gebhart/patrepeval huggingface dataset:
Photoisomerizations of 2-methylphenylcyclopropanes. Isotope effects and stereochemistry (1973)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotoisomerizations of 2-methylphenylcyclopropanes. Isotope effects and stereochemistryPaul H. Mazzocchi and Robert S. LustigCite this: J. Org. Chem. 1973, 38, 23, 4091–4092Publication Date (Print):November 1, 1973Publication History Published online1 May 2002Published inissue 1 November 1973https://pubs.acs.org/doi/10.1021/jo00987a041https://doi.org/10.1021/jo00987a041research-articleACS PublicationsRequest reuse permissionsArticle Views36Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Incidence and Predictors of Cognitive Decline in Patients with Left Ventricular Assist Devices (2015)

Cognitive decline occurs commonly in patients in the year after LVAD and is associated with older age and destination therapy. These results could have important implications for patient selection and improved communication of risks before LVAD implantation. Additional studies are needed to explore the association between cognitive decline and subsequent stroke, health status, and mortality in patients after LVAD.
Nongenetic Reprogramming of the Ligand Specificity of Growth Factor Receptors by Bispecific DNA Aptamers (2017)

The reprogramming of receptor-ligand interactions affords an opportunity to direct cells to respond to user-defined external cues. Although this has often been achieved via the genetic engineering of receptors, an alternative, nongenetic approach is highly demanded. In this article, we propose the design of oligonucleotide-based synthetic switches that feature the ability to reprogram the ligand specificity of the growth factor receptor. We demonstrated that our synthetic switches induced growth factor signaling via the formation of the dynamic complex with specific external cues that would otherwise not induce the signaling. This chemical approach may be applied to designing a new class of chemical tools that can control the activities of native cells and represent smart and safer regenerative drugs.
A high performance peak-detect and hold circuit for pulse height analysis (1992)

Peak extractor circuits are an important link in most pulse-height analysis systems. A novel architecture with performance exceeding previous state-of-the-art designs is presented. A droop rate ranging from 125 mu V/ mu s and a charge injection of 5 mV are reported along with a 2.2 MHz bandwidth, a 38 V/ mu s slew rate, and integral nonlinearity of 50 PPM. The low droop rate allows temporary storage of the signal in an analog FIFO (first-in first-out) with minimal peak broadening, suitable for high-resolution low-energy X-ray analysis. This configuration has been implemented in an analog-to-digital converter system using the peak-detect and hold circuit architecture. The complete system had a differential linearity of 1.5% at 64 K conversion gain, an integral linearity of +or-0.016%, and an effective conversion time of 1.9 mu s for a count rate of 210000 C/s to the input of a pulse processor producing 3- mu s-wide pulses.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
Cultured Cells as a Screen for Novel Treatments of Alzheimer's Disease (1989)

Two easily measured abnormal properties of fibroblasts from patients with Alzheimer's disease have been utilized to develop an in vitro test system for screening novel therapeutic agents for Alzheimer's disease. The abnormal properties selected for study were increased isoproterenol-stimulated cyclic adenosine monophosphate production and decreased pH (measured by the weak-acid distribution method). L-Carnitine was tested as a potential therapeutic agent, since it has been used to treat a variety of experimental metabolic encephalopathies. The addition of L-carnitine normalized both of these properties in the Alzheimer cells. Tissue culture may aid as a preliminary screen for identifying novel approaches to the treatment of Alzheimer's disease.
Persistently Electrified Pedicle Stimulation Instruments in Spinal Instrumentation (1997)

The persistently electrified pedicle stimulation instrument technique described here is useful for monitoring instrumented lumbar fusion procedures. The use of this protocol may help confirm intraosseous placement of pedicle screws and prevent neurologic injury.
Inter-personal motor interaction is facilitated by hand pairing (2022)

