gebhart/patrepeval huggingface dataset:
Hypoxic Preconditioning of Human Mesenchymal Stem Cells Overcomes Hypoxia-Induced Inhibition of Osteogenic Differentiation (2009)

Osteogenic differentiation of human mesenchymal stem cells (hMSCs) into osteoblasts is a prerequisite for subsequent bone formation. Numerous studies have explored osteogenic differentiation under standard tissue culture conditions, which usually employ 21% of oxygen. However, bone precursor cells such as hMSCs reside in stem cell niches of low-oxygen atmospheres. Furthermore, they are subjected to low oxygen concentrations when cultured on three-dimensional scaffolds in vitro, and even more so after transplantation when vascularization has yet to be established. Similarly, hMSCs are exposed to low oxygen in the fracture microenvironment following bony injury. Recent studies revealed that hypoxic preconditioning improves cellular engraftment and survival in low-oxygen atmospheres. In our study we investigated the osteogenic differentiation potential of hMSCs under 2% O(2) (hypoxia) in comparison to a standard tissue culture oxygen atmosphere of 21% (normoxia). We assessed the osteogenic differentiation of hMSCs following hypoxic preconditioning to address whether this pretreatment is beneficial for subsequent differentiation processes as well. To validate our findings we carefully characterized the extent of hypoxia exerted and its effect on cell survival and proliferation. We found that hMSCs proliferate better if cultured under 2% of oxygen. We confirmed that osteogenic differentiation of hMSCs is indeed inhibited if osteogenic induction is carried out under constant hypoxia. Finally, we showed for the first time that hypoxic preconditioning of hMSCs prior to osteogenic induction restores osteogenic differentiation of hMSCs under hypoxic conditions. Collectively, our results indicate that maintaining constant levels of oxygen improves the osteogenic potential of hMSCs and suggest that low oxygen concentrations may preserve the stemness of hMSCs. In addition, our data support the hypothesis that if low-oxygen atmospheres are expected at the site of implantation, hypoxic pretreatment may be beneficial for the cells' subsequent in vivo performance.
Efficient and targeted delivery of siRNA <i>in vivo</i> (2010)

RNA interference (RNAi) has been regarded as a revolutionary tool for manipulating target biological processes as well as an emerging and promising therapeutic strategy. In contrast to the tangible and obvious effectiveness of RNAi in vitro, silencing target gene expression in vivo using small interfering RNA (siRNA) has been a very challenging task due to multiscale barriers, including rapid excretion, low stability in blood serum, nonspecific accumulation in tissues, poor cellular uptake and inefficient intracellular release. This minireview introduces major challenges in achieving efficient siRNA delivery in vivo and discusses recent advances in overcoming them using chemically modified siRNA, viral siRNA vectors and nonviral siRNA carriers. Enhanced specificity and efficiency of RNAi in vivo via selective accumulations in desired tissues, specific binding to target cells and facilitated intracellular trafficking are also commonly attempted utilizing targeting moieties, cell-penetrating peptides, fusogenic peptides and stimuli-responsive polymers. Overall, the crucial roles of the interdisciplinary approaches to optimizing RNAi in vivo, by efficiently and specifically delivering siRNA to target tissues and cells, are highlighted.
Redundancy and divergence in the amyloid precursor protein family (2013)

Gene duplication provides genetic material required for functional diversification. An interesting example is the amyloid precursor protein (APP) protein family. The APP gene family has experienced both expansion and contraction during evolution. The three mammalian members have been studied quite extensively in combined knock out models. The underlying assumption is that APP, amyloid precursor like protein 1 and 2 (APLP1, APLP2) are functionally redundant. This assumption is primarily supported by the similarities in biochemical processing of APP and APLPs and on the fact that the different APP genes appear to genetically interact at the level of the phenotype in combined knockout mice. However, unique features in each member of the APP family possibly contribute to specification of their function. In the current review, we discuss the evolution and the biology of the APP protein family with special attention to the distinct properties of each homologue. We propose that the functions of APP, APLP1 and APLP2 have diverged after duplication to contribute distinctly to different neuronal events. Our analysis reveals that APLP2 is significantly diverged from APP and APLP1.
Low‐κ nanocomposite films based on polyimides with grafted polyhedral oligomeric silsesquioxane (2005)

