that in MCI and AD, neurodegeneration of temporal lobe structures important for affective signal detection and emotion inhibition are associated with up-regulation of emotion-generating mechanisms. Emotional contagion, a quantifiable index of empathic reactivity that is present in other species, may be a useful tool with which to study emotional alterations in animal models of AD.
CFC replacement solvents in aerosols

Briefly discusses the search for alternatives to CFCs in aerosols for precision cleaning applications. Gives properties of several solvents used in cleaning applications. Considers five key parameters for selecting a solvent for aerosol applications.
A new apparatus for the study of nuclear Bragg scattering

Abstract A new monochromator system has been constructed which provides an energy resolution of 0.005 eV and an angular divergence of 0.4 arc sec at an energy of 14.413 keV. In conjunction with a highly perfect crystal of isotopically enriched 57 Fe 2 O 3 , a beam of nuclear resonant photons was extracted from the synchrotron continuum with a signal-to-noise ratio of 100:1 and an intensity of > 2 quanta/s.
Optimization of photoluminescence lifetime for ZnO films grown on ZnO substrates at low temperature

Abstract ZnO films were grown on Zn-polar ZnO substrates with 0.5° miscut toward the [1EQ \O(1,¯)00] direction by plasma-assisted molecular beam epitaxy (PAMBE). An atomically flat surface with one or two monolayer step height along the [0001] direction was achieved at low growth temperature. Wet etching of the substrates and ozone exposure reduced defects and improved photoluminescence (PL) lifetime by a factor of two. A 20 min interval between oxygen plasma ignition and growth was found necessary for excellent crystallinity and yielded high PL lifetimes of 0.179 ns. By decreasing the growth temperature in the low temperature range, the growth rate was increased from 0.02 μm/h to 0.246 μm/h, and correspondingly PL lifetime was improved by an order of magnitude, from 0.018 ns to 0.3 ns.
Vehicle occupancy space for unmanned ground vehicles with actuation error

The Velocity Occupancy Space (VOS) algorithm was developed to allow an Unmanned Ground Vehicle (UGV) to avoid moving and stationary obstacles and navigate efficiently to a goal using only uncertain sensor data. The original VOS concept was designed for an ideal, holonomic UGV that was capable of perfect, repeatable and instantaneous velocity changes. The method presented here adapts VOS through the use of Extended Velocity Obstacles (EVOs) so that VOS can operate on experimental UGVs with actuation error. For this research, the EVOs have been designed based on the characteristics of a SuperDroid ATR, but they can be easily calibrated for other velocity-controlled UGVs. The proposed method is validated through numerous simulations and experimental trials.
Pancreatic pseudocysts involving the spleen

Pancreatic pseudocyst involving the splenic parenchyma itself is an unusual complication of pancreatitis. The diagnosis is best established by arteriography, isotopic studies, and sonography. Once confirmed, surgical intervention is mandatory because of the danger of secondary hemorrhage.
Ion channels and regulation of intracellular calcium in vascular endothelial cells.

Endothelial cells in vivo form an interface between flowing blood and vascular tissue, responding to humoral and physical stimuli to secrete relaxing and contracting factors that contribute to vascular homeostasis and tone. The activation of endothelial cell-surface receptors by vasoactive agents is coupled to an elevation in cytosolic Ca2+, which is caused by Ca2+ entry via ion channels in the plasma membrane and by Ca2+ release from intracellular stores. Ca2+ entry may occur via four different mechanisms: 1) a receptor-mediated channel coupled to second messengers; 2) a Ca2+ leak channel dependent on the electrochemical gradient for Ca2+; 3) a stretch-activated nonselective cation channel; and 4) internal Na+-dependent Ca2+ entry (Na+-Ca2+ exchange). The rate of Ca2+ entry through these ion pathways can be modulated by the resting membrane potential. Membrane potential may be regulated by at least two types of K channels: inwardly rectifying K channels activated upon hyperpolarization or shear stress; a...
TRPM7 channel is regulated by magnesium nucleotides via its kinase domain.

TRPM7 is a Ca2+- and Mg2+-permeable cation channel that also contains a protein kinase domain. While there is general consensus that the channel is inhibited by free intracellular Mg2+, the functional roles of intracellular levels of Mg·ATP and the kinase domain in regulating TRPM7 channel activity have been discussed controversially. To obtain insight into these issues, we have determined the effect of purine and pyrimidine magnesium nucleotides on TRPM7 currents and investigated the possible involvement of the channel's kinase domain in mediating them. We report here that physiological Mg·ATP concentrations can inhibit TRPM7 channels and strongly enhance the channel blocking efficacy of free Mg2+. Mg·ADP, but not AMP, had similar, albeit smaller effects, indicating a double protection against possible Mg2+ and Ca2+ overflow during variations of cell energy levels. Furthermore, nearly all Mg-nucleotides were able to inhibit TRPM7 activity to varying degrees with the following rank in potency: ATP > TTP > CTP ≥ GTP ≥ UTP > ITP ≈ free Mg2+ alone. These nucleotides also enhanced TRPM7 inhibition by free Mg2+, suggesting the presence of two interacting binding sites that jointly regulate TRPM7 channel activity. Finally, the nucleotide-mediated inhibition was lost in phosphotransferase-deficient single-point mutants of TRPM7, while the Mg2+-dependent regulation was retained with reduced efficacy. Interestingly, truncated mutant channels with a complete deletion of the kinase domain regained Mg·NTP sensitivity; however, this inhibition did not discriminate between nucleotide species, suggesting that the COOH-terminal truncation exposes the previously inaccessible Mg2+ binding site to Mg-nucleotide binding without imparting nucleotide specificity. We conclude that the nucleotide-dependent regulation of TRPM7 is mediated by the nucleotide binding site on the channel's endogenous kinase domain and interacts synergistically with a Mg2+ binding site extrinsic to that domain.
Attenuation Correction for SPECT: An Evaluation of Hybrid Approaches

