gebhart/patrepeval huggingface dataset:
Polymer-supported membranes. A new approach for modifying polymer surfaces (1983)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolymer-supported membranes. A new approach for modifying polymer surfacesSteven L. Regen, Piotr Kirszensztejn, and Alok SinghCite this: Macromolecules 1983, 16, 2, 335–338Publication Date (Print):February 1, 1983Publication History Published online1 May 2002Published inissue 1 February 1983https://pubs.acs.org/doi/10.1021/ma00236a034https://doi.org/10.1021/ma00236a034research-articleACS PublicationsRequest reuse permissionsArticle Views122Altmetric-Citations42LEARN 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
Learning in neural networks by reinforcement of irregular spiking (2004)

Artificial neural networks are often trained by using the back propagation algorithm to compute the gradient of an objective function with respect to the synaptic strengths. For a biological neural network, such a gradient computation would be difficult to implement, because of the complex dynamics of intrinsic and synaptic conductances in neurons. Here we show that irregular spiking similar to that observed in biological neurons could be used as the basis for a learning rule that calculates a stochastic approximation to the gradient. The learning rule is derived based on a special class of model networks in which neurons fire spike trains with Poisson statistics. The learning is compatible with forms of synaptic dynamics such as short-term facilitation and depression. By correlating the fluctuations in irregular spiking with a reward signal, the learning rule performs stochastic gradient ascent on the expected reward. It is applied to two examples, learning the XOR computation and learning direction selectivity using depressing synapses. We also show in simulation that the learning rule is applicable to a network of noisy integrate-and-fire neurons.
Expression and Relationship of Male Reproductive ADAMs in Mouse1 (2006)

A number of a disintegrin and metalloprotease (ADAM) family members are expressed in mammalian male reproductive organs such as testis and epididymis. These reproductive ADAMs are divided phylogenically into three major groups: ADAMs 1, 4, 6, 20, 21, 24, 25, 26, 29, 30, and 34 (the first group); ADAMs 2, 3, 5, 27, and 32 (the second group); and ADAMs 7 and 28 (the third group). Previous mouse knockout studies indicate that ADAM1, ADAM2, and ADAM3 have intricate expressional relationships, playing critical roles in fertilization. In the present study, we analyzed processing, biochemical characteristics, localization, and expressional relationship of the previously-unexplored, second-group ADAMs (ADAM5, ADAM27, and ADAM32). We found that all of the three ADAMs are made as precursors in the testis and processed during epididymal maturation, and that ADAM5 and ADAM32, but not ADAM27, are located on the sperm surface. Using sperm from Adam2(-/-) and Adam3(-/-) mice, we found that, among the three ADAMs, the level of ADAM5 is modestly and severely reduced in Adam3 and Adam2 knockout sperm, respectively. Further, we analyzed ADAM7, an epididymis-derived sperm surface ADAM from the separate phylogenetic group, in the knockout sperm. We found that the level of ADAM7 is also significantly reduced in both Adam2 and Adam3-null sperm. Taken together, our results suggest a novel expressional relationship of ADAM5 and ADAM7 with ADAM2 and ADAM3, which play critical roles in fertilization.
Efficacy of intermittent versus continuous administration of netilmicin in a two-compartment in vitro model (1985)

Several aminoglycoside dosage regimens were studied in a kinetic in vitro model. Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were exposed in serially placed artificial capillary units to netilmicin concentrations that changed based on human two-compartment pharmacokinetics. The same total dose per 24 h was administered as a continuous infusion (3.7 micrograms/ml) or in 1-h infusions given every 24 (24 micrograms/ml) or 8 h (8 micrograms/ml). The once daily administration showed the best response in terms of either faster killing of E. coli, K. pneumoniae, and S. aureus or greater reduction of the inocula of P. aeruginosa. After 28 h of treatment, however, all regimens reduced the nonpseudomonads by more than 99.99%, whereas all three P. aeruginosa strains regrew to greater than 10(8) CFU/ml due to selection of resistant subpopulations. In contrast to the bactericidal effect of the first dose, no killing occurred after subsequent doses if the ratio of peak drug concentration to MIC was low (less than or equal to 6). These results support the concept of administering high doses of aminoglycosides once every 24 h.
Synthesis of 3-Substituted 5,6-Diphenylpyrimidin-4-ones from Diphenylcyclopropenone and N-Substituted Amide Oximes (1984)

