gebhart/patrepeval huggingface dataset:
Development and Application of Stable Phantoms for the Evaluation of Photoacoustic Imaging Instruments (2013)

Photoacoustic imaging combines the high contrast of optical imaging with the spatial resolution and penetration depth of ultrasound. This technique holds tremendous potential for imaging in small animals and importantly, is clinically translatable. At present, there is no accepted standard physical phantom that can be used to provide routine quality control and performance evaluation of photoacoustic imaging instruments. With the growing popularity of the technique and the advent of several commercial small animal imaging systems, it is important to develop a strategy for assessment of such instruments. Here, we developed a protocol for fabrication of physical phantoms for photoacoustic imaging from polyvinyl chloride plastisol (PVCP). Using this material, we designed and constructed a range of phantoms by tuning the optical properties of the background matrix and embedding spherical absorbing targets of the same material at different depths. We created specific designs to enable: routine quality control; the testing of robustness of photoacoustic signals as a function of background; and the evaluation of the maximum imaging depth available. Furthermore, we demonstrated that we could, for the first time, evaluate two small animal photoacoustic imaging systems with distinctly different light delivery, ultrasound imaging geometries and center frequencies, using stable physical phantoms and directly compare the results from both systems.
Measuring Recent Thymic Emigrants in Blood of Normal and HIV-1–Infected Individuals before and after Effective Therapy (1999)

The role of the thymus in HIV-1 pathogenesis remains unclear. We developed an assay to quantify the number of recent thymic emigrants in blood based on the detection of a major excisional DNA byproduct (termed alpha1 circle) of T cell receptor rearrangement. By studying 532 normal individuals, we found that alpha1 circle numbers in blood remain high for the first 10-15 yr of life, a sharp drop is seen in the late teen years, and a gradual decline occurs thereafter. Compared with age-matched uninfected control individuals, alpha1 circle numbers in HIV-1-infected adults were significantly reduced; however, there were many individuals with normal alpha1 circle numbers. In 74 individuals receiving highly active antiretroviral therapy, we found no appreciable effect on alpha1 circle numbers in those whose baseline values were already within the normal range, but significant increases were observed in those with a preexisting impairment. The increases in alpha1 circle numbers were, however, numerically insufficient to account for the rise in levels of naive T lymphocytes. Overall, it is difficult to invoke thymic regenerative failure as a generalized mechanism for CD4 lymphocyte depletion in HIV-1 infection, as alpha1 circle numbers are normal in a substantial subset of HIV-1-infected individuals.
Peak to average power ratio reduction technique for OFDM using pilot tones and unused carriers (2008)

One of major drawbacks of Orthogonal Frequency Division Multiplexing (OFDM) is the high Peak-to-Average Power Ratio (PAPR) of the transmit signal. Due to the non-linear characteristics of the power amplifier (PA), significant out-of- band and in-band distortions occur when high peak signals exceed the saturation level of the PA. In this paper we present a new PAPR reduction technique which exploits the use of unused- carriers as well as the phase information of pilot signals in OFDM systems to reduce the PAPR while not degrading channel estimation or frequency offset. Compared to conventional techniques such as clipping and windowing, this technique introduces much less out-of-band distortions and provides a lower bit-error-rate (BER) since there is no interference to the original data signals. There is also no requirement for side information to be transmitted to the receiver.
A Real Estate Market Research Method to Screen Areas for New Construction Potential (1988)

This study uses a structured analysis to systematically examine demand factors needed to support any increase in supply of real estate space. The recent changes in population, employment, income and sales are compared with the record of seven major types of construction activity in a metropolitan area. A multiple regression model of economic-base variables and lagged construction activity identify the types of building activity that are not keeping up with economic-base variable changes, thus offering opportunity for new construction. The study results demonstrate the value in this method in searching for a metropolitan area and building type with the best construction opportunity.
A sophisticated electromechanical ventricular simulator for ventricular assist system testing. (1992)