The extent to which hand dominance may influence how each agent contributes to inter-personal coordination remains unknown. In the present study, right-handed human participants performed object balancing tasks either in dyadic conditions with each agent using one hand (left or right), or in bimanual conditions where each agent performed the task individually with both hands. We found that object load was shared between two hands more asymmetrically in dyadic than single-agent conditions. However, hand dominance did not influence how two hands shared the object load. In contrast, hand dominance was a major factor in modulating hand vertical movement speed. Furthermore, the magnitude of internal force produced by two hands against each other correlated with the synchrony between the two hands' movement in dyads. This finding supports the important role of internal force in haptic communication. Importantly, both internal force and movement synchrony were affected by hand dominance of the paired participants. Overall, these results demonstrate, for the first time, that pairing of one dominant and one non-dominant hand may promote asymmetrical roles within a dyad during joint physical interactions. This appears to enable the agent using the dominant hand to actively maintain effective haptic communication and task performance.
Clinical usefulness of endoscopic ultrasonography-guided fine-needle aspiration in the diagnosis and staging of lung cancer. (2007)

Lung cancer is the most common cause of cancer-related mortality in Singapore, and accurate staging of lung cancer is therefore of paramount importance. Several non-invasive and invasive modalities can be used to stage lung cancer. Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) is a safe procedure that is performed under conscious sedation and has a sensitivity of up to 90-98 percent in expert hands. In addition, nodal groups that are inaccessible by cervical mediastinoscopy (such as the aortopulmonary window lymph nodes) can be sampled by EUS-FNA. We present three cases in which EUS-FNA was used successfully to diagnose and stage lung cancer, thus avoiding surgery.
Role of GABAA receptors in cognition (2009)

Complex brains have developed specialized mechanisms for the grouping of principal cells into temporal coalitions of local or distant networks: the inhibitory interneuron 'clocking' networks. They consist of GABAergic (where GABA is gamma-aminobutyric acid) interneurons of a rich diversity. In cortical circuits, these neurons control spike timing of the principal cells, sculpt neuronal rhythms, select cell assemblies and implement brain states. On the basis of these considerations, the deficits in cognition, emotion and perception in psychiatric disorders such as anxiety, depression or schizophrenia are considered to manifest themselves through a dysregulation of the inhibitory interneuron 'clocking' network as a final common denominator, irrespective of the diverse underlying disease pathologies. The diversity of GABAergic interneurons is paralleled by a corresponding diversity of GABA(A) receptors in network regulation. The region-, cell- and domain-specific location of these receptor subtypes offers the possibility to gain functional insights into the role of behaviourally relevant neuronal circuits. Using genetic manipulation, the regulation of anxiety behaviour was attributed to neuronal circuits characterized by the expression of alpha(2)-GABA(A) receptors. Neurons expressing alpha(3)-GABA(A) receptors, located mainly in aminergic and basal forebrain cholinergic neurons, were related to a hyperdopaminergic phenotype, typical of schizophrenic symptoms. Temporal and spatial memory were selectively modulated by extrasynaptic alpha(5)-GABA(A) receptors. Chronic pathological pain was under the regulation of spinal and cortical alpha(2)- (and alpha(3)-) GABA(A) receptors. Thus the relevance of the diversity of inhibitory GABA(A) receptor subtypes for the regulation of cognition, emotion and memory is increasingly being recognized. The clinical proof-of-concept of a subtype-specific pharmacology is most advanced for the alleviation of cognitive dysfunctions in schizophrenia, based on the treatment of patients with an alpha(2)/alpha(3)-GABA(A) receptor ligand.
Network Polymers Formed Under Nonideal Conditions. (1986)