3-Substituted 5.6-diphenylpyrlmidin-4-ones were prepared regioselectively from dlphenylcyclopropenone and N-substituted amide oximes. Diphenylcyclopropenone (1) is a readily available and useful synthon for heterocycles."2There have been same reports about the formation of two isomeric pyrimidin-4-ones 5 and 8 from 1. ?-Substituted pyrimidin-4-ones>
Isolation and characterization of human apolipoprotein A-IV from lipoprotein-depleted serum (1983)

Human apolipoprotein A-IV is an acidic polypeptide of molecular weight 46,000 that is secreted into lymph on the surface of nascent chylomicrons, but which exists in circulation unassociated with lipoproteins. Previous studies of this protein have utilized material isolated from a d < 1.006 g/ml fraction of human serum and from human lymph. Although it has been suggested that apoA-IV circulating in plasma is the product of dissociation from the surface of nascent chylomicrons, it has been characterized by immunological techniques only. We have isolated human apoA-IV on a preparative scale from lipoprotein-depleted serum using a technique of adsorption to a phospholipid-triglyceride emulsion, followed by delipidation and preparative gel electrophoresis. The molecular weight, pI, and amino acid composition of material thus prepared agree with literature values for apoA-IV derived from chylomicrons. We have determined that apoA-IV is a glycoprotein containing 6% carbohydrate by weight (mannose 1.8%, galactose 1.55%, N-acetyl glucosamine 1.55%, sialic acid 1.1%). Electroimmunoassay of human serum using a monospecific rabbit antibody to serum-derived apoA-IV found 13.1 +/- 1.8 mg/dl, a value in agreement with determinations using antibodies to chylomicron-derived apoA-IV. We conclude that apoA-IV may be easily purified from normal human serum, and that the material thus isolated has identical chemical, physical, and immunological properties to apoA-IV obtained from human lymph. It is therefore likely that the dissociation of apoA-IV from the surface of nascent chylomicrons following their entry into circulation is not attended by changes in the structure or composition of this apoprotein.-Weinberg, R. B., and A. M. Scanu. Isolation and characterization of human apolipoprotein A-IV from lipoprotein-depleted serum.
Role of oxidative stress in cardiovascular diseases (2000)

The existing evidence support the view that oxidative stress may play a crucial role in cardiac and vascular abnormalities in different types of cardiovascular diseases and that the antioxidant therapy may prove beneficial in combating these problems.
Holographic subtraction using anisotropic centers in alkali halide crystals (1975)

Coherent partial holographic erasure and selective erasure of volume holograms is demonstrated using the linear record and erase capability of photodichroic crystals, i.e., alkali halides with anisotropic color centers.
Qualitative methodology in simulation model engineering* (1989)

Qualitative methodology in simulation requires high level model ing constructs such as causal graphs, bond graphs, or natural language. Even though there exists a virtual continuum between qualitative and quantitative simulation methods, it is important to discuss qualitative methods since they relate to notions of pro cess abstraction and discovery during model evolution. We will refer to the evolutionary process as simulation model engineer ing. We define the basic notions of qualitative simulation, give specific examples for a pendulum system, and finally discuss various issues and directions for future work.
Correction: Mapping Proprioception across a 2D Horizontal Workspace (2010)