Abstract Nanocomposites of polyimides (PI) with covalently grafted polyhedral oligomeric silsesquioxane (R 7 R′Si 8 O 12 or POSS) units were prepared by thermally‐initiated free‐radical graft polymerization of methacrylcyclopentyl‐POSS (MA‐POSS) with the ozone‐pretreated poly[ N , N ′‐(1,4‐phenylene)‐3,3′,4,4′‐benzophenonetetra‐carboxylic amic acid] (PAA), followed by thermal imidization. The chemical composition and structure of the PI with grafted methacrylcyclopentyl‐POSS side chains (PI‐ g ‐PMA‐POSS copolymers) were characterized by nuclear magnetic resonance (NMR), X‐ray diffraction (XRD), and thermogravimetric analysis (TGA). The POSS molecules in each grafted PMA side chain of the amorphous PI films retained the nanoporous crystalline structure, and formed an aggregate of crystallites. The PI‐ g ‐PMA‐POSS nanocomposite films had both lower and tunable dielectric constants, in comparison with that of the pristine PI films. Dielectric constants (κ's) of about 3.0–2.2 were obtained. The present approach offers a convenient way for preparing low‐κ materials based on existing PI's. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Implementation of IMDCT Block of an MP3 Decoder through Optimization on the DCT Matrix (2004)

The paper describes an attempt to create an efficient dedicatedMP3-decoder, according to the MPEG-1 Layer III standard. A new methodof Inverse Modified Discrete Cosine Transform by optimization on theDiscrete Cosine Transform (DCT) matrix is proposed and an assemblerprogram for Digital Signal Processor is developed. In addition, aprogram to calculate DCT using Lee's algorithm for any matrix of thesize 2M is created. The experimental results have proven that thedecoder is able to stream and decode MP3 in real time.
Colonoscopy Without Sedation (1998)

Colonoscopy is routinely performed with conscious sedation. We wanted to determine if colonoscopy can be successfully completed without sedation and to assess patient tolerance and acceptance. One hundred nine consecutive patients undergoing colonoscopy were examined. The risks and benefits of colonoscopy with or without sedation were explained in a standard format. Patients were then given the option of having colonoscopy without premedication. After the procedure, as well as 2 to 5 days later, patients rated on an analog scale (0, no pain; 5, severe) the severity of pain and willingness to undergo colonoscopy in the future without sedation. Eighty patients underwent colonoscopy without prior sedation. Only 6% (n=5) required sedation to complete the examination. When questioned, 5% experienced no pain, 41% slight or mild pain, 34% moderate pain, and 20% severe pain. Seventy-three percent (n=58) were willing to undergo repeat colonoscopy without sedation, 10% (n=8) were undecided, and 18% (n=14) would request sedation. Pain severity was a strong predictor (p=0.001) of future sedation preference. Colonoscopy without sedation may be completed successfully in most patients and does not undermine many patients' willingness to undergo a similar procedure in the future. Sedation by choice is more cost-effective, may be safer, and should be offered as an alternative to routine intravenous sedation.
Macromolecular absorption of food antigens in health and disease. (1984)

During the neonatal period, the development of the mucosal barrier against penetration of bacteria, toxins and antigens is an important protective mechanism against a variety of pathologic conditions such as inflammatory and allergic reactions. The closure of the gut with regard to the uptake of food antigens in macromolecular form is determined by non-immunologic mechanisms as well as by the immunologic system of the gut. Animal experiments show that various diseases affecting the gut may interfere with intestinal antigen handling. As a result, susceptibility to infection and allergic reactions may ensue. Studies performed in humans show that selective IgA deficiency, preterm delivery, intestinal helminth infection and type of feeding during the neonatal period may influence antigen uptake by the intestinal epithelium. These conditions, as well as various diseases affecting the gut, may cause increased absorption of intraluminal antigens and result in the triggering of allergic type responses.
IL-17 in Rheumatoid Arthritis and Precision Medicine: From Synovitis Expression to Circulating Bioactive Levels (2019)

