gebhart/patrepeval huggingface dataset:
Canonical Wnt signaling functions in second heart field to promote right ventricular growth (2007)

The second heart field (SHF), progenitor cells that are initially sequestered outside the heart, migrates into the heart and gives rise to endocardium, myocardium, and smooth muscle. Because of its distinct developmental history, the SHF is likely subjected to different signals from that of the first heart field. Previous experiments revealed that canonical Wnt signaling negatively regulated first heart field specification. We inactivated the obligate canonical Wnt effector beta-catenin using a beta-catenin conditional null allele and the Mef2c AHF cre driver that directs cre activity specifically in SHF. We also expressed a stabilized form of beta-catenin to model continuous Wnt signaling in SHF. Our data indicate that Wnt signaling acts in a positive fashion to promote right ventricular and interventricular myocardial expansion. Cyclin D2 and Tgfbeta2 expression was drastically reduced in beta-catenin loss-of-function mutants, indicating that Wnt signaling is required for patterning and expansion of SHF derivatives. Our findings reveal that Wnt signaling plays a major positive role in promoting growth and diversification of SHF precursors into right ventricular and interventricular myocardium.
Bipolar charge and current distributions in organic light-emitting diodes (1997)

The electron and hole charge distributions and the luminance profile in organic light-emitting diodes (OLEDs) depend upon the bulk properties of the emissive layer, as well as on the injection characteristics at the anode and cathode interfaces. We address the problem of separating the relative contributions of hole injection, electron injection, and recombination to the overall performance of single layer OLED devices. Using the approach of Parmenter and Ruppel [J. Appl. Phys. 30, 1548 (1959)], and including Langevin recombination, expressions are derived for the current–voltage and radiance–current dependencies in terms of electron and hole mobility, luminescence yield, and a “current balance” factor. When one carrier dominates the current flow, as in many practical cases, it is possible to obtain a simple asymptotic relationship which permits a test of the assumptions required to obtain the analytic solution. Experimental data from poly(2-methoxy-5(2′-ethyl)hexoxy-phenylenevinylene) diodes fabricated with various anode and cathode materials are evaluated in the context of this analytical approach.
Clinical outcome of patients 20 years after Fontan operation — effect of fenestration on late morbidity (2006)

Long-term survival after Fontan procedure is encouraging, but late morbidity remains suboptimal. During follow-up, emerging complications should be managed by surgical and interventional procedures. Fenestration in Fontan circulation provided better cardiac output and lower incidence of late tachyarrhythmias, suggesting a benefit of fenestration for late outcome.
Radiation thermodynamics with applications to lasing and fluorescent cooling (2005)

Laser cooling of bulk matter uses thermally assisted fluorescence to convert heat into light and can be interpreted as an optically pumped laser running in reverse. Optical pumping in such devices drives the level populations out of equilibrium. Nonthermal radiative energy transfers are thereby central to the operation of both lasers and luminescent coolers. A thermodynamic treatment of their limiting efficiencies requires a careful development of the entropy and effective temperatures of radiation, valid for the entire range of light from the blackbody to the ideal laser limiting cases. In particular, the distinct meaning and utility of the brightness and flux temperatures should be borne in mind. Numerical examples help illustrate these concepts at a level suitable for undergraduate physics majors.
Performance Enhancement of Multiuser Time Reversal UWB Communication System (2007)

UWB communication is a recent research area for indoor propagation channels. Time reversal (TR) communication in UWB has shown promising results for improving the system performance. In multiuser environment, the system performance is significantly degraded due to the interference among different users. TR reduces the interference caused by multiusers due to its spatial focusing property. The performance of a multiuser TR communication system is further improved if the TR filter is modified. In this paper, multiuser TR in UWB communication is investigated using simple TR filter and a modified TR filter with circular shift operation. The concept of circular shift in TR is analytically studied. Thereafter, the channel impulse responses (CIR) of a typical indoor laboratory environment are measured. The measured CIRs are used to analyze the received signal peak power and signal to interference ratio (SIR) with and without performing the circular shift operation in a multiuser environment.
High-level expression of functional rat neuronal nitric oxide synthase in Escherichia coli. (1995)

