gebhart/patrepeval huggingface dataset:
Synthesis of optically pure pipecolates from L-asparagine. Application to the total synthesis of (+)-apovincamine through amino acid decarbonylation and iminium ion cyclization (1985)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of optically pure pipecolates from L-asparagine. Application to the total synthesis of (+)-apovincamine through amino acid decarbonylation and iminium ion cyclizationBradley D. Christie and Henry RapoportCite this: J. Org. Chem. 1985, 50, 8, 1239–1246Publication Date (Print):April 1, 1985Publication History Published online1 May 2002Published inissue 1 April 1985https://pubs.acs.org/doi/10.1021/jo00208a017https://doi.org/10.1021/jo00208a017research-articleACS PublicationsRequest reuse permissionsArticle Views1550Altmetric-Citations67LEARN 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
Tracing human oligodendroglial development in vitro (2000)

Human neural precursor cell cultures (neurospheres) were established from fetal brain tissues of 15–20 gestation weeks and propagated for over a year in the presence of epidermal growth factor, basic fibroblast growth factor and leukemia inhibitory factor. Neurospheres were differentiated without the presence of above growth factors to follow the development of oligodendroglia. Oligodendroglial progenitors, identified by their bipolar morphology and expression of platelet-derived growth factor receptor-α (PDGFRα), emerged from spheres as early as 1 DIV; O4+ cells with bipolar to multipolar processes were observed at 3 DIV whereas O1+ multiprocess-bearing oligodendroglia did not appear until 5–7 DIV. They further differentiated to myelin basic protein-expressing oligodendrocytes after 2–3 weeks in culture. Thus, human oligodendroglial maturation in vitro follows the same pathway as rat cells but takes twice as long as their rodent counterparts. Bromodeoxyuridine incorporation indicated that PDGFRα–expressing cells but not O4+ oligodendroglia proliferated. More oligodendroglial progenitors incorporated BrdU and more O4+ cells survived when they were in contact with neurons and astrocytes than when they developed beyond the astrocyte layer. In addition, oligodendroglia on astrocytes had a complex process branching whereas those growing beyond astrocyte layer often formed membrane sheaths. Thus the survival, proliferation and maturation of oligodendroglia are influenced by other cell types. J. Neurosci. Res. 59:421–429, 2000 © 2000 Wiley-Liss, Inc.
Discovering Transcription Factor Binding Sites in Highly Repetitive Regions of Genomes with Multi-Read Analysis of ChIP-Seq Data (2011)

Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) is rapidly replacing chromatin immunoprecipitation combined with genome-wide tiling array analysis (ChIP-chip) as the preferred approach for mapping transcription-factor binding sites and chromatin modifications. The state of the art for analyzing ChIP-seq data relies on using only reads that map uniquely to a relevant reference genome (uni-reads). This can lead to the omission of up to 30% of alignable reads. We describe a general approach for utilizing reads that map to multiple locations on the reference genome (multi-reads). Our approach is based on allocating multi-reads as fractional counts using a weighted alignment scheme. Using human STAT1 and mouse GATA1 ChIP-seq datasets, we illustrate that incorporation of multi-reads significantly increases sequencing depths, leads to detection of novel peaks that are not otherwise identifiable with uni-reads, and improves detection of peaks in mappable regions. We investigate various genome-wide characteristics of peaks detected only by utilization of multi-reads via computational experiments. Overall, peaks from multi-read analysis have similar characteristics to peaks that are identified by uni-reads except that the majority of them reside in segmental duplications. We further validate a number of GATA1 multi-read only peaks by independent quantitative real-time ChIP analysis and identify novel target genes of GATA1. These computational and experimental results establish that multi-reads can be of critical importance for studying transcription factor binding in highly repetitive regions of genomes with ChIP-seq experiments.
Genetic variation in the tumor necrosis factor-? promoter region and in the stress protein hsp70-2 (2001)

Genetic variation in TNF-alpha and hsp70-2 may represent not only markers for the increased risk of breast carcinoma but also may predict the clinical outcome.
Multi-Wavelength QCL Based MIR Spectroscopy for Fluids and Gases (2013)

We demonstrate multi-color DFB QCLs with separated electrical pumping for independent single-mode emission of several wavelengths from the same ridge. This will be implemented in our mid-infrared spectroscopy sensors for gases (CO2) and liquids (cocaine).
Low temperature growth of high crystallinity GeSn on amorphous layers for advanced optoelectronics (2013)

