gebhart/patrepeval huggingface dataset:
Hydrogels Cross-Linked by Native Chemical Ligation (2009)

We describe the use of native chemical ligation (NCL) reaction to covalently cross-link soluble polymers into hydrogels. Macromonomers consisting of a four-armed poly(ethylene glycol) (PEG) core end-functionalized with either thioester or N-terminal cysteine peptide were designed and synthesized. Upon mixing aqueous solutions of the thioester and N-terminal cysteine macromonomers, rigid hydrogels formed within minutes. The gelation time was affected by choice of buffer, pH, polymer concentration, reaction temperature, and chemical composition of the N-terminal cysteine conjugate. The kinetics of gel formation and the viscoelastic behavior of selected hydrogels were further studied by oscillatory rheology, which demonstrated a minimum gel formation time of approximately two minutes and the formation of an elastic cross-linked hydrogel via the NCL reaction. A useful feature of this hydrogel strategy is the regeneration of thiol functional groups as a result of the NCL reaction, thereby allowing functionalization of the polymer hydrogel with biomolecules. This was demonstrated by conjugation of a maleimide-GRGDSPG-NH(2) peptide to an NCL hydrogel, permitting the attachment of human mesenchymal stem cells (hMSCs) on the hydrogel. Due to the mild reaction conditions, chemoselectivity, and potential for biological functionalization, our approach may prove useful as a general method for hydrogel formation, including hydrogels intended for biomedical applications.
Dexamethasone Inhibits CD4 T Cell Deletion Mediated by Macrophages from Human Immunodeficiency Virus–Infected Persons (2001)

Prednisolone slows the loss of CD4 T cells in individuals with human immunodeficiency virus (HIV) disease and inhibits antigen-induced apoptosis of recently HIV-infected CD4 cells in vitro. This study investigated whether dexamethasone inhibits the ability of macrophages to delete CD4 T cells via anti-CD4 antibody or immune-complexed HIV envelope protein gp120. Peripheral blood mononuclear cells from HIV-negative persons were incubated with CD4-reactive ch412 monoclonal antibody or with gp120/IgG immune complexes and resident macrophages, with and without dexamethasone. Dexamethasone inhibited CD4 cell deletion in a dose-dependent manner. The deletion of normal CD4 cells by macrophages from HIV-infected patients also was inhibited by dexamethasone. Furthermore, up-regulation of CD95 expression on T cells exposed to anti-CD4 and gp120/IgG, which predisposes T cells to CD95-mediated apoptosis, is inhibited by dexamethasone in a dose-dependent fashion. Dexamethasone inhibits the macrophage-mediated deletion of CD4 lymphocytes in HIV-infected persons.
Discordant effects of butyrate analogues on erythroleukemia cell proliferation, differentiation and histone deacetylase. (1995)

Actions of butyrate and structural analogues on histone deacetylase activity were compared with effects on proliferation and differentiation of erythroleukemia cells. Proliferation was inhibited by 5 mM tert- butylacetate, phenylacetate, phenylbutyrate, 3-bromopropionate and ethyl butyrate without induction of hemoglobin synthesis. n - Butyramide was a stronger inhibitor of cell proliferation and a more effective inducer of hemoglobin synthesis than isobutyramide. The data from combination studies were compatible with butyramide and isobutyramide being weaker agonists that competed for a common site with butyrate. Butyramide and isobutyramide were weaker inhibitors of histone deacetylase than 4-phenylbutyrate and phenylacetate, which in turn were less effective than 3-bromopropionate and butyrate. Butyrate and analogues had similar inhibitory effects on histone deacetylase activity in nuclei from mouse DS19 cells and human K562 cells. Effects on histone deacetylase did not show a consistent correlation with inhibition of cell proliferation or induction of hemoglobin synthesis.
Synaptic and Epidermal Accumulations of Human Acetylcholinesterase Are Encoded by Alternative 3′-Terminal Exons (1995)