Relatively few studies have been reported that document how proprioception varies across the workspace of the human arm. Here we examined proprioceptive function across a horizontal planar workspace, using a new method that avoids active movement and interactions with other sensory modalities. We systematically mapped both proprioceptive acuity (sensitivity to hand position change) and bias (perceived location of the hand), across a horizontal-plane 2D workspace. Proprioception of both the left and right arms was tested at nine workspace locations and in 2 orthogonal directions (leftright and forwards-backwards). Subjects made repeated judgments about the position of their hand with respect to a remembered proprioceptive reference position, while grasping the handle of a robotic linkage that passively moved their hand to each judgement location. To rule out the possibility that the memory component of the proprioceptive testing procedure may have influenced our results, we repeated the procedure in a second experiment using a persistent visual reference position. Both methods resulted in qualitatively similar findings. Proprioception is not uniform across the workspace. Acuity was greater for limb configurations in which the hand was closer to the body, and was greater in a forward-backward direction than in a left-right direction. A robust difference in proprioceptive bias was observed across both experiments. At all workspace locations, the left hand was perceived to be to the left of its actual position, and the right hand was perceived to be to the right of its actual position. Finally, bias was smaller for hand positions closer to the body. The results of this study provide a systematic map of proprioceptive acuity and bias across the workspace of the limb that may be used to augment computational models of sensory-motor control, and to inform clinical assessment of sensory function in patients with sensory-motor deficits.
High‐Resolution Ultrasound Elasticity Imaging to Evaluate Dialysis Fistula Stenosis (2008)

Accurate, noninvasive characterization of arterial wall mechanics and detection of fibrotic vascular lesions could vastly improve the ability to predict patient response to local treatments such as angioplasty. Current imaging and other techniques for determining wall compliance rely on imprecise or indirect estimates of wall motion. This study used high-resolution ultrasound imaging with phase-sensitive speckle tracking to obtain detailed and direct measurements of arterial stiffness in two subjects with dialysis fistula dysfunction. In both subjects, the absolute values of strain were much higher in normal regions of fistula than in regions of stenosis. The lower values of strain in stenotic fistula indicate greater stiffness of the vessel wall. The ultrasound speckle tracking technique used here may have potential to determine vascular mechanical properties noninvasively with a level of precision and accuracy not currently available.
Src-Class Kinases Act within the Agrin/MuSK Pathway to Regulate Acetylcholine Receptor Phosphorylation, Cytoskeletal Anchoring, and Clustering (2001)

Synaptogenesis at the neuromuscular junction requires agrin-induced stable localization of acetylcholine receptors (AChRs) at the endplate. The effects of agrin are transduced by the muscle-specific receptor tyrosine kinase (MuSK). This study provides evidence that Src-class protein tyrosine kinases mediate the effects of agrin-activated MuSK to regulate clustering and anchoring of AChRs in skeletal muscle. MuSK was complexed with both Src and Fyn in the C2 mouse muscle cell line. These associations were enhanced by agrin and by increasing protein tyrosine phosphorylation with pervanadate. Coupling between MuSK and the Src-class kinases in vivo appeared to be caused by a phosphotyrosine-SH2 domain interaction because binding of MuSK to the SH2 domains of Fyn and Src in vitro was specific, enhanced by phosphorylation, and dependent on MuSK autophosphorylation. In addition, Src and Fyn phosphorylated MuSK. AChR phosphorylation, stimulated by agrin or pervanadate, was inhibited by blocking Src-class kinases with PP1. Furthermore, agrin-induced clustering and cytoskeletal anchoring of AChRs was dependent on Src-family kinases. These data support the conclusion that Fyn and Src act downstream of MuSK to regulate the stable localization of AChRs at the neuromuscular endplate during agrin-induced synaptogenesis.
Incidence, course, and severity of delayed nausea and vomiting following the administration of high-dose cisplatin. (1985)