Interleukin (IL)-17A has a direct contribution in early induction and late chronic stages of various inflammatory diseases. <i>In vitro</i> and <i>in vivo</i> experiments have first characterized its local effects on different cell types and then its systemic effects. For instance, IL-17 axis is now identified as a key driver of psoriasis through its effects on keratinocytes. Similar observations apply for rheumatoid arthritis (RA) where IL-17A triggers changes in the synovium that lead to synovitis and maintain local inflammation. These results have prompted the development of biologics to target this cytokine. However, while convincing studies are reported on the efficacy of IL-17 inhibitors in psoriasis, there are conflicting results in RA. Patient heterogeneity but also the involvement of mediators that regulate IL-17 function may explain these results. Therefore, new tools and concepts are required to identify patients that could benefit from these IL-17 targeted therapies in RA and the development of predictive biomarkers of response has started with the emergence of various bioassays. Current strategies are also focusing on synovial biopsies that may be used to stratify patients. From local to systemic levels, new approaches are developing and move the field of RA management into the era of precision medicine.
Experimental study of achromatic volume holography with dispersive compensation in barium titanate (1992)

We carried out an experimental study to verify a proposed theory for achromatic volume holography using dispersive compensation in photorefractive barium titanate crystals. Compensation of the phase mismatch was observed and was consistent with the theory.
Surgical management of posteriorly dislocated silicone plate intraocular lenses (1998)

Silicone plate intraocular lenses do not adhere to the lens capsule and are placed under tension by postoperative contraction of the capsular bag. Recent reports suggest that a defect anywhere in the capsular bag can potentially lead to delayed posterior dislocation of silicone plate intraocular lenses. These implants are more difficult to grasp and manipulate inside the eye than traditional polymethylmethacrylate lenses and therefore, require special microsurgical techniques. Given sufficient anterior capsular support, posteriorly dislocated silicone plate implants can be repositioned in the ciliary sulcus and do not necessarily require intraocular lens exchange. With proper vitreoretinal surgical techniques, posteriorly dislocated silicone plate intraocular lenses can be repositioned or exchanged with excellent visual results and an acceptably low complication rate.
Ultrasensitive, Specific, Recyclable, and Reproducible Detection of Lead Ions in Real Systems through a Polyadenine-Assisted, Surface-Enhanced Raman Scattering Silicon Chip (2016)

It is of great significance to accurately and reliably detect trace lead(II) (Pb(2+)) ions, preferably at sub-nM level due to the possible long-term accumulation of Pb(2+) in the human body, which may cause serious threats to human health. However, a suitable Pb(2+) sensor meeting the demands is still scanty. Herein, we develop a polyadenine-assisted, surface-enhanced Raman scattering (SERS) silicon chip (0.5 cm × 0.5 cm) composed of core (Ag)-satellite (Au) nanoparticles (Ag-Au NPs)-decorated silicon wafers (Ag-Au NPs@Si) for high-performance Pb(2+) detection. Typically, strong SERS signals could be measured when DNAzyme conjugated on the SERS silicon chip is specifically activated by Pb(2+), cleaving the substrate strand into two free DNA strands. A good linearity exists between the normalized Raman intensities and the logarithmic concentrations of Pb(2+) ranging from 10 pM to 1 μM with a good correlation coefficient, R(2) of 0.997. Remarkably, Pb(2+) ions with a low concentration of 8.9 × 10(-12) M can be readily determined via the SERS silicon chip ascribed to its superior SERS enhancement, much lower than those (∼nM) reported by other SERS sensors. Additionally, the developed chip features good selectivity and recyclability (e.g., ∼11.1% loss of Raman intensity after three cycles). More importantly, the as-prepared chip can be used for accurate and reliable determination of unknown Pb(2+) ions in real systems including lake water, tap water and industrial wastewater, with the RSD value less than 12%.
A novel aromatic iodination method using fluorine (1990)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA novel aromatic iodination method using fluorineShlomo Rozen and Dov ZamirCite this: J. Org. Chem. 1990, 55, 11, 3552–3555Publication Date (Print):May 1, 1990Publication History Published online1 May 2002Published inissue 1 May 1990https://pubs.acs.org/doi/10.1021/jo00298a032https://doi.org/10.1021/jo00298a032research-articleACS PublicationsRequest reuse permissionsArticle Views1122Altmetric-Citations37LEARN 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
Cobalt-Catalyzed Reductive Coupling of Activated Alkenes with Alkynes (2007)