Abstract : Formation of polymer networks are discussed under nonideal conditions. The work accomplished falls into three categories: 1) probability models for determining molecular weight relations and network parameters, 2) study of epoxy systems, and 3) study of vinyl-divinyl systems. The general theoretical work on probability models has comprised the following: a) the crosslinking of chains with arbitrary length and site distribution, b) A3 and B2 step polymerization with cycles, and c) anionic, network-forming systems. Several nonidealities in epoxy systems have been and are being analyzed. Substitution effects and secondary reactions in epoxy-amine systems have been characterized and incorporated into a branching theory, and good agreement with experimental results obtained. Another problem in these systems is the effect of vitrification, so the variation of Tg with conversion has been studied for DGEBA-DDM and epoxy-novolac systems. In vinyl/divinyl systems, the formation of loops and the reduction in pendant double bond reactivity have been studied. A kinetic model was developed to predict the conversion of pendant double bonds to crosslinks and cycles, that information being employed in a branching theory. Good viscosity correlations were obtained. Further theoretical studies of cyclization were initiated as groundwork for systems for which cyclization may play an even larger role (e.g. in the formation of microgels).
A review of the microbiology, antibiotic usage and resistance in chronic skin wounds (2005)

Chronic leg and foot wounds represent an increasing burden to healthcare systems as the age of the population increases. The deep dermal tissues of all chronic wounds harbour microorganisms, however, the precise interaction between microbes in the wounds and impaired healing is unknown. With regard to antibiotic therapy, there is a lack of evidence concerning its effectiveness, optimal regimens or clinical indications for treatment. Despite this lack of evidence, antibiotics are frequently a feature of the management of chronic wounds and these patients receive significantly more antibiotic prescriptions (both systemic and topical) than age and sex-matched patients. Current guidelines for antibiotic prescribing for such wounds are often based on expert opinion rather than scientific fact and may present difficulties in interpretation and implementation to the clinician. Although the increasing prevalence of antibiotic resistance is widely recognized, the relationships between antibiotic resistance, chronic wound microbiology and rationales for antibiotic therapy have yet to be determined. This review discusses the role of microbes in chronic wounds from a clinical perspective with particular focus on the occurrence of bacteria and their impact on such wounds. The evidence and role of antibiotics in the treatment of such wounds are outlined and current practice of antibiotic usage for chronic wounds in the primary care setting described. The implications of antibiotic usage with regard to antibiotic resistance are also considered.
Nonlinear Dynamics and Control of Flexible Structures (1989)

Abstract : The goals of these research projects were to examine the nonlinear dynamics and control of flexible structures, some of which might be used for space applications. This project was a collaborative one involving structural, electrical and mechanical engineers. A major part of the research was on trusses/frames structures. Five different truss structures from three to ten meters in size were constructed, two with active controls. However, nonlinear dynamics of continuous beam type structures were also investigated. One of the principal themes was to explore what types of nonlinearities would result in chaotic and unpredictable vibrations. Loose joints in truss structures, friction, buckling and geometric nonlinearities were all found to lead to chaotic motions under certain periodic forcing conditions. Actuators and sensors for space truss active vibration suppression was investigated. New methods were developed for structural control using techniques for simulated annealing for actuator placement, nonlinear random vibrations of pin-jointed trusses, vibration analysis and new models to analyze chaotic dynamics in nonlinear structures with large deformations and friction forces. Finally, a major numerical effort resulted in new codes to predict large motions of structures under active control using parallel processing algorithms.
Compact self-started femtosecond Cr:forsterite laser for non-linear optical microscopy (2004)

We demonstrated a compact, prismless, self-started Cr:forsterite laser generating 300 mW of 85-fs pulses around 1226 nm. Based on a fiber pump laser, this compact laser system is a promising clinical source for portable nonlinear scanning microscope.
Computer model for the characterisation of the size distribution of spheroidal graphite in ductile cast iron (1998)