High crystallinity GeSn substitutional alloy thin films with up to 8.7 at.% Sn are directly grown on amorphous SiO2 layers at low crystallization temperatures of 370~470 °C for potential applications in 3D electronic-photonic integration on Si as well as inexpensive virtual substrates for tandem solar cells. The optimal Ge0.913Sn0.087 thin film demonstrates a strong (111) texture and an average gain size of 10 μm, and its grain boundaries are mostly twin and low-angle boundaries with low densities of defect recombination centers. The 8.7 at.% Sn incorporated substitutionally into the Ge lattice far exceeds the ~1 at.% equilibrium solubility limit. Correspondingly, the direct band gap is significantly red-shifted from 0.8 eV for pure Ge to ~0.5 eV for crystalline Ge0.913Sn0.087, right at the verge of the indirect-to-direct gap transition that occurs at 8-10 at.% Sn alloying. Optoelectronic properties are greatly enhanced due to this transition.
Low-Power Wearable Respiratory Sound Sensing (2014)

Building upon the findings from the field of automated recognition of respiratory sound patterns, we propose a wearable wireless sensor implementing on-board respiratory sound acquisition and classification, to enable continuous monitoring of symptoms, such as asthmatic wheezing. Low-power consumption of such a sensor is required in order to achieve long autonomy. Considering that the power consumption of its radio is kept minimal if transmitting only upon (rare) occurrences of wheezing, we focus on optimizing the power consumption of the digital signal processor (DSP). Based on a comprehensive review of asthmatic wheeze detection algorithms, we analyze the computational complexity of common features drawn from short-time Fourier transform (STFT) and decision tree classification. Four algorithms were implemented on a low-power TMS320C5505 DSP. Their classification accuracies were evaluated on a dataset of prerecorded respiratory sounds in two operating scenarios of different detection fidelities. The execution times of all algorithms were measured. The best classification accuracy of over 92%, while occupying only 2.6% of the DSP's processing time, is obtained for the algorithm featuring the time-frequency tracking of shapes of crests originating from wheezing, with spectral features modeled using energy.
A pilot study of the immunological effects of high-dose vitamin D in healthy volunteers (2012)

Although vitamin D deficiency is considered an environmental factor in multiple sclerosis (MS), the immunological and clinical effects of vitamin D supplementation remain unclear. We performed a pilot study of the immunomodulatory effects of vitamin D in healthy individuals (n=4), who took 5000-10,000 IU/day of vitamin D over 15 weeks. After 15 weeks of vitamin D supplementation, serum 25(OH) vitamin D levels rose significantly from baseline, with a corresponding increase in IL-10 production by peripheral blood mononuclear cells and a reduced frequency of Th17 cells. These data provide a strong rationale for randomised trials to assess the clinical effects of vitamin D supplementation in MS.
Long-Term Survival of Xenogeneic Pancreatic Islet Grafts Induced by CTLA4lg (1992)

Antigen-specific T cell activation depends on T cell receptor-ligand interaction and costimulatory signals generated when accessory molecules bind to their ligands, such as CD28 to the B7 (also called BB1) molecule. A soluble fusion protein of human CTLA-4 (a protein homologous to CD28) and the immunoglobulin (lg) G1 Fc region (CTLA4lg) binds to human and murine B7 with high avidity and blocks T cell activation in vitro. CTLA4lg therapy blocked human pancreatic islet rejection in mice by directly affecting T cell recognition of B7+ antigen-presenting cells. In addition, CTLA4lg induced long-term, donor-specific tolerance, which may have applications to human organ transplantation.
DNA Origami with Double-Stranded DNA As a Unified Scaffold (2012)

Scaffolded DNA origami is a widely used technology for self-assembling precisely structured nanoscale objects that contain a large number of addressable features. Typical scaffolds are long, single strands of DNA (ssDNA) that are folded into distinct shapes through the action of many, short ssDNA staples that are complementary to several different domains of the scaffold. However, sources of long single-stranded DNA are scarce, limiting the size and complexity of structures that can be assembled. Here we demonstrated that dsDNA (double-stranded DNA) scaffolds can be directly used to fabricate integrated DNA origami structures that incorporate both of the constituent ssDNA molecules. Two basic principles were employed in the design of scaffold folding paths: folding path asymmetry and periodic convergence of the two ssDNA scaffold strands. Asymmetry in the folding path minimizes unwanted complementarity between staples, and incorporating an offset between the folding paths of each ssDNA scaffold strand reduces the number of times that complementary portions of the strands are brought into close proximity with one another, both of which decrease the likelihood of dsDNA scaffold recovery. Meanwhile, the folding paths of the two ssDNA scaffold strands were designed to periodically converge to promote the assembly of a single, unified structure rather than two individual ones. Our results reveal that this basic strategy can be used to reliably assemble integrated DNA nanostructures from dsDNA scaffolds.
Development of an MFG-Based Retroviral Vector System for Secretion of High Levels of Functionally Active Human BMP4 (2001)