Cobalt complex/Zn systems effectively catalyze the reductive coupling of activated alkenes with alkynes in the presence of water to give substituted alkenes with very high regio- and stereoselectivity in excellent yields. While the intermolecular reaction of acrylates, acrylonitriles, and vinyl sulfones with alkynes takes place in the presence of CoI2(PPh3)2/Zn, the reaction of enones and enals with alkynes requires the use of the CoI2(dppe)/Zn/ZnI2 system. The intramolecular reductive coupling of activated alkenes (enones, enals, acrylates, and acrylonitriles) with alkynes also works efficiently. Further a variety of cyclic lactones and lactams were prepared using this methodology. Possible mechanistic pathways are proposed based on a deuterium-labeling experiment carried out in the presence of D2O.
Staining of Hybrid Composites with Coffee, Oolong Tea, or Red Wine (2006)

This study examined the surface staining mechanism of a photopolymerized composite by coffee, oolong tea, and red wine. Dental composite was subjected to an experimental 24-hour staining cycle: 17-hour immersion in artificial saliva solution containing 0.3% mucin followed by 7-hour immersion in coffee, tea, or wine. After one, two, and four weeks, digital images of the composite surface were analyzed in grayscale mode with an imaging analyzer. Specimens polished but not immersed were used as a baseline measurement for color change. Additionally, the effects of mechanical brushing and chlorhexidine on drink-induced staining were examined. Wine caused the most severe staining, followed by tea and coffee. After four weeks of immersion, brushing reduced surface staining by wine. On the contrary, chlorhexidine increased the staining effect of tea and coffee (p<0.05) when compared to the control specimens. In conclusion, we showed that common drinks stained the dental composite, but each by a specific mechanism that depended on external conditions such as the presence of chlorhexidine.
Avalanche instability in oxide charge balanced power MOSFETs (2011)

Power MOSFET designs have been moving to higher performance particularly in the medium voltage area. (60V to 300V) New designs require lower specific on-resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SP</sub> ) thus forcing designers to push the envelope of increasing the electric field stress on the shielding oxide, reducing the cell pitch, and increasing the epitaxial (epi) drift doping to reduce on resistance. In doing so, time dependant avalanche instabilities have become a concern for oxide charge balanced power MOSFETs. Avalanche instabilities can initiate in the active cell and/or the termination structures. These instabilities cause the avalanche breakdown to increase and/or decrease with increasing time in avalanche. They become a reliability risk when the drain to source breakdown voltage (BV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dss</sub> ) degrades below the operating voltage of the application circuit. This paper will explain a mechanism for these avalanche instabilities and propose an optimum design for the charge balance region. TCAD simulation was employed to give insight to the mechanism. Finally, measured data will be presented to substantiate the theory.
Characterization of GaAs(110) Nitrided by an Electron-Cyclotron Resonance Plasma Source Using N[sub 2] (2000)

Single‐wavelength in situ ellipsomeny shows that the interface formed during the deposition of silicon nitride using an electron‐cyclotron resonance nitrogen plasma source with silane introduced downstream is created by the initial nitridation reaction of the substrate. Angle‐dependent X‐ray photoelectron spectroscopy shows that the nitridation of GaAs forms a GaN layer separated from the substrate by a layer with As‐N bonds, and spectroscopic ellipsometry indicates that the GaN layer has a large void fraction. Interface‐state densities in the low range measured on capacitors did not change significantly if a Si interface control layer 0.8–2 nm thick was deposited on cleaved GaAs(110) surfaces prior to silicon nitride deposition. © 2000 The Electrochemical Society. All rights reserved.
Continuous bromodeoxyuridine labeling and bivariate ethidium bromide/hoechst flow cytometry in cell kinetics (1989)