Tissue-specific heterogeneity among mammalian acetylcholinesterases (AChE) has been associated with 3' alternative splicing of the primary AChE gene transcript. We have previously demonstrated that human AChE DNA encoding the brain and muscle AChE form and bearing the 3' exon E6 (ACHE-E6) induces accumulation of catalytically active AChE in myotomes and neuromuscular junctions (NMJs) of 2- and 3-day-old Xenopus embryos. Here, we explore the possibility that the 3'-terminal exons of two alternative human AChE cDNA constructs include evolutionarily conserved tissue-recognizable elements. To this end, DNAs encoding alternative human AChE mRNAs were microinjected into cleaving embryos of Xenopus laevis. In contrast to the myotomal expression demonstrated by ACHE-E6, DNA carrying intron 14 and alternative exon E5 (ACHE-I4/E5) promoted punctuated staining of epidermal cells and secretion of AChE into the external medium. Moreover, ACHE-E6-injected embryos displayed enhanced NMJ development, whereas ACHE-I4/E5-derived enzyme was conspicuously absent from muscles and NMJs and its expression in embryos had no apparent effect on NMJ development. In addition, cell-associated AChE from embryos injected with ACHE-I4/E5 DNA was biochemically distinct from that encoded by the muscle-expressible ACHE-E6, displaying higher electrophoretic mobility and greater solubility in low-salt buffer. These findings suggest that alternative 3'-terminal exons dictate tissue-specific accumulation and a particular biological role(s) of AChE, associate the 3' exon E6 with NMJ development, and indicate the existence of a putative secretory AChE form derived from the alternative I4/E5 AChE mRNA.
Preoperative PSA Velocity Is an Independent Prognostic Factor for Relapse After Radical Prostatectomy (2005)

The preoperative PSAV is a significant independent clinical factor predicting for relapse after RP and also predicts for larger, more aggressive, and more locally advanced tumors. Its inclusion will be useful in risk stratification, evaluation for alternatives to surgery, and patient selection for neoadjuvant or adjuvant therapies as part of randomized clinical trials.
Cell transplantation for stroke (2002)

Cell transplantation has emerged as an experimental approach to restore brain function after stroke. Various cell types including porcine fetal cells, stem cells, immortalized cell lines, and marrow stromal cells are under investigation in experimental and clinical stroke trials. This review discusses the unique advantages and limitations of the different graft sources and emphasizes the current, limited knowledge about their biology. The survival, integration, and efficacy of neural transplants in stroke patients will depend on the type, severity, chronicity, adequacy of circulation, and location of the stroke lesion.
Human Papillomavirus in Cervical Cancer Screening: Important Role as Biomarker (2008)

Cervical cytology screening has reduced cervical cancer morbidity and mortality but shows important shortcomings in terms of sensitivity and specificity. Infection with distinct types of human papillomavirus (HPV) is the primary etiologic factor in cervical carcinogenesis. This causal relationship has been exploited for the development of molecular technologies for viral detection to overcome limitations linked to cytologic cervical screening. HPV testing has been suggested for primary screening, triage of equivocal Pap smears or low-grade lesions and follow-up after treatment for cervical intraepithelial neoplasia. Determination of HPV genotype, viral load, integration status and RNA expression could further improve the effectiveness of HPV-based screening and triage strategies. The prospect of prophylactic HPV vaccination stresses the importance of modification of the current cytology-based screening approach.
Gene targeting, principles, and practice in mammalian cells (1999)

When a fragment of genomic DNA is introduced into a mammalian cell it can locate and recombine with the endogenous homologous sequences. This type of homologous recombination, known as gene targeting, is the subject of this chapter. Gene targeting has been widely used, particularly in mouse embryonic stem (ES) cells, to make a variety of mutations in many different loci so that the phenotypic consequences of specific genetic modifications can be assessed in the organism. The first experimental evidence for the occurrence of gene targeting in mammalian cells was made using a fibroblast cell line with a selectable artificial locus by Lin et al. (1), and was subsequently demonstrated to occur at the endogenous β-globin gene by Smithies et al. in erythroleukaemia cells (2). In general, the frequencies of gene targeting in mammalian cells are relatively low compared to yeast cells and this is probably related to, at least in part, a competing pathway: efficient integration of the transfected DNA into a random chromosomal site. The relative ratio of targeted to random integration events will determine the ease with which targeted clones are identified in a gene targeting experiment. This chapter details aspects of vector design which can determine the efficiency of recombination, the type of mutation that may be generated in the target locus, as well as the selection and screening strategies which can be used to identify clones of ES cells with the desired targeted modification. Since the most common experimental strategy is to ablate the function of a target gene (null allele) by introducing a selectable marker gene, we initially describe the vectors and the selection schemes which are helpful in the identification of recombinant clones (Sections 2-5). In Section 6, we describe the vectors and additional considerations for generating subtle mutations in a target locus devoid of any exogenous sequences. Finally, Section 7 is dedicated to the use of gene targeting as a method to express exogenous genes from specific endogenous regulatory elements in vivo, also known as ‘knock-in’ strategies. A targeting vector is designed to recombine with and mutate a specific chromosomal locus.
Restricted Transgene Expression in the Brain with Cell-Type Specific Neuronal Promoters (2012)