We sought to develop a retroviral vector system that would produce secretion of high levels of bone morphogenetic protein (BMP)-4 by optimizing the expression construct and developing an improved retroviral vector. Replacement of the propeptide domain of BMP4 with that of BMP2 increased the secretion level of mature BMP4 protein in transduced cells. The intact BMP2 pro-peptide sequence was essential, as deletion of a small part of the propeptide sequence of BMP2 from the BMP2/4 hybrid construct diminished BMP4 expression and secretion. Addition of a hemaglutinin tag to the carboxy terminus of BMP4 abolished the bioactivity of secreted BMP4. Transduction of rat marrow stromal cells (and fibroblasts) with an MFG-based retroviral vector pseudotyped with VSV-G envelope containing this BMP2/4 hybrid expression construct led to secretion of very high levels of mature BMP4 in conditioned medium (up to 1 microg/10(6) cells/24 hours). The secreted BMP4 was biologically active, as it induced alkaline phosphatase expression in C2C12 cells. The transduced rat marrow stromal cells expressing mature BMP4 induced de novo ectopic bone formation in syngenic immune-competent rats. We have developed an MFG-based retroviral vector system that causes secretion of high levels of functionally active human BMP4 protein.
Scene completion using millions of photographs (2008)

What can you do with a million images? In this paper, we present a new image completion algorithm powered by a huge database of photographs gathered from the Web. The algorithm patches up holes in images by finding similar image regions in the database that are not only seamless, but also semantically valid. Our chief insight is that while the space of images is effectively infinite, the space of semantically differentiable scenes is actually not that large. For many image completion tasks, we are able to find similar scenes which contain image fragments that will convincingly complete the image. Our algorithm is entirely data driven, requiring no annotations or labeling by the user. Unlike existing image completion methods, our algorithm can generate a diverse set of image completions and we allow users to select among them. We demonstrate the superiority of our algorithm over existing image completion approaches.
Transcriptional repression of the GLUT4 and C/EBP genes in 3T3-L1 adipocytes by tumor necrosis factor-alpha. (1991)

Fully differentiated 3T3-L1 adipocytes were chronically exposed to 5 nM tumor necrosis factor-alpha (TNF). This resulted in the development of an insulin resistance based on the inability of insulin to stimulate hexose uptake. Western blot analysis for glucose transporter protein in isolated membrane fractions indicated a total depletion of GLUT4 protein (insulin-responsive glucose transporter) in cells chronically treated with TNF. Plasma membrane content of GLUT1 protein (growth-related glucose transporter) was similar in both control and TNF-treated cells; however, the GLUT1 content of the intracellular membrane compartment had decreased markedly after TNF treatment. Continuous exposure to TNF resulted in an 85-90% decrease in the mRNA content for both GLUT4 and 422 (aP2, a lipid binding protein) genes relative to age matched controls, whereas insulin receptor mRNA levels declined by at least 50%. This was preceded by a marked decrease in mRNA accumulation for C/EBP, a transcription factor proposed to control expression of both GLUT4 and 422. The specificity of these observations was demonstrated by the lack of an effect of the chronic TNF treatment on either beta-actin or lipoprotein lipase mRNA content. The decreased content of GLUT4 and C/EBP mRNA was judged to be regulated at least in part at the level of transcription, based on the results of transcription run-on assays. Thus, the lack of response to insulin appeared due to a suppression of GLUT4 expression as well as a decreased intracellular content of GLUT1.
Fungal Biofilms and Polymicrobial Diseases (2017)

Biofilm formation is an important virulence factor for pathogenic fungi. Both yeasts and filamentous fungi can adhere to biotic and abiotic surfaces, developing into highly organized communities that are resistant to antimicrobials and environmental conditions. In recent years, new genera of fungi have been correlated with biofilm formation. However, <i>Candida</i> biofilms remain the most widely studied from the morphological and molecular perspectives. Biofilms formed by yeast and filamentous fungi present differences, and studies of polymicrobial communities have become increasingly important. A key feature of resistance is the extracellular matrix, which covers and protects biofilm cells from the surrounding environment. Furthermore, to achieve cell-cell communication, microorganisms secrete quorum-sensing molecules that control their biological activities and behaviors and play a role in fungal resistance and pathogenicity. Several in vitro techniques have been developed to study fungal biofilms, from colorimetric methods to omics approaches that aim to identify new therapeutic strategies by developing new compounds to combat these microbial communities as well as new diagnostic tools to identify these complex formations in vivo. In this review, recent advances related to pathogenic fungal biofilms are addressed.
Nonvolatile memory effects in nitrogen doped tetrahedral amorphous carbon thin films (1998)

Electrical measurements of nitrogen doped tetrahedral amorphous carbon (ta-C:N) thin films have revealed a reversible nonvolatile memory effect, related to the excitation and de-excitation of electrons between deep acceptor states and shallow donor states within the mobility gap. This effect is characterized by changes in the small signal film conductivity of up to 10 times, and has been used to fabricate 1-bit memory cells with effective memory retention times in the order of several months.
Effect of cyclophosphamide on oocyte and follicle number in Sprague-Dawley rats, C57BL/6N and DBA/2N mice. (1984)