Most techniques of flow cytometric cell cycle analysis are not capable of distinguishing the number of rounds of DNA synthesis that a cell has undergone since the start of an experiment. Continuous labeling with 5-bromodeoxyuridine (BrdUrd) offers such a potential. We illustrate here that the bivariate analysis of non-BrdUrd-quenched ethidium bromide vs. BrdUrd-quenched Hoechst 33258 fluorescence offers a high degree of resolution that enhances the analytical power of the technique, and that this approach can be applied to the analysis of a broad range of human and murine primary cells and established cell lines.
Neu differentiation factor (Heregulin) activates a p53-dependent pathway in cancer cells. (1996)

Previously we reported that neu differentiation factor (NDF)/heregulin (HRG) elevates tyrosine phosphorylation of its receptors erbB-3, erbB-4, and erbB-2 (through heterodimer formation). We also showed that both NDF/HRG and antibodies to erbB-2 can arrest growth and induce differentiation in breast cancer cells. In this study, we report on the mechanism of NDF/HRG-induced cellular effects. We show that NDF/HRG and antibodies to erbB-2 receptors up-regulate expression of p53 by stabilizing the protein. This is accompanied by up-regulation of the p53 inducible gene, p21CIP1/WAF1, in a variety of cell lines: MCF7 and their derivatives (MCF7/HER2, MN1 and MCF-7-puro), ZR75T and LnCap cells. The induction of p21 is further enhanced when cells are treated with both NDF/HRG and DNA-damaging chemotherapeutic agents (i.e. doxorubicin). The NDF/HRG mediated induction of p21 is dependent on wildtype p53, as it fails to occur in cells expressing dominant negative p53 (MDD2). Furthermore, p21 induction is capable of inactivating cdk2 complexes as measured by Histone H1 phosphorylation assays. Finally, we show that in primary cultures of breast and other cancers, p21 is significantly induced in response to NDF/HRG treatment. Collectively, these observations suggest that the mechanism of breast cancer cell growth inhibition and differentiation via erbB receptors activation is through a p53-mediated pathway.
Pathophysiology of Exacerbations of Chronic Obstructive Pulmonary Disease (2006)

Smokers with stable chronic obstructive pulmonary disease have a chronic inflammation of the entire tracheobronchial tree characterized by an increased number of macrophages and CD8 T lymphocytes in the airway wall and of neutrophils in the airway lumen. Exacerbations of chronic obstructive pulmonary disease are considered to reflect worsening of the underlying chronic inflammation of the airways, caused mainly by viral and bacterial infections and air pollution. During exacerbations, the inflammatory cellular pattern changes, with a further increase of eosinophils and/or neutrophils and various inflammatory mediators--for example, cytokines (tumor necrosis factor-alpha, RANTES [regulated upon activation normal T cell-expressed and secreted], and eotaxin-1), chemokines (CXCL5 [ENA-78], CXCL8), chemokine receptors (CCR3, CXCR1, and CXCR2), adhesion molecules (E-selectin and ICAM-1), and markers of oxidative stress (H(2)O(2) and 8-isoprostane, glutathione depletion). Worsening of inflammation is considered responsible for the deterioration of lung function and clinical status during exacerbations.
Inflammation enhances reflex and spinal neuron responses to noxious visceral stimulation in rats (2001)

To improve understanding of sensory processes related to visceral inflammation, the effect of turpentine-induced inflammation on reflex (cardiovascular/visceromotor) and extracellularly recorded lumbosacral dorsal horn neuron responses to colorectal distension (CRD) was investigated. A 25% solution of turpentine, applied to the colorectal mucosa, produced inflammation, decreased compliance of the colonic wall, and enhanced reflex responses in unanesthetized rats within 2-6 h. At 24 h posttreatment, pressor responses to CRD (80 mmHg, 20 s) were 20% greater, and intraluminal pressures needed to evoke visceromotor reflexes were 30% lower than controls. Parallel electrophysiological experiments in spinal cord-transected, decerebrate rats demonstrated that two neuronal subgroups excited by CRD were differentially affected by turpentine administered 24 h before testing. During CRD, abrupt neurons were 70% less active and sustained neurons were 25% more active than similar neurons in controls. In summary, reflex and neuronal subgroup (sustained neurons) responses to CRD were both potentiated by chemical inflammation. This suggests that the neurophysiological basis for inflammation-induced increases in reflex responses to CRD is increased activity of this neuronal subgroup.