Most methods that have been proposed for attenuation compensation in single-photon emission computed tomography (SPECT) either rely on simplifying assumptions, or use slow iteration to achieve accuracy. Recently, hybrid methods which combine iteration with simple multiplicative correction have been proposed by Chang and by Moore et al. In this study we evaluated these methods using both simulated and real phantom data from a rotating gamma camera. Of special concern were the effects of assuming constant attenuation distributions for correction and of using only 180° of projection data in the reconstructions. Results were compared by means of image contrast, %RMS error, and a ?2 error statistic. Simulations showed the hybrid methods to converge after 1-2 iterations when 360° data were used, less rapidly for 180° data. The Moore method was more accurate than our modified Chang method for 180° data. Phantom data indicated the importance of using an accurate attenuation map for both methods. The speed of convergence of the hybrid algorithms compared to traditional iterative techniques, and their accuracy in reconstructing photon activity, even with 180° data, makes them attractive for use in quantitative analysis of SPECT reconstructions.
Protocol development using an electronic nose for differentiating E. coli strains

The presence of Escherichia coli (E. coli) O157:H7 in the food industry continues to be a problem in America. The pathogenic bacteria, commonly associated with beef products, are the cause of numerous human health concerns. On the other hand, the nontoxic E. coli is present in the intestinal tracts of animals and humans and helps in digestion. Thus, the long-term research objective is to differentiate quickly the pathogen E. coli O157:H7 from the nontoxic strains of E. coli in the farm-to-fork industry chain before the infected food reaches the consumer. This paper describes a constructed gas-sensor electronic-nose system that detects the released gases (amines and alcohol compounds) occurring during the growth of the bacteria cultured in two types of media, namely nutrient broth and brain heart infusion (BHI) broth. The output is a gas signature for each bacterial sample. Eight different E. coli samples were used in testing; four O157:H7 and four non-O157:H7 isolates. Different concentrations of bacteria were used in the study, ranging from 10/sup 2/ to 10/sup 7/ colony-forming units per milliliter. The results of the research showed that E. coli O157:H7 had a distinctly different gas signature than that of the non-O157:H7 bacteria when grown in nutrient broth. Bacteria grown in BHI broth did not have differentiating results. The initiation of gas increase in the bacteria correlated directly with the initial cell concentration of the sample. The initial increase of gas released by the bacteria occurred during the exponential phase of bacterial growth. The electronic nose device was able to differentiate the gas signatures of non-O157:H7 E. coli and O157:H7 E. coli isolates grown in nutrient broth with excellent reproducibility. Potential applications include food and environmental safety from farm to fork.
Approximation Theory, Moment Problems and Distribution Functions

Results concerning distribution functions, moment problems and approximation theory are discussed.
Hierarchical spatial models for predicting pygmy rabbit distribution and relative abundance

Summary 1. Conservationists routinely use species distribution models to plan conservation, restoration and development actions, while ecologists use them to infer process from pattern. These models tend to work well for common or easily observable species, but are of limited utility for rare and cryptic species. This may be because honest accounting of known observation bias and spatial autocorrelation are rarely included, thereby limiting statistical inference of resulting distribution maps. 2. We specified and implemented a spatially explicit Bayesian hierarchical model for a cryptic mammal species (pygmy rabbit Brachylagus idahoensis). Our approach used two levels of indirect sign that are naturally hierarchical (burrows and faecal pellets) to build a model that allows for inference on regression coefficients as well as spatially explicit model parameters. We also produced maps of rabbit distribution (occupied burrows) and relative abundance (number of burrows expected to be occupied by pygmy rabbits). The model demonstrated statistically rigorous spatial prediction by including spatial autocorrelation and measurement uncertainty. 3. We demonstrated flexibility of our modelling framework by depicting probabilistic distribution predictions using different assumptions of pygmy rabbit habitat requirements. 4. Spatial representations of the variance of posterior predictive distributions were obtained to evaluate heterogeneity in model fit across the spatial domain. Leave-one-out cross-validation was conducted to evaluate the overall model fit. 5. Synthesis and applications. Our method draws on the strengths of previous work, thereby bridging and extending two active areas of ecological research: species distribution models and multistate occupancy modelling. Our framework can be extended to encompass both larger extents and other species for which direct estimation of abundance is difficult.
BUCKLING RESPONSE OF TRANSVERSELY LOADED COMPOSITE SHELLS

The transverse loading response of convex composite shell structures typical of aircraft fuselage sections was investigated experimentally. Important mechanisms in the response, particularly instabilities (buckling), were studied by investigating the forcedeflection response and the evolution of full-field deformation-shapes. Quasi-static tests were conducted to simulate impact of convex shells. The specimens were laminated, cylindrical shells sections in [±45n/0n]s configurations where n takes on values of 1, 2, and 3. The three structural parameters of radius, span, and thickness were varied according to a scaling relation and were chosen to represent approximate fuselage dimensions of general aviation and commercial transport aircraft. All specimens were evaluated for damage using dye-enhanced x-radiography and sectioning after mechanical testing. The structural response changes both quantitatively and qualitatively for the different shell geometries and was categorized into three "Types" based on the existence of the instability transition characteristics such as deformation shapes. The presence of the instability becomes more likely for deeper, thinner specimens where the ratio of membrane to bending stiffness is higher. This can be characterized by a structural parameter involving geometric and material factors. The majority of the specimens showed no damage but the limited experimental evidence did show plate-like damage occurring in the shell specimens prior to any instability. Suggestions for further work to extend these findings are made.