With the advent of chronically implanted left ventricular assist systems, new adaptive control algorithms are being developed to allow automatic device control under a variety of hemodynamic conditions. An electromechanical pump is described that accurately mimics ventricular function. A pusher-plate sac pump with tri-leaflet valves is coupled to a high-speed linear motor. Pump chamber volume and pressure are constrained to follow the time-varying elastance model of ventricular function by use of a microprocessor feedback loop.
Overcrowded molecules. III. 13,14-Bis(2-pyridyl)pentaphene and related compounds (1971)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOvercrowded molecules. III. 13,14-Bis(2-pyridyl)pentaphene and related compoundsDonald L. Fields, Thomas H. Regan, and R. E. GravesCite this: J. Org. Chem. 1971, 36, 20, 2995–3001Publication Date (Print):October 1, 1971Publication History Published online1 May 2002Published inissue 1 October 1971https://pubs.acs.org/doi/10.1021/jo00819a019https://doi.org/10.1021/jo00819a019research-articleACS PublicationsRequest reuse permissionsArticle Views99Altmetric-Citations19LEARN 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
Assembly of RecA-like recombinases: Distinct roles for mediator proteins in mitosis and meiosis (2001)

Members of the RecA family of recombinases from bacteriophage T4, Escherichia coli , yeast, and higher eukaryotes function in recombination as higher-order oligomers assembled on tracts of single-strand DNA (ssDNA). Biochemical studies have shown that assembly of recombinase involves accessory factors. These studies have identified a class of proteins, called recombination mediator proteins, that act by promoting assembly of recombinase on ssDNA tracts that are bound by ssDNA-binding protein (ssb). In the absence of mediators, ssb inhibits recombination reactions by competing with recombinase for DNA-binding sites. Here we briefly review mediated recombinase assembly and present results of new in vivo experiments. Immuno-double-staining experiments in Saccharomyces cerevisiae suggest that Rad51, the eukaryotic recombinase, can assemble at or near sites containing ssb (replication protein A, RPA) during the response to DNA damage, consistent with a need for mediator activity. Correspondingly, mediator gene mutants display defects in Rad51 assembly after DNA damage and during meiosis, although the requirements for assembly are distinct in the two cases. In meiosis, both Rad52 and Rad55/57 are required, whereas either Rad52 or Rad55/57 is sufficient to promote assembly of Rad51 in irradiated mitotic cells. Rad52 promotes normal amounts of Rad51 assembly in the absence of Rad55 at 30°C but not 20°C, accounting for the cold sensitivity of rad55 null mutants. Finally, we show that assembly of Rad51 is induced by radiation during S phase but not during G 1 , consistent with the role of Rad51 in repairing the spontaneous damage that occurs during DNA replication.
Excess Deaths Associated With Underweight, Overweight, and Obesity (2005)

Underweight and obesity, particularly higher levels of obesity, were associated with increased mortality relative to the normal weight category. The impact of obesity on mortality may have decreased over time, perhaps because of improvements in public health and medical care. These findings are consistent with the increases in life expectancy in the United States and the declining mortality rates from ischemic heart disease.
Estrogens Modulate the Responsiveness of in vivo Recorded Striatal Neurons to lontophoretic Application of Dopamine in Rats: Role of D1 and D22 Receptor Activation (1990)