The neuronal nitric oxide synthase (nNOS) has been successfully overexpressed in Escherichia coli, with average yields of 125-150 nmol (20-24 mg) of enzyme per liter of cells. The cDNA for nNOS was subcloned into the pCW vector under the control of the tac promotor and was coexpressed with the chaperonins groEL and groES in the protease-deficient BL21 strain of E. coli. The enzyme produced is replete with heme and flavins and, after overnight incubation with tetrahydrobiopterin, contains 0.7 pmol of tetrahydrobiopterin per pmol of nNOS. nNOS is isolated as a predominantly high-spin heme protein and demonstrates spectral properties that are identical to those of nNOS isolated from stably transfected human kidney 293 cells. It binds N omega-nitroarginine dependent on the presence of bound tetrahydrobiopterin and exhibits a Kd of 45 nM. The enzyme is completely functional; the specific activity is 450 nmol/min per mg. This overexpression system will be extremely useful for rapid, inexpensive preparation of large amounts of active nNOS for use in mechanistic and structure/function studies, as well as for drug design and development.
Fluctuations and determinism of respiratory impedance in asthma and chronic obstructive pulmonary disease (2010)

Asthma and COPD are chronic respiratory diseases that fluctuate widely with regard to clinical symptoms and airway obstruction, complicating treatment and prediction of exacerbations. Time series of respiratory impedance obtained by the forced oscillation technique are a convenient tool to study the respiratory system with high temporal resolution. In previous studies it was suggested that power-law-like fluctuations exist also in the healthy lung and that respiratory system impedance variability differs in asthma. In this study we elucidate such differences in a population of well-characterized subjects with asthma (n = 13, GINA 1+2), COPD (n = 12, GOLD I+II), and controls (n = 10) from time series at single frequency (12 min, f = 8 Hz). Maximum likelihood estimation did not rule out power-law behavior, accepting the null hypothesis in 17/35 cases (P > 0.05) and with significant differences in exponents for COPD (P < 0.03). Detrended fluctuation analysis exhibited scaling exponents close to 0.5, indicating few correlations, with no differences between groups (P > 0.14). In a second approach, we considered asthma and COPD as dynamic diseases, corresponding to changes of unknown parameters in a deterministic system. The similarity in shape between the combined probability distributions of normalized resistance and reactance was quantified by Wasserstein distances and reliably distinguished the two diseases (cross-validated predictive accuracy 0.80; sensitivity 0.83, specificity 0.77 for COPD). Wasserstein distances between 3+3 dimensional phase space reconstructions resulted in marginally better classification (accuracy 0.84, sensitivity 0.83, specificity 0.85). These latter findings suggest that the dynamics of respiratory impedance contain valuable information for the diagnosis and monitoring of patients with asthma and COPD, whereas the value of the stochastic approach is not clear presently.
Prognostic significance of altered expression of SDC2 and CYR61 in esophageal squamous cell carcinoma (2009)