Tissue-targeted expression is of major interest for studying the contribution of cellular subpopulations to neurodegenerative diseases. However, in vivo methods to investigate this issue are limited. Here, we report an analysis of the cell specificity of expression of fluorescent reporter genes driven by six neuronal promoters, with the ubiquitous phosphoglycerate kinase 1 (PGK) promoter used as a reference. Quantitative analysis of AcGFPnuc expression in the striatum and hippocampus of rodents showed that all lentiviral vectors (LV) exhibited a neuronal tropism; however, there was substantial diversity of transcriptional activity and cell-type specificity of expression. The promoters with the highest activity were those of the 67 kDa glutamic acid decarboxylase (GAD67), homeobox Dlx5/6, glutamate receptor 1 (GluR1), and preprotachykinin 1 (Tac1) genes. Neuron-specific enolase (NSE) and dopaminergic receptor 1 (Drd1a) promoters showed weak activity, but the integration of an amplification system into the LV overcame this limitation. In the striatum, the expression profiles of Tac1 and Drd1a were not limited to the striatonigral pathway, whereas in the hippocampus, Drd1a and Dlx5/6 showed the expected restricted pattern of expression. Regulation of the Dlx5/6 promoter was observed in a disease condition, whereas Tac1 activity was unaffected. These vectors provide safe tools that are more selective than others available, for the administration of therapeutic molecules in the central nervous system (CNS). Nevertheless, additional characterization of regulatory elements in neuronal promoters is still required.
Isolation and some characteristics of an adhesive factor of brain that enhances neurite outgrowth in central neurons. (1987)

Fractionation of octyl glucoside-solubilized proteins from young rat brain was monitored using rat brain neurons, which were cultured in microwells coated with various protein fractions to be studied. An adhesive protein that promotes neurite outgrowth in rat brain neurons was isolated by chromatography on heparin-Sepharose followed by Affi-Gel blue. The apparent molecular mass of the protein in sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions was about 30 kilodaltons (p30). Under nonreducing conditions a closely spaced doublet band was observed corresponding to 27-28-kilodalton size. Gel filtration in the presence of 4 M urea indicated the molecular size of 58 kilodaltons suggesting a dimeric structure. Western blotting experiments using affinity-purified rabbit antibodies detected p30 as an immunochemically distinct protein in brain and in N18 neuroblastoma cells. The p30 protein was also detected in the N18 cells by lactoperoxidase-catalyzed cell surface iodination. Western blotting of heparin-binding proteins solubilized from brains of rats of various age groups indicated that p30 is clearly more abundant in perinatal brain as compared to adult tissue. The neuron-binding and neurite outgrowth-promoting properties of p30 as well as the developmental regulation of its content in brain tissue suggest a role in neuronal growth.
Novel polysiloxane-based scintillators for neutron detection (2010)