Abstract Estrogens are known to affect the functioning of the extrapyramidal motor system. Their actions concern both pre- and postsynaptic components of the dopaminergic nigrostriatal neurotransmission. Postsynaptically, estradiol alters the electrophysiological responses of striatal neurons to dopamine application. The aim of this study was to determine the respective roles of D(1) and D(2) receptor subtypes in this modification of dopamine action. Eighty-three spontaneously firing caudate neurons of ovariectomized female rats were extracellularly recorded during iontophoretic ejection of dopamine or dopaminergic agonists or antagonists. Between 5 and 10 h after a single 17beta-estradiol injection (60 mug/kg), the predominant effect of dopamine was an activation of firing (63%), and the distribution of responses significantly differed from controls and from neurons recorded less than 5 h after estradiol injection (P<0.001) on which dopamine mainly elicited inhibitory effects (71% and 63%, respectively). The excitatory effects of dopamine on this subset of spontaneously firing striatal neurons were blocked by the D(1) antagonist SCH 23390 (56%), whereas the inhibitory actions were antagonized by sulpiride (62%), whose isolated application often had an excitatory effect (54%). The distributions of the responses to specific D(1) or D(2) agonists were not altered by estrogen treatment: the predominant effect of the D(2) agonist RU 24213 was in all groups a reduction of firing rate (54%), and the D(1) agonist SKF 38393 mainly induced either a decrease in mean firing rate (21%) or a biphasic effect consisting on an excitation-inhibition sequence (53%). These results suggest that estradiol does not qualitatively alter the coupling of D(1) or D(2) receptors to their electrophysiological effectors, but rather quantitatively changes the ratio between the D(1) and D(2) receptor-mediated components of dopamine actions, reinforcing the D(1) and/or attenuating the D(2) receptor-mediated component.
Isolation and partial characterization of follistatin: a single-chain Mr 35,000 monomeric protein that inhibits the release of follicle-stimulating hormone. (1987)

A Mr 35,000 protein with follicle-stimulating hormone release-inhibitory activity was isolated from porcine ovarian follicular fluid by heparin-Sepharose affinity chromatography, gel filtration on Sephacryl S-200, and multiple steps of high-performance liquid chromatography. The isolated molecule is highly enriched in cysteines and is composed of a single polypeptide chain. In addition, it has no sequence homology with the previously characterized follicular fluid inhibins, which are heterodimeric proteins of Mr 32,000 with follicle-stimulating hormone release-inhibiting activity. This protein specifically inhibits the basal secretion of follicle-stimulating hormone, but not that of luteinizing hormone, in the rat anterior pituitary monolayer culture system with a half-maximal effective dose of 2.5-6.0 ng/ml. Another form of the molecule of Mr 32,000 present in much lower concentration in follicular fluid was also isolated. It may differ from the Mr 35,000 form in glycosylation or carboxyl-terminal truncation. We suggest that this compound be called "follistatin" to signify its structural difference from inhibin.
Involvement of the polyamine transport system in cellular uptake of the radioprotectants WR-1065 and WR-33278 (1995)

High levels of the aminothiol WR-1065 protect cells from ionizing radiation, while much lower levels of this compound or its disulfide, WR-33278, impart anti-mutagenic effects. In view of the structural similarity of these agents to the essential cellular polyamines putrescine, spermidine and spermine we investigated the possibility transport system. WR-33278 appears to be a very close analog of spermidine or spermine in that it not only inhibits spermidine incorporation, but is also transported at the same velocity as spermidine, with a Kt of approximately 0.8 microM compared with 0.4 microM for the polyamine. Further, repression of the activity of the polyamine transporter by antizyme or its elimination by selected mutation affected both transport of WR-33278 and spermidine equally. In contrast, WR-1065 is not a good substrate for the polyamine transporter and appears to enter cells predominantly by non-mediated passive diffusion. There appears to be no uptake of either WR-33278 or the polyamines by this non-mediated diffusion. Thus both the form of the aminothiol and the activity of the polyamine transport system need to be considered in evaluating the efficacy of low exogenous levels of this drug on mutagenesis or carcinogenesis.
Observations after human immunodeficiency virus immunization and challenge of human immunodeficiency virus seropositive and seronegative chimpanzees. (1991)