A computer model was developed to establish the relationship between the two-dimensional (2D) and the three-dimensional (3D) parameters, specifically the number of particles and particle size distribution. The computer experiments were performed for both monodispersed and lognormally polydispersed systems. The model was based on a random distribution of a number of spherical grains in a cubic unit, with no intersection between the grains. The cubic unit was cut by a random plane and the number of particles which appeared in the section and the area fraction were measured. This procedure was repeated until the average number of particles and the average area fraction became constant. Finally, the 2D size distribution of the particles over all sections was obtained.It was concluded that the volume fraction is equal to the area fraction, irrespective of the particle size distribution, providing that the total number of measured 2D particles is large enough. As for the number of particles, an equation was found to calculate the number of 3D particles in a monodispersed system from the number of 2D particles and the volume fraction. However, in lognormally polydispersed systems the number of 3D particles could be calculated using the 3D mean and standard deviation, estimated from the 2D mean and standard deviation by a method specifically developed for the purpose.Finally, the method was applied to two ductile cast iron specimens and the applicability of the present model was verified.
Engineering translational multi-therapeutic targeted delivery vehicles for disease management (2015)

Thesis: Sc. D., Massachusetts Institute of Technology, Department of Chemical Engineering, June 2015.
Acoustic properties of oxide glasses at low temperatures (1995)

Acoustic properties of a-${\mathrm{B}}_{2}$${\mathrm{O}}_{3}$ and a-${\mathrm{GeO}}_{2}$ are investigated at low frequencies in the temperature range 10 mKT200 K, using a vibrating-reed technique; the results confirm earlier measurements on other amorphous dielectrics. Whereas the low-temperature data are well described by J\"ackle's perturbation theory in the framework of the tunneling model, the strong relaxation above 5 K requires a different approach. Up to 20 K incoherent tunneling of two-level systems seems to govern the relaxational dynamics; at still higher temperature the two-level description breaks down, and thermally activated barrier crossing leads to a Arrhenius-like relaxation rate.
Development of Mice with Osteoblast-Specific Connexin43 Gene Deletion (2003)

Genetic deficiency of Cx43 in vivo causes skeletal developmental defects, osteoblast dysfunction and perinatal lethality. To determine the role of Cx43 in the adult skeleton, we developed two models of osteoblast-specific Cx43 gene deletion using Cre mediated replacement of a "floxed" Cx43 allele with a LacZ reporter gene. Cre recombinase expression in osteoblasts was driven by either the osteocalcin OG2 promoter or the 2.3 kb fragment of the Colalpha1(I) promoter. Homozygous Cx43(fl/fl) mice, in which the Cx43 coding region is flanked by two loxP sites, were crossed with Cre expressing mice in a heterozygous Cx43-null background [Cx43(+/-); Colalpha1(I)-Cre or Cx43(+/-); OG2-Cre]. Cx43 gene ablation was demonstrated in tissues by selective X-gal staining of cells lining the endosteal surface, and in cultured osteoblastic cells from calvaria using different approaches. Although no LacZ expression was observed in proliferating calvaria cells, before osteoblast differentiation begins, post-proliferative cells isolated from conditional knockout mice [Cx43(fl/-); Colalpha1(I)-Cre or Cx43(fl/-); OG2-Cre] developed strong LacZ expression as they differentiated, in parallel to a progressive disappearance of Cx43 mRNA and protein abundance relative to controls. Selective Cre mediated Cx43 gene inactivation in bone forming cells will be useful to determine the role of Cx43 in adult skeletal homeostasis and overcome the perinatal lethality of the conventional null model.
Polyurethane Elastomers: Safe Replacements for EN-7. (2014)

Abstract not provided.
Patients with Type 1 Diabetes Treated with Insulin Pumps Need Widely Heterogeneous Basal Rate Profiles Ranging from Negligible to Pronounced Diurnal Variability (2020)

We observe substantial interindividual heterogeneity in the "dawn" phenomenon. However, widely different empirically derived basal insulin infusion profiles appear appropriate for individual patients, as indicated by similar plasma glucose concentrations, mainly in the target range, during a 24-hour fasting period.
Chemically designed inorganic polymer filters for aqueous mercury separation (2002)