Polysiloxane-based scintillators are promising for employment in harsh environments, owing to their outstanding radiation resistance and thermal properties over the traditional plastics (polyvinyltoluene and polystyrene). In this work, cross-linked polydimethyl-co-diphenylsiloxane (PMPS) scintillators with 22% molar percentage of diphenylsiloxane units have been synthesised. 2,5-Diphenyloxazole and Lumogen Violet (BASF) were employed as primary and secondary fluor, respectively. Thermal neutrons sensitivity was achieved through the addition of 3% wt of ortho-carborane. Scintillation yield measurements were made by exciting with (241)Am alpha source samples with different concentrations of dye molecules. PMPS-based scintillators with ∼50% light yield as compared with the commercial plastic scintillator EJ212 were produced. The scintillation yield of the B-loaded samples under thermal neutrons was tested with a moderated Am-Be source and compared with the commercially available EJ254 (5% wt B). 2.2 MeV neutrons were produced by irradiating with a 4.0 MeV proton beam an LiF target, thus exploiting the reaction (7)Li(p,n)(7)Be. Time-of-flight measurements were performed to distinguish pulses due to neutrons or gamma. A similar test was performed with an EJ254 commercial scintillator for comparison. Using the same set-up, polyethylene bricks were used as a moderator to produce low-energy neutrons for testing B-loaded samples.
Selective Laser Melting of NiTi shape memory components (2009)

Nickel-Titanium (NiTi) shape memory alloys (SMAs) can provide a thermal memory (one-way effect) and a mechanical memory (pseudoelasticity) which both allow a reversible deformation of the material up to 6% strain. The shape memory effect relies on the martensitic phase transformation. On cooling from the high temperature phase austenite (B2), a SMA starts to transform at the martensite start temperature MS into martensite (B19’). At MF, the transformation is completed (martensite finish temperature). During subsequent heating, the reverse transformation starts at AS and finishes at AF (austenite start and finish temperatures respectively). While NiTi SMAs are becoming increasingly successful for commercial and special engineering applications, laser assisted near-net-shape processing of NiTi has received less attention so far (Clare et al. 2007, Krishna et al. 2007, Chalker et al. 2006, Malukhin & Ehmann 2006, Shishkovsky 2005).
Properties of monocyte chemotactic and activating factor (MCAF) purified from a human fibrosarcoma cell line. (1990)

A monocyte chemotactic and activating factor (MCAF) has been purified from TNF-stimulated 8387 human fibrosarcoma cell line-conditioned media. The purified MCAF showed microheterogeneity yielding two bands on SDS-PAGE analysis. Fibrosarcoma-derived MCAF specifically competed with THP-1 (a human monocytic cell line)-derived 125I-labeled MCAF in binding to human PBMC, whereas a similar basic heparin-binding leukocyte chemoattractant, IL-8, did not. The purified MCAF stimulated superoxide anion and N-acetyl beta-D glucosaminidase-releasing activity in human monocytes, as well as monocyte cytostatic augmenting activity against tumor cells and chemotactic activity for monocytes. When injected subcutaneously into Lewis rat ears, the purified human MCAF also induced considerable in vivo local monocyte infiltration beginning at 3 h and becoming maximal at 18 h. In conclusion, the data presented in this paper indicate that MCAF is a potent activator of monocytes as well as a monocyte recruitment factor that acts through receptors that are specific for this novel molecule. This novel cytokine might have an important role in tumor growth control due to its ability to attract and activate monocytes.
An upstream region of the mouse ZP3 gene directs expression of firefly luciferase specifically to growing oocytes in transgenic mice. (1990)

The gene encoding the mouse egg primary receptor for sperm, a zona pellucida glycoprotein called ZP3, is expressed exclusively in growing oocytes within ovaries of sexually immature and mature female mice. We have constructed a transgene in which 6.5 kilobases of ZP3 gene 5'-flanking sequence is fused to the coding region of the firefly luciferase gene, and we have generated four independent lines of transgenic mice. In these animals, the transgene is expressed exclusively in ovaries. Furthermore, within ovaries, expression is confined to growing oocytes, and luciferase activity can be detected by assaying individual, isolated oocytes. The pattern of firefly luciferase expression during oocyte growth is similar to that observed in previous studies of ZP3 expression during oogenesis in mice. Observations reported here strongly suggest that cis-acting elements present in the ZP3 gene 5'-flanking region regulate oocyte-specific and, therefore, sex-specific expression of the sperm receptor gene during mouse development. They also suggest that such elements can be used to direct expression of cloned genes specifically to oocytes of transgenic mice and to evaluate the effects of such expression on various aspects of early mammalian development.
Research on power quality disturbance automatic recognition and location (2004)