Two human immunodeficiency virus (HIV)-seropositive chimpanzees (A-3 and A-86c) infected 4 yr earlier with HIV, along with one uninfected animal (A-36), were inoculated intramuscularly three times in a year with a gamma-irradiated gp120-depleted HIV immunogen in incomplete Freund's adjuvant. Both previously infected animals promptly developed an anamnestic humoral antibody response after the first dose, and the uninfected animal developed a primary humoral response to the first dose and then an anamnestic response to the second dose. Although HIV had been recovered repeatedly from the seropositive animals, they became persistently virus-culture negative at the time of or just before the first inoculation of the immunogen. Intravenous challenge with 40 chimpanzee-infectious-doses of a heterologous HIV strain (HIVIIIB) was done 4 mo after the third inoculation in the three treated chimpanzees and in an untreated control animal (A-189a). The immunized naive animal (A-36) and the unimmunized control (A-189a) became infected, and virus has been isolated from their peripheral blood mononuclear cells for greater than 2 yr after challenge. However, the two previously infected chimpanzees (A-3 and A-86c) resisted challenge and have remained virus negative by peripheral blood mononuclear cell cocultivation for greater than 2 yr of observation after challenge; moreover, no evidence of reinfection was detectable by PCR. Despite the in vivo resistance, however, peripheral blood mononuclear cells from the resistant animals (A-3, A-86c) remained susceptible to infection by HIV in vitro. These findings reveal that a state of immunity can develop and/or be induced to control and/or prevent HIV infection in the chimpanzees. In the absence of any detectable level of neutralizing antibody in A-3 and a low level in A-86c, the patterns of the responses to challenge seen in the four animals suggest that the cell-mediated immune mechanism must have played a significant role in the resistant chimpanzees both in control of their HIV infection and in their resistance to challenge.
Murine PGK‐1 promoter drives widespread but not uniform expression in transgenic mice (1994)

Pgk-1 is an X-linked gene encoding 3-phosphoglycerate kinase, an enzyme necessary in every cell for glycolysis. The regulatory sequences of the Pgk-1 gene were used to drive the E. coli lacZ reporter gene and 2 strains of transgenic animals created with this Pgk-lacZ transgene carried on autosomes. The levels of expression of Pgk-1 varied from one adult tissue to another and the transgene was similarly regulated. However, in situ staining of the beta-galactosidase encoded by the transgene indicated extensive cell-to-cell variability in its level of expression. A reproducible subset of cells stained darkly for the transgene product. Some of these beta-galactosidase positive cells were rapidly proliferating while others appeared to be metabolically very active, suggesting that the Pgk-1 promoter is regulated so as to be more active in cells requiring high levels of glycolysis. Although Pgk-1 is X-linked and subject to X chromosome inactivation, the transgenes were not inactivated in either female somatic or male germ cells. Thus, the Pgk-1 promoter drives transgene expression in all tissues but the levels of expression are not uniform in each cell.
Insulin-like growth factor-I receptor. Its role in cell proliferation, apoptosis, and tumorigenicity. (1995)

From the point of view of cell growth, the IGF-IR activated by its ligands has three important functions: (a) it is required for optimal growth both in vivo and in vitro, although some growth occurs even in its absence; (b) it is obligatory for the establishment and maintenance of the transformed phenotype and for tumorigenesis for several types of cells; and (c) it protects cells from apoptosis, both in vivo and in vitro. The IGF-I receptor does seem to occupy a central role in these processes. Whereas an overexpressed IGF-I receptor is mitogenic for IGF-I alone and is fully transforming and protects cells from apoptosis, the same cannot be said for overexpressed EGF and PDGF receptors (205, 206). These two receptors can neither induce growth or transform most cells lacking IGF-I receptors. The reversal of the transformed phenotype and the induction of apoptosis that occur when the levels of IGF-I receptors are artificially decreased also point out the essential role of the receptor in these three processes. An important distinction in this regard is that it is not so much an overexpressed IGF-I receptor that is important in transformation but the lack of it that does not allow the transformed phenotype. This distinction is extremely important if we wish to use the IGF-IR as an approach to therapeutic interventions. Returning to more basic questions, a mutational analysis of the IGF-I receptor has shown that specific domains are involved in its mitogenicity or its ability to facilitate transformation and that these two processes can be separated at the level of the receptor itself. This finding raises a crucial question: Is the transforming activity using a pathway that is separate from the mitogenic signaling pathway? Alternatively, is it simply a question of a quantitative effect? The answer to this question could be a very important contribution to the mechanism of transformation. Little is known about the mechanism(s) by which the IGF-I receptor protects cells from apoptosis; here again, some fundamental questions can be raised. Are there specific domains in the receptor for its antiapoptotic activity? Is this activity tied to mitogenesis and/or transformation? Which elements in the signal transduction pathway are involved in these three different functions of the IGF-I receptor? Although many problems are still unresolved, the last few years have seen a very rapid rise in the importance of the IGF-I receptor in both normal and abnormal growth.(ABSTRACT TRUNCATED AT 400 WORDS)
[ONXO]-Type Amine Bis(phenolate) Zirconium and Hafnium Complexes as Extremely Active 1-Hexene Polymerization Catalysts (2002)