The disposal of mercury [Hg] in dental waste water is recognized as a serious pollution control problem. Although technologies exist for effectively removing aqueous Hg ions from dental emissions, they are not commonly used because they are expensive, they can leach Hg back into the environment, they usually require the implementation of multiple separation techniques, and they have no potential for metal recovery. As the dental profession is among the leading environmental contributors of this cumulative protoplasmic poison (/spl sim/30 ktons/yr), it is essential that improved separation technologies be developed. As a novel solution, sol-gel processing technologies were used to develop chemically designed, inorganic polymer filters for the economic separation and recovery of aqueous mercury, N-[3-(Trimethoxysilyl) propyl] ethylenediamine [TRMSP-EDA, (CH/sub 3/O)/sub 3/Si(CH/sub 2/)/sub 3/NH(CH/sub 2/)/sub 2/NH/sub 2/] was polymerized via acid catalyzed (HF) hydrolysis and polycondensation reactions with distilled water and ethanol solvent (C/sub 2/H/sub 5/OH). The resultant silicone polymers covalently bond high concentrations of bidentate ethylenediamine (EDA) ligands which can chelate Hg into stable metal complexes at the polymer surface. To maximize filter efficiency and processing economy, the reactant concentrations and polymerization conditions were optimized to simultaneously maximize polymer yield and surface area. High surface area powders (20.11/spl plusmn/0.48 m/sup 2//g) were obtained in theoretical yields (58.43%, 20/spl deg/C) using respective molar ratios of 1.0 TRMSP-EDA: 3.0 H/sub 2/O: 2.0 C/sub 2/H/sub 5/OH: 0.05 HF. According to infrared spectroscopy, broad Si-O Si stretching frequencies of 1122 and 1038 cm/sup -1/ confirm the formation of an extended silicone polymer network, whereas primary and secondary amine stretching frequencies of 3410 and 3337 cm/sup -1/ confirm that the chelating EDA functional group is intact and unmodified. To evaluate the Hg filtration efficiency of these reactive polymer powders, cold vapor atomic absorption spectroscopy was employed by passing 1000 ppb solutions (8.5 ml) through reactive polymer powder (0.5 g) at various pH values (2-5). Single pass filtration effectively reduced the aqueous mercury concentration to undetectable levels, 13 ppb; corresponding to 99.97% filtration efficiency. FTIR analysis confirms the formation of surface Hg chelation compounds through N-H peak energy shifts and broadening, In conclusion, EDA functionalized silicone polymers can be used to effectively separate greater than 2000 ppb Hg.
Impact of HIV drug resistance on virologic and immunologic failure and mortality in a cohort of patients on antiretroviral therapy in China (2013)

HIVDR was common and was associated with higher mortality among Chinese patients on cART, particular when HIVDR was detected early in therapy. Our study reinforces the importance of improving patient adherence to cART in order to delay the emergence of HIVDR and obviate the need to switch to costly second-line drug regimens too early.
The Golf Course (2005)

With the background information of the earlier chapters and the practical advice of the later ones, together with some useful appendices, this book will be of particular value to all those with responsibility for the smooth and coherent maintenance and development of a golf course. It is also fascinating for any golfer whose interest goes beyond just playing the game.
Do Cervical Muscles Play a Role in Whiplash Injury? (2002)

There is a lack of consensus in the literature surrounding whether initially-relaxed cervical muscles can or cannot affect whiplash injury in a rear-end collision. For cervical muscles to play a role in whiplash injury biomechanics, both the timing and magnitude of the muscle response must be considered. This paper is a review of pertinent literature as well as past experiments in our laboratory to address whether initially-relaxed cervical muscles have the potential to alter the head and neck kinematics and kinetics resulting from a rear-end impact. Contrary to the common perception that cervical muscles activate too late and too slowly to affect whiplash injury, the literature indicates that the cervical muscles are active early in response to impact and are capable of generating forces sufficient to alter the head and neck kinematics. Assuming that induced head and neck kinematics and kinetics are related to whiplash injury, these findings indicate that initially-relaxed cervical muscles must be considered in the study of whiplash injury biomechanics.
CONDUCT, STRUCTURE AND RELATIVE WELFARE LOSSES IN QUANTITY-SETTING DUOPOLY (1982)

Health Economics and Policy, Industrial Organization