Oocyte and follicle destruction produced by cyclophosphamide was investigated in Sprague-Dawley (SD) rats, and inbred C57BL/6N (B6) and DBA/2N (D2) mice. Primordial oocytes were the most sensitive to destruction after intraperitoneal treatment with cyclophosphamide. A delayed decrease in the number of medium-sized follicles occurred between 1 and 2 weeks after treatment. No reduction in the number of large follicles was observed over the 3-week period of this experiment. Primordial oocyte destruction produced by cyclophosphamide occurred in a time-, dose-, strain-, and species-dependent fashion. The threshold for primordial oocyte/follicle destruction in B6 and D2 mice, and SD rats was less than 10, 40, and greater than 500 mg/kg, respectively. ED50S for primordial oocyte/follicle destruction were 49 and 137 mg/kg in B6 and D2 mice, respectively. The ED50 for oocyte destruction was greater than 500 mg/kg in SD rats. Primordial oocyte destruction occurred rapidly and was completed between 48 and 72 hours after treatment with cyclophosphamide in both murine strains. Oocyte destruction and premature ovarian failure is a significant side effect in women treated with alkylating agents. The rodent ovotoxicity model used in these experiments may be useful in elucidating mechanisms of ovotoxicity and evaluating treatment protocols designed to protect the ovary.
Theory and Methods Related to the Singular-Function Expansion and Landweber’s Iteration for Integral Equations of the First Kind (1974)

For the Fredholm integral equation of the first kind, written notationally as $Kf = g$, $g \in L_2 [0,1]$, we study the behavior of the iteration \[ \hat f_k = \hat f_{k - 1} + DK^ * (g - K\hat f_{k - 1} ),\quad k = 1,2, \cdots ,\] both with respect to its convergence properties and its response to singular functions of K. Here $K^ * $ is the adjoint of K, $\hat f_0 $ is a suitable starting function and D is a fixed linear operator to be chosen. The general theory of singular functions is interpreted and extended for the study of the iteration, and a quantitative method of choosing D to shape the response to singular functions of K is derived. Several specific matrix and integral-equation examples are presented.
High-power InGaAs/GaAs singlemode laser diodes with reactive-ion-etched ridges (1992)

Continuous-wave (CW)output powers in excess of 320 mW with fabrication yields as high as 90% have been realised from strained-layer InGaAs/GaAs ridge waveguide laser diodes fabricated by SiCl4 reactive ion etching. Single longitudinal mode operation to 100 mW and single spatial mode operation up to 200 mW CW at a wavelength of 965 nm wereachieved for 3.5 μm-wide, 650μ-long discrete devices mounted junction-side down. The relative intensity noise at frequencies of 1–2 GHz is ̃140 –150 dB/Hz.
On Estimation Of Harvest Indices (1989)

The application of analysis of variance of ratios on a plot basis is criticised and an alternative procedure for estimating harvest index using ratio of means is proposed. Comparison of the proposed estimate of harvest index with the conventional estimate was made using field data from Arachis hypogaea. The proposed estimate (based on ratio of means) is more precise and has a smaller bias compared to the conventional estimates of harvest index.
[Human pluripotent stem cell and neural differentiation]. (2008)

Recovery of lost brain function is an important issue in medical studies because neurons of the central nervous system (CNS) have poor potential for regeneration. Since few CNS diseases can be treated completely by medicines, regenerative therapy by using stem cells should be studied as a new type of therapeutic intervention. The efficacy of cell replacement therapy in Parkinson's disease has been well investigated. Several studies on fetal tissue transplantation have revealed that quantity and purity of transplanted cells are necessary for recovery of symptoms. SFEB (Serum-free floating culture of embryoid body-like aggregates) method is capable of inducing multi-potential CNS progenitors that can be steered to differentiate into region-specific tissues. On the basis of the existing knowledge of embryology, we have succeeded in the generating of various types of neurons such as telencephalic, cerebeller (Purkinje and granule cells), retinal (photoreceptor cells) and hypothalamic neurons. Application of this culture method to human ES (hES) cells is necessary for clinical purpose: however, poor survival of hES cells in SFEB culture might limit the possibility of using these cells for future medical applications. We found that a selective Rho-associated kinase (ROCK) inhibitor, Y-27632, markedly diminished the dissociation-induced apoptosis of hES cells and enabled the cells to form aggregates in SFEB culture. For both mouse and human ES cells, SFEB culture is a favorable method that can generate large amounts of region-specific neurons. However, stem cell-based therapy continues to face several obstacles. It is important that researchers in the basic sciences and clinical medicine should discuss these problems together to overcome both scientific and ethical issues related to stem cells.