Although many trials have evaluated the severity and treatment of nausea and vomiting immediately after cisplatin administration, no studies have focused on vomiting occurring more than 24 hours after chemotherapy--delayed emesis. Two consecutive trials were undertaken to evaluate the incidence, course (trial 1), and severity (trial 2) of delayed nausea and emesis and to develop methods to study these conditions. Eighty-six patients receiving cisplatin (120 mg/m2) for the first time were entered. On the day of cisplatin treatment, all received intravenous (IV) metoclopramide (3 mg/kg X 2 doses) plus dexamethasone (20 mg IV X 1 dose) with either diphenhydramine (50 mg IV) or lorazepam (1.0 to 1.5 mg/m2). Sixty-two percent of patients experienced no vomiting during the 24 hours immediately after administration of cisplatin. Overall, 93% of studied patients experienced some degree of delayed nausea or vomiting from 24 to 120 hours after cisplatin. In trial 1, the incidence of delayed vomiting ranged from 21% to 61% and delayed nausea from 24% to 78% in 58 patients. The highest incidence of both delayed nausea and emesis occurred during the period from 48 to 72 hours after administration of cisplatin. Patients who had no emesis during the initial 24 hours after cisplatin were less likely to experience delayed emesis. The severity of delayed nausea and vomiting was evaluated in 28 patients in trial 2. The amount of delayed nausea and vomiting was assessed daily by patients using a visual analogue scale and by an observer rating. The highest nausea and vomiting scores were seen during the period from 48 to 72 hours after administration of cisplatin, with acceptable correlation between patient scores and observer ratings. Although the nausea and vomiting occurring 24 or more hours after cisplatin administration is not as severe as that seen during the initial 24 hours after administration of cisplatin in patients not receiving antiemetics, it is a common condition that merits both further study and specific treatment.
Exploring the Frontiers of Therapeutic Exon Skipping for Duchenne Muscular Dystrophy by Double Targeting within One or Multiple Exons (2006)

Through antisense-induced single-, double-, and multiexon skipping, we have previously demonstrated restoration of dystrophin expression in Duchenne muscular dystrophy (DMD) patient-derived muscle cells in vitro. In this study we further explored the frontiers of this strategy by using specific combinations of 2'-O-methyl phosphorothioate antisense oligonucleotides (AONs) targeting either one or multiple exons. We show that skipping efficiencies may indeed be improved by targeting two putative splicing regulatory sequences within one exon. In particular, such double targeting was effective for the thus far "unskippable" exons 47 and 57. We previously reported the feasibility of multiexon skipping spanning exon 45 to exon 51, using a combination of AONs targeting both outer exons (45 and 51). This would be applicable to 13% of all DMD patients. We here explored the frontiers of multiexon skipping both to increase the number of patients that can be treated with the same set of AONs and to mimic large deletions found in relatively mildly affected BMD patients. We aimed at inducing larger multiexon-skipping stretches, such as exons 17-51, exons 42-55, and exons 45-59. However, this appeared complicated and may be dependent on cotranscriptional splicing and the size of the flanking introns.
Age‐related macular degeneration—emerging pathogenetic and therapeutic concepts (2006)

Today, the average life expectancy in developed nations is over 80 years and climbing. And yet, the quality of life during those additional years is often significantly diminished by the effects of age-related, degenerative diseases, including age-related macular degeneration (AMD), the leading cause of blindness in the elderly worldwide. AMD is characterized by a progressive loss of central vision attributable to degenerative and neovascular changes in the macula, a highly specialized region of the ocular retina responsible for fine visual acuity. Estimates gathered from the most recent World Health Organization (WHO) global eye disease survey conservatively indicate that 14 million persons are blind or severely visually impaired because of AMD. The disease has a tremendous impact on the physical and mental health of the geriatric population and their families and is becoming a major public health burden. Currently, there is neither a cure nor a means to prevent AMD. Palliative treatment options for the less prevalent, late-stage 'wet' form of the disease include anti-neovascular agents, photodynamic therapy and thermal laser. There are no current therapies for the more common 'dry' AMD, except for the use of antioxidants that delay progression in 20%-25% of eyes. New discoveries, however, are beginning to provide a much clearer picture of the relevant cellular events, genetic factors, and biochemical processes associated with early AMD. Recently, compelling evidence has emerged that the innate immune system and, more specifically, uncontrolled regulation of the complement alternative pathway plays a central role in the pathobiology of AMD. The complement Factor H gene--which encodes the major inhibitor of the complement alternative pathway--is the first gene identified in multiple independent studies that confers a significant genetic risk for the development of AMD. The emergence of this new paradigm of AMD pathogenesis should hasten the development of novel diagnostic and therapeutic approaches for this disease that will dramatically improve the quality of our prolonged lifespan.
Titanium(II)‐Mediated Cyclizations of (Silyloxy)enynes: A Total Synthesis of (‐)‐7‐Demethylpiericidin A1. (2006)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Antibody-forming cell induction during an early phase of germinal centre development and its delay with ageing. (1989)