The transforming growth factor beta (TGF-beta) signaling pathway plays an important role in growth and development, and is critically involved in the genesis and development of tumors. Syndecan-2 (SDC2) and Cysteine-rich 61 (CYR61) are important genes in this pathway and SDC2 is known to be a significant upstream regulator of TGF-beta signaling. However, the roles of SDC2 and CYR61 in the development of esophageal squamous cell carcinoma (ESCC) remain unclear. In the present study, we investigated the relationship between SDC2 and CYR61 mRNA expression levels and disease prognosis in patients with ESCC. The mRNA expression of SDC2 and CYR61 was detected by quantitative real-time RT-PCR in 77 tissue specimens. Quantitative real-time RT-PCR showed that SDC2 and CYR61 mRNA expression levels were aberrant in ESCC tissue (P<0.01) and that SDC2 mRNA expression was significantly associated with tumor size (P=0.024) in ESCC. CYR61 mRNA expression was significantly associated with regional lymph node metastasis (P=0.034) and tumor size (P=0.03). A positive correlation between SDC2 and CYR61 (r=0.770; P<0.001) mRNA expression was observed. Moreover, we observed significant associations between altered expression of SDC2/CYR61 and regional lymph node metastasis (P=0.009) and TNM stages (P=0.033). Aberrant mRNA expression of CYR61 and SDC2/CYR61 (P=0.005 and P=0.026, respectively) were significantly associated with patient survival time. The multivariate Cox regression analysis showed that SDC2 and CYR61 were independent prognostic factors for survival. Our findings suggest that SDC2 may act as an a upstream regulator of the TGF-beta signaling pathway and regulate the expression of downstream target genes. Moreover, SDC2 and CYR61 expression affect the severity of cancer, and the survival of patients with ESCC. Importantly, we report that SDC2 and CYR61 are significant, independent prognostic factors for survival in ESCC. These findings may have implications for targeted therapies in patients with ESCC.
Suicide Gene Therapy for Urogenital Cancer: Current Outcome and Prospects (2000)

Viral-mediated transfer of the herpes simplex virus thymidine kinase (HSV-tk) gene has been demonstrated by several investigators to confer sensitivity to nucleoside analogs such as ganciclovir (GCV) in a variety of tumor cells including brain, prostate, bladder, kidney, ovary, head and neck, lung, pancreas, and liver cancers. Fourteen suicide gene clinical protocols using adenovirus vectors have been conducted, including four in prostate cancer. Two additional protocols for prostate cancer are in preparation in Japan and the Netherlands. A study conducted at Baylor College of Medicine was the first to demonstrate the safety of HSV-tk plus GCV therapy for human prostate cancer and the anticancer activity of gene therapy in this disease. However, it is still in the early stage of its development, with a number of problems to be overcome. Systemic delivery, specific introduction, and specific expression of the target gene are the major issues to be managed in order to establish a clinically relevant treatment strategy.
HIV-1 gag-specific cytotoxic T lymphocytes recognize multiple highly conserved epitopes. Fine specificity of the gag-specific response defined by using unstimulated peripheral blood mononuclear cells and cloned effector cells (1991)

CTL directed at the highly conserved HIV-1 gag protein have been described in HIV-1 seropositive persons and may be an important host defense against this retrovirus. Presently only limited data are available regarding the specific epitopes recognized by these CTL. In this study, we have performed a detailed examination of the gag-specific CTL response in three HIV-1 seropositive subjects, using both unstimulated PBMC and cloned CTL. Lysis of gag-expressing targets was found to be mediated by CD3+CD8+ lymphocytes and restricted by class I Ag. Multiple class I Ag were found to restrict gag epitopes in each subject studied, with as many as three of these Ag involved in presenting gag CTL epitopes in a single subject. The majority of gag-specific CTL activity was found to be directed against epitopes in the p24 subunit of the gag protein, with at least seven different HLA class I-restricted CTL p24 epitopes identified in these three subjects. Less CTL activity was directed against p17 subunit of gag and two CTL epitopes were identified in this protein. Although as many as four different epitopes in gag were recognized using CTL from a single subject, none of the epitopes was recognized by CTL from more than one subject. Analysis of gag epitope recognition using cloned CTL demonstrated heterogeneity and specificity not appreciated using unstimulated PBMC. The identification of multiple relatively conserved epitopes in the HIV-1 gag protein and the heterogeneity of CTL responses to this protein may have important implications for vaccine development and our understanding of AIDS pathogenesis.
Free Radical Controlled Polymerization of Fluorinated Copolymers Produced in Microemulsion (2002)