A novel approach on power quality disturbance automatic recognition and location is presented in this paper. At first the DB4 wavelet is applied to decompose the signals containing disturbances, and to extract the feature vectors by wavelet coefficients at all scales according to Euclid distance measurement. Then disturbance types are recognized through the pattern recognition classifier based on neural network and genetic algorithm. Referred to the principle of differential protection in bus and line protections, the disturbance energy is defined as the characteristic, and disturbance location is solved by comparing the direction of disturbance energy and topology relation of related measurement points. The software system realizing above recognition and location of disturbances is developed for testing the approach. Numerical results show that the proposed approach is correct and effective.
Complement receptor-mediated phagocytosis is associated with accumulation of phosphatidylcholine-derived diglyceride in human neutrophils. Involvement of phospholipase D and direct evidence for a positive feedback signal of protein kinase. (1992)

Complement receptor (CR)-mediated phagocytosis is associated with an increased accumulation of diglyceride (sn-1,2-diacylglycerol and/or 1-O-alkyl-2-acyl-glycerol) in human neutrophils. The C3bi-mediated increase in diglyceride (5-20 min) was only partially impaired when phosphoinositide-specific phospholipase C (PLC) activity was abolished by reduction of cytosolic free Ca2+. At an early time point (1 min), however, diglyceride production was barely detectable in control cells, whereas production was considerable in cells with a reduced cytosolic free Ca2+ concentration. C3bi stimulation of 32P-labeled neutrophils caused a rapid and significant breakdown of [32P]phosphatidylcholine (PC) which was not affected by inhibition of Ca(2+)-dependent phosphoinositide-specific PLC. Thus, PC hydrolysis could be involved in C3bi-induced diglyceride formation. Stimulation of cells labeled with [3H]1-O-alkyl-lyso-PC ([3H]alkyl-lyso-PC), resulted in an increased formation of [3H]1-O-alkyl-phosphatidic acid ([3H]alkyl-PA) and a later and slower formation of [3H]1-O-alkyl-diglyceride ([3H]alkyl-diglyceride); this suggests activation of phospholipase D (PLD). When these labeled cells were stimulated in the presence of 0.5% ethanol a marked accumulation of [3H]1-O-alkyl-phosphatidylethanol ([3H]alkyl-PEt) was observed in both controls and calcium-reduced cells, further strengthening the suggested involvement of PLD activity. In parallel with the sustained increase in diglyceride formation, CR-mediated phagocytosis was also associated with phosphorylation of a cellular protein kinase C substrate (MARCKS). Therefore it seems reasonable to suggest a causal relationship between C3bi-induced PLD activation, which results in diglyceride formation, and activation of protein kinase C. In electropermeabilized cells which were incapable of ingesting particles, C3bi particles were still able to activate PLD and induce formation of diglyceride. This signaling event must therefore be triggered by binding of particles to the cell and not by the engulfment process. Most importantly, introduction of the protein kinase C inhibitor peptides, PKC(19-36) and PKC(19-31), into these permeabilized cells resulted in a clear reduction of the C3bi-induced production of diglyceride, indicating that CR-mediated activation of protein kinase C directly triggers a positive feedback mechanism for additional diglyceride formation. Taken together, these data further clarify the mechanisms of CR-mediated diglyceride formation and give added support to the concept that protein kinase C plays an important role in the phagocytic process.
A 100m-range 10-frame/s 340&#x00D7;96-pixel time-of-flight depth sensor in 0.18&#x03BC;m CMOS (2011)

This paper introduces a high-performance optical depth sensor in a 0.18μm CMOS technology. At the core of the sensor, macro pixels consisting of 6×2 single-photon detectors enable accurate and selective time-of-flight measurements by taking advantage of temporal and spatial correlations of photons. An array of 32 high-throughput time-to-digital converters allows for the digitization of time-of-flight data with a resolution of 208ps within a range of 853ns, thus resolving distances up to 128 meters. Quantitative characterization of the chip sensor is reported. Depth map data acquired in a real-world situation illustrates the effectiveness of the approach in a road traffic environment.