The present study was initiated to determine if an early phase of germinal centre (GC) development is associated with the generation of antibody-forming cells (AFC). Germinal centres in draining lymph nodes from immune mice were examined histochemically after secondary immunization for the presence of AFC at both the light and electron microscopic levels. Additionally, peanut agglutinin (PNA) high (Hi) GC B cells were isolated, placed in cell culture and specific antibody production was monitored at successive intervals. Electron microscopy showed that plasma cells in all stages of differentiation were present within GC at 3-5 days and to a lesser extent at 7 days following antigenic challenge. Furthermore, PNAHi GC B cells obtained between Days 3 and 5 spontaneously produced specific IgG when placed in culture. Germinal centre B cells isolated either before or after this period did not produce antibody without the addition of T-cell cytokines. Induction of AFC in GC occurred at the time when GC B cells acquire follicular dendritic cell (FDC)-derived, immune complex-coated bodies (iccosomes) and process and present this antigen to helper T cells. This suggested a causal relationship between iccosome release and AFC induction. Support for this was obtained by examination of AFC induction in aged mice where iccosome release has not been observed. Peanut agglutinin-positive GC B cells isolated from aged mice on Days 3-5 after antigen challenge failed to spontaneously produce specific antibody. Collectively, these data show that GC development 3-5 days after booster immunization results in AFC generation and suggests a role for FDC iccosomes in their induction.
Structural and enzymological characterization of deoxyribonucleic acid dependent adenosine triphosphatase from KB cell nuclei (1980)

We have purified to near homogeneity the single DNA-dependent ATPase activity that we have identified in extracts of KB cell nuclei. The protein structure of the enzyme was defined by sodium dodecyl sulfate gel electrophoresis, which revealed a single protein band of 75000 daltons that was coincident with the profile of ATPase activity resolved by the final step of agarose-ATP chromatography or by isoelectric focusing. The enzyme has a pI of 8.5, a Stokes' radius by gel filtration of 3.8 nm, and a sedimentation coefficient in high salt of 5.3 S. At low ionic strength the enzyme activity sediments at 7.0 S, suggesting that it may dimerize under these conditions. The purified enzyme has a specific activity of 5.9 X 10(5) nmol of ATP hydrolyzed per h per mg of protein and is devoid of endonuclease, exonuclease, RNA or DNA polymerase, nicking-closing, and gyrase activities at exclusion limits of 10(-6)-10(-8) of the ATPase activity. The enzyme can hydrolyze only ATP or dATP, to generate ADP or dADP plus Pi, but the other NTPs and dNTPs are competitive inhibitors of the enzyme with respect to ATP. A divalent cation (Mg2+ greater than Mn2+ greater than Ca2+) as well as a nucleic acid cofactor is required for activity. Single-stranded DNA or deoxyhomopolymers are most effective, but blunt-ended linear and nicked circular duplex DNA molecules are also used at Vmax values approximately 20% of that obtained with single-stranded DNA. Intact duplex DNA and polyribonucleotides are unable to support ATP hydrolysis. Velocity gradient sedimentation studies corroborate the interpretations of the kinetic analyses and demonstrate enzyme binding to single-stranded DNA and nicked duplex DNA but not to intact duplex DNA. Although we have not succeeded directly in demonstrating DNA unwinding by this protein, preliminary results suggest that in the presence of ATP, the ATPase can stimulate the reactivity of homogeneous human DNA polymerases alpha and beta on nicked duplex DNA substrates.