Controlled free-radical polymerization is an emerging technique which can in principle produce macromolecules with well defined microstructure, possibly tailored to specific applications. This work describes the application of such a process to the production of several hundreds of tons of a fluorinated copolymer per year. The aim is to control the microstructure of the product and, in particular, to produce branched macromolecules with relatively uniform chain lengths. The process operates in microemulsion and is complicated by the presence of branching reactions. A complete kinetic model is developed to identify the most appropriate operating conditions to produce copolymers with desired characteristics.
Polyacene and Cyclacene Geometries and Electronic Structures:  Bond Equalization, Vanishing Band Gaps, and Triplet Ground States Contrast with Polyacetylene (2001)

The ground-state geometries and excited singlet and lowest triplet energies of polyacenes from benzene through nonacene are predicted with B3LYP/6-31G* calculations and compared to experimental data where available. The results are compared to these data for cyclacenes and polyenes. The polyacenes and cyclacenes have geometries consisting of two fully delocalized nonalternating ribbons joined by relatively long bonds. Polyacenes are predicted to have smaller band gaps than the corresponding polyenes and triplet ground states for nine or more benzene rings. The fully delocalized nonalternating nature of polyacenes differs from the bond alternation resulting from Peierls distortion in polyenes. The differences are rationalized in terms of a simple MO model, and the results are compared to extensive prior theoretical work in the literature. Predictions about the electronic structure of analogues containing polyacene units are made.
Aberrant tubulointerstitial immunoexpression of matrix metalloproteinases MMP-2, MMP-9 and tissue inhibitor of matrix proteinase-2 (TIMP-2) in acute cellular rejection of human renal allograft. (2008)

Acute cellular rejection (ACR) may initiate chronic allograft dysfunction with alterations in the extracellular matrix compartment (ECM). Turnover of ECM proteins is regulated by matrix metalloproteinases (MMPs). The aim of the present study was to determine the immunoexpression of MMP-2, MMP-9 and TIMP-2 in ACR, and to examine the relationship between expression of MMPs and monocytes/macrophages, transforming growth factor beta-1 (TGFbeta-1), and alpha-smooth muscle actin (alpha-SMA). Immunoperoxidase study with antibodies against MMP-2, MMP-9, TIMP-2, CD68, TGFbeta-1 and alpha-SMA was carried out on 24 renal allograft biopsy specimens from patients with ACR and 11 allograft biopsy specimens from patients with no signs of rejection. Our study revealed increased immunoexpression of MMP-2, MMP-9 and TIM-2 in ACR as compared with controls, and significant positive correlations between immunostaining of MMP-2 and TGF-beta-1, as well as between MMP-2 and alpha-SMA. Increased immunoexpression of MMP-9 was positively correlated with alpha-SMA, and the number of interstitial CD68+cells. In conclusion our study supports a role of gelatinases in tissue damage in human renal acute cellular allograft rejection and provides some interesting insights into early renal remodeling which may lead to chronic allograft dysfunction.
SIRT1 Exerts Anti-Inflammatory Effects and Improves Insulin Sensitivity in Adipocytes (2008)

SIRT1 is a prominent member of a family of NAD(+)-dependent enzymes and affects a variety of cellular functions ranging from gene silencing, regulation of the cell cycle and apoptosis, to energy homeostasis. In mature adipocytes, SIRT1 triggers lipolysis and loss of fat content. However, the potential effects of SIRT1 on insulin signaling pathways are poorly understood. To assess this, we used RNA interference to knock down SIRT1 in 3T3-L1 adipocytes. SIRT1 depletion inhibited insulin-stimulated glucose uptake and GLUT4 translocation. This was accompanied by increased phosphorylation of JNK and serine phosphorylation of insulin receptor substrate 1 (IRS-1), along with inhibition of insulin signaling steps, such as tyrosine phosphorylation of IRS-1, and phosphorylation of Akt and ERK. In contrast, treatment of cells with specific small molecule SIRT1 activators led to an increase in glucose uptake and insulin signaling as well as a decrease in serine phosphorylation of IRS-1. Moreover, gene expression profiles showed that SIRT1 expression was inversely related to inflammatory gene expression. Finally, we show that treatment of 3T3-L1 adipocytes with a SIRT1 activator attenuated tumor necrosis factor alpha-induced insulin resistance. Taken together, these data indicate that SIRT1 is a positive regulator of insulin signaling at least partially through the anti-inflammatory actions in 3T3-L1 adipocytes.
SomaticHIF2AGain-of-Function Mutations in Paraganglioma with Polycythemia (2012)