Several [ONXO]-type zirconium and hafnium dibenzyl complexes of amine bis(phenolate) ligands, where X is a heteroatom donor located on a pendant arm, were synthesized directly from the ligand precursors and the corresponding tetrabenzylmetal complexes in quantitative yields (X = N, O, S). All complexes exhibited remarkable activities in the polymerization of 1-hexene, yielding high-molecular-weight polymers, the highest activity being unprecedented under the conditions employed. An unexpected metal-dependent activity pattern was demonstrated. The high activity of the complexes is derived from the binding of the side-arm donor to the metal and is affected by its nature. The activity order of the zirconium complexes as a function of the side-arm donor was found to be OMe > NMe2 > SMe (5:2:1). The X-ray structures of all zirconium complexes were solved and revealed very similar binding of the [ONO] ligand cores to the metal. The distances between the side-arm donor atoms and the zirconium are relatively long (Zr−O, 2.45 Å; Zr−N, 2.59 Å; Zr−S, 2.86 Å). The X-ray structures of all hafnium complexes were solved as well and found to be closely related to those of the zirconium analogues (Hf−O, 2.45 Å; Hf−N, 2.56 Å; Hf−S, 2.84 Å). However, the activity order was found to be different in the hafnium series, namely SMe > OMe > NMe2 (3.5:1.5:0.2), the [ONSO]-type complex exhibiting the highest activity ever reported for a hafnium complex under the conditions employed. Various NMR experiments supported the notion that the side-arm donor remains attached to the metal in the reactive compounds, which exist as well-separated ion pairs.
The relationship between defects in lymphocyte production of transforming growth factor-β1 in systemic lupus erythematosus and disease activity or severity (1999)

Transforming growth factor beta (TGF-beta) comprises of a family of proteins with pleiotropic signaling properties and potent immunoregulatory effects. In SLE we recently reported that lymphocyte production of the total and active forms of TGF-beta1 was decreased. Here we asked whether these defects correlate with disease activity and/or severity. TGF-beta1 production by blood lymphocytes from 17 prospectively studied SLE patients was compared with 10 rheumatoid arthritis (RA) patients and 23 matched healthy controls. The RA levels of active TGF-beta1 were lower than controls, but were not deceased to the extent found in SLE. Levels of constitutive and anti-CD2 stimulated active TGF-beta1 detected in picomolar amounts were markedly reduced in six untreated patients hospitalized with recent onset, very active and severe SLE and similarly reduced in 11 patients with treated, less active disease. By contrast, decreased production of total TGF-beta1 inversely correlated with disease activity. These studies suggest, therefore, that although impaired lymphocyte secretion of the latent precursor of TGF-beta1 may result as a consequence of disease activity, a decreased capacity to convert the precursor molecule to its active form may pre-date disease onset. Insufficient exposure of T cells to picomolar concentrations of TGF-beta1 at the time they are activated can result in impaired down-regulation of Ig synthesis. Therefore, decreased lymphocyte production of active TGF-beta1 in SLE could be an immunologic defect which contributes to the B cell hyperactivity characteristic of this disease.
Heteroleptic Ir(iii) phosphors with bis-tridentate chelating architecture for high efficiency OLEDs (2015)

Emissive Ir(<sc>iii</sc>) complexes bearing two tridentate chelates were synthesized. The multiple coordination mode of the chelate warrants a new class of metal-based phosphors for OLED applications.
Dosing Strategies of Clozapine-Fluvoxamine Cotreatment (2002)

Lu, Mong-Liang MD, MS; Lane, Hsien-Yuan MD, PhD; Jann, Michael W. PharmD; Chang, Wen-Ho MD Author Information