Hypoxia-inducible factors are transcription factors controlling energy, iron metabolism, erythropoiesis, and development. When these proteins are dysregulated, they contribute to tumorigenesis and cancer progression. However, mutations in genes encoding α subunits of hypoxia-inducible factors (HIF-α) have not previously been identified in any cancer. Here we report two novel somatic gain-of-function mutations in the gene encoding hypoxia-inducible factor 2α (HIF2A) in two patients, one presenting with paraganglioma and the other with paraganglioma and somatostatinoma, both of whom had polycythemia. The two mutations were associated with increased HIF-2α activity and increased protein half-life.
Microrheological Characterization of Collagen Systems: From Molecular Solutions to Fibrillar Gels (2013)

Collagen is the most abundant protein in the extracellular matrix (ECM), where its structural organization conveys mechanical information to cells. Using optical-tweezers-based microrheology, we investigated mechanical properties both of collagen molecules at a range of concentrations in acidic solution where fibrils cannot form and of gels of collagen fibrils formed at neutral pH, as well as the development of microscale mechanical heterogeneity during the self-assembly process. The frequency scaling of the complex shear modulus even at frequencies of ∼10 kHz was not able to resolve the flexibility of collagen molecules in acidic solution. In these solutions, molecular interactions cause significant transient elasticity, as we observed for 5 mg/ml solutions at frequencies above ∼200 Hz. We found the viscoelasticity of solutions of collagen molecules to be spatially homogeneous, in sharp contrast to the heterogeneity of self-assembled fibrillar collagen systems, whose elasticity varied by more than an order of magnitude and in power-law behavior at different locations within the sample. By probing changes in the complex shear modulus over 100-minute timescales as collagen self-assembled into fibrils, we conclude that microscale heterogeneity appears during early phases of fibrillar growth and continues to develop further during this growth phase. Experiments in which growing fibrils dislodge microspheres from an optical trap suggest that fibril growth is a force-generating process. These data contribute to understanding how heterogeneities develop during self-assembly, which in turn can help synthesis of new materials for cellular engineering.
A dedicated animal model for mechanical thrombectomy in acute stroke. (2006)

The model presented here allows selective and reliable thromboembolization of vessels that reproduce the anatomic and hemodynamic situation in acute cerebrovascular stroke. It permits visualization of the thrombus during angiography and intervention, providing unique insight into the behavior of both thrombus and device, which is potentially useful in the development and evaluation of mechanical clot retrieval in acute cerebrovascular stroke.
Prostaglandins. XI. Synthesis of 13-cis-prostaglandins via a highly stereoselective conjugate addition with a functionalized organocopper reagent (1972)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTProstaglandins. XI. Synthesis of 13-cis-prostaglandins via a highly stereoselective conjugate addition with a functionalized organocopper reagentArthur F. Kluge, Karl G. Untch, and John H. FriedCite this: J. Am. Chem. Soc. 1972, 94, 26, 9256–9258Publication Date (Print):December 1, 1972Publication History Published online1 May 2002Published inissue 1 December 1972https://pubs.acs.org/doi/10.1021/ja00781a062https://doi.org/10.1021/ja00781a062research-articleACS PublicationsRequest reuse permissionsArticle Views525Altmetric-Citations74LEARN 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